An integrated tea harvesting system based on a combined blowing and suction flow field

Abstract

This invention provides an integrated tea harvesting system based on a combined blowing and suction flow field, relating to the field of intelligent tea harvesting. The system includes a harvesting execution system (1), a collection pipe (2), a transportation loss reduction system (3), and a storage and preservation system (4). The harvesting execution system (1) is connected to the storage and preservation system (4) via the collection pipe (2). The transportation loss reduction system (3) is located outside the storage and preservation system (4) and is connected to it via a slide rail (301). The storage and preservation system (4) is placed on the slide rail (301) and connected via a slider. This system not only effectively improves harvesting efficiency and operational continuity but also reduces the risk of mechanical damage and physiological deterioration during harvesting, storage, and transportation, ensuring the freshness and integrity of the tea raw materials.

Description

Technical Field

[0001] This invention relates to the field of intelligent tea harvesting technology, specifically to an integrated tea harvesting system based on a combined blowing and suction flow field. Background Technology

[0002] As the tea industry develops towards large-scale and mechanized production, traditional harvesting and processing methods suffer from problems such as low efficiency, high losses, and difficulty in maintaining the quality of fresh leaves. In particular, in bulk tea production, existing equipment generally suffers from problems such as incomplete harvesting, tea blockage, fragile transport, heat generation and mold growth during storage, and severe damage during transportation, resulting in a persistently high overall loss rate.

[0003] Currently, although there are automated tea harvesting systems that integrate picking, collection, and transportation, such as Chinese patent document CN121605859A, which describes a fully automated tea picking device that integrates picking and transportation, the system achieves the linkage between picking and transportation through the collaboration of the picking machine and the transportation machine. However, this solution employs a single negative pressure suction mechanism and a non-blowing composite flow field. Furthermore, existing blow-suction composite flow field designs (such as Chinese patent document CN121032274A, "A Negative Pressure Tea Picking Machine and Tea Picking Method") rely on empirically preset values ​​for their blowing and suction airflow parameters, which cannot cope with real-time changes in the tea tree canopy shape, tea leaf density, and falling posture, easily leading to problems such as "empty blowing" or "leaking suction." Simultaneously, the lack of a storage and preservation structure means it cannot adapt to the real-time changes in the state of fresh leaves during harvesting, resulting in a short preservation period and susceptibility to spoilage and deterioration. Moreover, the device lacks a damping mechanism during transportation, lacking active vibration reduction capabilities and unable to cope with multi-directional bumps and impacts generated during transport, causing deterioration or damage to the quality of fresh leaves during transportation, affecting the quality and integrity of subsequent tea processing. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide an integrated tea harvesting system based on a blowing and suction composite flow field. This system constructs a highly efficient and low-loss operation system that integrates the entire process from field harvesting to storage and transportation. It not only effectively improves harvesting efficiency and operational continuity, but also reduces the risk of mechanical damage and physiological deterioration in harvesting, storage, and transportation, ensuring the freshness and integrity of tea raw materials and guaranteeing the quality of subsequent tea processing.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] An integrated tea harvesting system based on a combined blowing and suction flow field includes a harvesting execution system, a collection pipeline, a transportation loss reduction system, and a storage and preservation system. The harvesting execution system is connected to the storage and preservation system through the collection pipeline. The transportation loss reduction system is located outside the storage and preservation system and is connected to the storage and preservation system through a slide rail. The storage and preservation system is placed on the slide rail and connected by a slider (to achieve detachable collection function). The harvesting execution system includes a cutting mechanism, a centrifugal fan, an air blowing unit, a flow guide, a gripper bar, and a battery control module. The cutting mechanism is located at the foremost position, with a sensor module installed at its front end. The cutting mechanism is connected to the centrifugal fan. The centrifugal fan is connected to the air blowing unit and located behind the cutting mechanism. The flow guide is located above the cutting mechanism and the air blowing unit and is connected to the cutting mechanism. A visual perception unit consisting of a binocular high-speed camera and a line laser sheet light source is symmetrically arranged inside the flow guide and behind the cutting mechanism. The gripper bar is located above the flow guide. The battery control module includes a lithium battery and an NMPC control unit. The lithium battery is electrically connected to the centrifugal fan and the cutting mechanism. The NMPC control unit is electrically connected to the sensor module, the visual perception unit, and the centrifugal fan (receiving signals from the sensor module and the visual perception unit, solving for the optimal control quantity in real time, and dynamically adjusting the operating parameters of the air blowing array and the suction fan).

[0007] Based on further optimization of the above scheme, the cutting mechanism adopts a reciprocating blade to cut tea leaves; the sensor module includes a laser rangefinder and a near-infrared spectral sensor to acquire the height of the tea tree canopy, the moisture content of fresh leaves and tenderness in real time. The laser rangefinder array and the near-infrared spectral sensor are mounted on the upper part of the cutting mechanism and the outer front end of the guide shroud via a bracket, and are arranged linearly and equally spaced along the blade axis (the sensor signal lines are connected to the NMPC controller through shielded cables); two binocular cameras are symmetrically installed on the left and right side walls inside the guide shroud, located behind the cutting mechanism and above the air blowing unit, with the lenses facing the discharge area of ​​the cutting blade (the optical axis forms a 30° downward angle with the horizontal plane, completely covering the entire motion trajectory of the tea leaves after cutting); the line laser sheet light source is fixed in the middle position of the two binocular cameras, and the laser emission surface is parallel to the cutting blade edge (in conjunction with the binocular cameras to realize the real-time reconstruction of the three-dimensional point cloud and motion vector of the tea leaf cluster); the NMPC control unit is set on the gripper rod.

[0008] Based on further optimization of the above scheme, the transportation loss reduction system includes a pull rod, a transport box, a traveling mechanism, casters, a negative pressure fan, and an active vibration damping unit. The pull rod is located at the upper front end of the transport box, the traveling mechanism is located at the bottom of the transport box (to achieve stable transportation of tea), the casters are located at the bottom of the transport box in front of the traveling mechanism (to facilitate precise adjustment of the direction of movement during transportation), and the negative pressure fan is fixedly installed on the side wall of the transport box. The active vibration damping unit is located on the bottom surface inside the transport box and includes a support platform, four sets of magnetorheological dampers, four sets of helical composite springs, a damper drive controller, a three-axis accelerometer, and a gyroscope. The support platform is installed inside the transport box. The bottom surface of the support platform and the bottom surface of the transport box are connected by a composite vibration isolator consisting of four sets of "magnetorheological dampers + helical composite springs". The four sets of composite vibration isolators are arranged at the four corners of the support platform. A three-axis accelerometer and a gyroscope are installed at the center of the support platform (to detect the vibration acceleration, impact signal and box tilt angle in real time during transportation, and transmit the data to the damper drive controller and the central control system in real time). The damper drive controller is integrated into the central control system (based on the real-time vibration signal, it dynamically adjusts the excitation current of each magnetorheological damper, changes the damping force, actively counteracts the bumps and impacts during transportation, and reduces the vibration transmission rate).

[0009] Based on further optimization of the above scheme, the storage and preservation system includes a collection box, anti-damage airbags, a ventilation system, and a screen. The collection box is located inside the transport box and connected to the transport box via a bottom slide rail. Anti-damage airbags are installed on the outer sidewall of the collection box to reduce tea loss during transportation. The bottom anti-damage airbag is fixedly installed on the upper surface of the carrying platform, and the surrounding anti-damage airbags are respectively fitted and installed on the inner side of the surrounding limiting baffles at the installation position inside the collection box (forming an all-round flexible buffer). The ventilation system is located on the side of the collection box to achieve the tea preservation and storage function, and an exhaust grille is installed on the top of the collection box. The screen is used to connect the collection box and the collection pipe. The negative pressure airflow generated in the transport box enters the collection box through the screen and prevents tea from leaking out of the collection box under negative pressure.

