Fast path planning for robot manipulators by formation-posture decomposition

Abstract

Fast path planning is achieved by a special representation of the robot and a two-phase path planning procedure. The representation consists of defining sets of body formations and arm postures whose number depends on complexity of the environment and the required resolution of path planning. In the off-line planning phase, the defined formations and postures are generated, and a 2D collision table is set up which specifies collision with obstacles of various defined body formations and arm postures. In the online planning phase, a graph search is carried out to find a sequence of adjacent formations and postures. Because the time consuming collision checking is done off-line, the online path finding is extremely fast. Path planning is essentially performed in the work space thus avoiding the costly mapping of obstacles into the C-space. The path planner has been implemented on a SUN workstation that controls a Puma 560 manipulator.