應用適應性點對點測距及三角定位之協同式藍芽室內定位系統

Abstract

隨著近年來行動裝置的普及，使得以室內定位為基礎的服務被迫切需要，儘管目前已有許多定位的相關研究，新的藍芽4.0低功耗技術卻為室內定位帶來新的機會。在本文中，我們提出了一個稱作"適應性測距"的新概念，並將它應用到兩個面向："三角定位"與"裝置相遇"，來提升室內定位的精準度。適應性測距可以大幅減輕由於環境變動所產生無線訊號不穩定的問題，而其核心設計是利用beacon與beacon之間的訊號量測來了解目前的環境狀況，進而推測出兩個藍芽裝置間的距離。我們運用粒子過濾器整合這些資訊，讓使用者可以用合作的方式相互校準彼此的位置，並定出精確的定位結果。最後用實驗數據來驗證我們的定位系統可大幅改善因訊號不穩定而產生的定位誤差。

There are explosive demands on indoor localization services due to the popularity of mobile devices. Although there exist a lot of related studies, a new technology, Bluetooth Low Energy (BLE), has led to a new opportunity for low-cost localization. In this research, we propose a new concept called adaptive ranging and apply the concept to two directions, multi-lateration and mobile encountering, for improving the convenience and accuracy of indoor localization. With the proposed adaptive ranging technique, the wireless signal unstable problem due to environmental dynamics is greatly relieved. Central to own design is an inter-beacon measurement to understand the transient environment conditions and predict the distance between two BLE devices. We integrate these information under a particle filter (PF) framework that allows users to collaboratively calibrate each other's location. Extensive experiment results are presented to validate our claims.