外文文獻與翻譯-- 基于嵌入式平臺的智能小車控制器的設計

1、<p>　　Design of an Intelligent Car Controller</p><p>　　Based on Embedded Platform</p><p>　　Liu Gang Zhang Qingyu Wang Yanlin</p><p>　　(Key Laboratory of Modern Measurement &a

2、mp; Control Technology（Beijing Information Science & Technology University），Ministry of Education.)</p><p>　　(Beijing Information Science & Technology University Beijing 100192 China)</p><

3、p>　　Abstract: The paper presents a design of an intelligent car controller using embedded ARM7 chips as core component. Modular method has been applied in the design of the hardware; the paper focuses on layout of tra

4、cking circuit for the car and design ideas for the software. The experiment result proves that the designed intelligent car is stable in operation and good in tracking performance.</p><p>　　Keywords: ARM I

5、ntelligent Tracking</p><p>　　1 、Introduction</p><p>　　In the 21st century, with development of science and technology, researches on intelligent car and its correlative techniques have become

6、the focus in this field. Aiming to enhance practical ability， innovation, and teamwork performance of college students across the country, the Education Department sponsored National Undergraduate Intelligent Car Contest

7、. Based on the background, the paper introduces the design of multifunctional intelligent car controller on embedded platform, including desig</p><p>　　2、Design of hardware</p><p>　　By function

8、and application, the controlling platform for the intelligent car is divided into several modules as shown below.</p><p>　　2.1 Design of core module</p><p>　　AT91SAM7S256 microprocessor produced

9、 by ATMEL has been adopted for the controller of the car, which a 32-bit low-power RISC microprocessor chip based on ARM7 TDMI-S core, and embedded with 64KB SARM, 256KB high-speed Flash and JTAG port for downloading or

10、debugging of the program. As the core component of the car, the microprocessor plays a key role in controlling all running statuses of the car. PWM generating module inside it can be change duty cycle of outputted square

11、 wave by programming, an</p><p>　　2.2 Design of power module</p><p>　　The car is powered by four AA dry batteries. The voltage is outputted through low-Noise LDO regulator MIC5209-3.3 to supply

12、power for ARM7 chips and peripheral circuits. The working current of MIC5209-3.3 is as high as 500mA. When input voltage is above 3.5V, the module of MIC5209-3.3 can output stable voltage of 3.3V and achieve low power co

13、nsumption. </p><p>　　2.3 Temperature detection Module </p><p>　　Mono-line digital temperature sensor DS18B20 is used to detect temperature in the car. The measure range is from -55℃ to +125℃, wi

14、th increment of 0.5℃. It is low in power consumption and small in size, occupying only one I/O port.</p><p>　　2.4 Auto tracking module</p><p>　　2.4.1 Principles for tracking of intelligent car&l

15、t;/p><p>　　Tracking means that the car goes along the two-centimeter-wide black guide line on the white floor. Infrared acquisition and camera shooting acquisition are commonly used for it.</p><p>

16、　　Infrared acquisition: Taking advantage of the feature that infrared light can change its reflective quality according to object surface of various colors. During running the car continuously sends infrared light to the

17、 ground, which will, either be reflected back by the white floor and received by the receiving tube in the car, or be absorbed by the black guide line and thus missed by the receiving tube. By this means the black guide

18、line is positioned to identify the path for the car.</p><p>　　Camera shooting acquisition: In certain resolution sample the image by interlaced scanning. When scanning a point, image sensor transfers the gra

19、y threshold into corresponding voltage which will be outputted via video signal port. As the car achieves auto tracking by recognizing the black guide line on the track, the image processing is a process of extracting th

20、e destination guide line. The task of image processing program is to identify the dots in the black-and-white image and filter noise, r</p><p>　　2.4.2 Installation of tracking infrared probe</p><p

21、>　　Choosing proper detection method and sensor is the important factor to achieve tracking. Here we choose infrared acquisition. Correct installation of device is also a decisive factor for accomplishment of tracking

22、circuit. In terms of simplicity, easiness, practicality and reliability, four infrared probes need be installed on the front chassis of the car to fulfill two-staged directional correction control to enhance the reliabil

23、ity of tracking. Four tracking sensors have been fixed, all in one</p><p>　　3 Design of software</p><p>　　The software is developed in C language in Keil Uvision3 IDE, debugged and downloaded in

