Track: Modeling and Simulation

Abstract

In-vehicle handling one of the most important systems is the steering system. Typically, all vehicles have a steering system that allows the vehicle to be turned to either side, that is, left or right. In this paper, an idea of implemented considering a steering system for the rear wheel in addition to the front wheel, resulting in a four-wheel steering system. The turning radius required for four-wheel steering is less than that necessary for front-wheel steering after evaluating the effect of the four-wheel steering system. Some cars use four-wheel steering to improve steering response, increase vehicle stability while driving at high speeds, or reduce turning radius while maneuvering at low speeds. However, the improvement in turning radius is discussed using Ackermann steering geometry (ASG), from which the wheel critical turning angles are calculated for minimum turning radius. The steering system is implemented using a rack and pinion mechanism, and the design of the pinion and rack are obtained from ASG. In the study, the vehicle behavior for 4-wheel steering is done using a physical prototype and MATLAB Simulink model. Also, the steering of the front and rear wheel is performed using a servo motor which is controlled by the microcontroller. The vehicle's turning radius is reduced by 33% due to the four-wheel steering system. Improvements have also been made in high-speed handling while changing lane with the four-wheel steering system, in which excessive lateral displacement has been reduced by 77% and reduce the time required to change the lane. Also, the study of these forces for the four-wheel steering system is discussed for low-speed maneuvering.