電腦數(shù)值控制單元外文文獻(xiàn)翻譯@中英文翻譯@外文翻譯

英文原文 Computer Numerical Control Unit Today, computer numerical control (CNC) machines are found almost everywhere , from small job shops in rural communities to Fortune 500 companies in large urban areas. Truly , there is hardly a facet of manufacturing that is not in some way touched by what these innovative machine tools can do . Everyone involved in the manufacturing environment should be well aware of what is possible with these sophisticated machine tools. In this chapter, we will explore the basics of the core of CNC machine tool-CNC unit, showing you much of what is involved with its function, working principles ,hardware configuration and software structure. With so many types of CNC machine tools and CNC units in existence, it is next to impossible for this chapter to be extremely specific about any one particular type .The key concepts allow us to view the main features of CNC unit in more general terms, stressing why things are handled the way they are even more than the specific techniques used with any one particular CNC machine tool. With this broad background , you should be able to easily zero in on any kind of CNC machine tool you will be working with. 1 1 INTRODUCTION Machine controls are divided into two types： numerical control(NC)and computer numerical control(CNC) NC controls have to read the program each time a part is run； they have no means of editing existing programs CNC controls can store and allow editing of loaded programs All machines built today are CNC machines CNC unit is the heart of CNC machine. Nevertheless，in order to aid to understand the working principles of CNC unit， it is necessary that the principles of NC system be introduced firstly 1 1 1 NC system The NC machine can be divided into three basic areas. The first area is the control unit, which processes the commands from the input media. The second area is the drive mechanisms, and the last area is the machine itself The most basic function of any NC machine is automatic， precise， and consistent motion control A11 forms of NC equipment have two or more directions of motion， called axes These axes can be precisely and automatically positioned along their lengths of travel The two most common axis types are linear(driven along a straight path)and rotary(driven along a circular path) Instead of causing motion by manually turning cranks and handwheels as is required on conventional machine tools， NC machines allow motions to be actuated by servomotors under control of the NC， and guided by the part program Generally speaking， the motion type(rapid, linear， and circular)， the axes to move， the amount of motion and the motion rate(feed rate)are programmable with almost all NC machine tools Figure 1 1 shows the makeup of a linear axis of an NC machine Figure 1 1 The makeup of a linear axis of all NC machine An NC command executed within the control (commonly through a program) tells the drive motor to rotate a precise amount of angle The rotation of the drive motor in turn rotates the ballscrew And the ballscrew drives the linear axis A feedback device at the opposite end of the ballscrew allows the control to confirm that the commanded number of rotations has taken place All NC machine tools need numerical data for controlling the relative motion between cutting tool and piece part, the component dimensions normally emanating directly from engineering drawings-the geometric data Other digitized numerical data define feed rates， spindle speeds，tool identification numbers， and miscellaneous functions to perform such operations as tool or work changing， or coolant control-the technological data The combination of all this numerical information in a sequence understood by the machine tools controller is called a part program，and the process of creating the data in a correctly structured format is called programming Numerical controls use standard microelectronic modules that have been developed for computer hardware。 