engleski

CONCEPT OF ULTRASONICALLY-BASED MATERIALS CHARACTERIZATION IN NON-CHARACTERIZED ENVIRONMENT

Integration of an ultrasonically-based system for materials characterization and a hand-?probe was demonstrated to have a large potential in detection of buried mines for the purpose of humanitarian demining. In the integration, the absence of interferences with the conventional, contact technique of hand?probe use was emphasized. The characteristics of buried mines severely restrict hand-probe manoeuvrability and rate of additional information collectable within reasonable times, thereby lowering quality of the hand-probe-buried object contact. Additionally, the hand-probe penetration through the soil imposes restrictions on the applicable designs of hand-probe tip. All these restrictions influence the characteristics of the piezoelectric sensing part, which must on the one hand provide the operator with a signal of signal-noise ratio sufficiently high to make possible extraction of a statistically significant quantity of information about the buried object material, and on the other hand be as robust as possible, i.e., utilizable in a rather broad palette of mine-soil systems. In the paper we formulate the model of ultrasonic propagation in the system consisting of a piezoelectric element, hand-probe tip of variable geometry, realistic models of buried objects and characteristics of the non-homogeneous soil region in the close vicinity of the contact of hand-probe with the buried object. Capability of the presented concept in detecting buried mines is estimated, preliminary theoretical and experimental results discussed, and future development projected.

mine detection; ultrasound; materials characterization; FAST PROBE; expert center

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