An Analytical Framework for Control Synthesis of Cyber-Physical Systems with Safety Guarantee

TL;DR

This paper introduces an analytical framework that models various cyber resilient architectures for cyber-physical systems, enabling the synthesis of control policies that guarantee safety under faults and attacks, validated through a Boeing 747 case study.

Contribution

It provides a unified modeling framework for different cyber resilient architectures and offers a method to synthesize safe control policies.

Findings

Framework successfully models multiple architectures

Control policies synthesized guarantee safety

Validated on Boeing 747 lateral control

Abstract

Cyber-physical systems (CPS) are required to operate safely under fault and malicious attacks. The simplex architecture and the recently proposed cyber resilient architectures, e.g., Byzantine fault tolerant++ (BFT++), provide safety for CPS under faults and malicious cyber attacks, respectively. However, these existing architectures make use of different timing parameters and implementations to provide safety, and are seemingly unrelated. In this paper, we propose an analytical framework to represent the simplex, BFT++ and other practical cyber resilient architectures (CRAs). We construct a hybrid system that models CPS adopting any of these architectures. We derive sufficient conditions via our proposed framework under which a control policy is guaranteed to be safe. We present an algorithm to synthesize the control policy. We validate the proposed framework using a case study on lateral control of a Boeing 747, and demonstrate that our proposed approach ensures safety of the system.