IN-AIR ULTRASONIC RANGEFINDING AND ANGLE ESTIMATION USING AN ARRAY OF ALN MICROMACHINED TRANSDUCERS

Abstract

We describe a 2D ultrasonic depth sensor based an array of piezoelectric micromachined ultrasound transducer elements which measures range and direction to targets in air. The transducer consists of a single transmitter and seven receive elements arranged in a 6mm long linear array with half wavelength spacing. The system employs pulse-echo time-of-flight and difference of arrival time to determine target range and angle and operates up to a 750mm maximum range and 35 angle span with 3.5mm range and 3 angle worst case errors, respectively.