Mobile weeding device

Abstract

To simplify the configuration of a mobile weeder.SOLUTION: On a virtual plane on which a mobile weeder is located, at least one circular arc path is provided correspondingly to each of at least one beam irradiated from a laser part. The circular arc distance between a laser head of the beam and the circular arc path corresponding to the beam matches a working distance that can be set for the beam. A circular arc area including the circular arc path is provided correspondingly to the circular arc path. A control unit is configured to irradiate plants located in the circular arc area with the beam.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] There is known an autonomous weeding system that travels on arable land, detects unwanted plants based on an image generated by a three-dimensional imager, and irradiates the detected unwanted plants with a beam to remove them (for example, Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the removal systems disclosed in Patent Documents 1 to 3, the beam is irradiated onto unwanted plants captured at various positions where the distance to the light source of the beam is different. For this reason, it may be necessary to greatly change the working distance of the beam according to the distance between the unwanted plant and the light source of the beam. As a result, the time required for weeding may become longer, or the configuration of the system may become complicated.

[0005] In one aspect of the present disclosure, it is desirable to simplify the configuration of the mobile weeding device.

Means for Solving the Problems

[0006] One aspect of the present disclosure is a mobile weeding device comprising a camera, a laser unit, an adjustment unit, and a control unit. The camera is configured to photograph a target area below the mobile weeding device and generate an image. The laser unit is configured to emit at least one beam. The adjustment unit is configured to change the irradiation position from which the beam is emitted. The control unit is configured to detect predetermined plants located in the target area based on the image, and to change the irradiation position of the beam via the adjustment unit to irradiate the detected plants with the beam. In the virtual plane on which the mobile weeding device is located, there is provided at least one arc-shaped path corresponding to each beam, and the arc distance, which is the distance between the laser head emitting each beam and all points included in the arc-shaped path corresponding to the beam, is equal to the working distance that can be set for the beam. Corresponding to each arc-shaped path, there is provided an arc-shaped region which includes the arc-shaped path and extends in an arc shape. At least one arc-shaped region is located at all positions in the target area in the left-right direction perpendicular to the direction of travel of the mobile weeding device. The control unit is configured to irradiate plants located in an arc-shaped region with a beam corresponding to the arc-shaped path included in that region.

[0007] According to the above configuration, the beam is directed at plants located within an arc-shaped region determined by the working distance. Therefore, the beam can be directed at plants at an appropriate working distance without the need for a configuration to change the working distance. Alternatively, the amount of change in working distance required to achieve an appropriate working distance can be reduced, and as a result, the configuration for changing the working distance can be simplified. Consequently, the configuration of the mobile weed control device can be simplified.

[0008] In one aspect of this disclosure, the laser unit may be configured to emit at least one fixed beam with a fixed working distance. A single arc path may be provided corresponding to the fixed beam.

[0009] With the above configuration, a configuration for changing the working distance of the fixed beam is unnecessary. Therefore, the configuration of the mobile weed control device can be simplified. In one aspect of this disclosure, the laser unit may be configured to irradiate at least one variable beam, the working distance of which can be changed. A plurality of variable arc paths, each having a different arc distance, are provided corresponding to the variable beam, and the arc distance of each variable arc path may match the working distance that can be set for the variable beam corresponding to that variable arc path. An arc region containing the variable arc paths may be called a variable arc region. The control unit may be configured to irradiate plants located in each variable arc region with the variable beam corresponding to the variable arc path, with the working distance set according to the arc distance of the variable arc path included in the variable arc region.

[0010] According to the above configuration, the beam can be suitably irradiated onto the plants. [Brief explanation of the drawing]

[0011] [Figure 1] This is an explanatory diagram showing the mobile weeding device of the first embodiment viewed from the side. [Figure 2] This is an explanatory diagram showing the mobile weeding device of the first embodiment as viewed from above. [Figure 3] This is a flowchart of the weed control process in the first embodiment. [Figure 4] This is an explanatory diagram of the target area of ​​the second embodiment. [Figure 5] This is an explanatory diagram of the target area of ​​the third embodiment. [Figure 6] This is an explanatory diagram of the target area of ​​the third embodiment. [Figure 7] This is an explanatory diagram of the target area of ​​the third embodiment. [Figure 8] This is an explanatory diagram of the target area of ​​the fourth embodiment. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the embodiments of the present disclosure are not limited to the following embodiments, and various forms can be adopted as long as they belong to the technical scope of the present disclosure.