[0010] A tea harvesting method based on a combined blowing and suction flow field, employing the aforementioned integrated system, includes: Step S1, Adaptive Harvesting: First, move the integrated system to the tea row operation area, and then perform pre-operation calibration, cutting start-up, three-dimensional reconstruction of tea state, NMPC rolling optimization control, real-time resistance coefficient compensation, and anti-blocking pneumatic conveying in sequence. Step S2, Fresh Leaf Storage and Ventilation: After the tea leaves fall into the collection box through the conveying pipe, the micro fan of the ventilation system at the bottom of the box is activated, and outside air enters the box; the airflow penetrates the tea leaf accumulation layer from bottom to top, carrying away the hot and humid air generated by the respiration of the fresh leaves; subsequently, the hot and humid air is discharged through the exhaust grille, forming a continuous convection circulation. Step S3, Adaptive Collaborative Loss Reduction and Dynamic Freshness Preservation Transportation: The collection box filled with fresh leaves is pushed into the carrying platform of the transportation box via a slide rail, and the position of the collection box is locked; then, the transportation loss is reduced by anti-compression airbags and active vibration damping units; at the same time, the ventilation system of the collection box is kept connected to the external mobile air source during transportation to continuously supply fresh air into the box and maintain a slightly positive pressure environment inside the box. Step S4, Unloading: After arriving at the destination, shut down the active vibration damping platform, airbag supply system and mobile ventilation system, cut off the power source, then remove the collection box from the transport vehicle, open the box door, and pour the fresh leaves into the subsequent processing equipment.

[0011] Based on further optimization of the above scheme, the pre-operation calibration in step S1 specifically involves: firstly, acquiring tea tree canopy height distribution data and determining the optimal cutting height using a laser rangefinder sensor; and secondly, real-time detection of the average moisture content of fresh leaves using a near-infrared spectral sensor. w hs With tenderness level n ed Based on the collected fresh leaf parameters, the shear strength of the fresh leaves was dynamically corrected. : ; In the formula: Indicates the reference shear strength under standard conditions; Then, based on the real-time shear strength, the minimum cutting force required by the blade is calculated. F c With drive power P c Ensure smooth, unobstructed cutting without damaging buds or leaves: ; In the formula: A c Indicates the effective cross-sectional area of ​​a single cut; v c This is expressed as the cutting speed of the blade.

[0012] Based on further optimization of the above scheme, in step S1, the cutting start specifically involves: starting the cutting drive motor to drive the reciprocating blade to perform high-frequency cutting motion, and the operator pushing the device along the tea row... v c The blade moves forward at a constant speed, continuously cutting the fresh leaves on the tea bush surface, severing the tea leaves from the branches; during the cutting process, the load current of the blade drive motor is monitored in real time to ensure the actual cutting force. F c Satisfying "minimum cut threshold ≤ F c ≤ Upper limit threshold for bud and leaf damage.

[0013] Based on further optimization of the above scheme, the three-dimensional reconstruction of the tea leaves in step S1 specifically involves: First, the left and right images from the binocular camera are input into the embedded processing unit for image denoising and distortion correction. Then, an adaptive background subtraction method is used to eliminate the fixed background and retain the foreground area of ​​the tea clump (a pre-collected background image of the guide fairing without tea leaves is used as the reference background, and the real-time acquired image is subtracted from the reference background). Adaptive threshold segmentation is performed on the subtracted image to obtain a binary mask of the tea clump. Through morphological operations of opening and closing operations, noise holes in the mask are eliminated and the edges of the tea clump are smoothed to obtain a complete connected component of the tea clump. Connected component detection is performed on the binary mask, and connected components that meet the area threshold of the tea clump are selected. Then, the foreground mask region of the tea leaf cluster is defined as a Region of Interest (ROI), and semi-global stereo matching (SGM) is used to match the tea leaf cluster regions in the corrected left and right images, calculating the disparity value of each foreground pixel. d sc (Disparity = x-coordinate of left image pixel - x-coordinate of right image pixel of the same target); By checking left and right consistency and filtering disparity threshold, mismatched points with abnormal disparity are eliminated to obtain the disparity map of the tea ball; Next, for each valid pixel in the tea leaf cluster area, calculate its three-dimensional spatial coordinates (X, Y, Z) in the left camera coordinate system: ; In the formula: Z represents the depth value (distance along the camera's optical axis) corresponding to the pixel; f Indicates the camera's equivalent focal length; B Indicates the binocular baseline distance; (x, y) Represents the x and y coordinates of a pixel in an image; (c x ,c y ) Indicates the coordinates of the camera's principal point; Then, based on the 3D point cloud of the tea leaf cluster and the tracking trajectory of consecutive frames, the 3D centroid coordinates are obtained sequentially. (X c (t), Y c (t), Z c (t)) Three-dimensional motion vector (i.e., velocity vector) v(t) Actual acceleration of tea leaves a clus Real-time windward projection area of ​​tea leaves A proj Estimated quality of tea batch m clus ; Three-dimensional centroid coordinates (Xc (t), Y c (t), Z c (t)) : ; In the formula: N represents the number of effective points in the tea leaf dot cloud; (X i (t), Y i (t), Z i (t)) This represents the three-dimensional coordinates of the i-th point in the point cloud; Three-dimensional motion vector (i.e., velocity vector) v(t) : ; In the formula: Indicates the camera sampling period; Actual acceleration of tea leaves a clus : ; Stable acceleration values ​​were obtained by performing least-squares linear fitting on a velocity sequence of 3 to 5 frames. Real-time windward projection area of ​​tea leaves A proj : Determine the unit normal vector of the main airflow direction n f Establish a projected coordinate system: with the main direction of airflow as... Z’ The axis, the plane perpendicular to the airflow is X’OY’ The projection plane is used to transform the 3D point cloud of the tea leaf mass from the camera coordinate system to the projection coordinate system using a rotation matrix; then, all 3D points are projected onto the projection plane. X’OY’ Two-dimensional plane, ignoring the projected coordinate system Z’ The coordinates are used to obtain the two-dimensional projection point set of the tea ball; then, the minimum bounding contour of the projection point set is extracted using the convex hull algorithm, and the area of ​​the convex hull contour is calculated using the shoelace formula. This area is the real-time windward projection area of ​​the tea ball. A proj ; Estimated quality of tea group m clus First, divide the three-dimensional space containing the tea leaf point cloud into tiny voxels of equal size. Count the number of effective voxels occupied by the point cloud, multiply it by the volume of a single voxel, and obtain the apparent volume of the tea leaf. V clus Then, based on the bulk density of the fresh leaves, the estimated mass of the tea cake is obtained: ; In the formula: This indicates the bulk density of fresh leaves.

[0014] Based on further optimization of the above scheme, in step S1, the NMPC rolling optimization control specifically aims to minimize the deviation between the predicted trajectory of the tea ball centroid and the ideal capture point at the inlet of the collection pipe, while simultaneously controlling the actuator's action increments to be smooth, avoiding frequent actions of the fan and solenoid valve, and constructing a loss function: ; In the formula: N p Indicates the prediction time domain, N c Indicates control over the time domain; Predict the centroid position vector of the tea leaf cluster in the time domain. This represents the vector representing the ideal capture point location at the inlet of the collection pipe; This represents the incremental control sequence of blowing and inhaling air velocities; Q , R These represent the weight matrices for position deviation and control increment, respectively. The controller solves for the following in each control cycle: J NMPC The minimum optimal control sequence outputs the first set of control quantities to the actuator. The first set of control quantities includes the duty cycle of the solenoid valve corresponding to the air blowing unit and the air outlet velocity. v b Adjust the speed of the negative pressure fan accordingly and control the average flow rate at the suction inlet. v s .

[0015] Based on further optimization of the above scheme, in step S1, the real-time compensation of the resistance coefficient specifically means: based on the actual movement parameters of the tea ball, the resistance coefficient of the tea ball is corrected in real time and the blowing force is dynamically compensated. Real-time correction of tea leaf resistance coefficient: The real-time resistance coefficient is calculated by back-calculating the actual movement state of the tea leaf mass. C D,real : ; In the formula: g Represents gravitational acceleration; This indicates the air density at room temperature. This indicates the relative speed between the airflow and the tea leaves. Dynamically compensated blowing thrust: through real-time correction of the drag coefficient C D,real Compensating for airflow thrust, obtaining the airflow thrust on a single blade. F blow With blowing flow rate Q b: ; ; In the formula: A fro This indicates the real-time windward projection area of ​​the tea ball; A b This indicates the effective flow cross-sectional area of ​​the air-blowing nozzle.

[0016] Based on further optimization of the above scheme, in step S1, the anti-blocking pneumatic conveying is specifically as follows: under the guidance of the blowing and suction composite flow field, the tea leaves smoothly enter the collection pipe along the inner curved surface of the guide hood. The system dynamically adjusts the airflow speed in the pipe to achieve suspended conveying of the tea leaves without settling, without pipe blockage, and with low breakage, and finally falls into the collection box. Based on the real-time corrected drag coefficient, the minimum anti-clogging wind speed required to suspend tea leaves in the collection pipe is calculated: ; In the formula: d p Indicates the equivalent particle size of tea leaves; Indicates the density of the tea leaves; v set Indicates the free settling velocity of tea leaves; Calculate the total pressure loss of the piping system Ensure that the full pressure of the blower meets the conveying requirements: ; In the formula: Indicates the friction coefficient. L gd Indicates the length of the pipe. D gd Indicates the inner diameter of the pipe; Indicates the resistance coefficient (of elbows, reducers, tees, etc.); The system dynamically adjusts the speed of the variable frequency negative pressure fan to ensure that the actual airflow velocity in the duct always meets the following requirements: ; In the formula: v dam This indicates the critical wind speed at which tea leaves break.

