Passive wheel lift identification for an automotive vehicle using operating input torque to wheel

• US 7,233,236 B2
• Filed: 06/27/2003
• Issued: 06/19/2007
• Est. Priority Date: 09/25/2000
• Status: Expired due to Term

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lu, Jianbo, Brewer, Michael Edward, Meyers, Joseph Carr, Brown, Todd Allen
• Primary Examiner(s): GOINS, DAVETTA WOODS
• Application Number:
  US10/608,908
• Publication Number:
  US 20040010383A1
• Time in Patent Office: 1,453 Days
• Field of Search: 340/447, 340/444, 340/466, 340/467, 340/440, 340/441, 701/70, 701/38, 701/74, 701/75, 701/83, 701/84, 701/71, 303/140, 303/146, 180/197
• US Class Current: 340/440
• CPC Class Codes: B60G 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2300/026 Heavy duty trucks
• CPC Class Codes: B60G 2400/0521 Roll rate
• CPC Class Codes: B60G 2400/0523 Yaw rate
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/106 longitudinal with regard to vehicle, e.g. braking
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/208 of wheel rotation
• CPC Class Codes: B60G 2400/32 Torque on propulsion shaft
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2400/4122 Neutral position detection
• CPC Class Codes: B60G 2400/61 Load distribution
• CPC Class Codes: B60G 2401/12 Strain gauge
• CPC Class Codes: B60G 2401/174 Radar
• CPC Class Codes: B60G 2401/28 Gyroscopes
• CPC Class Codes: B60G 2800/012 Rolling condition
• CPC Class Codes: B60G 2800/0194 transversal with regard to vehicle
• CPC Class Codes: B60G 2800/215 by applying a braking action on each wheel individually
• CPC Class Codes: B60G 2800/24 Steering, cornering
• CPC Class Codes: B60G 2800/70 : Estimating or calculating vehicle parameters or state variables
• CPC Class Codes: B60G 2800/702 : Improving accuracy of a sensor signal
• CPC Class Codes: B60G 2800/85 : System Prioritisation
• CPC Class Codes: B60G 2800/91 : Suspension Control
• CPC Class Codes: B60G 2800/9122 : ARS - Anti-Roll System Control
• CPC Class Codes: B60G 2800/9124 : Roll-over protection systems, e.g. for warning or control
• CPC Class Codes: B60G 2800/92 : ABS - Brake Control
• CPC Class Codes: B60G 2800/922 : EBV - Electronic brake force distribution
• CPC Class Codes: B60G 2800/952 : Electronic driving torque distribution
• CPC Class Codes: B60G 2800/96 : ASC - Assisted or power Steering control
• CPC Class Codes: B60G 2800/962 : Four-wheel steering
• CPC Class Codes: B60R 16/0233 : Vehicle tilting, overturning or roll over
• CPC Class Codes: B60R 2021/0018 : Roll-over
• CPC Class Codes: B60R 2021/01122 : Prevention of malfunction
• CPC Class Codes: B60R 2021/01313 : monitoring the vehicle steering system or the dynamic control system
• CPC Class Codes: B60R 2021/01322 : comprising variable thresholds, e.g. depending from other collision parameters
• CPC Class Codes: B60R 2021/01327 : Angular velocity or angular acceleration
• CPC Class Codes: B60R 21/01 : Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents electrical circuits for transmission of signals between steering wheel and the vehicle itself B60R16/027; for electrically actuating belt retractor locking means B60R22/343
• CPC Class Codes: B60R 21/013 : including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/0132 : responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: B60T 17/22 : Devices for monitoring or checking brake systems; Signal devices
• CPC Class Codes: B60T 2210/22 : Banked curves
• CPC Class Codes: B60T 2230/03 : Overturn, rollover
• CPC Class Codes: B60T 2240/06 : Wheel load; Wheel lift
• CPC Class Codes: B60T 2270/413 : Plausibility monitoring, cross check, redundancy
• CPC Class Codes: B60T 8/00 : Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force by changing number of effective brake cylinders in power brake systems B60T17/10
• 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: B60T 8/175 : Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16
• CPC Class Codes: B60T 8/1755 : Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60T 8/243 : for roll-over protection
• CPC Class Codes: B60T 8/885 : using electrical circuitry
• CPC Class Codes: B60W 30/04 : related to roll-over prevention

Abstract

A control system (18) and method for an automotive vehicle (10) used for detecting lift of a wheel includes a speed sensor (20) coupled to the wheel producing a wheel speed signal and a torque control system (57) coupled to the wheel for generating an operating input torque to the wheel. A controller (26) is coupled to the torque control system (57) and the wheel speed sensor (20). The controller (26) determines a wheel response to the operating input torque and generates a wheel lift signal as a function of the operating input torque, the wheel speed signal and the wheel response.

