ISBN 978-3-8439-5685-7

978-3-8439-5685-7, Reihe Informationstechnik

Michael Gundall
Industrial Control as a Service: Realization of Networked and Mobile Control Services

197 Seiten, Dissertation Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau (2025), Softcover, A5

Zusammenfassung / Abstract

The fourth industrial revolution introduces new demands beyond traditional real-time requirements, emphasizing flexibility (batch size 1) and mobility of cyber-physical systems (CPS). However, operational technologies (OT) differ from information technology (IT), hindering support for these needs. To bridge this gap, Industrial Control as a Service (ICaaS) adapts Everything as a Service principles for industrial control systems.

A key challenge is virtualizing control systems into Virtual Process Controllers (VPCs) and enabling live migration of Virtual Process Control Functions (VPFs). Container virtualization is effective, with only 4.8 % overhead versus bare-metal, while virtual machines impose greater penalties. For ICaaS, the Macvlan network driver is recommended, reducing processing overhead by 25–35 % compared to overlay networks.

To support mobile and cloud-based control, seamless live migration is explored. Based on Parallel Process Migration (PPM), two concepts are developed: State and Output Convergence Live Migration (SOCLM) and Redundant Process Live Migration (RPLM). SOCLM uses predefined state variables and achieves up to three migrations per second; RPLM needs no process knowledge but is slower. Both reach downtimes below 1 ms, suitable for real-time class C.

Time synchronization of mobile CPSs is realized via the Reference Broadcast Infrastructure Synchronization (RBIS) protocol, adapted from Wi-Fi to 5G, achieving ±10 µs accuracy without infrastructure changes. Its extension, ERBIS, enables synchronization across multiple base stations, converging with 35–50 UEs in IMT-2020 scenarios.

Integrating legacy systems (Brownfield integration) remains vital. Future PLCs may act as sensor/actuator interfaces, offloading algorithms via wired or wireless networks. Measurements of Round Trip Time, determinism, and protocol efficiency identify optimal offloading for algorithms like the Leibniz formula, supporting flexible, efficient ICaaS.