Practical Prescribed Time Control for Space Manipulators Based on Fully Actuated System Approach

This paper proposes a fully actuated system approach (FASA)-based trajectory tracking control strategy for free flying space manipulator, whose pre-assignable tracking performance can be ensured within prescribed time under uncertain dynamics and input saturation. More specifically, the practical prescribed time control is introduced to ensure the convergence time and tracking accuracy regardless of initial condition. Through coordinate transformation, the considered tracking error system is transformed into the fully actuated systems (FASs). Then a FASA-based robust controller is designed to address the uncertain dynamics and system uncertainties. Moreover, an auxiliary system is used for tackling the input saturation. Furthermore, the boundedness of all system signals and global practical prescribed time performance can be ensured. Simulation results are presented to show the effectiveness of the proposed method.