[0017] Based on further optimization of the above scheme, step S2 specifically includes: First, based on data from the CO2 sensor (preset) inside the chamber, the real-time respiration rate of the fresh leaves is calculated. With total respiratory heat power : ; In the formula: Indicates the effective volume of the collection box; Represents unit of time within CO 2. Concentration changes; Indicates the quality of fresh leaves inside the box; Indicates the aerobic rate of fresh leaves; This indicates the enthalpy change of aerobic respiration; Then, based on real-time respiratory heat, the minimum ventilation volume required to remove heat is calculated. Simultaneously, humidity control and gas concentration stability are taken into account to obtain the final ventilation volume: ; In the formula: C p Indicates the specific heat capacity of air at constant pressure; indicates the allowable temperature difference between the inlet and outlet air. This indicates the amount of ventilation controlled by humidity. Indicates the ventilation volume for stable gas concentration; Next, the resistance of airflow penetrating the tea leaf accumulation layer was calculated. With air permeability coefficient K tq Ensure the static pressure of the fan meets ventilation requirements and avoid airflow short-circuiting: ; ; In the formula: Indicates the dynamic viscosity of air at room temperature; This indicates the porosity of the tea leaves. v face Indicates the wind speed over the empty bed surface; L hd Indicates the thickness of the tea leaf layer; based on and The speed of the micro fan and the opening of the air volume regulating valve are dynamically adjusted to ensure that the airflow penetrates the entire tea leaf accumulation layer evenly, avoid local heat accumulation that could cause the fresh leaves to turn red or moldy, and maintain the activity of the fresh leaves. When the fresh leaves in the collection box reach the rated loading capacity, the system shuts down the cutting mechanism, centrifugal fan, negative pressure fan and vision acquisition system, completing a single harvesting cycle and preparing to enter the transfer and transportation stage in step S3.

[0018] Based on the further optimization of the above scheme, step S3 is as follows: First, the collection box filled with fresh leaves is pushed into the carrying platform of the transport box through the slide rail, and the position of the collection box is locked. Then, the anti-pressure damage airbag control system is activated. Based on the amount of fresh leaves loaded in the collection box and the box's posture, the system calculates the optimal inflation pressure for each of the five independent chambers (front, rear, left, right, and bottom), and controls the inflation / deflation solenoid valves to inflate each airbag with gas at the corresponding pressure, forming an all-around flexible buffer. Specifically: For each airbag chamber, calculate the real-time load it bears: ; In the formula: i represents the chamber number (1 to 5, corresponding to the front, back, left, right, and bottom); m tea,i This indicates the equivalent mass of tea leaves contained in the corresponding chamber; This indicates the real-time tilt angle of the carriage (detected by a built-in gyroscope). a i This indicates the real-time acceleration in the corresponding direction; Based on real-time load, the optimal inflation pressure for each chamber is calculated. Balancing support and protection against crush damage: ; In the formula: P atm Indicates standard atmospheric pressure; K safe,i Indicates the safety factor; A cont,i This indicates the effective contact area between the airbag and the housing; Simultaneously obtain the airbag light box stiffness k qn-i : ; In the formula: V qn-i This indicates the real-time volume of the airbag chamber; Indicates the air insulation index; The system inflates each pressure-damage-prevention airbag with gas, monitors the internal pressure of the airbag in real time, and when it reaches... When the corresponding solenoid valve is closed, the airbag expands and fits tightly against the box and the wall of the carriage, which not only provides stable support but also prevents the fresh leaves from being crushed by excessive pressure. Subsequently, the multi-degree-of-freedom active vibration damping platform was activated. A three-axis accelerometer and gyroscope, sampling at a frequency of 1000Hz, collected vibration, impact, and tilt signals during transportation in real time. Based on these real-time signals, the damper drive controller dynamically adjusted the excitation current and damping force of the four sets of magnetorheological dampers, working in conjunction with the airbags to absorb impact energy. Specifically: Based on the vibration signals collected by sensors, the real-time impact kinetic energy during transportation is calculated: ; In the formula: m total Indicates the total mass of the collection box. v rms This indicates that we are testing the effective value of the vibration speed. Calculate the total energy absorbed by the airbag through passive energy absorption and the work done by magnetorheological active damping: ; In the formula: P 1,i Indicates the first i Initial pressure of each airbag chamber before impact. V 1,i Indicates the first i Initial volume of each airbag chamber before impact; P 2,i Indicates the first i Instantaneous pressure during the impact process of each airbag chamber V 2,i Indicates the first i The instantaneous volume of each airbag chamber after impact compression n air This indicates the air variability index; F mr This represents the magnetorheological damping force actively controlled by the controller. dx This represents the infinitesimal displacement element of the damper piston. Constraints: The damping force of the magnetorheological damper is dynamically adjusted based on constraints, and works in conjunction with the airbag to absorb the impact energy during transportation, significantly reducing the impact and vibration transmitted to the fresh leaves and avoiding mechanical damage. Meanwhile, during transportation, the ventilation system of the collection box is kept connected to an external mobile air source to continuously supply fresh air into the box. The ventilation volume is dynamically adjusted based on a vibration correction model of the respiration intensity of fresh leaves during transportation to maintain a slightly positive pressure environment inside the box. ; In the formula: This indicates the real-time respiration rate of fresh leaves during transportation; Indicates the resting respiratory rate. This represents the effective value of vibration acceleration.

[0019] Based on further optimization of the above scheme, step S4 specifically involves: upon reaching the destination, shutting down the active vibration damping platform, the airbag supply system, and the mobile ventilation system, cutting off the power source, and executing the pressure relief process. The system is based on the residual negative pressure attenuation formula and monitors the residual negative pressure in the collection box in real time. ; In the formula: Indicates after shutdown t end Constantly collect residual negative pressure inside the collection box; This indicates the rated negative pressure inside the collection tank before shutdown; R pq Indicates the exhaust resistance of the collection box;C sj Indicates the effective volume of the collection box; When the system detects When the negative pressure decay is complete, the airbag is controlled to naturally depressurize to atmospheric pressure to avoid the negative pressure residue causing the door to be difficult to open or the tea leaves to be adsorbed by the negative pressure and unable to be unloaded smoothly. Next, the collection box is removed from the transport vehicle and smoothly moved out of the transport box's slide rails. It is then transferred to the feed inlet of the subsequent processing equipment via a transfer trolley, ready for unloading. Open the box door, control the tilting angle of the box, and let the tea leaves slide smoothly down the box wall and be poured into the subsequent processing equipment; Based on the tilting angle of the container, the speed at which the tea leaves slide down is calculated: ; In the formula: v slide Indicates the speed at which the tea leaves slide down the slope; L tea This indicates the length of the tea leaves' downward sliding path (i.e., the diagonal length inside the collection box door). Indicates the tilt angle of the collection box; f tea This indicates the coefficient of friction between the tea leaves and the box wall; Calculate the total unloading time: ; In the formula: This indicates the total volume of fresh leaves piled up inside the collection box; This indicates the effective unloading area of ​​the collection box door; Based on the calculation results, the system controls the tilting speed and angle of the box, so that the tea leaves slide smoothly down the box wall, avoiding mechanical damage caused by high-speed impact, while ensuring that the unloading time is precisely matched with the feeding rhythm of the subsequent processing equipment.

[0020] The following are the technical effects of the present invention: This invention, through a harvesting execution system composed of a cutting mechanism, centrifugal fan, air blowing unit, flow guide, gripper rod, and battery control module, effectively solves the problems of incomplete harvesting, easy damage to buds and leaves, and jamming associated with traditional cutting methods. It avoids the problems of existing blowing and suction flow fields being unable to adapt to the real-time changes in the falling posture of tea leaves, leading to dry blowing or missed suction. It also solves problems such as easy clogging, insufficient suction, and reliance on empirically preset flow field parameters with single negative pressure suction. Furthermore, it avoids problems such as tea leaf collision and breakage, and settling and pipe blockage during the conveying process. Through the setting of a transportation loss reduction system, active and passive vibration isolation is achieved during the transportation of fresh leaves, avoiding problems such as crushing and damage caused by shaking during transportation, ensuring the quality of fresh leaves after harvesting and during transportation, and preventing quality deterioration. Through the setting of a storage and preservation system, real-time monitoring is achieved during the storage process of fresh leaves, preventing heat accumulation, mold, and reddening during storage, extending the shelf life; at the same time, it prevents tea leaf leakage and ensures the stability of pneumatic conveying.

