A device for trapping and exterminating insects and a method for controlling agricultural pests using the same

Abstract

The present application relates to the field of agricultural equipment and plant protection, in particular to a pest control device for agricultural pests; comprising centrifugal fan, pest control chamber, flexible trapping tube, micro vacuum pump and electric push rod and other components; the system fills the polyhedral silica particles in the double-layer film closed interlayer of the flexible trapping tube, and combines with the air pumping of the micro vacuum pump to realize the flexible adjustment of the tube body under low negative pressure and the rigid locking under high negative pressure; the core is that the high-pressure gas discharged by the centrifugal fan is introduced into the reverse prestressed air chamber to generate expansion force to offset the collapse force, and the electric push rod is extended and retracted to change the orientation of the air inlet; the present application solves the problems of easy centripetal collapse and local wrinkle deformation of ordinary flexible hose, and realizes flexible searching in space.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural equipment and plant protection, in particular to a device for trapping and killing pests in agronomy and a method thereof. BACKGROUND

[0002] When in the current scene of farmland pest control, the device for trapping and killing pests by pneumatic suction will continuously generate a negative pressure flow field. Due to the complex turbulence in the field and the small airflow obstruction caused by the pests passing through the pipeline, transient aerodynamic load fluctuations often occur inside the device. In order to capture pests, the existing scheme generally uses rigid suction pipes or ordinary flexible hoses with simple structures, that is, the pipe opening is fixed by a directional support, and then a fan provides constant suction negative pressure for collection. Although this scheme has certain trapping ability in static airflow scenes such as greenhouses, the rigid pipeline cannot change the posture of the trapping opening to adapt to the flight trajectory of the pests, and the ordinary flexible hose has the risk of centripetal collapse and local wrinkling under the condition of sudden increase of local transient negative pressure, and lacks a real-time stiffness feedback compensation mechanism for fan load fluctuations, resulting in limited system trapping space, unstable deformation of the pipeline wall structure, transient response lag, and difficulty in supporting dynamic tracking and high-intensity stable suction in complex wind load environments in the wild.

[0003] Therefore, how to realize the flexible posture self-adaptation of the trapping pipe in the low negative pressure tracking stage, and the transient stiffness locking and anti-collapse maintenance in the high negative pressure capture stage, has become a technical problem to be solved. SUMMARY

[0004] To solve the above technical problems, the present application provides a device for trapping and killing pests in agronomy and a method thereof. Specifically, the technical scheme of the present application is as follows: A device for trapping and killing pests in agronomy, comprising: a base; a centrifugal fan fixedly connected to the top of the base, comprising a driving motor, a centrifugal fan shaft, a centrifugal fan air inlet end, and a centrifugal fan positive pressure air outlet end, wherein the driving motor is connected to the centrifugal fan shaft; a pest killing cavity matched with the centrifugal fan air inlet end, having a pest killing cavity air inlet end and a pest killing cavity air outlet end, wherein the pest killing cavity air outlet end is connected to the centrifugal fan air inlet end; a flexible trapping pipe corresponding to the pest killing cavity air inlet end, comprising a double-layer silica gel flexible film tube body, wherein one end of the tube body is provided with a flexible trapping pipe air inlet, an airtight interlayer is formed between the inner layer film and the outer layer film, polyhedral silica particles are filled in the airtight interlayer, and a reverse prestress air chamber is integrally formed on the periphery of the outer layer film in a spiral line direction, and the reverse prestress air chamber air inlet end is physically connected to the centrifugal fan positive pressure air outlet end; a micro vacuum pump fixedly arranged on the side surface of the base, wherein the micro vacuum pump air suction end is communicated to the airtight interlayer; An electric push rod, hinged to the front end of the base, includes a telescopic rod, the end of which is connected to the outer edge of the air inlet of the flexible trapping tube; The control unit connects to and controls the drive motor, miniature vacuum pump, and electric actuator.

[0005] In one embodiment, the insect-killing chamber is a cylindrical stainless steel tank, and an insect discharge port is provided at the bottom of the insect-killing chamber.

[0006] In one embodiment, the air inlet of the centrifugal fan is connected to the exhaust end of the insect-killing chamber via a flange, and the air inlet of the insect-killing chamber is fixedly connected to the exhaust end of the flexible trapping tube via a clamp.

[0007] In one embodiment, the air inlet of the reverse prestressed air chamber is connected to the positive pressure exhaust end of the centrifugal fan via a flow bypass valve and a high-pressure hose.

[0008] In one embodiment, the pumping end of the micro vacuum pump is connected to the sealed interlayer via a polyurethane gas pipe.

[0009] In one embodiment, the end of the electric push rod telescopic rod is connected to the outer edge of the air inlet of the flexible trap tube via a ball joint.

[0010] A method for controlling agricultural pests by attracting and killing insects, comprising: S1. The host starts the drive motor to drive the centrifugal fan to generate a basic suction flow field, continuously collects the stator current data of the drive motor, performs fast Fourier transform on the stator current data to extract the low frequency band amplitude as the low frequency drift characteristics of the environmental wind load, establishes the reference current spectrum, and extracts the main peak amplitude of the reference current spectrum as the fundamental frequency amplitude. S2. Control the electric push rod to extend and retract, pushing the air inlet of the flexible trapping tube to change the curvature and orientation to achieve flexible searching, and form a variable cross-section throat in the section of the flexible trapping tube near the air inlet. S3. Continuously collect the stator current data and perform a fast Fourier transform to separate the high-frequency pulses in the current signal. When the amplitude of the high-frequency pulse is less than or equal to a preset amplitude threshold, return to step S3 to continue collecting data. When the amplitude of the high-frequency pulse is greater than the amplitude threshold, it is confirmed that the pest has passed through the variable cross-section throat of the flexible trapping tube, causing airflow obstruction. S4. Calculate the difference between the extracted high-frequency pulse amplitude and the fundamental frequency amplitude of the reference current spectrum, and divide the difference by the fundamental frequency amplitude to obtain the transient blocking ratio; S5. Multiply the transient blockage ratio by a preset aerodynamic conversion factor to obtain the transient aerodynamic load change, and convert the transient aerodynamic load change into the peak value of the centripetal collapse force. Combine the pipe wall geometric compressive strength model to calculate the critical yield stress required to resist the peak value of the centripetal collapse force. S6. Divide the critical yield stress by the preset friction coefficient factor to convert it into the theoretical negative pressure value of the sealed interlayer, and control the host to increase the operating power of the micro vacuum pump according to the theoretical negative pressure value. S7. Control the micro vacuum pump to draw the sealed interlayer to the theoretical negative pressure value so that the polyhedral silica particles lock together to complete rigid locking. At the same time, the centrifugal fan discharges high-pressure gas into the reverse prestressed gas chamber to generate expansion force to counteract the collapse force. S8. When the high-frequency pulse of the stator current data does not disappear or the spectrum does not recover to the reference current spectrum, maintain the theoretical negative voltage value; when the high-frequency pulse of the stator current data disappears and the spectrum recovers to the reference current spectrum, control the operating power of the micro vacuum pump to reduce so that the flexible trapping tube returns to a compliant state. Repeat steps S1 to S8.

[0011] In one embodiment, step S1 is preceded by: S0. Control the micro vacuum pump to operate at low power, so that the flexible trapping tube remains compliant.

[0012] In one embodiment, in step S6, the control host generates a pulse width modulation signal based on the theoretical negative pressure value to control and increase the operating power of the micro vacuum pump.

