Abstracts

Saverio Bolognani (Univ. Padova) Distributed Quasi-Newton Method and its Application to the Optimal Reactive Power Flow Problem
We consider a distributed system of N agents, on which we define a quadratic optimization problem subject to a linear equality constraint. We assume that the agents can estimate the gradient of the cost function element-wise by measuring the steady state response of the system. Even if the cost function cannot be decoupled into individual terms, and the linear constraint involves the whole system state, we are able to design a distributed, quasi-Newton optimization algorithm. We prove finite time convergence in its centralized version, and by using the tool of average consensus we design its distributed implementation in the case in which a communication graph is given. As a testbed for the proposed method, we consider the problem of optimal distributed reactive power compensation in smart microgrids.

Lara Briñon Arranz (INRIA Grenoble) Elastic Formation Control Based on Affine Transformations
This talk deals with the control of a fleet of non-linear systems representing AUVs. The purpose is here to design control laws to stabilize the fleet to time-varying formations which are not only circular. We propose a novel framework which is able to express in a simple manner the control law for a larger class of formations. This has been produced by applying a sequence of affine transformations such as translations, rotations and scalings. We consider also the problem of uniform distribution of all the agents along the formation. This is achieved taking into account the communication constraints using a cooperative control which includes the Laplacian matrix of the ommunication graph. The system was implemented in computer simulation, accessible through Web.

Piergiuseppe Di Marco (KTH) Analytical model of IEEE 802.15.4 for multi-hop networks
IEEE 802.15.4 multi-hop wireless networks are an important communication infrastructure for many applications, including industrial control, home automation, and smart grids. Existing analysis of the IEEE 802.15.4 medium access control (MAC) protocol are often based on assumptions of homogeneous traffic and ideal carrier sensing, which are far from the reality when predicting performance for multi-hop networks. In this paper, a generalized analysis of the unslotted IEEE 802.15.4 MAC is presented. The model considers heterogeneous traffic and hidden terminals due to limited carrier sensing capabilities, and allows us to investigate jointly IEEE 802.15.4 MAC and routing algorithms. The analysis is validated via Monte Carlo simulations, which show that routing over multi-hop networks is significantly influenced by the IEEE. 802.15.4 MAC performance. Routing decisions based on packet loss probability may lead to an unbalanced distribution of the traffic load across paths, thus motivating the need of a joint optimization of routing and MAC.

Stephan Huck (ETHZ) Filtering and estimation for localization of underwater plumes using AUVs
To locate the source of an underwater concentration field, e.g. a fresh water plume, using a fleet of AUVs it is desirable to estimate a set of parameters defining the plume shape and location based on measurement data collected by the AUVs. We investigate how this estimation can be carried out for simple plume shapes using batch optimization and recursive filtering techniques. To ensure that the estimation converges to the correct values, we investigate the identifiability of the underlying model structure. This brings up the issue of the information content of the obtained measurements which, in turn, relates to where the measurements have been taken, i.e. to finding the most informative formation or trajectory for the AUVs.

Kittipong Kittichokechai (KTH) Source Coding with Common Reconstruction and Action-dependent Side Information
We consider a source coding problem with common reconstruction and action‐dependent side information. An action is taken by an encoder at some costs, e.g., energy. We characterize the optimal rate region which in fact reduces to the sum‐rate distortion and cost function. The result provides a fundamental limit for networked control applications where the observer/encoder can use the actions to adapt the quality of side information about the state of the plant; meanwhile it can monitor the reconstructed state at the decoder/controller based on the common reconstruction constraint.

Enrico Lovisari (Univ. Padova) A Nyquist criterion for synchronization in networks of heterogeneous linear systems
We study the synchronization of a set of SISO subsystems interconnected via a time-invariant Laplacian matrix. By synchronization we mean that the outputs of all subsystems must be asymptotically equal to each other and behave in the same manner. We assume that the subsystems can be represented as the sum of a common nonzero transfer function plus a perturbation. A Nyquist-type criterion is established which ensures synchronization provided that the convex hull of the frequency responses of the subsystems does not intersect a certain region de ned by the spectrum of the interconnection matrix. The result is applied to a variety of examples of di erent nature for which synchronization takes place. A counter example for which complete synchronization is impossible is also presented.

