In this paper the control of exible joint manipulators is studied in detail. The model of N{axis exible joint manipulators are derived and reformulated in the form of singular perturbations, and integral manifold is used to separate fast dynamics from slow dynamics. A composite control algorithm is proposed for the exible joint robots, which consists of two main parts. Fast control, uf, which guarantees that the fast dynamics remains asymptotically stable, and the corresponding integral manifold remains invariant. Slow control ,us, itself consists of a robust PID designed based on the rigid model, and a corrective term designed based on the reduced exible model. The stability of the overall closed loop system is proved to be UUB stable, by Lyapunov stability analysis. Finally, the e ectiveness of the proposed control law is veri ed through simulations. It is shown that the proposed control law ensure the robust stability and performance, despite the modeling uncertainties.
H. D. Taghirad, M. A. Khosravi