RU2795590C2 - Insecticide sprayer - Google Patents

Abstract

FIELD: insecticidal spraying.

SUBSTANCE: invention relates to a method, apparatus and sensor for insecticidal spraying. An insect sensor for detecting airborne insects moving above the ground surface contains a lighting module configured to illuminate the detection volume, while the detection volume is raised above the soil surface by a minimum vertical distance, and one or more detectors configured to detect light from the detection volume. The lighting module is configured to emit a divergent beam of light, in particular with a divergence angle in at least one direction of 2° up to 45°, for example from 10° up to 30°. A unit for distributing insecticide over a piece of land, wherein the piece of land forms the surface of the ground, the unit includes: an insecticide distribution device configured to distribute the insecticide along said travel path while the vehicle is moving along the travel path; a distribution control system configured to control the amount of the insecticide to be distributed while the vehicle is traveling along the travel path; an insect sensor configured to detect airborne insects in the detection volume while the detection volume is moving relative to the ground surface; moreover, the detection volume is located in front of the vehicle in the direction of travel and is raised above the ground surface by a minimum vertical distance. The distribution control system is configured to receive sensor data from the insect sensor, wherein the sensor data indicates an insect detection result in the detection volume, with the possibility to control the amount of insecticide to be distributed depending on the received sensor data. The method includes the steps of detecting, by means of an insect sensor, insects in the air moving in the detection volume, while the detection volume is located in front of the moving vehicle, and the detection volume is raised above the ground surface by a minimum vertical distance; controlling the distribution of insecticides from said moving vehicle depending on the detection result of airborne insects. The insecticidal spraying control unit comprises an insect sensor and a control system capable of issuing a control signal for controlling the insecticide dispenser depending on the detection signal from the insect sensor.

EFFECT: increased efficiency of spraying and increased detection and identification of insects.

26 cl, 9 dwg

Description

The technical field to which the invention belongs

The present disclosure relates to an insecticidal spray apparatus, an insecticidal spray control method and apparatus, and an insect sensor for detecting insects.

State of the art

There is a general need to optimize the use of insecticides in agriculture.

In particular, when distributing insecticides to a crop field or other area where disinfestation is required, it is generally desirable that the types and amounts of insecticides used provide effective disinsection without the use of unnecessary, useless, or even environmentally harmful amounts of insecticides.

At the same time, the number of insects can be different not only at different times, but also in different parts of a single site, and therefore the use of effective amounts of insecticides is a difficult task. In particular, insects are often unevenly distributed over the site, and foci of local high concentrations of insects may occur. In addition, the location of such foci may be different at different times.

WO 2016/025848 discloses a mobile platform that is structurally and functionally capable of: collecting data on phenotypes and/or genotypes in situ (in the field); video data collection; taking tissue samples; selecting and/or counting plants growing on the site; plant height measurements; use of drugs and treatments on plants growing on the site (for example, standard insecticidal drugs or those used taking into account local characteristics); taking soil samples in places where plants grow; removal of weeds in such areas; analysis of all collected data and/or samples in real time. In particular, the mobile platform includes an imager suspended above the ground surface with a downward field of view covering one or more plants in the desired number of plant rows.

US 9,655,356 discloses a lawn care apparatus in which the presence of an area requiring selective treatment with a herbicide, pesticide or fungicide is detected by means of a scanner. Said apparatus contains a multi-chamber cartridge containing various chemicals and uses them selectively. In particular, this counter-document describes a lawnmower comprising a front scanner capable of optically scanning the area in front of the lawnmower. The front scanner emits a beam of light that illuminates the grass/weeds/ant piles in front of the mower.

Although the above prior art are systems for detecting pest-infested plants or insect swarms (such as anthills, termite mounds, etc.) on the ground, the problem remains that many agricultural machines scare away insects while the machine is moving through field. In addition, many of the insects to be treated against can fly or jump and therefore fly away or bounce, in particular if spooked by an agricultural vehicle, making them difficult to detect.

Therefore, there is a general need to improve the reliability of detection and identification of insects, in particular in the vicinity of a moving agricultural vehicle.

In addition, there is a general need for an easy-to-use and efficient apparatus for distributing insecticide on a piece of land.

There is also still a need for a simple, but reliable, insect sensor that can quickly detect moving insects.

Disclosure of the essence of the invention

According to one aspect, embodiments of an apparatus for distributing an insecticide over a piece of land, the piece of land forming a ground surface, are disclosed. The apparatus includes:

- a vehicle capable of moving along a travel path on the ground surface, wherein the direction of travel is set by the vehicle, the vehicle comprising an insecticide dispensing device configured to distribute the insecticide along said travel path while the vehicle is moving along the travel path;

a distribution control system configured to control the amount of insecticide to be distributed while the vehicle is moving along the travel path;

- an insect sensor configured to detect airborne insects in the detection volume during movement of the detection volume relative to the ground surface; moreover, the detection volume is located in front of the vehicle in the direction of travel and is raised above the ground surface by a minimum vertical distance;

moreover, the distribution control system is configured to receive data from the insect sensor, wherein the sensor data indicates the result of detection of insects in the detection volume, and control the distribution of the insecticide depending on the received sensor data.

In particular, the sensor data may indicate the number of insects detected in the moving detection volume during the sampling period. Thus, the distribution control system can be configured to control the distribution of the insecticide at the distribution site depending on the sensor data indicative of the local population of insects, in particular, indicating the result of insect detection in the detection volume above the detection site located near the distribution site.

Thus, the apparatus is configured to locally control the distribution of the insecticide depending on the actual presence of insects at or near the specified location, i.e. changing the amount of the insecticide distributed along the travel path depending on the insect detection result, thereby enabling the effective use of the insecticide. In addition, since the spreading is carried out depending on the result of detecting insects in front of the spreading vehicle and above the ground surface, the control is adjusted depending on current and local information and taking into account insects in the air, in particular flying or jumping insects.

Distribution control may include controlling the amount of insecticide to be distributed and/or the type of insecticide to be distributed at any given location along the travel path. To do this, the distribution control system may be configured to control one or more valves, pumps and/or other flow control devices to control the amount of insecticide or select the type of insecticide to be distributed by one or more dispensers.

For example, the distribution can be controlled by triggering the distribution of the insecticide only when the number of detected insects (or the number of detected insects of a certain type) is above a predetermined limit. In some embodiments, the vehicle is configured to dispense insecticide from a plurality of outlets, such as nozzles, for example, such that the respective outlets distribute the insecticide to the appropriate locations. The distribution control system can further control the distribution of insecticides through selected outlets, thereby providing even more precise distribution control. Such a selective distribution can be carried out, for example, depending on the result of the detection of insects in the respective parts of the detection volume.

The vehicle may be a ground vehicle, i. e. a vehicle operating while in contact with the ground. The ground vehicle may be moved, for example, on wheels or the like. For example, the ground vehicle may be a tractor or other agricultural vehicle. Other examples of vehicles include aircraft, such as an airplane, helicopter, or the like. The vehicle may be manned or unmanned.

The detection volume may have many different shapes and sizes, such as box-shaped, cylindrical, sphere, cone, pyramid, truncated cone, truncated pyramid, and the like. In some embodiments, the size of the detection volume is at least 0.2 m ³ , such as at least 0.5 m ³ , such as at least 1 m ³ , such as at least 2 m ³ , such as at least 3 m ³ . In some embodiments, the aspect ratio of the detection volume, e.g., defined as the ratio of the largest side to the smallest side of the minimum detection volume bounding box, is at most 10:1, e.g., at most 5:1, e.g., at most 3:1, e.g., no more than 2:1. For example, the aspect ratio may be 1:1 to 10:1, such as 1:1 to 5:1, such as 1:1 to 3:1, such as 2:1 to 3:1. The minimum bounding box can form a vertical side and two horizontal sides. The vertical side may be the smallest side of the minimum bounding box. For example, the ratio of each of the horizontal sides to the vertical side may be 2:1 to 10:1, such as 2:1 to 5:1, such as 2:1 to 3:1.

