Large-load plant protection unmanned aerial vehicle spraying device and automatic spraying method

Abstract

The invention discloses a large-load plant protection unmanned aerial vehicle spraying device and an automatic spraying method, and belongs to the technical field of plant protection spraying. The large-load plant protection unmanned aerial vehicle spraying device comprises an unmanned aerial vehicle body and an undercarriage fixed to the bottom of the unmanned aerial vehicle body; guide rail sliding block mechanisms are mounted on two longitudinal borders, in the front-back advancing direction of the unmanned aerial vehicle body, of the rectangular frame; the guide rail sliding block mechanism comprises two longitudinal moving guide rails arranged on two longitudinal borders of the rectangular frame, and longitudinal moving sliding blocks are connected to the two longitudinal moving guide rails in a sliding mode. Real-time compensation is carried out according to the flight forward speed and lateral deviation, the instant spraying area center is always made to coincide with the main route, the flight route of the unmanned aerial vehicle body is shortened, energy is saved, re-spraying and missing spraying are avoided, and uniform spraying is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of plant protection spraying, and in particular to a large-load plant protection unmanned aerial vehicle spraying device and an automatic spraying method. Background Art

[0002] Plant protection drones are spraying in the field. After entering the field, they usually do not rotate but only move horizontally. Even if they need to switch routes or perform non-linear movements, they still use horizontal movement. Figure 1 As shown in the figure, the nose of the aircraft is always parallel to the main flight route, and the interference of natural wind is ignored. The instantaneous spray area is always below the spray boom, and the spray direction is always perpendicular to the main flight route. The flight direction is changed only by translation.

[0003] When the plant protection UAV switches routes at the head of the field, it is carried out in the form of square wave flight in the early stage, which is "straight forward at a constant speed-straight forward deceleration-hovering at the head of the field-lateral translation perpendicular to the main flight route-hovering at the head of the field-straight backward acceleration-straight backward at a constant speed". At the same time, in order to ensure that the amount of pesticide per unit area of ​​farmland is constant, the spraying system adjusts the spray flow rate according to the real-time speed and stops spraying during hovering and lateral translation. At present, the industry increases the amount of pesticides carried by plant protection UAVs to increase the operating area of ​​a single mission and improve operating efficiency. However, due to the load of onboard batteries or fuel, most of the current products save energy by compressing the time of switching routes. The specific method is to change the square wave flight into a U-shaped curve flight to save the hovering and translation process and reduce the energy consumption of acceleration and deceleration. The curve drawing process also undergoes deceleration and acceleration. At the peak of the curve, the speed along the main flight route becomes 0, but there is a speed perpendicular to the main flight route. Although the spray flow rate is adjusted in real time like the square wave flight operation, the spraying is almost never stopped. However, the curved flight mode has brought new problems. When the UAV flies in square wave mode, the spray width can completely cover the entire spraying area, while the curved flight has problems such as repeated spraying and missed spraying. Figure 2 As shown, the shaded area is the area that receives the spray, which alternately forms a heavy spray area and a missed spray area.

[0004] Due to the problem of insufficient onboard energy, in addition to saving time for switching routes by adopting U-shaped curve flight, spraying is generally carried out by increasing the flight speed and increasing the flow rate to exhaust the carried liquid as soon as possible and end the single-flight mission. Sprinklers and other atomization devices have a recommended optimal flow range to ensure the atomization quality, but when the drone arrives at the field, the operating speed gradually approaches 0, resulting in the minimum spray flow rate always being close to 0. As the upper limit of the spray flow rate of large-load drones increases, the lower limit of the flow rate will usually also increase, which can easily cause the flow range that needs to be adjusted to exceed the optimal flow range of the nozzle. Therefore, it is necessary to design a large-load plant protection drone spray device and automatic spraying method. Summary of the invention

[0005] The object of the present invention is to provide a large-load plant protection UAV spray device and an automatic spray method to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a large-load plant protection drone spray device, comprising a drone body and a landing gear fixed at the bottom of the drone body, a rectangular frame is installed at the bottom of the landing gear through a lifting device, and a guide rail slider mechanism is installed on two longitudinal borders of the rectangular frame along the forward and backward travel direction of the drone body;

[0007] The guide rail slider mechanism includes two longitudinal movable guide rails arranged on the two longitudinal borders of the rectangular frame, and the two longitudinal movable guide rails are slidably connected with longitudinal movable sliders. A transverse movable guide rail is installed on the longitudinal movable slider through a rotating shaft, and a spray rod is slidably matched on the transverse movable guide rail, and a plurality of spray heads are provided on the spray rod.

