煤礦安全監(jiān)控系統(tǒng)外文翻譯

1、<p>　　A Coal Mine Environmental Monitor System with Localization Function Based on ZigBee-Compliant Platform</p><p>　　Dongxuan Yang</p><p>　　College of Computer and Information</p>&

2、lt;p>　　Engineering</p><p>　　Beijing Technology and Business</p><p>　　University</p><p>　　Beijing, China</p><p><b>　　Yan Chen</b></p><p>　　Co

3、llege of Computer and Information</p><p>　　Engineering</p><p>　　Beijing Technology and Business</p><p>　　University</p><p>　　Beijing, China</p><p>　　bjchy2

4、003@163.com</p><p>　　Kedong Wang</p><p>　　College of Computer and Information</p><p>　　Engineering</p><p>　　Beijing Technology and Business</p><p>　　Univer

5、sity</p><p>　　Beijing, China</p><p>　　Abstract—This paper describes and implements a new type of coal mine safety monitoring system, it is a kind of wireless sensor network system based on ZigBe

6、e technology. The system consists of two parts underground and surface. Wireless sensor networks are constituted by fixed nodes, mobile nodes and a gateway in underground. PC monitoring software is deployed in the surfac

7、e. The system can not only gather real-time environmental data for mine, but also calculate the real-time location of mobile</p><p>　　Keywords： ZigBee; localization; wireless sensor networks; coal Mine</p

8、><p>　　I.RESEARCH STATUS</p><p>　　As an important energy, coal plays a pivotal role in the economic development. Coal mine monitoring system, is the important guarantee for coal mine safety and hig

9、h efficiency production [1]. In order to ensure the safe operation, the installation of environment monitoring node in tunnels to real-time detection is very important. However, commonly used traditional monitoring node

10、wired connection to obtain communication with the control system, this node exist wiring difficulties, expensive and </p><p>　　The ZigBee wireless communication technology is used in this coal mine environme

11、ntal monitor system. This is a new short-range, low complexity, low power, low data rate, low-cost two-way wireless communication technology [2]. Now, wireless sensor network product based on ZigBee technology are quanti

12、ty and variety, but the real product can be applied in underground environments of special sensor node is very few[3]. The sensor node that we designed in the system is truly able to apply to in-well </p><p>

13、;　　II. SYSTEM ARCHITECTURE</p><p>　　This system is a comprehensive monitoring system which is combined with software and hardware. Hardware part includes wireless mobile nodes and fixed nodes which were depl

14、oyed in the underground tunnel, the main function of them is to collect coal mine environment data and require person’s location. Software part refers to the PC monitoring software which is designed in VC++ is used to su

15、mmarize and display the data of each node. Monitoring node is divided into mobile nodes and fixed nodes; they</p><p>　　Fixed node will sent received data from mobile node to the gateway, then the gateway tra

16、nsmits data to monitor computer through RS232 or optical fiber. The PC monitor software in the computer will process all data and display them in a visualization window. The PC software also calculates each mobile node’s

17、 real-time location through the specific localization algorithm, according to the received signal strength (RSSI) obtained from mobile nodes.</p><p>　　III. NODE DESIGN</p><p>　　Since the ZigBee

18、wireless network platform sold on present market was designed for the general environment, for special underground so they are not suitable for the environment. Therefore, we need to customize the system for underground

19、environment whit a special hardware circuit. Node photo are shown in Fig. 1</p><p>　　Then wireless microcontroller CC2530 chip is the core processor of the node device, it can constitute a ZigBee network wit

20、h very few peripheral circuits. The CC2530 is an IEEE 802.15.4 compliant true System-on-Chip, supporting the proprietary 802.15.4 market as well as the ZigBee, ZigBee PRO, and ZigBee RF4CE standards. Unlike other wireles

21、s chip, CC2530 built-in 8051 monolithic integrated circuits kernel, therefore we no longer need to use a single MCU to control the circuit, and this save us a</p><p>　　Mobile Node</p><p>　　The m