Except for special modules needed in servocontrol circuits， no individual modules are necessary， in contrast to traditional controls， which employ only components tailored to suit one specific control function In modern NC controllers extensive control and calculation tasks are performed by one or more integral microprocessors 。 These are termed computer numerical control system( CNCs ) 1 1 2 CNC system and functions of CNC unit Control systems based on industrial PC(abbreviation for personal computer)are increasingly used in automation technology Machine controls have changed greatly with the “age of the computer” Controls today are“softwired”,which allows greater flexibility in changing and upgrading the computer control In fact， many of machines operating characteristics can be changed by the operator， so that the machine operates the way he she wants it to. Parameter tables in CNC machines today allow each machine to be personalized to the needs of the job to be run The modern CNC machine tool is software driven Simply speaking， computer controls are programmed instead of hard-wired Definition： According to Electronic Industries Association(EIA)， CNC system is a special computer system that is equipped with certain interface circuits and servo drivers， and can do part or a11 the works an NC system do by running the software stored in its memories CNCs have expandable memories that can store large numbers of programs， plus subroutines and correction data。 Sophisticated graphic displays and dynamic simulation have also now become available as a result of the extensive memory capacity being built into current CNCs Within only few years， the capability and efficiency of machine controllers has increased to such an extent that the name“numerical control”is no longer appropriate； “computer numerical control”is more accurately descriptive Generally， CNCs comprises CNC unit， feed motion servo subsystem， spindle servo subsystem and some auxiliary control cells, as shown in Figure 1.2， CNC unit is the core of the whole CNC system It is composed of hardware and software。 The hardware comprising a CNC unit is made up of microprocessors， electronic memory modules， I 0 interfaces， and position control modules， etc CNC software controls all functions of the machine and its efficiency of operation， and manages all local programming at the machine tool and graphic simulation of the cutting process if available The hardware and the software work together to do all functions of CNC unit ， which an ordinary NC system can never do ， such as graphic display HMI(Human-Machine Interface)， system diagnosis， implementing of various complex tool-path controlling and compensation algorithms， intelligent controlling， online programming， and Web communications， etc The main functions and features of CNC unit are described as follows： Figure 1 2 CNC machining system (1)Controlling function (the number of control axes and synchronously control axes) Controlling function indicates the maximum axis-number the CNC unit can control and the number of axes the CNC unit can control synchronously It is also the mare features of CNC machine Axes to be controlled by CNC unit have linear axes and rotate axes, basic axes and auxiliary axes Generally， CNC machine needs only 2 axes to be controlled synchronously In case of double toolslides， four axes are needed CNC milling machine， boring machine, and CNC machine center need 3 or more controlled axes The more the number of Controlled axes, especially the number of axes being controlled synchronously, the more powerful functions of the CNC unit, and the more complex structure of the CNC unit， the more difficulty of programming (2)Preparatory function Preparatory function， also called G function， describes the motion modes of CNC machine The motion modes comprise instructions of basic motions， dwell， plane selections，coordinate system settings， tool compensations， reference point return， fixed operation circles，and metric inch unit