Method and system for motor velocity measurement

• US 6,791,217 B2
• Filed: 04/04/2002
• Issued: 09/14/2004
• Est. Priority Date: 09/16/1999
• Status: Expired due to Term

• Current Assignee: GM Global Technology Operations Incorporated (General Motors Company), Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Collier-Hallman, Steven James, Bressette, William J
• Primary Examiner(s): Mullins, Burton
• Application Number:
  US10/116,284
• Publication Number:
  US 20020149340A1
• Time in Patent Office: 894 Days
• Field of Search: 701/41, 701/42, 324/160-161, 324/163-164, 702/145-147, 310/68.B
• US Class Current: 310/68.00B
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01D 5/2033 controlling the saturation of a magnetic circuit by means of a movable element, e.g. a magnet
• CPC Class Codes: G01D 5/24461 by redundancy or plausibility
• CPC Class Codes: G01D 5/2448 Correction of gain, threshold, offset or phase control
• CPC Class Codes: G01D 5/24495 using previous values
• CPC Class Codes: G01P 3/487 delivered by rotating magnets
• CPC Class Codes: Y10S 310/06 Printed-circuit motors and components

Abstract

A method and system for determining the velocity of a rotating device is described herein. The system includes an apparatus with a set of sense magnets affixed to a rotating shaft of the rotating device and a circuit assembly. The circuit assembly includes a circuit interconnection having a plurality of sense coils and sensors affixed thereto. The circuit assembly is adapted be in proximity to the set of sense magnets on the rotating part. A controller is coupled to the circuit assembly, where the controller executes an adaptive algorithm that determines the velocity of the rotating device. The algorithm is a method of combining a derived velocity with a velocity from the tachometer. The algorithm includes a plurality of functions including: receiving a position signal related to the rotational position of the shaft; determining a derived velocity from the position signal; generating a plurality of tachometer velocity signals; determining a compensated velocity in response to the plurality tachometer velocity signals; and blending the compensated velocity with derived velocity to generate a blended velocity output.

Claims

1. A system for determining a velocity of a rotating device, comprising:

an apparatus having a rotational part including a set of sense magnets affixed to a rotating shaft of said rotating device configured to rotate about a rotation axis;

a circuit assembly, including a circuit interconnection having a plurality of sense coils, a sensor affixed to said circuit assembly, said circuit assembly adapted to be in proximity to said set of sense magnets;

wherein said set of sense magnets combines with said circuit assembly to form an air core electric machine such that voltages generated from each sense coil of said plurality of sense coils exhibits an amplitude proportional to said velocity;

a controller coupled to said circuit assembly, said controller adapted to execute an adaptive algorithm including;

receiving a position signal related to rotational position transmitted to said controller;

determining a derived velocity signal utilizing said position signal;

receiving a plurality of tachometer velocity signals;

determining a compensated velocity signal in response to said plurality of measured tachometer velocity signals;

blending said plurality of compensated velocity signals with said derived velocity signal under selective conditions to generate a blended velocity output indicative of said velocity of said rotating device.

2. The system of claim 1 wherein said derived velocity signal is determined as a difference between two measured positions of said rotating shaft divided by a time difference between said measured positions;

and filtering a resultant of said calculation.

3. The system of claim 1 wherein said plurality of tachometer velocity signals are the resultant outputs of said plurality of sense coils configured such that voltages generated thereby are in quadrature.

4. The system of claim 1 wherein said voltages generated from each sense coil of said plurality of sense coils exhibit a trapezoidal waveform with an amplitude proportional to said velocity.

5. The system of claim 1 wherein said blended velocity output is generated by combining said derived velocity signal and said compensated velocity signal under selective conditions based upon characteristics of said derived velocity signal and said plurality of tachometer velocity signals.

