Three-dimensional measurement of granular surface profile by ultrasonic array sensor

Creators Morimoto Eiji

Creators Egawa Naoki

Creators Itoi Shigeru

Creators Wada Kenzo

Ultrasonic measuring system has been developed to image three-dimensional surface of granular materials stored in a hopper for more accurate estimation of content amount than conventional level measuring method. Eight bimorph type linear array ceramic sensors compsed of eight receiving elements each were located in a concentric configuration around a condenser type emitter sendig 40kHz pulses. An incident angle to the arrays and a distance from surface were measured by a phase difference between adjacent receiving elements and by a sound propagation time between transducer, respectively. On the basis of properties studied by preliminary experiments on particle sizes, shapes, and surface conditions, model patterns of concave and convex in a vessel were tested to investigate the characteristics of the equipment. Estimated profiles were displayed in an stereogram manner showing good results especially for the concave profiles with an average error of ±8mm in height.

[ISSN]0386-3433

[NCID]AA0086073X