Multiple robot path coordination using artificial potential fields

A technique for coordinating the paths of multiple robots in the presence of obstacles is presented. To accomplish this, the robots are prioritized. A path that avoids only the stationary obstacles is planned for the highest-priority robot. A trajectory for the next-lowest priority robot is planned so that it avoids both the stationary obstacles and the higher-priority robot, which is treated as a moving obstacle. This process is continued until trajectories for all of the robots have been planned. The planning is accomplished by first mapping the real space of the robots into configuration-space-time. Potential fields are applied around the c-space-time obstacles and are used to modify the path of the robot. The advantage of using artificial potential fields is that they offer a relatively fast and efficient way to solve for safe trajectories around both stationary and moving obstacles. In the method used to perform path planning, a trial path through the c-span-time is chosen and then modified under the influence of the potential fields until an appropriate path is found.>