基於BIM之擴增實境輔助逃生系統

Abstract

在人口眾多的都市內，民眾的日常所需、交通、休閒娛樂圍繞著購物商場、車站、百貨公司、博物館等大型公共場域，這些大型公共場域的室內動線往往相當複雜，民眾雖然時常利用這些大型公共場域，卻鮮少注意過他們的緊急疏散路線，或對他們的逃生配置不熟悉。傳統的出口指示牌是以箭頭方向展示緊急出口位置，若遇到緊急事故，民眾可能因慌亂而誤判緊急逃生出口的方向，此時公共場域的營運單位必須派出大量員工協助民眾疏散。 為了有效地進行緊急疏散並減少營運單位疏散所需的人力，本研究實作一擴增實境輔助逃生系統，基於大型場域的建築資訊塑模 (Building Information Modeling, BIM)模型資訊，於手持智慧裝置中建置一虛擬建築模型，根據大型場域中佈置的iBeacon進行室內定位，計算使用者位置至最近緊急逃生出口的路徑，最後以擴增實境技術於手持智慧裝置螢幕顯示逃生路徑引導民眾疏散。 在BIM模型與手持智慧裝置的逃生導引系統間，本研究以純文字檔作為資料轉換格式，有效降低手持裝置的硬體需求以及資料的檔案大小。本研究驗證了iBeacon利用信號強度指示(Received Signal Strength Indication, RSSI)為權重的加權質心定位增加其精度後，其定位精度足夠使用在室內逃生導引，並且以BIM模型匯出的座標資訊建立以建築物牆和柱為障礙物的虛擬模型，能夠快速地在虛擬模型中使用障礙物尋路法找到前往逃生出口的最短路徑，從使用者視角顯示擴增實境路徑於手持智慧裝置的螢幕上，導引使用者疏散。

In urban city, people’s daily life is around large-scale buildings like train stations, museums or department stores. Their indoor circulations are always complicated, and people are not familiar with those emergency evacuation route. Traditionally, emergency exit signs use an arrow to lead people to the emergency exit. If there is an emergency happening, occupants may be nervous, resulting in their misjudging of the exit position. Therefore, the administration of the building needs to assign a lot of staffs to help occupants evacuate. This research developed a BIM-based augmented reality evacuation system to ensure effective evacuation and economize workforce used in an emergency evacuation. First, the system builds a virtual model in users’ smart phone based on information obtained from the BIM model of the building where the emergency is happening. Then, the system uses iBeacons for indoor positioning and calculates the safest and shortest path to the emergency exit. Lastly, occupants evacuate along the path shown in augmented reality view on their smart phone. This research only exports necessary coordinate data and uses .txt file to be the exchange format. Hence, it can reduce the exchange file size and hardware requirement between BIM model and evacuation system in smart phone. The exchange format was selected because it can reduce the exchange file size and hardware requirement for the process in this research. This research confirmed that after using weighted centroid localization algorithm based on received signal strength indication, the accuracy of iBeacon positioning is enough to be applied in indoor navigation. Also, by using coordinates exported from the BIM model to create obstacles in the virtual model, the system can find a shortest path around obstacles efficiently. Finally, the path shown in augmented reality view on users’ smart phone leads them to the nearest emergency exit and enables occupants evacuating by assessing their path to follow during the evacuation.