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1、<p><b>  文獻翻譯</b></p><p><b>  原文:</b></p><p>  Numerical Control</p><p>  One of the most fundamental concepts in the area of advanced manufacturing tec

2、hnologies is numerical control (NC).Prior to the advent of NC, all machine tools were manual operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominen

3、t than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator . Numerical control represents the first major </p><p&

4、gt;  Numerical control means the control of machine tools and other manufacturing systems though the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a prog

5、ram that issues operational instructions to the machine tool, For a machine tool to be numerically controlled , it must be interfaced with a device for accepting and decoding the p2ogrammed instructions, known as a reade

6、r.</p><p>  Numerical control was developed to overcome the limitation of human operator , and it has done so . Numerical control machines are more accurate than manually operated machines , they can produce

7、 parts more uniformly , they are faster, and the long-run tooling costs are lower . The development of NC led to the development of several other innovations in manufacturing technology:</p><p>  1.Electrica

8、l discharge machining.</p><p>  2.Laser cutting.</p><p>  3.Electron beam welding.</p><p>  Numerical control has also made machine tools more versatile than their manually operated

9、 predecessors. An NC machine tool can automatically produce a wide variety of par 4s , each involving an assortment of undertake the production of products that would not have been feasible from an economic perspective u

10、sing manually controlled machine tools and processes.</p><p>  Like so many advanced technologies , NC was born in the laboratories of the Massachusetts Institute of Technology . The concept of NC was develo

11、ped in the early 1950s with funding provided by the U.S Air Force .In its earliest stages , NC machines were able to make straight cuts efficiently and effectively.</p><p>  However ,curved paths were a prob

12、lem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter is the straight lines making up the step ,the smoother is the curve . Each line seg

13、ment in the steps had to be calculated.</p><p>  This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language for NC that uses statements similar to English language to de

14、fine the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the further development of NC technology. The original N

15、C system were vastly different from those used punched paper , which was later to replaced by magnetic plastic tape .A tap</p><p>  A major problem was the fragility of the punched paper tape medium . It was

16、 common for the paper containing the programmed instructions to break or tear during a machining process, This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the pape

17、r tape carrying the programmed instructions had to rerun thought the reader . If it was necessary to produce 100 copies of a given part , it was also necessary to run the paper tape thought the reader 100 </p><

18、;p>  This led to the development of a special magnetic tape . Whereas the paper tape carried the programmed instructions as a series of holes punched in the tape , theThis most mportant of these was that it was diffic

19、ult or impossible to change the instructions entered on the tape . To make even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also

20、 still necessary to run the tape thought the reader as many times as</p><p>  The development of a concept known as numerical control (DNC) solve the paper and plastic tape problems associated with numerical

21、 control by simply eliminating tape as the medium for carrying the programmed instructions . In direct numerical control, machine tools are tied, via a data transmission link, to a host computer and fed to the machine to

22、ol as needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However ,</p><p>  The evelopment of the microprocessor allowed f

23、or the development of programmable logic controllers (PLC) and microcomputers . These two technologies allowed for the development of computer numerical control (CNC).With CNC , each machine tool has a PLC or a microcomp

24、uter that serves the same purpose. This allows programs to be input and stored at each individual machine tool. CNC solved the problems associated downtime of the host computer , but it introduced another problem known a

25、s data managem</p><p>  There are numerous situations where analog signals to be processed in many ways, like filtering and spectral analysis , Designing analog hardware to perform these functions is possibl

26、e but has become less and practical, due to increased performance requirements, flexibility needs , and the need to cut down on development/testing time .It is in other words difficult pm design analog hardware analysis

27、of signals.</p><p>  The act of sampling an signal into thehat are specialised for embedded signal processing operations , and such a processor is called a DSP, which stands for Digital Signal Processor . To

28、day there are hundreds of DSP families from as many manufacturers, each one designed for a particular price/performance/usage group. Many of the largest manufacturers, like Texas Instruments and Motorola, offer both spec

29、ialised DSP’s for certain fields like motor-control or modems ,and general high-performance SP</p><p>  DSP’s more or less fall into two categories depending on the underlying architecture-fixed-point and fl

30、oating-point. The fixed-point devices generally operate on 16-bit words, while the floating-point devices operate on 32-40 bits floating-point words. Needless to say , the fixed-point devices are generally cheaper . Anot

31、her important architectural difference is that fixed-point processors tend to have an accumulator architecture, with only one “general purpose” register , making them quite tric</p><p>  There are thousands

