Path planning using a potential field representation

Findpath problem is the problem of moving an object to the desired position and orientation while avoiding obstacles. We present an approach to this problem using a potential field representation of obstacles. A potential function similar to the electrostatic potential is assigned to each obstacle, and the topological structure of the free space is derived in the form of minimum potential valleys. A path specified by a subset of valley segments and associated object orientations, which minimizes a heuristic estimate of path length and the chance of collision, is selected as the initial guess of the solution. Then, the selected path as well as the orientation of the moving object along the path are modified to minimize the cost of the path, which is defined as a weighted sum of the path length, required orientation changes during the motion, and the chance of collision along the path. Findpath problems possessing three different levels of difficulty are identified. Path optimization is performed in up to three stages according to the level of difficulty of the problem. These three stages are addressed by three separate algorithms which are automatically selected. The performance of the algorithms is illustrated on a variety of twoand three-dimensional problems. 1.