基于扰动观测器补偿的机械臂非奇异快速终端滑模控制

Non-singular fast terminal sliding mode control of manipulator based on disturbance observe compensation

中文关键词  机械臂控制  非奇异快速终端滑模控制器  fal函数  扰动观测器  滑模控制  有限时间收敛

英文关键词  manipulator control  non-singular fast terminal sliding mode controller  fal function  disturbance observer  sliding mode control  finite-time convergence

中文摘要

      针对机械臂系统在实际应用中存在的建模误差及未知扰动问题, 设计了一种基于扰动观测器的改进型非 奇异快速终端滑模控制策略. 通过扰动观测器准确估计系统存在的总扰动, 并设计恰当的非线性增益函数使扰动观 测误差指数收敛, 实现了对控制器的前馈补偿. 考虑到终端滑模存在的奇异性问题, 结合扰动观测器设计了非奇异 快速终端滑模控制器, 在保证跟踪误差有限时间收敛的同时抑制了滑模控制固有的抖振现象. 同时在控制器设计过 程中, 用fal函数代替sig函数有利于削弱滑模控制抖振, 提高系统稳定性及跟踪精度. 最后, 利用MATLAB软件进行 实验仿真, 验证了所设计控制器的有效性.

英文摘要

      In order to solve the associated modeling error problems and the unknown disturbances in the robotic manipulator system, based on a disturbance observer, an improved non-singular fast terminal sliding mode control strategy is designed. By using the disturbance observer, the total disturbance of the system is accurately estimated, then appropriate gain functions are designed to enhance the exponential convergence of the disturbance observation error and achieve feedforward compensation for the controller. Considering the singularity problem in the terminal sliding mode, a non-singular fast terminal sliding mode controller is expressed based on the disturbance observer, which can guarantee the finite-time convergence of tracking errors and alleviate the effect of chattering of the controller output. Besides, in the process of controller design, this work uses fal function instead of sig function to reduce the chattering influence and improves the stability of the system and the tracking performance. Finally, by utilizing MATLAB software to conduct experimental simulation, the effectiveness of the proposed controller is further verified.