IEEE CONTROL SYSTEMS SOCIETY TECHNICAL COMMITTEE
ON DISCRETE EVENT SYSTEMS

    Ryan J. Leduc
    Chair, IEEE CSS Technical Committee on DES
    Dept. of Computing and Software
    McMaster University
    1280 Main Street West
    Hamilton, Ontario
    Canada L8S 4K1

    Phone: (905) 525-9140 Ext. 27962
    Fax: (905) 524-0340
    e-mail: leduc@mcmaster.ca
    WWW: http://www.cas.mcmaster.ca/~leduc/

DESTC Web Page: http://www.cas.mcmaster.ca/destc/

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Contents:

1. Editorial

2. Announcements
 2.1 Adding Doctoral Thesis Announcements

3. Books
 3.1 Symbolic Synthesis and Verification of Hierarchical Interface-based
     Supervisory Control", by Raoguang Song

4. Conferences
 4.1 32nd Annual Conference of the IEEE Industrial Electronics Society
     (IECON-2006), Paris, France, November 7 - 10, 2006

5. Journals
 5.1 Selections from  IEEE Transactions on Automatic Control,  Volume:
     51,  Issue: 4, April 2006
 5.2 Selections from Automatica, Volume 42, Issue 5, May 2006
 5.3 Selections from Control Engineering Practice, Volume 14, Issue 8,
     August 2006

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

See http://www.cas.mcmaster.ca/destc/ for information on the DESTC.

Personal note from the editor:

Hello,	

Welcome to the April 2006 newsletter. I hope you will find useful our
new article type, doctoral theses.

Ryan

Contributed by: Ryan Leduc <leduc aT mcmaster DoT ca>

ADDING DOCTORAL THESIS ANNOUNCEMENTS

We have decided to add a new type of announcement to the newsletter:
Doctoral Theses.  After the doctoral thesis has been
successfully defended and available for download from the web, the
student or his/her supervisor are invited to add an announcement to
the newsletter containing the thesis abstract, bibliography
information, as well as a download link.  Master thesis announcements
are also permitted if they contain a new and interesting result.

To provide an example submission, I am including an announcement for
the thesis of one of my students who has just defended. I recommend
submitting thesis information as a book announcement.

Contributed by: Ryan Leduc <leduc aT mcmaster DoT ca>

SYMBOLIC SYNTHESIS AND VERIFICATION OF HIERARCHICAL INTERFACE-BASED
SUPERVISORY CONTROL

Raoguang Song
McMaster University, 2006

http://www.cas.mcmaster.ca/~leduc/index.html#studtheses

Abstract:

Hierarchical Interface-based Supervisory Control (HISC) is a method to
alleviate the state-explosion problem when verifying the controllable
and nonblocking properties of a large discrete event system. By
decomposing a system as a number of subsystems according to the HISC
method, we can verify the subsystems separately and the global system
controllability and nonblocking property are guaranteed, so that
potentially great computation effort is saved.

In the thesis, we first present a predicate-based synthesis algorithm
for each type of subsystem and then prove the correctness of the
algorithms. Then a predicate-based verification algorithm for each type
of subsystem is provided. Based on the predicate-based algorithms, a
symbolic implementation is proposed by using Binary Decision Diagrams
(BDD) and the fact that a subsystem is usually composed of a number of
components. With the symbolic implementation, we can handle a much
larger subsystem of each type.

Two large and complicated examples (with estimated worst-case
state-space on the order of 10^30) extended from the AIP example are
provided for demonstrating the capabilities of the algorithms and the
implementation. A software tool for the synthesis and verification
using our approach is also developed.

Bibliography Info: 

Raoguang Song, Symbolic Synthesis and Verification of Hierarchical
Interface-based Supervisory Control, M.A.Sc. Thesis, Dept. of Computing
and Software, McMaster University, March 2006.

Contributed by: Mariagrazia Dotoli <dotoli@deemail.poliba.it>

32ND ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY
(IECON-2006)
Paris, France
November 7 - 10, 2006

The 32nd Annual Conference of the IEEE Industrial Electronics Society 
(IECON-2006) will be held this November 7-10 in the beautiful city of 
Paris.

The technical program includes very interesting tutorials to be held
on November 6, 2006 - at no additional charge. We are also planning
exciting social highlights reflecting the atmosphere that is uniquely
Paris.

The general areas of technical interest are:
- Control Systems & Applications
- Electrical Machines & Drives
- Power Electronics
- Signal & Image Processing
- Industrial Informatics
- Mechatronics & Robotics
Additional information can be found at the conference website:
http://www.iecon06.iut-amiens.fr

Please note that the paper submission deadline will be extended to
April 28, 2006. We encourage you to submit papers in your area of
expertise. Moreover, we ask you to publicize this event among your
colleagues.

IECON is jointly sponsored by SICE (Japan) and historically attracts
a large international audience.  Please come and join us in this
memorable event. We look forward to hearing from you soon, and Paris
is waiting for you!

