Self-Triggered Feedback over Networked Control Systems

Sponsor: National Science Foundation ($160,000 - 2007-2010)
Award No: CNS-0720457 (201223-31025-20)
Principal Investigator: M.D.Lemmon, University of Notre Dame
Co-PI: X. Hu (Notre Dame)


ABSTRACT: Networked dynamical systems are found throughout the national infrastructure. Examples of such systems are seen in the national power grid, wastewater networks, and the national transportation system. As these networks grow in size, weak coupling across the network can blossom into system wide disturbances whose effects are felt over large geographical regions. There is, therefore, a compelling national need to devise more robust and cost-effect techniques for managing such networked systems. This project addresses this need through a self-triggered approach to decentralized control. In this approach, network subsystems use their current state information to determine the rate at which information must be exchanged to assure the networked system’s global L2 stability. These rates are cast as quality-of-service (QoS) constraints on the network’s traffic. This project uses these QoS constraints to develop soft real-time algorithms for scheduling message passing in networked control systems. The novel aspect of this work is that the resulting soft real-time control system provides guarantees on application performance that have traditionally been seen in hard real-time systems. The project is transferring the self-triggered technology to the private sector through collaborations with industry on another project that uses embedded sensor-actuator networks to control the frequency of combined-sewer-overflow (CSO) events. This CSO network is a good example of a networked cyber-physical system. To support the training of engineers qualified to manage such systems, this project is developing a set of lectures on the mathematical foundations of cyber-physical systems.


Event-triggered Control: Description and Findings
  1. Problem Statement
  2. Event-Triggered Embedded Control
  3. Event-Triggered Networked Control
  4. Event-triggered Optimization
  5. Movie of Event-Triggered 3DOF Helicopter

Generalized Elastic Scheduling: Description and Findings
  1. Problem Statement

Publications
  1. J. Yi, C. Poellabauer, X.S. Hu, and L. Zhang (2011), Minimum Bandwidth Reservations for Periodic Streams in Wireless Real-time Systems, IEEE Transactions on Mobile Computing, volume 10, number 4, pages 479-490, 2011.
  2. Y. Yu, S. Ren, and X.S. Hu, A Metric for Judicious Relaxation of Timing Constraints in Soft Real-time Systems, ACM Transactions on Design Automation of Electronic Systems, volume 16, number 3, article 34, June 2011.
  3. X. Wang (2009), Event-Triggering in Cyber-Physical System, Ph.D. Dissertation, Department of Electrical Engineering, University of Notre Dame,June 2009.
  4. M.D. Lemmon (2009), Event-triggered Feedback in Control, Estimation, and Optimizaiton, lectures presented at WIDE Ph.D. Summer School, University of Siena, Italy, July 9, 2009.
  5. Thidapat Chantem, Xiaobo Sharon Hu, and M.D. Lemmon (2009), Generalized Elastic Scheduling for Real-Time Tasks, IEEE Transactions on Computers, Volume 58, number 4, pages 480-495, March 2009..
  6. X. Wang and M. Lemmon (2009), Self-triggered Feedback Control Systems with Finite-Gain L2 Stability, IEEE Transactions on Automatic Control, Volume 45, number 3, pages 452-467, March 2009.
  7. P. Wan and M.D. Lemmon, An event-triggered distributed primal-dual algorithm for network utility maximization, IEEE Conference on Decision and Control (CDC), Shanghai, PRC, December 2009.
  8. X. Wang and M.D. Lemmon (2009), Event-Triggering in Distributed Networked Systems with Data Dropouts and Delays, Hybrid Systems: computation and control (HSCC), San Francisco California, April 2009.
  9. P. Wan and M. Lemmon (2009), Event triggered distributed optimization in sensor networks , Information Processing in Sensor Networks (IPSN), 2009.
  10. P. Wan and M. Lemmon (2009), Distributed Network Utility Maximization using Event-triggered augmented Lagrangian methods, American Control Conference, 2009.
  11. X. Wang and M. Lemmon (2009), Self-triggered Feedback Systems with State-Independent Disturbances , American Control Conference, 2009.
  12. P. Wan and M. Lemmon (2009), Distributed Network Utility Maximization using Event-Triggered Barrier Methods, European Control Conference, 2009.
  13. X. Wang and M. Lemmon (2009), Finite Gain L2 Stability in Distributed Event-Triggered Networked Control Systems with Data Dropouts, European Control Conference, 2009.
  14. T. Chantem, X. Wang, M.D. Lemmon, and X. Hu (2008), Period and Deadline Selection for Schedulability in Real-time Systems European Conference on Real-time Systems (ECRTS08), Prague, Czech republic, July 2008.
  15. X. Wang and M. Lemmon (2008), Event Design in Event-Triggered Feedback Control Systems , IEEE Conference on Decision and Control, December 2008.
  16. X. Wang and M. Lemmon (2008), Decentralized Event-triggering Broadcast over Networked Systems,, Hybrid Systems: computation and control, 2008.
  17. X. Wang and M. Lemmon (2008), State based Self-triggered feedback control systems with L2 stability, 17th IFAC world congress, 2008.
  18. X. Wang and M. Lemmon (2008), Event-triggered Broadcasting across Distributed Networked Control Systems,, American Control Conference,, 2008.
  19. T. Chantem, X.S. Hu, and M.D. Lemmon (2007), Period and Deadline Selection Problem for Real-Time Systems, Real Time Systems Symposium: work-in-progress track(RTSS07), 2007.
  20. M. Lemmon, T. Chantem, X. Hu, and M. Zyskowski (2007), On Self-Triggered Full Information H-infinity Controllers, Hybrid Systems: Computation and Control, April 2007.
  21. T. Chantem, X. Hu, and M.D. Lemmon (2006), Generalized Elastic Scheduling, IEEE Real Time Systems Symposium, 2006
  22. X. Hu, T. Chantem, and M.D. Lemmon (2006), Optimal Elastic Scheduling, IEEE Real-Time and Embedded Technology and Applications Symposium (works in progress track), 2006.
  23. Original Project Description Januay 2007
  24. Annual Reports, 2007, 2008, 2009, final report (2011.)
  25. J. Viramontes Perez and M.D. Lemmon, Implementation of an Event-triggered Controller in a Helicopter Model, unpublished technical report, Dept. of Electrical Engineering University of Notre Dame, September 2009
  26. C. Chen, Technical reports on Shark kernel, Implementation of Real-time control system using SHARK kernel, Technical Report, Dept. of Electrical Engineering, University of Notre Dame, February 2009
  27. Q. Ling, Stability and Performance of Control Systems with Limited Feedback Information , Ph.D. Dissertation, Dept. of Electrical Engineering, University of Notre Dame, May 2005