TRAILER LENGTH ESTIMATION IN HITCH ANGLE APPLICATIONS

• US 20140297128A1
• Filed: 06/11/2014
• Published: 10/02/2014
• Est. Priority Date: 04/19/2011
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lavoie, Erick Michael, Kyrtsos, Christos
• Granted Patent: US 9,335,163 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B60D 1/245 for facilitating push back or parking of trailers
• CPC Class Codes: B60D 1/62 involving supply lines, electric circuits, or the like
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 2050/143 Alarm means
• CPC Class Codes: B60W 2050/146 Display means
• CPC Class Codes: B60W 2300/14 Tractor-trailers, i.e. combinations of a towing vehicle and one or more towed vehicles, e.g. caravans; Road trains
• CPC Class Codes: B60W 2520/22 Articulation angle, e.g. between tractor and trailer
• CPC Class Codes: B60W 2540/00 Input parameters relating to occupants
• CPC Class Codes: B60W 2540/215 Selection or confirmation of options
• CPC Class Codes: B60W 30/00 Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: B60W 30/18036 Reversing
• CPC Class Codes: B60W 50/14 Means for informing the driver, warning the driver or prompting a driver intervention
• CPC Class Codes: B62D 13/06 for backing a normally drawn trailer
• CPC Class Codes: B62D 15/027 Parking aids, e.g. instruction means
• CPC Class Codes: G01B 21/06 specially adapted for measuring length or width of objects while moving

Abstract

A vehicle system for estimating a trailer length is disclosed and includes a first sensor for measuring a wheel steer angle and a second sensor for measuring a hitch angle. A processor is in communication with the first and second sensors and is operable to determine a wheel steer angle change and a hitch angle change. The processor performs a first computation if the wheel steer angle change and the hitch angle change satisfy a threshold requirement and performs a second computation if at least one of the wheel steer angle change and the hitch angle change does not satisfy the threshold requirement.

Claims

1. A device for estimating a trailer length, comprising:

a processor in communication with a wheel steer angle sensor and a hitch angle sensor, the processor operable to;

determine a wheel steer angle change and a hitch angle change;

perform a first computation if the wheel steer angle change and the hitch angle change are each within a predetermined range.

2. The device of claim 1, wherein the processor is further operable to perform a second computation if at least one of the wheel steer angle change and the hitch angle change is outside of the predetermined range.

3. The device of claim 2, wherein the predetermined range is between 0 and 0.035 radians.

4. The device of claim 3, wherein the first computation comprises calculating the trailer length based on a wheel base distance, a wheel steer angle measurement, and a hitch angle measurement.

5. The device of claim 4, wherein the second computation comprises:

sampling a wheel steer angle and a hitch angle to determine a peak wheel steer angle and a peak hitch angle;

computing a ratio between the peak wheel steer angle and the peak hitch angle; and

updating a running average of the ratio.

6. The device of claim 5, wherein the second computation further comprises calculating the trailer length based on an average ratio and a reference trailer length.

7. A vehicle system for estimating a trailer length, comprising:

a first sensor for measuring a wheel steer angle and a second sensor for measuring a hitch angle; and

a processor operable to;

determine a wheel steer angle change and a hitch angle change;

perform a first computation if the wheel steer angle change and the hitch angle change satisfy a threshold requirement; and

perform a second computation if at least one of the wheel steer angle change and the hitch angle change does not satisfy the threshold requirement.

8. The vehicle system of claim 7, wherein the threshold requirement is satisfied if the wheel steer angle change and the hitch angle change are within a predetermined range.

9. The vehicle system of claim 8, wherein the predetermined range is between 0 and 0.035 radians.

10. The vehicle system of claim 7, wherein the threshold requirement is satisfied if the wheel steer angle change and the hitch angle change each have an absolute value lesser than a predetermined minimum value.

11. The vehicle system of claim 10, wherein the predetermined minimum value is 0.035 radians.

12. The vehicle system of claim 7, wherein the first computation comprises calculating the trailer length based on a wheel base distance, a wheel steer angle measurement, and a hitch angle measurement.

13. The vehicle system of claim 7, wherein the second computation comprises:

sampling a wheel steer angle and a hitch angle to determine a peak wheel steer angle and a peak hitch angle;

computing a ratio between the peak wheel steer angle and the peak hitch angle; and

updating a running average of the ratio.

14. The vehicle system of claim 13, wherein the second computation further comprises calculating the trailer length based on an average ratio and a reference trailer length.

15. A method for estimating a trailer length, comprising the steps of:

sampling a wheel steer angle and a hitch angle to determine a wheel steer angle change and a hitch angle change;

determining if the wheel steer angle change and the hitch angle change satisfy a threshold requirement;

performing a first computation if the threshold requirement is satisfied; and

performing a second computation if the threshold requirement is not satisfied.

16. The method of claim 15, wherein the step of determining comprises comparing the wheel steer angle change and the hitch angle change to a predetermined range, wherein the threshold requirement is satisfied when the wheel steer angle change and the hitch angle change are within the predetermined range.

17. The method of claim 15, wherein the step of determining comprises:

taking an absolute value of the wheel steer angle change and the hitch angle change; and

comparing the absolute value of the wheel steer angle change and the hitch angle change to a predetermined minimum value;

wherein the threshold requirement is satisfied if the absolute value of the wheel steer angle change and the hitch angle change is greater than the predetermined minimum value.

18. The method of claim 15, wherein the step of performing the first computation comprises calculating the trailer length based on a wheel base distance, a wheel steer angle measurement, and a hitch angle measurement.

19. The method of claim 15, wherein the step of performing the second computation comprises:

sampling a wheel steer angle and a hitch angle to determine a peak wheel steer angle and a peak hitch angle;

computing a ratio between the peak wheel steer angle and the peak hitch angle; and

updating a running average of the ratio.

20. The vehicle system of claim 19, wherein the step of performing the second computation further comprises calculating the trailer length based on an average ratio and a reference trailer length.