Measuring range and bearing with a binaural ultrasonic sensor

Discusses the development of a binaural ultrasonic sensor for mobile robot navigation, which is capable of measuring the range and bearing angle to multiple targets. A novel aspect of the design of the sensor is that it calculates the bearing angle twice, using inter-aural time difference (ITD) and inter-aural amplitude difference (IAD). These calculations of bearing are independent of atmospheric fluctuations and the geometry of the reflecting object. These independent bearing calculations are used to solve the correspondence problem. Echo pairs whose bearings differ by more than an acceptable amount are discarded.