Virtual prototyping and digital twin

In recent years, the Cyber-Physical Systems (CPSs), have become a new trend to increase and to enrich the interactions between physical and virtual systems with the goal to create a truly connected world in which smart objects interact and exchange data with each other. The CPS is the core of the new industrial revolution called 'Industry 4.0', which promotes the computerization of manufacturing to make decentralized decisions. Within the modular structured smart factories, Cyber-Physical Systems monitor physical processes, create a virtual copy of the physical world, simulate parts of process and implement sophisticated control policies in order to take optimized decisions. This research proposes the modelling and simulation of an induction heating process for aluminium-steel mold, which is used in the production of footwear soles. The modelling supports the simulation of a CPS model related to the use of a multi-use LGV (Laser Guided Vehicle) which transports aluminum-steel molds from a mechanized warehouse to the final rotary production line, used for the soles foaming. In detail, a thermal model and an induction heating electronic circuit model have been studied to describe the whole mold heating system and they have been simulated using Simulink/MATLAB. In addition, two types of controllers, an induction preheating control technique based on a Model Predictive Controller (MPC), and another one based on PID, have been developed in order to analyse the different behaviour of the system.

Keywords: Automated Laser Guided Vehicles , Cyber Physical System , Footwear Industry , Industry 4.0 , Injection Molding , Model Predictive Controller , Preheating Molds

In the production of plastic components based on injection molding, like shoe sole manufacturing, the temperature control and the on-line process optimization are important issues in order to preserve the quality of the plastic components and improve the time performance, while maintaining high product quality. This research proposes an induction preheating control technique based on Model Predictive Controller (MPC) for a steel-aluminium mold for production of soles, performed on an automated Laser Guided Vehicle (LGV) with an innovative induction heating functionality. A thermal model has been studied using a finite-difference approach to describe the mold heating system. The resulting system has been simulated using Simulink/MATLAB. Then, three types of controllers have been modelled in the proposed simulation workflow, in order to compare the different behavior of the system. Due to the high mold thermal inertia, which increases the mold temperature even if the control system turns off the thermal power, innovative controllers are needed in order to track the desired temperature setpoint. The comparison with standard industrial controllers, based on PI and PID controllers, shows the effectiveness of proposed solution.

Keywords: Automated Laser Guided Vehicles , Footwear Industry , Injection Molding , Model Predictive Controller , Preheating Molds , Temperature Control

Nowadays, electromagnetic high-frequency induction is very used for different non-contact heating applications such as the molding process. Every molding process requires the preheating and the thermal maintenance of the molds, to enhance the filling phase and the quality of the final products. In this context, an induction heating system, mostly, is a customized equipment. The design and definition of an induction equipment depends on the target application. This technology is highly efficient and performant, however it provides a high-energy consumption. Therefore, optimization strategies are very suitable to reduce energy cost and consumption. The proposed paper aims to define a method to optimize the induction heating of a mold in terms of time, consumption, and achieved temperature. The proposed optimization method involves genetic algorithms to define the design parameters related to geometry and controller. A test case describes the design of an induction heating system for a polyurethane molding process, which is the soles foaming. This case study deals with the multiobjective optimization of parameters such as the geometrical dimensions, the inductor sizing, and the controller setting. The multi-objective optimization aims to reduce the energy consumption and to increase the wall temperature of the mold.

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

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

Along with increased digitalization, virtualization of processes and automation in industry, Industrial Internet of Things opens for new possible scenarios and business models. The opportunities of this technology rely, among the others, on new way for data and knowledge management. Knowledge Based Engineering (KBE) is greatly considered to support design activities related to digital technologies. The paper aims at analyzing the role of Industrial Internet of Things for supporting maintenance operations and evaluating whether the adoption of data structure and the integration with the KBE system can face the actual gaps and needs. After a brief overview of different technologies for knowledge management, a possible scenario has been identified. It represents the framework within IIoT technologies can be applied. This conceptual environment considers a multilevel structure: local facilities, the whole company, suppliers, retailers and global network have been involved into the analysis. Upon that scenario, how data and knowledge can be mapped and managed for each level have been investigated. Moreover, these data can be used to improve the predictive maintenance model as well as to enhance the design of new products through the acquisition and monitoring of an effective set of parameters. Finally, in order to demonstrate the feasibility of the proposed approach with the use of simulation as well as physical devices, a prototypical application related to the maintenance of refrigerated display cabinets has been developed.

