A walnut directional low-loss shell breaking device and a walnut posture automatic adjustment method

Abstract

The present application relates to a kind of walnut directional low-loss shell breaking device and walnut posture automation adjustment method, comprising: vibrating feeder mechanism, conveying mechanism, guide mechanism, image acquisition device, signal acquisition device, posture adjustment device, shell breaking mechanism and control system;The present application solves the key core problem of walnut posture adjustment on one hand, and on the other hand solves the key core problem of walnut conveying feeding, posture adjustment, shell breaking automatic collaborative work, realizes the low-loss shell breaking of walnut.

Description

Technical Field

[0001] This invention relates to the field of walnut processing technology, specifically to a walnut directional low-damage shell-breaking device and an automated method for adjusting the posture of walnuts. Background Technology

[0002] Unlike other nuts, walnuts are highly susceptible to damage during mechanical shelling. Research has found that this damage mainly includes two aspects: breakage damage and seed coat damage. Breakage damage primarily affects the size and grade of the walnut kernel; seed coat damage results in the walnut kernel lacking a complete coating (i.e., exposing the white part), leading to loss of oil, increased susceptibility to oxidation, browning, and mold, thus affecting the sensory quality of the walnut kernel. Both types of damage reduce the commercial value of the walnut kernel to some extent.

[0003] In production, manual shelling is widely used. Research and experiments have shown that manual shelling consistently yields over 70% half-kernels, with a half-kernel seed coat damage rate of less than 10% (the ratio of damaged kernel weight to total kernel weight), and the damaged area of ​​the seed coat is less than 1% (calculated by dividing the projected area of ​​the damaged half-kernel by the projected area of ​​the half-kernel's front). In contrast, mechanical shelling for most walnut varieties only achieves a half-kernel rate of 20%–50%, with over 50% of the kernels suffering varying degrees of seed coat damage, and the damaged area of ​​the seed coat accounting for approximately 10%. The advantages of mechanical shelling compared to manual processing are difficult to realize, severely hindering the widespread application of mechanized walnut shelling technology and equipment.

[0004] In recent years, some scholars have conducted research on directional shell-breaking technology for walnuts. Some scholars have used pneumatic adsorption to orient the walnuts, but this method suffers from problems such as unstable adsorption and failure to adsorb some walnuts. Other scholars have studied the vibration orientation method for walnuts, which achieves better orientation when the plane of the suture line is perpendicular to the horizontal plane. Still others have studied directional shell-breaking devices for walnuts, but the experimental feeding involved manual orientation.

[0005] However, through years of research on the characteristics of walnuts, the team discovered that the rate of shell breakage and kernel damage is high and low along the transverse diameter (thickness direction) of walnuts. Therefore, how to make the shell-breaking force act on the transverse diameter of the walnut, that is, how to make the force perpendicular or nearly perpendicular to the plane of the suture line (if the force is vertical, then the plane of the suture line needs to be parallel or nearly parallel to the horizontal plane), is the core problem that urgently needs to be solved. Summary of the Invention

[0006] To address the aforementioned problems, the purpose of this invention is to provide a walnut-oriented, low-loss shell-breaking device and an automated walnut posture adjustment method. This addresses both the key issue of walnut posture adjustment and the crucial issues of automated collaborative operation of walnut feeding, posture adjustment, and shell-breaking, thereby achieving low-loss shell-breaking of walnuts.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a walnut-oriented, low-loss shell-breaking device, comprising: a vibrating feeding mechanism for holding raw walnuts and conveying them to a conveying mechanism; a conveying mechanism located downstream of the vibrating feeding mechanism for conveying the raw walnuts; a guiding mechanism disposed on the conveying mechanism for removing stacked walnuts to guide them to be conveyed in a single row; an image acquisition device disposed above the conveying mechanism and downstream of the guiding mechanism for acquiring image information of walnuts at the second and third workstations below it and transmitting the image information to the development board of the control system; and a signal acquisition device disposed on the conveying mechanism for acquiring the position information of the tray and transmitting the image information to the control system development board. The position information is transmitted to the PLC of the control system; the attitude adjustment device is located below the conveying mechanism and opposite to the image acquisition device, and is used to adjust the attitude of the walnut; the shell-breaking mechanism is located above the conveying mechanism and downstream of the attitude adjustment device, and is used to crack the walnut after the attitude adjustment; the control system includes a development board and a PLC. The development board is used to control the attitude adjustment device according to the image information of the image acquisition device, and the PLC is used to control the operation of the vibrating feeding mechanism, the conveying mechanism, the guiding mechanism, the attitude adjustment servo cylinder in the attitude adjustment device, and the shell-breaking mechanism according to the position information of the signal acquisition device.

[0008] Preferably, the walnut directional low-loss shell-breaking device includes a vibrating feeding mechanism comprising: a hopper frame, a feeding hopper, a vibrating feeder, and a limiting plate; the feeding hopper is located on top of the hopper frame; one end of the vibrating feeder is positioned below the feeding hopper, and the other end is positioned above the first end of the conveying mechanism, with the vibrating feeder located in the middle of the hopper frame; the limiting plate has at least two elongated slots, and one side of the feeding hopper has slots corresponding to the positions of the elongated slots. The limiting plate has two mounting holes. It is connected to the side wall of the feeding hopper by a wing nut and bolt. The elongated slot can be adjusted in the vertical direction to open and close the feeding channel of the vibrating feeder. The limiting plate is located downstream of the discharge port of the feeding hopper. When the limiting plate opens the feeding channel of the vibrating feeder, the vibrating feeder continues to feed. When the limiting plate closes the feeding channel of the vibrating feeder, the vibrating feeder stops feeding.

[0009] Preferably, the walnut directional low-damage shell-breaking device includes a conveying mechanism comprising: a frame, a transmission sprocket assembly, chains, trays, and a power mechanism; two transmission sprocket assemblies are respectively disposed at both ends of the top of the frame, and two other transmission sprocket assemblies are respectively disposed at both ends of the bottom of the frame; two chains are respectively disposed on the front and rear sides of the frame, with the upper ends of each chain being tractably connected to the upper transmission sprocket assembly, and the lower ends being tractably connected to the lower transmission sprocket assembly; several trays are arranged in a single row between the two chains and move with the chains; each tray has a spherical groove for placing walnuts in its center, and the bottom of the spherical groove has a cross opening; the power mechanism is connected to one of the upper transmission sprocket assemblies via a belt to provide power to the transmission sprocket assembly.

[0010] Preferably, the walnut directional low-damage shell-breaking device has protective plates on both the front and rear sides of the frame; each protective plate has an end cover plate for the transmission component, an adjustment window for the attitude adjustment device, and a side discharge hopper; the end cover plate for the transmission component is openable on the protective plate to facilitate maintenance of the transmission sprocket assembly and to prevent external dust and impurities from affecting its normal operation; the adjustment window for the attitude adjustment device is openable on the protective plate and corresponds to the position of the attitude adjustment device, for convenient observation of the operating status of the attitude adjustment device and for its inspection and maintenance. Adjust the relative position of the posture adjustment device and the tray; one end of the side discharge hopper extends to the spherical groove of the tray below the shell-breaking mechanism, and the other end extends to the outside of the guard plate, for discharging the debris leaking from the cross opening at the bottom of the spherical groove outside the guard plate; the tail end of the conveying mechanism is provided with an end discharge hopper, the two sides of the end discharge hopper are connected to the guard plate, the first end extends to the bottom of the tray at the end, and the second end extends to the outside of the conveying mechanism, for discharging the shelled walnuts; the image acquisition device and the shell-breaking mechanism are covered with an organic cover.

[0011] The walnut directional low-damage shell-breaking device preferably further includes an outer baffle, an inner baffle, a feeding end cover, and a discharging end cover; the two outer baffles are respectively disposed on the top of the frame and located on the outer side of the two chains; the two inner baffles are respectively disposed on the integral formed by a plurality of the trays and located on the inner side of the two chains; the feeding end cover is disposed on the top of the outer baffle near the vibrating feeding mechanism end, and the discharging end cover is disposed on the top of the outer baffle near the end discharge hopper.

[0012] Preferably, the walnut directional low-damage shell-breaking device includes a material guiding mechanism comprising: an electric brush roller, a material guiding frame, and material guiding partitions; the electric brush roller is connected to the top of the frame at both ends via connectors, and its rotation direction is the same as that of the chain, used to rotate and remove stacked walnuts so that one walnut is left in the spherical groove of each tray; two material guiding frames are respectively disposed upstream and downstream of the electric brush roller, the material guiding frames having a door frame structure, and their two ends being fixed to the top of the frame; two material guiding partitions are respectively disposed on both sides of the electric brush roller, and the top of the material guiding partitions are respectively connected to the two material guiding frames.

[0013] Preferably, the image acquisition device of the walnut directional low-damage shell-breaking device includes: a camera bracket, a CCD camera, and an LED light source; the camera bracket is a door frame structure, with both ends fixed to the top of the frame; the CCD camera is mounted on the top crossbar of the camera bracket and is used to acquire image information of walnuts at the second and third workstations directly below it; the two LED light sources are respectively mounted on the top of the machine cover and are located upstream and downstream of the camera bracket, respectively, and the LED light sources are used to provide light for the image acquisition environment.

[0014] The walnut directional low-damage shell-breaking device, preferably, includes a signal acquisition device comprising: a sensor bracket, a laser-guided photoelectric switch sensor, and a positioning plate; two sets of sensor brackets are respectively fixedly mounted on the top of the frame, each set of sensor brackets including two opposing sensor brackets, which are respectively positioned on both sides of the tray; a pair of laser-guided photoelectric switch sensors are mounted on each set of sensor brackets; a positioning plate is mounted on each tray, the positioning plate being located on one side of the spherical groove; the installation height of the laser-guided photoelectric switch sensor is higher than the highest point of the walnut in the spherical groove of the tray, and the height of the positioning plate is simultaneously higher than both the highest point of the walnut in the spherical groove of the tray and the height of the laser-guided photoelectric switch sensor, to ensure that the laser-guided photoelectric switch sensor only responds to the passage of the positioning plate, and is not affected by the walnuts accidentally blocking the spherical groove, and also avoids the adverse effects caused by the size difference of the walnuts when using the walnuts themselves as positioning marks, thereby improving the consistency of the system response; the interval L between the two sets of sensor brackets is preferably not greater than half the width W of the tray.

[0015] The walnut directional low-damage shell-breaking device, preferably, includes an attitude adjustment device comprising: an attitude-adjusting electric cylinder base, an attitude-adjusting electric cylinder fixing plate, an attitude-adjusting servo electric cylinder, a dial wheel motor support plate, a dial wheel motor base, a first dial wheel motor, a first adjusting dial wheel, a second dial wheel motor, and a second adjusting dial wheel; the attitude-adjusting electric cylinder base is disposed at the bottom of the frame, the attitude-adjusting electric cylinder fixing plate is fixedly disposed at the top of the attitude-adjusting electric cylinder base, the bottom of the attitude-adjusting servo electric cylinder is fixedly disposed at the attitude-adjusting electric cylinder fixing plate, and the dial wheel motor support plate is fixedly disposed at the top of the attitude-adjusting servo electric cylinder; the first dial wheel motor and the second dial wheel motor are respectively fixed to the dial wheel motor support plate via a dial wheel motor base; the first adjusting dial wheel and the second adjusting dial wheel are respectively disposed below the trays at the second and third workstations, and after rising, they can contact the walnuts in the spherical grooves; the first adjusting dial wheel is mounted on the output shaft of the first dial wheel motor, and the second adjusting dial wheel... The first adjusting wheel is mounted on the output shaft of the second adjusting wheel motor, and the first adjusting wheel is located upstream of the second adjusting wheel. The first adjusting wheel is used to adjust the posture of the walnut in the X direction, and its rotation axis is parallel to the X-axis direction, which is parallel to the conveying direction of the chain. The second adjusting wheel is used to adjust the posture of the walnut in the Y direction, and its rotation axis is parallel to the Y-axis direction, which is perpendicular to the conveying direction of the chain. In the initial state, the posture adjustment servo cylinder is in a retracted state, so that the first adjusting wheel and the second adjusting wheel are respectively a set distance away from the lowest point of the spherical groove on the tray, thereby avoiding interference between the tray and the first adjusting wheel and the second adjusting wheel during the conveying process. In the posture adjustment state, the posture adjustment servo cylinder rises to a set position, so that the first adjusting wheel and the second adjusting wheel respectively contact the walnut in the corresponding spherical groove on the tray to achieve posture adjustment. When the posture adjustment is completed, the posture adjustment servo cylinder returns to the initial state.

