User-configurable steering control for steer-by-wire systems

• US 6,678,594 B2
• Filed: 02/02/2001
• Issued: 01/13/2004
• Est. Priority Date: 02/02/2001
• 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: Byers, Michael D., Murray, Brian Thomas, Amberkar, Sanket Suresh
• Primary Examiner(s): Nguyen, Tan
• Assistant Examiner(s): Tran, Dalena
• Application Number:
  US09/775,880
• Publication Number:
  US 20020107621A1
• Time in Patent Office: 1,075 Days
• Field of Search: 701/41, 701/42, 701/43, 180/422, 180/443, 180/446, 180/402, 388/907.5, 388/930
• US Class Current: 701/41
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence
• CPC Class Codes: B62D 6/007 adjustable by the driver, e.g. sport mode
• 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: Y10S 388/93 Load or torque

Abstract

A steer-by-wire control system comprising a master control system, a road wheel system, and a hand wheel system is disclosed. The road wheel system is connected to the master control system and includes a road wheel position sensor and a rack force sensor. The hand wheel system is connected to the master control system and the road wheel system and includes a hand wheel position sensor and a torque sensor. The steer-by-wire system also includes a vehicle speed sensor for producing a vehicle speed signal. In addition a hand wheel actuator configured to receive commands from the hand wheel system and a road wheel actuator configured to receive commands from the road wheel system are utilized. The hand wheel system and road wheel system each include a configurable control topology.

Claims

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

a master control system;

a road wheel system electrically connected to said master control system including a road wheel position sensor to produce and transmit a road wheel position and a rack force sensor to produce and transmit a rack force signal;

a hand wheel system electrically connected to said master control system and said road wheel system including a hand wheel position sensor to produce and transmit a hand wheel position signal and a torque sensor to produce and transmit a hand wheel torque signal;

a vehicle speed sensor for producing a vehicle speed signal, said vehicle speed sensor electrically connected to at least one of;

said master control system, said hand wheel system, and said road wheel system;

a hand wheel actuator configured to receive commands from said hand wheel system;

a road wheel actuator configured to receive commands from said road wheel system;

wherein said hand wheel system includes a configurable control topology; and

wherein said road wheel system includes a configurable control topology.

2. The steer-by-wire control system of claim 1 wherein said master control system calculates a hand wheel stability correction and a road wheel stability correction.

3. The steer-by-wire control system of claim 2 wherein said hand wheel system comprises a closed loop control system responsive to at least one of said hand wheel torque signal, said rack force signal, said vehicle speed signal, said hand wheel position signal and said hand wheel stability correction.

4. The steer-by-wire control system of claim 2 wherein said hand wheel system comprises a hand wheel reference command unit and a torque servo control unit.

5. The steer-by-wire control system of claim 4 wherein:

said hand wheel reference command unit is responsive to said rack force signal, said vehicle speed signal, said hand wheel position signal and said hand wheel stability correction and generates a hand wheel reference command signal; and

said torque servo control unit is responsive to said hand wheel torque signal and said hand wheel reference command signal to provide a command to said hand wheel actuator wherein said hand wheel actuator is configured to position a hand wheel thereby generating a reaction torque.

6. The steer-by-wire control system of claim 5 wherein said torque servo control unit includes a frequency based compensator configured to characterize spectral content of at least one of said hand wheel reference command signal and said hand wheel torque signal to maintain stability of said hand wheel system.

7. The steer-by-wire control system of claim 5 wherein said hand wheel system includes a configurable frequency based filter configured to characterize spectral content of said rack force signal to increase bandwidth of said hand wheel system.

8. The steer-by-wire control system of claim 7 wherein said configurable frequency based filter comprises a user configurable filter.

9. The steer-by-wire control system of claim 7 wherein said configurable frequency based filter comprises a second order discrete filter.

10. The steer-by-wire control system of claim 5 wherein said hand wheel system includes a configurable frequency based filter configured to characterize spectral content of said hand wheel position to control return force dynamic characteristics of said hand wheel system.

11. The steer-by-wire control system of claim 10 wherein said configurable frequency based filter comprises a user configurable filter.

12. The steer-by-wire control system of claim 10 wherein said configurable frequency based filter comprises a second order discrete filter.

13. The steer-by-wire control system of claim 10 wherein said hand wheel system includes another configurable frequency based filter configured to characterize spectral content of said rack force signal to increase bandwidth of said hand wheel system.

14. The steer-by-wire control system of claim 13 wherein said another configurable frequency based filter comprises a user configurable filter.

15. The steer-by-wire control system of claim 13 wherein said another configurable frequency based filter comprises a second order discrete filter.

