关键词: 飘浮基柔性空间机器人, 奇异摄动法, Terminal滑模控制, 柔性关节, 柔性臂

Abstract:

A Terminal sliding mode control was proposed for a free-floating space robot.To discuss such an under-actuated flexible-link flexible-joint space robot, a free-floating space robot with one flexible link and two flexible revolute joints was presented. The dynamical Lagrange equation was established by the momentum conservation. And a singularly perturbed model was formulated and used for designing a reduced-order controller, where the system was decoupled into two subsystems (a flexible space manipulator subsystem and a flexible-joint fast subsystem).A composite controller which consisted of two control components was proposed. A Terminal sliding mode controller was proposed to control the flexible space manipulator subsystem.A flexible-joint fast controller was designed to stabilize the flexible-joint fast subsystem around the equilibrium trajectory set up by the flexible space manipulator subsystem under the effects of the Terminal sliding mode controller. A numerical simulation was carried out, which confirmed the proposed controller is feasible and effective.The virtue of this control scheme is that the base linear position, the base linear velocity, the base linear acceleration need not be measured.In addition, it is ensured that the tracking errors of the manipulator joints converge to zero in finite time.

Key words: free-floating flexible space robot, singular perturbation approach, Terminal sliding mode control, flexible-joint, flexible-link