Wilamowski B.M., Irwin J.D. The Industrial Electronics Handbook. Second Edition: Industrial Communication Systems

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16-2 Industrial Communication Systems

16.2 agents and Multi-agent Systems

16.2.1 Intelligent agents Denition

Intelligent agents.can.be.regarded.as.autonomous,.problem-solving.computational.entities.with.social.

abil

ities

.that.are.capa

ble

.of.eec

tive

.proa

ctive

.beha

vior

.in.open.and.dyna

mic

.envi

ronments.

. ere.are.

a.numbe

.of.die

rent

.den

itions

.of.inte

lligent

.agen

.(cf..e.g.,.[1])

;

.many.of.them.asso

ciate

.the.foll

owing

prop

erties

.wit

.an.age

nt:

•

. Auto

nomy:

.An.inte

lligent

.agen

.has.cont

rol

.over.its.beha

vior,

.that.is,.it.oper

ates

.with

out

.the.dire

inte

rvention

.of.huma

.bein

.or.othe

.agen

ts,

.and.has.cont

rol

.over.its.inte

rnal

.stat

.and.its.goal

•

. Resp

onsiveness/Reactivity:

.An.inte

lligent

.agen

.perc

eives

.its.envi

ronment

.and.resp

onds

.in.a.time

fash

ion

.to.cha

nges

.tha

.occ

.in.it.in.ord

.to.sat

isfy

.its.desi

.obje

ctives/goals.

•

. Soci

al ability:

.An.inte

lligent

.agen

.is.capa

ble

.of.inte

racting

.with.othe

.agen

.(and.huma

ns)

.and.

will.do.so.if.that.helps.to.achieve.its.design.objectives/goals.or.organizational.or.combined.goals.

•

. Inte

lligence:

.An.agen

.has.spec

ic

.expe

rtise

.and.know

ledge.

. us,.it.is.capa

ble

.of.deal

ing

.with.and.

mayb

.sol

ving

.pro

blems

.tha

.fal

.into.its.dom

ain

.of.exp

ertise.

•

. Proa

ctiveness:

.An.inte

lligent

.agen

.is.goal.dire

cted,

.deli

berative,

.inte

lligent,

.oppo

rtunistic,

.and.

init

iative.

.Due.to.its.goal

-directed

.beha

vior,

.the.agen

.take

.init

iative

.when

ever

.ther

.is.an.oppo

tunity

.to.sati

sfy

.its.goal

.It.espe

cially

.may.reac

.proa

ctively

.to.chan

ges

.in.its.envi

ronment;

.that.is,.

it.res

ponds

.to.it.wit

hout

.bei

.exp

licitly

.ask

.for.it.fro

.the.out

side.

.most.popu

lar

.mode

.for.cogn

itive,

.inte

ntional

.agen

.is.the.beli

ef-desire-intention

.(BDI

)

.arch

itec-

ture

.(cf..[36]

.Here

.agen

.reac

.to.chan

ges

.in.thei

.envi

ronment

.with.the.help.of.prac

tical

.reas

oning.

Roughly.speaking.an.agent.comes.with.a.number.of.sets.. e.beliefs.reect.its.abstracted.understanding.

of.that.part.of.the.real.worl

.it.is.inte

rested

.in.. is.unde

rstanding

.is.subje

ctive

.to.the.agen

. e.desir

repr

esent

.the.goal

.of.the.agen

.In.orde

.to.achi

eve

.its.goal

.an.agen

.has.to.sens

.its.envi

ronment

.and.

reac

.to.rele

vant

.chan

ges,

.usua

lly

.by.exec

uting

.plan

.from.its.pred

ened

.set.of.plan

s/actions.

. us,.a.

reas

oning

.proc

ess

.rst.iden

ties

.the.aec

ted

.goal

.and.appr

opriate

.plan

.Reas

oning

.is.enab

led

.by.con-

itions

.that.are.anno

tated

.to.plan

.and.goal

. e.inte

nsions

.of.an.agen

.are.ree

cted

.by.a.data.stru

cture

that.list

.thos

.plan

s/actions

.in.an.appr

opriate/ordered

.way.an.agen

.has.chos

.to.exec

ute

.as.a.reac

tion

to.the.las

.(an

.pri

or)

.rel

evant

.eve

nts

.in.its.env

ironment.

16.2.2 Multi-agent Systems

Due.to.the.limited.capabilities.of.a.single.agent,.more.complex.real-world.problems.may.require.the.

comm

.and.coop

erative

.effo

.of.a.numb

.of.agen

.in.orde

.to.get.the.prob

lem

.at.hand.solv

ed.

A.mult

i-agent system

.(MAS

)

.is.a.fede

ration

.of.full

.auton

omous

.or.semi

autonomous

.agen

.(pro

blem

solv

ers)

.that.are.will

ing

.to.join.forc

.in.order.to.achi

eve

.thei

.indi

vidual

.goal

.and/

.the.over

all

goal

.of.the.fede

ration.

.In.order.to.succ

eed,

.they.rely.on.comm

unication,

.coll

aboration,

.nego

tiation,

and.resp

onsibility

.dele

gation,

.all.of.whic

.are.base

.on.indi

vidual

.rati

onality

.and.soci

.inte

lligence

of.the.invol

ved

.agen

ts.

. e.glob

.beha

vior

.of.a.MAS.is.den

.by.the.emer

gent

.inte

ractions

.amon

.its.

agen

ts,

.whic

.impli

.that.the.capa

bility

.of.a.MAS.surp

asses

.the.capa

bilities

.of.each.indi

vidual

.agen

Reduc

tion

.of.compl

exity

.is.achi

eved

.by.(rec

ursively)

.deco

mposing

.a.compl

.task.into.a.numb

.of.

well-

dened

.subt

asks,

.each.of.whic

.bein

.solv

.by.a.spec

ic

.agen

.Howev

er,

.unli

.hard-

wired

coop

eration

.doma

ins,

.thes

.coal

itions

.or.team

.are.very.exi

ble.

.Depe

nding

.on.the.orga

nizational

stru

cture,

.agen

.may.auton

omously

.join.or.leav

.the.coal

ition

.when

ever

.they.feel.like

—provided

.thei

comm

itments

.are.ful

lled.

For

.agen

ts,

.in.orde

.to.be.able.to.coop

erate,

.ther

.is.a.need.for.comm

unication.

. e.most.impo

tant

.comm

unication

.lang

uages

.Know

ledge

.Quer

.and.Mani

pulation

.Lang

uage

.(KQM

.stan

dard-

ized

.by.Defe

nse

.Adva

nced

.Rese

arch

.Proje

cts

.Agen

.(DAR

PA)

.and.agen

.comm

unication

.lang

uage

Industrial Agent Technology 16-3

(ACL,aFoundation.for.Intelligent.Physical.Agents.[FIPA].standard,.see.[29]).are.based.on.so-called.

spe

ech

.act

.tha

.de

.a.set.of.per

formatives

.and.the

.mea

ning

.lik

.agr

ee,

.pro

pose,

.ref

use,

.req

uest,

que

ry-if.

.Whi

.the.per

formatives

.of.a.com

munication

.lan

guage

.are.sta

ndardized,

.its.act

ual

.con

tents

are.not

—it

.var

ies

.fro

.sys

tem

.to.sys

tem.

.A.pop

ular

.for

.of.ind

irect

.com

munication

.bet

ween

.age

nts

.can.

be.done.via.bla

ckboards

.on.whi

.age

nts

.can.pos

.the

.mes

sages

.and.oth

.age

nts

.can.rea

.and.rea

.to.

the

.Ano

ther

.kin

.of.com

munication

.is.con

tract

.net.pro

tocols,

.whi

.are.sim

ilar

.to.pro

cedures

.tha

may.lea

.to.a.con

tract

.(ta

.ann

ouncement,

.bid

ding,

.awa

rding,

.sol

ution

.pro

viding,

.and.rew

arding).

16.2.3 Ontologies

Especially.deliberative.agents.are.supposed.to.exhibit.some.intelligence..In.order.to.understand.what.

the

.are.doi

.the

.usu

ally

.mai

ntain

.an.int

ernal

.mod

.of.tha

.par

.of.the.rea

.wor

.in.whi

.the

.are.

wil

ling

.to.act

.If.di

erent

.age

nts

.are.mea

.to.wor

.toge

ther

.the

.nee

.to.hav

.a.com

mon

.und

erstand-

ing

.abo

.the.ove

rall

.pro

blem

.to.be.sol

ved.