16. The steer-by-wire control system of claim 13 wherein said hand wheel reference command signal results from a summation including a hand wheel stability correction, a force feedback signal, and a position feed back signal.

17. The steer-by-wire control system of claim 16 wherein said force feedback signal results from a torque feed back look up table responsive to said vehicle speed signal and a resultant force signal.

18. The steer-by-wire control system of claim 16 wherein said force feedback signal results from a torque feed back look up table responsive to said vehicle speed signal and a resultant force signal.

19. The steer-by-wire control system of claim 18 wherein said torque feed back look up table is user configurable.

20. The steer-by-wire control system of claim 18 wherein said resultant force signal comprises a resultant from a configurable frequency based filter responsive to said rack force signal.

21. The steer-by-wire control system of claim 20 wherein said configurable frequency based filter is user configurable.

22. The steer-by-wire control system of claim 18 wherein said position feed back signal results from a torque return look up table responsive to said vehicle speed signal and a resultant position signal.

23. The steer-by-wire control system of claim 22 wherein said torque return look up table is user configurable.

24. The steer-by-wire control system of claim 22 wherein said resultant position signal results from another configurable frequency based filter responsive to said hand wheel position signal.

25. The steer-by-wire control system of claim 22 wherein said another configurable frequency based filter is user configurable.

26. The steer-by-wire control system of claim 5 wherein said hand wheel reference command signal results from a summation including a hand wheel stability correction, a force feedback signal, and a position feed back signal.

27. The steer-by-wire control system of claim 2 wherein said road wheel system comprises a closed loop control system responsive to at least one of said hand wheel position signal, said vehicle speed signal, said road wheel stability correction, said road wheel position.

28. The steer-by-wire control system of claim 2 wherein said road wheel system comprises a road wheel reference command unit and a road wheel servo control unit.

29. The steer-by-wire control system of claim 28 wherein:

said road wheel reference command unit is responsive to said hand wheel position signal, said vehicle speed signal, and said road wheel stability correction and generates a road wheel reference command signal; and

said road wheel servo control unit is responsive to said road wheel position and said road wheel reference command signal to provide a road wheel command to said road wheel actuator wherein said road wheel actuator is configured to position a road wheel.

30. The steer-by-wire control system of claim 29 wherein said road wheel servo control unit includes a frequency based compensator configured to characterize spectral content of at least one of said road wheel reference command signal and said hand wheel torque signal to maintain stability of said road wheel system.

31. The steer-by-wire control system of claim 29 wherein said road wheel system includes a configurable frequency based filter configured to characterize spectral content of said hand wheel position to constrain bandwidth of hand wheel inputs to said hand wheel system.

32. The steer-by-wire control system of claim 31 wherein said configurable frequency based filter comprises a user configurable filter.

33. The steer-by-wire control system of claim 31 wherein said configurable frequency based filter comprises a second order discrete filter.

34. The steer-by-wire control system of claim 29 wherein said road wheel command is a resultant of a frequency based compensator applied to a road wheel position error signal.

35. The steer-by-wire control system of claim 34 wherein said road wheel position error signal results from a difference of said road wheel reference command signal and said road wheel position.

36. The steer-by-wire control system of claim 35 wherein said road wheel reference command signal results from a summation of a road wheel stability correction and a road wheel reference position signal.

37. The steer-by-wire control system of claim 36 wherein said road wheel reference position signal results from a multiplication of a speed compensated steering ratio and a resultant hand wheel position signal.

38. The steer-by-wire control system of claim 37 wherein said speed compensated steering ratio results from a variable ratio look up table, responsive to said vehicle speed signal and said hand wheel position signal.

39. The steer-by-wire control system of claim 38 wherein said resultant hand wheel position signal results from a configurable frequency based filter responsive to said hand wheel position signal.

40. The steer-by-wire control system of claim 39 wherein said configurable frequency based filter is user configurable.

41. The steer-by-wire control system of claim 37 wherein said variable ratio, look up table is configurable.

42. The steer-by-wire control system of claim 1 wherein said configurable control topology comprises at least one of;

a configurable frequency based filter a look up table, which is user configurable.

43. A method of steering a vehicle, the method comprising:

receiving a hand wheel stability correction;

receiving a road wheel stability correction;

receiving a rack force signal responsive to a measured rack force;

receiving a road wheel position signal responsive to a road wheel position;

receiving a hand wheel position signal responsive to a hand wheel position;

receiving a hand wheel torque signal responsive to a hand wheel torque;

receiving a vehicle speed signal responsive to a vehicle speed;

generating a hand wheel actuator command signal;

generating a road wheel actuator command signal;

wherein said hand wheel actuator command signal is the resultant of a configurable control topology; and

wherein said road wheel actuator command signal is the resultant of a configurable control topology.

