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 Special Issue of Discrete Event Dynamic Systems

3. Conferences
 3.1 6th International Conference on Control and Automation (ICCA2007),
     Guangzhou, China, May 30 - June 1, 2007
 3.2 International Conference on Advances in Control and Optimization of
     Dynamical Systems (ACODS'2007), Bangalore, India, February 1 -
     2, 2007
 3.3 10th International Conference on Hybrid Systems: Computation and
     Control 2007, Pisa, Italy, April 3 - 5, 2007
 3.4 2nd International Symposium on Problems of Automation, Milan,
     Italy, September 18 - 18, 2006
 3.5 2nd International Workshop on Networked Control Systems Tolerant to
     Fault, Rende, Italy, November 23 - 24, 2006
 3.6 4th Workshop on Advanced Control and Diagnosis - ACD 2006, Nancy,
     France, November 16 - 17, 2006
 3.7 IFAC Workshop on Nonlinear Model Predictive Control for Fast
     Systems, Grenoble, France, October 9 - 10, 2006
 3.8 POSTA06 Second Multidisciplinary International Symposium on Positive
     Systems: Theory and Applications, Grenoble, France, August 30
     - September 1, 2006

4. Journals
 4.1 Selections from IEEE Transactions on Automatic Control, Volume: 51,
     Issue: 6, June 2006
 4.2 Selections from IEEE Transactions on Software Engineering, Volume:
     32, Issue: 5, June 2006
 4.3 Selections from IEEE Transactions on Systems, Man and Cybernetics, Part
     A, Volume: 36,  Issue: 4, July 2006
 4.4 Selections from IEEE Transactions on Systems, Man and Cybernetics, Part
     C, Volume: 36,  Issue: 4, July 2006
 4.5 Selections from IEEE Transactions on Control Systems Technology,
     Volume: 14, Issue: 4, July 2006
 4.6 Selections from IEEE Transactions on Systems, Man and Cybernetics, Part
     B, Volume: 36, Issue: 4, 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:

I only recently got back from WODES'06 and am still getting caught up.
It was my first opportunity to attend a WODES, and I found it quite
enjoyable. It was nice to attend a workshop with a large number of well
known DES researchers, many of which I have only conversed with before
by e-mail, if at all. The large number of high quality DES papers was
quite impressive.  I look forward to the next one. Congratulations on
the organizers and everyone involved for doing such a great job!

If you missed the closing comments at WODES'06, they announced that
WODES 2008 will be in Gothenburg, Sweden. It will be organized by the
Automation Research Group at Chalmers.	I hope to see you all there.

Ryan

Contributed by: Carla Seatzu <seatzu@diee.unica.it>

SPECIAL ISSUE OF DISCRETE EVENT DYNAMIC SYSTEMS

		      Call for Papers

Special Issue of Discrete Event Dynamic Systems:

Discrete Event Methodologies for Hybrid Systems

Guest Editors: C. Cassandras, A. Giua, C. Seatzu, J. Zaytoon

Recent technological innovations have caused an ever increasing 
interest in the study of hybrid systems. The distinguishing feature 
of hybrid systems is the interaction between continuous-time dynamics 
(governed by differential or difference equations), and discrete 
dynamics and logic rules (described by temporal logic, finite state 
machines, if-then-else conditions, discrete events, etc.). The 
growing interest by both academia and industry in hybrid systems is 
motivated not only by theoretical challenges, but mainly by their 
ability to model, analyse and synthesize controllers in a large 
variety of application areas.

However, hybrid dynamics are often so complex that a satisfactory 
feedback controller cannot be synthesized by using analytical tools 
similar to those that pertain to linear systems or to certain classes 
of nonlinear smooth systems. Heuristic design procedures usually 
require trial and error sessions, extensive testing, are time 
consuming, costly and often inadequate to deal with the complexity of 
the hybrid control problem properly. 

This special issue aims to present recent approaches that have been 
developed within the discrete event community and that can be used 
for the analysis and control of hybrid systems. Both logical and 
performance approaches are within the scope of the issue. 

