Torque determination system and method

Patent metadata

Field	Value
Publication number	US-10955302-B2
Application number	US-201816159369-A
Country	US
Kind code	B2
Filing date	Oct 12, 2018
Priority date	Oct 12, 2018
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

The system and method determines the torque applied to a rotating shaft by a load. A first sensor detects rotation of a first wheel and a second sensor detects rotation of a second wheel. A third sensor is proximate to the first sensor. A processor determines: 1) a magnitude of a phase angle (φ A ) based on the first and second sensors and having an unknown sign; 2) a magnitude of a phase angle (φ B ) based on the second and third sensors and having an unknown sign; and 3) a magnitude of a phase angle (φ C ) based on the first and third sensors and having a known sign. The processor determines a sign of the phase angle (φ A ) based on the values of the phase angles (φ B ) and (φ C ) and determines a torque value from the load applied to the shaft at least in part based on the magnitude and sign of the phase angle (φ A ).

First claim

What is claimed is:

1. A system for determining torque applied to a rotating shaft by a load, comprising:
a first wheel coupled to the shaft at a first axial position, the first wheel having a periphery with a plurality of first repeating target surfaces;
a second wheel coupled to the shaft at a second axial position axially spaced from the first axial position, the second wheel having a periphery with a plurality of second repeating target surfaces;
a first sensor proximate the periphery of the first wheel configured to detect rotation of the first wheel based on the first repeating target surfaces, corresponding to rotation of the shaft at the first axial position;
a second sensor proximate the periphery of the second wheel configured to detect rotation of the second wheel based on the second repeating target surfaces, corresponding to rotation of the shaft at the second axial position;
a third sensor proximate the periphery of the first wheel configured to detect rotation of the first wheel based on the first repeating target surfaces, wherein the third sensor is located at a fixed known angular displacement from the first sensor;
a processor configured to receive signals from the first sensor, the second sensor and the third sensor to:
determine a first voltage (V 1 ), a second voltage (V 2 ), and a third voltage (V 3 ), corresponding to an output of the first sensor, the second sensor, and the third sensor, respectively;
determine a first voltage difference (V 12 ) associated with the signals from the first sensor and the second sensor;
determine a second voltage difference (V 13 ) associated with the signals from the first sensor and the third sensor;
determine a third voltage difference (V 23 ) associated with the signals from the second sensor and the third sensor;
determine a magnitude of a phase angle (φ A ) of the first wheel with respect to the second wheel based on the first voltage difference (V 12 );
determine a sign of the phase angle (φ A ) based on the second voltage difference (V 13 ) and the third voltage difference (V 23 ); and

determine a torque value from the load applied to the shaft at least in part based on the magnitude and sign of the phase angle (φ A ).

2. The system of claim 1 , wherein the processor is configured to:
determine the magnitude of the phase angle (φ A ) based on the first voltage (V 1 ) and the second voltage (V 2 ), wherein the phase angle (φ A ) has an unknown sign;
determine the magnitude of a phase angle (φ B ) based on the second voltage (V 2 ) and the third voltage (V 3 ), wherein the phase angle (φ B ) has an unknown sign;
determine the magnitude of a phase angle (φ CR ) based on the first voltage (V 1 ) and the third voltage (V 3 ), the phase angle (φ D ) having a known sign;
assign the phase angle (φ A ) as positive or negative to resolve a sum of the phase angle (φ A )+the phase angle (φ B ) equal to the phase angle (φ C );
assign the phase angle delta (φ B ) as positive or negative to resolve the sum of the phase angle (φ A )+the phase angle (φ B ) equal to the phase angle (φ A ); and
determine the torque based on the magnitude of the phase angle (φ A ) and the assigned sign.

3. The system of claim 1 , wherein the processor is further configured to:
determine the magnitude of a phase angle (Q B ) based on the second voltage (V 2 ) and the third voltage (V 3 ); and
determine the magnitude of a phase angle (φ C ) based on the first voltage (V 1 ) and the third voltage (V 3 ).

