Economical large-breadth blue light laser weeding device with compact structure

Abstract

The invention provides an economical large-breadth blue light laser weeding device with a compact structure. The device comprises a 450nm semiconductor laser (1), a collimation focusing lens module (2), an X-Y scanning galvanometer (3), a pseudo coaxial structural member (6), a dichroscope (7) and a CCD camera (8), the 450nm semiconductor laser, the collimating and focusing lens module and the X-Y scanning galvanometer are sequentially fixed together through connecting pieces, zero deflection and maximum deflection of a laser beam correspond to a central and angular beam (4) during operation, and an area which can be scanned by the blue laser beam is an irradiation surface (5); the dichroscope is mounted right below the X-Y scanning galvanometer at an angle of 45 degrees through the pseudo coaxial structural member; the CCD camera is installed below the 450nm semiconductor laser through a pseudo-coaxial structural member, and the CCD camera is matched with a lens to meet the requirement that the field of view is larger than the irradiation surface of the laser. The device has the advantages of being high in response speed and precision, large in weeding area, low in cost, small in size, convenient to integrate and the like.

Description

Technical Field

[0001] The invention relates to the technical field of laser weeding, and in particular to a large-format blue-light laser weeding device with an economical and compact structure. Background Art

[0002] Weeds have always been considered a major biological disaster in agricultural production. They compete with crops for basic resources such as water, nutrients, space and sunlight. Due to their growth advantages, weeds often use these resources more efficiently than crops. In addition, weeds may become habitats for pests and pathogens, aggravating the growth pressure of crops and leading to a significant decrease in crop yield and quality. At present, the main method of weed control is chemical weeding, followed by mechanical weeding and manual weeding. Chemical weeding has dominated global agriculture due to its high efficiency and economy, but long-term dependence on chemical herbicides has caused environmental pollution, an increase in drug-resistant weeds, and potential threats to human health and ecological balance. Mechanical weeding technology has become one of the key technologies for sustainable agricultural development with its high efficiency and environmental protection characteristics, but in actual operation, there is a high rate of seedling injury when weeding crops with small plant spacing. Manual weeding is accurate and environmentally friendly, but it is labor-intensive and inefficient. Coupled with the aging population and labor shortage, the cost of weeding continues to rise, and it is difficult to control weed growth in a timely and effective manner. Faced with the limitations of traditional weed control methods and their potential impacts on the environment and human health, the agricultural sector is in urgent need of a new weed control technology.

[0003] Laser weeding is an innovative solution that uses high-energy laser beams to irradiate weeds, and high temperatures cause the weed cells to quickly dehydrate and rupture, thereby achieving physical targeted weeding. This solution is precise, efficient and environmentally friendly, and is expected to become a key technology for the green development of agriculture in the future. According to research, the laser weeding technology reported in relevant literature currently mainly uses fixed laser sources for mechanism research, and a few use multi-axis robotic arms or galvanometers to adjust the position and direction of the laser beam to achieve precise aiming for dynamic weeding. The multi-axis robotic arm achieves precise irradiation through optical fiber or by integrating semiconductor lasers in the end effector. The optical fiber solution can achieve long-distance high-power laser transmission, but the dynamic movement of the robotic arm causes the optical fiber to undergo repeated bending stress, which can easily cause microcracks or even breakage of the optical fiber; the end effector integrated semiconductor laser solution simplifies the system structure and improves the flexibility of the robotic arm, but this solution requires a higher load-bearing capacity of the robotic arm, and the heat dissipation problem of the laser is also prominent, and a more complex control system is required to ensure accurate positioning and stable output.

