Research On Electric Vehicle Drive-slip Control Strategy

Distributed drive electric vehicle is an important research focus and direction of electric vehicle technology, compared to the traditional internal combustion engine vehicles and the single-motor drive electric vehicles,It has a great advantage in the vehicle dynamics control and the driving force distribution. As an important part of automotive electronic control systems, slip regulation system treat the tire slip rate as the main control objective. By controlling the driving force of the tire, let it maintain a stable attachment state to obtain a good steering stability and power. This paper with the slip regulation system of the electric vehicle drive system as the research object,research its application in the vehicles drive.Firstly, analyse the hub motor output characteristics, single wheel and the vehicle mathematical model. Established the motor model based on the id = 0 control and do a preliminary simulations to verify the output of the motor model simulation of the response meet the requirements. Then, by analysing car rigid body motion, consider four wheels turning, the vehicle longitudinal, lateral movement of the vehicle body roll and yaw eight degrees of freedom to establish the vehicle model based on the magic formula and verify the necessity of the slip regulation system. Using the simulation method to prove its rationalitySecondly, design the vehicle state observer estimate parameters. It based on the wheel speed, lateral acceleration, yaw rate estimate the vehicle speed and the horizontal and vertical centroid sideslip angle, and then further estimate the vertical load of the four wheels. And use the identification based on the road characteristic values to do the real-time monitoring of the road conditions.Finally, describing the driving force distribution method and comparing the existing control methods. And then, select the logic threshold control and fuzzy control simulation model. Verify the two control methods could maintain good handling and stability of the vehicle in the single road,the butt road and the off road driving.