Adaptive trajectory tracking sliding mode control for agricultural tracked robot considering parameter uncertainty

Abstract

The trajectory tracking process of the robot is easily affected by the smoothness of the ground, the external uncertainty interference, the integrity of feedback information and other factors, which lead to the degradation of the trajectory tracking performance of the mobile robot. In order to improve the performance of tracking control of agricultural tracked robot, this paper takes tracked robot as the research object, and presents an adaptive sliding mode control. The main research contents are as follows: Based on the consideration of the kinematics model of the tracked robot and the dynamic characteristics of the motor drive model, an adaptive integral sliding mode switching function with variable tilt parameters is constructed. Based on the established sliding mode function, an adaptive sliding mode control composed of equivalent control and switching control was designed. The pose error of the robot and the time-varying uncertain parameters of the drive motor identified online were fed back into the controller, and the expected angular velocity of the left and right wheel drive motor was calculated to control the running of the tracked robot. Simulation results verified the effectiveness of the proposed method, and field test results showed that when the robot was running at the speeds of 1 m/s, 3 m/s, and 4 m/s, the distance error in the movement direction, the lateral distance error, and the heading angle error were -0.04m-0.04m, -0.09m-0.07m and -0.03-0.05rad. Therefore, the robot adaptive sliding mode control had good control accuracy and could meet the requirements of actual field operations. 1