It has been found that a detection volume of at least 0.2 m ³ , such as at least 0.5 m ³ , such as at least 1 m ³ , such as at least 2 m ³ , such as at least 3 m ³ is enough to detect insect populations with sufficient accuracy to effectively control the distribution of the insecticide. It has also been found that a low aspect ratio of the detection volume allows moving insects to be tracked for a relatively long period of time, regardless of the direction of insect movement, and thereby more accurately detect and identify insects.

The detection volume is raised above the ground surface by the minimum vertical distance. In some embodiments, the detection volume extends from the top of the canopy upwards. This avoids, or at least reduces, vegetation interference with the insect sensor, for example by blocking the light path. To this end, the minimum vertical distance can be predetermined, for example adjusted prior to use, for example to correct the minimum vertical distance according to the size of the vehicle on which the insect sensor is mounted and/or the vegetation currently to be treated. For example, the insect sensor may be mounted on a vehicle to correct the vertical distance from the insect sensor to the ground surface and/or the orientation of the insect sensor relative to the ground surface. The value of the vertical distance may depend on the height of the vegetation growing on the plot of land to be cultivated. It may be greater than the height of the vegetation, for example greater than the maximum height in the population of plants forming the vegetation to be treated, or greater than the average height in the population of plants to be treated. For example, the minimum vertical distance may be selected from 10 cm to 5 m, such as 20 cm to 3 m, such as 20 cm to 2 m, such as 50 cm to 2 m.

In particular, the insect sensor embodiments disclosed herein are suitable for detecting airborne insects, such as flying or jumping insects, in particular for detecting such insects from a moving vehicle. Embodiments of the insect sensor disclosed herein allow the detection of insects moving in the detection volume for observation periods long enough to reliably identify and distinguish different types of insects from each other, for example, by determining wing beat frequencies and/or by classifying trajectories.

It was found that these methods provide reliable detection and identification of insects with a sufficiently long stay of individual insects in the detection volume.

In some embodiments, the insect sensor comprises an illumination module configured to illuminate the detection volume, in particular the entire detection volume, and a detector module comprising one or more detectors configured to detect light from the detection volume, in particular the entire detection volume. In particular, the lighting module is configured to illuminate the detection volume with illuminating light, and the detection module is configured to detect a backscattered part of the illuminating light, this part being the result of backscattering by insects moving across the detection volume. The authors of the present invention have found that the detection and analysis of light, in particular back-scattered light from illuminated insects, allows you to reliably detect and identify insects.

The detection volume is a three-dimensional volume from which the insect sensor receives sensor input suitable for insect detection. Thus, the amount of detection may be wholly or partly dependent on the field of view and depth of field of the detector module. In embodiments where the detection volume illuminates the illumination module, the detection volume may be formed by an overlap between the volume illuminated by the illumination module and the volume dependent on the field of view and depth of field of the detector module.

The detection volume may have a predetermined shape, size and position relative to the illumination module and relative to the detector module, for example, relative to the aperture stop and/or the optical axis of the detector module. In particular, the detection volume may, during the entire detection process, be stationary with respect to the detection module and the illumination module. The detector module may contain one or more lenses that form the optical axis of the detector module and/or the focal length. The focal length may be constant throughout the entire detection process. The optical axis can also be constant, for example, relative to the lighting module and/or relative to the casing of the apparatus, during the entire detection process. It should be understood that the apparatus can be configured to pre-adjust and correct the size, shape and/or relative position of the detection volume, taking into account specific measurement conditions, for example, by changing the relative position and/or orientation of the illumination module and the detector module. The detector module may also include an aperture stop.

In some embodiments, the size of the detection volume is less than 20 m ³ , for example, less than 10 m ³ , for example, less than 5 m ³ , which provides uniform illumination with high brightness of the entire detection volume while providing reliable detection of wing beat trajectories and/or frequencies.

In some embodiments, the implementation of the lighting module contains a light source configured to emit non-coherent light. Suitable light sources include light emitting diodes (LEDs) and halogen lamps, as they are capable of simultaneously illuminating large detection volumes with sufficient light intensity. It is possible to use additional non-coherent light sources to provide monochromatic, speckle-free illumination of the detection volume, in particular simultaneous illumination of a large detection volume without the need for any scanning operation. This simplifies the optical system and makes it possible to reliably determine wing beat frequencies and/or trajectories even in the case of fast insect movement.

In this case, it is possible to use other light sources, including coherent light sources, such as lasers, instead of the above. In some embodiments, the light source is configured to continuously emit light, and in other embodiments, the light is switched on and off periodically, for example, in a pulsed mode.

In some embodiments, the illumination module comprises a light source configured to emit coherent or non-coherent light in the visible region and/or infrared and/or near infrared regions and/or light in one or more other wavelength ranges. Many insects are unable to perceive light in the infrared and/or near infrared regions (eg, light in the wavelength range from 700 nm to 1500 nm, eg from 700 nm to 1000 nm), so it does not affect their behavior.

In some embodiments, the illumination module is configured to selectively illuminate the detection volume with light in two or more wavelength ranges, in particular two or more wavelength ranges spaced apart. To this end, the lighting module may include a first light source, for example comprising one or more LEDs, configured to selectively emit light in a first wavelength range. The lighting module may further include a second light source, for example, comprising one or more LEDs configured to selectively emit light in a second wavelength range that may be spaced from the first wavelength range. The detector module may be configured to selectively detect waves in selected bands. In one embodiment, the lighting module is configured to emit light in a first wavelength range of 810 nm +/-25 nm and light in a second wavelength range of 980 nm +/-25 nm. This multispectral illumination system facilitates the detection of moving insects by color.

Conventional illumination of a relatively large detection volume, in particular simultaneous illumination of a detection volume, by means of a compact lighting module, can be achieved, for example, if the lighting module is configured to emit a divergent light beam, in particular a light beam with a divergence angle in at least one direction from 2 ° to 45°, for example, from 10° to 30°, measured as the total angle between rays emanating from the specified light source and crossing opposite ends of the beam diameter.

The lighting module may, for example, include one or more optical elements, for example, one or more reflectors and/or one or more lenses, directing light from a light source in the form of a light beam, for example, a divergent light beam, with a cross section of a suitable shape towards the detection volume. For example, the cross section of the light beam may be rectangular or round, such as oval or round.

Accordingly, the detection volume may be in the form of a truncated cone or a truncated pyramid.

When detecting moving insects in a vegetated field, it has been found that the preferred shape of the base/cross section of a frustoconical or frustopyramidal detection volume is, in particular, an oblong (eg elliptical or rectangular) shape. In particular, the width of the elongated cross section/base (measured in the horizontal direction) is greater than its height (measured in the vertical direction), e.g. the ratio of width to height is at least 3:2, e.g. at least 2:1, e.g. from 3 :2 to 5:1, eg 3:2 to 3:1, eg 2:1 to 3:1. A detection volume with an elongated cross-section and a horizontal longitudinal axis, where the detection volume is raised above the soil surface by a minimum vertical distance, makes it possible to locate the detection volume in the form of a relatively flat volume, for example, a flat box-shaped volume or a volume generally shaped like a flat sector, t .e. its location horizontally above the canopy of vegetation. This volume allows to reduce reflections, light scattering or other disturbing influences created by plants, which could otherwise interfere with the detection process. The inventors of the present invention have also found that such a detection volume makes it possible to efficiently use the available illumination power to illuminate the volume where most insect activity takes place.

