Collision avoidance for a 6-DOF manipulator based on empty space analysis of the 3-D real world

Describes an efficient method that finds collision-free paths for a multiple-degree-of-freedom manipulator with rotational joints and grasped object. The method first analyzes the structure of empty space in the 3D workspace. Based on this space analysis, the path search is divided and a most promising direction for path search is determined in the 3D workspace. Finally the path search is done systematically in the joint space in the direction equivalent to the promising direction. This method is applicable to various problems regardless of the number of degrees of freedom on the manipulator, its structure, and the presence of grasped object