[0016] Preferably, the walnut directional low-damage shell-breaking device comprises: a shell-breaking electric cylinder fixing frame, a shell-breaking electric cylinder fixing plate, a shell-breaking servo electric cylinder, a pressure sensor, and a shell-breaking housing; the shell-breaking electric cylinder fixing frame is fixedly installed on the top of the frame, and the shell-breaking electric cylinder fixing plate is fixedly installed on the top of the shell-breaking electric cylinder fixing frame; one end of the shell-breaking servo electric cylinder is connected to the shell-breaking electric cylinder fixing plate, and the other end is connected to the pressure sensor; the shell-breaking housing is connected to the pressure sensor; the head of the shell-breaking housing is a concave shell shape adapted to the shape of the walnut, and the bottom of the concave shell is provided with several protrusions or toothed grooves.

[0017] This invention also provides a method for automatically adjusting the posture of walnuts, comprising the following steps: The raw walnuts are poured into the vibrating feeder and then transferred to the conveyor. The conveyor operates intermittently, completing the work of five stations in each pause cycle. The five workstations operate as follows: The first workstation is for feeding: walnuts are fed in an orderly, single-kernel manner using a vibrating feeding mechanism, a guiding mechanism, and a conveying mechanism. When the first pair of laser-guided photoelectric switches detects the positioning plate, the PLC control system causes the servo motor of the conveying mechanism's power mechanism to decelerate. When the second pair of laser-guided photoelectric switches detects the positioning plate, the conveying mechanism stops, and the vibrating feeding mechanism stops. The PLC control system causes the attitude adjustment servo cylinder to rise according to a predetermined stroke, and the first and second adjustment wheels contact the walnuts. The PLC control system sends a high-level signal to the development board, and the development board's detection model begins inference. The second workstation is for X-direction attitude adjustment: the first adjustment wheel motor... After receiving the image recognition results from the development board, the first adjusting wheel is rotated according to the target position to correct the angle of the walnut in the chain conveying direction. The third station is for Y-axis posture adjustment: after receiving the image recognition results from the development board, the second adjusting wheel is rotated according to the target position to correct the angle of the walnut perpendicular to the chain conveying direction. The walnut posture adjustment time can be preset on the PLC display screen or adjusted during operation to meet both the posture adjustment effect and work efficiency. When the posture adjustment time is up, the PLC control system sends a low-level signal to the development board, the development board detection model stops inference, and the PLC control system causes the posture adjustment servo cylinder to descend according to the predetermined stroke. The first and second adjusting dials are separated from the walnuts; the fourth station is for shell breaking: the shell-breaking servo cylinder presses down according to preset stroke and speed parameters to complete the shell breaking. The stroke and speed parameters can be adjusted on the PLC display screen according to the shell-breaking effect. The pressing speed of the shell-breaking servo cylinder is divided into two segments, and the speed of the two segments can be adjusted as needed. Preferably, the first segment is a rapid downward movement, and the second segment is the remaining segment after approaching the walnut, with a slower speed. The return stroke speed is the same. The distance and speed of the first and second segments can be adjusted on the PLC display screen; the fifth station is for unloading: the end discharge hopper and the side discharge hopper respectively receive the high-quality material and shell fragments after shell breaking. The five stations work together until the end of one work cycle. The PLC control system then restarts the conveying mechanism and the vibrating feeding mechanism to enter the next work cycle. The walnuts that have completed the X-direction orientation adjustment at the second station enter the third station with the tray for Y-direction orientation adjustment. Thus, with the cooperation of the second and third stations, the plane where the walnut's stitch line is located is made parallel to the horizontal plane. The next walnut that has not been oriented enters the second station with the tray for X-direction orientation adjustment. Regardless of whether there are walnuts in the spherical grooves of the first to fifth stations, the PLC control system performs the same actions as when there are walnuts. When the five stations are working, the following is ensured: when the second, third, and fourth stations are working, the vibrating feeding mechanism and the conveying mechanism stop running. The precise positioning of the pallet at each workstation is achieved by the signal logic control of two pairs of laser photoelectric switch sensors and positioning plates, thereby ensuring continuous and controllable directional shell-breaking operations.

[0018] The walnut posture automatic adjustment method is preferably implemented in the fourth station when the walnuts are being shelled. The pressure sensor collects the force data on the material and displays it on the PLC screen in real time so that the technicians can compare it with the recommended shelling force data for walnuts of the same variety and grade. Based on the shelling effect, the stroke and speed of the shelling servo cylinder are adjusted to achieve a better shelling effect. The shell-breaking servo cylinder's downward pressing speed is divided into two segments. The speed of the two segments can be adjusted as needed. Preferably, the first segment is a rapid downward displacement, and the second segment is the remaining segment after approaching the walnut, with the speed decreasing, and the return stroke speed is the same. When the equipment is running, the stroke and speed of the shell-breaking servo cylinder can be preset or adjusted as needed during operation to achieve the following two shell-breaking processes: The first is a directional low-loss complete shell-breaking process, which performs directional low-loss complete shell-breaking treatment on the walnut after the posture adjustment is completed, realizing the separation of the shell and kernel; The second is a crack-assisted manual shelling process, which only cracks the walnut to replace the traditional manual knocking, chopping and other manual shell-breaking methods. Then, the cracked walnut is manually shelled to remove the kernel from the shell. This method can effectively reduce labor costs compared to pure manual shell-breaking operations. Although the efficiency is lower than the first process, it can obtain a higher half-kernel rate.

[0019] The aforementioned automated walnut posture adjustment method, preferably, includes the following steps for X-direction and Y-direction posture adjustment at the second and third workstations: Image acquisition and transmission: The CCD camera takes pictures of the walnuts in the trays of the second and third workstations to acquire walnut image data, and converts the acquired images into digital signals to transmit to the development board of the control system; Image processing and instruction generation: The development board in the control system calls the trained detection model to obtain the center point coordinates of the walnut and its suture line in real time. The control system performs vector operations on the center point coordinates to generate corresponding control instructions and sends them to the first and second dial motors. Posture adjustment: The first and second dial motors drive the corresponding first and second adjustment dials to rotate according to the received control commands. The friction force acts on the walnuts in the corresponding trays to adjust the posture of the walnuts. Cyclic posture adjustment: Once the walnut reaches the preset orientation standard, the posture adjustment task in that direction is completed; then, the walnut that has completed the posture adjustment in the second station moves forward with the tray to the third station for posture adjustment in the Y direction. At the same time, the next walnut that has not been adjusted moves into the second station with the tray for posture adjustment in the X direction. The preset orientation standard is: the second station adjusts the walnut's posture in the X direction, and the unit normal vector of the suture plane is λ, and the unit vector of the camera coordinate system is expressed as ( ),in , These are the camera coordinate systems. , The unit vector of the axis, the orientation standard of the second station satisfies any of the following conditions, A: the vector dot product λ·y c1 = 0 or B: No suture line can be detected in the current field of view, i.e., the suture line plane is parallel to the horizontal plane; In the next pause cycle, the walnut is moved to the third station for attitude adjustment in the Y direction. The orientation standard of the third station meets any of the following conditions: B: No suture line can be detected in the current field of view or C: and .

[0020] The aforementioned automated walnut posture adjustment method, preferably, involves the trained detection model implemented through the following steps: Data Acquisition: The development board in the control system opens the camera video stream, and the operator manually adjusts the posture of a single walnut. After each adjustment to the desired posture, the next frame of the video stream is captured and saved as an image via the keyboard. A set number of individual walnuts are collected, resulting in a set number of images with a set resolution of pixels. This dataset covers the appearance changes of walnuts under various postures. This dataset is used to train and validate the detection model for walnuts and suture lines, ensuring the robustness of the recognition algorithm to posture, scale, and surface details. Dataset Labeling: Labeling was performed using the roLabelImg tool, employing directional bounding boxes to label targets in the images. Walnuts were labeled "walnut," and suture lines were labeled "roulette." The labeling results were saved as an XML file. The complete suture line was divided into arc segments, with each largest labeling unit being a quarter-circle suture segment, labeled with a directional bounding box. Between two directional bounding boxes representing the same suture line, a corner point of each box was aligned to ensure continuity and spatial correlation between the box and the suture line arc segment. During labeling, the background within the target box was set to the surface texture of the walnut itself, avoiding excessive inclusion of irrelevant external background to improve the accuracy of the features learned by the model. For cases where the suture line is barely visible from a top-down view, only "walnut" was labeled, not "roulette." In other samples, each image typically includes one "walnut" label and two "roulette" labels to more accurately depict the suture line's positional information. Dataset augmentation: A set of labeled original images were divided into a training set of images and a test set of images according to a set ratio. After the division, the number of walnut labels and roulette labels in the training set was set; the number of walnut labels and roulette labels in the validation set was set. Then, a Python script was used to batch convert all XML format annotation files into normalized TXT format. The normalized TXT files recorded the key information of the target bounding boxes. Based on the normalized coordinate representation, the following seven transformations were applied to each image and its corresponding annotation simultaneously: left-right mirroring, top-bottom mirroring, increasing brightness, decreasing brightness, rotating 90°, 180°, and 270° clockwise around the image center as the origin. These seven transformations, together with the original image, resulted in a total of eight versions, thereby achieving an eightfold augmentation of the original data. After augmentation, the number of walnut labels in the training set increased to set, and the number of roulette labels increased to set, to improve the robustness of the model to scale, orientation, and illumination changes. Model framework: Considering the rotation and tilt features of the walnut suture line under different postures, the target detection method based on directional bounding boxes is selected to more accurately express the geometric information of the target. Based on this, YOLOv8s-obb is finally adopted as the basic model for training and inference. Model Training: The augmented training images and their normalized TXT annotation files were placed in the `train` folder, and the validation images and their annotations were placed in the `val` folder. The paths and category information were specified in the dataset YAML configuration file. The training hyperparameters were set as follows: the total number of training epochs was set to a set value, the input image size `imgsz` was a set value, `batch_size` was a set value, `workers` was a set value, and other parameters were default values. Mosaic data augmentation was used to improve sample diversity. The model was trained using the following workflow: In the first stage, `yolov8-obb.pt` was used as the initial weights and trained for approximately a set number of hours to obtain an initial model `best.pt`. In the second stage, the previously trained `best.pt` was used as the initial parameters, and the original training set was fine-tuned for another set number of epochs, while other training parameters remained unchanged, to further improve the model's accuracy and stability on this task. Mosaic was gradually disabled in the last few epochs of training to allow the model to better adapt to the distribution of real single images, improving convergence stability and actual inference performance. The training results were then validated. The aforementioned automated walnut posture adjustment method, preferably, includes the following steps in its control method: (1) Acquisition and detection: After receiving the high-level signal from the PLC, the control system starts working. Each walnut to be adjusted is placed on the tray in an arbitrary random posture. The CCD camera acquires the image of the current frame. After the image is preprocessed, it is input into the pre-trained YOLOv8s-obb model for directional bounding box regression to obtain the center position and rotation angle information of the walnut and the suture line. (2) Coordinate mapping: The detection center point and Mapping from the pixel plane to the actual tray plane, calculate the current pose vector and angle β. pi ; (3) Rotation direction of the first and second gear wheel motors: and By comparing relative positions, directional information can be obtained; (4) Generate control commands: based on the current attitude vector and angle The information simultaneously drives the first and second dial motors of the second and third workstations, and sends rotation commands according to the preset closed-loop control strategy. The current angle or position information of the walnut suture line is fed back through the detection result of the next frame. (5) Iterative adjustment: During the preset posture adjustment time, repeat steps (1) to (4) to continuously adjust the walnut posture through closed-loop feedback until one of the following conditions is met: When the walnut in the second station reaches the preset orientation standard A or B, stop the rotation of the first gear wheel motor; when the walnut in the third station reaches the preset orientation standard B or C, stop the rotation of the second gear wheel motor. (6) After the control system receives the high-level signal from the PLC, the model stops reasoning. During the operation of the equipment, the duration of the high-level signal from the PLC can be flexibly adjusted. It is recommended to use the longest posture adjustment time in the same batch of walnuts as the setting benchmark. This will ensure that each walnut has sufficient posture adjustment time to ensure that the posture adjustment effect meets the standard, and will also avoid invalid time occupation and maintain an efficient processing rhythm. (7) After one posture adjustment is completed, the walnut that has completed the posture adjustment at the second station moves forward with the tray to the third station for posture adjustment in the Y direction. At the same time, the next walnut that has not been adjusted enters the second station with the tray and repeats steps (1) to (6) to form a continuous cycle operation.