4. The system of claim 3 , wherein the processor is further configured to compare the phase angle (φ C ) to a sum of the phase angle (φ A )+the phase angle (φ B ) to determine a sign of the phase angle (φ A ).

5. The system of claim 3 , wherein the value of the phase angle (φ C ) is a known quantity based on a physical placement of the first sensor and the third sensor at the first wheel.

6. The system of claim 1 , wherein the first wheel and the second wheel are tone wheels.

7. The system of claim 1 , wherein the first sensor, the second sensor, and the third sensor are electromagnetic pickups.

8. The system of claim 1 , wherein the first repeating target surface and the second repeating target surface are physical teeth.

9. The system of claim 1 , wherein the first repeating target surface and the second repeating target surface are discrete magnetic portions of the peripheries of the first wheel and second wheel.

10. The system of claim 1 , wherein the torque is determined based on one or more calibration values including a sensitivity of the shaft and a no-load offset of the shaft.

11. The system of claim 1 , wherein the phase angle (φ C ) is estimated as a product of a quantity of repeating surfaces of the first repeating target surface and an angle (α) defined between the first sensor and the third sensor.

12. The system of claim 1 , wherein third sensor is located at a non-integer number multiple of repeating target surfaces relative to the first sensor.

13. The system of claim 1 , wherein the number of each of the first repeating target surfaces and second repeating target surfaces ranges from 10 to 150.

14. The system of claim 1 , wherein the first repeating target surfaces are the same as the second repeating target surfaces.

15. The system of claim 1 , wherein the number of repeating target surfaces on the first wheel is equal to the number of repeating target surfaces on the second wheel.

16. A method for determining torque applied to a rotating shaft by a load, the shaft having a first wheel disposed at a first axial position with a plurality of first repeating target surfaces on its periphery, a second wheel located at a second axial position with a plurality of second repeating target surfaces on its periphery, a first sensor proximate the periphery of the first wheel, a second sensor proximate the periphery of the second wheel, and a third sensor proximate the periphery of the first wheel, wherein the third sensor is located at a fixed known angular displacement from the first sensor, the method comprising:
determining a first voltage (V 1 ), a second voltage (V 2 ), and a third voltage (V 3 ), corresponding to an output of the first sensor, the second sensor, and the third sensor, respectively;
determining a first voltage difference (V 12 ) associated with the signals from the first sensor and the second sensor;
determining a second voltage difference (V 13 ) associated with the signals from the first sensor and the third sensor;
determining a third voltage difference (V 23 ) associated with the signals from the second sensor and the third sensor;
determining a magnitude of a phase angle (φ A ) of the first wheel with respect to the second wheel based on the first voltage difference (V 12 );
determining a sign of the phase angle (φ A ) based on the second voltage difference (V 13 ) and the third voltage difference (V 23 ); and
determining a torque value from the load applied to the shaft at least in part based on the magnitude and sign of the phase angle (φ A ).

17. The system of claim 1 , wherein the first wheel and the second wheel are tone wheels.

18. The system of claim 1 , wherein the first sensor, the second sensor, and the third sensor are electromagnetic pickups.

19. The system of claim 1 , wherein the first repeating target surface and the second repeating target surface are physical teeth.

20. A system for determining torque applied to a rotating shaft by a load, comprising:
a first wheel coupled to the shaft at a first axial position

Assignees

• Deere & Co

Inventors

• Appleton Andy B
• White Robert J

Classifications

• G01L3/08

  involving optical means for indicating · CPC title

• F16H59/16 Primary

  Dynamometric measurement of torque · CPC title

• G01L3/109 Primary

  involving measuring phase difference of two signals or pulse trains · CPC title

• B60R16/02

  electric {constitutive elements} · CPC title

• G01L3/101

  involving magnetic or electromagnetic means · CPC title