Method and system for vehicular guidance using a crop image

• US 7,570,783 B2
• Filed: 12/16/2005
• Issued: 08/04/2009
• Est. Priority Date: 07/01/2005
• Status: Active Grant

• Current Assignee: Deere & Company, Kansas State University Research Foundation
• Original Assignee: Deere & Company, Kansas State University Research Foundation
• Inventors: Han, Shufeng, Wei, Jiantao
• Primary Examiner(s): AZARIAN, SEYED H
• Application Number:
  US11/303,383
• Publication Number:
  US 20070003107A1
• Time in Patent Office: 1,327 Days
• Field of Search: 382/100, 382/103, 382/104, 382/106, 382/107, 382/153, 382/162, 382/164, 382/165, 382/168, 382/173, 382/181, 382193-203, 382/224, 382/232, 382/256, 382/274, 382/276, 382/286, 382/312, 382/305, 701/23, 701/28, 701/301, 700/50
• US Class Current: 382/100
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: G01C 11/025 by scanning the object
• CPC Class Codes: G06V 10/243 by compensating for image skew or non-uniform image deformations
• CPC Class Codes: G06V 20/10 Terrestrial scenes scenes under surveillance with static cameras G06V20/52; scenes perceived from the exterior of a vehicle G06V20/56; scenes perceived from the interior of a vehicle G06V20/59
• 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

The method and system for vehicular guidance comprises an imaging device for collecting color image data to facilitate distinguishing crop image data (e.g., crop rows) from background data. A definer defines a series of scan line segments generally perpendicular to a transverse axis of the vehicle or of the imaging device. An image parameter evaluator determines scan line image parameter data for each of the scan line segments. An alignment detector (e.g., search engine) identifies a preferential heading of the vehicle that is generally aligned with respect to a crop feature, associated with the crop image data, based on the determined scan line image parameter meeting or exceeding a maximum value or minimum threshold value. A reliability estimator estimates a reliability of the vehicle heading based on compliance with a criteria for scan line image parameter data associated with one or more crop rows.

Claims

1. A method of guiding a vehicle, the method comprising:

collecting color image data;

defining a series of scan line segments generally perpendicular to a transverse axis of the vehicle or of an imaging system;

determining a scan-line-image-parameter level for each of the scan lines, the scan-line-image-parameter level comprising a color-related parameter level; and

identifying a preferential heading of the vehicle that is generally aligned with respect to a crop feature, associated with the collected image data, based on the determined scan-line-image-parameter level meeting or exceeding a maximum value or minimum threshold value;

estimating, by a data processor, a reliability of the vehicle heading based on compliance with an image parameter level criteria associated with one or more crop rows;

determining a first image parameter value associated with a first crop row and a second image parameter value associated with a second crop row;

determining a spacing between a first crop row and a second crop row; and

determining a maximum image parameter value for the first crop row and the second crop row; and

considering vision guidance data reliable for a time period if the first image parameter value does not differ from the second image parameter value by more than a minimum threshold, if the determined spacing between the first crop row and the falls within a defined width range, and if the maximum image parameter value is greater than a certain threshold value.

2. The method according to claim 1 wherein the image parameter level is associated with or derived from one or more of the following:

a color value of a red component, green component, or blue component in RGB color space;

a composite color value of multiple components in RGB color space, a hue value in the HSV color space;

a hue value in the HSL color space;

a saturation value associated with vibrancy or purity of a color, a saturation value in HSV or HSL color space, a value indicative of observed or reflected light in the green visible light spectrum or for another plant color;

a value indicative of observed or reflected light with certain green hue value or another plant color; and

a value indicative of observed or reflected light in multiple spectrums (e.g., green light and infra-red or near infra-red light), an NDVI (normalized difference vegetation index), a greenness level, a plant color level, and a green-red difference level.

3. The method according to claim 1 further comprising:

determining the first image parameter value associated with the first crop row and the second image parameter value associated with the second crop row; and

considering vision guidance data unreliable for a minimum time period if the first image parameter value differs from the second image parameter value by more than a minimum threshold.

4. The method according to claim 1 further comprising:

determining the spacing between the first crop row and the second crop row; and

considering vision guidance data unreliable for a minimum time period if the spacing does not fall within a defined row width range.

5. The method according to claim 1 further comprising:

determining the maximum image parameter value for the first crop row and the second crop row; and

considering vision guidance data unreliable for a minimum time period if the maximum image parameter value is not greater than a certain threshold value.

6. The method according to claim 1 further comprising:

determining the first image parameter value associated with the first crop row and the second image parameter value associated with the second crop row; and

applying alternate guidance data other than vision guidance data for a minimum time period if the first image parameter value differs from the second image parameter value by more than a minimum threshold.