[0008] In a further embodiment, a rotating motor is provided on one side of the longitudinal moving slider, the output end of the rotating motor is connected to the rotating shaft, the positions of the rotating shafts on the two longitudinal moving sliders are staggered, and an electromagnet is provided inside the other side of the longitudinal moving slider.

[0009] An automatic spraying method of a large-load plant protection UAV spray device comprises the following steps:

[0010] S1. Before the main body of the UAV takes off, the rectangular frame is above the landing gear, and the two spray arms are located below the two longitudinal borders of the rectangular frame;

[0011] S2. After the main body of the UAV takes off, the rectangular frame is lowered to the bottom of the landing gear through the lifting device, and the lateral moving guide rails are rotated 90° clockwise. At this time, the two spray booms are side by side and aligned at both ends, close together and located in the middle of the rectangular frame, and enter the field to start spraying. The two spray booms are divided into the left spray boom that moves laterally along the lateral moving guide rail and the right spray boom that moves laterally along the lateral moving guide rail;

[0012] S3. The main body of the UAV enters the uniform flight spraying stage, all nozzles of the two spray booms spray, and the two spray booms slowly and synchronously move to the rear in the uniform flight spraying. During the moving process, the ground speed of the spray booms is slightly slower than the flight speed of the main body of the UAV. The flight speed of the main body of the UAV is slightly increased, and the increased flight speed is equal to the speed of the two spray booms moving backward, so that the ground speed of the two spray booms matches the spray flow rate of the straight uniform speed section. At a relatively far position before approaching the field head, before entering the deceleration flight spraying stage, ensure that the two spray booms have moved to the rearmost of the rectangular frame;

[0013] S4. The main body of the drone enters the deceleration flight spraying stage. When it approaches the field, as the speed decreases, the spray flow rate is reduced synchronously. When the flow rate of a single nozzle approaches Qmin, the nozzle of the right spray boom is closed, and the flow rate of the nozzle of the left spray boom is increased to twice the current flow rate. As the speed further decreases, the spray flow rate is reduced synchronously. When the flow rate of a single nozzle of the left spray boom approaches Qmin again, the nozzle flow rate no longer decreases. The left spray boom moves forward relative to the body to compensate for the decrease in flight speed, so that the ground speed of the left spray boom can still meet the required spray flow rate of not less than Qmin, maintaining a better atomization state until the left spray boom reaches the end of the field, and the spray is turned off;

[0014] S5. The main body of the UAV enters the arc flight spraying stage. In this stage, the speed component of the rightward translation increases. Therefore, it is necessary to move the left spray boom to the left to compensate for the instantaneous spray area deviating from the main route caused by the rightward movement of the body. The speed of the leftward movement is equal to the speed component of the rightward translation of the body.

[0015] S6. When the main body of the drone reaches the top of the U-shaped curve, the speed of the main body of the drone in the direction of the main route is 0, but there is still a speed of translation to the right. At this time, all the nozzles are in the spray-off state, the left spray boom is in the left front, and the right spray boom is in the right front. Then the spray starts from the right spray boom;

[0016] S7. The main body of the UAV enters the arc flight spraying stage. In this stage, there is still a speed component of rightward translation, so the right spray boom moves to the left to compensate for the rightward translation of the body. The speed of the leftward movement is equal to the speed component of the rightward translation of the body, and the two spray booms will move closer to the middle;

[0017] S8. The main body of the drone enters the accelerated flight spraying stage. The right spray boom reaches the starting point of the field and starts spraying. At this time, the drone has just started to accelerate and the body speed is low. To ensure that the spray flow rate of a single nozzle is not less than Qmin, the right spray boom moves backward to compensate for the insufficient flight speed. When the speed increases further, the spray flow rate of a single nozzle reaches 2 times Qmin, and the left spray boom also starts spraying. At this time, the flow rate of all nozzles on the two spray booms becomes Qmin, and the flow rate increases synchronously with the increase of flight speed;

[0018] S9. The main body of the drone enters the uniform flight spraying stage. When it first enters, the two spray booms are behind the rectangular frame. At this stage, the two spray booms slowly move to the front to cope with the work at the other end of the field. This cycle repeats until the task is completed after the spraying is completed.

