網路感測室內定位系統之環境影響研究

Abstract

相較於適用在戶外的全球定位系統，室內定位系統總是發展的不夠成熟，面臨許多突發狀況的干擾與環境的變化，使得室內定位系統要能夠去適應每種環境，且精確度要能夠在接受的範圍內變的不容易。 本論文透過部署無線感測網路在環境中，利用ZigBee低耗能與網路拓樸的特性為系統基礎。先假定真實生活中可能遭遇的環境去量測，根據電器用品的數量劃分三個等級，經由分析訊號變化與環境的關係，初步找出環境中的最佳參數；再透過材料性質對訊號衰退的影響程度，訂定系統在不同環境中適應的能力，以增進定位的可靠度。 真實測試各種的情境之後，不論是單一空間依據干擾數劃分的實驗，或是兩個空間有無轉角的實驗，此系統均能夠克服多變環境的影響，達到誤差值約1.5m，甚至達到1.1m，提供較可靠的定位精確度。並建立觀測介面與資料庫，紀錄每一個時間移動點的位置以供參考，此系統不僅本身能夠依環境特性自動調整參數，當環境面臨極為重大的變化時，可以透過介面的手動操作去發送訊號，使此系統仍然具有可靠度。Comparing with commonly using Global Positioning System (GPS) in outdoor, Indoor Positioning System (IPS) always develops slowly. IPS meets many resistances and is interfered by variety environments. These factors make IPS is difficult to suitable in different cases; the accuracy of location is also a challenge.

This thesis discusses the principle of using ZigBee that has features such as low-energy requirement, protocol network and wireless sensor network. First, assuming different environments that can be face in real life, according to the amount of the electric equipments to define three-level. Analyzing the relation between the signals and different environments to find the best parameters for each conditions. Then, seeking the relation is about the signals in decay from the property of different materials. Finally, defining the ability of the system in different environments raises the accuracy of location.

After many experiments in different environments including interferences or corners, the system could be reliable. The error would be below 1.5 meters, even 1.1 meters. According to recording position and time, the database could be used as reference. The system not only can automatic adjusting but also lets users send signals back to the system. Above all make the system strong and dependable in this research field.