[Newsletter] for June, 2013

                      ON DISCRETE EVENT SYSTEMS

Newsletter......................................... June, 2013

Editor: (Samuel) Qing-Shan Jia
         Chair, IEEE CSS Technical Committee on DES
         Center for Intelligent and Networked Systems
         Department of Automation
        Tsinghua University
         Beijing 100084

         Phone: (+86) 10-6277-3006
         Fax: (+86) 10-6279-6115
         e-mail: jiaqs@tsinghua.edu.cn
         WWW: http://cfins.au.tsinghua.edu.cn/personalhg/jiaqingshan/

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1. Editorial

2. Journals
  2.1 Selections from the Automatica
         Volume: 49, Issue: 7, July 2013
  2.2 Selections from the IEEE Transactions on Automatic Control
         Volume: 58, Issue: 5, May 2013



Welcome to the newsletter of the IEEE Control Systems Technical
Committee on Discrete Event Systems!

Personal note from the editor:




Contributed by: Yulin Lei < leiyl11@mails.tsinghua.edu.cn >

                                      SELECTIONS FROM THE AUTOMATICA
                                                       VOLUME: 49 ISSUE: 7
                                                               JULY 2013

1) Parsimonious event-triggered distributed control: A Zeno free approach

C. De Persisa, R. Sailerc, F. Wirthc,


Consider the problem of stabilizing large-scale systems by distributed controllers,
where the controllers exchange information via a shared limited communication
medium. Event-triggered sampling schemes are proposed, in which each system
decides when to transmit new information across the network based on the
crossing of some error thresholds, which only depend on information locally
available at individual subsystems. Stability of the interconnected large-scale
system is inferred by applying a generalized small-gain theorem.

Web site: http://www.sciencedirect.com/science/article/pii/S0005109813001726

2) Event based agreement protocols for multi-agent networks

Xiangyu Meng, Tongwen Chen


This paper considers an average consensus problem for multiple integrators
over fixed, or switching, undirected and connected network topologies. Event
based control is used on each agent to drive the state to their initial average
eventually. An event triggering scheme is designed based on a quadratic
Lyapunov function. The derivative of the Lyapunov function is made negative
by an appropriate choice of the event condition for each agent. The event
condition is sampled-data and distributed in the sense that the event detector
uses only neighbor information and local computation at discrete sampling instants.
The event based protocol design is illustrated with simulations.

Web site: http://www.sciencedirect.com/science/article/pii/S0005109813001714

Contributed by: Yulin Lei < leiyl11@mails.tsinghua.edu.cn >

                                            VOLUME: 58 ISSUE: 5
                                                    MAY 2013

1) Optimal Liveness-Enforcing Control for a Class of Petri Nets
Arising in Multithreaded Software

Liao, H.; Lafortune, S. ; Reveliotis, S. ; Wang, Y. ; Mahlke, S.


We investigate the synthesis of optimal liveness-enforcing control policies
for Gadara nets, a special class of Petri nets that arises in the modeling of the
execution of multithreaded computer programs for the purpose of deadlock
avoidance. We consider maximal permissiveness as the notion of optimality.
Deadlock-freeness of a multithreaded program corresponds to liveness of its
Gadara net model. We present a new control synthesis algorithm for liveness
enforcement of Gadara nets that need not be ordinary. The algorithm employs
structural analysis of the net and synthesizes monitor places to prevent the formation
of a special class of siphons, termed resource-induced deadly-marked siphons.
The algorithm also accounts for uncontrollable transitions in the net in a
minimally restrictive manner. The algorithm is generally an iterative process
and converges in a finite number of iterations. It exploits a covering of the
unsafe states that is updated at each iteration. The proposed algorithm is
shown to be correct and maximally permissive with respect to the goal of
liveness enforcement.

Web site: http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6365756

2) A General Formula for Event-Based Stabilization of Nonlinear Systems

Marchand, N.; Durand, S. ; Castellanos, J.F.G.


In this technical note, a universal formula is proposed for event-based stabilization of
general nonlinear systems affine in the control. The feedback is derived from the original
one proposed by E. Sontag in the case of continuous time stabilization. Under the
assumption of the existence of a smooth Control Lyapunov Function, it is proved that an
event-based static feedback, smooth everywhere except at the origin, can be designed so to
ensure the global asymptotic stability of the origin. Moreover, the inter-sampling time
can be proved not to contract at the origin. More precisely, it is proved that for any
initial condition within any given closed set the minimal inter-sampling time is proved to
be below bounded avoiding the infinitely fast sampling phenomena. Moreover, under
homogeneity assumptions the control can be proved to be smooth anywhere and the inter-
sampling time bounded below for any initial condition. In that case, we retrieve a control
approach previously published for continuous time stabilization of homogeneous systems.

Web site: http://ieeexplore.ieee.org/xpl/abstractAuthors.jsp?arnumber=6334427

3) Modeling and Synthesis of Event-Transferring Communicating Decentralized
Supervisors for Discrete-Event Systems

Mannani, A.; Gohari, P.


This work models and synthesizes communicating decentralized supervisors for
Discrete-Event System (DES) which communicate the information about observed
events. This is done within the authors' framework of Distributed Supervised
DESs (DSDESs), using agent-wise labeling maps to reveal the informational
dependencies among the supervisors. Communication between every two
supervisors is modeled by the maps from the sender's observable events to its
set of recently observed event, or an empty set. Thereby, the synthesis
of communicating decentralized supervisors is reduced to the design of these maps.

Web site: http://ieeexplore.ieee.org/xpl/abstractAuthors.jsp?arnumber=6340312


                                                              The End