generating ultrasonic waves relative to the fabric using a plurality of ultrasonic transducers;

receiving ultrasonic waves coupled through the fabric and generating a signal; and

integrating said generated signal to identify a peak energy signal;

utilizing a computer digital signal processor to perform the steps of:

digitizing said peak energy signal;

median value filtering said digitized signal to filter out high frequency noise;

calculating a mean value and standard deviation of said median value filtered signal;

identifying mean value thresholds; and

utilizing said calculated mean value and standard deviation and said identified mean value thresholds to detect a defect in the fabric.

Abstract: An ultrasonic method and system are provided for monitoring a fabric to identify a defect. A plurality of ultrasonic transmitters generate ultrasonic waves relative to the fabric. An ultrasonic receiver means responsive to the generated ultrasonic waves from the transmitters receives ultrasonic waves coupled through the fabric and generates a signal. An integrated peak value of the generated signal is applied to a digital signal processor and is digitized. The digitized signal is processed to identify a defect in the fabric. The digitized signal processing includes a median value filtering step to filter out high frequency noise. Then a mean value and standard deviation of the median value filtered signal is calculated. The calculated mean value and standard deviation are compared with predetermined threshold values to identify a defect in the fabric.

U.S. Class: (73/159) (73/602) (73/598) (73/618)

IPC: (G01L 5/04) (G01N 29/00)

US Patents Cited: 5271284 5305239 5398538 5408882 5438872 5454045 5471878 5513531

Related Data: BACKGROUND OF THE INVENTION

This is a continuation-in-part of prior application Ser. No. 08/301,120, filed Sep. 6, 1994 now abandoned.

OG Section: Electrical