The encoder bumper functions by having the robot push itself into a wall. As this fixes the bumper cage to the outside world, the interior body of the robot can then rotate in place, using the encoder readings to calculate how much it has turned. This is a novel way of navigating without directly "seeing" the environment. Additionally, as the position of the encoder is known when the robot is turned on. the absolute angle between the bumper cage and the interior robot can always be calculated. This can help with orienting the robot to absolute directions and not just relative turning.