利用位能場做具二自由度關節之多節物體之三維空間路徑規劃

Abstract

本論文研究在探討具有二自由度關節的連結物體的路徑規劃演算法。我們所提出的方法是以我們先前既有的適用於具有三自由度關節的連結物體的路徑規劃演算法為基礎。我們假設已經知道工作空間所有的幾何資訊，以多面體描述障礙物，並利用廣義位能場模型為連結物體找出一條無碰撞的、最安全的路徑。本論文所提出的方法與先前的方法，主要的差異在於連結物體的關節，本論文的連結物體具有二自由度關節，而先前的方法則主要是應用於具有三自由度關節的連結物體。所以我們需找出因為關節差異對於演算法的影響，進而發展出新的演算法使其能運用於具有二自由度關節的連結物體。結果顯示，我們為具有二自由度關節之連結物體所發展的路徑規劃演算法確實可行，而對於一般環境而言，路徑規劃所花費的時間通常比原先適用於三自由度關節之連結物體的路徑規劃演算法的規劃時間還要少，且在路徑安全上的損失並不多。事實上二自由度的關節，要比三自由度的關節更具強度也容易實際製作，因此本論文所提出的方法將比原有的演算法更為實用。

A path planning algorithm for 3D articulated objects of 2DOF joints based on the minimization of a potential function is presented in this thesis. This algorithm is an extension of our earlier research on similar path planning algorithm but for articulated objects of 3DOF joints. We assume that the obstacles are represented as polyhedra, and we want to find a safe and spatially smooth path for an articulated object using the generalized potential field. The main difference between the two algorithms is due to the difference in the degrees of freedom of the joints of articulated object, and a new algorithm for planning a path of an articulated object of 2DOF joints is developed accordingly. Simulation results show that the path planning algorithm proposed in this paper is more efficient in general while the loss of safety due to less freedom in the potential minimization is not significant. In fact, 2DOF joint is stronger in structure than 3DOF joint; therefore, the algorithm proposed in this paper will be more practical than the one we developed earlier.