Search

High quality standards and components downsizing are two main quests of the engineering designers in the nowadays automotive industry. To this aim, lightweight materials as aluminum are used. Moreover, most parts of the automotive chassis made of aluminum are assembled by means of welding techniques. Lightweight materials, such as aluminum, are more and more adopted in chassis design even if the assembly process represents a challenge from a technological point of view, especially due to the distortions caused by the welding process. In case of thin aluminum structures, non-convenient distortions occur due to a combination of effects of fixturing and cooling (after welding) process. The reduction of distortions or almost their prediction is still a very challenging issue, so that no conclusive technique has been found to exclusively fix the problem yet. In this paper, a “design for welding” approach is proposed as an integrated product design and process simulation method, with the aim of predicting the final distortion of an aluminum welded automotive chassis. Thermal-Elastic-Plastic (TEP) finite element analyses (FEA) simulations are capable to provide acceptable results, but require high computational efforts, especially in case of complex geometries as car chassis. To overcome this problem, in this paper, the local-global FEA approach has been adopted with satisfactory results. A top-class car automotive aluminum chassis has been chosen as a case study.

The airbag deployment against an out of position (OP) occupant is critical. The OP condition can be hardly expected during design, while a too close airbag deployment can cause serious injuries instead of mitigating the crash effects. An adaptive airbag system would be capable to adjust its deployment to the inside scenario. However, the integration between human passengers and intelligent vehicle requires the airbag control unit to be aware of the actual occupant(s) position. In the present research, a methodology for monitoring the occupant(s) position is developed and tested with a seat prototype. A layout of thin film sensors monitors the interface pressure between the occupant and the seat cover. An inertial measurement unit (IMU) monitors the accelerations of the vehicle, considered the reference moving platform. A microcontroller is programmed for pressure sensors calibration, IMU alignment with the vehicle reference system, signals processing, OP detection, and identification. Real driving experiments on a race track were performed in the correct position and in three different OPs. The comparison of the pressure center in longitudinal and transversal directions with the vehicle acceleration enables to identify the OPs.

Metal Additive Manufacturing technologies provide many advantages among industrial sectors. Most applications exploit design freedom for functional design enabled by Powder Bed Fusion processes, while Directed Energy Deposition systems are mainly restricted to the construction of large parts and reparation of damaged components. Nevertheless, the latter provide not only high deposition rates, but also high flexibility, and the possibility to process multi-materials, to grade and combine their characteristics for enhanced features and performance. Therefore, a rising application is the remanufacturing of existing components to produce functional design variants. Those parts can integrate different features and materials through direct deposition of metals over bounded areas. This work concerns the development of a Design for Additive Remanufacturing methodology for existing components with improved performances to be produced by the laser-based Direct Metal Deposition process. It relies on the use of CAD platforms for the integrated design of products and the associated processes. The design approach is based on the integration of CAE structural analysis and Topology Optimization, to define the location and the morphology of deposited structures. The design of an automotive suspension arm with enhanced performances is the use case to demonstrate the effectiveness of the approach, which could be extended to the remanufacturing of several bodies and chassis automotive subsystems.

Additive Manufacturing (AM) is a key technology in current industrial transformations thanks to the significant benefits that can bring to high-level sectors. Nevertheless, AM-based design approaches require improvements that are fundamental to exploit the potentials of the technology and reduce the lack of process consistency. This work focuses on integrated Design for Additive Manufacturing (DfAM) approaches for product-process design, to meet both functional and technological targets. The key aspects of process design and issues are summarized and the design method to perform metal AM process optimization is presented. The aim is therefore to minimize process-induced defects and flaws of AM-based manufacturing of metal products, such as residual stress and distortions. The approach consists of industrialization task improvement based on modelling optimization and build optimization sub-phases supported by numerical process simulation. Integration of CAD platforms allows embedding these steps to be performed downstream of the product design, which can be achieved through functional or multifunctional optimization techniques as well (e.g. topology optimization, latticing, graded structures/materials). The design method is finally applied to perform the industrialization phase of a high-performance automotive component. The case study is a formula SAE topology optimized brake caliper to be produced by Selective Laser Melting (SLM) process. Process simulation-driven studies on modelling and build preparation subphases (i.e. orientation definition, supports generation, model distortion compensation) are conducted to support the process design. The study demonstrates the part scale level method’s suitability to industrial context to improve industrialization in the redesign of components to be produced by metal AM.

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.

