WHEEL LIFTED AND GROUNDED IDENTIFICATION FOR AN AUTOMOTIVE VEHICLE

• US 20060261937A1
• Filed: 07/31/2006
• Published: 11/23/2006
• Est. Priority Date: 09/25/2000
• Status: Active Grant

• Current Assignee: Jianbo Lu, Joseph Carr Meyers, Michael Edward Brewer, Todd Allen Brown
• Original Assignee: Jianbo Lu, Joseph Carr Meyers, Michael Edward Brewer, Todd Allen Brown
• Inventors: Brewer, Michael Edward, Meyers, Joseph Carr, Brown, Todd Allen, Lu, Jianbo
• Granted Patent: US 7,323,976 B2
• Time in Patent Office: Days
• US Class Current: 340/446
• CPC Class Codes: B60R 2021/0018 Roll-over
• CPC Class Codes: B60T 2210/22 Banked curves
• CPC Class Codes: B60T 2240/06 Wheel load; Wheel lift
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60W 2040/1307 Load distribution on each wheel suspension
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/16 Pitch
• CPC Class Codes: B60W 2520/18 Roll
• CPC Class Codes: B60W 2520/26 Wheel slip
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: B60W 40/103 Side slip angle of vehicle body
• CPC Class Codes: B60W 40/12 related to parameters of the vehicle itself , e.g. tyre models

Abstract

A control system (18) for an automotive vehicle (10) has a first roll condition detector (64A), a second roll condition detector (64B), a third roll condition detector (64C), and a controller (26) that uses the roll condition generated by the roll condition detectors (64A-C) to determine a wheel lift condition. Other roll condition detectors may also be used in the wheel lift determination. The wheel lift conditions may be active or passive or both.

Claims

1. A method of controlling a vehicle having a plurality of wheels comprising:

determining at least one parameter selected from a linear corner velocity, a rolling radius of a wheel, a rolling radius wheel departure angle, slip rate, a heave normal load, a non-heave normal load, and road torque; and

Generating a wheel lift signal in response to said at least one parameter.

2. A method as in claim 1 wherein a plurality of said parameters are determined, and generating said wheel lift signal in response to said plurality of parameters.

3. A method as in claim 1 comprising:

determining a slip rate;

generating said wheel lift signal in response to said slip rate; and

controlling a safety system in response to said wheel lift signal.

12. A method as in claim 1 or 4 comprising:

determining said heave normal load and said non-heave normal load;

determining a total normal load as a function of said heave normal load and said non-heave normal load;

generating said wheel lift signal in response to said total normal load; and

controlling a safety system of an automotive vehicle in response to said wheel lift signal.

13. A method as in claim 12 wherein said heave normal load is a function of a vertical acceleration.

14. A method as in claim 12 wherein said heave normal load is a function of a roll angle.

15. A method as in claim 14 wherein said roll angle is a relative roll angle.

16. A method as in claim 14 wherein said roll angle is a function of roll rate.

17. A method as in claim 12 wherein said heave normal load is a function of a vertical acceleration and a relative roll angle.

18. A method as in claim 12 wherein the heave normal load is a function of pitch angle.

19. A method as in claim 18 wherein said pitch angle is a relative pitch angle.

20. A method as in claim 18 wherein said pitch angle is a function of a pitch rate.

21. A method as in claim 12 wherein said heave normal load is a function of a vertical acceleration, relative roll angle and pitch angle and a vehicle mass.

22. A method as in claim 12 wherein said non-heave normal load is a function of a vertical acceleration.

23. A method as in claim 12 wherein said non-heave normal load is a function of roll angle.

24. A method as in claim 23 wherein said roll angle is a relative roll angle.

25. A method as in claim 23 wherein said roll angle is a function of roll rate.

26. A method as in claim 12 wherein said non-heave normal load is a function of a vertical acceleration and relative roll angle.

27. A method as in claim 12 wherein the non-heave normal load is a function of pitch angle.

28. A method as in claim 27 wherein said pitch angle is a relative pitch angle.

29. A method as in claim 27 wherein the pitch angle is a function of a pitch rate.

30. A method as in claim 12 wherein said non-heave normal load is a function of a vertical acceleration, a relative roll angle, a pitch angle, and a spring rate of vehicle mass.

31. A method as in claim 1 or 4 further comprising:

determining a pitch angle;

determining a roll angle;

determining a vertical acceleration;

determining a normal loading due to a heave motion in response to said pitch angle, said roll angle, said vertical acceleration and a mass of the vehicle;

determining a normal loading due to non-heave motion in response to said pitch angle, said roll angle, said vertical acceleration and a spring rate of a suspension of the vehicle;

determining a total normal load as a function of the normal loading due to the heave motion and a normal load due to non-heave motion;

generating said wheel lift signal in response to the total normal load; and

controlling a safety system of an automotive vehicle in response to said wheel lift signal.

