Abstract: The paper presents a preliminary design activity and virtual prototyping of an innovative boat equipped with hydrofoils and hybrid propulsion, with the aim of extending the foil technology from the field of competition boats to recreational day-cruiser yachts and creating a craft with minimal environmental impact. Hydrofoils allow boats to rise from the water, greatly reducing resistance and increasing performance. The current work dealt with the preliminary design of a daysailer with foil technology and hybrid propulsion that allow to combine green and comfortable navigation both under sail and motor and that, when required, can sail in a more performing way by exploiting the foil technology and the thrust of the wind. After having deepened the theory and physics of sailing on foils, a MATLAB code was created to integrate the stability equations that characterize hydrofoil sailboats: connecting the acting forces and allowing to define the dimensions of the geometries, the code was fundamental in speeding up the iterative preliminary design process. The next step was to model the geometry of the hull and the appendages in the CAD environment and, subsequently, the wing movement mechanism so that it could both manage the incidence of the wings and retract the foils when the boat is moored. The hull, profiles, and wings were subsequently placed in a CFD and VPP virtual environment for testing their resistance. Future developments will include a detailed design and the physical prototyping of a first boat for water testing.

Keywords: Green | Hybrid | Hydrofoil | Virtual prototyping

Abstract: The constant growth in global energy demand, and corresponding prices rise, is soaring new engineering methods for reducing energy consumption in manufacturing processes. For decades, industrial robotics have been enabling quality enhancement of end-products by using flexible manufacturing processes, without much concern to energy cost, but now a makeover is happening. Calls for sustainable and green manufacturing processes are being promoted across the globe with the aim to produce more goods and with less consumption. In this paper, a new method is presented focusing on the optimization of energy intake by industrial robots, without the need to change their hardware set and just modifying the trajectory planning of the end-effector. A test case scenario consisting of a robotic cell with 4 pick-and-place manipulators has been set to validate the method. Starting from a pre-scheduled trajectory, robots are moved at the highest speed and acceleration and, by performing the sequenced operations, the optimal trajectories are defined. The goal is to find a trajectory that minimizes the time cycle and the total energy consumption, while avoiding collisions between the robots’ links: comparing the results thereof to those of the pre-scheduled trajectory, noticeable energy saving has been obtained along with possible decrease of the cycle time.

Keywords: Computer-aided engineering tools | Energy efficiency | Robot scheduling | Trajectory planning | Virtual prototyping

Abstract: Robotic surgery is a set of techniques and technologies used to plan, move, and perform surgery, exploiting the capabilities of robots to overcome human limitations in minimally invasive operations. The use of robots guided by augmented reality has allowed surgeons to improve vision and precision during surgery. Despite the results achieved over the years, there is still a high clinical demand for improvements, which can only be reached using intelligent physical or virtual tools. The present work aims to develop a virtual prototype of robotized bone milling operations, when there is the need to virtually predict operative performance. The proposed model leverages the active connection between Simulink, the well-known numerical tool, and RecurDyn, a commercial CAE solver. In particular, the model parametrization and the simulation process are managed from Matlab, whereas the mechanical system is solved in RecurDyn. After a proper validation of the simulation framework with data taken from the literature, a set of parametric studies has been carried out to investigate the influence of the input parameters on the cutting process.

Keywords: Passively compliant spindle | Robotic milling optimization | Robotic surgery | Virtual prototyping

Abstract: Humans are able to communicate by a wide variety of means. Gestures often play an important role in this multimodal communication. In order to also ensure robust interaction between humans and machines, it is important that machines are able to recognize human gestures. This typically requires time-consuming subject tests that limit the number of conditions that can be tested. However, by moving these tests from the physical to a virtual environment, each test condition can be evaluated quickly, eliminating the need for numerous repetitions. The purpose of this work was to validate the use of a virtual test environment in comparison to physical testing. This was done by conducting a subject test and developing a virtual model of the human upper limb. The motion profile of the subject performing a simple gesture was recorded with a visual optical motion capture system and used as input for the newly developed virtual model. Acceleration signals captured with an IMU attached to the subject's right wrist were used as a reference signal and compared to signals simulated by a digital twin of the sensor. The pilot study proved the capabilities of the proposed approach and showed some of its limitations.

Keywords: Digital twin | Human body model | Human gestures | Simulation | Virtual environment

Abstract: The current best-practice in the assembly process of aircraft skin panels involves several manual measurement-fit-adjust quality loops, such as loading part on the assembly frame, measuring gaps, off-loading parts, adding be-spoke shims and re-positioning parts ready for the fastening operation. The consequence is that the aircraft is re-assembled at least twice and therefore this process has been proved highly inefficient. This paper describes the framework developed under the “Integrated Smart Assembly Factory” (ISAF) project in the “Intelligent Factory” specialisation area in Italy. Taking advantage of the emerging tools brought by Industry 4.0 the ISAF framework spearheads innovation in the assembly process of aircraft skin panels by integrating smart and digital technologies such as in-line measurement systems with highly accurate sensors, large-scale physics-based simulations, multi-disciplinary process optimisation and additive manufacturing. ISAF implements a flexible alignment, which combines both rigid rotations/translations and local deformations to account part deformations. The proposed methodology allows predicting and fabricating shims using in-line measurement data with no need to iterate the measurement-fit-adjust quality loops. This will undoubtedly reduce inspection/measurement time and costs, enabling operators to virtually test assembly operations before installation in the field. The results were demonstrated during the assembly process of a vertical stabiliser for commercial aircrafts, and findings showed a significant time saving of 75%.

Keywords: Additive manufacturing | Digital twin | Flexible alignment | In-line measurement | Physical simulation | Shimming | Smart factory

Abstract: A leading challenge in the assembly process of aircraft skin panels is the precise control of part-to-part gaps to avoid excessive pre-tensions of the fastening element which, if exceeded, impair the durability and the response under dynamics loads of the whole skin assembly. The current practice is to measure the gap in specific points of the assembly with parts already at their final location, and then be-spoke shims are machined and inserted between the mating components to fill the gap. This process involves several manual measurement-fit-adjust quality loops, such as loading parts on the assembly frame, measuring gaps, off-loading parts, adding be-spoke shims and re-positioning parts ready for the fastening operation—as a matter of fact, the aircraft is re-assembled at least twice and therefore the current practice has been proved highly cost and time ineffective. Additionally, the gap measurement relies on manual gauges which are inaccurate and unable to follow the actual 3D profile of the gap. Taking advantage of emerging tools such as in-line measurement systems and large-scale physics-based simulations, this paper proposes a novel methodology to predict the part-to-part gap and therefore minimise the need for multiple quality loops. The methodology leverages a physics-driven digital twin model of the skin assembly process, which combines a physical domain (in-line measurements) and a digital domain (physics-based simulation). Central to the methodology is the variation model of the multi-stage assembly process via a physics-based simulation which allows to capture the inherent deformation of the panels and the propagation of variations between consecutive assembly stages. The results were demonstrated during the assembly process of a vertical stabiliser for commercial aircraft, and findings showed a significant time saving of 75% by reducing costly and time-consuming measurement-fit-adjust quality loops.

Keywords: Aircraft skin panels | Digital twin | Morphing mesh | Multi-stage assembly simulation | Physics-based modelling | Virtual shimming

Abstract: This article reports the analysis and preliminary design of a passive, wearable, upper limb exoskeleton to support workers in industrial environments in a vast range of repetitive tasks, offering an effective strategy to reduce the risk of injuries in production lines. The system primary purpose is to compensate for gravity loads acting on the human upper limb. The proposed exoskeleton is based on 6 Degrees-of-Freedom (DoFs) kinematics with 5-DoFs for the shoulder joint (two displacements plus three rotations) and 1-DoF for the elbow. Gravity compensation is implemented with passive elastic elements to minimize weight and reduce cost. A detailed analytical tool is developed to support the designer in the preliminary design stage, investigating the exoskeleton kinetic-static behaviour and deriving optimal design parameters for the springs over the human arm workspace. By defining specific functional requirements (i.e., the user’s features and simulated movements), computationally efficient optimization studies may be carried out to determine the optimal coefficients and positions of the springs, thus, maximizing the accuracy of the gravity balancing. Two different solutions for the arrangement of the elastic elements are investigated, and obtained results are validated with a commercial multi-body tool for some relevant movements of the user’s arm.

Keywords: Arms | Design Optimization | Exoskeletons | Gravity | Gravity balancing | Kinematics | Shoulder | Springs | Task analysis | Upper Limb Exoskeleton | Virtual Prototyping | Wearable Devices

Abstract: The fourth industrial revolution is characterized by flexible production systems that can respond to the demand for high variability and customization of the product. To maintain the efficiency of the production process, automated and flexible solutions are mandatory. This paper describes an approach to design Virtual Prototypes of robotic cells and support designer in the definition and simulation of the manufacturing system. The identified model is capable of replicating the performance of the cell under different aspects in a holistic manner: geometry, operating logic, performance, and physical behavior. The design approach is demonstrated on a robotic cell composed of two anthropomorphic robots for the flexible process of automatic assembly of mechanical parts. The resulting model proves to be straightforward, accurate and complete.

Keywords: Digital Twin | Physics-based simulation | Robotic assembly | Virtual Prototype

Abstract: Numerical simulations and Finite Element Analysis (FEA) have currently increased their applications in medical field for making preoperative plans to simulate the response of tissues and organs. Soft tissue simulations, such as colorectal simulations, can be adopted to understand the interaction between colon tissues and surrounding tissues, as well as the effects of instruments used in this kind of surgical procedures. This paper analyses through FEA the interaction between a surgical device and a colon tissue when it is fully clamped. Sensitivity analysis in the respect of the material mechanical behaviour, geometric approximation and the effect of thickness variation are investigated with the aim of setting up a virtual prototype of the surgical operation to aid mentoring and preliminary evaluation via haptic solutions. Through this investigation, the force feedback estimation that is necessary in many virtual-reality applications, may be estimated without discharging nonlinear effects that occur during clamping and that usually cannot be simulated efficiently to guarantee real-time solutions. Results are aligned with experimental data, confirming the reliability and right the set-up of FEA. Through them, the preliminary set-up of a haptic force feedback has been described and simulated through Simulink 3D animation, confirming the feasibility of the concept.

Keywords: FEA | Force feedback | Haptic device | Metamodeling | Surgical simulation | Virtual prototyping

Abstract: Nowadays, restoration is a multidisciplinary work that gathers knowledge and skills from different areas (technical, artistic, historical, architectural, …). In the field of ancient bronze statues, technical knowledge may also concern with materials behaviour and its preservation, surface quality, non-destructive diagnostics for integrity, a better understanding of the manufacturing technology, and of details, sometimes hidden, in not directly accessible sections of the artefact. This knowledge, got from different domains, can support restorers in their decision-making process. In many cases, they summarise it on pictorial views of the artefacts, or on images derived from the 3D model that is experimentally acquired through reverse engineering, to reference information on the interested areas. The aim of this paper is to explore the advantages related to a CAD-based framework able to gather the technical domains involved in the restoration of historical artifacts. Doing so, CAD functionalities and related benefits may be extended to cultural heritage applications as tools oriented for restoration, according to a life cycle perspective of the restorer’s activities and the artefact preservation and fruition. The proposed CAD-based framework has been implemented to manage the investigation for restoration and conservation of bronze statues. The approach has been applied to the Principe Ellenistico, part of the collection of Palazzo Massimo, one of the sites of Museo Nazionale Romano (in Rome). The obtained results show that the CAD-based framework may speed-up the investigation processes without losing accuracy and restorers’ good practices.

Keywords: CAD-CAE | Cultural heritage | Design for restoration | Principe Ellenistico | Virtual prototyping

Abstract: The main aim of this article is to describe the design of a new sensor to study the electromagnetic field portions of gravitational waves. On August 17, 2017, the observation of the gravitational wave event started the era of multi-messenger astronomy. Therefore, new tools and optimal synchronization of the available telescopes are needed. The sensor that is designed is a cross-cutting technology, it is named Crystal Eye: a wide field of view in the energy field from 10 keV to 10 meV with a structure made of pixels. As the detector will be involved in the mission in 2023, the virtual prototype phase needed for optimization and production of the payload has been completed. Particular attention was paid to the results of the FEM analysis carried out to examine and predict the thermal and vibration behavior of the conceived mock-up during the launch phase and under strong temperature variations in the space environment.

Keywords: Detector | FEM | Vibration and thermal analysis | Virtual prototyping

Abstract: Intelligent robotic manufacturing cells must adapt to ever-varying operating conditions, developing autonomously optimal manufacturing strategies to achieve the best quality and overall productivity. Intelligent and cognitive behaviors are realized by using distributed controllers, in which complex control logics must interact and process a wide variety of input/output signals. In particular, programmable logic controllers (PLCs) and robot controllers must be coordinated and integrated. Then, there is the need to simulate the robotic cells’ behavior for performance verification and optimization by evaluating the effects of both PLC and robot control codes. In this context, this work proposes a method, and its implementation into an integrated tool, to exploit the potential of ABB RobotStudio software as a virtual prototyping platform for robotic cells, in which real robots control codes are executed on a virtual controller and integrated with Beckhoff PLC environment. For this purpose, a PLC Smart Component was conceived as an extension of RobotStudio functionalities to exchange signals with a TwinCAT instance. The new module allows the virtual commissioning of a complete robotic cell to be performed, assessing the control logics effects on the overall productivity. The solution is demonstrated on a robotic assembly cell, showing its feasibility and effectiveness in optimizing the final performance.

