外文翻譯---車載無線傳感器網(wǎng)絡(luò)監(jiān)測(cè)系統(tǒng)設(shè)計(jì)

1、<p>　　江漢大學(xué)畢業(yè)論文（設(shè)計(jì)）</p><p><b>　　外文翻譯</b></p><p>　　原文來源 Wireless sensor network monitoring system design </p><p>　　中文譯文 車載無線傳感器網(wǎng)絡(luò)監(jiān)測(cè)系統(tǒng)設(shè)計(jì)</p><p>　　姓 名

2、 李俊杰 </p><p>　　學(xué) 號(hào) 200807201141 </p><p>　　2012年 1月 15 日</p><p>　　Wireless sensor network monitoring system design</p><p>　　Kang yi-mei,Zhao le

3、i,Hu jiang,Yang en-bo</p><p>　　(Study on Beijing University of Aeronautics and Astronautics)</p><p>　　Summary: A car wireless sensor network monitoring system based on IEEE 802.15.4 and ZigBee s

4、tandards. With universal wireless sensor networks, expansion of the scope of monitoring and monitoring functions for in-car system, car data acquisition and condition monitoring of equipment status and the necessary equi

5、pment control, topology control, topology query functions.</p><p>　　Keywords: wireless sensor networks; monitoring system</p><p>　　Introduction</p><p>　　In order to satisfy the peop

6、le to car safety, handling and comfort requirements, vehicle integrated with more and more electronic system .At present, car electronic equipment is widely used 16 or 32-bit microprocessor control. Creating in-vehicle m

7、onitoring system based on IEEE 802.15.4 and ZigBee standard for wireless sensor networks, designed to achieve a more optimized wireless sensor networks, the progressive realization of the network of automotive systems, i

8、ntelligent and controllable to p</p><p>　　System design</p><p>　　In this paper, the existing vehicle system, the data transmission mode is extended to the wireless transmission mode, the realiza

9、tion of a star network data acquisition system. And can place each data acquisition node of the acquired data is transmitted to the gateway, the gateway through the serial port to upload data to the host computer, in the

10、 host data real-time waveform display, and method of database to preserve, for the follow-up data processing. The application of system object is compo</p><p>　　As shown in Figure 1, the system is divided in

11、to 3 parts: Vehicle Monitoring Center, gateway and mobile sensor node. Gateway is the whole vehicle system core, and all vehicular sensor node communication. Vehicle monitoring center to the gateway sends a control comma

12、nd by the gateway, the control command is converted to an RF signal and sent to the vehicle sensor node. When the vehicle sensor nodes to transmit data, gateway into the data reception state, and upload data to the monit

13、oring center f</p><p>　　Vehicle sensor node life cycle is active and dormant periods. Nodes in the active phase of the completion of data acquisition, data sent to the gateway, receiving and executing gatewa

14、y command; in the dormant period off the wireless RF module in order to save energy, until the next active period. System through this mechanism of dormancy to reduce energy consumption, extend the time span of the syste

15、m as a whole.</p><p>　　The system used PC as the control center, PC machine monitoring software in VB development environment, is a dialog based application software. In order to improve the communication mo

16、dule of the intelligent level, in the design, its function is not limited to the real-time data display, all of the data collection by the monitoring software by sending a request signal to the trigger. Considering the o

17、riginal data for subsequent processing and in-depth analysis of the vehicle system, can accurate</p><p>　　Generally speaking, the whole network are controlled by the host monitoring software, the working pro

18、cess of every node of the network is the need of human participation.</p><p>　　2 hardware system design</p><p>　　2.1application chip introduction</p><p>　　MC13192with IEEE802.15.4 s

19、tandard, the operating frequency is2.405～ 2.480 GHz, data transmission rate of 250kbps, using 0-QPSK debugging mode. This feature-rich two-way 2.4GHz transceiver with a data modem which can be in the ZigBee technology ap

20、plication. It also has an optimized digital core, helps to reduce the MCU processing power, shorten the cycle of execution.</p><p>　　The main control MCU choose HCS08series of low power, high performance mic