[0013] [1. First Embodiment] [(1) Overview] The mobile weeding device 1 of the first embodiment removes unwanted plants P2 (such as weeds etc.) that are plants other than the crop P1 in the cultivated land 2 where the crop P1 is cultivated (see FIG. 1). The mobile weeding device 1 is self-propelled, detects the unwanted plants P2 while traveling on the cultivated land 2, and performs a weeding operation by irradiating the detected unwanted plants P2 with the beam B. Hereinafter, the direction parallel to the traveling direction of the mobile weeding device 1 is also described as the front-rear direction, and the direction orthogonal to the front-rear direction is also described as the left-right direction.

[0014] The mobile weeding device 1 includes a control unit 10, a laser unit 11, a camera 12, a lighting unit 13, a housing 14, a cover 15, and wheels 16, as well as a power source and a motor (not shown) (see FIGS. 1 and 2).

[0015] The housing 14 is located at the upper part of the mobile weeding device 1 and houses the control unit 10 and the power source. The cover 15 is a wall-like part provided so as to protrude downward from each side of the square lower surface of the housing 14, and surrounds the space below the housing 14 from all four sides. On the ground directly below the housing 14, a square target area 20 is located as an example surrounded by the cover 15. Note that the mobile weeding device 1 may not be provided with the cover 15.

[0016] The control unit 10 is a part that comprehensively controls the mobile weeding device 1 and includes a CPU and a memory. The CPU executes a program stored in the memory, and thereby, various functions of the mobile weeding device 1 are realized. Note that the various functions realized by the control unit 10 are not limited to being realized by the execution of a program, and a part or all of them may be realized using one or more hardware.

[0017] In addition to this, the control unit 10 is configured to detect the position of the mobile weeding device 1 (hereinafter referred to as the current location). Specifically, the control unit 10 may detect the current location by, for example, GPS, or may detect the speed and traveling direction of the mobile weeding device 1 by sensors and detect the current location based on these detection results.

[0018] The laser unit 11 is provided at the lower part of the housing 14 and irradiates the unwanted plant P2 located in the target area 20 with the beam B (details will be described later). The camera 12 is provided at the lower part of the housing 14, photographs the target area 20 from above, and generates an image of the target area 20.

[0019] The lighting unit 13 is provided at the lower part of the housing 14 and illuminates the target area 20 from above. The wheels 16 are provided at the lower part of the cover 15 and are driven by a motor provided near the wheels 16 in order to make the mobile weeding device 1 travel. However, it is not limited to this, and for example, at least one electric crawler may be used instead of the wheels 16, or the mobile weeding device 1 may move by flying.

[0020] The power source is configured as a rechargeable battery and supplies power to each part of the mobile weeding device 1. [(2) Laser unit] In the first embodiment, the laser unit 11 includes one laser head 11C, a laser oscillator 11A, and an optical system 11B, and is configured to irradiate one beam B (see FIGS. 1 and 2).

[0021] The laser head 11C is provided on the lower surface of the housing 14 and, as an example, irradiates the beam B generated by the laser oscillator 11A toward the target area 20 from a position at the center in the left - right direction.

[0022] The optical system 11B functions as an adjustment unit that adjusts the irradiation direction of beam B in response to instructions from the control unit 10, and for example, it includes a galvanometer mirror. By changing the irradiation direction of beam B, the irradiation position of beam B in the target region 20 is changed.

