Design and Simulation of Steer by Wire for Light Electric Vehicle

Abstract

The evolution of the vehicle steering system began with pure mechanical generation and progressed via hydraulic power-assisted steering (HPS), electro-hydraulic power-assisted steering (EHPS), electric power-assisted steering (EPS), and Steer-by-Wire (SBW) systems. In SBW the conventional steering system's hand-wheel link with the front wheels is eliminated, and instead, two electric motors are used to drive the front wheels and supply power to the vehicle driver for steering feel. In this thesis, the mathematical modelling of SBW systems is first explored, and two PID controllers designed to control the steering wheel angle and front wheel angle. The designed controller for SBW systems provides a comparative analysis of different optimization algorithms used to control tire angle and reveal the effect of system performance with disturbance and without disturbance at different driver torque input and steering angle. The simulation results show that the proposed vehicle steer by wire (VSBW) optimized by GWO algorithm produces 0.6032% overshoot and 0.1105s settling time which is lower than GA-PID and Auto-PID controller. That means its speed of response increased, stabile and reduced energy consumption to reach its desired tire angle positions. The GA and Matlab auto tuner have 2.1263% and 7.5229% overshoot, 0.2293s and 0.1983 settling time, respectively. This shows that the PID controller designed using GWO can effectively and efficiently control the operation of steering angle motor and tire angle while ensuring the comfort of driver and ensuring a smooth driving system. Finally, the simulation result reveals that GWO-PID controller strategy has smooth operation by reducing the vibration that occurs by the overshoot.