HITCH ANGLE DETECTION FOR TRAILER BACKUP ASSIST SYSTEM

• US 20170174023A1
• Filed: 07/27/2016
• Published: 06/22/2017
• Est. Priority Date: 12/17/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Hu, Zheng, Joyce, John P., Recker, Darrel Alan
• Granted Patent: US 9,796,228 B2
• Time in Patent Office: Days
• CPC Class Codes: B60C 5/00 Inflatable pneumatic tyres or inner tubes B60C1/00, B60C9/00 - B60C17/00 take precedence
• CPC Class Codes: B60D 1/06 Ball-and-socket hitches , e.g. constructional details, auxiliary devices, their arrangement on the vehicle
• CPC Class Codes: B60D 1/145 consisting of an elongated single bar or tube
• CPC Class Codes: B60D 1/245 for facilitating push back or parking of trailers
• CPC Class Codes: B60D 1/36 for facilitating connection, e.g. hitch catchers , visual guide means, signalling aids B60D1/465 takes precedence; vehicle signalling in general B60Q; optical arrangements specially adapted for viewing trailer-hitches B60R1/003
• CPC Class Codes: B60D 1/62 involving supply lines, electric circuits, or the like
• CPC Class Codes: B60K 2360/1438 Touch screens
• CPC Class Codes: B60K 35/00 Instruments specially adapted for vehicles; Arrangement of instruments in or on vehicles
• CPC Class Codes: B60K 35/10 Input arrangements, i.e. from user to vehicle, associated with vehicle functions or specially adapted therefor
• CPC Class Codes: B60Q 5/00 Arrangement or adaptation of acoustic signal devices
• 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 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2710/18 Braking system
• CPC Class Codes: B60W 2710/20 Steering systems
• CPC Class Codes: B60W 30/18036 Reversing
• CPC Class Codes: B62D 13/06 for backing a normally drawn trailer
• CPC Class Codes: G06V 20/56 : exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: H04N 23/60 : Control of cameras or camera modules

Abstract

A system for determining a hitch angle between a vehicle and a trailer is provided herein. An imaging device is configured to capture images of the trailer. A controller is configured to process image data to determine an optical flow. The controller distinguishes between optical flow vectors of pixels associated with the trailer and an operating environment. The controller calculates an average angular velocity for the pixels associated with the trailer and determines the hitch angle based on the average angular velocity.

Claims

1. A system for determining a hitch angle between a vehicle and a trailer, comprising:

an imaging device configured to capture images of the trailer; and

a controller configured to;

process image data to determine an optical flow;

distinguish between optical flow vectors of pixels associated with the trailer and an operating environment;

calculate an average angular velocity for the pixels associated with the trailer; and

determine the hitch angle based on the average angular velocity.

2. The system of claim 1, wherein the controller generates an optical vector field from the image data,

3. The system of claim 1, wherein the imaging device is located at a rear structure of the vehicle.

4. The system of claim 1, wherein the average angular velocity is determined relative a reference point.

5. The system of claim 4, wherein the reference point is an imaged hitch point between the vehicle and the trailer.

6. The system of claim 1, wherein the controller determines the hitch angle based on the average angular velocity, a steering angle, a drawbar length, a trailer length, a wheelbase length, and a longitudinal speed of the vehicle.

7. The system of claim 6, wherein the drawbar length is between a hitch point and a rear axle of the vehicle, the trailer length is between the hitch point and an axle of the trailer, and the wheelbase length is between a front axle and the rear axle of the vehicle.

8. A system for determining a yaw rate of a vehicle or a trailer, comprising:

an imaging device configured to capture images of an operating environment of the trailer; and

a controller configured to;

process image data to determine an optical flow;

identify pixels associated with the operating environment;

determine an angular velocity for each of the pixels associated with the operating environment; and

determine the yaw rate based on the angular velocity.

9. The system of claim 8, wherein the imaging device is located on the vehicle and is configured to capture images of the trailer.

10. The system of claim 8, wherein the controller is configured to distinguish between optical flow vectors of pixels associated with the trailer and the operating environment.

11. The system of claim 10, wherein the controller calculates an average angular velocity for the pixels associated with the trailer and determines the hitch angle based on the average angular velocity.

12. The system of claim 11, wherein the controller determines the hitch angle based on the average angular velocity, a steering angle, a drawbar length between a hitch point and a rear axle of the vehicle, a trailer length between the hitch point and an axle of the trailer, a wheelbase length between a front axle and the rear axle of the vehicle, and a longitudinal speed of the vehicle.

13. The system of claim 12, wherein the drawbar length is between a hitch point and a rear axle of the vehicle, the trailer length is between the hitch point and an axle of the trailer, and the wheelbase length is between a front axle and the rear axle of the vehicle.

14. The system of claim 8, wherein the imaging device is located on the trailer.

15. A method of determining a hitch angle between a vehicle and a trailer, comprising the steps of:

capturing images of the trailer with an imaging device; and

providing a controller configured to;

process image data to determine an optical flow;

distinguish between optical flow vectors of pixels associated with e trailer and an operating environment;

calculate an average angular velocity for pixels associated with the trailer; and

determine the hitch angle based on the average angular velocity.

16. The method of claim 15, wherein the controller generates an optical vector field from the image data.

17. The method of claim 15, wherein the average angular velocity is determined relative a reference point.

18. The method of claim 15, wherein the reference point is an imaged hitch point between the vehicle and the trailer.

19. The method of claim 15, wherein the controller determines the hitch angle based on the average angular velocity, a steering angle, a drawbar length, a trailer length, a wheelbase length, and a longitudinal speed of the vehicle.

20. The method of claim 19, wherein the drawbar length is between a hitch point and a rear axle of the vehicle, the trailer length is between the hitch point and an axle of the trailer, and the wheelbase length is between a front axle and the rear axle of the vehicle.