关键词: 履带式智能机器人, 轨迹跟踪, 机械特性, 不确定性, 干扰观测器, 自适应快速终端滑模鲁棒控制

Abstract: To improve the trajectory tracking accuracy of tracked intelligent robots under complex working conditions, an adaptive fast terminal sliding mode robust control method based on a fixed-time disturbance observer was proposed. Firstly, a dynamic mathematical model with lumped disturbances was established by comprehensively considering multiple influencing factors including mechanical characteristics of the tracked intelligent robot, contact surface uncertainties and unmodeled dynamic errors. Secondly, a fixed-time disturbance observer was designed, and the finite time convergence property was utilized to achieve accurate estimation of system disturbances. Then, an adaptive fast terminal sliding mode robust control law was designed to effectively avoid the chattering phenomenon in traditional sliding mode control, and ensured the tracked intelligent robot can quickly and accurately track trajectory instructions. Finally, the Lyapunov function was constructed to analyze the stability of the overall closed-loop control system, which verified that the closed-loop system was asymptotically stable under the proposed adaptive fast terminal sliding mode robust control law. The comparative simulation experiment results showed that the proposed adaptive fast terminal sliding mode robust control method had high accuracy and stability for trajectory tracking control of tracked intelligent robots, thus verifying the effectiveness and superiority of the proposed control method. Moreover, the test experimental results showed that the proposed control method can effectively overcome the disturbance effects inside and outside the tracked intelligent robot system. The maximum error and root mean square error of trajectory tracking were only 0.055 and 0.026 m, respectively, demonstrating strong engineering applicability and capable of meeting the needs of more complex working condition application scenarios.

Key words: tracked intelligent robots, trajectory tracking, mechanical characteristics, uncertainty, disturbance observer, adaptive fast terminal sliding mode robust control