Compensation using position for improved feel and stability in a steering system

• US 6,687,588 B2
• Filed: 08/30/2002
• Issued: 02/03/2004
• Est. Priority Date: 09/14/2001
• Status: Expired due to Term

• Current Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust), Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Bolourchi, Farhad, Demerly, Jon D., Millsap, Scott A.
• Primary Examiner(s): Zanelli, Michael J.
• Assistant Examiner(s): Gibson, Eric M
• Application Number:
  US10/231,892
• Publication Number:
  US 20030055546A1
• Time in Patent Office: 522 Days
• Field of Search: 701/41, 701/42, 180/402, 180/443, 318/432, 318/434
• US Class Current: 701/41
• CPC Class Codes: B62D 5/001 Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence
• CPC Class Codes: B62D 6/008 Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications
• CPC Class Codes: B62D 6/10 characterised by means for sensing or determining torque

Abstract

Disclosed herein is steer-by-wire control systems comprising: a road wheel unit responsive to a road wheel command signal including a road wheel position sensor and a road wheel force sensor. The steer-by-wire control system also includes a steering wheel unit responsive to a steering wheel torque command signal, including a steering wheel position sensor and a torque sensor. The steer-by-wire control system further includes a vehicle speed sensor, and a master control unit operatively connected to the vehicle speed sensor, the steering wheel unit, and the road wheel unit. The steering wheel unit is also responsive to the steering wheel position signal.

Claims

1. A steer-by-wire control system comprising:

a road wheel unit responsive to a road wheel command signal for steering a vehicle, said road wheel unit includes a road wheel position sensor to produce and transmit a road wheel position signal and a road wheel force sensor to produce and transmit a road wheel force signal;

a steering wheel unit responsive to a steering wheel torque command signal, said steering wheel unit includes a steering wheel position sensor to produce and transmit a steering wheel position signal and a torque sensor to produce and transmit a feedback torque sensor signal;

a vehicle speed sensor to produce and transmit a vehicle speed signal;

a master control unit operatively connected to said vehicle speed sensor, said steering wheel unit, and said road wheel unit; and

wherein said steering wheel unit is also responsive to said steering wheel position signal.

2. The steer-by-wire control system of claim 1 wherein said steering wheel unit exhibits a bandwidth sufficient to facilitate said master control unit maintaining stability of said steer-by-wire system.

3. The steer-by-wire control system of claim 1 wherein said steering wheel unit comprises a closed loop control system responsive to said steering wheel torque command signal said feedback torque sensor signal and said steering wheel position signal.

4. The steer-by-wire control system of claim 1 wherein at least one of said road wheel position sensor, said road wheel force sensor, said steering wheel position sensor, said torque sensor, and said vehicle speed sensor is selected and configured to ensure that at least one of said road wheel unit, said steering wheel unit, and said steer-by-wire system, exhibits selected performance characteristics.

5. The steer-by-wire control system of claim 4 wherein said selected performance characteristics include at least one of increased bandwidth, increased disturbance rejection, improved input impedance response, increased resolution and increased tracking accuracy over a steer-by-wire system not employing a steering wheel unit responsive to said steering wheel position.

6. The steer-by-wire control system of claim 1 wherein said steering wheel position sensor is selected from at least one of a steering wheel position sensor located in the vicinity of a steering wheel, a steering wheel motor position sensor located in a motor configured to manipulate said steering wheel, and road wheel position sensor located in a vicinity of a road wheel.

7. The steer-by-wire control system of claim 6 wherein said steering wheel position sensor is selected, positioned, and configured such that it exhibits selected performance characteristics.

8. The steer-by-wire control system of claim 7 wherein said selected performance characteristics include at least one of accuracy, resolution, and bandwidth.

9. The steer-by-wire control system of claim 1 wherein said steering wheel unit comprises a steering wheel control unit and a steering wheel plant dynamics unit.

10. The steer-by-wire control system of claim 9 wherein:

said steering wheel control unit is responsive to said steering wheel torque command signal, said feedback torque sensor signal, and said steering wheel position signal, and generates a position compensated torque command signal;

said steering wheel plant dynamics unit is responsive to said position compensated torque command signal and provides a reaction torque in response thereto to an operator; and

wherein said steering wheel plant dynamics unit comprises a motor configured to generate said reaction torque.

