TRAILER LENGTH ESTIMATION IN HITCH ANGLE APPLICATIONS

• US 20140277942A1
• Filed: 06/03/2014
• Published: 09/18/2014
• 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: Miller, Alex Maurice, Rhode, Douglas Scott, Kyrtsos, Christos, Pilutti, Thomas Edward
• Granted Patent: US 9,335,162 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• 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 2540/18 Steering angle
• 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 30/18036 Reversing
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• 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 21/02 for measuring length, width, or thickness G01B21/10 takes precedence
• CPC Class Codes: G01B 21/06 specially adapted for measuring length or width of objects while moving
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source
• CPC Class Codes: H04N 7/188 Capturing isolated or intermittent images triggered by the occurrence of a predetermined event, e.g. an object reaching a predetermined position signal generation from motion picture films H04N5/253

Abstract

A vehicle system for estimating a trailer length is disclosed. The system incorporates at least one sensor configured to measure a wheel steer angle and a trailer angle in communication with a processor. The processor is operable to determine a first length by a first computation method and determine a second length by a second computation method. The processor is further operable to validate an estimated trailer length based on the first length and the second length and perform a back-up function for the trailer based on the estimated trailer length.

Claims

1. An apparatus for determining an estimated trailer length comprising:

a processor operable to;

determine a first length having a first uncertainty;

determine a second length having a second uncertainty;

compare the first length to the second length in a first comparison; and

set the estimated trailer length to the first length based on the first comparison yielding a result less than a first predetermined value.

2. The apparatus according to claim 1, wherein comparing the first length and the second length comprises determining the difference between the first length and the second length to determine the result.

3. The apparatus according to claim 1, wherein the processor is further operable to:

compare the second length to a second predetermined value in a second comparison to determine if the second length is greater than the second predetermined value.

4. The apparatus according to claim 3, wherein the estimated trailer length is set to the first length in response to the first comparison and the second comparison to validate the estimated trailer length.

5. The apparatus according to claim 1, wherein the comparison of the first length and the second length comprises determining an optimized estimate of a trailer length uncertainty by combing the first uncertainty and the second uncertainty to determine the result as an absolute value of the difference between the first length and the second length.

6. The apparatus according to claim 1, wherein the processor is further operable to:

receive measurements of a wheel steer angle.

7. The apparatus according to claim 6, wherein the processor is further operable to:

receive measurements of a trailer angle.

8. The apparatus according to claim 7, wherein the first length is calculated based the wheel steer angle and a minimum error of the trailer angle with respect to time.

9. The apparatus according to claim 1, wherein the processor is further operable to:

determine a third length having a third uncertainty and set the trailer length to the third length in response to the comparison yielding a result greater than the first predetermined value.

10. A method for determining an estimated trailer length comprising:

receiving a steering angle from a steering module;

receiving a trailer angle from a hitch sensor;

calculating a first length based on the steering angle and a minimum error calculation of the trailer angle;

calculating a second length based on a radius of curvature of a trailer and a vehicle; and

evaluating the first length and the second length to determine the estimated trailer length.

11. The method according to claim 10, wherein the radius of curvature is calculated based on the steering angle and the trailer angle.

12. The method according to claim 10, wherein the first length and the second length are determined a plurality of times to improve the estimated trailer length over time.

13. The method according to claim 10, wherein the evaluating of the first length and the second length comprises:

determining a difference between the first length and the second length; and

comparing the difference to a first predetermined threshold to determine a first validation of the estimated trailer length.

14. The method according to claim 13, wherein the evaluating of the first length and the second length further comprises:

comparing the second length to a second predetermined threshold to determine a second validation of the estimated trailer length

15. The method according to claim 14, wherein the estimated trailer length is utilized for a vehicle trailer back-up assist function in response to the comparisons to the first predetermined threshold and the second predetermined threshold.

16. A vehicle system for estimating a trailer length comprising:

at least one sensor configured to measure a wheel steer angle and a trailer angle; and

a processor operable to;

determine a first length by a first computation method;

determine a second length by a second computation method; and

validate an estimated trailer length based on the first length and the second length; and

perform a back-up function for the trailer based on the estimated trailer length.

17. The vehicle system according to claim 16, wherein the first computation method comprises calculating the mean squared error of a rate of change of the trailer angle.

18. The vehicle system according to claim 16, wherein the second computation method comprises calculating a radius of curvature based on the wheel steer angle and the trailer angle.

19. The vehicle system according to claim 18, wherein the radius of curvature is calculated about a center of rotation of a vehicle in which the vehicle system is implemented.

20. The vehicle system according to claim 16, wherein the validation of the estimated trailer length comprises a comparison of the difference of the first length and the second length to a predetermined value.