Agricultural UAV plant protection precision spraying system and spraying method

Abstract

The agricultural drone plant protection precision spraying system includes a helicopter frame, a medicine barrel, a flow meter, a nozzle, and a water pump. The medicine barrel, the flow meter, the nozzle, and the water pump are connected by pipelines. The flow meter and the water pump are connected to the spraying control system. A weighing sensor module is arranged on the helicopter frame. The medicine barrel is suspended or supported on the weighing sensor module, and the weighing sensor module is connected to the spraying control system. The agricultural drone plant protection precision spraying method includes the following method: determining the relationship between the flight speed and the flow rate according to the following formula: M=β11.112a / (vF), where M: the total amount of liquid sprayed per mu; F: the effective spray width; V: the flight speed; a=the flow rate given by the flow meter; β: the flow meter correction coefficient = the actual flow rate / a. The positive and beneficial technical effect of the present invention is that it can overcome the metering error of the flow meter to a certain extent.

Description

Technical Field

[0001] The present invention relates to the field of agricultural drone plant protection, in particular to a precision spraying system and a spraying method in agricultural drone plant protection, and belongs to the technical field of agricultural plant protection. Background Art

[0002] Agricultural drone plant protection is an efficient, precise, low-cost, high-efficiency, and environmentally friendly operation method. Its efficiency is more than 50 times that of manual labor. The amount of pesticide applied to achieve the same effect is less than 80% of the amount used in traditional plant protection operations. Due to the use of spray spraying, water consumption is reduced by more than 90%. The use of drone plant protection can greatly improve the efficiency of agricultural production operations, reduce the amount of pesticides, reduce pesticide pollution entering the soil and the atmosphere, and ensure food safety. Therefore, drone plant protection has made great progress in recent years. The current drone spraying system includes a medicine barrel, a water pump, a flow meter, and an atomizing nozzle. During the application of pesticides, the flight speed and flow rate are determined according to the following formula The relationship between the quantities is: M=11.112a / (vF), where M is the total amount of liquid sprayed per mu, in liters / mu; F is the effective spray width, in meters; V is the flight speed, in meters / second; a=flow rate, in liters / minute. The control system adjusts the flow rate according to the total amount of pesticide applied and the flight speed. The flow rate is obtained by transmitting the signal of the flow meter to the spraying control system, that is, it is given by the flow meter. Therefore, if the measurement of the flow meter deviates, the actual amount of pesticide sprayed will be erroneous, resulting in the inability to apply the pesticide according to the designed plan, resulting in over-application or under-application. The occurrence of these two situations will lead to lean production problems in agricultural plant protection.Moreover, this situation has existed for a long time in the current agricultural plant protection, mainly for the following two reasons: First, in agricultural plant protection, it is necessary to determine the type and concentration of pesticides used according to various factors such as the type of crops and the disaster situation, so the viscosity of the liquid medicine formed after preparation is also inconsistent. When the liquid flow meter is used to measure liquids of different viscosities, the signal data displayed and fed back for the same volume of liquid is different; second, the flow meters currently used in agricultural helicopters are basically Hall-type turbine flow meters. The turbine flow meter generally includes a housing assembly, an impeller assembly, a guide assembly, a Hall sensor assembly and an operation assembly. Its general structure is as shown in Chinese patent application No. 2016207519343. The impeller assembly includes an impeller, a through shaft hole is opened in the center of the impeller, a main shaft is passed through the shaft hole, and both ends of the main shaft are passed through the shaft sleeve. There is a rotation relationship between the impeller and the main shaft. When liquid flows through and impacts the impeller to rotate, the impeller drives the Hall sensor component to rotate. The larger the liquid flow rate, the faster the speed, and the smaller the liquid flow rate, the slower the speed. According to the impeller The speed can be calculated to get the flow rate of the liquid. Since many of the measured liquids are corrosive, it is not suitable to set bearings at both ends of the main shaft and between the main shaft and the shaft hole of the impeller. This type of flow meter has been found to have the following problems in practical use in agricultural plant protection: Since the liquid passing through the flow meter contains pesticide components, when the liquid flows through the flow meter, the liquid will enter the gap between the main shaft and the shaft hole. When the flow meter is not working, the liquid remaining in the gap between the main shaft and the shaft hole will evaporate, and the solid pesticide particles that evaporate the water will adhere to the main shaft and the shaft hole, and stay in the gap between the main shaft and the shaft hole. Long-term use may even cause blockage, which changes the resistance of the impeller when it rotates, increases the resistance of the impeller rotation, and causes the flow meter to distort. The larger the contact area between the main shaft and the shaft hole, the larger the space in the gap, the easier this phenomenon is to occur, and the greater the resistance generated after it occurs. After the flow meter distorts the measurement, the flow data transmitted to the spraying control system is also very inaccurate. In particular, the second situation is basically insurmountable in the current drone plant protection. The deviation caused by this flow meter does not conform to the direction and requirements of lean operations in drone plant protection. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned problems existing in the current UAV plant protection spraying system and to provide an agricultural UAV plant protection precision spraying system and a spraying method.

