Generalized Variable Gain ADRC for Nonlinear Systems and Its Application to Delta Parallel Manipulators

Abstract

In this paper, a novel generalized variable gain active disturbance rejection control (VGADRC) method is proposed for the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> -th order nonlinear system. The generalized VGADRC, including generalized variable gain tracking differentiator (VGTD), generalized variable gain extended state observer (VGESO), and generalized variable gain controller (VGC), incorporates error-based variable gains to achieve desired control performance. Moreover, the stability analysis of VGADRC is performed, and the existence of feasible solutions are discussed and expressed explicitly. Finally, the generalized VGADRC method is applied to delta parallel manipulators, and the numerical simulation results and experiment results are presented to illustrate the effectiveness of the proposed method.