22、obile node is the end device of a ZigBee network that can be carried by miner; it should be a portable and low power consumption node. So the mobile node we designed is only as small as a mobile phone, and it is by built

23、-in lithium ion battery power supply. In power loss, the core processor CC2530 is a low power consumption chip, when it is in the sleep mode, it only need to use less then 1uA work current. In order to reduce power consu

24、mption as much as possible on the display, a 100*32 pix</p><p>　　Figure 1. Node photo.</p><p>　　The mobile node circuit includes the gas concentration sensor MJ4.0 and temperature sensor PT-1000

25、. As far as we know, many wireless sensor platforms use the digital type sensor. The communication between the digital sensor and the MCU need strict timing requirements. But considering the actual application, the wirel

26、ess MCU usually has a real-time operating system in general, if we use the microcomputer to simulate the strict timing, it will affect the real-time of whole operating system. These </p><p>　　B. Fixed Node&l

27、t;/p><p>　　Fixed node is installed in the wall of the underground tunnel. Because it is big than the mobile node, it is not appropriate to carry around. The circuit of the fixed node is almost same with the mob

28、ile node, it also use a CC2530 chip as core processor. Because of underground tunnels generally deploy with power cable, fixed nodes can use cable power-supply modes. At the same time, because we use wireless signal tran

29、smission, the deployment of new fixed nodes become very convenient, which also re</p><p>　　As a fixed node, the minor who is doing work may far from it, in order to facilitate the miners observed environment

30、al data around the fixed nodes, it uses LED digital display. At the same time, the large current LED lights and buzzer are designed in the circuit; it makes the fixed node with the function of sound-light alarm. Consider

31、ing that it may occur the emergency of without electricity, fixed node also built-in a lithium-ion battery. Under normal conditions, lithium-ion battery is in charg</p><p>　　Without regarding to fixed nodes’

32、 portability, we have a customized shell that has excellent explosion properties, and the internal space is enough to hold down the 2.4 GHz antenna. To ensure safety, all cables and the location of sensors are placed wit

33、h particular glue sealed, so that it has a good seal.</p><p>　　IV. POSITIONING FUNCTION</p><p>　　One of the important functions of the wireless sensor networks is localization, especially in the

34、 underground tunnel, it relates to the safe of the miner's life. Currently most widely used orientation method is GPS satellite positioning, it is a high precision, all-weather and global multifunctional system with

35、the function of radio navigation, positioning and timing. But the GPS positioning method is not suitable for the underground work environment of coal mine, once you enter the underground,</p><p>　　About the

36、TOA method, the distance between the two devices is determined by the product of the speed of light and transmission time [7]. Although the precision of this method is accurate, but it require a precise time synchronizat

37、ion, so it demand hardware is higher.</p><p>　　TDOA technology need ultrasonic signal，which is setting on a node with receive and transmit function. When measure the distance, it can sent ultrasonic wave and

38、 wireless signals together. By measuring the difference between two signals arrival time, we can calculate the distance between two devices [8]. Using this method can also obtain accurate result, but the method need to i

39、ncrease ultrasonic sending and receiving device on the node circuit, it will increase cost.</p><p>　　AOA technology needs to install multiple antennas through the nodes so it can obtain adjacent nodes’ signa

40、ls on deferent directions [9]. With this it can determine the location information from number of adjacent nodes and calculate its own position. This method not only need to add additional hardware, but also it's sti

41、ll very vulnerable to external disturbance, therefore it's not suitable for utilize.</p><p>　　RSSI ranging is a cheap and easy technology. By using this method, we don't need to add additional hardwa

42、re design. We also do not need very precise time requirements. This technique is about with measuring the wireless signals strength in the propagation of the loss, to measure the distance between two nodes. Because of th

43、is method requires hardware equipment is less, algorithm is simple, so it has been using in many wireless communication field. Comprehensive all conditions, positioning on the</p><p>　　A. Hardware Location E

