DETERMINING THE PATH SEARCH GRAPH AND FINDING A COLLISION-FREE PATH BY THE MODIFIED A* ALGORITHM FOR A 5-LINK CLOSED CHAIN

摘要

Abstract Two tightly coordinated 2-link planar manipulators and the straight line between their two bases can be considered as a 5-link closed chain. Since the coordination of robot manipulators has broad applications in manufacturing, hazardous material handling, undersea operation, and space exploration, automatic collision-free path planning for a 5-link closed chain is an important unsolved engineering problem. This paper describes a collision-free path planning algorithm for a 5-link closed chain with revolute joints. In the algorithm the 5-link closed chain is first represented by a path search graph that is built on the basis of the concept of the newly developed C subspace model. Subsequently, a collision-free path is searched upon the graph by the modified A* algorithm. The significance of this path planning algorithm is its convergence and efficiency. The convergence is guaranteed by the C subspace model, which constructs unique mapping between the planned path in C subspaces and that in the world space. The way we build the path search graph and evaluation functions of the A* algorithm is designed to increase the search speed and to preserve the maneuverability of the 5-link closed chain. Additional informationNotes on contributorsQING XUE Address correspondence to Qing Xue, Department of Computer and Information Science, Purdue University, School of Science at Indianapolis, 723 West Michigan Street, Indianapolis, IN 46202, USA.