Jose M. Maestre Torreblanca (Univ. Sevilla) Applications of Coalitional Game Theory to Distributed Control and Estimation
In this presentation we propose to study the underlying properties of a sensor and actuator network in which a set of agents switch between different communication strategies in order to minimize communicational costs. The problems of how to decide the communication strategy, share the benefits/costs and detect which are the most critical links in the network are solvedusing tools from game theory. The proposed scheme is demonstrated through different simulation examples.

Andrea Masiero (Univ. Padova) Multiple Tarket Tracking via a distributed network of cameras
In this talk we consider the problem of target tracking in a large network of cameras. In practical applications the computational complexity of a centralized tracking algorithm quickly increases with the number of targets and of cameras, e.g. in real motion capture systems the centralized tracking algorithm has to be executed offline as long as the system is formed by more than a dozen of cameras. Motivated by the interest in applying tracking algorithm in real-time in real motion capture systems, we consider the problem of improving the computational efficiency of commonly adopted tracking algorithms exploiting the distributed network framework.

Pablo Millan (Univ. Sevilla) Lyapunov-Krasovskii functionals for the study of stability and stabilisation of time-delay systems with application to networked control systems
Time-varying delays are a major source of instability in dynamical systems. Systems in which some of the states or feedback signals are affected by time-varying delays are called time-delay systems. The study of stability for these systems can be carried out using a Lyapunov-Krasovskii approach. Defining a suitable Lyapunov-Krasovskii functional, stability criteria are obtained by solving some Linear Matrix Inequalities. The input-delay approach allows modeling Networked Control Systems as a class of time-delay systems, in such a way that stability properties can be easily inherited. Moreover, others features can be achieved in the design of linear controllers, as an Hinf disturbance rejection or an H2 optimal control.

Davide Raimondo (ETHZ) Explicit nonlinear MPC: a set theoretic method for verifying feasibility
In this talk an algorithm for nonlinear explicit model predictive control, with guaranteed stability and constraint satisfaction is presented. A low complexity receding horizon control law is obtained by approximating the optimal control law using multiscale basis function approximation. Feasibility and stability of the approximate control law are ensured through the computation of a capture basin (region of attraction) for the closed loop system. In a previous work, interval methods were used to construct the capture basin (feasible region), yet this approach suffered due to slow computation times and high grid complexity. In this paper, we suggest an alternative to interval analysis based on zonotopes. The suggested method significantly reduces the complexity of the combined function approximation and verification procedure through the use of DC programming, Taylor expansion and recursive splitting.

Chithrupa Ramesh (KTH) On the Dual Effect in State-Based Scheduling of Networked Control Systems
In this paper, we show that there is a dual effect with state-based scheduling. In general, this makes the optimal scheduler and controller hard to find. However, by removing past controls from the scheduling criterion, we find that certainty equivalence holds. This condition is related to the classical result of Bar-Shalom and Tse, and it leads to the design of a sub-optimal scheduler with a certainty equivalent controller. Furthermore, we show that a mapping of the statebased scheduler into one which fulfills this condition, and consequently has an optimal certainty equivalent controller, does not result in an equivalent class of design in the sense of Witsenhausen. Finally, computing the estimate remains hard, but can be simplified by introducing a symmetry constraint on the scheduler.

Gabriel Rodrigues de Campos (INRIA Grenoble) Continuous-time double integrator consensus algorithms improved by an appropriate sampling
This presentation deals with the double integrator consensus problem. The objective is the design of a new consensus algorithm for continuous-time multi-agent systems. The dynamic of agents is assumed to be of double integrator type. The proposed algorithm considers that there are no sensors to measure the velocity of the agents. Thus the classical double integrator consensus algorithm leads to an oscillatory behavior if the communication graph is undirected and to instability if the graph is directed. The novel algorithm proposes to sampled, in an appropriate manner, part of the multi-agent systems state such that the algorithm converges. An expression of the consensus equilibrium is provided. Some examples are provided to show the efficiency of the new algorithm.

