State Parameter Observation And Yaw Stability Control Of FWID EV

Vehicle yaw stability control is one of the important contents of electric vehicles active safety,accurate and real-time acquisition of state parameter information in the process of driving is the premise of vehicle chassis yaw stability control.The four-wheel independent drive electric vehicle has many advantages,such as high transmission efficiency,fast and accurate response of hub motor,etc.,which can achieve independent control and rapid response of wheel torque,and easily generate the required yaw moment to realize the yaw stability control of the vehicle.Taking four-wheel independent driving electric vehicles as the research object,two parts of the lateral stability dynamic system are studied,including nonlinear estimation of state parameters and yaw stability control strategy,The main research contents are as follows:(1)The unscented Kalman filter algorithm is applied to the state estimation of the vehicle dynamics system,and the vehicle nonlinear dynamic model is introduced.The state parameter estimator is designed by using the data collected by on-board sensors provided by the four-wheel independent drive electric vehicle.Carsim/Simulink is used for simulation verification,and the results showed that under different working conditions,the state parameter estimator could effectively estimate the required state variables,with high observation accuracy.(2)The model predictive control algorithm is used to analyze the yaw stability of the vehicle dynamic system.Carsim/Simulink is used to establish the vehicle dynamics model and a 2-degree-of-freedom reference model,which is used to solve the expected yaw rate and the side slip angle to maintain the vehicle stability.The controller is designed based on the model predictive control algorithm.By changing the driving torque,additional yaw moment is obtained to control the vehicle yaw rate and the side slip angle.The simulation verifies that the model predictive control algorithm can ensure the stability of vehicle driving.(3)To validate the effectiveness of the proposed control strategy,a test platform based on dSPACE is built.Using the steering-wheel angular step input and sinusoidal input to verify the estimation of vehicle state parameters.The experimental results show that the proposed state parameter observation algorithm improves the state parameter observation accuracy and robustness of four-wheel independent drive electric vehicles.