Advertisement

Acoustical Holography Matrix Array Imaging System for the Underwater Inspection of Offshore Oil Platform Weldments

  • H. D. Collins
  • R. P. Gribble
  • T. E. Hall
  • W. M. Lechelt
  • J. T. Luebke
  • J. Spalek
  • E. M. Sheen
  • A. Stankoff
Part of the Acoustical Imaging book series (ACIM, volume 8)

Abstract

This paper describes a diver operated underwater optical-acoustical imaging system for the inspection of internal defects in offshore platform weldments. The two-dimensional acoustic array is electronically programmed with digital techniques to simulate focused and non-focused source-receiver scanning. The electronic simulated reference beam is programmable using erasable programmable read only memories (EPROMS). The imaging device consists of a diver hand held gun containing the acoustic array, miniature television camera and the visible light emitting diode (VLED) display array. The gun is connected via the diver pack and cable to the control unit, digital memory display and data recording units located in the submersible. The television camera provides an optical view of the external weld surface, identification marks, etc., which is integrated with the acoustical image on a standard television monitor. The acoustical array provides complete realtime inspection by electronically scanning and constructing multiple focused holograms through the entire weld volume. The defect images are presented in side, plan and pseudo three-dimensional views with the options of rotation, tilt and zoom magnification. The system has two permanent recording techniques. The focused holographic defect images and optical views are stored on videotape and the basic r-f data on digital tape. This system is now undergoing tests in the North Sea by International Submarine Services.

Keywords

Diver Pack Matrix Array Acoustic Control Digital Tape Shear Wave Image 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Kraus, John D., “Antennas,” Chapter 4, McGraw Hill, New York (1950).Google Scholar
  2. 2.
    Camp, Leon, “Underwater Acoustics,” Chapter 7, Wiley-Interscience (1970).Google Scholar
  3. 3.
    Wintermark, H., “Les Materiaux et le Soudage dans les Constructions,” Offshore Conference in Portevin, 1975.Google Scholar
  4. 4.
    Havlice, J., Kino, G., Koful, J., and Quate, C.; “An Electronically Focused Acoustic Imaging Device,” Acoustical Holography, Volume 5, Plenum Press, New York, New York, (1974).Google Scholar
  5. 5.
    Burkhardt, C., Grandchamp, P., Hoffman, H.; “Methods for In-creasing the Lateral Resolution in B-Scan,” Acoustical Holography, Volune 5, Plenum Press, New York, New York (1974).Google Scholar
  6. 6.
    Collins, H.D., “Acoustical Interferometry Using Electrically Simulated Variable Reference and Multiple Paths,” Acoustical Holography, Volume 6, Plenum Press, New York, New York (1975).Google Scholar
  7. 7.
    Cook, C.E. and Bernfield, M., “Radar Signals,”; An Introduction to Theory and Application, Academic Press, New York (1967).Google Scholar
  8. 8.
    Collins, H.D. and Brenden, B.B.; “Acoustical Holographic Trans-verse Wave Scanning Techniques for Imaging Flaws in Thick- Walled Pressure Vessels,” Acoustical Holography, Volume 5, Plenum Press, New York, New York (1975).Google Scholar
  9. 9.
    Harvey, J.F., “Theory and Design of Modern Pressure Vessels”; Van Nostrand Reinhold, (1974).Google Scholar
  10. 10.
    Timoshenko, S., and Woinowsky-Krieger, S., “Theory of Plates and Shells,” McGraw-Hill, Second Ed., (1959).Google Scholar

Copyright information

© Plenum Press, New York 1980

Authors and Affiliations

  • H. D. Collins
    • 1
  • R. P. Gribble
    • 1
  • T. E. Hall
    • 1
  • W. M. Lechelt
    • 1
  • J. T. Luebke
    • 1
  • J. Spalek
    • 1
  • E. M. Sheen
    • 1
  • A. Stankoff
    • 2
  1. 1.Holosonics, Inc.RichlandUSA
  2. 2.International Submarine ServicesSaudi Arabia

Personalised recommendations