6. The system of claim 1 wherein:

determining said compensated velocity includes;

extracting respective offsets and biases from said plurality of tachometer velocity signals;

scaling said plurality of tachometer velocity signals to produce a plurality of scaled velocity signals;

selecting one scaled velocity signal of said plurality of scaled velocity signals as said compensated velocity signal; and

wherein said scaling is responsive to calculated velocity errors.

7. The system of claim 6 wherein said extracting is accomplished by a selectable filter.

8. The system of claim 7 wherein said selectable filter conditionally subtracts low frequency spectral components from said plurality of tachometer velocity signals.

9. The system of claim 6 wherein said scaling is applied by a scale factor multiplication, where said scale factor is derived from an error determination process.

10. The system of claim 6 wherein said selecting includes selecting one tachometer velocity signals of said plurality of tachometer velocity signals based on magnitude.

11. The system of claim 6 wherein said calculated velocity error is responsive to a magnitude differential between said derived velocity signal and a time coherent version of said compensated velocity signal.

12. A method for determining a velocity of a rotating device, comprising:

generating a plurality of tachometer velocity signals and a position signal with an apparatus comprising;

a rotational part including a set of sense magnets affixed to a rotating shaft of said rotating device configured to rotate about a rotation axis;

a circuit assembly, including a circuit interconnection having a plurality of sense coils, a sensor affixed to said circuit assembly, said circuit assembly adapted to be in proximity to said set of sense magnets; and

wherein said set of sense magnets combines with said circuit assembly to form an air core electric machine such that voltages generated from each sense coil of said plurality of sense coils exhibits an amplitude proportional to said velocity;

executing an adaptive algorithm with a controller coupled to said circuit assembly, said controller;

receiving said position signal related to rotational position, and determining a derived velocity signal utilizing said position signal;

receiving said plurality of tachometer velocity signals;

determining a compensated velocity signal in response to said plurality of tachometer velocity signals; and

blending said plurality of compensated velocity signals with said derived velocity signal under selective conditions to generate a blended velocity output indicative of said velocity of said rotating device.

13. The method of claim 12 wherein said derived velocity signal is determined as a difference between two measured positions of said rotating shaft divided by a time difference between said measured positions;

and filtering a resultant of said calculation.

14. The method of claim 12 wherein said plurality of tachometer velocity signals are the resultant outputs of said plurality of sense coils configured such that the voltages generated thereby are in quadrature.

15. The method of claim 12 wherein said voltages generated from each sense coil of said plurality of sense coils exhibit a trapezoidal waveform with an amplitude proportional to said velocity.

16. The method of claim 12 wherein said blended velocity output is generated by combining said derived velocity signal and said compensated velocity signal under selective conditions based upon characteristics of said derived velocity signal and said plurality of tachometer velocity signals.

17. The method of claim 12 wherein:

determining said compensated velocity includes;

extracting respective offsets and biases from said plurality of tachometer velocity signals;

scaling said plurality of tachometer velocity signals to produce a plurality of scaled velocity signals;

selecting one scaled velocity signal of said plurality of scaled velocity signals as said compensated velocity signal; and

wherein said scaling is responsive to calculated velocity errors.

18. The method of claim 17 wherein said extracting is accomplished by a selectable filter.

19. The method of claim 18 wherein said selectable filter conditionally subtracts low frequency spectral components from said plurality of tachometer velocity signals.

20. The method of claim 17 wherein said scaling is applied by a scale factor multiplication, where said scale factor is derived from an error determination process.

21. The method of claim 17 wherein said selecting includes selecting one tachometer velocity signals of said plurality of tachometer velocity signals based on magnitude.

22. The method of claim 17 wherein said calculated velocity error is responsive to a magnitude differential between said derived velocity signal and a time coherent version of said compensated velocity signal.