44. The method of claim 43 wherein said hand wheel actuator command signal is responsive to said hand wheel torque signal, said hand wheel position signal, hand wheel stability command, and said vehicle speed signal.

45. The method of claim 44 wherein said rack force signal and a road wheel position signal are produced in a road wheel system electrically connected to a master control system.

46. The method of claim 45 wherein said road wheel system comprises a closed loop control system responsive to at least one of said hand wheel position signal, said vehicle speed signal, said road wheel stability correction, said road wheel position signal.

47. The method of claim 45 wherein said road wheel system comprises a road wheel reference command unit and a road wheel servo control unit.

48. The method of claim 47 further including:

generating a road wheel reference command signal in said road wheel reference command unit, responsive to said hand wheel position signal said vehicle speed signal, and said road wheel stability correction; and

,

providing said a road wheel actuator command signal to said road wheel actuator from said road wheel servo control unit, said road wheel actuator command signal responsive to said road wheel position signal and said road wheel reference command signal, and wherein said road wheel actuator configured to position a road wheel.

49. The method of claim 48 wherein said providing includes characterizing spectral content of at least one of said road wheel reference command signal and said hand wheel torque signal with a frequency based compensator configured to maintain stability of said road wheel system.

50. The method of claim 48 wherein said providing includes characterizing spectral content of said hand wheel position signal with a configurable frequency based filter configured to constrain bandwidth of hand wheel inputs to said road wheel system.

51. The method of claim 50 wherein said configurable frequency based filter comprises a user configurable filter.

52. The method of claim 50 wherein said configurable frequency based filter comprises a second order discrete filter.

53. The method of claim 48 wherein said road wheel actuator command signal is a resultant of a frequency based compensator applied to a road wheel position error signal.

54. The method of claim 53 wherein said road wheel position error signal results from a difference of said road wheel reference command signal and said road wheel position.

55. The method of claim 54 wherein said road wheel reference command results from a summation of a road wheel stability correction and a road wheel position reference position signal.

56. The method of claim 55 wherein said road wheel reference position signal results from a multiplication of a speed compensated steering ratio and a resultant hand wheel position signal.

57. The method of claim 56 wherein said speed compensated steering ratio results from a variable ratio look up table, responsive to said vehicle speed signal and said hand wheel position signal.

58. The method of claim 57 wherein said resultant hand wheel position signal results from a configurable frequency based filter responsive to said hand wheel position signal.

59. The method of claim 58 wherein said configurable frequency based filter is user configurable.

60. The method of claim 56 wherein said variable ratio look up table is configurable.

61. The method of claim 43 wherein said road wheel actuator command signal is responsive to said hand wheel position signal, said road wheel stability command, and said vehicle speed signal.

62. The method of claim 61 wherein said hand wheel position signal and a hand wheel torque signal are produced in a hand wheel system electrically connected to a master control system.

63. The method of claim 62 wherein said hand wheel system comprises a closed loop control system responsive to at least one of said hand wheel torque signal, said rack force signal, said vehicle speed signal, said hand wheel position signal and said hand wheel stability correction.

64. The method of claim 62 wherein said hand wheel system comprises a hand wheel reference command unit and a torque servo control unit.

65. The method of claim 64 further including:

generating a hand wheel reference command signal in said hand wheel reference command unit, responsive to said rack force signal, said vehicle speed signal, said hand wheel position signal and said hand wheel stability correction; and

,

providing said hand wheel actuator command signal to said hand wheel actuator from said torque servo control unit, said hand wheel actuator command signal responsive to said hand wheel torque signal and said hand wheel reference command signal, and wherein said hand wheel actuator is configured to position a hand wheel thereby generating a reaction torque.

66. The method of claim 65 wherein said providing includes characterizing spectral content of at least one of said hand wheel reference command signal and said hand wheel torque signal with a frequency based compensator torque servo control system configured to maintain stability of said hand wheel system.

67. The method of claim 65 wherein said providing includes characterizing spectral content of said rack force signal with a configurable frequency based filter configured to increase bandwidth of said hand wheel system.

68. The method of claim 67 wherein said configurable frequency based filter comprises a user configurable filter.

69. The method of claim 67 wherein said configurable frequency based filter comprises a second order discrete filter.

70. The method of claim 65 wherein said providing includes characterizing spectral content of said hand wheel position signal with a configurable frequency based filter configured to control return force dynamic characteristics of said hand wheel system.