[0021] The aforementioned automated walnut posture adjustment method, preferably, includes the following steps in its coordinate mapping: With the origin of the camera coordinate system Based on this, from top to bottom are the pixel plane and the tray plane, with the center of the tray denoted as... The radius of the tray is ; Starting on the tray surface, at the center of the suture line To the Walnut Center The vector represents the walnut posture; their projections onto the pixel plane are respectively... and ; The predicted coordinates are ( ), The predicted coordinates are set to (0, 0) in the normalized coordinate system; the equivalent radius of the walnut is denoted as... ,in, , These represent the width and height of the detection box for the walnut in the image, respectively. After mapping the image coordinates to actual geometric quantities, the predicted angle between the suture center vector and the horizontal plane is calculated. The predicted angle is used to evaluate the inclination of the suture relative to the horizontal plane, thereby determining the amount of rotation required. Its calculation expression is as shown in equation (1): (1) In the formula, The equivalent radius of the walnut (in pixels); , They are respectively The predicted x and y coordinates (in pixels).

[0022] The present invention has the following advantages due to the adoption of the above technical solutions: (1) This invention can realize automated and low-damage directional shell breaking of walnuts, effectively solving the key core technical problem of directional shell breaking of walnuts in current production. Compared with the relatively random shell breaking method of traditional machinery, it reduces the damage to the walnut kernel and the seed coat. Its detection and orientation technology has good stability and can meet the requirements of continuous operation in production. (2) The signal acquisition device of the present invention uses two pairs of laser-beam photoelectric switch sensors. The installation height of the optical lens of the laser-beam photoelectric switch sensor must be higher than the highest point of the walnut in the spherical groove of the tray. The height of the positioning piece is also higher than the highest point of the walnut in the spherical groove of the tray and the height of the optical lens of the laser-beam photoelectric switch sensor. This ensures that the sensor only responds to the passing of the positioning piece and is not affected by the walnut in the spherical groove being accidentally blocked. It also avoids the adverse effects caused by the size difference of the walnut when using the walnut itself as the positioning mark, thereby improving the consistency of the system response. When the first pair of laser-beam photoelectric switch sensors senses the positioning piece, the PLC control system causes the servo motor of the conveying mechanism power system to decelerate. When the second pair of laser-beam photoelectric switch sensors senses the positioning piece, the conveying mechanism stops. This ensures the accurate alignment and repeatability of the posture adjustment and shell breaking process. (3) This invention analyzes the positional relationship between the walnut body and the suture detection box in a two-dimensional image, calculates its three-dimensional spatial posture in real time, and quickly obtains the coordinate data of the walnut and the suture detection box based on the detection model (the detection rate can currently reach <20ms per image). Combined with the walnut morphological features, a spatial posture estimation model is established to achieve high-precision and high-efficiency posture recognition. (4) In order to avoid incomplete recognition of walnut suture line, the present invention divides the walnut suture line into two parts during the image calibration process, that is, uses one-quarter of the walnut suture line as the largest annotation unit for calibration, so that the model recognition effect is more advantageous, the walnut posture recognition accuracy is higher, and better posture adjustment effect can be obtained. (5) The present invention innovatively adopts a cross-shaped open tray and a coordinated mechanism of the first and second adjustment wheels. The individual posture of the walnut is adjusted through the mechanical cooperation between the mechanisms. The first and second adjustment wheels are located below the tray. This method effectively reduces the interference of the upper part on the detection field of view, improves the success rate of posture adjustment, and can be adapted to the processing needs of different varieties of walnuts. Attached Figure Description

[0023] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the walnut directional low-damage shell-breaking device described in this invention; Figure 2 yes Figure 1 Front view structural diagram; Figure 3 yes Figure 1 The schematic diagram of the transmission mechanism in the diagram shows the structure of the image acquisition device, the signal acquisition device, the attitude adjustment device, and the shell breaking mechanism. Figure 4 yes Figure 1 A magnified schematic diagram of the signal acquisition device in the diagram; Figure 5 yes Figure 1 A schematic diagram of the attitude adjustment device in the diagram; Figure 6 yes Figure 1 A top view of the tray structure; Figure 7 yes Figure 1 The structural diagram of the broken shell is shown in the figure, where (a) is a broken shell with protrusions and (b) is a broken shell with toothed grooves; Figure 8 This is a schematic diagram of the posture adjustment process in this invention; Figure 9 This refers to the case where the walnut posture angle in this invention is 90°; Figure 10 This refers to the case where the walnut posture angle is 0° in this invention; Figure 11 These are photographs of the same walnut in different poses in this invention; Figure 12 This is a schematic diagram of the walnut suture marking method in this invention; Figure 13 This corresponds to an 8-fold amplification effect of the marked box in this invention; Figure 14 This invention detects the accuracy and speed information of the model. Figure 15 This invention involves verifying the recognition effect of the detection model after training. Figure 16 This is a schematic diagram of object recognition and image display in this invention; Figure 17 This is the final result of the orientation adjustment in this invention; Figure 18 This is an overall flowchart of the control system of the present invention.

[0024] The labels for the attached figures are as follows: 1-Vibrating feeding mechanism; 101-Hopper frame; 102-Feeding hopper; 103-Vibrating feeder; 104-Limiting plate; 2-Conveying mechanism; 201-Frame; 202-Transmission sprocket assembly; 203-Chain; 204-Pattern; 2041-Spherical groove; 2042-Cross opening; 205-Power mechanism; 3-Guiding mechanism; 301-Electric brush roller; 302-Guiding fixing frame; 303-Guiding partition; 4-Image acquisition device; 401-Camera bracket; 402-CCD camera; 403-LED light source; 5-Signal acquisition device; 501-Sensor bracket; 502-Laser photoelectric switch sensor; 503-Positioning plate; 6-Attitude adjustment device; 601 - Attitude adjustment cylinder base; 602-Attitude adjustment cylinder fixing plate; 603-Attitude adjustment servo cylinder; 604-Dial motor support plate; 605-Dial motor base; 606-First dial motor; 607-First adjusting dial; 608-Second dial motor; 609-Second adjusting dial; 7-Shell breaking mechanism; 701-Shell breaking cylinder fixing frame; 702-Shell breaking cylinder fixing plate; 703-Shell breaking servo cylinder; 704-Pressure sensor; 705-Shell breaking shell; 8-Guard plate; 9-Transmission component end cover plate; 10-Attitude adjustment device adjustment window; 11-Side discharge hopper; 12-End discharge hopper; 13-Machine cover; 14-Outer baffle; 15-Inner baffle; 16-Feeding end cover plate; 17-Discharge end cover plate. Detailed Implementation

[0025] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0026] This invention provides a walnut-oriented, low-loss shell-breaking device and an automated walnut posture adjustment method. On the one hand, it solves the key core problem of walnut posture adjustment, and on the other hand, it solves the key core problem of automated and coordinated operation of walnut feeding, posture adjustment, and shell-breaking, thereby achieving low-loss shell-breaking of walnuts.

[0027] like Figures 1 to 3 As shown, the walnut directional low-loss shelling device provided by the present invention includes: a vibrating feeding mechanism 1, used to hold walnut raw materials and convey them to a conveying mechanism 2; a conveying mechanism 2, located downstream of the vibrating feeding mechanism 1, used to convey the walnut raw materials; a guiding mechanism 3, disposed on the conveying mechanism 2, used to remove stacked walnuts to guide the walnuts to be conveyed in a single row; an image acquisition device 4, disposed above the conveying mechanism 2 and downstream of the guiding mechanism 3, used to acquire image information of walnuts at the second and third workstations below it and transmit the image information to the development board of the control system; and a signal acquisition device 5, disposed on the conveying mechanism 2, used to acquire the position information of the tray and transmit the signal information to the control system development board. The system transmits information to the PLC of the control system; the posture adjustment device 6 is located below the conveying mechanism 2 and opposite to the image acquisition device 4, and is used to adjust the posture of the walnuts; the shell-breaking mechanism 7 is located above the conveying mechanism 2 and downstream of the posture adjustment device 6, and is used to crack the walnuts after the posture is adjusted; the control system includes a development board and a PLC. The development board is used to control the posture adjustment device 6 according to the image information of the image acquisition device 4, and the PLC is used to control the operation of the vibrating feeding mechanism 1, the conveying mechanism 2, the guiding mechanism 3, the posture adjustment servo cylinder 603 in the posture adjustment device 6, and the shell-breaking mechanism 7 according to the position information of the signal acquisition device 5.

[0028] It should be noted that PLC includes both the PLC control system and the PLC display screen.

[0029] In the above embodiments, preferably, the vibrating feeding mechanism 1 includes: a hopper frame 101, a feeding hopper 102, a vibrating feeder 103, and a limiting plate 104; the feeding hopper 102 is located on top of the hopper frame 101; one end of the vibrating feeder 103 is located below the feeding hopper 102, and the other end is located above the first end of the conveying mechanism 2, and the vibrating feeder 103 is located in the middle of the hopper frame 101; the limiting plate 104 is provided with at least two elongated slots, and one side of the feeding hopper 102 is provided with two slots corresponding to the positions of the elongated slots. There is a mounting hole, and the limiting plate 104 is connected to the side wall of the feeding hopper 102 by a wing nut and bolt. The elongated slot can be adjusted in the vertical direction by cooperating with the wing nut and bolt to open and close the feeding channel of the vibrating feeder 103. The limiting plate 104 is located downstream of the discharge port of the feeding hopper 102. When the limiting plate 104 opens the feeding channel of the vibrating feeder 103, the vibrating feeder 103 continues to feed. When the limiting plate 104 closes the feeding channel of the vibrating feeder 103, the vibrating feeder 103 stops feeding.

