Sensor Threat Isolation for Cyber-Physical Systems

Abstract

This paper considers the isolability of sensor faults and malicious cyber attacks in cyber-physical systems. Attacks and faults are characterized by their basis functions, which are utilized for threat isolation and to characterize their isolability. An isolability metric is proposed that exploits the threat basis function to quantify the threat isolability. It is rigorously proved that a threat is non-isolable if and only if this metric is zero. A methodology to analytically calculate the proposed isolability metric is developed by solving a minimax optimization problem. Our findings are validated with numerical simulations.