Active Disturbance Rejection Control for DC Motor with Measurement Delay Using the PDE-Backstepping Predictor

The extended state observer (ESO) is a vital component in feedback control design for nonlinear systems. However, the presence of measurement delay in physical systems can significantly compromise their performance and even result in instability. This paper presents a novel observer design that addresses the disturbance rejection problem in nonlinear plants with delayed output. The sensor delay effect is modeled as a first-order hyperbolic partial differential equation (PDE), and a predictor-based ESO is developed using the PDE-backstepping method. The proposed observer structure's effectiveness is demonstrated through a numerical example.