Recent Research Projects - 2008

Michael Lemmon, University of Notre Dame




Self-Triggered Feedback over Networked Control Systems - National Science Foundation (2007-2010)
Personnel: Dr. Michael Lemmon, Dr Xiaobo Hu, Xiaofeng Wang, Lichun Li

Description: This fundamental research project examines the minimum amount of feedback information required to achieve a specified level of performance in a networked control system. The project examines the use of event-triggered and self-triggered feedback as a means of tailoring the amount of feedback information to what's actually going on in the system. We're particularly interested in how such event triggering would work over wireless networks.
Publications:

  1. X. Wang and M. Lemmon (2008), Decentralized Event-triggering Broadcast over Networked Systems, , Hybrid Systems: computation and control, 2008.

  2. X. Wang and M. Lemmon (2008), State based Self-triggered feedback control systems with L2 stability, 17th IFAC world congress, 2008.

  3. X. Wang and M. Lemmon (2008), Self-triggered Feedback Control Systems with Finite-Gain L2 Stability,accepted to IEEE Transactions on Automatic Control, June, 2008.



Metropolitan Scale Sensor-Actuator Networks for Combined Sewer Overflows- Indiana 21st CTF and EmNet LLC (2007-2009)
Personnel: Dr. Michael Lemmon, Mr. Pu Wan, Lichun Li, Dr. Luis Montestruque

Description: A large-scale distributed system is a dynamical system consisting of several interconnected subsystems. A "centralized" approach for controlling such systems has a single controller regulating the behavior of all subsystems. This approach does not scale well since the complexity of the communication network supporting centralized feedback control becomes unwieldy as the number of subsystems increases. We therefore consider the possibility of using a group of "decentralized" controllers to regulate the overall system's behavior. In decentralized controllers, an individual subsystem's controller makes its decisions only based on information from a select set of neighbors. The communication required to support such a decentralized controller is usually a multi-hop communication network which can have inherent limits on the rate at which feedback data can be shared between subsystems. This research project is designing the control system to be used in a metropolitan-scale deployment of a sensor-actuator network being used to reduce the frequency of combined sewer overflow events in city sewer systems.
Publications:

  1. L. Montestruque and M.D. Lemmon (2008), CSOnet: a metropolitan scale wireless sensor-actuator network, International Workshop on Mobile Device and Urban Sensing (MODUS), 2008

  2. P. Wan and M. Lemmon (2007), Distributed Flow Control using Embedded Sensor-Actuator Networks for the Reduction of Combined Sewer Overflow (CSO) Events, IEEE Conference on Decision and Control, 2007.


OLD PROJECTS (2007)