Clamping mechanism and mulberry leaf picking device and method thereof

Abstract

This invention discloses a clamping mechanism and its mulberry leaf picking device and method, belonging to the technical field of sericulture equipment. The clamping mechanism includes: multiple spaced clamping plate units, which are inserted laterally into mulberry branches, dividing them into several rows and clamping them in place, so that each row of mulberry branches is arranged along the growth direction of the branches and does not overlap. Each clamping plate unit includes a left clamping plate and a right clamping plate, with their front ends set at an acute angle facing the insertion direction of the mulberry branches, and their rear ends connected by an elastic support component; the distance between the left and right clamping plates is adaptively adjusted by the deformation of the elastic support component. The mulberry leaf picking device includes: a clamping mechanism; a leaf-picking mechanism that moves in the opposite direction from the root to the tip of the mulberry branch to pick off the mulberry leaves from each row of branches; and a collection mechanism to collect the picked-off mulberry leaves. This invention significantly improves picking efficiency and is suitable for large-scale mulberry leaf harvesting.

Description

Technical Field

[0001] This invention relates to the field of sericulture-related equipment technology, and more specifically, to a clamping mechanism and its mulberry leaf picking device and method. Background Technology

[0002] Mulberry leaves are the core raw material for silkworm farming, and their harvesting efficiency directly affects the economic benefits of the silkworm industry. Traditional mulberry leaf harvesting mainly relies on manual operation, which suffers from high labor intensity, low efficiency, and easy hand injuries. With the development of agricultural mechanization, existing technologies are gradually introducing automated equipment to improve these problems. For example, the Chinese patent authorization text with publication number CN107309876B proposes a robotic arm harvesting control method, which uses stereo vision and GPS positioning to plan the robotic arm's movement path to achieve automated mulberry leaf harvesting. However, this solution still has significant limitations: the robotic arm needs to locate and grasp mulberry leaves one by one. When facing the natural structure of mulberry branches growing scattered and densely intertwined, the path planning is highly complex, resulting in a long harvesting cycle and limited efficiency improvement. In addition, the robotic arm's leaf-by-leaf harvesting mode is difficult to adapt to the characteristic of mulberry trees where "branches grow scattered from the root upwards," which can easily lead to missed harvesting or mechanical collisions due to overlapping branches, or even damage to the branches, affecting subsequent growth.

[0003] The root of the problem lies in the fact that mulberry branches grow radially upwards from the rootstock, forming dense, intertwined clumps of branches, and existing technologies lack designs adapted to this branch structure. Robotic arms or harvesters must locate each branch individually in complex spaces, resulting in high operational redundancy. Furthermore, the overlapping and intersecting branches increase the difficulty of obstacle avoidance for the robotic arm, further reducing harvesting efficiency. Therefore, an innovative solution is urgently needed that can adapt to the dispersed growth characteristics of mulberry branches, achieve efficient batch harvesting, and minimize branch damage.

[0004] The root of the problem lies in the fact that mulberry branches grow radially upwards from the rootstock, forming dense, intertwined clumps of branches, and existing technologies lack designs adapted to this branch structure. Robotic arms or harvesters must locate each branch individually in complex spaces, resulting in high operational redundancy. Furthermore, the overlapping and intersecting branches increase the difficulty of obstacle avoidance for the robotic arm, further reducing harvesting efficiency. Therefore, an innovative solution is urgently needed that can adapt to the dispersed growth characteristics of mulberry branches, achieve efficient batch harvesting, and minimize branch damage. Summary of the Invention

[0005] The purpose of this invention is to provide a clamping mechanism, a leaf-plucking device, and a method for mulberry leaf harvesting, solving the problems of low efficiency and difficulty in adapting to the dispersed growth structure of mulberry branches in existing technologies where robotic arms harvest leaves one by one. By using a clamping mechanism for separation and fixation and a leaf-plucking mechanism for batch leaf plucking, harvesting efficiency is significantly improved while reducing manual intervention and branch damage, making it suitable for large-scale mulberry leaf harvesting.

[0006] To achieve these objectives, the present invention provides a clamping mechanism for mulberry leaf picking, comprising: Multiple spaced clamping units are configured to be inserted laterally into the mulberry branch cluster, dividing the mulberry branches into several columns and clamping and fixing them so that each column of mulberry branches is arranged along the growth direction of the branches and does not cross or stack with each other.

[0007] Preferably, each clamping unit includes a left clamping plate and a right clamping plate, the front ends of the left clamping plate and the right clamping plate are set at an acute angle, the angle facing the direction of insertion of the mulberry branch; the rear ends of the left clamping plate and the right clamping plate are connected by an elastic support assembly, the elastic support assembly including springs or elastic rubber blocks spaced apart along the length of the clamping plate; the distance between the left clamping plate and the right clamping plate is adaptively adjusted by the deformation of the elastic support assembly.

[0008] Preferably, it further includes a vibration unit, which is fixed to the inner surface of the left and / or right clamping plates or the elastic support assembly; The vibration unit includes a miniature vibration motor, an eccentric wheel, or a piezoelectric ceramic actuator, configured to trigger periodic vibration when the clamp is inserted into the mulberry twigs, with the vibration direction parallel to the insertion direction of the clamp.

[0009] Preferably, the operating modes of the vibration unit include: Insertion mode: When the clamp is inserted into the mulberry twigs, it starts high-frequency low-amplitude vibration to help the clamp penetrate the gaps between the branches; Clamping mode: After clamping and fixing, it switches to low-frequency vibration, which continuously offsets external force disturbances and maintains clamping stability through micro-amplitude vibration.

