Stable Tracking Control of Distributed Driven Unmanned Vehicle in Limit Condition
In view of the phenomenon of the distributed driverless vehicle deviating from the target path and instability in the low attachment and high speed limit conditions,a stable tracking joint control strategy is proposed,which includes path tracking con-trol and lateral stability control,which can ensure the stability of the unmanned vehicle while improving the tracking accuracy.Based on the two degree of freedom model of the vehicle,the path tracking module establishes the optimal LQR path tracking con-troller,and introduces feedforward to improve the steady-state error.Secondly,considering the law of error change,the relation-ship between road and vehicle position and the driver preview model,the improved adaptive LQR controller with weight param-eters is designed;The stability module is based on the sliding mode fuzzy control principle which can reduce the chattering of the system,and combines the difference between the actual value and the expected value of the vehicle stability parameters to solve the yaw moment.Secondly,the constraint conditions are established when the torque of each wheel is distributed,which makes the tire load rate minimum to improve the vehicle handling stability.The simulation of Carsim/Simulink shows that the improved LQR controller can improve the tracking error effectively and has good robustness under the high speed and low attachment condi-tion.After adding stability controller,the adjustment time of yaw rate and center of mass yaw angle becomes shorter,which greatly improves the stability of unmanned vehicle under the limit condition.
Distributed Drive Unmanned VehicleAdaptive LQR ControlLimit Condition TrackingYaw Stabil-ity Control
万方数据
维普
