Research On Vibration Suppression Of In-wheel Motor For Electric Vehicle Based On Active Disturbance Rejection Controller

Due to its compact layout on electric vehicles,high power transmission efficiency,and easy implementation of four-wheel drive control,in-wheel motors have gradually become an important direction for the future development of the electric vehicle industry.Permanent magnet synchronous motors have become the preferred choice for domestic vehiclemounted motors due to their high energy efficiency,no excitation loss,and other advantages.However,during operation,the tire hop caused by random road surface excitation can easily cause the rotor of the motor to be asymmetric,leading to increased electromagnetic vibration caused by eccentricity of the air gap,which ultimately affects the stable operation of the motor and driving comfort.In engineering,traditional proportional integral control methods are used to suppress uncertainty disturbances,although they have a simple implementation,they still face the contradiction between fast response and overshoot.Moreover,the response accuracy in complex environments is relatively poor,which limits the improvement of the power performance of electric vehicles.This paper addresses the problem of vehicle vibration caused by motor air gap eccentricity resulting from random road surface excitation.Firstly,based on the working principle of in-wheel motors,the motor structure model is reasonably simplified,and different coordinate transformation mathematical models of in-wheel motors are established,and the control strategies of in-wheel motors are compared and analyzed.Secondly,1/4 electric vehicle vibration model and in-wheel motor air gap magnetic field model were separately established under random road surface excitation,and the unbalanced electromagnetic force generated during motor operation was derived based on Maxwell’s stress theory.MATLAB programming was used to simulate and analyze the electric vehicle vibration response considering air gap eccentricity.The results show that in-wheel motor air gap eccentricity increases with the increase of road unevenness,which leads to an increase in vehicle vibration amplitude.Then,based on the active disturbance rejection controller theory,the controller is designed and parameterized,and the random external excitation and internal electromagnetic excitation of the motor are viewed as unified disturbances for control compensation.Simulation verification of anti-load disturbance was performed using an example,and the results show that the designed controller not only responds quickly but also has almost no overshoot when facing load mutation.Finally,in-wheel motor electric vehicle vibration control model based on MATLAB/Simulink is built to simulate and analyze the vibration suppression effect of the vehicle under different operating conditions,and the simulation results are compared with traditional PID control.The results show that compared with PID control,the maximum vibration amplitudes of the motor and the body are reduced by 28.7% and 20.0%,respectively,when using active disturbance rejection controller.This validates that active disturbance rejection controller can effectively suppress vehicle vibration caused by in-wheel motor air gap eccentricity and is superior to PID control.The research results of this paper can effectively improve the vibration resistance of vehicles under different operating conditions,and also provide a certain theoretical reference for the design of in-wheel motors and vehicle vibration control related research.