[0030] In the above embodiment, preferably, the conveying mechanism 2 includes: a frame 201, a transmission sprocket set 202, a chain 203, a tray 204, and a power mechanism 205; two transmission sprocket sets 202 are respectively disposed at both ends of the top of the frame 201, and two other transmission sprocket sets 202 are respectively disposed at both ends of the bottom of the frame 201; two chains 203 are respectively disposed on the front and rear sides of the frame 201, and the upper two ends of the chains 203 are respectively tractably connected to the upper transmission sprocket set 202, and the lower two ends are respectively tractably connected to the lower transmission sprocket set 202. For specific connection methods, please refer to [reference needed]. Figure 3 Several trays 204 are arranged in a single row between two chains 203 and move with the chains 203. Each tray 204 has a spherical groove 2041 for placing walnuts in the middle, and the bottom of the spherical groove 2041 has a cross opening 2042 (see...). Figure 6 The power mechanism 205 is connected to one of the upper transmission sprocket groups 202 via a belt and is used to provide power to the transmission sprocket group 202.

[0031] In the above embodiments, preferably, as follows: Figure 1As shown, protective plates 8 are respectively provided on the front and rear sides of the frame 201; the protective plates 8 are respectively provided with transmission component end covers 9, attitude adjustment device adjustment windows 10, and side discharge hoppers 11; the transmission component end covers 9 are unclamped on the protective plates 8 to facilitate maintenance of the transmission sprocket assembly 202, while preventing external dust and impurities from entering and affecting its normal operation; the attitude adjustment device adjustment window 10 is unclamped on the protective plates 8 and corresponds to the position of the attitude adjustment device 6, for convenient observation of the operating status of the attitude adjustment device 6 and for maintenance and adjustment of the relative position of the attitude adjustment device 6 and the pallet 204; side discharge hopper 11. One end of the hopper 11 extends below the spherical groove 2041 of the tray 204 below the shell-breaking mechanism 7, and the other end extends outside the guard plate 8, for discharging the debris leaking from the cross opening 2042 at the bottom of the spherical groove 2041 outside the guard plate 8; the tail end of the conveying mechanism 2 is provided with an end discharge hopper 12, the two sides of the end discharge hopper 12 are connected to the guard plate 8, the first end extends below the end tray 204, and the second end extends outside the conveying mechanism 2, for discharging the shelled walnuts; the image acquisition device 4 and the shell-breaking mechanism 7 are covered with a machine cover 13, which is used to protect the image acquisition device 4 and the shell-breaking mechanism 7.

[0032] In the above embodiments, preferably, as follows: Figure 1 As shown, the present invention also includes an outer baffle 14, an inner baffle 15, a feeding end cover 16, and a discharging end cover 17; the two outer baffles 14 are respectively disposed on the top of the frame 201 and are respectively located on the outer side of the two chains 203; the two inner baffles 15 are respectively disposed on the whole formed by a plurality of trays 204 and are respectively located on the inner side of the two chains 203; the feeding end cover 16 is disposed on the top of the outer baffle 14 near the end of the vibrating feeder 1, and the discharging end cover 17 is disposed on the top of the outer baffle 14 near the end discharge hopper 12.

[0033] It should be noted that the outer baffle 14 is located on both sides of the long side above the frame 201; the inner baffle 15 is fixed inside the outer baffle 14, and its lower part is close to the upper surface of the tray 204. It can be made of elastic silicone pad or brush plate to prevent the material from falling out of the spherical groove 2041 of the tray 204 and entering the transmission area. To avoid motion interference, clearance holes are made on the feeding end cover plate 16, the discharging end cover plate 17, the end discharge hopper 12 and the guide partition plate 303, along the forward direction of the positioning piece and directly opposite the positioning piece. The outline dimensions (height × width) of the clearance holes are larger than the outer dimensions (height × thickness) of the positioning piece to provide a safe passage clearance.

[0034] In the above embodiments, preferably, as follows: Figure 1As shown, the material guiding mechanism 3 includes: an electric brush roller 301, a material guiding fixing frame 302, and a material guiding partition 303; the electric brush roller 301 is connected to the top of the frame 201 at both ends through connectors, and its rotation direction is the same as that of the chain 203, used to rotate and remove stacked walnuts so that one walnut is left in the spherical groove 2041 of each tray; the two material guiding fixing frames 302 are respectively set upstream and downstream of the electric brush roller 301, and the material guiding fixing frame 302 has a door frame structure, with both ends fixed to the top of the frame 201; the two material guiding partitions 303 are respectively set on both sides of the electric brush roller 301, and the top of the material guiding partitions 303 are respectively connected to the two material guiding fixing frames 302 so as not to obstruct the operation of the tray 204.

[0035] In the above embodiment, preferably, the image acquisition device 4 includes: a camera bracket 401, a CCD camera 402, and an LED light source 403; the camera bracket 401 is a door frame structure, with both ends fixed to the top of the frame 201; the CCD camera 402 is mounted on the top crossbar of the camera bracket 401 and is used to acquire image information of the walnuts at the second and third workstations directly below it; the two LED light sources 403 (see...) Figure 2 The LED light source 403 is respectively located on the top of the housing 13 (specifically the inner top) and upstream and downstream of the camera bracket 401, and is used to provide light source for the image acquisition environment.

[0036] In the above embodiments, preferably, as follows: Figure 4 As shown, the signal acquisition device 5 includes: a sensor bracket 501, a laser through-beam photoelectric switch sensor 502, and a positioning plate 503; two sets of sensor brackets 501 are respectively fixedly mounted on the top of the frame 201, each set of sensor brackets 501 includes two opposing sensor brackets 501, which are respectively mounted on both sides of the tray 204; a pair of laser through-beam photoelectric switch sensors 502 are mounted on each set of sensor brackets 501; a positioning plate 503 is mounted on each tray 204, and the positioning plate 503 is located on one side of the spherical groove 2041; the laser through-beam photoelectric switch sensor 502 is mounted on... The height of the positioning piece 503 is higher than the highest point of the walnut in the spherical groove 2041 of the tray 204, and the height of the positioning piece 503 is also higher than the highest point of the walnut in the spherical groove 2041 of the tray 204 and the height of the laser photoelectric switch sensor 502. This ensures that the laser photoelectric switch sensor 502 only responds to the passage of the positioning piece 503 and is not affected by the walnut in the spherical groove being accidentally blocked. It also avoids the adverse effects caused by the size difference of the walnut when using the walnut itself as a positioning mark, thereby improving the consistency of the system response. The interval L between the two sets of sensor brackets 501 is preferably no greater than half the width W of the tray 204.

[0037] It should be noted that a cross brace can be fixed at the bottom of the frame 201. The height of the lower end of the cross brace from the ground should be less than the height of the lower end of the positioning plate 503 from the ground to avoid damage to the positioning plate that may be caused by the loading and unloading of the equipment.

[0038] In the above embodiments, preferably, as follows: Figure 5 As shown, the attitude adjustment device 6 includes: an attitude adjustment cylinder base 601, an attitude adjustment cylinder fixing plate 602, an attitude adjustment servo cylinder 603, a dial motor support plate 604, a dial motor base 605, a first dial motor 606, a first adjustment dial 607, a second dial motor 608, and a second adjustment dial 609; the attitude adjustment cylinder base 601 is disposed at the bottom of the frame 201, the attitude adjustment cylinder fixing plate 602 is fixedly disposed at the top of the attitude adjustment cylinder base 601, the bottom of the attitude adjustment servo cylinder 603 is fixedly disposed on the attitude adjustment cylinder fixing plate 602, and the dial motor support plate 604 is fixedly disposed on the attitude adjustment servo cylinder base 609. At the top of cylinder 603, the first dial motor 606 and the second dial motor 608 are respectively fixed to the dial motor support plate 604 through a dial motor seat 605; the first adjusting dial 607 and the second adjusting dial 609 are respectively set below the tray 204 of the second station and the third station, and can contact the walnut in the spherical groove 2041 after rising. The first adjusting dial 607 is installed on the output shaft of the first dial motor 606, and the second adjusting dial 609 is installed on the output shaft of the second dial motor 608, and the first adjusting dial 607 is located upstream of the second adjusting dial 609. The first adjusting wheel 607 is used to adjust the posture of the walnut in the X direction, and its rotation axis is parallel to the X-axis direction. The X-axis direction is parallel to the conveying direction of the chain 203. The second adjusting wheel 609 is used to adjust the posture of the walnut in the Y direction, and its rotation axis is parallel to the Y-axis direction. The Y-axis direction is perpendicular to the conveying direction of the chain 203. Preferably, the outer periphery of the first adjusting wheel 607 and the second adjusting wheel 609 is provided with teeth to increase the friction between the first adjusting wheel 607 or the second adjusting wheel 609 and the walnut shell.

[0039] In the initial state, the attitude adjustment servo cylinder 603 is in the retracted state, so that the first adjustment wheel 607 and the second adjustment wheel 609 are respectively at a set distance from the lowest point of the spherical groove 2041 on the tray 204, thereby avoiding interference between the tray 204 and the first adjustment wheel 607 and the second adjustment wheel 609 during the conveying process. In the posture adjustment state, the posture adjustment servo cylinder 603 rises to the set position so that the first adjustment wheel 607 and the second adjustment wheel 609 respectively contact the walnut in the spherical groove 2041 on the corresponding tray 204 to achieve posture adjustment; When the attitude adjustment is completed, the attitude adjustment servo cylinder 603 returns to its initial state.

[0040] It should be noted that the operation process of the attitude adjustment servo cylinder 603 is as follows: After the conveying mechanism 2 stops, the PLC control system causes the attitude adjustment servo cylinder 603 to push the first dial motor 606 and the second dial motor 608 to rise to the set position at a set speed, that is, the first adjustment dial 607 and the second adjustment dial 609 respectively contact the corresponding walnuts. Then, the PLC sends a high-level 5V signal to the development board, and the development board control system calls the trained detection model to start attitude adjustment. After a set time, the PLC turns off the high-level 5V signal, the detection model stops inference, and at the same time, the attitude adjustment servo cylinder 603 starts to return.

[0041] In the above embodiments, preferably, as follows: Figure 1 As shown, the shell-breaking mechanism 7 includes: a shell-breaking electric cylinder fixing frame 701, a shell-breaking electric cylinder fixing plate 702, a shell-breaking servo electric cylinder 703, a pressure sensor 704, and a shell-breaking housing 705; the shell-breaking electric cylinder fixing frame 701 is fixedly installed on the top of the frame 201, and the shell-breaking electric cylinder fixing plate 702 is fixedly installed on the top of the shell-breaking electric cylinder fixing frame 701; one end of the shell-breaking servo electric cylinder 703 is connected to the shell-breaking electric cylinder fixing plate 702, and the other end is connected to the pressure sensor 704; the shell-breaking housing 705 is connected to the pressure sensor 704; the shell-breaking housing 705 (see...) Figure 7 The head of the walnut is a concave shell shape that conforms to the shape of the walnut, and the bottom of the concave shell is provided with several protrusions or tooth-shaped grooves.

[0042] It should be noted that the force data collected by the pressure sensor 704 on the material is displayed in real time on the PLC screen, so that technicians can compare it with the recommended shell-breaking force data for walnuts of the same variety and grade. Based on the shell-breaking effect, the stroke and speed of the shell-breaking servo cylinder 703 can be adjusted to achieve a better shell-breaking effect. The downward pressing speed of the shell-breaking servo cylinder 703 is divided into two stages. The speed of the two stages can be adjusted as needed. It is preferable that the first stage is a rapid downward displacement, and the second stage is the remaining stage after approaching the walnut, with a slower speed. The return stroke speed is the same.