21、roprocessor MC9S08GB60. The processor has a 60Application of KB programmable Flash、4 KB RAM,10 ADC,8 channel2 asynchronous serial communication interface ( SCI ),1 synchronous serial interface ( SPI ) and I2C bus module,

22、 can fully meet the requirement of vehicle gateway and node processor requirements.</p><p>　　2.2 MCl3192and MC9S08GB60hardware connection</p><p>　　MC13192and MC9S08GB60 hardware connection diagr

23、am as shown in figure 2. The MC13192control and data transmission on 4 wire serial peripheral interface ( SPI ) is completed, the4interface signals were MOS-I, MISO,, SPICLK. The main control MCU through the control sign

24、al exiting sleep mode or hibernation mode, through to reset the transceiver, through the RXTXEN to control the data sending and receiving, or force the transceiver into idle mode. The sensor output analog signal through

25、MCU 8 Channel</p><p>　　The 3system software design</p><p>　　3.1of overall software design</p><p>　　The software design is the design of the core, the key lies in the overall framewo

26、rk of software and data structure design. An important factor to consider is a efficiency, another is to design the clarity.</p><p>　　System software consists of the gateway node and the sensor node is compo

27、sed of two parts, the two parts are needed to complete the SMAC protocol transplantation, and according to the different needs for the upper communication applications with API interface function. Because the SMAC protoc

28、ol stack programming model using hierarchical design, only the underlying PHY and MAC program level and related hardware, and network layer and application layer procedures is not affected by hardware effect</p>&

29、lt;p>　　As shown in Figure 3, the design of the software for system platform layer, protocol layer and application layer 3layer. At the same time, defines 3API interface: system layer interface, protocol layer and appl

30、ication layer interface. System level interface defines a hardware register mapping, so C language to be able to directly access the hardware registers to control hardware. System platform based on real-time operating sy

31、stem μC/II protocol layer, to provide system services Hardware driving</p><p>　　3.2sensor node software design</p><p>　　Based on the long-term use of the functional requirements, sensor nodes in

32、 the software design is the key to achieve the required functions, and can minimize the energy consumption of the sensor nodes.</p><p>　　It was found, ZigBee module and the energy consumption is much larger

33、than the central processor and the energy consumption of sensor module. Therefore, the sensor node design of application software to try to make each module in a dormant state, and minimizing wakes ZigBee module number.

34、Therefore, the sensor nodes, power of each functional module initialization is completed, and joined the network, enter the Sleep state, the central processor cycles to be timed wake-up to send data to the gate</p>

35、<p>　　The 3.3 gateway node software design</p><p>　　Gateway downward management sensor node, to complete and PC monitoring center of interaction, the need for a complicated task management and schedul

36、ing, therefore, based on the uC / OS kernel of embedded operating system to manage the gateway, the application task efficiently provide good software support. According to gateway function demand, the μC / OS-II, SMAC p

37、rotocol organic union, form a network operating environment, the user can conveniently on the basis of its development and applicati</p><p>　　The 3.4 host monitoring software design</p><p>　　Thi

38、s system is the ultimate goal of the collected vehicle sensor data is transmitted in real-time to the host, and the host of display and preservation. Display is designed to get on-board sensor node monitoring environment

39、 of the initial situation, preservation is designed as an in-depth analysis of the data samples. In addition, the system as a whole the main prosecution and the data acquisition request initiator, need to be able to send

40、 the data request signal in accordance with the requireme</p><p>　?、賒ata waveform display module. The role of the module is a form of waveform data of the node to be displayed in real-time, it is the use of

41、MS Chart and Timer control.</p><p>　?、趖opology display module. When the user wants to know the wireless sensor network topology construction situation, you can view the topological information, understanding

42、 of network nodes join and loss.</p><p>　　The historical data display module. In vehicle network system to a certain period of the past, may need a certain period of time the original data for subsequent pro

43、cessing and in-depth analysis, so that the vehicle system of accurate judgement. With the aid of historical data display module, the control center from the gateway of the data obtained, according to the different attrib

