基於行人路徑推算及深度學習室內定位方法

The study of indoor positioning system based on pedestrian dead reckoning and deep learning

郭勝科(Sheng-Ke Guo)

指導教授 ： 李維聰

淡江大學/工學院/電機工程學系碩士班/碩士(2019年)

https://doi.org/10.6846/TKU.2019.00711

摘要

近年來科技的進步，人手一支智慧型手機已習以為常，也因智慧型手機的普及，相關的應用程式也數以萬計的增長。在手機提供的應用程式服務中，許多程式都需要使用到定位資訊所提供的資料，因此如何得到準確的定位資料就非常重要。而GPS 是目前室外應用中最為廣泛的定位系統，但在室內定位時會因為建築物而降低訊號強度，使得室內定位變得不準確，因此，有許多得室內定位方法被提出。
目前室內定位的方法有很多種，例如:WiFi定位、接收信號角度定位法(AOA)、到達時間差(TDOA)、接收信號強度指標(RSSI)、訊號紋比對（模式匹配）、iBeacon 定位系統、藍芽訊號定位等等的室內定位方法，但是WiFi、 Angle of Arrival, (AOA)等等的定位方法精準度不高，而iBeacon、Radio Frequency Identification(RFID)等等的定位方法需要布置大量的iBeacon及RFID設備，需要的成本也比較高，因此本文將提出一種複合式室內定位方法來提升定位的精準度及降低定位成本。
我們透過WiFi RSSI的資料收集，以及深度學習來判斷其室內位置，我們在實驗環境中架設3台WiFi AP，每隔一公尺設一個參考點收集RSSI數據，將數據進行整理後輸入至MLP(Multilayer Perceptron)進行訓練及學習，經過MLP(Multilayer Perceptron)學習後準確率約為6成。有了MLP的定位資料後，我們用航位推算法加上深度學習，依照測試目標的上個位置的資訊與陀螺儀的資訊推斷出測試目標下一個位置可能出現的範圍，並將出現的範圍套用在MLP所推算出的位置，將範圍外的數值去除，以達到更準確的定位路徑。
本論文研究結果顯示，如果單獨使用WiFi定位的話，誤差的距離約為兩公尺，但是用本文所提出的方法能將誤差的距離降低為一點五公尺，且使用航位推算加上深度學習的方式，可以去除MLP所推算出的錯誤定位資料改善室內定位的誤差。

關鍵字

WiFi ； 室內定位 ； 深度學習

並列摘要

In recent years, the advancement of technology, people are accustomedto use smart phone everyday, and because of the popularity of smart phones, related applications have also grown tens of thousands. In the application services provided by mobile phones, many programs need to use the information provided by the positioning information, so how to get accurate positioning information is very important, and GPS is the most widely used positioning system in outdoor applications. However,the signal strength will be reduced due to the building, and the indoor positioning will become inaccurate. Hence, many indoor positioning methods are proposed to improve the accuracy of indoor positioning.
At present, there are many methods for indoor positioning, such as: WiFi positioning, received signal Angle of Arrival positioning (AOA), Arrival Time difference (TDOA), received signal strength indicator (RSSI), signal pattern matching, iBeacon positioning system, Bluetooth, etc..But some of those methods, such as: WiFi, Angle of Arrival, (AOA), cannot providehigherpositioning accuracy; and some of them, such as:iBeacon, Radio Frequency Identification (RFID), need to arrange a large number of iBeacon and RFID devices to achieve higher accuracy and results in higher cost. Therefore, this paper proposes a composite indoor positioning method. to improve positioning accuracy and reduce positioning costs.
We collect WiFi RSSI data and feed data into deeplearning method to determinetarget’sindoor location. We set up a total of 3 WiFi APs in experimental environment, and set up a reference point per meterapart to collect RSSI data. Then, after the data preprocessing, feed the organized data into multilayer perceptron method for training and learning. After using MLP (Multilayer Perceptron) learning method, the accuracy of positioning is about 60%.Hence, we use the dead reckoning algorithm plus MLP to infer the possible range of the next position of the test target according to the information of the last position of the test target, and apply the range that are estimated by the MLP. The estimated locations which areoutside the range will beremoved to achieve a more accurate positioning location and moving path.
As the experimental results show that if the WiFi positioning is used alone, the positioning error is about two meters, but the method proposed in this thesiscan reduce the error to around 1.5 meters.Moreover,use the dead reckoning plus MLPcan reduce the estimation error of MLP and improve the indoor positioning accuracy.

並列關鍵字

WiFi ； indoor positioning ； deep learning

參考文獻

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[2] Pratap N. Misra, “The Role of the Clock in a GPS Receiver”, GPS World, April 1996.

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