Keywords: robotic cell | RobotStudio | TwinCAT | virtual commissioning | virtual prototyping

Abstract: Understanding user experience (UX) is essential to design engaging and attractive products, so nowadays has emerged an increasingly interest in user-centred design approach; in this perspective, digital technologies such as Virtual Reality (VR) and Mixed Reality (MR) could help designers and engineers to create a digital prototype through which the user feedback can be considered during the product design stage. This research aims at creating an interactive Digital Twin (DT) using MR to enable a tractor driving simulation and involve real users to carry out an early UX evaluation, with the scope to validate the design of the control dashboard through a transdisciplinary approach. MR combines virtual simulation with real physical hardware devices which the user can interact with and have control through both visual and tactile feedback. The result is a MR simulator that combines virtual contents and physical controls, capable of reproducing a plowing activity close to reality. The principles of UX design was applied to this research for a continuous and dynamic UX evaluation during the project development.

Keywords: Digital Engineering | Digital Twin | Human-centered Design | Mixed Reality | User experience design

Abstract: Since every structure in the human body can vary, customization is important to choose the most appropriate medical option according to the patient. Total knee arthroplasty (TKA) is a surgical procedure for the knee replacement that has a high rate of patient's dissatisfaction. Indeed, conventional prostheses are based on anthropometric data that accommodate common knees. However, mismatch can occur due to anatomical variations among the individuals. Thanks to the advances in imaging techniques and 3D modeling, it is possible to create customized knee implants starting from medical images. In this context, the present research proposes a methodology to design a customized knee implant taking into account clinical (e.g., prosthesis alignment and surgical cuts) and technical parameters (e.g., materials) that have a direct impact on TKA performance and patient's satisfaction. Changing these parameters, different scenarios have been modeled and simulated to understand the most suitable combination. Finite element analysis (FEA) has been employed to simulate and compare the proposed customized models, changing the different clinical and technical parameters. Stress induced by different combinations of the parameters has been evaluated to choose the optimal solution among the eight proposed scenarios. The optimum is reached with a physiological alignment, with six femoral facets and the ultra-high molecular weight polyethylene (UHMWPE) tibial insert. The implant design maintains the natural joint line and allows preserving more bone. The material is the parameter that mostly influences the stress distribution.

Keywords: computer aided design | computer aided engineering | customized knee implant | femoral component optimization | finite element analysis | knowledge engineering | patient-specific knee prosthesis | total knee arthroplasty | virtual prototyping

Abstract: The protection of artistic and cultural heritage is a major challenge due to its peculiarities and its exposure to significant natural hazards. Several methodologies exist to assess the condition of artistic heritage and to protect it from exceptional actions. Moreover, novel digital technologies offer many solutions able to deliver a digital replica of artifacts of interest, so that a reduction in the uncertainties in the analysis models can be achieved. A rational approach to the preservation and protection of artistic heritage is based on traditional approaches supported and integrated by novel technologies, so that qualitative and quantitative indicators of the current condition of artistic heritage can be defined and validated in an interdisciplinary framework. The present paper reports the results of an approach to the maintenance and preservation of art objects housed in a museum complex based on a comprehensive digital path towards a Historical Digital Twin (HDT). A workflow aimed at estimating the stress regime and the dynamic properties of two sculptures, based on the detailed three-dimensional model resulting from a laser scanner survey, is illustrated and dis-cussed. The results highlight the great advantages resulting from the integration of traditional and novel procedures in the field of conservation of artistic assets.

Keywords: 3D simulation | Conservation | Cultural heritage | Digital twin | Laser scanning | Maintenance

Abstract: This paper introduces a novel upper limb robotic exoskeleton designed to assist industrial operators in a wide range of manual repetitive tasks, such as tool handling and lifting/moving of heavy items. Due to its reduced size and high maneuverability, the proposed portable device may also be employed for rehabilitation purposes (e.g. as an aid for people with permanent neuromuscular diseases or post-stroke patients). Its primary function is to compensate the gravity loads acting on the human shoulder by means of a hybrid system consisting of four electric motors and three passive springs. The paper focuses on the exoskeleton mechanical design and virtual prototyping. After a preliminary review of the existent architectures and procedures aimed at defining the exoskeleton functional requirements, a detailed behavioral analysis is conducted using analytical and numerical approaches. The developed interactive model allows to simulate both kinematics and statics of the exoskeleton for every possible movement within the design workspace. To validate the model, the results have been compared with the ones achieved with a commercial multibody software for three different operator’s movements.

Keywords: Computer aided design | Gravity balancing | Robotic arm | Upper limb exoskeleton | Virtual prototyping

Abstract: Beam-based Compliant Mechanisms (CMs) are increasingly studied and implemented in precision engineering. Straight beams with uniform cross section are the basic modules in several design concepts, which can be deemed as standard CMs. Their behavioral analysis can be addressed with a large variety of techniques, including the Euler–Bernoulli beam theory, the Pseudo-Rigid Body (PRB) method, the beam constraint model and the discretization-based methods. This variety is unquestionably reduced when considering nonstandard CMs, namely design problems involving special geometries, such as curve/spline beams, variable section beams, nontrivial shapes and contact pairs. The 3D Finite Element Analysis (FEA) provides accurate results but its high computational cost makes it inappropriate for optimization purposes. This work compares the potentialities of computationally efficient modeling techniques (1D FEA, PRB method and chained-beam constraint model), focusing on their applicability in nonstandard planar problems. The cross-axis flexural pivot is used as a benchmark in this research due to its high configurable behavior and wide range of applications. In parallel, as an attempt to provide an easy-to-use environment for CM analysis and design, a multi-purpose tool comprising Matlab and a set of modern Computer-Aided Design/Engineering packages is presented. The framework can implement different solvers depending on the adopted behavioral models. Summary tables are reported to guide the designers in the selection of the most appropriate technique and software framework. Lastly, efficient design procedures that allow to configure nonstandard beam-based CMs with prescribed behavior are examined with two design examples.

Keywords: CAD/CAE software framework | Compliant Mechanisms | Cross-axis flexural pivot | Design methods | Shape optimization | Virtual Prototyping

Abstract: This paper reports about the design of a bio-inspired compliant wrist, whose mobility (i.e. ulnar-radial deviation and flexion-extension) has been realized by employing two pairs of contact-aided Cross-Axis Flexural Pivots (CAFPs), actuated via remotely-placed servo-motors and tendon transmissions. The human wrist behaves differently when deflecting in clockwise or anticlockwise direction, both in terms of maximum angular deflection and passive stiffness. The device proposed hereafter aims at mimicking such natural asymmetry, while withstanding unexpected external loads. In order to fulfill these requirements, two contacts are included: (i) a pure rolling contact (named passive contact), achieved via a cam mechanism guiding the CAFP deflection and ensuring the wrist resistance to compressive loads; (ii) a purposely shaped contact pair (named active contact), acting on one beam of the CAFP so as to increase its stiffness. The design procedures and tools specifically developed for the wrist optimization are described. In the first step, a CAFP shape optimization is performed, followed by the synthesis of the active contact pair. In the second step, the centrodes are computed and then used to generate the passive contact profiles. At last, the third step focuses on the definition of the tendons routing. To prove the validity of the numerical models, a physical prototype of the wrist is produced and tested. Direct comparisons between simulations and experiments confirm the efficacy of the proposed design method.

Keywords: CAD/CAE multi-software framework | Compliant mechanism | Cross-axis flexural pivot | Robotic wrist | Shape optimization | Virtual prototyping

Abstract: This article reports the preliminary analysis and design of a novel 6 degrees of freedom, passive, upper limb exoskeleton for industrial applications. The aim is to conceive a wearable device to support workers in a vast range of repetitive tasks, offering an effective strategy to reduce the risk of injuries in production lines. The exoskeleton primary purpose is to compensate for the gravity loads acting on the human upper limb via the action of five springs. By reaching the static balancing through the use of passive elements only, several advantages in terms of reduced weight and cost can be provided. In this scenario, a detailed analytical approach has been developed to study the exoskeleton statics and synthesize the springs within the human upper limb workspace. In particular, a 3R balancer is designed for the exoskeleton shoulder joint and a set of computationally efficient optimization studies are carried out to determine the optimal coefficients and positions of the springs. The obtained results have been validated with a commercial multibody tool.

Keywords: Design Optimization | Gravity Balancing | Upper Limb Exoskeleton | Virtual Prototyping | Wearable Devices

Abstract: The massive presence of plastic in the oceans, both in the form of large debris and micro-plastic, is raising global concern due to its severe effects on the marine environment and fauna, causing loss of biodiversity and potentially threatening human health. Even though this is due to poor waste management, the great production and consumption of single-use plastic is a significant exacerbating factor. Despite policies and bans can be effective measures, there is also the need to raise consumers’ awareness, so they can make more sustainable choices when purchasing, using, and dismissing products. In particular, educating young citizens and encouraging them to engage in pro-environmental behaviors is a fundamental task to reach this goal. In this work, we present Contact from the future, a digital game on plastic pollution for children, to create awareness and stimulate pro-environmental behaviors, discussing the definition of objectives and requirements, as well as the design and development of the application.

Keywords: Human computer interfaces/interactions | Virtual and augmented reality environments | Virtual prototyping

Abstract: Obstructive sleep apnea syndrome (OSAS) is a sleep disorder that causes pauses in breathing or periods of shallow breathing during sleep. Mandibular advancement devices (MADs) represent a non-invasive treatment for OSAS that has had the highest development in recent years. Nevertheless, literature has not primarily investigated the effects of mandibular advancement. This paper presents a finite element method numerical simulation model for evaluating the stress/strain distribution on the temporomandibular joint (TMJ) and periodontal ligaments caused by advancement devices used for the treatment of OSAS. Results highlight that the mandible lift phase generates significant stress values on TMJ, which cannot be neglected for extended usage of MADs. Furthermore, mandible molar teeth are more loaded than incisor ones.

Keywords: Computer-Aided Design | Finite element method | Mandibular advancement device | Obstructive Sleep Apnea Syndrome | Virtual prototyping

Abstract: Latest trends and developments in digital technologies have enabled a new manufacturing model. Digital systems can monitor, optimize and control processes by creating a virtual copy of the physical world and making decentralized decisions. This paradigm relies on the development of a digital counterpart, the Digital Twin, for each production resource taking part to the whole manufacturing process. Although real applications of Digital Twin may differ in technical and operational details, in the past years, a huge effort has been done in order to identify and define focal functionalities and properties, as well as main challenges for the practical implementation within real factories. This paper is intended to review and analyse principles, ideas and technological solutions of the Digital Twin vision for production processes focusing on the practical industrial implementation. The purpose of this document is therefore to summarize the current state-of-art on Digital Twin concepts, and to draw their up-to-date state for application and deployment in real industrial processes. Finally, future directions for further research are discussed.

Keywords: Digital twin | digital twin industrial architecture | industrial implementation | industry 4.0 | smart manufacturing

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: Within the era of smart factories, concerning the ergonomics related to production processes, the Digital Twin (DT) is the key to set up novel models for monitoring the performance of manual work activities, which are able to provide results in near real time and to support the decision-making process for improving the working conditions. This paper aims to propose a methodological framework that, by implementing a human DT, and supports the monitoring and the decision making regarding the ergonomics performances of manual production lines. A case study, carried out in a laboratory, is presented for demonstrating the applicability and the effectiveness of the proposed framework. The results show how it is possible to identify the operational issues of a manual workstation and how it is possible to propose and test improving solutions.

Keywords: Digital Twin | Ergonomics | Manufacturing | Production process

Abstract: The research on the use of virtual reality (VR) in the design domain has been conducted in a fragmentary way so far, and some misalignments have emerged among scholars. In particular, the actual support of VR in early design phases and the diffusion of practices involving VR in creative design stages are argued. In the present paper, we reviewed VR applications in design and categorized each of the collected 86 sources into multiple classes. These range from supported design functions to employed VR technologies and the use of systems complementing VR. The identified design functions include not only design activities traditionally supported by VR, such as 3D modelling, virtual prototyping, and product evaluation, but also co-design and design education beyond the early design phases. The possibility to support early design phases by means of VR is mirrored by the attention on products that involve an emotional dimension beyond functional aspects, which are particularly focused on in virtual assemblies and prototypes. Relevant matches between VR technologies and specific design functions have been individuated, although a clear separation between VR devices and supported design tasks cannot be claimed.

Keywords: 3D modelling | Co-design | Early design phases | Engineering design | Industrial design | Product design | Product evaluation | Technological development | Virtual prototyping | Virtual reality

Abstract: Eco-design strategies aim to integrate environmental considerations into product design and development. Several regulations, directives and standards have been issued on this topic during last years. In particular, European Directive (2009/125/EC) establishes the eco-design requirements related to domestic and commercial kitchen appliances (e.g. cookers, hobs, grills). The present paper focuses on the virtual product eco-design of domestic induction heating cookers, which are becoming one of the leading cooking systems due to their advantages, e.g. energy efficiency, rapid heating, cleanliness, and user safety. The adoption of numerical analysis tools for the simulation of cooktops use phase, based on thermodynamic modelling, allows to provide useful information regarding the performance of cooking system at each phase of cooking. The paper provides a progress beyond the state-of-art on thermodynamic models for induction hob simulation considering interaction between the cooktop and the pot in the work environment. The goal of the paper is therefore to propose a methodology able to support designers in evaluating heating performances of induction cooking appliances, early in the design phases, through a virtual and multi-physical product model. Thermodynamic performances are determined by measuring several parameters and reproducing the energy consumption test by the mean of a virtual prototyping tool. Results highlight how the proposed model is adherent with the real tests following a specific standard in this sector with a maximum deviation of 3.2% considering the different cooking pot sizes.

