Litchi moving and vibrating combined harvesting equipment and harvesting method thereof

Abstract

The invention discloses litchi moving and vibrating combined harvesting equipment and a harvesting method thereof. The litchi moving and vibrating combined harvesting equipment comprises a flexible multi-rod continuum parallel mechanism, an electric push rod lifting mechanism, a fruit collecting mechanism, a depth vision camera, a control box and a crawler, the flexible multi-rod continuum parallel mechanism is installed on a top platform of the electric push rod lifting mechanism, the electric push rod lifting mechanism is installed on a top platform of the crawler, and the fruit collecting mechanism is installed on the side face of the electric push rod lifting mechanism and located under a vibration comb of the flexible multi-rod continuum parallel mechanism. The depth vision camera is installed on a supporting frame of the flexible multi-rod continuum parallel mechanism and used for collecting litchi depth images and transmitting the litchi depth images to the industrial personal computer in the control box to be analyzed and processed, finally the flexible multi-rod continuum parallel mechanism and the electric push rod lifting mechanism are controlled to act in a combined mode, and vibration harvesting is conducted. The lychee harvester can effectively improve the harvesting efficiency and reduce the lychee harvesting cost.

Description

Technical Field

[0001] The present invention relates to the technical field of fruit harvesting instruments, and in particular to a litchi shifting and vibrating composite harvesting device and a harvesting method thereof. Background Technique

[0002] Litchi is a typical subtropical seasonal fresh fruit, and its centralized market period is from April to July every year. Due to the characteristics of high sugar and high water content in the pulp, it is extremely perishable and deteriorates easily after ripening. Therefore, the harvesting operation needs to be completed within a very short time after the fruit reaches the optimal maturity, and corresponding preservation treatments should be taken. During the litchi harvesting process, the harvesting link, as the core process, still mainly relies on manual operation at present, with problems such as low harvesting efficiency and high labor costs. Therefore, the introduction of mechanized harvesting can not only reduce labor costs but also significantly improve labor efficiency. At present, the main methods of litchi harvesting are shear harvesting and mechanical vibration harvesting. Shear harvesting is to cut off the litchi branches by a shear end effector to achieve the harvesting of a whole cluster of fruits. In the literature [Li Lanyun, Huang Huadong, Luo Dongwei, Chen Guanhai, Guan Zongliang, Zou Guangfu, A Litchi Picking Robot System, Patent Publication Number: CN117378361A, 2023], a litchi picking robot system is mentioned. This system is equipped with a shear picker at the end of a cylindrical coordinate picking manipulator. During operation, the litchi cluster is cut off from the litchi branch by shearing, and the litchi falls into the fruit buffer bin. This design is accurate and efficient during harvesting, but the subsequent processing still needs to add a step of removing the stalk, which is not convenient for subsequent processing; while mechanical vibration harvesting is to apply mechanical vibration to the fruit tree to shake it strongly so that the fruit stalk breaks under the centrifugal force to achieve the effect of forced batch separation of fruits. A litchi profiling vibration harvester mentioned in the literature [Li Jun, Jiang Runpeng, Mai Chaodong, Li Can, Li Zhao, Zeng Ye, Xia Juan, Wu Kaixuan, Zhang Meiqi, Ma Zhe, Cai Jiamin, Ke Senlan, A Litchi Profiling Vibration Harvester and Its Control Method, Patent Publication Number: CN118020495A, 2024] harvests fruits by driving the harvesting roller to vibrate the fruits through a crank-link mechanism. This harvesting method has high efficiency and speed and does not require subsequent branch and stalk removal treatment. However, this mechanism harvests from a large area of the tree crown, and it is easy to pat the fruits and cause fruit damage. A litchi harvesting device based on a movable and vibrating Delta parallel mechanism mentioned in the literature [Wang Weizu, Liang Yu, Chen Jiahong, Lao Leya, Cai Minghui, Zhao Ziyan, Li Jun, A Litchi Harvesting Device and Method Based on a Movable and Vibrating Delta Parallel Mechanism, Patent Publication Number: CN118489424A, 2024] has a working principle that a binocular vision camera takes a three-dimensional space image of the litchi, and an industrial control computer calculates the litchi coordinates. The Delta parallel mechanism completes two harvesting actions of positioning and vibrating the litchi; the motion decoupling characteristic of the parallel mechanism can effectively improve the positioning accuracy of the end effector, and its closed-loop motion chain structure is more conducive to the directional transmission of vibration energy; but the inertial load generated during high-speed vibration operation increases significantly, which puts higher requirements on the material strength of the support frame and the dynamic compensation ability of the drive system. Summary of the Invention