44、ngine</p><p>　　The CC2431 wireless microcontroller chip produced by TI Company has a hardware location engine. From the software's point of view, CC2431’s hardware location engine has a very simple API i

45、nterface, as long as writing the necessary parameters and waiting for calculation, it can read the location results [10].</p><p>　　The hardware location engine is also based on RSSI technology. The localizat

46、ion system includes reference nodes and blind nodes. The reference node is a fixed node that located in a known position, the node know their place and send a packet notify to other nodes. The blind node receives packets

47、 from reference nodes, which can obtains reference nodes’ location and the corresponding RSSI value and put them into the hardware location engine, and then the blind node’s location can be read from the </p><

48、p>　　On the surface, using the CC2431 hardware location engine targeting the program as a good choice, but considering the practical application, it will encounter the following problems. First of all, we have choose t

49、he CC2530 as the main chip of fixed nodes of the system, its internal programs is running in ZigBee2007 protocol, but CC2431 as a early chip, it applies only to ZigBee2006 protocol. In the communications between CC2431 a

50、nd CC2530 that will have compatibility problems. Secondly, CC2431 h</p><p>　　B. Software Location Engine</p><p>　　If we want to use CC2530 to implement location function, that we must write soft

51、ware location engine by ourselves. Because that chip do not have a hardware location engine inside of it. This software location engine is still used RSSI technology; meanwhile mobile node position is calculated by the P

52、C software, so as to reduce the burden of mobile node computing. To calculate the mobile node location, there must be at least three reference nodes. We will regard router nodes as reference nodes in </p><p>

53、;　　In order to let all router nodes can receive the packet which sending by mobile nodes, and send its RSSI values up to the gateway node, we need to modify the relevant function in Z- Stack protocol which is provided by

54、 TI. First we find the function named afIncomingData, it deals with the received data from the bottom of protocol, in which we add some code that can obtain packet’s RSSI value. Then through the osal_set_event function t

55、o add and send an event MY_RSSI_REPORT_EVT of RSSI value task t</p><p>　　In fact, this software location engine is not implementing with a single mobile node, but through the operation of the whole system to

56、 achieve. By which the mobile node is only responsible for sending unicast packets. The mobile node’s parent router node is responsible to forward the packet to the gateway. Other router nodes are not responsible for for

57、warding this packet, just clipping the mobile node of RSSI value, then forwarded to the gateway. Finally the gateway bring all RSSI values of the </p><p>　　V．SYSTEM IMPLEMENTATION</p><p>　　All s

58、oftware systems embedded in nodes are based on Z-Stack. Because Z-Stack is an open-source project, it is very beneficial to the secondary development. These nodes were tested in a real coal mine locate in Shanxi Province

59、. We deployed the fixed node every 50 meters in the tunnel, and also set a fixed node in each entrance of the work area. Because the fixed node have large size digital LED displays, so the display content of the fixed no

60、de can be seen far from away the miner. Each miner carr</p><p>　　The gateway node is placed at the entrance of the mine, through the RS232 cable connected to the monitoring computer in the control room. In t

61、his system all packets collected by the gateway node are transmitted to PC through a serial port, and it can save historical data backup to a SQL database. The main function of monitoring software is to display and store

62、 the data of every node, and calculates related mobile nodes’ location according to RSSI values. The monitoring software has two main dial</p><p>　　Figure 2. PC monitoring software.</p><p>　　VI

63、．SYSTEM EVALUATION</p><p>　　Through repeated testing of the system, we made the system an objective assessment. First is the power consumption assess for node hardware, fixed node’s working voltage is in 9V

64、~ 24V when the power supplied by cable. The maximum operating current for fixed node is 93mA; the average operating current is 92.2mA. When the power cable was disconnected, fixed node powered by lithium-ion battery. On

65、battery power, the fixed node’s maximum working current is 147mA; average working current is 146.3mA.</p><p>　　Another quite important performance is the location function of the system performance. At four

66、different locations of tunnel and working areas, mobile nodes were placed there. Two sets of different average error data were shown in From table 1. Because this system uses RSSI technology and it relies mainly on the s

