One, in recent years numerical control technology got foreword develop swift and violently, control system is joined by inchoate hardware means develops the system of present open mode numerical control that is based on PC. The high speed that although hardware technology is mixed,the flying development of software technology gives CNC / high accuracy treatment laid a foundation, but the process designing means that uses in NC treatment at present or the ISO6983(G/M code that before be based on half century, develop) standard, this kind of code includes a few simple motion to dictate merely (like G01, G02) and auxiliary instruction (like M03, M08) , and do not include method of appearance of spare parts geometry, cutting tool to generate, the information such as cutting tool choice, make bottleneck is formed between CNC and CAD/CAM passageway. The problem that the information such as difficulty of the process designing in CNC Machining, design and treatment cannot share completely restricted the further progress of numerical control system, make its are faced with change newly. To solve these problems, europe in all body plans at putting forward OPTIMAL 1997, STEP(Standard For The Exchange Of Product Model Date, ISO 10303) standard is outspread the rock-bottom equipment that makes to automation, developed the data model of a kind of STEP-NC, machine the data interface of process designing as milling. Standard of STEP of this interface comply with, have object-oriented feature. STEP-NC changes product model data standard STEP to expand to CNC domain, new formulate the interface between CAD/CAM and CNC, it asks CNC system uses the model of CAD three-dimensional data that accords with STEP standard directly (include workpiece geometry to data, parameter is configured and produce a feature) , craft information and cutting tool information produce machine program directly. 2, the STEP-NC of research current situation of STEP-NC is a standard of object-oriented international of interface of data of new-style NC process designing (ISO 14649) , it begins formulate at the beginning of 1996, 2001 the bottom becomes draft international standards (Draft International Standard, DIS) , name formally by committee of technology of data of industry of ISO/TC184 of international Organization for Standardization for ISO14649, its purpose aims to replace the ISO 6983 level that uses extensively in numerical control machine tool. In last few years, euramerican the project that had started a few concerned STEP-NC, wait like OPTIMAL, MATRAS, STEP-NC and Super Model Project. Among them STEP-NC project of Europe aims to come true and check milling to machine data interface, the business that shares 20 many CAD/CAM, NC and domain of numerical control machine tool and research organization participated in the research of this project to work. 2001, the CNC prototype that the 2 dimension that accord with STEP-NC standard machine a process to had been in company of Siemens, FIDIA and Europe to open type architecture OSACA with milling of three-dimensional numerical control partly is able to come true in the system, its function already got test and verify in lab environment. At present archetypal system already was in the first user -- Daimler Chrysler company undertakes evaluating, the bore treatment that already tested polyhedron part and 2 dimension half the number accuse milling to machine a process, begin to check milling of three-dimensional numerical control to machine a process now. Begin from 2000, company of American STEP Tools is in of NIST of association of national level technology aid financially issue those who started by a definite date 3 years " super model " (Super Model) project. This project (the main goal that calls Model Driven Intelligent Control Of Manufacturing) completely is to build to agree with the database of milling, turning and software tool, machine tool of CNC of test and verify whether read directly design extraction 3D and production data, undertake the fast, part that safety and intelligence spend is made. Summer 2001, the content in the project of international IMS STEP-NC that Super Model project and Korea develop is amalgamative. The NRL-SNT of lab of research of STEP-NC technology country of university of Korea POHANG science and technology began by a definite date 5 years in June 2000 (divide 2 phase to undertake) STEP-NC considers to plan, in beginning turning STEP-NC mainly, from data the model changes the research that processes relevant technique to intelligence. Japan is at starting a name 2001 " digital Great Master " (the project of DIIGITAL MASTER) , although this project did not include international IMS STEP-NC the item in, but research work and STEP-NC build a model to concern. Project of international IMS STEP-NC was started Spring 2001, the country that enter and area have European Union, Switzerland, United States and Korea to wait, was in Germany 2003 inferior treasure (Aachen) city began to carry out workshop of an IMS STEP-NC. Korea to make CAD/CAM system and CNC controller can exchange data at any time, the system mixes the operation standard that STEP Tools company established STEP-NC database to be safeguarded oneself, administrative system. 2000 the end of the year, this company achieved the goal of the first phase, demonstrated to use on conference of the 3rd IRB(Industrial Review Board) " super model " complete the whole process of treatment object milling that has some kind of fabricating characteristics. Additional, this company still cooperates with laboratory of Lawrence Livermore state, on the foundation of OMAC development went STEP-NC interface. After this, STEP-NC organization held a series of meetings inside alive bound limits, if was in Germany 2001 Hannuowei (Hanover) held the meeting that begins STEP-NC work, decided supplier of final user, system, and the composition with academic companionate research. Was in Germany in October 2001 inferior treasure (Aachen) held the meeting that cuts with Yu Xi, to be based on 2 dimension of Xi Menzi by final user half milling machined a solution to undertake detecting reaching assessment. The meeting of outline cutting experiment of STEP-NC was held in Italy in November 2001, the STEP-NC prototype that is used at lumber, glass and cutting of stone material outline to the first undertook detecting reaching evaluating. Was in Germany in August 2002 Situjiate