The fan map system:
in the fan map system possible positions are described by a fan like map.
each line on the fan is a possible path for the vehicle.
the base of the fan is always the current position, and goals and bounarys are superimposed on the fan map.
if a path crosses a boundary it is immediatelly discarded.
if a path meets a goal it is chosen immediately.
discarding paths first prevents goal paths from crossing the boundary.