11. The steer-by-wire control system of claim 10 wherein said position compensated torque command signal comprises a combination of a torque command signal and a position compensation signal.

12. The steer-by-wire control system of claim 11 wherein said combination comprises a summation.

13. The steer-by-wire control system of claim 11 wherein said torque command signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to enhance input impedance of said steer-by-wire system.

14. The steer-by-wire control system of claim 11 wherein said position compensation signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to enhance input impedance of said steer-by-wire system.

15. The steer-by-wire control system of claim 11 wherein said torque command signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to reduce free control oscillation of said steer-by-wire system.

16. The steer-by-wire control system of claim 11 wherein said position compensation signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to reduce free control oscillation of said steer-by-wire system.

17. The steer-by-wire control system of claim 11 wherein said torque command signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to increase the bandwidth of said steering wheel unit.

18. The steer-by-wire control system of claim 17 wherein said steering wheel unit exhibits a bandwidth of at least one Hertz.

19. The steer-by-wire control system of claim 18 wherein said steering wheel unit exhibits a bandwidth of about ten Hertz.

20. The steer-by-wire control system of claim 11 wherein said torque command signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to maintain stability of said steering wheel unit.

21. The steer-by-wire control system of claim 11 wherein said position compensation signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to increase the bandwidth of said steering wheel unit.

22. The steer-by-wire control system of claim 21 wherein said steering wheel unit exhibits a bandwidth of at least one Hertz.

23. The steer-by-wire control system of claim 22 wherein said steering wheel unit exhibits a bandwidth of about ten Hertz.

24. The steer-by-wire control system of claim 11 wherein said position compensation signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to maintain stability of said steering wheel unit.

25. The steer-by-wire control system of claim 11 wherein said steering wheel control unit includes a frequency based compensator configured to characterize spectral content of said torque command signal such that said steering wheel unit exhibits a bandwidth sufficient to facilitate generation of a steering wheel torque command signal by said torque control unit to maintain stability of said steer-by-wire system.

26. The steer-by-wire control system of claim 11 wherein said steering wheel control unit includes a frequency based compensator configured to characterize spectral content of said position compensation signal such that said steering wheel unit exhibits a bandwidth sufficient to facilitate generation of a steering wheel torque command signal by said torque control unit to maintain stability of said steer-by-wire system.

27. A steer-by-wire control system comprising:

a road wheel unit responsive to a road wheel command signal for steering a vehicle, said road wheel unit includes a road wheel position sensor to produce and transmit a road wheel position signal and a road wheel force sensor to produce and transmit a road wheel force signal;

a steering wheel unit responsive to a steering wheel torque command signal, said steering wheel unit includes a steering wheel position sensor to produce and transmit a steering wheel position signal and a torque sensor to produce and transmit a feedback torque sensor signal;

a vehicle speed sensor to produce and transmit a vehicle speed signal;

a master control unit operatively connected to said vehicle speed sensor, said steering wheel unit, and said road wheel unit;

wherein said steering wheel unit is also responsive to said steering wheel position; and

wherein said master control unit calculates said road wheel command signal in response to said vehicle speed signal, said feedback torque sensor signal and said steering wheel position signal; and

said master control unit calculates said steering wheel torque command signal responsive to a composite road wheel force signal, said feedback torque sensor signal, said steering wheel position signal and said vehicle speed signal.

28. A method for steering a vehicle with a steer-by-wire system comprising:

receiving a road wheel force signal;

receiving a road wheel position signal;

receiving a vehicle speed signal;

receiving a steering wheel position signal;

receiving a feedback torque sensor signal;

generating a steering wheel torque command signal responsive to said road wheel force signal, said vehicle speed signal, and said feedback torque sensor signal;

generating a road wheel command signal responsive to said road wheel position signal, said vehicle speed signal, said feedback torque sensor signal, and said steering wheel position signal; and

generating a position compensated torque command signal in a steering wheel unit responsive to said steering wheel position signal.

29. The method for steering a vehicle of claim 28 wherein said generating a position compensated torque command signal in a steering wheel unit is such that said steering wheel unit exhibits a bandwidth sufficient to facilitate a master control unit generating said steering wheel torque command signal to maintain stability of said steer-by-wire system.