Keywords: Design methodology | Eco-design strategies | Virtual Prototyping

Abstract: A robust machine health state recognition tool is a pillar for condition-based maintenance and Deep Learning approach finds its natural application in such a context. This paper investigates the recognition of machine failures by image classification through a convolutional neural network in a condition-based maintenance environment. The case study involves a refrigerator for large retail establishments. Experimental measures, while the machine is approaching failure, are difficult to be collected, especially in the quantity needed for training and testing the neural network. For this reason, a digital twin of the asset has been created to simulate the behavior of the machine and generate as many data as needed: physically-based models of the machine and failure modes have been included and the simulated behavior has been tuned by using experimental data. Finally, it has been employed to generate signals that, translated into images, test the suitability of the neural network.

Keywords: Condition based maintenance | Digital twin | Image classification | Neural network

Abstract: Simulation tools for liquid composite molding processes are a key to predict and solve manufacturing issues of composite materials. Numerical processes are commonly used to analyse and predict mould filling, considering also resin cure and exothermic reactions. These evaluations are usually performed through dedicated software tools that require highly specialized operators and purchasing costs. The present study relates to a multi-objective optimization approach for evaluating the effect of different process parameters of the resin transfer molding (RTM) process using a multi-purpose tool. Starting from a simple case, useful for analysing the effect of mesh type and size on the simulations, and then increasing the complexity of the models, virtual simulations have been validated through real tests. Afterward, this approach has been used for the optimization of the RTM process for the manufacturing of an automotive component. Gate positions, injection pressure and resin temperature have been optimized using finite-volume analysis with a multi-objective genetic algorithm. Finally, the parameters have been used in real experiments in order to validate the efficiency and the reliability of multi-purpose tool in simulating RTM processes.

Keywords: Multi-objective optimization | Process simulation | RTM | Virtual prototyping

Abstract: In this paper, an original approach for the virtual prototyping of composite pressure tanks is proposed. The main tests to be conducted for the homologation of the vehicle tank is the burst pressure, which is a quasi-static test. This method aims to reduce the finite element model development time by the integration between the computational software MATLAB and the FEA tool Abaqus. Since the dome shape has fundamental influence on the mechanical performances of the composite pressure vessel, the presented procedure allows the designer to quickly import the suitable dome geometry into Abaqus, without the need of going through CAD software. The first step of the method here reported is the definition of all the geometric and operational parameters necessary to the construction of the dome meridian profile. The second step is to enter those parameters in a MATLAB script, which is able to integrate the dome profile differential equation, to generate the whole tank profile and to import this profile into Abaqus. Once the geometry has been imported, a FE model of the high-pressure vessel can be built and virtual simulations can be performed. This approach could be implemented in a dome optimization process to find which dome meridian profile gives the best tank performances.

Keywords: Composite Vessels | Filament Winding | Virtual Prototyping

Abstract: Deburring operations are critical to automate when high quality is required, due to the unpredictable presence and variable thickness of burrs that necessitate singular optimized process planning. Industrial anthropomorphic manipulators could effectively perform high quality deburring operations, but still lack the intelligence needed to generate quality and time-optimal deburring cycles. This paper presents a novel architecture of Zero Defect intelligent deburring robotic cells. Vision systems and metrological sensors allow the identification of the burrs and the overall quality and pose of the workpiece, while a novel model-based supervisory control, based on a digital twin, automatically calculates the optimal sequence of operations and working parameters needed to achieve the desired quality, generating also the PLC and robot controllers validated code to perform each task. Finally, the prototype of the proposed Zero Defect intelligent deburring cell has been developed.

Keywords: Digital twin | Engineering methods | Industry 4.0 | Robotic manufacturing | Virtual prototyping | Zero defect 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: At present, energy consumption strongly affects the financial payback period of industrial robots, as well as the related manufacturing process sustainability. Henceforth, during both design and manufacturing management stages, it becomes crucial to assess and optimize the overall energy efficiency of a robotic cell by means of digital manufacturing tools. In practice, robotic plant designers and managers should be able to provide accurate decisions also aimed at the energy optimization of the robotic processes. The strong scientific and industrial relevance of the topic has led to the development of many solutions but, unfortunately, state of the art industrial manipulators are equipped with closed controllers, which heavily limit the feasibility and performance of most of the proposed approaches. In light of the aforementioned considerations, the present paper presents a novel simulation tool, seamlessly interfaced with current robot offline programming tools used in industrial practices, which allows to automatically compute energy-optimal motion parameters, thus reducing the robot energy consumption, while also keeping the same productivity and manufacturing quality. The main advantage of this method, as compared to other optimization routines that are not conceived for direct integration with commercial industrial manipulators, is that the computed parameters are the same ones settable in the robot control codes, so that the results can automatically generate ready-to-use energy-optimal robot code. Experimental tests, performed on a KUKA Quantec KR210 R2700 prime industrial robot, have confirmed the effectiveness of the method and engineering tool.

Keywords: Automatic code generation | Energy optimization | Industrial robotics | Industry 4.0 | Robot offline programming | Sustainable manufacturing | Virtual prototyping

Abstract: Robotic deburring (RD) still requires long and delicate physical tests to tune the process-parameters, thus drastically reducing the robotic cell productivity. Henceforth, engineering methods and tools are needed to optimise the RD application within a virtual environment, replicating the real behaviour of the robot tooling under different process conditions, namely unpredictable variety of burr size/shape and limited accuracy of the robot motions. To this purpose, the spindle compliance, which plays a fundamental role, is unfortunately not evaluated by state-of-the-art simulation tools. The present paper proposes a virtual prototype (VP) of a radially-compliant spindle, suitable to assess and optimise the deburring efficiency in different case scenarios. A multi-body model of the spindle, integrated with the process behavioural model, predicts process forces and optimal deburring parameters, delivering the contour maps of the envisaged deburring error as function of feed rate and tool compliance. An industrial case-study is provided.

Keywords: parameter design | passively compliant spindle | robotic deburring | virtual prototyping

Abstract: Interventions of ancient bronze statues restoration may last long periods, involving several activities from material and structural analysis to set-up of museum exhibitions, passing through reconstruction of fragments. In this paper, we describe procedures and methods used for evaluation of the current posture of “Principe Ellenistico”. In fact, the statue seems to present some inaccuracies, in the fragments assembly, made during the last restoration activity (one of this effect is clearly observed in the spear inclination). The final aims are: (1) evaluation of differences among the postures before and after the last restoration; (2) recognition of the original fragments embedded in a previous restoration; and (3) the study of a possible better positioning of them. Methods applied are related to feature recognition on acquired point clouds, image analysis through control points and algorithms to find centerline of the elements that could need to be repositioned. In the final part, a concept design for a new inner-support is presented, giving the possibility to avoid assembly inaccuracies. Future developments are presented as the prospect of additive manufacturing the support, firstly with a FDM prototype and then through SLM or similar technologies.

Keywords: 3D-reconstruction | Bronze statue restoration | Cultural heritage | Feature recognition | Virtual prototyping

Abstract: Virtual, Augmented and Mixed Reality technologies are more and more getting attention from tourism researchers and professionals, because of their recognized potential to support marketing activities. The paper describes the development of a multisensory environment thought for a travel agency, which combines visual, auditory, tactile and olfactory stimuli. The idea is to develop an experience able to provide a virtual preview of the desired holiday destination, resulting in both an attractive experience for the customer and an effective way to increase sales. A case study about the multisensory experience of a walk on Italian Alps has been developed. The multisensory experience is based on a video streaming, recorded in the real environment, synchronously matched with a haptic interface. The haptic interface is made up of a pair of slippers provided with actuators, and also an actuator positioned on the customer trunk, used to reproduce the feeling of a snowball hit. Moreover, an olfactory display is also used to provide pine smell during the walk. During the experience, the user is sitting on a yoga ball, whose inclination allows him/her to start and stop the multisensory virtual experience.

Keywords: Multisensory simulation | User experience | Virtual prototyping | Virtual tourism

Abstract: This paper describes the application of a novel virtual prototyping methodology to wind turbine blade design. Numeric modelling data and experimental data about turbine blade geometry and structural/dynamical behaviour are combined to obtain an affordable digital twin model useful in reducing the undesirable uncertainties during the entire turbine lifecycle. Moreover, this model can be used to track and predict blade structural changes, due for example to structural damage, and to assess its remaining life. A new interactive and recursive process is proposed. It includes CAD geometry generation and finite element analyses, combined with experimental data gathered from the structural testing of a new generation wind turbine blade. The goal of the research is to show how the unique features of a complex wind turbine blade are considered in the virtual model updating process, fully exploiting the computational capabilities available to the designer in modern engineering. A composite Sandia National Laboratories Blade System Design Study (BSDS) turbine blade is used to exemplify the proposed process. Static, modal and fatigue experimental testing are conducted at Clarkson University Blade Test Facility. A digital model was created and updated to conform to all the information available from experimental testing. When an updated virtual digital model is available the performance of the blade during operation can be assessed with higher confidence.

Keywords: Composite materials | Design | Digital twin | Finite element method | Modelling and simulation | Wind turbine

Abstract: Molding is one of the most widely used processing technologies in manufacturing. Among typical molding parameters, the mold temperature is a critical one for the quality of the molding process. A solution to this issue can be the employment of induction heating which, through a high-frequency electromagnetic field, produces eddy currents and a consequent rapid heating of the material into the cavity of the mold. The necessity to maintain the mold walls at the operative temperature makes the induction heating to be one of the most efficient non-contact means of heating. In fact, induction heating is characterized by quickness, efficiency, and energy saving; however, the design and the sizing of an induction heating system is complex due to different parameters involved in the electromagnetic and thermal phenomena. In this context, the paper aims to define a methodology to support engineers in the design and sizing of an induction heating system for molds, taking as case study a mold for composite parts. A model-based approach is proposed to analyze and simulate the mold heating, considering three different levels of modelling: Analytical (0D), Finite-Difference Methods (2D) and Finite Element Methods (3D). The Analytical approach investigates the solution of the physical equations applied to the volume of the material involved. Instead, the Finite-Difference approach (2D) solves the heat transfer problem by discretizing the domain and by solving for temperature at discrete points. Finally, the Finite Element method (3D) solves partial differential equations on a 3D discretized domain.

Keywords: Epoxy-Based carbon fiber prepregs | Induction heating | Model-Based simulations | Mold heating | Resin curing | Virtual prototyping

Abstract: Nowadays, design processes demand agile and flexible tools and methods to meet market needs. Virtual prototyping techniques are widespread in design strategies and practices, because these technologies reduce the project development lead-time and cost related to physical prototyping. The aim of this paper is the study and application of an approach for the modeling, simulation and geometrical optimization of fans for gas turbine air supply. Fan is a type of machine used to move a fluid, typically a gas such as air, exploiting the kinetic energy of a rotating impeller. It consists mainly of two components: housing and rotor. There is extensive literature on the design and optimization of industrial fan, but main works refer to a small or medium standardized fan, where it is possible to study many parameters and perform many experimental tests. The paper presents an approach for the efficiency optimization of large and customizable centrifugal industrial blowers for gas turbine air supply. The design variables investigated in this study were the blades quantity, orientation and shape. The proposed optimization method has been used for the design optimization of a blower for gas turbine power plant. The response surfaces allowed defining correlation between design variables and efficiency. The optimized design was 18 % more efficient than the original one.

Keywords: Computer aided engineering | Genetic algorithms | Geometric optimization | Industrial fan | Response surface methodology | Virtual prototyping

Abstract: Recently, human-centered design has become one of the most promising approaches for improving the entire production process design. During the design phase, among the main important aspects to investigate, ergonomic performance of the workplace (WP) plays a key role. It is well known that design errors can lead to significant delays in the design and engineering of a production process, especially when it is related to a complex system such as the assembly line of an automotive industry. Prediction of the ergonomic performance, which is often coarsely considered during the design phase, can represent a fundamental step in preventing ergonomic issues since the early design phase of a production process, avoiding also negative consequences on line balancing. Based on a concurrent engineering (CE) approach, the aim of this paper is to present a framework that uses digital twins of stations in order to minimise the time necessary to develop and design a new assembly line. The application of this procedure will allow avoiding the possibility of realising a line that reveals ergonomic problems and correcting design errors during the design phase and not just during the production phase. In this way, it is possible to achieve great advantages in terms of cost avoidance for the correction of the design errors and in terms of time to market, which will be significantly reduced. A digital twin of a real station of a Fiat Chrysler Automobiles (FCA) assembly line is presented to validate the numerical procedure and the design approach proposed in this paper. Finally, numerical results, regarding the evaluation of an ergonomic index, were compared with experimental ones achieved by analysing data collected during an experimental session.

Keywords: Digital twin | Ergonomics | Human-centered design | Managerial methodological framework | Simulation

Abstract: Automation plays a key role in the realisation of the Factory 4.0 and technological research, combined with the use of innovative materials, contributes to the improvement of products in terms of functional, technical and production quality. Within this context, the so-called Digital Twin allows to reproduce the real behaviour of a production system in a virtual environment, giving the possibility to numerically perform the desired analysis. Human-robot interaction (HRI) is increasing in those workplaces where the manual activity is not safe nor efficient in terms of performance (e.g. cycle time) and it is characterised by several levels of interaction (cooperation, collaboration and coexistence). The aim of this paper is to propose a numerical procedure that, based on the simulation, allows verifying the process feasibility, validating the interaction between human and robot and programming the logic controller to be implemented on the real robot. A case study about assembling of composite components of an aircraft fuselage panel is proposed. The use of the robot allows to speed up the processes of drilling and sealing, leaving to human less dangerous operations.

