TOWARD EFFICIENT PATH-PLANNING FOR ARTICULATED ROBOTS

Real-time issues are becoming more and more important in robot program ming. When a 6-dof manipulator is used, planning obstacle-avoiding pat hs is a time-consuming activity, usually done in simulation. We presen t the geometric models and the reasoning techniques we have implemente d while realizing a gross motion planner for a manipulator with six re volute joints. First, construction of a problem-oriented representatio n of the robot working space is explained. Then, the actual trajectory research carried out in our C-space representation is described. The whole C-space is not calcualted; instead, a sequential strategy is use d to determine the C-space only for the first two links. Our approxima tion of the obstacles, which occupy fixed and known positions, greatly speeds the computation, allowing us to reduce the problem to planar g eometric reasoning. The work is not limited to theoretical studies or simulations; experiments have been run very thoroughly, with various t ests, on a PUMA robot to assess the real efficiency and usability of o ur software. The method applies to robots in a fixed and known environ ment. (C) 1995 John Wiley & Sons, Inc.