Study On Four Wheel Steering And Yaw Moment Integrated Control For Four Wheel Independent Steering And Drive Electric Vehicle

Four wheel independent steering and drive electric vehicle has the advantages of four wheel angle,four wheel drive torque independently controlled and the motor responses rapidly.It is easy to realize four wheel steering and drive yaw moment control.How to carry out the four wheel steering and yaw moment control,improving the handling stability is an important study subject of four wheel independent steering and independent drive electric vehicle.Based on the project supported by the National Natural Science Foundation of China Study on dynamics control for four wheel independent drive and steering electrical vehicle considering driver characteristic(51675257),the project supported by the National Natural Science Foundation of China's Youth Fund Study on adaptive steering for intelligent four-wheel independently driven in-wheel motors electric vehicle(51305190),the four wheel steering control strategy and the integrated control strategy of the four wheel steering and yaw moment are studied on four wheel independent steering and drive electric vehicle in this paper.Firstly,the vehicle model of four wheel independent steering and drive electric vehicle is built.According to the four wheel independent drive and four wheel independent steering electric vehicle parameters,the simulink block is used to build the four wheel independent steering motor and the four wheel independent drive motor.The traditional car is selected from the Car Sim software as a prototype car and it is changed according to the parameters of the electric vehicle,the steering system and drive system is changed to external input.Based on MATLAB/Simulink and CarSim,the vehicle model is verified by co-simulation experiment.Secondly,the four wheel steering control strategy is studied.Four wheel steering control strategy is proposed in this paper,Ackerman four wheel steering is used when low speed,the proportion of four wheel steering is used when medium low speed,the four wheel steering with integrated control of four wheel steering and yaw moment is used when medium high speed.The four wheel steering control strategy is verified through the double lane change condition by co-simulation experiment.What's more,the integrated control strategy of four wheel steering and yaw moment is studied.The integrated control strategy is designed.The linear single track two-DOF model is used as the reference model.The optimal control theory is used to design the vehicle integrated controller.The four wheel drive torque is allocated according to the rules of the target drive torque and the additional yaw moment.The integrated control strategy is verified through the double lane change condition by co-simulation experiment.Finally,the integrated control strategy is verified based on the hardware in loop of the driving simulator experiment platform and the four wheel independent drive/four wheel independent steering electric vehicle.The function,structure and working principle of thedriving simulator hardware in the loop test bench is introduces.The vehicle integrated control strategy is built,analyzed and verified by the driving simulator hardware in the loop test bench and the electric vehicle.The research results show that the integrated control algorithm of four wheel steering and yaw moment can effectively improve the vehicle handling stability.