.How

ever,

.sinc

.the

.age

nts

.may.be.spe

cialists

.in.di

erent

el

.the

.may.not.be.abl

.to.und

erstand

.eac

.oth

er,

.mai

nly

.bec

ause

.the

.may.not.spe

.the.sam

.“la

guage”

.(di

erent

.voc

abulary)

.or.bec

ause

.the

.is.onl

.an.ove

rlap

.bet

ween

.the.exp

ertise

.of.two.age

nts

but.not.a.com

plete

.one

.In.suc

.cas

es,

.onto

logies

.may.hel

.An.ont

ology

.(cf

.[30

])

.is.a.for

mal,

.pre

ferably

mac

hine

.pro

cessable

.tax

onomy

.of.an.und

erlying

.dom

ain.

.As.suc

.it.con

tains

.all.rel

evant

.ent

ities

.or.

con

cepts

.wit

hin

.tha

.dom

ain,

.the.und

erlying

.axi

oms

.and.pro

perties,

.the.rel

ationships

.bet

ween

.the

and.con

straints

.on.the

.log

ically

.con

sistent

.app

lication;

.tha

.is,.it.de

nes

.a.dom

ain

.of.kno

wledge

.or.

dis

course

.by.a.(sh

ared)

.voc

abulary

.and

.by.tha

.per

mits

.to.rea

son

.abo

.its.pro

perties.

.Onto

logies

.are.

typ

ically

.spe

cied

.in.lan

guages

.tha

.all

.abs

traction

.and.exp

ression

.of.sem

antics,

.e.g

.rs

t-order

.log

lan

guages.

16.2.4 Self-Organization and Emergence

A.self-organizing.system.is.a.system.running.without.central.control,.which.means.that.it.is.function-

ing

.wit

hout

.ext

ernal

.dir

ection,

.con

trol,

.man

ipulation,

.int

erference,

.pre

ssures,

.or.inv

olvement

.(cf

.[31

]).

It.con

stantly

.tri

.to.imp

rove

.its.spa

tial,

.tem

poral,

.and

/or

.fun

ctional

.str

ucture

.in.the.cou

rse

.of.tim

.by.

orga

nizing

.its.com

ponents

.in.a.mor

.sui

table

.way.in.ord

.to.imp

rove

.its.beh

avior,

.per

formance,

.and

/or

acc

uracy.

. e.dri

ving

.for

.beh

ind

.the

.ali

gnments

.is.to.ach

ieve

.its.ove

rall

.goa

l(s)

.as.ec

iently

.as.pos

sible

.(cf

.[32

]).

. is.imp

lies

.tha

.the.comb

ined

.coo

perative

.beh

aviors

.of.the.ind

ividual

.ent

ities

.lea

.to.an.

eme

rgent

.co

herent

.re

sult.

Emergence

.(cf

.[33

–35])

.can.be.see

.as.an.evo

lving

.pro

cess

.tha

.lea

.to.the.cre

ation

.of.nov

.coh

erent

str

uctures,

.pat

terns

.of.beh

avior,

.and.pro

perties

.oe

.but.not.onl

.dur

ing

.the.pro

cess

.of.self

-organization

in.com

plex

.sys

tems.

.It.is.the.app

earance

.of.a.coh

erent

.pat

tern

.tha

.ari

ses

.out.of.int

eractions

.amo

sim

pler

.obje

cts

.(ag

ents)

.but.is.mor

.tha

.jus

.the

.sum

med

.beh

avior.

. is.imp

lies

.tha

.nov

.str

uctures

and.pat

terns

.of.beh

avior

.are.nei

ther

.dir

ectly

.des

cribed

.by.nor.ing

rained

.in.the.de

ning

.pat

terns

.and.

rul

.tha

.for

.the.fou

ndation

.of.the.sys

tem.

. us

.the.fun

ctioning

.of.the.sys

tem

.can.onl

.be.und

er-

stood

.by.loo

king

.at.eac

.of.the.par

.in.the.con

text

.of.the.sys

tem

.as.a.who

le,

.how

ever,

.not.by.simp

tak

ing

.the.sys

tem

.apa

.and.loo

king

.at.the.par

ts.

.As.a.con

sequence

.eme

rgence

.can.nei

ther

.be.con

trolled

nor.pr

edicted

.no

.ma

naged.

Self-organization

.and.eme

rgence

.hav

.som

.simi

larities

.and.som

.di

erences.

. ey.are.bot

.sel

sustained

.sys

tems

.tha

.can.nei

ther

.be.dir

ectly

.con

trolled

.nor.man

ipulated

.in.any.way.fro

.the.out

side.

 ey.bot

.evo

lve

.ove

.tim

.how

ever,

.onl

.sel

f-organizing

.sys

tems

.nee

.to.exh

ibit

.a.goa

l-directed

.dev

el-

opment.

.Eme

rgent

.sys

tems

.con

sist

.of.a.lar

ger

.numb

.of.low

-level

.(mi

cro-)entities

.tha

.col

laborate

.in.

ord

.to.exh

ibit

.a.hig

her

.lev

.(ma

cro-)behavior.

. e.una

vailability

.of.one.or.mor

.of.tho

.low

.lev

ent

ities

.doe

.not.abr

ogate

.the.fun

ctioning

.of.the.sys

tem

.(gr

aceful

.deg

radation)

.alt

hough

.thi

.may.be.the.

cas

.in.se

lf-organizing

.sy

stems.

16-4 Industrial Communication Systems

16.2.5 the Holonic Paradigm

One.of.the.rst.concepts.attempting.to.bring.agents.and.manufacturing.derived.from.the.holonic.para-

digm

.tha

.was.pro

posed

.by.Koe

stler

.(cf

.[2]

.So-

called

.hol

ons

.are.the.und

erlying

.con

cept

.of.suc

.a.

desi

gn.

.In.soc

ial

.and.bio

logical

.org

anizations,

.hol

ons

.rep

resent

.basi

.uni

ts.

.Basi

.her

.mea

.obs

erved

fro

.the.cur

rent

.lev

.of.abs

traction

.of.an.org

anization.

.It.doe

.not.mea

.tha

.a.uni

.can

not

.be.fur

ther

sub

divided

.whe

.ana

lyzed

.on.the.nex

.low

.lev

.of.abs

traction.

. us

.hol

ons

.may.con

sist

.of.sub

ordi-

nate

.hol

ons,

.whi

ch,

.in.tur

.mea

.tha

.the

.may.be.par

.of.a.lar

ger

.who

le.

.Alto

gether,

.the

.may.for

.a.

tre

e-like

.hie

rarchy,

.cal

led

.hol

archy.

.Its.memb

ers

.coo

perate

.in.ord

.to.ach

ieve

.a.com

plex

.goa

.or.obje

tive.

.A.hol

archy

.may.be.for

med

.in.an.ad.hoc.way.and.may.onl

.exi

.tem

porarily

.unt

.its.ove

rall

.goa

is.ach

ieved.

. e.hol

archy

.de

nes

.the.basi

.rul

.of.coo

peration

.bet

ween

.hol

ons.

. e.sta

bility

.of.hol

ons

and.ho

larchies

.st

ems

.fr

.th

.fa

.th

.ho

lons

.ar

.se

lf-sustained

.un

its

.th

.ha

.a.gi

ven

.de

gree

.of.in

de-

pendence.

. ey.han

dle

.cir

cumstances

.and.pro

blems

.on.the

.par

ticular

.lev

.of.exi

stence

.wit

hout

.nee

of.sup

port

.by.hig

her

.lev

.hol

ons.

.Dep

ending

.on.the.und

erlying

.org

anizational

.str

ucture,

.hol

ons

.may.

rec

eive

.in

structions

.fr

.an

.ma

.be.co

ntrolled

.to.a.ce

rtain

.ex

tent

.by.hi

gher

.le

vel

.ho

lons.

.hol

archy

.tha

.is.not.par

.of.an.enc

ompassing

.hol

archy

.is.a.hol

onic system/organization.

. e.str

ength

of.a.hol

onic

.org

anization

.is.tha

.it.ena

bles

.the.con

struction

.of.com

plex

.sys

tems

.tha

.are.non

etheless

ec

ient

.in.the.use.of.res

ources,

.hig

hly

.resi

lient

.to.dis

turbances

.(bo

.int

ernal

.and.ext

ernal),

.and.hig

hly

ada

ptable

.to.ch

anges

.in.th

eir

.en

vironment.

