Patent Grant
8269489
This application is related to the following co-pending U.S. patent application Ser. No. 11/935,118, entitled “Eddy Current Probe and Methods of Assembling the Same” assigned to the same assignee as this application, the entirety of which is hereby incorporated by reference herein.
The invention relates generally to a system for nondestructive inspection of parts, and more particularly, to a system for detecting flaws in parts employing eddy current method.
The presence of surface cracks and subsurface flaws in metallic structures, such as engine blades, have the potential to lead to failure of an engine. Harsh environment and extreme operating envelope for aircraft engines cause early failures in critical area of engine components. Various inspection methods have been developed and used heretofore for crack and flaw detection with varying degrees of success.
Several prior art inspection methods are deployed for a fine crack detection of aircraft body and engine components. One of methods is fluorescent penetrant inspection (FPI) that applies penetrant material over suspected areas and look for indications with ultraviolet light. The FPI is effective and widely used in aerospace industry and doesn't require stringent inspection environment such as close contact or curvature of parts, but its detectability isn't as good as eddy current inspection. The other is an eddy current inspection that investigates an indication of depth to ascertain crack and flaw severity. The eddy current probes require close proximity to the part. It also requires complex manipulators and inspection plan to follow contoured part geometry to maintain 100% inspection coverage and avoiding lift-off variation between the probes and the. Full coverage with eddy current probes is very time consuming. Spot checking may miss critical crack and defect areas.
Consequently, a need still exists for an improved inspection technique that will provide a solution to the aforementioned problem without introducing any new problems in place thereof.
In accordance with one aspect of the invention, an inspection system for inspecting a part is provided. The inspection system includes a multi-dimensional array of eddy current sensors that conforms to a contour of a three dimensional shape of the part. The inspection system also includes a controller coupled to the multi-dimensional array, wherein the controller is configured to electronically scan the part by sequentially connecting sensors in the array to an eddy current instrument. The inspection system further includes a processor coupled to the eddy current instrument, wherein the processor is configured to analyze output from the eddy current instrument and the controller to accomplish inspection of the part.
In accordance with another aspect of the invention, a multi-dimensional array of eddy current sensors that is conformable to a three dimensional shape of a part is provided. The multi-dimensional array of eddy current sensors includes a flexible grid. The multi-dimensional array of eddy current sensors also includes multiple eddy current sensors disposed throughout the flexible grid.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
As discussed in detail below, embodiments of the invention are directed to a system and method for inspection of parts with complex geometries. As used herein, the term “inspection” includes inspection for detecting flaws in a complex surface and a sub-surface region of the parts such as, but not limited to, internal cracks, external cracks and pits. A non-limiting example of the part includes an airfoil (turbine blade) in an aircraft engine. It should be appreciated that the methods and apparatus can be applied to a wide variety of components used within an aircraft engine, a steam turbine, a nuclear power plant, an automotive engine, or to inspect any mechanical component.
The flexible grid 14 may be supported by a backing material 18. A non-limiting example of the backing material includes soft durometer backing and shielding. In another embodiment, the grid 14 is non-flexible and the eddy current sensors 13 are interconnected flexibly. In one embodiment, the eddy current sensors may be directly fixed or ‘printed’ on a 3D surface of the grid 14 that matches a surface of the part to be inspected. In another embodiment, the eddy current sensors 13 include an absolute sensor, a differential, or a pitch-catch sensor. In yet another embodiment, the multi-dimensional array of eddy current sensors is mobile and may be physically scanned.
It is desirable for the eddy current signal due to the flaws to have a signal-to-noise ratio large enough to be detected in a response signal over background noise. Multi-frequency phase analysis enables achieving such signal-to-noise ratio. Further details of the multi frequency phase analysis may be obtained in U.S. Pat. No. 7,206,706 to Wang et al., entitled “Inspection of Non-planar Parts using Multifrequency Eddy Current with Phase Analysis” and assigned to the same assignee of the present invention, which is hereby incorporated herein by reference. Several compensation algorithms may be applied in the signal processing to reduce the sensitivity variation for different defect locations under the sensor array. Examples of the compensation algorithm include, but not limit to, using averaging or root mean square of adjacent channels. A display monitor 101 may be coupled to the processor 92 to display an indication of a presence of at least one flaw in the part 82 based upon the plurality of eddy current signals. It is possible that the controller and/or the processor and/or the display can be built on the probe body using miniature design within the space limit.
It should be noted that embodiments of the invention are not limited to any particular processor for performing the processing tasks of the invention. The term “processor,” as that term is used herein, is intended to denote any device capable of performing the calculations, or computations, necessary to perform the tasks of the invention. The device is capable of accepting a structured input and of processing the input in accordance with prescribed rules to produce an output. It should also be noted that the phrase “configured to” as used herein means that the processor is equipped with a combination of hardware and software for performing the tasks of the invention, as will be understood by those skilled in the art.
