Trajectory path planner for a vision guidance system

• US 6,385,515 B1
• Filed: 06/15/2000
• Issued: 05/07/2002
• Est. Priority Date: 06/15/2000
• Status: Expired due to Term

• Current Assignee: Blue Leaf IP Incorporated (CNH Industrial N.V.), CNH Industrial America LLC (CNH Industrial N.V.)
• Original Assignee: Case Corporation (CNH Industrial N.V.)
• Inventors: Han, Shufeng, Ni, Bingcheng, Dickson, Monte Andre, Reid, John F.
• Primary Examiner(s): Zanelli, Michael J.
• Assistant Examiner(s): Gibson, Eric M
• Application Number:
  US09/595,286
• Time in Patent Office: 691 Days
• Field of Search: 701/23, 701/28, 701/41, 348/119, 348/120, 56/102.F
• US Class Current: 701/28
• CPC Class Codes: A01B 69/001 Steering by means of optical assistance, e.g. television cameras steering devices for road marking vehicles E01C23/163
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: G06V 10/25 Determination of region of interest [ROI] or a volume of interest [VOI]
• CPC Class Codes: G06V 20/588 Recognition of the road, e.g. of lane markings; Recognition of the vehicle driving pattern in relation to the road

Abstract

An automatic vision guidance system for an agricultural vehicle is disclosed and described. The vision guidance system uses a K-means clustering algorithm in image processing to distinguish between crop and non-crop features. The vision guidance system utilizes moment algorithms to determine the location and orientation of crop rows, from which desired wheel angles are determined and steering is commanded. The vision guidance system may adjust the location and orientation of visually determined crop rows according to a predetermined distance between crop rows. Further, the vision guidance system may utilize a redundant number of regions of interest in determining crop row locations and orientations.

Claims

1. An automatic guidance system for an agricultural vehicle, the guidance system comprising:

an electromagnetic sensor for gathering information about field characteristics, the electromagnetic sensor configured to provide a signal representative of the field characteristics, the signal representative of pixels of an image;

a controller configured to receive the digital signal representative of the field characteristics; and

a trajectory planner configured to plan a trajectory and to determine a steering angle correction for the vehicle based on the digital signal representative of the field characteristics, wherein the trajectory planner estimates path points between a location in the image and a reference point on the vehicle.

2. The guidance system of claim 1, wherein the electromagnetic sensor includes a video camera.

3. The guidance system of claim 2, wherein the video camera includes a charge coupled device (CCD).

4. The guidance system of claim 2, wherein the video camera includes a complementary metal-oxide semiconductor (CMOS) array.

5. The guidance system of claim 1, wherein the electromagnetic sensor is configured to substantially sense electromagnetic radiation in the near infrared (NIR) spectrum.

6. An automatic guidance system for an agricultural vehicle, the guidance system comprising:

an electromagnetic sensor for gathering information about field characteristics, the electromagnetic sensor configured to provide a signal representative of the field characteristics, the signal representative of pixels of an image;

a controller configured to receive the digital signal representative of the field characteristics; and

a trajectory planner configured to plan a trajectory and to determine a steering angle correction for the vehicle based on the digital signal representative of the field characteristics, wherein the trajectory planner utilizes path curvature and vehicle speed to determine a look-ahead point.

7. The guidance system of claim 6, wherein the trajectory planner utilizes path points defined as crop row centers.

8. A method of steering a vehicle, comprising:

sensing electromagnetic radiation with an electromagnetic sensor;

communicating a signal representative of the sensed electromagnetic radiation, and representative of pixels of an image, to a processing device;

determining a look-ahead point in front of the vehicle;

determining a path proceeding substantially through the look-ahead point; and

updating a trajectory matrix with a point extracted from the image.

9. The method of claim 8, further comprising:

determining a turn angle based on the look-ahead point.

10. The method of claim 8, further comprising:

determining whether the path is substantially straight.

11. The method of claim 10, further comprising:

determining the vehicle speed.

12. A method of steering a vehicle, comprising:

sensing electromagnetic radiation with an electromagnetic sensor;

communicating a signal representative of the sensed electromagnetic radiation, and representative of pixels of an image, to a processing device;

determining a look-ahead point in front of the vehicle;

determining a path proceeding substantially through the look-ahead point; and

determining whether the path is substantially curved.

13. The method of claim 12, further comprising:

determining whether the path changes direction.

14. An agricultural vehicle configured to be guided through a field by an automatic guidance system, the agricultural vehicle comprising:

a visual means for gathering visual input about field characteristics in the format of a digitized image, including pixel information;

a means for determining a look-ahead point in front of the vehicle;

a means for determining a path proceeding substantially through the look-ahead point; and

a means for updating a trajectory matrix with a point extracted from the image.

15. The agricultural vehicle of claim 14, further comprising:

a means for determining a turn angle based on the look-ahead point.

16. The agricultural vehicle of claim 14, further comprising:

a means for determining whether the path is substantially straight.

17. An agricultural vehicle configured to be guided through a field by an automatic guidance system, the agricultural vehicle comprising:

a visual means for gathering visual input about field characteristics in the format of a digitized image, including pixel information;

a means for determining a look-ahead point in front of the vehicle;

a means for determining a path proceeding substantially through the look-ahead point; and

a means for determining whether the path is substantially curved.

18. A The agricultural vehicle of claim 17, further comprising:

a means for determining whether a substantially curved path changes direction.