23. A storage medium encoded with a machine-readable computer program code;

wherein said code includes instructions for causing a controller to implement a method for determining a velocity of a rotating device comprising;

generating a plurality of tachometer velocity signals and a position signal with an apparatus comprising;

a rotational part including a set of sense magnets affixed to a rotating shaft of said rotating device configured to rotate about a rotation axis;

a circuit assembly, including a circuit interconnection having a plurality of sense coils, a sensor affixed to said circuit assembly, said circuit assembly adapted to be in proximity to said set of sense magnets;

wherein said set of sense magnets combines with said circuit assembly to form an air core electric machine such that voltages generated from each sense coil of said plurality of sense coils exhibits an amplitude proportional to said velocity;

executing an adaptive algorithm with a controller coupled to said circuit assembly, said controller;

receiving said position signal related to rotational position, and determining a derived velocity signal utilizing said position signal;

receiving said plurality of tachometer velocity signals;

determining a compensated velocity signal in response to said plurality of tachometer velocity signals; and

blending said plurality of compensated velocity signals with said derived velocity signal under selective conditions to generate a blended velocity output indicative of said velocity of said rotating device.

24. A storage medium of claim 23 wherein said blended velocity output is generated by combining said derived velocity signal and said compensated velocity signal under selective conditions based upon characteristics of said derived velocity signal and said plurality of tachometer velocity signals.

25. A storage medium of claim 23 wherein:

determining said compensated velocity includes;

extracting respective offsets and biases from said plurality of tachometer velocity signals;

scaling said plurality of tachometer velocity signals to produce a plurality of scaled velocity signals;

selecting one scaled velocity signal of said plurality of scaled velocity signals as said compensated velocity signal; and

wherein said scaling is responsive to calculated velocity errors.

26. A computer data signal embodied in a carrier wave;

wherein said data signal comprises code configured to cause a controller to implement a method for determining a velocity of a rotating device, comprises;

generating a plurality of tachometer velocity signals and a position signal with an apparatus comprising;

a rotational part including a set of sense magnets affixed to a rotating shaft of said rotating device configured to rotate about a rotation axis;

a circuit assembly, including a circuit interconnection having a plurality of sense coils, a sensor affixed to said circuit assembly, said circuit assembly adapted to be in proximity to said set of sense magnets;

wherein said set of sense magnets combines with said circuit assembly to form an air core electric machine such that voltages generated from each sense coil of said plurality of sense coils exhibits an amplitude proportional to said velocity;

executing an adaptive algorithm with a controller coupled to said circuit assembly, said controller;

receiving said position signal related to rotational position, and determining a derived velocity signal utilizing said position signal;

receiving said plurality of tachometer velocity signals;

determining a compensated velocity signal in response to said plurality of tachometer velocity signals; and

blending said plurality of compensated velocity signals with said derived velocity signal under selective conditions to generate a blended velocity output indicative of said velocity of said rotating device.

27. A computer data signal of claim 26 wherein said blended velocity output is generated by combining said derived velocity signal and said compensated velocity signal under selective conditions based upon characteristics of said derived velocity signal and said plurality of tachometer velocity signals.

28. A computer data signal of claim 26 wherein:

determining said compensated velocity includes;

extracting respective offsets and biases from said plurality of tachometer velocity signals;

scaling said plurality of tachometer velocity signals to produce a plurality of scaled velocity signals;

selecting one scaled velocity signal of said plurality of scaled velocity signals as said compensated velocity signal; and

wherein said scaling is responsive to calculated velocity errors.

29. A system for determining a velocity of a rotating device comprising:

an apparatus in operable communication with said rotating device for generating a plurality of tachometer velocity signals and a position signal;

a controller coupled to said apparatus, said controller adapted to execute an adaptive algorithm including;

receiving said position signal related to rotational position;

determining a derived velocity signal utilizing said position signal;

receiving a plurality of tachometer velocity signals; and

determining a compensated velocity signal in response to said plurality of measured tachometer velocity signals.

30. The system of claim 29 wherein an apparatus comprises a rotational part including a set of sense magnets affixed to a rotating shaft of said rotating device configured to rotate about a rotation axis.