32、of different DSP’s on the market, and it is difficult task finding the most suitable DSP for a project. The best way is probably to set up a constraint and wishlist, and try to compare the processors from the biggest man

33、ufacturers against it.</p><p>  The “big four” manufacturers of DSP’s: Texas Instruments, Motorola, AT&T and Analog Devices.</p><p>  Digital-to-analog conversion</p><p>  In th

34、e case of MPEG-Audio decoding , digital compressed data is fed into the DSP which performs the decoding , then the decoded samples have to be converted back into the analog domain , and the resulting signal fed an amplif

35、ier or similar audio equipment . This digital to analog conversion (DCA) is performed by a circuit with the same name & Different DCA’s provide different performance and quality , as measured by THD (Total harmonic d

36、istortion ), number of bits, linearity , speed, filter char</p><p>  The TMS320 family DQP of Texas Instruments</p><p>  The TLS320family consists of fixed-point, floating-point, multiprocessor

37、digital signal processors (DSP’s) , and foxed-point DSP controllers. TMS320 DSP have an architecture designed specifically for real-time signal processing . The F/C240 is a number of the’C2000DSP platform , and is optimi

38、zed for control applications. The C24x series of DSP controllers combines this real-time processing capability with controller peripherals to create an ideal solution for control system applications. The fol</p>&

39、lt;p>  --- Very flexible instruction set</p><p>  --- Inherent operational flexibility </p><p>  ---High-speed performance</p><p>  ---Innovative parallel architecture</p>

40、<p>  ---Cost effectiveness</p><p>  Devices within a generation of the TMS320 family have the same CPU structure but different on-chip memory and peripheral configurations. Spin-off devices use new co

41、mbinations of On-chip memory and peripherals to satisfy a wide range of needs in the worldwide electronics market. By integrating memory and peripherals onto a single chip , TMS320 devices reduce system costs and save ci

42、rcuit board space.</p><p>  The 16-bit ,fixed-point DSP core of the C24x devices provides analog designers a digital solution that does not sacrifice the precision and performance of their system performance

43、 can be enhanced through the use of advanced control algorithms for techniques such as adaptive control , Kalman filtering , and state control. The C24x DSP controller offer reliability and programmability . Analog contr

44、ol systems, on the other hand ,are hardwired solutions and can experience performance degradation due</p><p>  The high-speed central processing unit (CPU) allows the digital designer to process algorithms i

45、n real time rather than approximate results with look-up tables. The instruction set of these DSP controllers, which incorporates both signal processing instructions and general-purpose control functions, coupled with th

46、e extensive development time and provides the same ease of use as traditional 8-and 16-bit microcontrollers. The instruction set also allows you to retain your software investment when</p><p>  The C24x arch

47、itecture is also well-suited for processing control signals. It uses a 16-bit word length along with 32-bit registers for storing intermediate results, and has two hardware shifters available to scale numbers independent

48、ly of the CPU . This combination minimizes quantization and truncation errors, and increases p2ocessing power for additional functions. Such functions might include a notch filter that could cancel mechanical resonances

49、in a system or an estimation technique that cou</p><p>  The C24xDSP controllers take advantage of an set of peripheral functions that allow Texas Instruments to quickly configure various series members for

50、different price/ performance points or for application optimization.</p><p>  This library of both digital and mixed-signal peripherals includes:</p><p><b>  ---Timers</b></p>

51、<p>  ---Serial communications ports (SCI,SPI)</p><p>  ---Analog-to-digital converters(ADC)</p><p>  ---Event manager</p><p>  ---System protection, such as low-voltage and w

52、atchdog timer</p><p>  The DSP controller peripheral library is continually growing and changing to suit the of tomorrow’s embedded control marketplace.</p><p>  The TMS320F/C240 is the first st

53、andard device introduced in the ‘24x series of DSP controllers. It sets the standard for a single-chip digital motor controller. The 240 can execute 20 MIPS. Almost all instructions are executed in a simple cycle of 50 n

54、s . This high performance allows real-time execution of very comple8 control algorithms, such as adaptive control and Kalman filters. Very high sampling rates can also be used to minimize loop delays.</p><p>

55、;  The 240 has the architectural features necessary for high-speed signal processing and digital control functions, and it has the peripherals needed to provide a single-chip solution for motor control applications. The

56、240 is manufactured using submicron CMOS technology, achieving a log power dissipation rating . Also included are several power-down modes for further power savings. Some applications that benefit from the advanced proc

