Specification of Resource Allocation Systems - Chalmers tekniska

178 Pages·2005·1.79 MB·English

Specification of Resource Allocation Systems
a STEP towards a unified framework
PETTER FALKMAN
Department of Signals and Systems
CHALMERS UNIVERSITY OF TECHNOLOGY
Go¨teborg, Sweden, 2005

THESIS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY
Specification of
Resource Allocation Systems
a STEP towards a unified framework
PETTER FALKMAN
DepartmentofSignalsandSystems
CHALMERS UNIVERSITY OF TECHNOLOGY
Go¨teborg,Sweden,2005
SpecificationofResource AllocationSystems
aSTEP towardsaunifiedframework
PETTERFALKMAN
ISBN 91-7291-694-X
DoktorsavhandlingarvidChalmerstekniskaho¨gskola
Nyserienr 2376
ISSN 0346-718X
DepartmentofSignalsandSystems
AutomationResearch Group
ChalmersUniversityofTechnology
SE-41296 Go¨teborg,Sweden
Telephone [phone]
(cid:1)c 2005PetterFalkman
PrintedbyChalmersReproservice
Go¨teborg,Sweden2005
TypesetbytheauthorwiththeLATEXDocumentationSystem
ToKerstin,WilliamandElsawithlove

abstract
SpecificationofResourceAllocationSystems
aSTEPtowardsaunifiedframework
PetterFalkman
DepartmentofSignalsandSystems
ChalmersUniversityofTechnology
In recent years growing demands on flexibility and ability to decrease time to market
hasmadeitincreasinglyimportantforengineeringcompaniestofindwaysofmakinginfor-
mationexchange between product designand manufacturingsystemsdesignmore efficient.
A much shortenediteration cycle could be obtainedif informationabout product designso-
lutions could be made instantly available for engineers involved in manufacturing systems
design. Due to the high costs associated with modifying and changing system implementa-
tions, the ability to model and simulate systems before they are implemented is becoming
more and more essential. Consequently it is vital that the system specifications used are
as clear and concise as possible. The present thesis deals with the specification of discrete
eventsystems,especiallyresourceallocationsystems. Acombinationofprocessalgebraand
Petrinetsispresented. Thiscombinationresultsinapowerfullanguage,calledprocessalge-
braPetrinets(PPN),forspecifyingresourceallocationsystems,deliveringbothconciseand
easy-to-read specificationsof large complexsystems. The fact that bothPetri net constructs
andalgebraexpressionscanbeusedinordertodecreasespecificationcomplexityalsomakes
itaflexiblelanguage. AmethodisalsopresentedthatformallyconvertsthePPNmodelsinto
finitestateautomata,whichmeansthatexistingformalevaluationtechniquesforsimulation,
verification,andcontrollersynthesiscanbeeasilyapplied.
Thepresentedlanguagedefinesanalgebrawheretheprocessoperatorsexpressthesame
processrelationsthat are possiblein theinternationalstandard STEP-AP214. To the bestof
our knowledge, the PPN language constitutes a first attempt at using a formal language in
order to create a tool that can automatically generate specifications according to the STEP
standard.
So farlittlehasbeen investigatedconcerningtheconnectionbetweeninformationmod-
elling and discrete event systems. The present work, however, researches this connection.
The presented mappingdefines the relationshipbetween the informationand theDES spec-
ification.
Finally, it can be said that the introduced method guarantees that the expected infor-
mation is delivered fast and without the errors potentially induced by manual handling,
something which is crucial when short lead times are required. Due to the fast informa-
tion exchange it also enables simulation, automatic controller synthesis and verification, to
beconductedearlyinthedevelopmentchain.
KEYWORDS: Flexible manufacturing systems, Resource allocation systems, supervisory
control theory, supervis synthesis, specification, Petri nets, Process algebra, finite state au-
tomata,STEPAP214.
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acknowledgements
I would like to thank everyone that in some way or another helped making this work
cometogether. First,mysincerestgratitudeofcoursegoestomysupervisorProfessorBengt
Lennartson,forintroducingmeintotheworldofscience sogenerouslysharinghistimeand
knowledgewith me, and always believingin me. Second, I wish to thank my co-supervisor
Associate Professor Martin Fabian for providing invaluable support throughout the process
ofwritingthisthesis. ThankyoualsotoKnut A˚kessonfor providingvaluablecommentson
earlierdraftsofthiswork.
Special thanks to my collaborators at KTH, especially Johan Nielsen and Astrid von
Euler-Chelpin.
IwouldalsoliketothankallmyfriendsandcolleagueswithinthedepartmentofControl
andAutomationLaboratory. Aspecialthanksgoestothemembersoftheautomationgroup,
for providingmoral supportand bandying ideas with me whenever I needed it, in particular
KristinAndersson,andJohanRichardsson.
Last, but certainly not least, I am forever indebted to my loving and supporting family
foralwaysbelievinginme: mywifeKerstinandmychildrenWilliamandElsa,mybrothers
Pa˚landPa¨r,myparentsJanandMarian,andGavinandKatarinaWatson.
Go¨teborg,November,2005
PetterFalkman
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