67、ignal strength, the signal quality will be affected by interferences. From different locations’ errors we can see that, the error in working areas was larger than it in tunnels, becaus</p><p>　　TABLE I. RESU

68、LT OF LOCALIZATION ERROR</p><p>　　ACKNOWLEDGMENT</p><p>　　We gratefully acknowledge Texas Instruments for devices provided to us free of charge. And also thank staffs of XinNuoJin Company for gi

69、ving us supports on system testing.</p><p>　　REFERENCES</p><p>　　[1] Xinyue Zhong Wancheng Xie. “Wireless sensor network in the coal mine environment monitoring“. Coal technology, 2009, Vol. 28,

70、 No. 9,pp.102-103.</p><p>　　[2] Shouwei Gao. “ZigBee Technology Practice Guide”. Beijing: Beijing University of Aeronautics and Astronautics Press , 2009, pp. 27-28.</p><p>　　[3] Yang Wang, Lius

71、heng Huang, Wei Yang. “A Novel Real-Time CoalMiner Localization and Tracking System Based on Self-Organized Sensor Networks”. EURASIP Journal onWireless Communications and Networking, Volume 2010, Article ID 142092.</

72、p><p>　　[4] Sang-il Ko, Jong-suk Choi, Byoung-hoon Kim. “Indoor Mobile Localization System and Stabilization of Localizaion Performance using Pre-filtering”. International Journal of Control, Automation and Sys

73、tems, Vol. 6, No. 2, pp. 204-213, April 2008.</p><p>　　[5] http://www.ti.com.</p><p>　　[6] Hawkins Warren, Daku Brian L. F, Prugger Arnfinn F. “Positioning in underground mines”. IECON 2006 - 3

74、2nd Annual Conference on IEEE Industrial Electronics, 2006, pp. 3159-3163.</p><p>　　[7] Zhu, Shouhong, Ding, Zhiguo, Markarian Karina. “TOA based joint synchronization and localization”. 2010 IEEE Internatio

75、nal Conference on Communications, ICC 2010, 2010, Article ID 5502036.</p><p>　　[8] Ni Hao, Ren Guangliang, Chang Yilin. “A TDOA location scheme in OFDM based WMANs”. IEEE Transactions on Consumer Electronics

76、, 2008, Vol. 54, No. 3, pp. 1017-1021.</p><p>　　[9] Dogançay Kutluyil, Hmam Hatem. “Optimal angular sensor separation for AOA localization”. Signal Processing, 2008, Vol. 88, No. 5, pp. 1248-1260.</

77、p><p>　　[10] K. Aamodt. “CC2431 Location Engine”. Texas Instruments, Application Note AN042, SWRA095.</p><p>　　[11] Tennina Stefano, Di Renzo Marco, Graziosi Fabio, Santucci Fortunato. “Locating z

78、igbee nodes using the tis cc2431 location engine: A testbed platform and new solutions for positioning estimation of wsns in dynamic indoor environments”. Proc Annu Int Conf Mobile Comput Networking, 2008, pp. 37-42.<

79、/p><p>　　摘要-本文介紹并設(shè)計(jì)了一個(gè)新類型的煤礦安全監(jiān)控系統(tǒng)，它是一種基于ZigBee技術(shù)的無線傳感器網(wǎng)絡(luò)系統(tǒng)。該系統(tǒng)包括地下和地面兩部分。地下的無線傳感器網(wǎng)絡(luò)由固定節(jié)點(diǎn)，移動(dòng)節(jié)點(diǎn)和網(wǎng)關(guān)構(gòu)成。電腦監(jiān)控軟件部署在地面。該系統(tǒng)不僅可以實(shí)時(shí)收集礦井環(huán)境數(shù)據(jù)，也可以通過計(jì)算礦工所穿的移動(dòng)節(jié)點(diǎn)來實(shí)時(shí)定位。</p><p>　　關(guān)鍵詞：ZigBee；定位；無線傳感器網(wǎng)絡(luò)；煤礦</p>