Topics of interest include, but are not limited to:
	Abstraction, model equivalence and bisimulation techniques
	Supervisory control of hybrid systems
	Control with communication
	Quantized systems
	Discrete event and hybrid simulation
	Markov jump linear systems
	Fluid models

Interested authors are invited to contact one of the guest editors 
and to submit full papers to Discrete Event Dynamic Systems by 
October 1st 2006 (http://www.springer.com/journal/10626/).

Christos G. Cassandras (cgc@bu.edu)
Alessandro Giua (giua@diee.unica.it)
Carla Seatzu (seatzu@diee.unica.it)
Janan Zaytoon (janan.zaytoon@univ-reims.fr)

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

6TH INTERNATIONAL CONFERENCE ON CONTROL AND AUTOMATION (ICCA2007)
Guangzhou, China
May 30 - June 1, 2007

ICCA'07 is jointly organized by the IEEE Control Systems Chapter, 
Singapore and IEEE Control Systems Chapter. It is to create a forum 
for scientists and practicing engineers throughout the world to 
present the latest research findings and ideas in the areas of 
control and automation. 

Three keynote speeches to be conducted by well known experts in the 
area, Professors John Baillieul (IEEE Fellow), Hanfu Chen (IEEE 
Fellow) and David Hill (IEEE Fellow), have been arranged for the 
conference.

The Proceedings of ICCA are indexed by ISI Proceedings, EI Compendex 
and IEEE Xplore. 

Topics of interest include but not limited to:

      Modeling of Complex Systems	   Optimal Control 
      Linear Systems			   Discrete Event Systems 
      Robust and H-infinity Control	   Adaptive Control 
      Nonlinear Systems and Control	   Learning Systems 
      Fuzzy and Neural Systems		   Intelligent and AI Based 
Control 
      Estimation and Identification	   Real-time Systems 
      Fault Detection			   Sensor and Data Fusion 
      Process Control & Instrumentation    Robotics 
      Motion Control			   Automated Guided Vehicles 
      Flexible Manufacturing Systems	   Control Education 
      Integrated Manufacturing		   Control Applications 
      Factory Modeling and Automation	   Process Automation 
      Petri-Nets and Applications	   Man-machine Interactions 
      Micro and Nano Systems		   Smart Structures 

Submission of Papers:

Authors should submit the full version of their manuscripts 
electronically online through the ICCA'07 manuscript submission site 
http://icca.elite.sg/. 
General inquiries should be addressed to the Program Chair, Professor 
Gang (Gary) Feng, at the City University of Hong Kong 
(icca2007@ntu.edu.sg). 

Proposals for invited sessions in the related areas are also 
solicited and should be submitted through email to the Invited 
Session Chair, Professor Yuan Wang, at Florida Atlantic University 
(icca2007@ntu.edu.sg). 

All materials must be written in English, and a paper should be 
submitted only if you intend to present the paper at the conference. 
The manuscript to be submitted to the conference should contain 
sufficient details including key concepts and novel features of the 
work. It should include the title, authors, mailing addresses, 
affiliations, telephone and fax numbers and email addresses.

Important Dates:

Paper Submission Deadline:		    November 1, 2006 
Notification of Acceptance:		    December 31, 2006 
Submission of Final Papers:		    March 1, 2007 
Conference:				    May 30-June 1, 2007 

Official Website:
http://www.ieee-icca.org (http://hdd.ece.nus.edu.sg/~icca07/)

web site: click here

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

INTERNATIONAL CONFERENCE ON ADVANCES IN CONTROL AND OPTIMIZATION OF
DYNAMICAL SYSTEMS (ACODS'2007)
Bangalore, India
February 1 - 2, 2007

The aim of ACODS'2007, to be held at Indian Institute of Science, 
Bangalore, India, is to bring together engineers, scientist and 
academics working in advanced areas of control and optimization of 
dynamical systems. The theme of the conference is broad enough to 
encompass both theory and applications. 
Application areas include, but are not restricted to robotics, 
aerospace vehicles, manufacturing, process control, computer aided 
control, biomedical engineering, automation, and mechanical and 
electrical systems. Papers are invited in these and other areas where 
control and optimization of dynamical systems plays an important role.