Since in some embodiments, the detection volume is formed by the area of overlap between the illuminated volume and the volume depending on the field of view and the depth of field of the detector module, the illumination module can be configured to illuminate a conical, or pyramidal, or truncated-conical, or truncated-pyramidal illuminated volume, in particular with an elongated base/cross-section, as disclosed above in the example of a detection volume.

In some embodiments, the detector module comprises a camera, in particular a camera with a field of view and a depth of field large enough to capture in-focus images of the entire detection volume. The camera allows detection of disturbing events, such as larger animals and plants crossing the detection volume. The camera can also serve as a detector for detecting background radiation. In some embodiments, captured images may be used for detection and/or identification by the processor of insects, for example, by detecting the trajectories of airborne insects and identifying types of insects from appropriate trajectory patterns. An example of a method for identifying insects from recorded insect trajectories is disclosed in also pending International Patent Application No. PCT/EP 2019/073119.

The processor of the apparatus according to the present invention is configured to implement the identification method disclosed in International Patent Application No. PCT/EP 2019/073119 for insect detection. It has been found that trajectory detection can in particular be used to detect insects in large detection volumes in front of an insecticide dispensing vehicle. In particular, it has been found that trajectory detection can be used in a system that uses multiple detection methods as appropriate features for different types of insects and is capable of identifying detected insects from a classifier whose input is multiple features. For example, path detection may be combined with one or more of the detection methods disclosed below.

In some embodiments, said one or more detectors comprise one or more photodiodes. Single photodiodes receiving light from the entire detection volume or from a portion of the detection volume allow rapid detection, with time resolution, of changes in backscattered light brightness. These signals can be used to determine the wingbeat frequency of flying insects, which, in turn, can detect the presence of insects and, optionally, distinguish insects of different types from each other by characteristics of wingbeat patterns, for example, by the amplitudes of multiple frequencies in the frequency spectrum corresponding to insect detection event.

In some embodiments, the detector module comprises a photodiode array, such as a linear array or a two-dimensional array. The detector module may be configured to direct light from different sub-volumes of the detection volume onto the corresponding photodiodes of the array, thereby enabling detection, at spatial resolution, of insects using the photodiodes.

In some embodiments, the photodiode or photodiode array is configured to selectively detect light at a predetermined wavelength or wavelengths in a small range. In some embodiments, the detector module is configured to selectively detect light with two or more wavelengths or wavelengths in two or more small ranges, wherein said two or more wavelengths or two or more ranges are spaced apart and do not overlap. To do this, the detector module may include one or more photodiodes or photodiode arrays configured to selectively detect light with two or more wavelengths or wavelengths in two or more small ranges, and these two or more wavelengths or two or more ranges are separated from each other. from each other and do not overlap. This can be achieved, for example, by a single photodiode array in which respective bandpass filters are selectively and alternately placed in front of the photodiode or photodiode array. Alternatively, the detector may include two or more photodiodes or photodiode arrays, each of which is configured to detect light of a respective wavelength or wavelengths in a respective range. In particular, it has been found that a detector module capable of selectively detecting light at wavelengths of 808 nm and 970 nm, respectively (for example, by means of appropriate photodiodes) is suitable for detecting and distinguishing different types of insects from each other, for example, in terms of the inverse ratio scattered light with corresponding wavelengths. In general, in some embodiments, said one or more photodiodes include at least a first photodiode capable of selectively detecting light in a first wavelength range; and at least a second photodiode configured to selectively detect light in a second wavelength range not overlapping the first wavelength range.

In general, the detector module may include a single detector or multiple detectors. Accordingly, the insect sensor may comprise a processor configured to determine, based on signals from one or more detectors, the number, eg, number, of insects detected in the detection volume. In some embodiments, the processor is configured to identify, based on signals from one or more detectors, one or more types of insects and determine the corresponding numbers of insects of said one or more types detected in the detection volume. Accordingly, the distribution control system can control the distribution of insecticides to target certain types of insects. In addition, the distribution control system may control the amount of insecticide to be dispensed depending on the number of detected insects or on a particular type of insect.

To do this, the processor may process the detector signals to detect one or more signs indicating the presence of one or more insects in the detection volume, and count the number of insects detected, for example, in a given period of time, in a sliding interval, or the like, for determining an estimate of the number of insects detected in the detection volume, for example, in terms of the number of insects detected in the detection volume, for example, per unit of time and/or unit of volume. The processor may even be configured to detect one or more features indicative of the type of insects detected and selectively determine an estimate of the number of detected insects of one or more types, e.g., insects of one or more species, insects that respond to particular types of insecticides, and the like. To do this, the processor is configured to implement a suitable classification model, for example based on neural networks and/or other classification methods, configured to determine the presence of a detected insect and/or identify a detected insect by a set of features. In general, the processor may provide sensor data indicative of the number of insects detected per sample period in the moving detection volume, or another parameter indicative of an estimate of the local population of insects in the detection volume and/or in the sample volume traversed by the detection volume.

In some embodiments, the processor is configured to identify one or more insect types based on one or more features selected from the following:

- the detected insect movement trajectory inside the detection volume;

- detected speed of insect movement inside the detection volume;

- one or more detected wing beat frequencies;

- degree of melanization;

- the degree of shine of insects.

Detection and/or identification of insects by wing beat frequencies, degrees of melanization and brilliance of insects are described in more detail in WO 2018/182440 and Gebru et al.: "Multiband modulation spectroscopy for the determination of sex and species of mosquitoes in flight", J. Biophotonics, 2018 (Gebru et al. “Multiband modulation spectroscopy for in-flight sex and species determination of mosquitoes”, Biophotonics, 2018). The above documents refer to these features in relation to a lidar system that uses the Scheimpflug principle; however, the inventors of the present invention have found that these methods can also be applied to a detection system based on other light sources illuminating a large volume, as opposed to a narrow laser beam.

Thus, the apparatus processes the sensor signals to calculate sensor data indicative of the number of insects detected in the moving detection volume. The number of detected insects can serve as an estimate of the local population of insects in the sample volume intersected by the detection volume over the measurement period. Depending on the insect detection result and/or the resulting estimate of the insect population and/or insect populations of the respective types, the distribution control system may select one or more suitable insecticides, appropriate quantities to be applied at a particular location, and control the outlets of the system to distribution of the selected quantity to it. To do this, the processor determining the number of detected insects and/or estimating the insect population may transmit sensor data indicating the determined number of insects detected in the detection volume and/or otherwise indicating the estimate of the local insect population to the distribution control system. In some embodiments, the distribution control system and the insect sensor processor may be implemented as a single processor module, i. e. a processor for processing sensor signals for detecting and optionally identifying insects may be part of the distribution control system.

As the vehicle moves across the land, the detection volume moves with the vehicle, with the insect sensor continuously or at least repeatedly updating estimates of the insect population in front of the vehicle. Thus, the distribution control system can control the distribution of the insecticide (eg, amount and/or type) depending on the current assessment of the insect population, for example, depending on the local insect population.

In some embodiments, the insect sensor is mounted on a vehicle separate from the vehicle dispensing the insecticide. For example, the insect sensor may be mounted on an unmanned aerial vehicle in front of the vehicle. In other embodiments, the insect sensor is mounted on the vehicle dispensing the insecticide, which simplifies the system and its use. The insect sensor may be mounted on a pole, frame, bracket, or other mounting structure mounted at or near the forward-facing end of the vehicle. In some embodiments, the mounting structure is adjustable on the vehicle, such as adjusting the vertical distance from the insect sensor to the ground based on, for example, vegetation height and/or types of insects to be detected. Similarly, the orientation of the insect sensor relative to the forward direction of the vehicle can be adjusted to control the location of the detection volume relative to the vehicle. For example, in some situations it may be desirable for the sensor to be positioned low but its field of view facing forward or up and forward, while in other situations a high position with a forward or downward and forward field of view may be preferred. The position and/or orientation of the sensor may be adjusted manually or automatically.

