Three-dimensional-positioning measurements based on echolocation using linear-period-modulated ultrasonic signal

This paper proposes an ultrasonic system for three-dimensional-positioning measurements. This ultrasonic system consists of one sound transmitter and four receivers. These devices are available to support the low-cost applications. To satisfy real-time signal processing, an echo is converted to a digital one-bit stream by a four-channel delta-sigma- modulation board. Then, FPGA is mentioned for cross-correlation based on one-bit signal processing. The object location is computed according to the distance from the sound source to an object, the angle of elevation, and the angle of azimuth. A spherical object is considered as a target of this system. The validity of experimental results is evaluated under statistics.