Indian Institute of Science, established in 1909, is widely 
recognized to be the best and most prolific scientific institute for 
advanced research in India. The Department of Aerospace Engineering, 
which is hosting the conference, has an active group of researchers 
in the area of control and optimization. Besides, Bangalore is one of 
the most vibrant cities in India, located in the middle of many 
historical tourist places.

Contributed papers are invited in two categories: Regular (8 pages) 
and short (4 pages). The regular papers are expected to describe 
fairly detailed account of completed work and the short papers will 
cover preliminary results or new ideas. The papers will be reviewed 
with the same rigour as other well-established international 
conferences. Our aim is to maintain the highest quality in accepted 
papers. The proceeding of ACODS'2007 will be brought out in a CD and 
will be available to each registered participant.

Key Dates
---------
Deadline for paper submissions	     : 31 August, 2006
Notification of Acceptance/Rejection : 31 October, 2006
Final manuscript submission deadline : 30 November, 2006
Author registration fee deadline     : 15 December, 2006
Conference dates		     : 01-02 February, 2007

Paper submission guidelines
---------------------------
Papers should be in the double column format on A4 size paper, with 
10pt. typeface. As a guideline, please refer to a standard format 
used for IEEE conferences. Pdf file of the paper only should be 
submitted. Please adhere to limits of 8 pages (for regular papers) 
and 4 pages (for short papers). In addition, on a separate sheet, 
please put the title, author names, abstract, contact address and 
email. Email  both documents in a zipped folder labeled with the 
first author's name  to ACODS2007@aero.iisc.ernet.in. Total size of 
the folder should be below 8MB.

Contact Information
-------------------
The organizing committee, ACODS'2007
ISRO-IISc Space Technology Cell
Department of Aerospace Engineering
Indian Institute of Science, Bangalore
560 012, India.

Phone: +91-80-23600525, 22932503, 22932760 
Fax:   +91-80-23601279 
E-mail: ACODS2007@aero.iisc.ernet.in

web site: click here

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

10TH INTERNATIONAL CONFERENCE ON HYBRID SYSTEMS: COMPUTATION AND
CONTROL 2007
Pisa, Italy
April 3 - 5, 2007

The conference, tenth in a series of succesful annual meetings, is 
dedicated to research in embedded reactive systems involving the 
interplay between symbolic/switching and continuous dynamical 
behaviors. Academic as well industrial researchers are invited to 
exchange information on the latest developments of applications and 
theoretical advancements in the design, analysis, control, 
optimization, and implementation of hybrid systems, with particular 
attention to embedded and networked control systems.

The conference is a forum for all aspects of hybrid systems, 
including:

- Models of heterogeneous systems
- Computability and complexity issues
- Real-time computing and control
- Embedded and resource-aware control
- Control and estimation over wireless networks
- Tools for analysis, verification, control, and design
- Programming languages support and implementation
- Applications, including automotive, communication networks, 
avionics, energy systems, transportation networks, biology and other 
sciences, manufacturing, and robotics

Accepted regular papers will be allotted 14 pages each in a volume to 
be published in the Springer-Verlag Lecture Notes in Computer Science 
(LNCS) series.

Submission of short papers (6 pages) accompanying a poster 
presentation will also be peer reviewed for inclusion in the 
conference proceedings.

Important Dates
October 9, 2006:   Deadline for paper submission (regular and short 
papers)
December 19, 2006: Submission of final manuscript
February 5, 2007:  Deadline for poster and hands-on demo submission

Alberto Bemporad, Antonio Bicchi, and Giorgio Buttazzo
HSCC'07 General Chairs

web site: click here

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

2ND INTERNATIONAL SYMPOSIUM ON PROBLEMS OF AUTOMATION
Milan, Italy
September 18 - 18, 2006

Convegno Internazionale sui Problemi dell'Automatismo
Symposium International sur les Problemes de l'Automation
International Symposium on Problems of Automation
Internationales Symposium uber Probleme der Automation

In April 1956, a conference was organized, which can be considered 
the "big bang" of modern control science in Italy.  This was the 
Convegno Internazionale sui Problemi dell'Automatismo. The conference 
was held in Milan under the aegis of CNR (Consiglio Nazionale delle 
Ricerche), with a large number of participants, from Italian and 
foreign universities, as well as from companies operating in the 
automation sector, research and development institutes. Mr. Giovanni 
Gronchi, the President of the Italian Republic, attended the closing 
ceremony of the conference. 