[0019] S10. Before the main body of the UAV lands, the lateral moving guide rails rotate 90° counterclockwise, and the rectangular frame rises above the landing gear to control the landing.

[0020] In a further embodiment, in S2, the two spray bars are close to each other, and the two close nozzles on the two spray bars can be approximately regarded as nozzles at the same point, reducing the upper limit of the flow rate of a single nozzle by half. The two nozzles at the same point are regarded as a group. When the required spray flow rate is large, the two nozzles can be turned on at the same time; when the required spray flow rate is small, one of the nozzles can be closed. The maximum flow rate and minimum flow rate recommended for a single nozzle are Qmax and Qmin respectively. As the upper and lower limits of the flow control actually used, the maximum flow rate of a group of nozzles is 2Qmax, and the minimum flow rate is Qmin, and Qmax≥2Qmin should be satisfied.

[0021] In a further embodiment, in S4, regardless of whether spraying is performed or not, the two spray booms move synchronously in the main heading during flight.

[0022] In a further embodiment, in S5, regardless of whether spraying is performed or not, the right spray bar follows the speed value of the left spray bar and moves in the opposite direction to the right side synchronously.

[0023] In a further embodiment, in S4 and S5, depending on the different flight speed settings, the drone body does not necessarily enter the arc flight spray stage when it just enters the deceleration flight spray stage. Similarly, the drone body does not necessarily enter the deceleration flight spray stage when it just enters the arc flight spray stage. It may also enter at the same time, but the two stages will overlap in the later stage, and the drone will fly in an arc while decelerating when approaching the top of the U-shaped curve; in S7 and S8, depending on the different flight speed settings, the drone body does not necessarily exit the arc flight spray stage when it just exits the acceleration flight spray stage. Similarly, the drone body does not necessarily exit the acceleration flight spray stage when it just exits the arc flight spray stage. It may also enter at the same time, but the two stages will overlap in the early stage, that is, it will accelerate and fly in an arc when approaching the top of the U-shaped curve.

[0024] In a further embodiment, in S9, the spray boom at the other end of the field needs to compensate for the flight speed from front to back, and moving space needs to be reserved in advance.

[0025] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention increases the number of nozzles at the same point by adding a second spray rod under the main body of the drone, adds a rectangular frame under the main body of the drone and between the spray rod, adjusts the positions and angles of the two spray rods during the spraying process through the guide rail slider mechanism on the rectangular frame, moves the spray rod for compensatory mobile spraying, separates the spray rod and the instantaneous spray area formed by it from the fuselage, performs real-time compensation according to the forward flight speed and lateral deviation, always makes the center of the instantaneous spray area coincide with the main route, shortens the flight route of the main body of the drone, saves energy, avoids repeated spraying and missed spraying, and ensures uniform spraying. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the translational flight of a plant protection UAV in the prior art;

[0027] Figure 2 This is a schematic diagram of the curved flight of a plant protection UAV in the prior art;

[0028] Figure 3 It is a schematic diagram of the double spray bar close-fitting structure of the present invention;

[0029] Figure 4 This is a schematic diagram of the spray bar of the present invention rotated 90° clockwise;

[0030] Figure 5 It is a schematic diagram of the double spray bars of the present invention being closely attached to and in the middle of a rectangular frame;

[0031] Figure 6 This is a schematic diagram of the route of the plant protection UAV in the prior art;

[0032] Figure 7 It is a schematic diagram of the rotation of the body of the plant protection UAV in the route of the prior art;

[0033] Figure 8 This is a schematic diagram of the translational flight of the main body of the UAV of the present invention;

[0034] Fig. 9 yes Figure 8 Schematic diagram of the improved scheme of spraying at the field boundary at two critical moments;

[0035] Fig.10 It is a schematic diagram of a new flight route of the UAV main body in translational flight of the present invention;

[0036] Fig.11 It is a schematic diagram of the structure of the landing gear of the present invention being located outside the rectangular frame;

[0037] Fig.12 It is a schematic diagram of the structure of the landing gear of the present invention being located in a rectangular frame;

[0038] The reference numerals in the drawings are: landing gear 1, rectangular frame 2, lifting device 3, longitudinal moving guide rail 4, longitudinal moving slider 5, rotating shaft 6, transverse moving guide rail 7, spray rod 8, and spray head 9. DETAILED DESCRIPTION

