XY工作臺與控制系統(tǒng)設計【數(shù)控X-Y工作臺設計（步進電機）】【說明書+CAD】

XY工作臺與控制系統(tǒng)設計【數(shù)控X-Y工作臺設計（步進電機）】【說明書+CAD】,數(shù)控X-Y工作臺設計（步進電機）,說明書+CAD,XY工作臺與控制系統(tǒng)設計【數(shù)控X-Y工作臺設計（步進電機）】【說明書+CAD】,xy,工作臺,控制系統(tǒng),設計,數(shù)控,步進,電機,機電,說明書,仿單,cad 大 學 畢業(yè)設計（論文）XY工作臺與控制系統(tǒng)設計院(系)、部： 學生姓名： 學 號: 專 業(yè)： 班 級： 指導教師： 完成時間： 摘 要一個較完善的機電一體化系統(tǒng)，應包含以下幾個基本要素：機械本體、動力與驅動部分、執(zhí)行機構、傳感測試部分、控制及信息處理部分。機電一體化是系統(tǒng)技術、計算機與信息處理技術、自動控制技術、檢測傳感技術、伺服傳動技術和機械技術等多學科技術領域綜合交叉的技術密集型系統(tǒng)工程。新一代的CNC系統(tǒng)這類典型機電一體化產(chǎn)品正朝著高性能、智能化、系統(tǒng)化以及輕量、微型化方向發(fā)展。關鍵字：機電一體化的基礎 基本組成要素 特點 發(fā)展趨勢Abstract A perfect integration of machinery system, should contain the following several base elements: Basic machine, power and actuation part, implementing agency, sensing measurement component, control and information processing part. The integration of machinery is the system technology, the computer and the information processing and management technology, the automatic control technology, the examination sensing technology, the servo drive technology and the mechanical skill and so on multi-disciplinary area of technology synthesis overlapping technology-intensive systems engineering. New generations CNC system this kind of model integration of machinery product toward the high performance, the intellectualization, the systematization as well as the featherweight, the microminiaturized direction develops. key words: Integration of machinery foundation basic component elements characteristic trend of development.目 錄第一章 滾珠絲杠副的選擇 3 1.1 滾珠絲杠副的支撐形式 31.2 滾珠絲杠副的特點 31.3 滾珠絲杠副的設計計算 41.4 選擇滾珠絲杠副 51.5 穩(wěn)定性驗算 71.6 剛度驗算 81.7 效率驗算 9第二章 導向機構的設計10 2.1導軌的功用10 2.2、 滾動直線導軌的選擇程序10 2.2、 直線運動滾動支承系統(tǒng)負荷的計算 10第三章 步進電動機的選擇 12 3.1 步進電動機的工作原理12 3.2 選擇電動機 13第四章 滾動軸承的計算 14 4.1 支撐方案的確定 14 4.2 軸承的校核 15第五章 機床數(shù)控系統(tǒng)硬件電路設17第一節(jié) 設計內(nèi)容17第二節(jié) 設計步驟17第三節(jié) 機床數(shù)控系統(tǒng)硬件電路設計21第六章 系統(tǒng)控制軟件設計22第七章 結束語與致謝29總 結 16參考文獻 17 第一章 滾珠絲杠副的選擇1.1 滾珠絲杠副的支承形式支承應限制絲杠的軸向竄動.較短的絲杠或垂直安裝的絲杠,可以一端固定,一端無支承.水平安裝絲杠較長時, 可以一端固定,一端游動;對于精密和高精度機床的滾珠絲杠副,為了提高絲杠的拉壓剛度,可以兩端固定.為了補償熱膨脹和減少絲杠下垂,兩端固定絲杠時還可以進行預拉伸。一般情況下,應以固定端作為軸向定位基準,從固定端起計算絲桿杠副的長度誤差.此外,應盡可能固定端作為驅動端?？紤]到本設計的結構與要求,我們決定采用一端固定一端游動(F-S)的支承形式, 如圖1.1所示。一端固定一端游動（FS）。固定端采用深溝球軸承2和雙向推力球軸承4，可分別承受徑向和軸向負載，螺母1、擋圈3、軸肩、支撐座5臺肩、端蓋7提供軸向限位，墊圈6可調(diào)節(jié)推力軸承4的軸向預緊力。游動端需徑向約束，軸向無約束。采用深溝球軸承8，其內(nèi)圈由擋圈9限位，外圈不限位，以保證絲杠在受熱變形后可在游動端自由伸縮。圖1.1 一端固定一端游動支承這種支承形勢有以下一些特點： 1.需保持螺母與兩端支撐同軸,故結構較復雜,工藝較困難。2.絲杠的軸向剛度較高。3.壓桿穩(wěn)定性和臨界轉速較高。4.絲杠有熱膨脹的余地。5.適用于較長的臥式安裝絲杠。1.2 滾珠絲杠副的特點1.傳動效率高 效率高達90%95%,耗費的能量僅為滑動絲杠的1/3。2.運動具有可逆性 即可將回轉運動變?yōu)橹本€運動,又可將直線運動變?yōu)榛剞D運動,且逆?zhèn)鲃有蕩缀跖c正傳動效率相同。3.系統(tǒng)剛度好 通過給螺母組件內(nèi)施加預壓來獲得較高的系統(tǒng)剛度,可滿足各種機械傳動要求,無爬行現(xiàn)象,始終保持運動的平穩(wěn)性和靈敏性。4.傳動精度高 經(jīng)過淬硬并精磨螺紋滾道后的滾珠絲杠副本身就具有和高的制造精度,又由于摩擦小,絲桿副工作時溫升和熱變形小,容易獲得較高的傳動精度。5.使用壽命長 滾珠是在淬硬的滾道上作滾動運動,磨損極小,長期使用后仍能保持其精度,因而壽命長,且具有很高的可靠性。其壽命一般比滑動絲杠高56倍。6.不能自鎖 特別是垂直安裝的絲杠，當運動停止后，螺母將在重力作用下下滑，故常需設置制動裝置。7.制造工藝復雜 滾珠絲杠和螺母等零件加工精度、表面粗糙度要求高，制造成本高。由于滾珠絲杠副獨特的性能而受到極高的評價,因而已成為數(shù)控機床,精密機械,各種省力機械設備及各種機電一體化產(chǎn)品中不可缺少的傳動機構。 1.3 滾珠絲杠副的設計計算有效行程100*100，實際工作時工件及夾具重最大120公斤，最大空運行速度,最大加工速度定位精度,重復定位精度,脈沖當量,壽命40000小時（1）步距角 ， ， ，。先假設p=。表1.1切削力速度時間比正常銑削5002.570%快速點定位0530%（2） 絲杠轉速 快速點定位30%，加工70%。（3） 當量轉速加工 點定位 （4） 絲杠負荷 當量載荷導軌摩擦力,。 精密加工=500N，加工時總載荷=507.2N 快速點定位= =7.2N（5） 當量負荷1.4 選擇滾珠絲杠副（1） 小時，由機電一體化系統(tǒng)設計手冊表2.8-63，2.8-64，查得：-壽命系數(shù)，。-轉速系數(shù)，。- 綜合系數(shù)， 其中為溫度系數(shù)，查表1-2得1； 為硬度系數(shù)，查表1-3得 1.0； 為精度系數(shù)，查表1-4得1.0（絲杠精度為13級）； 為負荷性質系數(shù)，查表1-5得1.3； 為可靠性系數(shù)，查表1-6得0.53（可靠性為90%）?？傻茫?。表1-2溫度系數(shù)工作溫度175表1-3 硬度系數(shù)硬度（HRC）5552.55047.54540動負荷硬度影響系數(shù)1.01.111.351.561.922.43.85靜負荷硬度影響系數(shù)1.01.111.401.672.12.654.5表1-4精度系數(shù)精度等級1、2、34、57101.00.90.80.7表1-5 負荷性質系數(shù)負荷性質無沖擊平穩(wěn)運轉一般運轉有沖擊和振動運動11.21.21.51.52.5表1-6 可靠性系數(shù)可靠度(%)9095969798991.000.620.53.44.330.21（2）根據(jù)選擇滾珠絲杠副1）假設選用FC1型號，按滾珠絲杠副的額定動載荷Ca等于或稍大于的原查教材表2-9選以下型號規(guī)格：FC1-2505-2.5 ，Ca=9610N由教材表2-9得絲杠副數(shù)據(jù)：公稱直徑 導程 螺旋角 =滾珠直徑 2）按教材表2-1中尺寸公式計算：滾道半徑 偏心距絲杠直徑1.5 穩(wěn)定性驗算1）由于一端軸向固定的長絲杠在工作時可能會發(fā)生失穩(wěn)，所以在設計時應驗算其安全系數(shù)S，其值應大于絲杠副傳動機構允許安全系數(shù)（見表1.2）。表1.7支撐方式有關系數(shù) 一端固定一端自由（F-O）一端固定一端游動（F-S）兩端固定（F-F）342.53.322/31.8753.9274.730 絲杠不會發(fā)生失穩(wěn)的最大載荷稱為臨界載荷按下式計算：式中，E為絲杠材料的彈性模量，對于剛，E=206GPa；為絲杠工作長度（m）; 為絲杠危險截面的軸慣性矩；為長度系數(shù)，見表1.2。依題意， 取，則安全系數(shù) 。查表1.2，=2.53.3 。 ， 絲杠是安全的，不會失穩(wěn)。 2）高速絲杠工作時可能發(fā)生共振，因此需要驗算其不會發(fā)生共振的最高轉速臨界轉速。要求絲杠的最大轉速。臨界轉速可按下式計算式中，為臨界轉速系數(shù)，見表1.2。取 ，則=834r/min。 所以絲杠工作時不會發(fā)生共振。3）此外滾珠絲杠副還會受值的限制，通常要求。所以該絲杠副工作穩(wěn)定。1.6 剛度驗算 滾珠絲杠在工作負載和轉矩共同作用下引起每個導程的變形量為式中，A-為絲杠面積，；-為絲杠的極慣性距，；G-為絲杠的切變模量，對鋼；-為轉矩。式中，-為摩擦角，其正切函數(shù)值為摩擦系數(shù)；-為平均工作負載。取摩擦系數(shù) 按最不利的情況?。ㄆ渲校﹦t絲杠在工作長度上的彈性變形所引起的導程誤差為通常要求絲杠的導程誤差應小于其傳動精度的1/2，即該絲杠的滿足上式，所以其剛度可滿足要求。