Fifty years later, a celebration day with a similar spirit will take 
place at the Politecnico di Milano. The meeting will feature 
historical addresses, lectures of introductory type, and tutorials of 
large interest.  The objective is to outline the contribution of 
automatic control to the development of science and technology in the 
XX centuryand to discuss the main lines of the future developments 
that the XXI Century can bring with.

Distinguished Speakers: 
- S. Barabaschi, The Early Years of Automatic Control in Italy 
(former President of ESTA - European Science and Technology 
Assembly)    
- G. Goodwin, Digital Control: Past, Present and Future 
(University of Newcastle, Australia) 
- H. Kimura, Control Issues in Life Sciences 
(Laboratory Head of Biological Control System Lab. at RIKEN, Nagoya, 
Japan) 
- G. Marro, The Geometric Approach to Control 
(Universita  di Bologna) 

Round table:
L. D'Alessandro
President ANIPLA - Associazione Nazionale Italiana Per L'Automazione
F. Gagliardi
President AEIT - Federazione Italiana di Elettrotecnica, Elettronica, 
Automazione, Informatica e Telecomunicazioni
A. Vicino
President of CIRA - Centro Interuniversitario di Ricerca in Automatica

web site: click here

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

2ND INTERNATIONAL WORKSHOP ON NETWORKED CONTROL SYSTEMS TOLERANT TO
FAULT
Rende, Italy
November 23 - 24, 2006

AIM 
The workshop will explore research opportunities in distributed and 
networked control systems with special emphasis in their fault-
tolerant properties. Preference will be given to papers describing 
algorithms, procedures and examples showing ability in the detection 
and isolation of anomalies (variances or irregularities in the 
networks and/or in the system) and in reconfiguring the underlying 
control strategies.

TOPIC OF MAIN INTEREST
-  Networked Control Systems
-  Intelligent Sensors and Sensor Networks
-  Real-Time Embedded Systems
-  Industrial Communication Systems
-  Fault Detection and Isolation (FDI)
-  Active Fault-Tolerant Control (FTC)
-  Autonomous Control, Coordination & Supervision in Networked Systems
-  Distributed Wireless Networks
-  Control Reconfiguration and Allocation
-  Distributed Consensus Methods
-  Applications to: Process Control, Transport, Robotics, Intelligent 
sensors & actuators, .
-  Distributed systems
-  Human-machine interaction and teleoperation

WORKSHOP LOCATION AND SEGRETARIAT
University of Calabria
Department of Electronics, Systems and Computer Engineering
Arcavacata di Rende (CS) - 87036 Italy
http://www.deis.unical.it/
Tél : +39 0994 494724
Fax : +39 0984 494713
e-mail : 2ndnecst@deis.unical.it

WORKSHOP LANGUAGE
The official language of the workshop is English.

IMPORTANT DATES
Sept  15 th, 2006 Submission of draft papers
October 1st, 2006 Notification of acceptance
October 15th, 2006 Submission final papers

SUBMISSION
Draft Papers & Special Session Proposals must be submitted in IFAC 
submission format (pdf or ps) to: e-mail : 2ndnecst@deis.unical.it

CONFERENCE PUBLICATION
All accepted  papers will be published in the conference proceedings. 
Selected papers will be considered for journal publication.

REGISTRATION FEES
200 Euro   Registration by October 15th ("Early Bird")
220 Euro   Registrations (up to the workshop)

The registration fees include the attendance to the workshop,  coffee 
breaks , lunches (Nov 23, Nov. 24), dinner (Nov. 24) and the Workshop 
Proceedings (book of abstracts and CDROM).

