Mobile weeding device

Abstract

To provide a mobile weeder capable of efficiently removing an unnecessary plant under an environment in which liquid is adhered to the unnecessary plant.SOLUTION: An aspect of the present disclosure is a mobile weeder including: a laser emitting device configured to emit laser light to a plant from above the plant; a camera configured to acquire an image obtained by imaging the plant from above; a control device configured to identify a plant on the basis of the image; a shielding wall arranged to enclose an emitting space of the laser light; and a device body holding the laser emitting device and the shielding wall and having a movement mechanism. An inner surface of the shielding wall is formed by a low reflection material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a mobile weeding device. [Background technology]

[0002] Weeding devices that remove unwanted plants (i.e., weeds) in farmland by irradiating them with laser light are known (see Patent Documents 1 to 3). These weeding devices irradiate unwanted plants with laser light from above, thereby damaging and killing the plants. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-53941 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-53942 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-62412 Summary of the Invention [Problem to be solved by the invention]

[0004] In weeding devices that use laser light, unwanted plants to be removed are recognized by, for example, image processing. However, if liquid such as water adheres to the unwanted plants, the recognition accuracy of the unwanted plants decreases due to the reflection of light.

[0005] An object of one aspect of the present disclosure is to provide a mobile weeding device that can efficiently remove unwanted plants in an environment where liquid adheres to the unwanted plants. [Means for solving the problem]

[0006] One aspect of the present disclosure is a mobile weeding device that includes a laser irradiator configured to irradiate a plant with laser light from above the plant, a camera configured to capture an image of the plant from above, a control device configured to identify the plant based on the image, a shielding wall arranged to surround the laser light irradiation space, and a device main body that holds the laser irradiator and the shielding wall and has a movement mechanism. The inner surface of the shielding wall is made of a low-reflectivity material.

[0007] With this configuration, the laser light irradiation space (i.e., the unwanted plant identification space) is surrounded by a shielding wall having an inner surface made of a low-reflectivity material, thereby suppressing light reflection by the liquid in the irradiation space. In addition, the shielding wall can suppress the influence of external light, such as natural light, on the image. As a result, the recognition accuracy of unwanted plants is improved, allowing unwanted plants to be removed efficiently.

[0008] In one aspect of the present disclosure, the shielding wall may have a light-shielding base material and an inner layer made of a low-reflectivity material disposed on the inner surface of the base material. This configuration prevents light from entering the shielding wall from outside, thereby stabilizing the brightness of the laser light irradiated space. As a result, the accuracy of recognizing unwanted plants is improved.

[0009] In one aspect of the present disclosure, the low-reflectivity material may be an anti-reflection film or an anti-reflection coating. With this configuration, it is possible to suppress reflection of light in the laser light irradiation space with a relatively simple shielding wall configuration.

[0010] In one aspect of the present disclosure, the inner surface of the shielding wall may be dark in color, which can enhance the effect of suppressing light reflection in the space irradiated with the laser light.

[0011] In one embodiment of the present disclosure, the arithmetic mean roughness Ra of the inner surface of the shielding wall may be 50 μm or more. With this configuration, the effect of suppressing reflection of light in the space irradiated with the laser light can be enhanced.

[0012] In one embodiment of the present disclosure, the wavelength of the laser light may be 400 nm or more and 550 nm or less. With this configuration, the laser light is less likely to be absorbed by the liquid, thereby increasing the efficiency of removing unwanted plants.

[0013] According to one aspect of the present disclosure, a water injector configured to inject water onto the laser light irradiation area can be further provided. This configuration can suppress the generation of smoke due to the laser light irradiation. Furthermore, even if the injected water adheres to the unwanted plants before removal, the shielding wall can suppress the reflection of light. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic side view of a mobile weeding device according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing an example of a movement path of the mobile weeding device of FIG. [Figure 3] FIG. 3 is a schematic diagram showing an example of liquid adhesion on unwanted plants. [Figure 4] FIG. 4 is a block diagram showing the configuration of the control device in the mobile weeding device of FIG. [Figure 5] FIG. 5 is a schematic front view of the mobile weeding device of FIG. [Figure 6] FIG. 6 is a schematic cross-sectional view of a shielding wall in the mobile weeding device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments to which the present disclosure is applied will be described with reference to the drawings. [1. First embodiment] [1-1.Configuration] The mobile weeding device 1 shown in Figure 1 is a device for removing unwanted plants P2 (i.e., weeds) that have grown around crops P1 in farmland. The mobile weeding device 1 includes a device main body 2, a laser irradiator 3, a camera 4, lighting 5, a water sprayer 6, a monitoring sensor 7, a control device 9, and a shielding wall 10.

