Decentralized Adaptive Control of Closed-Kinematic Chain Mechanism Manipulators

This paper presents a new decentralized adaptive control scheme for motion control of robot manipulators built based closed-kinematic chain mechanism (CKCM). By employing the synchronization technique and model reference adaptive control (MRAC) based on the Lyapunov direct method, the Decentralized Adaptive Synchronized Control (DASC) scheme is developed. The DASC scheme can ensure global asymptotic convergence of tracking errors while forcing all active joints to move in a predefined synchronous manner in the presence of uncertainties and sudden changes in payload. In addition, the control scheme has a simple structure that does not depend on the knowledge of the dynamic mathematical model of a robot manipulator resulting in computational efficiency of control scheme implementation. Results of computer simulation conducted to evaluate the performance of the control scheme applied to control the motion of a CKCM manipulator with 6 degrees of freedom are reported and discussed.