44、utes of the nodes, address and time are saved to the database of the corresponding field, and may be will displayed</p><p>　　The controlling module :In vehicle during system operation may be concerned about

45、a vehicle sensor value node, or to a sensor threshold settings, for monitoring environmental exceptions can be promptly reported to the system. These are available through the control module of the system are correspondi

46、ng to the set, the control module can also be on the system in which one does not need to delete the node.</p><p>　　In short, through the host monitoring software users can visually and many aspects of gener

47、al wireless sensor network systems to understand and use.</p><p>　　4 test and verification</p><p>　　4.1 testing</p><p>　　Testing equipment:4 MCl3192ZigBee chip node,1as a gateway no

48、de, the remaining 3as sensor nodes.</p><p>　　Test method: the gateway node power,4 LED and light, scanning channel if the search to the idle channel, the LED goes out and join the free channel for. The senso

49、r node power,4 LED scanning in the channel at the same time, polling light. LED1 flashes once when the sensor nodes receive the allocation address of the gateway node, So far, networking process and address binding proce

50、ss is complete.</p><p>　　4.2 Zigbee RF communication test</p><p>　　Testing equipment: ZigBee node 4, a computer terminal station</p><p>　　Test method: according to the ZigBee transm

51、ission frame format, the actual transmission total bytes for ( n 6), namely ( n 6) bytes for a data packet. According to the set parameters of the software, such as packet loss is the loss number plus 1. If the received

52、data packet, receives the data packet number plus 1, and then sends the data were compared with data, if the data is correct, the number of packets plus 1, and error packets number plus 1. The last statistic results, can

53、 know the data pa</p><p>　　Experimental analysis of: in a star network for data transmission, the test results significantly worse on a single point to single point transmission mode. This is mainly because,

54、 in the transmission process node must exist between the frequency interference and other interference.</p><p>　　4.3power test</p><p>　　System status and hibernation, respectively, using a multi

55、meter to test the gateway node and the power consumption of sensor nodes, the test results listed in Table 2.</p><p>　　Conclusion</p><p>　　This paper analyzes the IEEE 802.15.4 and ZigBee protoc

56、ol, combined with the general development principles of communication systems and embedded systems, IEEE802.15.4 protocol on the μC / OS-II operating system, select the appropriate hardware and software platform, focusin

57、g on software support for the platform, the software design of the overall structure of the communication protocol stack, and ultimately to achieve a compliant with the ZigBee specification car star wireless data acquisi

58、tion </p><p>　?、?system easy to install. Wireless interconnection makes the equipment installation location is flexible to meet the requirements of the automation system is installed. It is simply that the p

59、ower can take equipment. The network system can automatically complete the network configuration.</p><p>　?、?scalability. Equipment within the coverage of the vehicle gateway, turn on the device, the node wi

60、ll automatically join the network.③ network self-healing ability. If the network is a device fails, the vehicle gateway can automatically monitor, issue the command the device reset and re-network.</p><p>　　

61、車載無線傳感器網(wǎng)絡(luò)監(jiān)測(cè)系統(tǒng)設(shè)計(jì)</p><p>　　康一梅，趙 磊，胡 江，楊恩博 </p><p>　　（就讀于北京航天航空大學(xué)）</p><p>　　摘要：基于IEEE 802．15．4和ZigBee標(biāo)準(zhǔn)實(shí)現(xiàn)了一個(gè)車載無線傳感器網(wǎng)絡(luò)監(jiān)測(cè)系統(tǒng)。借助通用無線傳感器網(wǎng)絡(luò)，為車載系統(tǒng)擴(kuò)展了監(jiān)控范圍和監(jiān)控功能，實(shí)現(xiàn)了車載設(shè)備狀態(tài)的數(shù)據(jù)采集和狀態(tài)監(jiān)視，以及必要的設(shè)備控制、拓

