System and method of correcting a non-concentric ultrasonic iris inspection result

Patent metadata

Field	Value
Publication number	US-9726641-B2
Application number	US-201414478412-A
Country	US
Kind code	B2
Filing date	Sep 5, 2014
Priority date	Sep 5, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

Disclosed is an ultrasonic IRIS inspection system and a method of providing automatically compensated concentric B-scans by means of curve-fitting the unadjusted tube boundaries from inspection data, and from the curve fitted theoretical circle, using non-linear regression analysis to determine an adjusted center. The off-center distance between the adjust center and the misaligned center is then used to produce concentric inspection result by compensating the unadjusted inspection result with the off-center distance.

First claim

What is claimed is:

1. A non-destructive inspection apparatus with a probe assembly suitable for inspecting a test object of a shape of a tube having an inner surface and an outer surface, the probe attached to a centering roller and configured to travel along a nominal reference center inside and along the tube to inspect the tube during an inspection session, the inspection apparatus comprising:
a transducer residing within the probe assembly, configured to emit inspection energy to the tube and to receive corresponding echo signals;
a data acquisition unit electronically coupled with the transducer, configured to trigger and guide the inspection energy and receive the echo signals;
a data processing and display unit configured to process the echo signals to produce inspection data, firstly as an unadjusted inspection result, including an unadjusted inner boundary and/or an unadjusted outer boundary, the unadjusted inner and/or outer boundary is associated with a misaligned center, the data processing and display unit further comprising,
an off-center calculator configured to curve-fit a theoretical inner and/or outer circle and an adjusted reference center based on the unadjusted inner and/or outer boundary, correspondingly, and the off-center calculator further configured to calculate an off-center distance between the misaligned center and the adjusted reference center,
a center adjuster configured to produce an adjusted inspection result by compensating the unadjusted inspection result with the off-center distance.

2. The non-destructive inspection apparatus of claim 1 is an ultrasonic inspection apparatus and the inspection energy consists of ultrasonic pulses.

3. The non-destructive inspection apparatus of claim 2 , wherein the transducer is a single element ultrasonic transducer.

4. The non-destructive inspection apparatus of claim 2 , wherein the transducer is a multi-element or array element ultrasonic transducer.

5. The non-destructive inspection apparatus of claim 2 , wherein the inspection data and the associated inspection results are presented as B-scans.

6. The non-destructive inspection apparatus of claim 2 , wherein the inspection data and the associated inspection results are presented as C-scans.

7. The non-destructive inspection apparatus of claim 1 , wherein the nominal reference center is known to and entered by an operator to the apparatus prior to the inspection session.

8. The non-destructive inspection apparatus of claim 7 , wherein the nominal reference center is consistent with the center of the centering roller.

9. The non-destructive inspection apparatus of claim 1 , wherein the data processing and display unit further comprising an ID signal and angle generator and OD signal and angle generator for generating the unadjusted inner boundary and the unadjusted outer boundary, respectively.

10. The non-destructive inspection apparatus of claim 9 , wherein the off-center calculator further including an internal filter, an external filter, which filters out inspection data outside a predetermined threshold of an inner nominal circle or outer nominal circle, respectively.

11. The non-destructive inspection apparatus of claim 9 , wherein the off-center calculator further comprising an internal calculator and an external calculator, each configured to conduct curve fitting to produce a theoretical inner circle and a theoretical outer circle, based on the unadjusted inner boundary and the unadjusted outer boundary, correspondingly.

12. The non-destructive inspection apparatus of claim 11 , wherein the curve fitting is conducted by defining the inner or outer distance
R (φ j ;r 0 ,φ 0 )=√{square root over ( r 2 (φ j )+ r 0 2 −2 r (φ j )* r 0 *cos(φ j −φ 0 ))}

as from an assumed reference center ( 303 a ( j )) to the J boundary sample positions labelled j=1 . . . J, wherein R(φ j ;r 0 ,φ 0 ) is the radial position of the part boundary relative to assumed reference center 303 a ( j ), φ j is the angle of the j th boundary position relative to misaligned data center 302 , r 0 is the distance between the misaligned data center 302 and assumed reference center 303 a, φ 0 is the offset angle of assumed reference center 303 a ( j ) relative to the misaligned data center 302 , and r(φ j ) is the radial position of the part boundary relative to the misaligned data center 302 .

13. The non-destructive inspection apparatus of claim 10 , wherein the center adjuster further comprising a signal selector selecting a selected theoretical inner circle or the theoretical outer circle that is closest to the inner nominal circle or the outer nominal circle, respectively.

14. The non-destructive inspection apparatus of claim 10 , wherein the selected theoretical inner or the selected theoretical outer circle is used to produce the adjusted reference center.

15. The non-destructive inspection apparatus of claim 14 employs non-linear regression analysis to deduce the adjusted reference center from the selected theoretical inner circle or the selected theoretical outer circle, with the nominal reference center as a non-linear regression starting point.

16. The non-destructive inspection apparatus of claim 15 is further configured to seek the adjusted reference center, a special case of the assumed reference center defined by parameters r 0 and φ 0 , such that objective function S(r 0 , φ 0 ) is minimal, with

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Assignees

• Bourgelas Tommy
• St-Laurent Martin
• Painchaud-April Guillaume
• Olympus Scient Solutions Americas Inc

Inventors

• Bourgelas Tommy
• St-Laurent Martin
• Painchaud-April Guillaume

Classifications

• G01N2291/106

  one or more transducer arrays · CPC title

• G01N29/07

  by measuring propagation velocity or propagation time of acoustic waves · CPC title

• G01N2291/2636

  cylindrical from inside · CPC title

• G01N2291/101

  one transducer · CPC title

• G01N2291/011

  Velocity or travel time · CPC title