Analysis of Steering Geometry and Design of Steering Mechanisms for Four-Axle Vehicles

摘要

The purpose of this study is to understand the effects of steering geometry and to develop the proper steering mechanisms of a four-axle vehicle to improve the cornering behaviors. Firstly, based on kinematics and Newtonian mechanics, a 3-DOF steady-state cornering vehicle model, with considering Magic Formula of tire model and simplified suspension model, has been developed. The steady state cornering characteristics of a four-axle vehicle can be found by solving equations of motion. Secondly, implementing the suggested steering geometry, we can determine the optimized design parameters of the steering linkage by using a global search method. It is found that cornering behaviors of this new steering linkage can have better performance than the real four-axle vehicle we chose. Lastly, the effect of the fourth-axle is introduced and included into the investigation. The discussion on the steering geometry arrangements and its effect are presented. Based on the discussions and the design method developed in this work, the steering linkage of four-axle vehicle can be further developed to fit any case by achieving particular steering geometry.