基于指数增益迭代学习的机械臂二阶滑模控制方法  

The Second-order Sliding Mode Control Method for Manipulator Based on Exponential Gain Iterative Learning

作　　者：王策 杨升 张磊[1] 左信[1] 白小波 WANG Ce;YANG Sheng;ZHANG Lei;ZUO Xin;BAI Xiao-bo(College of Information Science and Engineering,China University of Petroleum(Beijing);PetroChina Northwest Marketing Co.Wuhan Branch)

机构地区：[1]中国石油大学(北京)信息科学与工程学院 [2]中国石油西北销售武汉分公司

出　　处：《化工自动化及仪表》2023年第5期644-651,共8页Control and Instruments in Chemical Industry

摘　　要：机械臂系统具有非线性和不确定性,针对其精确跟踪控制问题,提出基于指数增益迭代学习的二阶滑模控制算法。首先,采用滑模控制增强系统对外界非重复干扰的鲁棒性,采用二阶滑模方法使控制器产生连续的控制信号,以减轻传统滑模控制的抖振问题;其次,结合指数增益迭代学习控制逼近由摩擦力等周期性扰动引起的有界重复性扰动,通过设置指数增益系数以提高迭代的收敛速度,该方法既能减小系统的跟踪误差又能保证系统的全局渐近稳定性,提高系统的动态性能;最后,分析算法收敛的充分条件,以二自由度机械臂为例对所提方法进行理论数值仿真。仿真结果表明:所提控制方法可以保证系统的稳定运行,输出跟踪误差收敛到接近零的邻域,提高了系统的控制精度,对干扰保持了良好的鲁棒性。Considering manipulator system’s nonlinearity and uncertainty and its poor precision tracking control,a second-order sliding mode control algorithm based on exponential gain iterative learning was proposed.Firstly,having the sliding mode control used to enhance robustness of the system against external non-repetitive disturbances and the second-order sliding mode adopted to make the controller generate continuous control signals to weaken chattering in the traditional sliding mode control;secondly,having the exponential gain iterative learning control used to approximate the bounded repetitive disturbances caused by periodic disturbances such as friction and the exponential gain coefficient set to improve convergence speed of the iteration.This method can reduce tracking error of the system and ensure global asymptotic stability of the system as well as improve dynamic performance of the system;finally,having the sufficient conditions for convergence of the algorithm analyzed,and the theoretical numerical simulation of the proposed method carried out through taking a two-degree-of-freedom manipulator as an example.The simulation results show that,the control method proposed can ensure stable operation of the system,and the output tracking error converges to the neighborhood near zero to improve control accuracy of the system and maintain good robustness against interference.

关 键 词：二阶滑模控制 指数增益迭代学习控制 机械臂系统 轨迹跟踪 抖振 控制精度 

分 类 号：TP18[自动化与计算机技术—控制理论与控制工程]