電動輪椅跨階機構系統的模擬與評估

Abstract

本研究重點是發展能夠跨越高段差路面的電動輪椅跨障機構之設計流程，並利用模擬和實驗做為評估機構系統的依據。由於全球人口結構呈現老年化愈趨明顯，加上並非各國的社會福利設施都擁有相當完善的「無障礙空間」，使得肢體殘障人士無法單獨依靠自己的力量，順利地上下台階行動。基於這樣的需求下，也開始許多搭載貨物、病人升降樓梯裝置的研究，有千斤頂、履帶、組合輪、滑軌、曲柄連桿所形成的各式機構，主要的設計重點都是如何完成承載物垂直舉升加向前平移的運動。其中千斤頂和滑軌裝置雖然有利抬升高度，但要施予額外動力；履帶、組合輪和曲柄連桿的跨障裝置皆可成功登上段差路面，但結構過於複雜；而本研究所提出的跨階機構則是綜合前人設計經驗，針對本實驗室研擬的連桿型跨階輔助機構(NC_pwc_06)，在簡單、輕量的原則下進行機構系統的設計與研討。透過搜集現有電動輪椅資料和跨階機構專利，把各種電動輪椅跨階機構的優缺點進行分析比較，並且進行簡化模型的理論推導、模擬。為了進一步求得更加複雜龐大真實模型的運動分析數據，本研究選用機構運動模擬軟體MSC.ADAMS來做為相關運動力學、動力學模型分析和驗證的工具。在掌握各項設計要因之後，本研究提出了結合NASA的火星探險型機器人的設計與市售電動輪椅部份機構作結合，做為新型電動輪椅跨階機構的雛型，並利用ADAMS的參數化設計模組，進行機構尺寸的最佳化分析，完成一套發展電動輪椅跨階機構的基礎設計流程。而嘗試找出成功跨階參數的過程中，應用前述參數分析與歸納原則，測試出有效跨階的最佳設定值。此外，應用零矩點理論(ZMP)做為判斷電動輪椅行進間平衡準則的設計方法，可增進其跨爬段差路面時的穩定能力，亦是本研究討論的主題之一。在本文範例中針對跨階機構的各項影響參數進行分析與測試，將提出的範例機構做分析、歸納和改進，並加入ZMP平衡準則，提供其有參數化與最佳化設計流程的跨障電動輪椅的設計評估模式與經驗歸納，做為相關產業研發的參考。

The research focuses on the design processes of the powered wheelchair (PWC) mechanism for climbing high stepped obstacles. Simulation and experiments are enrolled to evaluate the proposed mechanism system. The proportion of the elder people in the global population is getting higher. There are not enough social welfare facilities (e.g. ” Barrier-Free Space”) in most of the country currently. Even that driving the power wheelchair climbing or descending the stepped obstacles, it was a hard work for them. Based on the demand, there are a lot of studies and discussions about the assisting devices carrying goods and patients climbing over a step obstacle. For examples, there are many designing project regarding the mechanism of a jack, a track, an assembly wheel, a slider/rail and a slider-crank mechanism, etc. The main points are how to accomplish an entire motion, moreover, support loading to lift and carry it forward. Though the example of a jack and a slider/rail devices are easy to lift, but it need extra power resources. The track, the assembly wheel or slider-crank apparatus are assisting well to climb, but structures of those devices are too complicated. After evaluating several critical design factors, the Robot of Mars exploration Rover Mission in NASA was chosen as a reference model, and integrated with the parts of existing PWC to form a new climbing PWC model. This research proposed the mechanism which adopting some former experiences to form the linkage-type auxiliary mechanism for climbing stepped obstacles in CIDM laboratory(NC_pwc_06). In current study, the NC_pwc_06 mechansim system was discussed and redesigned and keep simple and lightweight as a design principle. By selecting the existing data and patents for climbing PWC, we analyzed and compared its advantages and drawbacks. The simple model has been theoretically derivated and simulated. In order to getting more complex, enormous and real model data, we chose MSC.ADAMS as the tool. It could be analyzed and validated at the related kinematic and dynamic models. To use the parametric analyzed module in ADAMS, and we did the optimization on the mechanical size. At last we had completed a set of basic procedure which develop PWC mechanism for stair-climbing. For searching for the optimal parameters of the PWC on stair-climbing, we applied former parametric analysis, generalized principles and experimental testing for better climbing performance. Furthermore, the design method which applied ZMP theory for providing the PWC stability criterion. We analyzed and tested each affected parameter for proposed climbing mechanism, and also further to improve them and generalize the results from them. Adopting the ZMP stable criterion for evaluating the stability of the PWC climbing mechanism. The parametic analysis and dynamic simulation of a propsed step-climbing PWC in the current study have been evaluated by a series of experimental testing, and the evaluating results have demonstrated that the propsed methodology was a practical and deserved to be a preliminary design and evaluating tool for step-climbing power wheelchair.