[0043] During equipment operation, the stroke and speed of the shell-breaking servo cylinder 703 can be adjusted via the PLC display screen to achieve the following two shell-breaking processes: The first is a directional low-loss complete shell-breaking process, which involves performing directional low-loss complete shell-breaking on the walnuts after posture adjustment to separate the shell from the kernel; the second is a crack-assisted manual shelling process, which only cracks the walnuts to replace traditional manual knocking, chopping, and other manual shell-breaking methods. Then, the cracked walnuts are manually shelled to remove the kernel from the shell. This method can effectively reduce labor costs compared to purely manual shell-breaking operations. Although the efficiency is lower than the first process, it can achieve a higher half-kernel rate.

[0044] The working process of one cycle of the walnut directional low-damage shell-breaking device of the present invention is as follows: The first station is for feeding: walnuts are fed in an orderly, single-kernel manner by a vibrating feeding mechanism 1, a guiding mechanism 3, and a conveying mechanism 2. When the first pair of laser-guided photoelectric switch sensors 502 senses the positioning piece 503, the PLC control system causes the servo motor of the power mechanism 205 of the conveying mechanism 2 to decelerate. When the second pair of laser-guided photoelectric switch sensors 502 senses the positioning piece 503, the conveying mechanism 2 stops, and the vibrating feeding mechanism 1 stops. The PLC control system causes the attitude adjustment servo cylinder to rise according to a predetermined stroke, and the first adjustment wheel 607 and the second adjustment wheel 609 contact the walnut. The PLC control system sends a high-level signal to the development board, and the development board's detection model begins inference. The second station is for X-direction attitude adjustment: the first adjustment wheel motor 607... 06 After receiving the image recognition result from the development board, the first adjusting wheel 607 is rotated according to the target position to correct the angle of the walnut in the chain conveying direction. The third station is for Y-direction posture adjustment: After receiving the image recognition result from the development board, the second adjusting wheel motor 608 controls the second adjusting wheel 609 to rotate according to the target position to correct the angle of the walnut perpendicular to the chain conveying direction. The walnut posture adjustment time can be preset on the PLC display screen or adjusted during operation to meet both posture adjustment effect and work efficiency. When the posture adjustment time is up, the PLC control system sends a low-level signal to the development board, the development board detection model stops inference, and the PLC control system causes the posture adjustment servo cylinder 603 to move down according to the predetermined stroke. The first adjustment wheel 607 and the second adjustment wheel 609 are separated from the walnuts; the fourth station is shell breaking: the shell breaking servo cylinder 703 presses down according to preset stroke and speed parameters to complete the shell breaking. According to the shell breaking effect, the stroke and speed parameters can be adjusted on the PLC display screen. The pressing speed of the shell breaking servo cylinder 703 is divided into two stages. The speed of the first and second stages can be adjusted as needed. Preferably, the first stage is a rapid downward movement, and the second stage is the remaining stage after approaching the walnut, with a slower speed. The return stroke speed is the same. The distance and speed of the first and second stages can be adjusted on the PLC display screen; the fifth station is unloading: the end discharge hopper 12 and the side discharge hopper 11 respectively receive the high-quality material after shell breaking and the shell breaking. Debris; the five stations work together until the end of one work cycle; the PLC control system then restarts the conveyor mechanism 2 and the vibrating feeder mechanism 1 to enter the next work cycle. The walnuts that have completed the X-direction orientation adjustment at the second station enter the third station with the tray 204 for Y-direction orientation adjustment, so that the plane where the walnut's stitch line is located is parallel to the horizontal plane with the cooperation of the second and third stations. The next walnut that has not been oriented enters the second station with the tray 204 for X-direction orientation adjustment. Regardless of whether there are walnuts in the spherical grooves 2041 of the first to fifth stations, the PLC control system performs the same actions as when there are walnuts. When the five stations are working, the following is ensured: when the second, third, and fourth stations are working, the vibrating feeder mechanism 1 and the conveyor mechanism 2 stop running. Additionally, it should be noted that the above embodiments are described using a single channel, but the walnut directional low-damage shell-breaking device of the present invention can also use multiple channels. If multiple channels are set, preferably, a tray is set below the tray 204 corresponding to the shell-breaking mechanism to reduce the impact of the shell breaking on the tray during shell breaking.

[0045] This invention also provides a method for automatically adjusting the posture of walnuts, comprising the following steps: The raw walnuts are poured into the vibrating feeding mechanism and then transferred to the conveying mechanism. The conveying mechanism operates intermittently, completing the work of five stations in each pause cycle. The five workstations operate as follows: The first workstation is for feeding: walnuts are fed in an orderly, single-kernel manner by a vibrating feeding mechanism 1, a guiding mechanism 3, and a conveying mechanism 2. When the first pair of laser-beam photoelectric switch sensors 502 senses the positioning piece 503, the PLC control system causes the servo motor of the power mechanism 205 of the conveying mechanism 2 to decelerate. When the second pair of laser-beam photoelectric switch sensors 502 senses the positioning piece 503, the conveying mechanism 2 stops, and the vibrating feeding mechanism 1 stops. The PLC control system causes the attitude adjustment servo cylinder 603 to rise according to a predetermined stroke, and the first adjusting wheel 607 and the second adjusting wheel 609 contact the walnuts. The PLC control... The system sends a high-level signal to the development board, and the development board's detection model begins inference; the second station is for X-direction attitude adjustment: after receiving the image recognition result from the development board, the first dial motor 606 controls the first adjustment dial 607 to rotate according to the target position, realizing the angle correction of the walnut in the conveying direction of the chain 203; the third station is for Y-direction attitude adjustment: after receiving the image recognition result from the development board, the second dial motor 608 controls the second adjustment dial 609 to rotate according to the target position, realizing the angle correction of the walnut in the direction perpendicular to the conveying direction of the chain 203, thereby making the plane where the walnut's suture line is located parallel to the horizontal plane with the cooperation of the second and third stations (see Figure 8The walnut adjustment time can be preset on the PLC display screen or adjusted during operation to achieve both adjustment effect and work efficiency. When the adjustment time is up, the PLC control system sends a low-level signal to the development board, the development board detects the model and stops reasoning, and the PLC control system causes the adjustment servo cylinder 603 to descend according to the predetermined stroke, separating the first adjustment wheel 607 and the second adjustment wheel 609 from the walnut; the vibrating feeding mechanism 1 and the conveying mechanism 2 are started; the fourth station is shell breaking: the shell breaking servo cylinder 703 descends according to the preset stroke and speed parameters to complete the shell breaking. According to the shell breaking effect, the stroke and speed parameters can be adjusted on the PLC display screen. The downward speed of the shell breaking servo cylinder 703 is divided into two stages, and the speed of the two stages can be adjusted as needed. Preferably, the first stage is a rapid downward displacement, and the second stage is the remaining stage after approaching the walnut, with a slower speed, and the return stroke speed is the same. The distance and speed of the two travel segments can be adjusted on the PLC display screen; the fifth station is for unloading: the end discharge hopper 12 and the side discharge hopper 11 respectively receive the high-quality material and the broken shell debris after shelling; the five stations work together until the end of one work cycle; the PLC control system then restarts the conveying mechanism 2 and the vibrating feeding mechanism 1 to enter the next work cycle. The walnuts that have completed the X-direction orientation adjustment at the second station enter the third station with the tray 204 for Y-direction orientation adjustment, so that the plane where the walnut's stitch line is located is parallel to the horizontal plane with the cooperation of the second and third stations. The next walnut that has not been oriented enters the second station with the tray 204 for X-direction orientation adjustment. Regardless of whether there are walnuts in the spherical grooves 2041 of the first to fifth stations, the PLC control system performs the same actions as when there are walnuts. When the five stations are working, the following is ensured: when the second, third, and fourth stations are working, the vibrating feeding mechanism 1 and the conveying mechanism 2 stop running; The precise positioning of the tray 204 at each workstation is achieved by the signal logic control of two pairs of laser photoelectric switch sensors 502 and positioning plates 503, thereby ensuring continuous and controllable directional shell-breaking operations.

[0046] In the above embodiment, preferably, when the walnuts are being shelled at the fourth station, the pressure sensor 704 collects the force data on the material and displays it on the PLC display screen in real time, so that the technicians can compare it with the recommended shelling force data for walnuts of the same variety and grade, and adjust the stroke and speed of the shelling servo cylinder 703 in combination with the shelling effect to achieve a better shelling effect. The shell-breaking servo cylinder 703 has a two-stage downward pressing speed, which can be adjusted as needed. Preferably, the first stage is a rapid downward displacement, and the second stage is the remaining stage after approaching the walnut, with a slower speed and a consistent return stroke speed. During operation, the stroke and speed of the shell-breaking servo cylinder 703 can be preset or adjusted as needed to achieve the following two shell-breaking processes: The first is a directional low-loss complete shell-breaking process, which involves performing directional low-loss complete shell-breaking on the walnut after posture adjustment to separate the shell from the kernel; the second is a crack-assisted manual shelling process, which only cracks the walnut to replace traditional manual knocking, chopping, and other manual shell-breaking methods. The cracked walnut is then manually shelled to remove the kernel. This method can effectively reduce labor costs compared to purely manual shell-breaking operations. Although the efficiency is lower than the first process, it can achieve a higher half-kernel rate.

[0047] In the above embodiments, preferably, the X-direction pose adjustment and Y-direction pose adjustment of the second and third workstations include the following steps: Image acquisition and transmission: CCD camera 402 takes pictures of the walnuts in the second and third workstation trays 204 to acquire walnut image data, and converts the acquired images into digital signals to transmit to the development board of the control system; Image processing and instruction generation: The development board in the control system calls the trained detection model to obtain the center point coordinates of the walnut and its suture line in real time. The control system performs vector operation on the center point coordinates to generate corresponding control instructions and sends them to the first dial motor 606 and the second dial motor 608. Posture adjustment: The first dial motor 606 and the second dial motor 608 drive the corresponding first adjustment dial 607 and the second adjustment dial 609 to perform rotation actions according to the received control commands. Through friction, the walnuts in the corresponding tray 204 are adjusted to achieve the posture adjustment. Cyclic posture adjustment: Once the walnut reaches the preset orientation standard, the posture adjustment task in that direction is completed; then, the walnut that has completed the posture adjustment in the second station moves forward with the tray 204 to the third station for posture adjustment in the Y direction. At the same time, the next walnut that has not been adjusted enters the second station with the tray 204 for posture adjustment in the X direction. The preset orientation standard is: the second station adjusts the walnut's posture in the X direction, and the unit normal vector of the suture plane is λ, and the unit vector of the camera coordinate system is expressed as ( ),in , These are the camera coordinate systems. , The unit vector of the axis, the orientation standard of the second station satisfies any of the following conditions, A: the vector dot product λ·y c1 = 0 or B: No suture line can be detected in the current field of view, i.e., the suture line plane is parallel to the horizontal plane; In the next pause cycle, the walnut is moved to the third station for attitude adjustment in the Y direction. The orientation standard of the third station meets any of the following conditions: B: No suture line can be detected in the current field of view or C: and .

[0048] It should be noted that the walnut posture in this invention is defined as follows: When a walnut is placed on a horizontal surface and its shape is observed from above, for a mature walnut, its main visible feature is the suture line. Therefore, the positional relationship of the suture line on the walnut is used as the basis for posture determination. The suture line generally encircles the walnut, and its plane forms an angle with the horizontal plane. The posture angle is defined as follows from the top-view perspective, with the posture angle being 90°: the plane containing the suture line is basically perpendicular to the horizontal plane (see...). Figure 9 ); The attitude angle is 0°: the plane containing the suture is basically parallel to the horizontal plane, and the suture is not visible in the top view (see Figure 10 This state is the target posture for the posture adjustment of this system; the above definition facilitates the quantification of the walnut's posture in the image recognition and control system, and serves as a posture adjustment criterion to achieve precise control of the force direction during shell breaking, ensuring that force is applied along the transverse diameter of the walnut to achieve the purpose of shell breaking with low damage.

