Output regulation for a reaction-diffusion system with input delay and unknown frequency
Shen Wang, Zhong-Jie Han, Kai Liu, Zhi-Xue Zhao
TL;DR
This work tackles output regulation for a reaction-diffusion PDE subject to input delay and disturbances with unknown frequency. It develops a novel adaptive architecture that combines modal decomposition with a dual observer and an adaptive internal model to estimate both states and disturbances in real time, achieving exponential convergence of the tracking error $y_e(t)$ to the reference. The regulator design uses regulator equations, LMIs, and Lyapunov-Krasovskii analysis to handle delay and unknown frequency while allowing an unrestricted reaction coefficient $a$. Numerical simulations validate the approach, showing effective frequency estimation and robust tracking across parameter regimes, with potential applicability to broader parabolic PDEs. The framework advances distributed-parameter control by enabling simultaneous delay compensation and unknown-disturbance rejection without full-state feedback.
Abstract
This study solves the output regulation problem for a reaction-diffusion system confronting concurrent input delay and fully unidentified disturbances (encompassing both unknown frequencies and amplitudes) across all channels. The principal innovation emerges from a novel adaptive control architecture that synergizes the modal decomposition technique with a dual-observer mechanism, enabling real-time concurrent estimation of unmeasurable system states and disturbances through a state observer and an adaptive disturbance estimator. Unlike existing approaches limited to either delay compensation or partial disturbance rejection, our methodology overcomes the technical barrier of coordinating these two requirements through a rigorously constructed tracking-error-based controller, achieving exponential convergence of system output to reference signals. Numerical simulations are presented to validate the effectiveness of the proposed output feedback control strategy.
