【正文】 n power bigger characteristic target. May act according to the product specification, decided whether uses this kind of system. The direct current servo electrical machinery drives, encoder feedback semiclosure link numerical control system Half closedloop system examination part installs in among passes in the moving parts, indirectly surveys the executive ponent the position. It only can pensate a system ring circuit interior part of part the error, therefore, its precision pared to closedloop system precision low, but its structure and the debugging all pares the closedloop system to be simple. In makes the angular displacement examination part and the speed examination part and the servo electrical machinery time a whole then does not need to consider the position detector set installs the question. The current production numerical control system pany factory quite are many, overseas famous pany like German SIEMENS Corporation, Japanese FANUC Corporation。 Does not satisfy the production request to it the CNC system to carry on the renewal by newest CNC。 Second is NC, the addend reveals the installment on the ordinary 南 京 理 工 大 學(xué) 課程設(shè)計(jì)說明 書（英文翻譯） 9 engine bed, or adds the numerical control system, transforms the NC engine bed, the CNC engine bed。s started the largescale application numerical control engine bed. Its essence is, uses the information technology to the traditional industry (including the armed forces, airplane weapon industry) carries on the technological transformations. Except that uses outside the numerical control engine bed, FMC, FMS in the manufacture process, but also includes in the product development carries out CAD, CAE, CAM, the hypothesized manufacture as well as carries out MIS in the production management (management information system), CIMS and so on. As well as increases the information technology in its production product, including artificial intelligence and so on content. Because uses the information technology to the country foreign troops, the airplane weapon industry carries on the thorough transformation (to call it being an information based society), finally causes them the product in the international military goods and in the goods for civilian use market the petitive power greatly is the enhancement. But we in the information technology transformation tradition industry aspect pared to the developed country to fall behind approximately for 20 years. Like in our country engine bed capacity, numerical control engine bed proportion (numerical control rate) to 1995 only then %, but Japan has reached % in 1994, therefore every year has the massive mechanical and electrical products import. This also on from on macroscopic explained the engine bed numerical control transformation necessity. Thord, the numerical control transformation content and superiorly lacks 南 京 理 工 大 學(xué) 課程設(shè)計(jì)說明 書（英文翻譯） 8 Transformation industry starting In US, Japan and Germany and so on the developed country, their engine bed transforms took the new economical growth profession, thrives abundantly, is occupying the golden age. As a result of the engine bed as well as the technical unceasing progress, the engine bed transformation is the eternal topic. Our country39。s labor intensity, saved the labor force (a person to be possible to safeguard the multi Taiwan engine bed), reduced the work clothes, reduced the new product trial manufacturing cycle and the production cycle, might to the market demand make rapid reaction and so on. Above these superiority are the predecessor cannot imagine, is an extremely significant breakthrough. In addition, the engine bed numerical control carries out FMC (flexible manufacture unit), FMS (flexible manufacture system) as well as CIMS (puter integration manufacture system) and so on the enterprise being an information based society transformation foundation. The numerical control technology already became the manufacturing industry automation the core technology and the 南 京 理 工 大 學(xué) 課程設(shè)計(jì)說明 書（英文翻譯） 7 foundation technology. great watches the transformation the necessity From on macroscopic looked that, the industry developed country armed forces, the airplane weapon industry, in the end of the 7039。 1974 five dynasties microprocessor and 1990 sixth generation (overseas was called PCBASED) based on PC. Also must point out, although overseas already renamed as the puter numerical control (namely CNC). Also must point out, although overseas already renamed as the puter numerical control (namely CNC), but our country still the custom called the numerical control (NC). Therefore we daily say numerical control, the materially already was refers to puter numerical control. the numerical control future will develop tendency open style continues to, to develop based on the PC sixth generation of direction The software and hardware resources has which based on PC are rich and so on the characteristic, the more numerical controls serial production factory can step onto this path. Uses PC machine to take at least its front end machine, processes the manmachine contact surface, the programming, the association Question and so on correspondence, undertakes the numerical control duty by the original system. PC machine has the friendly manmachine contact surface, will popularize to all numerical controls system. The longdistance munication, the longdistance diagnosis and the service will be more mon. approaches and the high accuracy development This is adapts the engine bed to be high speed and the high accuracy direction need to develop. develops to the intellectualized direction Along with the artificial intelligence in the puter domain unceasing seepage and the development, the numer