31. The system of claim 30 wherein said apparatus comprises a circuit assembly, including a circuit interconnection having a plurality of sense coils, a sensor affixed to said circuit assembly, said circuit assembly adapted to be in proximity to said set of sense magnets.

32. The system of claim 31 wherein said set of sense magnets combines with said circuit assembly to form an air electric machine such that voltages generated from each sense coil of said plurality of sense coils exhibits an amplitude proportional to said velocity.

33. The system of claim 32 wherein said plurality of tachometer velocity signals are the resultant outputs of said plurality of sense coils configured such that voltages generated thereby are in quadrature.

34. The system of claim 31 wherein voltages generated from each sense coil of said plurality of sense coils exhibit a trapezoidal waveform with an amplitude proportional to said velocity.

35. The system of claim 29 wherein said derived velocity signal is determined as a difference between two measured positions of said rotating shaft divided by a time difference between said measured positions;

and filtering a resultant of said calculation.

36. The system of claim 29 further including:

said controller blending said plurality of compensated velocity signals with said derived velocity signal under selective conditions to generate a blended velocity output indicative of said velocity of said rotating device.

37. The system of claim 36 wherein said blended velocity output is generated by combining said derived velocity signal and said compensated velocity signal under selective conditions based upon characteristics of said derived velocity signal and said plurality of tachometer velocity signals.

38. The system of claim 29 wherein:

said determining said compensated velocity includes;

extracting respective offsets and biases from said plurality of tachometer velocity signals;

scaling said plurality of tachometer velocity signals to produce a plurality of scaled velocity signals;

selecting one scaled velocity signal of said plurality of scaled velocity signals as said compensated velocity signal; and

wherein said scaling is responsive to calculated velocity errors.

39. The system of claim 38 wherein said extracting is accomplished by a selectable filter.

40. The system of claim 39 wherein said selectable filter conditionally subtracts low frequency spectral components from said plurality of tachometer velocity signals.

41.The system of claim 38 wherein said scaling is applied by a scale factor multiplication, where said scale factor is derived from an error determination process.

41. The system of claim 38 wherein said selecting includes selecting one tachometer velocity signal of said plurality of tachometer velocity signals based on magnitude.

42. The system of claim 38 wherein said calculated velocity error is responsive to a magnitude differential between said derived velocity signal and a time coherent version of said compensated velocity signal.

43. A system for determining a velocity of a rotating device, comprising:

an apparatus in operable communication with said rotating device for generating a plurality of tachometer velocity signals and a position signal;

a controller coupled to said apparatus, said controller adapted to execute an adaptive algorithm including;

receiving said position signal related to rotational position;

determining a derived velocity signal utilizing said position signal;

receiving a plurality of tachometer velocity signals; and

blending said plurality of tachometer velocity signals with said derived velocity signal under selective conditions to generate a blended velocity output indicative of said velocity of said rotating device.

44. A method for determining a velocity of a rotating device, comprising:

receiving a position signal related to rotational position, and determining a derived velocity signal utilizing said position signal;

receiving a plurality of tachometer velocity signals; and

determining a compensated velocity signal in response to said plurality of tachometer velocity signals.

45. The method of claim 45 further including:

generating said plurality of tachometer velocity signals and said position signal with an apparatus in operable communication with said rotating device, the apparatus comprising;

a rotational part including a set of sense magnets affixed to a rotating shaft of said rotating device configured to rotate about a rotation axis;

a circuit assembly, including a circuit interconnection having a plurality of sense coils, a sensor affixed to said circuit assembly, said circuit assembly adapted to be in proximity to said set of sense magnets; and

wherein said set of sense magnets combines with said circuit assembly to form an air electric machine such that voltages generated from each sense coil of said plurality of sense coils exhibits an amplitude proportional to said velocity.

48. The method of claim 45 wherein said derived velocity signal is determined as a difference between two measured positions of said rotating device divided by a time difference between said measured positions;

and filtering a resultant of said calculation.

49. The method of claim 45 further including:

blending said plurality of compensated velocity signals with said derived velocity signal under selective conditions to generate a blended velocity output indicative of said velocity of said rotating device.

