具有不變之桿件與接頭數目之可變拓樸機構概念設計方法

Abstract

可變拓樸機構是可以藉由轉換其拓樸結構以執行多種功能的機構。當可變拓樸機構展現其多種功能中之其中一種時，可變拓樸機構為處於多個階段中之其中一個階段。本論文主要目的在於呈現一套系統化的設計方法以概念合成可變拓樸機構。首先，根據功能需求，組成每一個階段之功能運動鍊以代替其功能桿件之特徵運動。接著，決定機構之迴路數目，並由功能運動鍊中所給定之接頭自由度以求出每一個迴路之最小可行維度。為了使不同階段的迴路可以互相轉換，其迴路之維度必須被驗證是否可行。並且，相鄰迴路之迴路介面也必須被確認以確保相鄰之迴路可以互相傳遞。當利用結構需求找出可行之運動結構後，將其與功能運動鍊互相結合可以得到帶有未定接頭之相容運動結構。最後，標記出這些未定接頭，可行的可變拓樸機構可以被設計完成並可履行給定之設計特徵。除此之外，給定部分接頭之位置並替換至螺旋之中，可以得到接頭之位置限制與方向限制，進而幫助可變拓樸機構之尺寸設計。根據本方法論，分類的設計特徵與運動相容性可以引導設計者系統化地執行方法中的各個程序。在本論文中，利用一個SMIF栓鎖機構當作例子以利說明。

A variable topology mechanism (VTM) can execute variable functions by transforming its topology. A stage is a status that a VTM exhibits one of their many characteristic motions. This paper presents a systematic methodology for the conceptual design of VTMs satisfying the motion compatibility. From the characterized motions of functioning links, the functioning kinematic chain of each stage is constructed. After the number of the loops is decided, the minimum dimension of each loop can be derived from the known DOFs in the functioning kinematic chains. For successive transforming between different stages, the dimension of each loop should be evaluated. For effective transmission between adjacent loops, the loop interface of adjacent loops should be confirmed. Based on structural parameters, compatible kinematic structures with unspecified joints are identified. After labeling unspecified joints, feasible VTMs which fulfill the design specifications can be yielded. Substituting the locations of partial joints into the screws, the constraints on locations and orientations of joints are investigated to help the dimensional design of the VTMs. With this methodology, classified design specifications and motion compatibility are used to guide designer through various stages of the conceptual design process in a systematic manner. A SMIF latch mechanism is presented as an illustrative example.