Abstract
The cyber-layer of a cyber-physical system can be regarded as a discrete-event system that can be fully implemented in a computer, which monitors the working status of physical systems (usually differential equations) or allocates targets to physical systems. A labeled finite-state automaton (LFSA) can be seen as such a monitor and the control properties in LFSAs have been widely studied, where detectability is one of the fundamental inference-based control properties describing whether one could use output sequences to determine the current and subsequent states. In this paper, we study how an attacker affects strong detectability and weak detectability of an LFSA. We formulate an attacker as a K-memory attacker, which can remember and distort K-length output sequences generated by an LFSA. We give a systematic method to verify when this type of attackers affect detectability of an LFSA.