Output-based disturbance rejection control for non-linear uncertain systems with unknown frequency disturbances using an observer backstepping approach

• Published in: IET control theory & applications Vol. 10; no. 9; pp. 1052 - 1060
• Main Authors: Yang, Jun, Ding, Zhengtao, Chen, Wen-Hua, Li, Shihua
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 05.06.2016
• Subjects: adaptive control; adaptive internal model principle; closed loop systems; closed‐loop system; compact exogenous model; composite output feedback controller; control nonlinearities; control system synthesis; Control systems; Disturbances; dynamic estimator; Dynamical systems; feedback; harmonic disturbance; Lyapunov methods; Lyapunov stability criterion; missile roll stabilisation; nonlinear control systems; Nonlinear dynamics; nonlinear uncertain system; Nonlinearity; observer backstepping; observers; Output feedback; output feedback control design; output‐based disturbance rejection control; Stability; state estimation; uncertain systems; Uncertainty; unknown constant disturbance; unknown frequency disturbance; output feedback control design; Lyapunov stability criterion; uncertain systems; output-based disturbance rejection control; dynamic estimator; control system synthesis; adaptive control; missile roll stabilisation; adaptive internal model principle; unknown constant disturbance; unknown frequency disturbance; feedback; closed loop systems; compact exogenous model; nonlinear control systems; control nonlinearities; state estimation; composite output feedback controller; nonlinear uncertain system; harmonic disturbance; observers; closed-loop system; observer backstepping; Lyapunov methods
• ISSN: 1751-8644; 1751-8652
• DOI: 10.1049/iet-cta.2015.1160

This study is concerned with the output feedback control design for a class of non-linear uncertain systems subject to multiple sources of disturbances including model uncertainties, unknown constant disturbances, harmonic disturbances with unknown frequency and amplitude. The total disturbances and uncertainties are delicately represented by a compact exogenous model first. By incorporating the adaptive internal model principle, a set of dynamic estimators are developed for both state and disturbance observations. By means of observer backstepping technique, a composite output feedback controller is constructed based on the disturbance and state estimations. The stability of the closed-loop system is rigorously established based on Lyapunov stability criterion. A missile roll stabilisation example is finally investigated to validate the effectiveness of the proposed control approach.