基於旅遊地圖的導航系統

Abstract

旅遊地圖常被用在風景區、校園或主題樂園等地點。除了顯示可行走的道路之外，這類地圖還會標示出該地區的重要景點和地標。為了在有限的空間內加入這些標記，旅遊地圖上的路網往往經過變形和簡化，而這樣的改變常對地圖使用者造成困擾。為了解決這個問題，我們將GPS導航系統與旅遊地圖結合起來，直接在旅遊地圖上畫出使用者現在的位置來指引他們順利找到目標地點。我們假設旅遊地圖是由向量圖檔表示，所以系統使用者可以直接從道路圖層取得路網結構。我們接著嘗試找出旅遊地圖上的路網和真實世界路網的對應關係。由於可能的對應關係數目非常大，我們必須在搜尋過程中刪除不可能的組合以積極縮小搜尋空間。我們觀察到旅遊地圖上顯示的道路必然是真實世界道路的一個子集合，因此基本的地理關係和路網拓樸結構能幫助我們剔除不可能的組合。當路網間的對應關係確定後，我們再將整張真實地圖形變至旅遊地圖上，來作為將GPS訊號投影到旅遊地圖時的基準。最後，我們進行的使用者經驗研究顯示，我們提出的系統能有效縮短使用者找到地標的時間。

We present a GPS navigation system on a tourist map that can assist users to navigate themselves in a scenic area, campus, or theme park. The maps of these places are designed not only for navigation but also for highlighting points of interest. Therefore, relative distances of road crossings and intersections have been changed, and distortions are inevitable. To prevent users from becoming lost, we plot GPS coordinates on such maps to indicate user positions and navigate the users to arrive at the desired destinations. In this work, we assume that tourist maps are represented by vector graphics and the road networks on such maps can be easily obtained. Because roads on a correct tourist map must exist in the real world, one can simply assume that the road network on a tourist map is a subset of that on a general map. Accordingly, we explore the combinatorial tree to obtain the network correspondence. To prevent the exponential search space, basic geography and topology are utilized to identify and remove impossible correspondences. Finally, we warp the general map to accurately fit the road layout on the tourist map for calibrating GPS coordinates. The experiment results and the conducted user study demonstrate the effectiveness of the presented technique.