[0003] The object of the present invention is to overcome the disadvantages and deficiencies of the prior art, and provide a litchi moving and vibrating combined harvesting device and a harvesting method thereof, which can effectively improve the harvesting efficiency and reduce the litchi harvesting cost.

[0004] To achieve the above object, the technical solution provided by the present invention is: a litchi moving and vibrating combined harvesting device, including a flexible multi-bar continuum parallel mechanism, an electric push rod lifting mechanism, a fruit collection mechanism, a depth vision camera, a control box and a crawler vehicle; the flexible multi-bar continuum parallel mechanism is installed on the top platform of the electric push rod lifting mechanism, and the flexible multi-bar continuum parallel mechanism is provided with a moving platform connected by flexible rods, and a vibrating comb is installed on the moving platform. The moving platform and the vibrating comb are driven by a synchronous belt servo motor to achieve high-frequency vibration, and the litchi is vibrated and dropped onto the fruit collection mechanism; the electric push rod lifting mechanism is installed on the top platform of the crawler vehicle, and is used to control the heights of the flexible multi-bar continuum parallel mechanism and the fruit collection mechanism to ensure that the litchi fruit harvesting vibration point is within the working space of the flexible multi-bar continuum parallel mechanism; the fruit collection mechanism is installed on the side of the electric push rod lifting mechanism and is located directly below the vibrating comb of the flexible multi-bar continuum parallel mechanism, and is used to collect the vibrated and dropped litchi fruits; the depth vision camera is installed on the support frame of the flexible multi-bar continuum parallel mechanism, and is used to collect litchi depth images and transmit them to the industrial computer in the control box for analysis and processing, and finally control the combined action of the flexible multi-bar continuum parallel mechanism and the electric push rod lifting mechanism, and perform vibrating harvesting.

[0005] Furthermore, the flexible multi-rod continuum parallel mechanism includes a support frame, three synchronous belt linear modules, three synchronous belt servo motors, three flexible rod clamping seats, a flexible rod guiding mechanism, flexible rods, a moving platform, and a vibration comb. The three synchronous belt linear modules are respectively the first synchronous belt linear module, the second synchronous belt linear module, and the third synchronous belt linear module. The three synchronous belt linear modules are parallel to each other and horizontally installed on the support frame. The second synchronous belt linear module and the third synchronous belt linear module are arranged facing each other, and the first synchronous belt linear module is located below the two of them. The center lines of the three synchronous belt linear modules are equally distributed at 120° intervals in a circle. Each synchronous belt linear module is paired with a synchronous belt servo motor and a flexible rod clamping seat. The synchronous belt linear module is driven by the synchronous belt servo motor to move. The flexible rod clamping seat is installed on the slide table of the synchronous belt linear module. Each flexible rod clamping seat is paired with a flexible rod. The flexible rod is clamped and fixed by the flexible rod clamping seat and extends outward through its corresponding flexible rod guiding mechanism to be connected to the moving platform. The flexible rod guiding mechanism is installed on the support frame and is located in front of the corresponding synchronous belt linear module of the flexible rod. The vibration comb is installed on the moving platform. During operation, by respectively controlling the movement angles of the three synchronous belt servo motors, the flexible rods are directly driven to make the moving platform and the vibration comb reach the target fruit stalk space coordinates, and the respective synchronous belt servo motors are respectively controlled to move quickly, so that the moving platform and the vibration comb vibrate at a high frequency, thereby realizing effective vibration of the fruit stalks to complete litchi harvesting.