[0004] In addition, the galvanometer system guides the laser beam by precisely controlling the angles of the two XY reflective lenses to achieve precise irradiation and removal of weeds. This solution has the advantages of fast response speed, simple and compact structure, high-precision control capability, and high-speed automatic operation capability. However, the effective working area of ​​the current laser weeding solution based on the galvanometer system is limited. If laser weeding is to be achieved over a large area, the conventional solution requires adding a beam expander to the output end of the laser to increase the beam diameter, and matching it with a galvanometer with a large emitting surface to increase the removal range, and finally using a field lens to precisely control the size and position of the focused spot. The laser weeding system of this solution has a complex structure, and the components used are expensive, which further limits its widespread promotion and application in agriculture. Summary of the invention

[0005] In view of this, the present invention provides an economical and compact large-format blue laser weeding device to solve the above problems.

[0006] The present invention provides an economical and compact large-format blue laser weeding device, comprising: a 450nm semiconductor laser (1), a collimating and focusing lens module (2), an XY scanning galvanometer (3), a pseudo-coaxial structural component (6), a dichroic mirror (7), and a CCD camera (8); the 450nm semiconductor laser (1), the collimating and focusing lens module (2), and the XY scanning galvanometer (3) are fixed together in sequence through a connecting component, and during operation, the zero deflection and maximum deflection of the laser beam correspond to the center and angle beams (4), and the area that can be scanned by the blue laser beam is an irradiation surface (5); the 450nm semiconductor laser (1) is used to output the blue laser beam through spatial light; the collimating and focusing lens module (2) is used to collimate and focus the blue laser beam to a far field, The blue light is incident on the XY scanning galvanometer (3); the XY scanning galvanometer (3) is used to realize the rapid deflection of the blue light laser beam by controlling the swing of two reflection mirrors, so that the blue light laser beam can accurately irradiate the target weeds on the irradiation surface (5); the dichroic mirror (7) is installed at an angle of 45° directly below the XY scanning galvanometer (3) via the pseudo-coaxial structural component (6); the dichroic mirror (7) is used to realize 450nm laser transmission and visible light band reflection, and the visible light band is used for imaging by the CCD camera (8); the CCD camera (8) is installed below the 450nm semiconductor laser (1) via the pseudo-coaxial structural component (6); the CCD camera (8) meets the requirement that the field of view is larger than the irradiation surface (5) of the laser by matching the lens.

[0007] In another implementation of the present invention, the output power of the 450nm semiconductor laser (1) is precisely controlled by pulse width modulation, and the cooling method is a semiconductor cooler and a fan.

[0008] In another implementation of the present invention, the light-transmitting surfaces of the optical elements in the collimating and focusing lens module (2) are coated with an anti-reflection film at 450 nm; the number, curvature and spacing parameters of the lenses in the collimating and focusing lens module (2) are determined according to the working distance to the irradiation surface (5) and the size of the light spot on the irradiation surface (5).

[0009] In another implementation of the present invention, the optical lens in the collimating and focusing lens module (2) includes at least one plano-convex lens (202).

[0010] In another implementation of the present invention, the optical lens in the collimating and focusing lens module (2) includes at least one plano-concave lens (201).

[0011] In another implementation of the present invention, two mutually orthogonal reflective mirrors in the XY scanning galvanometer (3) are coated with a total reflection film at 450 nm.

[0012] In another implementation of the present invention, the XY scanning galvanometer (3) is composed of an X reflector (301) and a Y reflector (302); the reflectors allow a maximum incident light diameter of 10 mm and a center distance of 30 mm.

[0013] In another implementation of the present invention, the X-reflecting mirror (301) causes the blue laser beam to deflect 90° around the X-axis in an initial state, and the maximum scanning mechanical angle is ±20°; the Y-reflecting mirror (302) causes the laser beam to deflect 90° around the Y-axis in an initial state, and the maximum scanning mechanical angle is ±20°; the center and angle beams (4) correspond to the X-reflecting mirror (301) and the Y-reflecting mirror (302) in an initial and maximum scanning mechanical angle state, respectively.

[0014] In another implementation of the present invention, the method further comprises: adjusting the radiation area and the spot size at the irradiation surface (5) to match a specific weeding scene and weed type by changing the design parameters of the collimating and focusing lens module (2).

