Control of a flexible manufacturing cell by Petri

Control of a flexible manufacturing cell by Petri nets in Java language. 1

Objetives l Configurating the PCI SC/I-T controller board via CMD’s HLI. l Create a set of Java classes that can access to the bus. l Create a Java implementation of Petri nets to control the manufacturing cell via Interbus. 2

The PCI SC/I-T controller board 4 th. Generation Interbus controller board. l Remote interface for PCI bus. l Total configuration of the controlled system process data by CMD software. l Permits permanent storage of process data in its EEPROM memory. l 3

Interbus 4

CMD Phoenix-Contact bus configuration software l Can export bus configuration to a high-level languaje. l Auto-configuration. l 5

JNI Interconnect Java with C libraries. l Solution: changing the C functions created by HLI for being used from a Java application. l Java provides this funcionality: JNI (Java Native Interface). l Now we only have to find a method for representing the system to control: Petri nets. l 6

Java programming 7

Petri nets (PN) are a modelling and analysis tool especifically adapted to the study of discrete events systems. l A set of classes have been implemented for representing a PN: Place, Transition, Net. l Two ways for creating a PN: direct code writing or importing a PN from an external editor. l We have used HPSim, a free PN editor that exports a PN into a. txt file; the class Text. To. Net translates the created PN into a Net object inside our project. l 8

Inicialization net Station automatic production independent nets Global control net Petri nets 9

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Control Class Coordinator implements the evolution of the PN: habilited transitions, fires and marking. Actualizates the monitor/s values. l Monitors hold the variables: station inputs and outputs, array of orders, etc. l After a fixed delay the class Bus. Manager actualizates the station output variables from the monitor objects values and actualizates from the bus the input values. l 11

Xplore project Members Video (Media Player) Ramón Piedrafita Moreno Alberto Gran Tejero Oscar García Flores Video (Quicktime) Universidad de Zaragoza 12