無線感測器網路之 公分等級距離量測

High Precision Distance Measurement in Wireless Sensor Network

黃繼德(Ji-De Huang)

指導教授 ： 葉超雄

共同指導教授 ： 李世光(Chih-Kung Lee)

國立臺灣大學/工學院/應用力學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.03034

摘要

本論文結合了無線感測器網路與連網型嵌入式系統，成功的讓無線感測器網路得以透過網際網路，將資料收集到後端電腦。避免了少數區域控制器電力耗盡，造成整個感測器網路癱瘓的情況；而讓部份區域控制器透過網際網路傳遞資料的方式，亦使感測器網路的規模不再受限於無線收發器的頻寬。
本論文所採用的連網型嵌入式系統，為一般市售無線路由器所改造，並執行開放源碼之嵌入式Linux。藉由USB控制晶片以作為感測器網路的區域控制器，讓無線感測器網路得以與網際網路結合。近來政府積極推廣行動台灣計畫，許多公共場所均佈置了無線路由器；本論文提供了一個有效且可行的方式，使得無線感測器網路得以建立於這現有的網路基礎上，讓大規模無線偵測成為可能。
此外，並運用了物件導向的設計範式(Design Pattern)概念，為後端電腦開發了極具彈性的Java資料收集程式，只要稍加修改，即可收集要求的資料；而Java不必重新編譯便可移植到其他平臺的特性，讓這個程式更具彈性。
本論文也試著研發出公分等級距離量測技術。且成功使用市售電子零件，製作了低成本、picosecond等級的時間測量電路，具備60 ps解析能力。在論文中，雖然尚未做到真正的公分無線測量，只要結合這個測時電路與極低漂移量的RF收發器，則公分等級距離量測將可望問世。

關鍵字

無線感測器網路 ； 時間測量

並列摘要

In this study, a wireless sensor network architecture with internet connectivity has been realized by modifying a commercially available wireless router to serve as the local controller center (LCC). This newly developed sensor network architecture, just like any other well-designed sensor network, can collect data from widespread wireless sensor networks through internet effciently. The so-called LCC’s centers can control the traffic of the local sensor network, collect data, and relay the data to backend servers thorough internet.
This newly developed LCC runs open-source embedded ucLinux and is constructed by connecting a newly designed add-on transceiver to the USB port extention of a commercially available wireless Wi-Fi router. Recently, under the M-Taiwan program, the wireless LAN infrastructure has been widely built in public space. The architure proposed in this study provide quite an extensive route to extend the wireless LAN infrastrure into a sensor network infrastructure so as to facilitate large-scale sensor networks deployment..
By using the concept of Design Pattern in Object-Oriented Programming, a flexible Java-based data collecting program was also successly developed, which was detailed in this thesis as well. The native cross-platform characteristics of Java may realize the concept “Compile Once, Run Anywhere,” which can then provide us with an opportunity to extend the flexibility of the data collecting program on various hardware platforms.
In addition, this study also attempts to develop a centimeter distance location determination method using TOA (time of arrival) method. To have centimeter resolution by using the TOA mehod, the timing resolution has to be in the picosencos range. A low-cost picoseconds level timing measuremnt circuit was successfully developed and verified to have 80 picosencos resolution. To fully utilize this timing circuitry, a low-drift RF (radio frequency) transceiver must be developed to measure the travlling time between sensor nodes. Some preliminary study and proof of concept has been completed and found that the RF transceiver drifting can be controlled to within 2 nanoseconds, which corresponds to 60 cm spatial resolution. A more stable transceiver that has shorter pulse transimission capability is suggested to be the next task in order to enhance the spatial resolution.

並列關鍵字

Wireless Sensor Network ； TIM ； TOA ； picosecond ； Linux

參考文獻

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