F2008-12-011
Simulating Customer-Oriented Operating Loads of Chassis Components
Title: Simulating customer-oriented operating loads of chassis components
Main points: Car manufacturing, systematic collection of operating loads in customer opera-tion, considering chassis components as an example
Author: Dipl.-Ing. H. Kollmer, tel: 0531/391-2616, email: h.kollmer@tu-bs.de Co-authors: Dipl.-Ing. A. Janßen Prof. Dr.-Ing. F. Küçükay
Address: Technical University of Braunschweig Institute of Automotive Engineering tel.: 0531/391-2610 Hans-Sommer-Straße 4 38106 Braunschweig
A systematic approach of a quick and reliable simulation of customer-oriented operating loads of chassis components will be presented. Various customer types, differing in driving style, preferred vehicle load and chosen road, are defined to take different customer behaviours in the simulation systematically into account.
Extensive measurements taken in real traffic were statistically evaluated to describe the driver behaviour depending on traffic situation, road condition, performance class and load condition of the vehicle. The driver behaviour was filed in statistics, describing the driver actions depending on vehicle class (small car, compact class, saloon, minivan, SUV and off-road vehicle), type of road (auto-bahn, city, country road, mountain road) and driving style (economy, average and sporty). In the following driving simulation, a driver model is used which returns the statistically collected driver actions back into the time range. It allows simulation runs that can be as long as desired. The driving environment is represented by speed specification, bend, uphill gradient and road unevenness, which were recorded statistically by extensive measurements as well. The vehicle is represented by a two-track model to calculate the forces at the wheel hub centre. The operating loads of the chassis components are determined from the wheel hub forces by means of a superposition algorithm. The method presented here can be applied for depicting the natural distribution of operating loads without having to use repeating or measured driver actions. By comparing the results of the simulation and measuring data from customer vehicles, the performance and result quality of the simulation environment was proved.
Furthermore, correlations between driver actions and vehicle-specific parameters can be identi-fied through the systematic evaluation of measuring data. They can be used for assessing operating loads in the early phase of the development process where only little vehicle data is known. It will be shown that realistic, customer-oriented operating loads can already be deter-mined by specifying some overall vehicle parameters, without any necessary measurements of the real vehicle. Reliable load spectra for various model variations can already be generated in the concept phase due to the short computing times (ten times faster than in real time).
This abstract is supplemented by a PDF, which can be viewed here.
Session: Durability, Reliability, Materials