TRAVEL INFORMATION
The University of Calabria is located at Arcavacata di Rende, a 
village close to Cosenza.  It is served by the airport of Lamezia 
Terme with flights from Rome and Milan with Alitalia.  Some cut-price 
airlines fly to Lamezia Terme.	A detailed list of options to arrive 
at the University of Calabria will be provided at the workshop 
website.

ACCOMODATION AND LUNCHES
A small number of single or double rooms will be available inside the 
Campus at very low rates.  A list of selected hotels at a walking 
distance from the University will be also provided.  The lunches will 
be served at several cafeterias inside the Campus.

SOCIAL PROGRAM
On Saturday 25th November an all-day guided visit to Norman and 
Swabian castles in the Province of Cosenza will be organized for 
interested people.  
The tour includes an English-speaking local guide, bus trip and lunch 
in a typical Calabrian restaurant ("agritourism").  The tour ticket 
will cost an additional 40 Euro per person.

For further information, please see 
http://www.strep-necst.org/2ndWorkshop

web site: click here

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

4TH WORKSHOP ON ADVANCED CONTROL AND DIAGNOSIS - ACD 2006
Nancy, France
November 16 - 17, 2006

The 4th Workshop on Advanced Control and Diagnosis will highlight some
particular recent results in the development of methods and tools and 
also some prototype which are of a particular interest for academics 
and engineers. The emphasis is placed on practice of those 
technologies, but such theoretical researches as accompanied with 
practical experience/consideration will be also welcome. The topics 
are: Intelligent Methods for System Identification,Control, Fault 
Diagnosis, Fault Tolerance, Safety, Computational Intelligence,
Pattern Recognition, Decision, Prognostic techniques for 
Dependability with applications to: industrial processes, 
transportation systems, intelligent sensors and actuators, 
distributed systems, communication systems including human-machine 
interaction and tele-operation aspects, integration prototype.

PLEASE NOTICE THE FOLLOWING DEADLINES:
September 25, 2006 Submission of draft papers 
October 24, 2006 Notification of acceptance
November 3, 2006 Submission of Camera-ready papers
November 5, 2006 Papers available on the web site
November 16-17, 2006 Workshop on ACD 2006

WITH THE PARTICIPATION:
Necst Strep project (Network control systems tolerant to faults)
Integrated European project DYNAMITE (Dynamic decisions in 
maintenance)

FEE STRUCTURE
Only 100 euros for Full registration including the attendance to the 
workshop, lunches (Nov 16, Nov 17), the coffee breaks and the CD-ROM
proceedings

web site: click here

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

IFAC WORKSHOP ON NONLINEAR MODEL PREDICTIVE CONTROL FOR FAST SYSTEMS
Grenoble, France
October 9 - 10, 2006

SCOPE AND TOPIC:

It is now well recognized that nonlinear model predictive control 
(NPMC) is a particularly suitable control strategy when highly 
nonlinear dynamics and high quality/cost requirement are to be 
considered.

Although these facts are application independent, it is a fact that 
as soon as applications are considered, the use of NMPC schemes has 
been particularly intensive in the case of slow processes while few 
implementations are reported for relatively fast systems. This is 
because, first, chemical processes present the above mentioned 
features (Nonlinearities, constraints and economical issues) making 
the use of NMPC practically unavoidable, but it also results from the 
fact that the computational needs in the implementation of NMPC would 
be incompatible with systems with relatively fast dynamics.

The aim of the workshop is to put together researchers and users of 
NMPC schemes in order to focus on the potential use of NMPC for 
relatively fast systems (mechanical systems, electrical systems, 
Robotics, aerospace, etc). This may include both theoretical 
formulations leading to less computational requirements and 
successful applications of NMPC schemes to rather fast systems.

MEETING TOPICS:

In relation to the scope and objective, the main topics of the 
workshop are the following:

- New formulations of NMPC for fast computation
- Sub-optimal stability oriented NMPC schemes
- New Computational algorithms
- Comparison of algorithms
- Successful applications on relatively fast systems 
- Robotic systems
- Aerospace systems
- Electrical systems
- Networked control systems
- Transformation processes 

DEADLINES:

  February 10, 2006: Submissions of draft papers and invited sessions 
  April 20, 2006: Notification of acceptance 
  June 15, 2006: Submission of camera-ready papers 

 
PAPER SUBMISSION:

Contributed papers must be full papers written in English and must 
comply with yhe IFAC format and should not exceed 6 two-columns 
pages. For detailed formatting instructions, see the IFAC 
publications site www.elsevier.com/locate/ifac.

