Remote and Distributed Estimation over Shared Networks: New Results and Open Problems
This talk will focus on the design of distributed estimation systems that are formed by multiple non-collocated components. A shared network is used to disseminate information among the components. I will discuss two recent results: Assuming that the network is characterized by an incomplete directed communication graph, the first result characterizes the existence of omniscience-achieving schemes for which all components that observe only a portion of the output of an underlying plant can estimate the entire state with error that vanishes asymptotically. Our approach hinges on key concepts from decentralized control that are systematic and constructive. The second result characterizes the structure of certain optimal policies for the case in which the number of components exceeds the maximal number of simultaneous transmissions that the network can accept. In order to obtain a tractable framework for which design principles can be characterized analytically, I will consider the case in which there are two estimators that rely on information sent to them by two sensors that access dissimilar measurements. I will show the optimality of certain threshold-based policies, establish a connection with a problem of optimal quantization for which the distortion is non-uniform across representation symbols, present numerical approaches, discuss interpretations of the results and list related open issues.
Nuno Martins is Associate Professor of Electrical and Computer Engineering at the University of Maryland, College Park, where he also holds a joint appointment with the Institute for Systems Research. From 2012 until 2014 he was the Director of the Maryland Robotics Center. Martins holds a Ph.D. degree in Electrical Engineering and Computer Science with a minor in Mathematics from Massachusetts Institute of Technology (MIT), Cambridge. His research interests are in distributed control and estimation, team decision, optimization, networked control and communications. He received a National Science Foundation CAREER award in 2007, the 2006 American Automatic Control Council O. Hugo Schuck Award, the 2010 Outstanding Institute for Systems Research Faculty award and the 2008 IEEE CSS Axelby Award for the best paper in the IEEE Transactions on Automatic Control. He has served as a member of the editorial board of Systems and Control Letters (Elsevier), Automatica and of the IEEE Control Systems Society Conference Editorial Board. He was a program vice-chair for the IEEE Conference on Decision and Control in 2013 and 2014.