Keywords: Composite Assembly | Digital Twin | Robot | Simulation

Abstract: Effective identification of the optimal design in the early stages of product development is critical in order to obtain the best chances of eventual customer satisfaction. Currently, the advancements in prototyping techniques offer unique chances to evaluate the features of different design candidates by means of product experts acting as assessors and/or customers enrolled as testers. In this paper, the candidate identification using virtual and physical prototypes is described and a practical fuzzy approach toward the evaluation of the optimal design is presented. The proposed methodology is tested on a full case study, namely the choice of optimal design for the traditional Neapolitan coffeemaker, inspired by the prototypes of the Italian designer Riccardo Dalisi. Several concepts are developed in a virtual environment and four alternatives among them are realized using Additive Manufacturing. By allowing experts to interact with virtual and physical prototypes, they were able to express their opinion on a custom fuzzy evaluation scale (i.e. they were freely choosing more or less coarse linguistic scales as well as the related shapes of fuzzy sets to adequately represent the level of fuzziness of their judgments). Once the opinions are collected, the set of best candidate(s) is easily identified and useful suggestion can be obtained for further developing the product.

Keywords: Additive manufacturing | Concept design | Concept selection | Design method | Fuzzy set | Virtual prototyping

Abstract: Despite the widespread use of reverse total shoulder arthroplasty, the fundamental effects of implant configuration on certain biomechanical outcomes have not been completely elucidated especially for the most innovative prostheses. Aim of this work is to investigate the behaviour of a new reverse shoulder prosthesis, characterized by a humeral tray with a variable offset, designed to increase the range of motion and to reduce the impingement. The purposes of this study were to evaluate the effect of reverse shoulder implant design parameters on the deltoid muscle forces, required to produce abduction, and on the shoulder range of motion, in order to provide a more systematic understanding of the fundamental effects of humeral component positioning on the implant performances. The study has been implemented using virtual prototypes of the shoulder-prosthesis assembly. The shape of the prosthesis has been digitally acquired via a 3D scanner and the CAD models of all the components have been created. Through CT images, 3-dimensional models of the shoulder bones have been reconstructed and assembled with the prosthesis components. Numerical FEM models have been set up in order to evaluate how the abduction force changes depending on the humeral tray offset. Using the virtual prototypes of the shoulder-prosthesis assembly, a range of motion analysis has been carried out by setting up a collision detection analysis in a 3D parametric modeling environment. Different humeral tray positions were investigated and four different motions of the arm were simulated. Obtained results have demonstrated that a suitable positioning of the humeral tray can offer significant biomechanical advantages in terms of range of motion and abduction force.

Keywords: CAD | FEM | Reverse engineering | Reverse shoulder prosthesis | Virtual prototyping

Abstract: Both physical and virtual prototyping are core elements of the design and engineering process. In this paper, we present an industrial case-study in conjunction with a collaborative agile design engineering process and "methodology." Four groups of heterogeneous Post-doc and Ph.D. students from various domains were assembled and instructed to fulfill a multi-disciplinary design task based on a real-world industry use-case. We present findings, evaluation, and results of this study.

Keywords: Augmented reality (AR) | Collaborative design | Engineering design | Virtual prototyping | Virtual reality (VR)

Abstract: Lightweight engineering is a current topic in mechanical industry. The mass reduction is a common design objective to reduce product cost and environmental impacts. Virtual prototyping tools are widely applied to study new lightened solutions and check the compliance with regulations and standards. However, an integrated approach, involving simulations and life-cycle analysis, is necessary to support design optimization and decision-making. The scope of this study concerns the definition of an Ecodesign approach to support the lightweight engineering of cast iron parts through the redesign of the product shape. In particular, this paper deals with the optimization of a ductile cast iron manhole. The test case shows a redesign method which considers structural analysis with environmental impacts. The structural analysis has been evaluated using a finite element method tool. In particular, the simulation results have been compared and validated with physical tests. The environmental analysis is based on the methodology provided by the standardized ISO 14040:2006 and ISO 14044:2006. The proposed LCA study considers the phases of manufacturing and transport related to one ductile iron product. The described manufacturing phase is related to a Chinese foundry which produces roughly 12,000 tons of ductile cast-iron castings. The results show the possibility to achieve about 20% of mass reduction for one casting. Considering such mass decreasing, the related reduction in terms of carbon emission is about 7%. Summarizing, this paper shows a design approach to integrate the structural improvements with the reduction of the environmental impacts related to a lighter weight casting.

Keywords: Cast ductile iron | Design optimization | Life-cycle assessment | Lightweight engineering | Manhole | Virtual prototyping

Abstract: Nowadays, product configuration and optimization are very important topics in several industrial applications such as the manufacturing of Engineered-to-order (ETO) products, where there is a fierce increase in market competition. The product configuration allows past design solutions to be reused and new product variants to be defined and pre-designed. However, the delivery of new configurations of products requires a technical feasibility analysis before closing the contract of the order with the customer. There is a lack of commercial tools which can support the designer from the early configuration phase to the product optimization with the automatic generation of geometric models and simulations. While traditional software tools can be used for the product configuration, with automation in the CAD modeling, other ones can combine optimization algorithms with numerical simulations. However, the combination of all these design levels requires the development of a dedicated platform tools. The research aims to reduce time and cost related to the early design phase of an oil & gas system, focusing on gas turbine ducts. The paper proposes a methodological approach to integrate the design optimization with the product configuration using Model-Based simulations to verify the technical feasibility and to optimize the product design. As a test case, the early design of a gas turbine chimney is proposed.

Keywords: Model-Based simulation | oil & gas | Product configuration | Product optimization | Virtual prototyping

Abstract: Nowadays, several consumer goods are sold with an energy label which provides energy information about consumption, efficiency, noise, and performance. These labels are regulated by local energy policy and governments. Because of this, customers are becoming increasingly aware about the energy efficiency and consumption of products such as household appliances. In Europe, several household appliances are involved in the European Energy Labelling Directive. Therefore, the manufacturers are paying attention to Ecodesign tools and methods to support the development of eco-innovation and sustainable products. In this context, the paper proposes a design methodology to support the development of efficient cooker hoods using an approach based on a constraints satisfaction problem model. The scope of the proposed research is to reduce the time-to-market of household appliances considering the energy efficiency optimization from the early design phases to the embodiment design. A Case Based Reasoning is also implemented to define a pre-configured model of product before the CSP optimization. The CSP model has been developed as an analytical system, which can predict the energy label achieved by a final prototype of a cooker hood. The interaction of such tools can fill the gap between traditional design methods and eco-innovation approaches, in order to support the designer in the decision-making activity. The test case shows a cooker hoods optimization based on a CSP tool, developed using a programming framework based on Gecode platform.

Keywords: Case-based reasoning | Constraints satisfaction problem | Design optimization | Ecodesign | Energy label | Virtual prototyping

Abstract: Design optimization is a common practice in industry. Different mathematical algorithms have been developing to support the optimization in engineering design. The integration between optimization methods and simulations is an interesting issue in engineering design. A typical optimization workflow can include simulation steps; however, the Virtual Prototyping analysis is more time-consuming than analytical calculations. The study of Constraints Satisfaction Problems is a mathematical topic which can be applied for solving engineering issues in design. The strength of this approach is the velocity on searching the satisfied solutions. This paper proposes a design methodology which considers the use of CSP models and calculation tools to optimize the sizing of columns and beams in the design of a steel structure. The calculation tools regard analytical models and numerical analysis. While the analytical approach regards the computing of cost and weight, the numerical analysis is used to verify and check the engineering performance in terms of deformation and stress state. A customized application, based on MiniZinc platform, has been developed and proposed to solve the CSP model for a test case steel structure. The CSP problem has been limited to the calculation of analytical constraints such as cost and weight. Finally, the resultant set of solutions has been evaluated using numerical solution to complete the optimization analysis.

Keywords: Constraints Satisfaction Problems (CSP) | MiniZinc | Optimization | Steel Structures | Virtual Prototyping

Abstract: The paper defines a framework called virtual eco-design aiming to support designers and engineers in the development of sustainable energy-related products. Virtual prototyping is used to perform energy consumption tests according with ecodesign and energy label regulations. The goal is to build a knowledge-based repository in which virtual tests are stored and classified to create eco-knowledge. Induction hob has been analysed to verify the applicability of the approach and the integration in a traditional product development process. Results highlight how the proposed methodology increases company eco-knowledge providing a tangible support in the definition of energy-label compliant products.

Keywords: eco-design | eco-knowledge | energy labelling | energy-related products | virtual prototyping

Abstract: In this article, the information value is used in numeric analysis as both a method for data approximation and a measure of data equality among a set of values. To this end, a surface segmentation, based on a study for constructing a hierarchy for vectors clustering using certain similarity criteria, is presented. The technique is based on the analysis of vectors representing regions associated with given types of critical points. An approach based on the Max Entropy in Metric Space (MEMS) is introduced in the paper, in order to extract a cluster of local features and to obtain an analysis of mechanical systems in the 2D and/or 3D spaces. The approach proposed in the paper can be effectively used in virtual prototyping and optimal designing of mechanical systems.

Keywords: Computer Aided Design (CAD) | Max Entropy in Metric Space (MEMS) | Maxinf principle | Multibody Mechanical Systems (MBS) | Optimal design | Virtual prototyping

Abstract: Industrial process plants are increasingly becoming complex structures with high level of automation. Nonetheless, the final plant productivity and the overall equipment efficiency does not solely depend on an optimized engineering design/installation practice, but also on human operators supervision. In parallel, along with the classic demand to minimize costs and time-to-market during the design phases, issues concerning human safety and failure prevention play a crucial role, one of the highest target being the avoidance of dangerous process states. Within this context, Simulation-Based-Training (SBT) allows plant operators to learn how to command complex automated machineries within a secure virtual environment. Similar to its usage in medical, aerospace, naval and military fields, SBT for manufacturing systems can be employed in order to involve the user within a realistic scenario, thus providing an effective, lifelike, interactive training experience under the supervision of experienced personnel. In addition, also according to previous literature, industry-driven SBT may be effectively envisaged as a natural extension of the plant life-cycle simulation practice, comprising Design Simulation & Optimization, Virtual Commissioning, Operator Training, up to Plant Maintenance. In this context, since the overall system behavior depends both on manufacturing process dynamics and Control Logics, the main challenge for an effective SBT is related with the development of a real-time environment where control system responsiveness is fully reproduced. Owing to this consideration, this paper reports a successful industrial case study, concerning a novel SBT workbench used for steel plants operator training, discussing both the virtual prototyping phase and the development of a real-time simulation architecture. In particular, a hybrid process simulation is employed, where a virtual process model is coupled with physical PLC and Human–Machine Interface, thus achieving an accurate reproduction of the real plant/operator interaction.

Keywords: Hybrid virtual/physical simulation | Industrial case study | Simulation-based-training | Virtual commissioning | Virtual prototyping

Abstract: Virtual prototyping enables the validation and optimization of mechanical devices similar to physical testing, saving time and costs in the product development, especially in case of heavy machines with complex motions. However, virtual prototyping is usually deployed only at the end of the design process, when the product architecture has already been developed. The present paper discusses the introduction of virtual prototypes since the conceptual design stage as “Virtual Concepts”, in which coarse models of machinery design variants are simulated to interactively evaluate several solutions and support best design choices. Virtual concept modeling and interactive preliminary validation, along with its later integration into a virtual prototype, are expressly investigated using multi body dynamics software. A verification case study concerning a large vibrating screen is presented, in order to demonstrate that dynamic virtual concepts can enable an easier and effective interactive evaluation of the design variants, thus increasing the design process predictability. Finally, current challenges to be solved for the practical adoption of virtual concept simulations as an integral part of the industrial design process are critically discussed.

Keywords: CAD based simulation | Design process | Vibrating screen | Virtual concepts | Virtual prototyping

Abstract: The actual use of Industrial Robots (IR) for assembly systems requires the exertion of suitable strategies allowing to overcome shortcomings about IR poor precision and repeatability. In this paper, the practical issues that emerge during common “peg-in-hole” assembly procedures are discussed. In particular, the use of passive Remote Center of Compliance (RCC) devices, capable of compensating the IR non-optimal performance in terms of repeatability, is investigated. The focus of the paper is the design and simulation of a flexure-based RCC that allows the prevention of jamming, due to possible positioning inaccuracies during peg insertion. The proposed RCC architecture comprises a set of flexural hinges, whose behavior is simulated via a CAE tool that provides built-in functions for modelling the motion of compliant members. For given friction coefficients of the contact surfaces, these numerical simulations allow to determine the maximum lateral and angular misalignments effectively manageable by the RCC device.

Keywords: Compensation Strategies | Compliant Flexures | Peg-in-hole assembly | RCC Device | Robotic assembly | Virtual Prototyping

Abstract: According to recent researches, it is desirable to extend Industrial Robots (IR) applicability to strategic fields such as heavy and/or fine deburring of customized parts with complex geometry. In fact, from a conceptual point of view, anthropomorphic manipulators could effectively provide an excellent alternative to dedicated machine tools (lathes, milling machines, etc.), by being both flexible (due to their lay-out) and cost efficient (20-50% cost reduction as compared to traditional CNC machining). Nonetheless, in order to successfully enable highquality Robotic Deburring (RD), it is necessary to overcome the intrinsic robot limitations (e.g. reduced structural stiffness, backlash, time-consuming process planning/optimization) by means of suitable design strategies and additional engineering tools. Within this context, the purpose of this paper is to present recent advances in design methods and software platforms for RD effective exploitation. Focusing on offline methods for robot programming, two novel approaches are described. On one hand, practical design guidelines (devised via a DOE method) for optimal IR positioning within the robotic workcell are presented. Secondly, a virtual prototyping technique for simulating a class of passively compliant spindles is introduced, which allows for the offline tuning of the RD process parameters (e.g. feed rate and tool compliance). Both approaches are applied in the design of a robotic workcell for high-accuracy deburring of aerospace turbine blades.