16.2.6 Holonic Multi-agent Systems

A Holonic MASS,.as.a.special.and.important.type.especially.for.industrial.MASS,.combines.the.con-

cepts

.of.hol

onic

.wit

.the.con

cept

.of.MAS

.It.con

sists

.of.aut

onomous

.age

nts

.wit

.hol

onic

.pro

perties

tha

.rec

ursively

.gro

.tog

ether

.to.for

.hol

ons

.and

.by.thi

.hol

archies

.[3]

.lit

erature,

.thr

.mai

.arc

hitectures

.for.hol

onic

.MAS.wer

.pro

posed:

.the.hie

rarchical,

.the.fed

eration,

.and.the.auto

nomous

.age

nts

.app

roach.

.At.the.one.ext

reme

.of.the.spe

ctrum,

.the.hie

rarchical

app

roach,

.age

nts

.com

pletely

.giv

.up.the

.auto

nomy.

.Fro

.the.out

side

.it.may.eve

.loo

.lik

.the

.mer

into.a.new.age

nt.

. e.oth

.side.of.the.spe

ctrum,

.the.aut

onomous agents

.app

roach,

.is.de

ned

.by.a.loo

cou

pling

.of.the.age

nts.

. ey.sha

.a.com

mon

.goa

.for.som

.tim

.bef

ore

.sep

arating

.to.con

tinue

.to.wor

on.the

.own.goa

ls.

.Dur

ing

.the.col

laboration,

.all.age

nts

.are.equ

al.

. us

.auto

nomy

.is.not.res

tricted.

.In.

bet

ween

.tho

.ext

remes,

.all.oth

.kin

.of.ass

ociations

.are.pos

sible

.(fed

eration

.app

roach).

. is.mai

nly

mea

.tha

.age

nts

.giv

.up.par

.of.the

.auto

nomy,

.tha

.is,.tha

.the

.may.dep

end

.on.the

.sup

erordinate

age

.wit

.res

pect

.to.som

.asp

ects.

.Wha

.asp

ects

.exa

ctly

.are.giv

.up.is.eit

her

.sub

ject

.to.neg

otiation

bet

ween

.the.age

nts

.par

ticipating

.in.the.hol

.or.is.a.dir

ective

.fro

.a.sup

erordinate

.age

.alo

.the.hie

archy.

.Ho

wever,

.it.ev

olves

.in.th

.in

teraction

.pr

ocess

.an

.ca

nnot

.be.pr

edened

.by.th

.de

signer

.(c

.[4

]).

Holonic

.sys

tems

.comb

ine

.top-

down

.org

anizational

.str

ucture

.wit

.dec

entralized

.con

trol.

. e.lat

ter

rea

lizes

.a.bot

tom-up

.per

spective.

.Alt

hough

.it.is.pos

sible

.to.org

anize

.a.fed

erated

.hol

onic

.str

ucture

.in.a.

com

pletely

.dec

entralized

.mann

er,

.it.is.mor

.ee

ctive

.to.use.an.ind

ividual

.age

.to.rep

resent

.a.hol

.(cf

.[5]

Ref

.[6].ide

nties

.thr

.pos

sible

.app

roaches

.for.fed

eration

.arc

hitectures:

.fac

ilitators,

.bro

kers,

.and.med

ia-

tors.

.In.the.faci

litator

.app

roach,

.com

munication

.bet

ween

.the.age

nts

.of.the.fed

eration

.tak

.pla

.alw

ays

through.an.interface.called.a.facilitator..A.facilitator.is.responsible.only.for.a.designated.group.of.agents..

 e.bro

ker

.app

roach

.is.simi

lar

.to.the.fac

ilitator

.app

roach.

.How

ever,

.her

.eac

.age

.of.the.fed

eration

may.con

tact

.eac

.bro

ker

.in.the.sam

.fed

eration

.in.ord

.to.nd.app

ropriate

.ser

vice

.age

nts

.to.com

plete

the.de

sired

.ta

sk.

.the.med

iator

.app

roach,

.the.med

iator

.age

.exe

cutes

.the.rol

.of.a.sys

tem

.coo

rdinator.

.It.pro

motes

and.sup

ervises

.coo

peration

.amo

.int

elligent

.age

nts.

.It.may.eve

.lea

.by.thi

.fro

.the.beh

avior

.of.the.

inv

olved

.age

nts.

.In.eve

.non

leaf

.hol

on,

.exa

ctly

.one.(su

b-)agent

.act

.as.a.med

iator,

.tha

.is,.it.rep

resents

the.interface.between.the.agents.in.the.holon.(inbound duties).and.those.outside.of.the.holon.(outbound

duties).

. e.inb

ound

.dut

ies

.of.the.med

iator

.can.ran

.fro

.pur

.adm

inistrative

.tas

.to.the.aut

hority

.to.

Industrial Agent Technology 16-5

issue.directives.to.the.subordinate.agents.of.the.holon.. us,.it.may.broker.and/or.supervise.the.interactions.

bet

ween

.the.sub

holons

.of.tha

.hol

on.

. e.out

bound

.int

erface

.of.a.med

iator

.imp

lements

.the

interaction

of.the.hol

.wit

.the.res

.of.the.age

.soc

iety.

. e.med

iator

.can.pla

.and.neg

otiate

.for.the.hol

.on.the.

basi

.of.th

.co

mmon

.pl

ans

.an

.go

als

.of.it

.un

derlying

.ag

ents.

All

.thi

.thr

.kin

.of.fed

eration

.arc

hitectures

.per

mit

.to.coo

rdinate

.the.sys

tem

.act

ivity

.via.fac

ilita-

tion

.as.a.me

ans

.of.re

ducing

.ov

erheads,

.en

suring

.st

ability,

.an

.pr

oviding

.sc

alability

.(c

.[6

]).

16.2.7 How agents Can Be Implemented

In.order.to.implement.communities.of.agents,.several.layers.need.to.be.realized.. e.lowest.layers.are.

the.net

work

.and.com

munication

.lay

ers

.tha

.all

.age

nts

.to.abs

tract

.fro

.the

.exa

.phy

sical

.loc

ation

and.to.exc

hange

.mes

sages.

.On.the.nex

.lev

el,

.the.act

ual

.age

.inf

rastructure

.nee

.to.be.pro

vided,

.whi

mea

.tha

.usu

ally

.a.numb

.of.di

erent

.age

.typ

.nee

.to.be.pro

vided

.(th

.act

ual

.age

nts,

.bro

ker

age

nts,

.whi

.and.yel

low

.pag

es,

.etc

.as.wel

.as.onto

logies

.and.age

.lif

e-cycle

.man

agement

.ser

vices.

.rs

.lay

ers

.can.be.see

.as.syn

tactical

.lay

ers

.in.the.sen

.tha

.the

.do.not.re

ect

.the.act

ual

.int

el-

ligence

.of.th

.sy

stem—they

.ju

.pr

ovide

.th

.ne

cessary

.fo

undation

.fo

.a.MA

.to.fu

nction.

.Es

pecially

.fo

the

.“sy

ntactical”

.lay

ers,

.a.sign

icant

.numb

.of.com

mercial

.and.aca

demic

.age

.con

struction

.tool

are.ava

ilable,

.pro

viding

.a.var

iety

.of.ser

vices

.and.age

.mod

els,

.the.di

erences

.re

ecting

.the.phi

loso-

phy

.and.the.tar

get

.pro

blems

.env

isioned

.by.the.pla

tform

.dev

elopers.

.A.ref

erence

.for.a.bro

.numb

.of.

age

.con

struction

.tool

.can.be.fou

.on.the.Age

ntBuilder

.Web.site.(ht

tp://www.agentbuilder.com/

AgentTools)

.an

.in.[2

8].

Java

.Age

.DEve

lopment

.Fra

mework

.(JA

DE;

.cf..[27

])

.is.per

haps

.the.bes

t-known

.FIP

.(cf

.[29

])

com

pliant

.pla

tform

.to.dev

elop

.age

nt-based

.sol

utions.

.It.pro

vides

.the.man

datory

.com

ponents

.de

ned

.by.

FIP

.to.man

age

.the.age

nt’s

.inf

rastructure,

.whi

.are.the.age

.com

munication

.cha

nnel

.(AC

C),

.the.age

man

agement

.sys

tem

.(AM

S),

.and.the.dir

ectory

.fac

ilitator

.(DF

. e.AMS.age

.pro

vides

.whi

.pag

.and.

age

.lif

e-cycle

.man

agement

.ser

vices,

.mai

ntaining

.a.dir

ectory

.of.age

.ide

ntiers

.and.sta

tes,

.and.the.

DF.pro

vides

.yel

low

.pag

.ser

vices

.and.the.cap

ability

.of.fed

eration

.wit

hin

.oth

.DFs.on.oth

.exi

sting

pla

tforms.

. e.com

munication

.amo

.age

nts

.is.don

.via.mes

sage

.pas

sing.