57、essing power of the 240 include: </p><p>  ---Industrial motor drives</p><p>  ---Power inverters and controllers</p><p>  ---Automotive systems, such as electronic power steering ,

58、 antilock brakes, and climate control</p><p>  ---Appliance and HVAC blower/ compressor motor controls</p><p>  ---Printers, copiers, and other office products</p><p>  ---Tape driv

59、es, magnetic optical drives, and other mass storage products</p><p>  ---Robotic and CNC milling machines</p><p>  To function as a system manager, a DSP must have robust on-chip I/O and other p

60、eripherals. The event manager of the 240 is unlike any other available on a DSP . This application-optimized peripheral unit , coupled with the high performance DSP core, enables the use of advanced control techniques fo

61、r high-precision and high-efficiency full variable-speed control of all motor types. Include in the event manager are special pulse-width modulation (PWM) generation functions, such as a programmable d</p><p&g

62、t;  There independent up down timers, each with it’s own compare register, support the generation of asymmetric (noncentered) as well as symmetric (centered) PWM waveforms.</p><p>  Open-Loop and Closed-Loop

63、 Control</p><p>  Open-loop Control Systems</p><p>  The word automatic implies that there is a certain amount of sophistication in the control system. By automatic, it generally means That the

64、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 au

65、tomatic feature is achieved by feed.</p><p>  The feedback structure, it is called an open-loop system , which is the simplest and most economical type of control system.inaccuracy lies in the fact that one

66、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

67、 system is not capable of adapting to variations in environmental conitions or to external disturbances. In the case of</p><p>  An electric washing machine is another typical example of an open-loop system

68、, because the amount of wash time is entirely determined by the judgment and estimation of the human operator . A true automatic electric washing machine should have the means of checking the cleanliness of the clothes c

69、ontinuously and turn itsedt off when the desired degised of cleanliness is reached.</p><p>  Closed-Loop Control Systems</p><p>  What is missing in the open-loop control system for more accurat

70、e 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 compared with the reference input

71、, 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 pats like that just described is called a <

72、/p><p>  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 conti

73、nuously 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 closed-loop control. However

74、 , if one is told to reach for the object and then is blindolded, one can only </p><p><b>  譯文:</b></p><p><b>  控制系統(tǒng)基礎</b></p><p>  數(shù)字控制機床常常重達上百噸,但卻常常要求切削工具的

75、定位精度達到0.002毫米。控制系統(tǒng)必須使刀具在遇到負載的情況下的進給速度高達每秒8厘米,而負載在給定的軌道上的變化非常之大。數(shù)控機床必須具有動態(tài)響應特性以便能夠跟蹤復雜的輪廓,具有最小的軌跡誤差。很清楚,這些要求意味著控制系統(tǒng)必須與它所驅(qū)動的機械特性相匹配。</p><p>  控制系統(tǒng)是一個通過控制能源流以及其他往來資源實現(xiàn)控制操作的組合設備。實際上,控制系統(tǒng)是由相關(guān)的子系統(tǒng)組成,這些子系統(tǒng)可以完成在傳統(tǒng)機加

76、工過程中由勝任的人員操縱的任務。</p><p>  因此,數(shù)控機床的控制系統(tǒng)能代替及其操作員,更為重要的是甚至比做好的人操作還要更好。數(shù)字控制與它所替代的操作人員之間的一下操作十項類似的:</p><p>  感測機床的當前狀態(tài);</p><p>  做出完成動作所需要的邏輯判斷;</p><p>  向機床傳達決定,驅(qū)動是黨的機械裝置;&

77、lt;/p><p>  具有儲存信息的能力:指令、數(shù)據(jù)和邏輯判斷的決定。</p><p>  總之,機床控制系統(tǒng)是電子電路、感測元件和引導刀具沿預先確定的到運動的機械機構(gòu)組成的組合體。</p><p><b>  第七課 數(shù)字控制</b></p><p>  先進制造技術(shù)中的一個最基本的概念是數(shù)字控制(NC)。在數(shù)字技術(shù)出

78、現(xiàn)之前,所有的機床都是由人工操縱和控制的。在與人控制的機床有關(guān)的很多局限性中,操作者的技能大概是最突出的問題。采用人工控制時,產(chǎn)品的質(zhì)量直接與操作者的技能有關(guān)。數(shù)字控制代表了從人工控制機床走出來的第一步。</p><p>  數(shù)字控制意味著采用預先錄制的、存儲的符號指令,控制機床和其他制造系統(tǒng)。一個數(shù)控技師的工作不是去操縱機床,而是編寫能夠發(fā)出機床操縱指令的程序。對于一臺數(shù)控機床,其上必須裝有一個被稱為閱讀機的界

