Virtual prototyping and digital twin

Increasing the level of automation in air traffic management is seen as a measure to increase the performance of the service to satisfy the predicted future demand. This is expected to result in new roles for the human operator: he will mainly monitor highly automated systems and seldom intervene. Therefore, air traffic controllers (ATCos) would often work in a supervisory or control mode rather than in a direct operating mode. However, it has been demonstrated how human operators in such a role are affected by human performance issues, known as Out-Of-The-Loop (OOTL) phenomenon, consisting in lack of attention, loss of situational awareness and de-skilling. A countermeasure to this phenomenon has been identified in the adaptive automation (AA), i.e., a system able to allocate the operative tasks to the machine or to the operator depending on their needs. In this context, psychophysiological measures have been highlighted as powerful tool to provide a reliable, unobtrusive and real-time assessment of the ATCo's mental state to be used as control logic for AA-based systems. In this paper, it is presented the so-called “Vigilance and Attention Controller”, a system based on electroencephalography (EEG) and eye-tracking (ET) techniques, aimed to assess in real time the vigilance level of an ATCo dealing with a highly automated human–machine interface and to use this measure to adapt the level of automation of the interface itself. The system has been tested on 14 professional ATCos performing two highly realistic scenarios, one with the system disabled and one with the system enabled. The results confirmed that (i) long high automated tasks induce vigilance decreasing and OOTL-related phenomena; (ii) EEG measures are sensitive to these kinds of mental impairments; and (iii) AA was able to counteract this negative effect by keeping the ATCo more involved within the operative task. The results were confirmed by EEG and ET measures as well as by performance and subjective ones, providing a clear example of potential applications and related benefits of AA.

Keywords: adaptive automation , air traffic control , electroencephalography , eye-tracking , human–machine interface , Out-Of-The-Loop , passive brain–computer interface , vigilance

Product customization aims to consider individual customers preferences in the design of new products, in order to directly involve them in the product development process and to maximize their satisfaction. It can be considered a key competitive factor and a "hot topic" in several industrial sectors, including luxury apparel goods and high-end footwear products. However, currently the design and manufacturing of customized shoes are carried out through artisanal and non-standardized processes, based on the individual expertise of operators. The objective of this study is to define an innovative framework to support the different processes affected by customization. This framework is enabled by different digital technologies, as CAD-based tools, virtual/augmented reality systems, etc., opportunely integrated in the product development process. The main benefits related to the framework implementation in real industrial contexts are an increase of flexibility, the repeatability of processes, a higher efficiency in information exchange, a more effective involvement of final customers, and, as a consequence, the reduction of time to market and production costs for tailor-made shoes.

Keywords: Design for X (DfX) , Design process , Integrated product development

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

Introduction of new gas turbine machines on market is a complex project that requires optimization of different performance parameters such as power, efficiency, maintenance plan, product cost and life. The ability to control cost and impact on performances and life strongly decreases from conceptual to detailed design phase. Actually, 80 % of product's cost and performances are committed based on decisions made in conceptual design. This Paper describes a systematic procedure to estimate the cost of multiple design alternatives during conceptual design phase, comparing different cross sections for gas turbine solutions. Examples of parametric costing tool for part family will be described, to show the approach that allows to estimate costs in conceptual design phase, when detailed design has not been developed and lack of information is a daily topic. The idea is to be able to read design information of each part from an enhanced cross section and enter parametric costing tool to have a preliminary cost estimation in conceptual phase. Doing that for each part or module present, it will be possible to estimate total cost of the product. The scope is to create an internal database where the whole know-how and best practices are stored. This database can be examined in early program stages, to reduce time to market and avoid pursuing solutions that would not be viable or convenient, in a sort of digital twin approach. Another positive aspect pursued and presented, is the positive impact on engineering productivity, that directly reflects on program development cost.

Keywords: Conceptual costing , Gas turbine , New product introduction , Parametric cost estimation , Target cost

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

In a bolted joint, the preload level resulting from the tightening torque represents a very important parameter governing the stresses distributions involving the joint under the real loading conditions. This paper deals with the development of a Finite Element (FE) model for the investigation of the effects of some selected preload levels on the stress-strain states affecting both bolt and plate in a single lap joint. The aim of this FE model is to support the design phase of strain gauges instrumented bolt to evaluate experimentally the rate of tensile load applied to the joint that the bolt absorbs with different preloads. The test article consists of two steel plates, a steel bolt and an aluminum nut. The results herein presented showed firstly that, without bolt preload, the tensile load applied to the joint is completely transferred to the bolt and that the load transferred to the bolt almost linearly decreases as the preload increases. Moreover, at a selected preload level, the transversal and longitudinal stresses (with respect to the load direction) increase as the tensile load increases, while the stress along the plate thickness direction decreases, reaching negative values. On the other hand, at a selected tensile load level, the transversal and longitudinal stresses as well as the stress along the thickness direction decrease as the preload level increases. Predicting the mechanical behaviour of the only bolted joint, if the same bolt model will be used to simulate the mechanical behaviour in a hybrid single-lap joint, possible imperfections of the model will have to certainly be linked to the modelling of the adhesive.