[0015] The economical and compact large-format blue laser weeding device of the present invention adopts a combination of a laser and a galvanometer system, has a simple and compact structure, small motion inertia, and a relatively simplified control algorithm, thereby greatly improving the response speed and weeding accuracy; a collimating focusing lens is used to focus the laser output in the form of spatial light in the far field, and an XY scanning galvanometer with a small emitting surface is used to realize beam control, avoiding the use of other complex structures or expensive devices to expand the irradiation range, and the weeding area is large and the cost is low, which effectively solves the contradiction between the weeding area and the system cost; a 450nm semiconductor laser is used, which is relatively small in size and does not require large cooling equipment, thereby reducing the overall volume of the weed removal module and facilitating integrated application, thereby improving its application flexibility and practicality in the field of agricultural weeding. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. By reading the detailed description of the following implementations, the advantages and benefits of the solutions become clear to those skilled in the art. The drawings are only used to illustrate the preferred implementations and are not to be considered as limiting the present invention.

[0017] Figure 1 This is a schematic diagram of an economical and compact large-format blue light laser weeding device according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of a basic large-format blue light laser weeding device according to an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of a joint control scheme for multiple blue light laser weeding devices according to an embodiment of the present invention.

[0020] Figure 4 This is a Zemax optical path diagram of an economical and compact large-format blue laser weeding device 1 according to an embodiment of the present invention.

[0021] Figure 5 This is a Zemax simulation result diagram of an economical and compact large-format blue laser weeding device 1 according to an embodiment of the present invention.

[0022] Figure 6 This is a Zemax optical path diagram of an economical and compact large-format blue laser weeding device 2 according to an embodiment of the present invention.

[0023] Figure 7 This is a Zemax simulation result diagram of an economical and compact large-format blue laser weeding device 2 according to an embodiment of the present invention.

[0024] Description of the drawings: 1-450nm semiconductor laser, 101-LD light source; 2-collimating focusing lens module; 201-plano-concave lens; 202-plano-convex lens; 3-XY scanning galvanometer; 301-X reflector; 302-Y reflector; 4-center and corner beams; 5-irradiation surface; 6-pseudo-coaxial structural component; 7-dichroic mirror; 8-CCD camera. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be described clearly and in detail below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in the field based on the embodiments in the embodiments of the present invention should fall within the scope of protection of the embodiments of the present invention.

[0026] Figure 1 A schematic diagram of an economical and compact large-format blue laser weeding device provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, this embodiment mainly includes:

[0027] 450nm semiconductor laser (1), collimating and focusing lens module (2), XY scanning galvanometer (3), pseudo-coaxial structural component (6), dichroic mirror (7), CCD camera (8).

[0028] The 450nm semiconductor laser (1), the collimating and focusing lens module (2) and the XY scanning galvanometer (3) are fixed together in sequence through a connecting piece. During operation, zero deflection and maximum deflection of the laser beam correspond to the center and angular beams (4), and the area that can be scanned by the blue laser beam is the irradiation surface (5).

[0029] The 450nm semiconductor laser (1) is used to output the blue laser beam through spatial light.

[0030] The collimating and focusing lens module (2) is used to collimate and focus the blue laser beam to a far field, and to inject it into the XY scanning galvanometer (3).

[0031] The XY scanning galvanometer (3) is used to achieve rapid deflection of the blue laser beam by controlling the swing of two reflection mirrors, so that the blue laser beam can accurately irradiate the target weeds on the irradiation surface (5).

[0032] The dichroic mirror (7) is installed at an angle of 45° directly below the XY scanning galvanometer (3) via the pseudo coaxial structural component (6); the dichroic mirror (7) is used to achieve 450nm laser transmission and visible light band reflection; the visible light band is used for imaging by the CCD camera (8).

