Design methods for mobility

The present work is aimed at finding a correspondence between registered consumes for a Battery Electric Vehicle, using a dedicated algorithm, and data available installing a MEMS sensors platform in a scenario which recreates on-road driving conditions. The Virtual Reality (VR) setup is described in its composition together with the placement of MEMS equipment to configurate optimal conditions for driving tests. In specific, the use of SensorTile.box by STMicroelectronics was described in its functioning and for the measurement acquisition chain process. Also, the consumption model is implemented through Unity3D and Matlab software to obtain an estimation of power, State of Charge (SoC) and energy required to perform the simulation path. Afterwards, considering the available literature, it is posed in consideration how the obtained measures from sensors can be useful for a primary characterization of drivers' behavior. Finally, these results for single users are related to the energy requests to determine if and at which level these parameters are also indicators of impact on consumers.

Keywords: Battery Electric Vehicle , Driving behaviors , Eco-driving energy consumption , MEMS sensors

This paper investigates the development of collaboration modes between university and local industry, within a regional system having a diffused innovation process. As a case study, we analyse into an appreciative framework the roles of a medium-sized university as producer of knowledge, intermediary organisation and regional orchestrator over time, ultimately assuming a leading role in two specific university-industry programmes supporting the motor vehicle industry of Emilia–Romagna (IT). The paper contributes to the University-Industry stream of research by identifying the factors and mechanisms underpinning the evolution of university's role in its collaboration with local industry, by the time assuming a leading and central role in spreading innovative technology into the regional system. Our findings provide managerial and policy makers contributions, and could be extended to other similar medium-tech industry for supporting diffusion of knowledge and innovation processes.

Keywords: Academic engagement , Automotive industry , Regional innovation system , Technology transfer

This paper proposes the analysis of the tolerances (values, types, datum) and their effects on a mechanical assembly, as a high-performance car engine, by means of a Computer-Aided Tolerancing software. The 3D tolerance stack-ups are investigated to assess the fulfillment of the functional requirements as well as the performance specifications of the assembly. Moreover, after identifying the tolerances that mainly affect the product variability, we finally propose some corrective actions on the tolerances and assess their functional allocation, tightening or relaxing their values, ensuring assemblability and cost reduction.

Keywords: Automotive assembly , Car engine , Computer-Aided Tolerancing , Geometric dimensioning and tolerancing (GD&T) , Tolerance analysis method

The structural properties of cast aluminum parts are strongly affected by the solidification in the production process. The solidification dynamics determines the Secondary Dendrite Arm Spacing (SDAS), directly affecting the structural strength of the alloy. Simulation techniques enable the integrated design of chassis parts and their production equipment. However, in order to effectively predict the SDAS formation, the simulation models need to be investigated and calibrated. The present research investigates the SDAS formation models and identifies a robust relation to be used in Design by Simulation phases for AlSi7Mg0.3 parts.

Keywords: Integrated design , Low pressure die casting , Secondary Dendrite Arm Spacing , Simulation

Car driver and occupants monitoring is important for safety and comfort. The systems using vision sensors for monitoring the line of sight can be integrated with pressure sensors embedded in the seats to identify critical Out of Position conditions. A new modular car seat is here proposed to monitor the pressure distribution on different significant regions. The solution improves the limitations of existing technologies embedded in seats. The proportional and fast measurement enables online complex evaluations, while the layout reduces the risk of errors. The experiments proved the effectiveness of the prototype.

Keywords: Car seat pressure , Driver monitoring , Driver profiling , Intelligent vehicle , Modular car seat , Occupant classification , Safety system , Seat regions , Weight scale system

Main targets of this activity research are the making and the optimization of new detectors by means of the Systems Engineering methods. With the observation of the gravitational wave event of August 17th, 2017 and then with those of the extragalactic neutrino of September 22nd, the Multimessenger Astrophysics era began. It is a new way of exploring the Universe, powered by globally coordinated observations of several experiments. So, new X and gamma rays' detectors solutions are needed in order to provide competitive results in the energy range 10 keV–10 meV. Here is briefly described how the Systems Engineering can improve the development of the proposal of a new technique: The Crystal Eye, a wide field of view detector with a good spatial resolution obtained thanks to a high pixelation.

