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1、<p>  NC technology development trends</p><p>  1 NC system developments at home and abroad </p><p>  With the rapid development of computer technology, the traditional beginning of a funda

2、mental change manufacturing, the industrial developed countries spent huge sums of money on the modern manufacturing technology research and development, to create a new model. In modern manufacturing systems, CNC techno

3、logy is the key to technology, which combines microelectronics, computers, information processing, automatic detection, automatic control, such as the integration of advanced, a high-precision,</p><p>  For

4、a long time, China's CNC system for traditional closed architecture, but only as a non-intelligent CNC machine controller. Process variables based on experience in the form of pre-fixed parameters, processing procedu

5、res before the actual processing by hand or through CAD / CAM and automatic programming system prepared. CAD / CAM and CNC have no feedback control link, the entire manufacturing process CNC is a closed ring-opening impl

6、ementing agencies. In a complex and changing environment und</p><p>  2 NC technology development trends </p><p>  2.1 Performance development direction </p><p>  (1) high-speed hig

7、h-precision efficient speed, accuracy and efficiency of machinery manufacturing technology is the key performance indicators. As a result of the high-speed CPU chips, RISC chip, as well as multi-CPU control system with h

8、igh-resolution detector of the absolute exchange digital servo system, taken at the same time improve the machine dynamic and static characteristics of effective measures, the high-speed high-precision machine has been e

9、fficient greatly enhanced. </p><p>  (2) Flexible includes two aspects: CNC system itself flexibility, NC system is modular in design, functional coverage, can be cut and strong, and easy to meet the needs o

10、f different users; group control system flexibility, with a control system pursuant to the requirements of different production processes, materials flow and information flow automatically dynamically adjusted to maximiz

11、e their group control system performance. </p><p>  (3) Process of composite and multi-axis to reduce the process time for the main purpose of supporting the composite processing, and are moving towards mult

12、i-axis, multi-function control of the direction of series development. NC Machine Tool Technology composite refers to the workpiece in a single machine on a fixture, through an automatic tool change, rotating spindle hea

13、d or turntable, and other measures to accomplish multiple processes, multi-surface machining compound. Axis CNC technology, S</p><p>  (4) Real-time Intelligent early for the real-time system is usually rela

14、tively simple ideal environment, and its role is to scheduling tasks, to ensure that the task be completed within a specified time limit. And artificial intelligence is used to model the realization of mankind's vari

15、ous intelligent behaviors. To the development of science and technology today, real-time systems and artificial intelligence combined with each other towards artificial intelligence is a real-time response, a mor</p&g

16、t;<p>  2.2 functional development direction </p><p>  (1) The user interface is graphical user interface with the CNC system of dialogue between the user interface. Since different users interface re

17、quirements are different, thus the development of the workload of great user interface, user interface software developed into the most difficult part of. At present INTERNET, virtual reality, visualization in scientific

18、 computing and multimedia technologies, such as the user interface has put a higher demand. Graphical user interface greatly facilitate</p><p>  (2) visualization in scientific computing visualization in sci

19、entific computing can be used for efficient data processing and interpretation of data, so that the exchange of information is no longer limited to using the written word and language, and can direct the use of graphics,

20、 image, animation, video and other information. Visualization technology and virtual environment technology, to further broaden the application areas, such as a drawing design, virtual prototyping technology, which sho&l

21、t;/p><p>  (3) interpolation, and a variety of methods of compensation interpolation methods such as multiple linear interpolation, circular interpolation, cylindrical interpolation, space elliptical surface in

22、terpolation, thread interpolation, polar coordinates interpolation, 2 D +2 helical interpolation , NANO interpolation, interpolation NURBS (non-uniform rational B-spline interpolation), spline interpolation (A, B, C kind

23、), such as polynomial interpolation. A variety of functions such as compensation </p><p>  (4) high-performance PLC contents contents performance CNC system PLC control module can be directly used ladder dia

24、gram or high-level language programming, with intuitive online debugging and online help function. Programming tools include the standard used lathe and milling machine PLC user program an example, users may PLC user pro

25、gram standards on the basis of editorial changes, thus easily build their own applications. </p><p>  (5) application of multimedia technology of multimedia technology-computers, audio-visual and communicati