32. A method as recited in claim 31 wherein the roll angle is a relative roll angle.

33. A method as recited in claim 31 wherein the roll angle is a function of roll rate.

34. A method as recited in claim 31 wherein the pitch angle is a relative pitch angle.

35. A method as recited in claim 31 wherein the pitch angle is a function of a pitch rate.

36. A method as recited in claim 1 or 4 further comprising:

generating a pitch rate signal;

generating a roll rate signal;

determining a roll angle from the roll rate signal and a pitch angle from the pitch angle signal;

determining normal loading due to a heave motion in response to said pitch angle, said roll angle, a vertical acceleration and a mass of the vehicle;

determining a normal loading due to non-heave motion in response to said pitch angle, said roll angle, a vertical acceleration and a spring rate of a suspension of the vehicle;

determining a total normal load as a function of the normal loading due to said heave motion and a normal load due to said non-heave motion;

generating said wheel lift signal in response to the total normal load; and

controlling a safety system in response to said wheel lift signal.

37. A method as recited in claim 36 wherein said roll angle is a relative roll angle.

38. A method as recited in claim 36 wherein said pitch angle is a relative pitch angle.

39. A method as recited in claim 1 or 4 comprising:

determining an actual road torque applied to the wheel;

determining a calculated road torque; and

generating said wheel lift signal in response to the calculated road torque and the actual road torque.

40. A method as recited in claim 39 wherein determining an actual road torque comprises determining an actual road torque as a function of wheel acceleration.

41. A method as recited in claim 39 wherein determining an actual road torque comprises determining an actual road torque as a function of wheel acceleration and driving torque.

42. A method as recited in claim 39 wherein determining an actual road torque comprises determining an actual road torque as a function of wheel acceleration and braking torque.

43. A method as recited in claim 39 wherein determining an actual road torque comprises determining an actual road torque as a function of wheel acceleration, driving torque and braking torque.

44. A method as recited in claim 39 wherein determining a calculated road torque comprises determining a calculated road torque in response to normal loading.

45. A method as recited in claim 39 wherein determining a calculated road torque in response to normal loading comprises determining a heave normal load and a non-heave normal load, and determining a total normal load as a function of the heave normal load and non-heave normal load.

46. A method as recited in claim 39 wherein determining a calculated road torque comprises determining a calculated road torque in response to normal loading and longitudinal wheel slip.

47. A method as in claim 1 or 4 comprising:

determining a braking torque;

determining a driving torque;

determining a wheel acceleration;

determining an actual road torque as a function of said wheel acceleration, said driving torque, and said braking torque;

determining a total normal load;

determining a calculated road torque in response to said total normal load;

comparing said actual road torque and said calculated road torque;

when said actual road torque is less than said calculated road torque, generating said wheel lift signal; and

controlling a safety device in response to said wheel lift signal.

48. A method as recited in claim 47 wherein determining a total normal load comprises determining a heave normal load and a non-heave normal load, and determining a total normal load as a function of said heave normal load and said non-heave normal load.

49. A method as recited in claim 47 wherein determining a total normal load as a function of said heave normal load and said non-heave normal load comprises determining a heave load in response to said pitch angle, said roll angle, said vertical acceleration and a mass of the vehicle.

50. A method as recited in claim 47 wherein determining a total normal load as a function of said heave normal load and said non-heave normal load comprises determining a non-heave load as a function of said pitch angle, said roll angle, said vertical acceleration and a spring rate of a suspension.

51. A method as recited in claim 47 wherein determining a calculated road torque comprises determining a calculated road torque in response to normal loading a longitudinal wheel slip.

58. A method as in claim 1 or 55 comprising:

determining a wheel speed;

determining a vehicle speed;

determining said linear corner velocity of a wheel as a function of said vehicle speed;

determining said rolling radius of a wheel as a function of said wheel speed and said linear corner velocity;

determining a rolling radius wheel departure angle as a function of said rolling radius;

generating said wheel lift signal in response to said rolling radius departure angle; and

controlling a safety system in response to the wheel lift signal.

59. A method as in claim 1 or 55 comprising:

determining a wheel speed;

determining said linear corner velocity of a wheel;

determining said rolling radius of a wheel as a function of said wheel speed and said linear corner velocity;

determining a rolling radius wheel departure angle as a function of said rolling radius; and

determining a wheel lift condition as a function of the operating input torque, the rotational speed of the wheel and the wheel response.