Keywords: Astrophysics , Crystal Eye , Detectors , Optimization , Systems Engineering

The road transportation of critical components for cryogenic cryomodules is a challenging task. Indeed, the shipping and the handling of fundamental sub-assemblies can expose these components to harmful dynamic loads that can jeopardize their structural integrity. This article has the purpose of developing a finite element multibody model capable of assessing the acceleration on a test coupler for a cavity of the Single Spoke Resonator 1 subjected to a typical road transportation trip. A multibody model consisting of rigid bodies and finite element–imported flexible bodies has been created allowing a comparison of the simulated and experimental acceleration. Afterwards, an experimental on-road test, whose set-up is described in this article, has been carried out at Fermilab with instrumented components. Being able to effectively simulate and validate the dynamic effects on such sub-assemblies makes it possible, for the future, to simulate more complex structures subject to dynamic loadings, such as the entire cryomodules during shipping. Furthermore, the results from the simulations can be used to guide the design of new suspension systems suitable for the reduction mitigation of structural vibration during the road transportation of cryomodules.

Keywords: couplers , experimental data analysis , finite element analysis modelling , reduced order methods , road transportation , vibration measurement

The success of a human-machine interface (HMI) heavily depends on its usability. An highly usable interface allows the user to more easily achieve his/her goals and in general have a better User eXperience (UX). In work environments, a structured and ready-to-use usability testing protocol can encourage companies to carry out this type of study and focus on UX from the early design phases. Even though numerous methods to test usability exist, industrial companies still have great difficulties to apply them and choose the best ones for the specific purposes. They should be guided into the analysis by a universal step-by-step approach, which helps also not experienced designers selecting the most reliable and useful methods among the available ones. In this direction, the paper proposes a structured protocol to focus on UX and guide companies in testing setup, execution and debriefing in an easy and quick way. Checklists are defined to help during user testing and assure its success. As a consequence, end users can be easily involved to give an added value in design problems identification. The novelty of this paper is the definition of a ready-to-use study protocol that can also be used by non-usability experts, in order to make them familiar with UX analysis and extend this practice also in industrial HMI design. As validation, the proposed protocol was applied to the design of interfaces for agricultural tractors during two different stages of the HMI redesign process.

Keywords: Eye-tracking in user experience research , HMI , Universal design , Usability , User experience , User testing

In recent years, the use and demand of bicycles have increased thanks to the growing attention to the environment and due to the COVID-19 pandemic situation. At the same time, the design of the bicycles has remained substantially unchanged, improving in materials and components technology. In the off-road sector, two diametrically opposed categories have emerged in terms of comfort and pedalling efficiency. The goal of this research is to introduce a first methodological approach for the optimization of a mountain bike frame. The behaviour of the developed frame aims to combine the pedalling benefits now available only in different and non-comparable bicycle configurations. The first step concerns the modelling of a generic off-road bicycle frame, then its behaviour has been simulated for specific load cases. Subsequently, the part of the bicycle that best performed the double function of compliance and rigidity has been sought through an analysis of the strain energy using FE simulations. Hence, the reference region has been topologically optimized to provide adequate chassis travel performance. The analysis scheme has been iteratively repeated also on other parts of the frame until an acceptable solution is obtained for the utilize presented. The final configuration permits a rear tube and bottom bracket displacement of 10.4 mm and 2.4 mm compared to the 0.5 mm and 0.4 mm of the original frame respectively. The approach described can be proposed as a support for the search for an innovative design for products with unchanged geometries due to the inertia of the designers. At the same time, this methodology aims to expand the possible use of topological optimization, moving away from the classic constraint schemes present in various software.

