Real-time measuring of the spatial distribution of sprayed aerosol particles

• US 7,388,662 B2
• Filed: 09/30/2005
• Issued: 06/17/2008
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: Institut national d'optique
• Original Assignee: Institut national d'optique
• Inventors: Babin, François, Lévesque, Marc, Cantin, Daniel
• Primary Examiner(s): Chowdhury; Tarifur
• Assistant Examiner(s): Hansen; Jonathan M
• Application Number:
  US11/241,634
• Publication Number:
  US 20070076202A1
• Time in Patent Office: 991 Days
• Field of Search: 356335-343, 356/437, 356/301, 250/559.08, 701/50, 701/23, 342/357.13
• US Class Current: 356/338
• CPC Class Codes: A01M 7/0096 Testing of spray-patterns
• CPC Class Codes: G01N 15/0205 by optical means
• CPC Class Codes: G01N 15/0211 Investigating a scatter or diffraction pattern
• CPC Class Codes: G01N 2021/1793 Remote sensing
• CPC Class Codes: G01N 2021/4709 Backscatter
• CPC Class Codes: G01N 21/53 within a flowing fluid, e.g. smoke
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications

Abstract

An optical system for measuring in real-time the spatial distribution of aerosol particles, such as pesticides or the like, sprayed from a vehicle over an agricultural field. An optical sensor is mounted directly on the vehicle and sends an excitation light beam through the aerosol as it is being sprayed. The resulting scattered light is received and analyzed to deduce therefrom information on the spatial distribution of the particles. This information is relayed to a processing unit, which in turn provides spraying instructions, for example a warning signal, to the operator of the system. The spraying of the aerosol can therefore be controlled in real-time to avoid contamination of sensitive areas.

Claims

1. An optical system for measuring in real-time a spatial distribution of particles in an aerosol, said aerosol being sprayed from a sprayer mounted on a vehicle operated by an operator, said optical system comprising:

a short range LIDAR optical sensor comprising a light source assembly projecting an excitation light beam through the aerosol jointly to the spraying thereof, said excitation light beam being scattered by the particles, thereby producing scattered light, said optical sensor further comprising a detecting assembly for detecting a part of said scattered light and obtain therefrom information on the spatial distribution of the particles comprising an intensity value of said detected scattered light as a function of distance from said optical sensor, said optical sensor having a substantially flat spatial response wherein a same concentration of particles at any distance within said short range will generate a signal of substantially a same intensity;

mounting means for mounting said optical sensor on the vehicle; and

a processing unit in communication with the optical sensor for receiving therefrom said information on the spatial distribution of the particles said processing unit providing spraying instructions based on said information to said operator in real-time.

2. The optical system according to claim 1, wherein said mounting means comprise a sensor support pivotable in the horizontal plane for pivoting said optical sensor, thereby horizontally scanning said excitation light beam.

3. The optical system according to claim 2, wherein said sensor support is vertically tiltable for vertically moving said excitation light beam.

4. The optical system according to claim 1, wherein said detecting assembly is positioned contiguously to said light source assembly in order to detect a back-scattered portion of said scattered light.

5. The optical system according to claim 1, wherein said processing unit is located aboard said vehicle.

6. The optical system according to claim 1, wherein said processing unit is at a location remote from said vehicle, and wherein:

said optical sensor is provided with a wireless transmitter for transmitting said information; and

said processing unit is provided with a wireless receiver for receiving said information.

7. The optical system according to claim 1, wherein said light source assembly comprises a pulsed laser source generating said excitation light beam.

8. The optical system according to claim 7, wherein said detector assembly comprises a detector and light-receiving optics receiving the part of the scattered light.

9. The optical system according to claim 1, wherein said detecting assembly further comprises a spatial filter spatially filtering said part of the scattered light so as to flatten said spatial response of the optical sensor.

10. The optical system according to claim 1, wherein said spraying instructions comprise a warning signal provided to said operator when said information indicates a drift of the particles in a sensitive area.

11. The optical system according to claim 1, wherein said spraying instructions comprise a visual representation of the spatial distribution of the particles.

12. The optical system according to claim 1, further comprising a data storage unit for storing said information received by the processing unit.

13. An agricultural spraying system for the controlled spraying of aerosol particles over a delimited area, comprising:

a vehicle for circulating over said delimited area, said vehicle being operated by an operator;

a sprayer, mounted on said vehicle, for spraying said aerosol particles as said vehicle circulates over said delimited area; and

an optical system for measuring in real-time a spatial distribution of said particles, comprising;

a short range LIDAR optical sensor comprising a light source assembly projecting an excitation light beam through the aerosol jointly to the spraying thereof, said excitation light beam being scattered by the particles, thereby producing scattered light, said optical sensor further comprising a detecting assembly for detecting a part of said scattered light and obtain therefrom information on the spatial distribution of the particles comprising an intensity value of said detected scattered light as a function of distance from said optical sensor, said optical sensor having a substantially flat spatial response wherein a same concentration of particles at any distance within said short range will generate a signal of substantially a same intensity;

mounting means for mounting said optical sensor on the vehicle; and

a processing unit in communication with the optical sensor for receiving therefrom said information on the spatial distribution of the particles, said processing unit providing spraying instructions based on said information to said operator in real-time.

14. The agricultural spraying system according to claim 13, wherein said vehicle is a tractor.

15. The agricultural spraying system according to claim 13, wherein said sprayer comprises a plurality of nozzles.

16. The agricultural spraying system according to claim 13, wherein said operator is a person driving said vehicle.

17. The agricultural spraying system according to claim 13, wherein said operator is an automated system controlling said vehicle.

18. The agricultural spraying system according to claim 13, wherein said aerosol particles are selected from the group consisting of pesticides, herbicides and fertilizers.

19. The agricultural spraying system according to claim 13, wherein said mounting means comprise a sensor support pivotable in the horizontal plane for pivoting said optical sensor, thereby horizontally scanning said excitation light beam.

20. The agricultural spraying system according to claim 19, wherein said sensor support is vertically tiltable for vertically moving said excitation light beam.

21. The agricultural spraying system according to claim 13, wherein said detecting assembly is positioned contiguously to said light source assembly in order to detect a back-scattered portion of said scattered light.

22. The agricultural spraying system according to claim 13, wherein said processing unit is located aboard said vehicle.

23. The agricultural spraying system according to claim 13, wherein said processing unit is at a location remote from said vehicle, and wherein:

said optical sensor is provided with a wireless transmitter for transmitting said information; and

said processing unit is provided with a wireless receiver for receiving said information.

24. The agricultural spraying system according to claim 13, wherein said spraying instructions comprise a warning signal provided to said operator when said information indicates a drift of the particles in a sensitive area.

25. The agricultural spraying system according to claim 13, wherein said spraying instructions comprise a visual representation of the spatial distribution of the particles.

26. The agricultural spraying system according to claim 13, further comprising a data storage unit for storing said information received by the processing unit.

27. The agricultural spraying system according to claim 13, further comprising at least one environmental sensor for sensing environmental conditions of said spraying, said at least one environmental sensor providing said environmental conditions to the processing unit.

28. The agricultural spraying system according to claim 27, wherein said environmental conditions are selected from the group comprising a temperature, a humidity level, wind conditions, and a speed of the vehicle.

29. The agricultural spraying system according to claim 13, further comprising a GPS sensor tracking a position of the vehicle over said delimited area, said GPS sensor being in communication with the processing unit.

30. The agricultural spraying system according to claim 29, wherein said processing unit correlates the position of the vehicle tracked by the GPS sensor with the information on the spatial distribution of the particles to obtain an actual position of the aerosol with respect to said delimited area.