An efficient method for planning a safe trajectory for a Cartesian manipulator doing pick-and-place motion is described. A 3D grid model is used to represent the workspace of the manipulator. An algorithm, called the critical configuration algorithm, is introduced to support the path searching process in an environment cluttered with obstacles. The algorithm decomposes the movement of the manipulator into a departure motion, an intermediate motion, and an approach motion. Based on the information about the object being moved and the manipulator, a temporary intermediate motion is obtained, using the VGRAPH algorithm and the critical configuration algorithm, by transforming the problem into a 2D problem. The intermediate motion found in the first step is optimized according to heuristic information. A departure motion and an approach motion are then computed and optimized, and a global trajectory is determined. >
['Choong-Sik Lee', 'Phillip C.-Y. Sheu']
A divide-and-conquer approach with heuristics of motion planning for a Cartesian manipulator