[0021] Furthermore, this invention achieves fully closed-loop adaptive control of the harvesting process through an adaptive harvesting step, eliminating the need for manual parameter adjustments and completely resolving issues such as dry blowing and leakage, ensuring low-loss and unobstructed tea transport, preserving the integrity of fresh leaves, and significantly improving harvesting efficiency and continuity. Through a fresh leaf storage ventilation and preservation step, dynamic ventilation control based on the real-time respiration status of the fresh leaves avoids both heat accumulation and mold caused by insufficient ventilation and water loss and wilting caused by excessive ventilation, solving the problem of easy spoilage of fresh leaves during harvesting, significantly extending the shelf life of fresh leaves, and ensuring the consistency of quality throughout the box of fresh leaves. Adaptive collaborative loss reduction... With dynamic preservation and transportation steps, the system utilizes adaptive airbag inflation and active vibration damping units to form a dual loss reduction protection, synergistically absorbing the impact energy of bumps during transportation, significantly reducing mechanical damage and pressure during transportation, while avoiding spoilage caused by increased respiration of fresh leaves during transportation, ensuring the freshness of fresh leaves throughout the entire process, and adapting to different road conditions and different load capacities. Through the unloading step, the system ensures safe and smooth unloading, avoids unloading difficulties caused by negative pressure residue, and avoids fresh leaf breakage caused by unloading impact, ensuring the integrity of fresh leaves until the last stage of the entire process, thereby achieving seamless connection between harvesting and processing, and improving the overall production efficiency. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the integrated tea harvesting system in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the cutting mechanism of the integrated tea harvesting system in an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the harvesting execution system (excluding the cutting mechanism) of the integrated tea harvesting system in an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the transportation loss reduction system of the integrated tea harvesting system in an embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the storage and preservation system of the integrated tea harvesting system in this embodiment of the invention.

[0027] The components include: 1. Harvesting execution system; 11. Cutting mechanism; 12. Centrifugal fan; 13. Air blowing unit; 14. Flow guide; 15. Handle rod; 16. Lithium battery; 2. Collection pipeline; 3. Transportation loss reduction system; 301. Slide rail; 31. Pull rod; 32. Transport box; 33. Walking mechanism; 34. Casters; 35. Negative pressure fan; 4. Storage and preservation system; 41. Collection box; 42. Anti-compression airbag; 43. Ventilation system; 44. Screen. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. In the following description, specific details such as specific system structures and technologies are presented for illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention.

[0029] Example 1: An integrated tea harvesting system based on a combined blowing and suction flow field, such as... Figure 1 As shown, it includes a harvesting execution system 1, a collection pipe 2, a transportation loss reduction system 3, and a storage and preservation system 4; wherein, the harvesting execution system 1 is connected to the storage and preservation system 4 through the collection pipe 2, the transportation loss reduction system 3 is located outside the storage and preservation system 4 and is connected to the storage and preservation system 4 through a slide rail 301 (that is, the storage and preservation system is detachably installed in the cavity of the transportation loss reduction system 3), and the storage and preservation system 4 is placed on the slide rail 301 and connected by a slider (to realize the detachable collection function). The harvesting execution system 1 includes a cutting mechanism 11, a centrifugal fan 12, an air blowing unit 13, a flow guide shroud 14, a gripper rod 15, and a battery control module. The cutting mechanism 11 uses reciprocating blades to cut tea leaves (such as...). Figure 2 (As shown); the cutting mechanism 11 is located at the foremost end, and a sensor module is installed at the front end of the cutting mechanism 11. The sensor module includes a laser rangefinder and a near-infrared spectral sensor (both of which can be conventional models in the existing field, which those skilled in the art will know). It acquires the height of the tea tree canopy, the moisture content of the fresh leaves, and the tenderness in real time. The laser rangefinder array and the near-infrared spectral sensor are mounted on the upper part of the cutting mechanism 11 and on the outer side of the front end of the guide shroud 14 via a bracket, and are arranged linearly and equally spaced along the blade axis (the sensor signal lines are connected to the NMPC controller via shielded cables). The cutting mechanism 11 is connected to the centrifugal fan 12, and the centrifugal fan 12 is connected to the air blowing unit 13 and is located behind the cutting mechanism 11 (e.g.,Figure 3 As shown), the flow guide 14 is located above the cutting mechanism 11 and the air blowing unit 13, and the flow guide 14 is connected to the cutting mechanism 11. Inside the flow guide 14 and behind the cutting mechanism 11, a visual perception unit consisting of a binocular high-speed camera and a line laser sheet light source is symmetrically arranged. The two binocular cameras are symmetrically installed on the left and right side walls inside the flow guide 14, behind the cutting mechanism 11 and above the air blowing unit 13, with the lenses facing the material discharge area of ​​the cutting blade (the optical axis forms a 30° downward angle with the horizontal plane, completely covering the entire motion trajectory of the tea leaves after cutting); the line laser sheet light source is fixed in the middle position of the two binocular cameras, and the laser emission surface is parallel to the cutting blade edge (in conjunction with the binocular cameras to realize the real-time reconstruction of the three-dimensional point cloud and motion vector of the tea leaves). The gripper lever 15 is positioned above the flow guide shroud 14. The battery control module includes a lithium battery 16 and an NMPC control unit. The lithium battery 16 (via a hose) is electrically connected to the centrifugal fan 12 and the cutting mechanism 11. The NMPC control unit is positioned on the gripper lever 15 and is electrically connected to the sensor module, the vision sensing unit, and the centrifugal fan 12 (receiving signals from the sensor module and the vision sensing unit, solving for the optimal control quantity in real time, and dynamically adjusting the operating parameters of the blowing array and the suction fan).

[0030] The transportation damage reduction system 3 includes a pull rod 31, a transport box 32, a walking mechanism 33, casters 34, a negative pressure fan 35, and an active vibration damping unit; the pull rod 31 is located on the upper front end of the transport box 32 (e.g., Figure 4 As shown), the walking mechanism 33 is located at the bottom of the transport box 32 (to achieve stable transportation of tea leaves), and the casters 34 are located at the bottom of the transport box 32 in front of the walking mechanism 33 (to facilitate precise adjustment of the direction of movement during transportation). The negative pressure fan 35 is fixedly installed on the side wall of the transport box 32. The active vibration damping unit is located on the bottom surface inside the transport box 32, including a bearing platform, four sets of magnetorheological dampers, four sets of helical composite springs, a damper drive controller, a three-axis accelerometer and a gyroscope. The bearing platform is installed on the bottom surface inside the transport box 32, and the bearing platform and the bottom surface of the transport box 32 are connected by four sets of magnetorheological dampers and helical composite springs. The system consists of four composite vibration isolators, each positioned at one of the four corners of the platform. A three-axis accelerometer and a gyroscope are installed at the center of the platform to monitor vibration acceleration, impact signals, and box tilt angles during transport in real time. The data is transmitted to the damper drive controller and the central control system in real time. The damper drive controller is integrated into the central control system (which is the central hub controlling the operation of the entire integrated harvesting system; based on real-time vibration signals, it dynamically adjusts the excitation current of each magnetorheological damper to change the damping force, actively counteracting bumps and impacts during transport and reducing vibration transmission rate).

[0031] The storage and preservation system 4 includes a collection box 41, anti-damage airbags 42, a ventilation system 43, and a screen 44. The collection box 41 is located inside the transport box 32 and is connected to the transport box 32 via a bottom slide rail 301. Anti-damage airbags 42 are installed on the outer side wall of the collection box 41 to reduce tea loss during transportation (including five sets of airbags: front, rear, left, right, and bottom). The bottom anti-damage airbag 42 is fixedly installed on the upper surface of the carrying platform, and the surrounding anti-damage airbags 42 are respectively fitted and installed on the inner side of the surrounding limiting baffles of the installation position inside the collection box 41 (forming an all-round flexible buffer). The ventilation system 43 is located on the side of the collection box 41 to realize the tea preservation and storage function, and an exhaust grille is installed on the top of the collection box 41. The screen 44 is used to connect the collection box 41 and the collection pipe 20. The negative pressure airflow generated in the transport box 32 enters the collection box 41 through the screen 44 and prevents tea from leaking out of the collection box under negative pressure.

