H∞ fault-tolerant control for nonlinear singular system via a fault diagnosis observer

Dongwen Zhang¹, Xinguo An²

¹School of information science & engineering, Hebei University of Science &Technology, Shijiazhuang, China

²School of Sciences, Hebei University of Science &Technology, Shijiazhuang, China

An H∞ fault-tolerant control scheme based on fault diagnosis observer was developed for a class of nonlinear singular systems with external disturbances and actuator faults. A fault diagnosis observer was designed to estimate the system states and the actuator faults and a sufficient condition for the existence of this observer was presented in the form of feasibility problem of a linear matrix inequality. Based on linear matrix inequality (LMI) technique and the estimates of the states and faults, an H∞ fault-tolerant control scheme was worked out. The H∞ fault-tolerant control system via a state feedback controller can be made solvable, impulse free, asymptotically stable, and the effect of external disturbances on the system was attenuated in terms of the prescribed H∞ performance index. Finally, a simulation example was given to illustrate the procedure of designing the fault diagnosis observer and the state feedback controller, and the simulation result showed the effectiveness of the proposed method.