. e.mes

sages

.are.enc

oded

using.the.FIPA-ACL.and.their.content.is.formatted.according.to.the.FIPA-SL.(Semantic.Language),.both.

spe

cied

.by.FIP

.Onto

logies

.sho

uld

.be.use

.to.sup

port

.a.com

mon

.und

erstanding

.of.the.con

cepts

.of.

the

.kno

wledge

.dom

ain,

.pas

sed

.in.the.mes

sages’

.con

tent.

.Onto

logies

.can.be.desi

gned

.usin

.a.kno

wl-

edge

.rep

resentation

.tool

.suc

.as.Pro

tégé

.(se

.htt

p://protege.stanford.edu/),

.and.the

.tra

nslated

.into.

Jav

.cla

sses

.acc

ording

.to.the.JAD

.gui

delines

.tha

.fol

low

.the.FIP

.Onto

logy

.Ser

vice

.Rec

ommendations

spe

cications

.(c

.[2

9]).

JADE

.als

.pro

vides

.a.set.of.gra

phical

.tool

.tha

.all

ows

.sup

ervising

.the.sta

tus

.of.age

nts

.and.sup

porting

the.deb

ugging

.pha

.whi

.are.usu

ally

.qui

.com

plex

.tas

.in.dis

tributed

.sys

tems.

.Fig

ure

.16.

.ill

ustrates

FIGURE 16.1 Graphical.user.interfaces.of.the.Remote.Monitoring.and.Snier.agents.

16-6 Industrial Communication Systems

the.graphical.interface.of.two.tools.provided.by.JADE,.namely.the.Remote.Management.and.the.

Snif

fer

.agen

ts.

.The.last.one.is.a.debu

gging

.tool.that.allo

.trac

king

.mess

ages

.exch

anged

.in.a.JADE.

envi

ronment

.usin

.a.not

ation

.simi

lar

.to.Uni

ed

.Mod

eling

.Lan

guage

.(UM

.seq

uence

.dia

grams.

Jadex,

.as.an.exte

nsion

.of.Jade

.is.one.of.the.few.exam

ples

.of.a.plat

form

.that.also.prov

ides

.supp

ort

.for.

the.reas

oning

.capa

bilities

.of.agen

.(cf..http

://jadex.informatik.uni-hamburg.de/).

.Its.reas

oning

.engi

impl

ements

.the.Bel

ief-Desire-Intention

.mod

el.

16.3 agents and Multi-agent Systems in Industry

Classical.centralized.solutions.perform.well.in.static.industrial.environments.in.which.neither.the.phys-

ical

.layo

.of.the.plan

.nor.the.prod

uct

.port

folio

.vari

es.

. us,.thei

.rigi

.cont

rol

.arch

itecture

.does.not.

have.to.be.modi

ed,

.for.exam

ple,

.to.deal.with.new.unkn

own

.situa

tions.

.Mode

.indu

stries,

.howe

ver,

pose.die

rent

.chal

lenges

.to.whic

.the.cent

ralized

.appr

oach

.cann

.resp

ond.

. e.main.ones.are.ever.

chan

ging,

.unpr

edictable

.orde

.ows

.whic

.in.orde

.to.be.ful

lled,

.need.a.dyna

mic

.shop.oor

.Both.

requ

ire

.more.exi

ble

.appr

oaches

.that.can.be.natu

rally

.prov

ided

.by.MAS..In.fact

.MAS.are.desig

ned

as.a.grou

.of.auton

omous

.inte

racting

.unit

.that.purs

.(dir

ectly

.or.indi

rectly)

.a.comm

.goal

. is.is.

exac

tly

.wha

.mod

ern

.man

ufacturing

.sys

tems

.nee

Altogether,

.a.MAS

-based

.man

ufacturing

.con

trol

.has.to.sat

isfy

.the.fol

lowing

.cha

racteristics:

•

. Reliability and robustness:. e.system.must.respond.properly.to.disturbances.

•

. Adap

tability to changes:

.A.new.physi

cal

.layo

ut,

.chan

ges

.on.prod

uct

.desig

ns,

.exte

nsion

.of.the.

prod

uct

.port

folio,

.dema

.chan

ges,

.and.othe

.nove

lties

.shou

.not.prev

ent

.the.MAS.from.carr

ing

.out.its.tas

•

. Scal

ability:

.It.shou

.oer.an.easy.coup

ling

.of.new.part

.or.syst

ems

.and.shou

.easil

.allo

.inte

grating

.new.autom

ation

.devi

ces

.or.othe

.info

rmation

.syst

ems

.(e.g

.the.sche

duling

.syst

.with.

the.pla

.exe

cution,

.the.sup

ply

.cha

.man

ager,

.and.so.on)

•

. Easy

upgradeability to new technologies:

.In.case.of.a.new.versi

.of.plat

forms,

.proto

cols,

.or.bran

new.tec

hnologies,

.the.sys

tem

.sho

uld

.oe

.an.eas

.upg

rade

.pro

cedure.

•

. Real

-time response:

.It.sho

uld

.be.abl

.to.rea

.in.rea

.tim

.to.dis

turbances

.or.cha

nges.

•

. Port

ability and platform independence:

. e.MAS.shou

.not.depe

.on.a.cert

ain

.plat

form

.but.be.

able.to.wor

.und

.di

erent

.pla

tforms.

16.4 application areas

Responding.to.the.modern.trends.in.automation.such.as.mass.customization.and.dynamic.congura-

tion,

.over.the.last.deca

.dist

ributed

.syst

ems

.foun

.its.plac

.in.seve

ral

.indu

strial

.area

.like.manu

fac-

turing

.cont

rol,

.air.tra

.cont

rol,

.prod

uction

.plan

ning,

.logi

stics,

.supp

.chai

.mana

gement,

.or.tra

and.tran

sportation.

.Some.of.them.are.combi

ned

.unde

.the.umbre

lla

.of.the.plan

.autom

ation

.pyra

mid:

ente

rprise

.reso

urce

.plan

ning

.(ERP

.manu

facturing

.exec

ution

.syst

ems

.(MES

.and.eld.cont

rol.

.Due.to.

the.rigi

.natu

.of.the.ERP.syst

ems

.as.well.as.mach

ine-oriented

.eld.leve

ls,

.dist

ributed

.MESs.are.the.

ones.whe

.ind

ustrial

.age

nts

.are.mos

.wid

ely

.use

One

. of. the. best

-known

. arch

itectures

. for. dist

ributed

. manu

facturing

. exec

ution

. is. the. Prod

uct–

Resource–Order–Sta

.Arch

itecture

.(PRO

SA).

.It.is.a.holo

nic

.refe

rence

.arch

itecture

.base

.on.thre

.type

of.basic.holo

ns:

.prod

uct,

.orde

.and.reso

urce

.(cf..[24]

.Addi

tionally,

.typi

cally

.to.all.dist

ributed

.arch

tectures,

.the.nece

ssity

.to.obse

rve

.and.cont

rol

.the.shop.oor.and.to.prov

ide

.an.inte

rface

.to.the.ente

prise

.leve

.syst

ems

.evol

ved

.into.the.crea

tion

.of.a.four

.spec

ial

.type.of.comp

onents.

.In.PROS

.it.is.the.

sta.holo

.whic

.assis

.and.supe

rvises

.the.basic.holo

ns.

.Anot

her

.arch

itecture

.base

.on.the.holo

nic

manufacturing.systems.(HMS).concept—MetaMorph.and.its.follow-up.MetaMorph.II—uses.a.media-

tor

.cent

ric

.fede

ration

.arch

itecture

.for.inte

lligent

.manu

facturing

.(cf..[37]

.It.uses.a.team.medi

ator

.that.

prov

ides

.comm

unication

.mech

anisms

.to.die

rent

.syst

ems

.and.comp

onents

.and.take

.over.some.of.the.

Industrial Agent Technology 16-7

functionalities.of.the.MES..Generally.speaking,.a.mediator.is.a.supervisory.agent.that.temporarily.or.

permanently.takes.a.role.of.decision.making.and.combines.certain.resources.into.a.virtual.cluster.to.

solve.certain.problems..However,.please.keep.in.mind.that.MetaMorph.is.meant.to.be.an.integration.

tool.for.other.systems.rather.than.a.complete.solution.

Similar

.agent-based.architectures.with.slightly.dierent.implementation.focuses.are.Autonomous.Agents.

at.Rock.Island.Arsenal.(AARIA).(cf..[9]),.manufacturing.control.systems.capable.of.managing.production.

change.and.disturbances.(MASCADA).(cf..[26]),.and.ADAptive.holonic.COntrol.aRchitecture.(ADACOR).

for.distributed.manufacturing.systems.(cf..[38])..Architectures.like.Advanced.Fractal.Companies.Use.

