Row guidance parameterization with hough transform

• US 9,374,940 B2
• Filed: 08/26/2015
• Issued: 06/28/2016
• Est. Priority Date: 03/08/2013
• Status: Active Grant

• Current Assignee: Raven Industries Incorporated (CNH Industrial N.V.)
• Original Assignee: Raven Industries Incorporated (CNH Industrial N.V.)
• Inventors: Nelson, Robert Leonard Jr.
• Primary Examiner(s): Johns, Andrew W
• Application Number:
  US14/836,647
• Publication Number:
  US 20150359163A1
• Time in Patent Office: 307 Days
• US Class Current: 1/1
• CPC Class Codes: A01B 69/007 Steering or guiding of agricultural vehicles, e.g. steering of the tractor to keep the plough in the furrow
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: G05D 1/0219 ensuring the processing of the whole working surface
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G06T 2207/20061 Hough transform
• CPC Class Codes: G06T 7/536 from perspective effects, e.g. by using vanishing points

Abstract

Systems and techniques for row guidance parameterization with Hough transform are described herein. An electronic representation of a field (ERF) can be received. The ERF can include a set of feature sets including one of a set of crop row features or a set of furrow features. A first parameter space can be produced by applying a slope-intercept Hough transform (SLIHT) to members of a feature set. Peaks in the first parameter space can be identified. A second parameter space can be produced by application of the SLIHT to the peaks. A vanishing point can be calculated based on a vanishing point peak in the second parameter space. A track-angle error can be calculated from the vanishing point.

Claims

1. A non-transitory machine-readable medium including instructions that, when executed by a machine, cause the machine to perform operations comprising:

receiving an image with a set of features;

detecting a plurality of lines corresponding to the set of features;

calculating a vanishing point from the plurality of lines;

projecting a projected line from a point on the image representing a vehicle to the vanishing point;

calculating an angle error between the projected line and a vehicle direction line from the point on the image, wherein the vehicle direction line corresponds to a heading of the vehicle; and

providing the angle error to a steering module of a vehicle to which the image capture device is mounted.

2. The machine-readable medium of claim 1, wherein detecting the plurality of lines includes using a line voting mechanism.

3. The machine-readable medium of claim 2, wherein the voting mechanism includes:

identifying a candidate line from a predetermined pool of candidate lines;

applying the candidate line to the set of features; and

accumulating votes for the candidate line for features in the set of features that correspond to the candidate line.

4. The machine-readable medium of claim 3, wherein candidate pool of candidate lines are defined by a parameter space that describe the candidate lines.

5. The machine-readable medium of claim 1, wherein calculating the vanishing point from the plurality of lines includes:

mapping a first line and a second line from the image to respective features in a second feature set;

isolating a third line in the second feature set upon which both respective features lie;

mapping the third line to a point in a third feature set; and

translating the point in the third feature set to the vanishing point in the image.

6. The machine-readable medium of claim 1, comprising calculating a cross-track distance from the machine and a line parallel to one of the plurality of lines and providing the cross-track distance to the steering module.

7. A method comprising:

receiving, by a scene module, an image with a set of features;

detecting, by a transform module, a plurality of lines corresponding to the set of features;

calculating a vanishing point from the plurality of lines;

creating a projected line from a point on from a point on the image representing a vehicle to the vanishing point

calculating, by a track-angle error module an angle error between the projected line and a vehicle direction line from the point on the image, wherein the vehicle direction line corresponds to a heading of the vehicle; and

providing the angle error to a steering module of a vehicle to which the image capture device is mounted.

8. The method of claim 7, wherein detecting the plurality of lines includes using a line voting mechanism.

9. The method of claim 8, wherein the voting mechanism includes:

identifying a candidate line from a predetermined pool of candidate lines;

applying the candidate line to the set of features; and

accumulating votes for the candidate line for features in the set of features that correspond to the candidate line.

10. The method of claim 9, wherein candidate pool of candidate lines are defined by a parameter space that describe the candidate lines.

11. The method of claim 7, wherein calculating the vanishing point from the plurality of lines includes:

mapping afirst line and a second line from the image to respective features in a second feature set;

isolating a third line in the second feature set upon which both respective features lie;

mapping the third line to a point in a third feature set; and

translating the point in the third feature set to the vanishing point in the image.

12. The method of claim 7, comprising calculating a cross-track distance from the machine and a line parallel to one of the plurality of lines and providing the cross-track distance to the steering module.

13. A system comprising:

a scene module to receive an image with a set of features;

a transform module to;

detect a plurality of lines corresponding to the set of features; and

calculate a vanishing point from the plurality of lines; and

a track-angle error module to;

create a projected line from a point on the image representing a vehicle to the vanishing point

calculate an angle error between the projected line and a vehicle direction line from the point on the image, wherein the vehicle direction line corresponds to a heading of the vehicle; and

provide the angle error to a steering module of a vehicle to which the image capture device is mounted.

14. The system of claim 13, wherein to detect the plurality of lines includes the transform module arranged to use a line voting mechanism.

15. The system of claim 14, wherein the voting mechanism includes the transform module arranged to:

identify a candidate line from a predetermined pool of candidate lines;

apply the candidate line to the set of features; and

accumulate votes for the candidate line for features in the set of features that correspond to the candidate line.

16. The system of claim 15, wherein candidate pool of candidate lines are defined by a parameter space that describe the candidate lines.

17. The system of claim 13, wherein to calculate the intersection of the first line and the second line includes the transform module arranged to:

map a first line and a second line from the image to respective features in a second feature set;

isolate a third line in the second feature set upon which both respective features lie;

map the third line to a point in a third feature set; and

translate the point in the third feature set to the vanishing point in the first image.

18. The system of claim 13, comprising a cross-track distance module to calculate a cross-track distance from the machine and a line parallel to one of the plurality of lines.

19. The system of claim 18, wherein the cross-track distance module is to provide the cross-track distance to the steering module.