[0023] In the laser unit 11 of the first embodiment, the working distance of beam B cannot be changed, and the working distance is fixed to a predetermined value. The working distance is the distance between the output section of the laser head 11C and the focal point of beam B that has passed through the output section. The output section is the part that beam B passes through just before being output to the outside of the laser head 11C, and may be, for example, a protective cover. The output section corresponds to the light source of beam B in the laser head 11C. In other words, the focal point of beam B (in other words, the fixed beam) emitted from the laser unit 11 is formed at a position separated from the light source of the laser head 11C by the working distance.

[0024] [(3) Circular arc paths and circular arc regions] Assume that the mobile weeding device 1 travels along a virtual plane 3 (see Figure 1) to perform weeding work. In the area below the housing 14 on the virtual plane 3, an arc-shaped path 30 is provided, corresponding to beam B, extending from the right end to the left end of the target area 20 (see Figure 2). The arc-shaped path 30 is located in front of the light source of beam B in the laser head 11C. Furthermore, when the mobile weeding device 1 is stopped, the distance between all points included in the arc-shaped path 30 and the light source of beam B coincides with the working distance. In other words, the position of the arc-shaped path 30 is determined relative to the position of the laser head 11C, and the arc-shaped path 30 is displaced as the mobile weeding device 1 moves.

[0025] Furthermore, the region in the virtual plane 3 that includes the arc path 30 is defined as the arc region 31. The arc region 31 extends in an arc shape along the arc region 31 from the right end to the left end of the target region 20. For example, the arc region 31 has a band shape with a constant width, and the arc path 30 is located in the center of the arc region 31 in the width direction. However, it is not limited to this, and the width of the arc region 31 and the relative position of the arc region 31 with respect to the arc path 30 can be determined as appropriate.

[0026] Furthermore, the laser unit 11 can set all positions within the arc region 31 as beam B irradiation positions by changing the irradiation direction of beam B using the optical system 11B. The beam B irradiated onto the arc region 31 is tilted with respect to the virtual plane 3 so that it is directed downwards as it moves forward.

[0027] For example, the central angle of the circular arc path 30 is 60°, and the left-right distance of the target area 20 is 600 mm. In other words, because the irradiation direction of beam B is inclined, the range over which the optical system 11B changes the irradiation direction of beam B is limited, while beam B can irradiate a wide area from the right edge to the left edge of the target area 20.

[0028] Furthermore, the distance (in other words, height) between the light source of beam B of the laser head 11C and the virtual plane 3 is, for example, 400 mm, and the distance between the light source of beam B and the circular arc path 30 on the virtual plane 3 is, for example, 450 mm. In other words, due to the angle of beam B, the height of the light source of beam B is lower than this distance, and the height of the mobile weeding device 1 is suppressed.

[0029] [(4) Regarding weeding work] The mobile weeding device 1 travels across the cultivated field 2 according to the weeding path stored in the memory of the control unit 10 and performs weeding work (see Figures 1 and 2). The mobile weeding device 1 travels across the cultivated field 2 with its housing 14 positioned above the cultivation area (e.g., furrows) of the crop P1 in the cultivated field 2. This ensures that the target area 20 to be weeded is located within the cultivation area of ​​the crop P1.

[0030] The mobile weeding device 1 then travels from the start to the end of the weeding path, detecting unwanted plants P2 present in the target area 20, and removes them by irradiating them with beam B. Below, the weeding process performed by the mobile weeding device 1 as it travels along the weeding path across the cultivated field 2 will be explained using the flowchart in Figure 3.

[0031] In S100, the control unit 10 of the mobile weeding device 1, which is traveling across the cultivated field 2 along the weeding path, analyzes the image of the target area 20 captured by the camera 12 to detect unwanted plants P2 and to identify the location of the detected unwanted plants P2 (S105).

[0032] Furthermore, the control unit 10 may, for example, use AI (artificial intelligence) constructed using statistical methods to identify unwanted plants P2 from the above image and pinpoint their locations. Examples of statistical methods include supervised machine learning and multivariate analysis. In addition, the control unit 10 may determine the growth points of the unwanted plants P2 identified by the AI ​​and pinpoint their locations. Growth points are mainly the parts of the plant stem that contain actively dividing tissue and can be identified depending on the type of plant.