[0013] The present invention has the following beneficial effects: 1. This invention achieves flexible and adjustable trapping tubes under low negative pressure and rigid locking under high negative pressure by setting a sealed interlayer between the two layers of flexible silicone films and filling it with polyhedral silica particles, combined with the gas extraction control of a micro vacuum pump. At the same time, the high-pressure gas discharged from the centrifugal fan is introduced into the reverse prestressed gas chamber to generate expansion force to counteract the collapse force, solving the problem of easy centripetal collapse and local wrinkling deformation of ordinary flexible hoses. With the extension and retraction of the electric push rod to change the orientation of the air inlet, flexible and flexible searching in space is achieved. 2. This invention utilizes a control host to continuously collect stator current data of the drive motor and perform fast Fourier transform to accurately identify high-frequency pulses caused by pest blockage and calculate the critical yield stress, which is then converted into the theoretical negative pressure value of the sealed interlayer. Based on this, the system generates a pulse width modulation signal to increase the power of the micro vacuum pump in real time, enabling the particulate media to quickly lock together and complete stiffness compensation. This overcomes the shortcomings of existing devices that lack real-time stiffness feedback and have sluggish transient response, and improves the system's dynamic tracking and stable suction capabilities under complex wind loads and transient aerodynamic load fluctuations. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 A three-dimensional structural schematic diagram of the insect-attracting and insect-killing device for agricultural pest control provided in an embodiment of the present invention; Figure 2 for Figure 1 A partial cross-sectional view of the connection between the central insect-killing chamber, the centrifugal fan, and the flexible trapping tube; Figure 3 for Figure 1 A partial structural schematic diagram of the flexible trapping tube and air circuit connection shown; Figure 4 for Figure 1 A schematic diagram of the cross-sectional structure of the flexible trapping tube shown; Figure 5 for Figure 1 A partially enlarged schematic diagram of the connection between the electric push rod and the flexible trapping tube; Figure 6 This is a flowchart of the method of the present invention.

[0015] In the diagram: 100, base; 200, centrifugal fan; 201, drive motor; 202, centrifugal fan main shaft; 203, centrifugal fan inlet; 204, centrifugal fan positive pressure exhaust; 300, insect-killing chamber; 301, insect-killing chamber exhaust; 302, insect-killing chamber inlet; 303, insect discharge port; 400, flexible trapping tube; 401, double-layer silicone flexible film constructing the tube body; 402, inner film; 403, outer film; 404, sealed interlayer; 405, polyhedral silica gel. Silicon-containing particle media; 406, Reverse prestressed gas chamber; 407, Inlet end of reverse prestressed gas chamber; 408, Exhaust end of flexible trapping tube; 409, Outer edge of air inlet of flexible trapping tube; 500, Miniature vacuum pump; 501, Pumping end of miniature vacuum pump; 600, Electric push rod; 601, End of telescopic rod of electric push rod; 700, Control host; 801, Flange; 802, Clamp; 803, Flow bypass valve; 804, High-pressure hose; 805, Polyurethane air pipe; 806, Ball joint. Detailed Implementation

[0016] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention. Example

[0017] An insect-attracting and insect-killing device for agricultural pest control includes: Please see Figure 1 , base 100; Centrifugal fan 200 is fixedly connected to the top of base 100 and includes drive motor 201, centrifugal fan main shaft 202, centrifugal fan inlet end 203 and centrifugal fan positive pressure exhaust end 204. The drive motor 201 is connected to centrifugal fan main shaft 202. The insect-killing chamber 300 is matched and set at the air inlet end 203 of the centrifugal fan, and has an air inlet end 302 and an air outlet end 301 of the insect-killing chamber, with the air outlet end 301 of the insect-killing chamber connected to the air inlet end 203 of the centrifugal fan. The flexible trapping tube 400 is correspondingly set at the air inlet end 302 of the insect killing chamber. It includes a tube body 401 constructed of double-layer silicone flexible film. One end of the tube body is provided with a flexible trapping tube air inlet. A sealed interlayer 404 is formed between the inner film 402 and the outer film 403. The sealed interlayer 404 is filled with polyhedral silica particle medium 405. A reverse prestressed air chamber 406 is integrally formed around the outer film 403 along the spiral direction. The air inlet end 407 of the reverse prestressed air chamber is physically connected to the positive pressure exhaust end 204 of the centrifugal fan. A miniature vacuum pump 500 is fixedly installed on the side of the base 100, and its miniature vacuum pump pumping end 501 is connected to the sealed interlayer 404. An electric push rod 600 is hinged to the front end of the base 100 and includes a telescopic rod, the end 601 of which is connected to the outer edge 409 of the air inlet of the flexible trapping tube. The control host 700 is connected to control the drive motor 201, the miniature vacuum pump 500, and the electric push rod 600 to work. An insect-attracting and insect-killing device is adopted, which is installed on a mobile platform or fixed support in the field; the base 100 is made of steel plate with a thickness of 4mm to 8mm welded into a frame, the length can be set to 600mm to 1200mm, and the width can be set to 350mm to 700mm, which is used to support the centrifugal fan 200, the insect-killing chamber 300, the micro vacuum pump 500, the electric push rod 600 and the control host 700; Centrifugal fan 200 is fixed to the top of base 100. Its drive motor 201 is directly coaxially connected to the main shaft of centrifugal fan 200. Direct connection means that there is no pulley, gearbox or coupling buffer between the output shaft of drive motor 201 and impeller shaft, so that the pneumatic load fluctuation in the trapping tube can be directly transmitted to the electromagnetic load of drive motor 201, and the control host 700 can perform inversion through stator current. Inversion refers to using the ratio between the electromagnetic torque of the drive motor 201 and the stator current, and by monitoring the amplitude and frequency changes of the stator current waveform, to reverse-engineer and calculate the transient fluctuations of the mechanical load and airflow pressure borne by the impeller end of the fan. The centrifugal fan 200 can be a high-speed fan with a rated power of 300W to 1500W and a rated speed of 2500rpm to 12000rpm to form a negative pressure suction flow field at the inlet of the flexible trapping tube 400; the insect-killing chamber 300 is set in front of the air inlet of the centrifugal fan 200, so that the pests are sucked in through the flexible trapping tube 400 and then enter the insect-killing chamber 300, and the centrifugal fan 200 completes the exhaust gas extraction; Please see Figure 4 The flexible trap tube 400 is constructed with a double-layer silicone flexible film. The thickness of the inner film 402 can be set to 0.6mm to 2mm, and the thickness of the outer film 403 can be set to 0.8mm to 2.5mm. A closed interlayer 404 with a thickness of 5mm to 25mm is formed between the two films. The sealed interlayer 404 is filled with polyhedral silica particles 405 with a particle size of 0.1 mm to 2 mm. The polyhedral structure is used to increase the number of contact edges between particles. When the sealed interlayer 404 is evacuated to a negative pressure by the micro vacuum pump 500, the normal contact force between particles is increased, and the particle accumulation changes from a flowable state to a high-friction locked state, so that the flexible trapping tube 400 switches from a compliant state to a high-rigidity state in a short time. The flexible trapping tube 400 has an integrally formed reverse prestressed air chamber 406 around its outer membrane 403 along a spiral direction. The reverse prestressed air chamber 406 is a hollow and closed protruding tubular bladder attached to the outer surface of the outer membrane 403. The spiral direction allows the positive pressure to be distributed along the circumference and axial direction of the tube, which can generate radial outward support force and suppress local wrinkling. The air inlet of the reverse prestressed air chamber 406 is connected to the positive pressure exhaust end of the centrifugal fan 200, so that the high-pressure gas discharged by the centrifugal fan 200 can be directly used as the external support energy source without the need for an additional independent air source. A miniature vacuum pump 500 is installed on the side of the base 100, and its pumping end is connected to the sealed jacket 404. It is used to adjust the negative pressure value of the jacket according to the instructions of the control host 700. Specifically, the miniature vacuum pump 500 can be a DC oil-free diaphragm vacuum pump with a rated flow rate of 10L / min to 50L / min and an ultimate negative pressure of -50kPa to -90kPa. This parameter configuration can ensure that the sealed jacket 404 is pumped to the required rigid locking state within a response time of 1s to 3s, meeting the requirement of rapid stiffening under transient aerodynamic load changes. The electric push rod 600 is hinged to the front end of the base 100. The end of the telescopic rod is connected to the outer edge of the air inlet of the flexible trapping tube 400. It is used to change the curvature and orientation of the trapping opening to adapt to the flight trajectory of pests under turbulent conditions in the field. Due to the pressure difference between the external atmospheric pressure and the internal negative pressure, as well as the traction of the electric push rod 600, the section of the flexible trapping tube 400 near the air inlet forms a contracted flow section with a smaller cross-sectional area than other non-traction sections of the tube. This section is defined as the variable cross-section throat. The control host 700 is connected to the drive motor 201, the miniature vacuum pump 500, and the electric push rod 600. The control host 700 can be an industrial control board with an analog-to-digital conversion unit and a PWM output unit. It continuously collects the stator current data of the drive motor 201, calculates the transient aerodynamic load changes, and adjusts the power of the miniature vacuum pump 500 and the attitude of the electric push rod 600 accordingly. The device achieves flexible and adjustable trapping port under low negative pressure seeking state and anti-collapse retention under high negative pressure trapping state by combining the particle locking stiffening structure of the flexible trapping tube 400 with the homogeneous air pressure counter-pressure structure of the reverse prestressed air chamber 406. To ensure clear data flow and interaction between the control host 700 and each actuator, the control host 700 communicates with the drive motor 201, the miniature vacuum pump 500, and the electric actuator 600 using a standard industrial bus. Specifically, the control host 700 interacts with the underlying drivers of each component in real time via an RS-485 interface and based on the Modbus RTU protocol, exchanging commands and status data frames. For continuous acquisition of the stator current of the drive motor 201, the control host 700 adopts a built-in 16-bit high-speed analog-to-digital converter module. The sampled data is transferred in real time to the static random access memory of the main control chip through the direct memory access channel for caching, and is then called by the subsequent fast Fourier transform algorithm. This explicit hardware configuration and structured data flow path ensure the real-time recognition of high-frequency stator current pulses and the system's response speed to transient aerodynamic load fluctuations.