Rail–wheel interaction is one of the most significant and studied aspects of rail vehicle dynamics. The vibrations caused by rail–wheel interaction can become critical when the radial, lateral and longitudinal loads of the vehicle, cargo and passengers are experienced while the vehicle is in motion along winding railroad paths. This mainly causes an excessive production of vibrations that may lead to discomfort for the passengers and shortening of the life span of the vehicle's body parts. The use of harmonic response analysis (HRA) shows that the wheel experiences high vibrational amplitudes from both radial and lateral excitation. The present study describes a numerical and experimental design procedure that allows mitigation of the locomotive wheel resonance during radial and lateral excitations through viscoelastic layers. It is proven that these high frequencies can be reduced through the proper design of damping layer mechanisms. In particular, three parametric viscoelastic damping layer arrangements were analyzed (on the web of both wheel sides, under the rim of both wheel sides and on the web and under the rim of both wheel sides). The results demonstrate that the correct design and dimensions of these viscoelastic damping layers reduce the high-amplitude resonance peaks of the wheel successfully during both radial and lateral excitation.

Keywords: harmonic response analysis , lateral excitation , modal analysis , radial excitation , viscoelastic damping layers , web and rim parametric design

The hydrofoil is a craft where the weight is entirely supported by the lift generated by the submerged part of wings. The particular structure of the craft requires a thorough study of the architecture of the hull, whose structure differs from others high speed vessels since the lift on wing surfaces are transmitted to the hull in limited areas (wing attacks). The authors have developed a research to optimize geometry of hull and wing system on a hydrofoil capable to carry 250 passengers at a speed of 35 knots, operating among Sicilian island. The principal goals of the new hydrofoil concern both the fuel reduction that the improvement of the comfort in terms of seakeeping and levels of acoustic vibrations. In order to reduce the power engines and the acoustic vibrations and to increase the seakeeping during the cruising route and the takeoff, a thorough study of the bow sections (whose profile contributes during this step to exert a thrust which, added to that provided by the wing surfaces, drastically reduces takeoff times) is conducted. Several experimental tests, performed at the towing tank, have allowed to better define the shapes of the hydrofoil and the profile of the wings. An economic assessment was carried out in order to demonstrate that the innovation effort contributes to reducing both construction that operating costs.

Keywords: Economic assessment , Experimental analysis , Hydrofoil , Towing tank

The paper discusses the application of Reinforcement Learning to the control of an onshore Wave Energy Converter (WEC). The proposed WEC features a simple and low-cost architecture. It is characterized by an oscillating floating rocker arm which moves a four bar linkage in the vertical plane. A mechanical rectifier, based on two one-way clutches and a multiplier gearbox, transforms the low speed oscillating motion of the four bar into a higher-speed unidirectional rotation of the electrical generator. The dynamic model of the WEC, based on multibody approach and Linear Wave Theory, is presented. Then a Reinforcement Learning (RL) algorithm, a Q-learning method, is applied to dynamically adjust the generator speed-torque ratio as a function of the sea state. Simulation results show the effectiveness of this model-free adaptive control in tuning the system in order to maximize the generated power. Starting from a simple monochromatic model of the sea, the presented approach is verified according to sea conditions of increasing complexity, and finally to long term time series, obtained from measurements of real sea states in the considered geographical region. The tuning of the hyper-parameters of RL algorithm with respect to the speed of convergence and optimality of generated power is also discussed.

Keywords: Linear Wave Theory , Oscillating arm , Q-learning , Reinforcement Learning , WEC

This paper reports the study of a planar Cross-Axis Flexural Pivot (CAFP) comprising an additional contact pair. The proposed device may be useful for applications requiring a revolute joint that behaves differently when deflecting clockwise/anti-clockwise. The presence of the contact pair reduces the free length of one flexures, resulting in a considerable increment of the overall joint stiffness. The pivot behaviour is investigated, for different load cases, via the Chained-Beam-Constraint Model (CBCM), namely an accurate method to be applied in large deflection problems. A framework comprising Matlab and ANSYS is developed for testing the CAFP performances in terms of rotational stiffness, parasitic shift and maximum stress, with different combinations of geometrical aspect ratios and contact extensions. Results achieved via CBCM for a pure rotation applied to the CAFP's output link are then verified through Finite Element Analysis. The resulting performance maps show good agreement between the numerical results. Furthermore, the CBCM shows an improved computational efficiency, which is a crucial aspect for preliminary design steps. At last, direct comparison between simulations and experiments, developed by means of two custom test rigs, confirms the efficacy of the proposed design method for the modeling of contacts in large deflection problems.

