Abstract: The present work proposes an obstacle avoidance path planning algorithm for virtual simulations of hyper-redundant manipulators, with the possibility to customize the optimization criteria to select the best trajectory given in output. For test purposes, the effectiveness of the proposed Inverse Kinematic algorithm has been tested by simulating the Remote Maintenance (RM) tasks conducted by the HyRMan: the Hyper Redundant Manipulator developed for the Divertor Tokamak Test (DTT) project. The algorithm has been employed to simulate some critical handling tasks of the First Wall (FW) modules, with a specific optimization criterion as an example of its potentialities.

Keywords: Collision avoidance | DTT | Hyper-redundant manipulator | Path planning | Remote Maintenance | Tokamak

Abstract: The Divertor Tokamak Test (DTT) facility needs a large amount of heating power to study the problem of power exhaust in reactor-relevant conditions. Among the additional heating systems, the ion cyclotron resonance heating (ICRH) is characterized by radio frequency (RF) components based on standard technology and well-assessed solutions due to the tight schedule of the DTT construction. Considering the harsh fusion operating conditions, the ICRH antenna design involves different and interacting physical fields to be managed by the systems engineering (SE) approach. Therefore, following step by step this methodology, the design started with the definition of the main requirements of the whole system. Then, the main functions have been identified with the aim to define the logical architecture of the whole antenna structure. In the end, a preliminary 3-D parametric model of the ICRH antenna with its subsystems has been developed adopting a top-down modeling approach in the CATIA V5 environment provided by Dassault Systemes. Key aspects of the 3-D model are the clear definition of the position in the available space of all subsystems and of their interfaces, and its parametrization. They allow to quickly implement the modifications required by the multiple iterations between the geometrical modeling environment and several multiphysics simulation environments to check the compliance with mechanical, electrical, thermofluid dynamics, and remote handling requirements.

Keywords: 3-D parametric modeling | Antenna accessories | Antenna feeds | Antennas | ion cyclotron resonance heating (ICRH) antenna | Loaded antennas | Plasmas | Radio frequency | Solid modeling | systems engineering (SE) | virtual prototyping

Abstract: In engineering design, the selection of the optimal design solution represents a critical phase for the development of successful products. In this paper, we present ELIGERE, an open source decision support system targeted at engineering design applications. It allows to rank multiple design solutions with respect to different evaluation criteria according to the evaluations provided by a group of experts. ELIGERE is composed by three main modules: (1) a distributed web application, for generation and participation to the decision making session; (2) a mathematical engine, based on the fuzzy analytical hierarchy process, to quantify the results of the decision making session according to the evaluation of the experts; (3) a relational database, to collect and store data. The most important contribution of this paper is introducing a practical and effective software tool that facilitates decision-making analysis based on the fuzzy analytical hierarchy process, thereby allowing better-informed choices on concept selection, as it has been designed with a specific focus on the engineering field. In this paper we describe the key concepts of ELIGERE and its modalities of use in several real use cases. Finally, we compare ELIGERE with the widely used general purpose decision support software based on the fuzzy analytical hierarchy process.

Keywords: Concept selection | Decision support systems | Engineering design | System evaluation

Abstract: In this work, we present a general control architecture for robotic systems dedicated to the remote handling of in-vessel components in fusion machines. This control architecture will be tested for the inspection and maintenance of the first wall components of the RFX-mod2 experiment, in the scope of the New Equipment For the Experimental Research and Technological Advancement for the Rfx Infrastructure (NEFERTARI) project. The architecture is split into low-level and high-level layers. The former is used for the low-level control of the robotics systems and to manage safety; the latter is used for the high-level planning and implements several sub-modules, such as a Virtual Reality (VR) environment for the visualisation of the robot's digital twin. Moreover, an Application Programming Interface (API) is intended to connect the two layers, and the communication between modules and layers is provided by the ROS2 framework. A typical usage of such a framework involves a human operator who is teleoperating the real robot, data from motor encoders are used as inputs for the dynamic model module. This module is used to compute the forward dynamics in real-time, providing an accurate simulation of the robot (digital twin) in the virtual environment.

Keywords: Control architecture | Digital twin | Remote handling | Robotics | ROS2

Abstract: This paper introduces a unique, feature-based methodology for determining the best design features of a Virtual Reality Training System (VRTS). It offers a holistic approach by using a revised Technology Acceptance Questionnaire, which assesses design features from a user's perspective, rather than relying solely on objective measures of training effectiveness. We implemented the methodology in an experimental campaign, which involved simulating manual processes in two VR platforms with different features. Both novice and experienced VR users participated in the study, evaluating design features for perceived usefulness and ease of use. The findings provide insights into improving VRTS design based on user experience, highlighting the potential of our feature-based methodology.

Keywords: Design Features | Manual Layup | Technology Acceptance | User Experience | Virtual Reality | Virtual Training

Abstract: Nuclear fusion facilities, as tokamaks, are very complex devices, due to the harsh environmental conditions required to maintain the plasma advance confinement scenarios and the deuterium-tritium fusion reaction (huge temperatures, nuclear radiation, extreme electromagnetic loads). Therefore, several specific concerns shall be considered during the design process of a tokamak, and appropriate solutions shall be designed and provided. These concerns are treated in this paper and some of their possible solutions are explained. This is done following the flow of good practice design process, focusing on each stage from the material selection to the component procurement.

Keywords: Design Process | Fusion Reactors | Nuclear Fusion | Tokamak

Abstract: The conceptual design stage is one of the main challenging phases in System Engineering. Starting from the High-Level Requirements (provided by the project needs), defining the broad features and conditions that a product must ensure, different design solutions are often implemented. Several methodologies can aid whenever a decision-making process has to be performed. Among these, the Fuzzy Analytic Hierarchy Process (Fuzzy AHP) stands out, providing a rational framework for a needed decision by quantifying its criteria and alternative options, and for relating those elements to the overall goal. Fuzzy AHP centralizes the opinion of experts who, through objective and subjective opinions, can rank the conceptual alternatives. The paper deals with the assessment of components for thermonuclear reactors, in particular the design of the DTT Divertor In-Vessel Fixation System. The main requirements that the Fixation System must guarantee are strictly related to the geometric-dimensional constraints concerning the presence of the various in-vessel components. Furthermore, the Fixation System must withstand the strong loads acting on the Divertor due to the partial or full loss of plasma confinement (Disruption Events). The aim is, therefore, to identify, through Fuzzy AHP, among different alternatives, the solution which best matches the functional requirements, geometrical constraints and Remote Handling compatibility.

Keywords: AHP | DTT Divertor | System Engineering

Abstract: A physical Remote Handling (RH) test facility can play a key role in the Verification & Validation phase of the design and development of the Remote Handling System (RHS) of a fusion reactor and of the reactor itself. This key role is described in this paper, highlighting the achievements reachable in such a facility in support of the fusion reactor design and reporting the experience gained in the leading RH test facilities developed in the last decades. In the end, the project of an innovative RH test facility for fusion reactors, aimed at overcoming the limits of the already operative ones and the still present obstacles in the related scientific fields, is presented.

Keywords: Design | Facility | Fusion Reactor | Remote Handling | Verification & Validation

Abstract: The Product Lifecycle Management (PLM) systems lead the development of a product or a system from the early concept design until the end of the life allowing the knowledge management step by step. Among these systems, the 3DExperience platform adopts a Model Based Systems Engineering (MBSE) approach and allows to implement each phase of the design in a single co-simulation environment. This platform has been chosen for the development of the Divertor Tokamak Test (DTT) facility. The DTT tokamak, under construction at ENEA site in Frascati, has the main aim to contribute to the development of a reliable solution for power exhaust in a reactor, one of the major issues in the roadmap towards the realization of a nuclear fusion power plant. The divertor is one of the most challenging systems whose requirements coming from different physics and interfaces shall be balanced. The fixation system is the interface between the vacuum vessel and the divertor cassette body whose concept design has been carried out in a PLM system. This paper deals specifically with the application of the Requirement, Functional, Logical, Physical (RFLP) approach to the DTT divertor fixation system from the requirement elicitation and definition until the preliminary physical design, implementing each phase in the 3DExperience platform.

Keywords: Divertor Fixation System | DTT | MBSE | Requirements Management | RFLP

Abstract: In this work we briefly review some of the current available solutions of long reach manipulators that have been or are serving as robotic equipment for remote maintenance in fusion reactors. These robotic equipment are long reach since they are intended to access inside the fusion reactors through small–scaled access ports and are designed to remotely install/replace in-vessel mechanical components within the reactors. We start the work by analysing the design criteria commonly used and the most interesting concepts from the authors’ perspective, where we found a general scheme that could be adopted for the most cases when we study this kind of robots. Finally we present a discussion and draw our conclusions.

Keywords: Fusion Reactors | Long Reach Manipulators | Remote Maintenance

Abstract: This paper proposes a virtual reality-based dual-mode teleoperation architecture to assist human operators in remotely operating robotic manipulation systems in a safe and flexible way. The architecture, implemented via a finite state machine, enables the operator to switch between two operational modes: the Approach mode, where the operator indirectly controls the robotic system by specifying its target configuration via the immersive virtual reality (VR) interface, and the Telemanip mode, where the operator directly controls the robot end-effector motion via input devices. The two independent control modes have been tested along the task of reaching a glass on a table by a sample population of 18 participants. Two working groups have been considered to distinguish users with previous experience with VR technologies from the novices. The results of the user study presented in this work show the potential of the proposed architecture in terms of usability, both physical and mental workload, and user satisfaction. Finally, a statistical analysis showed no significant differences along these three metrics between the two considered groups demonstrating ease of use of the proposed architecture by both people with and with no previous experience in VR.

Keywords: control mode | digital twin | human-robot interface | man-machine systems | remote control | teleoperation | virtual reality

Abstract: The divertor remote handling (RH) of the upcoming Italian tokamak Divertor Tokamak Test (DTT) is designed to be carried out by two tele-operated robots: the cassette multifunctional mover (CMM) and the cassette toroidal mover (CTM). The CMM is designed to place/remove the divertor cassettes which are near the RH ports into/from the vessel; the CTM is, instead, designed to move the cassettes which are distant from an RH port inside the vessel toroidally. To date, CMM is under a more advanced development stage of design with respect to CTM. This article describes and illustrates in detail the virtual kinematic simulations of the CMM operative procedures. With regard to the CTM, only preliminary simulations are presented. These activities are part of the integration and verification stages of the CMM design process, carried out in a Systems Engineering approach and following the workflow prescribed by the V-model and its requirements, functions, logical, and physical architecture (RFLP) paradigm. Therefore, after an introduction to the CMM requirements, functions, and conceptual design, which have already been developed, the article focuses on the description of its virtual kinematic simulations and the analysis of their results, with the aim of verifying the feasibility of the handling procedures and the correct integration of the CMM in the surrounding environment, considering all the in-vessel geometric constraints. The simulations have been carried out following a forward-kinematics approach. Therefore, each simulation has been divided into a series of consecutive activities, assigning each of them a set of values for the five CMM joints able to reach the required final position of the end-effector. The software DELMIA, part of the Dassault Systèmes V5 platform which also includes the software for CAD modeling CATIA V5, has been used to perform the simulations. As for the CTM operation, since its concept design has not been completed yet, preliminary virtual kinematic simulations have been performed with a different goal: to evaluate alternative possible operative strategies, which can impact the device design.

Keywords: Cassette multifunctional mover (CMM) | cassette toroidal mover (CTM) | divertor | divertor tokamak test (DTT) | End effectors | kinematic simulation | Kinematics | Maintenance | remote handling (RH) | Robots | Software | systems engineering | Task analysis | Tokamak devices

Abstract: Tip steering by induced deformation constitutes one of the most prominent feature to effectively navigate constrained environments with soft growing robots. In this work, we analyze the effects of design parameters on the tip steering capabilities of pneumatically-actuated soft growing robots built from fabric. More specifically, we consider the variability of material, fabric Pneumatic Artificial Muscles (fPAM) diameter, and backbone internal pressure and statistically quantify the effect on the maximum curvature achieved by the robot when a constant fPAM input pressure is applied. In our considered settings, we found a statistically significant main effect (p<0.05 ) of the fPAM diameter and a relevant interaction effect between this and the material factor. These findings provide useful guidelines for the design of fabric-based PAM-actuated soft growing robots with enhanced tip steering capabilities.

Keywords: Design of bioinspired soft robots | Soft actuators | Soft robotics

Abstract: This paper proposes a methodology to exploit virtual prototypes for the development of both VR and AR-based Training systems, with the same Software-Hardware architecture. This architecture provides a unique collaborative environment to enable the interaction between several users even if geographically distant, allowing to switch easily and rapidly between VR, AR and mixed technologies. The proposed Training Systems concern a simple but structured workcycle about the assembly of some Lego bricks. The selected development platform is IC.IDO: a commercial software with an industrial footprint, produced by ESI Group. Despite IC.IDO is originally designed for VR and not compatible for AR applications, it resulted fully compliant with the requisites of the proposed methodology. The paper firstly describes the path outlined from the conversion of a Training session from VR to AR compatible, within IC.IDO. Thanks to the adoption of a colour-filtering software as OBS Studio, the IC.IDO session easily becomes AR-compatible, using a unique hardware architecture: the HTC Vive Pro HMD and a VIVE tracker. In this work, also the Oculus Rift S has been employed for the VR applications to demonstrate the system’s compatibility with other VR devices. For both VIVE and Oculus, the Virtual Desktop feature allowed to display the OBS Desktop window in the HMD. Furthermore, an innovative solution is proposed: thanks to IC.IDO’s Cooperative Environment, trainer and trainee will cooperate within the same scene using simultaneously VR and AR. Finally, the role of the trainer is discussed, to outline a process of progressive independence for the trainee.

Keywords: Augmented reality | Cooperative environment | Virtual prototype | Virtual reality | Virtual training system

Abstract: This paper describes the design of a novel fabric–based antagonistic pneumatic actuator with multiple chambers that can be used for the development of soft continuum manipulators for collaborative tasks. The concept consists of three pneumatic chambers of fabric material capable of being actuated independently. By connecting multiple actuators of this kind, it is possible to obtain soft continuum manipulators capable of complex movements and able to change the stiffness of their elements. In this work we highlight the design and prototyping of the soft actuator and we present the preliminary experiments in terms of motion and stiffening capabilities.

Keywords: Fabric pneumatic artificial muscles | Soft actuators | Soft continuum manipulators | Soft robotics

Abstract: Objective and reliable assessment of motor functions, such as dexterity, is a key point for evaluating worker’s abilities. In this context, the proposed work presents a tool for objective automatic assessment of the Minnesota Dexterity Test using cameras with depth sensors. Typical performance measurements (i.e., total time and associated percentiles) were estimated using custom algorithms. In addition, the possibility to identify the qualifiers for the code d440 of the International Classification of Functioning, Disability and Health was implemented in the developed algorithms. The proposed tool can also identify the mistakes most frequently committed by the subjects. To prove the capabilities of the proposed method, a series of experimental trials was conducted with 10 healthy young volunteers. Results showed that the developed tool helps clinicians to obtain performance feedback and evaluate patients’ dexterity quickly without bias.

Keywords: Automatic assessment | Biomechanics | Depth cameras | Manual dexterity | Motion capture

Abstract: This research focuses on the requirements management phase in the conceptual stage following a Systems Engineering approach. The development of a parametric associative master model is useful to implement requirements and available knowledge in the CAD model. The vertical decomposition from higher level requirements to lower level requirements is carried out. The decomposition of design parameters follows the mapping process according to Axiomatic Design principles. The functional requirements and design parameters relations enable to develop the parametric associative master model. Modifications related to requirements can be automatically propagated to the down-stream geometries, maintaining the relationships among geometrical features in the following design steps to choose the optimal candidate. The case study deals with the mechanical design of nuclear fusion devices focusing on the improvement of the concept design of neutron shielding plates, a divertor subsystem added to satisfy a high level requirement about divertor shielding performances on vacuum vessel. Among several variants, a few feasible configurations are generated.

Keywords: DEMO | Divertor | Nuclear fusion engineering | Requirements management | Systems Engineering

Abstract: This paper proposes a systematic approach for involving the clinicians in the design of medical devices, here used for the development of a soft robotic glove for rehabilitation. The approach considers the integration of different methodologies that take into account the emotional information of the clinicians considered as end–users (i.e. Kano–Kansei) and a deep analysis of the needs of both the patients and the clinicians (i.e. house of quality). Based on this user–centered approach, the paper develops different rehabilitation concepts realized through the technique referred to as design of experiments. Finally the optimal one is chosen re–involving the clinicians and using the ANOVA analysis.

Keywords: Hand rehabilitation | Product development | Soft robotics | User-centred design

Abstract: Artificial limbs can help people missing body parts to restore some of their daily-life activities. However, the user should spend up to a few months to intuitively control the new device. During this period, she/he may suffer pain due to wearing or using the prosthesis inappropriately. This research presents a virtual simulator that allows the user to carry out training sessions for controlling the prosthesis. A set of Surface Electromyographic (sEMG) sensors are used to acquire the signals from user's muscles and send them to a recognition algorithm that interprets the patient's intentions. Simultaneously, the patient observes the response of her/his device on the simulator. Two studies are presented: the first study evaluate the performance of three different recognition algorithms i.e., Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), and Multi-Layer Perceptron (MLP), based on the successful recognition of the patient's intentions. The second study investigates the least number of sEMG sensors to be used, as having less components improves the patient's wearability and decreases the processing time. The developed simulator represents a real prosthetic device, PRISMA hand II. The results showed the superiority of the MLP with 80% of successful recognition when 6-sEMG sensors are used. If a reduced set of gestures is considered (frequently needed by the patient), 90% of successful recognition could be achieved. Less sEMG sensors significantly degraded the performance of the recognition algorithm as only 53.8% of successful recognition could be achieved. All experiments were conducted with the help of a patient with below-elbow amputation.

Keywords: Active prosthetic hand | Biomechatronic application | Multi-Layer Perceptron (MLP) | Pattern recognition | Rehabilitation robotics | sEMG signal processing

Abstract: This paper proposes a System Engineering-based iterative design approach for the DTT HyRMan, an hyper redundant manipulator conceived to perform Remote Maintenance (RM) of the FW modules and inspection tasks in the DTT vacuum vessel. According to the “RFLP” paradigm of the “V-model” (Requirements, Functionalities, Logical and Physical architecture, with the respective test phases), after having defined the manipulator's Requirements and Functionalities, the Logical and Physical architectures have been established. In particular, the current design of hyper redundant manipulator is characterized by twelve joints (two prismatic and ten revolute), with a Planar and a Dexterous Arm. Once defined the ideal operative procedures, the Verification phase of Systems Engineering approach has been carried out. The HyRMan behaviour has been simulated and tested in virtual environment under the in-vessel geometric constraints, to evaluate the overall encumbrance and the remote operations feasibility. The kinematic analyses were performed simulating links and joints as rigid bodies, using the software Delmia in the same Dassault Systèmes V5 platform used for 3D CAD modelling (CATIA V5). Flexibility analyses performed in SimSOFT have confirmed that the HyRMan can be modelled using the rigid body assumption with sufficient confidence, as flexible effects along the length of the links are negligible with the current design of the manipulator. The workflow of actions implemented within the virtual platform and the obtained results are discussed in the paper, further to the evaluation of alternative design solutions in case of reachability or collision avoidance criticalities for the HyRMan.

Keywords: DTT | Flexibility simulation | Hyper redundant manipulators | Kinematic simulations | Remote handling system | Systems engineering

Abstract: The realization of a specific REMote HAndling Test and Training Facility (REMHAT) is necessary for the development and optimization of the Remote Handling (RH) system, to demonstrate the fulfilment of all its design requirements, for testing and validation of the RH maintenance procedures, for the qualification and acceptance testing of RH equipment and tooling. Furthermore, it provides training and certification to the RH maintenance operators, by making available to operators the knowledge, instructions and experiencing of the Virtual Simulator platform, the control room devices, the robots and tooling to be used for RH tasks. In this work, the preliminary architecture of the DTT REMHAT facility is described, with a focus on the added value of the adoption of Virtual Reality (VR) technologies enabling real-time alignment of virtual robots’ configuration with the real ones (Digital Twin). A first approach to the facility design is proposed, starting from the technical requirements: Environmental, Design, Physical, Functional, Operational, Human Factors and Product assurance and safety. The proposed logical architecture consists of four Sub-Systems (S/S): building and auxiliaries, mock-ups, robots and Control Room. In the present work, a particular attention is paid on the last one. The idea is to create a digital twin of the RH equipment mock-ups to be coupled with software of real-time structural simulation, in order to have at disposition and show in VR environment real-time additional information about the real environment, like robots’ deflections and/or vibrations, clearances and possible collisions detection. These data could be crucial for the operator's decision-making process about a sudden intervention on the RH system, further to their employment for future studies and optimization. Therefore, for each subsystem of the facility, the components identification and a description of the software and hardware aspects are provided. In conclusion, an overview of the critical issues of such complex system is presented, in order to prepare the ground for future research works.