Information.Supply.Chain.(ADRENALIN,.cf..[25]).consider.agent-based.resource.brokering.functionality.

enabling.a.decentralized.manufacturing.order.navigation.based.on.local.optimization.strategies.

.contrast.to.that,.Plant.Automation.Based.on.Distributed.Systems.(PABADIS,.cf..http://www.uni-

magdeburg.de/iaf/cvs/pabadis/,

.[8]).and.its.follow-up.PABADIS’PROMISE.(PABADIS-based.Product-

Oriented

.Manufacturing.Systems.for.Recongurable.Enterprises,.cf..http://www.pabadis-promise.org/).

provide.agent-based.architectures.that.cover.the.whole.automation.pyramid.but.with.the.primary.focus.

on.distributed.MES.(cf..[25]).

Due

.to.the.fact.that.dierent.MES.solutions.usually.focus.on.a.specic.area.of.implementation,.for.

example,.scheduling,.customer.support,.resource.utilization,.or.system.integration,.they.oen.cannot.be.

compared..For.this.article,.the.focus.is.set.on.systems.that.cover.the.complete.manufacturing.process,.

that.is,.on.systems.that.cover.the.vertical.integration.of.all.layers.of.the.automation.pyramid.from.the.

ERP.down.to.the.eld.control.level..More.specically,.the.focus.is.on.the.HMS-based.system.PROSA.

(and.some.aspects.of.MetaMorph).and.on.the.MAS-based.systems.PABADIS.and.PABADIS’PROMISE.

Although

.the.above-mentioned.solutions.dier.in.their.approaches,.they.exhibit.in.their.concepts.

common.patterns.in.approaching.MES.implementations.. e.main.pattern.is.the.division.of.decision.

making.into.two.main.entities:.orders.and.resources.. e.rst.one.represents.the.customers.and.the.

upper.layers.of.systems.that.provide.a.MES.with.the.orders.on.what.to.do.(in.practice.a.set.of.steps.how.

to.produce.a.product).that.are.then.distributed.into.the.agent.community..While.dierent.solutions.dif-

fer

.in.the.order.handling.concepts,.the.second.entity—representing.the.resources.on.the.shop.oor.that.

execute.particular.operations—has.similar.characteristics.in.all.solutions.

.addition.to.the.main.patterns,.all.solutions.provide.supervising.entities.that.show.how.far.each.

concept.deviated.from.conventional.centralized.approaches.(see.Figure.16.2)..And.last.but.not.least,.in.

order.to.glue.the.agents.together,.each.architecture.provides.certain.brokering.functionality—as.a.central-

ized

.entity.or.via.a.hierarchy.of.objects,.either.static.or.dynamic.

Enterprise resource planning

Stu holon

Order holon

Product

holon

Resource

holon

PROSA

Residential

agent

Product

agent

Plant management

agent

Look up

service

PABADIS

PROMISE

Field control

Resource

agent

Order agent

supervisor

Resource agent

supervisor

Ability

broker

FIGURE 16.2 General.patterns.in.distributed.MES.

16-8 Industrial Communication Systems

 e.following. analysis. of.solutions.is.mainly. based.on.resource.and.order.handling. approaches..

PRO

.im

plements

.th

.de.fa

cto

.st

ate

.of.th

.ar

. e.ot

her

.tw

.ar

.ev

olutions

.of.th

.PA

BADIS

.ar

chitec-

ture

.th

.di

er

.fr

.th

.HM

.co

ncept

.in.te

rms

.of.opt

imization

.ve

rsus

.e

xibility

.(c

.[8

]).

16.4.1 resource Handling

Resources.in.HMS.are.represented.by.the.resource.holons,.which.are.responsible.for.machine.level.rep-

resentations.

. e.res

ource

.hol

.con

sists

.of.a.phy

sical

.par

.nam

ely

.a.pro

duction

.res

ource

.in.HMS

and.an.inf

ormation

.pro

cessing

.par

.tha

.con

trols

.the.res

ource.

. is.sec

ond

.par

.hol

.the.met

hods

.to.

all

ocate

.the.pro

duction

.res

ources,

.and.the.kno

wledge

.and.pro

cedures

.to.org

anize,

.use

.and.con

trol

.the.

phy

sical

.pr

oduction

.re

sources

.to.dr

ive

.pr

oduction.

.ter

.of.PAB

ADIS,

.the.res

ource

.hol

.is.a.coo

perative

.man

ufacturing

.uni

.(CM

.tha

.is.a.bui

ld-

ing

.uni

.of.the.sho

.oo

. e.inf

ormation

.pro

cessing

.par

.of.the.res

ource

.hol

.per

fectly

.ts.the.con

cept

.of.the.res

ource

.age

.or.a.resi

dential

.age

.(RA

)

.as.it.is.cal

led

.in.PAB

ADIS,

.whi

.rep

resented

.the.

CMU.an

.pa

rtly

.co

ntrols

.a.ce

rtain

.pr

oduction

.or.lo

gical

.op

eration—so-called

.fu

nction.

.mai

.di

erences

.bet

ween

.HMS.and.PAB

ADIS

.are.(1).in.PAB

ADIS

.the.RA.is.mai

nly

.an.int

erface

bet

ween

.the.age

.com

munity

.and.CMU.(ma

chine,

.fun

ction

.uni

.and.(2).RA.has.a.gen

eric

.int

erface

ena

bling

.the.int

egration

.of.arb

itrary

.mac

hine

.har

dware.

.In.HMS

.the.res

ource

.hol

.is.mor

.tha

.thi

int

erface.

.It.is.rat

her

.a.CMU

-RA

.ana

log,

.whe

.the.who

.fun

ctionality

.of.the.CMU.(fu

nction,

.con

trol

lev

el,

.age

.com

munication

.lev

el)

.is.imp

lemented.

.PAB

ADIS

.dis

tinguishes

.the.sta

ndard

.(lo

gical)

.par

of.the.con

trol

.lev

el,

.whi

.can.be.use

.for.eac

.CMU

.fro

.the.“ma

chine”-specic

.par

.whi

.has.to.be.

imp

lemented

.by.the.cus

tomer

.of.the.sys

tem.

. is.mak

.the.sys

tem

.mor

.ex

ible

.and.enc

apsulates

.the.

MAS.fro

.the.con

trol

.lev

el.

. at.mak

.the.add

ing

.of.new.fun

ctionality

.easi

er,

.bec

ause

.the.cus

tomer

onl

.nee

.to.add.a.spe

cic

.pla

.dep

endent

.res

ource

.to.the.sys

tem

.and.doe

.not.nee

.to.tak

.into.

acc

ount

.the.int

eroperability

.of.the.new.com

ponent

.wit

.the.exi

sting

.con

trol

.sys

tem.

.Inc

orporation

.into.

the.system.is.provided.by.the.generic.RA,.which.is.capable.of.communicating.within.the.system.

Hierarchy

.of.res

ources

.is.a.key.dis

tinction

.poi

.of.dis

tributed

.con

cepts.

. e.PRO

.arc

hitecture

pro

vides

.str

ict

.con

trol

.of.res

ources

.ove

.eac

.oth

er.

.It.imp

roves

.res

ource

.uti

lization,

.but.mak

.it.com

plex

.to.imp

lement

.an.act

ual

.sys

tem

.and.has.pro

blems

.in.ada

pting

.to.a.cha

nging

.env

ironment.

.Sys

tems

lik

.PAB

ADIS,

.how

ever,

.tre

.res

ources

.tota

lly

.ind

ependent

.fro

.eac

.oth

er.

.PAB

ADIS

.res

ource

.age

nts

do.not.eve

.com

municate

.wit

.eac

.oth

er.

. is.mak

.sch

eduling

.or.ord

.han

dling

.ind

ependent

.fro

the.sh

.o

.co

nguration

.an

.hi

erarchy

.of.re

sources.

.PAB

ADIS’PROMISE

.app

roach

.of.res

ource

.age

nts

..is.simi

lar

.to.the.Met

aMorph

.app

roach

.in.

ter

.of.sch

eduling

.by.usin

.tem

porary

.clu

stering

.of.rel

ated

.res

ources

.and.pro

vides

.a.pos

sibility

.for.the.

res

ource

.age

nts

.to.all

ocate

.oth

.res

ources

.for.cer

tain

.tas

ks.

