System and method for characterizing the road bank for vehicle roll stability control

• US 20040030475A1
• Filed: 06/30/2003
• Published: 02/12/2004
• Est. Priority Date: 08/01/2002
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lu, Jianbo, Brown, Todd Allen, Samuel, Stephen Varghese
• Granted Patent: US 7,085,639 B2
• Time in Patent Office: Days
• US Class Current: 701/38
• 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 2400/41 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 2401/28 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 2800/702 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 2800/925 : Airbag deployment systems
• 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 2021/01313 : 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 21/013 : 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 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 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 8/1755 : 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: B60W 30/04 : related to roll-over prevention
• CPC Class Codes: B62D 6/002 : computing target steering angles for front or rear wheels B62D7/159 takes precedence

Abstract

A control system (18) for an automotive vehicle (10) having a vehicle body has a roll angular rate sensor (34) generating a roll angular rate signal corresponding to an roll angular motion of the vehicle body. A controller (26) is coupled to roll rate sensor and a plurality of sensors. The controller (26) generates a linear road bank angle, first reference bank angle and a relative roll angle in response to the roll angle generator and the plurality of sensor signals. The controller (26) determines a first reference bank angle and generates a second reference bank angle in response to linear bank angle and a first reference bank angle, a bank angle adjustment factor. The bank angle adjustment is a function of a relative roll angle estimate. The controller (26) controls the safety system in response to the second reference bank angle estimate.

Claims

1. A control system for an automotive vehicle having a vehicle body comprising:

a roll angle generator generating a relative roll angle signal;

a plurality of sensors generating a plurality of sensor signals;

a safety system; and

a controller coupled to roll angle generator and the plurality of sensors, said controller generating a linear road bank angle, first reference bank angle and a relative roll angle in response to the roll angle generator and the plurality of sensor signals, said controller determining a first reference bank angle and generating a second reference bank angle in response to linear bank angle and a first reference bank angle, a bank angle adjustment factor, said bank angle adjustment being a function of a relative roll angle estimate, said controller controlling the safety system in response to the second reference bank angle estimate.

2. A control system as recited in claim 1 wherein the roll angle generator comprises a roll rate sensor.

3. A control system as recited in claim 1 wherein the safety device comprises one selected from the group consisting of an active brake control system, an active rear steering system, an active front steering system, an active anti-roll bar system, and an active suspension system.

4. A method for controlling an automotive vehicle comprising:

determining a linear road bank angle;

determining a first reference bank angle;

generating a second reference bank angle in response to linear bank angle and a first reference bank angle, a bank angle adjustment factor, said bank angle adjustment being a function of a relative roll angle estimate; and

controlling a safety system in response to the second reference bank angle estimate.

5. A method as recited in claim 4 wherein the linear road bank angle is a difference between a global roll estimate and a relative roll angle estimate.

6. A method as recited in claim 4 wherein said bank angle adjustment factor is a function of a ramp rate.

7. A method as recited in claim 5 wherein the ramp rate is a function of a camber turn ramp rate.

8. A method as recited in claim 5 wherein the ramp rate is a function of a maximum ramp rate.

9. A method as recited in claim 4 wherein the bank angle adjustment factor is a function of a static roll boundary.

10. A method as recited in claim 4 wherein the bank angle adjustment factor is a function of a dynamic roll boundary.

11. A method as recited in claim 4 wherein the bank angle adjustment factor is a function of a pitch uncertainty rate.

12. A method as recited in claim 4 wherein the bank angle adjustment factor is a function of a static roll boundary, dynamic roll boundary, the relative roll estimate, a loop time and a maximum ramp rate and a pitch uncertainty rate.

13. A method as recited in claim 4 further comprising measuring a pitch rate;

and

adjusting the reference road bank angle as a function of pitch rate.

14. A method as recited in claim 4 further comprising measuring a pitch rate;

and

adjusting the reference road bank angle as a function of pitch rate and a wheel lift status.