Claims

1. A method for passively determining wheel lift of a wheel of an automotive vehicle comprising:

providing an operating input torque to the wheel;

determining the operating input torque to the wheel;

determining a rotational speed of the wheel;

determining a wheel response to the operating input torque;

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

determining a wheel response comprises determining a wheel slip rate for the wheel;

determining a wheel lift condition comprises determining a wheel lift condition in response to comparing the wheel slip rate to a slip rate threshold; and

determining a slip ratio in response to the rotational speed of the wheel and wherein determining a wheel response and a wheel lift condition comprises determining a sign of the slip ratio or a sign of the slip rate.

2. A method as recited in claim 1 wherein the slip rate threshold is a function of the operating wheel torque.

3. A method as recited in claim 1 wherein determining a wheel response comprises determining a wheel acceleration.

4. A method as recited in claim 3 wherein determining a wheel lift condition comprises determining a wheel lift condition in response to comparing the wheel acceleration to a wheel acceleration threshold.

5. A method as recited in claim 4 wherein the acceleration threshold is a function of the operating wheel torques.

6. A method as recited in claim 3 further comprising determining a slip ratio in response to the rotational speed of the wheel, wherein determining a wheel response further comprises determining a sign of the slip ratio and a sign of the wheel acceleration and wherein determining a wheel lift condition comprises determining a wheel lift condition as a function of the sign of the slip ratio and the sign of the wheel acceleration.

7. A method as recited in claim 1 wherein determining a wheel response comprises determining a wheel slip ratio for the wheel and a wheel acceleration.

8. A method as recited in claim 7 wherein determining a wheel lift condition comprises determining a wheel lift condition in response to comparing the wheel acceleration to a wheel acceleration threshold and comparing the wheel slip rate to a slip rate threshold.

9. A method as recited in claim 4 wherein the acceleration threshold and the slip rate threshold are a function of the operating input torque.

10. A method as recited in claim 1 further comprising determining a sign of the operating torque, determining a sign of the wheel slip ratio and determining a sign of the wheel acceleration, wherein determining a wheel lift condition comprises comparing the sign of the operating torque to the sign of the wheel slip ratio and the sign of the wheel acceleration.

11. A method as recited in claim 1 wherein determining a wheel lift condition comprises generating a possible wheel lift signal, a possibly grounded signal, a wheel grounded signal, a wheel lifted signal.

12. A method as recited in claim 1 further comprising determining a slip rate for the wheel, a wheel acceleration and a slip ratio wherein determining a wheel lift condition in response to the input torque, the rotational speed and the wheel response comprises determining a wheel lift condition in response to the input torque, the wheel acceleration, wheel slip ratio and wheel slip rate.

13. A method as recited in claim 1 further comprising repeating determining the operating input torque to the wheel, determining a rotational speed of the wheel, determining a wheel response to the operating input torque, determining a wheel lift for a predetermined number of cycles, and when the wheel lift condition is determined a predetermined number of times, generating a wheel lifted signal.

14. A method for passively determining wheel lift of a wheel of an automotive vehicle comprising:

providing an operating input torque to the wheel;

determining a magnitude of the operating input torque to the wheel;

determining a wheel response to the operating input torque comprising determining a wheel acceleration;

generating a wheel lift signal and a wheel grounded signal as a function of the magnitude of the operating input torque and the wheel response; and

determining a slip ratio in response to a rotational speed of the wheel, wherein determining a wheel response further comprises determining a sign of the slip ratio or a sign of the wheel acceleration.

15. A method as recited in claim 14 wherein determining a wheel response comprises determining a wheel slip rate for the wheel.

