TRAILER BACKUP ASSIST SYSTEM WITH HITCH ANGLE OFFSET ESTIMATION

• US 20170106796A1
• Filed: 10/18/2016
• Published: 04/20/2017
• Est. Priority Date: 10/19/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Daavettila, Tyler, Bell, Robert, Lavoie, Erick Michael, Mattern, Donald Jacob, Raad, Joseph M.
• Granted Patent: US 10,384,607 B2
• Time in Patent Office: Days
• CPC Class Codes: B60R 2300/207 using multi-purpose displays, e.g. camera image and navigation or video on same display
• CPC Class Codes: B60R 2300/302 combining image information with GPS information or vehicle data, e.g. vehicle speed, gyro, steering angle data
• CPC Class Codes: B60R 2300/8086 for vehicle path indication
• CPC Class Codes: B62D 13/06 for backing a normally drawn trailer
• CPC Class Codes: G01B 11/272 using photoelectric detection means

Abstract

A system for estimating hitch angle offset is provided herein. A sensor system is configured to measure hitch angles between a vehicle and a trailer attached thereto. A controller is configured to calculate hitch angle offsets for a plurality of measured hitch angles, and extrapolate additional hitch angle offsets based on the calculated hitch angle offsets.

Claims

1. A system for estimating hitch angle offset comprising:

a sensor system configured to measure hitch angles between a vehicle and a trailer attached thereto; and

a controller configured to;

calculate hitch angle offsets for a plurality of measured hitch angles; and

extrapolate additional hitch angle offsets based on the calculated hitch angle offsets.

2. The system of claim 1, wherein the sensor system comprises a camera of the vehicle that monitors a target on the trailer.

3. The system of claim 1, wherein each of the hitch angle offsets are calculated when a corresponding measured hitch angle is substantially constant.

4. The system of claim 1, wherein each of the hitch angle offsets are calculated as a function of a trailer length, a wheelbase length, a drawbar length, and a steering angle.

5. The system of claim 1, wherein each of the hitch angle offsets are calculated when a yaw rate of the vehicle and the trailer are substantially equal and constant.

6. The system of claim 1, wherein the controller performs a curve fit between the calculated hitch angle offsets to estimate the additional hitch angle offsets, the additional hitch angle offsets being related to measurable hitch angles falling within an operating range of a trailer backup assist system.

7. The system of claim 6, wherein the curve fit is one of a linear function and a higher order function.

8. A system for estimating hitch angle offset comprising:

a sensor system configured to measure hitch angles between a vehicle and a trailer attached thereto; and

a controller configured to;

calculate hitch angle offsets for a plurality of measured hitch angles when a yaw rate of the vehicle and the trailer are substantially equal and constant; and

extrapolate additional offsets based on the calculated hitch angle offsets.

9. The system of claim 8, wherein the sensor system comprises a camera of the vehicle that monitors a target on the trailer.

10. The system of claim 8, wherein each of the hitch angle offsets are calculated when a corresponding measured hitch angle is substantially constant.

11. The system of claim 8, wherein each of the hitch angle offsets are calculated as a function of a trailer length, a wheelbase length, a drawbar length, and a steering angle.

12. The system of claim 8, wherein the controller performs a curve fit between the calculated hitch angle offsets to estimate the additional hitch angle offsets, the additional hitch angle offsets being related to measurable hitch angles falling within an operating range of a trailer backup assist system.

13. The system of claim 12, wherein the curve fit is one of a linear function and a higher order function.

14. A method for estimating hitch angle offset comprising the steps of:

measuring hitch angles between a vehicle and a trailer attached thereto;

calculating hitch angle offsets for the measured hitch angles; and

extrapolating additional hitch angle offsets based on the calculated hitch angle offsets.

15. The method of claim 14, wherein the hitch angles are measured by a camera of the vehicle that monitors a target on the trailer.

16. The method of claim 14, wherein each of the hitch angle offsets are calculated when a corresponding measured hitch angle is substantially constant.

17. The method of claim 14, wherein each of the hitch angle offsets are calculated as a function of a trailer length, a wheelbase length, a drawbar length, and a steering angle.

18. The method of claim 14, wherein each of the hitch angle offsets are calculated when a yaw rate of the vehicle and the trailer are substantially equal and constant.

19. The method of claim 14, wherein the step of extrapolating comprises performing a curve fit between the calculated hitch angle offsets to estimate the additional hitch angle offsets, the additional hitch angle offsets being related to measurable hitch angles falling within an operating range of a trailer backup assist system.

20. The method of claim 19, wherein the curve fit is one of a linear function and a higher order function.