Wheel lift identification for an automotive vehicle

• US 20020056582A1
• Filed: 01/04/2002
• Published: 05/16/2002
• Est. Priority Date: 09/25/2000
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Chubb, Erik Christopher, Brown, Todd Allen
• Granted Patent: US 6,593,849 B2
• Time in Patent Office: Days
• US Class Current: 180/197
• CPC Class Codes: B60G 2400/208 of wheel rotation
• CPC Class Codes: B60G 2400/32 Torque on propulsion shaft
• CPC Class Codes: B60G 2800/012 Rolling condition
• CPC Class Codes: B60G 2800/70 Estimating or calculating vehicle parameters or state variables
• CPC Class Codes: B60G 2800/9124 Roll-over protection systems, e.g. for warning or control
• CPC Class Codes: B60G 2800/952 Electronic driving torque distribution
• CPC Class Codes: B60R 16/0233 Vehicle tilting, overturning or roll over
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 2240/06 Wheel load; Wheel lift
• CPC Class Codes: B60T 8/17551 determining control parameters related to vehicle stability used in the regulation, e.g. by calculations involving measured or detected parameters

Abstract

A system and method for detecting wheel lift of an automotive vehicle includes a yaw rate sensor (28) that generates a yaw rate signal, a lateral acceleration sensor (32) that generates a lateral acceleration signal, a roll rate sensor (34) generating a roll rate signal, and a longitudinal acceleration sensor (36) for generating a longitudinal acceleration signal. A controller (18) is coupled to the yaw rate sensor (28), the lateral acceleration sensor (32), the roll rate sensor (34), and the longitudinal acceleration sensor (36). The controller determines a dynamic load transfer acting on the plurality of wheels as a function of yaw rate, lateral acceleration roll rate, and longitudinal acceleration. Normal forces for each of the plurality of wheels is determined as a function of the dynamic load transfer. Wheel lift is indicated when at least one of the normal forces for each of the plurality of wheels is less than a normal force threshold.

Claims

1. A method for controlling an automotive vehicle having a plurality of wheels comprising:

measuring a yaw rate;

measuring a lateral acceleration;

measuring a roll rate;

measuring longitudinal acceleration; and

determining wheel lift as a function of yaw rate, lateral acceleration, roll rate and longitudinal acceleration.

2. A method as recited in claim 1 further comprising determining a pitch acceleration and, wherein determining wheel lift comprises determining wheel lift as a function of yaw rate, lateral acceleration, roll rate, longitudinal acceleration and pitch acceleration.

3. A method as recited in claim 1 further comprising determining a normal force attributable to a sway bar, wherein determining wheel lift comprises determining wheel lift as a function of yaw rate, lateral acceleration, roll rate longitudinal acceleration the normal force attributable to a sway bar.

4. A method as recited in claim 1 further comprising the step of counteracting wheel lift.

5. A method for determining wheel lift of a wheel of an automotive vehicle comprising:

estimating a normal force acting on the wheel;

comparing the normal force to a normal force threshold; and

indicating wheel lift when the normal force of the wheel is less than the normal force threshold.

6. A method as recited in claim 5 wherein determining a normal force comprises:

measuring a lateral acceleration;

measuring a yaw rate;

measuring a lateral acceleration;

measuring a roll rate;

measuring longitudinal acceleration; and

determining the normal force as a function of yaw rate, lateral acceleration, roll rate and longitudinal acceleration.

7. A method as recited in claim 6 further comprising determining a pitch acceleration and, wherein determining the normal force as a function of yaw rate, lateral acceleration, roll rate, longitudinal acceleration and pitch acceleration.

8. A method as recited in claim 6 further comprising determining a normal force attributable to a sway bar, wherein determining the normal force comprises determining the normal force as a function of yaw rate, lateral acceleration, roll rate longitudinal acceleration the normal force attributable to a sway bar.

9. A method as recited in claim 5 determining normal forces for wheels as a function of a static normal force and a dynamic load transfer.

10. A method as recited in claim 5 further comprising the step of counteracting wheel lift.

11. A method for monitoring a condition of an automotive vehicle having a plurality of wheels comprising:

determining a static normal force acting on said plurality of wheels;

determining a dynamic load transfer acting on said plurality of wheels;

determining normal forces for each of said plurality of wheels in as a function of the static normal force and the dynamic load transfer; and

indicating wheel lift when at least one of the normal forces for each of said plurality of wheels is less than the normal force threshold.

12. A method as recited in claim 11 wherein the normal forces are a function pitch angle.

13. A method as recited in claim 11 wherein the normal forces are a function of road bank angle.

14. A method as recited in claim 11 wherein determining a dynamic load transfer acting on said plurality of wheels comprises measuring a yaw rate;

measuring a lateral acceleration;

measuring a roll rate;

measuring longitudinal acceleration; and

determining a dynamic load transfer acting on said plurality of wheels as a function of yaw rate, lateral acceleration, roll rate and longitudinal acceleration.

15. A method as recited in claim 14 further comprising determining a pitch acceleration and, wherein a dynamic load transfer comprises determining a dynamic load transfer as a function of yaw rate, lateral acceleration, roll rate, longitudinal acceleration and pitch acceleration.

16. A method as recited in claim 14 further comprising determining a normal force attributable to a sway bar, wherein determining a dynamic load transfer comprises determining a dynamic load transfer as a function of yaw rate, lateral acceleration, roll rate longitudinal acceleration the normal force attributable to a sway bar.

17. A method as recited in claim 11 further comprising the step of counteracting wheel lift.

19. A system as recited in claim 18 wherein said controller determines a pitch acceleration and, determines a dynamic load transfer as a function of yaw rate, lateral acceleration, roll rate, longitudinal acceleration and pitch acceleration.

20. A system as recited in claim 18 wherein said controller determines a normal force attributable to a sway bar and determines a dynamic load transfer as a function of yaw rate, lateral acceleration, roll rate longitudinal acceleration the normal force attributable to a sway bar.

18. A system for detecting lift of a wheel of an automotive vehicle comprising:

a yaw rate sensor generating a yaw rate signal;

a lateral acceleration sensor generating a lateral acceleration signal;

a roll rate sensor generating a roll rate signal;

a longitudinal acceleration sensor generating a longitudinal acceleration signal; and

a controller coupled to said yaw rate sensor, said lateral acceleration sensor, said roll rate sensor and said longitudinal acceleration sensor, said controller determining a dynamic load transfer acting on said plurality of wheels as a function of yaw rate, lateral acceleration, roll rate and longitudinal acceleration, determining normal forces for each of said plurality of wheels as a function of the dynamic load transfer, and indicating wheel lift when at least one of the normal forces for each of said plurality of wheels is less than a normal force threshold.