Controllability for Complex Networks: Metrics and Limitations
Abstract:
This presentation will consider the problem of controlling complex networks, i.e., the joint problem of selecting a set of control nodes and of designing a control input to steer a network to a target state. For this problem, we propose a metric to quantify the difficulty of the control problem as a function of the required control energy and we derive bounds based on the system dynamics (network topology and weights) to characterize the tradeoff between the control energy and the number of control nodes. Our findings show several control limitations and properties. For instance, for symmetric networks, if the number of control nodes is constant, then the control energy increases exponentially with the number of network nodes. On the other hand, if the number of control nodes is a fixed fraction of the network nodes, then certain networks can be controlled with constant energy independently of the network dimension.
Asymmetric networks highlights richer scenarios. Indeed, it can be shown that, while asymmetric but isotropic networks are still difficult to control, sufficiently anisotropic networks are instead easy to control.
Biography:
Sandro Zampieri received the Laurea degree in Electrical Engineering and the Ph.D. degree in System Engineering from the University of Padova, Italy, in 1988 and 1993, respectively. Since 2002 he is Full Professor in Automatic Control at the Department of Information Engineering of the University of Padova. In 1991-92, 1993 and 1996 he was Visiting Scholar at Laboratory for Information and Decision Systems, MIT, Cambridge. He has held visiting positions also at the Department of Mathematics of the University of Groningen and at the Department of Mechanical Engineering of the University of California at Santa Barbara.
Prof. Zampieri has published more than 100 journal and conference papers. He has delivered several invited seminars and he was member of the Technical Program Committee for several international conferences. He was general chair of the 1st IFAC Workshop on Estimation and Control of Networked Systems 2009, program chair of the 3rd IFAC Workshop on Estimation and Control of Networked Systems 2012 and publication chair of the IFAC World Congress 2011. He served as an Associate Editor of the Siam Journal on Control and Optimization on 2002-2004 and as the chair of the IFAC technical committee "Networked systems" on 2005-2008. Since 2012 he is serving as an Associate Editor of IEEE Transactions of Automatic Control.
His research interests include automatic control and dynamical systems theory, and in particular distributed control and estimation and networked control and control under communication constraints.