Advanced robust desired compensation adaptive control for parallel robots: From concept to real-time validation

In this paper, a novel robust adaptive controller is proposed for Parallel Kinematic Manipulators (PKMs). The objective of this research is to merge a model-based adaptive controller with a robust non-model-based controller. The key contribution lies in the redesign of the feedback component of the Desired Compensation Adaptive Law (DCAL) controller using the Robust Integral of Sign of Error (RISE) scheme. This new design enhances the tracking performance compared to the DCAL controller by incorporating robust terms. These terms effectively compensate for non-modeled phenomena that are not handled by the model-based adaptive compensation in the original controller. Moreover, the inclusion of the integral of the error sign motivates the adaptation law redesign to minimize the feedback action instead of combined errors. The stability analysis of the proposed control solution is performed based on Lyapunov’s theory. To demonstrate the superiority of the proposed controller, a comparative study is conducted through various real-time experimental scenarios in different operating conditions involving a PKM testbed.