[0006] Furthermore, the electric push rod lifting mechanism includes a bottom platform, four vertical guide rails, a lifting platform, an electric push rod module, and a push rod servo motor. The bottom platform is installed on the top platform of the tracked vehicle. Four columns are installed thereon and are distributed in a rectangle. Each column is installed with a vertical guide rail. The lifting platform extends downward with four feet corresponding to the four vertical guide rails. A slider is installed on each foot. The slider and its corresponding vertical guide rail form a sliding pair to realize vertical guiding movement. The electric push rod module is located at the center of the rectangle formed by the four columns. One end of it is hinged to the bottom platform, and the other end extends upward and is rigidly connected to the lower surface of the lifting platform to control the lifting of the lifting platform. The push rod servo motor is installed on the bottom platform and is drivingly connected to the electric push rod module through a coupling to drive the electric push rod module to move.

[0007] Furthermore, the fruit collection mechanism includes a first folding mechanism, a second folding mechanism, and a collection net. The first folding mechanism and the second folding mechanism are symmetrically installed on the lifting platform of the electric push rod lifting mechanism. The collection net fills the space between the first folding mechanism and the second folding mechanism. Four corners of it are hung on the first folding mechanism and the second folding mechanism by screws, and are used to collect the litchi fruits vibrated and harvested by the flexible multi-rod continuum parallel mechanism.

[0008] Further, a lithium battery pack, a servo motor driver, and an industrial control computer are built into the industrial control box; the lithium battery pack provides power for the entire harvesting device; there are four servo motor drivers, which respectively correspond to three synchronous belt servo motors and one push rod servo motor, and transmit control information of the corresponding servo motors; the industrial control computer establishes a real-time communication connection with the servo motor driver through the EtherCAT industrial bus, and the built-in multi-axis motion control system thereof is configured with a harvesting process monitoring module, which can collect vibration comb pose information in real time, and realize full-process closed-loop control and abnormal condition diagnosis of the harvesting operation.

[0009] Further, the support frame is assembled by aluminum profiles and corner codes.

[0010] The present invention also provides a harvesting method for the above-mentioned litchi moving and vibrating composite harvesting device, including the following steps:

[0011] S1. After determining the harvesting area of the litchi, the tracked vehicle drives to the litchi harvesting point;

[0012] S2. The depth vision camera takes a depth image of the litchi and transmits the depth image to the industrial control computer. The control system in the industrial control computer calls the YOLOv11 neural network model optimized based on transfer learning according to the litchi depth image information collected by the depth vision camera, extracts the litchi morphological features through the feature pyramid network, and outputs the three-dimensional coordinates of the fruit stalk key points and the litchi cluster attitude angle;

[0013] S3. The industrial control computer uses the traveling salesman algorithm to plan the picking order for the picking coordinate points in the working space, obtains the obstacle point cloud data after denoising operation according to the depth image information and plans the optimal obstacle avoidance motion path by the RTT* algorithm, and obtains the obstacle avoidance motion data according to the inverse kinematics model of the mechanism;

[0014] S4. The industrial control computer sends a sequence of motion commands through the EtherCAT industrial bus. First, it drives the push rod servo motor for Z-direction positioning to make the picking coordinate within the working space of the flexible multi-rod continuum parallel mechanism, and then controls the synchronous belt linear module to move, and finally makes the vibration comb reach the target fruit stalk space coordinate; the industrial control computer transmits the motion information required for vibration to the servo driver, so that the synchronous belt servo motor reciprocates quickly, making the moving platform and the vibration comb vibrate at a high frequency, vibrating the litchi and dropping it into the fruit collection mechanism;

[0015] S5. The depth vision camera takes pictures of the litchi picking situation in real time and transmits the depth image to the industrial control computer in real time. After confirming that the litchi at the current target point has been completely picked, the industrial control computer repeats step S4 according to the picking order planned by the traveling salesman algorithm;

