Integrated Controller Design Methods and Communication Services for Networked Control Systems

PIs: Frank Allgöwer (University of Stuttgart), Kurt Rothermel (University of Stuttgart)

Overview

Digitally networked control systems (NCS) are steadily gaining importance for the implementation of so-called cyber-physical systems, where computers are used to control physical processes. Such systems comprise sensors, actuators, and digital controllers, which are often distributed over a wide area. Consequently, measurement and control signals have to be transferred using a communication network. On the one hand, the design of NCS often assumes network models that do not match real communication networks and communication methods accurately. On the other hand, there is a lack of communication methods that can serve as basis for control methods in order to guarantee a suitable quality of control. Therefore, the basic goal of this project is to develop methods to bridge the gap between control systems and communication systems. In particular, this includes the design of network models that can serve, on the one hand, as basis for control systems providing a guaranteed quality of control. On the other hand, these network models should allow for an efficient implementation in IP communication infrastructures. For the individual network models, suitable communication methods (routing and scheduling) and algorithms for the optimal placement of NCS controllers will be investigated. Moreover, corresponding controller design methods for time-triggered and event-based systems will be investigated. The performance of the designed methods will be evaluated using prototypical implementations for software-defined networks (SDN).

Principal Investigators

  • Frank Allgöwer (University of Stuttgart): Frank Allgöwer studied Engineering Cybernetics and Applied Mathematics in Stuttgart and at the University of California, Los Angeles (UCLA), respectively, and received his Ph.D. degree from the University of Stuttgart in Germany. He is the Director of the Institute for Systems Theory and Automatic Control and Executive Director of the Stuttgart Research Centre Systems Biology at the University of Stuttgart. His research interests include cooperative control, predictive control, and nonlinear control with application to a wide range of fields including systems biology. For the years 2017-2020 Frank serves as President of the International Federation of Automatic Control (IFAC) and since 2012 as Vice President of the German Research Foundation DFG.
  • Kurt Rothermel (University of Stuttgart): Kurt Rothermel received his doctoral degree in Computer Science from University of Stuttgart in 1985. From 1986 to 1987 he was ‘Post-Doctoral Fellow’ at IBM Almaden Research Center in San José, U.S.A., and then joined IBM’s European Networking Center in Heidelberg. Since 1990 he is a Professor for Computer Science at the University of Stuttgart. From 2003 to 2011 he was head of the Collaborative Research Center Nexus (SFB 627), conducting research in the area of mobile context-aware systems. He is a Director of the Institute of Parallel and Distributed Systems. His current research interests are in the field of distributed systems, computer networks, and mobile computing.

Involved PostDocs

  • Frank Dürr (Rothermel Group): Frank Dürr is a senior researcher and lecturer at the Distributed Systems Department of the Institute of Parallel and Distributed Systems (IPVS) at University of Stuttgart, Germany. He received both his doctoral degree and diploma in computer science from University of Stuttgart. Frank Dürr is currently leading the mobile computing and the software-defined networking (SDN) & time-sensitive networking (TSN) groups of the Distributed Systems Department. He has given tutorials on SDN at several national and international conferences, and as a lecturer he has been giving lectures and practical courses on networked systems and SDN. Besides SDN and TSN, Frank Dürr’s research interests include mobile and pervasive computing, location privacy, and cloud computing aspects overlapping with these topics like mobile cloud and edge computing, or datacenter networks.

Involved PhD candidates

  • Steffen Linsenmayer (Allgöwer Group): Steffen Linsenmayer: Steffen Linsenmayer studied Engineering Cybernetics at the University of Stuttgart from 2009 to 2014, finishing with a M.Sc. degree. During his Master studies, he had a stay at KTH, Royal Institute of Technology in Stockholm, Sweden. Since 2015 Steffen Linsenmayer is a research and teaching assistant at the Institute for Systems Theory and Automatic Control. His research interests are focused on event-based sampling strategies and networked control systems.
  • Jonathan Falk (Rothermel Group): Jonathan Falk: Jonathan Falk joined the Institute for Parallel and Distributed Systems of University of Stuttgart after receiving his Master’s degree in Electrical Engineering and Information Technology. He works on networks for cyber-physical systems.
  • Ben W. Carabelli (Rothermel Group): Ben W. Carabelli is a research and teaching assistant at the Institute of Parallel and Distributed Systems (IPVS), University of Stuttgart, Germany. He received his Diploma degree in Engineering Cybernetics from the University of Stuttgart in 2011. His research interests are focused on communication services for networked control systems.

Publications

  1. Linsenmayer, S., Dimarogonas, D. V., and Allgöwer, F.: A non-monotonic approach to periodic event-triggered control with packet loss, Proc. 55th IEEE Conf. Decision and Control (CDC), pages 507-512, Las Vegas, NV, USA, 2016.
  2. Carabelli, B. W., Blind, R., Dürr, F., and Rothermel, K.: State-dependent priority scheduling for Networked Control Systems, Proc. 2017 American Control Conf. (ACC), to appear, Seattle, WA, USA, 2017.
  • Blind, R., Uhlich, S., Yang, B., and Allgöwer, F.: Robustification and optimization of a Kalman filter with measurement loss using linear precoding, Proc. 2009 American Control Conf. (ACC), pages 2222-2227, St. Louis, MO, USA, 2009.
  • Blind, R., and Allgöwer, F.: On the stabilizability of continuous-time systems over a packet based communication system with loss and delay, Proc. 19th IFAC World Congress, pages 6466-6471, Cape Town, South Africa, 2014.
  • Blind, R., and Allgöwer, F.: Towards Networked Control Systems with guaranteed stability: Using weakly hard real-time constraints to model the loss process, Proc. 54th IEEE Conf. Decision and Control (CDC), pages 7510-7515, Osaka, Japan, 2015.