[0032] Example 2: As another preferred embodiment of the present invention, a tea harvesting method based on a blowing and suction combined flow field employs an integrated system as described in Example 1, comprising: Step S1, Adaptive Harvesting: First, move the integrated system to the tea row operation area, and then perform pre-operation calibration, cutting start-up, three-dimensional reconstruction of tea state, NMPC rolling optimization control, real-time resistance coefficient compensation, and anti-blocking pneumatic conveying in sequence. The pre-operation calibration process involves: first, acquiring tea tree canopy height distribution data using a laser rangefinder to determine the optimal cutting height; and then, using a near-infrared spectroscopy sensor to detect the average moisture content of the fresh leaves in real time. w hs With tenderness level n ed Based on the collected fresh leaf parameters, the shear strength of the fresh leaves was dynamically corrected. : ; In the formula: The standard shear strength (obtained experimentally; generally 1.2 × 10⁻⁶ for a single bud and leaf with 75% moisture content) represents the baseline shear strength. 6 Pa); Then, based on the real-time shear strength, the minimum cutting force required by the blade is calculated. F c With drive power P c Ensure smooth, unobstructed cutting without damaging buds or leaves: ; In the formula: A c This indicates the effective cross-sectional area of ​​a single cut (determined based on the width of the cut surface and the blade tooth pitch, typically 2.5 × 10⁻⁶).-4 m 2 ); v c This is expressed as the blade cutting linear speed (dynamically adjusted according to the tenderness of the fresh leaves; generally, it is 0.8–1.5 m / s for tenderness grades 1–2 and 1.5–2.0 m / s for tenderness grades 3–5).

[0033] Real-time detection of average moisture content of fresh leaves using a near-infrared spectroscopy sensor w hs With tenderness level n ed Specifically: First, samples of fresh tea leaves of different varieties and at different growth stages were collected, covering a moisture content range of 60% to 85% (moisture content was determined according to GB / T 8304-2013) and a tenderness grade of 1 to 5 (grade 1 fresh leaves are single buds, grade 2 fresh leaves are one bud and one leaf just beginning to unfold, grade 3 fresh leaves are one bud and one leaf or one bud and two leaves just beginning to unfold, grade 4 fresh leaves are one bud and two leaves or one bud and three leaves, and grade 5 fresh leaves are mature leaves or old leaves). Then, a near-infrared sensor was used to acquire the diffuse reflectance spectrum (wavelength range: 1100–2200 nm) of each sample, and the spectral absorbance was calculated. ; In the formula: Indicates wavelength Absorbance at that location; Indicates the sample at wavelength Reflectance at that location; These represent the light intensity reflected from the sample, the light intensity of the dark current, and the light intensity reflected from the standard white board, respectively. Next, the acquired raw spectra were preprocessed by performing Standard Normal Transform (SNV) and first derivative + SG smoothing: Standard normal variable transformation: ; In the formula: N A Indicates the number of wavelength points in a single spectrum; This represents the average absorbance of a single spectrum; First derivative + SG smoothing: ; In the formula: Indicates the wavelength interval (set according to the actual situation, such as 10nm); A partial least squares regression (PLSR) model was used to establish a correction model between the preprocessed spectrum and the water content reference value, thereby achieving the mapping from spectrum to water content. ; In the formula:b 0 represents the model intercept. b i Represents the regression coefficients for each characteristic wavelength (obtained from model training); Partial least squares discriminant analysis (PLS-DA) was used to establish a classification model between spectral density and tenderness grade: the tenderness grade was converted into dummy variable labels (e.g., grade 1 → 1, grade 2 → 2, ..., grade 5 → 5); a PLSR regression model was established between the preprocessed spectral density and the dummy labels, and the grade was determined based on the output value during prediction. ; In the formula, y pred The values ​​of the dummy variables represent the predictions made by the model; y k This represents the virtual label value (1-5) corresponding to the kth level. The real-time collected raw spectral data is input into the PLSR model and the PLS-DA model to obtain the average moisture content of fresh leaves. w hs With tenderness level n ed .

[0034] The cutting start-up process is as follows: The cutting drive motor is started, driving the reciprocating blade to perform high-frequency cutting motion. The operator pushes the device along the tea row... v c The blade moves forward at a constant speed, continuously cutting the fresh leaves on the tea bush surface, severing the tea leaves from the branches; during the cutting process, the load current of the blade drive motor is monitored in real time to ensure the actual cutting force. F c Satisfying "minimum cut threshold ≤ F c ≤ Upper limit threshold for bud and leaf damage.

[0035] The specific three-dimensional reconstruction of tea leaves is as follows: First, the left and right images from the binocular camera are input into the embedded processing unit for image denoising and distortion correction. Then, an adaptive background subtraction method is used to eliminate the fixed background and retain the foreground area of ​​the tea clump (a pre-collected background image of the guide fairing without tea leaves is used as the reference background, and the real-time acquired image is subtracted from the reference background). Adaptive threshold segmentation is performed on the subtracted image to obtain a binary mask of the tea clump. Through morphological operations of opening and closing operations, noise holes in the mask are eliminated and the edges of the tea clump are smoothed to obtain a complete connected component of the tea clump. Connected component detection is performed on the binary mask, and connected components that meet the area threshold of the tea clump are selected. Then, the foreground mask region of the tea leaf cluster is defined as a Region of Interest (ROI), and semi-global stereo matching (SGM) is used to match the tea leaf cluster regions in the corrected left and right images, calculating the disparity value of each foreground pixel.d sc (Disparity = x-coordinate of left image pixel - x-coordinate of right image pixel of the same target); By checking left and right consistency and filtering disparity threshold, mismatched points with abnormal disparity are eliminated to obtain the disparity map of the tea ball; Next, for each valid pixel in the tea leaf cluster area, calculate its three-dimensional spatial coordinates (X, Y, Z) in the left camera coordinate system: ; In the formula: Z represents the depth value (distance along the camera's optical axis) corresponding to the pixel; f Indicates the camera's equivalent focal length; B Indicates the binocular baseline distance; (x, y) Represents the x and y coordinates of a pixel in an image; (c x ,c y ) Indicates the coordinates of the camera's principal point; Then, based on the 3D point cloud of the tea leaf cluster and the tracking trajectory of consecutive frames, the 3D centroid coordinates are obtained sequentially. (X c (t), Y c [[ID= c (t)) Three-dimensional motion vector (i.e., velocity vector) ​ Actual acceleration of tea leaves a clus Real-time windward projection area of ​​tea leaves A proj Estimated quality of tea batch m clus ; Three-dimensional centroid coordinates (X c ​ c ​ c (t)) : ; In the formula: N represents the number of effective points in the tea leaf dot cloud; (X i ​ i ​ i (t)) This represents the three-dimensional coordinates of the i-th point in the point cloud; Three-dimensional motion vector (i.e., velocity vector) ​ : ; In the formula: This indicates the camera sampling period (generally no more than 5ms). Actual acceleration of tea leaves a clus : ; Stable acceleration values ​​were obtained by performing least-squares linear fitting on a velocity sequence of 3 to 5 frames. Real-time windward projection area of ​​tea leaves A proj : Determine the unit normal vector of the main airflow direction n f Establish a projected coordinate system: with the main direction of airflow as... Z’ The axis, the plane perpendicular to the airflow is ​ The projection plane is used to transform the 3D point cloud of the tea leaf mass from the camera coordinate system to the projection coordinate system using a rotation matrix; then, all 3D points are projected onto the projection plane. ​ Two-dimensional plane, ignoring the projected coordinate system Z’ The coordinates are used to obtain the two-dimensional projection point set of the tea ball; then, the minimum bounding contour of the projection point set is extracted using the convex hull algorithm, and the area of ​​the convex hull contour is calculated using the shoelace formula. This area is the real-time windward projection area of ​​the tea ball. A proj ; Estimated quality of tea group m clus First, divide the three-dimensional space containing the tea leaf point cloud into small voxels of equal size (e.g., 0.5mm × 0.5mm × 0.5mm). Count the number of effective voxels occupied by the point cloud, multiply it by the volume of a single voxel, and obtain the apparent volume of the tea leaf. V clus Then, based on the fresh leaf bulk density (experimental calibration value, generally 350 kg / m³), 3 ), to obtain the estimated quality of the tea shipment: ; In the formula: This indicates the bulk density of fresh leaves.