Amirpasha Shirazinia (KTH) Iterative Encoder-Controller Design Based on Approximate Dynamic Programming
We study the iterative optimization of the encoder‐controller pair for closed‐loop control of a multi‐dimensional plant over a noisy discrete memoryless channel. With the objective to minimize the expected linear quadratic cost over a finite horizon, we propose a joint design of the sensor measurement quantization, channel error protection, and optimal controller actuation. It was shown in our previous work that despite this optimization problem is known to be hard in general, an iterative design procedure can be derived to obtain a local optimal solution. However, in the vector case, optimizing the encoder for a fixed controller is in general not practically feasible due to the curse of dimensionality. In this paper, we propose a novel approach that uses the approximate dynamic programming (ADP) to implement a computationally feasible encoder updating policy with promising performance. Especially, we introduce encoder updating rules adopting the rollout approach. Numerical experiments are carried out to demonstrate the performance obtained by employing the proposed iterative design procedure and to compare it with other relevant schemes.

Ali A. Zaidi (KTH)Rate Sufficient Conditions for Closed-loop Control over Half-duplex AWGN Relay Channels
The problem of remotely controlling an unstable noiseless linear time invariant system over noisy half‐duplex relay channels with average power constraints is considered. For information transmission, we propose a coding scheme based on the Schalkwijk‐Kailath scheme. Therefore, we derive conditions on rate which are sufficient for mean square stability of the linearly controlled LTI system over non‐orthogonal, orthogonal, and two‐hop AWGN relay channels.

Morning

07.30-08.30: Registration
08.30-08.45: Opening Session C. Canudas de Wit, INRIA, FR
08.45-09.00: Welcome, B. Anderson, IFAC Representative,
09.00-10.00: Plenary session: F. Baccelli, INRIA, FR
10.00-11.30: Poster session 1 with Coffee
11.30-12.30: Plenary session: G. Vinnicombe, Cambrigde, UK

12.30-14.00: Lunch

Afternoon

14.00-15.00: Plenary session: K.H. Johansson, KTH, SW
15.00-16.00: Plenary session: F. Bullo, UCSB, USA
16.00-17.30: Poster session 2 with Coffee
17.30-18.30: Plenary session: M. Morari, ETH, CH

20.00:  Dinner at the Imperial Palace

Tuesday 14 September

Morning

09.00-10.00: Plenary session: S. Zampieri, UNIPD, IT
10.00-11.30: Poster session 3 with Coffee
11.30-12.30: Plenary session: J. Sifakis, VERIMAG, FR

12.30-14.00: Lunch

Afternoon

14.00-15.00: Plenary session: B. Hassibi, CalTech, USA
15.00-16.30: Poster session 4 with coffee
16.30-17.30: Plenary session: D. Hill, ANU, AU

20.00: Cocktail Wine & Cheese

Online program

https://ifac.papercept.net/conferences/conferences/ECNS10/program/

Introduction

The second FeedNetBack Annual Workshop, takes place on the 15th 16th of September 2010, in Annecy, France in conjunction with the Second IFAC Workshop on Estimation and Control of Networked Systems NecSys’10.

The goal of the workshop is to establish a dynamic annual forum for the latest advances of feedback techniques in modern control systems. It will be an opportunity to meet innovators from Europe’s research community as well as developers and users of related technologies and applications. It is expected that the workshop will stimulate discussions about diverse application domains.

Agenda

15th: Open Workshop

Registration fee: 100€ (includes coffee breaks and lunch)
Program.

16th: For FeedNetBack members only

1. Review meeting
   Registration fee: 100€ (includes coffee breaks and lunch)
2. Junior Workshop
   Ph.D. students and post-docs presentations.
   Registration fee: 50€ (lunch is not included)
   The Workshop’s program and presentation abstracts are available online.

Final submissions are open in Paperplaza. Submissions will close on July the 23rd.
Uploading of final paper is allowed only after regular rate registration.
Paper upload will be enabled manually, therefore allow up to one working day after reception of payment. You will be notified by email when you can upload your paper.
Follow the link:
https://ifac.papercept.net/conferences/scripts/start.pl
and click on « Submit a contribution to NecSys’10″ near the NecSys’10 item.