79、面裝置,用來接受和解譯編程指令。</p><p>  發(fā)展數(shù)控技術(shù)是為了克服人類操作者的局限性,而且它確實完成了這項工作。數(shù)控機床比人工操縱機床的精度更高,他們可以生產(chǎn)一致性更好的零件,它們更快,而且長期加工成本更低。數(shù)控技術(shù)的發(fā)展導致了制造工藝中其他幾項新發(fā)明的產(chǎn)生:</p><p><b>  電火花加工技術(shù);</b></p><p>&l

80、t;b>  激光切割;</b></p><p><b>  電子束焊接。</b></p><p>  數(shù)字控制還使得機床比它們采用人工操縱的前輩們的用途更為廣泛。一臺數(shù)控機床可以自動生產(chǎn)很多種類的零件,每個零件都可以有不同的和復雜的加工過程。數(shù)控可使生產(chǎn)廠家承擔哪些對于采用人工控制的機床和工藝來說,在經(jīng)濟上不劃算的產(chǎn)品任務。</p>&

81、lt;p>  與許多先進技術(shù)一樣,數(shù)控誕生于麻省理工學院的實驗室中。數(shù)控這個概念是20世紀50年代在美國空軍的資助下提出來的。在其最初的階段,數(shù)控機床可以經(jīng)濟和有效地進行直線切割。</p><p>  然而,曲線軌跡成為機床加工的一個問題,在編程時應該采用一系列的水平與豎直的臺階來生成曲線。構(gòu)成臺階的每個線段越短,曲線就越光滑。臺階中的每個線段都必須經(jīng)過計算。</p><p>  在

82、這個問題促使下,于1959年誕生了自動編程工具(APT)語言。這是一個專門適用于數(shù)控的編程語言,使用類似于英語的語句來定義零件的幾何形狀,描述切削刀具的現(xiàn)狀和規(guī)定必要的運動。APT語言的研究和發(fā)展是在數(shù)控技術(shù)進一步發(fā)展過程中的一大進步。最初的數(shù)控系統(tǒng)與今天應用的數(shù)控系統(tǒng)是很大差別的。在那時的機床中,只有硬線邏輯電路。指令程序?qū)懺诖┛准垘希ㄋ髞肀凰芰洗艓〈捎脦ч喿x機將寫在紙帶或磁帶上的指令給機器翻譯出來。所有這些共同構(gòu)成了機

83、床數(shù)字控制方面的巨大進步。然而,在數(shù)控發(fā)展的這個階段中還存在著許多問題。</p><p>  一個主要問題是穿孔紙帶的易損壞性。在機械加工過程中,載有編程指令信息的紙帶斷裂和被撕壞是常見的事情。在機床上加工一個零件的這段連續(xù)時間里,需要將載有程序指令的紙帶放入閱讀機中重新運行的情況使這個問題顯得更加嚴重。如果需要制造100個某種零件,則應該將紙帶分別通過閱讀機100次。易損壞的紙帶顯然不能承受嚴酷的車間環(huán)境和這種

84、重復使用。</p><p>  這就導致了一種專門的塑料磁帶的研制。在紙帶上通過采用一系列的小孔來載有編程指令,而在塑料帶上通過采用以一系列的磁點來載有編程指令。塑料帶的強度比紙帶的強度要高很多,這就可以解決常見的撕壞和斷裂問題。然而,它仍然存在著兩個問題。</p><p>  其中最重要的一個問題是,對輸入帶中的指令進行修改是非常困難的,甚至是根本不可能的。即使對指令程序進行最微小的調(diào)整

85、,也必須終端加工,制作一條新帶。而且磁帶通過閱讀機的次數(shù)還必須與要加工的零件的個數(shù)相同。幸運的事,計算機技術(shù)的實際應用很快解決了數(shù)控技術(shù)中與穿孔紙帶和塑料帶有關(guān)的問題。</p><p>  被稱為直接數(shù)字控制(DNC)概念的發(fā)展消除了用紙袋作為程序指令的載體,從而解決了數(shù)字控制中紙帶或塑料帶所帶來的問題。在直接數(shù)字控制中,幾臺機床通過數(shù)據(jù)傳輸線路連接到一臺主機算計上。操縱這些機床所需要的程序都存儲在這臺主計算機中