Keywords: Digital twin | DTT | Remote handling system | Test and training facility | irtual reality

Abstract: System engineering (SE) methods and principles are nowadays widely adopted in the product development processes, especially in the industrial sector, where saving production time and costs are primary goals. This work describes an application of a particular SE methodology, the V-model-based design, in which the system development lifecycle is divided on the basis of a graphical V-shaped scheme, called V-model. Following this approach, a new concept of charging arm for Robotic Train Inspection Monorail (TIM) of Large Hadron Collider (LHC) at CERN (Conseil Européen pour la Recherche Nucléaire) has been developed. The current charging arm version is affected by several issues and limits that have led to the necessity of a new solution. Starting from the first stages of functional requirements (FRs) definition and decomposition (left side of the “V”), a new concept has been implemented, in order to be tested for its verification and validation (right side of the “V”). As part of the principles of SE, the process has been based on virtual models of the product and on virtual simulations of its operation, rather than on the realization of time-consuming and expensive physical models and tests, even if a final physical prototype has also been built and some physical operative tests have also been carried out on it. These tests have showed that the new product appears to fulfill each one of its FRs and overcome the limits imposed by the previous version. The future commissioning and operative tests in the real operating condition and location shall definitely validate the new product.

Keywords: Additive manufacturing | Design for manufacturing | Finite element method | System engineering | V-model-based design | Virtual reality

Abstract: Systems Engineering allows to address the design of complex systems from the early stage until the end of its lifetime with the aim to realize successful systems. The intrinsic complexity of tokamak design requires to adopt Systems Engineering guidelines to write correctly and efficiently a large set of system requirements. Well-formed requirements would make efficient and consistent the downstream design, integration, and verification of a system. The process of requirements definition, conformed to Guide to System Requirements Definition recommended in fusion field, is far from simple and fast. The requirements definition phase encourages the early identification of issues that can be acted in the life cycle. This paper firstly highlights a new procedure to include requirements of a tokamak component in the requirement management tool of the whole system. This work identifies engineering requirements and constraints and describes their impact on the selection of the design principles of the EU-DEMO divertor system. The new identified procedure is developed using a participative approach involving experts belonging to different working groups.

Keywords: DEMO divertor | Requirements management | Systems engineering

Abstract: The basis of design for the Ion Cyclotron Range of Frequency (ICRF) antennas of the Divertor Tokamak Test facility (DTT) is defined and the most suitable design solutions abiding by such requirements are shown. DTT will be equipped with one, two or three ICRF modules - the final choice to be taken during the first years of operations - and each module will have two antennas. Each antenna has to reliably couple a radiofrequency (RF) power ≥1.5 MW in the range 60÷90 MHz to the single-null, 6 T, 5.5 MA, DTT scenario and allow for remote (dis)assembling and maintenance operations of its plasma-facing components. Most documented antenna concepts are considered and a large set of alternatives, based on toroidal arrays of two, three or four straps with different shapes and constraints, is quantitatively assessed in terms of RF performances. Two most promising candidates are identified: the one, selected to access a detailed design phase, relies on traditional radiating elements, the other is an innovative concept requiring some R&D.

Abstract: The paper reports the preliminary analysis of different typologies of ICRH launchers for chosing the most efficient solution for the ICRH system of the Divertor Tokamak Test facility (DTT), designed by the Italian DTT Limited Liability Consortium (S.C. a r.l.). In its final configuration this system will couple to the DTT plasma a nominal power of 6 MW in the 60 – 90 MHz frequency range by means of four launchers. This very preliminary analysis has been done with the ANSYS HFSS code.

Keywords: Current straps | Divertor Tokamak Test (DTT) | ICRF launcher | ICRF systems

Abstract: This work analyzes the impact of subjective factors on users’ immersive experience, while using glove-based handling devices as input system. A user-study has been conducted on a Virtual Training framework, evaluating usability and mental effort perceived with such devices.

Keywords: Frustration | Gloves | Handling devices | Usability | User study | Virtual Training

Abstract: In this paper we present the preliminary evaluation of an active soft bellow exoskeleton for assistance during overhead tasks. The evaluation was performed using objective (i.e., joint angles and muscle activations) and subjective (i.e., Borg Cr R-10 and System Usability Scale - SUS scales) measurements. The subject, involved in the experimental campaign, performed in laboratory conditions a drilling overhead task typical of the automotive industry, once using the exoskeleton and once without the exoskeleton. The preliminary results underlined the positive effect of the exoskeleton in terms of physical effort and usability.

Keywords: biomechanics | overhead tasks | soft exoskeletons | usability

Abstract: In this paper, a human-centered design methodology is proposed to support the interiors design of a Maritime Patrol Aircraft (MPA). The combined use of Immersive Virtual Reality (VR) tools and Digital Human Models (DHMs) are exploited to include both objective and subjective measurements in the ergonomic evaluation process. The main issue consisted in defining the optimal ergonomic design configuration for Operator Console Area and Observer Window Area of MPA's digital mock-up, provided by Leonardo S.p.A. The methodology is based on a five-step iteration process: once having identified the requirements, required input data and the design variables, the ideated configuration is evaluated using DHMs in order to retrieve objective measurements (i.e., interferences, visibility, reachability); finally, a subjective assessment within immersive VR environment is conducted. A real-time RULA analysis is carried out on DHMs, calibrated on selected users representing specific percentages of target population, by means of a full-body tracking system. The subjective assessment in immersive VR allows to take into account also other human factors (i.e. human ability, dexterity and cognitive aspects) that have not been previously considered and may significatively influence the validation of the final design configuration of MPA interiors.

Keywords: Digital Human Modeling | Digital Mock-up | Ergonomic Validation | Maritime Aircraft | Virtual Reality

Abstract: This work proposes a geometric approach to inverse kinematics of hyper-redundant manipulators used for remote maintenance of nuclear fusion reactors. The approach is particularly suited to be adopted in real-time human-in-the-loop control strategies involving high-frequency control feedback and requiring safe interaction between the manipulator and the in-vessel environment. The capability of the inverse kinematic method to find a solution for a set of different robot end-effector poses, inside a toroidal environment, was tested on the HyRMan kinematics, i.e. the Hyper Redundant Manipulator developed in the framework of the Divertor Tokamak Test (DTT) project. The simulation tests were aimed at assessing performance of the proposed method in terms of accuracy in the end-effector positioning, computational burden, distance from obstacle, distance from joint angles and torque limits and success rate of the task execution. The achieved results were compared to the ones obtained through an iterative method proposed in literature, i.e. the one based on the computation of the Jacobian pseudo-inverse, demonstrating overall higher performance of the proposed approach and comparable ability to safely avoid obstacles and joint limits.

Keywords: Hyper-Redundant Manipulators | Inverse Kinematics | Nuclear Fusion | Remote Maintenance

Abstract: Divertor Tokamak Test (DTT) is the next Italian facility for nuclear fusion research aiming at bringing alternative divertor solutions to a sufficient readiness level to be adopted by the European DEMOnstrating fusion power reactor (EU-DEMO). Since a non-negligible activation is expected on plasma-facing components after DTT shutdown, remote maintenance is mandatory. This work deals with the concept selection for the DTT remote maintenance strategy, in the 2019 reference configuration. First, we present the criteria that we have derived for evaluation of design alternatives. Then, we briefly present the design alternatives developed so far for divertor and first wall remote maintenance. With this regards, three alternatives have been developed for divertor remote maintenance and two alternatives have been developed for first wall remote maintenance. The concept selection process is based on the use of ELIGERE, a decision support tool for concept selection based on the Fuzzy Analytical Hierarchy Process. More than 20 experts from several European institutions have been involved in the concept selection process. The work concludes by presenting the results of the concept selection process, in terms of optimal strategies for divertor and first wall remote maintenance.

Keywords: DTT | Remote maintenance

Abstract: In this paper, we present a biomechanical analysis of the upper body, which includes upper-limb, neck and trunk, during the execution of overhead industrial tasks. The analysis is based on multiple performance metrics obtained from a biomechanical analysis of the worker during the execution of a specific task, i.e. an overhead drilling task, performed at different working heights. The analysis enables a full description of human movement and internal load state during the execution of the task, thought the evaluation of joint angles, joint torques and muscle activations. A digital human model is used to simulate and replicate the worker’s task in a virtual environment. The experiments were conduced in laboratory setting, where four subjects, with different anthropometric characteristics, have performed 48 drilling tasks in two different working heights defined as low configuration and middle configuration. The results of analysis have impact on providing the best configuration of the worker within the industrial workplace and/or providing guidelines for developing assistance devices which can reduce the physical overloading acting on the worker’s body.

Keywords: Biomechanics | Digital human models | Electromyography | Ergonomics | Industry | Overhead tasks

Abstract: This work proposes a novel virtual reality system which makes use of wearable sensors for testing and validation of cooperative workplaces from the ergonomic point of view. The main objective is to show, in real time, the ergonomic evaluation based on a muscular activity analysis within the immersive virtual environment. The system comprises the following key elements: a robotic simulator for modeling the robot and the working environment; virtual reality devices for human immersion and interaction within the simulated environment; five surface electromyographic sensors; and one uniaxial accelerometer for measuring the human ergonomic status. The methodology comprises the following steps: firstly, the virtual environment is constructed with an associated immersive tutorial for the worker; secondly, an ergonomic toolbox is developed for muscular analysis. This analysis involves multiple ergonomic outputs: root mean square for each muscle, a global electromyographic score, and a synthetic index. They are all visualized in the immersive environment during the execution of the task. To test this methodology, experimental trials are conducted on a real use case in a human–robot cooperative workplace typical of the automotive industry. The results showed that the methodology can effectively be applied in the analysis of human–robot interaction, to endow the workers with self–awareness with respect to their physical conditions.

Keywords: Cooperative workplace | Ergonomic analysis | Human– robot physical interaction | Virtual reality | Wearable sensors

Abstract: In a power plant scale fusion reactor, a huge amount of thermal power produced by the fusion reaction and external heating must be exhausted through the narrow area of the divertor targets. The targets must withstand the intense bombardment of the diverted particles where high heat fluxes are generated and erosion takes place on the surface. A considerable amount of volumetric nuclear heating power must also be exhausted. To cope with such an unprecedented power exhaust challenge, a highly efficient cooling capacity is required. Furthermore, the divertor must fulfill other critical functions such as nuclear shielding and channeling (and compression) of exhaust gas for pumping. Assuring the structural integrity of the neutron-irradiated (thus embrittled) components is a crucial prerequisite for a reliable operation over the lifetime. Safety, maintainability, availability, waste and costs are another points of consideration. In late 2020, the Pre-Conceptual Design activities to develop the divertor of the European demonstration fusion reactor were officially concluded. On this occasion, the baseline design and the key technology options were identified and verified by the project team (EUROfusion Work Package Divertor) based on seven years of R&D efforts and endorsed by Gate Review Panel. In this paper, an overview of the load specifications, brief descriptions of the design and the highlights of the technology R&D work are presented together with the further work still needed.

Keywords: DEMO | Divertor | Fusion reactor | High-heat-flux | Plasma-facing component | Power exhaust

Abstract: A Cayley map for the special Euclidean group SE(3) is introduced to relate, for a soft continuum robot, the Lie algebra of internal deformations with the Lie group of rigid–body motions. This Cayley map is used for approximated and exact kinematic shape reconstruction of soft continuum robots, under the hypothesis of constant deformations. This map could be used for deriving computationally efficient interpolation schemes for soft robots, since it does not involve transcendental functions as those introduced by the exponential parametrization of soft robot kinematics.

Keywords: Cayley transform | Differential geometry | Kinematics | Soft robotics

Abstract: Humans drive in a holistic fashion which entails, in particular, understanding dynamic road events and their evolution. Injecting these capabilities in autonomous vehicles can thus take situational awareness and decision making closer to human-level performance. To this purpose, we introduce the ROad event Awareness Dataset (ROAD) for Autonomous Driving, to our knowledge the first of its kind. ROAD is designed to test an autonomous vehicles ability to detect road events, defined as triplets composed by an active agent, the action(s) it performs and the corresponding scene locations. ROAD comprises videos originally from the Oxford RobotCar Dataset annotated with bounding boxes showing the location in the image plane of each road event. We benchmark various detection tasks, proposing as a baseline a new incremental algorithm for online road event awareness termed 3D-RetinaNet. We also report the performance on the ROAD tasks of Slowfast and YOLOv5 detectors, as well as that of the winners of the ICCV2021 ROAD challenge, which highlight the challenges faced by situation awareness in autonomous driving. ROAD is designed to allow scholars to investigate exciting tasks such as complex (road) activity detection, future event anticipation and continual learning. The dataset is available at https://github.com/gurkirt/road-dataset; the baseline can be found at https://github.com/gurkirt/3D-RetinaNet.

Keywords: action detection | Autonomous driving | Autonomous vehicles | Benchmark testing | decision making | Decision making | road agents | Roads | situation awareness | Task analysis | Vehicle dynamics | Videos

Abstract: Applications as robotic harvesting or pick and place in the agrifood domain require robotic grippers able to gently manipulate delicate products, while guaranteeing high gripping power and adhesion forces on smooth surfaces. Existing soft grippers are mainly based on pneumatic bending actuators which can guarantee a gentle manipulation, but they suffer from low gripping power and possibility of slip of the manipulated object. This paper describes a novel design concept of soft robotic pneumatic gripper with embedded suckers. The concept consists of four soft fingers, each one comprising an elastomeric structure with two separate air paths, one for pressurizing the finger for generating bending motion, one for vacuum–based adhesion to the object’s surface via suction pads distributed along the surface of the finger. In this work we highlight the concept design of the mechanical system and the pneumatic control unit.

Keywords: Bioinspired design | Concept design | Soft grippers | Soft robotics

Abstract: The presented work shows how a user centered approach might be used to generate and select the optimal design of smart garments for biosignal acquisition. Design is driven by human biosignal analysis, allowing the translation of subjective user’s feelings into technical specification and the definition of customized criteria for concepts evaluation. So, different concepts are generated and, involving users again, the optimal one is chosen using multi criteria decision making based on Fuzzy AHP theory. A case study on a wearable system (i.e., electromyographic shorts) for football performance and risk injury analysis is shown.

Keywords: Biological knowledge in engineering science | User centered design | Wearable technologies

Abstract: Today it is more and more mandatory for all commercial companies to comply with the principles and methodologies of Industry 4.0 and to achieve the related capabilities protecting their competitiveness and taking a leading-edge position on market as regards technologies. Specifically, the whole production and sale system must achieve the fundamental characteristics of Industry 4.0 approach, but specially the manufacturing companies must also change and update their management procedures, internal organization, resource training, assets and all production process to keep safe their current business capacities. This evolution process is even more critical for Small and Medium Enterprises (SME), that traditionally tend to be conservative and to protect their way of operation, usually characterized by a low level of automation. The work presented focuses on the design and integration of a semi-automatic welding cell of train bolster in a SME which is currently realizing a project aimed to the acquisition of Industry 4.0 capabilities, with special focus on manufacturing processes. Among them, one of the most important is the production of welded-steel critical structures, that the Company supplies to prime manufacturer of railway rolling stock systems. The experience gained during the activity, the criticalities due to the integration processes and the adopted design methodologies are here described. The work has been carried out consistently with the Systems Engineering principles, starting from the requirements elicitation and analysis to the systematic approach for the design and integration activities.

Keywords: CAD | Design methodologies | Industry 4.0 | Internet of things (IoT) | Systems engineering | Welding process

Abstract: In this study we propose a brief analysis of recent soft wearable robots for upper–limb which could have a major impact on future developments and applications. The systems are analysed with respect to: design concepts, actuation systems, sensing systems, control strategies and applications. Finally, a discussion and open issues are presented.

Keywords: Exoskeletons | Soft robotics | Wearable robotics

Abstract: The realization of nuclear fusion reaction as energy source is under investigation, among the scientific community, through the design and development of tokamak reactors. Among the several experiments worldwide, the ITER project is the major international experiment and it involves several research institutes from several countries. In such a project, a Systems Engineering (SE) approach is requested to organize and manage the design due to its highly integrated design, the safety requirements related to nuclear aspects and the complex procurement scheme. The SE discipline focuses the attention on the requirements which are crucial for every successful project, defining what the stakeholders want from a potential new system, namely what the system must do to satisfy stakeholders need. Correctly stating WHAT is needed for the system, it is possible to obtain its conceptual design (HOW) as much as possible complying the requirements. The incorrect definition of requirements often leads to the failing of a project. Stakeholders’ needs are written in Natural Language that is generally ambiguous, imprecise, incomplete and redundant. Their transformation into SMART requirements is crucial to avoid design failure. However, it requires a great expertise, unless a specific procedure is assessed. To this end, this work presents a specific procedure based on “like-mind” processes to make systematic the SMART requirements definition and assessment from stakeholders needs. The procedure is based on a demand/response framework and it is developed to obtain ITER requirements. However, it can be easily extended to every project using its own specifications. A specific case study on ITER Remote Handling is presented in this paper as example of the conceived requirements transformation procedure.

Keywords: ITER tokamak | Requirements engineering | SMART requirements | Systems engineering

Abstract: In this work we derive the requirements of a soft upper-limb exoskeletons starting from the biomechanical analysis of human workers while performing three different industrial overhead tasks in laboratory settings. The results of the work allow to define the degrees of freedom which need to be supported to reduce the biomechanical overloads, as well the dimensional characteristics, in terms of required lengths and forces, of the soft actuators of the wearable robot.

Keywords: Biomechanics | Design | Industrial tasks | Soft exoskeleton | Soft robotics | Wearable robotics

Abstract: This chapter presents the ergonomic assessment of a typical shelf filling task performed by the store clerk. The proposed methodology is based on a robust design approach, which considers all the main factors that have influence on the ergonomic assessment of a typical refilling operation. The ergonomic assessment is based on two ergonomic indices, one specific for establishing the ergonomically optimal working height for lifting, and one specific for selecting the refilling process modality which minimises the clerks’ effort. The research work has been performed using both virtual simulations and real laboratory experiments. The goal is to provide input to a suitably designed robotic handling unit encapsulating a standard supermarket trolley. The handling unit consists in a suitable SCARA-like arm and two actuated trays, which allow to serve the cases with the products contained in the trolley at an ergonomic height for the clerks, with the aim of reducing refilling-related musculoskeletal disorders and thus improve clerks’ health and wellbeing.

Keywords: Biomechanical risk | Collaborative robotics | Ergonomic assessment | Ergonomic indices

Abstract: This paper presents the preliminary design of a teleoperation system for a bimanual bartending robot, with reference to the BRILLO (Bartending Robot for Interactive Long Lasting Operations) project. The aim is to simulate the remote control of the robotic bartender by the human operator in an intuitive manner, using Virtual Reality technologies. The proposed Virtual Reality architecture is based on the use of commercial Head Mounted Display with a pair of hand controllers and the virtual simulation of the remote environment of the robot, with the robotic simulator CoppeliaSim. Originally, virtual simulations of the robot environment have allowed to identify the possible scenarios and interactions between the customers and the different robotic systems inside the automatized bar: the totem for the selection and payment of the order, the robotic bartender to prepare the cocktail and the mobile robot for the cocktail serving at the table. Secondly, focusing on a sequence of main tasks that the robotic bartender must perform for the cocktails preparation, the operator’s control on the simulated robotic system has been reproduced. In fact, the aim of this first experimental phase is to test the interaction between the human operator and the simulated immersive environment for the remote control of the robotic system. Two use cases have been reproduced: the first is related to the recovery from a failure situation such as the fall of a glass, while the second refers to the trajectory training to perform some repeating actions. Six operators (three males and three females), who already knew the taks, with an age between 25 and 40 years and a minimum experience with VR technology for personal entertainment, have been involved in the test phase. For this reason, the paper will finally discuss the perception of the involved operators about the use of the proposed VR architecture in terms of usability and mental workload.

Keywords: CoppeliaSim | HTC VIVE Pro | Remote control | Teleoperation | Virtual Reality

Abstract: In this paper we show an overview of the preliminary strategy planned for remote maintenance of neutron–activated and contaminated components of DTT machine, in the 2019 reference configuration. The remote maintenance of such a complex machine has impact on different aspects of the DTT machine: layout of the tokamak hall, vacuum vessel and cryostat structures, in–vessel components. To date, the number and size of vacuum vessel ports as well as the segmentation and size of in–vessel mechanical components of DTT have been established by a compromise between operational and maintenance needs. An extensive multidisciplinary work has been done in deriving the requirements for the DTT remote maintenance strategy. Each vacuum vessel sector is divided into five ports: in the current configuration, the top and bottom divertor cassettes are expected to be removed, respectively, from four lower lateral ports and from four equatorial horizontal ports; the first wall modules at the inboard side are expected to be installed/removed from all the upper ports; the first wall modules at the outboard and upper sides are segmented such that they can be removed from four equatorial horizontal ports. The work describes the current strategies for divertor and first wall remote maintenance systems, as well as a first conceptual design of the remote maintenance equipment of DTT machine.

Keywords: DTT | Remote maintenance

Abstract: The use of fast and accurate scanning systems for human worker digitization might pave the way towards the development of multiple best practices to be implemented in industry, for enhancing safety and wellness of workers. In this work, an advanced measurement system for human body 3D reconstruction is used for extracting anthropometric characteristics of a worker, which are then used for estimation of joint torques in a simulated lifting task.

