Method for determining the roll angle of a vehicle using an estimation of road bank angle

• US 6,804,584 B2
• Filed: 03/20/2002
• Issued: 10/12/2004
• Est. Priority Date: 03/20/2002
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Fodor, Michael G., Tseng, Hongtei Eric, Hrovat, Davorin David
• Primary Examiner(s): Nguyen, Thu V.
• Application Number:
  US10/101,998
• Publication Number:
  US 20030182025A1
• Time in Patent Office: 937 Days
• Field of Search: 701/1, 701/36-39, 701/41, 701/45, 701/48, 701/65, 701/71-75, 701/79-80, 701/82, 701/91-93, 701/121, 701/124, 244/179, 244/184, 180/271, 180/280, 180/282, 180/286, 180/289
• US Class Current: 701/1
• 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 17/019 characterised by the type of sensor or the arrangement thereof B60G17/01941 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 2400/0511 Roll angle
• CPC Class Codes: B60G 2400/0521 Roll rate
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2400/82 Ground surface
• CPC Class Codes: B60G 2600/602 high pass
• CPC Class Codes: B60G 2600/604 low pass
• CPC Class Codes: B60G 2800/012 Rolling condition
• CPC Class Codes: B60G 2800/0194 transversal with regard to vehicle
• CPC Class Codes: B60G 2800/24 Steering, cornering
• CPC Class Codes: B60G 2800/702 Improving accuracy of a sensor signal
• CPC Class Codes: B60T 2210/22 Banked curves
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• 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 2050/0055 High-pass filters
• CPC Class Codes: B60W 2050/0056 Low-pass filters
• CPC Class Codes: B60W 2510/20 : Steering systems
• CPC Class Codes: B60W 2520/10 : Longitudinal speed
• CPC Class Codes: B60W 2520/125 : Lateral acceleration
• CPC Class Codes: B60W 2520/18 : Roll
• CPC Class Codes: B60W 2540/18 : Steering angle
• CPC Class Codes: B60W 2552/00 : Input parameters relating to infrastructure
• CPC Class Codes: B60W 2552/15 : Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2720/18 : Roll
• CPC Class Codes: B60W 30/04 : related to roll-over prevention
• CPC Class Codes: B60W 40/112 : Roll movement

Abstract

A method for determining road bank angle in a vehicle includes a lateral acceleration sensor (22) that generates a lateral acceleration signal. A yaw rate sensor (18) generates a yaw rate signal. A roll rate sensor (23) generates a yaw rate signal. A controller (14) coupled to the sensors calculates a first roll angle signal in response to the roll rate signal and calculates a second roll angle signal corresponding to a suspension reference roll angle in response to the lateral acceleration signal. The controller calculates a bank angle signal in response to the lateral acceleration signal, the yaw rate signal, the steering wheel signal and the speed signal. The controller sums the first roll angle signal, the second roll angle signal and the bank angle signal to obtain a final roll angle estimate.

Claims

1. A system for controlling a vehicle comprising:

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

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

a steering wheel angle sensor generating a steering wheel angle signal corresponding to a steering wheel angle of the vehicle;

a speed sensor generating a speed signal corresponding to the longitudinal speed of the vehicle;

a roll rate sensor generating a roll rate signal; and

a controller coupled to said lateral acceleration sensor and said yaw rate sensor, said steering wheel angle sensor, said roll rate sensor and said speed sensor, said controller calculating a first roll angle signal in response to said roll rate signal, said controller calculating a second roll angle signal corresponding to a suspension reference roll angle in response to said lateral acceleration signal and a spring mass model, said controller calculating a first bank angle estimate dependent on said lateral acceleration signal, calculating a second bank angle estimate dependent on said yaw rate signal, calculating a third bank angle estimate dependent on both said lateral acceleration signal and said yaw rate signal, calculating a dynamic compensation factor 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 bands, reducing each of the plurality of third bank angle frequency bands 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, and determining a final roll angle estimate from the first roll angle signal, the second roll angle signal and the final bank angle bias estimate.

2. A system as recited in claim 1 further comprising a high pass filter filtering the first roll angle signal prior to determining.

3. A system as recited in claim 2 further comprising a first low pass filter filtering the dynamic compensation factor.

4. A system as recited in claim 1 further comprising a bank angle filter filtering the bank angle signal.

5. A system as recited in claim 1 wherein said controller comprises an integrator integrating said roll rate signal to obtain the first roll angle signal.

6. A method of determining a roll angle comprising:

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

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

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

providing a speed signal corresponding to a vehicle speed;

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

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

calculating a third bank angle estimate dependent on both said lateral acceleration signal and the yaw rate signal;

calculating a dynamic compensation factor 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 bands;

reducing each of the plurality of third bank angle frequency bands 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

calculating a suspension reference roll angle in response to said lateral acceleration signal and a spring mass model; and

calculating a conservative bank angle estimate signal in response to the final bank angle bias estimate and the suspension reference roll angle.

7. A method as recited in claim 6 further comprising providing a roll rate signal corresponding to the roll rate of the vehicle;

integrating the roll rate signal to obtain a roll-rate based roll angle; and

summing the conservative bank angle estimate, the suspension reference roll angle and the roll-rate based roll angle to obtain a final roll angle estimate.

8. A method as recited in claim 7 further comprising high pass filtering said roll-rate based roll angle prior to the summing.

9. A method as recited in claim 6 further comprising low pass filtering said conservative bank angle estimate signal.

10. The method according to claim 6, further comprising calculating said first bank angle estimate and said second bank angle estimate using said steering wheel angle signal and speed signal.

11. A method of determining a roll angle of a vehicle comprising:

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

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

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

providing a speed signal corresponding to a vehicle speed;

providing a roll rate signal corresponding to the roll rate of the vehicle;

calculating a first roll angle signal in response to said roll rate signal;

calculating a second roll angle signal corresponding to a suspension reference roll angle in response to said lateral acceleration signal and a spring mass model;

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

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

calculating a third bank angle estimate dependent on both said lateral acceleration signal and the yaw rate signal;

calculating a dynamic compensation factor 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 bands;

reducing each of the plurality of third bank angle frequency bands 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

determining a final bank angle bias estimate signal based on a sum of the plurality of reduced third bank angles; and

determining a final roll angle estimate in response to the first roll angle signal, the second roll angle signal, and the final bank angle bias estimate.

12. A method as recited in claim 11 further comprising high pass filtering said first roll angle signal before the step of summing.

13. A method as recited in claim 12 further comprising low pass filtering said second roll angle signal before summing and low pass filtering the bank angle signal before determining the final roll angle estimate.

14. A method as recited in claim 11 further comprising low pass filtering said dynamic compensation factor before determining the final roll angle estimate.

15. A method as recited in claim 11 wherein calculating a first roll angle signal comprises integrating the roll rate signal to obtain the roll-rate based roll angle.