LATERAL AND LONGITUDINAL VELOCITY DETERMINATION FOR AN AUTOMOTIVE VEHICLE

• US 20070005212A1
• Filed: 06/10/2005
• Published: 01/04/2007
• Est. Priority Date: 06/10/2005
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Xu, Li, Meyers, Joseph, Tseng, Hongtei
• Granted Patent: US 7,451,033 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60R 2021/01327 Angular velocity or angular acceleration
• 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 2250/04 Vehicle reference speed; Vehicle body speed
• 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 30/02 Control of vehicle driving stability
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: B60W 40/10 related to vehicle motion

Abstract

A system (18) for controlling a safety system (44) of an automotive vehicle (10) includes a longitudinal acceleration sensor (36), a vehicle speed sensor (20), a lateral acceleration sensor (32), a yaw rate sensor, and a controller (26). The controller (26) determines a stability index and provides a first observer that determines a reference longitudinal velocity in response to the longitudinal acceleration signal, the yaw rate signal, a pitch attitude and vehicle speed from wheel speed sensors. The controller (26) determines a reference lateral velocity in response to the lateral acceleration signal, the yaw rate signal, a roll attitude, a pitch attitude and vehicle speed from the wheel speed sensors. The controller provides a second observer that determines a second longitudinal velocity in response to the longitudinal acceleration signal, the yaw rate signal, a lateral velocity, the pitch attitude and a first adjustment based on the longitudinal reference velocity. The controller determines a second lateral velocity in response to the lateral acceleration signal, the yaw rate signal, a roll attitude, a pitch attitude and a second adjustment based on the lateral reference velocity. The controller determines an output lateral velocity and an output longitudinal velocity in response to the first observer, second observer and the stability index. The controller controls the safety system in response to the output lateral velocity and the output longitudinal velocity.

Claims

1. A system for controlling a safety system of an automotive vehicle comprising:

a plurality of wheel speed sensors;

a longitudinal acceleration sensor generating a longitudinal acceleration signal;

a vehicle speed sensor generating a vehicle speed signal;

a lateral acceleration sensor generating a lateral acceleration signal;

a yaw rate signal generating a yaw rate signal; and

a controller coupled to the longitudinal acceleration sensor, the vehicle speed sensor, the lateral acceleration sensor and the yaw rate sensor, said controller determining a stability index, providing a first observer determining a reference longitudinal velocity in response to the longitudinal acceleration signal, the yaw rate signal, a pitch attitude and vehicle speed from wheel speed sensors and determining a reference lateral velocity in response to the lateral acceleration signal, the yaw rate signal, a roll attitude, a pitch attitude and vehicle speed from the wheel speed sensors, said controller providing a second observer determining a second longitudinal velocity in response to the longitudinal acceleration signal, the yaw rate signal, a lateral velocity, the pitch attitude and a first adjustment based on the longitudinal reference velocity, said controller determining a second lateral velocity in response to the lateral acceleration signal, the yaw rate signal, a roll attitude, a pitch attitude and a second adjustment based on the lateral reference velocity, said controller determining an output lateral velocity and an output longitudinal velocity in response to the first observer, second observer and the stability index, said controller controlling the safety system in response to the output lateral velocity and the output longitudinal velocity.

2. A method as recited in claim 1 wherein the safety system comprises at least one of an antilock-brake system, roll stability control system, a traction control system and a yaw control system.

3. A method as recited in claim 1 wherein said controller determines an output lateral velocity and an output longitudinal velocity comprises said controller determining the output lateral velocity and the output longitudinal velocity in response to the first observer, second observer, the stability index and the wheel speed from wheel speed sensor.

4. A method of controlling a system of a vehicle comprising:

determining a stability index;

providing a first observer determining a reference longitudinal velocity in response to a longitudinal acceleration, yaw rate a pitch attitude and vehicle speed from wheel speed sensors and determining

a reference lateral velocity in response to a lateral acceleration, yaw rate, a roll attitude, a pitch attitude and vehicle speed from wheel speed sensors;

providing a second observer determining a second longitudinal velocity in response to a longitudinal acceleration, yaw rate, a lateral velocity, a pitch attitude and a first adjustment based on the longitudinal reference velocity and determining a second lateral velocity in response to a lateral acceleration, yaw rate, the roll attitude, the pitch attitude and a second adjustment based on the lateral reference velocity;

determining an output lateral velocity and an output longitudinal velocity in response to the first observer, second observer and the stability index;

controlling a vehicle system in response to the output lateral velocity and the output longitudinal velocity.

5. A method as recited in claim 4 wherein determining an output lateral velocity and an output longitudinal velocity comprises determining the output lateral velocity and the output longitudinal velocity in response to the first observer, second observer, the stability index and the wheel speed from wheel speed sensor.