Keywords: Chained-beam-constraint model , Contact-aided compliant mechanism , Cross-Axis Flexural Pivot , Multi software framework

REACTION is an EU Innovation Action Funded Project which aims to develop the first worldwide 200mm Silicon Carbide (SiC) Pilot Line for SiC based Power technology. The project, which mainly addresses the Smart Mobility societal challenge (car electrification), will allow to match the ever-increasing demand of requirements in terms of quality and cost constraint for next decade generation's power electronics. A major strength of the project is the complete value chain implementation of the Pilot Line, which integrates and optimizes the cooperation and partnership among producers of 8"SiC substrates and equipment developers, as well as SiC process technologists, RTOs and end-users partners, in order to deliver the final applications. Hence, to achieve innovative SiC power devices with improved performances, along with cost and size reduction, are the most relevant requirements addressed in the project that are expected to lead to a new stronger European supply chain for very compact SiC converters, ideal for the addressed Automotive application.

Keywords: Automotive , Package , Power Electronics , SiC , Smart Mobility

Feedback through the steering wheel is known as the most important source of information to the driver. The so-called steering feeling, composed of self-aligning actions coming from tyres and suspension geometry all the way through mechanical linkages to the driver's hands, provides vital communication for intuitive driving, and it is therefore utterly important for safety and for a pleasant driving experience as well. Subtle forces and vibrations, due to the interaction between the tyre contact patch and the road surface texture, also play a role, provided they are not heavily filtered or cancelled by the power steering system. Human perception is guided by experience in order to establish correlations between steering feedback and vehicle motion in terms of straight-line stability, cornering speed, tyre adhesion and available friction, vehicle balance, and so on. A front-wheel drive car is potentially a critical vehicle from this point of view, especially when the powertrain can deliver large torque figures, and even more so if a limited-slip differential (LSD) or a similar active device is present in order to improve traction capabilities. Any difference between the two wheels in terms of tractive force can result into the so-called torque steer issue, that is to say, a "pulling" sensation on the steering wheel or a shifting of the vehicle from the desired trajectory. This paper analyses the torque steer phenomenon on an all-wheel-drive, full electric sportscar where a significant portion of the torque is transferred to the front axle. The effects of suspension kinematics and the load variation at tyre contact patch level are taken into account. For evaluating the impact of steering feedback, the VI-grade® simulation software is adopted and a test campaign on the professional driving simulator available at the University of Brescia has been carried out in order to understand the impact of steering feedback on driver perception and performance.

Keywords: Electric cars , Steering feeling , Torque steer

Beyond the well-known benefits of electric and hybrid powertrains in terms of environmental impact, the peculiar torque curve of electric motors for automotive applications offers extensive opportunities for improved vehicle dynamics control, such as yaw moment control through the application of different tractive forces across the axle: the so-called Torque Vectoring [1]. This is made possible for instance by fitting an independent motor on each wheel of a drive axle. On the other side, whenever Torque Vectoring is achieved on the front axle it can give birth to the so called torque steer effect: an undesirable influence of tractive or braking torque on the steering [2]. This is perceived by the driver as a “tugging or pulling sensation in the steering wheel, or a veering of the vehicle from the intended path” [3]. The steering feedback and self-aligning properties, often considered a vital portion of the feedback required for safe and intuitive driving control [4, 5], are thus jeopardized, especially under heavy acceleration. This is very similar to what can be experienced on front-wheel-drive cars featuring a high torque-to-weight ratio, often requiring the adoption of a LSD or active differential device in order to optimize traction capabilities [6]. The paper presents an approach to the torque steer problem on high-performance electric and hybrid vehicles, where the effects of suspension and steering geometry as well as tyre contact patch load variation are taken into account and various design solutions are proposed as an improvement. The VI-grade® software tools for vehicle dynamics analysis are adopted, also in co-simulation with MATLAB-Simulink® whenever an active control strategy is used. The impact on steering feedback quality is assessed through a testing campaign carried out on a state-of-the-art driving simulator.