Design for Assembly (DfA) is a well-known technique that supports in the reduction of manufacturing costs. Traditional DfA methods are generally focused on the product design lacking of a holistic view. The proposed 4 M approach takes into account all the most important aspects involved in the manual assembly: Method, Machine, Man and Material. The final goal is to provide a means for the concurrent improvement of the product design, the workstation ergonomics, and the assembly tasks. Results obtained with the electric spindle motor case study confirmed the usefulness of the approach in optimizing the manual assembly.

Keywords: 4M approach , Design for assembly , Machine , Man , Material , Method

The paper presents a lifecycle approach and the related software tool for the analysis and management of resource consumptions and environmental impacts of manufacturing plants. The approach, based on the industrial metabolism model, takes into account all the production and assembly aspects. The tool is able to assess the optimum working conditions for the minimization of resource consumptions (e.g. electricity) or environmental emissions (e.g. CO2). It provides a tangible support to guide decision-making strategies to move manufacturing towards sustainability. A manufacturing plant has been analysed for the model validation and the management of production scenarios, optimizing environmental and energy loads.

Keywords: Environmnetal impacts optimization , Plant lifecycle management , Resource consumption optimization , Software tool , Sustainable production

During the last 10 years, manufacturing companies have faced new challenges for improving their value proposition and being more efficient and effective on the market, satisfying the customer needs. According to this trend, several technologies have been developed and applied in different sectors and with different aims, in order to support such the companies in their reconfiguration. For example, the recent advances in Information and Communications Technologies (ICT) could give also to manufacturing industries the competences required to develop novel sustainable products embedded with a dedicated infrastructure able to provide more service functionalities to customer. In this context, the application of Internet of Things (IoT) have allowed developing the so named Product Service Systems (PSSs). Moreover, the cross-fertilization between such the technologies with the development of other ones have fostered the application of these novel ICT technologies inside the manufacturing companies also at process level. This approach has encouraged the study and development of Cyber-Physical Systems (CPSs). The present paper deals with a real industrial use case, where the application of ICT technologies and specifically the adoption of IoT at a plant of plastic extrusion pipes have allowed optimizing the production process in terms of energy efficiency.

Keywords: CPS , Cyber Physical System design , ICT , Industry 4.0 , IoT

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

The tolerances of welded chassis are usually defined and adjusted in very expensive trials and errors on the shop floor. Computer Aided Tolerancing (CAT) tools are capable to optimize the tolerances of given product and process. However, the optimization is limited since the manufacturing process is already mostly defined by the early choices of product design. Therefore, we propose an integrated design method that considers the assembly operations before the detail design of the chassis and the concept design of the fixture system. The method consists in four phases, namely functional analysis in the CAD environment, as-sembly sequence modelling in the CAT tool, Design Of Simulation Experiment on the stack of the tolerance ranges and finally optimization of the tolerances. A case study on a car chassis demonstrates the effectiveness of the method. The method enables to selectively assign tight tolerances only on the main contributors in the stack, while generally requiring cheaper assembly operations. Moreover, a virtual fixture system is the input for the assembly equipment design as on optimized set of specifications, thus potentially reducing the number of trials and errors on the shop floor.

Keywords: 3D tolerancing , Car chassis , Computer aided tolerancing , Design op-timization , Tolerance allocation

The integration of experiments with numerical simulations can efficiently support a quick evaluation of the welded joint. In this work, the MIG welding operation on aluminum T-joint thin plate has been studied by the integration of both simulation and experiments. The aim of the paper is to enlarge the global database, to promote the use of thin aluminum sheets in automotive body industries and to provide new data. Since the welding of aluminum thin plates is difficult to control due to high speed of the heat source and high heat flows during heating and cooling, a simulation model could be considered an effective design tool to predict the real phenomena. This integrated approach enables new evaluation possibilities on MIG-welded thin aluminum T-joints, as correspondence between the extension of the microstructural zones and the simulation parameters, material hardness, transient 3D temperature distribution on the surface and inside the material, stresses, strains, and deformations. The results of the mechanical simulations are comparable with the experimental measurements along the welding path, especially considering the variability of the process. The results could well predict the welding-induced distortion, which together with local heating during welding must be anticipated and subsequently minimized and counterbalance.