26、on technology, and it has the computer integrated voice, text, images and video information. In NC technology, multimedia technology can be applied to information processing integrated, intelligent, real-time monitoring

27、system in the field and production equipment fault diagnosis, monitoring of process parameters such as production has a significant value. </p><p>  2.3 Development of the Architecture </p><p> 

28、 (1) integration of a highly integrated CPU, programmable RISC chips and large-scale integrated circuits FPGA, EPLD, CPLD and ASIC ASIC chips that can improve the CNC system integration and hardware and software operatin

29、g speed. Application FPD flat panel display technology can improve display performance. Flat-panel displays with high science and technology content, light weight, small size, low power consumption and portability advant

30、ages can be realized Supersized, a counterweight to the emerg</p><p>  (2) easy to implement modular hardware modular NC systems integration and standardization. According to various functional requirements,

31、 the basic modules, such as CPU, memory, position servo, PLC, the input and output interfaces, and communications modules, making the standard Series products, through functional building-block approach to cutting the nu

32、mber of steps and modules, a NC system at different grades. </p><p>  (3) machine interconnection network for remote control of unmanned operation. Machine through networking, can be in any one machine on th

33、e other machine programming, configuration, operation, operating, different machine can be displayed on the screen each machine on the screen. </p><p>  (4) general-open the closed-loop control mode to adopt

34、 a common computer component Bus, modular, open, embedded architecture, ease of cutting, expansion and upgrading, can be composed of different grades, different types, different degree of integration CNC system. Closed-l

35、oop control mode is the traditional CNC system only for single closed-open-loop control mode proposed. The manufacturing process is a multi-variable control and the role of integrated processing complex process, includin

36、g proc</p><p>  3 PCNC new generation of intelligent CNC system </p><p>  Research and Development adapted to the current complexity of the manufacturing process, with the structure of the close

37、d-loop control system, a new generation of intelligent PCNC CNC system has become possible. PCNC NC intelligent system will be a new generation of intelligent computer technology, network technology, CAD / CAM, servo con

38、trol, adaptive control, dynamic data management and dynamic tool compensation, dynamic simulation and other high technology into one, a tight closure of the man</p><p><b>  數控技術發(fā)展趨勢</b></p>

39、<p>  1 國內外數控系統(tǒng)發(fā)展概況</p><p>  隨著計算機技術的高速發(fā)展,傳統(tǒng)的制造業(yè)開始了根本性變革,各工業(yè)發(fā)達國家投入巨資,對現代制造技術進行研究開發(fā),提出了全新的制造模式。在現代制造系統(tǒng)中,數控技術是關鍵技術,它集微電子、計算機、信息處理、自動檢測、自動控制等高新技術于一體,具有高精度、高效率、柔性自動化等特點,對制造業(yè)實現柔性自動化、集成化、智能化起著舉足輕重的作用。目前,數控技

40、術正在發(fā)生根本性變革,由專用型封閉式開環(huán)控制模式向通用型開放式實時動態(tài)全閉環(huán)控制模式發(fā)展。在集成化基礎上,數控系統(tǒng)實現了超薄型、超小型化;在智能化基礎上,綜合了計算機、多媒體、模糊控制、神經網絡等多學科技術,數控系統(tǒng)實現了高速、高精、高效控制,加工過程中可以自動修正、調節(jié)與補償各項參數,實現了在線診斷和智能化故障處理;在網絡化基礎上,CAD/CAM與數控系統(tǒng)集成為一體,機床聯(lián)網,實現了中央集中控制的群控加工。</p>&l

41、t;p>  長期以來,我國的數控系統(tǒng)為傳統(tǒng)的封閉式體系結構,CNC只能作為非智能的機床運動控制器。加工過程變量根據經驗以固定參數形式事先設定,加工程序在實際加工前用手工方式或通過CAD/CAM及自動編程系統(tǒng)進行編制。CAD/CAM和CNC之間沒有反饋控制環(huán)節(jié),整個制造過程中CNC只是一個封閉式的開環(huán)執(zhí)行機構。在復雜環(huán)境以及多變條件下,加工過程中的刀具組合、工件材料、主軸轉速、進給速率、刀具軌跡、切削深度、步長、加工余量等加工參數,

