The Bilateral Control And Redundancy Algorithm Design For SBW System Of Vehicle

It is likely to realize various kinds of driving experience for Steer-By-Wire(SBW)system by controlling steering angle and torque of steering front wheels and hand wheel.To get the above target,this paper is focused on the control strategy of SBW system.The components and working principle of SBW system is analyzed firstly,and an introduction about overseas and domestic research status is demonstrated.The hardware-in-the-loop experiment platform is established on the basis of a rapid prototyping equipment A&D5435,which was used for validating control strategies of SBW system.Two different bilateral control strategies for SBW system is designed.One is named as position follow with toque feedback and the other type is called torque follow with position feedback.By developing the dynamic model and simulating with MATLAB/Simulink,these two control strategies are validated by the established hardware-in-the-loop experiment platform.The results show that the strategies turn out to be efficient and effective to realize the steering target and road feeling feedback.In order to improve the control strategy of position follow with toque feedback,a new road-feeling simulation algorithm is designed to replace the torque sensor which is used for measuring steering resisting torque and align torque.This part of research work is concentrated on road feeling simulation of SBW system.The dynamic model of steering actuator system is developed.Based on a linear vehicle model with 2 DOFs,yaw velocity observer is designed.A novel approach for road feeling simulation is proposed with estimated steering aligning torque,considering motor dynamic characters.The torque is set as the target of vector control for road feeling motor.The MATLAB/Simulink model is developed and model simulation is conducted to verify accuracy of the proposed control strategy for road feeling of SBW system.It is supposed to use redundancy technique to guarantee safety of SBW system when any fault happens.In this paper,an analytical redundancy algorithm is designed for steering angular sensor and lateral acceleration sensor.The signal range and signal difference range are detected respectively to check whether they are in the appropriate scope.A normal signal output is calculated by judging and identifying the fault sensors.The algorithm is verified by two types of sensor fault: the transient and persistent fault.The simulation results show the effectiveness of the algorithm to detect,judge and identify fault sensor for SBW system.