Robust Control for Uncertain Linear System Subject to Input Saturation

• Main Authors: Qingyun Yang, Mou Chen
• Format: Article
• Language: English
• Published: Hindawi Limited 2014-01-01
• Series: Journal of Applied Mathematics
• Online Access: http://dx.doi.org/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.