Trailer backup assist system with hitch angle offset estimation

Patent metadata

Field	Value
Publication number	US-10384607-B2
Application number	US-201615296638-A
Country	US
Kind code	B2
Filing date	Oct 18, 2016
Priority date	Oct 19, 2015
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

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.

First claim

The invention claimed is:

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;
extrapolate additional hitch angle offsets based on the calculated hitch angle offsets; and
assist with guiding the vehicle to reverse the trailer on a backing path based on the extrapolated additional 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 for operating 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;
extrapolate additional hitch angle offsets based on the calculated hitch angle offsets; and
assist with guiding the vehicle to reverse the trailer on a backing path based on the extrapolated additional 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 for operating 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;
extrapolating additional hitch angle offsets based on the calculated hitch angle offsets; and
assisting with guiding the vehicle to reverse the trailer on a backing path based on the extrapolated additional 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 for operating 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.

Assignees

• Ford Global Tech Llc

Inventors

• Lavoie Erick Michael
• Mattern Donald Jacob
• Raad Joseph M
• Daavettila Tyler
• Bell Robert

Classifications

• B60R2300/302

  combining image information with GPS information or vehicle data, e.g. vehicle speed, gyro, steering angle data · CPC title

• B60R2300/8086

  for vehicle path indication · CPC title

• G01B11/272

  using photoelectric detection means · CPC title

• B60R2300/207

  using multi-purpose displays, e.g. camera image and navigation or video on same display · CPC title

• B60R1/00 Primary

  Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles · CPC title