1.7 效率驗算滾珠絲杠副的傳動效率為要求在90%98%之間，所以該絲杠副合格。 經(jīng)上述驗證，F(xiàn)C1-2505-2.5各項性能均符合要求，可選用。第二章 導向機構的設計2.1 導軌的功用機電一體化產(chǎn)品要求其機械系統(tǒng)的各運動機構必須得到安全的支承，并能準確的完成其特定方向的運動。這個任務就由導向機構來完成。機電一體化產(chǎn)品的導向機構是導軌，其作用是支承和導向。2.2 滾動直線導軌的選擇程序在設計選用滾動直線導軌時，除應對其使用條件，包括工作載荷、精度要求、速度、工作行程、預期工作壽命進行研究外，還須對其剛度、摩擦特性及誤差平均、阻尼特性等綜合考慮，從而達到正確合理的選用，以滿足主機技術性能的要求。2.3 直線運動滾動支承系統(tǒng)負荷的計算直線運動支承系統(tǒng)的負荷與導軌配置形式(水平、豎直、傾斜等),移動件的重心和力作用點的位置,導軌上移動件牽引力作用點的位置,啟動及停止時的慣性力以及切削力等有關。本設計的直線運動導軌安裝形式為水平,采用臥式導軌、滑塊座移動。 圖2.1 導軌2.4 導軌的選擇 由機床設計要求可知對該導軌設計的基本要求為:作用在滑座上的載荷，滑座個數(shù)，單向行程長度，每分鐘往復次數(shù)為4，用于輕型機床的工作臺。 導軌的額定工作時間壽命=40000小時表2-1 硬度系數(shù)滾道表面硬度HRC6058555350451.00.980.900.710.540.38表2-2 溫度系數(shù)工作溫度/1001.001001500.901502000.732002500.61表2-3 接觸系數(shù)每根導軌上的滑塊數(shù)11.0020.8130.7240.6650.61表2-4負荷系數(shù)工作條件無外部沖擊或震動的低速運動場合。速度小于15m/min11.5無明顯沖擊或震動的中速運動場合。速度小于60m/min1.52無外部沖擊或震動的高速運動場合。速度大于60m/min22.5（1） 計算額定動載荷滑座的運動速度最大為5m/min15mmin，工作溫度在100以下，導軌滾道硬度為60HRC，無明顯沖擊和振動，每根導軌上滑塊配置數(shù)為2。由 得：因滑塊座M=4,所以每根導軌上2個，由表2-12-4確定， , , 則由式得 其中 選用的是漢江機床廠的HJG-D系列滾動直線導軌,查其產(chǎn)品手冊知, HJG-D型號的導軌的Ca值為17500N,能滿足五年的使用要求,所以可選用.第三章 步進電機的選擇步進電機在自動控制系統(tǒng)中作執(zhí)行元件。是位與電氣控制裝置和機械執(zhí)行裝置接點部位的一種能量轉換裝置，它能在控制裝置的控制下，將輸入的各種形式的能量轉換成機械能。3.1步進電機的工作原理三相反應式步進電機的工作原理如圖5.3所示，其中步進電機的定子上有6個齒，其上分別纏有、三相繞組,構成三對磁極,轉子上則均勻分布著4個齒。步進電動機采用直流供電。當、三相繞組輪流通電時，通過電磁力吸引步進電動機轉子一步一步地旋轉。圖3.13.1.1 步進電動機的通電方式和步距角如果步進電動機繞組的每一次通斷電操作稱為一拍，每拍中只有一相繞組通電，其余斷電，這種通電方式稱為單相通電方式。如果步進電動機通電循環(huán)的每拍中都有兩相繞組通電，這種通電方式稱為雙相通電方式。步距角是指步進電動機每一拍轉過的角度。一個m相步進電動機，如其轉子上有z個齒，則其步距角可通過下式計算，式中是通電方式系數(shù)，當采用單相或雙相通電方式時，當采用單雙向輪流通電方式是，。3.2 選電動機3.2.1電動機轉動慣量的計算滾珠絲杠的轉動慣量，已知名義直徑，螺距p=10mm.長度L=2741mm.則查表6.6-28（機床設計手冊）可得1m長的絲杠轉動慣量為35.76kg.cm。那么次滾珠絲杠的轉動慣量J=35.762.741=98.01kg.cm。 絲杠折算到電動機軸上的轉動慣量J=(2030)98.01=43.56kg.cm。 工作臺折算到絲杠的慣量，已知導程10mm，工作臺以上負載1000kg。，查表6.6-29得：重10000N的轉動慣量JG=25.80kg.cm。絲杠傳動是傳動系統(tǒng)折算到電動機軸上的總的轉動慣量 式中J船工系統(tǒng)折算到電動機軸上的轉動慣量（kg.cm） J1齒輪Z1的轉動慣量（kg.cm） J2-齒輪Z2轉動慣量（kg.cm） JS絲杠的轉動慣量（kg.cm） m工作臺及共建等移動部件的質量（N） L0絲杠得導程（cm） J1=0.78D1L110=0.78（5.988）310=3kg.cmJ2=0.78D2L210=0.78（9.02）310=15.5kg.cmJZ=JM+9.34+=81.06kg.cm3.2.2 電機力矩的計算由于此縱向進給系統(tǒng)不做切削運動，故只計算快速空載和快速進給力矩。 快速空載啟動時所需力矩Mq=MA+Mf+M0Mq快速空載時的啟動力矩（N.m）Mf折算到電動機上的摩擦力矩（N.m）M0由于絲杠的預緊折算到電動機軸上的附加摩擦力矩（N.m） 快速進給時所需力矩MJMJ=Mf+MO 因為MJMq，故不用計算這個力矩。Mq= JZ=81.06=424.214N.cm摩擦力矩Mf（N.） Mf=,式中F0導軌的摩擦力（N）i-齒輪降速比-傳動鏈效率，一般可取=0.70.85Mf=6.6N.cm附加力矩M0=式中F滾軸絲杠預加負荷，這里取FM=5000N.L0滾珠絲杠導程（）-滾珠絲杠未預緊時傳動效率，一般取大于0.9，這里取0.95M0= =60.8N.cmMq=MA+Mf+M0=424.214+6.6+60.8=491.65N.=4.92N.m3.2.3 電機的選型查表得，選擇電動機120MB100A，它的啟動轉矩9.31N.m。120MB100A屬于CB/MB系列交流伺服電機采用了高性能磁性材料和優(yōu)化的正弦波磁路設計，具有小型化、全密封、高精度、高相應、低噪音、地震動的特點，特別適合于對動態(tài)和穩(wěn)態(tài)定性要求高的場合。技術特點A、高性能銣鐵硼永磁材料，純正弦波磁路設計。B、鋁合金精美外觀，體積緊湊。C、小慣量CB系列和中慣量MB系列。D、動態(tài)性能好。E、過載能力強。以上數(shù)據(jù)機電一體化系統(tǒng)設計手冊 第四章 滾動軸承的計算4.1 支撐方案的確定考慮滾珠絲杠在軸向的伸縮變形，故考慮在支撐方面采用一端固定，一端游動。在綜合考慮后，決定用角接觸球軸承完成支承。固定端用一對背靠背接觸球軸承，而用單個角接觸球軸承支于游動端。 在選擇了滾珠絲杠的型號后，由于我們采用的是現(xiàn)存的絲杠。所以尺寸都已經(jīng)確定，初選固定端7307B/DB背對背型號內(nèi)徑d=35，D=80,B=42。 游動端采用7307B型號B=21軸承座連接孔14442、 M12-44.2 軸承型號選型及校核軸向力Fa=383.3N 徑向力Fr=10000/2=5000N 因為Fa/Fr=5000/383.31.14（查機械設計第七版表13-5） 則X=0.35,Y=0.57。 fp取1.5（中等沖擊或中等慣性力.查表13-6同上）動載荷P=fp(XFr+YFa)=1.5（0.355000+0.57883.3） =3380.25N 預計壽命Lh=5000h,轉速n=1000r/min1.5=666.7計算基本額定動載荷C= 滾動軸承受理分析圖 因為C=19768.15Ca=65600,所以符合要求。第五章 數(shù)控系統(tǒng)硬件電路設計第一節(jié) 設計內(nèi)容.按照總統(tǒng)方案以及機械結構的控制要求，確定硬件電路的方案，并繪制系統(tǒng)電氣控制的結構框圖；.選擇計算機或中央處理單元的類型；.根據(jù)控制系統(tǒng)的具體要求設計存儲器擴展電路；.根據(jù)控制對象以及系統(tǒng)工作要求設計擴展接口電路，檢測電路，轉換電路以及驅動電路等；.選擇控制電路中各器件及電氣元件的參數(shù)和型號；.繪制出一張清晰完整的電氣原理圖，圖中要標明各器件的型號，管腳號及參數(shù)；.說明書中對電氣原理圖以及各有關電路進行詳細的原理說明和方案論證。第二節(jié) 設計步驟.確定硬件電路的總體方案。數(shù)控系統(tǒng)的硬件電路由以下幾部分組成：1 主控制器。即中央處理單元CPU2 總線。包括數(shù)據(jù)總線，地址總線，控制總線。3 存儲器。包括只讀可編程序存儲器和隨機讀寫數(shù)據(jù)存儲器。4 接口。即I/O輸入輸出接口。數(shù)控系統(tǒng)的硬件框圖如下所示：中央處理單元CPU存儲器RAMROM外設：鍵盤，顯示器，打印機，磁盤機，通訊接口等輸入/輸出I/O接口信號變換控制對象.主控制器的選擇系列單片機是集中，端口及部分等為一體的功能性很強的控制器。只需增加少量外圍元件就可以構成一個完整的微機控制系統(tǒng)，并且開發(fā)手段齊全，指令系統(tǒng)功能強大，編程靈活，硬件資料豐富。本次設計選用芯片作為主控芯片。.存儲器擴展電路設計(）程序存儲器的擴展單片機應用系統(tǒng)中擴展用的程序存儲器芯片大多采用芯片。其型號有：2716，2732，2764，27128，27258，其容量分別為k,4k,8k,16k32k。在選擇芯片時要考慮與時序的匹配。所能讀取的時間必須大于所要求的讀取時間。此外，還需要考慮最大讀出速度，工作溫度以及存儲器容量等因素。在滿足容量要求時，盡量選擇大容量芯片，以減少芯片數(shù)量以簡化系統(tǒng)。綜合以上因素，選擇芯片作為本次設計的程序存儲器擴展用芯片。單片機規(guī)定0口提供為位地址線，同時又作為數(shù)據(jù)線使用，所以為分時用作低位地址和數(shù)據(jù)的通道口，為了把地址信息分離出來保存，以便為外接存儲器提高低位的地址信息，一般采用芯片作為地址鎖存器，并由發(fā)出允許鎖存信號ALE的下降沿，將地址信息鎖存入地址鎖存器中。由以上分析，采用EPROM芯片的程序存儲器擴展電路框圖如下所示： A12 A8 2764A7A0 D7 D0 P1.7 P1.0 P2.4 P2.0 ALE P0.7 P0.0 譯碼電路G74LS372擴展2764電路框圖(）數(shù)據(jù)存儲器的擴展由于內(nèi)部只有字節(jié)，遠不能滿足系統(tǒng)的要求。需要擴展片外的數(shù)據(jù)存儲器。單片機應用系統(tǒng)數(shù)據(jù)存儲器擴展電路一般采用6116,6262靜態(tài)RAM數(shù)據(jù)存儲器。本次設計選用芯片作為數(shù)據(jù)存儲器擴展用芯片。