In this paper, a novel decentralized control strategy with finite-time convergence is developed for the trajectory tracking of a space manipulator. The existing control schemes for a space manipulator can be classified into two main categories: centralized ones and decentralized ones. The former regards the robot as a high dimensional system with strong nonlinearity, thus the controllers are with multiple-input and multiple-output forms. The latter treats the system as a number of decoupled subsystems, each of which corresponds to a link of the manipulator. There are a set of decentralized single-input and single-output controllers for each subsystem. The centralized control has high performance and large calculation cost, whereas the decentralized control has relatively low control precision, but with high computational efficiency. This work combines the above two schemes to propose a compromised control strategy—recursive decentralized finite-time control. The space manipulator is viewed as a set of interconnected subsystems. The tracking error equations of each subsystem are firstly written based on the recursive dynamic model of the system. Then the decentralized non-singular terminal sliding mode (NTSM) control law is designed to make the tracking error converge to an arbitrarily small neighborhood of the origin within a finite time. Finally, numerical simulations of the trajectory tracking task for a space manipulator are given to verify the effectiveness and efficiency of the control scheme.

本文提出了一种新颖的具有有限时间收敛性的分散控制策略，用于空间机械臂的轨迹跟踪。现有的空间操纵器控制方案可分为两大类：集中式和分散式。前者将机器人视为具有强非线性的高维系统，因此控制器具有多输入和多输出形式。后者将系统视为许多解耦的子系统，每个子系统都对应于操纵器的链接。每个子系统都有一组分散的单输入和单输出控制器。集中控制具有较高的性能和较大的计算成本，而分散的控制具有较低的控制精度，但计算效率较高。这项工作结合了以上两种方案，提出了一种折衷的控制策略-递归分散式有限时间控制。空间操纵器被视为一组互连的子系统。首先基于系统的递归动态模型编写了每个子系统的跟踪误差方程。然后设计了分散的非奇异终端滑模（NTSM）控制律，以使跟踪误差在有限的时间内收敛到原点的任意小的邻域。最后，给出了空间操纵器轨迹跟踪任务的数值模拟，以验证控制方案的有效性和效率。空间操纵器被视为一组互连的子系统。首先基于系统的递归动态模型编写了每个子系统的跟踪误差方程。然后设计了分散的非奇异终端滑模（NTSM）控制律，以使跟踪误差在有限的时间内收敛到原点的任意小的邻域。最后，给出了空间操纵器轨迹跟踪任务的数值模拟，以验证控制方案的有效性和效率。空间操纵器被视为一组互连的子系统。首先基于系统的递归动态模型编写了每个子系统的跟踪误差方程。然后设计了分散的非奇异终端滑模（NTSM）控制律，以使跟踪误差在有限的时间内收敛到原点的任意小的邻域。最后，给出了空间操纵器轨迹跟踪任务的数值仿真，以验证控制方案的有效性和效率。然后设计了分散的非奇异终端滑模（NTSM）控制律，以使跟踪误差在有限的时间内收敛到原点的任意小的邻域。最后，给出了空间操纵器轨迹跟踪任务的数值模拟，以验证控制方案的有效性和效率。然后设计了分散的非奇异终端滑模（NTSM）控制律，以使跟踪误差在有限的时间内收敛到原点的任意小的邻域。最后，给出了空间操纵器轨迹跟踪任务的数值模拟，以验证控制方案的有效性和效率。