UNWANTED PLANT REMOVAL SYSTEM HAVING VARIABLE OPTICS

• US 20150075066A1
• Filed: 09/13/2013
• Published: 03/19/2015
• Est. Priority Date: 09/13/2013
• Status: Active Grant

• Current Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Stowe, Timothy David, Maeda, Patrick Yasuo, Curley, Tim
• Granted Patent: US 9,609,858 B2
• Time in Patent Office: Days
• US Class Current: 47/1.3
• CPC Class Codes: A01D 2101/00 Lawn-mowers
• CPC Class Codes: A01D 34/015 Cutting mechanisms not covered by another group
• CPC Class Codes: A01D 34/835 specially adapted for particular purposes
• CPC Class Codes: A01M 21/00 Apparatus for the destruction of unwanted vegetation, e.g. weeds control of undesirable vegetation on roads or permanent ways of railways E01H11/00
• CPC Class Codes: A01M 21/046 by electricity
• CPC Class Codes: G01N 2021/8466 Investigation of vegetal material, e.g. leaves, plants, fruits
• CPC Class Codes: G01N 21/29 using visual detection G01N21/31 takes precedence
• CPC Class Codes: G01N 21/84 Systems specially adapted for particular applications
• CPC Class Codes: G01N 2201/06113 Coherent sources; lasers
• CPC Class Codes: G06F 18/24 Classification techniques

Abstract

Embodiments of an apparatus and methods can removing unwanted plants or weeds from an area such as an agricultural plot or lawn. The apparatus includes a three-dimensional imager configured to capture plant images and locate plants; an image processor configured to distinguish between wanted and unwanted plants based upon the captured plant images; at least one laser device configured to emit a laser beam having power sufficient to damage the unwanted plants; a guidance system configured to direct at least one laser beam toward the unwanted plant; and a chassis configured to support the three-dimensional imager, the laser device, and the guidance system. The chassis is configured to be moved across the area.

Claims

1. An apparatus comprising:

an imager configured to capture plant images;

an image processor configured to distinguish between a wanted plant and an unwanted plant based on the captured plant images;

at least one laser device configured to emit a laser beam having power sufficient to damage a target on the unwanted plant;

a guidance system configured to direct the laser beam towards the target on the unwanted plant,

wherein the laser device has at least one of a variable depth of field, a variable width of field, a variable focal length, or a combination thereof; and

a chassis configured to support the three-dimensional imager, the at least one laser device and, optionally, the guidance system,

wherein the chassis is configured to be moved across an area.

2. An apparatus according to claim 1, wherein the imager comprises a light source with one or more scanning beams, collection optics, and one or more detectors.

3. An apparatus according to claim 1, wherein the laser device comprises an array of semiconductor lasers.

4. An apparatus according to claim 1, wherein the apparatus comprises a non-mechanical phased array beam steering module.

5. An apparatus according to claim 4, wherein the non-mechanical phased array beam steering module comprises a cylindrical-shaped MEMS mirror adaptive optical element.

6. An apparatus according to claim 1, wherein the laser device comprises at least one semiconductor laser configured to emit a laser beam having a wavelength of from about 430 nm to about 475 nm or from about 650 nm to about 675 nm.

7. An apparatus according to claim 1, wherein the laser device can emit a laser beam having an adjustable wavelength based upon information from the image processor.

8. An apparatus according to claim 1, wherein the laser device comprises at least one of a MEMS scanner, a MEMS adaptive optical, or a phased array modulator.

9. An apparatus according to claim 1, wherein the laser device is configured to change at least one of the depth of field, the width of field, or the focal length based upon information from the image processor.

10. An apparatus according to claim 1, wherein the three-dimensional imager, the laser device, and the guidance system are supported by the chassis.

11. An apparatus according to claim 1, wherein the guidance system can sense and adjust the direction of the laser beam in three-dimensions.

12. An apparatus according to claim 10, wherein the chassis comprises a three-dimensional gyro accelerometer sensor.

13. An apparatus according to claim 10, wherein the chassis adjusts all three-dimensions electro-optically.

14. A lawn weeding system comprising:

a lawn mower comprising cutting means; and

an apparatus according to claim 1, wherein the chassis is mechanically coupled to the lawn mower.

15. A lawn weeding system according to claim 14, wherein the cutting means are mechanical or electro-optical.

16. A lawn weeding system according to claim 14, wherein the lawn mower generates power to energize at least one of the three-dimensional imager, the image processor, the at least one laser device, and the guidance system.

17. A lawn weeding system according to claim 14, wherein the electro-optical cutting means and the laser beam having power sufficient to damage an unwanted plant can be provided by the same at least one laser diode.

18. A method of removing unwanted plants comprising:

capturing plant images using a three-dimensional imager;

distinguishing between a wanted plant and an unwanted plant after capturing plant images;

locating a target on the unwanted plant;

guiding at least one laser device configured to emit at least one laser beam to the target of the unwanted plant;

adjusting at least one of a depth of field, a width of field, or a focal length of the at least one laser beam;

directing the adjusted at least one laser beam to the target on the unwanted plant; and

damaging the target on the unwanted plant with the at least one laser beam.

19. A method of removing unwanted plants according to claim 18, further comprising mounting the three-dimensional imager and the at least one laser device on a chassis.

20. A method of removing unwanted plants according to claim 19, further comprising moving the chassis across an agricultural field or lawn.