[0039] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0040] See also Figure 3-Figure 12The present invention provides a technical solution: a large-load plant protection UAV spray device and an automatic spray method, comprising a UAV main body and a landing gear 1 fixed at the bottom of the UAV main body, a rectangular frame 2 is installed at the bottom of the landing gear 1 through a lifting device 3, and the UAV main body can be lowered by the lifting device 3 to be lower than the landing gear 1 after taking off, so as to prevent interference when the lateral moving guide rail 7 rotates. Before the UAV main body lands, the lifting device 3 can lift the rectangular frame 2 higher than the landing gear 1 to facilitate the landing of the UAV, and the landing gear 1 is located inside or outside the rectangular frame 2. A guide rail slider mechanism is installed on two longitudinal borders of the rectangular frame 2 along the forward and backward moving direction of the UAV main body;

[0041] The guide rail slider mechanism includes two longitudinal movable guide rails 4 arranged on the two longitudinal borders of the rectangular frame 2, and the two longitudinal movable guide rails 4 are slidably connected with longitudinal movable sliders 5. The longitudinal movable sliders 5 are installed with transverse movable guide rails 7 through rotating shafts 6. The transverse movable guide rails 7 are slidably matched with spray rods 8, and the spray rods 8 are provided with a plurality of spray heads 9.

[0042] In a further embodiment, a rotating motor is provided on one side of the longitudinal moving slider 5, and the output end of the rotating motor is connected to the rotating shaft 6, and the rotating shaft 6 is driven to rotate by the rotating motor. The positions of the rotating shafts on the two longitudinal moving sliders 5 are staggered with each other, and the two transverse moving guide rails 7 do not interfere with each other when rotating, thereby realizing the clockwise and counterclockwise rotation requirements of the transverse moving guide rail 7; an electromagnet is provided inside the other side of the longitudinal moving slider 5. When the transverse moving guide rail 7 rotates to the transverse direction, the electromagnet of the other longitudinal moving slider 5 is energized to attract the transverse moving guide rail 7 to prevent the transverse moving guide rail 7 from shaking during the spraying process.

[0043] An automatic spraying method of a large-load plant protection UAV spray device comprises the following steps:

[0044] S1. Before the main body of the drone takes off, the rectangular frame 2 is above the landing gear 1, and the two spray bars 8 are now located below the two longitudinal borders of the rectangular frame (2);

[0045] S2. After the main body of the UAV takes off, the rectangular frame 2 is lowered to the bottom of the landing gear 1 by the lifting device 3, and the transverse movable guide rails 7 are all rotated 90° clockwise. At this time, the two spray bars 8 are arranged side by side and aligned at both ends, close together and located in the middle of the rectangular frame 2, and enter the field to start spraying. The two spray bars 8 are divided into the left spray bar 8 that moves laterally along the transverse movable guide rail 7 and the right spray bar 8 that moves laterally along the transverse movable guide rail 7;

[0046] S3. The main body of the drone enters the uniform flight spray stage. In the uniform flight spray stage with the highest operation proportion, this stage is the stage with the highest flight speed of the main body of the drone, and the spray flow rate demand is also the largest. According to the agronomic requirements of plant protection operations, the setting of the maximum flight speed should be able to meet the corresponding flow rate less than 2Qmax. In this stage, the double spray boom nozzles spray simultaneously, and all the nozzles 9 of the two spray booms 8 spray. The two spray booms 8 slowly and synchronously move to the rear during the uniform flight spray. During the moving process, the ground speed of the spray boom 8 is slightly slower than the flight speed of the main body of the drone. The flight speed of the main body of the drone is slightly increased, and the increased flight speed is equal to the speed of the two spray booms 8 moving backward, so that the ground speed of the two spray booms 8 matches the spray flow rate of the straight uniform speed section. At a position far away before approaching the field head, before entering the deceleration flight spray stage, ensure that the two spray booms 8 have moved to the rear of the rectangular frame 2;

[0047] S4. The main body of the drone enters the deceleration flight spraying stage. After approaching the field head, as the speed decreases, the spray flow rate is synchronously reduced. When the flow rate of a single nozzle approaches Qmin, the nozzle 9 of the right spray boom 8 is closed, and the flow rate of the nozzle 9 of the left spray boom 8 is increased to twice the current flow rate, that is, a single nozzle replaces the double nozzle spray. As the speed further decreases, the spray flow rate is synchronously reduced. When the flow rate of a single nozzle 9 of the left spray boom 8 approaches Qmin again, the flow rate of the nozzle 9 no longer decreases at this time, so the left spray boom 8 moves forward relative to the body to compensate for the reduction in flight speed, so that the ground speed of the left spray boom 8 can still meet the required spray flow rate of not less than Qmin, maintaining a better atomization state, until the left spray boom 8 reaches the end of the field head, the spray is turned off, and the subsequent steps will switch to the right spray boom 8 to continue spraying. Therefore, regardless of whether spraying is performed, the double spray booms 8 move synchronously in the main heading during flight;