[0033] In the subsequent S110, the control unit 10 determines, based on the image captured by the camera 12, whether or not at least one unwanted plant P2 is located in the arc region 31 (see Figure 2). If the control unit 10 obtains a positive determination (S110: Yes), it proceeds to S115; if it obtains a negative determination (S110: No), it proceeds to S100.

[0034] In S115, the control unit 10 stops the mobile weeding device 1. The control unit 10 then changes the irradiation direction of beam B via the optical system 11B, aligning the irradiation position of beam B with any unwanted plant P2 in the arc region 31, and irradiates the unwanted plant P2 with beam B for a predetermined time (S120). At this time, the control unit 10 may also irradiate the growth point of the unwanted plant P2 with beam B.

[0035] When the control unit 10 has finished irradiating unwanted plants P2 with beam B, if there are other unwanted plants P2 in the arc region 31 that have not yet been irradiated with beam B, it similarly adjusts the irradiation position of beam B to those other unwanted plants P2 and irradiates them with beam B. When the irradiation of all unwanted plants P2 in the arc region 31 with beam B has been completed, the control unit 10 resumes the movement of the mobile weeding device 1 and proceeds to S125. The control unit 10 may also irradiate unwanted plants P2 in the arc region 31 with beam B while the mobile weeding device 1 is moving.

[0036] In S125, the control unit 10 determines whether the mobile weeding device 1 has reached the end of the weeding path. If the control unit 10 obtains a positive result (S125: Yes), it terminates this process; if it obtains a negative result (S125: No), it proceeds to S100.

[0037] [(5) Variant] In a modified version of the first embodiment, the optical system 11B of the laser unit 11 is configured as a variable optical system that can change the working distance of beam B (in other words, the variable beam) within the range of Xmin to Xmax. The arc distance of the arc path 30 is one of the values ​​within the range of Xmin to Xmax (for example, the median between Xmin and Xmax).

[0038] Then, in the weeding process S120, the control unit 10 measures the distance between the unwanted plants P2 in the arc region 31 and the light source of beam B (hereinafter referred to as the irradiation distance) based on the image captured by the camera 12. When the control unit 10 irradiates the unwanted plants P2 in the arc region 31 with beam B, it changes the working distance of beam B according to the irradiation distance of the unwanted plants P2, and then irradiates the unwanted plants P2 with beam B. For example, the working distance may be set to the irradiation distance of the unwanted plants P2 to which beam B is irradiated. By doing so, damage to the unwanted plants P2 can be inflicted more effectively.

[0039] [2. Second Embodiment] [(1) Overview] The mobile weeding device 1 of the second embodiment is configured similarly to the first embodiment, but the optical system 11B of the laser unit 11 is configured as a variable optical system, similar to the modified version of the first embodiment. Furthermore, the mobile weeding device 1 of the second embodiment differs from the first embodiment in that it has multiple (for example, three) arc paths (in other words, variable arc paths) and arc regions (in other words, variable arc regions) corresponding to the beam B (in other words, variable beam) (see Figure 4). Below, the configuration of the mobile weeding device 1 of the second embodiment will be described, focusing on the differences from the first embodiment.

[0040] [(2) Circular arc paths and circular arc regions] In the second embodiment, as an example, first to third arc paths 30A to 30C are provided corresponding to beam B, and first to third arc regions 31A to 31C are also provided (see Figure 4). The arc distances of the first to third arc paths 30A to 30C are different from each other and are the same as the working distance that can be set for beam B. Furthermore, the first to third arc regions 31A to 31C each contain the first to third arc paths 30A to 30C, with the first arc region 31A being located at the front and the third arc region 31C being located at the rear. As an example, each arc region is in contact with an adjacent arc region. However, a gap may be provided between adjacent arc regions.