[0018] The insect-killing chamber 300 is a cylindrical stainless steel tank, and an insect discharge port 303 is provided at the bottom of the insect-killing chamber 300. The insecticidal chamber 300 uses a cylindrical stainless steel tank. The inner diameter of the cylinder can be set from 120mm to 300mm, the height can be set from 250mm to 800mm, and the wall thickness can be set from 0.8mm to 2mm. Stainless steel is used because the insecticidal chamber 300 is in long-term contact with insect debris, humid air, and farmland dust, requiring the material to have both corrosion resistance, washability, and structural strength. The cylindrical structure helps to reduce the sharp angle separation of airflow after entering the cavity, and avoids the formation of dead corners for insect accumulation that cause local airflow stagnation in the cavity; the bottom of the insect killing cavity 300 is provided with an insect discharge port 303, which can adopt a circular opening structure with a diameter of 30mm to 100mm, and is equipped with any of the following sealing components: screw cap, gate valve or flap door. After the pests are drawn into the insect-killing chamber 300, the flow rate decreases because the cross-sectional area of ​​the chamber is larger than the cross-sectional area of ​​the air inlet of the flexible trapping tube 400. Under the deceleration of gravity and airflow, the pests sink to the bottom of the chamber, making it easy to periodically discharge them from the discharge port 303. With this structure, the insect-killing chamber 300 not only serves the function of collecting pests, but also acts as a buffer volume between the centrifugal fan 200 and the flexible trapping tube 400, reducing the impact of the direct return of transient load peaks on the local deformation of the upstream flexible trapping tube 400. The insecticidal effect in the insecticidal chamber 300 does not rely solely on static settling, but rather on the high-speed transport, sudden pressure changes, and collisions with the chamber wall or subsequent components that pests experience when entering the insecticidal chamber 300 and the area adjacent to the air inlet of the centrifugal fan 200. The technical logic is as follows: pests are first accelerated and sucked into the vicinity of the throat of the flexible trapping tube 400. After entering the insect-killing chamber 300 with a suddenly increased cross-sectional area, they are decelerated and their trajectory is deflected. Some of the insects collide with the chamber wall, the bottom of the chamber, or the insects that have already settled. The insects that do not settle immediately continue to approach the air intake of the centrifugal fan 200 with the airflow. Under the influence of the impeller-induced negative pressure and local vortex, they are impacted again. Since small agricultural pests have limited impact resistance on their body surface and wings, the repeated collisions, shearing and pressure differential impacts mentioned above will cause them to become inactive, injured or unable to fly out of the cavity. Therefore, the cavity works in conjunction with the downstream centrifugal fan 200 to kill or inactivate them after they are attracted in. The following objective technical effects can be achieved by adopting this structure: the insect-killing chamber 300 provides a deceleration collision space after the abrupt change in cross section, and is connected to the air intake disturbance area of ​​the subsequent centrifugal fan 200. Therefore, after entering, the pests are not only collected, but also gradually inactivated during the transportation process, and finally settle and are discharged from the insect discharge port 303.

[0019] Please see Figure 2 The air inlet of the centrifugal fan 200 is connected to the exhaust end of the insect-killing chamber 300 through flange 801, and the air inlet of the insect-killing chamber 300 is fixedly connected to the exhaust end of the flexible trapping tube 400 through clamp 802. The centrifugal fan 200 is connected to the air inlet end and the insect-killing chamber 300 is connected by a flange 801. The flange 801 can be a metal flat welding flange 801 or a reinforcing ring flange 801. A wear-resistant rubber sealing gasket is sandwiched between the flanges 801. The number of bolts can be set to 4 to 12 to ensure that the joint meets the required air tightness requirements when the centrifugal fan 200 is running. The purpose of using flange 801 connection is to ensure high axial concentricity and airtightness between centrifugal fan 200 and insect killing chamber 300, so that the load change on the impeller side can stably correspond to the aerodynamic disturbance in the pipeline; the air inlet end of insect killing chamber 300 and the exhaust end of flexible trapping tube 400 are fixedly connected by clamp 802, which can be stainless steel quick-release clamp 802 or worm gear type hose clamp; Since the flexible trapping tube 400 needs to bend, deflect and partially shrink under the action of the electric push rod 600, if both ends are rigidly connected, stress concentration is likely to form at the joint and damage the membrane tube. Using clamp 802 connection can allow a certain assembly deviation and small angle change while ensuring airtightness, which is conducive to the dynamic attitude adjustment of the flexible trapping tube 400. The combination of flange 801 connection and clamp 802 connection allows the upstream rigid assembly and downstream flexible assembly to match their mechanical properties in terms of connection method, which maintains the sealing of the high negative pressure system and also takes into account the deformation requirements of the flexible trapping tube 400.

[0020] like Figure 3 As shown, the air inlet of the reverse prestressed air chamber 406 is connected to the positive pressure exhaust end of the centrifugal fan 200 through a flow bypass valve 803 and a high-pressure hose 804. The air inlet of the reverse prestressed gas chamber 406 is connected to the positive pressure exhaust end of the centrifugal fan 200 via a bypass valve 803 and a high-pressure hose 804. The high-pressure hose 804 can be a fiber-reinforced hose with a pressure resistance of 0.3MPa to 1.5MPa and an inner diameter of 4mm to 20mm. The bypass valve 803 can be a manual needle valve, an electromagnetic proportional valve, or a spring-loaded one-way flow restrictor valve, used to regulate the gas flow rate and pressure entering the reverse prestressed gas chamber 406. The reverse prestressed gas chamber 406 is located around the outer membrane 403 of the flexible trapping tube 400. When the centrifugal fan 200 works and forms a negative pressure suction in the pipe, a positive pressure airflow is simultaneously formed at its exhaust end, which is diverted into the reverse prestressed gas chamber 406 through the diversion bypass valve 803. Since the positive pressure gas and the suction load of the centrifugal fan 200 come from the same pneumatic source, its pressure change is correlated with the internal negative pressure change, and it can provide radial support force simultaneously when the flexible trapping tube 400 is subjected to a centripetal collapse force exceeding the critical value of the tube wall structure. The bypass valve 803 is set to limit the amount of gas entering the reverse prestressed air chamber 406, so as to avoid excessive radial expansion of the flexible trapping tube 400 due to excessive air chamber pressure, which would affect the stability of the trapping port cross-sectional area. To ensure the matching of external support pressure and internal load, the adjustment range of the diversion bypass valve 803 can be set to maintain the positive pressure entering the reverse prestressed air chamber 406 in the range of 5 kPa to 25 kPa, thereby providing a radial external support force sufficient to counteract the centripetal collapse force without causing excessive expansion of the outer membrane 403. This connection structure utilizes the accompanying pressure at the exhaust end of the centrifugal fan 200 to form an external support pressure opposite to the internal negative pressure without adding an independent air supply device.