[0048] S5. The main body of the drone enters the arc flight spray stage. In this stage, the speed component of the rightward translation is increased. Therefore, it is necessary to move the left spray bar 8 to the left to compensate for the instantaneous spray area deviating from the main route caused by the rightward movement of the drone. The speed of the leftward movement is equal to the speed component of the rightward translation of the drone.

[0049] S6. When the drone body reaches the top of the U-shaped curve, the speed of the drone body in the main route direction is 0, but there is still a speed of translation to the right. At this time, all the nozzles 9 are in a spray-off state, the left spray bar 8 is in the left front, and the right spray bar 8 is in the right front. Ignoring the difference in the front-to-back position of the two, it can be considered that the positions of the two are symmetrical. Then the spraying starts from the right spray bar 8;

[0050] S7. The main body of the drone enters the arc flight spraying stage. In this stage, there is still a speed component of rightward translation, so the right spray bar 8 moves to the left to compensate for the rightward translation of the body. The speed of the leftward movement is equal to the speed component of the rightward translation of the body, and the two spray bars 8 will move closer to the middle;

[0051] S8. The main body of the drone enters the accelerated flight spraying stage. The right spray bar 8 reaches the starting point of the field and starts spraying. At this time, the drone has just started to accelerate and the speed of the drone is low. To ensure that the spray flow rate of a single nozzle 9 is not less than Qmin, the right spray bar 8 moves backward to compensate for the insufficient flight speed. When the speed is further increased, so that the spray flow rate of a single nozzle 9 reaches 2 times Qmin, the left spray bar 8 also starts spraying. At this time, the flow rates of all nozzles 9 on the two spray bars 8 become Qmin, and the flow rates increase synchronously with the increase of flight speed.

[0052] In S4 and S5, depending on the flight speed setting, the drone body does not necessarily enter the arc flight spray stage when it just enters the deceleration flight spray stage. Similarly, the drone body does not necessarily enter the deceleration flight spray stage when it just enters the arc flight spray stage. It may also enter at the same time, but the two stages will overlap in the later stage, and it will fly in an arc while decelerating when approaching the top of the U-shaped curve; in S7 and S8, depending on the flight speed setting, the drone body does not necessarily exit the arc flight spray stage when it just exits the acceleration flight spray stage. Similarly, the drone body does not necessarily exit the acceleration flight spray stage when it just exits the arc flight spray stage. It may also enter at the same time, but the two stages will overlap in the early stage, that is, it will accelerate and fly in an arc when approaching the top of the U-shaped curve;

[0053] S9. The main body of the drone enters the uniform flight spraying stage. When it first enters, the two spray rods 8 are behind the rectangular frame 2. At this stage, the two spray rods 8 slowly move to the front to cope with the work at the other end of the field. At the other end of the field, the spray rods 8 need to compensate for the flight speed from front to back, and the moving space needs to be reserved in advance. This goes back and forth. After spraying the liquid medicine, the task is completed;

[0054] S10. Before the main body of the UAV lands, the lateral movable guide rails 7 are all rotated 90° counterclockwise, and the rectangular frame 2 rises above the landing gear 1 to control the landing.

[0055] In the description of the operation process, uniform speed, deceleration, and acceleration refer to the velocity components in the direction of the main route, and the velocity components of the left and right translation are not included. The front, back, left, and right directions refer to the positions relative to the direction of the nose. When flying forward, they are consistent with the front, back, left, and right directions of the flight direction, and when flying backward, they are opposite to the front, back, left, and right directions of the flight direction. The actions of related mechanisms, the spray switch, and the flow control are all automatically controlled by the flight control system. The flight control system is a measurement and control system that controls the attitude, speed, and other flight-related aspects of the plant protection drone.