其擴展電路如下所示： P2.4 P2.0ALE P0.7 P0.0 A12 A8A7 6264A0D7D0 D0譯碼電路G74LS372擴展6264電路框圖(）譯碼電路在單片機應用系統(tǒng)中，所有外圍芯片都通過總線與單片機相連。單片機數(shù)據(jù)總線分時的與各個外圍芯片進行數(shù)據(jù)傳送。故要進行片選控制。由于外圍芯片與數(shù)據(jù)存儲器采用統(tǒng)一編址，因此單片機的硬件設計中，數(shù)據(jù)存儲器與外圍芯片的地址譯碼較為復雜?？刹捎镁€選法和全地址譯碼法。線選法是把單獨的地址線接到外圍芯片的片選端上，只要該地址線為低電平，就選中該芯片。線選法的硬件結構簡單，但它所用片選線都是高位地址線，它們的權值較大，地址空間沒有充分利用，芯片之間的地址不連續(xù)。對于和容量較大的應用系統(tǒng)，當芯片所需的片選信號多于可利用的地址線的時候，多采用全地址譯碼法。它將低位地址作為片內(nèi)地址，而用譯碼器對高位地址線進行譯碼，譯碼器輸出的地址選擇線用作片選線。本設計采用全地址譯碼法的電路分別如下圖所示：（4）存儲器擴展電路設計8031單片機所支持的存儲系統(tǒng)起程序存儲器和數(shù)據(jù)存儲器為獨立編址。該設計選用程序存儲器2764和數(shù)據(jù)存儲器6264組成8031單片機的外存儲器擴展電路，單片機外存儲器擴展電路如下：（5）擴展電路設計(a).通用可編程接口芯片單片機共有個位并行接口，但供用戶使用的只有1口及部分3 口線。因此要進行口的擴展。與微機接口較簡單，是微機系統(tǒng)廣泛使用的接口芯片。8155Y與8031的連接方式如下圖所示(b).鍵盤，顯示器接口電路鍵盤，顯示器是數(shù)控系統(tǒng)常用的人機交互的外部設備，可以完成數(shù)據(jù)的輸入和計算機狀態(tài)數(shù)據(jù)的動態(tài)顯示。通常，數(shù)控系統(tǒng)都采用行列式鍵盤，即用口線組成行，列結構，按鍵設置在行列的交點上。數(shù)控系統(tǒng)中使用的顯示器主要有和。下圖所示為采用接口管理的鍵盤，顯示器電路。它有鍵和位顯示器組成。為了簡化秒電路，鍵盤的列線及顯示器的字位控制共用一個口，即共用的P口進行控制，鍵盤的行線由口擔任，顯示器的字形控制由8155的PB口擔任。鍵盤顯示器接口電路如下所示：4步進電機驅動電路設計(1）脈沖分配器步進電機的控制方式由脈沖分配器實現(xiàn)，其作用是將數(shù)控裝置送來的一系列指令脈沖按一定的分配方式和順序輸送給步進電機的各相繞組，實現(xiàn)電機正反轉。數(shù)控系統(tǒng)中通常使用集成脈沖分配器和軟件脈沖分配器。本設計采用集成脈沖分配器YB013。采用YB013硬件環(huán)行分配器的步進電機接口線路圖如下：（2）光電隔離電路在步進電機驅動電路中，脈沖分配器輸出的信號經(jīng)放大后控制步進電機的勵磁繞組。如果將輸出信號直接與功率放大器相連，將會引起電氣干擾。因此在接口電路與功率放大器間加上隔離電路實現(xiàn)電氣隔離，通常使用光電耦合器。光電耦合器接線圖如下：（3）功率放大器脈沖分配器的輸出功率很小，遠不能滿足步進電機的需要，必須將其輸出信號放大產(chǎn)生足夠大的功率，才能驅動步進電機正常運轉。因此必須選用功率放大器，需根據(jù)步進電機容量選擇功率放大器。本設計選用功率放大器。5其它輔助電路設計（）的時鐘電路單片機的時鐘可以由兩種方式產(chǎn)生：內(nèi)部方式和外部方式。內(nèi)部方式利用芯片的內(nèi)部振蕩電路，在XTAL1,XTAL2引腳上外接定時元件，如下圖所示。晶體可以在.之間任意選擇，耦合電容在pF之間，對時鐘有微調(diào)作用。采用外部時鐘方式時，可將XTAL1直接接地，XTAL2接外部時鐘源。8031XTAL1XTAL2時鐘電路（）復位電路單片機的復位都是靠外部電路實現(xiàn)。在時鐘工作后，只要在引腳上出現(xiàn)ms以上的高電平，單片機就實現(xiàn)狀態(tài)復位，之后便從單元開始執(zhí)行程序。在實際運用中，若系統(tǒng)中有芯片需要其復位電平與復位要求一致時，可以直接相連。當晶振頻率選用z時，復位電路中取，取，取。實用復位電路圖如下所示：（）越界報警電路為了防止工作臺越界，可分別在極限位置安裝限位開關。利用光電耦合電路，將行程開關接至發(fā)光二極管的陰極，光敏三極管的輸出接至的口1.0。當任何一個行程開關被壓下的時候，發(fā)光二極管就發(fā)光，使光敏三極管導通，由低電平變成高電平?？衫密浖O計成查詢的方法隨時檢查有無越界信號。也可接成從光敏三極管的集電極輸出接至的外部中斷引腳（或），采用中斷方式檢查越界信號。越界報警電路如下圖所示第三節(jié) 機床數(shù)控系統(tǒng)硬件電路設計該系統(tǒng)選用系列的作為主控制器。擴展存儲電路為一片2732EPROM和一片6264RAM。程序存儲器擴展為，數(shù)據(jù)存儲器擴展為。的片選控制端直接接地，該電路始終處于選中狀態(tài)。系統(tǒng)復位以后，CPU從0000H開始執(zhí)行監(jiān)控程序。6264的片選端由譯碼器（74LS138）的Y2輸出提供。所以6264的空間地址為4000。系統(tǒng)的擴展I/O接口電路選用通用可編程并行輸入/輸出接口芯片8155。8155的片選端接至譯碼器（74LS138）的Y4的輸出端，故8155控制命令寄存器及PA，PB，PC口的地址號分別為8000H及8001H，8002H，8003H。8155RAM區(qū)的地址為8000H80FFH。8155的A口為控制工作抬X，Y向電機的接口。為防止功率放大器高電壓的干擾，不步進電機接口與功率放大器之間采用光電隔離。鍵盤與顯示器設計在一起，8155的PC口擔任鍵盤的列線及顯示器的掃描控制；PB口的PB0PB3為鍵盤的行線。8031的P1口為顯示器的字形輸出口。該系統(tǒng)采用4X6共24個行列式鍵盤和6位8段共陰極LED顯示器。為了增加數(shù)碼管顯示亮度，分別在字形口和字位口加74LS07進行驅動。PB口剩余的I/O線PB4PB7分別作為工作臺+X，+Y，-X，-Y四個方向的行程限位控制信號。在軟件設計上8155的PA口，PC口設置為輸出，PB口設置為輸入。計算機隨時巡回檢測PB4PB7的電平，當某I/O線為0時，應立即停止X，Y向電機的驅動，并發(fā)出報警信號。另外，光電隔離器的輸出端必須采用隔離電源。隔離電源選用7805三端集成穩(wěn)壓器設計。數(shù)控系統(tǒng)總的電氣原理圖以及圖中各元件的參數(shù)和型號見附（二），附（三）。第六章 系統(tǒng)控制軟件的設計(一).系統(tǒng)控制軟件的主要內(nèi)容數(shù)控系統(tǒng)是按照事先編好的控制程序來實現(xiàn)各種控制功能。按照功能可將數(shù)控系統(tǒng)的控制軟件分為以下幾個部分：1、系統(tǒng)管理程序：它是控制系統(tǒng)軟件中實現(xiàn)系統(tǒng)協(xié)調(diào)工作的主體軟件。其功能主要是接受操作者的命令，執(zhí)行命令，從命令處理程序到管理程序接收命令的環(huán)節(jié)，使系統(tǒng)處于新的等待操作狀態(tài)。2、零件加工源程序的輸入處理程序。該程序完成從外部I/O設備輸入零件加工源程序的任務。3、插補程序。根據(jù)零件加工源程序進行插補，分配進給脈沖。4、伺服控制程序。根據(jù)插補運算的結果或操作者的命令控制伺服電機的速度，轉角以及方向。診斷程序。包括移動不見移動超界處理，緊急停機處理，系統(tǒng)故障診斷，查錯等功能。6、機床的自動加工及手動加工控制程序。7、鍵盤操作和顯示處理程序。包括監(jiān)視鍵盤操作，顯示加工程序、機床工作狀態(tài)、操作命令等信息。(二).軟件設計1.系統(tǒng)控制功能分析數(shù)控X-Y工作臺的控制功能包括：（1）、系統(tǒng)初始化。如對I/O接口8155，8255A進行必要的初始化工作，預置接口工作方式控制字。（2）、工作臺復位。開機后工作臺應該自動復位，亦可手動復位。（3）、輸入和顯示加工程序。（4）、監(jiān)視按鍵，鍵盤及開關。如監(jiān)視緊急停機鍵及行程開關，鍵盤掃描等功能。（5）、工作臺超程顯示與處理。工作臺位移超過規(guī)定值時應該立即停止工作臺的運動，并顯示相應的指示字符。（6）、工作臺的自動控制。（7）、工作臺的手動控制。（8）、工作臺的聯(lián)動控制。2.系統(tǒng)管理程序控制 管理稱許是系統(tǒng)的主程序，開機后即進入管理程序。其主要功能是接受和執(zhí)行操作者的命令。在設計管理程序時，應確定接收命令的形式，系統(tǒng)的各種操作功能等。數(shù)控X-Y工作臺的基本操作功能有：輸入加工程序，自動加工，刀位控制，工作臺位置控制，手動操作，緊急停機等。根據(jù)以上分析，設計管理程序流程圖如下所示：開始系統(tǒng)初始化加工程序輸入鍵按下？機床復位 N加工數(shù)據(jù)輸入自動加工手動加工鍵按下？自動加工鍵按下？N Y N手動調(diào)整Y Y N管理程序流程3.自動加工程序設計（1）機床在自動加工時的動作順序：工作臺移動到位刀具快速進給加工退刀工作臺運動到下一位置；（2）計算機在加工過程中的操作：讀取刀具軌跡，控制機床完成加工；（3）由以上分析，設計自動加工程序框圖如下所示： 入口零件坐標地址指針讀零件坐標調(diào)步進電機子程序工作臺移動到位刀具快進加工快速退刀 零件坐標地址指針加1零件加工完成 N Y 返回4.步進電機控制子程序設計步進電機的控制包括速度，轉角及方向的控制。步進電機在突然啟動或停止時，由于負載和慣性，會使電機失步，所以電機運行時有一個加，減速過程。通過確定進給脈沖數(shù)和脈沖時間間隔，即可實現(xiàn)步進電機轉角與速度的控制。（1）時間常數(shù)的確定在步進電機控制程序中，利用單片機的定時器中斷，延時產(chǎn)生進給脈沖的時間間隔。此間隔由送入定時器的時間常數(shù)決定。時間常數(shù)由下式計算：式中：T為脈沖時間間隔（ms）；為單片機機器周期（s），在時鐘為6MHz時，=2s。（2）步進電機加，減速進給脈沖及脈沖時間間隔的確定設步進電機加，減速方式為直線加，減速。要使步進電機不失步，應滿足：式中：為步進電機啟動力矩；為負載力矩；為慣性力矩。由步進電機=3.92N.m，取步進電機的加速啟動力矩則使步進電機不失不的慣性力矩步進電機角加速度又式中：為上升到步進電機最高頻率所需時間，所以有：加速脈沖個數(shù)：確定加減脈沖個數(shù)都為54個又因為：所以脈沖時刻結合可以算出對應各脈沖時刻的計數(shù)器時間常數(shù)。 