Control Communication Co-Design for Wide Area Cyber-Physical Systems

TL;DR

This paper introduces a novel control-communication co-design approach for Wide Area Cyber-Physical Systems, demonstrating that LPWA wireless technologies can support control tasks with improved stability and performance.

Contribution

It presents the first LPWA-based MAC protocol and control scheme that guarantees stability for WA-CPSs, validated through simulation and real-world testing.

Findings

Achieved up to 50% better packet delivery ratios

Reduced average end-to-end delays by 80%

Maintained control stability comparable to wired systems

Abstract

Wide Area Cyber-Physical Systems (WA-CPSs) are a class of control systems that integrate low-powered sensors, heterogeneous actuators and computer controllers into large infrastructure that span multi-kilometre distances. Current wireless communication technologies are incapable of meeting the communication requirements of range and bounded delays needed for the control of WA-CPSs. To solve this problem, we use a Control-Communication Co-design approach for WA-CPSs, that we refer to as the $C^3$ approach, to design a novel Low-Power Wide Area (LPWA) MAC protocol called \textit{Ctrl-MAC} and its associated event-triggered controller that can guarantee the closed-loop stability of a WA-CPS. This is the first paper to show that LPWA wireless communication technologies can support the control of WA-CPSs. LPWA technologies are designed to support one-way communication for monitoring and are not appropriate for control. We present this work using an example of a water distribution network application which we evaluate both through a co-simulator (modelling both physical and cyber subsystems) and testbed deployments. Our evaluation demonstrates full control stability, with up to $50$\% better packet delivery ratios and $80$\% less average end-to-end delays when compared to a state of the art LPWA technology. We also evaluate our scheme against an idealised, wired, centralised, control architecture and show that the controller maintains stability and the overshoots remain within bounds.