Object-oriented Petri network modeling method in flexible manufacturing system

Abstract

The invention discloses an object-oriented Petri network modeling method in a flexible manufacturing system. Modeling steps are as follows: step one, establishment of a structure model in an FMS; step two, construction of a single physical object OPN model; and step three, establishment of an OPN model in the FMS; wherein when no task exists, various organization units in the system have no need for mutual connection; however, once the task appears, various basic units are stimulated so that the connectivility possessed by a manufacturing unit can function, the units mutually send connection requirements, and Gate 1, Gate 2 and Gate 3 are used for realizing the connection. Compared with a common Petri network, in the invention, an OOPN model in the FMS can be expanded and easily reconstructed, and an FMS control software based on the OOPN model can be directly and correspondingly obtained and can prevent deadlock and conflict from happening in the system.

Description

Technical field: [0001] The present invention relates to a method for analyzing and designing manufacturing units of a flexible manufacturing system (FMS) in a distributed control system, in particular to object-oriented Petri net modeling and modeling in a flexible manufacturing system (FMS). design method. Background technique: [0002] There are some basic problems in the ordinary Petri net model that limit its application in the design of complex FMS models, mainly in the following aspects: [0003] (1) For the establishment of ordinary object-oriented Petri nets, it is very difficult to establish models and modify models due to its complex structure and targeted systems, and ordinary Petri net modeling has high system independence, and lacks Features such as modularity, reusability and maintainability are required in FMS. [0004] (2) The simple Petri net is difficult to add nodes on the basis of the existing model, and cannot be changed on the original basis, so it i...

AI Technical Summary

Problems solved by technology

[0003] (1) For the establishment of ordinary object-oriented Petri nets, it is very difficult to establish models and modify models due to its complex structure and targeted systems, and ordinary Petri net modeling has high system independence, and lacks Features such as modularity, reusability and maintainability required in FMS

[0004] (2) The simple Petri net is difficult to add nodes on the basis of the existing model, and cannot be changed on the original basis, so it is used in actual engineering practice

[0005] (3) The traditional Petri net method ignores the planning / scheduling knowledge of the control logic, and also lacks the characteristics of direct mapping between the control model and the control software code, which may lead to conflicts in the entire system. changes, the entire model needs to be rebuilt

Images