Integral Backstepping Sliding-mode Control for Space Manipulator Modular Joint Using RBFN Observer

Considering space manipulator modular joint using permanent magnet synchronous motor (PMSM) is easy to be influenced by unknown nonlinearities, external disturbances and parameter perturbations in practical servo control system. In order to improve accuracy of trajectory tracking, integral backstepping sliding-mode control system was designed to compensate the uncertainties. To confirm the upper bound of uncertainties in sliding-mode control system, general Radial Basis Function Network (RBFN) was adopted to estimate the value of upper bound based on the stability of Lyapunov theorem. The results of simulation demonstrate that this method improves the performances of trajectory tracking and enhances the robustness to friction nonlinearities and external disturbances.