Coordination Control of Discrete Event Systems under Cyber Attacks

TL;DR

This paper develops methods for designing local supervisors to ensure safety in discrete event systems under cyber attacks, using attack models and conditions like CA-controllability and CA-observability.

Contribution

It introduces a new ALTER model for sensor attacks, derives conditions for supervisor existence, and proposes algorithms for local supervisor design under cyber attacks.

Findings

Conditions for supervisor existence are established.

Methods for local state estimation under attacks are developed.

Approaches work for both stealthy and non-stealthy attacks.

Abstract

In this paper, coordination control of discrete event systems under joint sensor and actuator attacks is investigated. Sensor attacks are described by a set of attack languages using a proposed ALTER model. Several local supervisors are used to control the system. The goal is to design local supervisors to ensure safety of the system even under cyber attacks (CA). The necessary and sufficient conditions for the existence of such supervisors are derived in terms of conditional decomposability, CA-controllability and CA-observability. A method is developed to calculate local state estimates under sensor attacks. Two methods are also developed to design local supervisors, one for discrete event systems satisfying conditional decomposability, CA-controllability and CA-observability, and one for discrete event systems satisfying conditional decomposability only. The approach works for both stealthy and non-stealthy attacks. A practical example is given to illustrate the results.