Control of a Space Robot with Flexible Manipulator Using Generalized Decoupling Technique

Abstract

This paper deals with the motion control of both the spacecraft and a two-link flexible space robot arm mounted on it in the presence of external force. Based on generalized nonlinear decoupling technique, the rigid motion and flexible modes of the system are separated. It contains two feedback loops. An inner loop consists of a non-linear feedback and is used to control the rigid motion of the system, while an outer loop based on a linear system, feedbacks the full states of the system. Based on the dynamic model of the system, a control law is developed in the joint space. In this paper, two different controllers; Linear Quadratic Regulator (LQR) and Model Predictive Control (MPC) algorithms are implemented to control the motion of the Flexible Space Robot System (FSRS). The performance of these two control laws is validated in the presence of the external force by numerical simulation. In addition, the simulation results of FSRS using these two control methods are compared.