.In.com

parison

.to.PRO

SA,

.thi

.app

roach

imp

roves

.the. ex

ibility

.of.the. sho

.oo

.bec

ause

.the

.is.no. dir

ect

.sta

tic

.con

nection

.bet

ween

.two.

res

ources,

.and.opti

mizes

.sys

tem

.per

formance

.by.inc

luding

.res

ource

.age

nts

.into.the.dec

ision-making

pro

cess

.du

ring

.sc

heduling.

16.4.2 Order Handling

Orders.are.represented.by.the.order.holon.in.PROSA,.product.agent.in.PABADIS,.and.order.agent.(OA).

in.PAB

ADIS’PROMISE.

.In.add

ition,

.PRO

.dis

tinguishes

.bet

ween

.the.ord

.man

agement

.ent

ity

.(or

der

hol

on)

.an

.pr

oduct

.sp

ecication

.ma

nager

.(p

roduct

.ho

lon).

.PAB

ADIS

.pro

duct

.age

.is.an.ins

tance

.tha

.man

ages

.the.who

.pro

duction

.pro

cess

.of.a.sing

.wor

pie

ce.

.It.bas

.its.dec

isions,

.act

ions,

.and.kno

wledge

.on.the.so-

called

.wor

.ord

.(WO

.whi

.giv

.a.

ful

.spe

cication

.of.the.pro

duction

.act

ivities,

.reg

arding

.the.tas

ks,

.whi

.hav

.to.be.ful

lled

.in.ord

.to.

com

plete

.the.pro

duct.

.At.the.sam

.tim

.the.WO.doe

.not.assi

.exa

.mac

hines;

.ins

tead

.it.des

cribes

.the.

fun

ction,

.whi

.has.to.be.use

.to.do.tha

. is.pri

nciple

.giv

.the.pro

duct

.age

.the.fre

edom

.to.dec

ide

wha

.ma

chine

.to.us

.an

.in

troduces

.a.po

ssibility

.to.ch

ange

.th

.ma

chine

.du

ring

.th

.ex

ecution.

Industrial Agent Technology 16-9

An.order.holon.has.simpler.logic.but.is.more.complex.in.hierarchy,.meaning.that.it.can.divide.a.

giv

.ord

.int

.sub

orders

.tha

.are.con

trolled

.by.a.par

ent

.hol

.of.a.hig

her

.lay

er.

.It.mai

nly

.rep

resents

the.cus

tomer

.req

uest,

.whe

.all.req

uirements

.on.the.pro

duct

.are.de

ned.

.It.has.an.adv

antage

.in.mas

pro

duction

.bec

ause

.an.ord

.hol

.is.not.att

ached

.to.a.sin

gle

.wor

.pie

ce.

.An.ord

.hol

.doe

.nei

ther

.dea

.wit

.sch

eduling

.tas

.nor.res

ource

.all

ocations

.bec

ause

.it.sim

ply

.doe

.not.hav

.kno

wledge

abo

.the.phy

sical

.lay

out

.of.the.pla

.and.the.pro

duct

.spe

cication.

. e.lat

ter,

.ins

tead,

.is.man

aged

by.a.sep

arate

.ent

ity—the

.pro

duct

.hol

on.

.It.is.not

hing

.mor

.tha

.a.“re

cipe”

.for.a.par

ticular

.typ

.of.

pro

duct.

.A.dis

advantage

.of.thi

.sol

ution

.is.the.lac

.of.cus

tomization

.of.pro

ducts—a

.maj

.rea

son

.for.

dis

tributed

.aut

omation

.sys

tems.

Similar

. to. the. oth

. asp

ects

. of. gen

eral

. pat

terns

. the

. is. alw

ays

. a. bal

ance

. bet

ween

. opti

mization

and.ex

ibility

.and.hie

rarchy

.of.ord

ers

.and.man

agement

.ent

ities

.rel

ated

.to.the

.Whi

.PRO

.org

nizes

.ord

ers

.in.a.str

ong

.hie

rarchy

.and.PAB

ADIS

.min

imizes

.int

erdependencies

.bet

ween

.the.ord

ers,

PAB

ADIS’PROMISE

.pro

vides

.wha

.can.be.cal

led

.an.“im

plicit

.hie

rarchy.”

. er

.is.no.str

ict

.dec

ision

mak

ing

.lik

.in.PRO

SA.

. e.org

anization

.is.imp

lemented

.via.the.str

ucture

.of.the.pro

duction

.ord

.tha

re

ects

.int

erdependencies

.bet

ween

.di

erent

.pro

duction

.ste

.(ca

lled

.pro

cess

.seg

ments)

.via.so-

called

nod

. ope

rators.

. e. mec

hanism

. of. ord

. dec

omposition

. dev

eloped

. in. PAB

ADIS’PROMISE

. all

ows

assi

gning

.auto

nomously

.act

ing

.OAs.to.eac

.pro

cess

.seg

ment.

.It.is.simi

lar

.to.the.PAB

ADIS

.app

roach

wit

.the.di

erence

.tha

.hig

her

.lev

.OAs.can.in

uence

.the.age

nts

.res

ponsible

.for.sub

tasks

.exe

cution.

For.ins

tance,

.the.OA.tha

.is.res

ponsible

.for.the.ass

embly

.of.a.car.nee

.an.eng

ine

.to.be.pro

duced

.bef

ore

performing.its.tasks.. erefore,.it.assigns.the.deadlines.for.the.engine.agent,.so.the.engine.is.delivered.

in.ti

me.

Another

.iss

.is.the.beh

avior

.of.age

nts

.inv

olved

.in.the.pro

duction.

.PRO

.wit

.its.hie

rarchy

.doe

not.nee

.to.pay.att

ention

.to.thi

.topi

.but.in.mor

.dis

tributed

.sys

tems

.suc

.as.PAB

ADIS

.it.has.hig

her

imp

ortance

.bec

ause

.it.can.inc

rease

.ec

iency

.and.per

formance.

.Pro

duct

.age

nts

.in.PAB

ADIS

.are.sel

ish

.in.nat

ure.

.As.a.res

ult,

.the.sys

tem

.pro

vides

.low

.opti

mization

.of.the.ord

.exe

cution

.com

pared

.to.

PRO

SA,

.but.muc

.mor

.ex

ibility.

.PAB

ADIS’PROMISE

.aim

.to.comb

ine

.bot

.ben

ets

.by.int

roducing

ben

evolent

.beh

avior

.of.age

nts;

.tha

.is,.whi

.age

nts

.rel

.on.a.cer

tain

.set.of.rul

.tha

.ben

et

.the

.loc

goa

.(e.

g.,

.ni

shing

.assi

gned

.pro

cess

.seg

ments

.on.tim

.the

.may

.nev

ertheless,

.sac

rice

.the

.goa

in.ord

.to.hel

.str

uggling

.age

nts

.to.mee

.the

.dea

dlines.

. is.app

roach

.imp

roves

.opti

mization

.con

siderably

.wit

hout

.red

ucing

.ex

ibility

.sub

stantially,

.thu

.gua

ranteeing

.hig

her

.ove

rall

.per

formance

.and.

sta

bility

.of.th

.sy

stem.

16.4.3 Comparison

From.a. general. point. of. view. PABADIS’PROMISE,. PROSA,. and. PABADIS. can. be. summarized. as.

fol

lows:

•

. Aut

onomy and aggregation:

.On.the.one.han

.PRO

.lac

.ex

ibility

.due.to.the.dir

ect

.con

trol

ove

.agg

regated

.ent

ities

.and

.on.the.oth

.han

.PAB

ADIS

.lac

.ec

iency

.bec

ause

.of.tota

.dis

tribution.

.PAB

ADIS’PROMISE

.de

nes

.pro

duction

.ord

.dec

omposition

.tha

.pro

vides

.rul

.for.

con

trolling

.au

tonomous

.en

tities

.wi

thout

.dr

amatically

.re

ducing

.e

xibility.

•

. Coo

peration and hierarchy:

.Whe

.PRO

.has.exp

licit

.hie

rarchy

.tha

.cau

ses

.rig

idness

.of.ord

cha

nges,

.PAB

ADIS

.pro

vides

.no.hie

rarchy

.tha

.imp

lies

.ove

rhead

.in.the.man

agement

.of.com

plex

pro

ducts.

. PAB

ADIS’PROMISE

. oe

. an. imp

licit

. hie

rarchy

. (pr

oduction

. ord

. dec

omposition;

exible.structure.of.orders;.dynamic.control.of.resources.by.resources).that.nds.the.balance.

bet

ween

.th

.r

.ap

proaches.

