Anisotropic Divergence Controlled Ultrasonic Transmitter Array for Three-Dimensional Range Imaging

A simple, cost effective and long-range three-dimensional (3D) measurement system has been developed using ultrasonic sound. The developed system consists of a high-power ultrasonic transmitter array (UTA) and an ultrasonic receiver array (URA). In some particular cases, measurement in wide horizontal plane is required instead of vertical direction. Therefore, anisotropic divergence control has been proposed and successfully controlled maintaining high peak power in the horizontal direction. The characteristics of the UTA are compared with the theory by generating a 40 kHz ultrasonic signal with modulated pulse width 2 ms. The measurable range without divergence control has been obtained over 17 m ± 0.5 m. Measurable range with anisotropic divergence control has been improved to 16 m ± 0.5 m on the isotropic divergence control from 14 m ± 0.5 m at the same divergence angle 10°. Awidest view angle has been obtained at 20° with the isotropic divergence control and further improvement in the view angle is observed with the anisotropic divergence control.