discussed turning craft, established the timetable that develops succeeding activity. The archetypal STEP-NC system that was used at electric spark treatment to the first on Swiss Geneva conference in December 2001 undertook checking reaching assessment. Discussed in Mu of German black Er in September 2002 CMM compositive the possibility in STEP-NC. Was in in November 2002 Situjiate decided Germany to examine in the conference, the crucial essential factor in electric spark treatment and outline cutting. The turning data model that conference of IMS STEP-NC project discussed to be used at AP238 agreement in October 2002 reachs relevant annotate. Found the annotate solution in turning model. Part program of a STEP-NC was created with CATIL software in American Boeing company in December 2002, undertook moving on the machine tool that has STEP-NC function in a of Xi Menzi company next, a variety of proof STEP-NC is supportable notting comply the machine tool of process designing of Lai Yu NC. Was in Germany in June 2003 the current progress that Situjiate introduced treatment of milling, turning, electric spark and outline cutting on the conference. The IMS STEP-NC meeting that held on March 12, 2003, main topic for discussion is the means that data exchanges, STEP Tools company demonstrated AP-203 file format (STEP standard) fast changeover becomes AP238 file form (STEP-NC standard) process. Will be in Germany in October 2004 inferior treasure (Aachen) holds STEP-NC to detect the conference of the respect, content involves: The solution of crucial question in discussing to detect with the progress work that at detecting the data model of content defines, discussion STEP-NC. 3, the numerical control construction of system that is based on STEP-NC from 20 centuries since 50 time, department of conventional numerical control integrates code of G of straight continue to use, M (ISO6983) , the data switch between CNC and CAD/CAM is one-way transmit, the spot cannot feedback directly to the modification of NC program CAD/CAM system. And use STEP-NC level, CNC and CAD/CAM can realize two-way data switch, the ground when making part program and optimized treatment description are reached feedbacks to design a section (CAD) , so that design a branch to undertake data is updated in time, those who reduce treatment message is missing. Current, STEP is fiducial had applied at CAD/CAPP/CAM system widely, the numerical control system that is based on STEP-NC consequently can read the STEP document that takes CAD/CAM system output directly (AP238 format) , the aftertreatment of treatment process designing in traditional CAD/CAM system implement the meeting in the process in CNC of → of CAD → CAM disappears gradually, those who replace is STEP-NC plug-in unit is joined in CAD/CAM system, output AP238 file directly. Replace ISO6983 completely to need to transfer considering ISO14649 periodic, because this is based on the numerical control system of STEP-NC besides executable AP238 file, still should have the function that executes traditional G/M code. It is so in the numerical control construction of system that is based on STEP-NC, should build STEP-NC interpreter not only (explanatory AP238 file) module, withhold the interpreter module of ISO6983 even, regard CNC as a subsystem of the system. STEP-NC and union of numerical control system have 3 kinds of pattern. Mode the 1 NC controller that still uses a convention, strictly speaking it just transfers one kind form, the CAD/CAM system that superstratum accords with STEP standard and STEP-NC interface realize two-way data to flow, lower level accords with STEP-NC standard code to change interface through increasing, STEP-NC data code changeover is the code such as G/M, realize the control of systems of pair of active numerical control then. Mode 2 it is mode of a kind of simpler, simple, with mode the distinction of 1 was using new-style STEP-NC controller at lower level, read directly take STEP data format to process a document. Mode 2 change mode and control way from iformation flow for, accord with the standard of STEP-NC already completely, had the character of machine tools of next generation numerical control, it is the model of is based on STEP-NC numerical control system on real significance. Mode 3 it is mode the development of 2 and perfect, of the system compositive degree taller, the function between design layer and workshop layer also will differentiate afresh, CAM system is macroscopical program and CAD system are compositive, the SFP(Shop Floor Programming) of module of spot process designing of microcosmic function and workshop layer is compositive. Change to make control a system to realize intelligence further, in mode of numerical control construction of system 3 in, still built the intelligent module that is based on STEP-NC, realize all sorts of intelligence to turn an operation, include knife course to generate, monitoring of the automatic choice of cutting tool, cutting tool, error detects compensation, online the advanced function that measure and breaks out incident processing to wait for a lot of numerical control systems, in order to improve manufacturing efficiency and treatment quality. 4, be based on STEP - the system of process designing of numerical control graph with the active and groovy system of process designing of numerical control graph of NC is based on ISO6983 standard, this standard is standard of a kind of numerical control process designing that faces treatment process. The mainstream Cheng of system of process designing of graph of conventional numerical control, the design information in flow all accords with IGES(Initial Graphics Exchange Specification) to convey a standard (the standard that IGES just exchanges about geometrical information, already was replaced by STEP place gradually as the development of numerical control technology) . The design news that CAD module makes undertakes cut and be computationaled through data module, undertake through interactive means technological process is designed at the same time, the knife that produces motion of descriptive cutting tool file, the numerical control code that creates campaign of drive machine tool via postposition processing module. As a result of code of ISO6983(G, M) the information content that the standard can describe is little, so system of this kind of process designing cannot provide more complex