Poster presentations

All contributed papers will be presented as posters. For the preparation of their posters, authors are not required to use a specific template, but it is strongly recommended to produce a portrait (vertical) A0 poster. Due to the size of the poster hangers that we will provide at the conference venue, the only acceptable sizes are portrait A0 (recommended) and portrait or landscape A1.

The authors are invited to provide a pdf version of their poster by mail to alexandre(dot)seuret(at)gipsa-lab(dot)grenoble-inp(dot)fr by Wenesday 01 September. Such files will be included in the CD of the workshop’s proceedings.

Proceedings

The Proceedings of the NecSys2010 Workshop will be hosted on-line on the IFAC-PapersOnLine.net website.

Submission Instructions

Authors are invited to submit full papers of up to 8 pages at submission and 6 pages at final submission in Conference Proceedings form, i.e. double column 10pt, through ifac.papercept.net.

Uploading of final paper is allowed only after regular rate registration.

IFAC paper style and layout

Authors are invited to comply with IFAC paper style and layout, and also notice that only PDF files compliant with the IFAC Publications  Requirements are acceptable for publication.

All information is available on the IFAC web site:
http://www.ifac-control.org/events/information-for-ifac-authors

INRIA Grenoble – Rhône-Alpes

Publishing Director

Carlos Canudas De Wit

Host

INRIA Grenoble – Rhône-Alpes
Inovallée
655 avenue de l’Europe
Monbonnot
38334 Saint-Ismier

Intellectual property

No portion of the information may be copied or reproduced without the prior written permission from INRIA.

The personal data contained in this Web server are meant for consultation purposes only but they must be neither modified nor captured, especially to supply databases, for instance for commercial or advertising use.

Offenders are laying themselves open to sanctions according to the provisions of section V of the new French penal code entitled « des atteintes aux droits des personnes résultant des fichiers ou des traitements informatiques » and of the chapter III entitled « des atteintes aux systèmes de traitement automatisé des données ».

This notice is true to the provisions of the French National Commission for Data Processing and Liberties and to the Act of 6 January 1978, on Data Processing, Data Files and Individual Liberties.

The photo of Imperial Palace hotel used in the header belongs to its ower « Centre de Congrès de L’Impérial Palace, Annecy », modified by INRIA (Communication department), all rights reserved, January 2010.

Lachlan Blackhall (The Australian National Univ.)

Title: On the Structural Controllability of Networks of Linear Systems Authors:Lachlan Blackhall, David J. Hill

Awarding committee:

John Lygeros (ETHZ)

Luca Schenato (Univ. di Padova)

Bruno Sinopoli (Carnegie Mellon Univ.)

Description: To recognize excellence in the Necsys Workshop paper whose primary contributor(s) is a (are) Student.

Eligibility: Primary contributor(s) of a paper, who was a (were) student(s) at the time of original submission.

Basis for Judgement: Originality, clarity, and potential impact on practical applications or theoretical foundations of estimation and control in networked systems.

Presentation: The winner will be announced during the banquet dinner.

Nomination: The nomination must be requested by email by 15 July 2010 to the address below from the student’s professor (advisor), specifying paper’s title and certifying that primary contributor(s) to the paper was a (were) student(s) at the time of the paper’s original submission.

Contact:
Dr. Alexandre Seuret
Department of Automatic Control
GIPSA-LAB
Email: alexandre.seuret(at)gipsa-lab.grenoble-inp.fr

J. Sifakis, VERIMAG, FR (Slides)

Topic: Embedded Systems – Scientific Challenges and Work Directions

Abstract: Embedded systems are components integrating software and hardware jointly and specifically designed to provide given functionalities, which are often critical. They are used in many applications areas including transport, consumer electronics and electrical appliances, energy distribution, manufacturing systems, etc.
Embedded systems design needs techniques taking into account extra-functional requirements regarding optimal use of resources such as time, memory and energy while ensuring autonomy, reactivity and robustness.
Jointly taking into account these requirements raises a grand scientific and technical challenge: extending Computer Science with paradigms and methods from Control Theory and Electrical Engineering. Computer Science is based on discrete computation models not encompassing physical time and resources which are by their nature very different from analytic models used by other engineering disciplines.
We discuss main aspects of this challenge and associated research directions for different areas such as modeling, programming, compilers, operating systems and networks.

