Robust fault detection and isolation for a class of uncertain single output non-linear systems

The problem of robust fault detection and isolation (FDI) is studied for a class of uncertain single output non-linear systems with q faults. By designing a switching law, a robust state observer is developed such that its state responses can asymptotically converge to the true system states for both fault-free and faulty cases. Based on this robust state observer and other q + 1 FDI observers, an efficient scheme is presented such that the FDI can be achieved for the considered single output non-linear systems. The theoretical results are illustrated through an example of a single-link flexible joint robot.