62、撲控制、拓?fù)洳樵兊裙δ?。關(guān)鍵詞：無線傳感器網(wǎng)絡(luò)；監(jiān)測(cè)系統(tǒng)；MC9S08GB60；MC13192引言</p><p>　　為了滿足人們對(duì)車載安全性、操控性以及舒適性的要求，車載上集成了越來越多的電子系統(tǒng)。目前，汽車電子設(shè)備廣泛采用16位或32位微處理器進(jìn)行控制。本文基于IEEE 802．15．4和ZigBee標(biāo)準(zhǔn)的無線傳感器網(wǎng)絡(luò)構(gòu)建車載監(jiān)測(cè)系統(tǒng)，設(shè)計(jì)實(shí)現(xiàn)更加優(yōu)化的無線傳感器網(wǎng)絡(luò)，逐步實(shí)現(xiàn)車載系統(tǒng)的網(wǎng)絡(luò)化、智能

63、化和可控性，以提，高車載系統(tǒng)的安全性。1 系統(tǒng)設(shè)計(jì)方案 本文在現(xiàn)有的車載系統(tǒng)上，將數(shù)據(jù)傳輸?shù)姆绞綌U(kuò)展為無線傳輸方式，實(shí)現(xiàn)一個(gè)星型網(wǎng)絡(luò)的數(shù)據(jù)采集系統(tǒng)。并能分別將各個(gè)數(shù)據(jù)采集節(jié)點(diǎn)的所獲得的數(shù)據(jù)傳輸?shù)骄W(wǎng)關(guān)，網(wǎng)關(guān)通過串口將數(shù)據(jù)上傳到主機(jī)上，在主機(jī)中實(shí)現(xiàn)數(shù)據(jù)的實(shí)時(shí)波形顯示，并以數(shù)據(jù)庫的方式加以保存，供后續(xù)數(shù)據(jù)處理。該采集系統(tǒng)的應(yīng)用對(duì)象由溫度傳感器、油壓傳感器、轉(zhuǎn)速傳感器、速度傳感器、電流傳感器、壓力傳感器等傳感器子系統(tǒng)所組成。這樣設(shè)計(jì)的

64、目的是用一個(gè)監(jiān)控主機(jī)端來檢測(cè)多個(gè)待測(cè)目標(biāo)環(huán)境，考慮到接入的數(shù)據(jù)吞吐量和軟件系統(tǒng)的復(fù)雜程度，采用時(shí)分復(fù)用的方式，逐個(gè)對(duì)網(wǎng)內(nèi)的終端采集點(diǎn)進(jìn)行控制采集。 如圖1所示，該車載系統(tǒng)分3個(gè)部分：車載監(jiān)控中心、車載網(wǎng)關(guān)和車載傳感器節(jié)點(diǎn)。車載網(wǎng)關(guān)是整個(gè)車載系統(tǒng)的核心，可以和所有</p><p>　　圖1 系統(tǒng)結(jié)構(gòu)總體圖</p><p>　　車載傳感器節(jié)點(diǎn)的生命周期由活躍期和休眠期構(gòu)成。節(jié)點(diǎn)在活躍期

65、完成數(shù)據(jù)采集，向網(wǎng)關(guān)發(fā)送數(shù)據(jù)，接收并執(zhí)行網(wǎng)關(guān)命令；在休眠期關(guān)閉無線射頻模塊以節(jié)省能量，直到下一個(gè)活躍期來臨。系統(tǒng)通過這種休眠機(jī)制來減少系統(tǒng)的能量消耗，延長(zhǎng)系統(tǒng)整體壽命。 本系統(tǒng)用PC機(jī)作為監(jiān)控中心，PC機(jī)上的監(jiān)控軟件在VB環(huán)境下開發(fā)，是一個(gè)基于對(duì)話框的應(yīng)用軟件。為了提高通信傳輸模塊的智能化水平，在設(shè)計(jì)中，它的功能不限于數(shù)據(jù)的實(shí)時(shí)顯示，所有的數(shù)據(jù)采集由監(jiān)控軟件通過發(fā)送請(qǐng)求信號(hào)的方式觸發(fā)。考慮到原始數(shù)據(jù)需要進(jìn)行后續(xù)的處理與深入的分析