Keywords: Engineering methods | Industrial robotics | Intelligent factory | Virtual prototyping

Abstract: In Europe, kitchen hoods currently come with an energy label showing their energy efficiency class and other information regarding the energy consumption and noise level, as established by the European Energy Labelling Directive. Because of recent regulations, designs of cooker hoods must consider new issues, such as the evaluation of the energy efficiency, analysis of the energy consumption, and product lifecycle impact. Therefore, the development of eco-driven products requires Ecodesign tools to support eco-innovation and related sustainability improvements. The scope of the proposed research is to define a method and an agile and affordable platform tool that can support designers in the early estimation of product energy performance, including the calculation of energy efficiency indexes. The approach also considers the use of genetic algorithm methods to optimize the product configuration in terms of energy efficiency. The research context concerns large and small productions of kitchen hoods. The paper describes the methodological approach within the developed tool. The results show a good correlation between real efficiency values and calculated ones. A validation activity has been described, and a test case shows how to apply the proposed approach for the design of a new efficient product with an A-class Energy Efficiency Index.

Keywords: Ecodesign | Energy label | Knowledge-based engineering | Optimization | Product configuration | Virtual prototyping

Abstract: During recent years the European Ecodesign Directive has introduced big changes in the design methodology of several energy-using products including consumer goods such as ovens, washing machines and kitchen hoods. Additionally, the introduction of the Energy Labelling Directive pushes manufacturers to implement new energy-saving features in many energy-related products sold in Europe. As a consequence, several companies have been encouraging the improvement of their energy using products paying attention to the related selling cost. Eco-driven products require eco-design tools to support the eco-innovation and the related sustainability improvement. The main scope of the proposed re-search is the reduction of the time-to-market for the energy-using products such as kitchen hoods. In this context, the paper aims to provide an approach to support a pre-evaluation of the energy labeling related to kitchen hoods. A prototypical software tool has been developed in order to simulate the energy performance of new kitchen hood configurations in term of energy efficiency. The approach also considers the introduction of virtual experiments in order to calculate the performance of virtual modules. This tool makes the product-engineer more aware in the decision-making about the energy-saving. As a test case, different product configurations have been compared analyzing the energy labelling and the overall energy performance.

Keywords: Ecodesign | Energy efficiency labeling | KBE | Kitchen hoods | Virtual prototyping

Abstract: The scope of the present research is the reduction of cost and time related to the design, prototyping and testing of a Li-ion battery pack, which is used in commercial full electric vehicles using tools for rapid product configuration and simulation. This objective is particularly important for small companies that produce many different batteries in small lots. To develop the product design support system, a preliminary study was necessary. A 3D model was analyzed to simulate real thermal behavior, reproducing a real electric load using a standard ECE-15 cycle. Experimental tests have been conducted on the vehicle and battery to validate the model. An analytical thermal model was developed to evaluate the heat generated by electrochemical reactions inside a Li-ion cell. The outcome of this analytical model was used as the boundary condition in the CFD simulation of the battery model to evaluate the cooling behavior. The rules and results deduced from these studies have allowed the implementation of an easy-to-use knowledge-based configuration tool that supports the designer in the definition of the layout of the battery pack to save time and evaluate costs. As a test case, the battery for an urban freight vehicle was designed using the proposed approach. The achieved results show good performance and robustness of the simplified approach in terms of temperature distribution evaluation and design process efficiency.

Keywords: Battery configuration | Battery cooling | Electric vehicle | Li-ion batteries | Virtual prototyping

Abstract: With increased acknowledgment of global climate change and warming, governments, consumers, and firms are responding collectively to create today's low-carbon economy. The eco-design of products is a crucial factor in the Community strategy on Integrated Product Policy. As a preventive approach, designed to optimize the environmental performance of products, while maintaining their functional qualities, it provides genuine new opportunities for manufacturers, consumers and society as a whole. This article presents an approach to support the designers during the energy labeling phases of products. The study starts with an analysis of the Eco-design regulations and proposes the virtualization of such tests. A case study on the application of the proposed method is described. The study results show that, the use of numerical simulations not only for product design but also during the testing and labeling phase, allowing a significant reduction in time to market and provides the company competition and economic, energy, and time savings.

Keywords: Design for enviroment | Design optimization | Eco-design | Energy labelling | Energy-related products | Virtual Prototyping

Abstract: This paper presents a structured User Centered Design (UCD) method to design and develop a highly usable smart home platform to manage the energy consumption of connected appliances. It exploits advanced Tangible Augmented Reality (TAR) technologies to virtually prototype the conceived design solutions and carry out usability testing with sample users. Usability tests are carried out both on traditional high fidelity prototypes and on an innovative Tangible Augmented Reality prototype. Experimental results prove the efficiency of the UCD approach supported by virtual prototypes, instead of traditional ones, the reliability of TAR prototypes to detect usability problems and assess user satisfaction, and its high interaction quality. Advantages obtainable by implementing the proposed structured UCD approach for web interface design, in the context of smart home, are discussed.

Keywords: Human Centered Computing | Human Computer Interaction | User Centered Design | User Interface Design | Virtual Prototyping | Virtual Reality

Abstract: Aim of this paper is to analyse and compare the characteristics of Feature Based and Direct Modeling techniques to determine their pros and cons for typical design processes. The first is one of the most common approach to create CAD models to be used for the machining phase of mechanical parts and assemblies. The second is a new method, alternative to the first one, based on a user-friendly approach, without rigid rules and constraints, that could represent the future of the CAD methodologies. Moreover, the Surface Modeling approach is analyzed and compared to the others, due to its common use in automotive and aeronautics fields. Considering the Feature Based Modeling as benchmark, three case studies were analysed to examine the peculiarities of these techniques, and to determine and highlight their advantages and their drawbacks. Several aspects were contemplated to perform the tests: the execution time for the realization of each operation, the easiness to create features and geometries, the possibility to adequately modify and upgrade the models and the number of operations needed to get the complete virtual prototype. In the end, the results were analysed and discussed focusing the attention on the possibility to adopt the Direct Modeling as substitute of the Feature Based and/or Surface Modeling and of the current CAD techniques.

Keywords: CAD | Direct modeling | Feature based modeling | Fuselage | Main landing fear | Surface modeling | Top-down approach | Virtual prototyping | Wing

Abstract: Position-controlled Servo-Systems (SeSs) may be envisaged as a key technology to keep the manufacturing industry at the leading edge. Unfortunately, based on the current state-of-the-art, these mechatronic devices are well performing but intrinsically energy intensive, thus compromising the overall system sustainability. Therefore, traditional design and optimization paradigms, previously focused on productivity and quality improvement, should be critically reviewed so as to introduce energy efficiency as an optimality criterion alongside with the global production rate. In particular, focusing on mono-actuator systems with one degree-of-freedom, among the several design factors that can influence the SeS overall performance, the end-effector motion law can be easily modified without either hardware substitution or further investments. In this context, the purpose of the present paper is twofold. On one side, an effective method for the quick set-up of an energy-predictive CAD-based virtual prototype is discussed. In parallel, an energy comparison of some commonly employed Point-To-Point motions and optimization cost functions is provided. For what concerns the trajectory interpolation scheme, a standard optimization problem based on the aforementioned virtual model is solved by means of either algebraic or trigonometric splines. For what concerns the optimality criterion, either the system energy consumption or the root-means square value of the actuator torque are taken into account. In general, torque-based approaches, which may be preferred since they do not require a full knowledge of the SeS electrical parameters, can be effectively employed only when friction effects are negligible as compared to purely inertial loads. In parallel, cubic algebraic splines outperform other types of trajectories, although losing continuity of the resulting jerk profile.

Keywords: CAD/MBD tools | Eco-Design methods | Servo-Systems | Trajectory comparison | Virtual prototyping

Abstract: In this paper, an engineering method for the power flow assessment of a position-controlled servo-mechanism is outlined. The considered system is composed of a permanent magnet synchronous motor coupled to a standard power converter, and directly connected to a slider crank mechanism. After the accurate description of a consistent power flow model, a sequential identification technique is discussed, which allows to determine the dynamic parameters of linkage, electric motor and electronic driver by means of non-invasive experimental measures. The proposed model allows to accurately predict the major sources of power loss within the system.

Keywords: Design of Experiments | Power flow assessment | Servo-actuated mechanism | Virtual prototyping

Abstract: At the current state-of-the-art, Robotic Deburring (RD) has been successfully adopted in many industrial applications, but it still needs improvements in terms offinal quality. In fact, the effectiveness of a RD process is highly influenced by the limited accuracyof the robot motions and by the unpredictable variety of burr size/shape. Tool compliance partially solves the problem, although dedicated engineering design tools are strictly needed, in order to identify those optimized parameters and RD strategies that allow achieving the best quality and cost-effectiveness. In this context, the present paper proposes a CAD-based Virtual Prototype (VP) of a pneumatic compliant spindle, suitable to assess the process efficiency in different case scenarios. The proposed VP is created by integrating a 3D multi-body model of the spindle mechanical structure with the behavioural model of the process forces, as adapted from previous literature. Numerical simulations are provided, concerning the prediction of both cutting forces and surface finishing accuracy.

Keywords: CAD-based tools | Compliant spindle | Robotic deburring | Virtual Prototyping

Abstract: Abstract: The product design process is based on a sequence of phases where the concept of the shape of a product is typically represented through a digital 3D model of the shape, and often also by means of a corresponding physical prototype. The digital model allows designers to perform the visual evaluation of the shape, while the physical model is used to better evaluate the aesthetic characteristics of the product, i.e. its dimension and proportions, by touching and interacting with it. Design and evaluation activities are typical cyclical, repeated as many times as needed in order to reach the optimal and desired shape. This reiteration leads to an increase of the development time and, consequently, of the overall product development cost. The aim of this research work is to develop a novel system for the simultaneous visual and tactile rendering of product shapes, thus allowing designers to both touch and see new product shapes already during the product conceptual development phase. The proposed system for visual and tactile shape rendering consists in a Tactile Display able to represent in the real environment the shape of a product, which can be explored naturally through free hand interaction. The device is designed in order to be portable, low cost, modular and high performing in terms of types of shapes that can be represented. The developed Tactile Display can be effectively used if integrated with an Augmented Reality system, which allows the rendering of the visual shape on top of the tactile haptic strip. This allows a simultaneous representation of visual and tactile properties of a shape. By using the Tactile Display in the initial conceptual phases of product design, the designers will be able to change the shape of a product according to the tactile evaluation, before the development of the physical prototype. This feature will lead to a decrease of the number of physical prototypes needed, thereby reducing, both cost and overall time of the product development process.

Keywords: augmented reality | shape rendering | Tactile display | virtual prototyping

Abstract: This study presents an approach based on Design of Experiment (DoE) technique for the optimization of an energy recovery ventilator (ERV). This system is one of the efficient ways to enhance the thermo-hygrometric comfort without increase excessively the thermal load in domestic kitchen. However, there is a major concern, which energy recovery cannot trade off ERV's fan power consumption. The goal of this study is to obtain the information about the relation between factors and response in an empirical way. This approach integrates three different levels of analysis: the virtual prototyping, Design of Experiment (DoE) and rapid prototyping. The virtual analysis allows to define the principal parameterization of a simplified model and to simulate the performance of each configuration at working condition. The proposed approach investigates the effect of the defined parameters and noise factor on the experimental results. In particular, the applied method for DoE analysis is based on virtual experiments in according to the necessity to reduce time and costs during the early design phase. The optimum parameters configuration, which is defined by the previous step, is useful to define the geometry and the working condition of a reliable virtual model. The final level is the realization of a 3D ERV with a rapid prototyping printer. The obtained component is now evaluable at the test bench to investigate the air flow rate and the electric power consumption.

Keywords: Design of Experiments | Energy Recovery Ventilator | Rapid Prototyping | Virtual Prototyping

Abstract: Numerous companies all around the world are shifting from traditional products to product-service solutions, thanks to the increased 'intelligence' and ' connectivity' of modern products and the more deep integration among mechanics, electronics, Information and Commutation Technologies (ICT) and Internet of Things (IoT). Such Product-Service Systems (PSSs) are usually designed and developed by considering product and service as separated entities with the consequent increase of design and validation difficulties. In addition, a final physical prototype has to be realized to validate the overall solution. In this context, Virtual Prototyping can support PSS design to reduce process iterations and time to market. However, actual virtual prototypes are usually conceived for product validation, and are not so effective for PSS. The paper defines a set of requirements for PSS simulation on digital models, and defines a set of tools for successful PSS prototyping.

Keywords: Model-in-the-loop | Product-Service System | Virtual Prototyping | Virtual Reality

Abstract: This paper quantitatively reports about a practical method to improve both position accuracy and energy efficiency of Servo-Actuated Mechanisms (SAMs) for automated machinery. The method, which is readily applicable on existing systems, is based on the 'smart programming' of the actuator trajectory, which is optimized in order to lower the electric energy consumption, whenever possible, and to improve position accuracy along those portions of the motion law which are process relevant. Both energy demand and tracking precision are computed by means of a virtual prototype of the system. The optimization problem is tackled via a traditional Sequential-Quadratic-Programming algorithm, that varies the position of a series of virtual points subsequently interpolated by means of cubic splines. The optimal trajectory is then implemented on a physical prototype for validation purposes. Experimental data confirm the practical viability of the proposed methodology.

