Research On Road Feeling Simulation Control Of Vehicle Steer-by-Wire System

As the steering-by-wire system eliminates the mechanical connection between the steering wheel and the steering wheel,the driver cannot directly obtain the road feeling information through the steering wheel.Therefore,this paper studies the road feeling simulation of steering-by-wire system,and considers the insufficient steering wheel turn-back phenomenon when the vehicle is steering at low speed,and designs the active turn-back control algorithm to realize the active steering wheel turn-back.Finally,the simulation and hardware-in-the-loop tests are carried out.The results show that the designed road feeling simulation control algorithm can make the vehicle have the advantages of light steering at low speed and steering feel clear at the hight speed,and can reduce the residual Angle of steering wheel return,and improve the vehicle return performance.According to the composition of the steering-by-wire system,the dynamic balance differential equation was established,and the corresponding simulation model was established in MATLAB/Simulink according to the differential equation.The co-simulation test was carried out in combination with the vehicle dynamics simulation software Carsim to verify the correctness of the model.The righting moment was calculated based on the dynamic model of righting moment,and the comprehensive road feeling simulation control strategy was designed based on vehicle speed and steering wheel Angle.Considering the different road feeling responsiveness of vehicles at different speed conditions,the friction compensation torque,limiting torque,damping torque and active righting torque are designed to compensate the road feeling,so that the designed road feeling conforms to the driver’s preference and improves the vehicle’s righting performance.Finally,the road feeling simulation algorithm is verified under several typical test conditions.The results show that the vehicle can achieve light steering at low speed,and the driver can get clear road feeling at high speed.In order to realize the circuit sensing simulation and steering wheel correction function,firstly,PID controller is designed to control the output target torque of the circuit sensing motor,so as to realize the circuit sensing simulation.The simulation test verifies that it can control the circuit sensing motor well to realize the circuit sensing simulation.Secondly,a sliding mode controller is designed to control the circuit sensing motor to realize the steering wheel’s righting.The simulation verifies that both PID controller and sliding mode controller can realize the steering wheel’s righting,and the sliding mode control has a faster convergence speed,which can make the steering wheel’s righting faster at low speed,and has good robustness.By building the hardware test platform of the steering by wire system,the double-pin line test,the center area test and the turn-back performance test were carried out.The results show that the designed road feeling simulation algorithm can meet the driver’s demand for road feeling at different speeds,and reduce the residual steering wheel turn-back Angle to less than 1°,which greatly improves the vehicle turn-back performance.