80、<p><b>　　一、研究現(xiàn)狀</b></p><p>　　作為一種重要的能源，煤炭在經(jīng)濟(jì)發(fā)展中起著舉足輕重的作用。煤礦監(jiān)控系統(tǒng)是煤礦安全和生產(chǎn)效率高的重要保證[1]。為了確保安全運(yùn)行，環(huán)境監(jiān)測(cè)節(jié)點(diǎn)的安裝是非常重要的。然而，常用的傳統(tǒng)監(jiān)控節(jié)點(diǎn)通過有線連接獲得與控制系統(tǒng)的通信，這個(gè)節(jié)點(diǎn)存在布線困難，價(jià)格昂貴等缺點(diǎn)。相比之下，無線傳感器網(wǎng)絡(luò)節(jié)點(diǎn)可以很容易地與當(dāng)前礦井監(jiān)測(cè)網(wǎng)絡(luò)連接，和

81、良好的兼容性，方便組成煤礦瓦斯監(jiān)測(cè)網(wǎng)絡(luò)，以適應(yīng)各種大小煤礦的應(yīng)用。由于無線節(jié)點(diǎn)是電池供電，所以完全擺脫線纜的束縛，縮短建設(shè)周期，可以隨時(shí)安排使用。</p><p>　　這是一個(gè)新的短距離，低復(fù)雜度，低功耗，低數(shù)據(jù)速率，低成本的雙向無線通信技術(shù)[2]。現(xiàn)在，無線傳感器ZigBee無線通信技術(shù)應(yīng)用于煤礦環(huán)境監(jiān)測(cè)系統(tǒng)?；赯igBee技術(shù)的網(wǎng)絡(luò)產(chǎn)品的數(shù)量和種類很多，但真正的產(chǎn)品可以應(yīng)用在地下環(huán)境中的特殊傳感器節(jié)點(diǎn)是很少

82、的[3]。我們?cè)O(shè)計(jì)的系統(tǒng)，是真正能夠適用于在井下環(huán)境，它通過無線傳感器網(wǎng)絡(luò)節(jié)點(diǎn)的安全認(rèn)證。同時(shí)，由于無線網(wǎng)絡(luò)的特殊性質(zhì)，它可以傳播無線信號(hào)，我們可以很容易地找到工作人員以便對(duì)煤礦安全監(jiān)控提供更多的保護(hù)[4]。</p><p><b>　　二、系統(tǒng)架構(gòu)</b></p><p>　　該系統(tǒng)是一個(gè)軟件和硬件綜合監(jiān)控系統(tǒng)的融合。硬件部分包括無線移動(dòng)節(jié)點(diǎn)和固定節(jié)點(diǎn)而被地下隧道部

83、署，它的主要功能是收集煤炭礦山環(huán)境的數(shù)據(jù)和人的位置。電腦監(jiān)控軟件由VC++設(shè)計(jì)，是用于以總結(jié)和展示每個(gè)監(jiān)控節(jié)點(diǎn)中移動(dòng)節(jié)點(diǎn)和固定節(jié)點(diǎn)的數(shù)據(jù)。他們正在使用的數(shù)據(jù)由無線傳輸ZigBee協(xié)議傳輸，由于在固定節(jié)點(diǎn)也使用無線數(shù)據(jù)傳輸?shù)姆椒?，所以在地下巷道部署變得非常方便。由于移?dòng)節(jié)點(diǎn)是由礦工進(jìn)行，就必須使用無線傳輸方法。在固定無線傳感器網(wǎng)絡(luò)節(jié)點(diǎn)是路由器設(shè)備，礦工移動(dòng)節(jié)點(diǎn)通常是終端設(shè)備，ZigBee網(wǎng)絡(luò)的路由器有沒有傳感器設(shè)備;，它是只負(fù)責(zé)數(shù)據(jù)轉(zhuǎn)發(fā)，

