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 p erturbation formulation of the manipulator equations of motion is used . The concept of aa integral manifold is utilized to construct the dyn amics of the slow subsystem. A fast subsystem is constructed to repres ent the dynamics of the elastic forces at the joints. A composite adap tive control scheme is developed with special attention to stability a nd robustness of the controller. The proposed controller is based on o n-line identification of the manipulator parameters and takes into acc ount the effect of a class of unmodeled dynamics, identification error s and parameter variations. Stability analysis of the resulting closed -loop full-order system is presented. To show the capability of the pr oposed algorithm, an example of a two-link flexible-joint manipulator is considered. Simulation results are given to illustrate the applicab ility of the proposed control scheme.