ROBUST ADAPTIVE CONTROLLER-DESIGN AND STABILITY ANALYSIS FOR FLEXIBLE-JOINT MANIPULATORS

The problem of controlling robot manipulators with flexible Joints is considered. A reduced-order flexible-joint model based on a singular perturbation formulation of the manipulator equations of motion is used. The concept of aa integral manifold is utilized to construct the dynamics of the slow subsystem. A fast subsystem is constructed to represent the dynamics of the elastic forces at the joints. A composite adaptive control scheme is developed with special attention to stability and robustness of the controller. The proposed controller is based on on-line identification of the manipulator parameters and takes into account the effect of a class of unmodeled dynamics, identification errors and parameter variations. Stability analysis of the resulting closed-loop full-order system is presented. To show the capability of the proposed algorithm, an example of a two-link flexible-joint manipulator is considered. Simulation results are given to illustrate the applicability of the proposed control scheme.