[0033] The CCD camera (8) is installed below the 450nm semiconductor laser (1) via the pseudo-coaxial structural component (6); the CCD camera (8) meets the requirement that the field of view is larger than the irradiation surface (5) of the laser by matching the lens.

[0034] For example, Figure 2As shown, a 450nm semiconductor laser (1) outputs a high-power blue laser beam through spatial light, and the divergent laser beam is collimated and focused to a far field through a collimating and focusing lens module (2). The laser beam is then incident on an XY scanning galvanometer (3) composed of two mutually orthogonal reflectors. The laser beam is rapidly deflected by controlling the swing of the two reflectors, so that the laser beam can be accurately irradiated onto the target weeds on the irradiation surface (5).

[0035] Further, in Figure 2 On the basis of the device, components such as a CCD camera (8) are added to realize the identification and positioning functions of the target weeds. The dichroic mirror (7) is coated with a corresponding film system to realize 450nm laser transmission and visible light band reflection. The dichroic mirror (7) allows the CCD camera (8) and the 450nm laser beam to share the same optical axis, and at the same time separates the laser beam and the visible light, ensuring that the CCD camera (8) can normally capture the weed image during the laser weeding process, and then use deep learning technology to identify and locate the weeds. According to the weed coordinate position information, the corresponding laser beam deflection angle is calculated, and the control unit sends a command to the XY scanning galvanometer (3), and then adjusts the two mutually orthogonal reflectors to quickly change the direction of the collimated and focused 450nm high-power blue laser beam, and finally accurately irradiates the identified weeds.

[0036] Preferably, if Figure 3 As shown, multiple blue light laser weeding devices are controlled in conjunction to further expand the cleaning range. The visual blue light laser weeding devices are equipped with independent 450nm semiconductor lasers (1), XY scanning galvanometers (3) and CCD cameras (8), and are equipped with a central control system to coordinate the operation of each device. According to the farmland topography, crop planting pattern and weed distribution, multiple visual blue light laser weeding devices can be controlled in conjunction to work together. The central control system is responsible for receiving image information from the cameras of each device, and using deep learning technology to perform image analysis, identify and locate weeds. Then, the system calculates the coordinates of the weeds that each device needs to aim at, and sends instructions to the corresponding XY scanning galvanometer (3) to adjust the direction of the laser beam to ensure that the laser can accurately irradiate the target weeds. In addition, the central control system needs to consider the collaborative operation between the devices to avoid repeated weeding or missing weeds.

[0037] The weeding device also includes a control board, a laser power supply, a galvanometer power supply, and a board power supply. The control board is used to receive external instructions, control the emission of the laser and the movement of the galvanometer, and ensure accurate control of the laser beam position, power, and irradiation time. The laser power supply, galvanometer power supply, and board power supply provide stable power support for the laser, galvanometer, and control board, respectively, to ensure the normal operation of the entire device.

[0038] The economical and compact large-format blue laser weeding device of the present invention adopts a combination of a laser and a galvanometer system, has a simple and compact structure, small motion inertia, and a relatively simplified control algorithm, thereby greatly improving the response speed and weeding accuracy; a collimating focusing lens is used to focus the laser output in the form of spatial light in the far field, and an XY scanning galvanometer with a small emitting surface is used to realize beam control, avoiding the use of other complex structures or expensive devices to expand the irradiation range, and the weeding area is large and the cost is low, which effectively solves the contradiction between the weeding area and the system cost; a 450nm semiconductor laser is used, which is relatively small in size and does not require large cooling equipment, thereby reducing the overall volume of the weed removal module and facilitating integrated application, thereby improving its application flexibility and practicality in the field of agricultural weeding.

[0039] In another implementation of the present invention, the output power of the 450nm semiconductor laser (1) is precisely controlled by pulse width modulation, and the cooling method is a semiconductor cooler and a fan.