[0021] The pumping end of the miniature vacuum pump 500 is connected to the sealed interlayer 404 via a polyurethane gas pipe 805. The pumping end of the miniature vacuum pump 500 is connected to the sealed interlayer 404 of the flexible trapping tube 400 via a polyurethane tube 805. The polyurethane tube 805 can be a flexible negative pressure resistant tube with an inner diameter of 2mm to 10mm and a wall thickness of 1mm to 3mm. Its material has the bending resistance to meet the turning angle of the electric push rod 600 and the gas sealing degree to meet the preset negative pressure maintenance requirements. It is suitable for moving with the device and withstanding repeated pulsating pumping. The tube and the sealed interlayer 404 can be heat-sealed onto the outer film 403 through a connector seat. The connector seat is made of metal or engineering plastic and has a clamping ring on its inner side to increase the contact area, so as to reduce the risk of film tearing near the interlayer interface. When the miniature vacuum pump 500 is working, the polyurethane air tube 805 extracts the air from the interlayer. The volume of the sealed interlayer 404 is compressed under the action of external atmospheric pressure, which increases the contact pressure between the polyhedral silica particles and the frictional resistance between the particles. Macroscopically, this is manifested as an increase in the bending stiffness and resistance to radial instability of the flexible trapping tube 400. Using polyurethane air tube 805 instead of rigid metal tube is beneficial for adapting to the relative displacement generated when the electric push rod 600 drives the trap tube to turn, and avoids additional constraints on the attitude of the flexible trap tube 400 due to excessive rigidity of the pipeline.

[0022] like Figure 5As shown, the end of the telescopic rod of the electric push rod 600 is connected to the outer edge of the air inlet of the flexible trap tube 400 via a ball joint 806; The telescopic rod end of the electric push rod 600 is connected to the outer edge of the air inlet of the flexible trapping tube 400 via a ball joint 806; the diameter of the ball head of the ball joint 806 can be set to 8mm to 25mm, and the allowable bidirectional swing angle can be set to 15° to 45°; an annular reinforcing ring can be provided on the outer edge of the air inlet of the flexible trapping tube 400, and the ball joint 806 is installed at the reinforcing ear plate on the reinforcing ring to disperse the force of the electric push rod 600 and prevent local tearing of the film; The electric actuator 600 can be a DC electric actuator with a stroke of 50mm to 300mm and a thrust of 100N to 1500N. Its tail is hinged to the front end of the base 100. When it extends or retracts, it can push the trap opening to produce lifting, lowering, deflection and local bending. The function of the ball joint 806 connection is to allow for angle self-adaptation between the actuator and the trap opening, avoiding excessive lateral force on the actuator caused by a pure hinge single degree of freedom connection. The flexible trapping tube 400 remains compliant under the low-power micro vacuum pump 500, and can change the orientation and curvature of the air inlet under the drive of the electric push rod 600 to expand the effective capture range. When the micro vacuum pump 500 increases its power to lock the sandwiched particles, the ball joint 806 can still withstand the spatial angle changes required to maintain the attitude of the trapping port, without causing a sudden change in the position of the tube opening due to rigid constraints. This connection relationship ensures the ability to continuously adjust the attitude during the search process. Example

[0023] Please see Figure 6 A method for controlling agricultural pests by attracting and killing insects, comprising: S1. The control host 700 starts the drive motor 201 to drive the centrifugal fan 200 to generate a basic suction flow field. It continuously collects the stator current data of the drive motor 201, performs fast Fourier transform on the stator current data to extract the low-frequency band amplitude as the low-frequency drift characteristics of the environmental wind load, establishes the reference current spectrum, and extracts the main peak amplitude of the reference current spectrum as the fundamental frequency amplitude. S2. Control the electric push rod 600 to extend and retract, pushing the air inlet of the flexible trapping tube 400 to change the curvature and orientation to achieve flexible searching, and forming a variable cross-section throat in the section of the flexible trapping tube 400 near the air inlet. S3. Continuously collect stator current data and perform fast Fourier transform to separate high-frequency pulses in the current signal. When the amplitude of the high-frequency pulse is less than or equal to the preset amplitude threshold, return to step S3 to continue collecting data. When the amplitude of the high-frequency pulse is greater than the amplitude threshold, it is confirmed that the pest has passed through the throat of the flexible trapping tube with a 400-degree cross-section, causing airflow obstruction. S4. Calculate the difference between the extracted high-frequency pulse amplitude and the fundamental frequency amplitude of the reference current spectrum, and divide the difference by the fundamental frequency amplitude to obtain the transient blocking ratio; S5. Multiply the transient blockage ratio by the preset aerodynamic conversion factor to obtain the transient aerodynamic load change, and convert the transient aerodynamic load change into the peak value of the centripetal collapse force. Combine the pipe wall geometric pressure resistance model to calculate the critical yield stress required to resist the peak value of the centripetal collapse force. S6. Divide the critical yield stress by the preset friction coefficient factor to convert it into the theoretical negative pressure value of the sealed interlayer 404. The control host 700 increases the operating power of the micro vacuum pump 500 according to the theoretical negative pressure value. S7. Control the micro vacuum pump 500 to draw the sealed interlayer 404 to the theoretical negative pressure value so that the polyhedral silica particle medium 405 locks each other to complete rigid locking. At the same time, the centrifugal fan 200 discharges high-pressure gas and presses it into the reverse prestressed gas chamber 406 to generate expansion force to counteract the collapse force. S8. When the high-frequency pulse of the stator current data does not disappear or the spectrum does not recover to the reference current spectrum, maintain the theoretical negative voltage value; when the high-frequency pulse of the stator current data disappears and the spectrum recovers to the reference current spectrum, control the micro vacuum pump 500 to reduce its operating power so that the flexible trap tube 400 returns to a compliant state; repeat steps S1 to S8. The control method is applied in the aforementioned device. The control host 700 adopts a controller with high-speed sampling function. The current sampling frequency can be set from 5kHz to 200kHz to ensure that the load disturbance frequency component in the stator current can be effectively separated. In S1, the control host 700 starts the drive motor 201 to drive the centrifugal fan 200 to run, forming a basic suction flow field. The drive motor 201 can operate in the range of 40% to 80% of its rated speed to establish a stable background flow. The control host 700 continuously collects the three-phase or single-phase stator current data of the drive motor 201, performs a fast Fourier transform on the current sequence within a predetermined time window, and sets the low-frequency band to 1Hz to 200Hz, extracting its amplitude as the low-frequency drift characteristics of the environmental wind load. The reason for extracting the low-frequency band is that the wind load changes caused by natural wind in the field are mainly characterized by slow drift, and the impact on the motor load is concentrated in the low-frequency region; the control host 700 forms a reference current spectrum based on this to distinguish the instantaneous high-frequency disturbances caused by subsequent pest invasion. In S2, the control host 700 outputs a displacement command to the electric push rod 600, causing the air inlet of the flexible trapping tube 400 to swing with a set amplitude in the horizontal and vertical directions. The swing angle can be set to 5° to 40°, and the swing period can be set to 0.5s to 8s, so as to change the relative flow direction of the trapping port and the local throat shape, realize flexible searching, and form a variable cross-section throat in the section of the flexible trapping tube 400 near the air inlet. In S3, the control host 700 continues to perform fast Fourier transform on the stator current data to separate high-frequency pulses from the spectrum; high-frequency pulses can be defined as discrete peaks or short-time broadband energy surges that are higher than the upper limit of the reference low-frequency band, and the frequency range can be set from 200Hz to 20kHz. When the amplitude of the high-frequency pulse is less than or equal to the preset amplitude threshold, it is assumed that there is only environmental disturbance or inherent system noise, and the control host 700 continues to collect data; when the amplitude of the high-frequency pulse is greater than the amplitude threshold, it is confirmed that the pest has passed through the variable cross-section throat of the flexible trapping tube 400. The physical basis lies in the fact that when pests pass through their throats, the cross-sectional area decreases instantaneously or the local flow around the insects changes abruptly, causing a short-term fluctuation in the suction load of the centrifugal fan 200 impeller. This fluctuation is reflected as a high-frequency transient disturbance signal in the stator current along the mechanical and electromagnetic coupling path of the drive motor 201. In S4, the control host 700 calculates the difference between the extracted high-frequency pulse amplitude and the fundamental frequency amplitude of the reference current spectrum, and divides the difference by the fundamental frequency amplitude to obtain the transient blocking ratio. The calculation formula is as follows:

