An Effiecient Algorithm for Finding a Collision-Free Path Among Polyhedral Obstacles - Li-Chen Fu and Dong-Yueh Liu
- To reduce the complexity of finding a collsion-free path by reducing the free space.
- Creation of a subvisibility graph from the visibility graph.
- Use the smaller subvisibility graph to determine the shortest collision-free path.
- Use of the smaller graph reduces the complexity of computing the visibility graph for a greater amount of free space, consequently having to compute visibility edges for obstacles that are not in the direct path between the robot and target.
Begin by defining a straight line from start vertex 'S' to terminal vertex 'T'.
Position obstacle1, O1, where it belongs and if O1 overlaps segment ST, then delete segment ST and create segments SiOi and TiOi where i is a vertex in O1, for all i if visible to S or T.
Continue for all Oi in a list of obstacles performing visibility graph algorithm only when each additional Oi overlaps an existing segment.
The end result will be a subvisibility graph which will work on only the obstacles that are in the direct path of segment ST, thereby reducing the overall complexity of the free space to a "sub" smaller free space.