Intelligent control of flexible-joint manipulator based on singular perturbation

Abstract

Intelligent control of space manipulator with flexible-link and flexible-joint is discussed based on the singular perturbation method. Owing to the combined effects of the link and joint flexibilities, the dynamic model of this kind of manipulator becomes more complex and leads to a series of unsolved control system. To simplify the design of the control system, singular perturbation method is used to obtain the two-time-scale simpler subsystem and a composite control method is designed to realize precise trajectory tracking and vibration suppression simultaneously for flexible-link/flexible-joint manipulator with payload. In the slow subsystem, a sliding-mode controller with RBFN is designed to decrease the influences of external disturbance and parameters uncertainties, in which the system stability and asymptotic trajectory tracking performance are guaranteed by Lyapunov function, while in the fast subsystem a linear-quadratic controller is designed to suppress the vibration. The performances of the discussed controller are illustrated by the simulation and experimental results.