Trailer length estimation in hitch angle applications

• US 9,335,163 B2
• Filed: 06/11/2014
• Issued: 05/10/2016
• 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
• Primary Examiner(s): CAMBY, RICHARD M
• Application Number:
  US14/301,919
• Publication Number:
  US 20140297128A1
• Time in Patent Office: 699 Days
• Field of Search: 701/41
• US Class Current: 1/1
• 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 vehicle system comprising:

a wheel steer angle sensor;

a hitch angle sensor; and

a processor configured to;

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

calculate a trailer length based on a wheel base distance, a wheel steer angle measurement, and a hitch angle measurement if the wheel steer angle change and the hitch angle change are each within a predetermined range.

2. The vehicle system of claim 1, wherein if at least one of the wheel steer angle change and the hitch angle change is outside of the predetermined range, the processor is further configured to:

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

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

update a running average of the ratio.

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

4. The vehicle system of claim 2, wherein the processor is further configured to calculate the trailer length based on an average ratio between the peak wheel steer angle and the peak hitch angle and a reference trailer length.

5. A vehicle system comprising:

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

a processor operable configured to;

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

calculate a trailer length based on a wheel base distance, a wheel steer angle measurement, and a hitch angle measurement if the wheel steer angle change and the hitch angle change satisfy a threshold requirement; and

calculate the trailer length based on an average ratio between a peak wheel steer angle and a peak hitch angle and a reference trailer length if at least one of the wheel steer angle change and the hitch angle change fails to satisfy the threshold requirement.

6. The vehicle system of claim 5, wherein the threshold requirement is satisfied if the wheel steer angle change and the hitch angle change are within a predetermined range.

7. The vehicle system of claim 6, wherein the predetermined range is between 0 and 0.035 radians.

8. The vehicle system of claim 5, 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.

9. The vehicle system of claim 8, wherein the predetermined minimum value is 0.035 radians.

10. The vehicle system of claim 5, wherein the processor is further configured to:

sample a wheel steer angle and a hitch angle to determine the peak wheel steer angle and the peak hitch angle;

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

update a running average of the ratio.

11. A method comprising the steps of:

providing a wheel steer angle sensor and a hitch angle sensor;

providing a processor configured to;

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

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

calculate a trailer length based on a wheel base distance, a wheel steer angle measurement, and a hitch angle measurement if the threshold requirement is satisfied.

12. The method of claim 11, wherein the processor compares the wheel steer angle change and the hitch angle change to a predetermined range, and wherein the threshold requirement is satisfied when the wheel steer angle change and the hitch angle change are within the predetermined range.

13. The method of claim 11, wherein the processor is further configured to:

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

compare 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.

14. The method of claim 11, wherein the processor is further configured to:

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

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

update a running average of the ratio.

15. The method of claim 14, wherein if the threshold requirement is not satisfied, the processor is further configured to calculate the trailer length based on an average ratio between the peak wheel steer angle and the peak hitch angle and a reference trailer length.