Adaptive multivariable generalized super-twisting algorithm based robust coordinated control for a space robot subjected to coupled uncertainties

Abstract

There often exist strong coupled characteristics between the space robot platform and the manipulators. The neglect of the coupled factors may induce undesired control performance or even lead to system crash. In this paper, a novel robust adaptive coordinated control scheme is developed for a space robot with coupled uncertainties and external disturbances. By proposing a multivariable generalized super-twisting algorithm, the bounded disturbances together with uncertainties could be compensated. An adaptation tuning approach is developed to deal with the unknown bounds. Meanwhile, the sliding mode disturbance observer is introduced to alleviate the system conservatism and improve convergence rate and accuracy. As a result, the accurate state tracking is achieved in finite time. A proof of the finite-time convergence is derived using the Lyapunov theory. Simulations are carried out on a space robot with a three-degrees-of-freedom manipulator to demonstrate the effectiveness and robustness of the proposed method.