[0024] in, Transient blocking ratio, This refers to the amplitude of a high-frequency pulse. This is the fundamental frequency amplitude; this ratio reflects the degree of airflow channel blockage caused by pest invasion. In S5, the control host 700 multiplies the transient blockage ratio by a preset aerodynamic conversion factor to obtain the transient aerodynamic load change. The aerodynamic conversion factor can be determined based on the minimum cross-sectional area of ​​the throat of the flexible trapping tube 400, the flow characteristic curve of the centrifugal fan 200, and the experimental calibration results. The value can be set to 0.1 to 50N. The change is equivalent to the peak value of the centripetal collapse force at the throat. The centripetal collapse force refers to the radial pressure difference formed by the atmospheric pressure outside the pipe and the center inside the pipe, which attempts to crush the pipe wall due to the sudden increase in the flow velocity inside the pipe and the sudden drop in local static pressure. Then, combined with the effective force-bearing area and structural geometry of the trapping pipe wall, the critical yield stress required to resist the collapse is calculated. In S6, the control host 700 divides the critical yield stress by the friction coefficient factor to obtain the theoretical negative pressure value required for the sealed interlayer 404. The friction coefficient factor reflects the influence of the particle size distribution, contact area and surface roughness of the polyhedral silica particle medium 405 on the particle locking ability, and can be obtained through experimental pre-calibration. The control host 700 increases the operating power of the micro vacuum pump 500 according to the theoretical negative pressure value, so that the interlayer negative pressure rises within a predetermined time. In S7, the micro vacuum pump 500 draws the sealed jacket 404 to the theoretical negative pressure value, locking the particulate media together, and the flexible trapping tube 400 changes from a compliant state to a high-rigidity state; at the same time, the centrifugal fan 200 discharges high-pressure gas through a bypass path into the reverse prestressed air chamber 406, and the air chamber applies an outward expansion force to the tube body, counteracting the radial inward contraction tendency caused by the internal negative pressure; the two effects work together to improve the structural stability of the trapping tube under high suction load; In S8, the control host 700 continuously monitors whether the high-frequency pulse disappears and whether the spectrum recovers to the reference current spectrum. If the high-frequency pulse does not disappear or the spectrum has not recovered, it indicates that the pest is still near the throat or the airflow has not stabilized. The control host 700 maintains the theoretical negative pressure value. When the high-frequency pulse disappears and the spectrum returns to the reference current spectrum, it indicates that the pest has left its throat and entered the insect-killing chamber 300. The control host 700 reduces the operating power of the micro vacuum pump 500, the negative pressure in the interlayer decreases, the particulate medium returns to a flowable state, and the flexible trapping tube 400 regains its shape-adjustable capability. By cyclically executing S1 to S8, the device can repeatedly complete background calibration, posture adjustment, intrusion identification, stiffness compensation, and recovery during continuous trapping. To ensure the feasibility of the above parameters and judgment conditions, the control host 700 processes the data in S1 to S8 in the following order: read the original sampled value of the stator current of the drive motor 201, and perform DC component removal and amplitude normalization processing in each time window; DC component removal refers to removing power supply bias and zero drift of sampling circuit. Amplitude normalization refers to converting the current value in the current time window into a proportional value relative to the no-load rated current of the drive motor, so that the spectrum results under different fan operating conditions can be compared. The processed time window data is subjected to a fast Fourier transform to obtain a spectral amplitude table arranged by frequency; the low-frequency part is sent to the reference current spectrum establishment module, and the high-frequency part is sent to the pest invasion identification module. The output of the reference current spectrum is a set of reference spectral amplitudes under the current wind speed, current attitude, and current wind turbine speed. This result also serves as the reference input for amplitude threshold setting in S3, fundamental frequency amplitude reading in S4, and spectrum recovery judgment in S8. The amplitude threshold is not a fixed isolated value, but a discrimination threshold used to distinguish between environmental noise and pest intrusion events. Its physical meaning is as follows: when the high-frequency amplitude is caused only by bearing vibration, impeller inherent pulsation, electromagnetic harmonics or random wind disturbance in the field, the amplitude should fall within the background fluctuation range; when pests cause short-term blockage through the throat, the high-frequency amplitude will be significantly higher than the background fluctuation range. The amplitude threshold can be determined by combining the device no-load test and the simulated blockage test. Specifically, it can be done as follows: record no less than 30 sets of high-frequency amplitude samples in a pest-free environment, and take their average value and upper limit of fluctuation; then pass standard samples of different sizes through the throat for a short time and record the corresponding high-frequency amplitude; set the boundary value between the two sets of data that can stably distinguish noise and blockage events as the amplitude threshold. The amplitude threshold can be set to 1.2 to 3 times the average of the reference high-frequency noise, or to 0.5% to 8% of the normalized amplitude of the rated current. The role of this threshold in the control process is to serve as the event triggering condition for S3. Only when this threshold is exceeded will the control host 700 enter the subsequent stiffness compensation calculation to avoid frequent false responses to ordinary environmental disturbances. The fundamental frequency amplitude of the reference current spectrum refers to the lowest peak amplitude in the spectrum corresponding to the fluctuations of the dominant aerodynamic load under the current basic suction flow field and current seeking attitude; its logical function is to provide a comparison benchmark that is updated in real time with changes in environmental wind load, rather than using a fixed constant. After continuously acquiring low-frequency lines of multiple time windows in S1, the control host 700 first removes abnormal peaks, and then performs a moving average on the amplitude of the remaining main peak to obtain the fundamental frequency amplitude. This fundamental frequency amplitude flows to S4 as a denominator input, which is used to convert the amplitude surge caused by pest invasion into the relative degree of blockage, so that the judgment results under different wind speeds and different motor speeds remain consistent. The physical meaning of the aerodynamic conversion factor is the bridging factor that converts the relative disturbance in the current spectrum into the equivalent aerodynamic load change on the flexible trap tube 400. Its source is not given by theoretical assumptions alone, but is determined by the fan performance curve, the cross-sectional area of ​​the trap tube throat, and calibration tests. During calibration, multiple sets of samples with known blocking areas can be sequentially set at the throat of the flexible trapping tube 400, and the corresponding high-frequency amplitude changes and fan intake load changes can be recorded to establish a table of correspondence between the blocking ratio and the load increment; when the control host 700 is running, it can look up the corresponding coefficients according to the current fan speed range by looking up the table or interpolating. The role of this coefficient in the control logic is to transform the dimensionless transient blocking ratio obtained from S4 into a mechanical quantity that can be connected with the structural collapse resistance requirements, so that S5 can continue to calculate the critical yield stress. The critical yield stress is the minimum resistance to deformation required to prevent the throat of the flexible trap tube 400 from continuing to shrink, wrinkle, or become unstable. The control host 700 obtains this index according to the following logic: first, the transient aerodynamic load change is equivalently distributed to the disturbed area of ​​the throat to obtain the additional load per unit area of ​​the area. Combining the current trapping orifice curvature, throat minimum diameter, and membrane interlayer thickness, it is determined whether the additional load has approached the local instability zone of the pipe wall; if it is close to or has entered the instability zone, the minimum compressive and shear strength required to maintain the flow passage section of the throat is defined as the critical yield stress; the result is then directly transmitted to S6 as the upstream input for calculating the theoretical negative pressure value. The friction coefficient factor is an empirical parameter that establishes a correspondence between the internal frictional locking capability of particulate media and the required theoretical negative pressure value. Its physical meaning is: under the same critical yield stress requirement, the more angular the particles, the rougher the surface, and the more favorable the particle gradation for interlocking, the lower the required negative pressure value for locking; conversely, the higher the value. This factor can be pre-calibrated through separate sandwich sample tests. During the test, the negative pressure is gradually increased and the bending stiffness or radial compression stiffness of the sample is measured to obtain the correspondence between the negative pressure and the macroscopic stiffness. Then, the friction coefficient factor database is formed by reverse calculation. The control host 700 calls the corresponding factor in S6 according to the type of particulate medium currently used and converts the critical yield stress into the theoretical negative pressure value. After this setting, the calculation object, source and control purpose in S6 are clearly corresponding. The spectrum recovery to the reference current spectrum means that after the high-frequency pulse disappears, the main frequency amplitude in the current time window returns to the allowable deviation band of the reference spectrum; the allowable deviation band can be set to ±5% to 15% of the reference main peak amplitude, or the average difference of three adjacent time windows does not exceed the preset stability threshold. Its physical meaning is that the airflow has returned to an unobstructed or nearly unobstructed state; the decision-making role of this recovery criterion in S8 is to prevent the flexible trap tube 400 from softening again before the pest has completely left its throat due to premature depressurization of the micro vacuum pump 500. To avoid misjudgment due to transient noise, the control host 700 can add a continuity condition to the determination of S3 and S8: only when the high-frequency pulse appears continuously within 2 to 5 adjacent time windows is it confirmed that pest intrusion has occurred; only when the high-frequency pulse disappears continuously and the spectrum continuously recovers to within the allowable deviation band for 2 to 10 adjacent time windows is the power reduction recovery compliant state executed. After adopting this continuity condition, the amplitude threshold, reference spectrum, and recovery criterion form a closed data link throughout the process, giving the control method a clear input source, processing order, and output direction. To prevent the reference current spectrum established in S1 from losing its reference meaning after the attitude adjustment in S2, the control host 700 uses attitude-related update logic for the reference current spectrum, instead of establishing it once and keeping it fixed. The processing method is as follows: when the electric push rod 600 causes the change in the angle, curvature or the amount of extension from the front end of the base 100 to exceed the preset attitude change threshold, the control host 700 marks the current attitude as a new working condition, and re-collects low-frequency data for several time windows under the new working condition to refresh the reference current spectrum; only after the refreshed reference spectrum is established will the spectrum corresponding to the attitude be sent to S3 to S8 as a comparison reference. If the attitude change does not exceed the threshold, the previous reference current spectrum will continue to be used. The reason for this setting is that after the orientation and curvature of the trap opening change, the airflow direction, the local resistance of the throat, and the background value of the fan aerodynamic load will all change synchronously. If the reference spectrum under the old attitude is still used, the load change caused by the normal attitude switching may be misjudged as a pest invasion event. By using the current attitude as one of the input conditions for the reference spectrum establishment module, the sequential relationship between S1 and S2 is refined into a data stream of initial modeling—attitude change—reconstruction of the reference according to the new attitude—and then high-frequency identification, thereby maintaining the consistency of the entire decision link logic. The critical yield stress and friction coefficient factor used in S5 and S6 are equivalent mechanical characterization quantities used for control decisions, rather than requiring the direct measurement of the actual yield limit of the particle monomer or the direct use of the dimensionless coulomb friction coefficient. The critical yield stress control means the minimum equivalent resistance to deformation that needs to be achieved to prevent the flexible trap tube 400 from collapsing further under the current throat geometry and current aerodynamic disturbance; the friction coefficient factor is the comprehensive conversion parameter used to convert this equivalent resistance to deformation into the target negative pressure of the interlayer, which already includes the morphology of the particulate medium, gradation, interlayer thickness, film constraint conditions, and the negative pressure stiffening response obtained during sample calibration. Therefore, the logic in S6 that divides the critical yield stress by the preset friction coefficient factor to convert it into the theoretical negative pressure value of the sealed interlayer 404 should be understood as follows: the control host 700 calls the pre-calibrated anti-deformation requirement-target negative pressure correspondence to map the structural collapse resistance requirement obtained from the upstream into an executable negative pressure command, rather than performing mechanical algebraic conversion on a single tribological parameter; after this processing, S5 outputs how much collapse resistance the structure needs, and S6 completes the mapping of this capacity requirement to the interlayer negative pressure setting value, forming a reliable data mapping and feedback closed loop between the two; To clearly demonstrate the internal logic of the algorithm and clarify the data flow and calculation rules in steps S4 to S6, a specific quantitative deduction example is provided: Assume that within the current running time window, the transient blockage ratio calculated by S4 is 0.15, which represents 15% effective blockage at the throat section, and the aerodynamic conversion factor called by the system based on the current fan speed is 30N. The transient aerodynamic load change calculated in S5 is the transient blockage ratio multiplied by the aerodynamic conversion factor, i.e., 0.15 multiplied by 30 equals 4.5N; this change is equivalent to the peak value of the centripetal collapse force. Assuming that the current effective force-bearing area of ​​the throat of the flexible trap tube 400 is 0.01m², the additional load per unit area is 4.5 divided by 0.01 equals 450Pa. Based on the pipe wall geometric compressive strength model, the system determines that the load has reached the instability range. The specific calculation rules of the pipe wall geometric compressive strength model are as follows: The control host 700 stores the instability critical pressure difference threshold curves of the flexible trapping tube 400 under different curvatures. This curve represents the maximum internal and external pressure difference limit that the membrane tube wall can withstand before radial buckling and wrinkling occurs at a specific bending angle. The system adds the unit area additional load to the basic compressive strength corresponding to the current curvature. If the sum exceeds the threshold curve, the stress to be compensated is the unit area additional load multiplied by the preset safety factor. For example, assuming the foundation compressive strength under the current curvature is 200 Pa, the calculated additional load is 450 Pa, and the sum of the two is 650 Pa, which exceeds the instability critical pressure difference threshold under the current curvature. The system thus determines that it has reached the instability range. Taking the preset safety factor as 1.11, the stress to be compensated is defined as the critical yield stress, that is, 450 Pa multiplied by 1.11 is approximately equal to 500 Pa. After entering S6, the control host 700 calls the friction coefficient factor of the current polyhedral silica particle medium 405. Assuming the pre-calibrated value is 0.05, the critical yield stress is converted into the theoretical negative pressure value of the sealed interlayer 404, that is, 500 divided by 0.05 equals 10000Pa, or 10kPa. Through the structured decomposition and quantitative deduction of the above business logic, the step-by-step conversion process from the dimensionless blocking ratio to the final physical negative pressure command is clearly defined, enabling those skilled in the art to directly write program code and complete parameter configuration.

