Adaptive Event-Triggered Security Control for Nonlinear CPSs Under Coexisting FDI Attacks and Actuator Faults

Area of Science:

• Cyber-Physical Systems Security
• Control Theory
• Networked Systems

Background:

• Nonlinear cyber-physical systems (CPSs) face increasing threats from coexisting False Data Injection (FDI) attacks and actuator faults.
• Existing security measures often struggle to address these dual threats simultaneously and efficiently.

Purpose of the Study:

• To develop an integrated security control and communication co-design for nonlinear CPSs.
• To propose a novel adaptive discrete event-triggered communication scheme (ADETCS) for enhanced resilience.
• To reduce communication and computational resource consumption in CPSs under attack.

Main Methods:

• Developed an adaptive discrete event-triggered communication scheme (ADETCS) with state-adaptive triggering thresholds.
• Migrated state estimation, fault estimation, and attack detection to the control unit.
• Established a closed-loop Takagi-Sugeno (T-S) fuzzy model for active defense.
• Designed a robust augmented observer using Lyapunov stability theory for joint estimation.
• Derived sufficient conditions for an integrated security controller.

Main Results:

• Effectively counteracted coexisting actuator faults and dual-end FDI attacks in a quadruple-tank system.
• Significantly reduced data transmissions by 91.1% (from time-triggered to 712 event-triggered transmissions over 800s).
• Reduced sensor-node computational load by migrating tasks to the control unit, decreasing executions from 8000 to 712.

Conclusions:

• The proposed ADETCS provides robust integrated security and fault tolerance for nonlinear CPSs.
• The event-triggered approach substantially conserves communication and computational resources.
• This co-design strategy offers a practical solution for securing critical CPS infrastructure.