Best regards,

Gerard-Andre Capolino - Fellow IEEE
Leopoldo Garcia Franquelo - Fellow IEEE

General Co-Chairs

web site: click here

Contributed by: Ryan Leduc <leduc At mcmaster Dot ca>

SELECTIONS FROM IEEE TRANSACTIONS ON AUTOMATIC CONTROL
VOLUME: 51, ISSUE: 4
APRIL, 2006

1) Stability Theory of Hybrid Dynamical Systems With Time Delay

Liu, X.; Shen, J.

Abstract:

By defining the bounded time lag space and other related concepts, this
note formulates the notion of hybrid dynamical systems with time delay,
which provides a unified framework for describing a large class of
systems and is suitable for qualitative analysis. It also investigates
stability properties of invariant sets by the method of Lyapunov
functions and the Razumihin techniques. Criteria on uniform stability
and uniform asymptotic stability are established for hybrid dynamical
systems with time delay. Those criteria are then applied to conduct
stability analysis for impulsive delay differential systems and
nonlinear sampled-data feedback control systems with time delay.

2) Heuristic Methods for Delay Constrained Least Cost Routing
Using$k$-Shortest-Paths

 Jia, Z.; Varaiya, P.

Abstract:

The delay constrained least cost (DCLC) problem is to find the least
cost path in a graph subject to a delay constraint. First formulated in
the context of routing in computer networks, the DCLC model also
applies to problems of path planning and other decision problems. DCLC
is$NP$-complete. Many heuristic methods have been proposed for it. This
note presents two new methods based on the$k$-shortest-path$(k
SP)$approach. These heuristic methods - one centralized, the other
distributed - are both polynomial. In numerical experiments the proposed
algorithms almost always find the optimal paths.

web site: click here

Contributed by: Ryan Leduc <leduc At mcmaster Dot ca>

SELECTIONS FROM AUTOMATICA
VOLUME 42, ISSUE 5
MAY, 2006

1) Analysis of contract net in multi-agent systems

Fu-Shiung Hsieh

Abstract:

Application of contract net protocol requires the development of a bid
evaluation procedure specific to the problem. Care must be taken to
apply contract net protocol to tasks that involve precedence
constraints among different operations and heterogeneous resources. The
lack of a process model in the original contract net protocol makes it
difficult to determine the feasibility of the resulting contracts. We
propose a model to facilitate the development of the bid evaluation
procedure by extending our previous results to handle tasks with more
complex process structure. We formulate an optimization problem to find
a minimal cost feasible execution sequence for a task.

2) Simultaneous state and input estimation of hybrid systems with
unknown inputs

Luis Pinaand Miguel Ayala Botto

Abstract:

This paper addresses the problem of the simultaneous state and input
estimation for hybrid systems when subject to input disturbances. The
proposed algorithm is based on the moving horizon estimation (MHE)
method and uses mixed logical dynamical (MLD) systems as equivalent
representations of piecewise affine (PWA) systems. So far the MHE
method has been successfully applied for the state estimation of
linear, hybrid, and nonlinear systems. The proposed extension of the
MHE algorithm enables the estimation of unknown inputs, or
disturbances, acting on the hybrid system. The new algorithm is shown
to improve the convergence characteristics of the MHE method by
reducing the delay of convergent estimates, while assuring convergence
for every possible sequence of input disturbances. To ensure
convergence the system is required to be incrementally input
observable, which is an extension to the classical incremental
observability property.

web site: click here

Contributed by: Ryan Leduc <leduc At mcmaster Dot ca>

SELECTIONS FROM CONTROL ENGINEERING PRACTICE
VOLUME 14, ISSUE 8
AUGUST, 2006

1)  A methodology based on distributed object-oriented technologies for
providing remote access to industrial plants 

Isidro Calvo, Marga Marcos, Dario Orive and Isabel Sarachaga

Abstract:

Remote access to industrial plants has proven a serious competitive
advantage. However, building efficient and safe systems is not a
trivial task. It requires the integration of diverse complex
technologies at different levels. Even though these technologies are
not extended in industrial environments, in the author's opinion, they
are mature enough to be used in industrial applications. This paper
proposes a systematic object-oriented methodology to build applications
with remote access to industrial plants through Internet-like networks.
The methodology guides the designer regarding key issues, such as
security, concurrency, distribution of alarms and monitoring
information to different kinds of users. A generic architecture for
building remote access applications is proposed. The central components
of the architecture are the so-called Application Servers (ASs). Each
of them offers services to remote users and directly accesses to
specific parts of the physical plants. The proposed methodology
suggests the basic structure for these ASs, based on several reusable
components, as well as mechanisms to determine the number of ASs
required. The instantiation of the generic architecture as well as the
stages of the methodology are validated through an industrial case
study: a laboratory manufacturing cell.

web site: click here