24、 J-Link ARM emulator. J-Link is a JTAG emulator which was brought out by SEGGER in USA to support emulation chips with ARM core. It works with IDEs such as IAREWARM, ADS, Keil, WINARM, and RealView, supports all ARM7/ARM

25、9 core chips simulation, and seamlessly connects with various IDE by RDI interface. Easy to operate and to connect to, it is the most practical tool for study and development of ARM.</p><p>　　The key for the

26、 design of software lies in the control process of tracking. The sensors are equipped with E3F-DS10C4 integrated infrared probes with photoelectric switch. There are only three wires（power wire, ground wire, and signal w

27、ire）at the output pin of the module. Connect the signal wire to I/O port of ARM7 chip, and execute enquiry check. Low level will be detected for the black guide line, while high level for the white floor. According to th

28、e principles stated above, flows of the algor</p><p>　　4 Debugging of the finished car</p><p>　　Based on the design scheme presented above, finish making of PCB board for hardware circuit of the

29、 car, welding of components, and debugging and downloading of the software. Test the car for several times on the track made of white KT board in the middle of which a two-centimeter-wide black guide line is pasted. The

30、results have showed that, the car runs steadily even at a high speed along straight black guide line. When around the curve, if control the speed properly, the car goes smoothly as w</p><p>　　E3F-DS10C4 phot

31、oelectric sensor should be fixed as close to the ground as possible to minimize the interference of environmental light to it. Vertical height of the sensor had better be 5~8mm. Too far distance from the ground causes we

32、ak reflective signal and unstable output of up level signal; too close distance may damage the sensor and intensify the effect of diffuse reflection.</p><p>　　Due to common DC motor adopted for it, the contr

33、ol of the car is not accurate and stable enough to perform a break turn unless several same photoelectric sensors are added to the bottom of the car.</p><p>　　5 Conclusion</p><p>　　Intelligent c

34、ar is a front subject which has synthesized many other subjects and has a widely-applied prospect. It particularly helps to develop the present Chinese undergraduates’ imagination, practical abilities, team awareness, an

35、d hi-tech innovation capacity.</p><p>　　References</p><p>　　[1] Wu Binghua, Huang Weihua, Cheng Lei among others, Systematic Design of Intelligent Car Based on Route Identification [J]. Applicat

36、ion of Electronic Technique, 2007(3): 80-83.</p><p>　　[2] Wang Chaoyi, Wang Yihuai. Design of Control System of Auto Tracking Car Based on Infrared Sensor [J]; Computer and Automation Techniques, 2008, 34(11

37、):60-62</p><p>　　[3] Li Yi, Lu Ren Yi, & Wu Tian. Intelligence Tracking Car [J]. Electronic Techniques, 2008, 45(1): 39-41</p><p>　　[4] Wen Quangang, Principles and Application of Embedded S

38、ystem Interface [M]. Beijing: Aeronautics and Astronautics University Press, 2009</p><p>　　[5] G.C.Hua, F.C.Lee. Soft-switching technique in PWM converter[J]. IEEE Trans. on Industrial Electronics 995.42(6):

39、595-603.</p><p>　　Author Biography</p><p>　　Liu Gang: (1963-) male, senior engineer, received his Bachelor’s degree from Beijing University of Aeronautics & astronautics in 1991, main resear

40、ch direction: computer measurement and control technology ete</p><p>　　基于嵌入式平臺的智能小車控制器的設計</p><p>　　劉剛 鄭清宇 王燕林</p><p>　　（教育部現(xiàn)代測量與控制技術(shù)主實驗室（北京信息科技大學））</p><p>　?。ū本┬畔?/p>

41、科技大學 中國 北京 100192）</p><p>　　摘要：本論文介紹了智能小車控制器的設計方案。其所使用的核心元件為嵌入式ARM7芯片。硬件設計采用模塊化方法。本論文致力于小車跟蹤電路的線路圖以及軟件的設計理念。實驗結(jié)果證明，設計的智能小車操作平穩(wěn)，跟蹤性能良好。</p><p>　　關(guān)鍵詞：ARM；智能；跟蹤</p><p><b>　　1.引言&

42、lt;/b></p><p>　　21世紀，隨著科學技術(shù)的發(fā)展，關(guān)于智能小車及其相關(guān)技術(shù)的研究已經(jīng)成為該領(lǐng)域的焦點。為了加強全國大學生的實際操作能力，創(chuàng)新思想和團隊合作意識，教育部主辦了全國在校生智能小車競賽?；谶@種情況，本論文介紹了嵌入式多功能智能小車控制器的設計方案，包括主要實用模塊上硬件電路和執(zhí)行軟件的設計。</p><p><b>　　2、硬件設計</b&g