[0041] The laser unit 11 is capable of irradiating beam B towards each of the first to third arc regions 31A to 31C. When irradiating each arc region with beam B, the optical system 11B sets the working distance of beam B to a value corresponding to the arc distance of the arc path included in the arc region to which beam B is irradiated. Specifically, the working distance may be set to the same value as the arc distance, or approximately the same value.

[0042] [(3) Regarding weeding work] In the second embodiment, as in the first embodiment, the mobile weeding device 1 performs weeding (see Figure 3) while traveling across the cultivated field 2. However, the weeding process in the second embodiment differs from that of the first embodiment in steps S110 and S120. These differences will be explained below.

[0043] In S110, it is determined whether at least one unwanted plant P2 that has not been irradiated by beam B is located in the first to third arc regions 31A to 31C (see Figure 4). In S120, beam B is irradiated onto unwanted plants P2 located in the first to third arc regions 31A to 31C. At this time, the working distance of beam B is set according to the arc distance of the arc path included in the arc region where the unwanted plants P2 irradiated with beam B are located. Once the irradiation of all unwanted plants P2 in the first to third arc regions 31A to 31C with beam B is complete, the process proceeds to S125.

[0044] In addition, in S120, similar to the modified example of the first embodiment, the control unit 10 may measure the irradiation distance of the unwanted plants P2 in the first to third arc regions 31A to 31C based on the image captured by the camera 12. Then, when irradiating the unwanted plants P2 with beam B, the control unit 10 may change the working distance of beam B according to the irradiation distance of the unwanted plants P2 before irradiating the unwanted plants P2 with beam B.

[0045] [3. Third Embodiment] [(1) Overview] The mobile weeding device 1 of the third embodiment is configured similarly to the first embodiment, but differs in that the laser unit 11 is configured to emit multiple (for example, two) beams B (see Figure 5). A circular arc path and circular arc region are provided corresponding to each beam B. In other words, in the third embodiment, multiple circular arc regions are provided, and at least one circular arc region 31 is located at every position in the left-right direction within the target region 20. The configuration of the mobile weeding device 1 of the third embodiment will be described below, focusing on the differences from the first embodiment.

[0046] [(2) Laser section] The laser unit 11 is equipped with two sets of laser oscillators 11A, optical systems 11B, and laser heads 11C, and each set emits one beam B (see Figure 5). The laser heads 11C are arranged side by side in the left-right direction. As in the first embodiment, the laser unit 11 is configured so that the working distance of each beam B cannot be changed. Also, as an example, the working distance of each beam B (in other words, fixed beam) is the same value.

[0047] [(3) Circular arc paths and circular arc regions] An arc path corresponding to the beam B emitted from each laser head 11C is provided in front of each laser head 11C (see Figure 5). The arc distances of these first and second arc paths 30A and 30B are the same as the working distance of the beam B corresponding to the arc path. In addition, a first arc region 31A including the first arc path 30A and a second arc region 31B including the second arc path 30B are provided.

[0048] For example, the first and second arc regions 31A and 31B are located on the right and left sides, respectively. The rightmost end R1 of the first arc region 31A is located at the rightmost end of the target region 20, and the leftmost end L2 of the second arc region 31B is located at the leftmost end of the target region 20. Furthermore, the leftmost end L1 of the first arc region 31A is connected to the rightmost end R2 of the second arc region 31B. Therefore, at least one arc region 31 is located at every position in the left-right direction within the target region 20.

[0049] Note that the working distances of each beam B may be different. In this case, as shown in Figures 6 and 7, the arc distances of the first and second arc paths 30A and 30B corresponding to each beam B will be different.

[0050] Furthermore, the left end L1 of the first arc region 31A and the right end R2 of the second arc region 31B may be connected, or they may be separated, as shown in Figures 6 and 7. Also, if the left end L1 of the first arc region 31A and the right end R2 of the second arc region 31B are separated, the positions of the left end L1 and the right end R2 may coincide in the left-right direction (see Figure 6). In addition, the portion of the first arc region 31A including the left end L1 and the portion of the second arc region 31B including the right end R2 may overlap in the front-back direction (see Figure 7). By arranging the left end L1 and the right end R2 in this way, at least one arc region 31 is located at every position in the left-right direction within the target region 20.

