Date & Time:
Friday, October 18, 2013; 12:00 PM
This talk will describe a method to stabilize a plant with a network of resource-constrained wireless nodes. As opposed to traditional networked control schemes where the nodes simply route information to and from a dedicated controller, our approach treats the network itself as the controller. Specifically, we formulate a strategy where each node repeatedly updates its state to be a linear combination of the states of neighboring nodes. We show that this causes the entire network to behave as a linear dynamical system, with sparsity constraints imposed by the network topology. We provide a numerical design procedure to determine the appropriate linear combinations for each node so that the transmissions of the nodes closest to the actuators are stabilizing. We also make connections to decentralized control theory and the concept of fixed modes to provide topological conditions under which stabilization is possible. We show that this "Wireless Control Network" requires low computational and communication overhead, simplifies transmission scheduling, and enables compositional design. We also consider the issue of security in this control scheme. Using structured system theory, we show that a certain number of malicious or misbehaving nodes can be detected and identified provided that the connectivity of the network is sufficiently high.
Dr. Shreyas Sundaram
University of Waterloo
Shreyas Sundaram is an Assistant Professor in the Department of Electrical and Computer Engineering at the University of Waterloo, and an executive committee member of the Waterloo Institute for Complexity and Innovation. He received his Ph.D. in Electrical Engineering from the University of Illinois at Urbana-Champaign in 2009, and was a Postdoctoral Researcher at the University of Pennsylvania from 2009 to 2010. His research interests include large-scale dynamical systems, network science, fault-tolerant and secure control, linear system and estimation theory, and the application of algebraic graph theory to system analysis. He received the Distinguished Performance Award from the University of Waterloo, and the M. E. Van Valkenburg Graduate Research Award and the Robert T. Chien Memorial Award from the University of Illinois for excellence in research. He was a finalist for the Best Student Paper Award at the 2007 and 2008 American Control Conferences.