Drawbar scan solution for locating trailer hitch point

Patent metadata

Field	Value
Publication number	US-9934572-B2
Application number	US-201514972956-A
Country	US
Kind code	B2
Filing date	Dec 17, 2015
Priority date	Dec 17, 2015
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

A system for locating an imaged hitch point 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 select two images captured by the imaging device and derive an edge map for each of the two images. The controller determines the location of the imaged hitch point based on differences in pixel intensity associated with a number of predefined pixel positions common to the two images.

First claim

The invention claimed is:

1. A method of locating an imaged hitch point between a vehicle and a trailer, comprising the steps of:
capturing images of the trailer using an imaging device;
providing a controller configured to:
a) select two images captured by the imaging device;
b) derive an edge map for each of the two images,
c) define a detection window centered at a common pixel position in each of the two images;
d) calculate an average pixel intensity of the pixels bounded by each detection window;
e) calculate an averaged pixel difference defined as an absolute value of the difference between the average pixel intensities calculated at d);
f) shift each detection window in a common direction such that the detection window in each of the two images is centered at a new common pixel position,
g) iterate d)-f) until the calculated averaged pixel difference meets or exceeds a threshold value; and
h) select as the imaged hitch point, the common pixel position associated with the calculated averaged pixel difference that meets or exceeds the threshold value.

2. The method of claim 1 , wherein the two images selected by the controller each show the trailer at a distinct hitch angle with regards to the vehicle.

3. The method of claim 2 , wherein the two images are successive or non-successive.

4. The method of claim 1 , wherein each detection window is shifted along a reference line that extends vertically across a middle column of the corresponding image.

5. The method of claim 4 , wherein the reference line coincides with a longitudinal axis of an imaged drawbar and intersects with the imaged hitch point.

6. A system for locating an imaged hitch point between a vehicle and a trailer, comprising:
an imaging device disposed on the vehicle and configured to capture images of the trailer;
a controller operably coupled to the imaging device and configured to:
a) select two images captured by the imaging device;
b) derive an edge map for each of the two images;
c) define a detection window centered at a common pixel position in each of the two images;
d) calculate an average pixel intensity of the pixels bounded by each detection window;
e) calculate an averaged pixel difference defined as an absolute value of the difference between the average pixel intensities calculated at d);
f) shift each detection window in a common direction such that the detection window in each of the two images is centered at a new common pixel position;
g) iterate d)-f) until the calculated averaged pixel difference meets or exceeds a threshold value; and
h) select as the imaged hitch point, the common pixel position associated with the calculated averaged pixel difference that meets or exceeds the threshold value.

7. The system of claim 6 , wherein the two images selected by the controller each show the trailer at a distinct hitch angle with regards to the vehicle.

8. The system of claim 7 , herein the two images are successive or non-successive.

9. The system of claim 6 , wherein each detection window is shifted along a reference line that extends vertically across a middle column of the corresponding image.

10. The system of claim 9 , wherein the reference line coincides with a longitudinal axis of an imaged drawbar and intersects with the imaged hitch point.

Assignees

• Ford Global Tech Llc

Inventors

• Hu Zheng
• Joyce John P

Classifications

• G06T7/0042 Primary

  Physics · mapped topic

• G06T7/0083

  Physics · mapped topic

• G06T7/0085

  Physics · mapped topic

• H04N7/183 Primary

  for receiving images from a single remote source · CPC title

• G06T7/73

  using feature-based methods · CPC title