Short biography: Joseph Sifakis is a CNRS researcher and the founder of the Verimag laboratory in Grenoble, France. He holds the INRIA-Schneider endowed industrial chair since September 2008 and he is the director of the CARNOT Institute « Intelligent Software and Systems ». He studied Electrical Engineering at the Technical University of Athens and Computer Science at the University of Grenoble. Joseph Sifakis is recognized for his pioneering work on both theoretical and practical aspects of Concurrent Systems Specification and Verification. He contributed to the emergence of the area of model-checking, currently the most widely-used method for the verification of industrial applications. His current research activities include component-based design, modeling, and analysis of real-time systems with focus on correct-by-construction techniques Joseph Sifakis is the founder of Verimag, a leading research laboratory in the area of critical embedded systems, and has broad experience with industry, including Airbus, Astrium, the European Space Agency, France Telecom, ST Microelectronics. He is the Scientific Coordinator of the European Network of Excellence ARTIST2 on Embedded Systems Design, which gathers 35 of the best European teams and in the area and key European industrial partners. Joseph Sifakis has received the Turing Award in 2007, with Ed Clarke and Allen Emerson, for their contribution to Model Checking. He is also the recipient of the CNRS Silver Medal in 2001, Grand Officer of the French National Order of Merit, and a member of Academia Europea and of the French National Academy of Engineering.

F. Baccelli, INRIA, FR (Slides)

Topic: Wireless Routing on a Poisson Point Process

Abstract: We introduce a new random graph for analyzing multihop routing in wireless ad hoc networks, the space-time SINR (Signal to Interference and Noise Ratio) random graph.
This random graph has both time and space components. The spatial component originates from the random (e.g. Poisson) locations of the network nodes in the Euclidean plane. The time component originates from the randomness in the medium access mechanisms and from randomness in propagation (fading, shadowing).
This random graph encodes the SINR experienced by all possible point to point channels at all times. For any given multihop routing algorithm, it fully determines the progression of packets once their destinations are given.
Optimal routes can then be analyzed in terms of first passage percolation on this random graph. We show that the associated time constant exhibits a phase transition.
We also analyze various geographic routing algorithms which consist in making locally optimal hops on this random graph. A typical example is that where a tagged node transmitting a packet selects as next hop the node which is the closest to the destination among those which successfully receive the packet.

Short biography: François Baccelli’s general research interests are in the theory of stochastic networks and in the modeling and performance evaluation of computer and communication systems. He coauthored research monographs on the following topics: point processes (with P. Bremaud in 87), the max plus algebra (with G. Cohen, G.J. Olsder and J.P. Quadrat in 1992), queueing theory (with P. Bremaud in 1994) and stochastic geometry for wireless networks (with B. Blaszczyszyn in 2009). His current research interest are focused on the analysis of large IP networks and on the development of new tools for the modeling of protocols with spatial components in wireless networks. He was the head of the modeling and performance evaluation research group of INRIA Sophia Antipolis, France, from its creation to 1999. He was a partner in several European projects including IMSE (Esprit 2) and ALAPEDES (TMR), and was the coordinator of the Qmips project (Basic Research Action). He is currently INRIA Directeur de Recherche in the Computer Science Department of Ecole Normale Superieure in Paris, where he started the research group on the theory of communication networks in 1999. F. Baccelli was awarded the 2002 France Telecom Prize by the French Academy of Sciences. He also got IBM academic awards in 2003 and in 2004. He became a member of the French Academy of Sciences in 2005.

K.H. Johansson, KTH, SW (Slides)

Topic: Wireless control: system architectures and medium access

Abstract: There is a growing deployment of wireless networks in industrial control systems. Lower installation costs and easier system reconfigurations for wireless devices can have a major influence on the future application of distributed control and monitoring. There is however a lack of theory for understanding if and how the allocation of communication resources should be integrated with the control application. In this talk, we will discuss how the access scheme for the wireless medium can influence the closed-loop performance of the networked control system. It will be argued that the underlying scheduling-control problem has a non-classical information structure. Appropriate models for medium access control protocols will be introduced. It will be shown how these protocols can be tuned for various wireless control applications. We will also see that by making asynchronous transmissions based on decisions taken locally at the sensor and actuator nodes, it is possible improve the design and to limit the use of the communication resources. The talk will be illustrated by several examples from ongoing projects with Swedish industry. The presentation is based on joint work with collaborators at KTH.

