Distributed Optimization, Estimation, and Control of Networked Systems through Event-triggered Message Passing

Sponsor: National Science Foundation ($298,899 - 2009-2013)
Award No.: ECCS-0925229 (201550-31025-20)
Principal Investigator: M.D.Lemmon, University of Notre Dame


ABSTRACT: The objective of this program is to develop event-triggered methods for message passing in the optimization, estimation, and control of networked dynamical systems. Prior work has demonstrated experimentally that event-triggering can greatly reduce communication usage while maintaining high levels of networked system performance. The main goal of this project is to develop formalisms that better explain the reason for these benefits and to develop a more systematic approach to designing event-triggered networked systems. Event-triggering provides a novel approach to the discretization of networked dynamical systems. This approach is based on the simple idea that messages between subsystems should only exchanged when there is novel information relevant to the performance of the overall system. This event-triggered approach therefore has subsystems transmit information when some internal measure of that information's novelty exceeds a time-varying and state-dependent threshold. The design of these thresholds is accomplished by enforcing stability concepts (such as input-to-state stability or input-output stability) subject to constraints on the frequency with which information can be passed within the overall system. The project's impact will be broadened through interactions with industrial partners EmNet LLC and Odyssian LLC. EmNet LLC is interested in using event-triggered message passing on the CSOnet system, a wireless sensor-actuator network being used to control the frequency of combined sewer overflow (CSO) events. Odyssian LLC is interested in using event-triggered methods for the intelligent control of event-triggered microgrids.

Video of Event-Triggered 3DOF Helicopter


Documentation:
  1. Original Project Description, February 2009
  2. Annual Reports, 2009, 2010, 2011, final report
  3. Lichun Li and M.D. Lemmon, Event-triggered output feedback control of finite horizon discrete-time multi-dimensional linear processes, Proceedings of IEEE Conference on Decision and Control, Atlanta, Georgia, December 2010.
  4. L. Li, M.D. Lemmon and X. Wang, Event-Triggered State Estimation in Vector Linear Processes, American Control Conference, Baltimore, USA, 2010.
  5. P. Wan and M.D. Lemmon, Optimal power flow in microgrids using event-triggered optimization, American Control Conference, Baltimore, USA, 2010
  6. X. Wang and M.D. Lemmon, Asympottic stability in distributed event-triggered networked control systems with delays, American Control Conference, Baltimore, USA, 2010
  7. X. Wang and M.D. Lemmon, Event-triggering in distributed networked control systems, IEEE Transactions on Automatic Control, Volume 56, number 3, pages 586-601, March 2011.
  8. Lichun Li, X. Wang, and M.D. Lemmon (2011), Efficiently Attentive Quantized Event-Triggered Systems, Workshop on Control of Computing Systems, December, 2011, Lund Sweden.
  9. X. Wang and M.D. Lemmon (2010), Self-triggering under state-independent disturbances, IEEE Transactions of Automatic Control, vol 55, no. 6, pages 1494-1500, 2010
  10. M.D. Lemmon (2010), Event-Triggered Feedback in Control, Estimation, and Optimization, editors A. Bemporad, M. Heemels, M. Johansson, Volume 405 Lecture Notes in Control and Information Sciences,pages 293-358, Springer-Verlag Berlin Heidelburg, 2010.
  11. X. Wang and M.D. Lemmon (2011), Minimum Attention Controllers for Event-triggered Feedback Systems, IEEE Conference on Decision and Control, Orlando Florida, December 2011.
  12. L. Li and M.D. Lemmon (2011), Performance and average sampling period of sub-optimal triggering event in event triggered state estimation, IEEE Conference on Decision and Control, Orlando Florida, December 2011
  13. L. Li and M.D. Lemmon (2011), Weakly coupled event triggered output feedback system in wireless networked control systems, Allerton 2011 workshop
  14. X. Wang and M.D. Lemmon (2012), On Event Design in Event-Triggered Feedback Systems, Automatica, volume 47 number 10, pages 2319-2322, October 2012.
  15. Lichun Li (2011), Event Triggered State Estimation and Output Feedback in Cyber-Physical Systems, Ph.D. Proposal, Dept. of Electrical Engineering, University of Notre Dame, May 2011.
  16. Lichun "Lucinda" Li, Bin Hu, and M.D. Lemmon (2012), Resilient Event Triggered Systems with Limited Communication, IEEE Conference on Decision and Control, Hawaii, USA, 2012.
  17. L. Li, X. Wang, and M.D. Lemmon (2012), Stabilizing Bit-Rates for Perturbed Event-Triggered Control Systems, IFAC conference on Analysis and Design of Hybrid systems, Eindhoven, Netherlands, June 2012.
  18. L. Li, M.D.Lemmon, and X. Wang (2012), Stabilizing Bit-Rates in Quantized Event Triggered Control Systems, Hybrid Systems: computation and control, Beijing, China, April 2012.
  19. Lichun "Lucinda" Li and M.D. Lemmon, Weakly Coupled Transmissions in Event Triggered Output Feedback Systems, to appear in Journal on Discrete Event-Dynamical Systems, May 2012
  20. Lichun "Lucinda" Li and M.D. Lemmon, Polynomial Approximation of Optimal Event Triggers for State Estimation Problems using SOSTOOLS, American Control Conference, 2013.
    Examples: Stable System, Unstable System, Helicopter System
  21. L. Li, X. Wang, and M.D. Lemmon (2013), Efficiently Attentive Event-Triggered Control Systems with Limited Bandwidth, submitted to IEEE Transactions on Automatic Control, April 2013.
  22. L. Li, Event-triggered state estimation and control with limited communication, Ph.D. Dissertation, Dept. of Electrical Engineering, University of Notre Dame, July 2013
Course Development:
  1. Special Studies in Networked Control Systems, University of Notre Dame, Spring 2011, Spring 2012

Technical Transfer and Industrial Outreach:
  1. Odyssian Technology South Bend, Indiana
  2. Managing the Impact of Excess Nutrients from Agricultural Land use on Aquatic Ecosystems , 2010-2013