Keywords: 3D body measurements | 3D body scanner | Digital human modeling | Industrial ergonomics

Abstract: Measurement and monitoring systems (MMSs) are intrinsically part of 4.0 and, in particular, of cyber-physical systems (CPSs). However, by introducing the 4.0 enabling technologies into MMSs, also the vice versa can be accomplished, and MMSs can evolve into a cyber-physical measurement system (CPMS). Starting from this consideration, in the present work, a preliminary case study of a CPMS is presented: an innovative robotic platform to be used for measurement systems in confined and constrained remote environments. The proposed system is a soft growing robot that includes a robot base, to be placed outside the remote environments, and a robot body that accesses the site through growth. A pneumatic actuation mechanism enables the controllable growth of the system (through lengthening at its tip), as well as its controllable steering. The system can be equipped with sensors to enable remote monitoring tasks, or can be used to transport sensors in remote locations. The ultimate goal is to achieve a self-adapting, fully-autonomous, reliable and safe system for monitoring applications, particularly useful for the remote inspection of unknown and/or constrained environments.

Keywords: 4.0 | Inspection | Monitoring systems | Remote monitoring | Soft continuum robots | Soft growing robots

Abstract: A physics and engineering analysis of alternative divertor configurations is carried out by examining benefits and problems by comparing the baseline single null solution with a Snowflake, an X- and a Super-X divertor. It is observed that alternative configurations can provide margin and resilience against large power fluctuations, but their engineering has intrinsic difficulties, especially in the balance between structural solidity and accessibility of the components and when the specific poloidal field coil positioning poses further constraints. A hybrid between the X- and Super-X divertor is proposed as a possible solution to the integration challenge.

Keywords: Alternative divertor configurations | DEMO | Divertor design

Abstract: In this paper, we propose a user-centered approach for the design of ergonomic workplaces. The method is based on the evaluation of subjective opinions and objective measures from the worker, while performing the industrial tasks. The ergonomic design of industrial workplaces will have impact in reducing the musculoskeletal disorders of workers.

Keywords: Adaptable workplace | Human-oriented design | Industry 4.0 | Worker ergonomics

Abstract: The present work has two main objectives: the realization of a Virtual Training system about assembly operations in two immersive virtual environments and the comparison between the features offered. The first solution proposed is the use of commercial software IC.IDO, produced by ESI Group. It is designed for applications throughout all the PLM, offering support both in the design and production phases, as well as after-sales assistance. At the opposition, the second solution proposed is the use of the Open-source software Unity. This graphics engine has found significant success in gaming field in the recent years, as it allows more flexibility to the developer for the implementation of the features but requires greater competence in terms of programming. The following paragraphs firstly address the path outlined from the collection of customer’s requirements to the virtual prototypes’ release, following the Systems Engineering approach. Secondly, a benchmark between IC.IDO and Unity’s features is illustrated to point out their main differences, strengths and weaknesses.

Abstract: Mathematical modeling of hybrid soft robots is complicated by the description of the complex shape that they undergone when subject to actuation and external loads. It might be noticed that several approaches have been used so far in robotics, and the problem is not yet fully solved. This short paper aims at presenting an overview of modeling and simulation approaches for soft robots based on finite element methods. Benefits and perspectives of future directions are also discussed.

Keywords: Finite element method | Modeling and simulation | Soft robotics

Abstract: Nowadays, technology in sport plays an important role to help training and judgement processes. This study proposes the use of a wearable inertial system to derive novel biomechanical indices for the assessment of performance and infringements in race-walking. These indices are built from five inertial-based parameters: loss of ground contact time, loss of ground contact step classification, step length ratio, step cadence and smoothness. The biomechanical indices are customized for elite race-walkers, and represented on a radar chart for an intuitive analysis of performance and infringements. From the radar chart, a synthetic index regarding the athlete’s overall gesture is derived. The validation of the biomechanical indices is carried out in field tests, involving nine elite race-walkers wearing an inertial sensor located at the end of the column vertebra (L5–S1). A statistical analysis is used to determinate the quality and reliability of the proposed indices and of their representation. The results show that these biomechanical indices can be implemented on a wearable inertial system for assistance in training and judgement in race-walking.

Keywords: Biomechanics | Field tests | Graphical data analysis | Infringements | Performance | Race-walking | Wearable sensors

Abstract: The pre-conceptual design of the DEMO divertor cassette with a novelty, alternative path of the main cooling pipes inside cassette body is presented in this paper, focusing on cassette design and Plasma Facing Components (PFC) integration. The divertor cassette design is reviewed, considering recent updates in the DEMO configuration model as presented by the Programme Management Unit (PMU) in 2018. The new configuration requires the cooling pipes to be integrated inside the cassette body. The components affected by these changes and the impact on the divertor design are analyzed. The study focuses on a new integration system between cassette and cooling pipes. The paper describes the integration on the new cassette geometry and the divertor sub-systems. The design activities related to this system are discussed in detail in terms of CAD modeling and considerations with respect to manufacturing such as welding technologies and non-destructive testing.

Keywords: Cooling pipes | DEMO | Divertor cassette | Divertor target

Abstract: One of the main challenges in the roadmap to the realization of fusion energy is to develop a heat and power exhaust system able to withstand the large loads expected in the divertor of a fusion power plant. The challenge of reducing the heat load on the divertor targets is addressed, within the mission 2 ‘Heat-exhaust systems’, through the investigation of divertor configurations alternative to the standard Single Null (SN), such as the Snowflake (SF), Double Null (DN), X and Super-X (SX) divertors. This paper focuses on a preliminary engineering assessment of the alternative configurations proposed for the EU DEMO reactor. Starting from the description of the optimized plasma shape developed for each configuration, the 3D geometrical description of the Magnet System and of the main Mechanical Structures (Vacuum Vessel and in-vessel components) is presented. Based on the 3D geometry, the compatibility of the location and dimensions of ports with Remote Maintenance needs is discussed and possible design optimizations are proposed both for the Magnets system and the mechanical structures design. Finally, the various configurations are compared with regard to the engineering and feasibility aspects.

Keywords: Alternative magnetic configurations | CAD | Conceptual design | DEMO | Divertor concept

Abstract: The design activities of an insulated Plasma Facing Components-Cassette Body (PFCs-CB) support has been carried out under the pre-conceptual design phase for Eurofusion-DEMO Work Package DIV-1 “Divertor Cassette Design and Integration” - Eurofusion Power Plant Physics & Technology (PPPT) program. The Eurofusion-DEMO divertor is a key in-vessel component with PFCs which directly interact with the plasma scrape-off layer. The PFCs have to cope with high heat loads, neutron irradiation and electromagnetic loads. The mechanical integrity of the PFCs and water cooling pipes can be jeopardized by high heat loads and by electromagnetic loads generated in a disruption event. In European-DEMO the possibility to estimate the heat load by measuring the relative thermocurrents is under investigation. In order to allow thermocurrents measurements, a divertor design option provides that PFCs are electrically insulated from CB. In this work authors aim to analyze the opportunity that the PFC-CB fixing system incorporates an electrical insulation system, thus acquiring also an important diagnostic role in the measurement of the thermocurrents and in the management of the current flows. The possible use of ceramic material (e.g. alumina) as the insulating layer between the support components is investigated.

Keywords: Divertor assembly | Divertor Plasma Facing Componentsfixation system | Eurofusion-DEMO

Abstract: The Eurofusion-DEMO design will complete the Pre Conceptual Design phase (PCD) with a PCD Gate, named G1, scheduled to take place in Q4 2020 that will focus on assessing the feasibility of the plant and its main components prior to entering into the Conceptual Design phase. In the paper first an overview is given of the Eurofusion-DEMO Divertor Assembly including design and interface description, systems and functional requirements, load specification, system classification, manufacturing procedures and cost estimate. Then critical issues are discussed and potential design solutions are proposed, e.g.: - Neutron material damage limits of the different (structural) materials present in the divertor assembly (as CuCrZr, Eurofer) and in the vacuum vessel (AISI 316 L(N)-IG); - Temperature hot spots in parts of the divertor assembly exposed to high nuclear heating and high heat radiation (from the plasma core or the separatrix) causing difficulties for active or passive cooling (e.g. cassette body structure, liner support structures, mechanical supports, divertor toroidal rails); - Arrangement and design of plasma-facing components and liner with pumping slot in the divertor cassette to enable pumping of exhaust gases from the lower port.

Abstract: The Divertor Tokamak Test facility is an Italian experimental facility under design and construction at ENEA C.R. Frascati. The main goal of DTT is to provide an integrated environment, relevant to DEMO, where testing possible solution to the power exhaust problem in a tokamak (like for example: i) Plasma facing components technology ; ii) Plasma and divertor shape; iii) impurity seeding to increase radiation). In this respect, DTT has been designed to be flexible and adopting technologies relevant to DEMO. After its initial inception in 2015, concluded with the publication of the DTT project proposal, a complete re-baseline has been provided oncluded with the publication of the DTT Interim Design Report in 2019, aimed at accommodating the request of flexibility coming from the international fusion community. During 2019, the engineering integration activity has started and the first construction contracts have been signed. This paper provides an overview of the integrated design activity towards the realization of the facility within 2025.

Keywords: divertor | DTT | nuclear fusion | superconducting magnets

Abstract: In this paper we present novel biomechanical indices for site-specific assessment of injury risk in cycling. The indices are built from a multifactorial analysis based on the kinematics and kinetics of the cyclist from the biomechanical side, and muscle excitations and muscle synergies from the neurophysiological side. The indices are specifics for three body regions (back, knee, ankle) which are strongly affected by overuse injuries in cycling. We use these indices for injury risks analysis of a recreational cyclist, who offered to participate in the experiments. The preliminary results are promising towards the use of such indices for planning and/or evaluating training schedule with the final goal of reducing non-traumatic injuries in cycling.

Keywords: biomechanics | cycling | electromyography | injury risk | laboratory test

Abstract: A fast and objective evaluation of kinematic characteristics of an elite athlete's gesture is necessary for refining her/his performance. When the athlete has a reduced capacity and/or reliability of expression, as in the case of subjects with intellectual impairment, objective performance analyses are even more important. In this work, we present a preliminary study regarding performance analysis on sprint tests performed by elite athletes with intellectual impairment, wearing an inertial sensor at the bottom end of their vertebral column. In particular, we compare three different inertial-based algorithms for automatic detection of temporal events, in steady-state velocity phase, with respect to the benchmark values obtained through video analysis.

Keywords: functional sports assessment | inertial sensors | intellectual impairment | kinematic parameters | sprint test

Abstract: Excessive values of force on L5/S1 joint can cause work-related musculoskeletal disorders, such as low back pain. Currently, the reference solution for estimating such variables is the combination of optoelectronic system and force platform, used for calculating the bottom up inverse dynamics in laboratory settings. Here we propose and validate a novel, completely wearable solution, composed by twelve inertial measurement units and pressure insole sensors. We validate the wearable solution with respect to the output of the reference solution, with data collected simultaneously on a subject performing lifting and releasing tasks with two different loads. The results are encouraging towards the use of the wearable methodology, considering the great impact of such a solution in a real manufacturing scenario.

Keywords: biomechanical loads | ergonomics | motion analysis | occupational disease | wearable system

Abstract: People with intellectual impairment show low performances in motor control, especially in complex movements. Performance analysis methods, based on wearable inertial sensor, are often used in typical developed swimmers but have never been used in swimmers with intellectual impairment, for whom the use of quantitative systems would be even more important. This paper presents a case study conducted on freestyle swimmers from the functional evaluation project of the Italian Sport Federation for athletes with Intellectual Impairment (FISDIR). The tests were conducted by five Italian elite swimmers with intellectual impairment using a structured experimental protocol which foresees an inertial sensor located on the wrist. Key freestyle temporal and kinematic parameters were assessed. A high-speed camera was used as a benchmark to validate the inertial-based parameters. The preliminary results indicate that the proposed inertial-based approach correlates over 90% with the performance indices obtained with the camera-based approach, and therefore it could represent a useful tool for monitoring and improving the training.

Keywords: intellectual impairment | performance analysis | sports biomechanics | swimming | wearable inertial sensor

Abstract: Plasma exhaust has been identified as a major challenge towards the realisation of magnetic confinement fusion. To mitigate the risk that the single null divertor (SND) with a high radiation fraction in the scrape-of-layer (SOL) adopted for ITER will not extrapolate to a DEMO reactor, the EUROfusion consortium is assessing potential benefits and engineering challenges of alternative divertor configurations. Alternative configurations that could be readily adopted in a DEMO design include the X divertor (XD), the Super-X divertor (SXD), the Snowflake divertor (SFD) and the double null divertor (DND). The flux flaring towards the divertor target of the XD is limited by the minimum grazing angle at the target set by gaps and misalignments. The characteristic increase of the target radius in the SXD is a trade-off with the increased TF coil volume, but, ultimately, also limited by forces onto coils. Engineering constraints also limit XD and SXD characteristics to the outer divertor leg with a solution for the inner leg requiring up-down symmetric configurations. Capital cost increases with respect to a SND configuration are largest for SXD and SFD, which require both significantly more poloidal field coil conductors and in the case of the SXD also more toroidal field coil conductors. Boundary models with increasing degrees of complexity have been used to predict the beneficial effect of the alternative configurations on exhaust performance. While all alternative configurations should decrease the power that must be radiated in the outer divertor, only the DND and possibly the SFD also ease the radiation requirements in the inner divertor. These decreases of the radiation requirements are however expected to be small making the ability of alternative divertors to increase divertor radiation without excessive core performance degradation their main advantage. Initial 2D fluid modeling of argon seeding in XD and SFD configurations indicate such advantages over the SND, while results for SXD and DND are still pending. Additional improvements, expected from increased turbulence in the low poloidal field region of the SFD also remain to be verified. A more precise comparison with the SND as well as absolute quantitative predictions for all configurations requires more complete physics models that are currently only being developed.

Keywords: DEMO | divertor | fusion reactor | plasma exhaust

Abstract: This paper presents an innovative safety training method based on digital ergonomics simulations and serious games, which are games that focus on education. Digital ergonomics is intended to disseminate the culture of safety among workers, while serious games are used to train the operators on specific safety procedures and verify their skills. The results of the experimentation in a real industrial environment showed that, compared to the traditional training methodology, multimedia contents and quantitative ergonomic analyses improve the level of attention and the awareness of the workers about their own safety. However, serious games turned out to be promising training tools with regard to standard operating procedures that are usually difficult or dangerous to simulate in a real working scenario without stopping production. Practitioner summary: Digital ergonomics and serious games are used to disseminate the culture of safety among the workers and for safety training. Our results show that the proposed methodology improves the level of attention and provides a better feedback about the actual skills of the workers than the standard educational strategies. Abbreviations:.

Keywords: Digital humans | occupational safety | serious games | training methods

Abstract: Most occupational safety regulations and international standards recognize the importance of keeping a corporate document that set all the safety procedures prescribed for a certain workplace. However, experience show that, to be truly effective, any piece of information must be kept updated and correctly delivered to the right recipient. From this point of view, the possibility, given by modern technology, to receive, process and send information in real time using common smartphones is a great opportunity. The authors developed a solution for mobile devices, which is based on augmented reality technologies and indoor positioning algorithms, aimed at speeding up and simplifying the information flow among safety managers, workers and casual users about safety-related content. Safety managers can use it as a support tool for the preparation of the risk assessment documentation, on the workers' side, the same application acts as an informational tool providing safety-related content when and where needed through augmented reality technologies. Preliminary results from in situ testing show that augmented reality may be a powerful tool to improve the occupational safety.

Keywords: Augmented reality | Mobile technologies | Workplace safety

Abstract: Most occupational safety regulations and international standards recognize the importance of keeping a corporate document that set all the safety procedures prescribed for a certain workplace. However, experience show that, to be truly effective, any piece of information must be kept updated and correctly delivered to the right recipient. From this point of view, the possibility, given by modern technology, to receive, process and send information in real time using common smartphones is a great opportunity. The authors developed a solution for mobile devices, which is based on augmented reality technologies and indoor positioning algorithms, aimed at speeding up and simplifying the information flow among safety managers, workers and casual users about safety-related content. Safety managers can use it as a support tool for the preparation of the risk assessment documentation, on the workers’ side, the same application acts as an informational tool providing safety-related content when and where needed through augmented reality technologies. Preliminary results from in situ testing show that augmented reality may be a powerful tool to improve the occupational safety.

Keywords: Augmented reality | Mobile technologies | Workplace safety

Abstract: This research discusses the use of a systematic design method, the Iterative and Participative Axiomatic Design Process (IPADeP), for the early conceptual design stage of large-scale engineering systems. The involvement of multiple and competing requirements has imposed high challenges for achieving an affordable design of complex systems in a reasonable lead time. Systems Engineering (SE) focuses on how to design and manage complex systems over their life cycles. Both must begin by discovering the real problems that need to be resolved and identifying from the early stage of the design the main stakeholder requirements and customer needs. The Axiomatic Design (AD) methodology is widely recognized in the literature to efficiently support the design of complex systems from the early conceptual stage. IPADeP provides a systematic methodology for applying AD theory in the conceptual design of large-scale engineering systems, aiming to minimize the risks related to the uncertainty and incompleteness of requirements and to improve the collaboration of multi-disciplinary design teams. IPADeP has been adopted as design methodology in the pre-conceptual design stage of a subsystem of the DEMOnstration fusion power plant (DEMO): the divertor cassette body-to-vacuum vessel locking system. In this paper improvements in IPADeP are presented and its validity is discussed by presenting the application to the divertor system design.

Keywords: Axiomatic Design | Design methods | Systems Engineering | Tokamak design

Abstract: This paper describes a mechanics–based framework for virtual prototyping of soft robots, i.e. robots with deformable bodies and flexible joints. The framework builds on top of the screw theory, and uses geometrically exact nonlinear beam models for describing the behavior of deformable bodies, as well as the finite element method for space discretization. The computer implementation of this framework results in SimSOFT, a physics engine for soft robots. The capabilities of the framework are illustrated with one general example, an articulated chain of rigid and soft links connected through rigid and flexible joints. Furthermore, several case studies are shown for industrial and medical applications.

Keywords: Continuum mechanics | Design methods | Multibody dynamics | Soft robotics | Virtual prototyping

Abstract: This paper shows how studies on the biomechanics and neuroscience of human movements might be used for the design of wearable systems customized for humans. Such design is driven by key biomechanical and neuromuscular parameters extracted from accurate measurements made on the human body motion, as well as by subjective data collected from the end-users of the products through questionnaires. We present three case studies developed at ERGOS Lab: a wearable system for sports performance analysis; a synergy-based approach for industrial wearable robots; a soft wearable robotic glove for hand rehabilitation.

Keywords: Biomechanics | Design methods | Neuromuscular activity | Wearable technology

Abstract: Mathematical modeling of soft robots is complicated by the description of the continuously deformable three-dimensional shape that they assume when subjected to external loads. In this article we present the deformation space formulation for soft robots dynamics, developed using a finite element approach. Starting from the Cosserat rod theory formulated on a Lie group, we derive a discrete model using a helicoidal shape function for the spatial discretization and a geometric scheme for the time integration of the robot shape configuration. The main motivation behind this work is the derivation of accurate and computational efficient models for soft robots. The model takes into account bending, torsion, shear, and axial deformations due to general external loading conditions. It is validated through analytic and experimental benchmark. The results demonstrate that the model matches experimental positions with errors <1% of the robot length. The computer implementation of the model results in SimSOFT, a dynamic simulation environment for design, analysis, and control of soft robots.

Keywords: continuum robots | Cosserat rods | differential geometry | dynamics | mathematical modeling | soft robotics

Abstract: Unfortunately, the affiliation of one of the authors “Salvatore Gerbino” was incorrect in the original publication, and the correct version is updated here.

Abstract: This paper presents an interactive design method aimed at improving workplace health and safety. Human performances and anthropometric variability are carefully considered to make the workplace “robust” from a safety point of view. This topic is of increasing interest to industries that plan to make safer workplaces without renouncing to their productivity targets. A challenging issue concerns the evaluation of the effects of sources of anthropometric variability in the process by using just a small sample of real or digital humans. The adoption of a discretization technique helps to solve this problem and saving time and resources. Through real industrial case studies, the authors investigate the main ergonomic and safety issues faced during the development of both manual and human–robot hybrid workcells.

Keywords: Design methods | Digital human modelling | Human–robot interaction | Robust design | Virtual ergonomics | Virtual safety

Abstract: The goal of this paper is to disseminate the main results achieved within the FlexARM project. The project deals with advanced modeling techniques and predictive control strategies for flexible mechanical systems intended to be used in remote tasks inside advanced nuclear fusion reactors. This article aims at underlying the main aspect of the FlexARM methodology and paves the way towards future research in the field.