[0016] <Device body> The device main body 2 is a housing that holds the laser irradiator 3, camera 4, lighting 5, water sprayer 6, monitoring sensor 7, control device 9, and shielding wall 10. The device main body 2 also has a movement mechanism.

[0017] The movement mechanism of this embodiment is composed of a plurality of wheels 21. The device body 2 is configured to travel on farmland using the plurality of wheels 21. The movement mechanism may be an electric type in which the wheels 21 are rotated by a motor, or a manual type in which the device body 2 is moved by an operator pushing or pulling it. Furthermore, the device body 2 may be equipped with one or more electric crawlers instead of the wheels 21 as the movement mechanism.

[0018] 2, the mobile weeding device 1 travels along the longitudinal direction of a plurality of ridges F. The mobile weeding device 1 irradiates laser light and sprays water onto unwanted plants P2 on each of the plurality of ridges F.

[0019] 3, liquids such as water, pesticides, and liquid fertilizer may adhere to unwanted plants P2 as droplets W1. Liquids also exist as puddles W2 in the furrows F (i.e., the ground) where unwanted plants P2 are located. The droplets W1 and puddles W2 reflect natural light or light from the lighting 5, forming white areas in the image captured by camera 4.

[0020] <Laser irradiator> 1 is configured to irradiate the unwanted plant P2 with laser light L from above the unwanted plant P2 identified by the control device 9. The laser irradiator 3 may be configured to irradiate the unwanted plant P2 with laser light L from above by changing the direction of the laser light L using an optical element such as a mirror.

[0021] The laser irradiator 3 damages (specifically burns) the unwanted plants P2 with the laser light L, thereby causing the unwanted plants P2 to wither and die. The laser light L is irradiated onto the growth point or the root of the unwanted plants P2. The growth point and the root of the unwanted plants P2 are determined by the control device 9 based on the image captured by the camera 4.

[0022] A known laser irradiation device having a battery, an oscillator, and a reflection control unit (for example, a galvanometer scanner, MEMS, etc.) can be used as the laser irradiator 3. The wavelength of the laser light from the laser irradiator 3 is 400 nm or more and 550 nm or less.

[0023] The laser irradiator 3 is configured to be able to change the irradiation direction, irradiation output, and irradiation time of the laser light L. The irradiation output is changed by a signal (for example, an analog input voltage) output from the control device 9 to the oscillator.

[0024] The laser irradiator 3 may irradiate the laser while the device main body 2 is moving, or may irradiate the laser while the device main body 2 is stationary. The laser irradiator 3 sequentially irradiates the laser onto the plurality of unwanted plants P2 identified by the control device 9.

[0025] <Camera> The camera 4 is configured to acquire an image obtained by photographing from above farmland containing at least one crop P1 and at least one unwanted plant P2.

[0026] The images captured by camera 4 include at least one crop P1, at least one unwanted plant P2, and other objects (for example, structures such as fences, obstacles such as stones, etc.). The imaging range of camera 4 changes as device main body 2 moves.

[0027] <Lighting> The lighting 5 is configured to illuminate the area photographed by the camera 4. That is, the lighting 5 irradiates light onto at least one unwanted plant P2.

[0028] <Water injector> The water injector 6 is configured to inject water for extinguishing the fire onto the area irradiated with the laser light L from above.

[0029] Specifically, the water injector 6 injects water toward the unwanted plants P2 after they have been irradiated with the laser light L. The coordinates and range over which the water injector 6 injects water are set by the control device 9. Water is supplied to the water injector 6 from, for example, a water tank (not shown) installed in the device main body 2.

[0030] <Monitoring sensor> The monitoring sensor 7 is a known device that detects the temperature and the presence or absence of smoke in the area irradiated with the laser light.

[0031] <Control device> The control device 9 mainly controls the laser irradiator 3 and the water injector 6. The control device 9 is configured by a computer including, for example, a processor, a storage medium such as RAM and ROM, a communication unit, and an input / output unit. As shown in FIG. 4, the control device 9 has an image processing unit 91, a laser control unit 92, an injection control unit 93, and a database 94.

[0032] The image processing unit 91 is configured to identify unwanted plants P2 from the image captured by the camera 4. The image processing unit 91 identifies unwanted plants P2 using AI (artificial intelligence) constructed using a known statistical method.

[0033] Statistical methods include, for example, supervised machine learning, multivariate analysis, etc. In supervised machine learning, a decision formula (i.e., a classifier) ​​is constructed by analyzing a large number of labeled plant images (i.e., training data) using a machine learning circuit.

[0034] The image processing unit 91 sets a target area including the growing point or base of the unwanted plant P2 identified by AI for the unwanted plant P2. The growing point is a part that includes tissue with active cell division, mainly at the tip of the plant stem, and can be identified depending on the type of plant.

