Probabilistic detection of FSM single state-transition faults based on state occupancy measurements

This note discusses a probabilistic methodology for detecting single permanent or transient functional changes in the state-transition mechanism of a deterministic finite-state machine (FSM). The associated probabilistic detector observes the empirical frequencies with which different states are occupied and detects faults by analyzing the discrepancy between the observed state occupancy measurements and the expected frequencies. In addition to state occupancy measurements, the detector requires a statistical characterization of the input, but does not need to know the order with which states appear or the exact input sequence that is applied to the FSM. These features can be useful in settings where the input/state order may not be known due to synchronization, communication or other constraints.