42、無法在現場環(huán)境下根據外部干擾和隨機因素實時動態(tài)調整,更無法通過反饋控制環(huán)節(jié)隨機修正CAD/CAM中的設定量,因而影響CNC的工作效率和產品加工質量。由此可見,傳統(tǒng)CNC系統(tǒng)的這種固定程序控制模式和封閉式體系結構,限制了CNC向多變量智能化控制發(fā)展,已不適應日益復雜的制造過程,因此,對數控技術實行變革勢在必行。</p><p>  2 數控技術發(fā)展趨勢</p><p>  2.1 性能發(fā)展方

43、向</p><p>  (1)高速高精高效化 速度、精度和效率是機械制造技術的關鍵性能指標。由于采用了高速CPU芯片、RISC芯片、多CPU控制系統(tǒng)以及帶高分辨率絕對式檢測元件的交流數字伺服系統(tǒng),同時采取了改善機床動態(tài)、靜態(tài)特性等有效措施,機床的高速高精高效化已大大提高。</p><p>  (2)柔性化 包含兩方面:數控系統(tǒng)本身的柔性,數控系統(tǒng)采用模塊化設計,功能覆蓋面大,可裁剪性強,便

44、于滿足不同用戶的需求;群控系統(tǒng)的柔性,同一群控系統(tǒng)能依據不同生產流程的要求,使物料流和信息流自動進行動態(tài)調整,從而最大限度地發(fā)揮群控系統(tǒng)的效能。</p><p>  (3)工藝復合性和多軸化 以減少工序、輔助時間為主要目的的復合加工,正朝著多軸、多系列控制功能方向發(fā)展。數控機床的工藝復合化是指工件在一臺機床上一次裝夾后,通過自動換刀、旋轉主軸頭或轉臺等各種措施,完成多工序、多表面的復合加工。數控技術軸,西門子88

45、0系統(tǒng)控制軸數可達24軸。</p><p>  (4)實時智能化 早期的實時系統(tǒng)通常針對相對簡單的理想環(huán)境,其作用是如何調度任務,以確保任務在規(guī)定期限內完成。而人工智能則試圖用計算模型實現人類的各種智能行為??茖W技術發(fā)展到今天,實時系統(tǒng)和人工智能相互結合,人工智能正向著具有實時響應的、更現實的領域發(fā)展,而實時系統(tǒng)也朝著具有智能行為的、更加復雜的應用發(fā)展,由此產生了實時智能控制這一新的領域。在數控技術領域,實時智能

46、控制的研究和應用正沿著幾個主要分支發(fā)展:自適應控制、模糊控制、神經網絡控制、專家控制、學習控制、前饋控制等。例如在數控系統(tǒng)中配備編程專家系統(tǒng)、故障診斷專家系統(tǒng)、參數自動設定和刀具自動管理及補償等自適應調節(jié)系統(tǒng),在高速加工時的綜合運動控制中引入提前預測和預算功能、動態(tài)前饋功能,在壓力、溫度、位置、速度控制等方面采用模糊控制,使數控系統(tǒng)的控制性能大大提高,從而達到最佳控制的目的。</p><p>  2.2 功能發(fā)展

47、方向</p><p>  (1)用戶界面圖形化 用戶界面是數控系統(tǒng)與使用者之間的對話接口。由于不同用戶對界面的要求不同,因而開發(fā)用戶界面的工作量極大,用戶界面成為計算機軟件研制中最困難的部分之一。當前INTERNET、虛擬現實、科學計算可視化及多媒體等技術也對用戶界面提出了更高要求。圖形用戶界面極大地方便了非專業(yè)用戶的使用,人們可以通過窗口和菜單進行操作,便于藍圖編程和快速編程、三維彩色立體動態(tài)圖形顯示、圖形模擬

48、、圖形動態(tài)跟蹤和仿真、不同方向的視圖和局部顯示比例縮放功能的實現。</p><p>  (2)科學計算可視化 科學計算可視化可用于高效處理數據和解釋數據,使信息交流不再局限于用文字和語言表達,而可以直接使用圖形、圖像、動畫等可視信息??梢暬夹g與虛擬環(huán)境技術相結合,進一步拓寬了應用領域,如無圖紙設計、虛擬樣機技術等,這對縮短產品設計周期、提高產品質量、降低產品成本具有重要意義。在數控技術領域,可視化技術可用于CA

