Abstract
Configuration space method is one of the general collision avoidance method for robot manipulators. Basing on the graph search algorithm, the configuration method is free from the dead-lock problems which may arise in the potential method. However, the number of nodes in the graph to describe the configuration space grows exponentially, correspondingly to the dimension of freedom of manipulator. Therefore, some methods to prevent from computational explosion for high d.o.f. manipulator is required. We apply a heuristic graph search algorithm for searching. The evaluation function for a search is defined by two sum of a distance between the links of a manipulator and the middle plane among obstacles and a distance between the end-effector and the subgoal on a desired trajectory. Taking into account that the computational cost for heuristic graph search algorithm grately depends on the shape of configuration space, we introduce subgoals on desired trajectory of end-effector. The introduction of subgoals reduces trivial search and lessen the computational cost for searching in the complicated configuration space.
The effectiveness has been verified by simulation studies.