66、，才能對(duì)車載系統(tǒng)的狀況進(jìn)行準(zhǔn)確的判定，軟件中還添加了數(shù)據(jù)文件形式的保存與數(shù)據(jù)文件回顯功能。 總體上來講，整個(gè)網(wǎng)絡(luò)的所有節(jié)點(diǎn)都受控于主機(jī)監(jiān)控軟件，工作過程中網(wǎng)絡(luò)的每一個(gè)節(jié)點(diǎn)都不需要人為的參與。2 系統(tǒng)硬件設(shè)計(jì)2．1 應(yīng)用芯片介紹 Freescale公司的MC13192符合IEEE 802．15．4標(biāo)準(zhǔn)，工作頻率是2．405～2．480 GHz，數(shù)據(jù)傳輸速率為250kbps，采用0-QPSK調(diào)試方式。這種功能豐富的雙向

67、2．4 GHz收發(fā)器帶有一個(gè)數(shù)據(jù)調(diào)制解調(diào)器，可以在ZigBee</p><p>　　圖2 MC13192與MC9S08GB60的硬件連接圖 </p><p>　　3 系統(tǒng)軟件設(shè)計(jì)3．1 軟件整體設(shè)計(jì) 軟件設(shè)計(jì)是本設(shè)計(jì)的核心，關(guān)鍵在于軟件的總體架構(gòu)和數(shù)據(jù)結(jié)構(gòu)的設(shè)計(jì)。著重要考慮的因素一個(gè)是效率，另一個(gè)是設(shè)計(jì)的清晰性。車載系統(tǒng)軟件由網(wǎng)關(guān)節(jié)點(diǎn)與傳感器節(jié)點(diǎn)兩大部分組成，這兩部分都需要完成

68、SMAC協(xié)議的移植，并根據(jù)不同需要為上層通信應(yīng)用提供API接口函數(shù)。因?yàn)镾MAC協(xié)議棧編程模型采用層次設(shè)計(jì)，只有底層的PHY和MAC程序?qū)优c硬件相關(guān)，而網(wǎng)絡(luò)層和應(yīng)用層程序則不受硬件影響。SMAC在不同硬件平臺(tái)的移植只需修改PHY和MAC層，其上各層可以屏蔽硬件差異直接運(yùn)行。 如圖3所示，本設(shè)計(jì)把軟件分為系統(tǒng)平臺(tái)層、協(xié)議層和應(yīng)用層3層。同時(shí)，定義了3個(gè)API接口：系統(tǒng)層接口、協(xié)議層接口和應(yīng)用層接口。系統(tǒng)層接口定義了硬件的寄存器映射

69、，這樣C語言就能直接訪問硬件寄存器來控制硬件。系統(tǒng)平臺(tái)層建立在μC／OS-II實(shí)時(shí)操作系統(tǒng)上，為協(xié)議層提供系統(tǒng)服務(wù)。硬件驅(qū)動(dòng)模塊提供硬件驅(qū)動(dòng)程序，所有對(duì)硬件的控制都通過該模塊提供的服務(wù)。系統(tǒng)平臺(tái)層通過協(xié)議層接口為協(xié)議層提供服務(wù)。協(xié)議層則實(shí)現(xiàn)了基于IEEE 802．15．4的物理層和鏈路層以及基于ZigBee的網(wǎng)絡(luò)層協(xié)議。應(yīng)用層通</p><p><b>　　圖3 軟件總體結(jié)構(gòu)</b><

70、/p><p>　　3．2 傳感器節(jié)點(diǎn)軟件設(shè)計(jì) 基于系統(tǒng)長(zhǎng)期使用的功能需求，傳感器節(jié)點(diǎn)中軟件設(shè)計(jì)的關(guān)鍵是既能實(shí)現(xiàn)所需的功能，又能最大限度地減少傳感器節(jié)點(diǎn)的能耗。 通過測(cè)試發(fā)現(xiàn)，ZigBee模塊的能耗要遠(yuǎn)遠(yuǎn)大于中央處理器和傳感模塊的能耗。因此，傳感器節(jié)點(diǎn)應(yīng)用軟件的設(shè)計(jì)既要盡量使各模塊處于休眠狀態(tài)，又要盡量減少喚醒ZigBee模塊的次數(shù)。因此，在傳感器節(jié)點(diǎn)上電各功能模塊初始化完成、并加入了網(wǎng)絡(luò)后，即進(jìn)入休眠