transfer， etc According to ISO standard， there are 100 types of Gcodes (from G00 to G99)used in CNC unit， which can be divided into two classes- nonmodal codes (which functions are valid only in the code segment including the codes themselves)and modal codes(which can keep effective before the coming of next Gcode of the same group) For the exact function of each G code used in your machine tools， you must reference your control manufacturers manual to find the list of functions for your machine (3)Interpolation function CNC unit does interpolation by using software realtime calculations Linear interpolation，circular interpolation， helical interpolation， and polar coordinate interpolation will do their best to help CNC unit generate tool track as close to various paths as possible (4)Feed function Feed function uses F (Feedrate designation)to designate the. feedrate to axis The method by which feedrate is programmed varies from one machine type to the next Generally speaking，machining centers only allow the feed rate to be specific in per-minute format(inches or millimeters per minute) ， such as ， F15000 means the federate is 15000 millimeters per minute Turning centers， which have position encoders in their spindles， also allow feed rate to be specified in per-revolution format(inches or millimeters per revolution)that is named synchronous feedrate (5)Spindle function An“S”word is used to specify the spindle speed(in RPM for machining centers). An M03 is used to turn the spindle on in a clockwise(forward)D1a11ner M04 turns the spindle on in a counter clockwise manner M05 turns the spindle off Note that turning centers also have a feature called constant surface speed， which allows spindle speed to be specified in surface feet per minute(or meters per minute) On operation panel， there is a button to turn the spindle on and off， as well as a rheostat to control spindle speed All of these functions are activated manually，through the Manual or Jog mode (6)Miscellaneous function Like preparatory functions， miscellaneous functions(M words， from M00 to M99)allow a variety of special functions Miscellaneous functions are typically used as programmable switches(1ike spindle on off， coolant on off， and so on). (7)Compensation function All types of CNC machine tools require some form(s)of compensation Though applied for different reasons on different machine types， all forms of compensation allow the CNC user to allow for unpredictable conditions related to tooling (8)Enhanced graphic display function CNC unit has a CRT or an LCD displayer to show programs， parameters， various compensation data， coordinates， fault information， menus of conversation programming， part graphs It also can monitor dynamic cutter tool paths while machining (9)Self-diagnosis function In CNC unit， various diagnosis programs are designed to prevent faults occurring or going worse With the aids of self-diagnosis programs， operators can find out the fault and its location in time， so that shorten the time of broken-down (10)Communication function A1l current model CNC controls come with an RS-232-C communications (serial) port. All current model personal computers come with a serial communications port By connecting a properly configured cable to the computer and CNC， the user can command that transmissions of CNC programs take place. (11)Programming function There are three methods of developing CNC programs-Manual programming ，conversational(shopfloor)programming， and CAM system programming 1 1 3 Functional interface between hardware and software in CNC unit As being described above， CNC unit comprises hardware and software， which work together to perform all functions of CNC unit Because that software is logically equivalent to hardware，just like in an ordinary computer system， hardware functions can also be implemented by software in CNC system Hardware and software have different characters Hardware can process in a higher speed than software， but it is more expensive； software is flexible when being designed，but it is a little slow on processing Hence， in a CNC system， the proportion between hardware and software is determined by costperformance of the CNC unit In practice， the functional interfaces between hardware and software are not fixed。 