Systems and methods for compensating for air gap sensitivity in torque sensors

Patent metadata

Field	Value
Publication number	US-10184846-B2
Application number	US-201615253522-A
Country	US
Kind code	B2
Filing date	Aug 31, 2016
Priority date	Aug 31, 2016
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A system may include a first sensor and a second sensor. The first sensor may include a driving pole that includes a driving coil that receives a driving current and emits a magnetic flux portion through a structure. The first sensor may also include a sensing pole that may include a sensing coil that receives the magnetic flux portion and generate a first signal based at least in part on the received magnetic flux portion. The first signal is based at least in part on a force on the structure. The second sensor may be disposed on the driving pole and may generate a second signal representative of a distance between the driving pole and the structure. The system may also include a circuit that may adjust the first signal based on the second signal.

First claim

The invention claimed is:

1. A system, comprising:
a first sensor comprising:
a driving pole comprising a driving coil configured to receive a driving current and to emit a magnetic flux portion through a structure;
a sensing pole comprising a sensing coil configured to receive the magnetic flux portion that exits the structure and to generate a first signal based at least in part on a change in the received magnetic flux portion relative to the emitted magnetic flux portion, wherein the first signal is indicative of a force on the structure;

a second sensor including a proximity coil disposed on the driving pole at a position closer to an end of the driving pole than the driving coil, wherein the second sensor is configured to measure a magnetic flux induced in the driving pole by the emitted magnetic flux portion, and to generate a second signal representative of a distance between the driving pole and the structure; and
a circuit configured to adjust the first signal based on the second signal.

2. The system of claim 1 , wherein the proximity coil is positioned at an end of the driving pole.

3. The system of claim 1 wherein the circuit is configured to compensate for one or more effects of the distance applied to the first signal based on the second signal.

4. The system of claim 1 , wherein the circuit is configured to apply a linear offset to the second signal, thereby generating a third signal.

5. The system of claim 4 , wherein the circuit is configured to combine the first signal and the third signal to compensate for effects of distance between the driving pole and the structure.

6. The system of claim 1 , wherein the first sensor comprises a magnetostrictive sensor.

7. A method, comprising:
emitting, by a driving coil mounted to a magnetically permeable driving pole, a magnetic flux portion through an object in response to receipt of a driving current;
generating, by a proximity sensor, a first signal indicative of a distance between the magnetically permeable driving pole and the object, wherein the proximity sensor includes a proximity coil, different from the driving coil, mounted to the magnetically permeable pole, and wherein the first signal is based at least in part a magnetic flux induced in the driving pole by the emitted magnetic flux portion;
generating, by a sensing coil, a second signal indicative of a force present on the object, wherein the sensing coil is mounted to a sensing pole, and wherein the second signal is based at least in part on a change in a magnetic flux portion received at the sensing coil relative to the emitted magnetic flux portion; and
adjusting, via a processor, the second signal based on the first signal.

8. The method of claim 7 , wherein adjusting the second signal comprises compensating for one or more effects of the distance applied to the first signal.

9. The method of claim 7 , comprising applying a linear offset to the first signal prior to adjusting the second signal.

10. The method of claim 7 , comprising applying a correction factor to the adjusted second signal.

11. The method of claim 7 , comprising:
generating, by a plurality of sensing coils mounted to respective sensing poles, a plurality of signals indicative of the force present on the object,
combining, via a circuit, the plurality of signals generated by the plurality of sensing coils, to generate the first signal.

12. A sensor, comprising:
a driving coil configured to emit a magnetic flux portion through a structure;
at least one sensing coil configured to receive the magnetic flux portion that exits the structure and to generate a first signal based at least in part on the received magnetic flux portion, wherein the first signal is based at least in part on a force on the structure;
a proximity sensor including a proximity coil configured to generate a second signal representative of a distance between a magnetically permeable pole, configured to couple to the proximity sensor, and the structure; and
a circuit configured to compensate for effects due to the distance present on the first signal based on the second signal;
wherein the driving coil and the proximity coil are different from one another and each is disposed on the magnetically permeable pole.

13. The sensor of claim 12 , wherein the magnetically permeable pole comprises a ferrite core.

14. The sensor of claim 12 , wherein the proximity coil is positioned at an end of the magnetically permeable pole.

15. The sensor of claim 12 , wherein the at least one sensing coil comprises four sensing coils, each configured to generate a respective first signal.

16. The sensor of claim 15 , wherein the circuit is configured to combine the four first signals generated by the four sensing coils to generate a combined first signal.

17. The sensor of claim 12 , wherein the circuit is configured to apply a linear offset to the second signal.

18. The sensor of claim 12 , wherein the circuit is configured to compensate for effects due to the distance present on the first signal based on the second signal by applying a correction factor to the first signal.

Assignees

• Gen Electric

Inventors

• Lu Dan Tho
• Turnbeaugh Lysle R
• Folkner David Erik

Classifications

• G01L1/127

  by using inductive means (G01L1/122, G01L1/125 take precedence) · CPC title

• G01L3/105

  involving inductive means (G01L3/102, G01L3/104 take precedence) · CPC title

• G01D5/2046

  by a movable ferromagnetic element, e.g. a core · CPC title

• G01B7/14

  for measuring distance or clearance between spaced objects or spaced apertures (G01B7/30 takes precedence) · CPC title

• G01L1/125

  by using magnetostrictive means (magnetostrictive sensors H10N35/101) · CPC title