This example shows one situation where the NF2 potential function yields
a stupid decision by the robot. If the goal of the robot is to go
straight forward and to rotate PI radians and the heavily weighted
control point is at the front of the robot, then that control point will
likely go directly towards its goal point. Once it reaches that point,
the other lightly weighted control point, which has to get around the
heavier control point, won't be able to move to it's goal point. This is
because the heavy point refuses to move, so the robot would have to
rotate around the heavy point. However, the light point's potential at
the arc of the circle with center where the heavy point is, are not any
lower than it's current location. Therefore, a random walk will have to
occur until the robot is situated properly to DESCEND to the goal. In
this example, two random walks actually occur.