Multi-agent fabrieksbesturing in Java.

Overview

What’s the topic of this thesis? General principles What have I achieved until now? What am I planning to do ?

What’s the topic of this thesis?

Contrast with current manufacturing control systems

2 main parts :– Emulation– Control

Coöperation with Agfa

Contrast with current manufacturing control systems

Decentralized– Until now: central system that controls everything.

Not robust Not flexible

– Use of agent systems should help to deal with changes without large efforts.

Emulation

What is emulated? Purpose General principles Silk

Emulation: what is emulated

Eventual goal :

Simulate a part of Agfa:– incoming film rolls– splitting according to a cutting plan– processing to the format desired– multiple machines can perform the same tasks

Emulation : purposes

Some knowlede of the ‘lead time’time needed to process the order, from order arrival at the plant to delivery of the final product at the customer

What happens with a current order?

Is the deadline achieved? Less storage -> lower costs

Emulation: General Purposes

Discrete-event simulation Control-events Entities

– Temporary entities– Servers

Estimating patterns in input – Collected data– Certain distribution

Emulation: General Principles

Discrete-event simulation

Emulation: General Principles

Taking processing time into account

General principles

Output Analysis– Confidence intervals– Eliminating errors in simulation through initial

conditions, so that a stable distribution is achieved after a certain time for a given output process

Silk

General framework Distributed by ThreadTec Offers animation

Silk

Entity:– is a silk - thread.

Difference with usual thread : – Silk wants to be in control of its entities. F.e new() cannot

be used, the method newEntity() has to be called instead.– Silk won’t accept interferance of the Java VM by calling

wait() of notify() from a Java thread.

– belangrijkste methode: process method

Decribes the life of an entity.

Silk

Simulation– Class responsible for storing data such as the

length of the simulation, the number of replicas, animation or no animation , ...

Silk– Mainclass that will coördinate the calls to the

Simulation and Entity classes.

What have i realized yet?

Problem analysis– use cases– conceptual model– First build– Second build

What have I realized yet?

Build 1– intention: starting with a simple example

emulation : a production plant with 1 machine, orders are arriving and are being sent to the control system. The control system passes the right instruction to the machine.

– collaboration diagram– class diagram– conclusion

Build 1

Build 1: Creator part

Build1: emulation part

Build1

Conclusie– Instable (random occuring errors) by:

Not respecting Silk, that wanted absolute control over HIS entities.

Scope of the project was to big ( initial control system and emulation in one build).

No strong division between Build and Emulation, and between different subsystems.

Build 2

Intention : – Emulation with a minimal control system– Strong division between subsystems

fe : emulation :– A part responsible for communication with the control

system.– A part that handles everything to do with Silk– A part responsible for communication with the gui.

– Division in packages, every package responsible for a subsystem, communication by facades

Build2: GebruiktExterneBibliotheek package

Build2: Inputverwerking package

Build2: controlpackage

Specificatie

BesturingsFacade

ResourceSpecificatie OrderSpecificatie

Build2

Conclusion:– Splitting in subsystems and implenting them one

for one was very usefull– Delays caused by the control system have to be

taken into account. Al lot of instructions arrive at the emulation when he has finished only.

What are we planning to do

Expanding the emulation to more than one machine.

Adding and removing machines at runtime. Machine failure. Reporting of results. Modelling transport.

What are we planning to do

Analysis of the results Taking the time of the calculations of the

control system into account.