Vibration distribution and acoustic directivity of an ultrasonic sensor

초록

This paper presents the vibration distribution and acoustic directivity of an ultrasonic sensor for ranging. Since the acoustic directivity depends on the vibration distribution of the sensor housing and the better directivity improves ranging distance, it is necessary to find the vibration distribution which improves the acoustic directivity. Theoretically, acoustic beam pattern and directivity have been calculated for the ultrasound radiating from the circular plate with uniform vibration distribution. By finite element method, the vibration distribution and acoustic directivity have been obtained for a real ultrasonic sensor which shows maximum vibration at the center of the plate. The sound pressure results have been displayed in the forms of distribution, a graph as a function of the directional angle, and a graph as a function of the distance as well as the acoustic beam pattern. Acoustic experiments have been carried out to compare with the analysis results. We have found that the sound pressure is larger along the central axis of the propagation as the vibration distribution is closer to a uniform one. © 25th International Congress on Sound and Vibration 2018, ICSV 2018: Hiroshima Calling. All rights reserved.