Keywords: DEMO remote maintenance | Flexible mechanical systems | Modeling | Vibration control

Abstract: In the current pre-concept phase of the European DEMO, integration studies of the systems in the Upper Port area are being carried out. In DEMO, the Upper Port of the Vacuum Vessel is extraordinarily large to allow for the vertical extraction of the Breeding Blanket segments. This requires a number of components inside and outside the port to be integrated with tight space constraints: The Upper Port structure and its annexes, the adjacent Toroidal and Poloidal Field Coils, the Thermal Shields, the piping connection to the Vacuum Vessel Pressure Suppression System, the Shield Plug and its inserts, the feeding pipework of the in-vessel components and part of the Breeding Blanket supporting structures. Apart from functional aspects, the design of these components is driven by considerations of structural integrity, maintainability and irradiation shielding, which are mutually competing in many areas. Several studies were conducted on the design of the Upper Port and the required configuration of the components within. The present article describes the development approach, the studied options and the respective results, the identified issues as well as the proposed engineering solutions, in particular with respect to the mechanical design of the Upper Port and the integrated Shield Plug.

Keywords: CAD | DEMO | Integration | Upper Port | Vacuum vessel

Abstract: In this work we present the latest progresses (September 2018) in the conceptual design of the main containment structures of DTT fusion reactor. The previous DTT baseline design is revised in terms of structural materials and overall reactor shape. The major change involves the vacuum vessel, which now foresees a welded double-wall stainless steel structure. The basic design includes eighteen sectors, with novel ports configuration for remote maintenance systems, diagnostics and heating equipment. New supports are designed for the first wall, which is conveniently segmented in view of assembly and remote replacement. The cryostat of the machine is conceived as a single-wall cylindrical vessel reinforced by ribs. The cryostat base is also in charge of supporting the vacuum vessel and the magnets system. A preliminary FEA analysis confirms that the main mechanical structure might withstand the design loads, in particular the ones resulting from possible plasma disruptions.

Keywords: CAD | DTT | EU-DEMO | FEM | Fusion reactor | Structural analysis

Abstract: The paper presents the design activities and testing plan of a vertical target mock-up, developed within the pre-conceptual design phase for DEMO Work Package DIV-1 “Divertor Cassette Design and Integration” - EUROfusion Power Plant Physics & Technology (PPPT) program. Activities concerning the Divertor Outboard Vertical Target cooling mock-up are presented in term of CAD model, thermal-hydraulic numerical simulation, structural analysis, structural integrity verification and manufacturing procedure. Moreover, the mechanical dimensions of support systems for Plasma Facing Components (PFCs), manifold and diffuser have been analyzed in detail, in order to avoid structural fault during the test. Test procedures are discussed, taking into account design parameters, design code and facility performances. The CuCrZr alloy selected for the PFCs of EU DEMO divertor has been used also for the mock-up, while two options are still under evaluation for manifolds/diffuser, CuCrZr and stainless Steel 316 L(N)-IG, depending on the joining technology. Since the mock-up is mainly intended to verify hydraulic performances, it has been simplified by removing the W monoblocks from its PFCs.

Keywords: DEMO | Divertor cassette | Divertor target cooling mock-up

Abstract: The water-cooled lithium-lead breeding blanket is in the pre-conceptual design phase. It is a candidate option for European DEMO nuclear fusion reactor. This breeding blanket concept relies on the liquid lithium-lead as breeder-multiplier, pressurized water as coolant and EUROFER as structural material. Current design is based on DEMO 2017 specifications. Two separate water systems are in charge of cooling the first wall and the breeding zone: thermo-dynamic cycle is 295–328 °C at 15.5 MPa. The breeder enters and exits from the breeding zone at 330 °C. Cornerstones of the design are the single module segment approach and the water manifold between the breeding blanket box and the back supporting structure. This plate with a thickness of 100 mm supports the breeding blanket and is attached to the vacuum vessel. It is in charge to withstand the loads due to normal operation and selected postulated initiating events. Rationale and progresses of the design are presented and substantiated by engineering evaluations and analyses. Water and lithium lead manifolds are designed and integrated with the two consistent primary heat transport systems, based on a reliable pressurized water reactor operating experience, and six lithium lead systems. Open issues, areas of research and development needs are finally pointed out.

Keywords: Breeding blanket | DEMO | EUROfusion | WCLL

Abstract: As part of an ongoing divertor upgrade of the TCV tokamak it is planned to add gas baffles to form a divertor chamber of variable closure. The baffles promise to increase the compression of neutral particles in the divertor and, thereby, extend the research on the TCV divertor towards more reactor relevant, highly dissipative divertor regimes. It is foreseen to construct the baffles entirely of polycrystalline graphite that was used for the existing TCV protection tiles. The thermal considerations of the baffle design are based on the heat loads expected during normal operation, where even an extremely large increase in the power carrying plasma channel towards the baffle over the entire 2 seconds duration of a TCV discharge gives no cause for concern. An electromagnetic analysis considers halo currents flowing through the baffles, which can occur during disruptions, as a worst-case scenario. It is found that a halo current of 250 kA results in an average vertical force in the baffles of up to 950 kN/m3. The fixture of the baffle tiles to the vacuum vessel is designed for a maximum tensile stress of 31 MPa and maximum compressive stress of 60 MPa that remains a factor of two below their respective material limits. The obtained results of the thermal, electromagnetic and structural analysis thus validate the proposed baffle design.

Keywords: Divertor | Finite element analysis | Plasma facing components | TCV

Abstract: The solution of the problem of heat exhaust has been pointed out as one of the main challenge towards the realization of magnetic confinement fusion. In the last years, two concepts have been proposed in alternative to the conventional divertor solution adopted for ITER: modification of the magnetic topology in the divertor region and liquid metal as plasma facing component. The role of the Divertor Tokamak Test facility (DTT) in the power exhaust implementation strategy is discussed. The evolution of the project, since the original proposal in 2015 to the present design, is shown. The DTT facility is well integrated in the European strategy and the final decision on the divertor configuration will be made, within 2022-23, on the basis of the indication of the Power Exhaust Group constituted by the EUROfusion Consortium. Finally, the main milestones and the timeline of the project are illustrated.

Keywords: Device | Fusion | Tokamak

Abstract: One of the most critical components in the design of DEMO Power Plant is the Breeding Blanket (BB). Currently, four candidates are under study as options for DEMO. One of these is the Water Coolant Lithium Lead (WCLL) Breeding Blanket (BB). During the previous years a conceptual design of WCLL BB has been developed. At the current stage some open issues related to its manufacturability and design are still under evaluation. Since DEMO project is still in the pre-concept phase, the WCLL BB design team decided to investigate, in parallel with the current studies, an alternative design of the WCLL BB internal structure inspired to studies conducted in ‘90 s. The main drivers, in developing the alternative design, consisted on reducing the complexity of the internal structure itself and increasing the performances of the single module in terms of neutron shielding, tritium self-sufficiency, heat extraction and transportation to the primary heat transfer system and magneto hydrodynamic effects. All that, taking into account the lesson learned by the studies carried out in the last three years. The segment has been conceived as a single box where the lithium lead flows inside the module in poloidal direction. The rear part of the module is entirely dedicated to the cooling water manifold. A first 3d model of the alternative design has been developed, structural analyses have been carried out to optimize the internal structure against an over pressurization scenario. The results and the optimized design of the alternative WCLL BB design are here presented and discussed.

Keywords: DEMO | FEM | Systems Engineering approach | WCLL Breeding Blanket

Abstract: The International Fusion Materials Irradiation Facility-DEMO Oriented Neutron Source (IFMIF-DONES) consists of complex systems and massive components that need to be on site assembled and maintained. For several of them it is required to perform maintenance, inspection and monitoring tasks over many years in a hostile environment and in efficient, safe and reliable manner. The maintenance of IFMIF-DONES’ systems and components, located mainly in the Test Systems (TS), in the Lithium Systems (LS) and in the Accelerator Systems (AS), is classified as a Remote Handling (RH) Class 1st activity and as such is considered a crucial and essential activity whose success will strictly depend on the IFMIF-DONES RH capability. According to this, a Remote Handling System (RHS) for IFMIF-DONES, which comprises the whole set of Remote Handling Equipment and tooling for the execution of maintenance tasks, has been designed. A wide range of technologies is involved: special cranes, manipulator arms, lift interface frames, special cameras, control systems and virtual reality. In this paper an overview on status of the design of the main robotic systems and tooling of the RHS of IFMIF-DONES, including design requirements, functions and maintenance tasks to be performed, is given.

Keywords: IFMIF-DONES | Maintenance | Remote handling maintenance

Abstract: This paper presents the recent progress in the pre-conceptual design activities for the EU-DEMO divertor Cassette Body, performed in the framework of the work package “Divertor” of the EUROfusion Power Plant Physics & Technology (PPPT) program. According to Systems Engineering Principles, the divertor CAD model is reviewed, considering the updates in the DEMO configuration model presented by the Programme Management Unit (PMU) in 2017. The design parameters affected by these changes and their impact on the divertor design and on the interfaced systems are analysed. Then, the paper focuses on the integration on the new cassette geometry of the divertor sub-systems. This includes the design of a “shielding liner” for cassette body and Vacuum Vessel protection, as well as the development of the cassette body-to-Vacuum Vessel fixation system. The design activities related to these main sub-systems are discussed in detail, in terms of CAD model and thermo-mechanical calculations.

Keywords: 3D CAD modelling | Divertor | Divertor fixation system | EU-DEMO | Shielding liner

Abstract: This paper presents the engineering aspects of the design review of the Italian DTT (Divertor Tokamak Test facility), illustrating the rationale for the design choices and focusing on the main differences with respect to the original proposal.

Keywords: Design | Devices | Divertor | Tokamak

Abstract: Soft continuum robots provide high dexterity in constrained spaces, while guaranteeing a compliant interaction with the surrounding environment. Over the last years, they have been used to improve many manipulation tasks, going from maintenance, inspection and repair in industrial-related environments to minimally invasive surgery in the medical field. This paper investigates the use of soft continuum robots for remote measurement tasks, and focuses on the following application scenarios where they have already demonstrated their benefits: space, aerospace, nuclear, marine and medical fields. The limitations of existing applications and perspectives of future directions are also discussed.

Abstract: Advanced measurement systems and techniques from neuroscience are used in this work to extrapolate reduced- order muscle activation patterns corresponding to the execution of overhead tasks classic of automotive industry. The approach is based on the analysis of electromyographic (EMG) signals measured from muscles of the upper limb. The preliminary experiments show that, for the selected tasks, one muscle synergy could account for > 98% of the total muscle activation. This approach might pave the way towards the development of bionic, synergy-based upper limb wearable robots for augmenting human performances in industrial workplaces.

Keywords: EMG | muscle synergies | wearable robots

Abstract: The musculoskeletal disorders represent one of the most common problems in industrial environment; they impact the health of workers and employees. In this work we present a preliminary study towards the use of biomechanical models for improving classic methods for ergonomic assessment in industry. To this end, we use OpenSim, a software for biomechanical simulation and analysis. With OpenSim, we reconstruct the human motion corresponding to the execution of industrial tasks, performed in laboratory settings. In particular, we compute the evolution over time of the joint angles that, according to a classic observation method for ergonomic assessment, are needed to evaluate the risks associated to the musculoskeletal disorders for the upper limb.

Keywords: biomechanics | digital human model | ergonomics | industry

Abstract: In this work we present a study for the experimental reconstruction of the human shoulder torque in the sagittal plane, since this is usually overloaded in industrial overhead tasks. To this end, we measure the three-dimensional motion of the human upper limb while performing selected movements using an optical motion capture system. Then, using a skeleton model implemented in one of the most common software for industrial ergonomic assessment, we reconstruct the shoulder angle and torque in the sagittal plane. A possible exploitation of this reconstruction strategy is presented for active compensation of this torque. The implementation of this simple strategy in a custom developed assistive device could augment human workers in performing repetitive jobs.

Keywords: biomechanics | digital human models | human motion analysis | industrial assistive devices

Abstract: In this work we will show some preliminary results on the use of a wearable inertial system for assessment of performances and infringements in race-walking. The proposed system is composed by two parts, one for measurement and one for management purposes. The management unit is based on biomechanical-based parameters for evaluating performances and infringements. The preliminary experimental results are promising towards the use of this system in real field training and competition scenarios, to respectively assist coaches and judges.

Keywords: race-walking | sports biomechanics | wearable inertial sensors

Abstract: The use of fast and accurate scanning systems for human body digitization might pave the way towards the development of less invasive processes for medical manufacturing. In this work, an advanced measurement system for human body 3D reconstruction is used to design tailored assistive devices. The system is a photogrammetric 3D body scanner developed by the authors.

Keywords: 3D body measurements | assistive devices | medical manufacturing

Abstract: In this paper, a novel concept of robotic manipulator is developed for direct additive manufacturing on non-planar surfaces. The application scenario is the metal coating of the internal surface of radome systems, using frequency selective surface patterns. The manipulator is presented from the design, modeling, and control point of view. It is developed following an application-driven approach, meaning that the requirements from the application and the additive manufacturing technology are translated into the design specifications of the robotic system. Simulation results demonstrate that the proposed control strategy based on a decentralized architecture is satisfactory to accurately control the motion of the robotic mechanisms along the trajectory foresees by the direct additive manufacturing task.

Keywords: Additive manufacturing | Aerosol jet printing | Design method | Robot control | Virtual prototyping

Abstract: Introduction and Objectives Fabrication processes for spinal orthoses require accurate three-dimensional (3D) models of the patients' trunk. Current methods for 3D reconstruction used in this field mainly include laser or structured light scanning; these methods are time expensive and invasive, especially for patients with partial disabilities. Therefore, a theoretically instant system for data acquisition of anatomical structure is highly desirable. The objective of this work is to show the feasibility of using digital photogrammetry for human body digitization to generate accurate 3D models of the patients' trunk for spinal orthoses fabrication. Materials and Methods Multiple synchronized two-dimensional images of the human torso are captured from different points of view using a photogrammetric scanner. A 3D model is generated using the state-of-the-art algorithms for point cloud and surface reconstruction. The digitized model is then used as input for the standard computer-aided design (CAD)/computer-aided manufacturing (CAM) process of fabrication. R4D from Rodin4D is used as prosthetics and orthotics CAD software. A robotic cell constituted by a six-axis KUKA KR 30-3 is used for milling a polyurethane foam. Vacuum forming is then adopted to generate the orthosis. Two spinal orthoses are fabricated using this approach and a classical one; then, they are evaluated using quantitative and qualitative metrics. Results The data acquisition using this approach lasts 50 milliseconds. The 3D reconstruction accuracy averages 0.21 ± 1.27 mm, which suits for the considered health care scenario. Results of the initial fitting of the orthoses fabricated with the presented method show better performances in terms of time (44%), product quality (35%), and patient experience (30%). Conclusions Digital photogrammetry can be used to enhance the data acquisition and data processing of anatomical surfaces for the CAD/CAM process of spinal orthoses. The data acquisition time, almost instant, allows an easy compliance of many patients. The data processing allows generating accurate models of the patient's body. The overall process generates orthoses with a better quality with respect to those manufactured using conventional procedures. ©

Keywords: CAD/CAM | fabrication techniques | photogrammetry | prosthetics and orthotics | spinal orthoses | three-dimensional reconstruction

Abstract: We propose to use an industrial redundant manipulator (KUKA LBR iiwa robot) as a haptic device to provide high force feedback for an orthopedic surgeon while performing the reaming of the acetabula in a virtual environment. Real experiments have been performed to validate the virtual reality training framework. The results show that the system resulted to be intuitive and reliable from the users experience.

Keywords: medical robotics force feedback virtual reality training

Abstract: Remote handling of heavy in-vessel components inside nuclear fusion reactors requires the use of large robotic mechanisms, whose numerical analysis is highly complex. As a matter of fact, these robots are subject to large deformations, either induced by the geometric configuration of their mechanical structure or by the heavy payloads they usually transport. This work was motivated by the need of deriving physical-based predictive models able to simulate the mechanical behavior of such large robotic mechanisms, while performing dynamic tasks. The method formulates the dynamics of robotic manipulators on a Lie group, and uses a finite element procedure to discretize the flexible bodies. The method is applied to a complex mechanism, the serial/parallel flexible manipulator which has been recently selected for DEMO blanket remote handling. The case studies investigated in this paper involve the simulations of this manipulator while handling the inboard and outboard blanket segments according to the sequence of maneuvers planned for their removal processes from the vessel. The results show that such dynamic simulations could give useful information for design, analysis and control of remote handling equipment. The generality of the method makes this approach prone to be easily used in simulating the dynamics of other flexible manipulators for remote handling of large in-vessel components inside nuclear fusion reactors.

Keywords: DEMO | Flexible manipulators | Remote maintenance | Robot dynamics | Tokamak

Abstract: Kinematic modeling of continuum robots is challenging due to the large deflections that these systems usually undergone. In this paper, we derive the kinematics of a continuum robot from the evolution of a three-dimensional curve in space. We obtain the spatial configuration of a continuum robot in terms of exponential coordinates based on Lie group theory. This kinematic framework turns out to handle robotic helical shapes, i.e. spatial configurations with constant curvature and torsion of the arm.

Keywords: Continuum robotics | Differential geometry | Kinematics

Abstract: Appropriate disposal of the non-neutronic energy and particle exhaust in a reactor is universally recognized as one of the high priority challenges for the exploitation of fusion as an energy source. The new Divertor Tokamak Test (DTT) facility, which will be built in Italy, is a tool to address that challenge in high-field, high performance tokamak with complete integration between core and edge plasma scenarios. Background. The controlled exhaust of energy and particle from a fusion reactor is a difficult issue that has to be solved before starting the design of DEMO. According to experimental and theoretical work (see for example [1]) one of the major risks comes from the size of the scrape off layer (SOL) power flow decay length lq, which - from data taken in existing experiments - scales as [2]: ?" (mm) = 1,35 P-./01.13 R1.15B701.85e1.53 (1) where PSOL is the power in the scrape-off-layer, R the major radius of the machine, Bp the poloidal magnetic field and e the inverse aspect ratio. Activity is ongoing to fully assess both theoretically and experimentally the behaviour of lq, taking into account the role of turbulence and of the main plasma parameters (see for example [3]) If this scaling holds true for ITER, it means that in that device lq is expected to be of the order of 1 mm. Considering the Q=10 scenario, with 500 MW of net fusion power (400 MW brought by neutrons and 100 MW heating the plasma and lost through radiation and thermal/particles losses) the expected power exhausted on the divertor in a low radiation case is about 90 MW. This means a heat flux on the divertor of the order of 50 MWm-2, a value far above the limit of present target materials. To cope with these challenges and following the recommendations of the EUROfusion roadmap [4], the Italian fusion community proposed in 2015 the DTT experiment.

Abstract: The complexity of the interaction between user and computer can limit usability in products. When products are aimed at individuals with disability, the complexity increases the cognitive load and can reduce performances. The identification of interaction models and usability issues plays a role in product development as it enables designers to reduce this complexity. Methodology to identify lacking areas in products are required and permits to correct issues leading to an improvement of performances. A custom Augmentative and Alternative Communication system was developed for a student of the University of Naples Federico II. The user has complex communication needs and motor impairments and requires a personalized device to communicate. To promote an efficient interaction, hardware and software interfaces were personalized. Several studies were conducted: a usability evaluation, determination of the learning rate and Hardware/Software layout optimization were used to reduce the cognitive demands required by the system in its functioning. In this paper the HW layout optimization is investigated and strategies to reduce the cognitive load modifying order and position of the sensors of the input peripherals are provided.

Keywords: Augmentative and Alternative Communication | Human-Computer Interaction | Usability Testing

Abstract: The present work focuses on the design assessment of the DEMO Upper Port. The size of the upper port is defined by the available space in between the toroidal field coils and the required space to integrate a thermal shield between the vacuum vessel (VV) port and the coils. Since the large breeding blanket (BB) segments will require periodic replacement via the upper vertical ports the space inside the upper port needs to be maximized. For this reason the optimization and verification of the upper port design is a critical aspect in the development of DEMO project. The work here presented investigates the possibility to have an upper port with single walled sidewalls to increase the space available inside the port for the integration of pipe work and to allow the handling of the BB segments. The work carried out evaluates the feasibility of the design solution from the structural and thermal point of view verifying the upper port structure against nuclear heating, in-vessel pressure, and electromagnetic loads due to a toroidal field coil fast discharge and plasma disruptions according to nuclear codes.

Keywords: DEMO | Electromagnetic analysis | FEM | Upper Port | Vacuum vessel

Abstract: This work focuses on an innovative training methodology based on the use of Virtual ergonomics and “serious games” in the field of occupational safety. Virtual Ergonomics was chosen as an effective and convincing tool for disseminating the culture of safety among the workers, while a “serious game” was developed to train operators on specific safety procedures and to verify their skills. The results of the experimentation in a real industrial case study showed that, compared to the traditional training methodology, multimedia contents and quantitative ergonomic analyses improve the level of attention and the awareness of the operators about their safety. On the other hand, Serious games turned out as promising tools to train the workers about safe operating procedures that are difficult to implement in a real working environment.