[0004] In order to achieve the purpose of the present invention, the following technical scheme is adopted: an agricultural UAV plant protection precision spraying system, including a helicopter frame, a medicine barrel, a flow meter, a nozzle, and a water pump. The medicine barrel, the flow meter, the nozzle, and the water pump are connected by pipelines. The flow meter and the water pump are connected to the spraying control system. A weighing sensor module is arranged on the helicopter frame, and the medicine barrel is suspended or supported on the weighing sensor module, and the weighing sensor module is connected to the spraying control system; further; a bracket is provided on the weighing sensor module, and a quick-connect structure is provided between the bracket and the medicine barrel; further; the quick-connect structure is: on the weighing sensor module It has a hanging bracket, at least two locating pins / locating pin holes are arranged on both sides of the hanging bracket in the up and down directions, and the medicine barrel is provided with locating pin holes / locating pins that match the number and position of the locating pins / locating pin holes on the hanging bracket, and the locating pins are inserted into the locating pin holes; further; there is a supporting bracket on the weighing sensor module, at least three vertical rods are arranged on the supporting bracket, and the three vertical rods are connected with a binding ring, and the shape of the binding ring is adapted to the peripheral contour of the medicine barrel; further; the flow meter is a Hall type liquid turbine flow meter, the flow meter includes an impeller assembly, and the impeller assembly includes an impeller, a circular blind hole is respectively opened at the center of both sides of the impeller, the axes of the two circular blind holes are located on the same straight line, a half shaft is respectively arranged in the two circular blind holes, a shaft sleeve is respectively arranged on both sides of the impeller, and the other ends of the two half shafts are respectively arranged in the shaft sleeves; further, one or two of the two blind holes are conical blind holes, and the end of the half shaft is a cone adapted to the conical blind hole.

[0005] The agricultural drone plant protection precision spraying method, using the above-mentioned spraying system, includes the following method: determining the relationship between the flight speed and the flow rate according to the following formula:

[0006] M=β11.112a / (vF), where M is the total amount of liquid sprayed per mu, in liters / mu; F is the effective spray width, in meters; V is the flight speed, in meters / second; a=the flow rate given by the flow meter, in liters / minute. The control system adjusts the total flow rate according to the total amount of spraying and the flight speed. β: the flow meter correction coefficient = actual flow rate / a. The actual flow rate is obtained as follows: during the spraying operation, the spraying control system collects the weight difference of the liquid in the medicine barrel at two adjacent time points through the weighing sensor module. The weight difference is divided by the specific gravity of the liquid to obtain the total volume of the liquid sprayed during the two adjacent time points. The total volume is divided by the specific gravity of the liquid. The actual flow rate within the two time points is obtained by dividing the actual flow rate by a, and the correction coefficient is obtained by dividing the actual flow rate by a. The correction coefficient is applied to M=β11.112a / (vF). Furthermore, during the spraying operation, the spraying control system continuously calculates the β value, and applies the latest β value obtained to the formula M=β11.112a / (vF). Furthermore, when the flight operation just starts spraying, the initial value of β is 1. Furthermore, before the flight operation starts, the flow meter is calibrated by spraying liquid, the spraying system is allowed to work, and the actual flow rate of the spraying system within a certain period of time is measured by a measuring tool, and compared with the total flow rate given by the flow meter, the initial flow meter correction coefficient β is obtained. 1 When the flight operation starts spraying, β is taken as β 1 The value of .

