Path planning by robot decomposition and parallel search

Path planning is achieved by a special decomposition of the robot manipulator, an off-line preprocessing stage and a two phase online path planning scheme. The decomposition consists of separating the robot into several chains where a chain consists of a number of consecutive links and joints. Preprocessing is performed by defining a set of postures for each chain and setting up a collision table which re-integrates the chains into full robot and specifies the collision of various defined robot postures with obstacles. In the first online phase, local planning is performed independently and simultaneously in joint subspaces associated with robot chains. In the second phase, the paths found for the chains are synthesized to obtain a collision-free path for the robot. This decomposition reduces dimensionality of the search problem substantially, and as a result it is possible to achieve short planning times for robots with many degrees of freedom. Analysis of computation time and success rate of the proposed method are presented