Keywords: Ergonomics | Occupational safety | Serious game | Virtual humans | Virtual reality

Abstract: The computerization of manufacturing is one of the major challenges of the so-called fourth industrial revolution or Industry 4.0. Virtualization of the smart factory should provide real-time vision, control and monitoring of production through interactive dashboards and synchronization of data coming from different factory functions. The latter characteristics are particularly difficult to implement when the manufacturing core relies on traditional manual labour rather than on automation, as in the case of manual assembly. Monitoring or even controlling the manual work in real-time is extremely difficult to put into practice. Therefore, realizing the principles of Industry 4.0 in manual or semi-automatic labour contexts means developing new production control systems that involve the worker in the monitoring process without negatively affecting the production times or the psychological status of the workers. In particular, the authors propose a computer-aided production control framework based upon multimedia manuals and smart completeness control systems that can be used to implement the principles of Industry 4.0 in manual or semi-automatic work environments. This technology has been successfully tested in laboratory on the basis of a real industrial case study. The response of the testers has been positive and the outcomes in terms of increased product quality are promising.

Keywords: Cyber-physical systems | Industry 4.0 | Interactive electronic technical manuals | Production monitoring | Smart manufacturing

Abstract: In Europe (EU), in the frame of the EUROfusion consortium activities, four Breeding Blanket (BB) concepts are being developed with the aim of fulfilling the performances required by a near-term fusion power demonstration plant (DEMO) in terms of tritium self-sufficiency and electricity production. The four blanket options cover a wide range of technological possibilities, as water and helium are considered as possible coolants and solid ceramic breeder in combination with beryllium and PbLi as tritium breeder and neutron multipliers. The strategy for the BB selection and operation has to account for the challenging schedule of the EU DEMO, the ambitious operational requirements of the BBs and the still large development needed to have a BB qualified and licensed for operating in DEMO. In parallel to the continuous design efforts on the four blanket concepts, their integration in-vessel and ex-vessel has started. On the one hand it has become clear that despite the numerous systems to be integrated in-vessel the protection of the blanket first wall has to be addressed with highest priority. On the other hand the ex-vessel interfaces and the requirements imposed by the blanket to the primary heat transfer system and to the PbLi loop components have a considerable impact on the whole DEMO Plant layout. The aim of this paper is: to present the strategy for the DEMO BB down selection and BB operation in DEMO; to describe the status of the design evolution of the four EU BB concepts; to provide an overview of the challenges of the in-vessel and ex-vessel integration of the main systems interfacing the BBs and describe their design status.

Keywords: Balance of plant | Breeding Blanket | In-vessel and ex-vessel components

Abstract: In this paper we present the design, prototyping and validation of a novel adjustable foot stretcher for indoor rowing training. The overall process is user-centered, in the sense that the athletes are directly involved in all the phases of the product development, from conceptual design to evaluation and validation. The conceptual design starts from well-known rowers needs. Accordingly, two design factors are selected to parametrize the prototype, namely the inter-axle spacing feet and the foot angle. The experimental evaluation and validation involve two phases, one based on a quantitative analysis of the performance, one based on subjective questionnaires submitted to the athletes. The performance-based analysis comprises the derivation of three pressure indices and one power transmission index. Indeed, the subjective analysis regards the users comfort and power transmission feelings. The results of both evaluations testify that an improvement in performance and comfort of the indoor rowing training session can be achieved.

Keywords: Performance evaluation | Robust design | Sports engineering | Sports equipment and technology | User-centered design

Abstract: In this paper we derive the analytic solutions for the statics of cantilever soft arm under external loading. The main motivation behind this work is the development of manageable and ready-to-use mathematical models of soft robotic arm for various purposes. We formulate the problem exploiting the Lie group structure of the arms' configuration space. This allows using the powerful mathematical tools from differential geometry. The model builds upon the theory of Cosserat rods: The mechanics-based perspective used to describe the kinematics and statics allows including into the model the large deformations due to axial, shear, torsion and bending effects. The position fields of the manipulators' shapes are analytically integrated and validated with respect to exact solutions and experiments.

Keywords: Cosserat rods | differential geometry | mathematical modeling | Soft robotics

Abstract: The water-cooled lithium-lead (PbLi) breeding blanket is one of the candidate systems considered for the implementation in the European Demonstration Power Plant (DEMO) nuclear fusion reactor. This concept employs PbLi liquid metal as tritium breeder and neutron multiplier, water pressurized at 15.5 MPa as the coolant, and EUROFER as the structural material. The current design is based on the single module segment approach and follows the requirements of the DEMO-2015 baseline design. The module is constituted by a basic toroidal-radial cell that is recursively repeated along the poloidal direction where the liquid metal flows along a radial-poloidal path. The heat generated by the fusion reactions is extracted by means of separate cooling systems for the breeding zone and the first wall. A back supporting structure is dedicated to withstand loads of the module during normal and off-normal operations. Water and PbLi manifolds are integrated with primary heat transport and tritium extraction systems. The status of the conceptual design is presented, critically discussing its rationale and main features as supported by neutronic, thermal-hydraulic, magneto-hydrodynamic, and thermo-mechanic analyses. Recent results are outlined, pointing out open issues and development needs.

Keywords: Breeding blanket (BB) | Demonstration Power Plant (DEMO) | fusion reactor design | liquid metal technology

Abstract: This paper presents a novel instant 3D whole body scanner for healthcare applications. It is based on photogrammetry, a digital technology which allows to reconstruct the surface of objects starting from multiple pictures. The motivation behind this work is the development of minimally invasive procedures for instant data acquisitions of anatomical structure. The scanner provides several features of interests in 3D body scanning technologies for the healthcare domains: (i) instant capture of human body models; (ii) magnitude of accuracy in the order of 1 mm; (iii) simplicity of use; (iv) possibility to scan using different settings; (v) possibility to reconstruct the texture. The system is built upon a modular and distributed architecture. In this paper we highlight its key concepts and the methodology which has led to the current product. We illustrate its potential through one of the most promising 3D scanning healthcare applications: the data acquisition and processing of human body models for the digital manufacturing process of prostheses and orthoses. We validate the overall system in terms of conformity with the the initial requirements.

Keywords: 3D reconstruction | Body scanning | Healthcare | Human body measurements | Human body visualization | Photogrammetry | Proshetics and orthotics

Abstract: The objective of the work is to describe the design and the realization of a virtual simulator of a metropolitan railway cockpit, aimed at improving the perception of safety by means of tests made by users in Virtual Reality, analysed through statistical methodologies. The user lives the experience of a driver in an immersive and interactive Augmented Reality session, interacting with the train dashboard and all its control and signalling devices. In particular, the user is proposed to test different dashboards, different configurations of the controls and different signalling and safety devices in order to compare different concept and select the optimum in terms of perception of dangerous situation, reaction to an event and cognitive response in different situations of the rail vehicle driving. The simulator consists of a simulacrum integrating different technologies, physically composed of a dashboard of the cockpit of a metropolitan train and a real seat. The geometry of the dashboard has been acquired through Reverse Engineering techniques from a real train dashboard. The user’s immersion in the virtual environment during the simulation is guaranteed by the scene displayed on the Augmented Reality device, while, simultaneously, the stereoscopic projection on a screen above the dashboard makes available the experience even to users not directly involved, seeing the scene from the driver’s point of view. The immersive Augmented Reality is realized through a Head-Mounted Display (HMD) by which the user, protagonist of the driving experience, sees the configuration of the virtual control devices (CAD geometries) overlapped with the physical dashboard in order to naturally interact into the immersive environment. The interaction between user and simulator happens through the NUI (Natural User Interfaces) based on markerless tracking of parts of the user’s body.

Keywords: Augmented reality | Head-mounted display | IDEAinVR | Natural user interfaces | Preventive safety | Railway design | Reverse engineering | Train dashboard | Vehicle driving | Vitual simulator

Abstract: This paper proposes to use robust command shaping methods for reducing the vibrations during remote handling of in-vessel components. The need of deriving efficient vibration control strategies for a safe transportation of large and heavy payloads during maintenance procedures in nuclear fusion reactors is the main motivation behind this work. The approach shapes the reference motion command to the component such that the vibratory modes of the system are canceled. We perform the dynamic simulations of a large in-vessel component of the DEMOnstrating fusion power reactor during a remote handling operation. The simulations shows that the method is a possible solution to reduce the vibrations induced by the motion, in both the transient and residual phases. The benefits introduced by command shaping make the method promising towards building control framework for remote handling of in-vessel components in various tokamak devices.

Abstract: The paper describes the activities of conceptual design of tools and procedures and the virtual simulation of the Remote Handling (RH) tasks provided in the maintenance of the systems present in the Access Cell (AC) of DONES (DEMO Oriented Neutron Source) facility. In particular, the RH maintenance of the Target Assembly (TA) is critical because of its position in the most severe region of neutron irradiation, the Test Cell (TC), where the material specimen are tested to understand the degradation of the materials properties throughout the reactor operational life. The main RH maintenance activity includes the replacement of the entire TA and the cleaning of the surfaces of connection in the TC. The cleaning operation is fundamental because it allows the removal of any lithium solid deposition from the surfaces: any further deposition on the surfaces could compromise the sealing of the TA. The RH is based on the idea of a reconfigurable modular chain of devices connected to the Access Cell Mast Crane (ACMC) located in the AC. To increase the modularity and to reduce the costs of the Remote Handling System (RHS), a telescopic boom is used equipped with a Gripper Change System (GCS) that allows the use of different end effectors. To perform the tasks, a Parallel Kinematic Manipulator (PKM) and a Robotic Arm (RA) are proposed, allowing the tools to move with more degree of freedom in the AC space. The modeling of the devices and the 3D kinematic simulations maintenance operations tasks were simulated and tested in virtual reality environment, aimed at developing and validating the implemented maintenance procedures, in collaboration with the IDEAinVR Laboratory of CREATE/University of Naples Federico II, and the research center at ENEA Brasimone, Italy.

Abstract: Kinematic modeling of continuum robots is challenging due to the large deflections that these systems usually undergone. In this paper, we derive the kinematics of a continuum robot from the evolution of a three-dimensional curve in space. We obtain the spatial configuration of a continuum robot in terms of exponential coordinates based on Lie group theory. This kinematic framework turns out to handle robotic helical shapes, i.e. spatial configurations with constant curvature and torsion of the arm.

Keywords: Continuum robotics | Differential geometry | Kinematics

Abstract: The use of Augmented Reality (AR) technologies is the new challenge of management models born under the “Industry 4.0” paradigm. The aim of the work is to evaluate the usability of two types of AR devices (tablet and see-through) employed in the training and information activities of workers according to the ISO/IEC 9126 and ISO 9241 standards. Starting from the state of the art, evaluating market and competitors and developing different concepts of interfaces, a dedicated application was programmed and, then, the usability of such devices for the professional figures involved was evaluated through experimental tests. Two reference scenarios were defined, the Department of Industrial Engineering of University of Naples Federico II and INAIL (National Institute for Insurance against Accidents at Work) laboratories, an user interface was designed and developed, as an aid in the drafting of the document for risk evaluation and subsequent training of workers. The activity is part of the IDEE Project (Interactive Design for Ergonomics), born by the collaboration between Joint Lab IDEAS and Contarp-INAIL-Regional Management for Campania. The data analysis allowed to evaluate the goodness of the devices and the degree of satisfaction in their use on the basis of the sample of users who conducted the tests. The use of AR devices produces better results than paperwork in terms of efficiency and effectiveness, but not all devices produce appreciable results in terms of user satisfaction. Although AR technologies are mature, the tasks need to be carefully defined to avoid rejection phenomena. The strong expectation, that they generate in potential users, risks to remain disappointed today for some usability limits found in currently available devices. It is necessary to start testing in pilot applications in various industrial fields in order to capture in time and adequately support this opportunity of innovation in Italy.

Keywords: Augmented reality | Risk assessment | Usability

Abstract: Tactile sensors are essential components for the implementation of complex manipulation tasks using robot grippers, allowing to directly control the grasping force according to the object properties. Virtual Reality represents an effective tool capable of visualizing complex systems in full details and with a high level of interactivity. After the implementation of cost-effective tactile arrays on a 3-finger Robotiq® gripper using an ARDUINO controller, it is presented an innovative VR interface capable of visualizing the pressure values at the fingertips in a 3D environment, providing an effective tool aimed at supporting the programming and the visualization of the gripper VR.

Keywords: Calibration | Robot | Virtual reality

Abstract: The water-cooled lithium–lead breeding blanket is a candidate option for the European Demonstration Power Plant (DEMO) nuclear fusion reactor. This breeding blanket concept relies on the liquid lithium–lead as breeder–multiplier, pressurized water as coolant, and EUROFER as structural material. The current design is based on DEMO 2015 specifications and represents the follow-up of the design developed in 2015. The single-module-segment approach is employed. This is constituted by a basic geometry repeated along the poloidal direction. The power is removed by means of radial–toroidal (i.e., horizontal) water cooling tubes in the breeding zone. The lithium–lead flows in a radial–poloidal direction. On the back of the segment, a 100-mm-thick plate is in charge of withstanding the loads due to normal operation and selected postulated initiating events. Water and lithium–lead manifolds are designed and integrated with a consistent primary heat transport system, based on a reliable pressurized water reactor operating experience, and the lithium–lead system. Rationale and features of the single-module-segment water-cooled lithium–lead breeding blanket design are discussed and supported by thermo-mechanic, thermo-hydraulic, and neutronic analyses. Preliminary integration with the primary heat transfer system, the energy storage system, and the balance of plant is briefly discussed. Open issues, areas of research, and development needs are finally pointed out. @EUROfusion Consortium*, 2017. *For more details see http://www.euro-fusionscipub.org/disclaimer-copyright.

Keywords: breeding blanket | DEMO | WCLL

Abstract: One of the main objectives of the DTT project is to test many divertor designs and configurations, so that the concept of the machine could change from the initial single null (SN) configuration to other configurations such as the SnowFlake Divertor (SFD). Furthermore the design of Vacuum Vessel, ports and In-Vessel Components should take into account the application and testing of a Liquid Metal Divertor. For this reason the divertor design has been developed having in mind the possibility of easily replacing the divertor itself by remote handling.

Keywords: Divertor | DTT | Liquid metal | Remote handling

Abstract: This paper describes the activity addressed to the conceptual design of the first wall and the main containment structures of DTT device. The work moved from the geometrical constraints imposed by the desired plasma shape and the configuration needed for the magnetic coils. Many other design constraints have been taken into account such as remote maintainability, space reservations for diagnostic and heating equipment, etc. The basic vessel design resulted in an all-welded single-wall toroidal structure made of 18 sectors. Proper supports have been designed for the first wall, which was conveniently segmented in view of remote maintenance. This provisional model allowed evaluating the electromagnetic loads on the metallic structure of the vacuum vessel resulting from the current quench due to a plasma disruption. After a FEA mechanical assessment, which was conducted according to ASME code, INCONEL® 625 has been provisionally selected as reference material for vacuum vessel. The design principles of the cryostat were chiefly based on cost minimization and functionality; thus it was conceived as a single-wall cylindrical vessel supported by a steel frame structure. The same structure will hold the vacuum vessel and the magnets.

Keywords: 3D CAD modeling | Conceptual design | Cryostat | FEM | First wall | Mechanical analysis | Vacuum vessel

Abstract: In the EU DEMO design (Romanelli, 2012; Federici et al., 2014), due to the large number of complex systems inside the tokamak vessel it is of vital importance to address the in-vessel integration at an early stage in the design process. In the EU DEMO design, after a first phase in which the different systems have been developed independently based on the defined baseline DEMO configuration, an effort has been made to define the interface requirements and to propose the strategies for the mechanical integration of the auxiliary heating and fuelling systems into the Vacuum Vessel and the Breeding Blanket. This work presents the options studied, the engineering solutions proposed, and the issues highlighted for the mechanical in-vessel integration of the DEMO fuelling lines, auxiliaries heating systems, and diagnostics.

Keywords: Breeding Blanket | Fuelling systems | Heating systems | In-vessel components | Vacuum Vessel

Abstract: Water-cooled lithium-lead breeding blanket is considered a candidate option for European DEMO nuclear fusion reactor. ENEA and the linked third parties have proposed and are developing a multi-module blanket segment concept based on DEMO 2015 specifications. The layout of the module is based on horizontal (i.e. radial-toroidal) water-cooling tubes in the breeding zone, and on lithium lead flowing in radial-poloidal direction. This design choice is driven by the rationale to have a modular design, where a basic geometry is repeated along the poloidal direction. The modules are connected with a back supporting structure, designed to withstand thermal and mechanical loads due to normal operation and selected postulated accidents. Water and lithium lead manifolds are designed and integrated with a consistent primary heat transport system, based on a reliable pressurized water reactor operating experience, and the lithium lead system. Rationale and features of current status of water-cooled lithium-lead breeding blanket design are discussed and supported by thermo-mechanics, thermo-hydraulics and neutronics analyses. Open issues and areas of research and development needs are finally pointed out.

Keywords: Breeding blanket | DEMO | WCLL

Abstract: Since 2014 preconceptual design activities for European DEMO divertor have been conducted as an integrated, interdisciplinary R&D effort in the framework of EUROfusion Consortium. Consisting of two subproject areas, ‘Cassette’ and ‘Target’, this divertor project has the objective to deliver a holistic preconceptual design concept together with the key technological solutions to materialize the design. In this paper, a brief overview on the recent results from the subproject ‘Cassette’ is presented. In this subproject, the overall cassette system is engineered based on the load analysis and specification. The preliminary studies covered multi-physical analyses of neutronic, thermal, hydraulic, electromagnetic and structural loads. In this paper, focus is put on the neutronics, thermohydraulics and electromagnetic analysis.

Keywords: Cooling | DEMO | Divertor cassette | Electromagnetic loads | Neutronics | Thermohydraulics

Abstract: This paper refers to the activity of structural design of DEMO Divertor in the framework of the EUROfusion Consortium. The structural analysis and its preparatory assessments were carried on since a year and the first results were published in a previous paper. The Cassette Body has been examined considering the most conservatives loads (e.g. coolant pressure, volumetric nuclear heating and electro-magnetic loads) according to their latest estimates. This work is based on the design-by-analysis approach adopted in the conceptual design phase of the DEMO Divertor. This design activity has been focused on some key parameters e.g. loads, main geometric dimensions, positions of the Cassette attachments on the vacuum vessel, way of loads application to characterize the structural behavior of the Divertor Cassette. In addition to the existing 3D solid element model, a shell element model has also been developed: with this new model a parametric analysis can be done for a fast optimization. The structural assessment was done according to the Design and Construction Rules for Mechanical Components of Nuclear Installation (RCC-MRx).

Keywords: DEMO | Divertor | FEM | RCC-MRx | Structural analysis | Thermal analysis

Abstract: One of the fundamental input parameters required for the thermo hydraulic and structural design of a divertor cassette is the operation temperature range. In the current design activities to develop European DEMO divertor in the frame of EUROfusion, reduced activation steel EUROFER97 was chosen as structural material for the divertor cassette body considering its low long-term activation and superior creep and swelling resistance under neutron irradiation (You et al., 2016) [1]. For specifying an operation temperature range (i.e. cooling condition) various, often conflicting requirements have to be considered. In this article the lower limit of allowed operation temperature window is defined for EUROFER97 for structural design of DEMO divertor cassette body. The underlying rationale and supporting experimental data from a number of previous irradiation tests are also presented. The motivation of this survey study is to explore the possibility to use EUROFER97 for water-cooled divertor cassette at temperatures below 350 °C which has been regarded as limit temperature to preserve ductility under irradiation. Based on the literature data of FTTT (Fracture Toughness Transition Temperature) calibrated by Master Curve method, it is concluded that EUROFER97 at the envisaged maximum dose of 6 dpa will have to be operated above 180 °C taking the embrittlement due to helium production into account.

Keywords: DEMO | Divertor cassette | EUROFER97 | Neutron fluence

Abstract: This paper presents the pre-conceptual design activities conducted for the European DEMO divertor, focusing on cassette design and Plasma Facing Components (PFC) integration. Following the systems engineering principles, a systematic design method, the Iterative and Participative Axiomatic Design Process (IPADeP), has been adopted. Basing on Axiomatic Design, IPADeP supports the early conceptual design of complex systems. The work moved from the geometrical and interface constraints imposed by the 2015 DEMO configuration model. Then, since different materials will be used for cassette and PFCs, the divertor geometry has been developed taking into account the cooling parameters of the cassette Eurofer steel and the integration of PFCs cooling system. Accordingly, the design process led to a double wall cassette structure with internal reinforcing ribs to withstand cassette coolant pressure and three different kinds of piping schemes for PFCs with dual circuits. These three solutions differs in the feeding pipes layouts and target manifold protection and they have been proposed and evaluated considering heat flux issues, shielding problems, interface requirements with blanket and vacuum vessel and remote maintenance needs. A cassette parametric shell model has been used to perform first structural analyses of the cassette body against coolant pressure. Taking advantages of the parametric surface modelling and its linkage with Finite Element (FE) code, the cassette ribs layout and thickness has been evaluated and optimized, considering at the same time the structural strength needed to withstand the coolant parameters and the maximum stiffness required for cassette preloading and locking needs.