[0025] Before step S1, the following steps are included: S0, controlling the micro vacuum pump 500 to operate at low power, so that the flexible trapping tube 400 remains compliant; Before entering S1, the control host 700 executes S0, controlling the micro vacuum pump 500 to be in a low-power operation state; the low-power operation state means that the interlayer negative pressure output by the micro vacuum pump 500 is lower than the particle locking threshold. The absolute negative pressure of the interlayer can be set from 0 kPa to 10 kPa, or set to no more than 20% of the rated negative pressure capacity; at this time, the polyhedral silica particle medium 405 still retains relative sliding ability, and the flexible trapping tube 400 exhibits a low bending stiffness state, which is convenient to change the air inlet direction and contraction shape under the action of the electric push rod 600. The reason for setting S0 is that if the interlayer is evacuated to a high negative pressure during the reference calibration or search stage, the trap tube will be in a rigid locked state. The thrust required for the electric push rod 600 to adjust the attitude will exceed the rated thrust range set by the system, and the trap port will be difficult to adapt to changes in the ambient flow. Maintaining low power operation can take into account both the contour stability and tube flexibility after slight evacuation of the interlayer, and avoid irregular wrinkles in the double-layer film when there is no evacuation, which would affect the stability of the reference current spectrum. The particle locking threshold refers to the negative pressure boundary value corresponding to the transition of the particle medium in the sealed interlayer 404 from a slippery stacking state to a clearly load-bearing locking state; its physical meaning is the inflection point of the flexible trapping tube 400 from easy attitude adjustment to structural rigidity and increased stiffness. This threshold can be obtained through the calibration of the prototype after assembly. During calibration, the negative pressure of the interlayer is gradually increased, and the end displacement or bending angle of the trapping tube under the same external force is measured simultaneously. When the negative pressure continues to increase and the displacement descent rate exceeds the preset displacement mutation threshold, the corresponding negative pressure can be used as the particle locking threshold. S0 requires the micro vacuum pump 500 to operate at low power, which essentially means keeping the actual negative pressure below the threshold, thereby ensuring that the adjustable tube shape characteristics on which the S1 reference current spectrum establishment and S2 flexible search depend are not destroyed. The output of S0 not only keeps the flexible trapping tube 400 in a compliant state, but also provides a unified initial condition for subsequent steps. Specifically, the control host 700 records the current interlayer negative pressure, the duty cycle of the micro vacuum pump 500 and the initial attitude of the trapping port at the end of S0, as a reference starting point for judging the increase and recovery of negative pressure during S1 to S8. With this setting, a corresponding relationship is formed between S0 and the subsequent S6 and S8, avoiding inconsistent control responses due to different starting states in each cycle.