This paper studies if adaptive grid refinement combined with finite-volume simulation of the incompressible RANS equations can be used to obtain grid-independent solutions of realistic flow problems. It is shown that grid adaptation based on metric tensors can generate series of meshes for grid convergence studies in a straightforward way. For a two-dimensional airfoil and the flow around a tanker ship, the grid convergence of the observed forces is sufficiently smooth for numerical uncertainty estimation. Grid refinement captures the details of the local flow in the wake, which is shown to be grid converged on reasonably-sized meshes. Thus, grid convergence studies using automatic refinement are suitable for high-Reynolds incompressible flows.

Keywords: Grid adaptation , Grid convergence , Hydrodynamic flows , Uncertainty estimation

Risk Management has become a taken-for-granted form of practice for manufacturing companies and in most cases a strategic for their success. The research goal is to define a multipath methodology that drives the analysts to find the proper ergonomics factors impacting on specific safety elements, how they relate to the workspace, the adopted tools, the overall production environment and to the workers' job, how to quantitatively and qualitatively measure these factors and which VP tools and experimental set-ups could be used to conduct simulations. A case study is used to illustrate the methodology.

Keywords: ergonomics on work efficiency and injuries' recduction , human behavior simulation , Management of risks postures , Virtual Prototyping-based tools , VP tools , work efficiency

In the present work, by means of an integrated approach, a new rear suspension for motorcycles, able to achieve the required progressiveness in terms of rigidity by using a constant-stiffness spring and a compact mechanism, has been studied. The key component is an eccentric system inserted in the shock absorber head. As reference, we analyzed the rear suspension of the Ducati Multistrada MY 2010, characterized by the use of a variable-stiffness spring. The aim of the paper is to prove that the new proposed solution can obtain a response, in terms of load to the wheel, similar to that of the actual system. At first, a mathematical model to simulate the kinematics of the new suspension is presented. This model is able to evaluate the influence of geometric dimensions of the components, checking successfully the ability to reproduce the behavior of the original suspension. After the preliminary design, the kinematic and static models are included within an optimization algorithm ad-hoc created to calculate the exact dimensions of each component. Two Matlab/Simulink® lumped mass models, respectively referred to the novel and reference suspension, are used to compare the dynamic responses during the travelling of a particular road profile used in Ducati's experimental tests. Finally, an accurate modeling of the components, considering also the production processes to be used for their creation, is provided.

Keywords: Dynamics , Integrated simulation , Motorcycle rear suspension

The paper presents a distributed model for implementing Cyber-Physical Systems aimed at controlling physical entities through the Internet of Things. The model tames the inherent complexity of the task by a recursive notion of modularity which makes each module both a controller and a controlled entity. Modules are arranged along part-whole tree-like hierarchies which collectively constitute the system. The behaviour of each module is strictly local since it has visibility only on its controlled modules, but not on the module which controls it. Each behaviour can be thus checked locally at design time against safety and liveness formulas, which still hold when component holons are composed into more complex ones, thus contributing, without the need of additional checks, to the overall safety and liveness of the final system.

Keywords: Cyber-Physical Systems , Holons , Industry 4.0 , Internet of Things , Safety engineering , Smart factories , State-based Control

In order to achieve more sustainable development processes, industries need not only to improve energy efficiency and reduce costs, but also to increase the operators' wellbeing to promote social sustainability. In this context, the present research focuses on the definition of a methodology based on human-centred virtual simulation to improve the social sustainability of maintenance tasks by enhancing system design and improving its serviceability. It is based on the operators' involvement and the analysis of their needs from the early design stages on virtual mock-ups. The methodology proposed merges a protocol analysis for human factors assessment and an immersive virtual simulation where immersive serviceability simulations can be used during design phases. To demonstrate the effectiveness of the proposed method, an industrial use case has been carried out in collaboration with CNH Industrial.

Keywords: Ergonomics , Human-Centred Design (HCD) , Serviceability , Sustainability , Virtual simulation

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

The paper tackles an integrated use of object-oriented modelling (OOM) and design of experiments (DoE) to determine the performance of a double bowden power window system in order to accomplish the expected system performances during the preliminary designing phase and, therefore, by accelerating the product development process. A DoE has been carried out by using the power window model, developed in Dymola environment. The response surface method (RSM) and ANOVA analysis are used to identify the significant factors. Then, an empirical equation is derived. It predicts the main system response i.e. the stroke time, expressed as dependency related to the significant factors. Finally, the use of the empirical relation inside a design flow of a power window, based on digital patterns, is presented.

Keywords: Design of experiments , Digital pattern for product development , Mechatronic systems , Object-oriented modeling , Power window systems