Keywords: DEMO | Divertor cassette | Divertor cooling | Divertor structural analysis

Abstract: One of the most critical components in the design of DEMO Power Plant is the Breeding Blanket. Currently, four candidates are investigated as options for DEMO. One of these is the Water Coolant Lithium Lead Breeding Blanket. A new concept design has been proposed and investigated in 2015. The first activity driving the Breeding Blanket design was the definition of the poloidal segmentation. Current trend in breeding blanket design is based on the multi module box approach, which has advantages in terms of manufacturing, in reducing the global stress and strain during the start-up and the shut-down phases and during operation, because the favourable thermal expansions; and in simplifying the First Wall layout and integration. Nevertheless, drawbacks are identified, such as the reduction of Tritium Breeding Ratio, the constraints in manifold and in Back Supporting Structure design and integration because the limited space available. The present work concerns a method that, starting from these constraints, defines and optimizes some of the main design drivers for the selection of the segmentation of the Water Coolant Lithium Lead Breeding Blanket. The method by definition is based just on geometrical parameters because it is used as first step of the design when any analysis and detailed data are available. It is based on the definition of Figures Of Merits, consisting in numerical parameters, such as the ratio between the modules volume and the overall volume of segment assigned, the approximation between the real profile of the modules and the theoretical one, the form factor of the modules, the ratio between the module thickness at the mid-plane and the segment thickness at the same position. The figures of merits support the choice among different options. In particular two different solutions of poloidal segmentation have been compared and, according to the proposed method, the best one was chosen for the design of Water Coolant Lithium Lead Breeding Blanket.

Keywords: Conceptual design | DEMO breeding blanket | Figure of merits | Poloidal segmentation | Water cooled lithium lead

Abstract: As indicated in the European Fusion Roadmap, the main objective of the Divertor Tokamak Test facility (DTT) is to explore alternative power exhaust solutions for DEMO so as to mitigate the risk that the conventional divertor based on detached conditions to be tested on the ITER device cannot be extrapolated to a fusion reactor. The issues to be investigated by DTT include: • demonstrate a heat exhaust system capable of withstanding the large load of DEMO in case of inadequate radiated power fraction;• close the gaps in the exhaust area that cannot be addressed by present devices;• demonstrate that the possible (alternative or complementary) solutions (e.g., advanced divertor configurations or liquid metals) can be integrated in a DEMO device. In this paper, we describe a proposal for such a DTT, presented by ENEA in collaboration with a European team of scientists. The selection of the DTT parameters (a major radius of 2.15 m, an aspect ratio of about 3, an elongation of 1.6-1.8, a toroidal field of 6 T, and a flat top of about 100 s) has been made according to the following specifications: • edge conditions as close as possible to DEMO in terms of dimensionless parameters;• flexibility to test a wide set of divertor concepts and techniques;• compatibility with bulk plasma performance.• an upper bound of 500 M€ for the investment costs. This paper illustrates this DTT proposal showing how the basic machine parameters and concept have been selected so as to make a significant step toward the accomplishment of the power exhaust mission.

Keywords: Design | Divertor | Tokamak devices

Abstract: This paper presents the foundation of a new class of input shapers, designed using a predictive approach. The method is used to control the transient and residual vibrations in flexible nonlinear systems with time-varying parameters. The motivation is the development of simple algorithms and architectures for controlling the motion in flexible nonlinear systems with minimal modeling effort. The approach trains an artificial neural network to obtain closed-form expressions used for calculating, in real time, the amplitudes and the time locations of the impulses required by a common input-shaping technique. In this work we use this idea to design a command shaper for controlling the motion of the simplest flexible nonlinear system, an overhead crane with a suspended payload. We validate the approach using simulations and experiments. The benefits of such a control system will, in the end, enable using this method for controlling the motion of complex nonlinear systems, resulting in almost zero vibrations.

Keywords: command shaping | Nonlinear dynamical systems | predictive control | vibration control

Abstract: The present work focuses on structural assessment of DEMO Vacuum Vessel Lower Port structure. Since previous studies have been addressed the structural scheme of the main vessel, this work investigates a feasible layout of vessel supports defining the position of the pumping port cut and different inclinations of the lower port. All design configurations have been analysed according to Design and Construction Rules for Mechanical Components of Nuclear Installations. The structure was checked against a vertical load due to a Vertical Displacement Event in combination with the estimated mass of all components supported by the vessel. The outcome of the assessment gives relevant information about the optimal position of the supports, the impact of the pumping port duct cut and the lower port inclination.

Keywords: DEMO | Elasto-plastic analysis | FEM | Vacuum vessel

Abstract: This paper presents eligere, a new open-source distributed software platform for group decision making in engineering design. It is based on the fuzzy analytical hierarchy process (fuzzy AHP), a multiple criteria decision making method used in group selection processes to rank a discrete set of alternatives with respect to some evaluation criteria. eligere is built following the paradigm of distributed cyber-physical systems. It provides several features of interest in group decision making problems: a web-application where experts express their opinion on the alternatives using the natural language, a fuzzy AHP calculation module for transforming qualitative into quantitative data, a database for collecting both the experts' answers and the results of the calculations. The resulting software platform is: distributed, interactive, multi-platform, multi-language and open-source. Eligere is a flexible cyber-physical information system useful in various multiple criteria decision making problems: in this paper we highlight its key concepts and illustrate its potential through a case study, i.e., the optimum selection of design alternatives in a robotic product design.

Keywords: Distributed information systems | Fuzzy AHP | Fuzzy sets | Multiple criteria decision making | Product design | Robotics

Abstract: The remote handling (RH) maintenance of components of International Fusion Materials Irradiation Facility (IFMIF) is one of the most challenging activities to be performed to guarantee the required high level of IFMIF plant availability. Among these components, the maintenance of the target assembly (TA) system appears to be critical, because it is located in the most severe region of neutron irradiation. The present European TA design is based on the so-called replaceable backplate (BP) bayonet concept. It was developed with the objective to reduce the waste material and to simplify the procedures for the target and BP replacement, thus reducing the intervention time for their substitution. The RH maintenance activity for the TA comprises a number of in situ refurbishment tasks, such as the removal of the BP, cleaning of surfaces from lithium solid deposition, inspection of the target body, installation of a new BP, and testing of the assembled system. However, there is also the possibility to replace the entire TA and to perform these refurbishment tasks offline in a dedicated hot cell. To accomplish all the refurbishment operations for the TA within the expected time for maintenance, the annual preventive maintenance period for IFMIF has been fixed in 20 days; several 3-D kinematic simulations in virtual reality environment and experimental activities aimed at developing and validating the implemented maintenance procedures for this component were carried out, in collaboration with the IDEAinVR Laboratory of CREATE/University of Naples Federico II, at the research center at ENEA Brasimone, Italy. The in situ refurbishment processes and the target replacement were simulated and tested and the feasibility of each maintenance operation was proved. In this paper, a description of the simulations and the validation activities carried out together with the main outcomes obtained are given.

Keywords: IFMIF | remote handling (RH) | target assembly (TA) | virtual simulations

Abstract: This study aims to develop an innovative approach based on a wearable inertial system, which enables objective evaluations on the of loss of ground contact in race-walking, in order to assist coaching and judging. The architecture of the system, its positioning on the human body and functional requirements were defined through a Kansei Engineering approach by using a significant sample of athletes, coaches and judges within the race-walking environment. The analysis of variance supports decisions concerning the optimal system architecture consisting of an inertial sensor positioned on the centre-of-mass of the subject and a control unit. The selected device was then validated in laboratory conditions by means of an integrated system, including dynamic (680 Hz) and kinematic (340 Hz) devices, which are more accurate than the inertial system (200 Hz). The experiment was carried out at the Fraunhofer JL IDEAS-MISEF at CESMA, Laboratory of Advanced Measures on Ergonomics and Shapes of the University of Naples Federico II where four elite race walkers performed 60 test-runs according to a well-defined experimental protocol. Results proved that the inertial system could improve the accuracy in detecting illegal steps. Through statistical classification, it was found that the proposed approach has achieved encouraging results in comparison with state of the art approaches and could be a good architecture to develop a valuable tool to assist experts.

Keywords: Experimental validation | Inertial sensor | Kansei engineering | Loss of ground contact | Race-walking | Statistical analysis

Abstract: The present work focused on the development of a new approach to the concept design of DEMO Divertor Cassette (DC) Remote Handling Equipment (RHE). The approach is based on three main assumptions: the DC remote handling activities and the equipment shall be simplified as much as possible; technologies well known and consolidated in the industrial context can be adopted also in the nuclear fusion field; the design of the RHE should be based on a simply supported beam approach instead of cantilever approach. In detail, during the maintenance activities the barycentre of the DC is centred with respect to DC supports. This solution could simplify the design of RHE with a consequent reduction of the design and development costs. Moreover also the DC remote handling tasks shall be simplified in order to better manage the DC maintenance processes. For this reason the DC assembly and disassembly process has been simplified dividing the main sequences in basic movements. For each movement a dedicated tool has been conceived.

Keywords: DEMO | Divertor cassette | Maintenance | Remote handling

Abstract: This paper presents a nonlinear finite element formalism for modelling the dynamics of flexible manipulators using the special Euclidean group SE(3) framework. The method is based on a local description of the motion variables, and results in a singularity-free formulation which exhibits important advantages regarding numerical implementation. The motivation behind this work is the development of a new class of model-based control systems which may predict and thus avoid the deformations of a real flexible mechanism. Finite element methods based on the geometrically exact beam theory have been proven to be the most accurate to account for flexibility: in this paper we highlight the key aspects of this formulation deriving the equations of motion of a flexible constrained manipulator and we illustrate its potential in robotics through a simple case study, the dynamic analysis of a two-link manipulator, simulating different model assumptions in order to emphasize its real physical behavior as flexible mechanism.

Keywords: differential geometry | Flexible manipulators | motion formalism | nonlinear finite element | robot simulation | soft robots

Abstract: Dip-Brazing is a metal-joining process in which two or more metal items are joined together using a low-temperature melting element as filler. In telecommunication field, this process is used to fabricate radar antenna systems. The process begins with the assembly of the parts constituting the antenna and the thin filler sheet used to join the parts. The mechanical deformations of the micro-pins of the parts allow to obtain a more compact mechanical assembly, before than the antenna system is subjected to an immersion cycle used for adjoining the parts. In this work, we present the design of the robotic cell to automate the assembly procedure in the aluminum dip-brazing of antenna in MBDA missile systems. In particular, we propose a robotic cell using two stations: i) assembly, using a SCARA manipulator; ii) riveting, using a three-axis cartesian robot designed for positioning a radial riveting unit. Motion control of the robots and scheduling of the operations is presented. Experiments simulated in a virtual environment show an almost perfect tracking of the designed trajectories. The standardization of the procedure as well as the reduction of its execution time is thus achieved for the industrial scenario.

Keywords: industrial robots | manufacturing automation | motion control | radar antennas | robotic assembly

Abstract: Nowadays digital substitutes of human beings (digital humans), capable of interacting with digital mock-ups in Virtual Reality, are widely used in many fields of engineering (e.g. ergonomics, product design, maintenance, and training). Nevertheless, the animation process of digital humans is still a time-consuming task, and its accuracy and reliability strongly depend on the experience and the skills of the operator. This paper presents an innovative algorithm capable of significantly speeding up the animation process of digital humans, allowing the operator to focus only on the so-called "task-related control points". This approach allows also to easily conduct biomechanical analyses. The algorithm has been tested with reference to several application scenarios in Virtual Reality.

Keywords: Algorithm | Digital humans | Kinematics | Virtual reality

Abstract: The current trend in manufacturing is to obtain a flexible work cell in which human and robot can safely interact and collaborate. Virtual Reality (VR) represents an effective tool capable of simulating such complex systems with a high level of immersion. In order to take advantage of VR technologies to study Human-Robot Cooperation (HRC), a digital model of a redundant manipulator (KUKA LBR iiwa) has been developed starting with kinematic modeling and then coupled with the real robot. This approach allows simulating HRC in several scenarios, to reproduce the safe behavior on the real robot, as well as to train operators.

Keywords: Human-robot collaboration | Modelling | Simulation | Virtual reality

Abstract: This work explores the use of an industry-oriented digital human modelling tool for the estimation of the musculoskeletal loads corresponding to a simulated human activity. The error in using a static analysis tool for measuring articulations loads under not-static conditions is assessed with reference to an accurate dynamic model and data from real experiments. Results show that, for slow movements, static analysis tools provide good approximation of the actual loads affecting human musculoskeletal system during walking.

Keywords: Biomechanics | Dynamics | Gait analysis | Kinematics | Virtual simulation

Abstract: This paper focuses on a preliminary structural analysis of the current concept design of DEMO vacuum vessel (VV). The VV structure is checked against a vertical load due to a Vertical Displacement Event in combination with the weight force of all components that the main vessel shall bear. Different configurations for the supports are considered. Results show that the greatest safety margins are reached when the tokamak is supported through the lower ports rather than the equatorial ports, though all analyzed configurations are compliant with RCC-MRx design rules.

Keywords: DEMO vacuum vessel | Elastoplastic analysis | Finite element method (FEM)

Abstract: The work behind this paper took place in the Eurofusion remote maintenance system project (WPRM) for the EU Demonstration Fusion Power Reactor (DEMO). Following ITER, the aim of DEMO is to demonstrate the capability of generating several hundreds of MW of net electricity by 2050. The main objective of this paper was the study of the most efficient design of the maintenance port for replacing the divertor cassettes in a Remote Handling (RH) point of view. In DEMO overall design, one important consideration is the availability and short down time operations. The inclination of the divertor port has a very important impact on all the RH tasks such as the design of the divertor mover, the divertor locking systems and the end effectors. The current reference scenario of the EU DEMO foresees a 45° inclined port for the remote maintenance (RM) of the divertor in the lower part of the reactor. Nevertheless, in the optic of the systems engineering (SE) approach, in early concept design phase, all possible configurations shall be taken into account. Even the solutions which seem not feasible at all need to be investigated, because they could lead to new and innovative engineering proposals. The different solutions were compared using an approach based on the Analytic Hierarchy Process (AHP). The technique is a multi-criteria decision making approach in which the factors that are important in making a decision are arranged in a hierarchic structure. The results of these studies show how the application of the AHP improved and focused the selection on the concept which is closer to the requirements arose from technical meetings with the experts of the RH field.

Keywords: AHP | Concept design | DEMO | Remote handling | Systems engineering

Abstract: This paper describes the development of a master model concept of the DEMO vacuum vessel (VV) conducted within the framework of the EUROfusion Consortium. Starting from the VV space envelope defined in the DEMO baseline design 2014, the layout of the VV structure was preliminarily defined according to the design criteria provided in RCC-MRx. A surface modelling technique was adopted and efficiently linked to the finite element (FE) code to simplify future FE analyses. In view of possible changes to shape and structure during the conceptual design activities, a parametric design approach allows incorporating modifications to the model efficiently.

Keywords: CAD-FEA associativity | Conceptual design | DEMO vacuum vessel | Surface modelling

Abstract: The EUROfusion Consortium is setting up – as part of the EU Fusion Roadmap – the framework for the implementation of the (pre)conceptual design phase of the DEMO reactor. Configuration management needs have been identified as one of the key elements of this framework and is the topic of this paper, in particular the configuration of the CAD design data. The desire is to keep the definition and layout of the corresponding systems “light weight” and relatively easy to manage, whilst simultaneously providing a level of detail in the definition of the design configuration that is fit for the purpose of a conceptual design. This paper aims to describe the steps followed during the definition of the configuration management system of the DEMO design data in terms of (i) the identification of the appropriate product data management system, (ii) the description of the philosophy of the configuration management of the design data, and (iii) the introduction of the most important enabling processes.

Keywords: CDA | Configuration | DEMO | Design | Management

Abstract: This paper investigates the thermal and fluid dynamic effects of a cold air jet generated by a Ranque-Hilsch vortex tube on the cutting tool of a milling machine. A simulation model that predicts the temperature field and the displacements of the tool due to the thermal effects was developed. Such a model can help to correct machining errors and improve cutting accuracy of air-cooled milling machines. Experimental results validated the model. Eventually, the post-processing of the computational fluid dynamics (CFD) data has been conducted in virtual reality.

Keywords: CFD analysis | Dry machining | Flux simulation | FSI method | Heat transfer | Machine tool | Ranque-Hilsch vortex tube | Thermo-energetic investigation | Tool | Virtual reality post-processing

Abstract: Complete and detailed 3D scanning of cultural heritage artifacts is a still time-consuming process that requires skilled operators. Automating the digitization process is necessary to deal with the growing amount of artifacts available. It poses a challenging task because of the uniqueness and variety in size, shape and texture of these artifacts. Scanning devices have usually a limited focus or measurement volume and thus require precise positioning. We propose a robotic system for automated photogrammetric 3D reconstruction. It consists of a lightweight robotic arm with a mounted camera and a turntable for the artifact. In a virtual 3D environment, all relevant parts of the system are modeled and monitored. Here, camera views in position and orientation can be planned with respect to the depth of field of the camera, the size of the object and preferred coverage density. Given a desired view, solving inverse kinematics allows for collision-free and stable optimization of joint configurations and turntable rotation. We adopt the closed-loop inverse kinematics (CLIK) algorithm to solve the inverse kinematics on the basis of a particular definition of the orientation error. The design and parameters of the solver are described involving the option to shift the weighting between different parts of the objective function, such as precision or mechanical stability. We then use these kinematic solutions to perform the actual scanning of real objects. We conduct several tests with different kinds of objects showing reliable and sufficient results in positioning and safety. We present a visual comparison involving the real robotic system with its virtual environment demonstrating how view poses for different-sized objects are successfully planned, achieved and used for 3D reconstruction.

Keywords: 3D scanning | Automation | Inverse kinematics | Robotic arm | View planning

Abstract: This paper presents the role of distributed information systems in enhancing multiple criteria decision making problems. This goal is achieved showing the architecture and implementation of ELIGERE, a distributed software platform designed to rank a discrete set of alternatives with respect to multiple evaluation criteria. ELIGERE distributed architecture provides several features of interest in group decision making: A web-based interface where experts express their opinion, a remote computational module implementing a multiple criteria decision making method (fuzzy AHP) for ranking the alternatives, a database for collecting both the answer of the experts and the results of the calculations from the computational module. The motivation behind this work is to speed up the concept selection in product design. An illustrative example, the concept selection of a sensored platform for mobile robots, shows how the distributed architecture of ELIGERE results in an enhancement of the concept selection, in terms of both time and experts' interactive experience.

Keywords: distributed information systems | fuzzy AHP | group decision making | product design and development | robotics | web services

Abstract: Aim of this study was to validate an inertial system able to detect the loss of ground contact (LOGC) in race-walking through outdoor tests in real training conditions. An inertial sensor was placed at L5/S1 of the vertebral column of a Italian national team athlete to acquire timing measurements of the LOGC. Data were encoded by a well-defined protocol. After a preliminary laboratory study, the athlete performed outdoor-field-tests at different velocities. A specific e-bike with a high-speed camera allowed to acquire a video and to validate sensor measurements. Results indicate that the inertial system can improve the accuracy in detecting the visible LOGC.

Keywords: inertial sensor | loss of contact | outdoor test | Race walking | video analysis

Abstract: This paper describes a new motion analysis protocol for race-walking. The protocol has been tested under laboratory conditions on a real athlete of the Italian national race-walking team. The experimental setup included a motion capture system and a force platform to record both kinematic and dynamic aspects of the athletic action. Thus, any infringement of the rules can be detected, based on the measure of knee flexion-extension and the loss of ground contact. The biomechanical efficiency can be determined from the joint angles and the temporal components of gait. The results of experiments show that the protocol can be a valuable tool to assist athletes and trainers in improving race-walking technique.

Keywords: Biomechanics | Dynamics | Experimental protocol | Gait Analysis | Kinematics | Motion Capturing | Race-walking

Abstract: In view of the ITER conceptual design review, the design of the ancillary systems of the European test blanket systems presented in [1] has been updated and made consistent with the ITER requirements for the present design phase. Europe is developing two concepts of TBM, the helium cooled lithium lead (HCLL) and the helium cooled pebble bed (HCPB) one, having in common the cooling media, pressurized helium at 8 MPa [2]. TBS, namely helium cooling system (HCS), coolant purification system (CPS), lead lithium loop and tritium extraction/removal system (TES-TRS) have the purpose to cool down the TBM and to remove tritium to be driven to TEP from breeder and coolant. These systems are placed in port cell 16 (PC#16), chemical and volume control system (CVCS) area and tritium building. Starting from the pre-conceptual design developed in the past, more mature technical interfaces with the ITER facility have been consolidated and iterative design activities were performed to comply with design requirements/specifications requested by IO to conclude the conceptual design phase. In this paper the present status of design of the TBS is presented together with the preliminary integration in ITER areas.

Keywords: Breeding blanket | Integration in ITER | Tritium extraction and management

Abstract: The paper describes a concept design of a remote handling (RH) system for replacing divertor cassettes and cooling pipes in future DEMO fusion power plant. In DEMO reactor design important considerations are the reactor availability and reliable maintenance operations. The proposed divertor mover is a hydraulic telescopic boom driven from the transportation cask through the maintenance tunnel of the reactor. The boom is divided in three sections and it is driving an end-effector in order to perform the scheduled operations of maintenance inside the vacuum vessel. Two alternative designs of the end effector to grip and manipulate the divertor cassette are presented in this work. Both concepts are hydraulically actuated, based on ITER previous studies. The divertor cassette end-effector consists of a lifting arm linked to the divertor mover, a tilting plate, a cantilever arm and a hook-plate. Taking advantage of the ITER RH background and experience, the proposed hydraulic RH system is compared with the rack and pinion system currently designed for ITER and is an object of simulations at Divertor Test Platform (DTP2) in VTT's Labs of Tampere, Finland. Pros and cons will be put in evidence.