[0040] For example, the 450nm semiconductor laser (1) directly outputs spatial light, the working mode is continuous wave, the output power can be precisely controlled by pulse width modulation (PWM), and the cooling method is semiconductor refrigerator (Thermo Electric Cooler, TEC) and fan heat dissipation.

[0041] In another implementation of the present invention, the light-transmitting surfaces of the optical elements in the collimating and focusing lens module (2) are coated with an anti-reflection film at 450 nm; the number, curvature and spacing parameters of the lenses in the collimating and focusing lens module (2) are determined according to the working distance to the irradiation surface (5) and the size of the light spot on the irradiation surface (5), thereby achieving weed control within a large area (5).

[0042] In another implementation of the present invention, the optical lens in the collimating and focusing lens module (2) includes at least one plano-convex lens (202).

[0043] In another implementation of the present invention, the optical lens in the collimating and focusing lens module (2) includes at least one plano-concave lens (201).

[0044] In another implementation of the present invention, two mutually orthogonal reflectors in the XY scanning galvanometer (3) are coated with a total reflection film at 450nm, and the reflectors can be selected to be small in size so as to allow a maximum incident light diameter of 10mm. The XY scanning galvanometer does not need to be equipped with a beam expander and a large-format field mirror, thereby reducing the hardware requirements for the XY scanning galvanometer.

[0045] In another implementation of the present invention, the XY scanning galvanometer (3) is composed of an X reflector (301) and a Y reflector (302); the reflectors allow a maximum incident light diameter of 10 mm and a center distance of 30 mm.

[0046] In another implementation of the present invention, the X-reflecting mirror (301) causes the blue laser beam to deflect 90° around the X-axis in an initial state, and the maximum scanning mechanical angle is ±20°; the Y-reflecting mirror (302) causes the laser beam to deflect 90° around the Y-axis in an initial state, and the maximum scanning mechanical angle is ±20°; the center and angle beams (4) correspond to the X-reflecting mirror (301) and the Y-reflecting mirror (302) in an initial and maximum scanning mechanical angle state, respectively.

[0047] In another implementation of the present invention, the method further comprises: adjusting the radiation area and the spot size at the irradiation surface (5) to match a specific weeding scene and weed type by changing the design parameters of the collimating and focusing lens module (2).

[0048] In another implementation of the present invention, Figure 4 As shown, the working distance from the light outlet of the 450nm semiconductor laser (1) to the irradiation surface (5) is set to 600mm. The 450nm LD light source (101) is focused in the far field by a plano-convex lens (202), and then the laser beam is incident on an XY scanning galvanometer (3) composed of an X reflector (301) and a Y reflector (302). The laser beam is rapidly deflected by controlling the swing of the two reflectors, so that the laser beam can be accurately irradiated onto the target weeds on the irradiation surface (5).

[0049] like Figure 5 As shown, it is a Zemax simulation result diagram of an economical and compact large-format blue laser weeding device 1. The size of the irradiated surface (5) at 600mm from the light outlet is about 510mm×460mm, the radial radius of the center and corner beams (4) on the irradiated surface is no more than 2.0mm, and the spot radius within the range of 590-640mm from the light outlet is less than 2.2mm. This spot size can match the size of the meristem of the weeds.

[0050] The size of the light outlet of the 450nm semiconductor laser (1) is 2mm×2mm, and the divergence angles of the fast axis and the slow axis are both 0.3°.

[0051] The optical lens in the collimating and focusing lens module (2) in the weeding device 1 includes only one plano-convex lens (202), which is made of K9 glass, has a focal length f=630mm@587.6nm, an aperture D=25mm, and a center thickness d=1.78mm. The distance from the S1 surface of the plano-convex lens (202) to the light source is 80mm, and the distance from the S2 surface to the X-reflection surface is 40mm.