[0016] S6. When all the litchis within the field of view of the depth vision camera have been harvested, the industrial control computer controls the flexible multi-rod continuum parallel mechanism and the electric push rod lifting mechanism to reset, and the harvesting operation ends.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] 1. The present invention adopts a flexible parallel mechanism design. The flexible rod material used has both stiffness and flexibility characteristics, which can effectively buffer the rigid impact generated by picking vibration, is beneficial to the subsequent maintenance of the mechanism, and significantly improves the service life of the mechanism. On the premise of ensuring the same harvesting effect as the traditional rigid structure, the overall mass of the mechanism is significantly reduced, the frame structure is lighter, which is convenient for assembly and transportation, and at the same time, the operation safety performance is improved.

[0019] 2. When the present invention performs harvesting operations, the flexible rod is pressed and bent by the movement of the sliding table to achieve precise positioning of the litchi within the working area; during vibration harvesting, the elastic potential energy provided by the compression and bending of the flexible rod is converted into kinetic energy to provide a large acceleration, and the high-frequency reciprocating motion effectively shakes off the litchi.

[0020] 3. The present invention integrates the spatial positioning function and the vibration harvesting function of the flexible parallel mechanism, significantly improving the harvesting operation efficiency. Under the guidance of the machine vision system, the flexible parallel mechanism has multiple degrees of freedom and high flexibility in spatial positioning. The flexible parallel mechanism can quickly move to the harvesting point, and after positioning, drive the flexible parallel mechanism to perform high-frequency reciprocating motion to shake off the litchi. This integrated design not only effectively simplifies the mechanical structure but also reduces the manufacturing cost.

[0021] 4. With the support of machine vision, the present invention can accurately position to avoid damaging other branches, so as to achieve effective vibration harvesting of litchi, greatly reducing the labor cost and further improving the litchi picking efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 One of the structural schematic diagrams of the litchi moving and vibrating composite harvesting equipment.

[0023] Figure 2 Another structural schematic diagram of the litchi moving and vibrating composite harvesting equipment.

[0024] Figure 3 One of the structural schematic diagrams of the flexible multi-rod continuum parallel mechanism.

[0025] Figure 4 Another structural schematic diagram of the flexible multi-rod continuum parallel mechanism.

[0026] Figure 5 One of the structural schematic diagrams of the electric push rod lifting mechanism.

[0027] Figure 6 Another structural schematic diagram of the electric push rod lifting mechanism.

[0028] Figure 7 It is a schematic structural diagram of the fruit collection mechanism.

[0029] Figure 8 It is a schematic internal diagram of the control box.

[0030] Figure 9 It is a schematic diagram of the working process of the litchi moving and vibrating combined harvesting equipment. Specific embodiments

[0031] The present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0032] As Figures 1 to 8 shown, this embodiment discloses a litchi moving and vibrating combined harvesting equipment, including a flexible multi-rod continuum parallel mechanism 1, an electric push rod lifting mechanism 2, a fruit collection mechanism 3, a depth vision camera 4, a control box 5 and a tracked vehicle 6; the flexible multi-rod continuum parallel mechanism 1 is installed on the top platform of the electric push rod lifting mechanism 2, and the flexible multi-rod continuum parallel mechanism 1 is provided with a moving platform 107 connected by a flexible rod 106, and a vibration comb 108 is installed on the moving platform 107. The moving platform 107 and the vibration comb 108 are driven by a synchronous belt servo motor 103 to achieve high-frequency vibration, and the litchis are vibrated and dropped onto the fruit collection mechanism 3; the electric push rod lifting mechanism 2 is installed on the top platform of the tracked vehicle 7 and is used to control the heights of the flexible multi-rod continuum parallel mechanism 1 and the fruit collection mechanism 3 to ensure that the vibration points for harvesting litchi fruits are within the working space of the flexible multi-rod continuum parallel mechanism 1; the fruit collection mechanism 3 is installed on the side of the electric push rod lifting mechanism 2 and is located directly below the vibration comb 108 of the flexible multi-rod continuum parallel mechanism 1, and is used to collect the vibrated and dropped litchi fruits; the depth vision camera 4 is installed on the support frame 101 of the flexible multi-rod continuum parallel mechanism 1 and is used to collect litchi depth images and transmit them to the industrial computer 503 in the control box 5 for analysis and processing, and finally control the combined action of the flexible multi-rod continuum parallel mechanism 1 and the electric push rod lifting mechanism 2 and perform vibration harvesting.