description for spare parts treatment. Additional, because the data between the patulous part of etc of CAD/CAM system, numerical control system cannot have two-way trade, a large number of information in creating treatment process change the job to repeat the appearance that have. Be based on STEP - in the Cheng of mainstream of system of process designing of graph of new-style numerical control of NC, CAD graph designs the data that module generates to convey a form to accord with STEP standard, wait for field to become by model information, geometry information and diagnostic information. Among them model information is the basis that process designing system uses the treatment model that accords with this product from the extraction in standard model library, geometrical information is the basis that uses contrail of affirmatory and particular cutting tool, diagnostic information is the basis that undertakes technological process is designed. After the information that designs module delivers technology program module, add craft information to generate numerical control to dictate place wants information, pass an instruction to create module again, make NC statement. Generate cutting tool contrail finally, hand-in-hand travel cutting is emulated and collision is checked, form examination information. If produce collision, this information will undertake feedbacking modification, because detect,information expression also accords with STEP standard, can be identified by design module so, each module all can undertake modification according to feedback information. Compare with photograph of active numerical control system, the place know exactly about sth of this system accords with STEP standard according to expression, systematic interior data can realize two-way flow. 5, at present STEP-NC standard finished the development trend of STEP-NCCNC Machining means only one part, consider domestic and internationally to be in to be based on the numerical control technology of STEP-NC start level, but its development momentum is powerful. Acquired studies achievement makes clear, this technology accuses logarithm technology and even mechanical manufacturing industry to bring far-reaching influence, basically reflect in the following respects: Numerical control machine tool will be deserted the code such as the G with long already continue to use, M (ISO 6983) , acting with more efficient, understand easily and operate the numerical control language with stronger sex of more convenient, description. Program of this kind of numerical control is passed a series of treatment task (working measure) all operations in describing production process, with object-oriented (is not to face an action) process designing makes interface of spot process designing changes greatly. According to current progress speculation, the wide application of STEP-NC will come true inside nearly 10 years, code of G, M will make the history from now on. Can come true between CAD/CAM/CNC without seam join. The two-way data of CAD/CAM and CNC flows, make design branch can understand treatment what is actually happening clearly, the information that and can be returned according to spot process designing comes back undertakes seasonable and fast adjustment to producing a program, attainable huge improves manufacturing efficiency. Additional, the function between CAD, CAM, CNC will differentiate afresh: The macroscopical program of CAM system will be as compositive as CAD system, microcosmic function will be as compositive as CNC. Realize the CNC Machining of open mode intelligence on complete meaning. As a result of ISO-6983(G/M code) treatment information content is too little, outside undertaking basic semantics to G code because of business of production of this each machine tool patulous, each other is incompatible between the system of control of numerical control machine tool that creates all sorts of kinds, the communication of block up data and information are shared, form " information Gu island " , realize open sex of the system hard. As contrary as this, if use STEP-NC level, standard of its data format, interface agrees completely, and all information that STEP-NC data contained treatment product place to need, to STEP-NC controller, it needs to tell CNC the content that should machine only, specific action by CNC write one's own ticket, make the program has good each other to operate gender and can transplant quality, the open sex that is CNC system and intelligence are changed laid solid foundation. Network is designed / make become reality. Contemporary production company shares all sorts of information through the network, the standard of STEP-NC data interface that because the whole world makes an enterprise use,unites at the same time, the data flow between the enterprise is OK undertake directly between the CNC machine tool that is based on a PC and database server, the three-dimensional work model in operating personnel to need pair of databases only undertakes simple parameter is installed, can make machine tool implementation expects an action. Imagine not hard, on the foundation that is based on network to make, database of many digitlization product model will appear, the number is made more hasten diversity. 6, last word STEP-NC is by international Organization for Standardization (ISO) develops a when rise cosmopolitan standard in recent years, it STEP fiducial and patulous to CNC Machining domain, the open sex that is CNC and intelligence are changed provided vast development space, at the same time it also solved CNC and CAD/CAM between two-way without crack connective core problem, eliminated long-term since the data that perplexes people is incompatible problem, also make for the network, make adroitly, fictitious make, the advanced production technology such as collateral project and mode offerred a technology to assure. According to the research of STEP Tools company data makes clear: Time of preparation of the data before the application of STEP-NC will make be machined at present decreases 75% , technology program time decreases 35% , handling time decreases 50% . Visible, develop the CNC system that is based on STEP-NC energetically (especially metric system is decided, database and STEP-NC controller) research to improving our country numerical control level and even raising automation to make a standard in the round is crucial. CNC Milling