SYSTEM AND METHODS FOR INSPECTING INTERNAL CRACKS

• US 20080278151A1
• Filed: 05/07/2007
• Published: 11/13/2008
• Est. Priority Date: 05/07/2007
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Wang, Changting, Nath, Shridhar Champaknath, Griffin, Weston Blaine, Al-Khalidy, Abdul Rahman Abdallah, Hallman, Darren Lee, Fields, Michael Wayne
• Application Number:
  US11/745,122
• Publication Number:
  US 20080278151A1
• Time in Patent Office: Days
• US Class Current: 324/219
• CPC Class Codes: G01N 27/902 by moving the sensors
• CPC Class Codes: G01N 27/9046 by analysing electrical signals

Abstract

A method for inspecting an internal cavity in a part is provided. The method includes inserting a probe into the internal cavity. The method also includes controlling movement of the probe using a defined scan path to scan the probe over a region of interest in the internal cavity. The method also includes applying multiple multifrequency excitation signals to the probe to generate a number of multifrequency response signals. The multifrequency excitation signals are applied at multiple positions within the internal cavity. The method further includes performing a multifrequency phase analysis on the multifrequency response signals to inspect the internal cavity.

Claims

1. A method for inspecting an internal cavity in a part, the method comprising:

inserting a probe into the internal cavity;

controlling movement of the probe using a defined scan path to scan the probe over a region of interest in the internal cavity;

applying a plurality of multifrequency excitation signals to the probe to generate a plurality of multifrequency response signals, wherein the applying step is performed along the defined scan path within the internal cavity; and

performing a multifrequency phase analysis on the multifrequency response signals to inspect the internal cavity.

2. The method of claim 1, wherein the controlling comprises controlling movement of the probe using a robot.

3. The method of claim 2, further comprising supplying information regarding a position of the probe, and correlating the multifrequency response signals with the information of the position to identify the location of a plurality of inspection data within the internal cavity.

4. The method of claim 1, wherein the probe is an eddy current probe.

5. The method of claim 4, wherein the applying step induces a plurality of eddy currents in the part, and wherein the multifrequency response signals are generated by the eddy currents induced in the part with the eddy current probe.

6. The method of claim 1, further comprising generating the defined scan path using a computer model of the part and a computer model of the probe.

7. The method of claim 5, wherein the defined scan path is generated to satisfy a plurality of constraints comprising:

enabling a constant contact of the probe with a surface of the part;

orienting the probe in a normal direction to the surface of the part;

inspecting an area of interest within the internal cavity of the part; and

avoiding a collision between the probe and the part.

8. The method of claim 7, wherein the constraints further comprise generating a smooth defined scan path.

9. A method for inspecting an internal cavity in a part, the method comprising:

generating a defined scan path to inspect a region of interest within the internal cavity, wherein the generating is performed using a computer model of the part and a computer model of an eddy current probe;

inserting the eddy current probe into the internal cavity;

controlling movement of the probe using the defined scan path to scan the eddy current probe over the region of interest;

applying a plurality of excitation signals to the probe to generate a plurality of response signals, wherein the applying step is performed at a plurality of positions within the internal cavity; and

analyzing the response signals to inspect the internal cavity.

10. The method of claim 9, wherein the controlling comprises controlling movement of the eddy current probe using a robot.

11. The method of claim 9, further comprising supplying information regarding position of the probe, and correlating the response signals with the information of the position to identify the location of a plurality of inspection data within the internal cavity.

12. The method of claim 9, wherein the generating of defined scan path comprises satisfying a plurality of constraints comprising:

enabling a constant contact of the eddy current probe with a surface of the part;

orienting the eddy current probe in a normal direction to the surface of the part;

inspecting an area of interest within the internal cavity of the part; and

avoiding a collision between the probe and the part.

13. The method of claim 12, wherein the constraints further comprise generating a smooth defined scan path.

14. The method of claim 12, wherein the step of satisfying the constraints comprises using at least one of collision detection algorithms, potential field algorithms and virtual elastic algorithms.

15. An inspection system comprising:

an eddy current probe configured to induce eddy currents in a part;

an eddy current instrument coupled to the eddy current probe, wherein the eddy current instrument is configured to apply a plurality of excitation signals to the eddy current probe to generate a plurality of response signals;

a robot coupled to the eddy current probe and configured to insert the eddy current probe into an internal cavity in the part and to scan the eddy current probe over a region of interest within the internal cavity in accordance with a defined scan path; and

a processor configured to analyze the response signals from the eddy current instrument to inspect the region of interest within the internal cavity of the part.

16. The inspection system of claim 15, wherein the eddy current instrument is configured to supply the excitation signals at selective frequencies, and wherein the processor is configured to perform a multifrequency phase analysis on the response signals to inspect the region of interest within the internal cavity of the part.

17. The inspection system of claim 15, wherein the part comprises a blade.

18. The system of claim 15, wherein the defined scan path is configured to satisfy a plurality of constraints comprising:

direct contact of the probe with a surface of the part;

normal orientation of the probe to the surface of the part;

an area of interest inspected is within the internal cavity of the part; and

a collision is avoided between the probe and a remaining portion of the part.