[0033] Specifically, the flexible multi-bar continuum parallel mechanism 1 includes a support frame 101, three synchronous belt linear modules, three synchronous belt servo motors 103, three flexible rod clamping seats 104, a flexible rod guiding mechanism 105, flexible rods 106, a moving platform 107, and a vibration comb 108. The support frame 101 is assembled from aluminum profiles and corner codes. The three synchronous belt linear modules are the first synchronous belt linear module 102-1, the second synchronous belt linear module 102-2, and the third synchronous belt linear module 102-3 respectively. The three synchronous belt linear modules are parallel to each other and horizontally installed on the support frame 101. The second synchronous belt linear module 102-2 and the third synchronous belt linear module 102-3 are arranged opposite to each other, and the first synchronous belt linear module 102-1 is located below the two of them. The center lines of the three synchronous belt linear modules 102 are equally distributed at 120° intervals in a circle. Each synchronous belt linear module is paired with a synchronous belt servo motor 103 and a flexible rod clamping seat 104. The synchronous belt servo motor 103 drives the synchronous belt linear module to move. The flexible rod clamping seat 104 is installed on the slide 102-4 of the synchronous belt linear module. Each flexible rod clamping seat 104 is paired with a flexible rod 106. The flexible rod 106 is clamped and fixed by the flexible rod clamping seat 104 and extends outward through the corresponding flexible rod guiding mechanism 105 to be connected to the moving platform 107. The flexible rod guiding mechanism 105 is installed on the support frame 101 and is located in front of the corresponding synchronous belt linear module of the flexible rod 106. The vibration comb 108 is installed on the moving platform 107. During operation, by respectively controlling the movement angles of the three synchronous belt servo motors 103, the flexible rods 106 are directly driven to make the moving platform 107 and the vibration comb 108 reach the target fruit stalk space coordinates, and the respective synchronous belt servo motors 103 are respectively controlled to move quickly, so that the moving platform 107 and the vibration comb 108 vibrate at a high frequency, thereby realizing effective vibration of the fruit stalk to complete litchi harvesting.

[0034] Specifically, the electric push rod lifting mechanism 2 includes a bottom platform 201, four vertical guide rails 202, a lifting platform 203, an electric push rod module 204 and a push rod servo motor 205; the bottom platform 201 is installed on the top platform of the tracked vehicle 6, on which four columns are installed and distributed in a rectangle, and each column is equipped with a vertical guide rail 202. The lifting platform 203 extends downward with four feet corresponding to the four vertical guide rails 202, and each foot is equipped with a slider, and the slider forms a sliding pair with its corresponding vertical guide rail 202 to achieve vertical guiding movement; the electric push rod module 204 is located at the center of the rectangle surrounded by the four columns, one end of which is hinged to the bottom platform 201, and the other end extends upward and is rigidly connected to the lower surface of the lifting platform 203 to control the lifting and lowering of the lifting platform 203; the push rod servo motor 205 is installed on the bottom platform 201 and is drivingly connected to the electric push rod module 204 through a coupling to drive the electric push rod module 204 to move.

