Model-based fault diagnosis of two-time scales singularly perturbed systems

The aim of this paper is to detect and to isolate sensor faults in singularly perturbed systems (SPS), with emphasis on the use of slow subsystem. Firstly, we considered the fast subsystem as a modelling error by the approximation of the SPS with the slow subsystem. Structured residuals were generated, using robust parity space, to the fault diagnosis of the SPS. A second approach was to design a set of observer-based residuals based on the slow subsystem. In order to validate the proposed approaches, we applied the results on a F-8 aircraft example.