Piezoelectric sensor arrangement and a method of discriminating signals
AssigneeSaab AB
InventorsTony Holm, Johan Östlund
Life of this patent
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Abstract
A piezoelectric sensor arrangement for use in a projectile comprises a piezoelectric sensor enveloped by a damping layer adapted to attenuate signals of frequencies above a predetermined cutoff frequency whereby the voltage output signal of the piezoelectric sensor upon impact on a desired hard target can be discriminated from voltage output signals originating from impact on undesired soft objects. A method of discriminating voltage outlet signals by means of the piezoelectric sensor arrangement and the use of a piezoelectric sensor arrangement in a projectile to safeguard unintentional detonation does not occur is described herein.
Claims8
A piezoelectric sensor arrangement for use in a projectile, said piezoelectric sensor arrangement comprising a piezoelectric sensor fully or partially enveloped by a damping layer adapted to
- attenuate at least some mechanical wave frequencies, wherein the piezoelectric senor is arranged to generate a voltage output signal indicative of a mechanical wave traveling through the body of the projectile upon impacting on an object,
- wherein the sensor arrangement is arranged to integrate the voltage output signal over time, wherein the sensor arrangement is arranged to compare said integrated value with a predetermined threshold, wherein integral values above said threshold are indicative of the projectile impacting objects that are hard targets, and
- wherein the damping layer attenuation of mechanical wave and the integration of the voltage output signal together are arranged to filter mechanical wave frequencies above a predetermined cutoff frequency, wherein mechanical wave frequencies above said cutoff frequency are indicative of the projectile impacting objects that are soft objects, and wherein said predetermined cutoff frequency is at most 800 Hz.
Dependencies are inferred from the claim text.