[0056] In the early design of the spraying route of plant protection drones, the path was Figure 6 (a) in square wave form, Figure 6 (b) The elongated rectangle and gray affect and Figure 1 The same, represents the spray bar and the instantaneous spray area it forms, Figure 6 (b) The two instantaneous spray areas at the top. The width of the spray area is the spray width, which is the spray when it reaches the field boundary. Once it reaches the boundary, the spray is turned off until the route is switched. As the drone flies, the instantaneous spray area is swept to form Figure 6 In the gray spray area shown in (c), the spray width of the round-trip route is perfectly spliced. As the drone gets closer to the field boundary, the speed becomes slower until it reaches zero. As the flow rate decreases simultaneously, the atomization performance of the nozzle deteriorates. Therefore, the earliest method adopted was for the drone to fly over the field boundary and then switch routes outside the field. In this way, when reaching the field boundary, the speed will not be zero, and the nozzle can still maintain a certain atomization performance. However, the drone is prone to collision with obstacles such as trees on the edge of the field, and the flight time is wasted. After the drone increases its load, the energy utilization efficiency must be further improved.

[0057] When the drone body rotates, Figure 7 As shown in the figure, as long as there is a rotation of the heading, the spray area formed by a round trip, the left front and the right front can never completely eliminate the missed spraying area, and the heavy spraying area can indeed be eliminated, but a new problem arises. In the rotational spraying, the speed of the outer side of the rotating route, that is, the speed of the left side of the drone, is greater than the speed of the inner side, that is, the speed of the right side of the drone. This is the linear velocity difference caused by the angular velocity. In order to ensure that the amount of pesticide received by the crop is constant, the amount of spray required on the left side is greater than that on the right side. Plant protection drones usually install 2-4 nozzles in the spray direction, which are combined to form a spray width of 3-8 meters, that is, each nozzle independently forms a spray width of about 2 meters. Although the flight control system can calculate the speed of each nozzle according to the current speed of the drone, steering angle, nozzle installation position and other motion and geometric relationships, so as to adjust the flow of a single nozzle in real time, so that the flow of the left nozzle is greater than that of the right nozzle, but within the spray width range of a single nozzle, that is, for a single nozzle, the flow on the left side also needs to be greater than the flow on the right side, but this is impossible to achieve. Therefore, it can only be roughly realized that the flow on the left side is greater than the flow on the right side, and then the uniform amount of pesticide received cannot be well satisfied.

[0058] like Figure 8 As shown, the present application is based on another flight mode used in the industry, that is, pure translational flight without rotation, and the spray area formed is as follows Figure 2As shown, dark gray represents repeated spraying. Through the device designed in this application, the spray bar 8 and the instantaneous spray area formed by it are separated from the aircraft body, and real-time compensation is performed according to the forward flight speed and lateral deviation, so that the center of the instantaneous spray area always coincides with the main route, so that the spray width splicing of the round-trip route formed is equivalent to the early square wave flight, such as Figure 8 At the moment shown in (a), the drone has not reached the field boundary. The left spray boom 8 has come in front of the drone to compensate for the slowdown in flight speed. At this time, the left spray boom 8 has reached the field boundary. After spraying at the boundary, the nozzle 9 is immediately closed. The drone continues to fly toward the field boundary according to the preset flight route, but because the nozzle 9 is already outside the field, the nozzle 9 remains closed until Figure 8 At the moment shown in (b), the UAV reaches the boundary of the field. At this time, the left spray boom 8 moves to the far left front. Whether the left spray boom 8 continues to move after the nozzle 9 is closed does not affect the subsequent actions. In order to save energy, it can also stop moving. The figure shows that it continues to move, while the right spray boom 8 always keeps synchronous movement with the left spray boom 8, only the left and right are opposite. Therefore, the right spray boom 8 is also symmetrically in the right front. The UAV continues to move to the new right route according to the preset flight route. The movements of the right spray boom 8 and its nozzle 9 are exactly opposite to those of the left spray boom 8 and its nozzle 9 when operating on the left route. When the spray boom 8 re-enters the boundary of the field, the right spray boom 8 and its nozzle 9 start spraying.

[0059] Further improvement, due to Figure 8 (a) From and to Figure 8 (c) Previous stages, such as Fig. 9 The spray at the two critical moments shown is already at the field boundary. During this stage, the nozzles 9 are all in a closed state. Therefore, the top of the preset route does not actually have to coincide with the field boundary. Fig.10 As shown, Fig.10 (a) is the critical moment for the spray head 9 of the left spray boom 8 to close the spray, Fig.10 (b) immediately following Fig.10 (a) At the next moment, the right spray bar 8 nozzle 9 opens the spray, so that the new route is shorter than the old route. Fig.10 In the operation mode, when the apex of the U-shaped curve is reached, the two spray booms 8 continue to spray, and the right spray boom 8 sprays immediately after the left spray boom 8.

