LPV Yaw Response Control Method Forfour Wheel Independent Motor-Drive Electric Vehicle

The torque of each wheel of in-wheel-motor electric vehicles can be controlled separately,which is very beneficial to vehicle dynamics control,and the research of in-wheel-motor electric vehicles has become more popular in the field of electric vehicles.As a new kind of electric vehicles,the in-wheel-motor electric vehicles has a larger change in control mode than the conventional fuel vehicle,simplifying the structure of the vehicle.With its four wheel torque controllable characteristics,it is possible to study the yaw rate and lateral speed tracking of the hub electric vehicle.At present,the study of yaw rate and lateral speed tracking of in-wheel-motor electric vehicles is mainly for normal working conditions.For the extreme conditions of high-speed steering,because the vehicle state is at the unstable boundary,it is easy to cause deterioration of control performance.This paper studies how to make the yaw rate and the transverse speed tracking expected on the high-speed car.When the vehicle is turning at a high speed,the wheel side electric angle of the hub electric vehicle is large,and there may be longitudinal slip.To this end,the Dugoff nonlinear tire model is used to describe the lateral forces of the wheel with longitudinal slip and side yaw.For the high-speed steering condition with longitudinal slip,a LPV-_∞robust controller is adopted,which effectively realizes the tracking of yaw rate and lateral vehicle speed with longitudinal slip.When the vehicle speed is high,the vehicle yaw rate is at the constraint boundary,and it is difficult to increase the yaw rate only by adjusting the wheel torque difference.Thus this paper designs a yaw rate and lateral vehicle speed tracking controller by combining the longitudinal vehicle speed and the yaw rate and the transverse vehicle speed.The outer ring adjusts the longitudinal speed and the inner ring to the yaw rate.Tracking control with the lateral speed allows the yaw rate and the lateral speed to track the expected value,improve the steering performance of the car,and reduce the steering radius of the car.Under the high-precision dynamics simulation system veDYNA,the feasibility of the proposed method is tested by setting a variety of simulation conditions.