30. The method for steering a vehicle of claim 28 wherein said steering wheel torque command signal and said feedback torque sensor signal, and said steering wheel position signal from a steering wheel position sensor are employed in a steering wheel unit comprising a closed loop control system responsive thereto.

31. The method for steering a vehicle of claim 28 wherein at least one of said road wheel position signal, said road wheel force signal, said steering wheel position signal, said feedback torque sensor signal, and said vehicle speed signal are responsive to a road wheel position sensor, a road wheel force sensor, a steering wheel position sensor, a torque sensor, and a vehicle speed sensor respectively, selected and configured to ensure that at least one of a road wheel unit, a steering wheel unit, and said steer-by-wire system, exhibits selected performance characteristics.

32. The method for steering a vehicle of claim 31 wherein said selected performance characteristics include at least one of increased bandwidth, increased disturbance rejection, improved input impedance response, increased resolution and increased tracking accuracy over a steer-by-wire system not employing a steering wheel unit responsive to said steering wheel position.

33. The method for steering a vehicle of claim 28 wherein said steering wheel position sensor is selected from at least one of a steering wheel position sensor located in the vicinity of a steering wheel, a steering wheel motor position sensor located in a motor configured to manipulate said steering wheel, and road wheel position sensor located in a vicinity of a road wheel.

34. The method for steering a vehicle of claim 33 wherein said steering wheel position signals selected, positioned and configured such that said steering wheel position signal exhibits selected performance characteristics.

35. The method for steering a vehicle of claim 34 said selected performance characteristics include at least one of accuracy, resolution, and bandwidth.

36. The method for steering a vehicle of claim 28 wherein said steering wheel unit comprises a steering wheel control unit and a steering wheel plant dynamics unit.

37. The method for steering a vehicle of claim 36 wherein:

said position compensated torque command signal is generated in a steering wheel control unit responsive to said steering wheel torque command signal, said steering wheel position signal, and said feedback torque sensor signal;

said steering wheel plant dynamics unit is responsive to said position compensated torque command signal and provides a reaction torque in response thereto to an operator; and

wherein said steering wheel plant dynamics unit comprises a motor configured to position a steering wheel thereby generating said reaction torque.

38. The method for steering a vehicle of claim 37 wherein said position compensated torque command signal comprises a combination of a torque command signal and a position compensation signal.

39. The method for steering a vehicle of claim 38 wherein said combination comprises a summation.

40. The method for steering a vehicle of claim 38 wherein said position compensation signal is responsive to frequency based compensation to characterize spectral content of said position compensated torque command signal to enhance input impedance of said steer-by-wire system.

41. The method for steering a vehicle of claim 40 wherein said steering wheel unit exhibits a bandwidth of about ten Hertz.

42. The method for steering a vehicle of claim 38 wherein said torque command signal is responsive to frequency based compensation to characterize spectral content of said position compensated torque command signal to enhance input impedance of said steer-by-wire system.

43. The method for steering a vehicle of claim 38 wherein said position compensation signal is responsive to frequency based compensation to characterize spectral content of said position compensated torque command signal to reduce free control oscillation of said steer-by-wire system.

44. The method for steering a vehicle of claim 38 wherein said torque command signal is responsive to frequency based compensation to characterize spectral content of said position compensated torque command signal to reduce free control oscillation of said steer-by-wire system.

45. The method for steering a vehicle of claim 38 wherein said position compensation signal is responsive to frequency based compensation to characterize spectral content of said position compensated torque command signal to maintain stability of said steering wheel unit.

46. The method for steering a vehicle of claim 38 wherein said position compensation signal is responsive to frequency based compensation to characterize spectral content of said position compensated torque command signal to increase bandwidth of said steering wheel unit.

47. The method for steering a vehicle of claim 46 wherein said steering wheel unit exhibits a bandwidth of at least one Hertz.

48. The method for steering a vehicle of claim 47 wherein said steering wheel unit exhibits a bandwidth of about ten Hertz.

49. The method for steering a vehicle of claim 38 wherein said torque command signal is responsive to frequency based compensation to characterize spectral content of said position compensated torque command signal to maintain stability of said steering wheel unit.