[0051] [(4) Regarding weeding work] In the third embodiment, as in the first and second embodiments, the mobile weeding device 1 performs weeding (see Figure 3) while traveling across the cultivated field 2. However, the weeding process in the third embodiment differs from that of the first and second embodiments in steps S110 and S120. These differences will be explained below.

[0052] In S110, it is determined whether at least one unwanted plant P2 that has not been irradiated by beam B is located in the first and second arc regions 31A and 31B (see Figures 5-7). In S120, the unwanted plants P2 located in the first and second arc regions 31A and 31B are irradiated with beam B corresponding to the arc region in which the unwanted plants P2 are located. Once the irradiation of all unwanted plants P2 in the first and second arc regions 31A and 31B with beam B is complete, the control unit 10 proceeds to S125.

[0053] [(3) Variant] In the third embodiment modification 1, each optical system 11B in the laser unit 11 is configured as a variable optical system, similar to the modifications of the first embodiment and the second embodiment. In other words, each beam B (in other words, a variable beam) emitted from the laser unit 11 can have its working distance changed.

[0054] Then, in step S120 of the weeding process (see Figure 3), the control unit 10 measures the irradiation distance between the unwanted plant P2 and the light source of beam B corresponding to the arc region 31 where the unwanted plant P2 is located, based on the image captured by the camera 12. When irradiating the unwanted plant P2 in each arc region 31 with beam B, the control unit 10 changes the working distance of beam B corresponding to the arc region 31 according to the irradiation distance of the unwanted plant P2, and then irradiates the unwanted plant P2 with beam B.

[0055] Furthermore, a portion of each optical system 11B in the laser unit 11 may be configured as a variable optical system. In the weeding process S120, when the control unit 10 irradiates unwanted plants P2 with a beam B whose working distance can be changed, it may change the working distance of the beam B according to the irradiation distance to the unwanted plants P2.

[0056] [4. Fourth Embodiment] [(1) Overview] The mobile weeding device 1 of the fourth embodiment is configured similarly to the third embodiment, but differs in that each optical system 11B of the laser unit 11 is configured as a variable optical system, similar to the modified version of the first embodiment and the second embodiment. The range of working distance that can be set for each beam B (in other words, variable beam) may be the same or different. Furthermore, the mobile weeding device 1 of the fourth embodiment differs from the third embodiment in that multiple (for example, two) arc paths (in other words, variable arc paths) and arc regions (in other words, variable arc regions) are provided corresponding to each beam B (see Figure 8). Below, the configuration of the mobile weeding device 1 of the fourth embodiment will be described, focusing on the differences from the third embodiment.

[0057] [(2) Circular arc paths and circular arc regions] In the fourth embodiment, as an example, first and second arc paths 30A and 30B are provided corresponding to each beam B, similar to the second embodiment, and first and second arc regions 31A and 31B are also provided (see Figure 8). The arc distances of the first and second arc paths 30A and 30B are different from each other and are the same as the working distance that can be set for the corresponding beam B. Furthermore, the first and second arc regions 31A and 31B each contain the first and second arc paths 30A and 30B, with the first arc region 31A located on the front side and the second arc region 31B located on the rear side.

[0058] As an example, the arc distances of each first arc distance 30A are the same, and the arc distances of each second arc distance 30B are also the same. However, this is not limited to this; the arc distances of each first arc distance 30A may be different from each other, and the arc distances of each second arc distance 30B may be different from each other.

[0059] Here, the beam B emitted from the right laser head 11C is referred to as the right beam B, and the beam B emitted from the left laser head 11C is referred to as the left beam B. For example, the rightmost R1 of the first and second arc regions 31A and 31B corresponding to the right beam B is located at the rightmost end of the target region 20, and the leftmost L2 of the first and second arc regions 31A and 31B corresponding to the left beam B is located at the leftmost end of the target region 20. Furthermore, the leftmost L1 of the first and second arc regions 31A and 31B corresponding to the right beam B is connected to the rightmost R2 of the first and second arc regions 31A and 31B corresponding to the left beam B, respectively. Therefore, at least one arc region 31 is located at every position in the left-right direction within the target region 20.