Short biography: Karl H. Johansson is Director of the ACCESS Linnaeus Centre and Professor at the School of Electrical Engineering, Royal Institute of Technology, Sweden. He is a Wallenberg Scholar and holds a Senior Researcher Position with the Swedish Research Council. He received MSc and PhD degrees in Electrical Engineering in 1992 and 1997 from Lund University in Sweden. He has held visiting positions at UC Berkeley (1998-2000) and California Institute of Technology (2006-07). He is the Chair of the IFAC Technical Committee on Networked Systems since 2008. He has served on the IEEE Control Systems Society Board of Governors. He is on the editorial boards of the IEEE Transactions on Automatic Control and the IET Control Theory & Applications, and previously of Automatica. He was awarded an Individual Grant for the Advancement of Research Leaders from the Swedish Foundation for Strategic Research in 2005. He received the triennial Young Author Prize from IFAC in 1996 and the Peccei Award from the International Institute of System Analysis, Austria, in 1993. He received Young Researcher Awards from Scania in 1996 and from Ericsson in 1998 and 1999.

G. Vinnicombe, Cambrigde, UK (Slides)

Topic: Noise reduction and information transfer in the cell: Fundamental limitations

Abstract: It is well known that, for a molecule being produced at a constant rate and degraded exponentially (constitutive gene expression for example) the intrinsic noise in the molecule number will be such that its variance equals the mean. Such variance can be reduced by feedback, and there is much feedback in the cell, yet the cell is nevertheless observed to be an extremely noisy place.
This talk will combine tools from both control and information theory to establish fundamental limits on the amount of noise reduction that can be obtained by regulation, irrespective of the complexity of the network, in terms of observables such as the number of intermediate molecules produced and the time it takes to synthesize them. The conclusion is that, whilst it is straightforward in principle to reduce the noise to low levels, in practice the cost to the cell can be astronomical.

Short biography: Glenn Vinnicombe received the B.A. degree in engineering and the Ph.D. degree from the University of Cambridge, Cambridge, U.K., in 1984 and 1993, respectively. From 1984 to 1987, he was with British Aerospace, working primarily on the design and flight test of control systems on the Airbus A320. He returned to the University of Cambridge in 1987 as a College Lecturer at Churchill College. He has held faculty positions with the Department of Mechanical Engineering, University of Minnesota, and the Department of Aeronautical Engineering, Imperial College, London, and is currently on the faculty of the Department of Engineering, University of Cambridge.

M. Morari, ETH, CH (Slides)

Topic: Real-time Optimization for Distributed Model Predictive Control

Abstract: Distributed Model Predictive Control aims to control massively complex networks of coupled subsystems in a scalable fashion. The paradigm functions by solving many small MPC optimization problems in parallel at each of the subsystems before exchanging information and repeating the process. The ability to reliably solve these small-scale problems in real-time is a critical piece of the distributed MPC puzzle, and is the focus of this talk.
I will discuss some of our recent work that brings the benefits of model predictive control to small-scale, high-speed systems and that can dramatically reduce online MPC loop execution to microsecond timescales. We show how our new real-time MPC schemes provide constraint satisfaction and stability, while optimizing for performance, at speeds several orders of magnitude faster than state-of-the-art. No single real-time optimization method will be able to tackle the broad range of possible problem classes, and so we present three techniques suitable for fast-sampled systems in the range of nano-, micro- and milli-seconds respectively. The controller synthesis methodologies are unique in that they take the available online computational resources as input and produce a controller that will execute within these bounds while satisfying constraints and stabilizing the system.
I will motivate our work on real-time MPC with several applications, including wave power systems, camera networks, racing cars and smart power grids. Industrial examples will be presented throughout, which serve to highlight theoretical advancements and the extensive software tools that help to bring the developed theory to bear in practical scenarios.

