藍芽室內定位技術實現居家物品協尋系統

Indoor object tracking system via Bluetooth Technology

邱褚淵(Chu-Yuan chiou)

指導教授 ： 李達生

國立臺北科技大學/機電學院/能源與冷凍空調工程系碩士班/碩士(2012年)

摘要

本文設計一套可直接使用廢棄手機之藍芽裝置，建構一套居家定位系統。
此系統包含三項技術應用：其一為室內定位法，透過接收訊號強度法(RSSI)進行定位，但考慮空間中有過多的訊號干擾與繞射，導致訊號強度的誤差，並建立演算法，以提高精準度；其二為天線設計，為加強藍芽模組所搭配之單極天線，因其不具有指向性，對於應用在家中進行物品偵測之效果並不佳，為此，本研究自行開發指向性天線，加強特定位置之傳輸與接收訊號靈敏度及接收訊號準位，以強化定位精準度，並透過微波暗室量測出天線於各角度的接收效果；其三為裝置與電力線傳輸系統(PLC)之結合，以克服藍芽通訊上至多七個節點的限制，因此藍芽裝置在空間中搜尋完畢，即透過電力線將訊號回傳至主機，此方法不但解決佈點問題，同時也降低藍芽節點在2.45GHz頻寬中過多封包的互相干擾，導致回傳主機的封包碰撞而造成遺失。
整合三項技術之應用，經實際測試後證明，本文所提出定位系統之精準度達55%時，定位誤差為0.73m。

關鍵字

藍芽定位 ； 訊號強度法 ； 平板天線 ； 電力線傳輸系統

並列摘要

The proposes of this research is a system model for localizing and tracking Bluetooth devices by having sensor nodes measure the RSSI value of the tracked device.
This system combines with three techniques of Bluetooth. By transferred collected signal values from three different Bluetooth nodes, and base on the power of the signal between each node to track the object location. Due to the signal interfere and diffraction in the space, which affected the accuracy of object tracking, we used three technologies to perfective this tracking system.
The first, we design the directional antenna to replace the monopole antenna, due to directional antenna allow to radiate greater power in one, or more directions. Able to increased performance on transmit and receive, also reduced interference from unwanted sources.
The second, we apply a Minimum Mean Square Error Method (MMSE) to minimum the position inaccuracy of indoor wireless network.
The third, Bluetooth systems have a restricted number of seven connecting nodes in the same time. In order to overcome this problem, Bluetooth nodes are connect to the power supply, and integrated Power Line Communication system with this object tracking system.
In a case study, routers are inserted into wall sockets distributed at a PC room in a dimension of 7.5 m long and 5.6m width. For several tests, the location is estimated and the average error distance is 0.73m.

並列關鍵字

Bluetooth ； indoor positioning system ； power line communication

參考文獻

[8] locata corporation, http://www.locatacorp.com/

[10] A. Ward, A. Jones, A. Hopper, “A New Location Technique for the Active office”, Volume 4, Issue 5, IEEE Wireless Communications, 1997, pp. 42-47

[13] P. Bahl, V. N Padmanabhan, ”RADAR: An In-building RF-based User Location and Tracking System”, Volume 2, IEEE Computer and Communications Conference, 2000, pp. 775-784.

[15] L. M. Ni, Y. Liu, Y. C. Lau ,A. P. Patil “LANDMARC: Indoor Location Sensing Using Active RFID” Proceedings of the First IEEE international Conference on Pervasive Computing and Communications, pp. 407-415, March 2003.

[16] W. Tsai, H. Y. Chung, “Design an Innovative Localization Engines into WSN via ZigBee and SOC”, Proceedings of 2008 CACS International Automatic Control Conference National Cheng Kung University, Tainan, Taiwan, Nov. 21-23, 2008.