Fault tolerant control of asynchronous sequential machines with transient faults in non-fundamental mode

Abstract

This paper addresses fault tolerant corrective control of asynchronous sequential machines (ASMs) against transient faults causing unauthorized state transitions. While the prior work considers only those kinds of faults that comply with fundamental mode operations, the constraint is relaxed in this study. Hence the transient faults may occur not only in fundamental mode, or when the machine stays at a stable state, but also in non-fundamental mode, or when the machine passes through transient states. The condition for overcoming transient faults occurring in non-fundamental mode turns out to be stricter than the case of fundamental mode. A novel scheme of corrective control is presented to make the closed-loop system immune against any fault occurrence in non-fundamental mode. An illustrative example is provided to demonstrate the synthesis procedure of the proposed corrective controller.