Acoustic leak-detection system
AssigneeRobotic Vision Systems, Inc.
InventorPaul E. Rademacher
Life of this patent
Estimating the term…
Abstract
Leak detector arrangement for the detection of small openings in car bodies or other enclosures or containers which may permit undesired passage of water, fumes, or other fluids in which phase coded or linearly frequency modulated sound waves are directed towards potential leak areas. The portion of these waves which pass through the leak openings is received, and these signals are processed so as to discriminate these leak signals from other sound waves normally entering the receiver from other parts or from other sources. The discriminated signals are compared with a threshold so as to determine the absence or presence of a leak.
Claims15
A method for detecting regions of imperfect sealing along seams formed by overlapping sheet materials that would allow gas or liquid penetration, comprising the steps of:
- generating a modulation code;
- generating ultrasonic energy;
- modulating said energy by said modulation code;
- illuminating one side of a reference seam to be inspected with the modulated ultrasonic energy;
- transporting a microphone on the opposite side of said reference seam by a robotic positioner;
- processing the output signal of said microphone to enhance the signal to noise ratio;
- detecting singularities in said signal;
- recording said singularities as reference singularities;
- repeating the steps of illuminating, transporting, processing and detecting on a seam similar to said reference seam;
- comparing said detected singularities with said recorded reference singularities;
- and declaring as imperfect any region containing a new singularity or significantly larger singularity.
An arrangement for detecting regions of imperfect sealing along seams formed by overlapping sheet materials that would allow gas or liquid penetration comprising:
- means for generating a pseudo random modulation waveform;
- means for generating a carrier signal;
- means for modulating said carrier signal by said modulation waveform;
- transducer means for generating ultrasonic energy by said modulated carrier signal;
- means for directing said ultrasonic energy toward one side of a seam to be investigated;
- robotic positioner means;
- sonic energy detecting means transported on the opposite side of said seam by said robitic positioner means;
- signal processing means for enhancing the signal to noise ratio of a signal from said detecting means;
- computation means for detecting and recording a reference signal pattern;
- computation means for comparing a detected signal with said reference pattern to declare singularities;
- and storage means for recording said robotic positioner means position and said singularities.
A method for detecting regions of imperfect sealing along seams formed at the juncture of two materials that would allow gas or liquid penetration comprising the steps of:
- generating a periodic modulation waveform with specified period;
- providing a source of acoustic energy;
- frequency modulating said acoustic energy by said modulation waveform;
- illuminating one side of a reference seam with said modulated acoustic energy;
- transporting an acoustic sensor along the opposite side of said seam;
- multiplying the signal output of said acoustic sensor by a signal proportional to said modulated acoustic energy;
- filtering the signal generated by multiplying to attenuate frequencies greater than a predetermined value;
- recording said filtered signal to provide a reference record;
- repeating the illuminating, transporting, multiplying filtering and recording steps on a seam to be inspected to provide an inspection record;
- and declaring leaks at locations where said inspection record signal is greater than said reference record signal by a designated amount.
Dependencies are inferred from the claim text.