•

. Dec

ision making:

.Whi

.dec

ision-making

.in.PRO

.is.cen

tralized,

.mea

ning

.the

.is.one.con

trol

ent

ity

.per.fun

ctionality,

.PAB

ADIS

.sup

ports

.com

pletely

.dis

tributed

.dec

ision-making

.mec

hanism.

PAB

ADIS’PROMISE

.pro

vides

.a.sem

i-distributed

.app

roach

.bas

.on.clu

stering

.of.res

ources

.at.the.

sho

.o

.an

.pr

oduction

.or

der

.de

composition

.at.th

.ME

.la

yer.

16-10 Industrial Communication Systems

•. Data interoperability:.In.PROSA,.one.has.to.deal.with.implementation.specic.data.that.may.

cau

.di

culties

.dur

ing

.sys

tem

.ins

tallation.

.In.PAB

ADIS,

.dat

.vir

tually

.doe

.not.hav

.an.est

ab-

lished

.con

nection

.to.the.ERP.sys

tem.

.In.PAB

ADIS’PROMISE,

.the.onto

logy

.is.spr

ead

.thr

oughout

the.en

tire

.au

tomation

.py

ramid

.li

nking

.al

.th

ree

.la

yers

.(E

RP–MES–eld

.co

ntrol)

.tog

ether.

•

. Con

trol ow:

.PRO

.has.a.str

ict

.ver

tical

.con

trol

.ow.tha

.lac

.fee

dback

.to.the.upp

.lay

.of.

the.ERP

.PAB

ADIS

.has.a.lim

ited

.fee

dback

.to.the.ERP

.It.act

ually

.app

roaches

.it.onl

.at.the.end.

of.the.pro

duction

.cyc

le.

.PAB

ADIS’PROMISE

.sup

ports

.per

manent

.con

nection

.wit

.the.ERP.via.

pla

nned,

.pe

riodic,

.or.ev

ent-based

.re

ports

.du

ring

.th

.pr

oduction

.or

der

.li

.cy

cle.

16.4.4 Challenges of Industrial agents’ Usage

All.above-mentioned.architectures.approach.the.manufacturing.automation.from.the.conceptual.point.

of.vie

.and.oe

.ove

rlook

.the.app

lication-related

.asp

ects

.tha

.are.imp

lied

.by.the.dis

tributed

.nat

ure

.of.

the.con

cepts.

.In.par

ticular,

.sec

urity,

.pro

duct

.ide

ntication,

.and.dat

.int

eroperability

.are.vit

.asp

ects

for.pr

actical

.im

plementations.

Distributed

.sys

tems

.lac

.a.sin

gle

.poi

.of.con

trol

.wit

.deci

sion-making

.bei

.spr

ead

.ove

.mul

tiple

.ent

ties

.tha

.com

municate

.wit

.eac

.oth

er.

. is.cau

ses

.hig

her

.secur

ity

.ris

ks,

.due.to.the.int

ensive

.com

munica-

tion

.tha

.suc

.arc

hitectures

.req

uire

.and.the.fac

.tha

.the

.is.no.sin

gle

.ent

ity

.tha

.con

trols

.the.sys

tem.

Another

.cha

llenge

.for.dis

tributed

.sys

tems

.is.to.pro

vide

.a.gen

eral

.ove

rview

.of.the.pro

cesses

.and.com

po-

nents

.on.the.sho

.oo

.It.is.di

cult

.to.kee

.tra

.of.the.pro

ducts,

.wor

k-in-progress,

.and.mat

erials

.in.the.

pla

nt,

.whi

.imp

lies

.tha

.tra

cking

.the.exa

.loca

tion

.of.pie

ces

.is.a.hug

.cha

llenge.

. er

efore,

.mor

.adv

anced

ide

ntication

.of.the.wor

.pie

ces

.is.req

uired

.in.ord

.to.gua

rantee

.the.ec

ient

.ope

ration

.of.the.sys

tem.

Last

.but.not.lea

st,

.dis

tribution

.of.dec

ision-making

.fun

ctionality

.req

uires

.int

eroperability

.of.inf

orma-

tion

.ow.ove

.all.thr

.lay

ers

.of.the.auto

mation

.pyr

amid

.as.wel

.as.mec

hanisms

.of.dis

tributed

.dat

abases.

efore,

.a.com

mon

.onto

logy

.wit

.mec

hanisms

.of.dat

.abs

traction

.for.di

erent

.con

trol

.ent

ities

.is.

req

uired

.to.gu

arantee

.th

.co

ordination

.wi

thin

.th

.sy

stem.

16.4.5 Other application areas in Brief

While.agent-based.applications.have.not.yet.achieved.a.noteworthy.penetration.in.industry.they.never-

theless

.are.hea

vily

.kno

cking

.at.the.doo

.of.sev

eral

.ind

ustrial

.app

lication

.are

as,

.inc

luding

.man

ufacturing

and.sup

ply

.cha

.man

agement,

.log

istics,

.pro

cess

.con

trol,

.tel

ecommunication,

.(ai

.tra

c

.and.tra

ns-

portation,

.or.def

ense

.(cf

.e.g

.[7]

.In.the.cen

ter

.of.man

.of.tho

.age

nt-based

.ind

ustrial

.sys

tems

.sta

asp

ects

.lik

.coo

rdination,

.coo

peration,

.sel

f-organization,

.tim

ely

.and.rea

sonable/intelligent

.rea

ctions

.to.

unf

oreseen

.dev

elopments,

.pla

nning

.and.dec

ision-making,

.esp

ecially

.als

.und

.rea

l-time

.con

straints

and.mai

nly

.in.dis

tributed

.are

.whe

.the.ind

ividual

.uni

.are.sup

posed

.to.be.auto

nomous,

.and.in.int

el-

ligent

.be

havior

.in.ge

neral.

. avi

ation

. and. spa

. con

trol

. ind

ustry

. is. ano

ther

. fro

ntrunner

. of. age

. tec

hnology.

. Esp

ecially,

aut

onomous

.mis

sions,

.suc

.as.col

lision

.con

trol

.syst

ems

.for.unm

anned,

.oe

.als

.ref

erred

.to.as.“un

in-

habited”

.or.“re

motely

.pil

oted”

.aer

ial

.veh

icles

.(UA

.hav

.att

racted

.a.lot.of.(in

dustrial)

.res

earch

.(cf

.e.g

[10

–13,15,17,18]).

.In.the.AGE

NTFLY

.pro

ject

.(cf

.[15

])

.dev

eloped

.in.the.Ger

stner

.Lab

oratory,

.Cze

.Tec

hnical

Uni

versity

.(CT

.in.Pra

gue

.has.bee

.wor

king

.wit

.the.Air.For

.Res

earch

.Lab

oratory,

.New.Yor

.on.

a.so

ware

.pro

totype

.sup

porting

.the.pla

nning

.and.exe

cution

.of.aer

ial

.mis

sions

.of.UAV

.tha

.inc

ludes

.the.

fre

e-ight-based

.col

lision

.avo

idance

.of.UAV

.wit

.oth

.aer

ial

.veh

icles.

.Her

.UAV

.are.tru

.aut

onomous

ent

ities

.who

.aut

onomy

.is.rea

lized

.by.its.own.set.of.int

elligent

.so

ware

.age

nts.

.Eac

.ig

.mis

sion

.is.ten

tatively

.pla

nned

.bef

ore

.tak

e-o,

.obv

iously

.wit

hout

.bei

.abl

.to.con

sider

.alr

eady

.lik

ely

.col

lisions.

.Dur

ing

a.ig

ht,

.the.age

nts

.det

ect

.pos

sible

.col

lisions

.and.eng

age

.in.pee

r-to-peer

.neg

otiations

.aim

.at.sop

histicated

rep

lanning

.in.ord

.to.avo

.any.col

lisions.

.Ref

.[10

]

.des

cribes

.a.sim

ilar

.pro

ject,

.in.whi

.two.di

erent

app

roaches

.for.add

ing

.aut

onomous

.con

trol

.to.an.exi

sting

.UAV.are.exp

lored,

.tes

ted,

.and.eva

luated.

. e.

