抄録
An efficient method that finds collision-free paths for a manipulator with 6 revolute joints is described. The method first describes a global structure of the free space in the 3-D joint space of the arm. Both the collision-free space of the arm and a large open space in the workspace defined as a space where any orientation of the hand is possible are represented in this description.
Given the initial position and orientation of the hand, a path is searched for to the nearby open space as follows. A local space is described in the real 3-D workspace around the hand at the initial position. Then the description is analyzed, and candidates of the intermediate goal specifying the hand position and orientation are generated. The candidates of the intermediate goal are checked one by one until a path is found from the initial point to the intermediate goal and from the intermediate goal to the nearby open space.
The path planning system has been implemented for the ETA-2 (ETL's Torque Controlled Arm v. 2). The system has successfully planned paths in tightly cluttered workspaces.