[0035] The laser control unit 92 instructs the laser irradiator 3 to irradiate the coordinates of the unwanted plants P2 identified by the image processing unit 91 with laser light. Specifically, the laser control unit 92 instructs the laser irradiator 3 to irradiate the target area set by the image processing unit 91 with laser light.

[0036] The injection control unit 93 instructs the water injector 6 to inject water into an area where the monitoring sensor 7 detects a high temperature or an area where smoke is detected. Furthermore, regardless of the detection result of the monitoring sensor 7, the injection control unit 93 may instruct the water injector 6 to inject water onto the unwanted plants P2 that have been irradiated with laser light after the laser irradiator 3 has completed irradiating the unwanted plants P2 with laser light.

[0037] The control device 9 may be configured to output, to a monitor installed in the device body 2, the results of identification of unwanted plants P2 by the image processing unit 91, the results of temperature and smoke detection by the monitoring sensor 7, and the like.

[0038] <Shielding wall> As shown in FIG. 5, the shielding wall 10 is a cylindrical member arranged to surround the space irradiated with the laser light L from the laser irradiator 3.

[0039] In this embodiment, the shielding wall 10 has a rectangular cylindrical shape that surrounds the irradiation space of the laser light L from all sides. However, the shielding wall 10 may have a polygonal cylindrical shape other than a rectangular cylindrical shape, or may have a cylindrical shape. In this embodiment, the shielding wall 10 does not have any openings or holes. Furthermore, the upper end of the shielding wall 10 is closed by the device main body 2.

[0040] 6, the shielding wall 10 has a base material 11 and an inner layer 12. The base material 11 is made of a light-shielding steel plate, resin plate, cloth, or the like. From the viewpoints of weather resistance and durability, the material of the base material 11 is preferably, for example, a stainless steel plate or a plated steel plate.

[0041] The inner layer 12 is disposed so as to be superimposed on the inner surface of the base material 11 (i.e., the surface facing the irradiation space of the laser light L). The inner layer 12 forms the inner surface of the shielding wall 10 (i.e., the surface facing the irradiation space of the laser light L). The inner layer 12 is made of a low-reflectivity material. Therefore, the inner surface of the shielding wall 10 is made of a low-reflectivity material.

[0042] A low-reflectivity material is a material whose surface reflectance is less than 10%. In other words, the reflectance of the inner surface of the shielding wall 10 is less than 10%. The low-reflectivity material constituting the inner layer 12 is preferably an anti-reflection film or an anti-reflection coating film.

[0043] The anti-reflection film is attached to the inner surface of the substrate 11 by, for example, an adhesive. The anti-reflection coating is formed by, for example, applying an anti-reflection agent to the inner surface of the substrate 11. The anti-reflection film or anti-reflection coating can suppress reflection of light in the space irradiated with laser light with a relatively simple configuration of the shielding wall 10.

[0044] The inner surface of the shielding wall 10 (i.e., the inner surface of the inner layer 12) is preferably dark in color. That is, the inner layer 12 preferably contains a dark-colored paint. The dark color of the inner surface of the shielding wall 10 can enhance the effect of suppressing light reflection in the space irradiated with the laser light L. Note that a "dark color" is a color whose brightness in the Munsell color system is 1 or less.

[0045] The arithmetic mean roughness Ra of the inner surface of the shielding wall 10 is preferably 50 μm or more. When the inner surface of the shielding wall 10 is such a rough surface, the effect of suppressing reflection of light in the space irradiated with the laser light L can be enhanced.

[0046] The shielding wall 10 also has the function of suppressing scattering of the laser light L outside the irradiation space. This protects the worker from the laser light L, thereby improving safety during weeding work.

[0047] As shown in Fig. 5, the shielding wall 10 has an upper portion 10A and a lower portion 10B. The lower portion 10B is a portion that may interfere with crops P1 or unwanted plants P2 that have grown to a certain extent when the device main body 2 is moved. In other words, the lower portion 10B is a portion that is within a certain distance (i.e., height) from the surface of the farmland. The upper portion 10A is a portion above the lower portion 10B.

[0048] The lower portion 10B is less rigid than the upper portion 10A and is configured to bend when it comes into contact with a plant. For example, in the lower portion 10B, the base material 11 is made of cloth and has multiple slits extending in the vertical direction. On the other hand, the base material 11 of the upper portion 10A is made of a highly rigid steel plate.

[0049] The lower portion 10B is provided on the shielding wall 10 on walls (i.e., the front wall and rear wall) that intersect with the traveling direction of the device body 2. On the other hand, the lower portion 10B is not provided on the shielding wall 10 on walls (i.e., the two side walls) that are parallel to the traveling direction of the device body 2. On the two side walls, for example, the base material 11 is made of a steel plate across the entire vertical direction.