78. A method as in claim 3 or claim 63 comprising:

determining said slip rate with respect to a wheel;

comparing said slip rate to a threshold;

generating said wheel lift signal in response to said slip rate when said slip rate is above a threshold.

79. A method as recited in claim 78 further comprising generating a wheel grounded signal in response to slip rate.

80. A method as recited in claim 78 wherein the slip rate is a function of a slip ratio.

84. A method as in claim 3 or 63 comprising:

generating a plurality of wheel speed signals including a first wheel speed signal;

generating a vehicle velocity signal;

determining a slip ratio in response to said wheel speed signal and said vehicle velocity signal;

determining a slip rate in response to said slip ratio, when the slip rate is above a threshold; and

generating said wheel lift signal in response to said slip rate.

85. A method as recited in claim 84 wherein said plurality of wheel speed signals are used to generate said vehicle velocity signal.

86. A method as recited in claim 84 wherein said plurality of wheel speed signals are used to generate a corner velocity signal, wherein the slip rate is a function of said corner velocity signal.

87. A method as recited in claim 86 further comprising generating a yaw rate signal, said slip ratio being a function of said yaw rate signal.

4. A method of controlling a vehicle having a plurality of wheels comprising:

determining a wheel departure angle;

determining an actual road torque;

determining a wheel longitudinal slip; and

determining a wheel lift status for said plurality of wheels in response to said wheel departure angle, said actual road torque, and said wheel longitudinal slip.

5. A method as recited in claim 4 further comprising:

determining a relative roll angle;

determining a rolling radius-based wheel departure angle;

determining normal loading at each wheel; and

determining a wheel lift status for said plurality of wheels in response to said relative roll angle, said rolling radius-based wheel departure angle, and said normal loading at each wheel.

6. A method as recited in claim 5 wherein determining a relative roll angle comprises:

measuring a roll rate;

measuring a vehicle lateral acceleration; and

determining the relative roll angle in response to a vehicle roll rate and the vehicle lateral acceleration.

7. A method as recited in claim 6 wherein determining a rolling radius-based wheel departure angle comprises:

measuring a wheel speed;

determining a wheel linear velocity; and

determining the rolling radius-based wheel departure angle in response to the wheel speed and the wheel linear velocity.

8. A method as recited in claim 5 wherein determining normal loading at each wheel comprises determining a heave and non-heave load at each of the plurality of wheels.

9. A method as recited in claim 4 wherein determining a wheel departure angle comprises:

measuring a roll rate;

measuring a vehicle lateral acceleration; and

determining the wheel departure angle in response to a vehicle roll rate and the vehicle lateral acceleration.

10. A method as recited in claim 4 wherein determining an actual road torque comprises determining a driving torque, determining a braking torque and determining a wheel rotation inertia.

11. A method as recited in claim 4 wherein determining a wheel longitudinal slip comprises determining a slip power and a slip rate, and wherein determining a wheel lift status comprise determining a wheel lift status for said plurality of wheels in response to said slip power and said slip rate.

52. A method for controlling an automotive vehicle having a plurality of wheels comprising:

determining a first wheel lift condition;

determining a second wheel lift condition;

determining a third wheel lift condition; and

generating a wheel lift flag in response to said first wheel lift condition, said second wheel lift condition, and said third wheel lift condition.

53. A method as recited in claim 52 wherein generating a wheel lift flag comprises generating a wheel lift flag for each of the plurality of wheels.

54. A method as recited in claim 52 further comprising:

comparing the first wheel lift condition to a first threshold;

comparing the second wheel lift condition to a second threshold; and

comparing the third wheel lift condition to a third threshold;

wherein generating a wheel lift flag comprises generating a wheel lift flag in response to comparing said first wheel lift condition to a first threshold, comparing said second wheel lift condition to a second threshold, and comparing said third wheel lift condition to a third threshold.

55. A method for controlling an automotive vehicle comprising:

generating a plurality of wheel speed signals including a first wheel speed signal;

generating a vehicle velocity signal;

determining a slip ratio in response to the wheel speed signal and the vehicle velocity signal;

determining a slip power in response to the slip ratio, when the slip power is positive;

generating a wheel lift signal; and

controlling a safety system in response to the wheel lift signal.

56. A method as recited in claim 55 wherein the plurality of wheel speed signals are used to generate the vehicle velocity signal.

57. A method as recited in claim 55 further comprising generating a yaw rate signal, said slip ratio being a function of said yaw rate signal.

60. A method as in claim 55 comprising:

determining a slip power for a wheel;

determining convergence or divergence of the slip power;

generating said wheel lift signal in response to a divergence of said slip power; and

controlling a safety system in response to the wheel lift signal.