86、。當需要時,通過數(shù)據(jù)傳輸線路提供給每臺機床。直接數(shù)字控制是在穿孔紙帶和塑料帶基礎上的一大進步。然而,它也有著與其他依賴于主計算機的技術(shù)一樣的局限性。當主計算機出現(xiàn)故障時,由其控制的所有機床都將停止工作。這個問題促使了計算機數(shù)字控制技術(shù)的產(chǎn)生。</p><p>  微處理器的發(fā)展為可編程邏輯控制器和微型計算機的發(fā)展做好了準備。這兩種技術(shù)為計算機數(shù)字控制(CNC)的發(fā)展打下了基礎。采用(CNC)技術(shù)后,每臺機床上都有

87、一個可編程邏輯控制器或者微機對其進行數(shù)字控制。這可以使得程序被輸入和存儲在每臺機器內(nèi)部。它還可以在機床以外編制程序,并且將其下載到每臺機床中。計算機數(shù)控解決了主計算機發(fā)生故障所帶來的問題,但是它產(chǎn)生了另一個被稱為數(shù)據(jù)管理的問題。同一個程序可能要分別裝入十個相互之間沒有通信聯(lián)系的微機中。這個問題正在解決之中,它是通過采用局部區(qū)域網(wǎng)絡將各個微機連接起來,以利于更好地進行數(shù)據(jù)管理。</p><p>  第八課 數(shù)字信

88、號處理器</p><p>  在很多情況下需要對模擬信號進行多種處理,例如濾波和譜分析。設計一個模擬硬件電路完成這些工作是完全可以的,但是因為不斷提高的性能要求,適應性要求,以及縮短開發(fā)和試驗時間的要求使得這樣做已經(jīng)變得越來越不可行了。換句話說,就是難以設計一個模擬硬件電路來完成現(xiàn)在高級的信號分析功能。</p><p>  對一個模擬信號進行采樣使其成為數(shù)字信號,利用運算法對數(shù)字信號進行處

89、理以及在將處理之后的數(shù)字信號還原成模擬信號的做法稱為數(shù)字信號處理。最近15年以來出現(xiàn)的處理器主要研究嵌入的信號處理操作,這樣的處理器稱做DSP,它表示數(shù)字信號處理器?,F(xiàn)在,許多生產(chǎn)商開發(fā)了上百個DSP系列產(chǎn)品,每一種都針對特定的價格、性能和用戶群而設計。許多最大的生產(chǎn)商,像德州儀器公司和摩托羅拉公司既可以提供為某些領(lǐng)域如汽車控制或調(diào)制解調(diào)器生產(chǎn)的專用DSP,也可以提供通信的高性能DSP,它們可以完成很寬領(lǐng)域的處理任務。相應的開發(fā)器和軟件

90、都可以找到。許多公司生產(chǎn)DSP軟件開發(fā)工具,它可以使編程器利用簡單的拖放實現(xiàn)復雜的處理運算。</p><p>  根據(jù)其內(nèi)在結(jié)構(gòu)——定點運算或者浮點運算,DSP大體上可以分為兩種。定點運算設備通常為16位自唱,而浮點運算設備為32~40位自唱。當然,定點設備的價格一般較低。另外一個結(jié)構(gòu)上的差異是定點處理器往往是單寄存器結(jié)構(gòu),只有一個一般用途的寄存器,使得編程相當困難和更加重要,使得C編譯器變得不再滿足要求。浮點運

91、算的DSP則像普通的多用途CPU,具有寄存器。</p><p>  市場上有很多成千上萬的不同的DSP,所以,尋找能夠適合你的項目需要的DSP是一項艱巨的任務。最好的方法或許是設置約束和期望,根據(jù)這些對最大的生產(chǎn)商的DSP產(chǎn)品進行比較。最大的四個DSP生產(chǎn)商是:德州儀器公司,摩托羅拉,AT&T,ADI(Analog Devices)。</p><p><b>  數(shù)模轉(zhuǎn)換

92、</b></p><p>  在對MPEG音頻譯碼時,數(shù)字壓縮數(shù)據(jù)輸入執(zhí)行譯碼的DSP中,然后經(jīng)過譯碼的采樣必須重新轉(zhuǎn)換回模擬域,所形成的信號在輸入一個放大器或者類似的音頻設備。這個數(shù)字到模擬的轉(zhuǎn)換(DAC)由一個具有相同名字的電路完成。不同的DAC產(chǎn)生不同的性能和質(zhì)量,通過以下參數(shù)的測量確定:THD(總諧波失真),數(shù)位,線波器,速度,濾波器特性及其他。</p><p>  德