[0060] In a further embodiment, in S2, the two spray rods 8 are close to each other, and the two close nozzles 9 on the two spray rods 8 can be approximately regarded as nozzles at the same point. The upper limit of the flow rate of a single nozzle 9 is reduced by half. The two nozzles 9 at the same point are regarded as a group. When the required spray flow rate is large, the two nozzles 9 can be opened at the same time; when the required spray flow rate is small, one of the nozzles 9 can be closed. The recommended maximum flow rate and minimum flow rate of a single nozzle 9 are Qmax and Qmin respectively. As the upper and lower limits of the flow control actually used, the maximum flow rate of a group of nozzles 9 is 2Qmax, and the minimum flow rate is Qmin, and Qmax≥2Qmin should be satisfied.

[0061] The preferred specific embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above specific embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical scheme of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A large-load plant protection drone spray device, comprising a drone body and a landing gear (1) fixed at the bottom of the drone body, characterized in that: A rectangular frame (2) is installed at the bottom of the landing gear (1) via a lifting device (3), and a guide rail slider mechanism is installed on two longitudinal borders of the rectangular frame (2) along the forward and backward travel direction of the drone body; The guide rail slider mechanism comprises two longitudinal movable guide rails (4) arranged on two longitudinal frames of the rectangular frame (2), the two longitudinal movable guide rails (4) are slidably connected with longitudinal movable sliders (5), the longitudinal movable sliders (5) are mounted with transverse movable guide rails (7) via rotating shafts (6), the transverse movable guide rails (7) are slidably matched with spray rods (8), and the spray rods (8) are provided with a plurality of spray heads (9).

2. A large-load plant protection drone spray device according to claim 1, characterized in that: A rotating motor is provided on one side of the longitudinal moving slider (5), the output end of the rotating motor is connected to a rotating shaft (6), the positions of the rotating shafts (6) on the two longitudinal moving sliders (5) are staggered, and an electromagnet is provided inside the other side of the longitudinal moving slider (5).

3. The automatic spraying method of a large-load plant protection drone spray device according to claim 1, characterized in that: The steps include: S1. Before the main body of the UAV takes off, the rectangular frame (2) is above the landing gear (1), and the two spray bars (8) are located below the two longitudinal borders of the rectangular frame (2); S2. After the main body of the UAV takes off, the rectangular frame (2) is lowered to the bottom of the landing gear (1) by the lifting device (3), and the transverse movable guide rails (7) are rotated 90° clockwise. At this time, the two spray bars (8) are arranged side by side and aligned at both ends, close together and located in the middle of the rectangular frame (2), and enter the field to start spraying. The two spray bars (8) are divided into a left spray bar (8) that moves laterally along the transverse movable guide rail (7) and a right spray bar (8) that moves laterally along the transverse movable guide rail (7); S3. The main body of the UAV enters the uniform flight spraying stage, all the nozzles (9) of the two spray bars (8) spray, and the two spray bars (8) slowly and synchronously move to the rear during the uniform flight spraying. During the moving process, the ground speed of the spray bars (8) is slightly slower than the flight speed of the main body of the UAV. The flight speed of the main body of the UAV is slightly increased, and the increased flight speed is equal to the speed of the two spray bars (8) moving backward, so that the ground speed of the two spray bars (8) matches the spray flow rate of the straight uniform speed section. At a relatively far position before approaching the field head, before entering the deceleration flight spraying stage, ensure that the two spray bars (8) have moved to the rearmost of the rectangular frame (2); S4. The main body of the UAV enters the deceleration flight spraying stage. When approaching the field, as the speed decreases, the spray flow rate is reduced synchronously. When the flow rate of a single nozzle approaches Qmin, the nozzle (9) of the right spray rod (8) is closed, and the flow rate of the nozzle (9) of the left spray rod (8) is increased to twice the current flow rate. As the speed further decreases, the spray flow rate is reduced synchronously. When the flow rate of a single nozzle (9) of the left spray rod (8) approaches Qmin again, the flow rate of the nozzle (9) no longer decreases. The left spray rod (8) moves forward relative to the body to compensate for the decrease in flight speed, so that the ground speed of the left spray rod (8) can still meet the required spray flow rate of not less than Qmin, maintaining a better atomization state until the left spray rod (8) reaches the end of the field, and the spray is turned off; S5. The main body of the drone enters the arc flight spraying stage. In this stage, the speed component of the rightward translation is increased. Therefore, it is necessary to move the left spray bar (8) to the left to compensate for the instantaneous spray area deviating from the main route caused by the rightward movement of the drone. The speed of the leftward movement is equal to the speed component of the rightward translation of the drone. S6. When the drone body reaches the top of the U-shaped curve, the speed of the drone body in the main route direction is 0, but there is still a speed of translation to the right. At this time, all the nozzles (9) are in the spray-off state, the left spray bar (8) is in the left front, and the right spray bar (8) is in the right front. Then the spray starts from the right spray bar (8); S7. The main body of the drone enters the arc flight spraying stage. In this stage, there is still a velocity component of rightward translation. Therefore, the right spray bar (8) moves to the left to compensate for the rightward translation of the drone. The speed of the leftward movement is equal to the speed component of the rightward translation of the drone. The two spray bars (8) will move closer to the middle. S8. The main body of the UAV enters the accelerated flight spraying stage. The right spray rod (8) reaches the starting point of the field and starts spraying. At this time, the acceleration has just begun and the body speed is low. In order to ensure that the spray flow rate of a single nozzle (9) is not less than Qmin, the right spray rod (8) moves backward to compensate for the insufficient flight speed. When the speed is further increased, so that the spray flow rate of a single nozzle (9) reaches 2 times Qmin, the left spray rod (8) also starts spraying. At this time, the flow rates of all nozzles (9) on the two spray rods (8) become Qmin, and the flow rates are increased synchronously with the increase of flight speed; S9. The main body of the UAV enters the uniform flight spraying stage. When it first enters the stage, the two spraying rods (8) are behind the rectangular frame (2). At this stage, the two spraying rods (8) slowly move to the front to cope with the work at the other end of the field. This process repeats until the spraying is completed and the task is completed. S10. Before the main body of the UAV lands, the lateral moving guide rails (7) are rotated 90° counterclockwise, and the rectangular frame (2) rises above the landing gear (1) to control the landing.

