Measurement method and device for the measurement of a path covered

• US 7,401,506 B2
• Filed: 05/28/2004
• Issued: 07/22/2008
• Est. Priority Date: 06/02/2003
• Status: Expired due to Fees

• Current Assignee: OneSubsea IP UK Limited (SLB)
• Original Assignee: Cameron International Corporation (SLB)
• Inventors: Biester, Klaus, Kunow, Peter
• Primary Examiner(s): Noori; Max
• Application Number:
  US10/558,577
• Publication Number:
  US 20060283242A1
• Time in Patent Office: 1,516 Days
• Field of Search: 731/61
• US Class Current: 73/161
• CPC Class Codes: G01B 5/30 for measuring the deformation in a solid, e.g. mechanical strain gauge
• CPC Class Codes: G01B 7/18 using change in resistance
• CPC Class Codes: G01D 5/16 by varying resistance
• CPC Class Codes: G01D 5/183 Sensing rotation or linear movement using strain, force or pressure sensors
• CPC Class Codes: G01L 1/042 of helical springs
• CPC Class Codes: G01L 1/044 of leaf springs
• CPC Class Codes: G01L 1/046 of spiral springs

Abstract

With a measurement method and a measurement device for the measurement of a path covered by a first object (1) in relation to a second object (2), a measurement body (3) is deformed by a relative movement of the objects and at least a first deformation sensor (4) assigned to the measurement body (3) converts the measurement body (3) deformation into a measurement signal. The measurement signal is converted by an evaluation device (20) into information on the path covered. In order to increase the precision and measurement speed in a way that is simple structurally and saves space, the measurement signal is emitted when an area of the measurement body (3) is stretched along the longitudinal axis (6) of the measurement body (3) and a further area is compressed along the longitudinal axis (6) of the measurement body (3).

Claims

1. A method for measuring a path traveled by a first object relative to a second object, comprising:

deforming a measurement body by moving the first object relative to the second object;

deforming a first deformation sensor and a second deformation sensor in response to the deformation of the measurement body;

emitting a signal from each sensor indicative of the deformation; and

evaluating the signals to determine the path traveled by the first object relative to the second object.

2. The method according to claim 1, wherein the measurement body comprises a helix and the first deformation sensor winds along the helix.

23. The method according to claim 2, wherein the second deformation sensor winds along the helix in a direction opposite that of the first deformation sensor.

24. The method according to claim 23, wherein processing the signals comprises compensating for temperature drift.

25. The method according to claim 23, further comprising:

arranging the first and second deformation sensors and the measurement body in an electrical bridge circuit to measure the deformation of at least one of the sensors; and

wherein emitting the signal from each sensor comprises emitting a signal indicative of the electrical resistance of each sensor.

3. Measurement method for the measurement of a path covered by a first object in relation to a second object, whereby a measurement body is deformed by the relative movement of the objects and at least one first deformation sensor assigned to the measurement body converts the measurement body deformation into a first measurement signal and then an evaluation device converts the first measurement signal at least into information on the path covered, comprising:

the measurement body undergoes a deformation in which it is stretched in an area along a measurement body longitudinal axis and compressed in a further area along the measurement body longitudinal axis, whereby the first deformation sensor is stretched or compressed in one of the areas and a change in a physical property of the first deformation sensor caused by the stretching/compression is emitted as the first measurement signal; and

at least a second deformation sensor arranged essentially spirally around the measurement body longitudinal axis in the opposite direction to the first deformation sensor emits a second measurement signal.

4. Measurement method according to claim 3, wherein the first and second measurement signals are evaluated jointly to compensate for temperature drift and converted into information on the path covered.

5. Measurement method according to claim 3, wherein the first and second deformation sensors and the measurement body are arranged in an electrical bridge circuit to measure the electrical resistance as a physical property.

6. An apparatus for measuring a path traveled by a first object relative to a second object, the apparatus comprising:

a measurement body that is deformable when the first object moves relative to the second object;

a first deformation sensor and a second deformation sensor, each sensor deformable by the deformation of the measurement body and able to emit a measurement signal corresponding to its deformation; and

an evaluation device capable of evaluating the signals to determine the path traveled by the first object relative to the second object.

7. The apparatus according to claim 6, wherein the measurement body comprises a helix and the first deformation sensor winds along the helix.

8. The apparatus according to claim 6, wherein the second deformation sensor winds along the helix in a direction opposite that of the first deformation sensor.

9. The apparatus according to claim 6, wherein each deformation sensor comprises a physical property that changes in response to the deformation of the sensor and wherein the change in the physical property results in a change in the measurement signal.

10. The apparatus according to claim 9, wherein the physical property comprises electrical resistance.

11. The apparatus according to claim 6, wherein the measurement body comprises a spring.

12. The apparatus according to claim 6, wherein the measurement body comprises a spring bar.

13. The apparatus according to claim 6, wherein the deformation sensors comprise conductors arranged on a surface of the measurement body and electrically insulated from the measurement body.

14. The apparatus according to claim 13, wherein each conductor comprises a conductive wire fixed on the surface of the measurement body.

15. The apparatus according to claim 6, wherein each conductive wire is glued on the surface of the measurement body.

26. The apparatus according to claim 6, wherein the first and second deformation sensors are connected at one end with each other and at their other ends to a power source.

27. The apparatus according claim 6, wherein the first and second deformation sensors are connected in a bridge circuit.

28. The apparatus according to claim 27, wherein the measurement body is electrically conductive and is connected in the bridge circuit.

29. The apparatus according to claim 6, wherein the measurement body is electrically insulated from at least one of the first object and the second object.

16. Measurement device for the measurement of a path covered by a first object in relation to a second object with at least one measurement body which can be deformed by the relative movement, to which at least a first deformation sensor is allocated to produce a measurement signal corresponding to the deformation, comprising:

the deformed measurement body is stretched in an area along a measurement body longitudinal axis and is compressed in a further area along its measurement body longitudinal axis, whereby the first deformation sensor is essentially positioned along one of the areas; and

wherein the first and second deformation sensors are connected at one end with each other and at their other ends in each case to a power source.

17. Measurement device for the measurement of a path covered by a first object in relation to a second object with at least one measurement body which can be deformed by the relative movement, to which at least a first deformation sensor is allocated to produce a measurement signal corresponding to the deformation, comprising:

the deformed measurement body is stretched in an area along a measurement body longitudinal axis and is compressed in a further area along its measurement body longitudinal axis, whereby the first deformation sensor is essentially positioned along one of the areas; and

at least the first and second deformation sensors are connected up in a bridge circuit.

18. Measurement device according to claim 17, wherein the measurement body is electrically conductive and is connected up in the bridge circuit.

20. The apparatus according to claim 17, wherein the bridge circuit is connected to the evaluation device.

21. The apparatus according to claim 17, wherein the bridge circuit is assigned a control circuit.

22. The apparatus according to claim 21, wherein the control circuit is formed with corresponding connections as an integrated circuit.

19. Measurement device for the measurement of a path covered by a first object in relation to a second object with at least one measurement body which can be deformed by the relative movement, to which at least a first deformation sensor is allocated to produce a measurement signal corresponding to the deformation, comprising:

the deformed measurement body is stretched in an area along a measurement body longitudinal axis and is compressed in a further area along its measurement body longitudinal axis, whereby the first deformation sensor is essentially positioned along one of the areas; and

the measurement body is electrically insulated in relation to the first and/or second object.