[0036] The NMPC rolling optimization control specifically aims to minimize the deviation between the predicted trajectory of the tea leaf ball's centroid and the ideal capture point at the inlet of the collection pipe. Simultaneously, it controls the actuator's motion increments to be smooth, avoiding frequent actions of the fan and solenoid valve. A loss function is constructed as follows: ; In the formula: N p This indicates the prediction time domain (typically 10–20). N c Indicates the control time domain (typically 3 to 5); Predict the centroid position vector of the tea leaf cluster in the time domain. This represents the vector representing the ideal capture point location at the inlet of the collection pipe; This represents the incremental control sequence of blowing and inhaling air velocities; Q , R The weight matrices representing position deviation and control increment respectively (generally) Q Take the identity matrix × 10, R (Take the identity matrix × 0.1). The controller solves for the following within each control cycle (generally no more than 10ms): J NMPC The minimum optimal control sequence outputs the first set of control quantities to the actuator. The first set of control quantities includes the duty cycle of the solenoid valve corresponding to the air blowing unit and the air outlet velocity. v b Adjust the speed of the negative pressure fan accordingly and control the average flow rate at the suction inlet. v s .

[0037] The real-time drag coefficient compensation specifically involves: based on the actual motion parameters of the tea ball, the drag coefficient of the tea ball is corrected in real time, and the blowing thrust is dynamically compensated. Real-time correction of tea leaf resistance coefficient: The real-time resistance coefficient is calculated by back-calculating the actual movement state of the tea leaf mass. C D,real : ; In the formula: g This represents the acceleration due to gravity (typically 9.81 m / s²). 2 ); This indicates the air density at room temperature (typically 1.205 kg / m³). 3 ); This indicates the relative speed between the airflow and the tea leaves. Dynamically compensated blowing thrust: through real-time correction of the drag coefficient C D,real Compensating for airflow thrust, obtaining the airflow thrust on a single blade. F blow With blowing flow rate Q b : ; ; In the formula: A fro This indicates the real-time windward projection area of ​​the tea ball; A b This indicates the effective flow cross-sectional area of ​​the air-blowing nozzle.

[0038] The anti-blocking pneumatic conveying method is as follows: under the guidance of the blowing and suction composite flow field, the tea leaves smoothly enter the collection pipe along the inner curved surface of the guide hood. The system dynamically adjusts the airflow speed in the pipe to achieve suspended conveying of the tea leaves without settling, without pipe blockage, and with low breakage, and finally falls into the collection box. Based on the real-time corrected drag coefficient, the minimum anti-clogging wind speed required to suspend tea leaves in the collection pipe is calculated: ; In the formula: d p This indicates the equivalent particle size of tea leaves (obtained through experimental measurement; generally, bulk tea is 8 × 10⁻⁶). -3 m); This indicates the density of the tea leaves (generally 1200 kg / m³). 3 ); v set Indicates the free settling velocity of tea leaves; Calculate the total pressure loss of the piping system Ensure that the full pressure of the blower meets the conveying requirements: ; In the formula: This indicates the friction coefficient (generally 0.015 to 0.02 for stainless steel pipes). L gd Indicates the length of the pipe. D gd Indicates the inner diameter of the pipe; The resistance coefficient (of elbows, reducers, tees, etc.) is indicated (obtained through experimental calibration based on actual conditions). The system dynamically adjusts the speed of the variable frequency negative pressure fan to ensure that the actual airflow velocity in the duct always meets the following requirements: ; In the formula: v dam This indicates the critical wind speed for tea leaf breakage (obtained from experimental measurements, generally 18 m / s).

[0039] Step S2, Fresh Leaf Storage and Ventilation: After the tea leaves fall into the collection box through the conveying pipe, the micro fan of the ventilation system at the bottom of the box is activated, and outside air enters the box; the airflow penetrates the tea leaf accumulation layer from bottom to top, carrying away the hot and humid air generated by the respiration of the fresh leaves; subsequently, the hot and humid air is discharged through the exhaust grille, forming a continuous convection circulation. The system dynamically adjusts fan speed and ventilation volume based on real-time data from sensors inside the chamber to maintain a stable storage environment for fresh leaves. First, based on data from the preset CO2 sensor inside the chamber, the system calculates the real-time respiration rate of the fresh leaves. With total respiratory heat power : ; In the formula: Indicates the effective volume of the collection box; Represents unit of time within ​ 2. Concentration changes; Indicates the quality of fresh leaves inside the box; Indicates the aerobic rate of fresh leaves; This indicates the enthalpy change of aerobic respiration (generally, 14.2 J of heat is released for every 1 mg of O2 consumed). Then, based on real-time respiratory heat, the minimum ventilation volume required to remove heat is calculated. Simultaneously, humidity control and gas concentration stability are taken into account to obtain the final ventilation volume: ; In the formula: C p It indicates the specific heat capacity of air at constant pressure (generally 1005 J / (kg·K)); it indicates the allowable temperature difference between the inlet and outlet air (generally 3 to 5 K). This indicates the amount of ventilation controlled by humidity. Indicates the ventilation volume for stable gas concentration; Next, the resistance of airflow penetrating the tea leaf accumulation layer was calculated. With air permeability coefficient K tq (Evaluate ventilation uniformity) Ensure the fan static pressure meets ventilation requirements and avoid airflow short-circuiting: ; ; In the formula: This indicates the dynamic viscosity of air at room temperature (typically 1.81 × 10⁻⁶). -5 Pa·s); This indicates the packing porosity of tea leaves (generally 0.4–0.5). v face Indicates the wind speed over the empty bed surface; L hd Indicates the thickness of the tea leaf layer; based on and The speed of the micro fan and the opening of the air volume regulating valve are dynamically adjusted to ensure that the airflow penetrates the entire tea leaf accumulation layer evenly, avoid local heat accumulation that could cause the fresh leaves to turn red or moldy, and maintain the activity of the fresh leaves. When the fresh leaves in the collection box reach the rated loading capacity (e.g., the material layer thickness ≤ 600mm), the system shuts down the cutting mechanism, centrifugal fan, negative pressure fan and vision acquisition system, completing a single harvesting cycle and preparing to enter the transfer and transportation stage in step S3.

[0040] Step S3, Adaptive Collaborative Loss Reduction and Dynamic Freshness Preservation Transportation: First, the collection box filled with fresh leaves is pushed into the carrying platform of the transport box via a slide rail, and the position of the collection box is locked (ensuring that the ventilation duct and control line are sealed and connected, and the signal transmission is stable). Then, the anti-pressure damage airbag control system is activated. Based on the amount of fresh leaves loaded in the collection box and the box's posture, the system calculates the optimal inflation pressure for each of the five independent chambers (front, rear, left, right, and bottom), and controls the inflation / deflation solenoid valves to inflate each airbag with gas at the corresponding pressure, forming an all-around flexible buffer. Specifically: For each airbag chamber, calculate the real-time load it bears: ; In the formula: i represents the chamber number (1 to 5, corresponding to the front, back, left, right, and bottom); m tea,i This indicates the equivalent mass of tea leaves contained in the corresponding chamber; This indicates the real-time tilt angle of the carriage (detected by a built-in gyroscope). a i This indicates the real-time acceleration in the corresponding direction; Based on real-time load, the optimal inflation pressure for each chamber is calculated. Balancing support and protection against crush damage: ; In the formula: P atm This indicates standard atmospheric pressure (typically 101325 Pa). K safe,i This indicates the safety factor (1.2 for static conditions and 1.5 to 2.0 for dynamic conditions under impact). A cont,i This indicates the effective contact area between the airbag and the housing; Simultaneously obtain the airbag light box stiffness k qn-i : ; In the formula: V qn-i This indicates the real-time volume of the airbag chamber; This indicates the air insulation index (typically 1.4). The system inflates each pressure-damage-prevention airbag with gas, monitors the internal pressure of the airbag in real time, and when it reaches... When the corresponding solenoid valve is closed, the airbag expands and fits tightly against the box and the wall of the carriage, which not only provides stable support but also prevents the fresh leaves from being crushed by excessive pressure. Subsequently, the multi-degree-of-freedom active vibration damping platform was activated. A three-axis accelerometer and gyroscope, sampling at a frequency of 1000Hz, collected vibration, impact, and tilt signals during transportation in real time. Based on these real-time signals, the damper drive controller dynamically adjusted the excitation current and damping force of the four sets of magnetorheological dampers, working in conjunction with the airbags to absorb impact energy. Specifically: Based on the vibration signals collected by sensors, the real-time impact kinetic energy during transportation is calculated: ; In the formula: m total Indicates the total mass of the collection box. v rms This indicates that we are testing the effective value of the vibration speed. Calculate the total energy absorbed by the airbag through passive energy absorption and the work done by magnetorheological active damping: ; In the formula: P 1,i Indicates the first i Initial pressure of each airbag chamber before impact. V 1,i Indicates the first i Initial volume of each airbag chamber before impact; P 2,i Indicates the first i Instantaneous pressure during the impact process of each airbag chamber V 2,i Indicates the first i The instantaneous volume of each airbag chamber after impact compression n air This indicates the air variability index (typically 1.4). F mr This represents the magnetorheological damping force actively controlled by the controller. ​ This represents the infinitesimal displacement element of the damper piston. Constraints: The damping force of the magnetorheological damper is dynamically adjusted based on constraints, and works in conjunction with the airbag to absorb the impact energy during transportation, significantly reducing the impact and vibration transmitted to the fresh leaves and avoiding mechanical damage. Meanwhile, during transportation, the ventilation system of the collection box is kept connected to an external mobile air source to continuously supply fresh air into the box. The ventilation volume is dynamically adjusted based on a vibration correction model of the respiration intensity of fresh leaves during transportation to maintain a slightly positive pressure environment inside the box. ; In the formula: This indicates the real-time respiration rate of fresh leaves during transportation; Indicates the resting respiratory rate. This represents the effective value of vibration acceleration.