[0010] Preferably, the vibration frequency and amplitude of the vibration unit are adjustable, specifically dynamically matched by a controller according to the density and thickness of the mulberry branches, including: The clamping unit is equipped with a pressure sensor and an optical sensor. The pressure sensor is used to detect the squeezing force of the mulberry branches on the clamping plate in real time during the clamping process, and the optical sensor is used to scan the gap density and branch diameter of the mulberry branch cluster. The controller calculates the actual density level S and average diameter D of the mulberry branches based on the extrusion pressure change rate of the pressure sensor and the scanning data of the optical sensor, and generates dynamic adjustment instructions. The controller has a pre-stored vibration parameter mapping table, which associates the mulberry branch density level S, average diameter D, with vibration frequency F and amplitude A. Specifically, the mapping table includes: When the density level S ≥ the threshold, the vibration frequency F increases to 50-100Hz and the amplitude A decreases to 0.5-1mm, so as to decompose the resistance of dense branches with high-frequency vibration. When the average diameter D≤5mm, the vibration amplitude A is increased to 2-3mm and the frequency F is reduced to 20-40Hz, so as to avoid the breakage of twigs by low-frequency large-amplitude vibration. The controller retrieves matching vibration parameters from the mapping table based on the real-time calculated S and D values, and drives the vibration unit to execute the corresponding vibration mode through a pulse width modulation (PWM) signal. During the vibration process, the pressure sensor continuously monitors the change in the resistance of the mulberry branches. If the resistance value exceeds the preset range, the controller fine-tunes the vibration parameters until the resistance value returns to the stable range.

[0011] Preferably, the clamping surfaces of the left and right clamping plates are provided with a plurality of smooth elastic protrusions, the elastic protrusions are distributed at intervals along the length of the clamping plates, and an accommodating gap is formed between adjacent elastic protrusions; The width of the accommodating gap is 5-20mm, configured to accommodate one or more mulberry branches; The elastic protrusion is made of silicone or rubber material, with a height of 3-8mm. Its surface is hemispherical or wavy, and it has an embedded elastic support skeleton to provide radial buffering force through deformation during clamping.

[0012] Preferably, the spacing density of the elastic protrusions is adaptively adjusted according to the average diameter of the mulberry branches, including: The clamping surface of the clamping plate is provided with a sliding groove, and the bottom of the elastic protrusion is slidably connected to the sliding groove by a slider; Adjacent sliders are connected in series by an elastic telescopic component, which includes a spring or a shape memory alloy component, and its natural length is preset according to the average diameter of the mulberry branch. The spacing density of the elastic protrusions is dynamically adjusted in the following way: During the insertion stage: When the clamp is inserted into the mulberry twigs, the mulberry twigs squeeze the elastic protrusions, forcing the slider to slide along the groove, compressing or stretching the elastic expansion joints, so that the distance between adjacent elastic protrusions increases or decreases to match the actual distribution density of the mulberry twigs. During the clamping stage: After clamping is completed, the restoring force of the elastic telescopic component drives the slider to reset, so that the spacing density of the elastic protrusions (27) is restored to the preset reference value, providing initial adaptation conditions for the next harvest; The slide is marked with scales for manually adjusting the initial length of the elastic telescopic component.

[0013] The present invention provides a mulberry leaf picking device, comprising: The clamping mechanism described in any one of the claims is configured to be inserted laterally into the mulberry branch cluster, dividing the mulberry branches into several columns and clamping and fixing them so that each column of mulberry branches is arranged along the growth direction of the branches and does not cross or stack with each other. A leaf-plucking mechanism is located below the clamping mechanism. The leaf-plucking mechanism is configured to move in the opposite direction from the root to the tip of the mulberry branch after the clamping mechanism has fixed the mulberry branch, so as to pluck the mulberry leaves off each row of mulberry branches. A collection mechanism, located below the leaf-plucking mechanism, is used to collect the plucked mulberry leaves.

[0014] The present invention provides a method for operating the mulberry leaf picking device, comprising: Step S1: Scan the target mulberry twig cluster using an optical sensor to obtain data on branch density distribution and average diameter; adjust the clamping plate spacing of the clamping mechanism according to the scanning results. Step S2: Insert the clamping plate of the clamping mechanism horizontally or at an acute angle into the mulberry bushes; activate the insertion mode of the vibration unit. The controller dynamically matches high-frequency low-amplitude vibration based on real-time pressure sensor data and optical scanning results to assist the clamping plate in penetrating the gaps between the branches; the elastic support component and the elastic protrusion work together to adaptively adjust the clamping plate spacing to disperse resistance until the mulberry branches are separated into several rows and clamped and fixed. Step S3: Switch the vibration unit to clamping mode, and adjust the vibration parameters of the controller to low-frequency micro-amplitude vibration; start the leaf-picking mechanism so that it moves at a constant speed in the opposite direction from the root of the mulberry branch to the tip of the branch to peel off the mulberry leaves. Step S4: The peeled mulberry leaves fall into the leaf-receiving frame of the collecting mechanism; after harvesting, the controller turns off the vibration unit, the elastic telescopic component drives the slider to reset, and the clamping plate interval returns to the preset reference value; the clamping mechanism and the leaf-plucking mechanism return to the initial position according to the memory path, ready for the next harvesting cycle.

[0015] Preferably, the operation method further includes step S5: if the pressure sensor detects that the squeezing force exceeds the limit or the optical sensor identifies that the branch is broken, the controller immediately stops the equipment and issues an alarm.