AER

IAL

.pro

ject

.(cf

.[13

])

.is.a.dis

tributed

.syst

.tha

.is.abl

.to.ens

ure

.coo

rdination

.and.con

trol

.of.a.ee

Industrial Agent Technology 16-11

of.UAVs.involved.in.temporally.constrained.mission..Ref..[12].uses.a.dierent.technology,.namely.swarm.

int

elligence,

.for.coo

rdinating

.the.mov

ements

.of.mul

tiple

.UAV

. e.con

trol

.log

.is.exe

cuted

.aut

onomously

by.a.UAV.tha

.res

ults

.in.a.sit

uation

.whe

.a.sin

gle

.hum

.is.abl

.to.mon

itor

.an.ent

ire

.swa

.of.UAV

.ins

tead

of.at.lea

.one.hum

.for.eac

.UAV

.In.Ref

.[17

.UAV

.wit

.sma

.rec

eived

.sig

nal

.str

ength

.ind

icator

.sen

sors

.coo

peratively

.wor

.tog

ether

.to.loc

ate

.tar

gets

.emi

tting

.rad

.fre

quency

.sig

nals

.in.a.lar

.are

.Ref

.[11

]

des

cribes

.a.dec

ision

.mak

ing

.par

tnership

.bet

ween

.a.hum

.ope

rator

.and.an.int

elligent

.UAV

.Her

.the.int

el-

ligence

.is.pro

vided

.by.a.MAS

. e.MAS.con

trols

.the.UAV.and.sel

f-organizes

.to.ach

ieve

.the.tas

.set.by.the.

ope

rator,

.how

ever,

.als

.thr

ough

.int

eraction

.via.wha

.the

.cal

.a.var

iable

.aut

onomy

.int

erface

.wit

.the.ope

ra-

tor.

.In.all.the

.pro

jects,

.esp

ecially

.the.aut

onomy

.and.int

elligence

.asp

ects

.are.rea

lized

.by.age

.tec

hnology.

Aut

onomy,

.how

ever,

.req

uires

.a.lot.of.com

munication

.in.ord

.for.a.set.of.aut

onomous

.uni

.to.ach

ieve

.the

goa

.coo

peratively.

. us

.com

munication

.and.dec

ision-making

.pla

.a.maj

.rol

.in.tho

.pro

jects.

.to.sup

ply

.cha

.man

agement

.is.log

istics

.in.gen

eral.

.In.log

istics,

.the.inf

ormation

.and.dat

req

uired

.for.ec

ient

.pla

nning

.are

.for.var

ious

.rea

sons,

.typ

ically

.not.ava

ilable

.cen

trally.

.Qui

.a.numb

of.sys

tems

.hav

.bee

.dep

loyed

.in.thi

.are

.fro

.whi

.onl

.two.wil

.be.pre

sented

.bri

ey.

. e.Liv

ing

Sys

tems/Adaptive

. Tra

nsport

. Net

work

.(LS

/ATN,

. cf.. [40

]),

. pro

vided

. by. Whi

testein

.Tec

hnologies,

. for.

exa

mple,

.to.ABX

.a.Eur

opean

.log

istics

.com

pany,

.is.an.age

nt-based

.sys

tem

.for.net

work

.pla

nning

.and.

tra

nsportation

.opt

imization

.for.cha

rter

.bus

iness

.log

istics.

.Based.on.a.sim

ulation

.stu

.tha

.was.per

formed

by.Whi

testein

.on.the.basi

.of.350

.tra

nsportation

.req

uests,

.11.

.cos

.sav

ings

.wer

.ach

ieved.

. e.oth

ver

.suc

cessful

.com

mercial

.dep

loyment

.is.the.Mag

enta

.i-s

cheduler,

.an.int

elligent,

.eve

nt-driven

.log

is-

tics

.scheduling.system.based.on.Magenta.agent.technology..It.is.characterized.by.a.number.of.unique,.

adv

anced

.fea

tures

.suc

.as.rea

l-time,

.inc

remental,

.con

tinuous

.sch

eduling

.and.sch

edule

.imp

rovement,

sca

lability

.fro

.sma

.to.ver

.lar

.ent

erprise

.net

works,

.whi

.als

.inc

ludes

.bal

ancing

.of.the

.con

icting

.int

erests,

.mul

ti-criteria

.sch

edule

.ana

lysis,

.and.ric

.dec

ision

.sup

port

.for.the.use

. e.sys

tem

.is.

dep

loyed

.alr

eady

.in.a.numb

.of.ind

ustrial

.app

lications.

.As.a.sch

eduling/logistics

.sys

tem

.for.Tan

kers

Int

ernational,

.it.pro

vides

.int

elligent

.sup

port

.in.the.sch

eduling

.of.a.46-

strong

.ver

.lar

.cru

.car

rier

(VL

CC)

.ee

.I-s

cheduler

.imp

lements

.vir

tual

.mar

ketplaces

.wit

.abo

.100

.age

nts

.run

ning

.dur

ing

.a.

typ

ical

.exe

cution

.of.the.sys

tem

.(cf

.[19

]).

.I-s

chedulers

.wer

.als

.dep

loyed

.in.sev

eral

.roa

.tra

nsportation

app

lications

.wit

.sev

eral

.U.K

.roa

.log

istics

.ope

rators

.(cf

.[21

]).

. e.app

lication

.rep

orted

.in.[20

]

.cop

wit

.abo

.150

.ord

ers

.dai

ly,

.in.650.loc

ations,

.150.own.tru

cks,

.and

.add

itionally,

.25.thi

rd-party

.car

riers.

I-S

cheduler

.assi

gns

.an.auto

nomous

.age

.to.eve

.pla

yer

.in.the.tra

nsportation

.sys

tem

.and

.add

ition-

ally,

.tas

king

.age

nts

.to.obt

ain

.the.bes

.pos

sible

.dea

.for.the

.cli

ents.

.Pla

yers

.inc

lude

.the.tra

nsportation

ent

erprise

.as.a.who

.and.all.ind

ividual

.tra

nsportation

.dem

ands

.and.res

ources,

.lik

.dri

vers

.and.res

ource

own

ers.

.Dem

ands

.and.res

ources

.tha

.hav

.com

mon

.int

erests

.sel

f-organize

.into.gro

ups

.rep

resented

.by.

a.sing

.age

nt.

.Age

nts

.may.dec

ide

.to.com

pete

.or.coo

perate

.dep

ending

.on.pre

vailing

.cir

cumstances.

.To.

con

struct

.a.sch

edule,

.a.for

mal

.des

cription

.of.bus

iness

.dom

ain

.kno

wledge

.(On

tology),

.of.par

ticular

sit

uations

.(a.Sc

ene),

.of.ag

ent

.go

als

.(e

.g.,

.to.in

crease

.pr

ot),

.an

.of.re

al-world

.ev

ents

.ar

.us

ed.

Another

.pro

minent

.are

.for.age

nt-based

.sys

tems

.is.vir

tual

.org

anizations

.(VO

)

.or.ent

erprises

.(VE

.(se

.e.g

[14

]

.for.a.nic

.ove

rview).

.VOs.may.dee

ply

.int

egrate

.all.manu

facturing

.and.sup

ply

.cha

.asp

ects,

.sal

.net

works,

as.wel

.as.sup

pliers,

.cus

tomers,

.and.thi

rd-party

.mai

ntenance

.and.coo

rdination.

.Her

.aga

in,

.the.coo

peration

and.coo

rdination

.asp

ect

.of.suc

.con

glomerates

.sta

.in.the.cen

ter

.of.wha

.age

nts

.are.sup

posed

.to.pro

vide.

.rec

ently,

.res

earch

.tri

.to.add.mor

.sem

antics

.to.ind

ustrial

.app

lication

.sys

tems.

. is.usu

ally

mea

.tha

.onto

logy-based

.con

cepts

.are.int

egrated.

.A.nic

.ove

rview

.abo

.thi

.tre

.is.giv

.in.[22

An.exa

mple

.for.a.pro

minent

.and.suc

cessful

.app

roach

.is.pre

sented

.in.[23

. e.OOO

NEIDA

.con

sor-

tium

.pro

vides

.a.tec

hnological

.inf

rastructure

.for.a.new

.ope

.kno

wledge

.eco

nomy

.for.auto

mation

.com

ponents

.and.auto

mated

.ind

ustrial

.pro

ducts.

. ei

.fra

mework

.aim

.to.pro

vide

.int

eroperability

.on.the.

har

dware

.as.wel

.as.on.the.so

ware

.at.all.lev

els

.of.the.auto

mation

.com

ponents

.mar

ket,

.tha

.is,.fro

dev

ice

.and.mac

hine

.ven

dors

.to.sys

tem

.int

egrators

.up.to.the.ind

ustrial

.ent

erprises.

.In.the.cen

ter

.of.the

app

roach

.are.the.so-

called

.sea

rchable

.rep

ositories

.of.auto

mation

.obje

cts.

.Her

.eac

.pla

yer

.can.dep

osit

its.enc

apsulated

.int

ellectual

.pro

perty

.alo

.wit

.app

ropriate

.sem

antic

.inf

ormation

.to.fac

ilitate

.sea

rch-

ing

.by.in

telligent

.re

pository

.ag

ents.