[0026] In step S6, the control host 700 generates a pulse width modulation signal based on the theoretical negative pressure value to control and increase the operating power of the micro vacuum pump 500. In S6, the control host 700 generates a pulse width modulation signal based on the calculated theoretical negative pressure value and outputs it to the drive circuit of the miniature vacuum pump 500. The pulse width modulation signal adjusts the speed of the built-in motor of the miniature vacuum pump 500 in real time by changing the average supply voltage of the built-in motor, thereby changing the actual pumping speed of the vacuum pump. The frequency of the pulse width modulation signal can be set from 5kHz to 50kHz, and the duty cycle can be set from 10% to 95%. The control host 700 internally stores a calibration table between the theoretical negative pressure value and the actual pumping capacity of the micro vacuum pump 500. The calibration table is established through pre-experimentation, during which the time required for the sealed interlayer 404 to reach a stable negative pressure and the stable value are recorded under different duty cycles. After receiving the critical yield stress result calculated by S5, the control host 700 converts it into a theoretical negative pressure value, and then determines the corresponding PWM duty cycle by looking up the table or interpolation, so that the micro vacuum pump 500 can quickly reach the target pumping power. Using pulse width modulation control instead of simple on / off control, the speed of the micro vacuum pump can be continuously adjusted by 500, reducing the overshoot of the interlayer negative pressure and maintaining a predictable stiffness change relationship when the particulate medium approaches the required locking strength. If the control host 700 detects that the high-frequency pulses in the subsequent spectrum continue, it can increase the duty cycle by 1% to 10% in a predetermined step based on the current duty cycle; if the spectrum recovers to the reference, it can gradually reduce the duty cycle so that the flexible trap tube 400 can smoothly return to the compliant state. This method establishes a clear control correspondence between the theoretical negative pressure value and the output power of the 500 micro vacuum pump, ensuring that the calculation results in the method steps can be implemented in actual operation. The processing flow for generating a pulse width modulation signal based on the theoretical negative pressure value can be executed in the following order: First, the control host 700 reads the theoretical negative pressure value output by S6 and compares it with the actual negative pressure value of the current interlayer recorded at the end of S0 or the previous cycle, to obtain the negative pressure increment required for this round; the calculation formula is as follows:

[0027] in, This represents the increase in negative pressure required for this round, in Pa. This represents the theoretical negative pressure value for this round of testing, in Pa. The first step is to retrieve the actual negative pressure value of the current interlayer from the sensor, in Pa; the second step is for the control host 700 to find the target range that is closest to the target negative pressure in the calibration table, and read the recommended PWM frequency, initial duty cycle and expected settling time corresponding to the range. The third step is that the control host 700 first drives the micro vacuum pump 500 to run with the initial duty cycle, and confirms the operation by feedback through the negative pressure sensor or the estimated negative pressure value obtained by converting the pump's operating current and response time; the fourth step is that when the actual negative pressure is still lower than the theoretical negative pressure value, the duty cycle is gradually increased by a predetermined step size; when the actual negative pressure reaches the theoretical negative pressure value or enters the allowable error zone, the current duty cycle is maintained; when the actual negative pressure is higher than the theoretical negative pressure value and exceeds the allowable error zone, the duty cycle is gradually decreased by a predetermined step size. Fifth, after S8 determines that the airflow has stabilized, the duty cycle is gradually reduced in the reverse order of the lifting process until it returns to the low power range corresponding to S0. Through the above processing sequence, the PWM signal generation process has clear input, gradual adjustment and clear output, rather than just giving the final control result. The allowable error band is used to define the acceptable deviation range between the theoretical negative pressure value and the actual result. Its physical meaning is to avoid frequent power increases and decreases of the miniature vacuum pump 500 due to small errors. The allowable error band can be set to ±3% to 10% of the theoretical negative pressure value, or set to an absolute negative pressure deviation of no more than 1 kPa to 5 kPa. Once the actual negative pressure enters the allowable error band, the control host 700 will use the current PWM duty cycle as the locked duty cycle and maintain it unchanged, unless S8 still detects the continued presence of high-frequency pulses. The role of this allowable error band in the control process is to form a stable interface between the theoretical calculated value and the actuator's adjustment capability, thereby reducing overshoot and oscillation. The calibration table can be established using a segmented test method: during factory calibration or maintenance calibration of the device, drive the micro vacuum pump 500 with multiple fixed duty cycles, record the corresponding stable negative pressure of the interlayer, the time required to reach the stable negative pressure, and the return pressure speed after the drive is released; organize the data into a lookup table according to the negative pressure range. When the control host 700 is running, there is no need to recalculate complex calculations. It only needs to call the corresponding interval parameters based on the theoretical negative pressure value. If the theoretical negative pressure value falls between two adjacent calibration points, linear interpolation is used to determine the intermediate duty cycle. In this way, the control boost action in S6 has a clear data source and execution basis, so that the system has a clear input-output mapping and closed-loop feedback control logic. To ensure consistency between this step and the upstream calculation results of S6, the theoretical negative pressure value is treated as the target interlayer negative pressure command in this step. The control host 700 does not directly perform PWM control on the critical yield stress itself, but first calls the aforementioned calibration table or parameter database to convert the upstream output target interlayer negative pressure into pump drive parameters. The input to this step is the executable negative pressure target range, and the output is the combination of PWM frequency, duty cycle and hold time corresponding to that range; the feedback result from the negative pressure sensor or the estimated negative pressure module is then sent back to the PWM regulation unit to form a closed-loop data flow of target negative pressure - pump drive - actual negative pressure - recalibration. After adopting this closed-loop relationship, the causal link between the theoretical negative pressure value, the actual negative pressure value and the PWM control signal is clearer. That is, because the target interlayer negative pressure needs to reach a certain range, the control host 700 generates a PWM signal that matches the range; and because the actual air pumping capacity is affected by the hose length, the amount of air leakage in the interlayer and the ambient temperature, it is also necessary to fine-tune the PWM signal with the actual negative pressure feedback to ensure that the particle locking action in S7 can occur stably. To enable those skilled in the art to accurately implement the generation and closed-loop regulation logic of pulse width modulation signals, a specific quantitative deduction example of calibration table calling and data interaction is provided: Assume that the theoretical negative pressure value of the upstream output of S6 is 10kPa, and the current actual negative pressure recorded by the control host 700 in the previous cycle is 2kPa, that is, the negative pressure increment requirement is 8kPa. The control host 700 queries the two-dimensional calibration table in the internal flash memory. The table uses the target negative pressure range and the current negative pressure range as a joint index to match the corresponding drive parameter structure and reads the recommended PWM frequency of 20kHz, the initial duty cycle of 65%, and the estimated setup time of 1.5s. The hardware timer inside the control host 700 configures the comparison register and outputs the PWM waveform to the miniature vacuum pump 500 drive circuit. When the system enters the closed-loop feedback stage, the negative pressure sensor returns the actual negative pressure value to the control host 700 every 50ms via the I2C bus for comparison. If the actual negative pressure only reaches 9 kPa after 1.5 seconds of operation, which is below the allowable error range, the software adjustment module will increase the duty cycle in a preset 2% step to 67% until the target requirement is met. Through this specific business logic decomposition, the pulse width modulation control process has a clear data structure input, processing process and communication interaction feedback, becoming a transparent technical solution that can be directly programmed.

