Resilient Supervisor Synthesis for Labeled Petri Nets Against Sensor Attacks

This article studies the supervisory control problem (SCP) of discrete-event systems under sensor attacks. The plant is modeled with a labeled Petri net (LPN) and the attacker has the ability to replace and erase the sensor readings in the communication channel. Our goal is to synthesize a maximally permissive and resilient supervisor for the LPN such that the controlled system satisfies the safety specification under attack. Given a set of safe markings, the basis reachability graph (BRG) for control is defined. We prove that the resilient supervisor synthesis problem of LPNs against sensor attacks can be reduced to the SCP of its BRG. In this way, exhaustive enumeration of the reachability space of the LPN is avoided. Then, a method of supervisor synthesis for the BRG is proposed. The complexity of the proposed method remains the same as that of solving a standard SCP without attacks.