[0007] The positive and beneficial technical effect of the present invention is that: through the weighing sensor module, the weight change of the liquid medicine in the medicine barrel within a certain period of time (that is, the weight of the liquid medicine sprayed within the period of time) can be collected during the spraying operation, and the weight divided by the specific gravity of the liquid medicine can be obtained to obtain the total volume of the liquid medicine sprayed within the period of time, and the total volume divided by the duration of the time period (duration in minutes) can be obtained to obtain the actual flow rate (liters / minute) within the time period. When the flow meter has an error, the actual flow rate is not equal to the feedback signal flow rate of the flow meter. By comparing the actual flow rate with the feedback signal flow rate of the flow meter, a flow meter correction coefficient β can be obtained. The meter correction coefficient is applied to the formula M=11.112a / (vF) to obtain the latest spraying formula M=β11.112a / (vF), which can be used to correct the amount of sprayed liquid. By continuously updating β, it can ensure that the error between the actual amount of sprayed medicine and the required amount of sprayed medicine is minimized. The specific gravity of the liquid medicine can be calculated through the relationship between weight and volume during preparation. The specific gravity of the liquid medicine can also be obtained by filling a fixed-volume medicine barrel with liquid medicine and placing it on a weighing sensor. The specific gravity of various liquid medicines that may be used can also be measured in advance and stored in the database for use during spraying operations. The correction coefficient in the present invention can be obtained by turning on the spraying system when the helicopter is not flying, or by collecting the weight change of the medicine barrel at two time points in real time during the flight operation. The flow meter of the present invention uses a blind hole on the shaft hole of the impeller, which greatly reduces the contact area between the main shaft and the shaft hole, reduces the gap between the main shaft and the shaft hole, and reduces the resistance caused by the pesticide being retained in the gap. The metering error caused by this resistance can be reduced to a certain extent. Combined with the spraying method of the present invention, accurate spraying can be achieved. . BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram of this system.

[0009] Figure 2 It is a schematic diagram of the main structure using a restraining ring between the medicine barrel and the bracket.

[0010] Figure 3 It is a top view schematic diagram of the structure using a restraining ring between the medicine barrel and the bracket.

[0011] Figure 4 is a schematic diagram of the impeller assembly on the flow meter.

[0012] Figure 5 yes Figure 4 Schematic diagram of the impeller. DETAILED DESCRIPTION

[0013] In order to more fully explain the implementation of the present invention, the implementation examples of the present invention are provided. These implementation examples are merely elaborations of the present invention and do not limit the scope of the present invention. The flow meter and the water pump in the present invention can be integrated into a flow pump, and the flow pump is an equivalent replacement of the flow meter and the water pump in the system.

[0014] The present invention is further explained in detail in conjunction with the accompanying drawings, in which the marks are: 1: medicine barrel; 2: pipeline; 3: water pump; 4: flow meter; 5: nozzle; 6: spray control system; 7: weighing sensor module; 8: hanging bracket; 9: positioning pin; 10: supporting bracket; 11: vertical rod; 12: restraining ring; 13: impeller; 14: half shaft one; 15: half shaft two; 16: shaft sleeve one; 17: shaft sleeve two; 18: conical blind hole one; 19: conical blind hole two.

