Adaptive coordinated control of uncertain free-floating space manipulators with prescribed control performance

Abstract

The paper proposes an adaptive coordinated control scheme on free-floating space manipulators at the dynamic level, with kinematic and dynamic uncertainties. The free-floating space manipulator can be controlled to realize the end-effector trajectory tracking task and the spacecraft attitude regulation task simultaneously, based on the carefully designed prescribed performance error transformations and the reaction null space. In face of nonlinearly parametric feature of the uncertain free-floating space manipulators, a novel attractive manifold control method is proposed by introducing the nonlinear filters on dynamics of the free-floating space manipulators. The parameter estimation error terms can converge to zero, independent of persistent excitation conditions. The proposed adaptive coordinated control scheme can guarantee that both the end-effector tracking error and the spacecraft attitude regulation error possess the prescribed control performances, in the presence of the nonlinearly parametric feature and the nonzero linear and angular momenta of the free-floating space manipulators. The simulation results show the effectiveness of the proposed control scheme.