[0041] Step S4, Unloading: Upon arrival at the destination, shut down the active vibration damping platform, airbag supply system, and mobile ventilation system, cut off the power source, and execute the pressure relief procedure: The system is based on the residual negative pressure attenuation formula and monitors the residual negative pressure in the collection box in real time (to ensure safe unloading): ; In the formula: Indicates after shutdown t end Constantly collect residual negative pressure inside the collection box; This indicates the rated negative pressure inside the collection tank before shutdown; R pq Indicates the exhaust resistance of the collection box; C sj Indicates the effective volume of the collection box; When the system detects When the negative pressure decay is complete, the airbag is controlled to naturally depressurize to atmospheric pressure to avoid the negative pressure residue causing the door to be difficult to open or the tea leaves to be adsorbed by the negative pressure and unable to be unloaded smoothly. Next, the collection box is removed from the transport vehicle and smoothly moved out of the transport box's slide rails. It is then transferred to the feed inlet of the subsequent processing equipment via a transfer trolley, ready for unloading. Open the box door, control the tilting angle of the box, and let the tea leaves slide smoothly down the box wall and be poured into the subsequent processing equipment; Based on the tilting angle of the container, the downward speed of the tea leaves is calculated (ensuring the speed is within a safe range to avoid breakage of fresh leaves due to unloading impact): ; In the formula: v slide Indicates the speed at which the tea leaves slide down the slope; L tea This indicates the length of the tea leaves' downward sliding path (i.e., the diagonal length inside the collection box door). Indicates the tilt angle of the collection box (generally 30°~45°); f tea This indicates the coefficient of friction between the tea leaves and the box wall (generally 0.2 to 0.3). Calculate the total unloading time (to ensure it matches the feeding rhythm of subsequent processing equipment): ; In the formula: This indicates the total volume of fresh leaves piled up inside the collection box; This indicates the effective unloading area of ​​the collection box door; Based on the calculation results, the system controls the tilting speed and angle of the box, so that the tea leaves slide smoothly down the box wall, avoiding mechanical damage caused by high-speed impact, while ensuring that the unloading time is precisely matched with the feeding rhythm of the subsequent processing equipment.

[0042] Example 3: As another preferred embodiment of the present invention, based on the embodiment 2, after unloading, compressed air is used to clean the collection box, conveying pipeline, harvesting mechanism, etc., to remove residual tea leaves and impurities; the system automatically stores the full process parameters of this operation (including harvesting parameters, ventilation data, transportation vibration reduction data, fresh leaf status data, etc.), completing a complete harvesting-storage-transportation operation closed loop, providing data support for subsequent operation optimization.

Claims

1. An integrated tea harvesting system based on a combined blowing and suction flow field, characterized in that: It includes a harvesting execution system, a collection pipeline, a transportation loss reduction system, and a storage and preservation system; wherein, the harvesting execution system is connected to the storage and preservation system through the collection pipeline, the transportation loss reduction system is located outside the storage and preservation system and is connected to the storage and preservation system through a slide rail, and the storage and preservation system is placed on the slide rail and connected by a slider. The harvesting execution system includes a cutting mechanism, a centrifugal fan, an air blowing unit, a flow guide, a gripper bar, and a battery control module. The cutting mechanism is located at the foremost position, with a sensor module installed at its front end. The cutting mechanism is connected to the centrifugal fan. The centrifugal fan is connected to the air blowing unit and located behind the cutting mechanism. The flow guide is located above the cutting mechanism and the air blowing unit and is connected to the cutting mechanism. A visual perception unit consisting of a binocular high-speed camera and a line laser sheet light source is symmetrically arranged inside the flow guide and behind the cutting mechanism. The gripper bar is located above the flow guide. The battery control module includes a lithium battery and an NMPC control unit. The lithium battery is electrically connected to the centrifugal fan and the cutting mechanism, and the NMPC control unit is electrically connected to the sensor module, the visual perception unit, and the centrifugal fan.

2. The integrated tea harvesting system based on a combined blowing and suction flow field according to claim 1, characterized in that: The cutting mechanism uses a reciprocating blade to cut tea leaves; the sensor module includes a laser rangefinder and a near-infrared spectral sensor. The laser rangefinder array and the near-infrared spectral sensor are mounted on the upper part of the cutting mechanism and the outer front end of the flow guide via a bracket, and are arranged linearly and equally at intervals along the blade axis; two binocular cameras are symmetrically mounted on the left and right side walls inside the flow guide, located behind the cutting mechanism and above the air blowing unit, with the lenses facing the material discharge area of ​​the cutting edge; the line laser sheet light source is fixed in the middle position of the two binocular cameras, and the laser emitting surface is parallel to the cutting edge of the cutting blade; the NMPC control unit is mounted on the gripper rod.

3. The integrated tea harvesting system based on a combined blowing and suction flow field according to claim 1 or 2, characterized in that: The transportation loss reduction system includes a tie rod, a transport box, a traveling mechanism, casters, a negative pressure fan, and an active vibration damping unit. The tie rod is located at the upper front end of the transport box, the traveling mechanism is located at the bottom of the transport box, the casters are located at the bottom of the transport box in front of the traveling mechanism, and the negative pressure fan is fixedly installed on the side wall of the transport box. The active vibration damping unit is located on the inner bottom surface of the transport box and includes a support platform, four sets of magnetorheological dampers, four sets of helical composite springs, a damper drive controller, a three-axis accelerometer, and a gyroscope. The support platform is installed on the inner bottom surface of the transport box, and the support platform and the bottom surface of the transport box are connected by four sets of composite vibration isolators composed of "magnetorheological dampers + helical composite springs". The four sets of composite vibration isolators are respectively arranged at the four corners of the support platform. The three-axis accelerometer and gyroscope are installed at the center of the support platform. The damper drive controller is integrated into the central control system.

4. A tea harvesting integrated system based on a blowing and suction combined flow field according to claim 2 or 3, characterized in that: The storage and preservation system includes a collection box, anti-pressure airbags, a ventilation system, and a screen. The collection box is located inside the transport box and connected to it via a bottom slide rail. Anti-pressure airbags are installed on the outer sidewalls of the collection box, with the bottom anti-pressure airbag fixedly installed on the upper surface of the support platform, and the surrounding anti-pressure airbags respectively fitted to the inner sides of the limiting baffles at the installation positions inside the collection box. The ventilation system is located on the side of the collection box, and an exhaust grille is installed on the top of the collection box. The screen is used to connect the collection box and the collection pipe, and the negative pressure airflow generated in the transport box enters the collection box through the screen.

