Adaptive compensation of dynamics and friction for a planar parallel manipulator with redundant actuation

Abstract

In order to improve the actual tracking accuracy of a planar parallel manipulator with redundant actuation, a new adaptive compensation of dynamics and friction is developed. Firstly, the dynamic model is established in the task space for the parallel manipulator, and a linear parametrization expression with respect to the model parameters is formulated. Then, based on the dynamic model, a new adaptive control law which contains dynamics compensation, friction compensation and tracking error elimination items is designed. The parameter adaptation law is derived by the Lyapunov method, and the convergence of the tracking error and the error rate is proved by the Barbalat's lemma. At last, the proposed controller is implemented in the trajectory tracking experiments of an actual planar parallel manipulator with redundant actuation.

Robust Adaptive Sliding Mode Synchronous Control for a Planar Redundantly Actuated Parallel Manipulator

“…For dynamics uncertainty and disturbance of mechanisms, many modern controllers are designed such as adaptive controller [ 5] [ 6], robust controller [ 7], sliding mode controller [ 8]. Actually , those methods are usually combined.…”

“…J. W. Mi proposed synchronization controller to control this structure [10]. W. W. Shang proposed many control methods such as adaptive computed torque [11], adaptive compensation of dynamics and friction [6]509-511 , nonlinear adaptive task space control [12], coordination controller in task space [13] .…”