基于WNN的全弹性空间机器人自适应非奇异快速终端滑模控制算法  

An adaptive nonsingular fast terminal sliding mode control algorithm based WNN for flexible-base flexible-joint and flexible-link space robot

作　　者：付晓东 陈力[1] FU Xiaodong;CHEN Li(College of Mechanical Engineering and Automation,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福州大学机械工程及自动化学院,福州350108

出　　处：《中国惯性技术学报》2021年第5期672-679,共8页Journal of Chinese Inertial Technology

基　　金：国家自然科学基金(11372073,11072061);福建省重大研发平台项目(2014H21010011)。

摘　　要：针对基座、关节、臂全弹性空间机器人存在建模误差及外部干扰情况下的运动控制及多重振动抑制问题,提出了基于小波神经网络(WNN)、混合轨迹法的自适应非奇异快速终端滑模复合控制算法。利用假设模态法、质心定理、拉格朗日方程,建立了全弹性空间机器人动力学模型。然后根据奇异摄动理论将模型降维分解成慢、快变子系统,并设计了应用于慢变子系统的自适应非奇异快速终端滑模控制及快变子系统的双重减振线性最优控制构成的复合控制器。慢变控制器采用WNN结构逼近系统建模误差及扰动的上界,控制器参数通过自适应学习算法在线调整。仿真结果表明,复合控制器能将基座、关节、臂的弹性振动分别抑制在±5 mm、±0.1 rad、±1.8 mm等许可范围内,对建模误差及外部干扰具有鲁棒性,且在2 s内实现对期望轨迹的渐进稳定跟踪。An adaptive nonsingular fast terminal sliding mode composite control algorithm based on wavelet neural network(WNN)and hybrid trajectory method is proposed for flexible-base flexible-joint and flexible-link space robot under the condition of modeling error and external interference.The dynamic model of fully elastic space robot is established by using assumed mode method,mass center theorem and Lagrange equation.The model is decomposed into slow and fast subsystems using singular perturbation theory.The adaptive nonsingular fast terminal sliding mode control is designed for the slow subsystem,and the double damping linear optimal control is designed for the fast subsystem.The compound control algorithm consists of two sub-controllers.The WNN structure is used to approximate the upper bound of the system modeling error and disturbance,and the controller parameters are adjusted online by adaptive learning algorithm.The simulation results show that the composite controller can suppress the elastic vibration of the base,joints and links within the allowable range of ±5 mm,±0.1 rad and ±1.8 mm respectively,it is robust to modeling errors and external disturbances,and can realize the asymptotic stable tracking of the desired trajectory within 2 s.

关 键 词：弹性基座 柔性臂 柔性关节 空间机器人 非奇异快速终端滑模控制 

分 类 号：TP241[自动化与计算机技术—检测技术与自动化装置]