Modeling And Simuiation Of FMS Logistics System Based On Petri Nets

FMS logistic system affects directly working performance of whole flexible manufacturing system,therefore,that researching logistic process control method of FMS logistic system in order to improve logistic process efficiency of the system will play an important role in achieving whole FMS coordinated running and improving total performance.A model based on object-oriented technology and colored Petri-net theory for FMS logistics system is established,and FMS logistics process control issue is investigated in this paper.When modeling,the colored Petri-net method using object-oriented technology will be introduced into establishing the model of FMS,which is consisted of parts,machine tools,Automated Guided Vehicles(AGV) and auto-stereo warehouse object;the firing principle and controlling methods of controlled transitions in this model will be analyzed.Because of using object-oriented technology,the model possess good extensibility and good transplant ability characteristic. It is a integrated FMS logistics system model that include machining system,transportation system and storage system in that auto-stereo warehouse is introduced into the model.In order to realized the model with software program,a mapping idea is presented to convert FMS logistics system Petri-nets model into logistics system simulation program. A method that places mapping program data,transitions mapping program functions and the system Petri subnets model mapping FMS basic class in program is put forward in this paper. The degree of difficulty is greatly decreased by using this method during analyzing how to design FMS simulation software system,and it is not only simple and easier to realized,but also the software program show a good agreement with the model.Hypothesis data is used as original data of simulation system running,FMS logistics system is simulated by running simulation system software program. Hypothesis data has the better identification effect for system and simulation program,the model and simulation system program is proved to be right and effective by simulating and analyzing the result of simulation.The principle and method for experiment of FMS logistics system semi-physical simulation is presented,set up a frame of logistics system semi-physical simulation,carry out specific experiment,further prove the performance of the model and simulation software.