EPROM存儲器中，時間常數(shù)依次安排在首地址為1000H的存儲單元中，每個時間常數(shù)占據(jù)兩個字節(jié)，低位地址存放時間常數(shù)低8位，高位地址存放時間常數(shù)高8位。在程序中，設置加速，恒速，減速脈沖計數(shù)器N0，N1，N2。以計數(shù)器的值是否為0作為相應過程是否結束的標志。步進電機控制程序框圖如下所示：步進電機控制子程序：開始中斷初始化設時間常數(shù)地址指針首地址指向1000H加速減速 脈沖計數(shù)器賦初值恒速送時間常數(shù)至計數(shù)器中 N返回關中斷？開中斷啟動定時器 Y 步進電機控制中斷服務程序：中斷服務程序入口送時間常數(shù) 步進電機進一步N0=0？N1=0？時間常數(shù)地址指針加1N1N1-1N2=0？N0N0-1時間常數(shù)地址指針加1關中斷N2N2-1 中斷返回5.編語言程序設計（1）內(nèi)存地址分配 加速脈沖數(shù)計數(shù)器N0地址設為20H；恒速脈沖數(shù)計數(shù)器N1低8位字節(jié)地址為21H，高8位字節(jié)地址位22H；減速脈沖數(shù)計數(shù)器N2地址位23H。加速，減速，恒速脈沖總數(shù)寄存器N低位字節(jié)地址位24H，高位字節(jié)地址位25H；步進電機進給控制子程序FEED首地址位0E80H。每調(diào)用一次該程序，步進電機按規(guī)定方向進給一步。（2）程序清單N0 EQU 20H ;加速N1L EQU 21H ;恒速N1H EQU 22H N2 EQU 23H ;減速NL EQU 24H ;脈沖總數(shù)寄存器NH EQU 25HDS EQU 26H ；地址指針偏移量FEED EQU 0E80HORG 0E00H0E00 758160 START： MOV P，#60H0E03 758901 MOV TMOD，#01H ；設計數(shù)器工作方式為1，16位定時器0E06 75201B MOV N0，#01A4H ；設N0為3200E09 75231B MOV N2， #1A4H0E0C E520 MOV A ， N0 ；計算2XN00E0E 23 RL A0E0F F8 MOV R0， A0E10 C3 CLR C ；計算N1=N-2N00E11 E524 MOV A， NL0E13 98 SUBB A， R00E14 F521 MOV N1L， A0E16 E525 MOV A， NH0E18 9400 SUBB A，#00H0E1A F522 MOV N1H，A0E1C 901000 MOV DPTR， #1000H ；設時間常數(shù)指針初值為1000H0E1F 752600 MOV DS， #00H ；設地址偏移量初值為00H0E22 93 MOVC A, A+DPTR ；從EPROM中讀時間常數(shù)0E23 F58A MOV TL0， A ；送時間常數(shù)至定時器0中0E25 0526 INC DS0E27 E526 MOV A，DS0E2 93 MOVC A，A+DPTR 0E2A F58C MOV TH0，A0E2C 0526 INC DS0E2E D2AF SETB EA ；開中斷允許0E30 D2A9 SETB ET0 ；允許定時器0中斷0E32 D28C SETB TR0 ；啟動定時器0開始計算0E34 20AFFD WAIT：JB EA，WAIT ；中斷允許返回0E37 22 RET中斷服務程序： ORG 000BH000B 02F00 LJMP 0F00H0F00 93 MOVC A，A+DPTR0F03 F58A MOV TL0， A0F05 0526 INC DS0F07 E526 MOV A，DS0F09 93 MOVC A，A+DPTR0F0A F58C MOV TH0， A0F0C 0526 INC DS ；修改地址偏移量指針0F0E D180 ACALL FEED ；調(diào)FEED子程序0F10 E520 MOV A， N0 ；判斷N0是否為00F12 B400 CJNE A， #00H， LOOP10F15 E52 MOV A， N1H ；判斷N1是否為0 0F17 B40010 CJNE A，#00H， LOOP20F1A E522 MOV A，N1H0F1C B4000B CJNE A，#00H，LOOP20F1F E523 MOV A，N2 判斷N2是否為0 0F21 B40014 CJNE A，#00H，LOOP30F24 C2AF CLR EA ；N2為0 ，減速結束，關中斷0F26 32 RETI0F27 1520 LOOP1：DEC N0 ；N0不為0，則N0N0-10F29 32 RETI0F2A E521 LOOP2：MOV A，N1L ；N1不為0，則N1N1-10F2C C3 CLR C0F2D 9401 SUBB A， #01H0F2F F521 MOV N1L， A0F31 E522 MOV A， N1H0F33 9400 SUBB A，#00H0F35 F522 MOV N1H，A0F37 32 RETI0F38 1523 LOOP3：DEC N2 ；N2不為0，則N2N2-10F3A 32 RETI第七章 結束語在查閱相關的數(shù)控機床資料，類比同類機床的進給系統(tǒng)結構，以及漢江機床廠提供的相關零部件資料的基礎上，用AutoCAD進行總裝圖的優(yōu)化設計和繪制。零件的繪制。通過要求完成了畢業(yè)論文書寫內(nèi)容。對機床設計過程有了深刻的了解和認識。通過此次畢業(yè)設計,使我們的綜合運用能力進一步加強,把大學四年來所學的專業(yè)理論知識與實踐很好的結合起來，從方案確定到選型、校核、畫圖等一系列都在很大程度上開發(fā)了我們的設計思維和應用能力。當然這次畢業(yè)設計中我們也認識到自身的不足之處。雖然在設計中能夠認真獨立地思考、分析問題。但知識面不夠廣泛以及實際經(jīng)驗欠缺等諸多因素,造成設計中很多疏漏的地方以及大多方案都停留在已有基礎上,創(chuàng)新很少。而且在優(yōu)化設計方面做得很少，可以說整個設計很粗糙，當然我會在以后的工作學習生產(chǎn)不斷積累經(jīng)驗，爭取做得更好，敬請原諒本次設計中的不足之處。參考文獻1 徐穎.機械設計手冊(第2版) (第三卷)，機械工業(yè)出版社 2 齊占慶.燕山大學.機床電氣控制技術(第三版)，機械工業(yè)出版社3 清華大學.華中工學院.鄭州工學院.鑄造設備，機械工業(yè)出版社4 大連理工大學工程畫教研室.機械制圖，高等教育出版社5 龔桂義.機械設計課程設計指導書，高等教育出版社6 濮良貴.紀名剛.機械設計(第六版)，西北工業(yè)大學，高等教育出版社, 19967 廖念釗主編.互換性與技術測量(第四版附錄譯文：The open system merit of Computer Numerical Control and Numerical control of production equipmentsAbstractThe open system merit is the system simple, the cost low, but the shortcoming is the precision is low. The reverse gap, the guide screw pitch error, stop inferiorly can affect the pointing accuracy by mistake. Following several kind of improvements measure may cause the pointing accuracy distinct improvement.The key word:numerical control 、NC 、the open systerm 1）reverse gap error compensates The numerical control engine bed processing cutting tool and the work piece relative motion is depends upon the drive impetus gear,the guide screw rotation, thus the impetus work floor and so on moves the part to produce moves realizes. As traditional part gear, guide screw although the manufacture precision is very high, but always unavoidably has the gap. As a result of this kind of gap existence, when movement direction change, starts the section time to be able tocause inevitably actuates the part wasting time, appears the instruction pulse to push the motionless functional element the aspect. This has affected the engine bed processing precision, namely the instruction pulse and actual enters for the step does not tally,has the processing error therefore, the split-ring numerical control system all establishes generally has the reverse gap errorcompensatory function, with by makes up which wastes time the step reverse gap difference compensates is first actual reverse enters for the error, converts the pulse equivalent number it, compensates the subroutine as the gap the output, when the computer judgment appearswhen instruction for counter motion, transfers the gap to compensate the subroutine immediately, compensates the pulse after the output to eliminate the reverse gap to carry on again normally inserts makes up the movement. 