15. A method as recited in claim 4 further comprising measuring a pitch rate;

and

adjusting the reference road bank angle as a function of pitch rate, a wheel lift status and a convergent/non-convergent condition.

16. A method as recited in claim 4 further comprising adjusting the reference road bank angle in response to an absolutely grounded condition.

17. A method as recited in claim 4 further comprising generating a wheel departure angle as a function of the reference road bank angle in response to the absolutely grounded condition.

18. A method as recited in claim 4 wherein the second reference bank angle is determined as a function of roll acceleration.

19. A method as recited in claim 4 wherein the second reference bank angle is determined as a function of lateral acceleration.

20. A method controlling an automotive vehicle comprising:

determining a linear road bank angle;

determining whether the vehicle is operating in a linear roll region, a transitional roll region or a divergent roll region;

when the vehicle is operating in the linear roll region, generating a second reference bank angle in response to a global roll and a linear bank angle adjustment factor;

when the vehicle is operating in the transitional roll region, generating a second reference bank angle in response to a first reference bank angle, a bank angle adjustment factor, said bank angle adjustment being a function of a relative roll angle estimate;

when the vehicle is operating in the divergent region, holding constant the reference bank angle; and

controlling a safety system in response to the second reference road bank angle.

21. A method as recited in claim 20 wherein determining whether the vehicle is operating in a linear roll region, a transitional roll region or a divergent roll region is performed in response to a relative roll angle.

22. A method as recited in claim 20 wherein determining whether the vehicle is operating in a linear roll region, a transitional roll region or a divergent roll region comprises determining a roll angle;

and

comparing the roll angle to a dynamic roll boundary and a static roll boundary.

23. A method as recited in claim 22 wherein when the roll angle is below the dynamic roll boundary, setting a region as a linear region.

24. A method as recited in claim 22 wherein when the roll angle is above the static roll boundary, setting a region as a divergent roll region.

25. A method as recited in claim 22 wherein when the roll angle is between the dynamic roll boundary and the static roll boundary, setting a region as a transitional roll region.

26. A method as recited in claim 20 wherein the linear road bank angle is a difference between a global roll estimate and a relative roll angle estimate.

27. A method as recited in claim 20 wherein said bank angle adjustment factor is a function of a ramp rate.

28. A method as recited in claim 27 wherein the ramp rate is a function of a camber turn ramp rate.

29. A method as recited in claim 27 wherein the ramp rate is a function of a maximum ramp rate.

30. A method as recited in claim 27 wherein the bank angle adjustment factor is a function of a static roll boundary.

31. A method as recited in claim 20 wherein the bank angle adjustment factor is a function of a dynamic roll boundary.

32. A method as recited in claim 20 wherein the bank angle adjustment factor is a function of a pitch uncertainty rate.

33. A method as recited in claim 20 wherein the bank angle adjustment factor is a function of a static roll boundary, dynamic roll boundary, the relative roll estimate, a loop time and a maximum ramp rate and a pitch uncertainty rate.

34. A method as recited in claim 20 further comprising measuring a pitch rate;

and

adjusting the reference road bank angle as a function of pitch rate.

35. A method as recited in claim 20 further comprising measuring a pitch rate;

and

adjusting the reference road bank angle as a function of pitch rate and a wheel lift status.

36. A method as recited in claim 20 further comprising measuring a pitch rate;

and

adjusting the reference road bank angle as a function of pitch rate, a wheel lift status and a convergent/non-convergent condition.

37. A method as recited in claim 20 further comprising adjusting the reference road bank angle in response to an absolutely grounded condition.

38. A method as recited in claim 20 further comprising generating a wheel departure angle as a function of the reference road bank angle in response to the absolutely grounded condition.

39. A method as recited in claim 20 wherein the second reference bank angle is determined as a function of roll acceleration.

40. A method as recited in claim 20 wherein the second reference bank angle is determined as a function of lateral acceleration.

41. A method as recited in claim 20 wherein activating a safety device comprises one selected from the group consisting of an active brake control system, an active rear steering system, an active front steering system, an active anti-roll bar system, and an active suspension system.