Method and system for calibrating a vehicle speed

• US 20060265112A1
• Filed: 05/18/2005
• Published: 11/23/2006
• Est. Priority Date: 05/18/2005
• Status: Active Grant

• Current Assignee: FCA US LLC (Stellantis NV)
• Original Assignee: Chrysler Group LLC (Stellantis NV)
• Inventors: Hoeffel, James J., Basson, David A., Kocher, Charles W. II
• Granted Patent: US 7,574,292 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: B60T 2210/36 Global Positioning System [GPS]
• CPC Class Codes: B60T 2240/08 Spare wheel detection; Adjusting brake control in case of spare wheel use
• 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 2050/0075 Automatic parameter input, automatic initialising or calibrating means
• CPC Class Codes: B60W 2556/45 External transmission of data to or from the vehicle
• CPC Class Codes: B60W 40/105 Speed

Abstract

A method and system for calibrating speed of a vehicle having a plurality of wheels includes a wheel speed sensor coupled to each of the wheels for providing a first vehicle speed based on an average tire size associated with the plurality of wheels. A GPS sensor provides a second vehicle speed based on a change in position of the vehicle over a predetermined period of time. A control module automatically calibrates the speed of the vehicle based on a comparison of the first and second vehicle speeds.

Claims

1. A system for calibrating speed of a vehicle having a plurality of wheels, the system comprising:

a wheel speed sensor coupled to each of the wheels for providing a first vehicle speed based on an average tire size associated with the plurality of wheels;

a GPS sensor for providing a second vehicle speed; and

a control module for automatically calibrating the speed of the vehicle based on a comparison of the first and second vehicle speeds.

2. The system as recited in claim 1 wherein the control module is further provided for automatically calibrating the speed of the vehicle upon sensing a predetermined event.

3. The system as recited in claim 2 wherein the predetermined event is an ignition on of the vehicle.

4. The system as recited in claim 1 further comprising a vehicle speed display for displaying the calibrated speed of the vehicle.

5. The system as recited in claim 1 wherein the control module, in automatically calibrating the speed of the vehicle, further comprises:

determining a tire size error based on the first and second vehicle speeds;

comparing the tire size error to a predetermined threshold error; and

updating the average tire size if the tire size error exceeds the predetermined threshold error.

6. The system as recited in claim 1 wherein the control module, in automatically calibrating the speed of the vehicle, is further provided for determining if the vehicle is traveling in a straight direction.

7. The system as recited in claim 6 wherein the control module, in determining if the vehicle is traveling in a straight direction, further comprises:

determining a traveled wheel distance of each of the wheels of the vehicle; and

determining if any one of the traveled wheel distances differs from any one of the other traveled wheel distances.

8. The system as recited in claim 6 where the control module, in automatically calibrating the speed of the vehicle, is further provided for determining if the second vehicle speed exceeds a predetermined threshold speed.

9. A method for calibrating speed of a vehicle having a plurality of wheels, the method comprising:

sensing a first vehicle speed based on an average tire size associated with the plurality of wheels;

sensing a second vehicle speed based on global positioning data; and

automatically calibrating the speed of the vehicle based on a comparison of the first and second vehicle speeds.

10. The method as recited in claim 9 wherein the step of automatically calibrating the speed of the vehicle includes sensing a predetermined event.

11. The method as recited in claim 10 wherein the predetermined event is an ignition on of the vehicle.

12. The method as recited in claim 9 further comprising displaying the calibrated speed of the vehicle.

13. The method as recited in claim 9 wherein the step of automatically calibrating the speed of the vehicle further comprises the steps of:

determining a tire size error based on the first and second vehicle speeds;

comparing the tire size error to a predetermined threshold error; and

updating the average tire size if the tire size error exceeds the predetermined threshold error.

14. The method as recited in claim 9 wherein the step of automatically calibrating the speed of the vehicle further includes the step of determining if the vehicle is traveling in a straight direction.

15. The method as recited in claim 14 wherein the step of determining if the vehicle is traveling in a straight direction further comprises the steps of:

determining a traveled wheel distance of each of the wheels of the vehicle; and

determining if any one of the traveled wheel distances differs from any one of the other traveled wheel distances.

16. The method as recited in claim 14 wherein the step of automatically calibrating the speed of the vehicle further includes the step of determining if the second vehicle speed exceeds a predetermined threshold speed.