The material submitted for presentation at an IFAC meeting (congress, 
symposium, conference, workshop) must be original, not published or 
being considered elsewhere. All papers accepted for presentation will 
appear in the Preprints of the meeting and will be distributed to the 
participants. Papers duly presented will be archived and offered for 
sale, in the form of Proceedings, by Elsevier Science Ltd, Oxford, 
UK. The presented papers will be further screened for possible 
publication in the IFAC Journals (Automatica, Control Engineering 
Practice, Annual Reviews in Control, Journal of Process Control and 
Engineering Applications of Artificial Intelligence), or in IFAC 
affiliated journals. All papers presented will be recorded on the 
IFAC Publications website: http://www.elsevier.com/locate/ifac

web site: click here

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

POSTA06 SECOND MULTIDISCIPLINARY INTERNATIONAL SYMPOSIUM ON POSITIVE
SYSTEMS: THEORY AND APPLICATIONS
Grenoble, France
August 30 - September 1, 2006

SCOPE AND OBJECTIVE:

Positive Systems are systems in which the relevant variables assume 
nonnegative values. These systems are quite common in applications 
where variables represent positive quantities such as populations, 
comsumption of goods, concentrations of chemical species, 
probabilities... 
The aim of the Symposium is to help researchers working on the 
modelling of systems in different areas, such as economics, 
biomedicine, chemistry, telecommunications, and so on, to meet in a 
multidisciplinary forum where they have the opportunity to exchange 
ideas and compare results in a unifying framework.
The Proceedings of the Symposium will be published as a volume of the 
Springer Lectures Notes in Control and Information Sciences series. 
 
  
TOPICS OF INTEREST

Theory and applications of:

- POSITIVE SYSTEMS 
- COMPARTMENTAL SYSTEMS 
- MARKOV and HIDDEN MARKOV MODELS 
- QUEUEING SYSTEMS 
- BIOLOGICAL MODELS 
- MAX-PLUS ALGEBRA 
- 2D SYSTEMS 
- BEHAVIOURAL APPROACH 
- CONSTRAINED CONTROL AND OPTIMIZATION 
- NONNEGATIVE MATRICES 
- TRAFFIC MODELS 
- NONLINEAR SYSTEMS 
- ECONOMICS

web site: click here

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

SELECTIONS FROM IEEE TRANSACTIONS ON AUTOMATIC CONTROL
VOLUME: 51, ISSUE: 6
JUNE, 2006

1) Reachability and Control Synthesis for Piecewise-Affine Hybrid
Systems on Simplices

Habets, L.C.G.J.M.; Collins, P.J.; Van Schuppen, J.H.

Abstract:

In this paper, we consider the synthesis of control laws for
piecewise-affine hybrid systems on simplices. The construction is based
on the solution to the control-to-facet problem at the continuous
level, and on dynamic programming at the discrete level. The
construction is given as an explicit algorithm using only linear
algebra and reach-set computations for automata; no numerical
integration is required. The method is conservative, in that it may
fail to find a control law where one exists, but one cannot hope for a
sharp algorithm for control synthesis since reachability for
piecewise-affine hybrid systems is undecidable.

2) Logic-Based Solution Methods for Optimal Control of Hybrid Systems

Bemporad, A.; Giorgetti, N.