Keywords: Energy Efficiency | Position Accuracy | Trajectory Optimization | Virtual Prototyping

Abstract: Programmable servo-actuated mechanisms can enhance the flexibility and the reconfigurability of modern manufacturing systems. Differently from fully mechanical design solutions (such as mechanical cams) and especially in the case of high-dynamic motions, servomechanism performance depends on several interacting factors, namely electric motor and linkage dynamics, controller efficacy, and requested motion law. In particular, point-to-point (PTP) trajectories are usually designed in order to comply with technological constraints, imposed by the required interaction with the handled product, and to maximize some optimality criterion such as, for instance, energy efficiency or limited actuation torques. In this context, the present paper proposes a novel method for designing energy and peak-power optimal PTP motions. A standard optimization problem is solved by means of either cubic or quintic splines. Nonetheless, differently from previous approaches, the optimization cost functions are based on a virtual prototype of the system, which comprises behavioral models of power converter, controller, and electric motor coupled with the mechanical system. Results are then compared with experimental data obtained on a physical prototype. The comparison quantitatively shows that better-behaved PTP trajectories can be designed by including the dynamic contribution of each subsystem component.

Keywords: Electronic cams | high-speed machinery | intelligent manufacturing | mechatronic design methods | trajectory generation | virtual prototyping

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: In the field of pharmaceutical processing, last generation automatic machines autonomously modify their behavior in order to achieve the best manufacturing quality and productivity despite ever changing process requirements. Mechatronics, as a synergistic integration of electro-mechanical equipment and software control logics, enables such adaptive self-optimizing behaviors. Unfortunately, due to the complex interactions between the different technologies, the final performance of these systems can be effectively validated and optimized only on a physical prototype, with limited possibilities to introduce possible design changes. Therefore, in order to enable validation/optimization of high performance machinery during engineering design stage, a mechatronic Virtual Prototyping (VP) technology is strongly needed. Within this context, the present work discusses a mechatronic VP method based on a Hardware-in-the-Loop, hybrid-process simulation approach, where interactive real-time simulations can effectively assess the real final performance under changing process scenarios. In particular, a case study concerning a high-speed automatic machines for pharmaceutical capsules filling is thoroughly discussed.

Keywords: Hardware-in-the-Loop | Intelligent Manufacturing | Mechatronic Design | Virtual Prototyping

Abstract: This paper quantitatively reports about potential energy savings on robotic assembly lines for the automotive industry. At first, a detailed system model is described, which improves previously published results by explicitly considering both manipulator and electrical drive dynamics. The model closely captures experimental data in terms of actuation torques and servodrive voltages, which are directly used to derive the plant input power. Two practical methods are then evaluated for reducing the overall energy consumption. The methods rely on: 1) implementation of energy-optimal trajectories obtained by means of time scaling, concerning the robots' motion from the last process point to the home positions and 2) reduction of energy consumption by releasing the actuator brakes earlier when the robots are kept stationary. Simulation results, based on the production timing characteristics measured at a real plant, clearly shows that the system energy consumption can be effectively reduced without negative effects on the production rate. © 2004-2012 IEEE.

Keywords: Energy efficient robotics | robotic manufacturing | trajectory planning | virtual prototyping

Abstract: In the product development process one of the crucial phases is the evaluation of the design of the product that must satisfy the marketing targets based on the users' needs analysis. It is commonly acknowledged that a product is successful if people like and buy it. In the phase of ideation of a new product, it is paramount to test functionality and performances as well as the users' appreciation and feeling towards the new product. More specifically, in the case of consumer products characterised by a plurality of offers, interaction and experience should be addressed in addition to function and aesthetics in the user studies. Recent research has focused on the study of the user's emotional reaction when interacting and experiencing products, which is correlated with the global appreciation of the product and of its attributes. This paper presents an emotional engineering methodology using interactive virtual prototyping for evaluating the user experience and the emotional response with newly designed products early in the development process. The methodology suggests a way to optimise those aspects at the product concept phase. © 2014 © 2014 Taylor & Francis.

Keywords: emotional engineering | product experience | virtual prototyping

Abstract: Designing physical interfaces, like the doors of consumer products, able to elicit a positive experience when interacting with them, is now becoming a key priority for design teams. One of the main difficulties of this activity consists of translating all the qualitative perceptual feedback that can be captured from the customers into quantitative specifications. Performing this translation is not an easy task since there are still no effective tools, methodologies or approaches able to guide designers in accomplishing this goal. To overcome this lack a reverse engineering-based approach is proposed. This one guides designers towards the modelling, parameterisation and reproduction of the behaviour of the product interface to be redesigned, within a multisensory virtual environment. The intent is to let the user experience different behaviours in order to ask them to identify the desired one or to express preferences for updating it in real-time according to indications provided. At the same time a detailed physics model, built by the designer, is used to convert this desired behaviour, into detailed quantitative design specifications. The method is defined as a reverse engineering one for two main reasons: first the new interaction is derived on the basis of the behaviour of an existing interface, taken as reference, and second a reverse engineering of the user's perceptual preferences is applied to derive new specifications. A case study is discussed to demonstrate the method effectiveness and to highlight its limitations. © 2014 Taylor & Francis.

Keywords: haptics | interactive systems | product experience | reverse engineering | virtual prototyping

Abstract: This paper presents a new concept of a desktop haptic shape display that allows rendering and exploring virtual surfaces. Such device allows continuous and free hand contact on a developable plastic strip that is actuated by a modular handling system. Each module is based on an absolute positioning approach, which allows controlling the represented trajectory, thus overcoming the limits of relative handling systems. The developed system is able to manage the elastic behaviour of the strip in terms of bending, twisting and local curvature control. The latter allows us to handle the local tangency of the strip to the rendered trajectory. The absolute approach allows configuring the system with a variable number of modules, so as to customize it according to the application needs. © 2014 IEEE.

Keywords: Curve rendering | Desktop haptic system | Haptic strip | Virtual Prototyping

Abstract: This paper presents a novel transportable and cost-effective Augmented Reality system developed to support interior design activities in the contract design sector. The main functioning principles and technical information about its implementation are provided to show how this system allows overcoming some of the issues related to the use of the Augmented Reality in interior design activities. The effectiveness of this system is verified through two different testing sessions based on a case study, which relates to the contract design sector. The testing sessions involved many interior designers with the intent of demonstrating the possibility of integrating this Augmented Reality system in the "everyday" interior design practice in the specific context of the contract design. © 2014 CAD Solutions, LLC.

Keywords: augmented reality | interior design | virtual prototyping

Abstract: In common industrial practice the definition of shapes of styling products is performed by product designers. They usually produce aesthetic shapes by handcrafting scale models made of malleable material like clay, and often expensive physical prototypes are also manufactured. The paper describes a Desktop Mechatronic System (DMS) that has been conceived to support designers in the creation, evaluation and modification of aesthetic virtual shapes. The objective in designing this system is to develop a system allowing a continuous and smooth free hand physical interaction with a virtual shape, which is rendered through a dynamic cross-sectional contour or curve in three-dimensional (3D) space. The DMS is a useful tool for designers, who are not certain about the quality of the shape of the product, and can use it for testing out ideas. The DMS consists of a servo-actuated developable metallic strip, which reproduces 3D cross-sectional contours, which has been devised and implemented by using the Minimal Energy Curve (MEC) spline approach in which the equidistant interpolation points scheme has been adopted to imitate the virtual object created via a Computer Aided Design (CAD) tool on a physical bendable strip-like surface. © 2013 © 2013 Taylor & Francis.

Keywords: 2D cross-section rendering | CAD associativity | desktop mechatronic system | industrial design | virtual prototyping

Abstract: Nowadays, electric vehicles fill a relevant car market share. The Li-Ion batteries currently represent the best solution in term of environmental impact and performance. Thermal management for Li-Ion batteries is a very interesting topic, since high temperatures accelerate degradation rate of a cell and compromise its safety level. The battery thermal modeling can be quite challenging. The proposed approach describes a methodology to simulate different thermal management algorithms in order to obtain an uniform temperature distribution in a Li-Ion battery pack. A test case has been developed where the application of an thermal algorithm has been analyzed through CFD simulations.

Keywords: CFD | Hybrid electric vehicle | Li-ion battery | Simulation | Thermal management | Virtual prototyping

Abstract: Virtual prototyping lacks of application in SME due to the costs of software systems and the necessity of skilled operators. The aim is to improve dripper emitters design process reducing costs. A knowledge base is presented to gather data on products behaviour in terms of experimental data and simulation results for a set of meaningful test cases. Input design parameters were linked to performance indices on the base of the correlations emerged in the analysis. Specifications for a new product can be used to extract similar cases and to define a possible solution in terms of a combination of them.

Keywords: Design of experiments | Drip emitters | Knowledge based engineering | Virtual prototyping

Abstract: Quality of life of various types of people can strongly benefit of a design process developed to take into account needs and requirements of end users. In this context the paper present a study on the cognitive and physical abilities of elderly persons, to design a friendly kitchen, that is considered one of the most complex home environment for the provided functionalities and involved human capabilities. A robust inclusive design approach is conceived to make simple and intuitive the interaction between humans and the systems installed in the kitchen environment. An investigation of virtual prototyping techniques is proposed to find the best Virtual Reality system to create a living lab to involve elderly in user-based assessment.

Keywords: home environment | mixed reality | user-centred-design | virtual prototyping

Abstract: A strong integration between different design tools is desirable to improve the work of engineers, reducing the number of errors and speeding up the design process. In this article, the authors present a strong integration between three-dimensional computer-aided design models and multidomain simulation applied to the design of a magnetomechanical energy harvester. A MATLAB framework controls a block-oriented Simulink model, drives the Finite Element Method Magnetic simulation and manages the updating of the Solid Works computer-aided design models of the device. The parameters involved in the different simulations and in the computer-aided design models are stored in a unique data file. Moreover, constructive drawings are automatically updated and are immediately suitable for tolerance and design constraint checks and also for the effective prototyping of the device. Constructed prototypes are immediately suitable to validate the performance predicted by the model.

Keywords: Computer-aided design-computer-aided engineering integration | Energy Scavenging | Multidomain simulation | Virtual prototyping

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: In this work a new distal interlocking system has been developed which is easy to use, allows a reduction of the operating time and consequently the exposure to radiations both for surgeon and patient. The main goal of this study has been the design of a new intramedullary nail for tibial fractures able to simplify and speed up the distal locking operation phases. After a preliminary stage during which several candidate concepts have been proposed and analysed, the best solution has been developed and deeply investigated. The new system, called "expansion nail", has been firstly modelled by setting up a full parametric CAD model and, then, tested by running non linear FEM analyses to evaluate stresses and stability of the joining during normal working conditions. The new design has shown very high mechanical stability in the axial compression and torsional load cases. Since its very simple self-locking system, the new expansion intramedullary nail would reduce the operating time and the exposure to radiations for the surgeons as well as the patients. © 2012 Springer-Verlag France.

Keywords: Intramedullary nail | Non linear FEM analyses | Parametric CAD model | Redesign | Virtual prototyping

Abstract: This article concerns the design of lower limb prosthesis, both belowand above knee. It describes a newcomputer-based design framework and a digital model of the patient around which the prosthesis is designed and tested in a completely virtual environment. The virtual model of the patient is the backbone of the whole system, and it is based on a biomechanical generalpurpose model customized with the patient's characteristics (e.g. anthropometric measures). The software platform adopts computer-aided and knowledge-guided approaches with the goal of replacing the current development process, mainly hand made, with a virtual one. It provides the prosthetics with a set of tools to design, configure and test the prosthesis and comprehends two main environments: the prosthesis modelling laboratory and the virtual testing laboratory. The first permits the three-dimensional model of the prosthesis to be configured and generated, while the second allows the prosthetics to virtually set up the artificial leg and simulate the patient's postures and movements, validating its functionality and configuration. General architecture and modelling/simulation tools for the platform are described as well as main aspects and results of the experimentation. © 2013 The Author(s) Published by the Royal Society. All rights reserved.

Keywords: Digital patient | Human modelling | Lower limb prosthesis | Virtual prototyping

Abstract: In this paper, we propose a knowledge-based approach to design lower limb prostheses; in particular, we focus on the 3D modelling of the socket, the most critical component. First, the architecture of a dedicated design framework is described, detailing features of the main design steps. Then, the paper discusses the acquisition and formalisation of the knowledge related both to the prosthesis manufacturing process and to the considered component. Finally, we present the computer-aided module, named socket modelling assistant-SMA, we specifically developed to design the socket. It is a virtual laboratory where the socket virtual prototype is generated directly on the digital model of patient's residual limb. It guides and supports the designer during each step in an automatic and/or semi-automatic way applying design rules and procedures. The modelling steps and available interactive tools that emulate orthopaedic technician's operations are described. Results of the experimentation phase are described. At current state of the prototype development, they are encouraging and have permitted to preliminarily validate the proposed approach and envisage future improvements. Copyright © 2013 Inderscience Enterprises Ltd.

Keywords: 3D socket modelling | Knowledge-based design | Lower limb prosthesis | Virtual prototyping

Abstract: Servo-actuated mechanisms are increasingly sub-stituting fully mechanical drives in order to increase flexibility and reconfigurability of modern automatic machines. The overall servomechanism performance, especially in the case of high-dynamic motions, is the direct consequence of several interacting factors, namely electric motor and linkage dynamics, controller efficacy, and requested motion law. In particular, Point-To-Point (PTP) trajectories are usually designed in order to comply with technological constraints, imposed by the required interaction with the handled product, and to maximize some optimality criterion such as, for instance, energy efficiency or limited actuation torques. In this context, the present paper proposes a novel method for generating either energy-optimal or torque-optimal PTP motions described by piecewise fifth-order polynomials. The optimization cost functions are based on a virtual prototype of the system, which comprises behavioral models of power converter, controller and electric motor coupled with the mechanical system. Results are then compared with experimental data obtained on a physical prototype. The comparison quantitatively shows that better-behaved PTP trajectories can be designed by including the dynamic contribution of each sub-system component. © 2013 IEEE.

