The system dynamics analysis, resilient and fault-tolerant control for cyber-physical systems

TL;DR

This paper develops a novel detection and control framework for cyber-physical systems that enhances resilience against cyber-attacks and process faults, using residual-based detection and modified observer configurations.

Contribution

It introduces a new cyber-physical system configuration transmitting residual combinations, improving detection of stealthy attacks and fault tolerance over standard methods.

Findings

Effective detection of cyber-attacks demonstrated on Robotino system

Enhanced fault-tolerant control schemes improve system resilience

Detection of stealthy attacks that degrade control performance

Abstract

This paper is concerned with the detection, resilient and fault-tolerant control issues for cyber-physical systems. To this end, the impairment of system dynamics caused by the defined types of cyber-attacks and process faults is analyzed. Then, the relation of the system input and output signals with the residual subspaces spanned by both the process and the controller is studied. Considering the limit capacity of standard observer-based detection and feedback control schemes in detecting and handling the cyber-attacks, a modified configuration for cyber-physical systems is developed by transmitting the combinations of the input and output residuals instead of the input and output signals, which is facile for dealing with both the process faults and cyber-attacks. It is followed by the integrated design of fault and attack detection, resilient and fault-tolerant control schemes. To enhance the detectability of cyber-attacks, the potential stealthy attack mechanisms on deteriorating the tracking behavior and feedback control performance are developed from the attackers' point of view, and the associated detection schemes for such stealthy attacks are proposed from the defenders' point of view. A case study on the robotino system is utilized to demonstrate the proposed resilient cyber-physical configuration.