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 on a 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 scheme (DASCS) is developed. The DASCS 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. Furthermore, the control scheme has a simple structure, independent of the manipulator’s dynamic model, ensuring computational efficiency. Results of computer simulations conducted to evaluate the performance of the control scheme applied to controlling the motion of a CKCM manipulator with six degrees of freedom are reported and discussed.