Ultrasound inspection system of limited access composite structures

Patent metadata

Field	Value
Publication number	US-9188566-B2
Application number	US-201213526698-A
Country	US
Kind code	B2
Filing date	Jun 19, 2012
Priority date	Jun 19, 2012
Publication date	Nov 17, 2015
Grant date	Nov 17, 2015

Abstract

A method for and apparatus for inspecting a location on a test object with a number of obstructions to reaching the location. An elongate optical fiber carrier holding a number of optical fibers is moved to the location on the test object with the number of obstructions to reaching the location. A pattern of light is transmitted from the number of optical fibers onto a surface of the test object at the location. The pattern of the light is configured to cause sound waves in the test object when the pattern of the light encounters the surface of the test object. A response is detected to the sound waves using the number of optical fibers.

First claim

What is claimed is:

1. An apparatus comprising:
a platform;
an interferometer system connected to the platform;
an elongate optical fiber carrier connected to and extending from the interferometer system;
a light source in optical communication with the elongate optical fiber carrier, the light source configured to emit a light;
a movement system connected to the elongate optical fiber carrier, the movement system configured to move the elongate optical fiber carrier into an opening of a test object, to move into a cavity of the test object, and to bypass a number of obstructions while moving the elongate optical fiber carrier to a location that is inside the test object and obstructed from the opening by the number of obstructions while the interferometer system remains outside the opening;
a fiber bundle inside the elongate optical fiber carrier, the fiber bundle comprising a first plurality of optical fibers, the fiber bundle configured to receive and then transmit the light from the light source;
an end effector disposed on an end of the elongate optical fiber carrier, the end opposite the interferometer system, the end effector comprising:
a cylinder lens inside the housing and in optical communication with the first plurality of optical fibers, wherein the cylinder lens is configured to cause the light to have a first Gaussian profile in an “X” direction relative to a plane and a second Gaussian profile in a “Y” direction relative to the plane, and wherein the cylinder lens is configured to cause the first Gaussian profile and the second Gaussian profile to be different;
a first mirror inside the housing and in optical communication with the cylinder lens, the first mirror further disposed such that light emitted from the cylinder lens is transmitted in a pattern of light onto a test object, wherein the pattern of light is configured to cause sound waves in the test object and a response light from the test object;
a second mirror inside the housing and configured to receive the response light; and
a plurality of collimators configured to receive the response light from the second mirror;

a second plurality of optical fibers inside the elongate optical fiber carrier, the second plurality of optical fibers connected to the plurality of collimators, each optical fiber of the second plurality of optical fibers connected to a corresponding collimator of the plurality of collimators; and
wherein the interferometer system is configured to receive the response light and generate data from the response light, the data used to determine whether an inconsistency is present in the test object at the location.

2. The apparatus of claim 1 , wherein the platform comprises a robotic arm.

3. The apparatus of claim 1 , wherein the elongate optical fiber carrier comprises a hand-held tool.

4. The apparatus of claim 1 , wherein the movement system comprises a plurality of joints.

5. The apparatus of claim 1 , wherein the light source comprises a plurality of lasers, the apparatus further comprising:
a delay line and a delay circuit separating the plurality of lasers, the delay line and the delay circuit configured to reduce cross-talk in optical fibers in the optical fiber carrier.

6. The apparatus of claim 1 , further comprising:
a number of optical elements configured to modify transmission of the light.

7. The apparatus of claim 6 , wherein the number of optical elements is selected from the group consisting of: a lens, a mirror, a diffractive optical element, a polarizer, a wave plate, and a periodically poled Lithium niobate crystal.

8. A method of identifying an inconsistency using a platform, an interferometer system connected to the platform, an elongate optical fiber carrier connected to and extending from the interferometer system, a fiber bundle inside the elongate optical fiber carrier, the fiber bundle comprising a first plurality of optical fibers, the fiber bundle configured to receive and then transmit the light from the light source, an end effector disposed on an end of the elongate optical fiber carrier, the end opposite the interferometer system, a light source in optical communication with the elongate optical fiber carrier, the light source configured to emit a light, and a movement system connected to the elongate optical fiber carrier, the method comprising:
moving, using the movement system, the elongate optical fiber carrier into a cavity of a test object through an opening of in the test object;
bypassing a number of obstructions within the cavity while moving the elongate optical fiber carrier to a location that is inside the test object and obstructed from the opening by the number of obstructions while the interferometer system remains outside the opening;
causing, using a cylinder lens inside the housing and in optical communication with the first plurality of optical fibers, the light to have a first Gaussian profile in an “X” direction relative to a plane and a second Gaussian profile in a “Y” direction relative to the plane;
causing, using the cylinder lens, the first Gaussian profile and the second Gaussian profile to be different;
transmitting, using a first mirror inside the housing and in optical communication with the cylinder lens, light emitted from the cylinder lens in a pattern onto a test object, wherein the pattern is configured to cause sound waves in the test object and a response light from the test object;
receiving, at a second mirror inside the housing, the response light;
receiving, at a plurality of collimators, the response light from the second mirror, wherein a second plurality of optical fibers is inside the elongate optical fiber carrier, the second plurality of optical fibers connected to the plurality of collimators, each optical fiber of the second plurality of optical fibers connected to a corresponding collimator of the plurality of collimators;
receiving, at the interferometer system, the response light;
generating data from the response light; and
determining, using the data, whether an inconsistency is present in the test object at the location.

9. The method of claim 8 , wherein the platform comprises a robotic arm.

10. The method of claim 8 , wherein the elongate optical fiber carrier comprises a hand-held tool.

11. The method of claim 8 , wherein the movement system comprises a plurality of joints and the method further comprises:
bending the joints.

12. The method of claim 8 , wherein the light source comprises a plurality of lasers, the method further comprising:
reducing cross-talk in optical fibers in the optical fiber carrier using a delay line and a delay circuit separating the plurality of lasers.

13. The method of claim 8 further comprising:
modifying transmission of the light using a number of optical elements.

14. The method of claim 13 , wherein the number of optical elements is selected from the group consisting of: a lens, a mirror, a diffractive optical element, a polarizer, a wave plate, and a periodically poled Lithium niobate crystal.

Assignees

• Georgeson Gary E
• Bossi Richard H
• Gordon Iii Clarence L
• Kollgaard Jeffrey R
• Motzer William P
• Stewart Alan Frank
• Boeing Co

Inventors

• Georgeson Gary E
• Bossi Richard H
• Gordon Iii Clarence L
• Kollgaard Jeffrey R
• Motzer William P
• Stewart Alan Frank

Classifications

• G01N29/265

  by moving the sensor relative to a stationary material · CPC title

• G01N2291/2694

  Wings or other aircraft parts · CPC title

• G01N2021/1706

  in solids · CPC title

• G01N21/1702

  with opto-acoustic detection, e.g. for gases or analysing solids · CPC title

• G01N2291/0231

  Composite or layered materials · CPC title