49、D/CAM,如自動編程設計、參數自動設定、刀具補償和刀具管理數據的動態(tài)處理和顯示以及加工過程的可視化仿真演示等。</p><p>  (3)插補和補償方式多樣化 多種插補方式如直線插補、圓弧插補、圓柱插補、空間橢圓曲面插補、螺紋插補、極坐標插補、2D+2螺旋插補、NANO插補、NURBS插補(非均勻有理B樣條插補)、樣條插補(A、B、C樣條)、多項式插補等。多種補償功能如間隙補償、垂直度補償、象限誤差補償、螺距和

50、測量系統(tǒng)誤差補償、與速度相關的前饋補償、溫度補償、帶平滑接近和退出以及相反點計算的刀具半徑補償等。</p><p>  (4)內裝高性能PLC 數控系統(tǒng)內裝高性能PLC控制模塊,可直接用梯形圖或高級語言編程,具有直觀的在線調試和在線幫助功能。編程工具中包含用于車床銑床的標準PLC用戶程序實例,用戶可在標準PLC用戶程序基礎上進行編輯修改,從而方便地建立自己的應用程序。</p><p>  

51、(5)多媒體技術應用 多媒體技術集計算機、聲像和通信技術于一體,使計算機具有綜合處理聲音、文字、圖像和視頻信息的能力。在數控技術領域,應用多媒體技術可以做到信息處理綜合化、智能化,在實時監(jiān)控系統(tǒng)和生產現場設備的故障診斷、生產過程參數監(jiān)測等方面有著重大的應用價值。</p><p>  2.3 體系結構的發(fā)展</p><p>  (1)集成化 采用高度集成化CPU、RISC芯片和大規(guī)??删幊碳?/p>

52、成電路FPGA、EPLD、CPLD以及專用集成電路ASIC芯片,可提高數控系統(tǒng)的集成度和軟硬件運行速度。應用FPD平板顯示技術,可提高顯示器性能。平板顯示器具有科技含量高、重量輕、體積小、功耗低、便于攜帶等優(yōu)點,可實現超大尺寸顯示,成為和CRT抗衡的新興顯示技術,是21世紀顯示技術的主流。應用先進封裝和互連技術,將半導體和表面安裝技術融為一體。通過提高集成電路密度、減少互連長度和數量來降低產品價格,改進性能,減小組件尺寸,提高系統(tǒng)的可靠

53、性。</p><p>  (2)模塊化 硬件模塊化易于實現數控系統(tǒng)的集成化和標準化。根據不同的功能需求,將基本模塊,如CPU、存儲器、位置伺服、PLC、輸入輸出接口、通訊等模塊,作成標準的系列化產品,通過積木方式進行功能裁剪和模塊數量的增減,構成不同檔次的數控系統(tǒng)。</p><p>  (3)網絡化 機床聯(lián)網可進行遠程控制和無人化操作。通過機床聯(lián)網,可在任何一臺機床上對其它機床進行編程、設

54、定、操作、運行,不同機床的畫面可同時顯示在每一臺機床的屏幕上。</p><p>  (4)通用型開放式閉環(huán)控制模式 采用通用計算機組成總線式、模塊化、開放式、嵌入式體系結構,便于裁剪、擴展和升級,可組成不同檔次、不同類型、不同集成程度的數控系統(tǒng)。閉環(huán)控制模式是針對傳統(tǒng)的數控系統(tǒng)僅有的專用型單機封閉式開環(huán)控制模式提出的。由于制造過程是一個具有多變量控制和加工工藝綜合作用的復雜過程,包含諸如加工尺寸、形狀、振動、噪聲

55、、溫度和熱變形等各種變化因素,因此,要實現加工過程的多目標優(yōu)化,必須采用多變量的閉環(huán)控制,在實時加工過程中動態(tài)調整加工過程變量。加工過程中采用開放式通用型實時動態(tài)全閉環(huán)控制模式,易于將計算機實時智能技術、網絡技術、多媒體技術、CAD/CAM、伺服控制、自適應控制、動態(tài)數據管理及動態(tài)刀具補償、動態(tài)仿真等高新技術融于一體,構成嚴密的制造過程閉環(huán)控制體系,從而實現集成化、智能化、網絡化。</p><p>  3 智能化

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