If the sensor is predominantly facing forward, i.e. the detection volume is located in front of the vehicle along the driving path, the detection volume is less affected by disturbing influences generated by the driving vehicle, such as the influence of dust, exhaust gases, or the like. The system may also process sensor data from the detection volume at the first location along the travel path for the time required for the vehicle to reach the first location to enable the insecticide distribution control to be adjusted to the characteristics of the first location based on the data obtained at said first location.

This disclosure relates to various aspects, including the apparatus disclosed above and hereinafter, related devices, systems, methods and/or articles, each of which provides one or more of the effects and advantages described in connection with one or more other aspects. , and has one or more embodiments corresponding to the embodiments disclosed in connection with one or more other aspects and/or disclosed in the appended claims.

In particular, according to one aspect, the present disclosure relates to an insect sensor.

The insect sensor can be configured to be mounted on a vehicle, wherein the vehicle is configured to move along a path along a piece of land, while the direction of movement is set by the vehicle, while the vehicle contains an insecticide distribution device configured to distribute the insecticide along the specified path of movement during the movement of the vehicle along the path of movement; wherein the insect sensor is configured, when mounted on the vehicle, to detect insects in the detection volume; moreover, the detection volume is located in front of the vehicle in the direction of travel; wherein the insect sensor is configured to output sensor data to the distribution control system, wherein the distribution control system is configured to receive sensor data from the insect sensor, the sensor data indicating the result of detecting insects in the detection volume, and controlling the amount of insecticide to be distributed depending on the accepted sensor data.

In particular, according to one aspect, embodiments of an insect sensor for detecting airborne insects moving over a ground surface are disclosed, wherein the insect sensor comprises:

- a lighting module configured to illuminate the detection volume, while the detection volume is raised above the ground surface by a minimum vertical distance, and

- one or more detectors configured to detect light from the detection volume;

moreover, the lighting module is configured to emit a divergent beam of light, in particular with an angle of divergence in at least one direction of 2° to 45°, for example from 10° to 30°.

The embodiments of the insect sensor disclosed herein are robust and uncomplicated, making them economical, durable, and suitable for placement on moving vehicles. In addition, embodiments of the insect sensor disclosed herein provide reliable detection and classification of airborne insects.

It should be understood that insects differ significantly from each other in size and behavior. Insects can range in size from less than one millimeter to several centimeters, and insect trajectories vary from hovering in the air in one place to jumping along ballistic trajectories. The insect apparatus and sensor embodiments disclosed herein have been found to be applicable to various types of airborne insects, including flying insects with wings and jumping insects, such as jumping leaf beetles, such as rapeseed fleas (psylliodes chrysocephala).

If a jumping flea jumps to a height h, then the vertical speed with which the flea leaves the ground to reach the indicated height can be estimated by assuming an essentially ballistic flight path. For example, if a flea jumps 0.5 m above the ground, then the initial vertical speed of the flea will be about 3.2 m/s, which reflects the order of magnitude of the speed of movement of insects in a volume with a ballistic trajectory. In order to detect such a fast event involving insects smaller than 5-10 mm, it is necessary to ensure the length of the detection volume and, consequently, the illuminated volume, taking into account the need to cover a significant part of the trajectory and the detection speed to decompose the motion in time. In addition, the detector module must ensure the decomposition of such events in time and space. Similarly, as disclosed herein, in order to detect flying insects from wing beat patterns, it is necessary to meet similar requirements for detection volume and temporal and spatial resolution of the insect sensor.

In some embodiments, the insect sensor and distribution control system are integrated into a vehicle-mountable unit and communicate with a vehicle-mounted distributor to control the distribution of insecticide from the distributor.

Hereinafter, the meaning of the term "processor" should be construed as including any circuitry and/or device capable of performing the functions disclosed herein. In particular, the meaning of the term "processor" includes a general purpose or special purpose programmable microprocessor, such as the central processing unit (CPU) of a computer or other data processing system, a digital signal processor (DSP), an application specific integrated circuit (AIS), a programmable logic array (PLM), field programmable gate array (FPGA), special purpose electronic circuit, etc. or a combination of them. It should be understood that the processor and/or distribution control system may be implemented as a client/server or similar distributed system in which the signal detection and optionally some of the processing steps are performed locally in the vehicle and other parts of the data processing and classification tasks can be performed by a remote host system that communicates with the client device.

According to another aspect, embodiments of a method for controlling an insecticidal spray are disclosed, comprising the steps of:

- detect airborne insects moving in the detection volume, while the detection volume is located in front of the moving vehicle, while the detection volume is raised above the ground surface by a minimum vertical distance;

- control the distribution of insecticides from the specified moving vehicle depending on the result of detection of insects in the air.

According to another aspect, embodiments of an insecticidal spray control apparatus are disclosed, comprising an insect sensor disclosed above and hereinafter, and a control system, such as a computer-based control system, configured to provide a control signal for controlling an insecticide dispenser in response to an insect dispenser detection signal.

Additional features and advantages will become apparent from the following section "Carrying out the Invention" in which embodiments are disclosed in the examples of the accompanying drawings.

Brief description of the drawings

Preferred embodiments will be explained in more detail with reference to the accompanying drawings, of which:

FIG. 1 is a schematic view of an insecticidal spray apparatus.

FIG. 2 schematically illustrates the operation of an insecticidal spray apparatus.

FIG. 3 schematically illustrates an embodiment of an insect sensor.

FIG. 4 schematically illustrates an example of an insect sensor detector module.

FIG. 5 schematically illustrates another example of an insect sensor detector module.

FIG. 6 schematically illustrates another embodiment of an insect sensor.

FIG. 7 schematically illustrates an example of a sensor signal from the detection module of the insect sensor embodiment disclosed herein.

FIG. 8 and 9 illustrate examples of detection volumes.

Implementation of the invention

FIG. 1 is a schematic plan view of an insecticidal sprayer. The apparatus includes an agricultural vehicle 100 such as a tractor or other land vehicle. It should be understood that, as an alternative, it is possible to use an aircraft.

The vehicle is made with the possibility of moving along the path of movement through the field or on another surface of the soil of the land plot to be disinfested. The vehicle sets the direction of travel as shown by arrow 101. The direction of travel is also referred to as the "forward direction of the vehicle" in the following.

The vehicle includes an insecticide dispensing device 110 having one or more insecticide dispensing outlets. For example, the dispenser 110 may include a bar extending transversely, ie. across the direction 101 of movement.

A plurality of spray nozzles are located on the boom, for example distributed along the length of the boom. The distributor may be located at the rear or towards the rear of the vehicle, although other positions are possible. The vehicle further comprises a distribution control unit 140, such as a suitable control circuit, such as a suitably programmed microprocessor or the like. The distribution control unit is operatively connected to the distributor and is configured to control the amount of insecticide dispensed by the distributor 110. To do this, the distribution control device may be configured to control a valve or similar flow control device to control the flow rate of insecticide from the insecticide tank (not explicitly shown) into the distributor outlets. In some embodiments, distribution control unit 140 may control multiple valves to control the flow rate of insecticide to respective individual outlets. In some embodiments, the implementation of the vehicle may contain several tanks of insecticides, for example, to accommodate different types of insecticides. In such an embodiment, the distribution control unit may be configured to selectively control the flow rate of insecticides from the respective tanks to the distributor, for example, to select the type of insecticide or combination of insecticides to be distributed. The distribution control unit can control the distribution of insecticides in real time, i. change the amount and/or type of insecticide to be distributed while the vehicle is moving along the route. Accordingly, the distribution control unit may trigger the distribution of different amounts and/or types of insecticide at different locations along the travel path.