Abstract:

Combinatorial optimization over continuous and integer variables is a
useful tool for solving complex optimal control problems of hybrid
dynamical systems formulated in discrete-time. Current approaches are
based on mixed-integer linear (or quadratic) programming (MIP), which
provides the solution after solving a sequence of relaxed linear (or
quadratic) programs. MIP formulations require the translation of the
discrete/logic part of the hybrid problem into mixed-integer
inequalities. Although this operation can be done automatically, most
of the original symbolic structure of the problem (e.g., transition
functions of finite state machines, logic constraints, symbolic
variables, etc.) is lost during the conversion, with a consequent loss
of computational performance. In this paper, we attempt to overcome
such a difficulty by combining numerical techniques for solving convex
programming problems with symbolic techniques for solving constraint
satisfaction problems (CSP). The resulting hybrid solver proposed
here takes advantage of CSP solvers for dealing with satisfiability of
logic constraints very efficiently. We propose a suitable model of the
hybrid dynamics and a class of optimal control problems that embrace
both symbolic and continuous variables/functions, and that are tailored
to the use of the new hybrid solver. The superiority in terms of
computational performance with respect to commercial MIP solvers is
shown on a centralized supply chain management problem with uncertain
forecast demand.

3) Complexity of Control on Finite Automata

Delvenne, J.-C.; Blondel, V.D.

Abstract:

We consider control questions for finite automata viewed as
input/output systems. In particular, we find estimates of the minimal
number of states of an automaton able to control a given automaton. We
prove that, on average, feedback closed-loop control automata do not
have fewer states than open-loop control automata when the control
objective is to steer the controlled automaton to a target state. We
compare our approach to other ways of formalizing of formalizing
analogous control objectives.

4) Formalizing Real-Time Scheduling Using Priority-Based Supervisory
Control of Discrete-Event Systems

Janarthanan, V.; Gohari, P.; Saffar, A.

Abstract:

In this note, we formalize real-time task scheduling by applying an
extension of supervisory control theory (SCT) of discrete-event systems
to real-time models. The set of all possible timed traces of the system
is specified by a discrete timed automaton where each transition is
associated with an event occurrence or the passage of one unit of time.
We introduce priorities to SCT, and apply them to the setting of
discrete timed automata in order to develop a formal and unified
framework for task scheduling on a single CPU.

web site: click here

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

SELECTIONS FROM IEEE TRANSACTIONS ON SOFTWARE ENGINEERING
VOLUME: 32, ISSUE: 5
JUNE, 2006

1) Design Synthesis from Interaction and State-Based Specifications

Jun Sun, Jin Song Dong

Abstract:

Interaction-based and state-based modeling are two complementary
approaches of behavior modeling. The former focuses on global
interactions between system components. The latter concentrates on the
internal states of individual components. Both approaches have been
proven useful in practice. One challenging and important research
objective is to combine the modeling power of both effectively and then
use the combination as the basis for automatic design synthesis. We
present a combination of interaction-based and state-based modeling,
namely, Live Sequence Charts and Z, for system specification. We then
propose a way of generating distributed design from the combinations.
Our approach handles systems with intensive interactive behaviors as
well as complex state structures.

web site: click here

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

SELECTIONS FROM IEEE TRANSACTIONS ON SYSTEMS, MAN AND CYBERNETICS, PART
A
VOLUME: 36, ISSUE: 4
JULY, 2006

1) Fuzzy-Petri-Net-Based Disassembly Planning Considering Human Factors

Tang, Y.; Zhou, M.; Gao, M

Abstract:

Disassembly, as the process of systematic removal of desirable
constituent parts from an assembly, is of growing importance due to the
increasing environmental and economic pressure. Although disassembly in
practice is manual and labor intensive, little attention has been paid
to the human intervention in the disassembly process. This paper
addresses this deficiency by developing a fuzzy attributed Petri net
(FAPN) model to mathematically represent uncertainty in disassembly due
to a large amount of human intervention. An algorithm based upon this
model is further proposed for optimal disassembly planning with a view
to making the technique more applicable to real industry settings. The
benefit of the proposed model and algorithm is illustrated through the
disassembly of a personal computer (PC) in a prototypical disassembly
system.

web site: click here

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

SELECTIONS FROM IEEE TRANSACTIONS ON SYSTEMS, MAN AND CYBERNETICS, PART
C
VOLUME: 36, ISSUE: 4
JULY, 2006

1) Differential Petri net models for industrial automation and
supervisory control

Demongodin, I.; Koussoulas, N.T.

