Note (General)In this research, a new backtrack free path-planning algorithm (BFA) for multi-arm manipulators that calculates paths by searching grid points in Euclidean space directly instead of Configuration space is implemented. Currently available resolution complete path-planning algorithms cannot be applied to manipulators with many arms, because their computation time and memory space for calculating collision free paths increase exponentially with the number of arms. Here, it is assumed that positions in the workspace of manipulators are approximated by finite number of grid points, and a resolution complete algorithm is the one that can determine the existence of paths and find correct paths if they exist, when grid sizes are small enough. Therefore usual planners adopt heuristics that are not adequate for automated and real time applications, i.e. sometimes they cannot find paths even they exist, and it is not possible to estimate path calculation times in advance. A newly proposed backtrack free path planning algorithm (BFA) solves this problem. BFA is an exact algorithm, i.e. it is backtrack free and resolution complete. Different from existing resolution complete algorithms, its computation time and memory space are proportional to the number of arms. Therefore paths can be calculated within practical and predetermined time even for manipulators with many arms, and it becomes possible to operate multi-arm manipulators in complicated and fully automated environments. This thesis describes the implementation and evaluation results of BFA. BFA was implemented for the path planning in 2-dimensional environments and evaluated while changing the number of arms and obstacle placements. Its performance under locus and attitude constraints was also evaluated. In all of the experiments, collision free paths were found within less than few seconds. The computation volume of the algorithm is almost the same as the theoretical one even for complicated cases. Namely, BFA calculates paths with much shorter time than existing algorithms with constant performance independent of environments. Also BFA enables easy locus and attitude constrained path calculations.
Collection (particular)国立国会図書館デジタルコレクション > デジタル化資料 > 博士論文
Date Accepted (W3CDTF)2020-01-16T18:57:33+09:00
Data Provider (Database)国立国会図書館 : 国立国会図書館デジタルコレクション