The apparatus further comprises an insect sensor 120 for detecting insects in front of the vehicle 100 while the vehicle is moving in the travel direction 101 . To do this, the insect sensor can be mounted at or near the front end of the vehicle.

Alternatively, the insect sensor may be mounted elsewhere on the vehicle, or even on a separate vehicle, such as an unmanned aerial vehicle or an unmanned ground vehicle in front of, next to, or above the vehicle 100.

Insect sensor 120 in the embodiment of FIG. 1 includes a bar or frame 133 mounted at the front end of the vehicle. The insect sensor further comprises an illumination module 131 and a detection module 130, each mounted on a rod or frame 133. It should be understood that other embodiments may include more than one illumination module and/or more than one detector module. It should also be understood that the illumination module and the detector module may be implemented as separate devices, i. e. each of the modules can have its own casing. In other embodiments, the implementation of the lighting module and the detector module can be placed in a single housing or otherwise form a single unit. In other embodiments, the insect sensor may be otherwise mounted to the vehicle, such as without a rod or frame.

The lighting module 131 includes a light source, such as one or more halogen lamps, one or more LEDs, and the like, configured to illuminate an area to be illuminated in front of the vehicle. The lighting module may be communicatively connected to the distribution control unit 140 to enable the distribution control unit to control the operation of the lighting module. Detector module 130 includes one or more detectors and one or more optical elements configured to receive backscattered light from at least a portion of the illuminated volume and direct the received light to one or more detectors. The illuminated volume from which the insect detection detection unit receives light is referred to as the "detection volume 150". The detector module 130 is communicatively connected to the distribution control unit 140 and sends detector signals, optionally processed detector signals, to the distribution control unit. The distribution control unit processes the received signals of the detector with the possibility of detecting insects in the detection volume. Depending on the insect detection results, the distribution control unit 140 controls the operation of the dispenser so as to start the distribution of the insecticide by the dispenser depending on the insect detection results in the detection volume. In some embodiments, the distribution control unit may control the dispenser to distribute the insecticide when the dispenser reaches the location in the detection volume that was decided to distribute. Alternatively, the insect sensor comprises a processor configured to perform insect detection and send information about the detected insect population to a distribution control system.

Thus, as the vehicle travels along the travel path, the detector module receives light from the detection volume in front of the vehicle, i.e. the detection volume moves along the path in front of the vehicle. Therefore, the distribution control unit may continuously (or at least periodically) control the dispenser to adjust the distribution of the insecticide depending on the current (or latest) insect detection result in front of the vehicle. It should be understood that the regulation can be carried out with a delay, taking into account the lag of the movement of the dispensing device from the movement of the detection volume along the movement path, as well as the waiting time for the analysis of the detector signals. In other embodiments, control of the dispenser may occur after the vehicle has already passed the detection volume on which the control is based. However, the inventors of the present invention have found that this delay is acceptable and allows a fairly accurate correction of the distribution of insecticides.

FIG. 2 schematically illustrates the operation of an insecticidal spray apparatus. In particular, FIG. 2 illustrates the selection criteria for the size and shape of the detection volume.

FIG. 2 shows the insect sensor 120 and vehicle dispenser 110 of FIG. 1. The movement of the insect sensor and the spreader is in the direction of movement 101, with the insect sensor moving in front of the spreader. The insect sensor faces forward and monitors the detection volume 150 also moving in the direction of motion 101 in front of the insect detector.

FIG. 2, the detection volume is shown as a box-shaped volume with a height H, a width W and a depth D. It should be understood that the shape of the detection volume may be different from the box-shaped one. Preferred embodiments of the detection volume will be disclosed below with reference to FIGS. 8 and 9. In general, the shape and size of the detection volume, as well as its position relative to the vehicle, depend on the lighting module and the insect sensor detection module. In general, the detection volume can be defined as the volume from which the detection module receives sensor signals from which insects can be detected. The detection volume is usually formed by the overlap of the volume illuminated by the illumination module and the volume dependent on the field of view and the depth of field of the detector module.

Detection of insects can be carried out on the basis of the signals registered during the sampling period t. In general, if the insect sensor is movable relative to the ground surface, for example, due to the fact that the insect sensor is mounted on a moving vehicle, the detection volume moves relative to the ground surface. Accordingly, if the sensor data indicates the insect detection result in the detection volume in the time period t, then the sensor data indicates the insect detection result in the volume traversed by the moving detection volume in the time t. Hereinafter, the volume traversed by the moving detection volume in the sampling period t is also referred to as the "sample volume". Accordingly, the sensor data indicating the result of the detection of insects in the detection volume may be an estimate of the local population of insects in the sample volume above the ground surface, with the detection volume intersecting the sample volume during the movement of the detection volume relative to the ground surface over the sampling period t. For example, if a vehicle is moving at a constant speed v on the ground surface, then the total sample size for sample period t is V _samples = V ₀ + A*v*t, where V ₀ is the detection volume (in the example above, V ₀ = H*w*D), and A is the cross-sectional area of the sample volume in the direction of travel (in the example above, A = W*H).

The inventors of the present invention have found that in order to decide whether or not to carry out an insecticidal spray, it is preferable to perform a local sampling of at least a 1 m ³ sampling volume to obtain a result indicative of the insect population.

If the vehicle speed is 20 km/h, the distance from the insect sensor to the detection volume is 6 m, the box-shaped detection volume has a height H = 1 m, a width W = 1 m, and a depth D = 0.6 m, the detection volume is V ₀ = 0.6 m ³ , then for sampling in the sample volume V = 1 m ³ time t = 0.1 seconds is needed. At the same time, in order to obtain more accurate detection results, it may be preferable that the size of the detection volume be larger. Accordingly, it has been found that, given the typical speeds of agricultural vehicles, detection volumes of at least 0.2 m ³ , such as at least 0.5 m ³ , such as at least 1 m ³ , such as at least 2 m ³ .

Another criterion relates to the shape of the detection volume. For reliable detection and identification of an insect (for example, to determine the frequency of the insect's wingbeats), it is preferable that it stays in the detection volume for at least 0.1 second. In order for insects to stay in the detection volume for as long as possible, regardless of the direction of insect movement (and regardless of the movement of the detection volume in the direction of movement), it is desirable that the linear dimensions of the detection volume be comparable in all directions. However, it has been found in practice that suitable ratios of the largest detection volume size to the smallest detection volume size are no more than 10:1, preferably no more than 5:1, preferably no more than 3:1, more preferably no more than 2:1.

Another criterion relates to the position of the detection volume 150 relative to the vehicle and relative to the ground. In some embodiments, a detection volume may be selected that is located at a sufficient distance in front of the vehicle to allow the distribution control unit (or other processor) to perform the data processing necessary to obtain a detection result within the time during which the distribution device travels the distance between distribution device and detection volume. In this case, it is desirable that the detection volume be located close enough to the vehicle so that the result of the detection of the insect population is guaranteed to accurately indicate the population of insects in any place at the moment when the dispensing device arrives at that place. If the detection volume is too far away from the dispenser, a significant change in the insect population may occur by the time the dispenser has traveled the distance from the dispenser to the detection volume.

The preferred vertical distance by which the detection volume is elevated above the ground surface and/or the height of the detection volume may depend on the type of crop/vegetation and the type of insects to be detected. For airborne insects and optical insect sensors, the detection volume is preferably located above the reference plane, most preferably directly above it. The reference plane can be formed, for example, by the vegetation cover of a piece of land or by another horizontal plane spaced vertically from the ground surface.

Next, embodiments of an insect sensor that can be mounted on an agricultural vehicle, such as the one discussed in the example of FIG. 1, or may be otherwise placed, such as fixed or movable.