[0035] Specifically, the fruit collection mechanism 3 includes a first folding mechanism 301-1, a second folding mechanism 301-2 and a collection net 302. The first folding mechanism 301-1 and the second folding mechanism 301-2 are symmetrically installed on the lifting platform 203 of the electric push rod lifting mechanism 2; the collection net 302 fills the space between the first folding mechanism 301-1 and the second folding mechanism 301-2, and its four corners are hung on the first folding mechanism 301-1 and the second folding mechanism 301-2 by screws, and is used to collect the litchi fruits vibrated and harvested by the flexible multi-rod continuum parallel mechanism 1.

[0036] Specifically, the industrial control box 5 is internally provided with a lithium battery pack 501, a servo motor driver 502 and an industrial control computer 503; the lithium battery pack 501 provides power for the entire harvesting device; there are four servo motor drivers 502, which respectively correspond to three synchronous belt servo motors 103 and a push rod servo motor 205, and transmit the control information of the corresponding servo motors; the industrial control computer 503 establishes a real-time communication connection with the servo motor driver 502 through the EtherCAT industrial bus, and the multi-axis motion control system embedded therein is configured with a harvesting process monitoring module, which can collect the pose information of the vibration comb 108 in real time, and realize the full-process closed-loop control and abnormal working condition diagnosis of the harvesting operation.

[0037] As Figure 9 shown, the following is the harvesting process of the above-mentioned litchi moving and vibrating composite harvesting device in this embodiment, and its specific process is as follows:

[0038] S1. After determining the harvesting area of the litchi, the tracked vehicle 6 drives to the litchi harvesting point;

[0039] S2. The depth vision camera 4 captures the depth image of the litchi and transmits the depth image to the industrial control computer 5. The control system in the industrial control computer 5 calls the YOLOv11 neural network model optimized based on transfer learning, extracts the morphological features of the litchi through the feature pyramid network, and outputs the three-dimensional coordinates of the key points of the fruit stalk and the attitude angle of the litchi cluster;

[0040] S3. The industrial control computer 5 uses the traveling salesman algorithm to plan the picking order for the picking coordinate points in the working space, obtains the obstacle point cloud data after denoising operation according to the depth image information and plans the optimal obstacle avoidance motion path by the RTT* algorithm, and obtains the obstacle avoidance motion data according to the inverse kinematics model of the mechanism;

[0041] S4. The industrial control computer 5 sends a sequence of motion instructions through the EtherCAT industrial bus. First, it drives the push rod servo motor 205 for Z-axis positioning to make the picking coordinate within the working space of the flexible multi-rod continuum parallel mechanism 1, and then controls the movement of the synchronous belt linear module. Finally, it makes the vibrating comb 108 reach the target spatial coordinates of the fruit stalk. The industrial control computer 503 transmits the motion information required for vibration to the servo driver 502, makes the synchronous belt servo motor 103 reciprocate rapidly, makes the moving platform 107 and the vibrating comb 108 vibrate at a high frequency, shakes the litchi off and drops it into the fruit collection mechanism 3;

[0042] S5. The depth vision camera 4 captures the litchi picking situation in real time and transmits the depth image to the industrial control computer 503 in real time. After confirming that the litchi at the current target point has been completely picked, the industrial control computer 503 repeats step S4 according to the picking order planned by the traveling salesman algorithm;

[0043] S6. When all the litchis within the field of view of the depth vision camera 4 have been harvested, the industrial control computer 503 controls the flexible multi-rod continuum parallel mechanism 1 and the electric push rod lifting mechanism 2 to reset, and the harvesting operation ends.

