Study On Key Techniques Of DNC System Oriented Networked Manufacturing

Networked manufacturing mode with repaid responsive mechanism to the market demands is needed to be built because of the change of manufacturing circumstance In age of network. As a major method to satisfy information-machine integration in workshop, DNC (Direct Numerical Control or Distributed Numerical Control) needs to produce based on networked manufacturing, implements to share in numerical control machines throngh network, and optimizes to configure and reorganize numerical control resources. The paper does study the DNC system oriented networked manufacturing -Web-DNC system. Its main contents are the key technology of Web-DNC system, which are building technology of the NC resource integration service platform and DNC communication technology.Firstly, the functions of the Web-DNC system are described based on analyzing the characteristic of networked manufacturing. They include information integration of shop floor the share of the manufacturing data, real-time monitoring and inter-OSibilty. The layer structures of Web-DNC system consist of Customer layer, Server layer, Agent layer find Equipment layer. Server layer represents as CNC resources integrated service platform. Agent layer represents as DNC communication platform and CNC information collecting platform. In this paper, serial communication machine tool is regarded as studying object. Based on an analysis of DNC communication structure, different Web-DNC communication structures that may be Point-to-Point and Intranet structure should be adopted according to different application object. So are there two communication modes in Agent layer. They are Point-to-Point and Intranet communication structure. In all the function layers, Server layer and Agent layer are the keys of realizing Web-DNC system.Because of Point-to-Point communication mode making DNC system have the limitations of simple function, complicated manipulate and less of portability, the universal DNC notion is presented to realize selecting different communication protocol by using the common customer interface. The function model of universal DNC communication system is fabricated. It includes three child-models of send, receive and remote function. Communication protocol and parameter of CNC are analyzed and the technologies of putting different function models into effect are described. Then, the universal CNC class is established using the thoughts of O-O technology and the models of send process, receive process and remote process is expressed by UML language. At last, Visual C++ realizes the universal DNC communication system.As Ethernet technology develops, especially the developments of bandwidth and data exchange technology of Ethernet make it possible to use the Ethernet as the basis of DNC communication. In this paper, emphasize on discussing the possibility of stableness, accuracy and real-time of data exchange. Then, the function model of DNC communication technology-in-based on Ethernet is fabricated. The BL2010 is selected as DNC controller based on the analysis of the performance demands of DNC controller. After lucubrating the problem of data transfer velocity matching, buffer technology that is used to solve the problem is presented and all the parameters of the technology are given. The means of achieving communication platform, events receive platform and DNC controller core are defined. DNC communication structure based on Ethernet not only realizes delivering data, collecting machines tool's status information and network distributed by a simple Single Chip Micyoco, but also makes numeric machine tools connect to the shop floor network directly by DNC controller. This technology simples the hierarchy of DNC communication structure and realizes consistency, integrality and penetrative of information in shop floor. It is proved that Web-DNC system is a low cost, compact and high efficiency DNC system.A series of experiments are carried out to prove the practicability of Web-DNC system. Experiments consist of simulation experiments and field test...