16. A method as recited in claim 15 wherein determining a wheel lift condition comprises determining a wheel lift condition in response to comparing the wheel slip rate to a slip rate threshold.

17. A method as recited in claim 15 further comprising determining a slip ratio in response to a rotational speed of the wheel and wherein determining a wheel response further comprises determining a wheel response comprises determining a sign of the slip ratio and a sign of the slip rate and wherein generating a wheel lift signal comprises generating a wheel lift signal as a function of the sign of the slip ratio and the sign of the slip rate.

18. A method as recited in claim 14 wherein determining a wheel response comprises determining a wheel acceleration.

19. A method as recited in claim 18 wherein generating a wheel lift signal comprises generating a wheel lift signal in response to comparing the wheel acceleration to a wheel acceleration threshold.

20. A method for passively determining wheel lift of a wheel of an automotive vehicle comprising:

applying an operating input torque to a wheel;

passively determining an input torque magnitude and input torque direction;

determining wheel slip for the wheel;

determining a wheel response to the operating input torque;

determining a wheel response threshold in response to the operating input torque;

comparing the wheel response to the wheel response threshold; and

generating a wheel lifted signal or wheel grounded signal in response to the operating input torque, the wheel slip and comparing the wheel response.

21. A method as recited in claim 20 wherein indicating comprises indicating a possibly lifted signal or possibly grounded signal.

22. A method as recited in claim 20 wherein the wheel response comprises a wheel slip rate and the wheel response threshold comprises a wheel slip rate threshold.

23. A method as recited in claim 20 wherein the wheel response comprises wheel acceleration and the wheel response threshold comprises a wheel acceleration threshold.

24. A method as recited in claim 20 wherein the wheel response comprises a wheel slip rate and wheel acceleration.

25. A method for passively determining wheel lift of a wheel of an automotive vehicle comprising the steps of:

applying an operating input torque to a wheel;

passively determining an input torque magnitude and input torque direction;

determining a wheel slip in response to the operating input torque;

determining a wheel slip threshold in response to the operating input torque;

comparing the wheel slip to the wheel slip threshold;

generating a wheel lifted signal when the wheel slip is above the wheel response threshold, the input torque magnitude is high and the and the wheel slip is diverging; and

when the input torque magnitude is large, the wheel slip is near zero, generating a grounded wheel signal.

26. A method as recited in claim 25 further comprising when the input torque is near zero and the wheel slip is converging, generating a grounded wheel signal.

27. A method as recited in claim 25 further comprising when the input torque is near zero and the wheel slip is non-convergent, generating a wheel lift signal.

28. A method as recited in claim 25 wherein wheel slip comprises a wheel slip rate.

29. A method as recited in claim 25 wherein wheel slip comprises a slip ratio.

30. A method as recited in claim 25 further comprising determining a wheel acceleration in response to the operating input torque;

determining a wheel acceleration threshold in response to the operating input torque;

comparing the wheel acceleration to the wheel acceleration threshold; and

generating a wheel lifted signal when the wheel acceleration is above the wheel acceleration threshold, the wheel slip is above the wheel slip threshold, the input torque magnitude is high and the wheel slip and acceleration are diverging.

31. A system for detecting lift of a wheel of an automotive vehicle comprising:

a speed sensor coupled to the wheel producing a wheel speed signal;

a torque control system coupled to the wheel for generating an operating input torque to the wheel; and

a controller coupled to the said torque control system and the wheel speed sensor, said controller determining a wheel response in response to the operating input torque, said controller generating a wheel lift signal as a function of the operating input torque, the wheel speed signal and the wheel response, said controller further determining a wheel lift condition in response to the input torque, the wheel acceleration, the slip ratio, and the slip rate;

further determining a slip ratio in response to a rotational speed of the wheel and wherein determining a wheel response and generating a wheel lift signal comprises determining a sign of the slip ratio or a sign of the slip rate.

32. A system as recited in claim 31 further comprising a yaw rate sensor generating a yaw rate signal, said slip ratio being a function of the yaw rate signal.

33. A system as recited in claim 31 wherein the wheel response comprises a wheel slip ratio.

34. A system as recited in claim 31 wherein the wheel response comprises a wheel acceleration.

35. A system as recited in claim 31 wherein the wheel response comprises a wheel slip rate.