Seoul 2000 FISITA World Automotive Congress
June 12-15, 2000, Seoul, Korea
Theoretical Study of Steering Effort
- using Autosim Park Il Rae
Chassis Design Team 1, 700, YangJung, Buk-Ku, Ulsan, Korea
The steering effort is an important characteristic of vehicles because it influences driver comfort directly. Steering effort and steering feel are of interest in this report. This report used AutoSim to model the vehicle and to prepare simulation code. FORTRAN was used to analyse the non-linear behaviour of vehicle and was also used for tire modeling using the
Magic Formula. A parametric study of these parameters is carried out to get their effects on the steering effort. The influences of design parameters and driving conditions were computed.
Keywords: Steering Effort controllability and stability of the driver/vehicle system.
INTRODUCTION
Steering wheel Torque vs. Angle Characteristics Two parameters are used to characterise this plot as shown in
Figure 1. These are the steering wheel torque at 0 degree and steering torque gradient at 0 degree, commonly referred to as “steering stiffness” which shows whether the steering system requires precise handling.
Steering feel, a driver’s perception of steering characteristics, has become an important issue in recent years. Steering effort according to the vehicle speed and steer speed is directly affecting the steering feel and driving comfort. Steering effort can be conveniently divided into parking manoeuvre and driving manoeuvre categories. The driving manoeuvre class can be further broken down into on-centre and off-centre sections. Steering effort on parking and on driving manoeuvre is generated by different procedures. In a parking manoeuvre, steering effort is developed due to the elastic deformation of the tire tread due to the friction between tire surface and ground. Selfaligning moment, couple due to side force and pneumatic trail, is the main parameter in a
References: [1] Bakker, E., and Nyborg, Pacejka H.B. 1987. Tire modelling for use in vehicle dynamics studies [4] Norman, Kenneth D. 1984. Objective evaluation of oncentre handling performance. [5] Reimpell, J. and Stoll, H. 1996. The Automotive Chassis: Engineering Principles