[0052] The XY scanning galvanometer (3) is composed of an X-reflection mirror (301) and a Y-reflection mirror (302). The two reflectors allow a maximum incident light diameter of 10 mm and a center distance of 30 mm. In the initial state of the X-reflection mirror (301), the laser beam is deflected 90° around the X-axis, and the maximum scanning mechanical angle is ±20°. In the initial state of the Y-reflection mirror (302), the laser beam is deflected 90° around the Y-axis, and the maximum scanning mechanical angle is ±20°. The center and angle beams (4) correspond to the X-reflection mirror (301) and the Y-reflection mirror (302) in the initial and maximum scanning mechanical angle states, respectively.

[0053] In another implementation of the present invention, Figure 6 As shown, the working distance from the light outlet of the 450nm semiconductor laser (1) to the irradiation surface (5) is set to 1500mm. The 450nm LD light source (101) is focused in the far field by a plano-concave lens (201) and a plano-convex lens (202), and then the laser beam is incident on an XY scanning galvanometer (3) composed of an X reflector (301) and a Y reflector (302). The laser beam is rapidly deflected by controlling the swing of the two reflectors, so that the laser beam can be accurately irradiated onto the target weeds on the irradiation surface (5).

[0054] like Figure 7 As shown, it is a Zemax simulation result diagram of an economical and compact large-format blue laser weeding device 2. The size of the irradiated surface (5) at 1500mm from the light outlet is about 1200mm×1100mm, the radial radius of the center and corner beams (4) on the irradiated surface is no more than 2.0mm, and the spot radius within the range of 1100-1550mm from the light outlet is less than 2.0mm. This spot size can match the meristem of weeds.

[0055] The size of the light outlet of the 450nm semiconductor laser (1) is 2mm×2mm, and the divergence angles of the fast axis and the slow axis are both 0.3°.

[0056] The optical lens in the collimating and focusing lens module (2) of the weeding device 2 includes a plano-concave lens (201) and a plano-convex lens (202). The plano-concave lens (201) is made of K9 glass, with a focal length of f=-25mm@587.6nm, an aperture of D=10mm, and a center thickness of d=1.5mm. The plano-convex lens (202) is made of K9 glass, with a focal length of f=63mm@587.6nm, an aperture of D=10mm, and a center thickness of d=1.9mm. The distance from the S1 surface of the plano-concave lens (201) to the light source is 30mm, the distance from the S2 surface to the S1 surface of the plano-convex lens (202) is 39.3mm, and the distance from the S1 surface of the plano-convex lens (202) to the X-reflector (301) is 80mm.

[0057] The XY scanning galvanometer (3) is composed of an X-reflection mirror (301) and a Y-reflection mirror (302). The two reflectors allow a maximum incident light diameter of 10 mm and a center distance of 30 mm. In the initial state of the X-reflection mirror (301), the laser beam is deflected 90° around the X-axis, and the maximum scanning mechanical angle is ±20°. In the initial state of the Y-reflection mirror (302), the laser beam is deflected 90° around the Y-axis, and the maximum scanning mechanical angle is ±20°. The center and angle beams (4) correspond to the X-reflection mirror (301) and the Y-reflection mirror (302) in the initial and maximum scanning mechanical angle states, respectively.

[0058] In addition, studies have shown that compared with 10.6μm carbon dioxide gas lasers, 1064nm Nd:YAG and 532nm frequency-doubled solid-state lasers and 1080nm Yb-doped fiber lasers, 450nm blue light semiconductor lasers have better application prospects in weed control due to their compact size, high absorption rate and high reliability.

[0059] There is no literature report on a compact large-format laser weeding device based on a combination of a blue light semiconductor laser that outputs in the form of spatial light and a scanning galvanometer.

[0060] Thus far, specific embodiments of the present invention have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve the desired results. Additionally, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing may be advantageous.

[0061] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0062] In the description of the present invention, the terms "first" and "second" are only used to facilitate the description of different components or names, and cannot be understood as indicating or implying a sequential relationship, relative importance, or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0064] It should be noted that although the specific embodiments of the present invention are described in detail in conjunction with the accompanying drawings, it should not be understood as limiting the scope of protection of the present invention. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still belong to the scope of protection of the present invention.

