METHOD AND APPARATUS FOR SENSING UNDERWATER SIGNALS

• US 20130312522A1
• Filed: 02/07/2012
• Published: 11/28/2013
• Est. Priority Date: 02/07/2011
• Status: Active Grant

• Current Assignee: DIGICOURSE LLC
• Original Assignee: ION Geophysical Corporation
• Inventors: Deng, Ken Kan
• Granted Patent: US 9,294,011 B2
• Time in Patent Office: Days
• US Class Current: 73/514.33
• CPC Class Codes: G01H 11/08 using piezoelectric devices
• CPC Class Codes: G01P 15/09 by piezoelectric pick-up
• CPC Class Codes: G01P 15/0915 of the shear mode type
• CPC Class Codes: G01P 15/123 by piezo-resistive elements, e.g. semiconductor strain gauges
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/0805 being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends
• CPC Class Codes: G01V 1/18 Receiving elements, e.g. seismometer, geophone or torque detectors, for localised single point measurements
• CPC Class Codes: G01V 1/38 specially adapted for water-covered areas G01V1/28 takes precedence
• CPC Class Codes: G01V 13/00 Manufacturing, calibrating, cleaning, or repairing instruments or devices covered by groups G01V1/00 – G01V11/00
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence
• CPC Class Codes: Y10T 29/49005 Acoustic transducer

Abstract

Methods and apparatuses are disclosed that assist in sensing underwater signals in connection with geophysical surveys. One embodiment relates to a transducer including a cantilever coupled to a base. The cantilever may include a beam and a first coupling surface angularly oriented from the beam, and the base may include a second coupling surface angularly oriented from the beam and substantially parallel to the first coupling surface of the cantilever. The transducer may further include a sensing material coupled between the first coupling surface of the cantilever and the second coupling surface of the base.

Claims

1. A transducer, comprising:

a cantilever coupled to a base, the cantilever comprising a beam and a first coupling surface angularly oriented from the beam and defined by a forward end of the cantilever, and the base comprising a second coupling surface angularly oriented from the beam and substantially parallel to the first coupling surface of the cantilever; and

a sensing material coupled between the first coupling surface of the cantilever and the second coupling surface of the base;

wherein one or both of the first and second coupling surfaces defines an acute or obtuse angle with respect to a longitudinal axis of the beam.

4. The transducer of claim 1, wherein the sensing material comprises first and second surfaces and the sensing material is configured to operate in a shear mode.

5. The transducer of claim 4, wherein the first surface of the sensing material is in contact with the first coupling surface of the cantilever and the second surface of the sensing material is in contact with the second coupling surface of the base.

6. The transducer of claim 1, wherein the sensing material has a rectangular cross-section.

7. The transducer of claim 1, further comprising a tine that couples the cantilever to the base.

8. The transducer of claim 7, wherein the tine is configured to reduce the cross-axis sensitivity of the transducer and further is configured to enhance shear stress applied to the sensing material.

9. The transducer of claim 7, wherein the cantilever comprises the tine and the tine extends into a void in the base.

10. The transducer of claim 7, wherein the base comprises the tine and the tine extends into a void in the cantilever.

11. The transducer of claim 1, further comprising a proof mass.

14. The transducer of claim 1, wherein the sensing material comprises a piezoelectric or piezoresistive element.

16. The transducer of claim 1, wherein the cantilever, the base, and the sensing material together form a first accelerometer, further comprising a second accelerometer and a third accelerometer, the first, second, and third accelerometers mounted in a housing and together forming a vector sensor.

2. (canceled)

3. (canceled)

12. (canceled)

13. (canceled)

15. (canceled)

17. A transducer, comprising:

a cantilever coupled to a base, the cantilever comprising a beam; and

a sensing material embedded within the beam of the cantilever,

wherein the sensing material comprises first and second surfaces that are angularly oriented from the beam.

18. The transducer of claim 17, wherein the sensing material comprises it first piezoelectric element and further comprising a second piezoelectric element embedded within the beam, the second piezoelectric element comprising third and fourth surfaces angularly oriented from the beam, and the transducer also comprises third and fourth piezoelectric elements embedded within the beam, the third piezoelectric elements oriented parallel to the first piezoelectric element and the fourth piezoelectric element oriented parallel to the second piezoelectric element.

20. The transducer of claim 17, wherein the sensing material comprises a piezoelectric shear mode element, and the sensing material has a parallelogram cross-section.

22. The transducer of claim 17, wherein the cantilever is coupled to the base at a first end of the cantilever and further comprising a proof mass coupled to a second end of the cantilever.

23. The transducer of claim 17, wherein the cantilever is coupled to the base at a first end of the cantilever and the sensing material is embedded in the cantilever near the first end of the cantilever.

24. The transducer of claim 17, wherein the beam comprises a groove having a first inner wall, a second inner wall, and a third inner wall, the third inner wall substantially parallel to the first inner wall, and the sensing material embedded within the groove, further wherein the sensing material is bonded to the first and third inner walls, but not the second inner wall.

19. (canceled)

21. (canceled)

25. (canceled)

26. A method comprising the acts of:

acquiring data from a transducer coupled to a body, the transducer comprising;

a cantilever coupled to a base and comprising a beam defining at least one coupling surface that is acutely or obtusely angularly oriented with respect to a longitudinal axis of the beam; and

at lease one sensing element coupled to the at least one coupling surface, wherein the sensing element is subjected to shear stress as the beam is deflected relative to the base.

27. (canceled)

28. A method comprising the acts of:

acquiring data from a transducer coupled to a body, the transducer comprising;

a cantilever coupled to a base and comprising a beam defining at least one coupling surface; and

at least one sensing element coupled to the at least one coupling surface, wherein the sensing element is a shear mode piezoelectric element.

29. The method of claim 28, further comprising the act of processing the data from the transducer to determine acoustic acceleration of the body in at least one directional component.