In this paper, a method to build a more efficient world map for mobile robot is presented using tri-aural ultrasonic sensor system without a prior information about the environment around the robot. The tri-aural sensor system is composed of three sensors; a center sensor used for both receiver and transmitter, and two side ones used for receivers.
In the traditional method using single sensor system, the beam-width of sonar causes the ambiguity of degree, which increases the difference between the real world and the sonar map. But, the proposed method of this paper achieves the correction of a certain degree and the descrimination of the plane and the corner without additional scanning. Simulation and experimental results show that the proposed method has some improvements of the similarity between the real world and the sonar map.