FIG. 3 schematically illustrates an embodiment of an insect sensor. The insect sensor includes a forward-facing detection module 130 and an illumination module 131. In this example, the illumination module is formed by two oblong arrays of LEDs. Each of the arrays extends laterally from each side of the detector module. The matrices create an illuminated volume 151 illuminated by both matrices. The detector module includes an imaging system configured to project an object plane 152 within the illuminated volume onto at least one image plane of the detector module. The field of view of the imaging system and the depth of field 153 of the imaging system are adjusted so that the imaging system projects at least a portion of the illuminated volume onto the image plane of the detector module. The portion of the illuminated volume projected by the imaging system to be detected by one or more detectors of the detector module and used for insect detection forms the detection volume 150 .

For example, the detector module may include an image sensor, such as a charge-coupled device (CCD) or complementary metal-oxide-conductor (CMOS) sensor, to enable imaging of insects in the illuminated volume. It was found that the formation of images of insects in the detection volume makes it possible to identify insects by the trajectories of insects moving in the detection volume, i.e. within the depth of field of the imaging system. This makes it possible to detect and identify even those insects that are difficult or impossible to detect and identify by wing beat frequencies. An example of such an insect is the jumping rapeseed flea.

For example, an imaging system based on a camera lens with a focal length of f = 24 mm and an aperture of f/2.8 and a ¾-inch image sensor, configured to focus on an object plane at a distance of 2 m from the lens, has a field of view of approximately 1.7 m×1.7 m and a depth of field of approximately 1.3 m, resulting in a detection volume of approximately 3.7 m ³ .

It should be understood that other imaging systems may be used. It is also possible to use additional and alternative detectors.

It should also be understood that the illumination module may be positioned differently relative to the detector module and/or may include different types and/or numbers of light sources.

In general, in order to maximize the amount of backscattered light from insects within the detection volume, the lighting module may preferably be adjacent to or otherwise be located near the detection module so that the angle between the illumination direction and the viewing direction is was relatively small, eg less than 30°, eg less than 20°. In some embodiments, the implementation of the lighting module is configured to emit a beam of light in the direction of illumination, while the detector module forms the direction of observation, for example, in the form of an optical axis of the detector module, and the direction of illumination and the direction of observation form an angle between them, while the angle is from 1 ° to 30°, e.g. 5° to 20°.

FIG. 4 schematically illustrates an example of an insect sensor detector module. The detector module includes an image sensor 411 and two photodiode arrays 405 and 409, respectively. The image sensor 411 registers an image of the detection volume 150 as discussed above. To this end, the detector module includes lenses 401, 403 and 410 for projecting the object plane in the detection volume at a suitable depth of field onto the image sensor. In particular, the lens 401 projects the plane of the object onto the virtual plane 420 of the image. Lens 403 collimates light from the virtual image plane, and lens 410 focuses collimated light onto an image sensor. The beam splitter 404 directs part of the collimated light to another lens, which focuses the light onto the photodiode array 405.

Similarly, the beam splitter 407 directs the other portion of the collimated light onto a lens 408 focusing the light onto the photodiode array 409. Beam splitter 404 is configured to selectively direct light of a first wavelength, such as 970 nm, to photodiode array 405, and beam splitter 407 is configured to selectively direct light of a second, different wavelength, such as 808 nm, to array 409. photodiodes.

Thus, the photodiodes of each of the arrays detect, with time resolution, backscattered light from the respective portions of the detection volume. Alternatively, separate photodiodes or image sensors may be used instead of photodiode arrays.

From the signals thus obtained, the system can detect insects in the respective parts of the detection module by the detected wing beat frequency, gloss degree and/or melanization degree, for example as disclosed in WO 2018/182440.

Similarly, based on the images captured by the image sensor 411, the system can determine additional or alternative features that can determine the presence of insects and, optionally, identify them. To do this, the method may involve the use of suitable machine vision techniques, for example, object recognition and/or detection and recognition of insect movement trajectories, for example, as disclosed in the also pending International Patent Application No. PCT/EP 2019/073119.

In particular, it has been found that the combination of different detection signals, and hence different types of features, allows reliable detection of insects, including insects that are difficult to detect, for example, only by the frequency of wing beats.

It should be understood that other embodiments of the detector modules may include only one of the above detectors or only some of them, for example, only an image sensor, or only an image sensor in combination with a single photodiode or an array of photodiodes, or only a combination of two photodiodes. or arrays of photodiodes. Furthermore, in alternative embodiments, the photodiodes or photodiode arrays can be configured to selectively detect light at alternative or additional wavelengths.

In addition, although in the embodiment of FIG. 4 uses a combined optical system with the possibility of directing light to several sensing elements, alternative detector modules may contain separate detectors with their own optical system each, for example, as illustrated below in FIG. 5.

FIG. 5 schematically illustrates another example of an insect sensor detector module. In particular, FIG. 5 illustrates a detector module comprising three detectors 130A-C, respectively, each receiving light from the same detection volume illuminated by the same illumination module (not shown). In other alternative embodiments, the detectors are configured to receive light from different detection volumes that may be illuminated by the same illumination module or respective illumination modules. Each of the detectors 130A-C includes its own optical system such as its own lenses and the like.

In this example, the detector module includes a detector 130A for detecting light at a first wavelength and optionally in a first polarization state. To this end, detector 130A may include a suitable bandpass filter, such as a filter that selectively transmits 808 nm light to a detector sensing element, such as a photodiode or photodiode array. Detector 130A may also include a polarizing filter.

Detector 130B includes a digital camera, such as that disclosed in FIG. 3 or 4.

Detector 130C is configured to detect light at a second wavelength (different from and spaced from the first wavelength) and optionally in a second polarization state. To this end, detector 130C may include a suitable bandpass filter, such as a filter that selectively transmits 970 nm light to a detector sensing element, such as a photodiode or photodiode array. Detector 130C may also include a polarizing filter.

It should be understood that alternative insect sensors may include additional or alternative detectors, such as less than three or more than three detectors.

FIG. 6 schematically illustrates another embodiment of an insect sensor. The insect sensor, collectively referenced as 120, includes a processing unit 140, a detector module 130, and a lighting module 131, all of which are located within housing 110. In this example, the lighting module and detector module are vertically aligned with each other, with the lighting module placed under the detector module. However, other arrangements are also possible.

The lighting module includes an array 161 of light emitting diodes (LEDs) and a corresponding array of lenses 161 for directing light from the respective LEDs in the form of a divergent beam 163 of light in the illumination direction 164 . The light emitting diode array may comprise a first set of diodes configured to selectively emit light in a first wavelength range, such as 810 nm +/-25 nm. The light emitting diode array may also comprise a second set of diodes configured to selectively emit light in a second wavelength range different from the first wavelength range, in particular spaced from the first wavelength range, such as 980 nm +/-25 nm. In other embodiments, the light emitting diode array may include alternative or additional types of LEDs. For example, in some embodiments, LEDs may be configured to emit light in a wide range of visible, near infrared, and/or infrared wavelengths.

The detector module 130 includes an optical system 132 in the form of a Fresnel lens. It is possible to use an alternative lens system. The detection module 130 includes a photosensitive element 133, for example, one or more photodiodes, for example, a photodiode array, a CCD or CMOS image sensor, and the optical system directs light from the detection volume to the photosensitive element. In some embodiments, the implementation of the optical system projects the plane 152 of the object inside the illuminated volume onto the photosensitive element. The field of view of the optical system and the depth of field of the optical system are set so that the optical system directs light from a part of the volume illuminated by the lighting module to the photosensitive element. The part of the illuminated volume from which the optical system receives light with the possibility of detecting it by the photosensitive element and using it for detecting insects forms the detection volume 150 . The optical system 132 defines an optical axis 134 intersecting the illumination direction 164 at a small angle, such as 10°.