[0049] In the above embodiments, preferably, the trained detection model is implemented through the following steps: Data Acquisition: The development board in the control system opens the camera video stream, and the operator manually adjusts the posture of each walnut. After each adjustment to the desired posture, the operator triggers the capture of the next frame of the video stream via the keyboard and saves it as an image. A total of 200 individual walnuts were acquired, resulting in 1,800 images with a resolution of 320×320 pixels. This dataset covers the appearance changes of walnuts under various postures. Several examples of photographing the same walnut under different postures are shown below. Figure 11 This dataset was used to train and validate the walnut and suture detection model, ensuring the robustness of the recognition algorithm to pose, scale, and surface details. Dataset Labeling: Labeling was performed using the roLabelImg tool. Oriented bounding boxes (represented in x, y, w, h, angle format) were used to label targets in the images. Labeling categories included: walnuts were labeled "walnut," and suture lines were labeled "roulette." The labeling results were saved as XML files for subsequent model training and management. To ensure consistency between training and testing, a unified labeling standard was followed throughout the entire dataset labeling and training process to enhance the robustness of the detection model. The main standards are as follows: Suture lines are often curved or partially circular, and a single oriented bounding box often cannot fully represent the geometric features of the entire suture line. Furthermore, suture lines may be partially occluded or incompletely identified in the image. Therefore, the complete suture line was divided into arc segments, with each largest labeling unit being approximately a quarter-circle suture line segment, and each segment was labeled with an oriented bounding box (see figure). Figure 12 Between two oriented rectangles representing the same suture line, try to make a corner point of the two boxes coincide to ensure the continuity and spatial correlation between the box and the suture line arc segment; when annotating, try to make the background inside the target box the surface texture of the walnut itself, and avoid including too much external background unrelated to the walnut inside the box, so as to improve the accuracy of the features learned by the model; for cases where the suture line is basically invisible from a top view (see...), Figure 10 In the first case, only the walnut label is labeled, without the roulette label; this type accounts for about 5%-6% of all annotations. In the remaining most samples, each image usually contains one walnut label and two roulette labels (corresponding to the two arc segments of the same suture line respectively) to more accurately characterize the positional information of the suture line. The above annotation strategy aims to balance annotation accuracy and operability, so that the training data can fully reflect the local geometric features of the suture line under different poses, occlusions and lighting conditions, thereby improving the recognition accuracy and stability of the detection model in the actual pose adjustment process.

[0050] Dataset Expansion: The 1,800 original labeled images were divided into a training set of 1,440 images and a test set of 360 images in an 8:2 ratio. After the split, the training set contained 1,440 walnut labels and 2,720 roulette labels; the validation set contained 360 walnut labels and 688 roulette labels. A Python script was then used to batch convert all XML-formatted annotation files to normalized TXT format. The normalized TXT files recorded key information about the target bounding boxes, namely the coordinates of the four corner points (or their corresponding normalized representations), facilitating consistent geometric transformations between the images and annotations. Based on the normalized coordinate representation, the following seven transformations were applied simultaneously to each image and its corresponding annotation: left-right mirroring, top-bottom mirroring, increasing brightness, decreasing brightness, rotating 90° clockwise around the image center, rotating 180°, and rotating 270°. Including the original image, there are a total of eight versions, thus achieving an 8-fold amplification of the original data. After amplification, the number of Walnut labels in the training set increased to 11,520, and the number of Roulette labels increased to 21,760. The examples of the amplified effects are as follows: original image, horizontally symmetrical, vertically symmetrical; increased brightness, decreased brightness; and clockwise rotation of 90°, 180°, and 270° based on the image center, as shown in the examples. Figure 13 This augmentation strategy improves the model's robustness to changes in scale, orientation, and illumination by increasing pose, brightness, and orientation diversity.

[0051] Model Framework: Considering the rotation and tilt characteristics of walnut suture lines under different postures, the Oriented Bounding Box (OBB)-based target detection method is chosen to more accurately represent the geometric information of the target. Therefore, YOLOv8s-obb is ultimately adopted as the base model for training and inference. Key points are as follows: Reason for Selection: The YOLO series offers a good trade-off between speed and accuracy. YOLOv8s-obb is lightweight (s version) and supports variants of the Oriented Bounding Box, enabling faster inference speed and higher detection accuracy with limited computing power and data volume, making it suitable for online real-time walnut posture recognition and control scenarios. Advantages of Oriented Bounding Boxes: Compared to traditional horizontal rectangular boxes (HBB), OBB can directly express the target's orientation (rotation angle), providing more accurate detection of suture lines with arbitrary rotation (thin, arc-shaped), reducing redundant background and improving IoU / regression accuracy, thus facilitating subsequent posture estimation and vector calculation. Labeling and Input Format: The original labels use normalized coordinates of the four vertices (class_index, x1, y1, x2, y2, x3, y3, x4, y4) for easy manual labeling and visualization storage; during the training and loss calculation phases, the bounding box information is parameterized by centering as (x... i y i w i hi r i Formal input and regression, x i y i Centered on, w i h i For width and height, r i This represents the rotation angle. Training and loss considerations: The OBB model's regression loss includes not only center coordinates and scale regression, but also rotation angle regression, along with rotation IoU (or a directional version of GIoU / CIoU) to improve detection accuracy; during training, it's crucial to ensure consistency between the labeled and model angle conventions. Data processing chain: The format of the labeled four corner points can be automatically converted to the training required (x... i y i w i h i r i In this format, data augmentation (flipping, rotation, brightness changes) requires simultaneous transformation of the four corner points or centering parameters to ensure label consistency. Inference and Application: After training, the model directly outputs the (x) of the orientation box. i y i w i h i r i This can be used to determine the spatial position and orientation of the walnut and suture line in real time, providing precise center point and angle information for the subsequent adaptive attitude adjustment control system, thereby generating control commands through vector operations. In summary, YOLOv8s-obb, while maintaining real-time performance, accurately represents the rotational features of the suture line with oriented bounding boxes. Combined with a consistent annotation and transformation process and a training strategy for angle regression, it can effectively improve the accuracy and stability of walnut attitude recognition.

[0052] Model Training: The training data preparation and environment configuration are as follows: 11,520 augmented training images and their normalized TXT annotation files were placed in the `train` folder, and 360 validation images and their annotations were placed in the `val` folder. The paths and category information were specified in the dataset YAML configuration file. Training was conducted in the official Ultralytics YOLOv8 implementation environment. The main software and hardware environment were: Ultralytics YOLOv8.2.85, Python 3.8.19, PyTorch 2.3.0+cu121, CUDA (corresponding graphics card driver), and the training device was an NVIDIA GeForce RTX 4090 (24,564 MiB of VRAM). Model and Hyperparameters: The lightweight bounding box model YOLOv8s-obb was used. The initial weights used the official pre-trained model yolov8-obb.pt to accelerate convergence and improve few-shot generalization ability. Training hyperparameter settings: The total number of training epochs (first stage) was set to 1000 epochs, input image size imgsz=320, batch_size=64, workers=0, and other parameters remained at their default values. Data augmentation strategies such as Mosaic were used during training to improve sample diversity. Training process: In the first stage, approximately 105 hours of training was performed using yolov8-obb.pt as the initial weights to obtain an initial model (best.pt). In the second stage, the previously trained best.pt was used as the initial parameters, and the original training set was fine-tuned for another 100 epochs, while other training parameters remained unchanged, to further improve the model's accuracy and stability on this task. In terms of training strategies, Mosaic enhancement was enabled in most training stages to increase image combinations and background variations; in the last few epochs of training (e.g., the last 10 epochs), Mosaic was gradually disabled to allow the model to better adapt to the distribution of real single images, improving convergence stability and actual inference performance. Training results and validation: The model performance was monitored through training / validation curves during the training process. The results showed no obvious underfitting or overfitting phenomena (see details). Figure 14 (Accuracy and speed information). After training, the detection and bounding box regression results on the walnut pose test set are as follows: Figure 15 As shown, the model can effectively detect the walnut body and the suture line arc segment, and provide information on the center, scale, and rotation angle, meeting the needs of subsequent attitude estimation and posture control.

[0053] In the above embodiments, preferably, the control method of the control system includes the following steps: (1) Acquisition and detection: The control system starts working after receiving a high-level signal from the PLC. Each walnut to be oriented is placed on the tray 204 in an arbitrary random posture. The CCD camera 402 acquires the image of the current frame. After preprocessing, the image is input into the pre-trained YOLOv8s-obb model for directional bounding box regression to obtain the center position and rotation angle information of the walnut and the suture line (see Figure 16 ); (2) Coordinate mapping: The detection center point and Mapping from the pixel plane to the actual plane of tray 204, calculate the current pose vector and angle. ; (3) Rotation direction of the first dial motor 606 and the second dial motor 608: and By comparing relative positions, directional information can be obtained; (4) Generate control commands: based on the current attitude vector and angle The information simultaneously drives the first dial motor 606 and the second dial motor 608 of the second and third workstations, and sends rotation commands according to the preset closed-loop control strategy. The current angle or position information of the walnut suture line is fed back through the detection result of the next frame. (5) Iterative adjustment: During the preset posture adjustment time, repeat steps (1) to (4) to continuously adjust the walnut posture through closed-loop feedback until one of the following conditions is met: When the walnut at the second station reaches the preset orientation standard A or B, stop the rotation of the first dial motor 606; When the walnut at the third station reaches the preset orientation standard B or C, stop the rotation of the second dial motor 608. (6) After the control system receives the high-level signal from the PLC, the model stops reasoning. During the operation of the equipment, the duration of the high-level signal from the PLC can be flexibly adjusted. It is recommended to use the longest posture adjustment time in the same batch of walnuts as the setting benchmark. This will ensure that each walnut has sufficient posture adjustment time to ensure that the posture adjustment effect meets the standard, and will also avoid invalid time occupation and maintain an efficient processing rhythm. (7) After one orientation adjustment is completed, the conveying mechanism moves forward one tray 204 positions and moves the walnut that has completed the orientation adjustment in the X direction on the second station to the third station to continue the orientation adjustment in the Y direction; at the same time, the second station receives the next walnut that has not been oriented and repeats steps (1) to (6) to form a continuous cycle operation.

[0054] In the above embodiments, preferably, the coordinate mapping includes the following steps: With the origin of the camera coordinate system Based on this, from top to bottom are the pixel plane and the tray plane, with the center of the tray denoted as... The radius of the tray is ; Starting on the tray surface, at the center of the suture line To the Walnut Center The vector represents the walnut posture; their projections onto the pixel plane are respectively... and , The predicted coordinates are ( ), The predicted coordinates are set to (0, 0) in the normalized coordinate system, and the equivalent radius of the walnut is denoted as . ,in, , These represent the width and height of the detection box for the walnut in the image, respectively. After mapping the image coordinates to actual geometric quantities, the predicted angle between the suture center vector and the horizontal plane is calculated. The predicted angle is used to evaluate the inclination of the suture relative to the horizontal plane, thereby determining the amount of rotation required. Its calculation expression is as shown in equation (1): (1) In the formula, The equivalent radius of the walnut (in pixels); , They are respectively The predicted x and y coordinates (in pixels).

[0055] This angle is used to evaluate the inclination of the suture relative to the horizontal plane, thus determining the amount of rotation required. Feedback control strategy: Feedback amount selection: based on the center of the suture orientation frame predicted by the model ( ) and the width and height of the walnut orienting frame ( ),calculate The suture line is used as an angle feedback quantity. Control objective: To make the suture line invisible in the top view (i.e., the suture line rotates to the side or horizontal position of the walnut). This typically corresponds to the detected suture line center projection being located at the edge of the walnut or exceeding the effective visual detection range due to self-occlusion. Control implementation: The development board generates rotation commands for the dial motor based on the feedback quantity and sends them to the dial motor via serial communication. Using X and Y axis dial motors in conjunction, the walnut can be rotated in different directions individually or simultaneously, facilitating attitude adjustment along any axis. The rule for determining the rotation direction is: when the suture line is located on one side of the image, rotate as far away from the camera's field of view as possible until the detection model can no longer recognize the key suture line features. The specific correspondence between the rotation amplitude and direction is executed according to a preset table (as shown in Table 1).