6. A method as recited in claim 4 wherein determining an output lateral velocity and an output longitudinal velocity comprises determining the output lateral velocity and the output longitudinal velocity in response to the first observer when the yaw rate is above the stability index.

7. A method as recited in claim 4 wherein determining an output lateral velocity and an output longitudinal velocity comprises determining the output lateral velocity and the output longitudinal velocity in response to the first observer when the yaw rate is above the stability index and the wheel speed from wheel speed sensor is reliable.

8. A method as recited in claim 4 wherein determining an output lateral velocity and an output longitudinal velocity comprises determining the output lateral velocity and the output longitudinal velocity in response to the second observer when the yaw rate is below the stability index or the wheel speed from wheel speed sensor is unreliable.

9. A method as recited in claim 7 wherein the wheel speed is unreliable during antilock braking.

10. A method as recited in claim 4 further comprising resetting the reference lateral velocity and the second lateral velocity in response to a linear slip angle of a rear axle.

11. A method as recited in claim 4 further comprising resetting the reference lateral velocity and the second lateral velocity in response to a linear slip angle of a rear axle about zero.

12. A method as recited in claim 4 wherein the second observer is a kinematic-based observer.

13. A method of controlling a system of a vehicle comprising:

Generating a plurality of vehicle speed signals and generating vehicle speed in response to the plurality of wheel speed signals;

generating a lateral acceleration signal;

generating a yaw rate signal;

generating a longitudinal acceleration signal;

determining a stability index in response to the yaw rate signal;

determining a reference longitudinal velocity in response to the longitudinal acceleration signal, the yaw rate signal, a pitch attitude and vehicle speed from the plurality of wheel speed sensors;

determining a second longitudinal velocity in response to the longitudinal acceleration signal, the yaw rate signal, a lateral velocity, a pitch attitude;

determining an output longitudinal velocity from either the reference longitudinal velocity, the second longitudinal velocity in response to the stability index; and

controlling a vehicle system in response to the output longitudinal velocity.

14. A method as recited in claim 13 wherein determining an output longitudinal velocity comprises determining the output longitudinal velocity in response to the first observer, second observer, the stability index and the wheel speed from wheel speed sensor.

15. A method as recited in claim 13 wherein determining an output lateral velocity and an output longitudinal velocity comprises determining the output lateral velocity and the output longitudinal velocity in response to the first observer when the yaw rate is above the stability index.

16. A method as recited in claim 13 wherein determining an output lateral velocity and an output longitudinal velocity comprises determining the output lateral velocity and the output longitudinal velocity in response to the first observer when the yaw rate is above the stability index and the wheel speed from wheel speed sensor is reliable.

17. A method as recited in claim 13 wherein determining an output lateral velocity and an output longitudinal velocity comprises determining the output lateral velocity and the output longitudinal velocity in response to the second observer when the yaw rate is below the stability index or the wheel speed from wheel speed sensor is unreliable.

18. A method of controlling a system of a vehicle comprising:

generating a plurality of vehicle speed signals and generating vehicle speed in response to the plurality of wheel speed signals;

generating a lateral acceleration signal;

generating a longitudinal acceleration signal;

generating a yaw rate signal;

determining a stability index in response to the yaw rate signal;

determining a reference lateral velocity in response to the lateral acceleration signal, the yaw rate signal, a roll attitude, a pitch attitude and the vehicle speed from the plurality of wheel speed sensors;

determining a second lateral velocity in response to the lateral acceleration signal, the yaw rate signal, the roll attitude, the pitch attitude and a second adjustment based on the lateral reference velocity;

determining an output lateral velocity from either the reference lateral velocity, the second lateral velocity in response to the stability index; and

controlling a vehicle system in response to the output lateral velocity.

19. A method as recited in claim 18 further comprising resetting the reference lateral velocity and the second lateral velocity in response to a linear slip angle of a rear axle about zero.

20. A method as recited in claim 18 wherein determining an output lateral velocity and an output longitudinal velocity comprises determining the output lateral velocity and the output longitudinal velocity in response to the first observer when the yaw rate is above the stability index.

21. A method as recited in claim 18 wherein determining an output lateral velocity and an output longitudinal velocity comprises determining the output lateral velocity and the output longitudinal velocity in response to the first observer when the yaw rate is above the stability index and the wheel speed from wheel speed sensor is reliable.

22. A method as recited in claim 18 wherein determining an output lateral velocity and an output longitudinal velocity comprises determining the output lateral velocity and the output longitudinal velocity in response to the second observer when the yaw rate is below the stability index or the wheel speed from wheel speed sensor is unreliable.