The Research Of Wheel Drive Vehicle Yaw Stability Control

Wheel drive is an important structural form of new energy vehicle, and theyaw stability control of wheel drive vehicle can significantly improve thevehicle’s driving stability. Aiming wheel drive vehicle the yaw stabilitycontroller is designed in this paper. Based on theory of model predictive control awheel drive vehicle yaw stability control algorithm is proposed.Firstly, according to the functional requirements of wheel drive vehicle yawstability control, hardware of the yaw stability controller is designed based onMPC5643L which is a32-bit microcontroller of Freescale. The function of thehardware is collecting the sensor data, driving the hydraulic control unit andcommunicating with CAN. The software of the wheel drive vehicle yaw stabilitycontrol is designed. The software is divided into the application layer, dataprocessing layer and the bottom layer. And the procedures of the bottom layerhave been debugged..Then a nonlinear dynamic model of wheel drive vehicle is establishedaccording to vehicle dynamics. The model takes into account the longitudinalmotion, the lateral motion and the yaw motion. By ignoring the nonlinearcharacteristics of the tire, the model is simplified for the controller design. Withthe simulation between the high-precision automotive nonlinear dynamics modelveDYNA and the model established in this paper, the nonlinear dynamic modelof wheel drive vehicle is able to response the condition of the vehicle and can beused for the design of the wheel drive vehicle yaw stability controller.Finally, a wheel drive vehicle yaw stability control algorithm is proposedbased on the nonlinear dynamic model of wheel drive vehicle established in thispaper with the method of LTV-MPC. With the independent driving or brakingcontrol of the four wheels, keeps the vehicle tracking the driver’s intention. Inthe high-precision automotive nonlinear dynamics simulation environment, thesimulation of different conditions shows that the yaw stability control algorithmproposed can guarantee the yaw stability of the vehicle, and at the same time thelongitudinal characteristics of the vehicle is guaranteed.