Phase magnitude signal detector

• US 5,902,934 A
• Filed: 08/01/1995
• Issued: 05/11/1999
• Est. Priority Date: 12/10/1990
• Status: Expired due to Fees

• Current Assignee: Sensortech LP
• Original Assignee: Sensortech LP
• Inventors: Sprague, Fred P., Vigmostad, Erik B., Klauber, Robert D.
• Primary Examiner(s): Dombroske, George M.
• Application Number:
  US08/509,733
• Time in Patent Office: 1,379 Days
• Field of Search: 73/116, 73/117.2, 73/117.3, 73/DIG. 2, 73/862.333, 73/862.334, 73/862.335, 73/862.336, 73/763, 73/779, 73/805, 73/814
• US Class Current: 73/779
• CPC Class Codes: B60G 17/019 characterised by the type of sensor or the arrangement thereof B60G17/01941 takes precedence
• CPC Class Codes: B60G 2204/11 Mounting of sensors thereon
• CPC Class Codes: B60G 2400/30 Propulsion unit conditions
• CPC Class Codes: B60G 2400/60 Load
• CPC Class Codes: B60G 2400/91 Frequency
• CPC Class Codes: B60G 2401/172 Hall effect
• CPC Class Codes: B60G 2600/602 high pass
• CPC Class Codes: B60G 2600/604 low pass
• CPC Class Codes: B60G 2800/802 Diagnostics
• CPC Class Codes: G01L 3/102 involving magnetostrictive means magnetostrictive sensors H10N35/101
• CPC Class Codes: G01L 3/105 involving inductive means G01L3/102, G01L3/104 take precedence
• CPC Class Codes: G01M 15/11 by detecting misfire
• CPC Class Codes: Y10S 73/02 Magnetostrictive

Abstract

A magnetostrictive stress and torque sensor using the component of the output signal in-phase with the drive voltage to monitor stress or torque. In some embodiments, it may use the quadrature or out-of-phase component, or some combination of the in-phase and out-of-phase components. Such phase component monitoring has several advantages over magnitude detection, including a response which is a more linear function of torque, and which is not subject to overmodulation problems.

Claims

1. A magnetostrictive stress sensing system comprising

means for generating an input signal,

a one of a solenoidal, single core, and cross design magnetostrictive sensor, said magnetostrictive sensor including an excitation means wherein said excitation means generates an alternating magnetic flux in a stress carrying element and wherein said alternating magnetic flux is dependent on the input signal, said one magnetostrictive sensor further including

a detection means for detecting changes in magnetic flux resulting from load induced stress variation in the stress carrying element, said detection means producing

an output signal dependent on the changes in magnetic flux detected by the detection means, and

a phase related means for detecting a phase related component of the output signal relative to the input signal so as to detect variations in stress in the stress carrying element.

2. The magnetostrictive stress sensing system of claim 1 wherein the phase related component is an in-phase component in phase with the input signal.

3. The magnetostrictive stress sensing system of claim 2 wherein the output signal is a voltage.

4. The magnetostrictive stress sensing system of claim 2 wherein the output signal is a current.

5. The magnetostrictive stress sensing system of claim 2 wherein the phase related means is a quadrant multiplier.

6. The magnetostrictive stress sensing system of claim 2 wherein the load induced stress variation is a force induced stress variation and the stress carrying member is a force carrying member.

7. The magnetostrictive stress sensing system of claim 2 wherein the load induced stress variation is a torque induced stress variation and the stress carrying member is a torque carrying member.

8. The magnetostrictive stress sensing system of claim 1 wherein the phase related component is a quadrature component ninety degrees out of phase with the input signal.

9. The magnetostrictive stress sensing system of claim 8 wherein the output signal is a voltage.

10. The magnetostrictive stress sensing system of claim 8 wherein the output signal is a current.

11. The magnetostrictive stress sensing system of claim 8 wherein the phase related means is a quadrant multiplier.

12. The magnetostrictive stress sensing system of claim 8 wherein the load induced stress variation is a force induced stress variation and the stress carrying member is a force carrying member.

13. The magnetostrictive stress sensing system of claim 8 wherein the load induced stress variation is a torque induced stress variation and the stress carrying member is a torque carrying member.

14. The magnetostrictive stress sensing system of claim 1 wherein the phase related means detects both an in-phase component in phase with the input signal and a quadrature component ninety degrees out of phase with the input signal.

15. The magnetostrictive stress sensing system of claim 1 wherein the phase related means detects both an in-phase component in phase with the input signal and a quadrature component ninety degrees out of phase with the input signal, and both the in-phase component and the quadrature component are used to detect variations in stress.

16. The magnetostrictive stress sensing system of claim 1 wherein the phase related component is a combination of an in-phase component in phase with the input signal and a quadrature component ninety degrees out of phase with the input signal.

17. The magnetostrictive stress sensing system of claim 1 wherein the phase related component has a non-zero phase angle relative to the input signal.

18. The magnetostrictive stress sensing system of claim 1 wherein the phase related means detects phase and magnitude of a change in the output signal as stress varies.

19. The magnetostrictive stress sensing system of claim 18 wherein the magnitude of the change in the output signal is used to detect variations in stress.

20. The magnetostrictive stress sensing system of claim 18 wherein the phase of the change in the output signal is used to detect variations in stress.