43、t;</p><p>　　就功能和應用而言，智能小車的控制平臺可分為以下幾個模塊。</p><p>　　2.1、核心模塊的設計</p><p>　　小車的控制器采用了ATMEL生產(chǎn)的AT91SAM7S256微處理器。該處理機帶有一個基于ARM7 TDMI-S核心的32位低能RISC微型處理芯片，同時被嵌入了64KB SRAM，256KB高速閃光存儲器和JTAG端口以

44、供程序的下載與調(diào)試。</p><p>　　作為小車的核心元件，微處理器在控制小車所有運行狀態(tài)方面起著關(guān)鍵作用。它里面的PWM生成模塊可以通過編程設計來改變輸出矩形波的填充系數(shù)，并從而改變馬達上的電壓，增強對馬達運行速度的控制。PWM模塊上的端口PA0，PA1，PA2 and PA3分別控制DC馬達和轉(zhuǎn)向馬達來執(zhí)行一些功能，比如前進，后</p><p><b>　　退和轉(zhuǎn)彎等等。&

45、lt;/b></p><p>　　2.2、電源模塊的設計</p><p>　　小車的電源是四節(jié)AA干電池。電壓是通過低噪音LDO調(diào)節(jié)器MIC5209-3.3輸出的，可以給ARM7芯片和外圍電路供電。MIC5209-3.3的工作電流高達500mA。輸入電壓高于3.5V時，MIC5209-3.3模塊可以輸出3.3V的穩(wěn)定電壓，實現(xiàn)低能量消耗。</p><p>&l

46、t;b>　　2.3、檢溫器模塊</b></p><p>　　單向數(shù)字測溫傳感器DS18B20是用于檢測小車內(nèi)部溫度。測量范圍是-55~+125攝氏度，有0.5攝氏度的增額。它耗能低，尺寸小，僅占一個I/O端口。</p><p><b>　　2.4、自動跟蹤器</b></p><p>　　2.4.1 智能小車的跟蹤原則</

47、p><p>　　跟蹤意味著小車沿著白色地板上兩厘米寬的黑色導航路線運行。紅外線探測和相機拍攝探測被廣泛用在這里。</p><p>　　紅外線探測：利用了紅外線可以根據(jù)各種顏色物體表面來改變其反光品質(zhì)的特征。</p><p>　　在運行過程中，小車不斷向地面發(fā)出紅外線，紅外線就會被白色地板反射回來，并被小車上的接收管接收，或者紅外線被黑色導航路線吸收，從而無法被接收管接收

48、。通過這種方法，就設置了黑色導航路線來讓小車識別道路。</p><p>　　相機拍攝探測：通過隔行掃描，以特定分辨率來抽樣檢驗圖像，當掃描到一個點時，圖像傳感器會將灰度閾值轉(zhuǎn)換成相應的電壓，然后再通過視頻信號端口將電壓輸出。當小車能夠通過識別軌道上黑色導航線來實現(xiàn)自動跟蹤時，圖像處理就成了一個提取終點導航線的過程。圖像處理程序的任務就是識別黑白圖像上的點和過濾噪音，記錄與圖像有關(guān)的點位置，最后通過控制策略的運算法

49、則，實現(xiàn)小車沿著導航線的跟蹤和轉(zhuǎn)向。</p><p>　　2.4.2 跟蹤紅外線探測器的安裝</p><p>　　選擇合適的檢測方法，傳感器是實現(xiàn)跟蹤的重要因素。這里我們選擇紅外線探測。設備的正確安裝也是完成跟蹤電路的一個決定性因素。就簡單，容易，實用性和可靠性而言，小車的前方底盤上應安裝四臺紅外線探測器。這是為了完成兩階段的方向矯正以加強跟蹤的可靠性。四個跟蹤傳感器全部被安裝在一條線上，