Short biography: Manfred Morari was appointed head of the Department of Information Technology and Electrical Engineering at ETH Zurich in 2009. He was head of the Automatic Control Laboratory from 1994 to 2008. Before that he was the McCollum-Corcoran Professor of Chemical Engineering and Executive Officer for Control and Dynamical Systems at the California Institute of Technology. He obtained the diploma from ETH Zurich and the Ph.D. from the University of Minnesota, both in chemical engineering. His interests are in hybrid systems and the control of biomedical systems. In recognition of his research contributions he received numerous awards, among them the Donald P. Eckman Award and the John R. Ragazzini Award of the Automatic Control Council, the Allan P. Colburn Award and the Professional Progress Award of the AIChE, the Curtis W. McGraw Research Award of the ASEE, Doctor Honoris Causa from Babes-Bolyai University, Fellow of IEEE, the IEEE Control Systems Field Award, the Bode Lecture Prize of the IEEE Control Systems Society and was elected to the National Academy of Engineering (U.S.). Manfred Morari has held appointments with Exxon and ICI plc and serves on the technical advisory boards of several major corporations.

F. Bullo, UCSB, USA (Slides)

Topic: Synchronization of Power Networks and Non-uniform Kuramoto Oscillators

Abstract: Motivated by recent interest for multi-agent systems and smart power grid architectures, we discuss the synchronization problem for the network-reduced model of a power system with non-trivial transfer conductances. Our key insight is to exploit the relationship between the power network model and a first-order model of coupled oscillators. Assuming overdamped generators (possibly due to local excitation controllers), a singular perturbation analysis shows the equivalence between the classic swing equations and a non-uniform Kuramoto oscillator model. Here, non-uniform Kuramoto oscillators are characterized by multiple time constants, non-homogeneous coupling, and non-uniform phase shifts. Extending methods from transient stability, synchronization theory and consensus protocols, we establish sufficient conditions for synchronization of non-uniform Kuramoto oscillators. These conditions reduce to and improve upon previously-available tests for standard Kuramoto model. Combining our singular perturbation and Kuramoto analyses, we derive concise and purely algebraic conditions that relate synchronization and transient stability of a power network to the underlying system parameters and initial conditions.

Short biography: Francesco Bullo received the Laurea degree « summa cum laude » in Electrical Engineering from the University of Padova, Italy, in 1994, and the Ph.D. degree in Control and Dynamical Systems from the California Institute of Technology in 1999. From 1998 to 2004, he was an Assistant Professor with the Coordinated Science Laboratory at the University of Illinois at Urbana-Champaign. He is currently a Professor with the Mechanical Engineering Department at the University of California, Santa Barbara. His research interests include motion coordination for multi-agent networks, motion planning for autonomous vehicles, and geometric control of mechanical systems.

S. Zampieri, UNIPD, IT (Slides)

Topic: The consensus algorithm and its application to distributed clocks synchronization

Abstract: In this talk we will first describe the consensus algorithm and we will show some of its simple possible applications. Then we will show how this algorithm can extended to systems described as heterogeneous double integrators. The consensus algorithm working for heterogeneous double integrators is then used as a possible distributed algorithm yielding clocks synchronization. The evolution of the clocks time estimates obtained through this algorithm can be modeled as the state of a nonlinear system, and this system can be proved to be a perturbation of the linear system describing the consensus for double integrators. Hence, using center manifold theorem, we can prove that the proposed distributed clock synchronization algorithm yields local asymptotic synchronization.

Short biography: Sandro Zampieri received the Ph.D. degree in System Engineering from the University of Padova 1993. In 1991-92, 1993 and 1996 he was Visiting Scholar at Laboratory for Information and Decision Systems, MIT. Since 2002 he is Full Professor in Automatic Control at the University of Padova. 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. His research interests include automatic control and dynamical systems theory, networked control and the relations between control and information theory.