[0016] The present invention has at least the following beneficial effects: 1. This invention enables efficient batch harvesting and improves efficiency. Through the comb-shaped clamping plate design of the clamping mechanism and the synergistic effect of the vibration unit, it separates the cross-stacked mulberry branches into several rows. Combined with the leaf-plucking mechanism, it peels off mulberry leaves in batches at once, completely changing the inefficient mode of traditional robotic arms picking leaves one by one, and significantly increasing the harvest yield per unit time. By optimizing the insertion mode (high-frequency low-amplitude vibration) and clamping mode (low-frequency micro-amplitude vibration) of the vibration unit in stages, the insertion resistance of the mulberry branches is greatly reduced, shortening the harvesting cycle.

[0017] 2. This invention can achieve protection and damage inhibition of mulberry branches. Its clamping mechanism employs elastic support components, elastic protrusions, and anti-slip textures. Through flexible clamping and vibration buffering, it decomposes mechanical stress, avoiding branch breakage or epidermal damage caused by rigid compression or hard friction. Furthermore, a controller uses optical and pressure sensors to monitor the condition of the mulberry branches in real time, dynamically adjusting vibration parameters (frequency, amplitude) and clamp spacing to ensure adaptive protection of weak branches.

[0018] 3. This invention features intelligent dynamic adaptation capabilities. Through the linkage between the elastic telescopic component and the sliding block, the spacing density of the clamping plates dynamically adjusts according to the diameter and distribution density of the mulberry branches, accommodating the morphological characteristics of mulberry trees at different growth stages. Furthermore, by combining multi-sensor data with a pre-stored parameter mapping table, the controller optimizes vibration parameters in real time, achieving the goal of high-density, high-frequency penetration and low-frequency protection for weak branches. Additionally, it supports manual calibration (sliding block scale) and parameter mapping table updates, adapting to various mulberry orchard scenarios such as mixed planting of new and old trees and high-density planting.

[0019] 4. This invention features a closed-loop control system covering the entire process from mulberry branch scanning and clamping insertion to leaf collection, reducing manual intervention and operational complexity. Through batch harvesting and intelligent control, it significantly reduces labor costs and is suitable for large-scale mulberry orchard harvesting needs.

[0020] 5. This invention solves the core problems of low efficiency, high damage and poor adaptability in the prior art, and provides a highly reliable and compatible technical path for the mechanized harvesting of mulberry leaves, promoting the upgrading of the sericulture industry towards intelligence and large-scale production.

[0021] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the clamping mechanism described in this invention; Figure 2 This is a schematic diagram of the clamping unit described in this invention; Figure 3 This is a schematic diagram of the structure of the elastic protrusion of the present invention; Figure 4 This is a schematic diagram of the mulberry leaf picking device described in this invention; Figure 5 This is a schematic diagram of the module structure for dynamic matching of the vibration unit of the present invention; Figure 6 This is a flowchart illustrating the operation method of the mulberry leaf picking device described in this invention. Figure 7 This is a picture of mulberry tree branches.

[0023] The components include: a collecting mechanism 1, a cylinder 101, a clamping mechanism 2, a clamping plate unit 2a, an included angle 2b, a center plate 2c, a connecting rod 2d, a seat plate 2e, a telescopic cylinder 2f, a slide 2g, a left clamping plate 21, a right clamping plate 22, an elastic support assembly 23, a vibration unit 25, a controller 26, a pressure sensor 261, an optical sensor 262, an elastic protrusion 27, a support frame 271, anti-slip particles 272, a sliding groove 273, a slider 274, a side groove 274a, an elastic telescopic component 275, a scale mark 276, a accommodating gap 28, and a leaf-plucking mechanism 3. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to examples, so that those skilled in the art can implement it based on the description.

[0025] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0026] like Figures 1-4 As shown, a clamping structure for picking mulberry leaves includes: The clamping mechanism includes multiple spaced clamping units 2a, which are configured to be inserted laterally into the mulberry branch cluster to divide the mulberry branches into several columns and clamp and fix them so that each column of mulberry branches is arranged along the growth direction of the branches and does not cross or stack with each other.

[0027] like Figure 1 As shown, three clamping plate units are arranged at intervals on the base plate 2e, forming a clamping space between them. Driven laterally by a telescopic cylinder 2f, they insert or remove mulberry branches. A sliding block 2g is fitted at the bottom of the telescopic cylinder 2f, which engages with the vertical drive track of the mulberry leaf picking device. Preferably, the clamping plate units are made of aluminum alloy with a polished surface to reduce friction. Preferably, the spacing between the clamping plate units is adjustable within the range of 50 to 150 mm.

[0028] During implementation, in actual operation, operators manually or through the harvesting device push the clamping plates laterally into the mulberry tree branches. This creates an isolation channel between adjacent clamping plates, forcing the originally intertwined branches to naturally align longitudinally. "Lateral insertion" means the clamping plates move perpendicular or nearly perpendicular to the axis of the mulberry branch's main trunk (a slight tilt is also acceptable). This insertion method effectively disperses the lateral forces between branches, providing favorable conditions for subsequent leaf removal and harvesting, and reducing the likelihood of broken branches during harvesting.

[0029] Furthermore, in another implementation, such as Figure 1 and 2As shown, each clamping unit includes a left clamping plate 21 and a right clamping plate 22. The front ends of the left clamping plate 21 and the right clamping plate 22 form an acute angle 2b, and the angle α is set to be an acute angle, with the angle 2b pointing towards the direction of insertion of the mulberry branch. The rear ends of the left clamping plate 21 and the right clamping plate 22 are supported by an elastic support assembly 23, which includes springs or elastic rubber blocks spaced apart along the length of the clamping plate. The distance between the left clamping plate 21 and the right clamping plate 22 is adaptively adjusted by the deformation of the elastic support component 23.

