Modeling and adaptive backstepping sliding mode control of autonomous driving leveling system
To solve the problem that the vehicle-mounted hedge trimmer cannot adaptively balance itself according to the topographic relief during autonomous driving operations,and improve the operational safety and the dimensional accuracy of hedge trimming,an autonomous driving vehicle body electro-hydraulic leveling system was designed.The system used a tilt sensor to monitor the vehicle body tilt angle in real time,and established a mathematical model of the leveling system based on the dynamics theory of the vehicle body leveling mechanism.In view of the uncertainty,nonlinear characteristics,and external environmental interference of the electro-hydraulic leveling system parameters,an adaptive backstepping sliding mode controller was designed by combining sliding mode control and adaptive backstepping method.According to the idea of backstepping method,the system was decomposed into multiple subsystems,and appropriate Lyapunov functions were selected for each subsystem.Through the recursive method,the control law of the control system and the adaptive law of the uncertain parameters was obtained,and the convergence of the system tracking error was proved.In view of the chattering problem caused by sliding mode control,a saturation function was used instead of the traditional sign function,which weakened the chattering of the system.The simulation results show that under the condition of a vehicle body tilt of 20°,the actual output angle can accurately and rapidly track the reference angle,with a short response time,strong adaptability and robustness to parameter changes,and can achieve rapid and accurate vehicle body leveling.Compared with the PID controller,the leveling time is reduced by 5 times,and the system leveling error is less than 1°,making the leveling process more stable.
electro-hydraulic leveling systemadaptive backstepping controlsliding mode control
万方数据
维普
