Estimation of position and size of an object in a homogeneous medium by electrical and ultrasonic integrated sensor

AbstractIn this paper, three parameters, the position and size of an object inserted between the sensor and the temperature in the equipment, are estimated by using an electrical and ultrasonic integrated sensor. The integrated sensor consists of a pair of piezoelectric ceramics. The propagation time is measured by a pair of piezoelectric ceramics, and the conductance between a pair of piezoelectric ceramics is also measured by an electrode on the piezoelectric ceramic surface. Therefore, the electrical and ultrasonic properties are obtained by the proposed sensor. In the experiment, a gypsum specimen was inserted between a pair of piezoelectric ceramics arranged inside a cylindrical vessel filled with saline water of 0.1% concentration, and the conductance and propagation time were measured by a pair of piezoelectric ceramics at temperatures of 20, 25, and 30°C. Three gypsum specimens, with diameters of 35, 50, and 65 mm, were prepared. The positions and diameters of the gypsum specimens and the temperature in the equipment were estimated from the propagation time and conductance measured by the integrated sensor. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 163(4): 42–47, 2008;