Reasearch center in scientific and technical information

Cerist

Avignon, Dec 9-11 Bionetics 2009

Presented by: Hakima Mellah

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New communication flows emerge

IS4

IS2

IS1IS3

IS4

IS2IS1

IS3

IS4

IS2IS

1

IS3’

IS4

IS2IS1

The coordination and the maintenance of connectivity in a network take from peer to peer systems (P2P). One of the major problems characterizing this type of systems is the establishment and the maintenance of the co-operation between nodes. However, this difficulty can arise in any communication network, ad hoc network, multi agents systems(for which the node will be regarded as an agent,),…

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A production system is a set of resources realizing a A production system is a set of resources realizing a productive activity. The production is the productive activity. The production is the transformation of resources (machines and materials) transformation of resources (machines and materials) leading to the creation of goods or services. The leading to the creation of goods or services. The transformation is done by a succession of operations transformation is done by a succession of operations (tasks) that use resources (machines and operators), (tasks) that use resources (machines and operators), and modify the raw materials or components that and modify the raw materials or components that enter into the PS in order to create outgoing finished enter into the PS in order to create outgoing finished products of this system and assigned to be consumed products of this system and assigned to be consumed by customers.by customers.

What is?

(i) Information and decision subsystem (ii) physical production subsystem

Systems Theory

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Production System

Example Features

Task7

Task6Task 5Task 4

Task 3

Task2

Task1

Ffinished product

Product semi-

finished

Produit semi-

finished

oroduct

stock

Machine F

Machine E

Machine D

Machine B

Machine A

Machine C

Transpormeant

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The critical and important problem to solve within PS is fault tolerance. The control system must provide very powerful mechanisms fault tolerance in order to ensure the continuous operations of PS that are detection, prevention and correction,

What?

How?

production

management ? MULTI-AGENTS SYSTEMS

Enterprise requirements Competitivity.Very high reliability constraints.Minimising dysfonctionning.

What can offer a MAS decentralised controlNew manners to communicate.

MAS MAS is composed by autonomuous entities, called agents. They

evolve in a common environment, have a collective behaviour to reach a desired function.

Communication protocols: Contract

Acquaintances Net protocol Model

Organisation & self organisationOrganisation is the way that a set is constituted and the action to organise.By SO, an agents organisation allows agents to adapt to changing situations.

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CC

SC

PP

P

P

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The principal goal through this protocol is to ensure: (i) New bonds of communications(ii) an important co-operation between the agents of the same neighbourhood;(iii) a MAS self organization made concrete by the emergence of communication bonds, that make cooperate agents which are not directly connected;(iv) take decision to add/remove agents when it is necessary;

 Concepts within BC Computational interpretation Food Energie /information Removing food source Destroy a link between sources, or

the source itself. Pattern communication structure

(organisation) Bacteria IS component Chemotaxis Search direction Gradient morphogen Distance compared to an IS;

information of position Inhibition &local competition Information on decision   Local Control Failures detection    

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Most important primitives

Positioning process

Election process

Routing process

Checking process

Grouping process

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Morphogen Gradient and information of position:

-More the morphogen is diffused and more its concentration is higher.-Each gradient morphogen implies an activity assured by a bacteria group-morphogen concentration represents the distance between a bacteria and a source of food-Morphogen allows the bacteria to know where it is situated between two differents sources

Figure 3. Morphogen diffusion

Positioning process

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Local inhibition and competition

-Within a group, cells differentiate to take a new role. one cell that decide to differentiate, diffuses a signal (morphogen) that inhibit others to differentiate.

Election process

Mathematical formulation of positioning process:

A position message: position(ai, role, posi), i IN, ai A, the whole of agents positions

with their identification are stored in a table. j IN, ai A, if eij =1 aj aj is a direct

neighbour of ai and can received ai messages. k IN, ak A / eik =1 ak receives position(ai, role, posi), ak receives position(ai, role, posi) for the first

time Possrcposi ; posk possrc +1;

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Piloting ressource Agent(PRA)User Agent (UA)Interface Agent(IA)

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UA

IA

PRA

Setting production plan

Dispatching tasks to PRA

Realising piloting system functions

1. Agent failure (i)RA(breakdown) is the alone agent of another RA. (ii)RA has several neighbours.

2. Communication bond failure i)RA isolated or the system is broken down into two subsystems.(ii)Isolated RA is a neighbor of an agent RA belonging to a sub system.(iii)The two RA belong to the same subsystem.

1. Agent failure (i)RA(breakdown) is the alone agent of another RA. (ii)RA has several neighbours.

2. Communication bond failure i)RA isolated or the system is broken down into two subsystems.(ii)Isolated RA is a neighbor of an agent RA belonging to a sub system.(iii)The two RA belong to the same subsystem.

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-Soft failure

Agent in failure

Communication bond destroyed

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-Hard failure-At least one RA can execute the tasks of the agent responsible for the breakdown resource-No agent can perform the tasks of the breakdown agent and in this case the operator has to intervene.

Fig. 2. Collaboration diagram of the system functioningt

Production system is able to be fault tolerant by:Detecting and localizing a failurefinding a solution to each MAS situationMinimizing operator intervention

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Realize the study on a concrete case of production systems.Considering a MAS in multi postes

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THANK YOU FOR YOUR KIND ATTENTION

Algiers by night

Université SAAD DAHLEB, Blida. USDB

Présenté par : RAIAH AHMED & TIGUMOUNINE AREZKI 20

Reasearch center in scientific and technical information

Cerist

Avignon, Dec 9-11 Bionetics 2009

Presented by: Hakima Mellah