Parity space fault detection based on irregularly sampled data

In this paper, we study fault detection and isolation in non-uniformly sampled systems. In these systems the control input is generated and the process output is sampled at non-uniformly distributed time instants. A parity space residual generator is constructed and optimized to minimize the sensitivity of the residual to disturbances. The residual generator is developed assuming that fault and disturbance signals are constant during the sampling intervals. This assumption is practically acceptable if sampling intervals are small. For larger sampling intervals, a method is proposed to improve the performance. No periodicity assumption is made for the sampling instants (i.e., irregularly sampled data is considered).