【導(dǎo)讀】在先進(jìn)制造技術(shù)領(lǐng)域最根本的觀念之一是數(shù)控。數(shù)控來臨之前，所有機(jī)。床是手工操作和控制。手動(dòng)控制機(jī)床有許多限制，或許沒有比操作者的技能更突。用手動(dòng)控制，產(chǎn)品質(zhì)量直接相關(guān)，并僅限于操作者的技能。車床主要是為了進(jìn)行車外圓、車端面和鏜孔等項(xiàng)工作而設(shè)計(jì)的機(jī)床。由于車床還可以用來鉆孔和鉸孔，車床的多功能性可以使工件在一。次安裝中完成幾種加工。因此，在生產(chǎn)中使用的各種車床比任何其他種類的機(jī)床。件在各種速度下回轉(zhuǎn)。主軸箱基本上由一個(gè)安裝在精密軸承中的空心主軸和。一系列變速齒輪所組成。它提供動(dòng)力，并可使工一般按等比級數(shù)排列。一種正在不斷增長的趨勢是通過。常安裝在預(yù)緊后的重型圓錐滾子軸承或球軸承中。主軸中有一個(gè)貫穿全長的通孔，語句來定義幾何零件，描述刀具配置，并制定所需的方案。重大的一步，推動(dòng)數(shù)控技術(shù)的進(jìn)一步發(fā)展。原來的數(shù)控系統(tǒng)廣泛使用穿孔紙，后。項(xiàng)技術(shù)的發(fā)展，計(jì)算機(jī)數(shù)字控制允許的數(shù)控系統(tǒng)。F/C240是C2020DSP平臺，并控制應(yīng)用而優(yōu)化。

　　

【正文】 Power inverters and controllers Automotive systems, such as electronic power steering , antilock brakes, and climate control Appliance and HVAC blower/ pressor motor controls Printers, copiers, and other office products Tape drives, magic optical drives, and other mass storage products Robotic and CNC milling machines To function as a system manager, a DSP must have robust onchip I/O and other peripherals. The event manager of the ‘ 240 is unlike any other available on a DSP . This applicationoptimized peripheral unit , coupled with the high performance DSP core, enables the use of advanced control techniques for highprecision and highefficiency full variablespeed control of all motor types. Include in the event manager are special pulsewidth modulation (PWM) generation functions, such as a programmable deadband function and a space vector PWM state machine for 3phase motors that provides stateoftheart maximum efficiency in the switching of power transistors. There independent up down timers, each with it’ s own pare register, support the generation of asymmetric (noncentered) as well as symmetric (centered) PWM waveforms. OpenLoop and ClosedLoop Control Openloop Control Systems The word automatic implies that there is a certain amount of sophistication in the control system. By automatic, it generally means That the system is usually capable of adapting to a variety of operating conditions and is able to respond to a class of inputs satisfactorily . However , not any type of control system has the automatic feature. Usually , the automatic feature is achieved by feed. g the feedback structure, it is called an openloop system , which is the simplest and most economical type of control lies in the fact that one may not know the exact characteristics of the further ,which has a definite bearing on the indoor temperature. This alco points to an important disadvantage of the performance of an open loop control system, in that the system is not capable of adapting to variations in environmental conitions or to external disturbances. In the case of the furnace control, perhaps an experienced person can provide control for a certain desired temperature in the house。 but id the doors or windows are opened or closed intermittently during the operating period, the final temperature inside the house will not be accurately regulated by the 第 頁 共 12 頁 openloop control. ClosedLoop Control Systems What is missing in the openloop control system for more accurate and more adaptable control is a link or feedback from the output to the input of the system . In order to obtain more accurate bontrol, the controlled signal c(t) must be fed back and pared with the reference input , and an actuating signal proportional to the difference of the output and the input must be sent through the system to correct the error. A system with one or more feedback pat(s like that just described is called a closedloop system. human being are probably the most plex and sophisticated feedback control system in existence. A human being may be considered to be a control system with many inputs and outputs, capable of carrying out highly plex operations. To illustrate the human being as a feedback control system , let us consider that the objective is to reach for an object on aperform the task. The eyes serve as a sensing device which feeds back continuously the position of the hand . The distance between the hand and the object is the error , which is eventually brought to zero as the hand reacher the object. This is a typical example of closedloop control. However , if one is told to reach for the object and then is blindolded, one can only reach toward the object by estimating its exact position. It isAs anther illustrative example of a closedloop control system, shows the block diagram of the rudder control system ofThe basic alements and the bloca diagram of a closedloop control system are shown in fig. In general , the configuration of a feedback control system may not be constrained to that of fig amp。 . In plex systems there may be multitude of feedback loops and element blocks. 第 頁 共 12 頁 指 導(dǎo) 教 師 評 語 外文翻譯成績： 指導(dǎo)教師簽字： 年 月 日 注： 1. 指導(dǎo)教師對譯文進(jìn)行評閱時(shí)應(yīng)注意以下幾個(gè)方面：①翻譯的外文文獻(xiàn)與畢業(yè)設(shè)計(jì)（論文）的主題是否高度相關(guān)，并作為外文參考文獻(xiàn)列入畢業(yè)設(shè)計(jì)（論文）的參考文獻(xiàn)；②翻譯的外文文獻(xiàn)字?jǐn)?shù)是否達(dá)到規(guī)定數(shù)量（ 3 000 字以上）；③譯文語言是否準(zhǔn)確、通順、具有參考價(jià)值。 2. 外文原文應(yīng)以附件的方式置于譯文之后。