[0028] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An insect-attracting and insect-killing device for agricultural pest control, characterized in that, include: Base (100); Centrifugal fan (200), fixedly connected to the top of the base (100), including drive motor (201), centrifugal fan main shaft (202), centrifugal fan inlet end (203) and centrifugal fan positive pressure exhaust end (204), the drive motor (201) is connected to centrifugal fan main shaft (202); The insect-killing chamber (300) is matched and set at the air inlet end (203) of the centrifugal fan, and has an air inlet end (302) and an air outlet end (301) of the insect-killing chamber, wherein the air outlet end (301) of the insect-killing chamber is connected to the air inlet end (203) of the centrifugal fan. A flexible trapping tube (400) is correspondingly set at the air inlet end (302) of the insect-killing chamber. It includes a tube body (401) constructed with a double-layer silicone flexible film. One end of the tube body is provided with a flexible trapping tube air inlet. A sealed interlayer (404) is formed between the inner film (402) and the outer film (403). The sealed interlayer (404) is filled with polyhedral silica particle medium (405). A reverse prestressed air chamber (406) is integrally formed around the outer film (403) along the spiral direction. The air inlet end (407) of the reverse prestressed air chamber is physically connected to the positive pressure exhaust end (204) of the centrifugal fan. A miniature vacuum pump (500) is fixedly installed on the side of the base (100), and its miniature vacuum pump pumping end (501) is connected to the sealed interlayer (404). An electric push rod (600) is hinged to the front end of the base (100) and includes a telescopic rod, the end of which (601) is connected to the outer edge (409) of the air inlet of the flexible trap tube. The control host (700) is connected to control the operation of the drive motor (201), the miniature vacuum pump (500), and the electric push rod (600).

2. The insect-attracting and insect-killing device for agricultural pest control according to claim 1, characterized in that, The insect-killing chamber (300) is a cylindrical stainless steel tank, and an insect discharge port (303) is provided at the bottom of the insect-killing chamber (300).

3. The insect-attracting and insect-killing device for agricultural pest control according to claim 1, characterized in that, The centrifugal fan inlet (203) is connected to the insect-killing chamber exhaust end (301) via a flange (801), and the insect-killing chamber inlet (302) is fixedly connected to the flexible trapping tube exhaust end (408) via a clamp (802).

4. The insect-attracting and insect-killing device for agricultural pest control according to claim 1, characterized in that, The inlet end (407) of the reverse prestressed air chamber is connected to the positive pressure exhaust end (204) of the centrifugal fan via a bypass valve (803) and a high-pressure hose (804).

5. The insect-attracting and insect-killing device for agricultural pest control according to claim 1, characterized in that, The pumping end (501) of the micro vacuum pump is connected to the sealed interlayer (404) through a polyurethane gas pipe (805).

6. The insect-attracting and insect-killing device for agricultural pest control according to claim 1, characterized in that, The end of the electric push rod telescopic rod (601) is connected to the outer edge (409) of the air inlet of the flexible trap tube via a ball joint (806).

7. A control method, applied to the insect-attracting and insect-killing device for agricultural pest control as described in claim 1, characterized in that, include: S1. The control host (700) starts the drive motor (201) to drive the centrifugal fan (200) to generate a basic suction flow field, continuously collects the stator current data of the drive motor (201), performs fast Fourier transform on the stator current data to extract the low frequency band amplitude as the low frequency drift characteristics of the environmental wind load, establishes the reference current spectrum, and extracts the main peak amplitude of the reference current spectrum as the fundamental frequency amplitude. S2. Control the electric push rod (600) to extend and retract to push the air inlet of the flexible trapping tube (400) to change the curvature and orientation to achieve flexible searching, and form a variable cross-section throat in the section of the flexible trapping tube (400) near the air inlet. S3. Continuously collect the stator current data and perform a fast Fourier transform to separate the high-frequency pulse in the current signal. When the amplitude of the high-frequency pulse is less than or equal to the preset amplitude threshold, return to step S3 to continue collecting data. When the amplitude of the high-frequency pulse is greater than the amplitude threshold, it is confirmed that the pest has passed through the variable cross-section throat of the flexible trapping tube (400) and caused airflow obstruction. S4. Calculate the difference between the extracted high-frequency pulse amplitude and the fundamental frequency amplitude of the reference current spectrum, and divide the difference by the fundamental frequency amplitude to obtain the transient blocking ratio; S5. Multiply the transient blockage ratio by a preset aerodynamic conversion factor to obtain the transient aerodynamic load change, and convert the transient aerodynamic load change into the peak value of the centripetal collapse force. Combine the pipe wall geometric compressive strength model to calculate the critical yield stress required to resist the peak value of the centripetal collapse force. S6. Divide the critical yield stress by the preset friction coefficient factor to convert it into the theoretical negative pressure value of the sealed interlayer (404), and control the host (700) to increase the operating power of the micro vacuum pump (500) according to the theoretical negative pressure value. S7. Control the micro vacuum pump (500) to draw the sealed interlayer (404) to the theoretical negative pressure value so that the polyhedral silica particle medium (405) locks each other to complete rigid locking. At the same time, the centrifugal fan (200) discharges high-pressure gas into the reverse prestressed gas chamber (406) to generate expansion force to counteract the collapse force. S8. When the high-frequency pulse of the stator current data does not disappear or the spectrum does not recover to the reference current spectrum, maintain the theoretical negative voltage value; When the high-frequency pulse of the stator current data disappears and the spectrum returns to the reference current spectrum, the operating power of the micro vacuum pump (500) is reduced so that the flexible trap tube (400) returns to a compliant state; steps S1 to S8 are executed in a cycle.

8. The control method according to claim 7, characterized in that, Before step S1, the following steps are included: S0, controlling the micro vacuum pump (500) to operate at low power, so that the flexible trapping tube (400) remains compliant.

9. The control method according to claim 7, characterized in that, In step S6, the control host (700) generates a pulse width modulation signal based on the theoretical negative pressure value and controls the increase of the operating power of the micro vacuum pump (500).

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