[0056] Table 1 Rotation and Orientation Relationship Table The final result of the walnut orientation adjustment in this invention is as follows: Figure 17 As shown, the control flow of the control system is as follows: Figure 18 As shown.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A walnut-oriented, low-damage shell-breaking device, characterized in that, include: The vibrating feeder is used to hold the raw walnuts and transport them to the conveying mechanism. The conveying mechanism, located downstream of the vibrating feeder, is used to convey walnut raw materials; A guiding mechanism, disposed on the conveying mechanism, is used to remove stacked walnuts so as to guide the walnuts to be conveyed in a single row; An image acquisition device is installed above the conveying mechanism and downstream of the guiding mechanism. It is used to acquire image information of walnuts at the second and third workstations below it and transmit the image information to the development board of the control system. A signal acquisition device is installed on the conveying mechanism to acquire the position information of the pallet and transmit the position information to the PLC of the control system; An attitude adjustment device is located below the conveying mechanism and opposite to the image acquisition device, and is used to adjust the attitude of the walnut. The shell-breaking mechanism is located above the conveying mechanism and downstream of the attitude adjustment device, and is used to break the shells of the walnuts after the attitude has been adjusted. The control system includes a development board and a PLC. The development board is used to control the attitude adjustment device based on the image information from the image acquisition device. The PLC is used to control the operation of the vibrating feeder, conveying mechanism, guiding mechanism, attitude adjustment servo cylinder in the attitude adjustment device, and shell breaking mechanism based on the position information from the signal acquisition device.

2. The walnut directional low-damage shell-breaking device according to claim 1, characterized in that, The vibrating feeding mechanism includes: a hopper frame, a feeding hopper, a vibrating feeder, and a limiting plate; The feeding hopper is located on top of the hopper frame; One end of the vibrating feeder is located below the feeding hopper, and the other end is located above the first end of the conveying mechanism, and the vibrating feeder is located in the middle of the hopper frame; The limiting plate is provided with at least two elongated slots, and the feeding hopper is provided with two mounting holes on one side corresponding to the positions of the elongated slots. The limiting plate is connected to the side wall of the feeding hopper by a wing nut and bolts, and the elongated slots and the wing nut and bolts can be used to adjust the position of the limiting plate in the vertical direction to open and close the feeding channel of the vibrating feeder. The limiting plate is located downstream of the feed hopper outlet. When the limiting plate opens the feeding channel of the vibrating feeder, the vibrating feeder continues to feed. When the limiting plate closes the feeding channel of the vibrating feeder, the vibrating feeder stops feeding.

3. The walnut directional low-damage shell-breaking device according to claim 1, characterized in that, The conveying mechanism includes: a frame, a transmission sprocket assembly, a chain, a pallet, and a power mechanism; Two of the aforementioned drive sprocket sets are respectively disposed at both ends of the top of the frame, and the other two of the aforementioned drive sprocket sets are respectively disposed at both ends of the bottom of the frame; Two chains are respectively disposed on the front and rear sides of the frame, and the upper two ends of the chains are respectively tractably connected to the upper drive sprocket assembly, and the lower two ends are respectively tractably connected to the lower drive sprocket assembly. Several trays are arranged in a single row between two chains and move with the chains. Each tray has a spherical groove for placing walnuts in the middle and a cross opening at the bottom of the spherical groove. The power mechanism is connected to one of the upper transmission sprocket groups via a belt and is used to provide power to the transmission sprocket group.

4. The walnut directional low-damage shell-breaking device according to claim 3, characterized in that, The frame is provided with guard plates on the front and rear sides respectively; the guard plates are respectively provided with transmission component end cover plates, attitude adjustment device adjustment windows and side discharge hoppers; The end cover of the transmission component is detachably mounted on the protective plate, which facilitates the maintenance of the transmission sprocket assembly and prevents external dust and impurities from entering and affecting its normal operation. The adjustment window of the attitude adjustment device is detachably mounted on the protective plate and corresponds to the position of the attitude adjustment device, so as to facilitate observation of the operating status of the attitude adjustment device and to inspect and adjust the relative position of the attitude adjustment device and the tray. One end of the side discharge hopper extends to the spherical groove of the tray below the shell breaking mechanism, and the other end extends to the outside of the guard plate, for discharging debris leaking from the cross opening at the bottom of the spherical groove outside the guard plate. The tail end of the conveying mechanism is provided with an end discharge hopper. The two sides of the end discharge hopper are connected to the guard plate. Its first end extends to the bottom of the end tray, and its second end extends to the outside of the conveying mechanism, for exporting the shelled walnuts. The image acquisition device and the shell-breaking mechanism are enclosed by an organic cover.

5. The walnut directional low-damage shell-breaking device according to claim 4, characterized in that, It also includes an outer baffle, an inner baffle, a feeding end cover, and a discharging end cover; Two outer baffles are respectively installed on the top of the frame and are located on the outside of the two chains; Two inner baffles are respectively disposed on the integral formed by the plurality of said trays, and are respectively located on the inner side of the two chains; The feeding end cover is located on the top of the outer baffle near the vibrating feeding mechanism, and the discharge end cover is located on the top of the outer baffle near the end discharge hopper.

6. The walnut directional low-damage shell-breaking device according to claim 4, characterized in that, The material guiding mechanism includes: an electric brush roller, a material guiding frame, and a material guiding partition; The electric brush roller is connected to the top of the frame at both ends by connectors, and its rotation direction is the same as that of the chain. It is used to rotate and remove stacked walnuts so that one walnut is left in the spherical groove of each tray. Two material guide fixing frames are respectively set upstream and downstream of the electric brush roller. The material guide fixing frames are door frame-shaped structures, and their two ends are fixed to the top of the frame. Two guide baffles are respectively disposed on both sides of the electric brush roller, and the top of the guide baffles is respectively connected to the two guide fixing frames.

7. The walnut directional low-damage shell-breaking device according to claim 4, characterized in that, The image acquisition device includes: a camera bracket, a CCD camera, and an LED light source; The camera bracket has a door frame-shaped structure, with both ends fixed to the top of the frame; The CCD camera is mounted on the top crossbar of the camera bracket and is used to acquire image information of the walnuts in the second and third work positions directly below it. The two LED light sources are respectively disposed on the top of the housing and located upstream and downstream of the camera bracket, and are used to provide light for the image acquisition environment.

8. The walnut directional low-damage shell-breaking device according to claim 3, characterized in that, The signal acquisition device includes: a sensor bracket, a laser photoelectric switch sensor, and a positioning plate; Two sets of sensor brackets are fixedly installed on the top of the frame. Each set of sensor brackets includes two oppositely arranged sensor brackets, which are respectively arranged on both sides of the tray. Each sensor bracket is equipped with a pair of laser-guided photoelectric switch sensors; Each tray is provided with a positioning piece, which is located on one side of the spherical groove; The installation height of the laser through-beam photoelectric switch sensor is higher than the highest point of the walnut in the spherical groove of the tray. The height of the positioning piece is also higher than the highest point of the walnut in the spherical groove of the tray and the height of the laser through-beam photoelectric switch sensor, so as to ensure that the laser through-beam photoelectric switch sensor only responds to the passing of the positioning piece and is not affected by the walnut in the spherical groove being accidentally blocked. The interval L between the two sets of sensor brackets is preferably no greater than half the width W of the tray.

9. The walnut directional low-damage shell-breaking device according to claim 3, characterized in that, The attitude adjustment device includes: an attitude adjustment cylinder base, an attitude adjustment cylinder fixing plate, an attitude adjustment servo cylinder, a dial motor support plate, a dial motor base, a first dial motor, a first adjustment dial, a second dial motor, and a second adjustment dial; The attitude adjustment electric cylinder base is disposed at the bottom of the frame, the attitude adjustment electric cylinder fixing plate is fixedly disposed at the top of the attitude adjustment electric cylinder base, the bottom of the attitude adjustment servo electric cylinder is fixedly disposed at the attitude adjustment electric cylinder fixing plate, the dial motor support plate is fixedly disposed at the top of the attitude adjustment servo electric cylinder, and the first dial motor and the second dial motor are respectively fixed to the dial motor support plate through a dial motor base; The first adjusting wheel and the second adjusting wheel are respectively disposed below the trays of the second and third work stations, and can contact the walnuts in the spherical groove after being raised. The first adjusting wheel is mounted on the output shaft of the first adjusting wheel motor, the second adjusting wheel is mounted on the output shaft of the second adjusting wheel motor, and the first adjusting wheel is located upstream of the second adjusting wheel. The first adjustment wheel is used to adjust the posture of the walnut in the X direction, and its rotation axis is parallel to the X-axis direction, which is parallel to the conveying direction of the chain. The second adjustment wheel is used to adjust the posture of the walnut in the Y direction, and its rotation axis is parallel to the Y-axis direction, which is perpendicular to the conveying direction of the chain. In the initial state, the attitude adjustment servo cylinder is in the retracted state, so that the first adjustment wheel and the second adjustment wheel are respectively at a set distance from the lowest point of the spherical groove on the tray, thereby avoiding interference between the tray and the first adjustment wheel and the second adjustment wheel during the transport process; In the posture adjustment state, the posture adjustment servo cylinder rises to the set position so that the first adjustment wheel and the second adjustment wheel respectively contact the walnut in the spherical groove on the corresponding tray to achieve posture adjustment; When the attitude adjustment is completed, the attitude adjustment servo cylinder returns to its initial state.

10. The walnut directional low-damage shell-breaking device according to claim 3, characterized in that, The shell-breaking mechanism includes: a shell-breaking electric cylinder fixing frame, a shell-breaking electric cylinder fixing plate, a shell-breaking servo electric cylinder, a pressure sensor, and a shell to be broken; The shell-breaking electric cylinder fixing frame is fixedly installed on the top of the frame, and the shell-breaking electric cylinder fixing plate is fixedly installed on the top of the shell-breaking electric cylinder fixing frame; One end of the shell-breaking servo electric cylinder is connected to the shell-breaking electric cylinder fixing plate, and the other end is connected to the pressure sensor. The shell to be broken is connected to the pressure sensor. The head of the shell is a concave shape adapted to the shape of a walnut, and the bottom of the concave shell is provided with several protrusions or toothed grooves.

