Asymptotic tracking and disturbance rejection of time-varying signals with a discontinuous PID controller

摘要

A novel non linear PID controller is introduced in this paper, which has a discontinuous integral term. It is able to robustly asymptotically track any time-varying reference while rejecting perturbations with bounded derivatives for uncertain SISO nonlinear plants of well-defined relative degree two and with bounded zero dynamics. This is achieved because the discontinuous integral term takes the role of a universal internal model for this class of references and perturbations. The proposed controller is compared with a well established solution for this problem in the literature to illustrate its advantages. The main benefit is possibly the simplicity of the controller structure and its universality, since it applies to a large class of plants, references and perturbations without modifications. (C) 2020 Elsevier Ltd. All rights reserved.