2）often the value systematic characteristic position error compensatesA kind of storehouse by transfers for the designer. Like this in the components design stage, the designer only must input the characteristic the parameter, the system direct productioncharacteristic example model: We must save the related characteristic class in the database the structure information, the database table collection are use in saving this part of related information. According to the characteristic type definition need, we defined the characteristic class code table, the characteristic class edition information have outstanding shown the characteristic type; Defined the characteristic class structure outstanding to reach the characteristic class the structure; And relates through the components characteristic disposition table and the components characteristic level information. The characteristic level data sheet collection isthis components model database design core, has recorded characteristic example information and so on model design, craft. The characteristic structure table has recorded the characteristicgeometry structure; The characteristic size table, the characteristic shape position table of limits, the characteristic surface roughness table has recorded the characteristic project semantics quotation; The size table, the shape position table of limits, the surface roughnesstable saved all components characteristic data message. In the characteristic level, using characteristic ID, geometry principal linkage and so on essential factor ID, size ID, common difference ID, roughness ID carries on the data retrieval. We apply this components information model database under the factory environment some module CAD in the AM integrative system, has realized CAD and the CAPP characteristic information sharing well. Main use ready-made CAD/the CAM software (Unigra phics 1I) carries on the product design and the NC programming in this system, and through carries on two times of developments gains components to this software the size information; At the same time uses the dialogue window which develops voluntarily, lets design the personnel to input other characteristic information alternately, realizes this software and the system sharing database connection. When assistance technological design, the technological design personnel through the procedure inquiry function, inquires the components information from the sharing database which needs, carries on the interactive technological design. Thus has facilitated the CAPP components information acquisition, enhanced the technological design efficiency. When carries on the NC programming using UG, may from the sharing database gain the craft and the manufacture information which needs, carries on various working procedures the knife axle design and the processing simulation establishes an absolute zero spot on the numerical control engine bed, the actual various coordinate axes syzygy completely position error, makes the curve in order to determined compensates the spot. Attempts l to show is an actual position error curve, (error) carries on this curve y-coordinate take the pulse equivalent as the unit the division, makes the horizontal line, each horizontal line and the curve point of intersection namely compensates the spot for the goal. Chart 1 the center 1 to 6 oclock place position errors for, needs to do reduces the pulse to compensate; But needs to carry on 6 to 9 adds the pulse to compensate in the chart the shadow partially for to compensate the area. Compensates the range of points these to become the error The calibration corrections stores the computer, when work table by zero displacement in position, installs sends out the absolute zero point localization signal in the absolute zero point micros witch, later computer as necessary will send out the goal to compensate to compensate the signal, will carry on the position error to the engine bed to compensate. The cosine generator assigns slide guage initiation signal a electricity and by step of transmission.3） feedbacks compensates the open-loop control Chart 2 has produced this kind of system schematic diagram. This system surveys two parts by the open-loop control and the induction synchromesh direct position to be composed. Here position examination does not serve as the position the feedback, but is compensates