Keywords: Bolted joints , Numerical modeling , Tightening torque

This study used the Finite Element (FE) method to numerically analyze the thermo-mechanical behavior and residual stresses in dissimilar welded T-joints. Residual stresses induced by the fusion arc-welding of steel joints in power generation plants are a concern to the industry. The structural integrity assessment of welded structures requires the consideration of weld-induced residual stresses for the safe operations in power plants, which may be compromised by their presence. Details on the used thermo-mechanical FE model and the results analysis are herein presented.

Keywords: Finete Element Method , Residual Stresses , T-Joint , Welding

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

Augmented reality is considered one of the enabling technologies of the fourth industrial revolution, within the Industry 4.0 program and beyond. Indeed, augmented reality solutions can increase the working quality and the productivity and allow a better use of the human resources. This technology can help the operator in the industrial applications during the crucial phases of the processes. Since the quality assessment of the surfaces is recognized to be a key phase in the polishing process, in this paper we propose a novel method that exploits augmented reality to support the operators during this phase. The metrology data measured by a surface measurement system are directly projected on the polished component through an augmented reality headset worn by the operators and used to assess the quality of the worked surfaces. Rather than imagine how a certain parameter change can affect the result achieved, the information is directly there on the component's surface. Users can see from the data where refinements are required and make better and faster decisions, which is compelling for its potential beyond industrial polishing. The proposed method is implemented and validated on an industrial cell, where the robot automatically perform the polishing task and move the head of the surface measurement system along the surface to measure the metrology parameters. Thanks to the proposed approach, the end-user and the operator can directly see on the component if the quality reached satisfies the specifications or if some parts of the surface require further refinements through additional polishing steps.

Keywords: Augmented reality , Industrial robotic solutions , Robotic polishing

Surface polishing can be counted among the most challenging manufacturing operations, especially when high qualitative levels in terms of surface texture characteristics are requested, such as in the case of polishing operations for plastic injection moulds. Robot-based solutions for surface polishing and quality assessment operations have been proposed at the state of the art, but it still is required the involvement of skilled workers for process supervision and final tuning operations. The introduction of human-machine collaborative solutions opens new opportunities, as the use of symbiotic polishing approaches, where both the humans and the machines capabilities can be shared to improve process effectiveness. The current work proposes a human-robot collaborative approach for surface polishing processes that integrates state of the art robot-based polishing and surface quality assessment technologies in a human-safe shared working environment. As a proof of approach feasibility, the paper presents the prototype of a reconfigurable platform designed to implement a flexible human-robot collaborative scenario for execution of polishing and quality assessment operations. Preliminary demonstrative polishing sessions on simple and complex components validate the system effectiveness with respect to manufacturing efficiency and reconfigurability capabilities. The results obtained provide a first positive response that symbiotic approach can objectively improve the polishing processes.

Keywords: Collaborative Robotics , Computer Integrated Manufacturing , Polishing Processes , Reconfigurable Systems , Robotics

This article proposes the use of an expert knowledge-based system capable of identifying possible machine tool failures caused by accidental events (e.g., cable disconnection, incorrect parameterization of machining, impact event, etc.). The proposed approach aims to identify the unpredictable causes of failures, starting from the analysis of the process data provided by the PLC Data Logger, without requiring to sensorize the machine in order to collect ad hoc condition monitoring data. To this end, it uses the experts rules and Fuzzy Logic algorithms to activate data analysis based on known machine fault conditions. The proposed approach has been validated on real case studies. A prototype system was developed in Python to identify electrospindle failures that occur when the spindle of a CNC machining center for woodworking is subjected to a strong axial impact. The results show that the proposed system is capable of effectively detecting failures caused by impact events and reduces the time needed for the diagnosis by 80%.

Keywords: Expert systems , Fuzzy logic , Machine diagnostics

Predictive Maintenance concerns the smart monitoring of machine to avoid possible future failures, since because it is better to intervene before the damage occurs, saving time and money. In this paper, a Predictive Maintenance methodology based on Machine learning approach is presented and it is applied to a real cutting machine, a woodworking machinery in a real industrial group, producing accurate estimations. This kind of strategy is important to deal with maintenance problems given the ever increasing need to reduce downtime and associated costs. The Predictive Maintenance methodology implemented allows dynamical decision rules that have to be considered for maintenance prediction using a combined approach on Azure Machine Learning Studio. The Three models (RF, GBM and XGBM) allowed the accurately predict machine down ever gripped bearing thanks to the pre-processing phases.

Marine archaeologists study a large number of submerged sites of interest around the world, which require continue diving explorations and monitoring. Although technology has improved a lot the research in the underwater environment, human intervention is preferred whenever depth makes the sites accessible by divers. This paper presents the concept, the first steps and the preliminary results of the Lab4Dive project, which is co-funded by the EMFF programme of EU, that aims to design, develop, and validate an innovative, marketable and competitive product for surveying, documenting and preserving Underwater Cultural Heritage. The archaeologist will be provided with an underwater tablet equipped with environmental sensors, where a properly designed data gathering system will be accessible through a dedicated application. Lab4Dive aims also to train young researchers and to encourage multi-disciplinary cooperation through the concept of a “Blue Lab”.

