High Precision Distance Measurement in Wireless Sensor Network
| Autor: | Ji-De Huang, 黃繼德 |
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| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 94 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. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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