[0044] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A litchi shifting and vibrating combined harvesting device, characterized in that, It includes a flexible multi-rod continuum parallel mechanism (1), an electric push rod lifting mechanism (2), a fruit collection mechanism (3), a depth vision camera (4), a control box (5) and a crawler vehicle (6); the flexible multi-rod continuum parallel mechanism (1) is installed on the top platform of the electric push rod lifting mechanism (2), and the flexible multi-rod continuum parallel mechanism (1) is provided with a moving platform (107) connected by flexible rods (106), a vibration comb (108) is installed on the moving platform (107), and the moving platform (107) and the vibration comb (108) are driven by a synchronous belt servo motor (103) to achieve high-frequency vibration, so as to shake down the lychees to the fruit collection mechanism (3); the electric push rod lifting mechanism (2) is installed on the top platform of the crawler vehicle (7) and is used to control the heights of the flexible multi-rod continuum parallel mechanism (1) and the fruit collection mechanism (3) to ensure that the vibration points for harvesting lychee fruits are within the working space of the flexible multi-rod continuum parallel mechanism (1); the fruit collection mechanism (3) is installed on the side of the electric push rod lifting mechanism (2) and is located directly below the vibration comb (108) of the flexible multi-rod continuum parallel mechanism (1) and is used to collect the shaken-down lychee fruits; the depth vision camera (4) is installed on the support frame (101) of the flexible multi-rod continuum parallel mechanism (1) and is used to collect the depth images of the lychees and transmit them to the industrial computer (503) in the control box (5) for analysis and processing, and finally control the combined action of the flexible multi-rod continuum parallel mechanism (1) and the electric push rod lifting mechanism (2) to perform vibration harvesting.

2. The litchi shifting and vibrating combined harvesting device according to claim 1, characterized in that, The flexible multi-rod continuum parallel mechanism (1) includes a support frame (101), three synchronous belt linear modules, three synchronous belt servo motors (103), three flexible rod clamping seats (104), a flexible rod guiding mechanism (105), flexible rods (106), a moving platform (107), and a vibration comb (108); the three synchronous belt linear modules are respectively a first synchronous belt linear module (102-1), a second synchronous belt linear module (102-2), and a third synchronous belt linear module (102-3). The three synchronous belt linear modules are parallel to each other and are horizontally installed on the support frame (101). The second synchronous belt linear module (102-2) and the third synchronous belt linear module (102-3) are oppositely arranged facing each other. The first synchronous belt linear module (102-1) is located below the two of them. The center lines of the three synchronous belt linear modules (102) are equally distributed at 120° intervals in a circle; each synchronous belt linear module is paired with a synchronous belt servo motor (103) and a flexible rod clamping seat (104). The synchronous belt servo motor (103) drives the synchronous belt linear module to move. The flexible rod clamping seat (104) is installed on the slide table (102-4) of the synchronous belt linear module. Each flexible rod clamping seat (104) is paired with a flexible rod (106). The flexible rod (106) is clamped and fixed by the flexible rod clamping seat (104) and extends out through the corresponding flexible rod guiding mechanism (105) to be connected to the moving platform (107). The flexible rod guiding mechanism (105) is installed on the support frame (101) and is located in front of the corresponding synchronous belt linear module of the flexible rod (106). The vibration comb (108) is installed on the moving platform (107); during operation, by respectively controlling the movement angles of the three synchronous belt servo motors (103), the flexible rods (106) are directly driven to make the moving platform (107) and the vibration comb (108) reach the target fruit stalk space coordinates, and the movement of each synchronous belt servo motor (103) is respectively controlled to move quickly, so that the moving platform (107) and the vibration comb (108) vibrate at a high frequency, thereby realizing effective vibration of the fruit stalk to complete litchi harvesting.

3. The litchi shifting and vibrating composite harvesting device according to claim 2, wherein The electric push rod lifting mechanism (2) includes a bottom platform (201), four vertical guide rails (202), a lifting platform (203), an electric push rod module (204) and a push rod servo motor (205); the bottom platform (201) is installed on the top platform of the tracked vehicle (6), and four columns are installed thereon and are distributed in a rectangle. A vertical guide rail (202) is installed on each column. The lifting platform (203) extends downward with four feet corresponding to the four vertical guide rails (202), and a slider is installed on each foot. The slider and its corresponding vertical guide rail (202) form a sliding pair to achieve vertical guiding movement; the electric push rod module (204) is located at the center of the rectangle surrounded by the four columns. One end of it is hinged to the bottom platform (201), and the other end extends upward and is rigidly connected to the lower surface of the lifting platform (203) to control the lifting and lowering of the lifting platform (203); the push rod servo motor (205) is installed on the bottom platform (201) and is drivingly connected to the electric push rod module (204) through a coupling to drive the electric push rod module (204) to move.

