Cyber-Physical Secure Observer-Based Corrective Control under Compromised Sensor Measurements

In this paper we introduce the objectives and design principles of corrective control under cyber-physical attacks. We propose two types of observer-based corrective control for both the open-loop stable and the open-loop unstable LTI systems. The basic idea of our corrective control design is to use the observer as the ground-truth during the attack, making the plant dynamics follow the observer behavior. This is the opposite to the no-attack-detected period in which the observer is designed to follow the plant dynamics. We show stability of the proposed control under compromised sensor measurements, and quantify the effects of the discrepancy between the observer and the plant. Numerical examples, with illustrations using microgrid energy dynamics, are presented to show benefits of the proposed corrective control.