Active Disturbance Rejection Tajectory Tracking Control of a Delta Robot Based on LMI

Abstract

In this paper, an LMI-based auto-disturbance rejection trajectory tracking controller for a Delta parallel robot is designed. The tracking performance of a Delta robot is usually affected by unknown external disturbances, model inaccuracies, and uncertain couplings, which are considered as disturbances in the system. Auto-disturbance rejection control can achieve active compensation for the total disturbance without an accurate dynamic system model, but the gain matrices of the observer and controller are difficult to obtain. In order to solve the gain matrices of the observer and feedback controller, a method using linear matrix inequalities (LMI) is proposed to solve the above gain matrices. First, a computational torque controller is designed for the highly nonlinear Delta parallel robot system. Then, an observer and a feedback controller are designed based on this controller, and the specific process of solving the gain matrix based on linear matrix inequalities is given. In addition, the finite-time stability of the closed-loop control system is proved using the Lyapunov stability theory. Finally, simulation results verify the effectiveness and robustness of the proposed controller.