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Modularized Modeling And Reliability Analysis Of Manufacture Systems Based On GSPN & ESPN

Posted on:2009-09-13Degree:DoctorType:Dissertation
Country:ChinaCandidate:J Y ZhangFull Text:PDF
GTID:1102360308478829Subject:Mechanical design and theory
Abstract/Summary:PDF Full Text Request
Recently, Stochastic Petri Net has become a powerful tool for the research of discrete event dynamic system and especially succeeded in the system capability evaluation field. More and more attention is paid to the application of Stochastic Petri Net in the manufacture system. With a view to analyses the problems of reliability about manufacturing systems, the whole system can be classified by times distribution, and then generalized stochastic Petri nets (GSPN) and extended stochastic Petri nets (ESPN) are adopted to modularized model respectively. At last, performance analysis will be gone on.The principal research results and contents can be outlined as following:â… ) Establishing reliability measure of manufacturing systemsAccording to the states of manufacturing system and its operating, it adopts some correlation reliability indexes as follows:basic reliability index, availability index, maintainability index and stability production rate; function and multitask reliability are presented, they can measure reliability of the whole level when the system is operating in degradable or multitask.â…¡) Generalized stochastic Petri nets or extended stochastic Petri nets is presented to model for reliability of manufacturing systems(â…°) Various resources and their correlations can be described to places, transitions and corresponding behaviors of Petri nets. According to the various transition time delay distribution, system can be classified to exponential and non-exponential distribution systems, and then adopt different stochastic Petri nets to model respectively.(â…±) Mixed modeling method is presented for reliability model of manufacturing system. For system structure, it is built the modeling from its top to its bottom, it can be separated into five layers:plant layer, job shop layer, manufacturing cell layer, equipment module layer and machine resource layer; and for manufacturing resource, it is built the modularized modeling from its bottom to its top. it can be separated into three modules: equipment module,transport equipment module and storage module and so on. Here, reliability analysis equipment module.â…¢) Reliability analysis of manufacturing systemsTo systems of exponential distribution, the buffers influences to operation performance of manufacturing equipments can be classified. Similarly, it can get the classes of operation state of manufacturing equipments. And then obtain the quantization values by solving state transition equations; and to systems of non-exponential distribution, transfer functions can be obtained after getting behavior expressions. Furthermore, by using moment generating functions, realize performance analysis of model for extended generalized stochastic Petri nets.
Keywords/Search Tags:manufacturing systems, reliability modularized modeling, stochastic Petri nets, buffers availability, behavior expression, reliability index
PDF Full Text Request
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