2-DOF Active Disturbance Rejection Controller Design for High Order System based on Expected Dynamics

Abstract

Aiming at the problem that the control performance of low-order active disturbance rejection control (ADRC) is not good when it is applied to high-order system, the reason is analyzed from the view of observation error. Combined with previous studies, a design method of ADRC using high-order system model information for compensation is proposed, its quantitative parameter setting formula is given, and its expected dynamics are deduced. In addition, from the perspective of expected dynamics, a design method of ADRC controller with two degrees of freedom structure is proposed based on the above-mentioned compensated ADRC, which can make the tracking and disturbance rejection control performance of the system be designed separately and independent of each other. Simulations show that the proposed compensation structure can significantly improve the control effect of low-order ADRC on high-order systems, and the designed two-degree-of-freedom structure can make the set-point tracking and disturbance rejection effect meet expectations respectively, which has a good potential for engineering promotion.