Usage of Coloured Petri Nets for the Performance Evaluation of the Metallographic Samples Analysis Automated Systems

Abstract

This paper presents the results that we attained about modeling and simulation of the metallographic samples preparation and analysis automated systems, made of two subsystems. The first subsystem polishes the samples and assesses the surface state by means of a microscope. In the second subsystem the samples are reagent attacked, washed, dried and analyzed by the electronic microscope. The evaluation of the system performance and the identification of possible bottlenecks was made by means of coloured Petri nets modeling and simulation. The CPN Tools software was used to make the model. Three coloured Petri nets models were developed. The first version assumes the analysis of the system operation by means of coloured Petri nets with simple colours, and such a simple colour was assigned to each entity of the subsystem: samples to be analyzed, robots, storage devices, microscopes etc. For a better observation of the analyzed sample path within the system, the second model version was designed, with complex colours assigned to the marks. The third version considers the time factor. The models with timed coloured Petri nets allow the system performance evaluation considering the number of analyzed samples in a given time interval. This paper presents the first and the third model, as the last one includes the second model.