Development of a parametric packaging and sizing tool for autonomous electric bus system

The demand for autonomous electric public transport is increasing globally. New vehicle models and variants are increasing the development complexity and hence the overall development time. Therefore, there is a requirement for a vehicle-packaging tool that can translate user inputs into an optimised vehicle package and can be visualised instantly. The aim of this paper is to develop a parametric tool for designing different concepts for electric autonomous buses. The scope of application is intended in the early phase of the vehicle development process to enable a fast and efficient creation of a flexible bus concept. Through a graphical user interface (GUI), the user is able to size and select all the required components for the autonomous vehicle concepts. The vehicle specification is initiated by selection of one of the three classes of vehicle, the desired number of passengers and then the bus interior’s seat arrangement design. An appropriate powertrain and chassis will then automatically be configured in the next steps. The HVAC simulation allows for the design of different components of the refrigeration circuit to ensure proper cabin temperature. For evaluating the concept, the energy consumption is analysed through simulations, and an estimated initial cost of vehicle concepts and individual systems completes the concept. A spider chart summarises all characteristics and offers an overview of the vehicle concept, providing the possibility to compare with other concepts simultaneously. The tool can create 9600 different bus concepts and provides interfaces for expansion.

evoDash – A Transdisciplinary Vision for an Education Platform and a Simulation-Based Vehicle Development Process

In the wake of environmental disasters and accelerating climate change the challenges facing humanity seem bigger than ever. In the public eye private transport and mobility are two of the most apparent fields in need of a sustainable evolution. Around the globe car manufacturers and developers of innovative mobility solutions are hard at work in shaping the future of transport and travel. Like many modern problems these fields require a transdisciplinary approach and collaboration of disciplines in order to design a solution. At Trier University of Applied Sciences, the student team proTRon has been building highly efficient mobility concepts since 2005 and developing the prototype for a law- and safety-compliant urban vehicle concept since 2015. In this industry-oriented collaboration project the students get the chance to work in a realistic environment emulating a vehicle development process, preparing them for a job in the mobility industry as the next generation of system developers and engineers with a transdisciplinary attitude. Within the framework of this project students acquire competencies in communication and cooperation as well as gain expertise in areas like sustainability, efficiency, and organization. This paper introduces “evoDash”, a human-vehicle interface prototype for the urban vehicle concept proTRon EVOLUTION with a focus on usability and modularity. Designed and developed by students it is a software architecture based on Android and central part of a vision for a transdisciplinary education platform, which provides the foundation for future software and hardware development projects working towards an innovative and sustainable human-vehicle interface. The modular architecture of the platform provides the necessary interfaces and layout options for the functionalities that result from innovative ideas and student projects, embedding them into a usable and individually adjustable framework that will be subject to continuous iterations in order to optimize usability, safety and security. This paper proposes a simulation-based process model focused on rapid prototyping. It aims at providing a possible framework for transdisciplinary engineering projects and education.

Enabling ISO 26262 Compliance with Accelerated Diagnostic Coverage Assessment

Modern vehicles are integrating a growing number of electronics to provide a safer experience for the driver. Therefore, safety is a non-negotiable requirement that must be considered through the vehicle development process. The ISO 26262 standard provides guidance to ensure that such requirements are implemented. Fault injection is highly recommended for the functional verification of safety mechanisms or to evaluate their diagnostic coverage capability. An exhaustive analysis is not required, but evidence of best effort through the diagnostic coverage assessment needs to be provided when performing quantitative evaluation of hardware architectural metrics. These metrics support that the automotive safety integrity level—ranging from A (lowest) to D (strictest) levels—was obeyed. In this context, this paper proposed a verification solution in order to build an approach that can accelerate the diagnostic coverage assessment via fault injection in the semiconductor level (i.e., hardware description language). The proposed solution does not require any modification of the design model to enable acceleration. Small parts of the OpenRISC architecture (namely a carry adder, the Tick Timer peripheral, and the exception block) were used to illustrate the methodology.

Deck Lid Surround Fit Correlation Study Between Dimensional Variation Simulation and Physical Vehicle

During vehicle development process, dimensional variation simulation has been applied to evaluate fit performance of build variation widely, including front end area, rear end area, interior and chassis. Both product and process variation are simulated based on rigid assumptions in traditional variation simulation model, but many components are not rigid and deformed after assembled on physical vehicle, which make the variation simulation model result not correlate with physical build well. Deck lid is kinetic and easy to be elastic deformed that is caused by torque rod and seal force, which would affect deck lid surround fit, especially for deck lid to body side outer flush, but these situations are not considered in traditional variation simulation model. In order to improve the correlation between dimensional variation simulation and physical vehicle variation, in this paper, deck lid deformation is considered in new variation simulation model. Compared with traditional method, the correlation between new variation simulation model and build variation on physical vehicle improved by 17%. This calculation method and result are closer to physical build than traditional variation simulation, limit of this study is seal margin variation, striker and bumper adjustment are not considered in FEA model. In future study, need to improve the correlation by considering all these factors. This study could be applied to identify actual vehicle fit risk in product development phase, it could also save tooling change cost in build period.

Assessment of running gear performance in relation to rolling contact fatigue of wheels and rails based on stochastic simulations

In this work, the authors present a methodology for assessing running gear with respect to rolling contact fatigue of wheels and rails. This assessment is based on the wheel/rail contact data of different wheel profile wear states obtained from a wheel profile prediction methodology. The approach allows a cumulative assessment of the rolling contact fatigue of rails in different curve radii (e.g. the sum of damage over the lifetime of wheel profiles). Furthermore, the assessment of the rolling contact fatigue can be undertaken at different wear states of the wheel profiles to provide an insight on how the rolling contact fatigue of wheels and rails varies depending on the evolution of wheel wear. The presented methodology is exemplarily applied to two bogie types, the UIC-Y25 standard bogie and the so-called FR8RAIL bogie with a mechanical wheelset steering device. The presented methodology has been shown to be a useful tool for the optimisation of vehicles already in an early stage of the vehicle development process.

Survey and Classification of Automotive Security Attacks

Due to current development trends in the automotive industry towards stronger connected and autonomous driving, the attack surface of vehicles is growing which increases the risk of security attacks. This has been confirmed by several research projects in which vehicles were attacked in order to trigger various functions. In some cases these functions were critical to operational safety. To make automotive systems more secure, concepts must be developed that take existing attacks into account. Several taxonomies were proposed to analyze and classify security attacks. However, in this paper we show that the existing taxonomies were not designed for application in the automotive development process and therefore do not provide enough degree of detail for supporting development phases such as threat analysis or security testing. In order to be able to use the information that security attacks can provide for the development of security concepts and for testing automotive systems, we propose a comprehensive taxonomy with degrees of detail which addresses these tasks. In particular, our proposed taxonomy is designed in such a wa, that each step in the vehicle development process can leverage it.

Numerical simulation of thermal loads of the truck’s power train mounting system due to vibrations

Dynamic simulation based on modelling has a significant role during a vehicle development process. It is especially important in the first design stages, when relevant parameters are to be defined. Power train mounting system is exposed to thermal loads which can lead to damage and degradation of its characteristics. Therefore, this paper aims to analyse conversion of mechanical work into heat energy in power train mounting system using a method of dynamic simulation. Considering the presence of classic–mechanical and hydraulic power train mounting systems in modern trucks, analysis of power train mounting thermal loads of FAP 1213 vehicle was conducted. Thermal loads of vehicle power train mounts were calculated by dynamic simulation, while their cooling process was not analysed.