Keywords: Concept design | DEMO | Divertor | Hydraulic telescopic boom | Remote handling

Abstract: The fusion advanced study torus (FAST), with its compact design, high toroidal field and plasma current, faces many of the problems met by ITER, and at the same time anticipates much of the DEMO relevant physics and technology. The conceptual design of the first wall (FW) and the vacuum vessel (VV) has been defined on the basis of FAST operative conditions and of "Snow Flakes" (SF) magnetic topology, which is also relevant for DEMO. The EM loads are one of the most critical load components for the FW and the VV during plasma disruptions and a first dimensioning of these components for such loads is mandatory. During this first phase of R&D activities the conceptual design of the FW and VV have been assessed estimating, by means of FE simulations, the EM loads due to a typical vertical disruption event (VDE) in FAST. EM loads were then transferred on a FE mechanical model of the FAST structures and the mechanical response of the FW and VV design for the analyzed VDE event was assessed. The results indicate that design criteria are not fully satisfied by the current drawing of the VV and FW components. The most critical regions have been individuated and the effect of some geometrical and material changes has been checked in order to improve the structure.

Keywords: DEMO | Electromagnetic analysis | FAST | First wall | Thermo-structural analyses assessment | Vacuum vessel

Abstract: Divertor is a crucial component in Tokamaks, aiming to exhaust the heat power and particles fluxes coming from the plasma during discharges. This paper focuses on the optimization process of FAST divertor, aimed at achieving required thermo-mechanical capabilities and the remote handling (RH) compatibility. Divertor RH system final layout has been chosen between different concept solutions proposed and analyzed within the principles of Theory of Inventive Problem Solving (TRIZ). The design was aided by kinematic simulations performed using Digital Mock-Up capabilities of Catia software. Considerable electromagnetic (EM) analysis efforts and top-down CAD approach enabled the design of a final and consistent concept, starting from a very first dimensioning for EM loads. In the final version here presented, the divertor cassette supports a set of tungsten (W) actively cooled tiles which compose the inner and outer vertical targets, facing the plasma and exhausting the main part of heat flux. W-tiles are assembled together considering a minimum gap tolerance (0.1-0.5 mm) to be mandatorily respected. Cooling channels have been re-dimensioned to optimize the geometry and the layout of coolant volume inside the cassette has been modified as well to enhance the general efficiency.

Keywords: Digital Mock-Up | Divertor | FAST | Finite element EM and mechanical analyses | Remote handling

Abstract: Satellite tokamaks are conceived with the main purpose of developing new or alternative ITER- and DEMO-relevant technologies, able to contribute in resolving the pending issues about plasma operation. In particular, a high criticality needs to be associated to the design of plasma facing components, i.e. first wall (FW) and divertor, due to physical, topological and thermo-structural reasons. In such a context, the design of the FW in FAST fusion plant, whose operational range is close to ITER's one, takes place. According to the mission of experimental satellites, the FW design strategy, which is presented in this paper relies on a series of innovative design choices and proposals with a particular attention to the typical key points of plasma facing components design. Such an approach, taking into account a series of involved physical constraints and functional requirements to be fulfilled, marks a clear borderline with the FW solution adopted in ITER, in terms of basic ideas, manufacturing aspects, remote maintenance procedure, manifolds management, cooling cycle and support system configuration.

Keywords: cooling cycle | first wall | fusion technologies | locking system | plasma-wall interaction | remote handling | tokamak design

Abstract: The WEST project (W-Environment in Steady-State Tokamak) aims to transform the Tore Supra limiter configuration to an x-point divertor, providing a test bed for ITER-like plasma-facing components (actively cooled W monoblocs) under high heat flux, steady-state plasma irradiation. The lower divertor includes an actively cooled, W-coated CuCrZr baffle to provide neutral compression and improve particle exhaust. As part of the new diagnostic equipment of Tore Supra within WEST project, a set of Langmuir probes will find place on the baffle in order to provide plasma flux and electron temperature measurements for physics studies and real-time machine protection functions during steady-state discharges. On the baffle top surface, irradiation coming from the plasma, energetic ripple-ions losses, photons and energetic neutrals from charge exchange reactions produce power fluxes up to 3 MW/m2, representing a challenge for the Langmuir probes operating conditions. In this paper Copper-Chrome-Zirconium (CuCrZr) cylindrical probe concept design is proposed. Finite element thermo-mechanical analysis (FEA) confirmed the consistency of this solution under the steady-state plasma condition in the worst case (highest thermal load).

Keywords: Baffle | Diagnostics | Divertor | Langmuir probes | Supra | Tore | WEST

Abstract: This paper explores a possible integration of some ancillary systems of helium-cooled lithium lead (HCLL) and helium-cooled pebble-bed (HCPB) test blanket modules in ITER CVCS area. Computer-aided design and ergonomics simulation tools have been fundamental not only to define suitable routes for pipes, but also to quickly check for maintainability of equipment and in-line components. In particular, accessibility of equipment and systems has been investigated from the very first stages of the design using digital human models. In some cases, the digital simulations have resulted in changes in the initial space reservations.

Keywords: CAD | Design for maintainability | Digital human modeling | Piping layout design

Abstract: The present paper proposes a structured Product Development Lifecycle (PDL) model to deal with the concept design stage of complex assemblies. The proposed method provides a systematic approach to design, aimed to improve requirements management, project management and communication among stakeholders as well as to avoid project failures reducing project development time. This research also provides suggestions and recommendations for utilizing different analysis, synthesis and assessment methodologies along with the proposed approach. The process developed, named Iterative and Participative Axiomatic Design Process (IPADeP), is consistent with ISO/IEC 15288:2008 – “Systems and software engineering”, and INCOSE Systems engineering handbook. It is an iterative and incremental design process, participative and requirements driven, based on the theory of Axiomatic Product Development Lifecycle (APDL). IPADeP provides a systematic methodology in which, starting from a set of experts’ assumptions, a number of conceptual solutions are generated, analysed and evaluated. Based on the results obtained, new iterations can be performed for each level of decomposition while product requirements are refined. In this paper, we applied IPADeP to the initial phase of conceptual design activities for DEMO divertor-to-vacuum vessel locking system in order to propose new innovative solutions.

Keywords: Axiomatic Design | Concept design | DEMO divertor locking system | Fuzzy-AHP | Systems engineering

Abstract: This paper deals with an application of Discrete Event Simulation (DES) within the manufacturing process of a high-speed train. Today, the use of a DES tool is common for supporting engineers in designing the production lines and planning the production, representing a valid help in what-if analyses and in the measurement or validation of a solution. In this research activity, differently from the common use, it has been developed a DES model whose function is not to measure and/or validate a solution of a problem, but to generate a solution that will be nearly to the optimum. This paper describes DES tools, the methodology used in this work, the model built, the case-study and the obtained results.

Keywords: Discrete event simulation | Production planning | Scheduling optimization | Virtual manufacturing

Abstract: This paper deals with the development of a Knowledge Based Engineering (KBE) methodology for supporting a manufacturing company, in particular railway manufacturers, in their analyses for reusing existing products in new projects. The proposed methodology is based on the development of a Decision Support System (DSS) and the use of an analysis, called Adopt/Adapt/Innovate (AAI), aimed at identifying products already designed that fully or partly fit what required by new bids. The DSS is built within a PLM software and part of the research concentrated on comparing the PLM suites available in the market searching for the best tool able to act the role of a centralized management dashboard for knowledge reuse. DSS and AAI analysis are the base for future research activities for obtaining a KBE system that automatically models complex railway products starting from the customer requirements, drastically reducing the time to market.

Abstract: The main objective of this work was to design an innovative skidding winch aimed to improve timber harvesting productivity, operators' safety, and reduce environmental damage in contexts in which mechanized harvesting is limited. The study area is the north-western Black Sea region of Turkey. In the proposed methodology, the harvesting process was simulated with Discrete Event Simulation (DES) software in order to identify bottlenecks. An alternative process was compared with the original one within the DES software itself in order to validate further steps oriented to generate new innovative product concepts. The development of the product was focused towards customer satisfaction, collecting customer requirements and identifying quality characteristics with a Quality Function Deployment approach. Contradictions identified in the design phase were solved using the TRIZ contradiction toolkit, generating different product concepts. Inventive solutions provided by TRIZ were designed within parametric CAD software. The concepts were compared in virtual environment with focus on ergonomics, selecting an optimal solution. The results show that with the concept adopted is possible to achieve a substantial increase in productivity, from 121% to 133%, in terms of kilograms of logs per hour deposited on the landing. Moreover, the final concept allows for ergonomic loading operations and reduces environmental damage to soil and vegetation.

Abstract: The Iterative and Participative Axiomatic Design Process (IPADeP) deals with the early conceptual design stage of complex mechanical assemblies. It provides a systematic approach based on the theory of Axiomatic Product Development Lifecycle and aims to minimize the risks related to the uncertainty and incompleteness of the requirements, considering that the requirements will be refined and completed during the process. IPADeP has an iterative nature and is focused on the experience of the people involved in the design process. The functional requirements and the design parameters are conceived through brainstorming sessions and the concept selection is performed involving several experts through a Multi Criteria Decision Making technique. IPADeP has been adopted as methodology to address the early conceptual design stage of a subsystem of the DEMOnstration fusion power plant: the divertor cassette-to-vacuum vessel locking system. A first iteration was performed, resulting in the selection of a "high level" rough solution. According with IPADeP this paper presents an improvement of this solution, performing a new iteration of the process, since the system is ripe to proceed with the decomposition and zigzagging to the second level and new requirements are coming in from the development of the interfaced systems.

Keywords: Axiomatic Design | Conceptual Design | fusion engineering | IPADeP

Abstract: This paper deals with pre-concept studies of DEMO divertor cassette-to-vacuum vessel locking system under the work program WP13-DAS-07-T06: Divertor Remote Maintenance System pre-concept study. An iterative design process, consistent with Systems Engineering guidelines and named Iterative and Participative Axiomatic Design Process (IPADeP), is used in this paper to propose new innovative solutions for divertor locking system, which can overcome the difficulties in applying the ITER principles to DEMO. The solutions conceived have been analysed from the structural point of view using the software Ansys and, eventually, evaluated using the methodology known as Fuzzy-Analytic Hierarchy Process. Due to the lack and the uncertainty of the requirements in this early conceptual design stage, the aim is to cover a first iteration of an iterative and incremental process to propose an innovative design concept to be developed in more details as the information will be completed.

Keywords: Concept design | DEMO divertor locking system | FEM analysis | Fuzzy-AHP | Remote maintenance | System engineering

Abstract: In contexts in which mechanized harvesting is limited, such as in the northwestern Black Sea region of Turkey, it is important to improve timber harvesting productivity while preserving operators’ safety and reducing environmental damage. This study aims to introduce a methodology in which the harvesting process is simulated with discrete-event simulation (DES) software in order to identify bottlenecks. An alternative process is compared to the original within the DES software, carrying out further steps oriented to the generation of new innovative product concepts. As a case study, the design of an innovative skidding winch is proposed. The development of the product was focused towards customer satisfaction by collecting customer requirements and identifying quality characteristics with a quality function deployment approach. Contradictions identified in the design phase were solved using the TRIZ contradiction toolkit, generating different product concepts. Inventive solutions provided by TRIZ were designed within parametric CAD software. The concepts were compared in a virtual environment, eventually selecting an optimal solution. The results showed that, with the concept adopted, it is possible to achieve a substantial increase in productivity, from 121% to 133%, in terms of kilograms of logs per hour deposited on the landing.

Keywords: Discrete-event simulation | Forest harvesting | Quality function deployment | TRIZ

Abstract: This paper is based on the remote maintenance system project (WPRM) for the demonstration fusion power reactor (DEMO). Following ITER, DEMO aims to confirm the capability of generating several hundred of MW of net electricity by 2050. The main objective of these activities is to develop an efficient and reliable remote handling (RH) system for replacing the divertor cassettes. This paper presents the preliminary results of the concept design of the divertor RH system. The proposed divertor mover is a hydraulic telescopic boom driven from the transportation cask through the maintenance tunnel of the reactor. The boom is divided in three sections of 4 m each, and it is driving an end-effector in order to perform the scheduled operations of maintenance inside the vacuum vessel. Two alternative design of the end effector to grip and manipulate the divertor cassette are also presented in this work. Both the concepts are hydraulically actuated, basing on the ITER previous studies. The divertor cassette end-effector consists of a lifting arm linked to the divertor mover, a tilting plate, a cantilever arm and a hook-plate. The main objective of this paper is to illustrate the feasibility of DEMO divertor remote maintenance operations.

Keywords: Concept design | DEMO | Diverter | Hydraulic telescopic boom | Remote handling

Abstract: The paper deals with the design issues concerning the remote maintenance of divertors in fusion advanced studies torus (FAST), a satellite tokamak acting as a test bed for the study and the develop of innovative technologies oriented to ITER and DEMO programs, pilot examples of the feasibility of energy production from nuclear fusion on the Earth. FAST remote handling (RH) solutions are provided according to an "interactive design review" philosophy based on virtual prototyping techniques. Assuming an ITER configuration as start point, it foresees an iterative process of design review, carried out in virtual reality (VR) environment and oriented to obtain a sort of best solution from the RH point of view. Any iteration includes the analysis of the current solution and the proposal of new and alternative ones, based on the requirements fulfillment and the improvement of critical points highlighted. In such a way, and this is the main novelty introduced by the paper, the interactive design review in a VR collaborative environment becomes the tool able to put in cooperation and in positive competition various and different competences, required by a multidisciplinary problem as the realization of nuclear fusion machine, in order to reach a shared solution. A first preliminary FAST RH solution is hereinafter presented, accompanied by the design of a compatible support system, due to the strict relationship between the divertor maintenance and the support configuration. The work was carried out via the collaboration of the "Divertor Test Platform 2" (DTP2) team, in charge of ITER divertor RH tests and located in VTT's Labs of Tampere (Finland), and the IDEAinVR team of CREATE Consortium, with competence in interactive design and VR simulations and located in the Virtual Reality Lab of University of Naples Federico II (Italy). © 2013 Springer-Verlag France.

Keywords: Fusion engineering | Interactive design | Remote handling | Tokamak design | Virtual prototyping

Abstract: The object of this paper is the development of a decision support system involved in the bidding for invitations to tender in the railway field. The proposed methodology is based on the characterization of the whole train and its components, through several attributes according to a digital pattern approach. In particular some key components were chosen such as the traction motor, the bogie and the auxiliary equipment converter. The system measures the extent to which the products offered by the company fit the one required by the customer, comparing the homologous attributes. Such analysis is called 'adopt/adapt/innovate' (AAI). In this way it is possible to identify products already designed that fully or partly fit what required, obtaining huge benefits in terms of effectiveness and efficiency.

Keywords: Bid | Decision support system | Digital pattern | Digital portfolio | Virtual prototyping

Abstract: This paper deals with the development of a knowledge-based engineering (KBE) approach able to support railway manufacturers in their assessments on the convenience of participating in competitive tendering and, subsequently, in the offer definition and in the designing phase. The proposed approach is based on a Decision Support System (DSS) that allows an analysis, called Adopt-Adapt-Innovate (AAI), to be made, which helps the company in the search of its products that best suit the requirements of new bids. Digital pattern techniques, configuration design methods and parametric modeling are the tools proposed to optimize the process that starts with the tender notice, passes through the offer definition and ends with the design. The paper describes the railway market logics, the proposed methodology and the first obtained results. © 2014 WIT Press.

Keywords: Decision support system | Digital pattern | Knowledge-based engineering | Parametric modeling

Abstract: We conducted a comparative study of chipping logging residues at the roadside landing or at the yarder pad, the latter inaccessible to heavy road vehicles. Field data was collected from real operations in the Italian mountain, and it was used for building a simulation model that could generalize the results of the study. The model was built with Arena 14 and carefully reflected interaction delays between individual units along the chain. Chipping at the pad with a chipper and two shuttles was the best compromise solution of low supply cost and fuel consumption. At a mean cost of €22.7 per fresh tonne, this solution was 10% cheaper than chipping at the landing. Using three chip shuttles did not allow a meaningful reduction of supply cost over a two-shuttle chain, but resulted in a 7% increase of fuel consumption. The distance between the pad and the roadside landing was by far the most important factor in determining supply cost, and accounted for 80% of the variability in the data, for both systems. Under these circumstances, the higher speed and payload of the chip shuttles made it preferable to chip at the pad, provided enough shuttles are available. © 2014 © 2014 Taylor & Francis.

Keywords: biomass | chipping | energy | logistics | simulation

Abstract: The paper focuses on the application of the Theory of Inventive Problem Solving (TRIZ) to divertor Remote Handling (RH) issues in Fusion Advanced Studies Torus (FAST), a satellite tokamak acting as a test bed for the study and the development of innovative technologies oriented to ITER and DEMO programs. The objective of this study consists in generating concepts or solutions able to overcome design and technical weak points in the current maintenance procedure. Two different concepts are designed with the help of a parametric CAD software, CATIA V5, using a top-down modeling approach; kinematic simulations of the remote handling system are performed using Digital Mock-Up (DMU) capabilities of the software. The evaluation of the concepts is carried out involving a group of experts in a participative design approach using virtual reality, classifying the concepts with the help of the Analytical Hierarchy Process (AHP). © 2013 Elsevier B.V.

Keywords: AHP | Concept design | FAST tokamak | Interactive design | Remote handling | TRIZ

Abstract: Fusion advanced study torus (FAST) has been designed with the aim to tackle the power exhaust problem with ITER and DEMO relevant bulk plasma. Considerable analysis effort has been spent in EM (electromagnetic) designing of FAST divertor components capable of withstanding the electromagnetic loads expected from the foreseen FAST operative conditions. Plasma disruption EM loads are one of the most critical load conditions for the divertor. Consequently a first dimensioning of the divertor for EM loads is mandatory. The foreseen FAST divertor structure is compact and the configuration is aimed to give to the structure the required mechanical and thermal capability as well as being remote handling compatible. The conceptual EM design of the divertor has been designed for FAST operative conditions and for DEMO relevant "Snow Flake" (SF) magnetic topology. Recently a "Snow Flake" (SF) magnetic topology has been suggested for the divertor region, capable to spread the plasma power flow on a much wider areas, with the possibility of reducing by a factor 4 the power flowing to the divertor tiles [1]. The conceptual design of the divertor has been obtained during activities based on the estimation of EM loads due to a typical Plasma Fast Down disruption event in FAST for the normal configuration and for SF magnetic topology. © 2013 Elsevier B.V.

Keywords: DEMO | Divertor | Electromagnetic analysis | FAST | First wall

Abstract: The Fusion Advanced Study Torus (FAST), with its compact Tokamak design, high toroidal field and plasma current, will face many of the problems that ITER will meet and will anticipate many DEMO relevant physics and technology issues. The Design Upgrade of the Vessel and In-Vessel Components is presented in this paper. Relevant modifications were performed to the Vacuum Vessel (VV) and to the Plasma Facing Components (PFCs), i.e. the First Wall (FW) and the Divertor. The VV was modified to insert active reduction coils (ARC), between VV and the toroidal field (TF) coils to keep toroidal field magnet ripple lower than 0.3% and to allow Remote Handling for the FW and the Divertor. The FW, was modified to house coils for ELMs control and other plasma instabilities. A 3D thermo-hydraulic analysis using ANSYS code was performed to check FW heat removal capability. A new Divertor was designed to withstand the largest thermal loads of the high performance, low density, H-mode and to be able to comply with a recent magnetic topology called as "Snow Flake", increasing up a factor 4 the flux expansion. An exhaustive 3D thermo-hydraulic analysis using ANSYS code was carried out to show the capability of the Divertor to comply these high requirements. Design criteria were satisfied by present components of the upgraded machine. © 2013 Elsevier B.V.

Keywords: ANSYS code | FAST | PFC

Abstract: The paper presents a concept design of a remote handling (RH) system oriented to maintenance operations on the divertor second cassette in FAST, a satellite of ITER tokamak. Starting from ITER configuration, a suitably scaled system, composed by a cassette multifunctional mover (CMM) connected to a second cassette end-effector (SCEE), can represent a very efficient solution for FAST machine. The presence of a further system able to open the divertor port, used for RH aims, and remove the first cassette, already aligned with the radial direction of the port, is presumed. Although an ITER-like system maintains essentially shape and proportions of its reference configuration, an appropriate arrangement with FAST environment is needed, taking into account new requirements due to different dimensions, weights and geometries. The use of virtual prototyping and the possibility to involve a great number of persons, not only mechanical designers but also physicist, plasma experts and personnel assigned to remote handling operations, made them to share the multiphysics design experience, according to a concurrent engineering approach. Nevertheless, according to the main objective of any satellite tokamak, such an approach benefits the study of enhancements to ITER RH system and the exploration of alternative solutions. © 2013 Elsevier B.V.

