Multi-stage solution for trailer hitch angle initialization

• US 9,827,818 B2
• Filed: 12/17/2015
• Issued: 11/28/2017
• 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, Lavoie, Erick Michael
• Primary Examiner(s): Geroleo, Francis G
• Application Number:
  US14/972,831
• Publication Number:
  US 20170174022A1
• Time in Patent Office: 712 Days
• Field of Search: 348148
• CPC Class Codes: B60D 1/245 for facilitating push back or parking of trailers
• CPC Class Codes: B60D 1/30 for sway control , e.g. stabilising or anti-fishtail devices; Sway alarm means
• CPC Class Codes: B60D 1/62 involving supply lines, electric circuits, or the like
• CPC Class Codes: B60R 1/00 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 Class Codes: B60R 2300/806 for aiding parking
• CPC Class Codes: B60R 2300/808 for facilitating docking to a trailer
• CPC Class Codes: B62D 13/06 for backing a normally drawn trailer
• CPC Class Codes: B62D 15/023 by measuring on the king pin
• CPC Class Codes: B62D 15/027 Parking aids, e.g. instruction means
• CPC Class Codes: G06F 18/22 Matching criteria, e.g. proximity measures
• CPC Class Codes: G06T 2207/20112 Image segmentation details
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/13 Edge detection
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06T 7/74 involving reference images or patches
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: G06V 20/584 of vehicle lights or traffic lights
• CPC Class Codes: G06V 40/20 Movements or behaviour, e.g. gesture recognition recognition of facial expressions G06V40/16
• CPC Class Codes: H04N 7/18 : Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

A system for initializing hitch angle detection is provided herein. An imaging device is configured to capture images of a trailer connected to a vehicle. A controller is configured to select between a plurality of hitch angle detection routines based on at least one of a current driving condition and an availability of a template image of the trailer.

Claims

1. A system for initializing hitch angle detection, comprising:

an imaging device configured to capture images of a trailer connected to a vehicle;

a controller configured to select between a plurality of hitch angle detection routines based on at least one of a current driving condition and an availability of a template image of the trailer;

wherein if the template image is available, the controller selects a first hitch angle detection routine that comprises matching the template image to a search image to determine a hitch angle between the vehicle and the trailer;

wherein if the template image is unavailable and the vehicle and trailer are moving in a straight direction, the controller processes images captured by the imaging device to derive the template image and selects the first hitch angle detection routine.

2. The system of claim 1, wherein if the template image is unavailable and the vehicle and trailer are not moving in a straight direction, the controller selects a second hitch angle detection routine that comprises:

processing images captured by the imaging device;

deriving an edge map and identifying trailer pixels therein;

locating a centerline of the trailer pixels; and

determining the hitch angle based on an angular position of the centerline relative to a reference line.

3. The system of claim 2, wherein if the hitch angle between the vehicle and the trailer becomes constant while the second hitch angle detection routine is the currently selected hitch angle detection routine, the controller chooses between two hitch angle detection routines.

4. The system of claim 3, wherein if the hitch angle is a constant zero value, the controller processes images captured by the imaging device to derive the template image and selects the first hitch angle detection routine.

5. The system of claim 3, wherein if the hitch angle is a constant non-zero value, the controller selects a third hitch angle detection routine that comprises determining the hitch angle as a function of a trailer length, a wheelbase length, a drawbar length, and a steering angle.

6. The system of claim 5, wherein if the hitch angle ceases to remain at the constant non-zero value while the third hitch angle detection routine is the currently selected hitch angle detection routine, the controller selects the second hitch angle detection routine.

7. A method of initializing hitch angle detection, comprising the steps of:

using an imaging device to capture images of a trailer connected to a vehicle; and

providing a controller configured to select between a plurality of hitch angle detection routines based on at least one of a current driving condition and an availability of a template image of the trailer;

wherein if the template image is available, the controller selects a first hitch angle detection routine that comprises matching the template image to a search image to determine a hitch angle between the vehicle and the trailer;

wherein if the template image is unavailable and the vehicle and trailer are moving in a straight direction, the controller processes images captured by the imaging device to derive the template image and selects the first hitch angle detection routine.

8. The method of claim 7, wherein if the template image is unavailable and the vehicle and trailer are not moving in a straight direction, the controller selects a second hitch angle detection routine that comprises:

processing images captured by the imaging device;

deriving an edge map and identifying trailer pixels therein;

locating a centerline of the trailer pixels; and

determining the hitch angle based on an angular position of the centerline relative to a reference line.

9. The method of claim 8, wherein if the hitch angle between the vehicle and the trailer becomes constant while the second hitch angle detection routine is the currently selected hitch angle detection routine, the controller chooses between two hitch angle detection routines.

10. The method of claim 9, wherein if the hitch angle is a constant zero value, the controller processes images captured by the imaging device to derive the template image and selects the first hitch angle detection routine.

11. The method of claim 9, wherein if the hitch angle is a constant non-zero value, the controller selects a third hitch angle detection routine that comprises determining the hitch angle as a function of a trailer length, a wheelbase length, a drawbar length, and a steering angle.

12. The method of claim 11, wherein if the hitch angle ceases to remain at the constant non-zero value while the third hitch angle detection routine is the currently selected hitch angle detection routine, the controller selects the second hitch angle detection routine.

13. A method of initializing hitch angle detection, comprising the steps of:

using an imaging device to capture images of a trailer connected to a vehicle; and

providing a controller configured to select between a first, second, and third hitch angle detection routine based on at least one of a current driving condition and an availability of a template image of the trailer;

wherein if the template image is available, the controller selects the first hitch angle detection routine that comprises matching the template image to a search image to determine a hitch angle between the vehicle and the trailer; and

wherein if the template image is unavailable and the vehicle and trailer are moving in a straight direction, the controller processes images captured by the imaging device to derive the template image and selects the first hitch angle detection routine.

14. The method of claim 13, wherein if the template image is unavailable and the vehicle and trailer are not moving in a straight direction, the controller selects the second hitch angle detection routine that comprises:

processing images captured by the imaging device;

deriving an edge map and identifying trailer pixels therein;

locating a centerline of the trailer pixels; and

determining the hitch angle based on an angular position of the centerline relative to a reference line.

15. The method of claim 14, wherein if the hitch angle between the vehicle and the trailer becomes constant while the second hitch angle detection routine is the currently selected hitch angle detection routine, the controller processes images captured by the imaging device to derive the template image and selects the first hitch angle detection routine if the hitch angle is a constant zero value, otherwise, if the hitch angle is a constant non-zero value, the controller selects the third hitch angle detection routine that comprises determining the hitch angle as a function of a trailer length, a wheelbase length, a drawbar length, and a steering angle.