Tri-aural perception on a mobile robot

To overcome the problems associated with the use of ultrasonic sensors for navigation purposes, the authors propose a measurement system composed of three ultrasonic sensors, one transmitting and three receiving, placed on a moving vehicle. By triangulation, this tri-aural sensor is able to determine the position, both distance and bearing, of the objects in the field of view. However, based on the information from one single snapshot, the sensor cannot distinguish between corners and walls. A statistical test that combines consecutive sightings of the same object to determine whether it is a wall or a corner is derived. This test is formulated as a sequential test which guarantees that the object will be recognized after the minimal number of measurements given a predetermined error probability. Preliminary experimental data show the feasibility of the approach