Research On Some Key Technologies Of MES And Its Application In Discrete Manufacturing Enterprises

In the 21th century, China is supposed to transfer from "big manufacturing country" to "strong manufacturing country", accordingly, manufacturing enterprises must realize the great transformation from "production capability" to "innovation ability and rapid response ability ". It's great demand in our manufacturing enterprises to improve shop floor digital manufacturing execution capability.In order to improve unitary production efficiency, enterprises must solve the following problems : product engineering designing information, production process information and manufacturing information are difficult to integrate and feedback timely, then it can be realized to integrate shop floor manufacturing executing layer and designing layer as well as management layer timely and bidirectionally. Integrated model of BOM is put forward in view of BOM life management mode, and bidirectional mutual BOM sharing model is built between MES and CAD system. So the goal of integration is realized among shop floor manufacturing executing layer and designing layer as well as management layer timely and bidirectionally, which satisfies MES data management in the aspect of data accuraty,data coherence and sharing. Prototype system is developed and the effectiveness of integrated model is verified.In MES, equipment management needs appropriate management modes and methods within complex circumstances. For the irregular complex dynamic circumstance, the method of complexity description on equipment management based on information entropy is given, and the model of complexity measurement is set up, which is well applied into applicable analysis in production planing. By analyzing historical data, a method on the distribution forecasting of equipment maintenance time is put forward for production scheduling, with the usage of statistic modeling theory. Considering process interchangeability of the parts, by adopting max-tree fuzzy clustering method, the problem on manufacturing capability comparability among equipments is solved. Applicability and efficacy of the recommended methods above are verified by cases. In fact, the executive object of enterprise product scheduling is production cell. To embody the validity of production scheduling, the object of production scheduling is changed from single equipment level to production cell level. Taking production cell scheduling as assignment problem, and the algorithm oriented to prodution cell scheduling is given out under general conditions. In view of actual practical limits in shop floor, two conceptions are introduced: virtul producion unit and virtul order, and then optimal algorithm on production cell scheduling is surposed, under the conditon that producion cell didn't match with production task in the aspect of number. By which the flexiblility of traditional production is solved, and OEE(Overall Equipment Efficiency) is improved greatly.Manufacturing resources reconfiguration is an advanced management techonolgy, which is able to integrate distributed manufacturing resources, exploit the core competitive power of every shop floor. Based on the opinion that the origination of MES reconfigure is manufacturing resource reconfiguration and optimation, this paper introduces the basic concept and character of MES resources reconfiguration. The analytic hierarchy process (AHP) is explored and adopted for the manufacturing resources reconfiguration. Based on the principle of AHP, four algorithms on manufacturing resources reconfiguration are given, such as the algorithm on single procedure reconfiguration under the conditions of full information and deficient information, the geometrical mean algorithm and the arithmetic mean algorithm on multiple procedures reconfiguration , whose efficacy are proven by an illlustration.As production management system and real-time information system for shop floor, MES primarily solves execution problem of production task, and fills up the gap between the upper production planning and lower industry control. Through timely monitoring and harmonious optimized control on powerflow, logistics and equipment states, MES arrives to the goals of responsing manufacturing rapidly and decline energy.