[0060] Furthermore, similar to the third embodiment, the left end L1 of the first arc region 31A corresponding to the right beam B may be connected to or separated from the right end R2 of the first arc region 31A corresponding to the left beam B. The first arc region 31A corresponding to the right beam B and the first arc region 31A corresponding to the left beam B are arranged, similar to the third embodiment, such that at least one first arc region 31 is located at all positions in the left-right direction within the target region 20. Similarly, the second arc region 31B corresponding to the right beam B and the second arc region 31B corresponding to the left beam B are also arranged in the same manner as the first arc regions 31A corresponding to the right beam B and left beam B, respectively.

[0061] Furthermore, similar to the second embodiment, the laser unit 11 is capable of irradiating each beam B onto the first and second arc regions 31A and 31B corresponding to the beam B. When irradiating each arc region with beam B, the optical system 11B sets the working distance of beam B to a value corresponding to the arc distance of the arc path included in the arc region to which beam B is irradiated.

[0062] [(3) Regarding weeding work] In the fourth embodiment, as in the first to third embodiments, the mobile weeding device 1 performs weeding (see Figure 3) while traveling across the cultivated field 2. However, the weeding process in the fourth embodiment differs from that of the first to third embodiments in steps S110 and S120. These differences will be explained below.

[0063] In S110, it is determined whether at least one unwanted plant P2 that has not been irradiated by beam B is located in the first and second arc regions 31A and 31B (see Figure 8) corresponding to each beam B.

[0064] In S120, the beam B corresponding to the arc region in which the unwanted plants P2 are located is irradiated to the first and second arc regions 31A and 31B corresponding to each beam B. At this time, the working distance of beam B is set according to the arc distance of the arc path included in the arc region in which the unwanted plants P2 being irradiated by beam B are located. Once the irradiation of all unwanted plants P2 in these arc regions with beam B is complete, the control unit 10 proceeds to S125.

[0065] In addition, in S120, similar to the modification of the first embodiment, the control unit 10 may measure the irradiation distance of the unwanted plants P2 in the first and second arc regions 31A and 31B based on the images captured by the camera 12. Then, when irradiating the unwanted plants P2 with beam B, the control unit 10 may change the working distance of beam B according to the irradiation distance of the unwanted plants P2 before irradiating the unwanted plants P2 with beam B.

[0066] [(4) Modified Version] A portion of each optical system 11B in the laser unit 11 may be configured as a variable optical system. In other words, the laser unit 11 may emit a beam B whose working distance can be changed and a beam B whose working distance is fixed.

[0067] Furthermore, the arc path and arc region corresponding to beam B with a fixed working distance (in other words, a fixed beam) may be configured in the same way as in the first and third embodiments. Also, the arc path and arc region corresponding to beam B with a variable working distance (in other words, a variable beam) may be configured in the same way as in the fourth embodiment.

[0068] Furthermore, in the weed control process, unwanted plants P2 located in the arc region corresponding to the fixed beam may be irradiated with the fixed beam in the same manner as in the first and third embodiments. On the other hand, unwanted plants P2 located in the arc region corresponding to the variable beam may be irradiated with the variable beam in the same manner as in the fourth embodiment.

[0069] [5. Effects] When irradiating unwanted plants P2 with beam B, it is preferable that the irradiation distance between the beam B light source and the unwanted plants P2 matches or is approximately matched with the working distance of beam B in order to effectively damage the unwanted plants P2. In contrast, according to the first to fourth embodiments, beam B is irradiated to unwanted plants P2 located in an arc region determined based on the working distance.

