System and method for accurately characterizing and mapping agricultural plants and foliage

• US 6,862,083 B1
• Filed: 12/19/2001
• Issued: 03/01/2005
• Est. Priority Date: 12/19/2000
• Status: Expired due to Fees

• Current Assignee: Schwartz Electro-Optics Incorporated
• Original Assignee: Schwartz Electro-Optics Incorporated
• Inventors: Taylor, Matthew G., McConnell, Robert E. Sr., Hoppenfeld, Robert A.
• Primary Examiner(s): Hellner, Mark
• Application Number:
  US10/025,374
• Time in Patent Office: 1,168 Days
• Field of Search: 359/4.01, 47/17
• US Class Current: 356/4.01
• CPC Class Codes: A01B 79/005 Precision agriculture
• CPC Class Codes: G01S 17/06 Systems determining position data of a target
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/4817 relating to scanning

Abstract

A lazer rangefinder employs time-of-flight measurements for providing high resolution when measuring range and intensity in a system for accurately mapping and classifying agriculture foliage. Profiles and parameters of the foliage and trees are measured and calculated for classifying the tree, controlling mechanical devices for applying only a pre-selected amount of treatment materials to the tree, and estimating production yeilds. Using a global positioning receiver, a global location for the center of each tree, whether fully grown, juvenile, or dead is identified and used in mapping the measured trees.

Claims

1. A method of controlling an application of selected treatment materials to a selected area of target vegetation by a vehicle, the method comprising:

scanning an optical beam in a predetermined pattern about a vegetation for measuring a plurality of ranges from a sensor operable with a vehicle useful in distributing the selected treatment materials;

measuring range and intensity of reflected beams from the vegetation for a plurality of locations sufficient for determining multiple parameters for the vegetation including a center of the vegetation, vegetation height, vegetation width, and vegetation foliage volume;

measuring a distance traveled for the sensor; and

providing a control signal to the vehicle for distributing the selected treatment materials based on at least one of the parameters.

2. A method according to claim 1, wherein the scanning is provided by a pulsed laser beam emitted from a rotating reflecting surface.

3. A method according to claim 1, wherein determining the center of the vegetation comprises:

representing the vegetation by a grid structure having multiple areas; and

determining one area within the grid structure wherein the one area includes a minimum amount of non-return values of the reflected beams when compared to the areas within the grid structure.

4. A method according to claim 1, wherein determining the center of the vegetation comprises:

representing the vegetation by a grid structure having multiple areas; and

determining one area within the grid structure wherein the one area represents a closest range to the sensor when compared to the areas within the grid structure.

5. A method according to claim 1, wherein determining the center of the vegetation comprises:

representing the vegetation by a grid structure having multiple areas; and

determining one area within the grid structure wherein the one area represents a maximum height measurement of the vegetation when compared to the areas within the grid structure.

6. A method according to claim 1, wherein determining the center of the vegetation comprises:

representing the vegetation by a grid structure having multiple areas; and

determining a first area within the grid structure wherein the first area includes a minimum amount of non-return values of the reflected beams when compared to the areas within the grid structure;

determining a second area within the grid structure wherein the second area represents a closest range to the sensor when compared to the areas within the grid structure;

determining a third area within the grid structure wherein the one area represents a maximum height measurement of the vegetation when compared to the areas within the grid structure; and

combining at least two of the first, second, and third areas for determining the center of the vegetation.

7. A method according to claim 1, further comprising a mapping of multiple vegetations using measured distances between the centers of each vegetation within the multiple vegetations.

8. A method according to claim 7, further comprising a global positioning of the vegetations using a signal from a global positioning device.

9. A method according to claim 1, wherein determining the vegetation foliage volume comprises:

representing the vegetation by a grid structure including multiple grid areas;

assigning each grid area a median intensity value measured from all laser pulses received within the grid area; and

averaging the median intensities over the entire grid structure.

10. A method according to claim 1, further comprising determining foliage density comprising:

representing the vegetation by a grid structure including multiple grid areas forming the grid structure;

assigning each grid area a median intensity value measured from all pulses received within the grid structure; and

providing a ratio of a sum of the median intensities from all grid areas and a sum of all grid areas having received a pulse therein.

11. A method according to claim 10, further comprising modifying the foliage density by a foliage density coefficient empirically determined from physical measurements.

12. A method according to claim 1, wherein determining vegetation height comprises:

measuring a range for a highest laser beam returned for the reflected beams; and

modifying results of the measuring based on a measured shape of the vegetation at an uppermost portion thereof using a percentage change of a maximum height measurement across the canopy of the vegetation.

13. A method according to claim 1, wherein determining vegetation width comprises using range and intensity data for defining edges of a canopy of the vegetation when a gap exists between adjacent vegetations.

14. A method according to claim 1, wherein determining vegetation width comprises determining a center of mass for the vegetation, the height of the vegetation, and the intensity of returned laser pulses to determine a vegetation edge when the vegetation is within a hedgerow.

15. A method according to claim 1, further comprising classifying a vegetation based on at least one of the parameters, wherein the vegetation is classified as being one from a group consisting of a producing vegetation, a juvenile vegetation, and a dead vegetation.