Robust observer-based fault detection for periodic systems

We provide an observer-based fault detection and isolation scheme for periodic systems. The observer is designed using the lift for the periodic system. To provide robustness with respect to disturbance inputs, we develop a novel parity approach for periodic systems. Disturbance rejection is achieved by designing a finite impulse response (FIR) annihilator for the transfer function of the system lift with the disturbance as input. The resulting annihilator is then used to obtain constant weighting matrices for the residuals of the periodic system at different sampling points. Two illustrative examples, including computer simulation of the periodic systems, are provided