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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
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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
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 • 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.