[0070] Therefore, as in the first and third embodiments, even without a configuration for changing the working distance, the beam B can be irradiated onto unwanted plants P2 at an appropriate working distance. Furthermore, in the second and fourth embodiments, the amount of change in working distance required to achieve an appropriate working distance can be reduced, and as a result, the configuration of the optical system 11B for changing the working distance can be simplified. Consequently, the configuration of the mobile weeding device 1 can be simplified, and as a result, the cost of the mobile weeding device 1 can be reduced.

[0071] Furthermore, by eliminating the need for a working distance or reducing the amount of change required for the working distance, the processing time required to irradiate unwanted plant P2 with beam B can be shortened.

[0072] [6. Other Embodiments] (1) In the first to fourth embodiments, the irradiation position of beam B is adjusted by changing the irradiation direction of beam B using the optical system 11B in the laser unit 11. However, the irradiation position of beam B may also be adjusted by an adjustment unit that mechanically changes the position and / or orientation of the laser head 11C without using the optical system 11B of the laser unit 11. Alternatively, the irradiation position of beam B may be changed by mechanically changing the position and / or orientation of the laser head 11C while simultaneously changing the irradiation direction of beam B using the optical system 11B.

[0073] (2) In the first to fourth embodiments, the irradiation direction of beam B is inclined downward and toward the front, and an arc path and arc region are provided in front of the laser head 11C. However, the irradiation direction of beam B may also be inclined downward and toward the rear, right, or left. The position of the arc path and arc region may be determined according to the irradiation direction of beam B.

[0074] (3) Multiple functions of one component in the above embodiment may be realized by multiple components, or one function of one component may be realized by multiple components. Also, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, some of the configurations of the above embodiment may be omitted. Also, at least some of the configurations of the above embodiment may be added to or replaced with the configurations of other above embodiments. [Explanation of symbols]

[0075] 1...Mobile weeding device, 10...Control unit, 11...Laser unit, 11A...Laser oscillator, 11B...Optical system, 11C...Laser head, 12...Camera, 13...Illumination unit, 14...Housing, 15...Cover, 16...Wheels, 2...Cultivated land, 20...Target area, 3...Virtual plane, 30...Circular arc path, 31...Circular arc region, B...Beam, P1...Crop, P2...Weed.

Claims

1. A portable weed control device, A camera configured to photograph the target area below the aforementioned mobile weeding device and generate an image, A laser unit configured to emit at least one beam, An adjustment unit configured to change the irradiation position to which the beam is irradiated, The system includes a control unit configured to detect predetermined plants located in the target area based on the aforementioned image, and to change the irradiation position of the beam via the adjustment unit, thereby irradiating the detected plants with the beam, In the virtual plane on which the mobile weeding device is located, at least one arc-shaped path is provided corresponding to each of the beams, and the arc distance, which is the distance between the laser head that emits each beam and all points included in the arc path corresponding to the beam, is the working distance that can be set for the beam. Corresponding to each of the aforementioned arc paths, an arc region is provided which includes the said arc path and extends in an arc shape. At all positions in the target area in the left-right direction perpendicular to the direction of travel of the mobile weeding device, at least one of the arc regions is located. The control unit is configured to irradiate the plants located in the arc region with the beam corresponding to the arc path included in the arc region. Mobile weeding equipment.

2. A mobile weeding device according to claim 1, The laser unit is configured to irradiate at least one fixed beam, the working distance of which is fixed, as the beam. Corresponding to the aforementioned fixed beam, one of the aforementioned arc paths is provided. Mobile weeding equipment.

3. A mobile weeding device according to claim 1 or claim 2, The laser unit is configured to emit at least one variable beam, the working distance of which can be changed, as the beam. In correspondence with the variable beam, a plurality of variable arc paths are provided, each having a different arc distance, and the arc distance of each of the variable arc paths matches the working distance that can be set for the variable beam corresponding to that variable arc path. The arc region including the variable arc path is defined as the variable arc region. The control unit is configured to irradiate the plants located in each of the variable arc regions with the variable beam corresponding to the variable arc path, with the working distance set according to the arc distance of the variable arc path included in the variable arc region. Mobile weeding equipment.

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