Distributed displacement sensor

• US 6,556,288 B1
• Filed: 12/21/2000
• Issued: 04/29/2003
• Est. Priority Date: 12/21/1999
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Chovan, Joseph L.
• Primary Examiner(s): STAFIRA, MICHAEL PATRICK
• Application Number:
  US09/745,210
• Time in Patent Office: 859 Days
• Field of Search: 356/138, 356/626, 356/614, 250/227.16, 250/227.24, 250/227.28, 250/221, 250/224, 736/55
• US Class Current: 356/138
• CPC Class Codes: G01D 5/268 using optical fibres G01D5/28 - G01D5/38 take precedence

Abstract

A system and method for monitoring deformations in a cavity comprising a method for sensing deformations within a body comprising inserting into the body an optical, deforrmable probe having a plurality of imaging devices spaced at predetermined positions within the probe, providing a light source for illuminating the probe at a first time instant, processing first composite imaging information in response to activation of the light source; at a second time instant, processing second composite imaging information in response to activation of the light source; and comparing the processed first and second imaging information to obtain positional information indicative of movement of at least a portion of the probe occurring between the first and second time instants.

Claims

1. An apparatus for sensing deformations within a body comprising:

a deformable conduit comprising a plurality of imaging devices at predetermined positions within said conduit, said plurality of imaging devices responsive to an optical source for providing imaging data, wherein said plurality of imaging devices includes a plurality of imaging masks and lenses; and

a detector for processing said imaging data to obtain positional information indicative of movement of at least a portion of said conduit from a prior position.

2. The apparatus of claim 1, wherein at least a subset of said imaging devices each includes an imaging mask and lens combination.

3. The apparatus of claim 2, wherein each imaging mask includes a unique mask pattern.

4. The apparatus of claim 2, wherein each said imaging mask and lens combination is spaced apart from one another by about twice its focal length.

5. The apparatus of claim 1, wherein said detector comprises a solid state imager.

6. The apparatus of claim 5, wherein each of said plurality of imaging devices includes an image mask, and wherein said detector further comprises a correlator for correlating said image information from each of said imaging devices to obtain correlation peaks associated with the transverse positions of said image masks.

7. The apparatus of claim 1, further comprising a storage device coupled to said detector for storing the imaging information for later retrieval.

8. The apparatus of claim 2, wherein each imaging mask comprises a substantially random pattern.

9. The apparatus of claim 8, wherein said substantially random pattern comprises two levels of transparency.

10. The apparatus of claim 9, wherein said substantially random pattern comprises about equal proportions of said two levels of transparency.

11. A method for sensing deformations within a body comprising:

inserting into said body an optical, deformable probe having a plurality of imaging devices spaced at predetermined positions within said probe;

providing a light source for illuminating said probe;

at a first time instant, processing first composite imaging information from at least a subset of said plurality of imaging devices in response to activation of said light source;

at a second time instant, processing second composite imaging information from at least a subset of said plurality of imaging devices in response to activation of said light source; and

comparing said processed first and second imaging information to obtain positional information indicative of movement of at least a portion of said probe occurring between said first and second time instants.

12. A method of sensing deformations within a cavity comprising:

inserting into said cavity an optical, deformable probe having a plurality of imaging devices at predetermined positions within said probe;

providing a light source illuminating said probe;

receiving at an output of said probe, imaging information associated with said plurality of imaging devices in response to activation of said light source; and

processing said imaging information using previous image information to obtain positional information indicative of movement of at least a portion of said probe from a prior position.

13. The method of claim 12, wherein the step of processing comprises correlating image data associated with at least of subset of said plurality of imaging devices.

14. The method of claim 12, wherein the step of processing comprises autocorrelating image data associated with each of said plurality of imaging devices to provide autocorrelation peaks, each autocorrelation peak associated with a respective one of said imaging devices.

15. The method of claim 14, wherein the step of processing further comprises determining the positions of each of said image devices based on said associated correlation peaks.

16. The method of claim 14, wherein each image device comprises a mask and lens combination.

17. The method of claim 12, wherein said plurality of image devices comprises a plurality of transparency masks.

18. The method of claim 17, wherein each of said plurality of transparency masks comprises a substantially random pattern.

19. An apparatus for sensing deformations within a body comprising:

a deformable conduit having a longitudinal axis and a plurality of imaging devices positioned within said conduit and longitudinally separated from one another, said plurality of imaging devices responsive to an optical source for providing imaging data; and

a detector for processing said imaging data to obtain positional information indicative of movement of at least a portion of said conduit from a prior position.

20. The apparatus of claim 19, wherein said plurality of imaging devices is responsive to an optical source that is positioned about a first end of the conduit, and wherein the detector is positioned about a second end of the conduit.

21. An apparatus for sensing deformations within a body comprising:

a deformable conduit comprising a plurality of imaging devices at predetermined positions within said conduit, said plurality of imaging devices responsive to an optical source for providing imaging data; and

a detector for processing said imaging data to obtain positional information indicative of movement of at least a portion of said conduit from a prior position, wherein each of said plurality of imaging devices includes an image mask, and wherein said detector further comprises a correlator for correlating image information from each of said imaging devices to obtain correlation peaks associated with the transverse positions of said image masks.

22. An apparatus for sensing deformations within a body comprising:

a deformable conduit;

an optical source positioned at a first end of the conduit;

an optical detector positioned at a second end of the conduit; and

a plurality of imaging devices disposed within the conduit between the source and the detector, said imaging devices being responsive to the optical source for providing imaging data to the detector, and said detector being operative for processing said imaging data to obtain positional information indicative of movement of at least a portion of said conduit from a prior position.