The various embodiments of a system and method for inspection of parts described above thus provide a way to enable inspection of a complex, contoured surface with high productivity. The system and method also reduce rework and reinspection caused by false calls, and improve first time yield. Furthermore, the technique provides an efficient and cost effective means for inspection. The system also allows for inspection of quality of new parts as well as parts that have been in-service to prevent critical part failures. A specific arrangement of the eddy current sensors also allow for full coverage of an inspection area.
Of course, it is to be understood that not necessarily all such objects or advantages described above may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the systems and techniques described herein may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
Furthermore, the skilled artisan will recognize the interchangeability of various features from different embodiments. For example, the use of a circular flexible tube described with respect to one embodiment can be adapted for use with a soft durometer backing material described with respect to another. Similarly, the various features described, as well as other known equivalents for each feature, can be mixed and matched by one of ordinary skill in this art to construct additional systems and techniques in accordance with principles of this disclosure.
While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4310821 | Frances | Jan 1982 | A |
| 4427940 | Hirama et al. | Jan 1984 | A |
| 4706020 | Viertl et al. | Nov 1987 | A |
| 5006800 | Hedengren et al. | Apr 1991 | A |
| 5182513 | Young et al. | Jan 1993 | A |
| 5237271 | Hedengren | Aug 1993 | A |
| 5262722 | Hedengren et al. | Nov 1993 | A |
| 5278498 | Vernon et al. | Jan 1994 | A |
| 5315234 | Sutton, Jr. et al. | May 1994 | A |
| 5345514 | Mahdavieh et al. | Sep 1994 | A |
| 5371461 | Hedengren | Dec 1994 | A |
| 5371462 | Hedengren et al. | Dec 1994 | A |
| 5389876 | Hedengren et al. | Feb 1995 | A |
| 5418457 | Hedengren et al. | May 1995 | A |
| 5442286 | Sutton, Jr. et al. | Aug 1995 | A |
| 5510709 | Hurley et al. | Apr 1996 | A |
| 5659248 | Hedengren et al. | Aug 1997 | A |
| 5801532 | Patton et al. | Sep 1998 | A |
| 5841277 | Hedengren et al. | Nov 1998 | A |
| 5895439 | Fisher et al. | Apr 1999 | A |
| 5903147 | Granger, Jr. et al. | May 1999 | A |
| 5966011 | Goldfine et al. | Oct 1999 | A |
| 6135627 | Beissner et al. | Oct 2000 | A |
| 6150809 | Tiernan et al. | Nov 2000 | A |
| 6252393 | Hedengren | Jun 2001 | B1 |
| 6452384 | Becker et al. | Sep 2002 | B1 |
| 6504363 | Dogaru et al. | Jan 2003 | B1 |
| 6608478 | Dziech et al. | Aug 2003 | B1 |
| 6693425 | Wache | Feb 2004 | B2 |
| 6707297 | Nath et al. | Mar 2004 | B2 |
| 6720775 | Plotnikov et al. | Apr 2004 | B2 |
| 6727691 | Goldfine et al. | Apr 2004 | B2 |
| 6784662 | Schlicker et al. | Aug 2004 | B2 |
| 6812697 | McKnight et al. | Nov 2004 | B2 |
| 6822443 | Dogaru | Nov 2004 | B1 |
| 6888346 | Wincheski et al. | May 2005 | B2 |
| 6888347 | Batzinger et al. | May 2005 | B2 |
| 6911826 | Plotnikov et al. | Jun 2005 | B2 |
| 6933717 | Dogaru et al. | Aug 2005 | B1 |
| 6992482 | Shay et al. | Jan 2006 | B2 |
| 7015690 | Wang et al. | Mar 2006 | B2 |
| 7049811 | Schlicker et al. | May 2006 | B2 |
| 7095224 | Goldfine et al. | Aug 2006 | B2 |
| 7106055 | Goldfine et al. | Sep 2006 | B2 |
| 7161351 | Goldfine et al. | Jan 2007 | B2 |
| 7188532 | Goldfine et al. | Mar 2007 | B2 |
| 7206706 | Wang et al. | Apr 2007 | B2 |
| 20040232911 | Schlicker et al. | Nov 2004 | A1 |
| 20050140366 | Bar et al. | Jun 2005 | A1 |
| 20060017434 | Tenley et al. | Jan 2006 | A1 |
| 20060023961 | Suh et al. | Feb 2006 | A1 |
| 20060109001 | Suh et al. | May 2006 | A1 |
| 20060170420 | Nishimizu et al. | Aug 2006 | A1 |
| 20060290349 | Na et al. | Dec 2006 | A1 |
| 20090115410 | McKnight et al. | May 2009 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20100127699 A1 | May 2010 | US |
