Fault diagnosis and fault tolerant control for a class of nonlinear singular systems

A new fault detection and diagnosis approach is developed in this paper for a class of nonlinear singular systems via the use of adaptive updating rules. Both detection and diagnostic observers are established, where Lyapunov stability theory is used to obtain the required adaptive tuning rules for the estimation of the actuator faults. This has led to stable observation error systems for both fault detection and diagnosis. Based on the fault estimation information, a reconfiguration controller can be constructed to keep the post-fault system stable, leading to active fault tolerant control of the nonlinear singular system. A simulated numerical example is included to demonstrate the use of the proposed methods and encouraging results have been obtained.