Robust Control for Uncertain Linear System Subject to Input Saturation

• Published in: Journal of Applied Mathematics Vol. 2014; no. 2014; pp. 776 - 787-779
• Main Authors: Yang, Qingyun, Chen, Mou
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Limiteds 01.01.2014; Hindawi Puplishing Corporation; Hindawi Publishing Corporation; John Wiley & Sons, Inc; Wiley
• Subjects: Algorithms; Closed loop systems; Colleges & universities; Control systems; Controllers; Design; Disk drives; Disturbances; Feedback; Feedback control; Inequalities (Mathematics); Linear systems; Mathematical research; Nonlinear theories; Observers; Robust control; Saturation
• ISSN: 1110-757X; 1687-0042
• DOI: 10.1155/2014/803842

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.