Las companias fabricantes de automoviles continuamente promueven la innovacion de los productos de automocion y los procesos de fabricacion relacionados, basandose principalmente en metodos dedicados para el diseno de chasis de automocion y en los procesos de montaje con soldadura relacionados a ese diseno. Los primeros de ellos buscan mejorar la calidad final de todo el chasis a traves de optimizacion del ratio rigidez/ peso y a traves del uso de materiales de alto rendimiento. Los segundos buscan mejorar el rendimiento del chasis y reducir los costes de produccion total reduciendo los residuos mediante lineas de soldadura roboticas reconfigurables. Por consiguiente, se requieren nuevas metodologias de diseno integradas que tengan en cuenta las restricciones y especificaciones de las fases de diseno del proceso/producto, a la vez que se sugiere un uso concurrente de metodologias numericas y herramientas de simulacion para evaluar la configuracion de los sistemas roboticos y la programacion de los robots. Esta investigacion presenta una metodologia de diseno novedosa que busca reducir las desventajas de las actuales metodologias por medio de la evaluacion de operaciones de ensamblado antes de diseno en detalle del chasis y del diseno conceptual del sistema de fijacion, explotando las herramientas asistidas por ordenador. En particular este trabajo se centra en la fase de proceso de la metodologia de diseno, que busca integrar las herramientas de programacion offline de robots, para predecir las distorsiones de soldadura debido a la modificacion de los parametros de entrada del robot de acuerdo con los valores de tolerancia requeridos. Los resultados experimentales en relativos al submontaje de un chasis de referencia que se une siguiendo procesos de soldadura basados en herramientas asistidas por ordenador demuestran la efectividad del metodo propuesto. Palabras clave: Metodo integrado basado en CAD, analisis de tolerancia acumuladas, prediccion de distorsiones de soldadura, ensamblaje de soldadura robotica.

Easy-to-use collaborative robotics solutions, where human workers and robots share their skills, are entering the market, thus becoming the new frontier in industrial robotics. They allow to combine the advantages of robots, which enjoy high levels of accuracy, speed and repeatability, with the flexibility and cognitive skills of human workers. However, to achieve an efficient human–robot collaboration, several challenges need to be tackled. First, a safe interaction must be guaranteed to prevent harming humans having a direct contact with the moving robot. Additionally, to take full advantage of human skills, it is important that intuitive user interfaces are properly designed, so that human operators can easily program and interact with the robot. In this survey paper, an extensive review on human–robot collaboration in industrial environment is provided, with specific focus on issues related to physical and cognitive interaction. The commercially available solutions are also presented and the main industrial applications where collaborative robotic is advantageous are discussed, highlighting how collaborative solutions are intended to improve the efficiency of the system and which the open issue are.

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.

The Dimensional Management (DM) is well known as the reference methodology for the management of dimensional and geometric variations of industrial products. Over the years, it has assumed a central role, thanks to the development of a specific design approach, known as Design for Tolerancing (DfT). Based on the Geometric Dimensioning and Tolerancing (GD&T) symbolic language, DfT allows to check and verify functional and qualitative requirements from the early design phases. Although its strength and potential to improve design optimization, DfT industrial application is still limited. Consolidated design practices, complexity of tolerance specification process, lack of support from Computer-Aided tools still limit the tolerance specification to final validation of product design. The paper aims to define a tolerance specification model for systematic application of GD&T specification. The model formalizes the identification and translation of product requirements on the components geometry, through the definition of the main step of tolerance design. Based on the integration between the GD&T-based approach and parametric three-dimensional CAD modelling, the model has been applied to validate the GD&T and the tolerance specification of two mechanical assemblies with common features. The methodology proves its general effectiveness to support engineers in tolerance design and selection of the most suitable GD&T schemes.

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.

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.

Additive Manufacturing is having a great trend since its implementation possible benefits have been widely discussed and efforts in technology improvements are having impact on process reliability and industrial application. The aims of this work are to analyze the current and forthcoming scenario of methods for the specific development of parts to be produced by metal AM including topology optimization as a basic design step and to demonstrate that systematical design approaches can be introduced in order to better exploit potentials offered by AM implementation. The general framework composed by the main tasks is introduced and discussed. Key factors such as advance in different design solutions exploration, product-related and process-related design constraint implementation in the design phase and method effectiveness in product development lead time minimization are presented. Linear and iterative workflows are described, considering features, decision making points, pros and cons, possible variants and research hints. A strong connection between methods and actual means is highlighted and workflow implementation using standard and integrated commercial tools is considered. Such methods are related to several automotive case studies presented in order to demonstrate their applicability and to show actual results and possible further development.

Additive Manufacturing based on Powder Bed Fusion processes enables the construction of end-use functional metal components, making it feasible to design several level of geometrical complexity. Nevertheless, the printing process leads to material and shape defects, residual stress and induced distortions on final components that mainly are caused by the high thermal gradients associated to the intense and nonuniform power energy sources used to selectively melt metal powders. In this paper, techniques to reduce or prevent these effects are summarized. The more broadly Design for Additive Manufacturing approach based on the use on CAD platforms for product-process design is the backbone upon this research is based on. Specifically, the work presents a design method to predict drawbacks and improve the industrialization subphase. Laser-based Powder Bed Fusion technique is considered and the implementation and validation of the Selective Laser Melting process simulation is performed in order to support the method. Two case studies are presented. The former demonstrates the simulation implementation feasibility through a CAD platform. The latter validates the simulation results compared to experimental data for further method application.