the feedback as the position error. Its cardinal principle is: Installs the instruction pulse by the engine bed numerical control which CNC sends out, on the one hand the supplies open system, thecontrol step-by-steps the electrical machinery according to the instruction revolution, and the direct drive platen moves, constitutes the open-loop control; On the other hand this instruction pulse supplies the induction synchromesh the measurement system (namely digitally, cosine generator), as position demand signal a by. The work in the warning way induction synchromesh this time not only is the position sensor, also is the comparator, it by, The cosine generator assigns slide guage initiation signal a electricity and by step of transmission.4） conclusions Under the CIMS environment the technology which develops unceasingly based on characteristic components information modeling, how enhances the components order of complexity which the characteristic design can complete; How causes question and so on request which the characteristic design adoption trick recognition, the characteristic semantics transforms also to wait for the people to solve. This article introduced the characteristic technology in the components information modeling application, describes this components data model database realization with emphasis; Establishes the components information database system may satisfy the CIMS system well to the letter. Numerical control (NC) is a form of programmable automation in which the processing equipment is controlled by means of numbers, letters, and other symbols. The numbers, letters, and symbols are coded in an appropriate format to define a program of instructions for a particular workpart or job. When the job changes, the program of instructions is changed. The capability to change the program is what makes NC suitable for low-and medium-volume production. It is much easier to write new programs than to make major alterations of the processing equipment.Basic components of NC A numerical control system consists of the following three basic components:Program of instructionsMachine control unitProcessing equipmentThe general relationship among the three components is illustrated in Fig.2.1. The program is fed into the control unit, which directs the processing equipment accordingly.The program of instructions is the detailed step-by-step commands that direct the processing equipment. In its most common form, the commands refer to positions of a machine tool spindle with respect to the worktable on which the part is fixtured. More advanced instructions include selection of spindle speeds, cutting tool, and other function. The most common medium in use over the last several decades has been 1-in. -wide punched tape. Because of the widespread use of the punched tape, NC is sometimes called “tape control”. However, this is a misnomer in modern usage of numerical control. Coming into use more recently have been magnetic tape cassettes and floppy diskettes.The machine control unit (MCU) consists of the electronics and control hardware that read and interpret the program of instruction and convert it into mechanical actions of the machine tool or other processing equipment.The processing equipment is the third basic component of an NC system. It is the component that performs useful work. In the most common example of numerical control, one that performs machining operations, the processing equipment consists of the worktable and spindle as well as the motors and controls needed to drive them.TYPES OF CONTROL SYSTEMSThere are two basic types of control systems in numerical control: point-to-point and contouring. In the point-to-point system, also called positioning, each axis of the machine is driven separately by leadscrews and, depending on the type of operation, at different velocities. The machine moves initially at maximum velocity in order to reduce nonproductive time but decelerates as the tool reaches its numerically defined position. Thus in an potation such as drilling or punching, the positioning and cutting take place sequentially. After the hole is drilled or punched, the tool retracts, moves rapidly to another position, and repeats the operation. The path followed from one position to another is important in only one respect: The time required should be minimized for efficiency. Point-to-point systems are used mainly in drilling, punching, and straight milling operations.In the contouring system, also known as the continuous path system, positioning and cutting operations are