| Many algorithms have been proposed that create a path for a robot in
an environment with obstacles. Most methods are aimed at finding a
solution. However, for many applications, the path must be of a good
quality as well. That is, a path should be short and should keep some
amount of minimum clearance to the obstacles. Traveling along such
a path reduces the chances of collisions due to the difficulty of measuring
and controlling the precise position of the robot. This paper
reports a new technique, called Partial shortcut, which decreases the
path length. While current methods have difficulties in removing all
redundant motions, the technique efficiently removes these motions
by interpolating one degree of freedom at a time. Two algorithms are
also studied that increase the clearance along paths. The first one
is fast but can only deal with rigid, translating bodies. The second
algorithm is slower but can handle a broader range of robots, including
three-dimensional free-flying and articulated robots, which may
reside in arbitrary high-dimensional configuration spaces. A big advantage
of these algorithms is that clearance along paths can now
be increased efficiently without using complex data structures and
algorithms. Finally, we combine the two criteria and show that highquality
paths can be obtained for a broad range of robots. |
