飘浮基两杆柔性空间机械臂基于速度观测器的增广自适应控制  

Velocity observers-based augmented adaptive control for a free-floating two-link flexible space manipulator

作　　者：于潇雁[1] 陈力[1] YU Xiao-yan CHEN Li(School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou 350116)

机构地区：[1]福州大学机械工程及自动化学院,福州350116

出　　处：《振动与冲击》2017年第11期176-182,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(11372073);福建省工业机器人基础部件技术重大研发平台(2014H21010011);福建省自然科学基金(2016J01228)

摘　　要：讨论了载体位置、姿态均不受控情况下,存在外部扰动漂浮基两杆柔性空间机械臂的基于速度观测器的增广自适应运动控制与振动最优控制问题。选择合适的联体坐标系,利用Lagrange方法并结合动量守恒原理建立了飘浮基两杆柔性空间机械臂系统的动力学方程。利用奇异摄动法,将两杆柔性空间机械臂系统分解为一个关于载体姿态、关节轨迹跟踪的慢变子系统与一个描述柔性杆振动的快变子系统。以此为基础,提出了一个包含慢变控制项与快变控制项的复合控制器。利用自适应滑模观测器得到慢变子系统的观测速度向量,基于这个观测速度向量设计得到系统的增广自适应慢变控制律来实现关节轨迹的跟踪。利用线性观测器得到快变子系统的观测速度向量,基于这个观测速度向量并运用线性系统的最优控制理论得到了系统的快变控制律来实现柔性杆振动最优控制。系统的数值仿真证实了方法的有效性。该控制方案不需直接测量关节角速度、关节角加速度与柔性振动模态坐标导数以及漂浮基的位置、移动速度、移动加速度。The augmented kinematic control and vibration suppress based velocity observer for a free-floating two-flexible-link space manipulator with external disturbances is addressed. Firstly the dynamic model of a free-floating two-flexible-link space manipulator is established by the momentum conservation and the Lagrange equations. Secondly based on singular perturbation approach，a singular perturbation model has been formulated, which consists of a slow subsystem and a flexible-link fast subsystem. The fast subsystem represents the vibration of the flexible links, and the slow subsystem represents the rigid movement of the system. Then a composite controller which consists of a slow control component and a fast control component is proposed. The slow subsystem’s estimated velocity is constructed by an adaptive sliding velocity observer. Based on the estimated velocity of the slow subsystem, an augmented adaptive control algorithm is applied to the slow subsystem to track the desired trajectory of the base attitude and the joints. The estimated velocity of the fast subsystem is constructed by a linear velocity observer. Based on the estimated velocity of the fast subsystem, the fast controller is designed to damp out the vibration of the flexible links by using optimal Linear Quadratic Regulator （LQR） method. Finally the numerical simulation is carried out, which demonstrates the controller proposed is feasible and effective. The virtue of this control scheme is that the linear position, linear velocity, linear acceleration of the base, the angular velocities, angular accelerations of the joints as well as the derivatives of the flexible vibration modes needn’t be measured directly.

关 键 词：飘浮基两杆柔性空间机械臂 奇异摄动法 自适应控制 增广法 速度观测器 振动最优控制 

分 类 号：V42[航空宇航科学与技术—飞行器设计] TP241[自动化与计算机技术—检测技术与自动化装置]