WHEEL LIFTED AND GROUNDED IDENTIFICATION FOR AN AUTOMOTIVE VEHICLE

• US 20080120005A1
• Filed: 01/27/2008
• Published: 05/22/2008
• Est. Priority Date: 09/25/2000
• Status: Active Grant

• Current Assignee: Jianbo Lu, Joseph Meyers, Michael Brewer, Todd Brown
• Original Assignee: Jianbo Lu, Joseph Meyers, Michael Brewer, Todd Brown
• Inventors: Brown, Todd, Brewer, Michael, Meyers, Joseph, LU, JIANBO
• Granted Patent: US 7,881,850 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• 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 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.

2. A method as recited in claim 1 wherein the plurality of wheel speed signals are used to generate the vehicle velocity signal.

3. A method as recited in claim 1 further comprising generating a yaw rate signal, said slip ratio being a function of said yaw rate signal.

4. A method as in claim 1 comprising:

determining a wheel speed;

determining a vehicle speeds

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.

5. A method as in claim 1 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.

6. A method as in claim 1 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.

7. A method as recited in claim 6 further comprising generating a wheel grounded signal in response to convergence of the slip power.

8. A method as recited in claim 6 wherein the slip power is a function of a slip ratio.

9. A method as recited in claim 8 wherein said slip ratio is determined as a function of wheel speed and the vehicle velocity.

10. A method as recited in claim 9 wherein said slip ratio is determined as a function of wheel speed, yaw rate and the vehicle velocity.

11. A method as in claim 1 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.

12. A method as recited in claim 11 further comprising when said slip power is negative, generating a wheel grounded signal.

13. A method as recited in claim 11 further comprising controlling a safety system in response to said wheel grounded signal.

14. A method as recited in claim 11 wherein determining a slip power comprises determining said slip power in response to the slip ratio and a time derivative of said slip ratio.

15. A method as recited in claim 11 wherein determining a slip ratio is determined as a function of wheel speed and said vehicle velocity.

16. A method as recited in claim 11 wherein determining a slip ratio is determined as a function of wheel speed, yaw rate and the vehicle velocity.

17. A method as in claim 1 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.

19. A method as in claim 9 further comprising generating a wheel grounded signal in response to said slip rate.

20. A method as in claim 9 further comprising controlling said safety system in response to said wheel grounded signal.

21. A method as in claim 9 wherein determining a slip rate comprises determining said slip rate in response to a velocity and a time derivative of a slip ratio.

22. A method as in claim 12 wherein said slip ratio is determined as a function of wheel speed and the vehicle velocity.

23. A method as in claim 12 wherein said slip ratio is determined as a function of wheel speed, yaw rate and the vehicle velocity.

24. A method as in claim 9 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.

25. A method as recited in claim 24 further comprising generating a wheel grounded signal in response to slip rate.

26. A method as recited in claim 24 wherein the slip rate is a function of a slip ratio.

30. A method as in claim 9 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.

31. A method as recited in claim 30 wherein said plurality of wheel speed signals are used to generate said vehicle velocity signal.

32. A method as recited in claim 30 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.

33. A method as recited in claim 32 further comprising generating a yaw rate signal, said slip ratio being a function of said yaw rate signal.

18. 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.

27. A method as recited in claim 27 wherein determining a slip ratio is determined as a function of wheel speed and said vehicle velocity.

28. A method as recited in claim 27 wherein said slip rate is a function of the time derivative of said slip ratio.

29. A method as recited in claim 27 wherein determining a slip ratio is determined as a function of wheel speed, yaw rate and said vehicle velocity.