Abstract
A robust control scheme using composite nonlinear feedback (CNF) technology is proposed to improve tracking control performance for the uncertain linear system with input saturation and unknown external disturbances. A disturbance observer is presented to estimate the unknown disturbance generated by a linear exogenous system. The designed gain matrix of the disturbance observer is determined by solving linear matrix inequalities (LMIs). Based on the output of the designed disturbance observer, a robust CNF controller including a linear feedback control item and a nonlinear item is developed to follow the desired tracking signals. The linear feedback controller is designed using LMIs and the stability of the closed-loop system is proved via rigorous Lyapunov analysis. Finally, the extensive simulation results are presented to illustrate the effectiveness of the proposed control scheme.
Highlights
As is well known, almost all practical control systems have limitations on the amplitudes or rates of the control input [1]
A composite nonlinear feedback (CNF) control scheme based on the disturbance observer has been proposed to achieve satisfactory tracking control performance for the linear system subject to input saturation, parametric uncertainties, and unknown external disturbance
The disturbance observer has been designed to approximate the system disturbance generated by a linear exogenous system
Summary
Almost all practical control systems have limitations on the amplitudes or rates of the control input [1]. The input saturation which can cause the nonlinearity usually appears in most of the physical systems in our real life, such as aircraft, robot [2, 3], and industry control systems [4–6]. The input saturation problem is of great importance because it may lead to performance degradation and even destroy the stability of the control systems if they are ignored in the process of controller design [7, 8]. The control performance of linear systems is severely affected by uncertainties. The task that designs high performance feedback control schemes for systems with input saturation and parametric uncertainties is theoretically challenging and critical for practical applications [10, 11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