[0050] [1-2.Effects] According to the embodiment described above in detail, the following effects can be obtained. (1a) The laser light irradiation space (i.e., the unwanted plant identification space) is surrounded by a shielding wall 10 having an inner surface made of a low-reflectivity material, thereby suppressing light reflection by liquid in the irradiation space. In addition, the shielding wall 10 can suppress the influence of external light, such as natural light, on the image. As a result, the recognition accuracy of unwanted plants is improved, allowing unwanted plants to be removed efficiently.

[0051] (1b) The light-blocking properties of the base material 11 prevent light from entering the shielding wall 10 from the outside, stabilizing the brightness of the laser light irradiated space. As a result, the accuracy of recognizing unwanted plants is improved.

[0052] (1c) By setting the wavelength of the laser light to 400 nm or more and 550 nm or less, the laser light is less likely to be absorbed by the liquid, thereby increasing the efficiency of removing unwanted plants.

[0053] (1d) The generation of smoke due to laser light irradiation can be suppressed by the water injector 6. Furthermore, even if the sprayed water adheres to unwanted plants before removal, the shielding wall 10 can suppress the reflection of light.

[0054] 2. Other Embodiments Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take on various forms.

[0055] (2a) In the mobile weeding device of the above embodiment, the shielding wall does not necessarily have to have a base material and an inner layer. For example, the shielding wall may have only a base material made of a low-reflectivity material.

[0056] (2b) In the mobile weeding device of the above embodiment, the control device does not necessarily have to be attached to the device body. For example, the control device may be installed on farmland or in a facility away from farmland, and may be configured to wirelessly communicate with a camera, a laser illuminator, etc.

[0057] (2c) The mobile weeding device of the above embodiment does not necessarily need to be equipped with lighting. If an image that allows unwanted plants to be recognized can be obtained by taking in external light or adjusting the brightness of the camera, lighting can be omitted.

[0058] (2d) In the mobile weeding device of the above embodiment, the mode of movement of the device body is not limited to traveling. The mobile weeding device may move by flying, for example.

[0059] (2e) The function of one component in the above embodiments may be distributed among multiple components, or the functions of multiple components may be integrated into one component. Also, part of the configuration of the above embodiments may be omitted. Furthermore, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. All aspects included in the technical idea identified by the wording of the claims are embodiments of the present disclosure. [Explanation of symbols]

[0060] 1...Mobile weeding device, 2...Device body, 3...Laser irradiator, 4...Camera, 5...Lighting, 6...water injector, 7...monitoring sensor, 9...control device, 10...shielding wall, 10A... upper portion, 10B... lower portion, 11... substrate, 12... inner layer, 21... wheel, 91...image processing unit, 92...laser control unit, 93...ejection control unit, 94...database.

Claims

1. a laser irradiator configured to irradiate a laser beam toward the plant from above the plant; a camera configured to acquire an image of the plant taken from above; a control device configured to identify the plant based on the image; a shielding wall disposed so as to surround the laser light irradiation space; an apparatus main body that holds the laser irradiator and the shielding wall and has a movement mechanism; Equipped with the inner surface of the shielding wall is made of a low-reflectivity material, the shielding wall has a front wall and a rear wall that are two walls that intersect with a traveling direction of the device body, and two side walls that are two walls that are parallel to the traveling direction, The front wall and the rear wall each have a lower portion that is a portion within a certain range of distance from the ground on which the plants grow, and an upper portion that is a portion above the lower portion, The mobile weeding device, wherein the lower portion has lower rigidity than the upper portion and is configured to bend upon contact with the plants.

2. A mobile weeding device according to claim 1, The mobile weeding device, wherein each of the two side walls has equal rigidity over the entire vertical direction.

3. The mobile weeding device according to claim 1 or 2, The shielding wall is a substrate having a light-blocking property; an inner layer made of the low-reflectivity material and disposed on the inner surface of the base material; A mobile weeding device having:

4. The mobile weeding device according to claim 1 or 2, A mobile weeding device, wherein the low-reflectivity material is an anti-reflection film or an anti-reflection coating.

5. The mobile weeding device according to claim 1 or 2, The mobile weeding device, wherein the inner surface of the shielding wall is dark in color.

6. The mobile weeding device according to claim 1 or 2, A mobile weeding device, wherein the arithmetic mean roughness Ra of the inner surface of the shielding wall is 50 μm or more.

7. The mobile weeding device according to claim 1 or 2, A mobile weeding device, wherein the wavelength of the laser light is 400 nm or more and 550 nm or less.

8. The mobile weeding device according to claim 1 or 2, The mobile weeding device further comprises a water injector configured to inject water into the irradiation area of ​​the laser light.

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