ULTRASONIC TESTING INSTRUMENT WITH DITHERY PULSING

• US 20140109675A1
• Filed: 10/18/2012
• Published: 04/24/2014
• Est. Priority Date: 10/18/2012
• Status: Active Grant

• Current Assignee: Evident Scientific Incorporated (Evident Corporation)
• Original Assignee: Olympus Ndt Incorporated (Olympus Corporation)
• Inventors: Langlois, Pierre, Cournoyer, Benoit
• Granted Patent: US 9,638,673 B2
• Time in Patent Office: Days
• US Class Current: 73/596
• CPC Class Codes: G01N 29/343 pulse waves, e.g. particular sequence of pulses, bursts
• CPC Class Codes: G01N 29/4463 Signal correction, e.g. distance amplitude correction [DAC], distance gain size [DGS], noise filtering
• CPC Class Codes: G01N 29/449 Statistical methods not provided for in G01N29/4409, e.g. averaging, smoothing and interpolation

Abstract

Disclosed is an ultrasonic device optimized with both averaging and dithery pulsing techniques. The averaging technique significantly removes white noise; on the other hand, the dithery pulsing significantly removes acoustic noise, which is otherwise accumulated during conventional averaging processes.

Claims

1. A non-destructive inspection or testing (NDT/NDI) device configured for inspecting a test object, comprising:

a probe configured for pulsing a test object during a testing cycle at a testing location with N pulses to produce and receive N sets of wave responses, and to produce therefrom N sets of electric echo signals;

at least one analog to digital converter configured to digitize the N sets of echo signals and to produce therefrom N sets of digitized signal samples, which correspond respectively to N sets of acquired signal samples and N sets of noise signal samples;

a digital logic device, having a data processing unit configured to execute an averaging process by which the N sets of signal samples are summed and averaged to produce a final testing result;

wherein the digital logic device further comprises a pulser control unit configured to control the pulsing according to a dithery pulsing sequence by which the probe is pulsed in a dithery pattern between one pulse and another so that the combination effect of the N sets of the noise signal samples is decimated during the averaging process and in the testing result.

2. The device of claim 1, wherein N is an averaging factor used by the digital logic device for the averaging process.

3. The device of claim 1, wherein the digital logic device further comprises an averaging unit for executing the averaging process, the averaging unit further including an averaging controller, a digital memory, an adder and a divider.

4. The device of claim 1, wherein the pulser control unit further comprises a timing controller, a pulser counter, a timing adder, a main counter and pulser controller to apply the dithery pulsing.

5. The device of claim 1, wherein the dithery pulsing sequence is governed by T₀+nT+D_n, wherein n=1˜

N, with n to be sequence number at which the probe is pulsed and N to be the averaging factor and D_n, are dither values and are much less than T.

6. The device of claim 5, wherein D_n, are random and small numbers around zero.

7. The device of claim 5, wherein D_n, are pairs of small positive and negative numbers very small in value comparing to T.

8. The device of claim 1, wherein the probe includes a single element ultrasonic transmitter.

9. The device of claim 1, wherein the probe includes a single element transceiver.

10. The device of claim 1, wherein the probe is a dual element probe.

11. The device of claim 1, wherein the probe is a phased array probe.

17. The method claim 5, wherein D_n, are random and small numbers around zero.

18. The method claim 5, wherein D_n, are pairs of small positive and negative very small in value.

19. The method claim 1, wherein the probe includes a single element ultrasonic probe.

20. The method claim 1, wherein the probe is a multiple or array element ultrasonic probe.

12. A method of pulsing a non-destructive inspection or testing (NDT/NDI) device having a probe configured for pulsing a test object during a testing cycle, the method comprises the steps of:

pulsing the probe with N pulses according to a pulsing sequence,

causing the probe to receive N sets of wave responses, and to produce therefrom N sets of electric echo signals;

digitizing the N sets of echo signals to produce N sets of digitized signal samples, which correspond respectively to N sets of acquired signal samples and N sets of noise signal samples;

averaging said N sets of acquired signal samples;

wherein the pulsing sequence has a dithery pattern between one pulse and another so that the combination effect of the N sets of the noise signal samples is decimated during the averaging step and in the testing result.

13. The method of claim 12, wherein the steps of pulsing, digitizing and averaging are executed by a digital logic device.

14. The method of claim 13, wherein the digital logic device further comprises an averaging unit for executing the averaging process, the averaging unit further including an averaging controller, a digital memory, an adder and a divider.

15. The method claim 13, wherein the logic device further comprising a pulser control unit which further comprises a timing controller, a pulser counter, a timing adder, a main counter and pulser controller to apply the dithery pulsing.

16. The method claim 12, wherein the dithery pulsing sequence is governed by T₀+nT+D_n, wherein n=1˜

N, with n to be sequence number at which the probe is pulsed and N to be averaging factor and D_n, are dither values and are much less than T.