5. The tea harvesting method of the integrated tea harvesting system based on a blowing and suction combined flow field according to claim 4, characterized in that: include: Step S1, Adaptive Harvesting: First, move the integrated system to the tea row operation area, and then perform pre-operation calibration, cutting start-up, three-dimensional reconstruction of tea state, NMPC rolling optimization control, real-time resistance coefficient compensation, and anti-blocking pneumatic conveying in sequence. Step S2, Fresh Leaf Storage and Ventilation: After the tea leaves fall into the collection box through the conveying pipe, the micro fan of the ventilation system at the bottom of the box is activated, and outside air enters the box; the airflow penetrates the tea leaf accumulation layer from bottom to top, carrying away the hot and humid air generated by the respiration of the fresh leaves; Subsequently, the hot and humid air is discharged through the exhaust grille, forming a continuous convection circulation; Step S3, Adaptive Collaborative Loss Reduction and Dynamic Freshness Preservation Transportation: The collection box filled with fresh leaves is pushed into the carrying platform of the transportation box via a slide rail, and the position of the collection box is locked; then, the transportation loss is reduced by anti-compression airbags and active vibration damping units; at the same time, the ventilation system of the collection box is kept connected to the external mobile air source during transportation to continuously supply fresh air into the box and maintain a slightly positive pressure environment inside the box. Step S4, Unloading: After arriving at the destination, shut down the active vibration damping platform, airbag supply system and mobile ventilation system, cut off the power source, then remove the collection box from the transport vehicle, open the box door, and pour the fresh leaves into the subsequent processing equipment.

6. The tea harvesting method of the integrated tea harvesting system based on a blowing and suction combined flow field according to claim 5, characterized in that: In step S1, the pre-operation calibration specifically involves: firstly, acquiring tea tree canopy height distribution data and determining the optimal cutting height using a laser rangefinder sensor; and secondly, using a near-infrared spectral sensor to detect the average moisture content of fresh leaves in real time. w hs With tenderness level n ed Based on the collected fresh leaf parameters, the shear strength of the fresh leaves was dynamically corrected. : ； In the formula: Indicates the reference shear strength under standard conditions; Then, based on the real-time shear strength, the minimum cutting force required by the blade is calculated. F c With drive power P c Ensure smooth, unobstructed cutting without damaging buds or leaves: ； In the formula: A c Indicates the effective cross-sectional area of ​​a single cut; v c This is expressed as the cutting speed of the blade.

7. The tea harvesting method of the integrated tea harvesting system based on a blowing and suction combined flow field according to claim 6, characterized in that: In step S1, the three-dimensional reconstruction of the tea leaves specifically involves: First, the left and right images from the binocular camera are input into the embedded processing unit for image denoising and distortion correction. Then, the adaptive background subtraction method is used to eliminate the fixed background and retain the foreground area of ​​the tea cluster. Adaptive threshold segmentation is performed on the difference image to obtain a binary mask of the tea cluster. Through morphological operations of opening and closing operations, noise holes in the mask are eliminated and the edges of the tea cluster are smoothed to obtain a complete connected component of the tea cluster. Connected component detection is performed on the binary mask to filter connected components that meet the area threshold of the tea cluster. Then, the foreground mask region of the tea cluster is defined as a Region of Interest (ROI), and semi-global stereo matching is used to match the tea cluster regions in the corrected left and right images, calculating the disparity value of each foreground pixel. d sc By checking left-right consistency and filtering disparity thresholds, mismatched points with abnormal disparity are eliminated to obtain the disparity map of the tea cake. Next, for each valid pixel in the tea leaf cluster area, calculate its three-dimensional spatial coordinates (X, Y, Z) in the left camera coordinate system: ； In the formula: Z represents the depth value corresponding to the pixel; f Indicates the camera's equivalent focal length; B Indicates the binocular baseline distance; (x,y) Represents the x and y coordinates of a pixel in an image; (c x ,c y ) Indicates the coordinates of the camera's principal point; Then, based on the 3D point cloud of the tea leaf cluster and the tracking trajectory of consecutive frames, the 3D centroid coordinates are obtained sequentially. (X c (t), Y c (t), Z c (t)) 3D motion vector v(t) Actual acceleration of tea leaves a clus Real-time windward projection area of ​​tea leaves A proj Estimated quality of tea batch m clus ; Three-dimensional centroid coordinates (X c (t), Y c (t), Z c (t)) : ； In the formula: N represents the number of effective points in the tea leaf dot cloud; (X i (t),Y i (t),Z i (t)) This represents the three-dimensional coordinates of the i-th point in the point cloud; Three-dimensional motion vector v(t) : ； In the formula: Indicates the camera sampling period; Actual acceleration of tea leaves a clus : ； Stable acceleration values ​​were obtained by performing least-squares linear fitting on a velocity sequence of 3 to 5 frames. Real-time windward projection area of ​​tea leaves A proj : Determine the unit normal vector of the main airflow direction n f Establish a projected coordinate system: with the main direction of airflow as... Z’ The axis, the plane perpendicular to the airflow is X'OY' The projection plane is used to transform the 3D point cloud of the tea leaf mass from the camera coordinate system to the projection coordinate system using a rotation matrix; then, all 3D points are projected onto the projection plane. X'OY' Two-dimensional plane, ignoring the projected coordinate system Z’ The coordinates are used to obtain the two-dimensional projection point set of the tea ball; then, the minimum bounding contour of the projection point set is extracted using the convex hull algorithm, and the area of ​​the convex hull contour is calculated using the shoelace formula. This area is the real-time windward projection area of ​​the tea ball. A proj ; Estimated quality of tea group m clus First, divide the three-dimensional space containing the tea leaf point cloud into tiny voxels of equal size. Count the number of effective voxels occupied by the point cloud, multiply it by the volume of a single voxel, and obtain the apparent volume of the tea leaf. V clus Then, based on the bulk density of the fresh leaves, the estimated mass of the tea cake is obtained: ； In the formula: This indicates the bulk density of fresh leaves.

8. The tea harvesting method of the integrated tea harvesting system based on a blowing and suction combined flow field according to claim 7, characterized in that: In step S1, the NMPC rolling optimization control specifically aims to minimize the deviation between the predicted trajectory of the tea ball's centroid and the ideal capture point at the inlet of the collection pipe, while simultaneously smoothing the incremental movements of the actuators to avoid frequent actions of the fan and solenoid valve, and constructing a loss function: ； In the formula: N p Indicates the prediction time domain, N c Indicates control over the time domain; Predict the centroid position vector of the tea leaf cluster in the time domain. This represents the vector representing the ideal capture point location at the inlet of the collection pipe; This represents the incremental control sequence of blowing and inhaling air velocities; Q , R These represent the weight matrices for position deviation and control increment, respectively. The controller solves for the following in each control cycle: J NMPC The minimum optimal control sequence outputs the first set of control quantities to the actuator. The first set of control quantities includes the duty cycle of the solenoid valve corresponding to the air blowing unit and the air outlet velocity. v b Adjust the speed of the negative pressure fan accordingly and control the average flow rate at the suction inlet. v s .

9. The tea harvesting method of the integrated tea harvesting system based on a blowing and suction combined flow field according to claim 8, characterized in that: In step S1, the real-time compensation of the resistance coefficient specifically involves: based on the actual motion parameters of the tea ball, the resistance coefficient of the tea ball is corrected in real time and the blowing force is dynamically compensated. Real-time correction of tea leaf resistance coefficient: The real-time resistance coefficient is calculated by back-calculating the actual movement state of the tea leaf mass. C D,real : ； In the formula: g Represents gravitational acceleration; This indicates the air density at room temperature. This indicates the relative speed between the airflow and the tea leaves. Dynamically compensated blowing thrust: through real-time correction of the drag coefficient C D,real Compensating for airflow thrust, obtaining the airflow thrust on a single blade. F blow With blowing flow rate Q b : ； ； In the formula: A fro This indicates the real-time windward projection area of ​​the tea ball; A b This indicates the effective flow cross-sectional area of ​​the air-blowing nozzle.

10. The tea harvesting method of the integrated tea harvesting system based on a blowing and suction combined flow field according to claim 9, characterized in that: In step S1, the anti-blocking pneumatic conveying is specifically as follows: under the guidance of the blowing and suction composite flow field, the tea leaves smoothly enter the collection pipe along the inner curved surface of the guide hood. The system dynamically adjusts the airflow speed in the pipe to achieve suspended conveying of the tea leaves without settling, without pipe blockage, and with low breakage, and finally falls into the collection box. Based on the real-time corrected drag coefficient, the minimum anti-clogging wind speed required to suspend tea leaves in the collection pipe is calculated: ； In the formula: d p Indicates the equivalent particle size of tea leaves; Indicates the density of the tea leaves; v set Indicates the free settling velocity of tea leaves; Calculate the total pressure loss of the piping system Ensure that the full pressure of the blower meets the conveying requirements: ； In the formula: Indicates the friction coefficient. L gd Indicates the length of the pipe. D gd Indicates the inner diameter of the pipe; Indicates the drag coefficient; The system dynamically adjusts the speed of the variable frequency negative pressure fan to ensure that the actual airflow velocity in the duct always meets the following requirements: ； In the formula: v dam This indicates the critical wind speed at which tea leaves break.

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