The pre-operative planning of a hip arthroplasty entails the choice of the prosthetic hip model and of the position of both joint components with reference to bone. Assessing the impact of geometrical factors on the final hip range of motion (ROM) is not trivial, since it requires performing 3D evaluations. Nonetheless, it deserves to be studied since hip impingement and dislocation are still relevant complications in hip arthroplasty.This work pertains a numerical model for the assessment of the hip ROM in relation to cotyle position. External/internal rotation is considered as a benchmark, and multiple combinations of acetabular anteversion/inclination are considered.According to results, over two hundred different geometric configurations can be examined in few minutes, and the cotyle position can be so optimized with relevant benefits in term of hip ROM.

Today manufacturing enterprises aim not only to deliver high-value, cost-effectively products in a sustainable way, but also to consider the quality of the working environments. The analysis of human factors, which strongly affect time and quality of manufacturing processes, are crucial for satisfying people involved in the manufacturing process and making them safe, preventing diseases, errors and excessive workload. The paper presents a structured procedure to automatically extract data from virtual analysis made by digital manufacturing tools and measure a set of indicators to validly assess manufacturing ergonomics. The research considers the state of the art in manufacturing ergonomics and defines a set of indicators suitable for manufacturing manual operations, focusing on assembly tasks. Furthermore, it defines a methodology to automatically extract data valorising the selected indicators and an application, based on Visual Basic, to generate the specific task list and related assessment. The result is a rapid and objective assessment, independent from the experience of the user, which can be executed during process design. The procedure has been applied to an industrial case study, where the manual assembly of cabin supports on the tractor chassis has been analysed in order to correct the most uncomfortable steps and obtain a more ergonomic process. A decrease of the EAWS score, calculated with the proposed method, allowed to validate the proposed solution, suggesting a redesign of the assembly cycle to improve the working conditions. Such a procedure anticipates the analysis of the workers' wellbeing during the design stage to support the definition of human-centric manufacturing processes, simplifying and accelerating the assessment activities. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.

Keywords: Digital Manufacturing , Human Factors , Human-Centered Design (HCD) , Manufacturing Ergonomics , Virtual Engineering

Human-centred design is based on the satisfaction of the user needs mainly related to performances, interaction, comfort, usability, accessibility, and visibility issues. However, the “real” user experience (UX) is hidden and usually difficult to detect. The paper proposes a multimodal system based on the collection of physiological and anthropometrical performance data on field and within a mixed prototyping set-up. The mixed environment makes users interact with virtual and digital items and users' performance to be capture and digitalized, simulating human-machine interaction, while physiological and anthropometrical data collection allows to objectify the users' physical and mental workload during task execution. Such a system has been applied to an industrial case study focusing on agricultural machinery driving and control to support the definition of a new cabin and its control board, in terms of seat features, commands' positioning and grouping, and positioning of additional devices.

Keywords: Ergonomics , Human-centred design , Human-machine interaction , Mixed prototyping , User experience

Armrest in tractors is like a control dashboard for trains or airplanes; it is fundamental for managing and properly setting the machine. For this reason, there is the need to adjust it for each operator's size and application. Nowadays, armrests are usually very big and intrusive, because they are full of controls and sometimes they are not really comfortable for each user size and need. Furthermore, agricultural equipment is often used under difficult conditions: steep terrain and extreme weather conditions require products able to guarantee total safety and maximum comfort, minimizing the risk of human error caused by excessive fatigue. The aim of the project is to create an “ergonomic - compact armrest”, focused on the users' need, with the application of Ergonomics and Human Machine Interface (HMI) principles, shifting the focus from how a machine works to how a task is performed. For designing the “ergonomic - compact armrest” a new system based on the collection of “real” users biomechanical performance within a virtual lab was adopted. In this virtual environment, it was possible to test many different configurations of controls, checking which controls are mostly used, and measure the comfort index and mental work load for each configuration. On this basis, a “digital twin” of the user was created, consisting in a set of scalable virtual manikins that can interact with virtual items, and a comfort index was defined as an objective and reliable measure to evaluate workload during any task execution. Thanks to this new methodology, the “ergonomic - compact armrest” is 30% smaller than the previous one, but at the same time it accommodates in comfort the 95% of the population size, keeping on board only frequent controls positioned in ergonomic way. The results of this study could be used for other tractors controls layout design, so that human comfort can be improved and any task can be felt as natural as possible, encouraging good posture and safe behaviours, and reducing cost of prototypes and time to market.

The present work deals with the best method and tool design for chopping hazelnut kernels. The requested final product must have a standard appearance both in size and shape. This is not easy to be achieved. A geometrical study using 3D models—both for kernel and cutting tools—simulates the industrial process and forecasts shape and size distribution of the final product. Final comparison between 3D simulation and experimental results shows an acceptable agreement. A simplified and symmetrical geometry is discussed in the present paper. Work is in progress and further and more complete results are expected, but the method of 3D simulation proved to be very useful.