On the Vehicle Dynamic Response to the Steering Control - Experimental Evaluation of the Response and Analytical Approach to the Design of the Performance with Seven Degrees Model

This paper describes experimental and analytical approaches which were developed for the purpose of planning, designing and tuning up not only steady state but also dynamic characteristics of the vehicle maneuvering performance.

As regards experimental approaches, outlines of the testing methods and relationship between the measured typical characteristics and the drivers' feeling are presented. They were investigated and developed in order to qualify the general characteristics of produced vehicle dynamics, effectively and accurately, and to apply the results to the vehicle design. As regards analytical approaches, the seven degrees' theoretical model is introduced. It is established for the purpose of analyzing the influences on vehicle performances by changes in design parameters, including the lateral rigidity of tires, the torsional rigidity of the steering system, and some nonlinear dampings in steering and suspension systems. The results of studies about the relationship between design parameters and vehicle characteristics -- particularly dynamic characteristics -- are then described. Some of the new points of view about dynamic vehicle performances are indicated and experimental data are used for substantiation.

As the results of these researches, selecting procedures of vehicle parameters for designing and tuning vehicle performances are presented in the field of stability and controllability.