High Resolution Mobile Robot Obstacle Detection Using Low Directivity Ultrasonic Sensor Ring

This paper presents the obstacle detection of a mobile robot using an ultrasonic sensor ring with overlapped beam pattern. A set of ultrasonic sensors with low directivity are assumed to be installed at regular intervals along the side of a circular mobile robot. First, due to the overlapped beam pattern, the positional uncertainty inherent to an ultrasonic sensor is shown to be reduced significantly. Second, given measured distances from adjacent ultrasonic sensors, the geometric method to compute the position of an obstacle with reference to the center of a mobile robot is described. Third, taking into account both positional uncertainty and computational cost, the sensor models of an overlapped ultrasonic sensor ring adequate for the obstacle detection are established.