For example, if an optical system based on a camera lens with a focal length of f = 24 mm and an f / 2.8 aperture and a photosensitive element includes a ¾-inch image sensor, the detector module can be configured to focus on a plane object at a distance of 2 m from the lens, which corresponds to a field of view of approximately 1.7 m×1.7 m and a depth of field of approximately 1.3 m, resulting in a detection volume of approximately 3.7 m ³ .

The detector module 130 is communicatively connected to the processing unit 140 and directs the radiation received by the photosensitive element to the processing unit. Processing unit 140 may include an appropriately programmed computer or other suitable processing device or system. The processing unit receives a sensor signal, for example, an image or an image stream, and/or one or more time series of sensor signals from the corresponding one or more photodiodes and, optionally, additionally receives detector signals from the detector module and processes the received sensor signals with the possibility of detection and identification insects in the detection volume, and outputs sensor data indicating an estimate of the insect population.

FIG. 7 schematically illustrates an example of a sensor signal from the detector module of the insect sensor embodiment disclosed herein, such as the insect sensor disclosed in any of the previous figures. In this example, the sensor signal from the detector module includes a corresponding time series of detected light intensities in two narrow wavelength ranges, for example, recorded by appropriate photodiodes provided with appropriate band pass filters. In some embodiments, it is possible to combine or otherwise combine signals from multiple photodiodes, an image sensor, and/or the like.

In this example, time series 701 corresponds to detected light at 808 nm and time series 702 corresponds to detected light at 975 nm. However, in other embodiments, it is possible to use other wavelengths, and/or more than two wavelengths or wavelength ranges.

The insect sensor processing unit may process said time series to detect the presence of an insect in the detection volume and optionally determine the type of insect detected. Alternatively, some or all of the signal and data processing may be performed by a data processing system outside of the image sensor.

In this example, the method implemented by the processing unit and/or an external data processing system allows detecting the presence of detected radiation in excess of a predetermined limit and/or determining the fundamental harmonic of the detected frequency response with the possibility of detecting the presence of an insect.

Alternatively or in addition, this method allows one or more features to be calculated from which the type of insect can be determined. Examples of these traits include fundamental wing beat frequency (WBF), body-wing ratio (BWR), and melanization degree (BWR). melanization (MEL)).

For example, the method makes it possible to calculate the fundamental wing beat frequency (PFF) from the fundamental harmonic of the frequency response of the detected detection event as determined above. The method makes it possible to calculate the ratio of the body length to the wing length in the form of an average ratio of the wing signal to the body signal. The body signal can be defined as the baseline detection event signal 711 representing the scattering from the insect with folded wings, and the wing signal can be defined as signal levels 712 at the scattering peaks.

The degree of melanization can be defined as the average ratio of the signal strengths of the two recorded channels during the detection event.

The method makes it possible to determine, from one or more of the above features, optionally in combination with other parameters, the type of insect, for example the type of insect. The determination may be based on suitable lookup tables, a classification model such as a machine learning model, or the like.

Other examples of parameters that allow the detection of insect sensor embodiments disclosed herein suitable for detecting and/or classifying flying or jumping insects include the motion trajectories of insects detected in the detection volume, for example, as disclosed in the also pending International Patent Application No. PCT/EP 2019/073119, the contents of which are hereby incorporated by reference in their entirety.

In general, in the insect sensor embodiments disclosed herein, the detection volume is large enough for the detection module to capture a number of insects indicative of population density in an area, such as an area to be treated with pesticides. However, the detection volume is small enough to be uniformly illuminated to provide a high signal strength to the image sensor.

In addition, the observation periods in the apparatus embodiments disclosed herein are short, for example, in order to provide input on which the control system of a pesticide sprayer moving across the area to be treated can act.

In this case, the periods of observation in the embodiments of the apparatus disclosed herein are long enough to reliably classify flying insects.

FIG. 8 and 9 illustrate examples of detection volumes. FIG. 8 schematically depicts an example of a truncated-conical detection volume resulting from the emission of a divergent light beam of a generally circular cross-section by the illumination module. FIG. 9 schematically illustrates an example of a frusto-pyramidal detection volume.

In order to make a decision to spray, it is preferable that the recorded insect activity should give an idea of the area under consideration. This requires sufficiently high statistical values of the count. The inventors of the present invention have found that observing at least 10, preferably at least 50, more preferably at least 100 insects provides a reasonable indication of insect activity.

The inventors of the present invention have also found that the typical values of insect activity observed on the respective land plots range from 0.2 to 2 insects per second per m ³ . In the case of mounting on a moving vehicle, the detection volume V moves forward at the speed v of the vehicle. For example, if the detection volume of the sensor is on the order of 3 m ³ and the insect activity is 1 insect per m ³ , it will take 33 seconds to get a count value of 100 insects. If the vehicle speed is 20 km/h, during this time the vehicle will advance approximately 110 m. Considering typical sprayer boom lengths and the fact that the areas to be treated can typically exceed several tens of hectares, detection can be performed with a resolution of , sufficient to make decisions on spraying, taking into account the local features of the relevant parts of the land to be treated.

In some of the insect sensor embodiments disclosed herein, one or more time series of light scattering by one or more insects in flight is recorded with one or more wavelengths of said light. Based on the recorded time series, it is possible to calculate the frequency of wing beats and/or the ratio of scattering from the body and wings, respectively. At the same time, in order to obtain a reliable and accurate detection result, it is desirable that the recorded time series be long enough to make many wing beats. The wing beat frequency of insects in flight ranges from about 100 Hz to about 1000 Hz. To obtain more than 10 wing beats, it is desirable that in the worst case the insect stays in the detection volume, preferably more than 100 milliseconds. Similarly, to facilitate detection from recorded flight paths, observation periods should be long enough to record paths of sufficient length.

Thus, the insect sensor embodiments disclosed herein use a detection volume whose shape and size allows sufficiently long observation periods even if the sensor is moving across a piece of land.

The speed of a conventional agricultural vehicle on a piece of land may be, for example, 20 km/h or so. At this speed, in 100 milliseconds, the forward movement of the vehicle and therefore the detection volume will be 0.55 m. Therefore, it is desirable that the amount of detection in the direction of travel of the vehicle is preferably greater than 1 m, such as greater than 2 m, such as greater than 5 m. to guarantee a high probability of the insects staying long enough inside the moving detection volume.

For example, the length of the detection volume in the direction of travel may be less than 100 m, such as less than 50 m, such as less than 20 m.

In addition, as mentioned above, it is preferable that the value of the detection volume was not less than about 1 m ³ , for example, more than 1 m ³ . In order to create such a detection volume with a small and economical image sensor, it is preferable that the illumination module be carefully configured.

The illuminated detection volumes in FIG. 8 and 9 form large detection volumes in the vicinity of the image sensor, i.e. with the possibility of representative and local measurements.

Detection volumes in FIG. 8 and 9 are the overlapping area of the illuminated volume illuminated by the insect sensor illumination module and the detection volume from which the insect sensor detector receives light, i.e. the detected volume may depend on the field of view and the depth of field of the detector. In one embodiment, the lighting module comprises one or more suitable light sources, such as one or more high power LEDs, emitting light radiating from the lighting module in a manner that can distribute the light to a large volume. In one particular embodiment, the lighting module is configured to emit light with a total horizontal divergence angle greater than 5°, such as greater than 10°, such as greater than 20°, while the vertical divergence is limited to angles of less than 2°, such as less than 5°. This embodiment is preferred as it results in an optimal amount of detection directly above the crops. In addition, in this embodiment, the amount of light disappearing in the upward direction or in the crops is limited.

