Event diagnosis of discrete-event systems with uniformly and nonuniformly bounded diagnosis delays

Various notions of diagnosability reported in literature deal with uniformly bounded finite detection or counting delays. The uniformity of delays can be relaxed while delays remain finite. We introduce various notions of diagnosability allowing nonuniformly bounded finite delays. A polynomial-time verification algorithm for diagnosability with nonuniformly bounded finite indefinite-counting delays is presented. A similar technique is applied to give a computationally better verification algorithm for diagnosability with uniformly bounded finite indefinite-counting delays than algorithms previously reported in literature. Finally, we develop a new on-line diagnosis algorithm that has a lower time and space complexity than on-line diagnosis algorithms reported in literature for counting the occurrence of repeated/intermittent faults.