Method for robust estimation of road bank angle

• US 6,351,694 B1
• Filed: 01/16/2001
• Issued: 02/26/2002
• Est. Priority Date: 01/16/2001
• Status: Expired due to Term

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Yester, John, Kuang, Ming Lang, Tseng, Hongtei Eric
• Primary Examiner(s): Beaulieu, Yonel
• Application Number:
  US09/761,157
• Time in Patent Office: 406 Days
• Field of Search: 701/1, 701/41, 701/72, 701/73, 701/71, 701/70, 303/140, 303/146, 303/150, 303/148, 180/197
• US Class Current: 701/1
• CPC Class Codes: B60T 2210/22 Banked curves
• 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

Abstract

A method for determining road bank angle in vehicle includes a lateral acceleration sensor (22) that generates a first signal corresponding to lateral acceleration. A yaw rate sensor (18) generates a second signal corresponding to a yaw rate signal. A controller (14) coupled to the sensors performs the step of calculating a first bank angle estimate dependent on the first signal, calculating a second bank angle estimate dependent on the second signal, calculating a third bank angle estimate dependent on both the first and second signals, calculating a dynamic compensation factor based as a function of the first bank angle estimate, the second bank angle estimate and the third bank angle estimate, decomposing the third bank angle estimate into a plurality of third bank angle frequency layers, reducing each of the plurality of third bank angle frequency layers in response to a multiplicative factor, said multiplicative factor being a function of the dynamic compensation factor to obtain a plurality of reduced third bank angles, and calculating a final bank angle bias estimate based on a sum of the plurality of reduced third bank angles.

Claims

1. A method of detecting a bank angle for use in a yaw control system for a motor vehicle, said method comprising the steps of:

providing a first signal corresponding to a lateral acceleration of the vehicle;

calculating a first bank angle estimate dependent on said first signal;

providing a second signal corresponding to a yaw rate of the vehicle;

calculating a second bank angle estimate dependent on said second signal;

calculating a third bank angle estimate dependent on both said first and second signals;

calculating a dynamic compensation factor based as a function of said first bank angle estimate, said second bank angle estimate and said third bank angle estimate;

decomposing the third bank angle estimate into a plurality of third bank angle frequency layers;

reducing each of the plurality of third bank angle frequency layers in response to a multiplicative factor, said multiplicative factor being a function of said dynamic compensation factor to obtain a plurality of reduced third bank angles;

calculating a final bank angle bias estimate based on a sum of the plurality of reduced third bank angles.

2. The method according to claim 1, further comprises the steps of:

providing a third signal responsive to a sensed steering wheel angle of the vehicle;

providing a fourth signal responsive to a vehicle longitudinal speed; and

calculating said first and second bank angle estimates using said third and said fourth signals.

3. The method according to claim 1, wherein said second signal corresponding to said yaw rate of said motor vehicle is determined using yaw rate sensor.

4. The method according to claim 1, wherein said second signal corresponding to said yaw rate of said motor vehicle is determined using a global positioning system.

5. The method according to claim 1, wherein said second signal corresponding to said yaw rate of said motor vehicle as a function of using wheel speed data.

6. The method according to claim 1, wherein said first signal corresponding to said lateral acceleration of said motor vehicle is determined using a lateral acceleration sensor.

7. The method according to claim 1, wherein said first signal corresponding to said lateral acceleration of said motor vehicle is determined using a GPS global positioning system.

8. The method according to claim 1, wherein said first signal corresponds to said lateral acceleration of said motor vehicle which is determined using a longitudinal velocity and a steering wheel angle.

9. The method according to claim 1, wherein said multiplicative factor may be characterized as a function output value having a range of between zero and one.

10. The method according to claim 1, further comprising the step of determining the multiplicative factor by determining a rate of change for said third road bank estimate.

11. The method according to claim 1, further comprising the step of determining the multiplicative factor by filtering said dynamic compensation factor.

12. The method according to claim 1, wherein the step of reducing comprises the step of reducing each of the plurality of third bank angle frequency layers in response to the multiplicative factor being a function of said dynamic compensation factor and said rate of change for said third road bank estimation.

13. The method according to claim 1, further comprising the step of estimating the lateral dynamics of the vehicle using the final road bank angle.

20. The method according to claim 13, further comprising the steps of calculating a second bank angle estimate dependent on said first signal, said third signal, and said fourth signal;

calculating a third bank angle estimate dependent on said second signal, said third signal, and said fourth signal; and

calculating a dynamic compensation factor as a function of said first bank angle, said second bank angle and said third bank angle.

21. The method according to claim 20, further comprising the step of determining the multiplicative factor by determining a rate of change for said first road bank estimation.

22. The method according to claim 20, further comprising the step of determining the multiplicative factor by filtering said dynamic compensation factor.

23. The method according to claim 20, wherein the step of reducing comprises the step of reducing each of the plurality of bank angle frequency layers in response to a multiplicative factor being a function of said dynamic compensation factor and said rate of change for said first road bank estimation.

14. A method of detecting a bank angle for use in a yaw control system for a motor vehicle, said method comprising the steps of:

providing

a first signal corresponding to a lateral acceleration of the vehicle;

providing a second signal corresponding to a yaw rate of the vehicle;

providing a third signal responsive to a sensed steering wheel angle of the vehicle;

providing a fourth signal corresponding to a vehicle speed;

calculating a first bank angle estimate dependent on said first signal, said second signal, and said fourth signal;

calculating a dynamic compensation factor in response to said first signal, said second signal, said third signal and said fourth signal;

decomposing the first bank angle estimate into a plurality of bank angle frequency layers;

reducing each of the plurality of bank angle frequency layers using a multiplicative factor, said multiplicative factor being a function of said dynamic compensation factor to obtain a plurality of reduced bank angles;

calculating a final bank angle estimate based on a sum of the plurality of reduced bank angles.

15. The method according to claim 14, wherein said second signal corresponding to said yaw rate of said motor vehicle is determined using wheel speed data.

16. The method according to claim 14, wherein said first signal corresponding to said lateral acceleration of said motor vehicle is determined using a longitudinal velocity and a steering wheel angle.

17. The method according to claim 14, wherein said function may be characterized as a function output value having a range of between zero and one.

18. The method according to claim 14, wherein said second signal corresponds to said yaw rate of said motor vehicle is determined using a yaw rate sensor.

19. The method according to claim 14, wherein said first signal corresponds to said lateral acceleration of said motor vehicle and is determined using a lateral acceleration sensor.

24. A system for controlling a vehicle comprising:

a lateral acceleration sensor generating a first signal corresponding to a lateral acceleration of the vehicle;

a yaw rate sensor generating a second signal corresponding to a yaw rate of the vehicle;

a controller coupled to said lateral acceleration sensor and said yaw rate sensor, said controller calculating a first bank angle estimate dependent on said first signal, calculating a second bank angle estimate dependent on said second signal, calculating a third bank angle estimate dependent on both said first and second signals, calculating a dynamic compensation factor based as a function of said first bank angle estimate, said second bank angle estimate and said third bank angle estimate, decomposing the third bank angle estimate into a plurality of third bank angle frequency layers, reducing each of the plurality of third bank angle frequency layers in response to a multiplicative factor, said multiplicative factor being a function of said dynamic compensation factor to obtain a plurality of reduced third bank angles, and calculating a final bank angle bias estimate based on a sum of the plurality of reduced third bank angles.