7. The method according to claim 1 further comprising:

determining the spacing between the first crop row and the second crop row; and

applying alternate guidance data other than vision guidance data for a minimum time period if the spacing does not fall within a defined row width range.

8. The method according to claim 1 further comprising:

determining the maximum image parameter value for the first crop row and the second crop row; and

applying alternate guidance data other than vision guidance data for a minimum time period if the maximum image parameter value is not greater than a certain threshold value.

9. The method according to claim 1 further comprising:

determining the first image parameter value associated with the first crop row and the second image parameter value associated with the second crop row; and

considering vision guidance data unreliable for a minimum time period if the first image parameter value and the second image parameter value do not comply with the individual predetermined threshold, an aggregate predetermined threshold, or both.

10. The method according to claim 1 further comprising:

determining an offset from a desired path; and

determining the vision guidance data is reliable if the determined offset is less than or equal to a maximum offset value.

11. A system of guiding a vehicle, the system comprising:

an imaging device for collecting color image data;

a definer for defining a series of scan line segments generally perpendicular to a transverse axis of the vehicle or of an imaging system;

an intensity evaluator for determining a scan-line-image-parameter level for each of the scan lines, the scan-line-image-parameter level comprising a color-related parameter level, wherein the intensity evaluator determines a first image parameter value associated with a first crop row and a second image parameter value associated with a second crop row, the intensity evaluator determining a maximum image parameter value for the first crop row and the second crop row;

an alignment detector for identifying a preferential heading of the vehicle that is generally aligned with respect to a crop feature, associated with the collected image data, based on the determined scan-line-image-parameter level meeting or exceeding a maximum value or minimum threshold value;

a reliability estimator for estimating a reliability of the vehicle heading based on compliance with an image parameter level criteria associated with one or more crop rows;

a data processor determining a spacing between a first crop row and a second crop row; and

the reliability estimator considering vision guidance data reliable for a time period if the first image parameter value does not differ from the second image parameter value by more than a minimum threshold, if the determined spacing between the first crop row falls within a defined width range, and if the maximum image parameter value is greater than a certain threshold value.

12. The system according to claim 11 wherein image parameter level is associated with or derived from one or more of the following:

a color value of a red component, green component, or blue component in RGB color space;

a composite color value of multiple components in RGB color space, a hue value in the HSV color space;

a hue value in the HSL color space;

a saturation value associated with vibrancy or purity of a color, a saturation value in HSV or HSL color space, a value indicative of observed or reflected light in the green visible light spectrum or for another plant color;

a value indicative of observed or reflected light with certain green hue value or another plant color; and

a value indicative of observed or reflected light in multiple spectrums (e.g., green light and infra-red or near infra-red light), an NDVI (normalized difference vegetation index), a greenness level, a plant color level, and a green-red difference level.

13. The system according to claim 11 wherein the intensity evaluator determines the first image parameter value associated with the first crop row and the second image parameter value associated with the second crop row;

and

the reliability estimator considering vision guidance data unreliable for a minimum time period if the first image parameter value differs from the second image parameter value by more than a minimum threshold.

14. The system according to claim 11 wherein the intensity evaluator determines the spacing between the first crop row and the second crop row;

and

the reliability estimator considering vision guidance data unreliable for a minimum time period if the spacing does not fall within a defined row width range.

15. The system according to claim 11 wherein the intensity evaluator determines the maximum image parameter value for the first crop row and the second crop row;

and

the reliability estimator considering vision guidance data unreliable for a minimum time period if the maximum image parameter value is not greater than a certain threshold value.

16. The system according to claim 11 wherein the intensity evaluator determines the first image parameter value associated with the first crop row and the second image parameter value associated with the second crop row:

and

a vehicle guidance controller applying alternate guidance data other than vision guidance data for a minimum time period if the first image parameter value differs from the second image parameter value by more than a minimum threshold.

17. The system according to claim 11 wherein the intensity evaluator determines the spacing between the first crop row and the second crop row;

and

a vehicle guidance controller applying alternate guidance data other than vision guidance data for a minimum time period if the spacing does not fall within a defined row width range.

18. The system according to claim 11 wherein the intensity evaluator determines the maximum image parameter value for the first crop row and the second crop row;

and

a vehicle guidance controller applying alternate guidance data other than vision guidance data for a minimum time period if the maximum image parameter value is not greater than a certain threshold value.

19. The system according to claim 11 wherein the intensity evaluator determines the first image parameter value associated with the first crop row and the second image parameter value associated with the second crop row;

and

a vehicle guidance controller considering vision guidance data unreliable for a minimum time period if the first image parameter value and the second image parameter value do not comply with the individual predetermined threshold, an aggregate predetermined threshold, or both.

20. The system according to claim 11 further comprising:

an offset calculator for determining an offset from a desired path; and

a reliability estimator for determining the vision guidance data is reliable if the determined offset is less than or equal to a maximum offset value.