Research On Operation Scheduling In Mold Collaborative Manufacturing Execution System

Mold industry is an important part of national economics, and the development level of mold manufacturing represents the level of national manufacturing at some degree. As an advanced manufacturing mode, Collaborative Manufacturing (CM) can combine the various mold ralative enterprises and units to a mold Extended Enterprise (EE or E2), and furthermore improve the competitive power of the mold enterprise. The injection mold is the research object in this dissertation. The characteristics of mold manufacturing are studied. The necessity of the importing CM mode to mold manufacturing is analyzed. The mold collaborative manufacturing execution system (c-MES) model based on SOA (Service-Oriented Architecture) is built. The operation scheduling ralatived problem of the mold manufacturing is studied.Mold EE has the following characteristics: distributed in locality, tight cooperation and frequent information exchange. It needs a Web based, collaborative, high efficient, intelligent and reliable manufacturing management system. The solution is the mold c-MES based on SOA. As a distributed integrated architecture, the SOA has many advantages, such as loose coupling, reusable, coarse-grained, platform-independent, and so on. SOA can meet the needing of information integration for mold EE. The feature of Web Service platform is analyzed. The necessity and feasibility of importing Web Service to mold c-MES are discussed. Every service module's function of the mold c-MES is described in detail, including the functions it supplies and the mechanism of information interaction among them. The feasibility of mold c-MES model is validated by a real mold manufacturing case. The impletation of this solution can bring more performance increasing to mold EE.It is important to perform an optimized scheduling on mold operations reasonably when manufacturing them to improve the manufacturing efficiency and shorten the manufacturing period. There are many various constraints among the mold manufacturing operations. They can be classified to two kinds: sequence constraint and combination constraint. The expression method based on relational database is designed. The different workpieces in one mold and the different operations in one workpiece can be made in different places among mold EE. So, the workpiece's transportation time must be considered. The transportation time database is designed. It can be queried when decoding the chromosome for despatching the job time parameter.GA is a universal evolutionary algorithm. With the chrasteristics of mold manufacturing considered, the hybrid algorithm of GA and heuristic algorithm is adopted to optimize the mold operation scheduling. The genetic arithmetic operators for operation based representation and workpiece based representation are designed, including the population initialization, reproduction, crossover and mutation. The relative parameters in the arithmetic operators are studied.When the operation-based chromosome representation is adoped in GA for mold operation scheduling, the invalid chromosome will be generated unavoidably during the computing period of population initialization, reproduction, crossover and mutation of chromosome. So, an adjustment algorithm is proposed to ensure the validity of chromosome before decoding. The feasibility of the algorithm is validated by computing cases. We should get the available time parameters of the machine resource before making the scheduling plan. In order to compute conveniently, the GA mathematics model should be idealized in some extent. Traditional scheduling model supposed that the available time buffer is continuous and has no length limitation. However, this over idealized supposition brings the result out of accord with mold production practice. The decoding algorithm is proposed for various job time properties, and it can bring the computing result in accord with mold production practice much more. The solution is validated by a typical mold manufacturing case, and it can carry out the satisfied scheduling plan which meets the mold production practice.The mold c-MES prototype system based on SOA is built, and the mold operation scheduling service module and the relative database are implemented. Mold c-MES is coarse-grained, loose coupling, platform-independent, Web based, and it can support the mold CM perfectly.