61. A method as recited in claim 60 further comprising generating a wheel grounded signal in response to convergence of the slip power.

62. A method as recited in claim 60 wherein the slip power is a function of a slip ratio.

63. A method as recited in claim 62 wherein said slip ratio is determined as a function of wheel speed and the vehicle velocity.

64. A method as recited in claim 63 wherein said slip ratio is determined as a function of wheel speed, yaw rate and the vehicle velocity.

65. A method as in claim 55 comprising:

determining a slip ratio;

determining a slip power in response to the slip ratio;

when the slip power is positive, generating a wheel lift signal; and

controlling a safety system in response to said wheel lift signal.

66. A method as recited in claim 65 further comprising when said slip power is negative, generating a wheel grounded signal.

67. A method as recited in claim 65 further comprising controlling a safety system in response to said wheel grounded signal.

68. A method as recited in claim 65 wherein determining a slip power comprises determining said slip power in response to the slip ratio and a time derivative of said slip ratio.

69. A method as recited in claim 65 wherein determining a slip ratio is determined as a function of wheel speed and said vehicle velocity.

70. A method as recited in claim 65 wherein determining a slip ratio is determined as a function of wheel speed, yaw rate and the vehicle velocity.

71. A method as in claim 55 comprising:

generating a plurality of wheel speed signals including a first wheel speed signal;

generating a vehicle velocity signal;

determining a slip ratio in response to said wheel speed signal and said vehicle velocity signal;

determining a slip rate in response to said slip ratio, when the slip rate is above a threshold; and

generating said wheel lift signal in response to said slip rate.

73. A method as in claim 63 further comprising generating a wheel grounded signal in response to said slip rate.

74. A method as in claim 63 further comprising controlling said safety system in response to said wheel grounded signal.

75. A method as in claim 63 wherein determining a slip rate comprises determining said slip rate in response to a velocity and a time derivative of a slip ratio.

76. A method as in claim 66 wherein said slip ratio is determined as a function of wheel speed and the vehicle velocity.

77. A method as in claim 66 wherein said slip ratio is determined as a function of wheel speed, yaw rate and the vehicle velocity.

72. A method of controlling automotive vehicle comprising:

determining a slip rate;

generating a wheel lift signal in response to slip rate; and

controlling a safety system in response to the wheel lift signal.

81. A method as recited in claim 81 wherein determining a slip ratio is determined as a function of wheel speed and said vehicle velocity.

82. A method as recited in claim 81 wherein said slip rate is a function of the time derivative of said slip ratio.

83. A method as recited in claim 81 wherein determining a slip ratio is determined as a function of wheel speed, yaw rate and said vehicle velocity.

88. A method of controlling an automotive vehicle having a wheel comprising:

determining an actual road torque applied to the wheel;

determining a calculated road torque; and

generating a wheel lift signal in response to the calculated road torque and the actual road torque.

89. A method as recited in claim 88 wherein determining an actual road torque comprises determining an actual road torque as a function of wheel acceleration.

90. A method as recited in claim 88 wherein determining an actual road torque comprises determining an actual road torque as a function of wheel acceleration and driving torque.

91. A method as recited in claim 88 wherein determining an actual road torque comprises determining an actual road torque as a function of wheel acceleration and braking torque.

92. A method as recited in claim 88 wherein determining an actual road torque comprises determining an actual road torque as a function of wheel acceleration, driving torque and braking torque.

93. A method as recited in claim 88 wherein determining a calculated road torque comprises determining a calculated road torque in response to normal loading.

94. A method as recited in claim 88 wherein determining a calculated road torque in response to normal loading comprises determining a heave normal load and a non-heave normal load, and determining a total normal load as a function of the heave normal load and non-heave normal load.

95. A method as recited in claim 88 wherein determining a calculated road torque comprises determining a calculated road torque in response to normal loading and longitudinal wheel slip.

96. A method for controlling an automotive vehicle having a plurality of wheels comprising:

measuring a yaw rate;

determining a lateral acceleration;

determining a roll rate;

determining longitudinal acceleration;

generating said wheel lift signal as a function of said yaw rate, said lateral acceleration, said roll rate and said longitudinal acceleration; and

controlling a safety system in response to said wheel lift signal.

97. A method as recited in claim 96 further comprising determining a pitch acceleration and, wherein determining wheel lift comprises determining wheel lift as a function of said yaw rate, said lateral acceleration, said roll rate, said longitudinal acceleration and said pitch acceleration.

98. A method as recited in claim 96 further comprising controlling said safety system to counteract wheel lift.