Keywords: Servo-Actuated Mechanism | Trajectory Generation | Virtual Prototyping

Abstract: This paper reports about the design and modeling process of high performance servo-actuated mechanisms for automatic machines.Besides being a delicate and time consuming process, coupled simulations based on virtual prototyping finally offer the chance to integrate engineering methods proper of control system engineering and mechanical design. In particular, the main target of this work isto investigate how different virtual prototyping approaches, each havingincreasing level of detail, can contribute to the appropriate prediction of the expected machine performance.These results are then compared with experimental data obtained on a real servomechanism prototype. The comparison quantitatively demonstrate the improvement on torque prediction and position error reduction when detailed models of the controller and the electric motor dynamics are coupled with the mechanical system model. © (2013) Trans Tech Publications, Switzerland.

Keywords: Co-simulation | Digital product design | Integrated mechatronic design | Virtual prototyping

Abstract: The interest in novel methods and tools for opt imizing the energy consumption in robotic systems is cur- rently increasing. From an industrial point of view,it is desirable to develop energy saving strategies also applicable to established manufacturing systems with no need for either hardware substitu tion or further investme nts. Within this scenario,the present paper reports amethod for reducing the total energy con- sumption of pick-and-place manipulators for given TCP position profiles.Firstly,electromechanical mod- els of both serial and parallel manipulators are derive d.Then,the energy-optimal trajectories are calculated, by means of constant time scaling,starting from pre-scheduled trajectories comp atible with the actuation limits. In this manner,the robot work cycle can be energetically optimized also when the TCP position profiles have been already definedon the basis of technological constraints and/or design choices aimed at guarante eing manufacturing process efficacy/robustness.The effectiveness of the pro- posed procedure is finallyevaluated on two simulation case studies. Copyright © 2013 Published by Elsevier Ltd. All rights reserved.

Keywords: Electromechanical modeling | Energy efficiency | Robotic manufacturing | Virtual prototyping

Abstract: The term User Experience (UX) is commonly associated with interactive computer-based systems. Companies operating in the consumer market are recently discovering the importance of designing UX, and in particular multisensory UX, of any kind of system, and not necessarily high-tech products. One of the most effective ways to design UX is to enable users interacting with the prototype of the system during the design process, and in particular already during its initial stages. These prototypes should provide the same experience occurring while interacting with the corresponding real product. To this aim Virtual Prototypes (VPs) may be effectively used, especially in the early design stages when the activities are still in progress and changes are frequent. Multisensory UX can be effectively designed through VPs only if all the senses involved in the real interaction are recreated into the virtual simulation. To date, despite a growing interest of research and industry in the development and use of VPs, many applications are still limited to visual and sound simulations. This paper focuses on the use of VPs to design multisensory UX, concentrating on the introduction of the sense of touch in the simulation. The methodological approach as well as the development of a case study are described in the paper. © 2013 IEEE.

Keywords: Haptics | User experience design | Virtual prototyping

Abstract: The need for companies to improve their competitiveness may lead to innovation and the reconceptualization of traditional products and processes, with companies making an effort to enhance product elements related to functionality, attractiveness, technology and sustainability, and implementing mass-customisation concepts. Mass-customised products are developed to satisfy specific customer needs, in line with increasing demand for product variety and customisation. The analysis of what customers really want, capturing the Voice of the Customer (VOC), is one of the strategies used to establish effective product development processes. Using a VOC survey, it is possible to transform customer needs into the functional and psychological requirements of the product. This paper presents a methodology based on Virtual Reality (VR) technologies to support the capturing of the VOC in regard to the visual, haptic and auditory characteristics of products. This method can be applied to the beginning of the product development process, to allow companies to deduce from the data the requirements of new industrial customised products. A flexible and interactive Virtual Prototype (VP) of a product category is then developed as a product platform in a draft version by designers and configured according to customer needs, using an immersive VR environment. This method, based on the use of VP, reduces the number of physical prototypes that need to be manufactured during the product development process, thus reducing overall costs. In addition, the VP based method supports the mass-customisation process of products through the real-time integration and collection of data for product configuration preferences, involving as many users as possible representative of the target users of the new products. To demonstrate this process a case study concerning the development of the VP for a washing machine, a summary of test sessions with users and results are presented. Specifically, the results presented in this paper are related to improvements in capturing the VOC and reductions in Virtual Prototyping cost and time. © 2012 Springer Science+Business Media, LLC.

Keywords: Product customisation | Virtual Prototyping | Voice of the Customer

Abstract: The paper describes the results of an on-going research activity whose aim is to allow companies, operating in the consumer goods market, to design the multisensory experience of their products. In case of the household appliances market, which is the research context of this study, the user experience derives from the interaction with specific product features such as the door, buttons, and drawers. Designing a good multisensory experience is complex since it means taking into account a combination of visual, hearing and haptic feedbacks a user perceives when interacting with the product. Virtual Reality offers the technologies to design and test that experience thought virtual prototypes, even if to date there is a lack of methodological approaches to practically guide and support this design activity. Relying on the results of previous authors' researches, the paper describes further methodological advances focused on making usable the proposed approach in the current design practice. The case study chosen to demonstrate the effectiveness of the method is a dishwasher door and the paper describes how to re-engineer the haptic feedback of a commercial model in order to make it more perceptually appealing at the moment of purchase. © 2013 CAD Solutions, LLC.

Keywords: Haptic interaction | Reverse engineering | User experience design | Virtual prototyping

Abstract: The paper describes an application based on Virtual and Augmented Reality technologies specifically developed to support maintenance operations of industrial products. Two scenarios have been proposed. In the first an operator learns how to perform a maintenance operation in a multimodal Virtual Reality environment that mixes a traditional instruction manual with the simulation, based on visual and haptic technologies, of the maintenance training task. In the second scenario, a skilled user operating in a multimodal Virtual Reality environment can remotely train another operator who sees the instructions about how the operations should be correctly performed, which are superimposed onto the real product. The paper presents the development of the application as well as its testing with users. Furthermore limits and potentialities of the use of Virtual and Augmented Reality technologies for training operators for product maintenance are discussed. © 2013 Copyright Taylor and Francis Group, LLC.

Keywords: assembly | haptics | virtual prototyping

Abstract: In the domain of industrial product development, products have been traditionally communicated to final users by means of technical drawings, sketches and physical prototypes. Recently, companies have tended to develop digital versions of products, which can be used with the purpose of communicating a new product to users, and also with the aim of allowing users to evaluate the product and its variants before its physical construction. Virtual prototyping is a relatively recent practice used in various industrial domains, which aims at anticipating a product that does not exist in reality yet. This practice can be used for evaluating the aesthetic quality of a product, its functional features and also its ergonomic and usability aspects. Current virtual reality technology well supports the implementation of effective virtual prototypes. In fact, one can touch, move, manipulate, and operate the virtual prototypes of products, such as household appliances, electronic devices, etc., with a good degree of realism. In order to do this, the interaction with virtual prototypes is multimodal and multisensory, and is often based on the combination of visual, haptic and auditory modalities. This paper shows how virtual prototypes can be used instead of physical artefacts or mock-ups for the communication of a new product or of variants of an existing product, and for the preliminary evaluation of its usage. The effectiveness of this practice is proved by tests performed by users. © 2013 Copyright Taylor and Francis Group, LLC.

Keywords: haptic interaction design | virtual environments | virtual prototyping

Abstract: Today, the tests of a new product in its conceptual and design stage can be performed by using digital models owning various levels of complexity. The level of complexity depends on the nature and on the accuracy of the tests that have to be performed. Besides, the tests can involve or not the interaction with humans. Particularly, this second aspect must be taken into account when developing the simulation model. In fact, this introduces a different kind of complexity with respect to simulations where humans are not involved. Simulation models used for numerical analyses of the behavior of the product (such as Finite Element Analysis, multi- body analysis, etc.) are typically named Digital Mock- Ups. Instead, simulations that are interactive in their nature, requiring humans- in- the- loop, are named interactive Virtual Prototypes. They cannot be intended as a simple upgrade of a CAD model of a product, but they are instead a combination of functional models, mapped into sensorial terms and then accessed through multisensory and multimodal interfaces. In this paper, the validity of this concept is demonstrated through some case studies where interactive Virtual Prototypes are used to substitute the corresponding physical ones during activities concerning the product conceptualization and design. © 2013 CAD Solutions, LLC.

Keywords: CAD modeling | Mixed prototyping | Simulations | Virtual prototyping

Abstract: An automatic manufacturing system design must be optimized with a simulation including all the interacting devices. The simulation should be controlled by the real control system with a hardware in the loop approach. So the techniques for modeling the mechanisms must be effective for the model to be run without violating the real-time protocol. This paper reports a method to model the motor load by means of a reduced moment of inertia, where all the part downstream from the motor output shaft is transformed in function of the only one mechanism degree of freedom. The resulting model behaves as the real nonlinear mechanism, but it is computationally efficient since it is not ruled by the multibody 3D CAD mathematics. © (2013) Trans Tech Pudlications, Switzerland.

Keywords: Co-simulation | Digital product design | Virtual prototyping

Abstract: Computer-aided tools can help to realize custom-fit products characterized by a strict interaction with human body and definitely improve quality of life, in particular of people with disabilities. The paper refers to this context and to a specific custom-fit product, the lower limb prosthesis. It presents an innovative framework centred on virtual models of the patient's body, to design and configure lower limb prosthesis, both transfemoral and transtibial. The framework integrates virtual prototyping and knowledge-based tools to support the orthopaedic technician during all the steps of the lower limb prosthesis design, suggesting rules and procedures for each task. First, the considered product is introduced, and then, the new design framework is described as well as main steps and related tools, from socket modelling to standards component selection and final prosthesis assembly. Results of preliminary experimentation and final remarks conclude the paper. © 2012 Springer-Verlag.

Keywords: Custom-fit products | Knowledge-based systems | Lower limb prosthesis | Socket | Virtual prototyping

Abstract: Engineering changeability-oriented and cost-driven approaches are needed by enterprises to design and optimize manufacturing and assembly systems for the demanding production requirements of the present industrial scenario. The integrated design of Reconfigurable Systems addresses tailored flexibility through modularity, integrability of resources, product and process customization, and system convertibility and diagnosability. The cooperation of robot and humans in hybrid environments offers a good trade-off between changeability, high quality and low costs, by exploiting the human dexterity and cognitive proactivity, together with robotic accuracy and performances. Virtual prototyping methods and digital manufacturing solutions are now mature and effective enough to play a strategic role within the hybrid reconfigurable system (H-RS) design and optimization process. The present research work proposes an engineering method to design and optimize H-RSs, by using virtual prototyping and digital manufacturing as a strategic support for the analysis and synthesis of the technical solutions, especially those related to human-robot cooperation. An industrial case study on a hybrid reconfigurable assembly system of a top class car aluminum chassis is finally presented. © 2011 Springer-Verlag.

Keywords: Automotive industry | Digital manufacturing | Hybrid reconfigurable system | Virtual prototyping

Abstract: Nowadays, Virtual Reality technologies have spread in numerous industrial and research contexts for their ability to provide the perception of virtual spaces and objects by an appropriate combination of sensory channels stimuli. Haptic feedback enhances the user's perceptual immersion during the interaction with virtual prototypes. Commercial haptic force feedback devices are affected by some functional limitations, such as the size of workspace and the type of contact they can provide. The present work aims at developing an innovative device starting from the customization of an anthropomorphic arm. This allows to increase the workspace, to provide a surface contact and to improve the whole ergonomics of the system. The system multi-layer architecture is designed to have a lower level of robot control and a higher level of highly usable graphic user interface, which displays both the virtual prototype and the manipulating virtual probe. © 2012 IEEE.

Keywords: Anthropomorphic arm | FFD | Virtual Prototyping

Abstract: This paper concerns the usage of virtual humans to validate lower limb prosthesis design. In particular, we are developing an innovative design framework centered on digital models of the whole patient or of his/her anatomical districts, which constitute the backbone of the design process. The framework integrates a set of virtual "assistants" to guide the technicians during each design task providing specific knowledge and design rules. In this paper, we focus the attention on the last step of the prosthesis deign process, i.e., the final set-up with the patient using a biomechanical model of the amputee. First, we describe the state of art on virtual humans and main features of the new design framework. Then, the application of virtual humans for the prosthesis set-up is presented as well as preliminary results. Copyright © 2011 by ASME.

Keywords: Lower limb prosthesis | Product development | Virtual humans | Virtual prototyping

Abstract: The ability to capture customers' needs and the voice of customers, and to translate them into a set of product specifications that at best satisfy the target customers has increasingly become a key element of business strategy. The common practice consists in evaluating products at the end of the design process through physical prototypes with the participation of users and potential customers. The same practice can be implemented by using virtual replica of real products, reducing cost and time necessary to build some variants. The paper presents a methodology for the development of the virtual prototype of a piece of furniture, produced by a company that is interested in studying how customers perceive and evaluate some variants of the hinge mechanism. The virtual prototype has been implemented using a tool for virtual reality applications oriented to non-expert programmers. The modularity and flexibility of the approach used for implementing the virtual replica has allowed us to re-use the components, and to easily change the parameters, also during the test activities. © 2011 Springer-Verlag.

Keywords: Fast Prototyping | Virtual Products | Virtual Prototyping

Abstract: Several haptic devices have been developed in recent years in order to reproduce the sensation of physical contact with virtual objects. Many of these devices are point-based, and some haptic interfaces behave like small surfaces that conform to a virtual shape. None of these allow a full-hand contact with the shape, and they are, in general, too small to render big surfaces. The simulation of tasks, such as the exploration of aesthetic surfaces made by industrial designers in order to check the quality of prototypes, require full-hand contact with the shape on a one-to-one scaled representation of the object. These explorations follow trajectories that can be approximated with planar or geodesic curves. In this paper, we describe the design and implementation of a linear haptic device that is able to render these trajectories. The device is part of a multimodal system including stereoscopic visualization that allows visual representation of the entire surface. Industrial designers use the system for checking the quality of shapes while exploiting their manual and visual skills. The system has been tested by industrial designers and the results are reported in this paper. © 2011 IEEE.