71. The method of claim 70 wherein said configurable frequency based filter comprises a user configurable filter.

72. The method of claim 71 wherein said configurable frequency based filter comprises a second order discrete filter.

73. The method of claim 70 wherein said providing includes characterizing spectral content of said rack force signal with another configurable frequency based filter configured to increase bandwidth of said hand wheel system.

74. The method of claim 73 wherein said another configurable frequency based filter comprises a user configurable filter.

75. The method of claim 73 wherein said another configurable frequency based filter comprises a second order discrete filter.

76. The method of claim 73 wherein said hand wheel reference command results from a summation including a hand wheel stability correction, a force feedback signal, and a position feed back signal.

77. The method of claim 76 wherein said force feedback signal results from a torque feed back look up table responsive to said vehicle speed signal and a resultant force signal.

78. The method of claim 76 wherein said force feedback signal results from a torque feed back look up table responsive to said vehicle speed signal and a resultant force signal.

79. The method of claim 78 wherein said torque feed back look up table is user configurable.

80. The method of claim 78 wherein said resultant force signal comprises a resultant from a configurable frequency based filter responsive to said rack force signal.

81. The method of claim 80 wherein said configurable frequency based filter is user configurable.

82. The method of claim 78 wherein said position feed back signal results from a torque return look up table responsive to said vehicle speed signal and a resultant position signal.

83. The method of claim 82 wherein said torque return look up table is user configurable.

84. The method of claim 82 wherein said resultant position signal results from another configurable frequency based filter responsive to said hand wheel position signal.

85. The method of claim 84 wherein said another configurable frequency based filter is user configurable.

86. The method of claim 65 wherein said hand wheel reference command results from a summation including a hand wheel stability correction, a force feedback signal, and a position feed back signal.

87. The method of claim 43 wherein said vehicle speed signal is produced with a vehicle speed sensor electrically connected to a master control system and a hand wheel system.

88. The method of claim 43 wherein said hand wheel stability correction and a road wheel stability correction are calculated in a master control system.

89. The method of claim 43 wherein said configurable control topology comprises at least one of;

a configurable frequency based filter, a look up table, which is user configurable.

90. A storage medium encoded with a machine-readable computer program code for steering a vehicle, said storage medium including instructions for causing a computer to implement a method comprising:

receiving a hand wheel stability correction;

receiving a road wheel stability correction;

receiving a rack force signal responsive to a measured rack force;

receiving a road wheel position signal responsive to a road wheel position;

receiving a hand wheel position signal responsive to a hand wheel position;

receiving a hand wheel torque signal responsive to a hand wheel torque;

receiving a vehicle speed signal responsive to a vehicle speed;

generating a hand wheel actuator command signal;

generating a road wheel actuator command signal;

wherein said hand wheel actuator command signal is the resultant of a configurable control topology; and

wherein said road wheel actuator command signal is the resultant of a configurable control topology.

91. A computer data signal for steering a vehicle, said computer data signal comprising code configured to cause a computer to implement a method comprising:

receiving a hand wheel stability correction;

receiving a road wheel stability correction;

receiving a rack force signal responsive to a measured rack force;

receiving a road wheel position signal responsive to a road wheel position;

receiving a hand wheel position signal responsive to a hand wheel position;

receiving a hand wheel torque signal responsive to a hand wheel torque;

receiving a vehicle speed signal responsive to a vehicle speed;

generating a hand wheel actuator command signal;

generating a road wheel actuator command signal;

wherein said hand wheel actuator command signal is the resultant of a configurable control topology; and

wherein said road wheel actuator command signal is the resultant of a configurable control topology.

92. A steer-by-wire control system, comprising:

a master control system;

a road wheel system electrically connected to said master control system including a road wheel position sensor to produce and transmit a road wheel position and a rack force sensor to produce and transmit a rack force signal;

a hand wheel system electrically connected to said master control system and said road wheel system including a hand wheel position sensor to produce and transmit a hand wheel position signal and a torque sensor to produce and transmit a hand wheel torque signal;

a vehicle speed sensor for producing a vehicle speed signal, said vehicle speed sensor electrically connected to at least one of;

said master control system, said hand wheel system, and said road wheel system;

a hand wheel actuator configured to receive commands from said hand wheel system;

a road wheel actuator configured to receive commands from said road wheel system;

wherein said hand wheel system includes a configurable control topology;

wherein said road wheel system includes another configurable control topology;

wherein said configurable control topology and said another configurable control topology are limited and interlocked to ensure configurations that maintain stability of said steer-by-wire control system.