4. The automatic spraying method of a large-load plant protection drone spray device according to claim 3 is characterized by: In S2, the two spray bars (8) are close together, and the two nozzles (9) close to each other on the two spray bars (8) can be approximately considered as nozzles at the same point. The upper limit of the flow rate of a single nozzle (9) is reduced by half. The two nozzles (9) at the same point are regarded as a group. When the required spray flow rate is large, the two nozzles (9) can be turned on at the same time; when the required spray flow rate is small, one of the nozzles (9) can be turned off. The maximum flow rate and minimum flow rate recommended for a single nozzle (9) are Qmax and Qmin, respectively, which are used as the upper and lower limits of the flow control actually used. The maximum flow rate of a group of nozzles (9) is 2Qmax, and the minimum flow rate is Qmin, and Qmax≥2Qmin should be satisfied.

5. The automatic spraying method of a large-load plant protection drone spray device according to claim 3 is characterized by: In S4, regardless of whether spraying is performed or not, the two spray bars (8) move synchronously in the main heading during flight.

6. The automatic spraying method of a large-load plant protection drone spray device according to claim 3, characterized in that: In S5, regardless of whether spraying is performed or not, the right spray bar (8) follows the speed value of the left spray bar (8) and moves synchronously in the opposite direction to the right.

7. The automatic spraying method of a large-load plant protection drone spray device according to claim 3, characterized in that: In S4 and S5, depending on the different flight speed settings, the drone body does not necessarily enter the arc flight spray stage when it just enters the deceleration flight spray stage. Similarly, the drone body does not necessarily enter the deceleration flight spray stage when it just enters the arc flight spray stage. It may also enter at the same time, but the two stages will overlap in the later stage, and the drone will fly in an arc while decelerating when approaching the top of the U-shaped curve; in S7 and S8, depending on the different flight speed settings, the drone body does not necessarily exit the arc flight spray stage when it just exits the acceleration flight spray stage. Similarly, the drone body does not necessarily exit the acceleration flight spray stage when it just exits the arc flight spray stage. It may also enter at the same time, but the two stages will overlap in the early stage, that is, it will accelerate and fly in an arc when approaching the top of the U-shaped curve.

8. The automatic spraying method of a large-load plant protection drone spray device according to claim 1, characterized in that: In S9, the spray rod (8) at the other end of the field needs to compensate for the flight speed from front to back, and a moving space needs to be reserved in advance.

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