Keywords: curve rendering | Haptic strip | industrial design | mixed reality | multimodal interfaces | virtual prototyping

Abstract: Nowadays, Virtual Prototyping (VP) methods are widely used for product design and development purposes. In particular, VP methods are now used also for the orthopedic products development process, to better understand the functional performance of prostheses or implants within the musculoskeletal system. In fact, developing validated virtual models of joints or of other anatomical structures may reduce design and prototyping costs and compress development cycles. The purpose of this paper is to point out first the state of art of both the VP technologies and the kinds of virtual models used in the medical field, with particular attention to those used for the design and development of orthopedic products. Then, it focuses on a qualitative analysis of some biomechanical simulation software packages (LifeMOD, AnyBody, and OpenSim) as tools for the improvement of the product design and development processes. Copyright © 2011 by ASME.

Keywords: Biomechanical simulation | Orthopedic devices | Product design and development cycle | Virtual prototyping

Abstract: In this paper, we propose a knowledge-based approach to design lower limb prostheses; in particular, we focus on the 3D modelling of the socket, the most critical component. First, the architecture of a dedicated knowledge based engineering framework is described, detailing features of the main design steps. Then, the paper discusses the acquisition and formalization of the knowledge related both to the prosthesis manufacturing process and to the considered component. Finally, we present a computer-aided module, named Socket Modelling Assistant-SMA, to design the socket; it is a virtual laboratory where the socket virtual prototype is generated directly on the digital model of patient's residual limb. It guides and supports the designer during each step in an automatic and/or semi-automatic way applying design rules and procedures. The guided modelling steps and available tools are described. Work in progress and future developments conclude the paper. © Organizing Committee of TMCE 2010 Symposium.

Keywords: 3d socket modelling | Knowledge-based design | Lower limb prosthesis | Virtual prototyping

Abstract: Most of the activities concerning the design review of new products based on Virtual Reality are conducted from a visual point of view, thus limiting the realism of the reviewing activities. Adding the sense of touch and the sense of hearing to traditional virtual prototypes, may help in making the interaction with the prototype more natural, realistic and similar to the interaction with real prototypes. Consequently, this would also contribute in making design review phases more effective, accurate and reliable. In this paper we describe an application for product design review where haptic, sound and vision channels have been used to simulate the interaction with a household appliance. © 2010 Springer-Verlag.

Keywords: Interaction Design | Multimodal Interaction | Product Design Review | Virtual Prototyping

Abstract: The paper describes a haptic device whose aim is to permit the assessment of digital prototypes of industrial products with aesthetic value. The device haptically renders curves belonging to digital surfaces. The device is a haptic strip consisting of a modular servo-controlled mechanism able to deform itself, allowing the user to feel the resulting shape with his free hands. The haptic strip is also equipped with two force sensitive handles placed at the extremities, and a capacitive touch sensor along its length, which are used for applying deformations to the digital shape. © 2010 Springer-Verlag Berlin Heidelberg.

Keywords: Haptic linear strip | Multimodal application | Virtual Prototyping

Abstract: The paper presents a system we have studied and developed to aid the stereoscopic visualisation of virtual models of products whose shape can be explored and modified using a haptic interface. The haptic system has a wide working space that allows users to stand in front of the system and to operate as they are used to do in real life for making physical prototypes. The paper also shows several visualisation solutions that have been studied before obtaining the best performing one in which the stereoscopic glasses worn by the user as well as his point of view are tracked in order to enhance the realistic perception of the 3D mixed image. Some initial tests have been performed with end-users, both CAS designers and model makers, with the support of human factors experts in order to correctly assess the usability of the system and to understand how potentially effective it is in aiding product designers in their work. © 2010 Inderscience Enterprises Ltd.

Keywords: haptic interfaces | projection based visualisation systems | stereoscopic visualisation | virtual prototyping | visuo-haptic display

Abstract: The paper presents the results of a research project aiming to develop an innovative framework for the conceptual design of products based on haptic technology. The system consists of a Computer-Aided Design (CAD) system enhanced with intuitive designer-oriented interaction tools and modalities. The system integrates innovative haptic tools with 6 Degrees of Freedom (DOF) for modelling digital shapes, with sweep operators applied to class-A surfaces and force computation models based on chip formation models. The system aims to exploit designers' skills in modelling products, improving the products' design process by reducing the necessity to build several physical models for the evaluation and testing of product designs. The system requirements have been defined after observing designers during their daily work and translating the way they model shapes using their hands and craft tools into specifications for the system. The system has been tested by designers, who have found it intuitive and effective to use. Copyright © 2010 Inderscience Enterprises Ltd.

Keywords: Conceptual design | Haptic modeling | Product design | Product development | Virtual prototyping

Abstract: The design of industrial products is a process based on the collaboration of different experts with different technical knowledge and backgrounds. For example during the first stages of the design process the shape of the product is defined by designers from the aesthetic point of view. Late in the process the same shape is analyzed by engineers and refined. Today, due to the use of different specific computer-aided tools, it happens that sometimes the representation of the product made by the different members of the design team is not the same. Then the different backgrounds of the members of the team may cause the use of different languages and concepts to represent the same information. So the exchange of information in the design team can become the bottleneck of the entire design process. This paper describes an annotation tool integrated in a Mixed Reality environment whose aim is to try to reduce the time and augment the level of collaboration. The Mixed Reality environment, in which the two phases of the definition and analysis of the shape have been integrated, makes use of a semi-immersive visualization system and some haptic technologies. The application has been validated through some user tests and the results have highlighted the potentialities of the entire application in terms of collaboration and the limits in terms interaction that are basically due to the fact that some users are still not familiar with these technologies. © Organizing Committee of TMCE 2010 Symposium.

Keywords: Annotation systems | Collaborative design and engineering | Knowledge management | Virtual prototyping

Abstract: 3D CAD systems are powerful tools for modelling rigid bodies but they are not adequate in order to model flexible material components, especially if a realistic simulation of physical behaviour is required as in virtual prototyping. This paper describes the methodology used to develop a knowledge-based system in order to automatically create virtual prototypes of uniaxial flexible components like cables, pipes and wires. The method has been translated in an operative design software system for metallic-reinforced elastomer hoses. The resulting VP tool integrates the 3D CAD technology and suitable structural simulation methods. The robustness of software system has been verified and errors are assessed. A dedicated experimental set-up has been realised in order to compare the virtual results with the real component behaviour. The system has been applied in the design of multifunctional agricultural machines showing reduction of physical prototypes and the lead-time due. © 2010 Inderscience Enterprises Ltd.

Keywords: fem simulation | flexible components design and modelling | knowledge-based design | virtual prototyping

Abstract: The efficacy of virtual reality (VR) as a design support technique is widely recognised by industries. However, the efficiency of the routine employment of VR into the product development process (PDP) still finds an obstacle in the poor integration of the tools employed. The use of VR still needs long and quite hard procedures to work effectively; the models have to be converted into a format that is compatible with VR systems and each task requires an effort to prepare the virtual environment or to post-process the results that depend on the complexity of the task. This work analyses some VR applications into the PDP and describes some ideas to effectively support the operator that prepares the virtual environment. These ideas have been tested by developing four software interfaces, able to create an easy data exchange link between VR and other design tools like CAD, CAE and computer aided control engineering (CACE). © 2007 Springer-Verlag London Limited.

Keywords: CACE | CAD | CAD-VR integration | CAE | Virtual prototyping | Virtual reality

Abstract: Although the 3D shape recovery of a real object have been greatly improved in the last few years, modeling a complex virtual object by starting from the real prototype is still a very time-consuming activity. In this paper an originally conceived method and testing software to recover a CAD model from a real object is presented. The developed software tool joins a professional Computer-Aided Design (CAD) and a Mixed Reality (MR) tool in the same interface, enabling the operator to use standard CAD tools and features together with a camera, which provides external image streaming displayed in the workspace background. Moreover, a special programmed library performs a real-time calculation of camera position and other parameters with respect to standard markers in order to drive the CAD 3D virtual camera and align it to external world. In that way rendered virtual models may be superimposed to external images of reality grabbed by the video camera. Thus with MR-CAD tool the operator may easily recover a complex shape directly from the external views of a real object or may start the object re-design from the previous reconstructed geometry. Furthermore the interface is totally integrated in a CAD environment, both avoiding to work with unfamiliar new software and exploiting CAD geometry database and tools. Finally, MR-CAD can be considered a significant step ahead in the bi-directional interaction of virtual and real models, reducing also the gap between real prototypes and CAD data.

Keywords: Augmented reality | Mixed-reality | Reverse engineering | Virtual prototyping

Abstract: This paper presents a plug-in, named Cloth Assembler, implemented in the framework of the Italian PRIN Project (Research Project of National Interest) VI-CLOTH (Virtual CLOTHing). The base idea is to allow the designer to interactively define/the necessary information to assemble 2D panels on a virtual mannequin and to generate the 3D physical model in its initial configuration, initial step for the garment simulation process. Starting from 2D single pieces, ClothAssembler allows a user, as a virtual tailor, to specify assembly rules among cloth panels (e.g., cut lines, dart, and buttons), insert accessories, such as zips and hooks, and, finally specify finishings on single pieces and the presence of different textile multilayer, pockets, reinforcement lines, etc. The plug-in can be easily integrated with any commercial 2D CAD system and represents the connection element between 2D cloth world and 3D physics-based modelling and simulation systems. It has been validated with three real test-cases, a T-shirt, a denim skirt, and a pair of trousers.

Keywords: Apparel design | Assembly process | CAD | Cloth models | Virtual prototyping

Abstract: The paper presents the results of a research project aimed at developing an innovative system for modeling industrial products based on haptic technology. The system consists of a Computer Aided Design (CAD) system enhanced with intuitive designer-oriented interaction tools and modalities. The system integrates innovative six degrees of freedom (DOF) haptic tools for modeling digital shapes, with sweep operators applied to class-A surfaces and force computation models based on chip formation models. The system aims at exploiting designers' existing skills in modeling products, improving the products design process by reducing the necessity of building several physical models for evaluating and testing the product designs. The system requirements have been defined observing designers during their daily work and translating the way they model shapes using hands and craft tools into specifications for the modeling system and the haptic tool. The system prototype has been tested by designers who have found it intuitive and effective to use. © Springer-Verlag London Limited 2005.

Keywords: Haptic modeling | Haptics | Product design | Virtual prototyping

Abstract: The paper presents two applications of haptic technologies to demonstrate how they can increase human computer interaction during different steps of design process. The first application aims at developing a system to generate digital shapes by manipulating haptic tools that resemble the physical ones that the modelers use in everyday work. The second is focused on the use of haptic interfaces to evaluate ergonomics of virtual products control boards. We designed and developed the mentioned haptic devices; the first uses two FCS HapticMaster equipped with a innovative strong and stiff 6 DOF device carrying simulated clay modeling tools. The second is an "ad hoc" mechatronic device able to simulate some controls with rotary motions (knobs). The described haptic devices are integrated in more complex virtual reality applications; the paper describes their architecture and the methodologies proposed to simulate material shaping and ergonomic validation. The main aspects of haptic modeling and rendering are also discussed. © 2006 Elsevier Ltd. All rights reserved.

Keywords: Haptic modeling | Haptics | Product design | Virtual prototyping

Abstract: Current tools aimed at supporting the conceptual phase of product design are not intuitive to use, and do not exploit designers' skill and creativity. This paper presents the results of a research work aiming at integrating user-friendly and effective ways of interaction based on ad-hoc haptic interfaces into free-form shape modeling systems. Copyright © 2005 by the Association for Computing Machinery, Inc.

Keywords: Concept product design | Free-form shape modeling | Haptic modeling | Haptics | Virtual prototyping

Abstract: Gestures, besides speech, represent the mostly used means of expression by humans. For what regards the product design field, designers have multiple ways for communicating their ideas and concepts. One of them concerns the model making activity, where designers make explicit their concepts by using some appropriate tools and specific hand movements on plastic material with the intent of obtaining a shape. Some studies have demonstrated that visual, tactile and kinesthetic feedbacks are equally important in the shape creation and evaluation process [1]. The European project "Touch and Design" (T'nD) (www.kaemart.it/touch-and-design) proposes the implementation of an innovative virtual clay modeling system based on novel haptic interaction modality oriented to industrial designers. In order to develop an intuitive and easy-to-use system, a study of designers' hand modeling activities has been carried out by the project industrial partners supported by cognitive psychologists. The users' manual operators and tools have been translated into corresponding haptic tools and multimodal interaction modalities in the virtual free-form shape modeling system. The paper presents the project research activities and the results achieved so far. Copyright 2005 ACM.

Keywords: Haptic interaction | Haptic modeling | Virtual prototyping

Abstract: This paper outlines new trends in geometric modelling, showing how systems are moving from a geometry-based approach to a physically-based approach. The possibility to simulate the actual behaviour of a product is at the basis of Virtual Prototypes that are becoming a common practice in today's product development process. As a consequence, also interaction modalities and techniques have to be improved in order to satisfy new system requirements and functionalities. The research work described in this paper shows how haptic interaction techniques represent an evolution of current interaction technologies providing intuitive and realistic modalities for interacting with virtual applications. In particular, the paper describes a research work we have carried out integrating haptic technologies together with physically-based modelling and simulation techniques. © 2001 Springer Science+Business Media New York.

Keywords: Haptic interaction | Human-computer interaction | Non-rigid material modelling | Physically-based modelling | Virtual prototyping