both along controlled paths but at different velocities. Because the tool cuts as it travels along a prescribed path, accurate control and synchronization of velocities and movements are important. The contouring system is used on lathes, milling machines, grinders, welding machinery, and machining centers.Movement along the path, or interpolation, occurs incrementally, by one of several basic methods. In all interpolations, the path controlled is that of the center of rotation of the tool. Compensation for different tools, different diameter tools, or tool wear during machining, can be made in the NC program.There are a number of interpolation schemes that have been developed to deal with the various problems that are encountered in generating a smooth continuous path with a contouring-type NC system. They include:Linear interpolationCircular interpolationHelical interpolationParabolic interpolationCubic interpolationEach of these interpolation procedures permits the programmer (or operator) to generate machine instructions for linear or curvilinear paths, using a relatively few input parameters. The interpolation module in the MCU performs the calculations and directs the tool along the path.Linear interpolation is the most basic and is used when a straight-line path is to be generated in continuous-path NC. Two-axis and three-axis linear interpolation routines are sometimes distinguished in practice, but conceptually they are the same. The program is required to specify the beginning point and end point of the straight line, and the feed rate that is to be followed along the straight line. The interpolator computes the feed rates for each of the two (or three) axes in order to achieve the specified feed rate.Linear interpolation for creating a circular path would be quite inappropriate because the programmer would be required to specify the line segments and their respective end points that are to be used to approximate the circle. Circular interpolation schemes have been developed that permit the programming of a path consisting of a circular arc by specifying the following parameters of the arc: the coordinates of its end points, the coordinates of its center, its radius, and the direction of the cutter along the arc. The tool path that is created consists of a series of straight-line segments, but the segments are calculated by the interpolation module rather than the programmer. The cutter is directed to move along each line segment one by one in order to generate the smooth circular path. A limitation of circular interpolation is that the plane in which the circular arc exists must be a plane defined by two axes of the NC system.Helical interpolation combines the circular interpolation scheme for two axes described above with linear movement of a third axis. This permits the definition of a helical path in three-dimensional space.Parabolic and cubic interpolation routines are used to provide approximations of free-form curves using higher-order equations. They generally require considerable computational power and are not as common as linear and circular interpolation. Their applications are concentrated in the automobile industry for fabricating dies for car body panels styled with free-form designs that cannot accurately and conveniently be approximated by combining linear and circular interpolations.PROGRAMMING FOR NCA program for numerical control consists of a sequence of directions that causes an NC machine to carry out a certain operation, machining being the most commonly used process. Programming for NC may be done by an internal programming department, on the shop floor, or purchased from an outside source. Also, programming may be done manually or with computer assistance.The program contains instructions and commands. Geometric instructions pertain to relative movements between the tool and the workpiece. Processing instructions pertain to spindle speeds, feeds, tools, and so on. Travel instructions pertain to the type of interpolation and slow or rapid movements of the tool or worktable. Switching commands pertain to on/off position for coolant supplies, spindle rotation, direction of spindle rotation, tool changes, workpiece feeding, clamping, and so on. Manual Programming Manual part programming consists of first calculating dimensional relationships of the tool, workpiece, and work table, based on the engineering drawings of the part, and manufacturing operations to be performed and their sequence. A program sheet is then prepared, which consists of the necessary information to