4. The litchi shaking and vibration combined harvesting device according to claim 3, characterized in that, The fruit collection mechanism (3) includes a first folding mechanism (301-1), a second folding mechanism (301-2) and a collection net (302). The first folding mechanism (301-1) and the second folding mechanism (301-2) are symmetrically installed on the lifting platform (203) of the electric push rod lifting mechanism (2); the collection net (302) fills the space between the first folding mechanism (301-1) and the second folding mechanism (301-2), and its four corners are hung on the first folding mechanism (301-1) and the second folding mechanism (301-2) by screws for collecting litchi fruits vibrated and harvested by the flexible multi-rod continuum parallel mechanism (1).

5. The litchi shaking and vibration combined harvesting device according to claim 4, wherein, The industrial control box (5) is internally provided with a lithium battery pack (501), a servo motor driver (502) and an industrial control computer (503); the lithium battery pack (501) provides power for the entire harvesting device; there are four servo motor drivers (502), which respectively correspond to three synchronous belt servo motors (103) and a push rod servo motor (205) to transmit control information of the corresponding servo motors; the industrial control computer (503) establishes a real-time communication connection with the servo motor driver (502) through the EtherCAT industrial bus. The multi-axis motion control system embedded in it is configured with a harvesting process monitoring module, which can collect the pose information of the vibration comb (108) in real time to realize the full-process closed-loop control and abnormal working condition diagnosis of the harvesting operation.

6. The litchi moving and vibrating composite harvesting device according to claim 5, characterized in that, The support frame (101) is assembled by aluminum profiles and corner codes.

7. A harvesting method for the litchi shifting and vibrating composite harvesting device according to any one of claims 1 to 6, characterized in that, Including the following steps: S1. After determining the litchi harvesting area, the tracked vehicle (6) drives to the litchi harvesting point; S2. The depth vision camera (4) captures the depth image of the litchi and transmits the depth image to the industrial control computer (5). The control system in the industrial control computer (5) calls the YOLOv11 neural network model optimized based on transfer learning according to the litchi depth image information collected by the depth vision camera (4), extracts the morphological features of the litchi through the feature pyramid network, and outputs the three-dimensional coordinates of the key points of the fruit stalk and the attitude angle of the litchi cluster; S3. The industrial control computer (5) uses the traveling salesman algorithm to plan the picking order for the picking coordinate points in the working space, obtains the obstacle point cloud data after denoising operation according to the depth image information and plans the optimal obstacle avoidance motion path by the RTT* algorithm, and obtains the obstacle avoidance motion data according to the inverse kinematics model of the mechanism; S4. The industrial control computer (5) sends a sequence of motion instructions through the EtherCAT industrial bus. First, it drives the push rod servo motor (205) for Z-axis positioning to make the picking coordinate within the working space of the flexible multi-rod continuum parallel mechanism (1), and then controls the movement of the synchronous belt linear module. Finally, it makes the vibrating comb (108) reach the target fruit stalk spatial coordinates. The industrial control computer (503) transmits the motion information required for vibration to the servo driver (502), makes the synchronous belt servo motor (103) reciprocate quickly, makes the moving platform (107) and the vibrating comb (108) vibrate at high frequency, shakes the litchi off and drops it into the fruit collection mechanism (3); S5. The depth vision camera (4) captures the litchi picking situation in real time and transmits the depth image to the industrial control computer (503) in real time. After confirming that the litchi at the current target point has been completely picked, the industrial control computer (503) repeats step S4 according to the picking order planned by the traveling salesman algorithm; S6. When all the litchis within the field of view of the depth vision camera (4) have been harvested, the industrial control computer (503) controls the flexible multi-rod continuum parallel mechanism (1) and the electric push rod lifting mechanism (2) to reset, and the harvesting operation ends.

Images