50. The method for steering a vehicle of claim 38 wherein said torque command signal is responsive to frequency based compensation to characterize spectral content of said position compensated torque command signal to increase bandwidth of said steering wheel unit.

51. The method for steering a vehicle of claim 50 wherein said steering wheel unit exhibits a bandwidth of at least one Hertz.

52. The method for steering a vehicle of claim 38 wherein said steering wheel control unit includes a frequency based compensator configured to characterize spectral content of said torque command signal such that said steering wheel unit exhibits a bandwidth sufficient to facilitate generation of a steering wheel torque command signal by said torque control unit to maintain stability of said steer-by-wire system.

53. The method for steering a vehicle of claim 38 wherein said steering wheel control unit includes a frequency based compensator configured to characterize spectral content of said position compensation signal such that said steering wheel unit exhibits a bandwidth sufficient to facilitate generation of a steering wheel torque command signal by said torque control unit to maintain stability of said steer-by-wire system.

54. A torque control system responsive to position comprising:

a torque control unit responsive to a torque command signal for controlling torque, said torque control unit includes a position sensor to produce and transmit a position signal and a torque sensor to produce and transmit a torque sensor signal;

wherein said torque control unit comprises a closed loop control system responsive to said torque command signal and said torque sensor signal as feedback;

wherein said torque control unit includes feedforward control based on said position signal;

wherein at least one of said position sensor, and said torque sensor, is selected and configured to ensure that at least one of said torque control unit, and said torque control system, exhibits selected performance characteristics; and

wherein said selected performance characteristics include at least one of increased bandwidth, increased disturbance rejection, improved input impedance response, increased resolution and increased tracking accuracy over a torque control system not employing a torque control unit responsive to said position sensor.

55. The torque control system of claim 54 wherein said torque command signal is generated by a master control unit operatively connected to said torque control unit.

56. The torque control system of claim 54 wherein said position sensor is selected from at least one of a position sensor located in the vicinity of an operator mechanical input, a motor position sensor located in a motor configured to manipulate said operator mechanical input, and a position sensor located in a vicinity of a mechanical response to said motor.

57. The torque control system of claim 56 wherein said position sensor is selected, positioned, and configured such that said position signal exhibits selected performance characteristics.

58. The torque control system of claim 57 wherein said selected performance characteristics include at least one of accuracy, resolution, and bandwidth.

59. The torque control system of claim 54 wherein said torque control unit comprises a control unit and a plant dynamics unit.

60. The torque control system of claim 59 wherein:

said control unit is responsive to said master torque command signal, said torque sensor signal, and said steering wheel position signal, and generates a position compensated torque command signal;

said plant dynamics unit is responsive to said position compensated torque command signal and provides a reaction torque in response thereto; and

wherein said plant dynamics unit comprises a motor configured to generate said reaction torque.

61. The torque control system of claim 60 wherein said position compensated torque command signal comprises a combination of a torque command signal and a position compensation signal.

62. The torque control system of claim 61 wherein said combination comprises a summation.

63. The torque control system of claim 61 wherein said torque command signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to enhance input impedance of said torque control system.

64. The torque control system of claim 61 wherein said position compensation signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to enhance input impedance of said torque control system.

65. The torque control system of claim 61 wherein said torque command signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to reduce free control oscillation of said torque control system.

66. The torque control system of claim 61 wherein said position compensation signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to reduce free control oscillation of said torque control system.

67. The torque control system of claim 61 wherein said torque command signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to increase the bandwidth of said torque control unit.

68. The torque control system of claim 67 wherein said torque control unit exhibits a bandwidth of at least one Hertz.

69. The torque control system of claim 68 wherein said torque control unit exhibits a bandwidth of about ten Hertz.

70. The torque control system of claim 63 wherein said torque command signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to maintain stability of said torque control unit.

71. The torque control system of claim 61 wherein said position compensation signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to increase the bandwidth of said torque control unit.

72. The torque control system of claim 71 wherein said steering wheel unit exhibits a bandwidth of at least one Hertz.

73. The torque control system of claim 72 wherein said torque control unit exhibits a bandwidth of about ten Hertz.

74. The torque control system of claim 61 wherein said position compensation signal is responsive to a frequency based compensator configured to characterize content of said position compensated torque command signal to maintain stability of said torque control unit.