[0015] As shown in the attached drawings, the agricultural UAV plant protection precision spraying system includes a helicopter frame, a medicine barrel 1, a flow meter 4, and a nozzle 5. The medicine barrel, the flow meter, and the nozzle are connected through a pipeline 2. The flow meter is connected to a spraying control system 6. A weighing sensor module 7 is arranged on the helicopter frame, and the helicopter frame is not shown in the figure. The medicine barrel 1 is suspended or supported on the weighing sensor module, and the weighing sensor module is connected to the spraying control system 6; there is a bracket on the weighing sensor module, and there is a quick-connect structure between the bracket and the medicine barrel; the quick-connect structure in the figure is: on the weighing sensor module The sensor module is provided with a suspension bracket 8, and the entire weight of the suspension bracket 8 falls entirely on the weighing sensor module. At least two positioning pins / positioning pin holes are arranged on both sides of the suspension bracket in the up-and-down directions. Positioning pin holes / positioning pins that match the number and positions of the positioning pins / positioning pin holes on the suspension bracket are arranged on the medicine barrel, and the positioning pins are inserted into the positioning pin holes; the positioning pins / positioning pin holes are positioning pins or positioning pin holes. When there are positioning pin holes on the suspension bracket, there are positioning pins on the medicine barrel; when there are positioning pins on the suspension bracket, there are positioning pin holes on the medicine barrel. Figure 1 In the embodiment, there is a positioning pin on the medicine barrel, which can be integrated with the medicine barrel or can be a component fixedly connected to the medicine barrel. Figure 3 , Figure 4 The figure shows another connection structure in which the medicine barrel is located on the weighing sensor. The weighing sensor module has a support bracket 10, and at least three vertical rods are arranged on the support bracket. Figure 3Four vertical rods are shown in the figure, and the four vertical rods are connected with a binding ring, and the shape of the binding ring is adapted to the peripheral contour of the medicine barrel; the flow meter is a Hall type liquid turbine flow meter, and the flow meter includes an impeller assembly, and the impeller assembly includes an impeller 13, and a circular blind hole is respectively opened at the center of both sides of the impeller, and the axes of the two circular blind holes are located on the same straight line, and a half shaft is respectively arranged in the two circular blind holes, and the two half shafts are shown in 14 and 15, and one or both of the two blind holes are conical blind holes, and the end of the half shaft is a cone adapted to the conical blind hole; Figure 4 , Figure 5 The two blind holes shown in the figure are both conical blind holes, as shown in 18 and 19. The ends of the half shafts are cones adapted to the conical blind holes. A shaft sleeve is provided on both sides of the impeller, as shown in 16 and 17 in the figure. The other ends of the two half shafts are respectively provided in the shaft sleeves.

[0016] The agricultural drone plant protection precision spraying method, using the above-mentioned spraying system, includes the following method: determining the relationship between the flight speed and the flow rate according to the following formula:

[0017] M=β11.112a / (vF), where M is the total amount of liquid sprayed per mu, in liters / mu; F is the effective spray width, in meters; V is the flight speed, in meters / second; a=the flow rate given by the flow meter, in liters / minute. The control system adjusts the total flow rate according to the total amount of spraying and the flight speed. β: the flow meter correction coefficient = actual flow rate / a. The actual flow rate is obtained as follows: during the spraying operation, the spraying control system collects the weight difference of the liquid in the medicine barrel at two adjacent time points through the weighing sensor module. The weight difference is divided by the specific gravity of the liquid to obtain the total volume of the liquid sprayed during the two adjacent time points. The total volume is divided by the specific gravity of the liquid. The actual flow rate within the two time points is obtained by dividing the actual flow rate by a, and the correction coefficient is obtained by dividing the actual flow rate by a. The correction coefficient is applied to M=β11.112a / (vF). Furthermore, during the spraying operation, the spraying control system continuously calculates the β value, and applies the latest β value obtained to the formula M=β11.112a / (vF). Furthermore, when the flight operation just starts spraying, the initial value of β is 1. Furthermore, before the flight operation starts, the flow meter is calibrated by spraying liquid, the spraying system is allowed to work, and the actual flow rate of the spraying system within a certain period of time is measured by a measuring tool, and compared with the total flow rate given by the flow meter, the initial flow meter correction coefficient β is obtained. 1 When the flight operation starts spraying, β is taken as β 1 The value of .