84、但考慮到實(shí)際應(yīng)用，我們?cè)诼酚善魃细郊拥膫鞲衅髟O(shè)備，將更好地監(jiān)測(cè)煤礦井下環(huán)境，這讓我們進(jìn)一步確定ZigBee網(wǎng)路拓?fù)浣Y(jié)構(gòu)。因此，在我們的設(shè)計(jì)中，路由器還具有環(huán)境監(jiān)測(cè)功能。 固定節(jié)點(diǎn)和移動(dòng)節(jié)點(diǎn)通過網(wǎng)關(guān)發(fā)送接收到的數(shù)據(jù)，然后網(wǎng)關(guān)通過RS232或光纖將數(shù)據(jù)傳輸?shù)奖O(jiān)控計(jì)算機(jī)。通過電腦的計(jì)算機(jī)軟件處理所有數(shù)據(jù)，并通過一個(gè)可視化窗口顯示出來。根據(jù)從移動(dòng)節(jié)點(diǎn)接收到的信號(hào)強(qiáng)度（RSSI），PC軟件通過特定的定位算法計(jì)算每個(gè)移動(dòng)節(jié)點(diǎn)的實(shí)時(shí)定位。&l

85、t;/p><p><b>　　三、節(jié)點(diǎn)設(shè)計(jì)</b></p><p>　　目前市場(chǎng)上出售的ZigBee無線網(wǎng)絡(luò)平臺(tái)，適用于一般的環(huán)境，而在特殊的地下，所以他們不適合的環(huán)境，因此，我們需要定制一個(gè)適合地下特殊的硬件電路系統(tǒng)。節(jié)點(diǎn)的照片如圖1。 無線單片機(jī)CC2530的芯片是節(jié)點(diǎn)設(shè)備的核心處理器，它可以用很少的外圍電路構(gòu)成一個(gè)ZigBee網(wǎng)絡(luò)。CC2530是一個(gè)IEEE

86、 802.15.4兼容的系統(tǒng)的芯片，支持專有的802.15.4市場(chǎng)以及的ZigBee的ZigBee PRO和ZigBee RF4CE的標(biāo)準(zhǔn)。CC2530不同于其他的無線芯片，內(nèi)置8051單片機(jī)集成電路的內(nèi)核，因此我們不再需要使用一個(gè)單一的單片機(jī)控制電路，這為我們節(jié)省了大量的成本[5]。A。移動(dòng)節(jié)點(diǎn) 移動(dòng)節(jié)點(diǎn)是一個(gè)由ZigBee網(wǎng)絡(luò)組成的礦工移動(dòng)的終端設(shè)備，它應(yīng)該是一種便攜式低功耗節(jié)點(diǎn)，所以我們?cè)O(shè)計(jì)的移動(dòng)節(jié)點(diǎn)是小如手機(jī)，它是通過

87、內(nèi)置鋰離子電池供電， CC2530的核心處理器是低功耗的芯片，它在睡眠模式時(shí)，只需要使用小于1uA的工作電流。為了盡可能降低在顯示屏上的功耗，使用1100*32無背光液晶屏幕的像素矩陣。移動(dòng)節(jié)點(diǎn)的的電池容量是1500mAh，所以它足以滿足礦工在地下長(zhǎng)時(shí)間工作</p><p><b>　　圖1：節(jié)點(diǎn)的照片</b></p><p>　　移動(dòng)節(jié)點(diǎn)的電路包括氣體濃度的傳感器M

88、J4.0和溫度傳感器PT-1000。據(jù)我們所知，許多無線傳感器平臺(tái)使用數(shù)字式傳感器，數(shù)字傳感器和MCU之間的通信需要嚴(yán)格的時(shí)序要求?？紤]到實(shí)際應(yīng)用中，無線MCU通常有一個(gè)一般的實(shí)時(shí)操作系統(tǒng)，如果我們用微機(jī)模擬嚴(yán)格的時(shí)序，它會(huì)影響整個(gè)操作系統(tǒng)的實(shí)時(shí)。這兩個(gè)傳感器輸出的模擬信號(hào)，而不是數(shù)字信號(hào)。輸入到差分放大器，我們可以得到適當(dāng)?shù)男盘?hào)，可以由CC2530的芯片內(nèi)的ADC模式轉(zhuǎn)換為數(shù)字信號(hào)。為了方便攜帶，不使用外接天線，在我們的移動(dòng)節(jié)點(diǎn)天線是