21. The magnetostrictive stress sensing system of claim 1 wherein the phase related means detects phase of the change in the output signal as stress varies and said phase is used to detect stress variations.

22. The magnetostrictive stress sensing system of claim 1 wherein the phase related means detects magnitude of the change in the output signal as stress varies and said magnitude of the change is used to detect stress variations.

23. The magnetostrictive stress-sensing system of claim 1 wherein the detection means comprises a coil.

24. The magnetostrictive stress sensing system of claim 1 wherein the detection means comprises a Hall effect sensor.

25. The magnetostrictive stress sensing system of claim 15 wherein the load induced stress variation is a force induced stress variation and the stress carrying member is a force carrying member.

26. The magnetostrictive stress sensing system of claim 15 wherein the load induced stress variation is a torque induced stress variation and the stress carrying member is a torque carrying member.

27. The magnetostrictive stress sensing system of claim 16 wherein the load induced stress variation is a force induced stress variation and the stress carrying member is a force carrying member.

28. The magnetostrictive stress sensing system of claim 16 wherein the load induced stress variation is a torque induced stress variation and the stress carrying member is a torque carrying member.

29. A magnetostrictive stress sensor comprising:

a drive coil for generating an excitation field in response to an alternating electrical stimulus, said alternating electrical stimulus having a drive phase component;

a pick-up coil for generating an alternating electrical output signal in response to said excitation field, said alternating electrical output signal having a first excitation phase component that is substantially in phase with said drive phase component and having a second excitation phase component that is out of phase with said drive phase component; and

quadrant multiplier means connected to said drive coil and to said pick-up coil for detecting said first excitation phase component and for generating an electrical signal in response to said first excitation phase component.

30. A magnetostrictive stress sensor as set forth in claim 29 and further comprising a ferromagnetic torque transmitting element mounted for rotation adjacent said drive coil and said pick-up coil such that said output signal is indicative of stress variations in said torque transmitting element.

31. A magnetostrictive stress sensor as set forth in claim 29 wherein said alternating electrical output signal is a voltage.

32. A magnetostrictive stress sensor as set forth in claim 29 wherein said alternating electrical output signal is a current.

33. A magnetostrictive stress sensor as set forth in claim 29 wherein said second excitation phase component is a quadrature component 90°

out of phase with said alternating electrical stimulus.

34. A magnetostrictive stress sensing system comprising:

a ferromagnetic stress carrying element;

a one of a solenoidal, single core, and cross design magnetostrictive sensor, said one magnetostrictive adjacent said stress carrying element;

driver means for generating an input signal to an excitation means wherein said excitation means generates an alternating magnetic flux in said stress carrying element and wherein said alternating magnetic flux is dependent on said input signal;

detection means for detecting changes in magnetic flux resulting from load induced stress variations in said stress carrying element and for generating an output signal dependent on changes in magnetic flux detected by said detection means; and

phase related means for detecting a phase related component of said output signal relative to said input signal so as to detect variations in stress in said stress carrying element.

35. A magnetostrictive stress sensing system comprising:

means for generating an input signal to an excitation means wherein said excitation means generates an alternating magnetic flux in a stress carrying element and wherein said alternating magnetic flux is dependent on the input signal;

a detection means which detects changes in magnetic flux resulting from load induced stress variation in the stress carrying element;

an output signal produced by the detection means wherein said output signal is dependent on the changes in magnetic flux detected by the detection means;

a quadrant multiplier for detecting an in-phase component of said output signal in phase with said input signal, wherein said in-phase component is used to detect variations in stress in the stress carrying element.

36. A magnetostrictive stress sensing system comprising:

means for generating an input signal to an excitation means wherein said excitation means generates an alternating magnetic flux in a stress carrying element and wherein said alternating magnetic flux is dependent on the input signal;

a detection means which detects changes in magnetic flux resulting from load induced stress variation in the stress carrying element;

an output signal produced by the detection means wherein said output signal is dependent on the changes in magnetic flux detected by the detection means;

a quadrant multiplier for detecting a quadrature component of the output signal ninety degrees out of phase with the input signal, wherein said quadrature component is used to detect variations in stress in the stress carrying element.

37. A magnetostrictive stress sensing system comprising:

means for generating an input signal to an excitation means wherein said excitation means generates an alternating magnetic flux in a stress carrying element and wherein said alternating magnetic flux is dependent on the input signal;

a Hall effect sensor which detects changes in magnetic flux resulting from load induced stress variation in the stress carrying element;

an output signal produced by the detection means wherein said output signal is dependent on the changes in magnetic flux detected by the detection means;

a phase related means for detecting a phase related element of the output signal relative to the input signal, wherein said phase related element is used to detect variations in stress in the stress carrying element.

38. A magnetostrictive stress sensor comprising:

a drive coil for generating an excitation field in response to an alternating electrical stimulus, said alternating electrical stimulus having a drive phase characteristic;

a pick-up coil for generating an alternating electrical output signal in response to said excitation field, said alternating electrical output signal having a first excitation phase characteristic that is substantially in phase with said drive phase characteristic and having a second excitation phase characteristic that is out of phase with said drive phase characteristic and is a quadrature component 90°

out of phase with said alternating electrical stimulus; and

quadrant multiplier means connected to said drive coil and to said pick-up coil for detecting said first excitation phase characteristic and for generating an electrical signal in response to said first excitation phase characteristic.