[0065] The examples of the embodiments of the present invention are intended to concisely illustrate the technical features of the embodiments of the present invention so that those skilled in the art can intuitively understand the technical features of the embodiments of the present invention, and are not intended to be improper limitations of the embodiments of the present invention.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An economical and compact large-format blue laser weeding device, characterized in that: include: 450nm semiconductor laser (1), collimating and focusing lens module (2), XY scanning galvanometer (3), pseudo coaxial structural component (6), dichroic mirror (7), CCD camera (8); The 450nm semiconductor laser (1), the collimating and focusing lens module (2) and the XY scanning galvanometer (3) are fixed together in sequence through a connecting piece, and during operation, the zero deflection and the maximum deflection of the laser beam correspond to the center and the angular beam (4), and the area that can be scanned by the blue laser beam is the irradiation surface (5); The 450nm semiconductor laser (1) is used to output the blue laser beam through spatial light; The collimating and focusing lens module (2) is used to collimate and focus the blue laser beam to a far field, and to make it incident on the XY scanning galvanometer (3); The XY scanning galvanometer (3) is used to realize rapid deflection of the blue laser beam by controlling the swing of two reflective mirrors, so that the blue laser beam can accurately irradiate the target weeds on the irradiation surface (5); The dichroic mirror (7) is installed at an angle of 45° directly below the XY scanning galvanometer (3) via the pseudo coaxial structural component (6), and the dichroic mirror (7) is used to achieve 450nm laser transmission and visible light band reflection, and the visible light band is used for imaging by the CCD camera (8); The CCD camera (8) is installed below the 450nm semiconductor laser (1) via the pseudo-coaxial structural component (6); the CCD camera (8) meets the requirement that the field of view is larger than the irradiation surface (5) of the laser by matching the lens.

2. The device according to claim 1, characterized in that The output power of the 450nm semiconductor laser (1) is precisely controlled by pulse width modulation, and the cooling method is a semiconductor refrigerator and a fan for heat dissipation.

3. The device according to claim 1, characterized in that The light-transmitting surfaces of the optical elements in the collimating and focusing lens module (2) are all coated with an anti-reflection film at 450 nm; The number, curvature and spacing parameters of the lenses in the collimating and focusing lens module (2) are determined according to the working distance to the irradiation surface (5) and the size of the light spot on the irradiation surface (5).

4. The device according to claim 3, characterized in that The optical lens in the collimating and focusing lens module (2) comprises at least one plano-convex lens (202).

5. The device according to claim 4, characterized in that The optical lens in the collimating and focusing lens module (2) comprises at least one plano-concave lens (201).

6. The device according to claim 1, characterized in that Two mutually orthogonal reflectors in the XY scanning galvanometer (3) are coated with a total reflection film at 450nm.

7. The device according to claim 6, characterized in that The XY scanning galvanometer (3) is composed of an X reflection mirror (301) and a Y reflection mirror (302); The reflector allows a maximum incident light diameter of 10 mm and a center distance of 30 mm.

8. The device according to claim 7, characterized in that In the initial state, the X-reflecting mirror (301) causes the blue laser beam to deflect 90° around the X-axis, and the maximum scanning mechanical angle is ±20°; In the initial state, the Y reflector (302) causes the laser beam to deflect 90° around the Y axis, and the maximum scanning mechanical angle is ±20°; The center and angle light beams (4) correspond to the X-reflecting mirror (301) and the Y-reflecting mirror (302) being in the initial and maximum scanning mechanical angle states respectively.

9. The device according to claim 1, characterized in that Also includes: By changing the design parameters of the collimating and focusing lens module (2), the radiation area and the size of the light spot at the irradiated surface (5) are adjusted to match the specific weeding scene and weed type.

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