Active disturbance rejection trajectory tracking control for two-joint driven by pneumatic artificial muscles

摘要

Active disturbance rejection control is proposed to study the problems on trajectory tracking and decoupling for a two-joint system driven by pneumatic artificial muscles. Because of coupling and nonlinearity, it is very hard to obtain good performance in trajectory tracking for the two-joint system. The active disturbance rejection nonlinear controller includes a tracking differentiator, an extended state observer and a nonlinear error feedback controller. The tracking differentiator is introduced to arrange a transitional process to track input signal and get differential signal. The extended state observer is designed to estimate the non-linearity of system. The nonlinear error feedback controller is designed to improve the performance of system. Simulation results are given to show the effectiveness of proposed controller in this paper.