Keywords: Torque steer

Multicrieria Decision-making methods (MCDM) are efficiently used as a support to engineering design, even if tested procedures and experience-based approaches are often preferred in SMEs and several industrial contexts. An extended critical review investigates how decision-making methods can help solving engineering design problems in automotive design. In particular, in this work, a classification of decision-making methods related to engineering design, is proposed, in which decisional techniques are matched with the design phases, and to corresponding automotive industry design problems. In literature a large amount of paper is dedicated to the selection of materials and manufacturing processes in the detail design phase. Also, hybrid methods, namely a combination of decision-making methods with other mathematical methods will be investigated to overcome some methodological drawbacks in MCDM methods. Due to the high impact of the problem in both industrial and research field, this work could help increasing production rate by reducing redesign errors related to material/processes selection problems, and concurrently transferring the knowledge of decision-making methods within the industrial context.

Keywords: Automotive design , Detail design , Material selection , Multicriteria decision making

Advanced composite materials have been attracting the interest of many automotive companies for producing light and high-performance components. Out-Of-Autoclave methods have been recognized as the most promising processes to produce CFRP components. One of the most interesting process is Compression-RTM. The aim of this research is to demonstrate the validity of the C-RTM process for producing parts with a thickness greater than 10 mm. The authors fabricated a preform made by 17 layers of PAN based carbon fibre 800 g/m2 and 600 g/m2 twill fabric and injected more than 700 g of matrix. Process simulations have been run to test different boundary conditions without producing physical prototypes. Flexural tests have been performed to compare the behavior of thick parts produced by C-RTM with the ones produced by prepreg and autoclave. The results show comparable strength values between the samples tested. DSC, void content and ultrasound measurements have been investigated to fully understand the physical properties of the finished component. Moreover, cycle times has been analysed to demonstrate the effectiveness of the method both from process and product performances points of view. Results show that thanks to the use of C-RTM the manufacturing time decreases by 68% with respect to the autoclave processes.

Keywords: Compression Resin Transfer Molding , Experimental tests , Process simulation , Thick CFRP components

Today the assembly lines of cars chassis are highly automated by robotic operations. Even in the top class automotive sector, the production of aluminium chassis involves numerous automated operations, such as TIG and MIG welding, riveting and gluing. This practice allows, on the one hand, to reduce time and costs, improve process repeatability and quality standards. On the other hand, it requires the quality improvement of the whole process (from supplied parts approval to welding reworks minimization). The industrialization phase of a new car chassis and the launch of its automated assembly line are particularly critical, even more if the line has already been designed and only minimally modifiable. Therefore, this paper proposes the implementation of a quality framework to manage the launch of an automated assembly line of a new aluminium chassis of top class cars, selected as a case study. The framework was implemented, aiming at improving the entire process quality, and finally validated by critically comparing the results obtained with those relating to models currently in production. Due to their importance to the final quality, we focused on the welding operations, which require actions both on process parameters and supplied parts approval (e.g. tolerances on parts end cuts). The new line shows a clear improvement compared to the past, with highly significant reduction of welding non-conformances, high quality level and lack of many critical issues of the previous lines thanks to corrective actions taken in the early process stages, during the pilot phase.

In the era of Industry 4.0, several advantages for industries come by the implementation of new technologies that play a key role for improving production processes, focusing on working times, product quality, accuracy of operations and other important parameters of the production systems. In order to evaluate these parameters, simulation may be used as a tool to verify (i) the improvement adopted on existing production lines or (ii) the design solutions adopted for a new line, optimizing the processes. The aim of this paper is to investigate the possibility to assess the before said parameters in a specific case study by implementing a Discrete Event Simulation (DES). The study concerns two consecutive workplaces of an automotive assembly line in which three workers are involved in assembly activities. The results demonstrated that the Digital Manufacturing (DM) approach and simulation may be used for verifying the performances of the line, thanks to the evaluation of important parameters, such as the Overall Equipment Effectiveness (OEE).

Keywords: Overall Equipment Effectiveness , Simulation , Work measurement