Reactionless augmented adaptive fuzzy fast terminal sliding mode control of a free-floating space manipulator with joint dead zone

Reaction Null Space (RNS) planning and control are proposed for a free-floating space manipulator with joint dead zone during its pre-capturing a spinning target. Firstly, the Lagrange dynamic model of the space manipulator was obtained. And the RNS mathematical model was derived. Then an adaptive fuzzy fast terminal sliding mode (TSM) control algorithm was designed, which consisted of a fuzzy TSM term and an adaptive compensation term. The fuzzy TSM term improved the convergence speed by introducing a variable coefficient double power reaching rate and nonsingular quick TSM surface, and the fuzzy control term ameliorated system chattering. Meanwhile, the adaptive term compensated for the influences of dead zone and the exterior disturbances. Furthermore, the algorithm stability was proved by the Lyapunov function method. Finally, the feasibility and validity of the proposed RNS planning and control algorithm were verified by numerical simulations.