Wireless Control for Cyber-physical Systems

  Graph: Cyber-physical systems and a multi hop Wireless Network Copyright: © Dominik Baumann / MPI-IS  

Cyber-physical systems, CPS for short tightly integrate physical processes with computing and communication. Through this tight integration, CPS enable emerging applications such as coordinating autonomous vehicles or controlling factory automation machinery over wireless networks. The adoption of wireless technology offers unprecedented flexibility in sharing data between these systems, for example, to increase collective information or take collaborative action, but also comes with severe challenges. Wireless networks are orders of magnitude less reliable than wired communication, while feedback control typically poses strict requirements on reliability and timeliness of data.

Within this project, we develop novel feedback control strategies in order to realize the full potential of future CPS. The key enabler for this is a tight co-design of wireless embedded and control systems. We design the wireless embedded system such that natural imperfections of wireless networks are tamed to the extent possible. The control design then takes the remaining imperfections (delays and packet losses) into account to realize stable closed-loop control over low-power multi-hop networks. This integration at design time enables provably stable feedback control of fast physical systems over low-power multi-hop networks, which we practically demonstrate on a novel cyber-physical testbed as you can see in our publications ICCPS 2019, TCPS 2019 and CPSBench 2018.

A further challenge in wireless CPS is that they can easily be overloaded when multiple systems communicate over the same network. To address this issue, we complement the integration at design time with integration at run time: in our papers CDC 2016, IoT-J 2019 and NecSys 2019 by letting the control systems reason about communication demands in advance, we enable the communication system to allocate resources to those systems in need, while simultaneously supporting lower-priority traffic and saving energy if possible (L-CSS 2020).