Keywords: Divertor | FAST | Fusion engineering | ITER | Remote handling | Virtual prototyping

Abstract: The ISO 9001: 2000 requires the phase of design validation in order to demonstrate that the design output are able to satisfy specified or forecasted user requirements; for this reason, generally, physical prototype are realized in order to evaluate real product performances and their correlation with simulated ones. In this paper, the use of virtual inspection probes to validate playground equipment design is studied, pointing out limits and defining the optimal test strategies. Through the use of Robust Design techniques the authors show that the combined use of real time shadows and positional sound feedback allows to reduce the percentage of wrong inspections in the validation phase of playground equipment design. The authors develop an inspection probe simulation tool in virtual immersive environment. In particular, this tool ensures the collision detection through visual and sound feedback and increases the realism of the immersive environment. Finally, an experimental session, using a physical prototype of playground equipment, is carried out in order to compare these results with the ones coming out from the VR experiments. For a standard entrapment test, the authors assess the dependences of false and missed alarm by the diameter of the openings to evaluate and establish an acceptability threshold for the usability of the virtual probes. © 2013 Springer-Verlag France.

Keywords: Design validation | Grasping techniques | Playground equipment | Usability | Virtual reality

Abstract: This paper focuses on a structured methodology that uses virtual reality (VR) and digital human modeling (DHM) to study maintenance procedures of industrial products. VR technologies help to highlight the most critical aspects of maintenance operations, while DHM tools allow detailing working sequences. Data coming from these analyses are then used to draw up a multimedia maintenance manual based on digital video animations, audio comments, explanatory images and written recommendations. Information is available to maintenance personnel directly on the working site through portable electronic devices. Further, web-based multimedia manuals can be updated on-line and help to shorten learning time and maintenance downtimes. © 2013 Springer-Verlag France.

Keywords: Design for maintainability | Digital human modelling | Multimedia maintenance manuals | Virtual design review

Abstract: The aim of the paper is to address an innovative methodology for assessing the usability of a product. This methodology is particularly suitable for designing products that provide their main functions through their control interfaces. In particular, this case study relates to the usability assessment of two control devices for a wheelchair-mounted robot manipulator to assist physically disabled people. The study focuses on defining a synthetic usability index on the basis of two currently used methods: the multi criteria decision analysis and the Saaty's analytic hierarchy process. Several virtual reality (VR)-based experiments have been conducted, set up in accordance with a cross-array experimental plan, that adequately caters for both control and noise factors. Quantitative measures and subjective user evaluations have been collected to maximize the effectiveness, the efficiency and the satisfaction perceived by users while using the product. Compared to the literature on the subject, the proposed approach provides both more flexibility in defining quantitative indexes and more adequate results, even when involving only a small sample of users in the participatory design session. The use of VR technologies for the collection of the experimental data has been essential in terms of safety, costs and repeatability of the tests, as well as of the robustness with respect to noise factors. © 2012 Springer-Verlag London Limited.

Keywords: Analytic hierarchy process (AHP) | Assistive robotics | Participatory design | Usability index | Virtual reality experiments

Abstract: The Fusion Advanced Study Torus (FAST) has been proposed as a high magnetic field, compact size tokamak providing a flexible integrated environment to study physics and technology issues in ITER and DEMO relevant conditions. FAST has a quite large natural toroidal field ripple (around 1.5%) due to its compactness and to the number of access ports: this ripple must be lowered to an acceptable level to allow safe operations and a good confinement quality. An Active Ripple Compensating System (ARCS) has been designed, based on a set of poloidal coils placed between the plasma chamber and the Toroidal Field Coils (TFCs). These ARCS coils will be fed with adjustable currents, opposite in direction respect to the TFC currents, and will allow lowering the ripple up to zero and beyond. The CAD model of FAST including the ARCS coils has been completed and preliminary electromagnetic and thermal analyses have been carried out. Moreover, a Feedback Active Control System (FACS) composed of two arrays of in-vessel saddle coils has been designed to allow safe high plasma current, low safety factor operation and to mitigate possibly large ELMs effects in FAST. These FACS coils will be fed by a feedback system to control MHD modes: a first engineering assessment of the current requirements has been carried out. © 2013 Euratom-ENEA Association sulla Fusione.

Keywords: Control | DEMO | FAST | ITER | MHD modes | Toroidal field ripple

Abstract: Trailers are used to carry logs having specific dimensions for logging extraction operations, secondary transportation, and agricultural activities. The main objective of this study was the design of a timber trailer capable of manual loading operations and suitable for rough terrain conditions to be used in combination with a farm tractor in the western Black Sea region of Turkey. In the proposed methodology, a House of Quality diagram was used to transfer customer requirements into quality characteristics, and focus the development of the product toward customer satisfaction. Negative correlations between quality characteristics were solved using the TRIZ contradiction toolkit and generating different concepts. Inventive solutions provided by TRIZ were designed with parametric CAD software. Several concepts were compared in a participative design review session in an immersive virtual reality environment. To choose an optimal concept, the analytic hierarchy process (AHP) was used. The final concept has a total length of 3.35 m, width of 1.34 m, and height of 1.8 m. The mass is 2700 kg, the payload capacity is about 2.33 m3, and the total volume of the chassis is 2.68 m3 The angle of rollover is 26.9°, the door is reachable by 90% of the population, and the lower back analysis performed for the loading operation showed a maximum value of 2597 N. The final concept is capable of movement in steep terrain and with the presence of obstacles, carrying logs up to 3-m long. It is more productive among high-density stand trees, allows for ergonomic loading operations, and reduces environmental damage to soil and vegetation. © TÜBİTAK.

Keywords: AHP | Ergonomics | Forest harvesting | Interactive design | QFD | TRIZ

Abstract: Nowadays, economical, technical and ergonomic factors have a great importance on the design of the agricultural tractors. The paper illustrates the use and the management of heterogeneous product information (manual measurements and drafts, 2D drawings, technical documentation, photos), advanced CAD modeling tools and digital human models, for the redesign and the ergonomic optimization of an agricultural tractor's driver cab. The project development has been organized using a top-down approach in a collaborative environment. At first, a manual measurement with gauges allowed to realize a technical draft of the whole agricultural tractor and of each component part of the driver cab. Then a main skeleton has been created in Catia V5 environment in order to specify all the datum elements necessary to model each sub-assembly of the tractor. Cabin, platform, engine, tires, seat, dashboard and controls have been organized separately and modeled considering the details related to the manual measurements and to the technical standards. Once obtained the 3D CAD model of the tractor, an opportune questionnaire was prepared and a test campaign was carried out with real operators in order to define the more critical control devices within the driver cab, as regards to usability and ergonomic issues. An "Ergonomics' Evaluation Index" (EEI) was defined taking into account the posture angles of the operator and the Rapid Upper Limb Assessment analysis tool available in the "Ergonomics Design & Analysis" module of Catia V5 based on the use of a digital human model. The index was validated comparing the results of tests carried out using virtual manikins of different percentiles performing a specific driving task, with the results of tests carried out by real operators, of the same percentiles, performing the same driving task. Critical values of the EEI obtained during some driving tasks in virtual environment, suggested to modify the shape and the position of some control devices in order to optimize the ergonomics of the driver cab. The adoption of the top-down modeling based approach allowed each change on a singular component part to be automatically propagated on the whole assembly, making easy the changes on the virtual prototype. Copyright © 2012 by ASME.

Abstract: In this work we apply an innovative participative design approach for the quality evaluation of virtual prototypes of new industrial products (i.e. concept designs), by adopting statistical procedures and carrying out tests in an immersive VR environment. This methodology has been fully exploited through a case study concerning the choice of the optimal design for the interiors of a new regional train. Following this approach, the optimal concept design is defined at the end of a process consisting of five phases: identification of the quality elements of the concept design, classification of the quality elements, generation and quality evaluation of product concepts and, finally, definition of the optimal concept. According to the applied methodology after the identification of the customer's needs, a structured set of quality elements has been defined and, successively, classified according to Kano's theory. Following the approach of conjoint analysis, the design factors have been combined according to an experimental plan to form product virtual concepts. During the concepts generation phase we have explored those product architectures that integrate design characteristics correlated to the set of quality elements. The concepts have been created according to comfort, ergonomic and safety criteria. In particular we have considered the ergonomics of places and furniture dimensions, through the use of virtual manikins. The evaluation of the quality of the different concepts has been carried out in the VR laboratory (named "VRTest") of the Competence Centre for the Qualification of Transportation Systems founded by Regione Campania according to an original statistical procedure and has involved a group of experts in train's interiors design and a group of common users of regional trains. Copyright © 2012 by ASME.

Keywords: Concept design | Participative design | Quality engineering | Railway engineering | Virtual Reality

Abstract: The preventive knowledge of serviceability times is a critical factor for the quantification of after-sales services costs of a vehicle. Predetermined motion time system are frequently used to set labor rates in industry by quantifying the amount of time required to perform specific tasks. The first such system is known as Methods-time measurement (MTM). Several variants of MTM have been developed differing from each other on their level of focus. Among them MTM-UAS is suitable for processes that average around 1-3 min. However experimental tests carried out by the authors in Elasis (Research Center of FIAT Group) demonstrate that MTM-UAS is not the optimal approach to measure serviceability times. The reason is that it doesn't take into account ergonomic factors. In the present paper the authors propose to correct the MTM-UAS method including in the task analysis the study of human postures and efforts. The proposed approach allows to estimate with an "acceptable" error the time needed to perform maintenance tasks since the first phases of product design, by working on Digital Mock-up and human models in virtual environment. As a byproduct of that analysis, it is possible to obtain a list of maintenance times in order to preventively set after-sales service costs. © 2012 Springer-Verlag.

Keywords: Digital humans | Ergonomics | MTM-UAS | Predetermined time analysis | Virtual maintenance | Work measurement

Abstract: An algorithm for both human-like motion generation and joint torques computation for digital humans is addressed in this paper. This goal has been achieved using techniques derived from robotics. In particular, the so-called augmented Jacobian has been used to solve the inverse kinematics problem with a single closed loop inverse kinematics algorithm. Furthermore, a position control for the center of mass of the kinematic chain, and for its projection on the support plane (center of pressure), has been implemented to achieve easy posture control. Thus, the inverse kinematics can be solved taking into account the static balance of the digital human. Moreover, the proposed algorithm allows simulating quite complex tasks, which involve the motion of the whole body, by means of only few task-related control points arbitrary located on the whole kinematic chain. The resulting movements are quite natural even for complex tasks as can be seen on the simulation experiments reported which show the effectiveness of the proposed approach. Finally, the joint torques can be computed thanks to the kinetostatics duality: the results are in accordance with biomechanical analyses. © 2011 Springer-Verlag.

Keywords: Digital humans | Human-like motion generation | Kinetostatic duality | Low-back biomechanical analysis | Multiple-point kinematic control | Posture control

Abstract: This work concerns the usability assessment of two control devices for a wheelchair-mounted robot manipulator aimed at assisting physical disabled people. The assessment of the usability is a crucial issue for the design of such products, since they communicate with their users not only through their shape, but especially through their control interfaces. In a first phase, the study focuses on defining a synthetic usability index on the basis of the methodologies currently in use. In a second phase, some experiments in Virtual Reality (VR) have been carried out. The use of VR technologies for the collection of the experimental data has been fundamental in terms of safety, costs and repeatability of the tests. Another important result has been the reduction of the sources of noise, thanks to preliminary simulations in VR and non-invasive questionnaires and interviews for capturing the subjective perceptions of users. Finally, it is worth noticing that the developed model may show its validity also in evaluating the usability of other products. Indeed, it provides a basis for a more extensive use of VR experiments for evaluating different design solutions in terms of global usability requirements. © Organizing Committee of TMCE 2010 Symposium.

Keywords: Analytic Hierarchy Process (AHP) | Assistive robotics | Participatory design | Usability index | Virtual reality experiments

Abstract: The paper represents the contribution to the PUODARSI (Product User-Oriented Development based on Augmented Reality and Interactive Simulation) research project in the development of a design environment which integrates modeling tools and CAE simulation capabilities. Typically, aerodynamic and mechanical performances of the object shape are in contrast with the stylistic requirements. Integrated tools and numerical simulations are then needed to support designers during the conceptualization of a new shape or when re-designing a product. This work combines Reverse Engineering methodologies and CAE tools to easily analyze the interaction between the aerodynamic behavior and the stress-strain state, due to viscous and pressure loads, of a physical object. A friendly interactive tool, based on MatLAB® and linked to Comsol Multiphysics®, was developed to drive user during the simulation and the visualization of results. © Springer-Verlag 2009.

Keywords: CAE | Design review | Meshing control | Reverse engineering

Abstract: The present paper deals with the manufacturing process of a railway carriage. In the first part of the paper, the authors focus on a "virtual railway factory" that uses a very innovative assembly cycle, if compared to the traditional manufacturing processes in the railway field. The case study refers to a railway carriage consisting of four modules, that are singularly set up of furnishings and other systems in dedicated workplaces. On one hand, the virtual simulation has highlighted several critical aspects to be improved, in order to achieve a greater feasibility and to reduce time and cost. On the other hand, the designers have been able to evaluate the movements of the parts and the assembly sequences of the components, by considering each geometric, functional and technological constraint and also some safety requirements. The second part of the paper deals with the simulation of the assembling operations and the analysis of tolerance chains, which have been performed through a Computer Aided Tolerancing system. In particular, the precision requirements have been also evaluated and we have compared the accumulation of dimensional and geometric deviations when using both rivets and traditional welds to fasten the modules. © 2009 Springer-Verlag.

Keywords: Computer Aided Tolerancing | Train design | Virtual manufacturing

Abstract: The paper aims at providing a methodological contribution to the concept design of train interior in order to improve the quality perceived by users in compliance with railway standards. Indeed, the combined use of advanced CAD tools, experimental statistical methods and Virtual Reality tools allows developing, selecting and experimentally evaluating new concepts. The design cycle starts both from designers' proposal and the identification of user's needs; then, it makes use of datum-based CAD models in order to generate virtual concepts that satisfy railway standards; the cycle proceeds with the immersive evaluation of virtual prototypes, performed by potential and expert users in Virtual Reality. The identification of the optimal concept closes the design process. This procedure can be iterated in order to improve the quality of train interiors, evaluated thanks to the user's involvement in the design cycle. In this work a case study on seat design of a regional train is presented, developed at the Virtual Reality laboratory, named, of the Regional Centre for the qualification of transportation systems set up by Campania Regional Authority. © 2009 Springer-Verlag.

Keywords: CAD models | Concept design | Designfor quality | Kano methodology | Virtual reality

Abstract: The design of solutions for robotic extenders of wheelchairs must take into account both objective and subjective metrics for everyday activities in human environments. Virtual Reality (VR) constitutes a useful tool to effectively test design ideas and to verify performance criteria. This paper presents the development of a simulation environment, where three different manipulators to be mounted on a commercially available wheelchair have been considered. Experimental results are discussed in a significant case study, based upon users' feedback. © The Eurographics Association 2008.

Keywords: Human robot interaction | Kinematics | Rehabilitation robotics | Virtual Reality

Abstract: The present work deals with the re-designing of a locomotive, according to in force European standards, in the field of active and passive safety. The paper illustrates the use and the management of heterogeneous product information (2D drawings, technical documentation, photos), Virtual Reality tools and digital human models, for the re-designing of a locomotive, using a collaborative approach with a total absence of the reference digital models. The project development has been organised using a top-down approach in a collaborative environment. Finally, by means of the digital prototype of locomotive, a series of aesthetic, functional and ergonomic analyses, in virtual environment, has been performed. © Springer Verlag France 2007.

Keywords: Collaborative design | Ergonomics | Top-downapproach | Virtual reality

Abstract: In this paper, we describe a framework which helps designers visualize and verify the results of robotic work cell simulation in a Virtual Environment (VE). The system aims at significantly reducing production costs and error sources during manufacturing processes. The means to achieve these goals are the development of a prototypical VE for the support of robots planning tasks, reuse of animation events, and the implementation of customization tools for animation elements and their behavior. By using advanced Virtual Reality (VR) techniques, the system is also able to direct the focus of the observer to interesting events, objects and time-frames during robotic simulations in order to highlight the Human Robot Interaction within the manufacturing systems. © The Eurographics Association 2007.

Abstract: The paper deals with the developing of a virtual training system to be implemented in an aeronautic company. The strength of the training method based on the use of Virtual Reality is the high degree of interactivity that it is possible to obtain in a virtual environment. In fact, unlike the traditional methods based on classroom lessons supported by slides and videos that only allow a passive participation of the users to the training, Virtual Reality, with its immersive environments, allows the students both to visualize realistically the contents of the lesson, and to interact with the represented objects. According to that, thanks to the collaboration with Alenia, one of the most important Italian companies in the aeronautical field, we elaborated an innovative virtual training methodology, named AVIRA, specifically dedicated to the users working with composed materials. For the development of this system we started from a real case regarding a particular production process of a specific component. The considered production process is the stratification/lamination of carboresin, used for the fabrication of aeronautical components of high technological content, that is currently active at Alenia Aeronautica in Foggia. © The Eurographics Association 2007.

Abstract: The aim of the paper is to make up a virtual showroom and work-through of a train model in order to allow railway companies showing new trains prototypes, in phase of concept, and present their new design in more exhaustive way than simply technical documentation. The possibility of applying Virtual Reality (VR) methodologies to make a scene more realistic as possible is a great advantage for the effectiveness of the presentation, in order to increase their competitivity. Shader technology allows the programmers to have control over shape, appearance (such as colour, lighting, reflection) and animation of objects, in order to make very realistic real-time rendering. In the paper the authors describe the use of shader technology in Virtual Design 2 (VD2) for realistic presentation of train prototypes in VR. The software VD2 is an extensive tool that allows following many phases of product development, from the creation of showroom for realistic presentations supporting shader technology to the assembly simulation or ergonomics analysis. Moreover, the possibility of interfacing with a wide range of input/output devices and the possibility to access to the API made this software to be chosen for Virtual Reality applications in the VR laboratory of the Competence Center for the Qualification of Transportation Systems founded by Campania Region (www.centrodicompetenzatrasporti.unina.it).© 2006 The Eurographics Association.

Keywords: Concept design | Shader technology | Train design | Virtual Reality

Abstract: The early identification of the optimal concept is a critical task of the design process in order to increase the chances of satisfying customers. The challenging aspect of the approach proposed in this work relies in the quality evaluation of virtual prototypes of new industrial products (i.e. concept designs) by adopting a statistical procedure previously applied to service industries. Following this approach, the optimal concept design is defined at the end of a process consisting of five phases: identification of the quality elements of the concept design, classification of the quality elements, generation and quality evaluation of product concepts and, finally, definition of the optimal concept. Currently, virtual reality (VR) environment offers the opportunity to evaluate the characteristics of different virtual prototypes by involving experts and/or customers, overcoming the need for several physical prototypes. On the other side, the dynamics of simulation and the stereoscopic visualization in VR environment provides a more realistic and impressive interaction with virtual prototypes than in CAD environment. The proposed methodology is fully exploited through two case studies: the choice of the optimal design for a traditional Neapolitan coffee maker, addressed by the Italian designer Riccardo Dalisi, and for a subassembly of a new minicar. © 2006.

Keywords: Concept design | Quality engineering | Virtual reality

Abstract: The whole of trading enterprises with many average/big saling-centres forms what is today commonly known as Large Organized Distribution (LOD). The main risks regarding the people working in the LOD are: MM, repetitive motion of upper limbs, fixed postures, unfavourable microclimatic conditions and, moreover, the probability of labour accidents. In order to analyse the risks due to MM and false postures, we have used the ergonomic software "Classic Jack" distributed by EAI-UGS, which has beeen very helpful to find out the most dangerous labour operations (e.g. charging and discharging of goods, fragmentation and reassembling of manufactures, goods-shelving, branding and labelling). We have, then, suggested a programme of health surveillance that includes a medical examination, eventual x-Ray exams, specialized examination and a posturologic visit. This posturologic visit has got an olistic diagnostics approach, whose research after the causes that could be responsible for the checked diseases concerns not only the damaged area, but also other parts of the body (ocular system, auditive system, podalic system, masticatory apparatus). © PI-ME, Pavia 2005.

Keywords: Health surveillance | Large organized distribution

Abstract: In this work the Authors propose a methodology based on the use of an ergonomic software in alternative to the traditional methods to evaluate muscular-skeletal diseases caused by incongruous postures or conditions of mechanical overload. This methodology allows to simulate, in a virtual environment, both a workplace and a digital human model whose behaviours are similar, from a kinematical and a dynamical point of view, to that ones of a real person. Through the simulation in a virtual environment of an operation of Manual Material Handling (MMH) in a pharmaceutics industry, the Authors have evaluated, in real time, the strengths and the reaction-moments in the axial, sagittal and lateral plane on the L4 and L5 lumbar vertebras and on the shoulder of the workers. In the work the single movements carried out by the operator are analysed using manikins of different percentiles. The results are compared with the ones coming from the use of the traditional methods to evaluate muscular skeletal disease. © PI-ME, Pavia 2005.

Keywords: Digital human models | Ergonomics | Manual material handling | Virtual simulations