75. The torque control system of claim 61 wherein said torque control unit includes a frequency based compensator configured to characterize spectral content of said position compensation signal such that said torque control unit exhibits a bandwidth sufficient to facilitate generation of a master torque command signal by said master control unit to maintain stability of said torque control system.

76. The torque control system of claim 61 wherein said torque control unit includes a frequency based compensator configured to characterize spectral content of said torque command signal such that said torque control unit exhibits a bandwidth sufficient to facilitate generation of a master torque command signal by said master control unit to maintain stability of said torque control system.

77. A method for controlling torque with a torque control system responsive to position, the method comprising:

receiving a position signal from a position sensor;

receiving a torque sensor signal;

receiving a master torque command signal;

generating a position command torque signal in a torque control unit responsive to said master torque command signal, said torque sensor signal, and said position signal;

wherein said position compensated torque command signal, said position signal, and said torque sensor signal are employed in a torque control unit forming a control system;

wherein at least one of said position signal and said torque sensor signal are responsive to a position sensor and a torque sensor respectively, selected and configured to ensure that at least one of a torque control unit and said torque control system, exhibits selected performance characteristics; and

wherein said selected performance characteristics include at least one of increased bandwidth, increased disturbance rejection, improved input impedance response, increased resolution and increased tricking accuracy over a torque control system not employing a torque control unit responsive to said position sensor.

78. The method for controlling torque of claim 77 wherein said master torque command signal is generated by a master control unit operatively connected to said torque control unit forming a closed loop control system with said torque control unit.

79. The method for controlling torque of claim 77 wherein said position sensor is selected from at least one of a position sensor located in the vicinity of an operator input device, a motor position sensor located in a motor configured to manipulate said operator input device, and a position sensor located in a vicinity of a mechanical response to said motor.

80. The method for controlling torque of claim 79 wherein said position signal is selected, positioned, and configured such that said position signal exhibits selected performance characteristics.

81. The method for controlling torque of claim 80 wherein said selected performance characteristics include at least one of accuracy, resolution, and bandwidth.

82. The method for controlling torque of claim 77 wherein said torque control unit comprises a control unit and a plant dynamics unit.

83. The method for controlling torque of claim 82 wherein:

said position compensated torque command signal is generated in a control unit responsive to said master torque command signal, said position signal, and said torque sensor signal;

said plant dynamics unit is responsive to said position compensated torque command signal and provides a reaction torque in response thereto; and

wherein said plant dynamics unit comprises a motor configured to generate said reaction torque.

84. The method for controlling torque of claim 83 wherein said position compensated torque command signal comprises a combination of a torque command signal and a position compensation signal.

85. The method for controlling torque of claim 84 wherein said combination comprises a summation.

86. The method for controlling torque of claim 84 wherein said torque command signal is responsive to frequency-based compensation to characterize spectral content of said position compensated torque command signal to enhance input impedance of said torque control unit.

87. The method for controlling torque of claim 84 wherein said position compensation signal is responsive to frequency-based compensation to characterize spectral content of said position compensated torque command signal to enhance input impedance of said torque control unit.

88. The method for controlling torque of claim 84 wherein said torque command signal is responsive to frequency-based compensation to characterize spectral content of said position compensated torque command signal reduce free control oscillation of said torque control unit.

89. The method for controlling torque of claim 84 wherein said position compensation signal is responsive to frequency-based compensation to characterize spectral content of said position compensated torque command signal to reduce free control oscillation of said torque control unit.

90. The method for controlling torque of claim 84 wherein said position compensation signal is responsive to frequency-based compensation to characterize spectral content of said position compensated torque command signal to maintain stability of said torque control unit.

91. The method for controlling torque of claim 84 wherein said position compensation signal is responsive to frequency-based compensation to characterize spectral content of said position compensated torque command signal to increase bandwidth of said torque control unit.

92. The method for controlling torque of claim 91 wherein said torque control unit exhibits a bandwidth of at least one Hertz.

93. The method for controlling torque of claim 92 wherein said torque control unit exhibits a bandwidth of about ten Hertz.

94. The method for controlling torque of claim 84 wherein said torque command signal is responsive to frequency-based compensation to characterize spectral content of said position compensated torque command signal to maintain stability of said torque control unit.

