Event-triggered active disturbance rejection control for nonlinear network control systems subject to DoS and...

Area of Science:

• Control Systems Engineering
• Cybersecurity
• Nonlinear Dynamics

Background:

• Networked control systems are susceptible to unknown dynamics and cyberattacks like denial-of-service (DoS) and physical attacks.
• Network congestion necessitates efficient data transmission, making traditional periodic updates suboptimal.
• Ensuring system stability and performance under such adversarial conditions is a critical challenge.

Purpose of the Study:

• To develop an event-triggered active disturbance rejection control (ADRC) strategy for nonlinear network control systems (NCS).
• To address the simultaneous presence of unknown system dynamics, physical attacks, and random denial-of-service (DoS) attacks.
• To guarantee the stability of both the observer and the overall closed-loop system.

Main Methods:

• An event-triggered communication mechanism was implemented to reduce network load by transmitting data only when necessary.
• A Markov jump indicator was used to model the stochastic nature of DoS attacks.
• An extended state observer (ESO) was employed to estimate system states and lumped disturbances (unknown dynamics + physical attacks).
• A composite controller was designed based on ESO estimates for system stabilization and disturbance elimination.
• The cone-complementarity linearization algorithm was utilized for controller and observer parameter tuning.

Main Results:

• Sufficient conditions for ensuring the stability of the observer and the controlled system were derived.
• The proposed event-triggered ADRC method effectively estimated and compensated for unknown dynamics and physical attacks.
• Simulation and application examples validated the feasibility and efficacy of the control strategy.
• Achieved a steady-state error within 0.02 in approximately 3 seconds.

Conclusions:

• The proposed event-triggered ADRC framework provides a robust solution for nonlinear NCS under complex disturbances and attacks.
• The integration of event-triggered communication and ESO-based control enhances system resilience and performance.
• The method demonstrates practical applicability and effectiveness in achieving precise control objectives.