Abstract:

Supervisory control systems play a central role in modern industrial
automation. However, control theory has recently made significant
advances in modeling mixed continuous/discrete event systems ("hybrid
control systems"), whose typical instantiations include the industrial
supervisory controller. This article shows how differential Petri nets,
a model for hybrid control systems, can be used to represent industrial
supervisory systems in a unified way. Typical industrial automation
tests can be modeled, whereas the effect of communication protocols and
software can be straightforwardly included using conventional Petri
nets. Therefore, a global model for the operation of an industrial
control system can be formed and its behavior analyzed.

2) Performance-oriented integrated control of production scheduling

Rong-Lei Sun; Han-Xiong Li; Youlun Xiong

Rule-based production scheduling is analyzed from the perspective of
closed-loop control. An integrated feedback control methodology is
proposed to enhance the performance of rule-based scheduling. The
integrated control system consists of a state feedback control module,
a performance-based feedback module, and a supervisory control module.
Performance criteria are analyzed and classified into job-related and
resource-related criteria. The key factors of performance are
identified and used as state variables in the feedback control. The
performance-based feedback control compensates for the errors that are
caused by the scheduling rules. The supervisory control is designed to
enhance the overall performance by adjusting the feedforward gains
according to scheduling objectives. Simulation results show that the
integrated control scheme can significantly improve the overall
performance of the scheduling system.

web site: click here

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

SELECTIONS FROM IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY
VOLUME: 14, ISSUE: 4
JULY, 2006

1) Hierarchical interface-based supervisory control of a flexible
manufacturing system

 Leduc, R.J.; Lawford, M.; Pengcheng Dai

Abstract:

Flexible manufacturing systems have long been touted as an application
area for supervisory control theory. Unfortunately, due to the typical
exponential growth of state space with the number of interacting
subsystems, concurrent systems such as manufacturing applications have,
for the most part, remained beyond the reach of existing supervisory
control theory tools. This paper demonstrates how, by imposing a
hierarchical, modular, interface-based architecture on the system,
significant gains can be made in the size of applications that can be
handled by supervisory control theory. We first review hierarchical
interface-based supervisory control, providing the theory necessary to
motivate the creation of well-defined automata-based interfaces between
components. This architecture permits the verification of global safety
(controllability) and nonblocking properties to be decomposed into a
set of local checks, each of which only involves an individual
component subsystem and its interface automata. The paper then provides
a detailed description of how the theory can be applied to the design
and verification of a flexible manufacturing system work cell. The work
cell model is based on the Atelier Interetablissement de Productique
flexible manufacturing workcell, a system that has been previously
studied in the literature with limited success.

web site: click here

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

SELECTIONS FROM IEEE TRANSACTIONS ON SYSTEMS, MAN AND CYBERNETICS, PART
B
VOLUME: 36, ISSUE: 4
AUGUST, 2006

1) Supervisory Control of Mobile Sensor Networks: Math Formulation,
Simulation, and Implementation

Giordano, V.; Ballal, P.; Lewis, F.; Turchiano, B.; Zhang, J.B.

Abstract: 

This paper uses a novel discrete-event controller (DEC) for the
coordination of cooperating heterogeneous wireless sensor networks
(WSNs) containing both unattended ground sensors (UGSs) and mobile
sensor robots. The DEC sequences the most suitable tasks for each agent
and assigns sensor resources according to the current perception of the
environment. A matrix formulation makes this DEC particularly useful
for WSN, where missions change and sensor agents may be added or may
fail. WSN have peculiarities that complicate their supervisory control.
Therefore, this paper introduces several new tools for DEC design and
operation, including methods for generating the required supervisory
matrices based on mission planning, methods for modifying the matrices
in the event of failed nodes, or nodes entering the network, and a
novel dynamic priority assignment weighting approach for selecting the
most appropriate and useful sensors for a given mission task. The
resulting DEC represents a complete dynamical description of the WSN
system, which allows a fast programming of deployable WSN, a computer
simulation analysis, and an efficient implementation. The DEC is
actually implemented on an experimental wireless-sensor-network
prototyping system. Both simulation and experimental results are
presented to show the effectiveness and versatility of the developed
control architecture.

web site: click here