It is also preferable that the lighting module is configured to direct the illuminating light along the central optical axis of the emitted light (i.e., in the direction of illumination), directed upward at such an angle that the light does not hit the crops, for example, from 1° to 30° , for example from 2° to 30°, for example from 5° to 20°.

An example of the detection volume created by such a divergent, sector-shaped forward and upward illumination beam is illustrated in FIG. 9. In particular, FIG. 9 shows a three-dimensional view of the detection volume 150 as well as a side view and a top view of the detection volume. In the example of FIG. 9, the distance d ₀ from the aperture stop of the detector module to the beginning of the detection volume is approximately 1 m. The distance from the aperture stop of the detector module to the far end of the detection volume is approximately 10 m _. the divergence of a diverging light beam in the vertical direction (full angle) is approximately 4°, and the angle θ _{is horizontal.} divergence in the horizontal direction (full angle) is approximately 20°. It should be understood that in other embodiments, the implementation of the size and/or shape may be different.

In general, locating the detection volume close to the insect sensor facilitates effective illumination of the detection volume and reliable detection of small insects. It also makes it easier to control the distribution depending on the detection result of local insect populations. For example, the boundary of the detection volume closest to the aperture stop of the detector module may be 10 cm to 10 m away from the aperture stop of the detector module, such as 10 cm to 5 m, such as 10 cm to 2 m. detector module, the boundary of the detection volume can be separated from the aperture diaphragm of the detector module at a distance of 3 m to 100 m, for example, from 5 m to 20 m, for example, from 8 m to 12 m.

Although the invention has been disclosed by way of examples of certain particular embodiments, various modifications will be apparent to those skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims (40)

1. An insect sensor for detecting airborne insects moving above the ground, comprising: - a lighting module configured to illuminate the detection volume, while the detection volume is raised above the ground surface by a minimum vertical distance, and - one or more detectors configured to detect light from the detection volume; moreover, the lighting module is configured to emit a divergent beam of light, in particular with an angle of divergence in at least one direction of 2° to 45°, for example from 10° to 30°. 2. An insect sensor according to claim 1, wherein the lighting module includes a light source configured to emit non-coherent light, in particular one or more light emitting diodes and/or one or more halogen lamps. 3. The insect sensor according to claim 1 or 2, in which the diverging light beam has a horizontal divergence angle measured in the horizontal plane and a vertical divergence angle measured in the vertical plane, and the vertical divergence angle is less than the horizontal divergence angle. 4. The insect sensor of claim 3, wherein the vertical divergence angle is 2° to 10°, such as 3° to 8°, and the horizontal divergence angle is 10° to 45°, such as 10° to 30°. °. 5. An insect sensor according to any one of paragraphs. 1-4, in which the lighting module is configured to simultaneously illuminate the entire detection volume. 6. An insect sensor according to any one of paragraphs. 1-5, wherein the lighting module comprises a first light source configured to selectively emit light in a first wavelength range, the lighting module further comprising a second light source configured to selectively emit light in a second wavelength range spaced from the first wavelength range. wavelengths. 7. An insect sensor according to any one of paragraphs. 1-6, wherein the one or more detectors include a camera and/or one or more photodiodes. 8. An insect sensor according to any one of paragraphs. 1-7, in which one or more detectors are configured to selectively detect light in a first wavelength range and in a second wavelength range that does not overlap the first wavelength range. 9. Insect sensor according to any one of paragraphs. 7, 8, wherein the one or more detectors include at least one photodiode array, each array photodiode being configured to receive light from a respective detection volume subvolume. 10. An insect sensor according to any one of paragraphs. 1-9, comprising a processor configured to determine, based on signals from one or more detectors, the number of insects detected in the detection volume. 11. An insect sensor according to any one of paragraphs. 1-10, containing a processor configured to identify, based on signals from one or more detectors, one or more types of insects and determine the corresponding numbers of insects of one or more types detected in the detection volume, in particular, according to one or more signs selected from the following: - the detected insect movement trajectory inside the detection volume; - detected speed of insect movement inside the detection volume; - one or more detected wing beat frequencies; - degree of melanization; - the degree of shine of insects. 12. An insect sensor according to any one of paragraphs. 1-11, wherein the vertical distance is selected from 10 cm to 5 m, such as 20 cm to 3 m, such as 20 cm to 2 m, such as 50 cm to 2 m. 13. An apparatus for distributing an insecticide over a piece of land, while the piece of land forms the surface of the soil, while the apparatus includes: - a vehicle capable of moving along a travel path on the ground surface, wherein the direction of travel is set by the vehicle, the vehicle comprising an insecticide dispensing device configured to distribute the insecticide along said travel path while the vehicle is moving along the travel path; a distribution control system configured to control the amount of insecticide to be distributed while the vehicle is moving along the travel path; - insect sensor according to any one of paragraphs. 1-12 configured to detect airborne insects in the detection volume while the detection volume is moving relative to the ground surface; moreover, the detection volume is located in front of the vehicle in the direction of travel and is raised above the ground surface by a minimum vertical distance; moreover, the distribution control system is configured to receive sensor data from the insect sensor, wherein the sensor data indicates the result of detection of insects in the detection volume, and with the ability to control the amount of insecticide distributed depending on the received sensor data. 14. Apparatus according to claim 13, wherein the size of the detection volume is at least 0.2 m ³ , for example at least 0.5 m ³ , for example at least 1 m ³ , for example at least 2 m ³ , for example at least 3 m ³ . 15. Apparatus according to claim 14, wherein the size of the detection volume is less than 20 m ³ , such as less than 10 m ³ , such as less than 5 m ³ . 16. Apparatus according to any one of paragraphs. 13-15, wherein the aspect ratio of the detection volume, defined as the ratio of the largest side to the smallest side of the minimum detection volume bounding box, is 10:1 or less, such as 5:1 or less, such as 3:1 or less, such as 2 or less :1. 17. Apparatus according to claim 16, wherein the aspect ratio is 1:1 to 10:1, such as 1:1 to 5:1, such as 1:1 to 3:1, such as 2:1 to 3: 1. 18. The apparatus of claim 16 or 17, wherein the smallest side is the vertical side of the minimum bounding box. 19. Apparatus according to claim 18, wherein the minimum bounding box defines a vertical side and two horizontal sides, wherein the ratio of each of the horizontal sides to the vertical side is between 2:1 and 10:1, such as between 2:1 and 5:1, e.g. 2:1 to 3:1. 20. Apparatus according to any one of paragraphs. 13-19 in which the detection volume extends from the top of the canopy upwards. 21. Apparatus according to any one of paragraphs. 13-20, in which the length of the detection volume, measured in the direction of travel, is at least 1 m, such as at least 2 m, such as at least 5 m. 22. Apparatus according to any one of paragraphs. 13-21, in which the detection volume has the shape of a truncated cone or a truncated pyramid. 23. A method for controlling insecticidal spraying, which includes the steps in which: - detected by means of an insect sensor according to any one of paragraphs. 1-12, airborne insects moving in the detection volume, while the detection volume is located in front of the moving vehicle, while the detection volume is raised above the ground surface by a minimum vertical distance; - control the distribution of insecticides from the specified moving vehicle depending on the result of detection of insects in the air. 24. The method of claim 23, wherein the detection step detects insects moving through the detection volume over a sampling period t. 25. The method according to p. 24, in which at the stage of detection receive sensor data indicating an estimate of the population of insects in the sample volume above the ground surface; wherein the detection volume intersects the sampling volume during the movement of the detection volume relative to the ground surface over the sampling period t. 26. Apparatus control insecticidal spraying containing an insect sensor according to any one of paragraphs. 1-12 and a control system configured to provide a control signal for controlling the insecticide dispenser in response to a detection signal from an insect sensor.

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