89、我們定制一個(gè)像手機(jī)大小的外殼，而不是使用一個(gè)2.4GHz貼片天線。設(shè)計(jì)的PCB和元件選擇，都進(jìn)行了安全評(píng)估，這足以考慮到它所有的電路板、傳感器和電池爆炸性能不是很好。B.固定節(jié)點(diǎn) 固定節(jié)點(diǎn)安裝在地下隧道的墻壁。因?yàn)樗潜却蟮囊苿?dòng)節(jié)點(diǎn)，它是不適合隨身攜帶。電路的固定節(jié)點(diǎn)與移動(dòng)節(jié)點(diǎn)幾乎是相同的，它也使用CC2530的芯片核心處理器。由于在地下隧道，一般部署電力電纜，固定節(jié)點(diǎn)可以使用電纜供電模式。同時(shí)，因?yàn)槲覀兪褂玫臒o線信號(hào)傳輸，新

90、的固定節(jié)點(diǎn)的部署變得非常方便，這也解決了問題信號(hào)線條部署。 作為一個(gè)固定的節(jié)</p><p>　　固定節(jié)點(diǎn)不方便攜帶，我們有一個(gè)定制的外殼，具有良好的爆炸性能，內(nèi)部空間足以容納2.4 GHz天線。為了確保安全，所有的電纜和傳感器的位置放置，特別是膠密封，因此它具有良好的密封性。 四，定位功能 無線傳感器網(wǎng)絡(luò)的重要功能之一是定位，特別是地

91、下隧道，它涉及到礦工的生命安全。目前使用最廣泛的定位方法是GPS衛(wèi)星定位，它是一個(gè)高精度，全天候和全球無線電導(dǎo)航定位和定時(shí)的多功能系統(tǒng)，但在全球定位系統(tǒng)定位方法是不適合的煤礦井下工作環(huán)境，一旦你進(jìn)入地下，就不能收到衛(wèi)星信號(hào)，從而無法達(dá)到目標(biāo)[6]。我們需要考慮如何使用無線網(wǎng)絡(luò)實(shí)現(xiàn)定位功能。定位現(xiàn)有的無線設(shè)備之間的距離測(cè)量技術(shù)的設(shè)備之間的通信手段使用無線信號(hào)基本上是以下幾種方法：TOA，TDOA，AOA和RSSI。  關(guān)

92、于的TOA方法，在兩個(gè)設(shè)備之間的距離是由產(chǎn)品的高速光傳輸時(shí)間確定[7]。雖然這種方法的精確度是準(zhǔn)確的，但它需要一個(gè)精確的時(shí)間同步，所以它要求的硬件高。 TDOA技術(shù)需要的超聲波信號(hào)，這是一個(gè)節(jié)點(diǎn)上設(shè)置接收和發(fā)送功能。測(cè)量距離時(shí)，它可以發(fā)出超聲波和無線信</p><p>　　無線微控制器芯片TI公司生產(chǎn)的CC2431有一個(gè)硬件定位引擎。從軟件的角度來看，CC2431的硬件定位引擎有一個(gè)非常簡(jiǎn)單的API接口，