[0030] In the illustration, the left and right clamping plates are hinged at their front ends and connected to the center plate 2c via connecting rod 2d, forming a deformable linkage mechanism. Elastic support components 23 are disposed between the left and right clamping plates and the center plate. Their number and elastic coefficient are set according to the clamping force requirements. In the illustration, the elastic support components are support springs. Preferably, the support spring group adopts a stiffness gradient design, with lower stiffness at the front end to accommodate thin branches and higher stiffness at the rear end to stabilize thick branches, or fewer springs at the front end and more springs at the rear end.

[0031] During implementation, when the front end of the clamp contacts the twig cluster, the acute-angled structure naturally separates the twig to both sides. As the insertion depth increases, the lateral pressure generated by the twig compresses the spring, and the clamp spacing automatically widens to the appropriate size. In one example, when clamping a mulberry branch with a diameter of 12 mm, the spring compression reaches 8 mm, providing an effective clamping force of 150 Newtons, with a branch slippage rate of less than 3%. Preferably, the variable stiffness characteristic of the conical spring ensures that the pressure does not exceed 20 Newtons when clamping thin branches (less than 5 mm in diameter), avoiding damage to the branches.

[0032] The deformation characteristics of the elastic support component 23 in this embodiment allow the spacing between the clamping plate units to be dynamically adjusted according to the density and thickness of the mulberry branches, avoiding excessively tight clamping that could cause branch breakage or excessively loose clamping that could cause clamping failure. The acute angle (α, preferably 20~80°) design optimizes the guidance of the clamping plate when inserted into the mulberry branch cluster, while also adapting to the morphological characteristics of the naturally dispersed growth of mulberry branches.

[0033] Furthermore, in another implementation, such as Figure 2 As shown, it also includes a vibration unit 25, which is fixed to the inner surface of the left clamping plate 21 and / or the right clamping plate 22 or the elastic support assembly 23. The vibration unit 25 includes any one of a micro vibration motor, an eccentric wheel, or a piezoelectric ceramic actuator, and is configured to trigger periodic vibration when the clamp is inserted into the mulberry twigs, with the vibration direction parallel to the insertion direction of the clamp.

[0034] In the illustration, the vibration unit 25 is fixed inside the left clamping plate 21. A miniature eccentric wheel motor with a power of 15 watts can be selected. The vibration frequency can be adjusted within the range of 30 to 120 Hz, and the amplitude can be set within the range of 0.5 to 3 mm. Preferably, the vibration unit generates longitudinal vibration along the insertion direction. Preferably, the motor is fixed by rubber shock-absorbing pads to reduce energy loss.

[0035] During the insertion phase, the motor starts a high-frequency vibration mode of 80 Hz, causing the clamping plate to produce a small amplitude reciprocating motion. The vibration energy is mainly concentrated in the front 200 mm area, which can effectively reduce insertion resistance and reduce damage to the branch bark.

[0036] In this embodiment, the elastic support component 23 enables the left and right clamps to have elastic vibration characteristics. When inserting mulberry branches, the vibration can disperse the resistance of the intersecting branches and reduce the damage to the branches caused by hard collisions.

[0037] Furthermore, in another implementation, such as Figure 2 As shown, the operating modes of the vibration unit 25 include: Insertion mode: When the clamp is inserted into the mulberry twigs, it starts high-frequency low-amplitude vibration to help the clamp penetrate the gaps between the branches; Clamping mode: After clamping and fixing, it switches to low-frequency vibration, which continuously offsets external force disturbances and maintains clamping stability through micro-amplitude vibration.

[0038] In this embodiment, "high frequency and low amplitude" refers to a parameter combination with a frequency exceeding 50 Hz and an amplitude of less than 1 mm, which is suitable for decomposing the resistance of dense branches; "low frequency vibration" refers to continuous micro-amplitude vibration with a frequency below 40 Hz, which is mainly used to maintain a stable clamping state.

[0039] For example, the insertion mode uses a 100 Hz frequency with a 1 mm amplitude, while the clamping mode switches to a 25 Hz frequency with a 0.3 mm amplitude. The mode switching is automatically triggered by the Hall sensor detecting the displacement of the clamping plate. When the insertion depth reaches the preset 300 mm, the system completes the state transition within 0.2 seconds.

[0040] The phased vibration strategy of the insertion mode and the clamping mode in this embodiment ensures that the clamping plate can quickly penetrate the twigs, while maintaining clamping stability through low-frequency vibration to prevent the mulberry branches from slipping off.

[0041] Furthermore, in another implementation, such as Figure 5 As shown, the vibration frequency and amplitude of the vibration unit 25 are adjustable, specifically dynamically matched by the controller 26 according to the density and thickness of the mulberry branches, to further disperse the resistance of the interlacing branches and guide the mulberry branches to be evenly distributed along the gap of the clamp. The dynamic matching system specifically includes: The surface of the clamping plate (21, 22) is provided with a pressure sensor 261, and the clamping mechanism or other suitable position (such as on the seat plate 2e) is provided with an optical sensor 262. The pressure sensor is used to detect the squeezing force of the mulberry branch on the clamping plate in real time during the clamping process, and the optical sensor is used to scan the gap density and branch diameter of the mulberry branch cluster. The controller 26 calculates the actual density grade (S) and average diameter (D) of the mulberry branches based on the extrusion pressure change rate of the pressure sensor 261 and the scanning data of the optical sensor 262, and generates dynamic adjustment instructions. The controller has a pre-stored vibration parameter mapping table, which associates the matching relationship between mulberry branch density grade (S), average diameter (D), and vibration frequency (F) and amplitude (A), specifically including: When the density level (S) is greater than or equal to the threshold, the vibration frequency (F) is increased to 50-100Hz and the amplitude (A) is reduced to 0.5-1mm to decompose the resistance of dense branches with high-frequency vibration. When the average diameter (D) is ≤5mm, the vibration amplitude (A) is increased to 2-3mm and the frequency (F) is reduced to 20-40Hz to avoid the breakage of twigs by low-frequency large-amplitude vibration. The controller retrieves matching vibration parameters from the mapping table based on the real-time calculated (S) and (D) values, and drives the vibration unit 25 to execute the corresponding vibration mode through a pulse width modulation (PWM) signal. During the vibration process, the pressure sensor continuously monitors the change in the resistance of the mulberry branches. If the resistance value exceeds the preset range, the controller fine-tunes the vibration parameters based on the fuzzy PID algorithm until the resistance value returns to the stable range.

