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US 6,029,522 AGranted
Ultrasonic apparatus for characterizing wooden members
AssigneesPerceptron, Inc., The United States of America as represented by the Department of Agriculture
InventorsMark E. Schafer, Robert J. Ross
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Abstract
Ultrasonic techniques are applied to the measurement of wooden members to identify localized anomalies internal to the wooden members substantially smaller than the full width of the ultrasonic beam. Multiple spatially displaced measurements allow generation of comprehensive maps of the wooden members to aid in computer cutting and grading of the wooden members.
Claims14
An apparatus for detecting localized anomalies in wooden members comprising:
- at least one pair of opposed ultrasonic transducers positionable across an axis about wooden members to be qualified;
- driving circuitry for driving a first ultrasonic transducer so as to produce an ultrasonic wave of known characteristics to produce an ultrasonic beam having a beam width in the wooden member wherein the beam width is greater than the width of the localized anomaly;
- detection circuitry connected to a second ultrasonic transducer receiving the ultrasonic wave after passage through the wooden members along multiple paths within the beam width, first paths passing only through the localized anomaly and second paths not passing through the localized anomaly whereby the ultrasonic waves along the first and second paths interfere with each other to practice an interference ultrasonic wave;
- an electronic computer communicating with the driving and detection circuits and executing a stored program to:
- (a) compare the interference ultrasonic wave against a standard to detect a distortion of the interference ultrasonic wave caused by an interference between portions of the ultrasonic wave passing along the first and second paths;
- and
- (b) provide an output indicating the presence of localized anomalies based on the comparison.
4 more elements
A method of identifying localized anomalies within wooden members comprising the steps of:
- (a) positioning a standard material of known characteristics between at least one pair of opposed ultrasonic tranducers;
- (b) transmitting a first ultrasonic wave of known characteristics between the transducers through the standard material so as to produce a standard parameter;
- (c) positioning the wooden members to be qualified between the opposed ultrasonic transducers separated along an axis;
- (d) transmitting a second ultrasonic wave of known characteristics between the transducers through the wooden members to produce a beam therethrough having a beam width wherein the beam width is greater than the width of the localized anomaly;
- (e) analyzing the received secodn ultrasonic wave to produce at least one measurement parameter based on distortion of the received second ultrasonic signal caused by interference between portions of the second ultrasonic wave passing through the localized anomaly and portions of the second ultrasonic wave not passing through the localized anomaly;
- (f) comparing at least one measurement parameter against the standard parameter to identify the presence of a localized anomaly in the wooden member;
- and
- (g) outputting an indication of the presence of localized anomalies based on the comparison.
5 more elements
Dependencies are inferred from the claim text.