[0018] In order to avoid the error of the weighing sensor in the case of vertical acceleration, the weight data of the medicine barrel is not collected when the helicopter has up and down acceleration, or the weight data at the time point with up and down acceleration is eliminated after collection, and the β value is best obtained under uniform spraying operation.

[0019] After describing the implementation mode of the present invention in detail, people familiar with the technology can clearly understand that various changes and modifications can be made without departing from the scope and spirit of the above-mentioned patent application. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention, and the present invention is not limited to the implementation mode of the examples given in the specification.

Claims

1. An agricultural drone plant protection precision spraying system includes a helicopter frame, a medicine barrel, a flow meter, a nozzle, and a water pump. The medicine barrel, the flow meter, the nozzle, and the water pump are connected through pipelines. The flow meter and the water pump are connected to a spraying control system. The system is characterized in that: A weighing sensor module is arranged on the helicopter frame, a medicine barrel is suspended or supported on the weighing sensor module, and the weighing sensor module is connected to a spraying control system; a bracket is arranged on the weighing sensor module, and a quick-connect structure is arranged between the bracket and the medicine barrel; a hanging bracket is arranged on the weighing sensor module, and at least two positioning pins / positioning pin holes in the upper and lower directions are arranged on both sides of the hanging bracket, and positioning pin holes / positioning pins that match the number and position of the positioning pins / positioning pin holes on the hanging bracket are arranged on the medicine barrel, and the positioning pins are inserted into the positioning pin holes; a supporting bracket is arranged on the weighing sensor module, and at least Three vertical rods, at least three of which are connected with a binding ring, the shape of which is adapted to the peripheral contour of the medicine barrel; the flow meter is a Hall-type liquid turbine flow meter, which includes an impeller assembly, and the impeller assembly includes an impeller, a circular blind hole is respectively opened at the center of both sides of the impeller, the axes of the two circular blind holes are located on the same straight line, a half shaft is respectively arranged in the two circular blind holes, a shaft sleeve is respectively arranged on both sides of the impeller, and the other ends of the two half shafts are respectively arranged in the shaft sleeves; one or both of the two blind holes are conical blind holes, and the end of the half shaft is located at a cone adapted to the conical blind hole; Use the following method: Determine the relationship between flight speed and flow rate according to the following formula: M=β11.112a / (vF), where M is the total amount of liquid sprayed per mu, in liters / mu; F is the effective spray width, in meters; V is the flight speed, in meters / second; a=the flow rate given by the flow meter, in liters / minute. The control system adjusts the total flow rate according to the total amount of spraying and the flight speed. β: the flow meter correction coefficient = actual flow rate / a. The actual flow rate is obtained by collecting the weight change of the liquid in the medicine barrel within a certain period of time during the spraying operation through the weighing sensor module, and dividing the weight by the specific gravity of the liquid to obtain the total volume of the liquid sprayed within the period of time. The total volume Divide by the length of the time period to get the actual flow rate in that time period. When the flow meter has an error, the actual flow rate is not equal to the feedback signal flow rate of the flow meter. The actual flow rate is compared with the feedback signal flow rate of the flow meter to get a flow meter correction coefficient β. Apply the flow meter correction coefficient to the formula M=β11.112a / (vF) to get the latest spraying formula M=β11.112a1 / (vF), where a1 is the current flow rate given by the flow meter. The amount of liquid sprayed is corrected. By continuously updating β, the error between the actual amount of sprayed medicine and the required amount of sprayed medicine can be minimized.

2. The agricultural drone plant protection precision spraying system according to claim 1 is characterized by: When the flight operation just starts spraying, the initial value of β is 1.

3. The agricultural drone plant protection precision spraying system according to claim 1 is characterized by: Before the flight operation begins, the flow meter is calibrated by spraying liquid, the spraying system is put into operation, and the actual flow of the spraying system in a certain period of time is measured by a measuring tool. The actual flow rate is compared with the total flow rate given by the flow meter to obtain the initial flow meter correction coefficient β1. When the flight operation starts spraying, β takes the value of β1.

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