Resilient Control of Platooning Networked Robotic Systems via Dynamic Watermarking

TL;DR

This paper introduces a dynamic watermarking approach for networked robotic systems, such as vehicle platoons, to detect cyber attacks and maintain safety despite malicious message alterations.

Contribution

It develops a novel networked linear time-varying dynamic watermarking method enabling each agent to detect cyber attacks in robotic platoons.

Findings

The method detects cyber attacks altering communication messages.

Attacks can cause instability, but the watermarking detects and mitigates this.

The system maintains safety by degrading to non-communicative control when attacked.

Abstract

Networked robotic systems, such as connected vehicle platoons, can improve the safety and efficiency of transportation networks by allowing for high-speed coordination. To enable such coordination, these systems rely on networked communications. This can make them susceptible to cyber attacks. Though security methods such as encryption or specially designed network topologies can increase the difficulty of successfully executing such an attack, these techniques are unable to guarantee secure communication against an attacker. More troublingly, these security methods are unable to ensure that individual agents are able to detect attacks that alter the content of specific messages. To ensure resilient behavior under such attacks, this paper formulates a networked linear time-varying version of dynamic watermarking in which each agent generates and adds a private excitation to the input of its corresponding robotic subsystem. This paper demonstrates that such a method can enable each agent in a networked robotic system to detect cyber attacks. By altering measurements sent between vehicles, this paper illustrates that an attacker can create unstable behavior within a platoon. By utilizing the dynamic watermarking method proposed in this paper, the attack is detected, allowing the vehicles in the platoon to gracefully degrade to a non-communicative control strategy that maintains safety across a variety of scenarios.