[0042] For example, an integrated thin-film piezoelectric pressure sensor and an optical sensor are used. The pressure sensor has a range of 0 to 300 Newtons, and the optical sensor uses time-of-flight ranging technology to achieve millimeter-level accuracy. The controller has a built-in parameter mapping table that divides branch density into five levels (S1 to S5) and diameter into three grades (D1 to D3). For example, D1 is less than 5 mm, D2 is 5 to 10 mm, and D3 is more than 10 mm.

[0043] When an S3-level density is detected in conjunction with a D2-level diameter (5 to 10 mm), the system automatically selects vibration parameters with an 80 Hz frequency and a 1.2 mm amplitude. During dynamic adjustment, the controller samples data 20 times per second and corrects the parameters in real time using a composite control algorithm. This composite control algorithm combines fuzzy logic and proportional-integral-derivative control, effectively handling nonlinear changes in branch parameters.

[0044] The optical sensor 262 employs a laser 3D scanning module based on the time-of-flight (TOF) principle, equipped with an 850 nm wavelength VCSEL laser source, covering a scanning angle of 120° × 60°. The sensor incorporates a 1280 × 720 pixel SPAD array detector, enabling depth image acquisition at 200 frames per second. Within a working distance of 0.5-1.2 meters from the mulberry branches, the spatial resolution reaches ±1 mm, and the depth accuracy is ±3 mm. One example of its data processing workflow includes: the raw 3D point cloud data is first downsampled through voxel mesh filtering, reducing the point density from 500,000 points per frame to 100,000 points while preserving key features. An improved RANSAC algorithm is then used to separate the mulberry branches from the background based on the cylindrical geometric features, eliminating leaf interference. The number of branch axes per unit volume (10 cm³) was statistically analyzed to establish a density index S ranging from 0 to 5. Piecewise circular fitting was performed on individual branches, and the median was used as the average diameter D. A 9-dimensional feature vector (S / D combination) was constructed, and the optimal vibration parameters (F / A) were matched using a pre-trained random forest model. Controller 26 updates the vibration parameters every 50 ms, obtaining baseline parameters from a table based on the real-time S / D value. Based on 10 kHz sampling data from pressure sensor 261, real-time fine-tuning was performed using a fuzzy PID algorithm: when the resistance change rate > 5 N / s, the frequency was instantaneously increased by 10%; when the pressure fluctuation standard deviation > 3 N, the amplitude was increased by 15%.

[0045] This implementation allows for adjustable frequency and amplitude, enabling vibration parameters to be precisely adapted to different mulberry branch conditions (such as the difference between the flexibility of new branches and the hardness of old branches), thus improving equipment compatibility in complex scenarios. Through multi-sensor fusion, parameter mapping, and closed-loop control mechanisms, the dynamic matching process of the vibration unit is transformed into a quantifiable and replicable technical solution, solving the problems of reliance on experience and poor adaptability in vibration parameter adjustment in existing technologies, and significantly improving the intelligence level of the equipment in complex mulberry groves.

[0046] The above implementation method solves the problems of high insertion resistance and poor adaptability caused by the interlacing of branches in the prior art, and is especially suitable for mulberry gardens with high-density planting.

[0047] Furthermore, in another implementation, such as Figures 1-3 As shown, multiple smooth elastic protrusions 27 are provided on the clamping surfaces of the left clamping plate 21 and the right clamping plate 22. The elastic protrusions 27 are distributed at intervals along the length of the clamping plate, and an accommodating gap 28 is formed between adjacent elastic protrusions. The width of the accommodating gap 28 is 5-20mm, and it is configured to accommodate one or more mulberry branches; The elastic protrusion 27 is made of silicone or rubber material, with a height of 3-8mm. Its surface is hemispherical or wavy, and an elastic support skeleton 271 is embedded inside to provide radial buffering force through deformation during clamping. Radial buffering force refers to the elastic reaction force perpendicular to the clamping plate surface generated when the protrusion is pressed. It is suitable for mulberry branches with rough surfaces, reducing bark damage and improving the stability of branch fixation.

[0048] Specifically, the elastic protrusion 27 is made of silicone material with a Shore hardness of 40A, and is hemispherical with a diameter of 10 mm and a height of 5 mm. The spacing between adjacent protrusions is designed to be 15 mm, forming an accommodating gap 28. The internal support frame 271 is made of 0.8 mm thick spring steel sheet pre-bent into an arc or wave-shaped structure, which can provide a radial cushioning force of about 8 Newtons per millimeter.

[0049] During insertion, the mulberry branch slides over the elastic protrusion surface and enters the receiving gap 28. During the clamping process, the protrusion undergoes elastic deformation, thereby increasing the contact area.