71、狀態(tài)，中央處理器周期地被定時(shí)喚醒向網(wǎng)關(guān)發(fā)送數(shù)據(jù)，并接收網(wǎng)關(guān)的命令。傳感器節(jié)點(diǎn)的工作流程如圖4所示。</p><p>　　圖4 傳感器節(jié)點(diǎn)主程序流程</p><p>　　3．3 網(wǎng)關(guān)節(jié)點(diǎn)軟件設(shè)計(jì) 車載網(wǎng)關(guān)向下管理傳感器節(jié)點(diǎn)，向上完成和PC監(jiān)控中心的交互，需要進(jìn)行復(fù)雜的任務(wù)管理和調(diào)度，因此，采用基于uC／OS內(nèi)核的嵌入式操作系統(tǒng)管理整個(gè)網(wǎng)關(guān)，為應(yīng)用任務(wù)的高效運(yùn)行提供良好的軟件平臺(tái)支撐。

72、根據(jù)網(wǎng)關(guān)的功能需求，將μC／OS-II、SMAC協(xié)議有機(jī)的結(jié)合，構(gòu)成一個(gè)網(wǎng)絡(luò)化的操作環(huán)境，用戶可以方便地在其基礎(chǔ)上開發(fā)應(yīng)用程序?；讦藽／OS-II擴(kuò)展的網(wǎng)關(guān)軟件平臺(tái)結(jié)構(gòu)如圖5所示?；讦藽／OS-II操作系統(tǒng)，分別構(gòu)建系統(tǒng)任務(wù)SYS_task()、SMAC星型組網(wǎng)任務(wù)START_task()、網(wǎng)關(guān)和傳感器節(jié)點(diǎn)交互任務(wù)COMM_task()、PC臨控中心端口監(jiān)聽任務(wù)SER_task()等一系列應(yīng)用任務(wù)，從而實(shí)現(xiàn)網(wǎng)關(guān)軟件的應(yīng)用功能。<

73、;/p><p>　　3．4 主機(jī)監(jiān)控軟件的設(shè)計(jì)</p><p>　　本系統(tǒng)最終目的是將采集到的車載傳感器數(shù)據(jù)實(shí)時(shí)地傳送到主機(jī)，并在主機(jī)</p><p>　　中得到顯示和保存。顯示的目的是獲得被車載傳感器節(jié)點(diǎn)所監(jiān)控環(huán)境的初步情況，保存的目的是作為深入分析的數(shù)據(jù)樣本。除此以外，作為整個(gè)系統(tǒng)的主控方和數(shù)據(jù)采集請(qǐng)求的發(fā)起者，需要能夠按照要求發(fā)送數(shù)據(jù)請(qǐng)求信號(hào)。根據(jù)以上要求，在VB

74、環(huán)境下開發(fā)了一個(gè)基于對(duì)話框的應(yīng)用程序。這個(gè)應(yīng)用程序包括了4個(gè)模塊： ①實(shí)時(shí)數(shù)據(jù)顯示波形模塊。該模塊的作用是將節(jié)點(diǎn)的數(shù)據(jù)以波形的形式實(shí)時(shí)地進(jìn)行顯示，實(shí)現(xiàn)的方式是利用MSChart和Timer控件。</p><p>　?、谕?fù)滹@示模塊。當(dāng)用戶希望了解無線傳感器網(wǎng)絡(luò)的拓?fù)錁?gòu)建情況時(shí)，可以查看拓?fù)湫畔冢私饩W(wǎng)絡(luò)中節(jié)點(diǎn)的加入和丟失情況。 ③歷史數(shù)據(jù)顯示模塊。在車載網(wǎng)絡(luò)系統(tǒng)運(yùn)行到一定時(shí)期，可能需要對(duì)過去某一

