Improving Handling Stability Performance of Four-Wheel Steering Vehicle Based on the H2/H∞ Robust Control

Fei-Xiang Xu,Bing-Wei Cao,Wei Chen,Xin-Hui Liu,Chen Zhou

doi:10.3390/app9050857

Abstract

Considering the demand for vehicle stability control and the existence of uncertainties in the four-wheel steering (4WS) system, the mixed H2/H∞ robust control methodology of the 4WS system is proposed. Firstly, the linear 2DOF vehicle model, the nonlinear 8DOF vehicle model, the driver model, and the rear wheel electrohydraulic system model were constructed. Secondly, based on the yaw rate tracking strategy, the mixed H2/H∞ controller was designed with the optimized weighting functions to guarantee system performance, robustness, and the robust stability of the 4WS vehicle stability control system. The H∞ method was applied to minimize the effects of modeling uncertainties, sensor noise, and external disturbances on the system outputs, and the H2 method was used to ensure system performance. Finally, numerical simulations based on Matlab/Simulink and hardware-in-the-loop experiments were performed with the proposed control strategy to identify its performance. The simulation and experimental results indicate that the handling stability of the 4WS vehicle is improved by the H2/H∞ controller and that the 4WS system with the H2/H∞ controller has better handling stability and robustness than those of the H∞ controller and the proportional controller.

Highlights

With the development of electronic and control technologies, the four-wheel steering (4WS)system for automobiles has been actively studied as an effective vehicle maneuvering technology that can improve the maneuvering of vehicles at low speeds and enhance their stability at high speeds [1].In order to enhance control performance, many studies have focused on the control strategies of the Various control strategies have been performed on vehicle stability control, such as PID control [6], fuzzy control [7], and neural network control [8]
The results demonstrated the effectiveness of the H∞ controller by analyzing the control performance of the yaw rate and sideslip angle
The simulations based on Matlab/Simulink were performed with the proposed H2/H∞ control

Summary

Introduction

In order to enhance control performance, many studies have focused on the control strategies of the Various control strategies have been performed on vehicle stability control, such as PID control [6], fuzzy control [7], and neural network control [8]. These control approaches enhance vehicle stability to a certain extent, neural network control needs a wide variety of experimental data, fuzzy control requires human experience to construct the fuzzy rules, and PID control shows weak robustness against external disturbances.

Methods

Results

Conclusion