51. The method of claim 45 wherein:

said determining said compensated velocity includes;

extracting respective offsets and biases from said plurality of tachometer velocity signals;

scaling said plurality of tachometer velocity signals to produce a plurality of scaled velocity signals;

selecting one scaled velocity signal of said plurality of scaled velocity signals as said compensated velocity signal; and

wherein said scaling is responsive to calculated velocity errors.

46. The method of claim 46 wherein said plurality of tachometer velocity signals are the resultant outputs of said plurality of sense coils configured such that the voltages generated thereby are in quadrature.

47. The method of claim 46 wherein said voltages generated from each sense coil of said plurality of sense coils exhibit a trapezoidal waveform with an amplitude proportional to said velocity.

50. The method of claim 50 wherein said blended velocity output is generated by combining said derived velocity signal and said compensated velocity signal under selective conditions based upon characteristics of said derived velocity signal and said plurality of tachometer velocity signals.

52. The method of claim 52 wherein said extracting is accomplished by a selectable filter.

54. The method of claim 52 wherein said scaling is applied by a scale factor multiplication, where said scale factor is derived from an error determination process.

55. The method of claim 52 wherein said selecting includes selecting one tachometer velocity signals of said plurality of tachometer velocity signals based on magnitude.

56. The method of claim 52 wherein said calculated velocity error is responsive to a magnitude differential between said derived velocity signal and a time coherent version of said compensated velocity signal.

53. The method of claim 53 wherein said selectable filter conditionally subtracts low frequency spectral components from said plurality of tachometer velocity signals.

57. A method for determining a velocity of a rotating device, comprising:

receiving a position signal related to rotational position, and determining a derived velocity signal utilizing said position signal;

receiving a plurality of tachometer velocity signals;

blending said plurality of tachometer velocity signals with said derived velocity signal under selective conditions to generate a blended velocity output indicative of said velocity of said rotating device.

58. A storage medium encoded with a machine-readable computer program code;

wherein said code includes instructions for causing a controller to implement a method for determining a velocity of a rotating device comprising;

receiving a position signal related to rotational position, and determining a derived velocity signal utilizing said position signal;

receiving a plurality of tachometer velocity signals; and

determining a compensated velocity signal in response to said plurality of tachometer velocity signals.

59. A storage medium of claim 59 wherein said blended velocity output is generated by combining said derived velocity signal and said compensated velocity signal under selective conditions based upon characteristics of said derived velocity signal and said plurality of tachometer velocity signals.

60. A storage medium of claim 59 wherein:

said determining said compensated velocity includes;

extracting respective offsets and biases from said plurality of tachometer velocity signals;

scaling said plurality of tachometer velocity signals to produce a plurality of scaled velocity signals;

selecting one scaled velocity signal of said plurality of scaled velocity signals as said compensated velocity signal; and

wherein said scaling is responsive to calculated velocity errors.

61. A computer data signal embodied in a carrier wave;

wherein said data signal comprising code configured to cause a controller to implement a method for determining a velocity of a rotating device, comprising;

receiving a position signal related to rotational position, and determining a derived velocity signal utilizing said position signal;

receiving a plurality of tachometer velocity signals; and

determining a compensated velocity signal in response to said plurality of tachometer velocity signals.

62. A computer data signal of claim 62 wherein said blended velocity output is generated by combining said derived velocity signal and said compensated velocity signal under selective conditions based upon characteristics of said derived velocity signal and said plurality of tachometer velocity signals.

63. A computer data signal of claim 62 wherein:

said determining said compensated velocity includes;

extracting respective offsets and biases from said plurality of tachometer velocity signals;

scaling said plurality of tachometer velocity signals to produce a plurality of scaled velocity signals;

selecting one scaled velocity signal of said plurality of scaled velocity signals as said compensated velocity signal; and

wherein said scaling is responsive to calculated velocity errors.