11. A method for automatically adjusting the posture of a walnut based on the walnut orientation and low-damage shell-breaking device according to any one of claims 1 to 10, characterized in that, Includes the following steps: The raw walnuts are poured into the vibrating feeding mechanism and then transferred to the conveying mechanism. The conveying mechanism operates intermittently, completing the work of five stations in each pause cycle. The five workstations operate as follows: The first workstation is for feeding: walnuts are fed in an orderly, single-kernel manner using a vibrating feeding mechanism, a guiding mechanism, and a conveying mechanism. When the first pair of laser-guided photoelectric switches detects the positioning plate, the PLC control system causes the servo motor of the conveying mechanism's power mechanism to decelerate. When the second pair of laser-guided photoelectric switches detects the positioning plate, the conveying mechanism stops, and the vibrating feeding mechanism stops. The PLC control system causes the attitude adjustment servo cylinder to rise according to a predetermined stroke. The first and second adjustment wheels contact the walnuts, and the PLC control system sends a high-level signal to the development board, initiating the inference process of the development board's detection model. The second workstation is for X-direction attitude adjustment: the first wheel motor receives... After receiving the image recognition results from the development board, the first adjusting wheel is rotated according to the target position to correct the angle of the walnut in the chain conveying direction. The third station is for Y-axis posture adjustment: after receiving the image recognition results from the development board, the second adjusting wheel is rotated according to the target position to correct the angle of the walnut perpendicular to the chain conveying direction. The walnut posture adjustment time is preset on the PLC display screen. When adjustment is needed, it is performed during operation to meet the posture adjustment effect while taking into account work efficiency. When the posture adjustment time is up, the PLC control system sends a low-level signal to the development board, the development board detection model stops reasoning, and the PLC control system causes the posture adjustment servo cylinder to move according to the predetermined stroke. The first and second adjusting dials separate from the walnuts as the walnuts descend. The fourth station is for shell breaking: the shell-breaking servo cylinder presses down according to preset stroke and speed parameters to complete the shell breaking. The stroke and speed parameters can be adjusted on the PLC display screen based on the shell-breaking effect. The speed of the shell-breaking servo cylinder during the pressing process is divided into two segments, and the speed of the two segments can be adjusted as needed. Preferably, the first segment is a rapid downward movement, and the second segment is the remaining segment after approaching the walnut, with a slower speed. The return stroke speed is the same. The distance and speed of both the first and second segments can be adjusted on the PLC display screen. The fifth station is for unloading: the end discharge hopper and the side discharge hopper respectively receive the high-quality material after shell breaking and the shelled material. Debris; the five stations work together until the end of one work cycle; the PLC control system then restarts the conveying mechanism and the vibrating feeding mechanism to enter the next work cycle. The walnuts that have completed the X-direction orientation adjustment at the second station enter the third station with the tray for Y-direction orientation adjustment, so that the plane where the walnut's stitch line is located is parallel to the horizontal plane with the cooperation of the second and third stations. The next walnut that has not been oriented enters the second station with the tray for X-direction orientation adjustment. Regardless of whether there are walnuts in the spherical grooves of the first to fifth stations, the PLC control system performs the same actions as when there are walnuts. When the five stations are working, the following is ensured: when the second, third, and fourth stations are working, the vibrating feeding mechanism and the conveying mechanism stop running. The precise positioning of the pallet at each workstation is achieved by the signal logic control of two pairs of laser photoelectric switch sensors and positioning plates, thereby ensuring continuous and controllable directional shell-breaking operations.

12. The automatic walnut posture adjustment method according to claim 11, characterized in that, When the walnuts are being cracked at the fourth station, the pressure sensor collects the force data on the walnuts and displays it on the PLC screen in real time. This allows technicians to compare the data with the recommended cracking force data for walnuts of the same variety and grade. Based on the cracking effect, the stroke and speed of the cracking servo cylinder are adjusted to achieve a better cracking effect. The shell-breaking servo cylinder's downward pressing speed is divided into two segments. The speed of the two segments can be adjusted as needed. Preferably, the first segment is a rapid downward displacement, and the second segment is the remaining segment after approaching the walnut, where the speed slows down, and the return stroke speed is the same. When the equipment is running, the stroke and speed of the shell-breaking servo cylinder can be preset or adjusted as needed during operation to achieve the following two shell-breaking processes: The first is a directional low-loss complete shell-breaking process, which performs directional low-loss complete shell-breaking treatment on the walnut after the posture adjustment is completed, realizing the separation of the shell and kernel; the second is a crack-assisted manual shelling process, which only cracks the walnut to replace the traditional manual knocking, chopping and other manual shell-breaking methods, and then the cracked walnut is manually shelled to remove the kernel from the shell.

13. The method for automatically adjusting the posture of walnuts according to claim 11, characterized in that, The X-axis and Y-axis pose adjustment of the second and third stations includes the following steps: Image acquisition and transmission: The CCD camera takes pictures of the walnuts in the trays of the second and third workstations to acquire walnut image data, and converts the acquired images into digital signals to transmit to the development board of the control system; Image processing and instruction generation: The development board in the control system calls the trained detection model to obtain the center point coordinates of the walnut and its suture line in real time. The control system performs vector operations on the center point coordinates to generate corresponding control instructions and sends them to the first and second dial motors. Posture adjustment: The first and second dial motors drive the corresponding first and second adjustment dials to rotate according to the received control commands. The friction force acts on the walnuts in the corresponding trays to adjust the posture of the walnuts. Cyclic posture adjustment: Once the walnut reaches the preset orientation standard, the posture adjustment task in that direction is completed; then, the walnut that has completed the posture adjustment in the second station moves forward with the tray to the third station for posture adjustment in the Y direction. At the same time, the next walnut that has not been adjusted moves into the second station with the tray for posture adjustment in the X direction. The preset orientation standard is: the second station adjusts the walnut's posture in the X direction, and the unit normal vector of the suture plane is λ, and the unit vector of the camera coordinate system is expressed as ( ),in , These are the camera coordinate systems. , The unit vector of the axis, the orientation standard of the second station satisfies any of the following conditions, A: the vector dot product λ·y c1 = 0 or B: No suture line can be detected in the current field of view, i.e., the suture line plane is parallel to the horizontal plane; In the next pause cycle, the walnut is moved to the third station for attitude adjustment in the Y direction. The orientation standard of the third station meets any of the following conditions: B: No suture line can be detected in the current field of view or C: and .

14. The automatic walnut posture adjustment method according to claim 13, characterized in that, The trained detection model is implemented through the following steps: Data Acquisition: The development board in the control system opens the camera video stream, and the operator manually adjusts the posture of a single walnut. After each adjustment to the desired posture, the next frame of the video stream is captured and saved as an image via the keyboard. A set number of individual walnuts are collected, resulting in a set number of images with a set resolution of pixels. This dataset covers the appearance changes of walnuts under various postures. This dataset is used to train and validate the detection model for walnuts and suture lines, ensuring the robustness of the recognition algorithm to posture, scale, and surface details. Dataset Labeling: Labeling was performed using the roLabelImg tool, employing directional bounding boxes to label targets in the images. Walnuts were labeled "walnut," and suture lines were labeled "roulette." The labeling results were saved as an XML file. The complete suture line was divided into arc segments, with each largest labeling unit being a quarter-circle suture segment, labeled with a directional bounding box. Between two directional bounding boxes representing the same suture line, a corner point of each box was aligned to ensure continuity and spatial correlation between the box and the suture line arc segment. During labeling, the background within the target box was set to the surface texture of the walnut itself, avoiding excessive inclusion of irrelevant external background to improve the accuracy of the features learned by the model. For cases where the suture line is barely visible from a top-down view, only "walnut" was labeled, not "roulette." In other samples, each image typically includes one "walnut" label and two "roulette" labels to more accurately depict the suture line's positional information. Dataset augmentation: A set of labeled original images were divided into a training set of images and a test set of images according to a set ratio. After the division, the number of walnut labels and roulette labels in the training set was set; the number of walnut labels and roulette labels in the validation set was set. Then, a Python script was used to batch convert all XML format annotation files into normalized TXT format. The normalized TXT files recorded the key information of the target bounding boxes. Based on the normalized coordinate representation, the following seven transformations were applied to each image and its corresponding annotation simultaneously: left-right mirroring, top-bottom mirroring, increasing brightness, decreasing brightness, rotating 90°, 180°, and 270° clockwise around the image center as the origin. These seven transformations, together with the original image, resulted in a total of eight versions, thereby achieving an eightfold augmentation of the original data. After augmentation, the number of walnut labels in the training set increased to set, and the number of roulette labels increased to set, to improve the robustness of the model to scale, orientation, and illumination changes. Model framework: Considering the rotation and tilt features of the walnut suture line under different postures, the target detection method based on directional bounding boxes is selected to more accurately express the geometric information of the target. Based on this, YOLOv8s-obb is finally adopted as the basic model for training and inference. Model Training: The augmented training images and their normalized TXT annotation files were placed in the `train` folder, and the validation images and their annotations were placed in the `val` folder. The paths and category information were specified in the dataset YAML configuration file. The training hyperparameters were set as follows: the total number of training epochs was set to a set value, the input image size `imgsz` was a set value, `batch_size` was a set value, `workers` was a set value, and other parameters were default values. Mosaic data augmentation was used to improve sample diversity during training. The model was trained using the following workflow: In the first stage, `yolov8-obb.pt` was used as the initial weights and trained for approximately a set number of hours to obtain an initial model `best.pt`. In the second stage, the previously trained `best.pt` was used as the initial parameters, and the original training set was fine-tuned for another set number of epochs, while other training parameters remained unchanged, to further improve the model's accuracy and stability on this task. Mosaic was gradually disabled in the last few epochs of training to allow the model to better adapt to the distribution of real single images, improving convergence stability and actual inference performance. The training results were then validated.

15. The method for automatically adjusting the posture of walnuts according to claim 13, characterized in that, The control method of the control system includes the following steps: (1) Acquisition and detection: After receiving the high-level signal from the PLC, the control system starts working. Each walnut to be adjusted is placed on the tray in an arbitrary random posture. The CCD camera acquires the image of the current frame. After the image is preprocessed, it is input into the pre-trained YOLOv8s-obb model for directional bounding box regression to obtain the center position and rotation angle information of the walnut and the suture line. (2) Coordinate mapping: The detection center point and Mapping from the pixel plane to the actual tray plane, calculate the current pose vector and angle β. pi ; (3) Rotation direction of the first and second gear wheel motors: and By comparing relative positions, directional information can be obtained; (4) Generate control commands: based on the current attitude vector and angle The information simultaneously drives the first and second dial motors of the second and third workstations, and sends rotation commands according to the preset closed-loop control strategy. The current angle or position information of the walnut suture line is fed back through the detection result of the next frame. (5) Iterative adjustment: During the preset posture adjustment time, repeat steps (1) to (4) to continuously adjust the walnut posture through closed-loop feedback until one of the following conditions is met: When the walnut in the second station reaches the preset orientation standard A or B, stop the rotation of the first gear wheel motor; when the walnut in the third station reaches the preset orientation standard B or C, stop the rotation of the second gear wheel motor. (6) After the control system receives the high-level signal from the PLC, the model stops reasoning. During the operation of the equipment, the duration of the high-level signal from the PLC can be flexibly adjusted. The duration is based on the longest posture adjustment time among the same batch of walnuts. (7) After one posture adjustment is completed, the walnut that has completed the posture adjustment at the second station moves forward with the tray to the third station for posture adjustment in the Y direction. At the same time, the next walnut that has not been adjusted enters the second station with the tray and repeats steps (1) to (6) to form a continuous cycle operation.

16. The method for automatically adjusting the posture of walnuts according to claim 15, characterized in that, The coordinate mapping includes the following steps: With the origin of the camera coordinate system Based on this, from top to bottom are the pixel plane and the tray plane, with the center of the tray denoted as . The radius of the tray is ; Starting on the tray surface, at the center of the suture line To the Walnut Center The vector represents the walnut's posture; The projections on the pixel plane are respectively and ; The predicted coordinates are , The predicted coordinates are set to (0, 0) in the normalized coordinate system, and the equivalent radius of the walnut is denoted as R. ai = (w i + h i ) / 4, where w i h i These represent the width and height of the detection box for the walnut in the image, respectively. After mapping the image coordinates to actual geometric quantities, the predicted angle β between the suture center vector and the horizontal plane is calculated. pi The predicted angle is used to evaluate the inclination of the suture relative to the horizontal plane, thereby determining the amount of rotation required. Its calculation expression is as shown in equation (1): (1) In the formula, Let be the equivalent radius of the walnut. , They are respectively The predicted x and y coordinates.

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