具有適應性導航的輪椅系統

Abstract

電動輪椅是老年人與身心殘障人士重要的行動輔具之一，然而對於不善於使用電動輪椅上的搖桿裝置之使用者，會因為不善於操作而造成意外的發生，因此能夠發展出一套自動導航系統，不論室外或室內皆可以降低人為操作的不當及看護等人力資源的浪費。此外，現行的文獻中針對輪椅導航系統皆以資訊產品的衛星導航系統來做輔助，然而這種資訊產品內建的導航功能並不是以電動輪椅來設計，且導航功能僅限於室外，一旦使用者進入到室內此導航系統便無法使用。 本研究的目標是以多主多從系統(M3S)規範的可適性輪椅系統中，針對室內與室外提出一個新的自動導航的演算架構，以符合電動輪椅能夠實際在室內與室外使用，我們稱作此演算架構為智慧型路由法。智慧型路由法是一種啟發式演算法(Heuristic Algorithm)，採取「貪婪法則」和「動態繞路」的方向選擇判斷，當輪椅路由方向選擇時，先用Dijkstra演算法(貪婪法則)來計算最短路徑的推薦方向，若輪椅進行中發生前方無法前進時，則推測此推薦方向已有障礙物或道路施工的情況發生，此時輪椅的導航系統在避免重新計算最短路徑時發生路徑再次將已無法行駛的路徑中納入進來，因此會啟動回溯修正路由流程(Backtrack Reroute Process)來實行「動態繞路」之替代路由，來達到提高輪椅運輸機動性的效果。此外為了減輕電腦上記憶體的空間，在貪婪法則加上動態(Dynamic partition programming)地圖階層式的演算架構，將複雜的地圖切成數個小塊地圖。 從模擬實驗與實際試驗的結果，這智慧型路由法會自動地驅駛輪椅開往該地，因此相信藉由此方法的應用，將可替身心障礙者帶來許多便利，尤其是在特定的場所中(如機場、學校)，更能發揮此套系統的效果。

Powered wheelchair is an important mobility aid for the elder and the disabled persons. However, accident may happen due to inappropriate usage. If the wheelchair has an auto-navigating system, mistaken manipulation and the waste of nursing will be decreased. However, GPS is not suitable for indoor. This study presents an adaptive navigated powered wheelchair system. The wheelchair is build to meet the multiple-master multiple-slave (M3S) specification. An automatic navigated framework is also build into the wheelchair to facilitate indoor and outdoor use. This framework is installed with an intelligent routing heuristic algorithm derived from 'greedy method' and 'dynamic routing'. Dijkstra algorithm (greedy method) is first used to show the shortest path. However, if the recommended path has obstacles, the path is marked and initiate backtracking reroute process using 'dynamic routing' to select alternative route. In addition, in order to reduce computer memory space, dynamic partition programming is used to cut complex map into several simple pieces. Simulation results with practical tests showed that this adaptive navigation system can automatically drive the wheelchair to its destination. This system will surely benefit the impaired. Thus, this system will be very helpful in airport, schools and hospitals.