Research On The Return Control Strategy Of Electric Power Steering System Based On Sliding Mode Control

With the continuous progress of automobile technology,people’s requirements for automobile quality are gradually improving.The electric power steering system can ensure the portability and stability of the vehicle to a certain extent.At the same time,the system can save energy to a certain extent,and the environmental protection is strong.With the above advantages,the system has been widely used in various models.To sum up,this paper will study the forward control strategy of electric power steering system.This paper takes an electric vehicle as the research object,establishes a simulation model of electric power steering system,takes steering wheel Angle and vehicle speed as input,and uses fuzzy algorithm to design a suitable power characteristic curve.According to the characteristics of the system,the power control strategy and the back control strategy are designed.The PID control model and sliding mode control model are used to study the lightness,stability and back control characteristics of the electric power steering system.Using Matlab/Simulink and Carsim co-simulation test,set three characteristic speed,the vehicle at 1s to give the steering wheel to 50 degrees of Angle,compared with no power control and PID control,the sliding mode control designed by the driver required to input the steering wheel torque is smaller,yaw speed is smaller,reach the steady state time is shorter;Under the normal condition,the residual Angle of correction is smaller and the time of correction is shorter.Finally,the steering wheel is rotated at 100° when the steering is in place,and the hardware-in-the-loop test platform is used to verify the positive return characteristics of the electric power steering system.The experimental results show that the torque of the vehicle is small and it cannot return to the zero position of the steering wheel when there is no turn-back control.When sliding mode control is added,the steering wheel responds faster and can return to the zero position of the steering wheel in time.