Controller Design for an Automobile Steer-By-Wire System

The purpose of this study is to propose a control scheme for an automobile Steer-By-Wire (SBW) system. A mathematical model of SBW system is built. A co-simulation platform in software of MATLAB/Simulink and a Hardware-in-the Loop (HIL) system is developed. By using ARX algorithm, the parameters of the SBW system are identified. Then, an Internal Model Controller (IMC) for the SBW system is designed to track desired motion states of controlled vehicle. In typical driving conditions, simulations are carried out to examine the effectiveness of designed controller. Compared with a PID controller, the results demonstrate that designed IMC controller is able to provide better control performance. To reduce the steering efforts of the driver, meanwhile ensure the stability of the vehicle in different driving conditions, a variable gearing ratio control strategy is proposed, and also its characteristics are examined in different cases. Besides, a Slide Mode Controller (SMC) for tracking desired yaw rate is designed to realize the active steering. Co-simulation results show that desired yaw rate can be tracked satisfactorily by using the designed controllers, with enhanced handling and stability performance.