B. Hassibi, CalTech, USA

Topic: Estimation and Control over Lossy Networks: A Random Matrix Approach

Abstract: Distributed estimation and control over lossy networks is finding applications in areas such as distributed sensor networks, control of distributed autonomous agents, collision avoidance, distributed power systems, etc. Central to the study of such systems is the study of random Lyapunov and Riccati recursions—the analogy is to traditional LTI systems where deterministic Lyapunov and Riccati recursions and equations play a prominent role. Unfortunately, to date, the tools for analyzing such systems are woefully lacking, ostensibly because the recursions are both nonlinear and random, and hence intractable if one wants to analyze them exactly.
We exploit tools from the theory of large random matrices to find the asymptotic eigendistribution of the matrices in the random Riccati recursions when the number of states in the system, n, is large. In many cases, the eigendistribution contains sufficient information about the overall behavior of the system, such as stability and mean-square- or worst-case-performance. Furthermore, the approach often allows one to identify and exhibit the universal behavior of the system, i.e., behavior that does not depend on the microscopic details of the system (where losses occur, what the exact topology of the network is, what the underlying distributions are), but rather on some simple macroscopic properties. The main idea of the approach is to replace a high-dimensional matrix-valued nonlinear and stochastic recursion by a scalar-valued deterministic functionalrecursion (involving an appropriate transform of the eigendistribution), which is much more amenable to analysis and computation. To the best of our knowledge, such an approach has neither been suggested in systems and control theory nor in random matrix theory. We will present case studies and mention some open problems.

Short biography: Babak Hassibi is Professor and Executive Officer of Electrical Engineering at the California Institute of Technology, where he has been since 2001. Prior to that he was with the Mathematical Sciences Research Center at Bell Laboratories and with Stanford University where he obtained his PhD in 1996. His research interests span communications, control and signal processing. Among other awards he is a recipient of the O. Hugo Schuck best paper award of the American Automatic Control Council, the National Science Foundation Career Award, the Okawa Foundation Research Grant, the David and Lucille Packard Fellowship for Science and Engineering and the Presidential Early Career Award for Scientists and Engineers (PECASE).

D. Hill, ANU, AU (Slides)

Topic: Networked control of power networks

Abstract: The modernization of electricity grids worldwide aims to achieve substantial new capabilities including integration of renewable and alternative energy sources, the infrastructure for plug-in hybrid vehicles and accompanying improvements in efficiency and effectiveness despite the vastly increased uncertainty. It is clear that all this can only be achieved by greater reliance on sensing, communications, computing and control, these days captured in the term ‘smart grids’. This talk will outline the more fundamental issues in developing automation and control architectures which will deliver the needed self-awareness, self-organisation and self-healing processes. There are many points of difference with other information networks such as the Internet, a major one being the need for quality of service guarantees. A range of unsolved problems in networked sensing, communications and control emerge which demand collaboration between computer, control and network sciences. These issues will be related to a major ‘smart grid smart city’ project involving government and utility funding in Australia.

Short biography: David J Hill received the BE (Electrical) and BSc (Mathematics) degrees from the University of Queensland, Australia, in 1972 and 1974, respectively. He received the PhD degree in Electrical Engineering from the University of Newcastle, Australia, in 1976. He is currently a Professor in the School of Engineering at The Australian National University and the NICTA Canberra Research Laboratory. He is also a Chief Investigator of the Australian Research Council Centre of Excellence for Mathematics and Statistics of Complex Systems. During 2005-2010, he was an Australian Research Council Federation Fellow at ANU. He has held academic and substantial visiting positions at the universities of Melbourne, California (Berkeley), Newcastle (Australia), Lund (Sweden), Sydney and Hong Kong (City University). His research interests are in network systems, stability analysis, nonlinear and distributed control and applications, mainly to infrastructure type networks. He is a Fellow of the Institution of Engineers, Australia, the Institute of Electrical and Electronics Engineers, USA, the Society for Industrial and Applied Mathematics, USA, and the Australian Academy of Science; he is also a Foreign Member of the Royal Swedish Academy of Engineering Sciences.

Vice-General Chair:
Alexandre Seuret, GIPSA-Lab / CNRS, France
Alexandre[dot]Seuret@gipsa-lab[dot]inpg[dot]fr

Webmaster:
Nicolas Cardoso De Castro, INRIA, France
nicolas[dot]cardosodecastro[at]inrialpes[dot]fr

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