95. The method for controlling torque of claim 84 wherein said torque command signal is responsive to frequency-based compensation to characterize spectral content of said position compensated torque command signal to increase bandwidth of said torque control unit.

96. The method for controlling torque of claim 95 wherein said torque control unit exhibits a bandwidth of at least one Hertz.

97. The method for controlling torque of claim 96 wherein said torque control unit exhibits a bandwidth of about ten Hertz.

98. The method for controlling torque of claim 84 wherein said torque control unit includes a frequency based compensator configured to characterize spectral content of said force compensation signal such that said torque control unit exhibits a bandwidth sufficient to facilitate generation of a master torque command signal by said master control unit to maintain stability of said torque control system.

99. The method for controlling torque of claim 84 wherein said torque control unit includes a frequency based compensator configured to characterize spectral content of said position command signal such that said torque control unit exhibits a bandwidth sufficient to facilitate generation of a master torque command signal by said master control unit to maintain stability of said torque control system.

100. A storage medium:

encoded with a machine readable computer program code;

said code including instructions for causing a computer to implement a method for steering a vehicle with a steer-by-wire system, the method comprising;

receiving a road wheel force signal;

receiving a road wheel position signal;

receiving a vehicle speed signal;

receiving a steering wheel position signal;

receiving a feedback torque sensor signal;

generating a steering wheel torque command signal responsive to said road wheel force signal, said vehicle speed signal, and said feedback torque sensor signal;

generating a road wheel command signal responsive to said road wheel position signal, said vehicle speed signal, said feedback torque sensor signal, and said steering wheel position signal; and

generating a position compensated torque command signal in a steering wheel unit responsive to said steering wheel position signal.

101. A computer data signal, said computer data signal comprising:

instructions for causing a computer to implement a method for steering a vehicle with a steer-by-wire system, the method comprising;

receiving a road wheel force signal;

receiving a road wheel position signal;

receiving a vehicle speed signal;

receiving a steeling wheel position signal;

receiving a feedback torque sensor signal;

generating a steering wheel torque command signal responsive to said road wheel force signal, said vehicle speed signal, and said feedback torque sensor signal;

generating a road wheel command signal responsive to said road wheel position signal, said vehicle speed signal, said feedback torque sensor signal, and said steering wheel position signal; and

generating a position compensated torque command signal in a steering wheel unit responsive to said steering wheel position signal.

102. A storage medium:

encoded with a machine readable computer program code;

said code including instructions for causing a computer to implement a method for controlling torque with a torque control system responsive to position, the method comprising;

receiving a position signal from a position sensor;

receiving a torque sensor signal;

receiving a master torque command signal;

generating a position compensated torque command signal in a torque control unit responsive to said master torque command signal, said torque sensor signal, and said position signal;

wherein said position compensated torque command signal, said position signal, and said torque signal are employed in a torque control unit forming a control system;

wherein at least one of said position signal and said torque sensor signal are responsive to a position sensor and a torque sensor respectively, selected and configured to ensure that at least one of a torque control unit and said torque control system, exhibits selected performance characteristics; and

wherein said selected performance characteristics include at least one of increased bandwidth, increased disturbance rejection, improved input impedance response, increased resolution and increased tracking accuracy over a torque control system not employing a torque control unit responsive to said position sensor.

103. A computer data signal, said computer data signal comprising:

instructions for causing a computer to implement a method for controlling torque with a torque control system responsive to position, the method comprising;

receiving a position signal from a position sensor;

receiving a torque sensor signal;

receiving a master torque command signal;

generating a position compensated torque command signal in a torque control unit responsive to said master torque command signal, said torque sensor signal, and said position signal;

wherein said position compensated torque command signal, said position signal, and said torque signal are employed in a torque control unit forming a control system;

wherein at least one of said position signal and said torque sensor signal are responsive to a position sensor and a torque sensor respectively, selected and configured to insure that at least one of a torque control unit and said torque control system, exhibits selected performance characteristics; and

wherein said selected characteristics include at least one of increased bandwidth, increased disturbance rejection, improved input impedance response, increased resolution and increased tracking accuracy over a torque control system not employing a torque control unit responsive to said position sensor.