Fixed-time Terminal Sliding-mode Control for Free-Floating Space Manipulator

This article focuses on the tracking problem for n-link free-floating space manipulators (FFSM) subject to uncertainties. Based on a non-singular terminal sliding mode, a fixed time controller is well-designed, where the sliding surface is supposed to be reachable and the irrelevance between convergence time and system states’ initial value is proved. Meanwhile, the uncertainties during modeling are well suppressed through the proposed robust control algorithm. At last, the Lyapunov stability theory is adopted to verify the fixed-time convergence of the closed-loop FFSM system. Simulation experiments taking a 6-DOF FFSM validate the effectiveness of the proposed control scheme.