93、只要編寫必要的參數(shù)和計(jì)算，就可以讀取位置結(jié)果[10]。 硬件定位引擎基于RSSI的技術(shù)，包括參考節(jié)點(diǎn)和盲節(jié)點(diǎn)，參考節(jié)點(diǎn)是一個(gè)固定的節(jié)點(diǎn)，節(jié)點(diǎn)在一個(gè)已知的位置，知道自己的位置和發(fā)送報(bào)文通知其他節(jié)點(diǎn)。盲節(jié)點(diǎn)接收數(shù)據(jù)包的參考節(jié)點(diǎn)，從而獲得參考節(jié)點(diǎn)的位置和相應(yīng)的RSSI值，進(jìn)入硬件定位引擎，然后盲節(jié)點(diǎn)的位置可以從發(fā)動(dòng)機(jī)讀取[11]。  表面上使用了CC2431的硬件定位引擎是為一個(gè)不錯(cuò)的選擇方案，但考慮到實(shí)際應(yīng)用中，會(huì)

94、遇到以下問題。首先，我們選擇作為主芯片CC2530的系統(tǒng)固定節(jié)點(diǎn)ZigBee2007協(xié)議，但CC2431的其內(nèi)部運(yùn)行的程序?yàn)橐粋€(gè)早期的芯片，它適只用于ZigBee2006協(xié)議。第二，在CC2431和CC2530的之間的通信，這將有兼容性問題。CC2431的硬件定位引擎使用分布式計(jì)算，所有的移動(dòng)自行計(jì)算節(jié)點(diǎn)的位置，然后上傳到網(wǎng)關(guān)節(jié)點(diǎn)的信息，這將不僅占據(jù)了移動(dòng)節(jié)點(diǎn)的處理時(shí)間，而且占用更多的網(wǎng)絡(luò)資源。出于這個(gè)原因，我們不得不暫時(shí)擱置這個(gè)方&l

95、t;/p><p><b>　　圖2.電腦監(jiān)控軟件</b></p><p><b>　　六、系統(tǒng)評(píng)價(jià)</b></p><p>　　我們通過反復(fù)的系統(tǒng)測(cè)試，系統(tǒng)客觀的評(píng)估首先是節(jié)點(diǎn)的硬件功耗評(píng)估，固定節(jié)點(diǎn)的工作電壓在9V～24V，電源通過電纜提供。固定節(jié)點(diǎn)的最大工作電流目前是93毫安，當(dāng)斷開電源線，固定節(jié)點(diǎn)由電池供電的鋰離子電池供

96、電，平均工作電流是92.2毫安，固定節(jié)點(diǎn)的最大工作電流是147毫安平均工作電流是146.3毫安，固定節(jié)點(diǎn)可以至少工作8小時(shí)。 節(jié)點(diǎn)的另外一個(gè)很重要的表現(xiàn)是系統(tǒng)的定位功能。在隧道和工作區(qū)的四個(gè)不同地點(diǎn)，移動(dòng)節(jié)點(diǎn)被放置在那里。兩套不同的平均錯(cuò)誤數(shù)據(jù)，從表1所示，由于本系統(tǒng)使用的RSSI技術(shù)和它主要依賴信號(hào)強(qiáng)度，信號(hào)質(zhì)量將受干擾的影響，從不同的地點(diǎn)的錯(cuò)誤我們可以看到，在工作領(lǐng)域更大的地方誤差更大，因?yàn)樗淼朗且话阒保ぷ黝I(lǐng)域有不確定性

97、。 表一、定位誤差結(jié)果</p><p>　　我們非常感謝德州儀器公司為我們免費(fèi)提供的設(shè)備，而且還感謝給予我們支持系統(tǒng)測(cè)試XinNuoJin公司的員工。</p><p><b>　　參考文獻(xiàn)</b></p><p>　　[1] Xinyue Zhong Wancheng Xie. “W

98、ireless sensor network in the coal mine environment monitoring“. Coal technology, 2009, Vol. 28, No. 9,pp.102-103.</p><p>　　[2] Shouwei Gao. “ZigBee Technology Practice Guide”. Beijing: Beijing University of

99、 Aeronautics and Astronautics Press , 2009, pp. 27-28.</p><p>　　[3] Yang Wang, Liusheng Huang, Wei Yang. “A Novel Real-Time CoalMiner Localization and Tracking System Based on Self-Organized Sensor Networks”