[0050] In this embodiment, the smooth, elastic protrusion 27 buffers the clamping pressure through deformation, avoiding damage to the mulberry branch bark caused by rigid contact, and is especially suitable for the protection of tender branches.

[0051] In this embodiment, the flexible structure of the elastic protrusion 27 is combined with the vibration wave transmission of the vibration unit 25 to further decompose the resistance of the branches and improve the penetration efficiency of the clamping mechanism through high-density mulberry branches.

[0052] Furthermore, in another implementation, such as Figure 1 and 3 As shown, the spacing density of the elastic protrusions 27 is adaptively adjusted according to the average diameter of the mulberry branches, including: The clamping surfaces of the clamping plates (21, 22) are provided with sliding grooves 273, and the bottom of the elastic protrusion 27 is slidably connected to the sliding grooves 273 via a slider 274; Figure 3 As shown, side grooves 274a are provided on both sides of the slider, and the side grooves 274a slide in cooperation with the two sides of the slide groove 273. Adjacent sliders 274 are connected in series by elastic telescopic members 275, which include springs or shape memory alloy components, and their natural length is preset according to the average diameter of the mulberry branches. The spacing density of the elastic protrusions 27 is dynamically adjusted in the following manner: Insertion stage: When the clamp is inserted into the mulberry twigs, the mulberry twigs squeeze the elastic protrusions 27, forcing the slider 274 to slide along the groove 273, compressing or stretching the elastic telescopic member 275, so that the distance between adjacent elastic protrusions 27 increases or decreases to match the actual distribution density of the mulberry twigs. During the clamping stage, after clamping is completed, the restoring force of the elastic telescopic member 275 drives the slider 274 to reset, so that the spacing density of the elastic protrusions 27 returns to the preset reference value, providing initial adaptation conditions for the next harvest. The slide 273 is provided with scale markings 276 for manually adjusting the initial length of the elastic telescopic component 275 to adapt to the average diameter range of mulberry branches in different mulberry orchards.

[0053] In the illustration, adjacent sliders 274 are connected in series via elastic telescopic members 275. The two sliders at the ends are connected to the slide rail via elastic telescopic members 275. The elastic telescopic members 275 use springs with a preset restoring force of 12 Newtons. The slide rail surface has graduations 276 in 5-millimeter increments, corresponding to adjustments for mulberry branches with diameters ranging from 3 to 18 millimeters. During insertion, the branch presses against the elastic protrusion 27, causing the sliders 274 to slide, resulting in elastic deformation of the springs. After clamping is complete, the springs drive the sliders to return to their original position.

[0054] In this embodiment, through the linkage of the slider 274 and the elastic telescopic component 275, the spacing density of the elastic protrusions 27 responds in real time to the distribution density of mulberry branches during insertion, avoiding errors caused by manual pre-setting. The restoring force of the elastic telescopic component 275 ensures that the spacing density automatically resets after clamping, guaranteeing consistent adaptability for repeated use of the equipment. The scale markings 276 support manual calibration, suitable for specific scenarios with significant differences in mulberry branch diameters (such as mixed new and old mulberry orchards). The rigid guiding design of the groove 273 and the slider 274 prevents the elastic protrusions 27 from shifting out of control, ensuring uniform force on the clamping surface.

[0055] This implementation achieves dynamic adjustment of the elastic protrusion spacing density through a mechanically adaptive structure, transforming the real-time perception of mulberry branch diameter and distribution density into physical deformation of the spacing. This solves the problem of insufficient clamping compatibility caused by the fixed spacing design in the prior art, and significantly improves the equipment's universality for mulberry trees at different growth stages.

[0056] Furthermore, such as Figure 3 As shown, the top of the elastic protrusion is provided with anti-slip particles 272, which are used to increase the frictional contact area with the surface of the mulberry branch and at the same time avoid scratching the bark of the mulberry branch.

[0057] like Figure 4 As shown, the present invention provides a mulberry leaf picking device, comprising: The clamping mechanism 2 described in any one of the present invention is configured to be inserted laterally into the mulberry branch cluster, dividing the mulberry branches into several columns and clamping and fixing them so that each column of mulberry branches is arranged along the growth direction of the branches and does not cross or stack with each other. Leaf-plucking mechanism 3 is located below the clamping mechanism. The leaf-plucking mechanism 3 is configured to move in the opposite direction from the root to the tip of the mulberry branch after the clamping mechanism fixes the mulberry branch, so as to pluck the mulberry leaves off each row of mulberry branches at once. The collecting mechanism 1, located below the leaf-plucking mechanism, is used to collect the plucked mulberry leaves.

[0058] Preferably, the clamping mechanism has adjustable clamping plate spacing to accommodate the need to separate mulberry branches of different densities and thicknesses. Preferably, the movement path of the leaf-plucking mechanism is consistent with the natural downward direction of the mulberry branches, ensuring efficient leaf removal and reducing branch damage.

[0059] In the illustration, the collecting mechanism 1 includes a leaf-collecting frame, which comprises a left half and a right half, and is constructed using an aluminum alloy frame. The leaf-collecting frame is hinged to form a ring-like structure. A double-acting cylinder 101 is installed in the middle to drive the opening and closing mechanism, which is also driven by a telescopic component. After the clamping mechanism secures the mulberry branches, the cylinder 101 pushes the left and right half-frames to close, forming an enclosing space with a diameter of 80-200mm, encircling a group of mulberry branches. Mulberry leaves are received below the leaf-collecting frame. A negative pressure device can also be added to achieve rapid adsorption and collection of mulberry leaves.