93、州儀器公司的TMS320家族的DSP</p><p>  TMS320系列由定點、浮點、多處理器數(shù)字信號處理器(DSPs)和定點DSP控制器組成。TMS320 DSPs具有專門為實時信號處理而設計的結(jié)構(gòu)。F/C240是大量C2000 DSP的平臺,最適用于控制使用。C24x系列的DSP控制器將實時處理能力與外界設備相結(jié)合形成了控制系統(tǒng)應用的理想的解決方案。下列特點使得TMS320系列成為廣闊的處理應用的正確選擇:

94、</p><p>  —非常靈活的指令系統(tǒng);</p><p>  —內(nèi)在的操作適應性;</p><p><b>  —高速性能;</b></p><p><b>  —創(chuàng)新的平行結(jié)構(gòu);</b></p><p><b>  —成本低廉。</b></p

95、><p>  TMS320系列的同一代DSP都具有相同的CPU,但是具有不同內(nèi)部存儲器和外圍配置。由此而派生的、采用新的內(nèi)部存儲器和外圍配置組合方式的DSP是為了滿足世界電子市場的廣泛需求。通過將存儲器和外圍設備集成在一個芯片上,使得 TMS320減少了系統(tǒng)成本和電路板占用的空間。</p><p>  C24x的16位定點DSP核心可以模擬電路設計師提供數(shù)字解決方案,且不會損失系統(tǒng)的精度和性能

96、。事實上,在某些技術(shù)上,例如自適應控制,Kalman濾波和狀態(tài)控制中使用先進的控制運算方法可以提高系統(tǒng)的性能。C24Xdsp具有很好的可靠性的和編程性。另一方面,模擬控制系統(tǒng)是硬件電路,由于元件老化,參數(shù)誤差和漂移必然產(chǎn)生性能蛻化。</p><p>  高速的中央處理單元將容許 數(shù)字設計師實時地進行運算,而不是查表得來的近似結(jié)果。這些DSP控制器的指令系統(tǒng)既具有信號處理指令又具有多用途控制功能,同時,隨著支持C2

97、4x的廣泛的技術(shù)發(fā)展,使得開發(fā)時間縮短,而且就像使用8~16位微控制器一樣方便。該指令系統(tǒng)還容許你反復利用軟件開發(fā)投資,你可以將它移植到多用途的TNS320定點DSP中。它的源碼和目標碼與C2xx代的其他品種兼容,源碼與C2x代兼容,更高的源碼則與德州儀器公司的’C5x代DSP兼容。</p><p>  C24x的結(jié)構(gòu)也能很好地適應處理控制信號。它使用16位字長和32位寄存器,用來存儲中間結(jié)果,并且有兩個硬件轉(zhuǎn)換

98、器獨立地度量CPU數(shù)值。這種組合使量化誤差和截斷誤差最小,同時增加了額外的處理能力。這些能力包括可以刪除系統(tǒng)的機械共振的陷波濾波器,可以消除系統(tǒng)的狀態(tài)傳感器的估計技術(shù)。</p><p>  C24Xdsp控制器利用德州儀器公司已有的外圍設備產(chǎn)品來快速形成各種不同價格/性能的產(chǎn)品并使其應用效果達到最佳。數(shù)字信號和符合信號的外圍設備包括:</p><p><b>  —定時器;<

99、;/b></p><p>  —串行通信口(SCI,SPI);</p><p>  —模數(shù)轉(zhuǎn)換器(ADC);</p><p><b>  —事件管理器;</b></p><p>  —系統(tǒng)保護,例如低電壓保護和看門狗定時器。</p><p>  DSP的外設庫在不斷增大和變化以適應明天的控制

100、市場的需要。TMS320F/C240是第一個引入24x系列的DSP控制器的標準設備。它建立了單片數(shù)字電機控制器標準。24x每秒鐘可以執(zhí)行20萬條指令??梢栽?0納秒的周期內(nèi)執(zhí)行幾乎所有指令。這種高性能容許實時地執(zhí)行所有非常復雜的控制運算,例如自適應控制和Kalman濾波器。還可以采用很高的采樣頻率來減小循環(huán)延遲。</p><p>  240具有高速信號處理和數(shù)字控制功能所必須的結(jié)構(gòu)特點,具有實現(xiàn)電機控制單片解決方

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