Validation of a Real-Time Capable Multibody Vehicle Dynamics Formulation for Automotive Testing Frameworks Based on Simulation

The growing functionalities implemented on vehicles have increased the importance of simulation in the design process. This complexity is mainly driven by the introduction of electrified powertrains, Advanced Driver Assistance Systems (ADAS) and Automated Driving Systems (ADS). Additionally, the automotive industry must reduce development times and cost, while keeping flexible development capabilities and fulfilling demanding regulation standards for safety-critical systems. Existing testing frameworks based on simulation implement typically analytical models to ensure real-time performance, and provide limited flexibility to perform Hardware in the Loop (HiL) setup based tests. In this work a vehicle modelling approach which guarantees high accuracy and real-time capabilities is proposed. Moreover, the proposed approach is validated firstly with real vehicle data, demonstrating that it can fairly reproduce the behaviour of the vehicle tested; and secondly, in a HiL setup to demonstrate the real-time execution capabilities of the approach

Light Commercial Vehicle ADAS-Oriented Modelling: An Optimization-Based Conversion Tool from Multibody to Real-Time Vehicle Dynamics Model

In the last few years, the number of Advanced Driver Assistance Systems (ADAS) on road vehicles has been increased with the aim of dramatically reducing road accidents. Therefore, the OEMs need to integrate and test these systems, to comply with the safety regulations. To lower the development cost, instead of experimental testing, many virtual simulation scenarios need to be tested for ADAS validation. The classic multibody vehicle approach, normally used to design and optimize vehicle dynamics performance, is not always suitable to cope with these new tasks; therefore, real-time lumped-parameter vehicle models implementation becomes more and more necessary. This paper aims at providing a methodology to convert experimentally validated light commercial vehicles (LCV) multibody models (MBM) into real-time lumped-parameter models (RTM). The proposed methodology involves the definition of the vehicle subsystems and the level of complexity required to achieve a good match between the simulation results obtained from the two models. Thus, an automatic vehicle model converter will be presented together with the assessment of its accuracy. An optimization phase is included into the conversion tool, to fine-tune uncertain vehicle parameters and to compensate for inherent modelling differences. The objective function of the optimization is based on typical performance indices used for vehicle longitudinal and lateral dynamics assessment. Finally, the simulation results from the original and converted models are compared during steady-state and transient tests, to prove the conversion fidelity

Wheel-rail contact force measurement. A comparison between distance laser and strain gauges measuring technology

The development of this PhD thesis is focus on the wheel/rail contact force measurement on a 1 : 10 scaled railway vehicle. To that end, the author has designed and manufactured a dynamometric wheelset instrumented with several sensors for the direct measurement of forces applied on the instrumented wheel. Two di erent technologies have been used for the wheelset instrumentation: On the one hand, a set of strain gauges measure the radial strains experienced by the wheel-web when a lateral load is applied on the wheel. On the other hand, three high precision lasers have been installed on the axel that measure the lateral de ection experienced by the wheel due to the applied lateral loads. Normal contact forces are measured independently throughout the de ection experienced by the primary suspension. This is also measured with laser distance sensors. After being instrumented, the wheelset has been submitted to a calibration process. A calibration test bench where controlled loads can be applied to the wheelset has been also designed and manufactured. Finally the instrumented wheelset has been installed on the scaled vehicle and tested on a 5 inches wide scale track. The force measurements obtained in the experiments with both set of sensors have been compared with numerical results drawn from a computational model of the vehicle. A novel procedure to measure the track irregularities applied to the scaled track has been also include as part of this thesis.El desarrollo de esta tesis se centra en la medici on experimental de fuerzas de contacto rueda carril en un veh culo ferroviario a escala 1 : 10. Para ello, el autor ha dise~nado y fabricado un eje dinamom etrico instrumentado con multiples sensores para la medici on directa de las fuerzas aplicadas en las ruedas. Para la instrumentaci on del sistema se han utilizado dos tecnolog as distintas: Por un lado se dispone de un conjunto de bandas extensom etricas que miden las deformaciones radiales experimentadas por el velo de la rueda debidas a la carga lateral aplicada en la misma. Por otro lado se han instalado tres l aseres de alta precisi on que miden la de exi on experimentada por la rueda debidas tambi en a las cargas lateral aplicadas. Las fuerzas normales a las que se ve sometida la rueda son calculadas a trav es de la medici on de la de exi on experimentada por la suspensi on primaria del veh culo, siendo tambi en medida mediante sensores de distancia l aser. Tras la instrumentaci on el eje dinamom etrico ha sido sometido a un proceso de calibraci on, para el cual se ha dise~nado y fabricado un banco de pruebas a escala donde puden aplicarse cargas al eje de forma controlada y conocer la respuesta de los sensores. Finalmente el mencionado eje dinamom etrico ha sido instalado en el veh culo a escala y su funcionamiento ha sido probado en una v a a escala de 5 inches de ancho. En los experimentos realizados se han contrastado las mediciones de fuerzas realizadas por ambos sensores y comparado con resultados num ericos obtenidos de un modelo multicuerpo de simulaci on del veh culo. Como parte de esta tesis se incluye tambi en la descripci on del novedoso proceso de auscultaci on y c alculo de irregularidades realizado en del trazado ferroviario a escala

Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015

This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version

Mathematical models for assessment of vehicle crashworthiness: a review

publishedVersio

Dynamic Human Body Models in Vehicle Safety: An Overview

Significant trends in the vehicle industry are autonomous driving, micromobility, electrification and the increased use of shared mobility solutions. These new vehicle automation and mobility classes lead to a larger number of occupant positions, interiors and load directions. As safety systems interact with and protect occupants, it is essential to place the human, with its variability and vulnerability, at the center of the design and operation of these systems. Digital human body models (HBMs) can help meet these requirements and are therefore increasingly being integrated into the development of new vehicle models. This contribution provides an overview of current HBMs and their applications in vehicle safety in different driving modes. The authors briefly introduce the underlying mathematical methods and present a selection of HBMs to the reader. An overview table with guideline values for simulation times, common applications and available variants of the models is provided. To provide insight into the broad application of HBMs, the authors present three case studies in the field of vehicle safety: (i) in-crash finite element simulations and injuries of riders on a motorcycle; (ii) scenario-based assessment of the active pre-crash behavior of occupants with the Madymo multibody HBM; (iii) prediction of human behavior in a take-over scenario using the EMMA model

Combining Sensors and Multibody Models for Applications in Vehicles, Machines, Robots and Humans

The combination of physical sensors and computational models to provide additional information about system states, inputs and/or parameters, in what is known as virtual sensing, is becoming increasingly popular in many sectors, such as the automotive, aeronautics, aerospatial, railway, machinery, robotics and human biomechanics sectors. While, in many cases, control-oriented models, which are generally simple, are the best choice, multibody models, which can be much more detailed, may be better suited to some applications, such as during the design stage of a new product