[0060] The leaf-plucking mechanism can employ two sets of adjustable-speed rotating brush rollers, with a speed range of 50 to 200 rpm and a bristle length of 30 mm. After the clamping mechanism fixes the branch, the brush rollers move against the branch's growth direction at a speed of 120 rpm, with a moving speed of 0.4 m / s; the bristles contact the base of the mulberry leaf petiole tangentially, applying a peeling force of 3-5 N; the peeled mulberry leaves fall into the leaf-collecting frame, and are then collected below the frame.

[0061] Alternatively, the leaf-plucking mechanism can adopt the same structure as the clamping mechanism of this invention, differing only in the number or elastic setting of the elastic support components 23. For example, the number of elastic support components 23 is reduced from 3 to 2, and the spacing is increased to 200mm; the spring stiffness coefficient is reduced from 50N / mm to 20N / mm. These differences allow for greater mobility between the clamping plate of the leaf-plucking mechanism and the mulberry tree, facilitating leaf plucking while reducing damage to the mulberry tree. In summary, the leaf-plucking process involves the clamping plate lightly clamping the branch with a pre-tightening force of 15N, the opening and closing degree adaptively adjusted to the branch diameter + 2mm, and the leaf-plucking mechanism moving downwards along the branch at a speed of 0.3m / s.

[0062] like Figure 6 and Figure 7 As shown, the operating method of the mulberry leaf picking device provided by the present invention includes: Step S1: Pre-adjustment of mulberry branch positioning and clamping mechanism The target mulberry twigs were scanned using an optical sensor 262 to obtain data on branch density distribution and average diameter. Adjust the clamping plate spacing of the clamping mechanism according to the scanning results, and adjust the initial length of the elastic telescopic member 275 according to the scale mark 276 on the slide groove 273 so that the initial spacing of the elastic protrusion is adapted to the average diameter of the mulberry branch. Step S2: Insertion of clamping mechanism and vibration damping Insert the clamping plate of the clamping mechanism horizontally or at an acute angle into the mulberry bushes (e.g., Figure 7 ); The vibration unit 25 is activated in insertion mode. The controller 26 dynamically matches high-frequency low-amplitude vibration (50-100Hz, 0.5-1mm) based on the real-time pressure sensor 261 data and optical scanning results, assisting the clamping plate in penetrating the gaps between branches. The elastic support component 23 and the elastic protrusion 27 work together to adaptively adjust the spacing of the clamping plates to disperse resistance until the mulberry branches are divided into several columns and clamped and fixed. Step S3: Optimize clamping state and execute leaf removal Switch the vibration unit 25 to the clamping mode. The controller 26 adjusts the vibration parameters (20-40Hz, 2-3mm) based on the fuzzy PID algorithm to counteract external force disturbances through low-frequency micro-amplitude vibration. The leaf-plucking mechanism is activated, causing it to move at a constant speed in the opposite direction from the root of the mulberry branch to the tip. The clamping mechanism restricts the sliding of the mulberry branch, ensuring that the mulberry leaves are peeled off in one go. The optical sensor 262 monitors the integrity of the mulberry leaves in real time. If residual mulberry leaves are detected, the controller 26 triggers the leaf-picking mechanism to reciprocate and re-collect leaves. Step S4: Mulberry leaf collection and equipment reset The stripped mulberry leaves are guided by the leaf-plucking mechanism into the leaf-receiving frame of the collection mechanism, and then received by the collection bag; After harvesting, the controller 26 shuts off the vibration unit 25, and the elastic telescopic component 275 drives the slider 274 to reset, restoring the preset reference value at intervals. The clamping mechanism and the leaf-picking mechanism return to their initial positions according to the memorized path, ready for the next picking cycle.

[0063] Furthermore, in another embodiment, the operation method further includes: Step S5: Anomaly Handling and Parameter Calibration If the pressure sensor 261 detects that the compressive force exceeds the limit or the optical sensor 262 identifies that the branch is broken, the controller 26 immediately stops the equipment and issues an alarm. The operator intervenes manually based on the alarm information, adjusting the 273 scale of the slide or updating the vibration matching rules in the parameter mapping table, and restarts the equipment after completing the system calibration.

[0064] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention. Further modifications can be readily implemented by those skilled in the art.

Claims

1. A clamping mechanism for picking mulberry leaves, characterized in that, include: Multiple spaced clamping units are configured to be inserted laterally into the mulberry branch cluster, dividing the mulberry branches into several columns and clamping and fixing them so that each column of mulberry branches is arranged along the growth direction of the branches and does not cross or stack with each other. Each clamping unit includes a left clamping plate and a right clamping plate. The front ends of the left clamping plate and the right clamping plate are set at an acute angle, with the angle facing the direction of mulberry branch insertion. The rear ends of the left clamping plate and the right clamping plate are connected by an elastic support assembly, which includes springs or elastic rubber blocks spaced apart along the length of the clamping plate. The distance between the left clamping plate and the right clamping plate is adaptively adjusted by the deformation of the elastic support assembly. It also includes a vibration unit, which is fixed to the inner surface of the left and / or right clamping plates or to an elastic support assembly; The operating modes of the vibration unit include: Insertion mode: When the clamp is inserted into the mulberry twigs, it starts high-frequency low-amplitude vibration to help the clamp penetrate the gaps between the branches; Clamping mode: After clamping and fixing, it switches to low-frequency vibration, which continuously offsets external force disturbances and maintains clamping stability through micro-amplitude vibration; The vibration frequency and amplitude of the vibration unit are adjustable, specifically dynamically matched by a controller based on the density and thickness of the mulberry branches. This includes: The clamping unit is equipped with a pressure sensor and an optical sensor. The pressure sensor is used to detect the squeezing force of the mulberry branches on the clamping plate in real time during the clamping process, and the optical sensor is used to scan the gap density and branch diameter of the mulberry clump. The controller calculates the actual density grade S and average diameter D of mulberry branches based on the extrusion pressure change rate of the pressure sensor and the scanning data of the optical sensor, and generates dynamic adjustment instructions. Multiple smooth, elastic protrusions are provided on the clamping surfaces of both the left and right clamping plates, and the elastic protrusions are spaced apart along the length of the clamping plates. Furthermore, the spacing density of the elastic protrusions is adaptively adjusted according to the average diameter of the mulberry branches, including: The clamping surface of the clamping plate is provided with a sliding groove, and the bottom of the elastic protrusion is slidably connected to the sliding groove through a slider; Adjacent sliders are connected in series by elastic telescopic components, which include springs or shape memory alloy components, and their natural length is preset according to the average diameter of the mulberry branches.

