Reduction of free-space-loss for good and rapid 3D path planning of 6DOF robots

This paper deals with a new approach to solve the up to 6DOF robots global collision-free path planning. This problem seems to be more difficult when big or very long pieces are manipulated in cluttered and occupied environments. Moreover, the computational effort increases if the necessary path resolution is very high. The developed algorithm is based on the c-space technique. Different robot models are used for rapid c-spaces computation. Each one for different parts of a typical pick and place task. The algorithm selectively uses these global or local c-spaces. This strategy leads to fast global c-space computation without a considerable loss of free-space caused by the simplified robot model, and to quasi real-time local c-space computation. The paths searching in the computed c-spaces can be performed by several techniques: cell (cube) mapping, octree, and slice, which are rule-base selected in an adequate way. Finally, the results of the algorithm implementation in several real robots are presented.