Parity Space-Based Fault Detection for Networked Control Systems Under DoS Attacks.

Area of Science:

• Control Systems Engineering
• Cybersecurity in Control Systems
• Fault Detection and Diagnosis

Background:

• Networked control systems (NCSs) are vulnerable to denial-of-service (DoS) attacks, leading to packet dropouts and compromising system integrity.
• Existing fault detection (FD) methods struggle to maintain performance under DoS attack scenarios.
• Robust fault detection is crucial for the safe and reliable operation of NCSs, particularly in critical applications.

Purpose of the Study:

• To develop a parity space-based fault detection (FD) method for NCSs that is resilient to DoS attacks causing packet dropouts.
• To design a residual generator and evaluation function that effectively distinguish between system faults and DoS attack effects.
• To enhance the robustness and sensitivity of the FD system through H-/H2 optimization and adaptive thresholding.

Main Methods:

• Construction of a DoS-aware parity relation using available input/output data within a time-varying window.
• Development of a novel residual generator that mitigates transmission errors introduced by DoS attacks.
• Application of an H-/H2 optimization scheme for residual design, balancing fault sensitivity and disturbance/noise robustness.
• Proposal of an adaptive residual evaluation function with a unified threshold for both normal and DoS attack conditions.
• Exploration of the relationship between traditional and proposed residual generators, leading to an online FD algorithm.

Main Results:

• The proposed parity space-based FD method effectively detects faults in NCSs under DoS attacks with packet dropouts.
• The H-/H2 optimized residual generator demonstrates a favorable trade-off between fault sensitivity and robustness to noise.
• The adaptive residual evaluation function provides reliable fault detection across scenarios with and without DoS attacks.
• The online FD algorithm, derived from the proposed residual generator, shows practical applicability.
• Validation on an autonomous underwater vehicle (AUV) model confirms the effectiveness and superiority compared to existing methods.

Conclusions:

• The presented parity space-based FD method offers a robust solution for NCSs facing DoS attacks and packet dropouts.
• The developed techniques, including the DoS-aware parity relation and adaptive evaluation, significantly improve fault detection performance under cyber-attacks.
• The approach is validated and shows promise for enhancing the security and reliability of autonomous systems like AUVs.