2. The clamping mechanism as described in claim 1, characterized in that, The vibration unit includes a miniature vibration motor, an eccentric wheel, or a piezoelectric ceramic actuator, configured to trigger periodic vibration when the clamp is inserted into the mulberry twigs, with the vibration direction parallel to the insertion direction of the clamp.

3. The clamping mechanism as described in claim 1, characterized in that, The controller has a pre-stored vibration parameter mapping table, which associates the mulberry branch density level S, average diameter D, with vibration frequency F and amplitude A. Specifically, the mapping table includes: When the density level S ≥ the threshold, the vibration frequency F increases to 50-100Hz and the amplitude A decreases to 0.5-1mm, so as to decompose the resistance of dense branches with high-frequency vibration. When the average diameter D≤5mm, the vibration amplitude A is increased to 2-3mm and the frequency F is reduced to 20-40Hz, so as to avoid the breakage of twigs by low-frequency large-amplitude vibration. The controller retrieves matching vibration parameters from the mapping table based on the real-time calculated S and D values, and drives the vibration unit to execute the corresponding vibration mode through a pulse width modulation (PWM) signal. During the vibration process, the pressure sensor continuously monitors the change in the resistance of the mulberry branches. If the resistance value exceeds the preset range, the controller fine-tunes the vibration parameters until the resistance value returns to the stable range.

4. The clamping mechanism according to claim 1, characterized in that, An accommodating gap is formed between adjacent elastic protrusions; the width of the accommodating gap is 5-20mm, configured to accommodate one or more mulberry branches; the elastic protrusion is made of silicone or rubber material, with a height of 3-8mm, and its surface is hemispherical or wavy, with an elastic support skeleton embedded inside, used to provide radial buffering force through deformation when clamped.

5. The clamping mechanism according to claim 4, characterized in that, The spacing density of the elastic protrusions is dynamically adjusted in the following ways: During the insertion stage: When the clamp is inserted into the mulberry twigs, the mulberry twigs squeeze the elastic protrusions, forcing the slider to slide along the groove, compressing or stretching the elastic expansion joints, so that the distance between adjacent elastic protrusions increases or decreases to match the actual distribution density of the mulberry twigs. During the clamping stage: After clamping is completed, the restoring force of the elastic telescopic component drives the slider to reset, so that the spacing density of the elastic protrusions is restored to the preset reference value, providing initial adaptation conditions for the next harvest. The slide is marked with scales for manually adjusting the initial length of the elastic telescopic component.

6. A mulberry leaf picking device, characterized in that, include: The clamping mechanism according to any one of claims 1 to 5 is configured to be inserted laterally into the mulberry branch cluster, dividing the mulberry branches into several columns and clamping and fixing them, so that each column of mulberry branches is arranged along the growth direction of the branches and does not cross or stack with each other. A leaf-plucking mechanism is located below the clamping mechanism. The leaf-plucking mechanism is configured to move in the opposite direction from the root to the tip of the mulberry branch after the clamping mechanism has fixed the mulberry branch, so as to pluck the mulberry leaves off each row of mulberry branches. A collection mechanism, located below the leaf-plucking mechanism, is used to collect the plucked mulberry leaves.

7. A method for operating the mulberry leaf picking device according to claim 6, characterized in that, include: Step S1: Scan the target mulberry twig cluster using an optical sensor to obtain data on branch density distribution and average diameter; adjust the clamping plate spacing of the clamping mechanism according to the scanning results. Step S2: Insert the clamping plate of the clamping mechanism horizontally or at an acute angle into the mulberry bushes; activate the insertion mode of the vibration unit. The controller dynamically matches high-frequency low-amplitude vibration based on real-time pressure sensor data and optical scanning results to assist the clamping plate in penetrating the gaps between the branches; the elastic support component and the elastic protrusion work together to adaptively adjust the clamping plate spacing to disperse resistance until the mulberry branches are separated into several rows and clamped and fixed. Step S3: Switch the vibration unit to clamping mode, and adjust the vibration parameters of the controller to low-frequency micro-amplitude vibration; Start the leaf-plucking mechanism so that it moves at a constant speed in the opposite direction from the root of the mulberry branch to the tip of the branch, and peel off the mulberry leaves. Step S4: The peeled mulberry leaves fall into the leaf-receiving frame of the collecting mechanism; after harvesting, the controller turns off the vibration unit, the elastic telescopic component drives the slider to reset, and the clamping plate interval returns to the preset reference value; the clamping mechanism and the leaf-plucking mechanism return to the initial position according to the memory path, ready for the next harvesting cycle.

8. The operating method as described in claim 7, characterized in that, It also includes step S5: if the pressure sensor detects that the squeezing force exceeds the limit or the optical sensor identifies that the branch is broken, the controller immediately stops the equipment and issues an alarm.

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