75、段時(shí)間的原始數(shù)據(jù)進(jìn)行后續(xù)的處理與深入的分析，以便對(duì)車載系統(tǒng)的狀況進(jìn)行準(zhǔn)確的判定。借助歷史數(shù)據(jù)顯示模塊，可以將監(jiān)控中心從車載網(wǎng)關(guān)中得到的數(shù)據(jù)，按照不同節(jié)點(diǎn)的屬性、地址和時(shí)間分別保存到數(shù)據(jù)庫的相應(yīng)字段中，并可以通過波形圖的方式將歷史數(shù)據(jù)顯示出來，供用戶分析。 ④控制模塊。在車載系統(tǒng)運(yùn)行過程中可能關(guān)心某一個(gè)車載傳感器節(jié)點(diǎn)的數(shù)值，或者需要對(duì)某一個(gè)傳感器進(jìn)行閾值設(shè)置，以便待監(jiān)測(cè)的環(huán)境出現(xiàn)異常情況可以及時(shí)地報(bào)告給系統(tǒng)。這些都可以通過控制模塊

76、對(duì)系統(tǒng)進(jìn)行相應(yīng)的設(shè)置，控制模塊還可以對(duì)系統(tǒng)中的某個(gè)不需要的節(jié)點(diǎn)進(jìn)行刪除操作?？傊?，通過主機(jī)監(jiān)控軟件用戶可以直觀且多方面地對(duì)通用無線傳感器網(wǎng)絡(luò)系統(tǒng)進(jìn)行了解和使用。4 測(cè)試與驗(yàn)證 4．1 組網(wǎng)測(cè)試 測(cè)試設(shè)備：4個(gè)MCl3192 ZigBee芯片節(jié)點(diǎn)，1個(gè)作為網(wǎng)關(guān)節(jié)點(diǎn)，其余3個(gè)作為傳感器節(jié)點(diǎn)。 測(cè)試方法：網(wǎng)關(guān)節(jié)點(diǎn)上電后，4個(gè)LED同時(shí)點(diǎn)亮，掃描信道</p><p>　　實(shí)驗(yàn)分析：在星形網(wǎng)絡(luò)中進(jìn)行

77、數(shù)據(jù)傳輸，測(cè)試結(jié)果明顯差于單點(diǎn)對(duì)單點(diǎn)傳輸方式。這主要是因?yàn)?，在傳輸過程中節(jié)點(diǎn)之間存在一定的頻率干擾和其他干擾。4．3 功耗測(cè)試 作狀態(tài)和休眠狀態(tài)下，分別使用萬用表測(cè)試網(wǎng)關(guān)節(jié)點(diǎn)和傳感器節(jié)點(diǎn)的功耗情況，測(cè)試結(jié)果如表2所列。</p><p>　　結(jié)語 本文分析E 802．15．4和ZigBee協(xié)議，結(jié)合通信系統(tǒng)和嵌入式系統(tǒng)的一般開發(fā)原則，在μC／OS-II操作系統(tǒng)上實(shí)現(xiàn)IEEE802．15．4協(xié)議，選

78、擇合適的軟硬件平臺(tái)，著重于軟件支撐平臺(tái)的構(gòu)建、軟件總體結(jié)構(gòu)設(shè)計(jì)以及通信協(xié)議棧的實(shí)現(xiàn)，最終實(shí)現(xiàn)了一個(gè)符合ZigBee規(guī)范的車載星型無線數(shù)據(jù)采集網(wǎng)絡(luò)。該系統(tǒng)具有以</p><p>　　下的優(yōu)勢(shì)：①系統(tǒng)安裝方便。無線互連使得設(shè)備安裝位置靈活，同時(shí)滿足了系統(tǒng)安裝的自動(dòng)化要求。人們只需要把設(shè)備上電就可以了。該車載網(wǎng)絡(luò)系統(tǒng)能夠自動(dòng)完成網(wǎng)絡(luò)的配置。②可擴(kuò)展性。把設(shè)備放在車載網(wǎng)關(guān)的覆蓋范圍以內(nèi)，打開設(shè)備電源，節(jié)點(diǎn)將自動(dòng)加入網(wǎng)