利用地球磁場進行不同手機之適應性校正與室內定位的研究

賴傳疆 ； 葉生正 ； 駱有聲

《TANET2017 臺灣網際網路研討會》 2017年 (2017/10) Pp. 908-913

https://doi.org/10.6728/TANET.201710.0158

摘要

適地性服務（Location-based Service, LBS）對智慧型行動裝置使用者而言也越來越重要。室內定位技術的研究也相對增加。室內定位技術包括了紅外線、超聲波、超寬頻、射頻識別等，但應用上都有些問題要克服，而目前最常見的Wi-Fi和藍芽之無線室內定位則有一些困難尚未解決，使其定位精準度或可靠性難以提升，針對這幾點，近年有一些研究嘗試用地磁進行室內定位的輔助。智慧型手機一般都內建有磁力及加速度感測器，且地球磁場不易變動的特性，讓手機搭配地磁進行室內定位之可能性增加。因此本研究將探討智慧型手機在測量地球磁場的有效性，以及不同廠牌的手機在室內定位的差異。實驗結果確定地球磁場的位置特徵不易隨時間變動，而且每個地點有各自的地球磁場特徵，故可直接以此作為定位參考。至於不同手機間測量的差異，則可採取磁感應強度及其水平分量的比值進行適應性校正，故不同位置的地球磁場特徵便可應用於手機之LBS服務開發。

關鍵字

適地性服務 ； 室內定位 ； 磁力計 ； 加速度計 ； 地球磁場

並列摘要

Location-based services (LBS) are becoming increasingly important for mobile device users. Indoor positioning technology research is also relatively increased. Indoor positioning technology include infrared, ultrasound, ultra-wide frequency, radio frequency identification, but these applications has some problems to overcome. The most common wireless indoor positioning is Wi-Fi and Bluetooth. There are some difficulties yet to solve, so that positioning accuracy or reliability is difficult to improve. In recent years, some studies try to use the magnetic field to assist the positioning. Because the intelligent device has a magnetometer and accelerometer, the Earth's magnetic field will not change suddenly and the mobile phone with the magnetic field a magnetometer and accelerometer could indoor positioning easily. Therefore, this study explores the effectiveness of mobile phones in measuring the Earth's magnetic field and the differences in indoor positioning of different brands of mobile phones. The results show that the location of the Earth's magnetic field is not easy to change with time. Each location has its own magnetic field characteristics, it can be used as a reference for positioning. As for the measurement of the error between the phone can take the magnetic induction and its XY component ratio as a position feature to locate. Therefore, the direct positioning of the magnetic field should be applied to the LBS of smartphone.

並列關鍵字

LBS ； indoor positioning ； magnetometer ； accelerometer ； earth magnetic field