OBJECTIVE LABORATORY AND ROAD METHODS FOR THE EVALUATION OF THE PERFORMANCE OF STEERING SYSTEMS IN PASSENGER VEHICLES

摘要

When drivers evaluate the handling performance of vehicles, steering feel is one of the first and most important points they notice. The fact that drivers make constant steering corrections with very small amplitudes in a variety of driving conditions means that steering precision, delay and sharpness are crucial characteristics of the handling impression of a vehicle. This paper presents several sophisticated experimental methods for evaluating the steering precision of passenger vehicles. The methods combine objective road measurements that quantify the subjective evaluations made by experienced drivers, and laboratory analysis that are linked to with the objective road metrics. The correlation level between both evaluations is presented.The different ranges of vehicle performance will be evaluated, including various amplitude and frequency levels covering the most significant input types that normal drivers apply on the road. The study discusses all the practical aspects of the approach to this concern, including: - the instrumentation and laboratory devices that allow the main vehicle dynamic parameters to be characterised, - a close investigation of different test procedures (standard and otherwise) using various test input ranges and test conditions, and - an evaluation of the most important parameters that come out of the final analysis and its influence on the vehicle performance. The combination of these methods makes it possible to quantify and closely isolate the most important vehicle variables that affect the complex evaluation of the steering feel of a vehicle. Therefore, this paper shows a new evaluation method that uses conventional and nonconventional measurement tools that will be of valuable application to the development programs of chassis systems of different types of vehicles.