In the earlier NC equipments， all functions were implemented by hardware。 As the developing of computer technology， computer was introduced into numerical control system ， formed so-called CNC system. But the participation of computer are different in different CNC units and in different time. Figure 1.3 show four different kinds of functional interfaces between hardware and software in CNC systems. Figure1.3 中文譯文 電腦數(shù)值控制單元 今天，計(jì)算機(jī)數(shù)值控制（ CNC）機(jī)床幾乎隨處可見，從農(nóng)村社區(qū)小商店工作，財(cái)富 500強(qiáng)企業(yè)在大城市地區(qū)。真的，幾乎沒有一個(gè)小的制造，是不是有點(diǎn)感動這些創(chuàng)新機(jī)床能做的。人人參與的制造環(huán)境應(yīng)該很清楚什么是可能與這些精密的工具機(jī)。 在本章中，我們將探討數(shù)控機(jī)床的數(shù)控裝置的核心基礎(chǔ)，告訴你什么是參與其功能，工作原理，硬件結(jié)構(gòu)和軟件結(jié)構(gòu)。有這么多種類型的數(shù)控機(jī)床和數(shù)控單元的存在，幾乎是不可能的這一章是關(guān)于任何一個(gè)特定類型的非常具體的關(guān)鍵概念。讓我們看數(shù)控系 統(tǒng)的主要特點(diǎn)在更一般的條件的單位，強(qiáng)調(diào)為什么事情的處理他們比使用任何一個(gè)特定的數(shù)控機(jī)床的具體技術(shù)更加的方式。在這個(gè)背景之下，你可以很容易的在零上的任何類型的數(shù)控機(jī)床將要和你一起工作。 1.1 引言 機(jī)器控制分為兩種類型：數(shù)控（ NC）和計(jì)算機(jī)數(shù)值控制（ CNC）。數(shù)控控制讀取的程序每次一部分運(yùn)行；他們沒有編輯現(xiàn)有的 c 控制手段可以存儲和允許加載程序編輯。所有的機(jī)器建立的今天是數(shù)控 c 單元是數(shù)控機(jī)器的心臟。然而，為了幫助理解數(shù)控裝置的工作原理，它是必要的，數(shù)控系統(tǒng)的原理是首先 介紹了。 1.1.1 數(shù)控系統(tǒng) 數(shù)控機(jī)床可分為三個(gè)基本環(huán)節(jié)。第一區(qū)的控制單元，處理命令的輸入媒體。第二個(gè)區(qū)域是驅(qū)動機(jī)制，和最后一個(gè)領(lǐng)域是機(jī)器本身。 任何數(shù)控機(jī)床最基本的功能是自動的，精確的，和數(shù)控設(shè)備一致的運(yùn)動 control.a11形式有兩個(gè)或兩個(gè)以上的方向運(yùn)動，稱為軸。這些軸可以自動準(zhǔn)確定位沿其長度的旅行。最常見的兩種類型的線性（驅(qū)動軸沿直線路徑）和旋轉(zhuǎn)（沿圓形路徑）。 而造成運(yùn)動通過手動轉(zhuǎn)動曲柄和手輪是普通機(jī)床，數(shù)控機(jī)床允許的運(yùn)動是驅(qū)動伺服電機(jī)的數(shù)控控制下，通過部分程序的引導(dǎo)。一般來說，運(yùn)動型（快速，線性 ，和圓形），移動軸，運(yùn)動量與運(yùn)動速度（進(jìn)給速度）都是可編程的幾乎所有的數(shù)控機(jī)床。 圖 1.1 顯示了一個(gè)數(shù)控機(jī)床直線軸的化妝。圖 1.1 組成的數(shù)控機(jī)床直線軸數(shù)控指令執(zhí)行的控制范圍內(nèi)（通常通過一個(gè)程序）告訴驅(qū)動電機(jī)旋轉(zhuǎn)角度的精確量。反過來驅(qū)動電機(jī)的旋轉(zhuǎn)的滾珠絲杠和滾珠絲杠傳動。線性軸。在滾珠絲杠的相對端的反饋裝置允許控制來確定所要求的數(shù)量的旋轉(zhuǎn)運(yùn)動的發(fā)生。 所有的數(shù)控機(jī)床需要數(shù)值數(shù)據(jù)控制刀具和零件之間的相對運(yùn)動，組件的尺寸通常直接從所產(chǎn)生的工程圖紙 幾何數(shù)據(jù)。其他數(shù)字化數(shù)值數(shù)據(jù)定義的進(jìn)給率，主軸轉(zhuǎn)速，刀具識別號碼，和雜項(xiàng)功能執(zhí)行的工具或工作變換等操作，或冷卻控制 技術(shù)數(shù)據(jù)。在一個(gè)序列中的機(jī)床控制器理解這一切的數(shù)值信息的組合稱為程序的一部分，并在正確的結(jié)構(gòu)化的格式創(chuàng)建的數(shù)據(jù)的過程稱為程序設(shè)計(jì)。 數(shù)值控制使用標(biāo)準(zhǔn)微電子已開發(fā)的模塊，對計(jì)算機(jī)硬件。除特殊模塊，伺服控制電路所需，沒有單獨(dú)的模塊是必要的，在對比傳統(tǒng)的控制，只采用組件適合一個(gè)特定的控制功能。在現(xiàn)代數(shù)控控制器廣泛的控制和計(jì)算任務(wù)都由一個(gè)或多個(gè)微處理器進(jìn)行積分。這些被稱為計(jì)算機(jī)數(shù)控系統(tǒng)（ CNC）。 1.1.2 數(shù)控系統(tǒng)和功能的數(shù)控單元 基于工業(yè) PC 的控制系統(tǒng)（ 個(gè)人計(jì)算機(jī)的縮寫）越來越多地應(yīng)用于自動化技術(shù)。機(jī)控制已經(jīng)發(fā)生了很大的變化，“計(jì)算機(jī)時(shí)代”。今天是“軟接線”控件，允許更大的靈活性在變化升級計(jì)算機(jī)控制。事實(shí)上，許多機(jī)器的操作特性，可由操作員改變，使機(jī)器的方式，他她想要工作。今天，在數(shù)控機(jī)床參數(shù)表允許每臺機(jī)器進(jìn)行個(gè)性化的工作需要運(yùn)行?，F(xiàn)代數(shù)控機(jī)床的軟件驅(qū)動。簡單地說，計(jì)算機(jī)控制程序代替硬接線。 定義：根據(jù)電子工業(yè)協(xié)會（ EIA），數(shù)控系統(tǒng)是一種特殊的計(jì)算機(jī)系統(tǒng)，配備一定的接口電路和伺服驅(qū)動器，可以部分或全部作品的數(shù)控系統(tǒng)的運(yùn)行做存儲在其記憶軟件。 數(shù)控 系統(tǒng)，可以存儲大量的節(jié)目可膨脹的回憶，加子程序和校正數(shù)據(jù)。復(fù)雜的圖形顯示和動態(tài)仿真也現(xiàn)在由于廣泛的內(nèi)存容量建成為當(dāng)前數(shù)控系統(tǒng)成為可能。在短短的幾年中，能力和機(jī)控制器的效率提高到這樣的程度，的名字“數(shù)控”不再是合適的；“數(shù)控”更準(zhǔn)確的描述。 一般來說，數(shù)控機(jī)床包括數(shù)控裝置，伺服系統(tǒng)進(jìn)給運(yùn)動，主軸伺服系統(tǒng)和一些輔助的控制單元，如圖 1.2 所示，數(shù)控單元是整個(gè)數(shù)控系統(tǒng)的核心。它是由硬件和軟件組成。硬件包括數(shù)控單元由微處理器，電子存儲模塊，我 0 接口，和位置控制模塊， c 軟件控制機(jī)器及其運(yùn)行效率的所有 功能，并管理所有本地編程時(shí)的機(jī)床和切削過程中如果可用圖形仿真。硬件和軟件一起做數(shù)控裝置的所有功能，一個(gè)普通的數(shù)控系統(tǒng)可以不做，如圖形顯示的HMI（人機(jī)界面），系統(tǒng)診斷，實(shí)現(xiàn)各種復(fù)雜的刀具路徑控制和補(bǔ)償算法，智能控制，在線編程 ， 和 網(wǎng) 絡(luò) 通 信 ， 等 主 要 功 能 和 數(shù) 控 單 元 的 特 點(diǎn) 如 下 ： 圖 1.2 數(shù)控加工系統(tǒng) （ 1） 控制功能（控制軸數(shù)和同步控制軸）控制函數(shù)表示的最大軸數(shù)數(shù)控單元可控制軸的數(shù)控單元可控制同步的數(shù)量。這也是數(shù)控機(jī)床的母