carry out the operation, such as cutting tools, spindle speeds, feeds, depth of cut, cutting fluids, power, and tool or workpiece ally a paper tape is first prepared for trying out and debugging the program. Depending on how often it is to be used, the tape may be made of more durable Mylar.Manual programming can be done by someone knowledgeable about the particular process and able to understand, read, and change part programs. Because they are familiar with machine tools and process capabilities, skilled machinists can do manual programming with some training in programming. However, the work is tedious, time consuming, and uneconomical-and is used mostly in simple point-to-point applications. Computer-Aided Programming Computer-aided part programming involves special symbolic programming languages that determine the coordinate points of corners, edges, and surfaces of the part. Programming language is the means of communicating with the computer and involves the use of symbolic characters. The programmer describes the component to be processed in this language, and the computer converts it to commands for the NC machine. Several languages having various features and applications are commercially available. The first language that used English-like statements was developed in the late 1950s and is called APT (for Automatically Programmed Tools). This language, in its various expanded forms, is still the most widely used for both point-to-point and continuous-path programming.Computer-aided part programming has the following significant advantages over manual methods: Use of relatively easy to use symbolic languageReduced programming time. Programming is capable of accommodating a large amount of data concerning machine characteristics and process variables, such as power, speeds, feed, tool shape, compensation for tool shape changes, tool wear, deflections, and coolant use. Reduced possibility of human error, which can occur in manual programming Capability of simple changeover of machining sequence or from machine to machine. Lower cost because less time is required for programming.Selection of a particular NC programming language depends on the following factors: Level of expertise of the personnel in the manufacturing facility. Complexity of the part. Type of equipment and computers available. Time and costs involved in programming.Because numerical control involves the insertion of data concerning workpiece materials and processing parameters, programming must be done by operators or programmers who are knowledgeable about the relevant aspects of the manufacturing processes being used. Before production begins, programs should be verified, either by viewing a simulation of the process on a CRT screen or by making the part from an inexpensive material, such as aluminum, wood, or plastic, rather than the material specified for the finished part.Reference:1 Zhang Huashu under. parallel environment based on characteristic components definition model J. mechanical science with technology, 1,999, 18 (1): 14l 144.2 forest morning star, Du full text, Xu Jianxin. characteristic and (,M)/CAPP/CAM integrative system J. the computer-aided design and makes, 1998, 28 (5): 5155.3 Zeng Hui E, Zhou Qingzhong. studied J based on the characteristic mechanical product modelling . the machinery to suppose Counts with the manufacture the regulation, 1,999, 28 (2): 12 l4.譯文：數(shù)控機床開環(huán)控制伺服系統(tǒng)與數(shù)控生產(chǎn)設備摘要開環(huán)系統(tǒng)的優(yōu)點是系統(tǒng)簡單、成本低，但缺點是精度低。反向間隙、絲杠螺距誤差、起停誤差等都會影響定位精度。下面幾種改進措施可以使定位精度明顯改善。關鍵字：數(shù)控系統(tǒng)、開環(huán)系統(tǒng)1） 反向間隙誤差補償數(shù)控機床加工刀具與工件的相對運動是依靠驅動裝置帶動齒輪、絲杠轉動，從而推動工作臺面等移動部件產(chǎn)生位移來實現(xiàn)的。作為傳統(tǒng)元件的齒輪、絲杠盡管制造精度很高，但總免不了存在間隙。由于這種間隙存在，當運動的方向改變時，開始段時間必然會引起驅動元件的空走，出現(xiàn)指令脈沖推不動執(zhí)行元件的局面。這就影響了機床的加工精度，即指令脈沖與實際進給步數(shù)不相符合，產(chǎn)生加工誤差 因此，開環(huán)數(shù)控系統(tǒng)一般都設置有反向間隙誤差補償功能，用以補足空走的步數(shù)反向間隙差補償就是首先實測反向進給的誤差，把它折算成脈沖當量數(shù)，作為間隙補償子程序的輸出量，當計算機判斷出現(xiàn)的指令為反向運動時，隨即調(diào)用間隙補償子程序，通過輸出補償脈沖消除反向間隙后再進行正常的插補運行。2） 常值系統(tǒng)性定位誤差補償類庫以供設計者調(diào)用。這樣在零件的設計階段，設計者只需輸入特征的參數(shù)，系統(tǒng)直接生成特征的實例模型：在數(shù)據(jù)庫中我們必須存儲相關的特征類的結構信息，數(shù)據(jù)庫表集就是用于存儲這一部分的相關信息。根據(jù)特征類型定義的需要，我們定義了特征類編碼表、特征類版本信息表表示特征類型；定義了特征類構造表表達特征類的結構；并通過零件特征配置表與零件的特征層信息聯(lián)系起來。特征層數(shù)據(jù)表集是本零件模型數(shù)據(jù)庫設計的核心，記錄了特征實例模型的設計、工藝等信息。特征構造表記錄了特征的幾何結構；特征尺寸表、特征形位公差表、特征表面粗糙度表記錄了特征的工程語義引用；尺寸表、形位公差表、表面粗糙度表存儲了所有零件特征的數(shù)據(jù)信息。在特征層，利用特征ID、幾何要素ID、尺寸ID、公差ID、粗糙度ID等主鍵進行數(shù)據(jù)檢索。我們將該零件信息模型的數(shù)據(jù)庫應用于工廠環(huán)境下某型組件的CAD AM 集成系統(tǒng)中，較好地實現(xiàn)了CAD與CAPP的特征信息共享。在該系統(tǒng)中主要使用現(xiàn)成的CADCAM 軟件(Unigraphics 1I)進