50、其中L1和R1是控制方向的主要傳感器；L2和R2是次要傳感器。兩個同側(cè)傳感器之間的距離應該不超過黑色航向控制線的寬度。當小車運行時，黑色導航線應一直恰好被控制在兩個主要傳感器L1和R1之間。當小車脫離黑色航線時，兩個主要傳感器就能檢測到。然后ARM7芯片檢測水平跨越并執(zhí)行之前預備的矯正程序去把小車引航回軌道上。次要傳感器實際上就是主要傳感器的備份。一旦小車由于慣性偏移出軌道，超出主要探測器的檢測范圍時，次要傳感器就開始運行去矯正小車的運

51、動，從而確保跟蹤的可靠性。</p><p><b>　　3.軟件的設計</b></p><p>　　軟件是用C語言Keil Uvision3 IDE開發(fā)設計，用J-Link ARM仿真器調(diào)試和下載的。J-Link是一種JTAG仿真器，是美國SEGGER為了給ARM核心提供仿真芯片而生產(chǎn)出來的。它和IDEs, 比如IAREWARM, ADS, Keil, WINARM,

52、和RealView等一起運行，支持所有ARM7/ARM9核心仿真芯片，并通過RDI接口流暢地與各種各樣的IDE相連接。由于操作簡單，連接方便，它是研究和開發(fā)ARM的最實用工具。</p><p>　　跟蹤軟件的流程圖表：</p><p>　　啟動---初始化I/O接口--啟動馬達—檢測黑線？---不是，繼續(xù)；是，減速—（L1—是L2？--不是，向左調(diào)好；是，向左調(diào)）；（R1—是R2？--不是

53、，向左調(diào)好；是，向右調(diào)）---恢復速度—完成。</p><p>　　軟件設計的關(guān)鍵在于跟蹤的控制過程。傳感器配備了帶有光電開關(guān)的E3F-DS10C4集成紅外線探測儀。模塊的輸出插頭上僅有三根電線（電源線，地線和信號線）。將信號線連接在ARM7芯片的I/O端口上，并執(zhí)行詢問核對。黑色導航線的低電平和白色地板磚的高電平都將被檢測出來。為了確保小車與黑色導航線的吻合度，可以采用兩階段控制方法，效果很令人滿意。</

54、p><p><b>　　4.成品小車的調(diào)試</b></p><p>　　根據(jù)以上介紹的設計方案，完成小車硬件電路上PCB模板的制作，各個元件的焊接以及軟件的調(diào)試與下載。讓小車在白色KT板制成的軌道上進行幾次測試。KT板的中間應有一條兩厘米寬的黑色導航線。測試結(jié)果顯示，小車沿著筆直的黑色導航線能平穩(wěn)甚至高速行駛。當軌道為曲線時，如果將速度控制好，小車也能順利行駛。以下兩條經(jīng)

55、驗是親身經(jīng)歷所得：</p><p>　?。?）E3F-DS10C4光電傳感器應該安裝得盡可能靠近地面，是為了最小化環(huán)境光</p><p>　　對它的干擾。傳感器的垂直高度最好為5~8mm。與地面距離太遠會引起反射信號弱和高電平信號輸出不穩(wěn)定；距離太近可能會損害傳感器并加劇漫反射的影響。</p><p>　　（2）由于小車采用的是普通DC馬達，所以小車的操控不是那么精

56、準，執(zhí)行急轉(zhuǎn)彎時也不是很平穩(wěn)，除非能在小車的底部多加幾個相同的光電傳感器。</p><p><b>　　5.結(jié)論</b></p><p>　　智能小車是一個綜合了許多其他學科的前沿學科，有著廣泛的應用前景。它特別有助于開發(fā)當前中國大學生的想象力，實用能力，團隊意識，以及高科技創(chuàng)新能力。</p><p><b>　　6.參考文獻<

57、/b></p><p>　　【1】.吳炳華，黃衛(wèi)華，程雷等人.智能小車基于路線標識的系統(tǒng)設計[J].電子科技的應用，2007（3）：80-83</p><p>　　【2】.王超逸，王宜懷.自動追蹤小車基于紅外線傳感器的控制系統(tǒng)設計[J].計算機及自動化技術(shù)，2008,34（11）：60-62</p><p>　　【3】.劉毅，魯仁義和吳天.智能跟蹤小車[J].

58、電子技術(shù)，2008,45（1）：39-41</p><p>　　【4】.溫全剛.嵌入式系統(tǒng)電路的原理及應用[M].北京航空航天大學出版，2009</p><p>　　【5】.G.C.Hua, F.C.Lee. Soft-switching technique in PWM converter[J].IEEE Trans. On Industrial Electronics 995,42(6