Intelligent Longjing tea careful selection method based on image contour analysis and uniform stacking equipment

Abstract

The invention discloses a Longjing tea careful selection method and uniform stacking equipment based on image contour analysis, and belongs to the technical field of intelligent manufacturing equipment.The uniform stacking equipment comprises a feeding mechanism used for carrying out corresponding feeding operation on multiple types of primarily selected Longjing tea; the mixing mechanism is used for uniformly mixing and flatly spreading the primarily selected longjing tea of the plurality of feeding mechanisms; the impurity removal mechanism is used for performing impurity removal operation on the primarily selected longjing tea treated by the mixing mechanism; the fine selection mechanism is used for performing fine sorting operation on the primarily selected longjing tea in a visual photographing manner. The invention further comprises a Longjing tea selection method based on image contour analysis, and the selection operation of special-grade Longjing tea is realized by adopting an image contour analysis mode for the Longjing tea.

Description

Technical Field

[0001] This solution relates to intelligent manufacturing equipment, and particularly to a method for selecting high-quality Longjing tea based on image contour analysis and a blending equipment. Background Art

[0002] Longjing tea has always been renowned for its emerald green color, beautiful shape, fragrant aroma, and mellow taste. Its unique "light and distant", "fragrant and clear" extraordinary charm and exceptional quality make it stand out among many famous teas. Longjing tea is a special product of Zhejiang Province and a national geographical indication product in China. Super-grade Longjing tea is flat, smooth, straight, with a tender green and shiny color, a fresh and high aroma, a fresh, brisk, and mellow taste, and delicate leaves in a bud shape.

[0003] The production of Longjing tea (flat tea), especially West Lake Longjing tea, usually includes a rough processing workshop (stir-frying tea) and a refining workshop (screening and blending). Among them, the refining workshop is the main technical area. The main work of the refining workshop is to screen, grade, blend, and remove impurities from the stir-fried dry tea to obtain tea products with stable quality. Screening, grading, and impurity removal are relatively simple, but the blending process is relatively complex and crucial for the quality stability of the product.

[0004] Blending is to evenly mix the teas of the same grade but from different origins, picking times, and batches according to different indicators such as taste, aroma, and color, in order to reduce the quality differences between different batches and achieve relatively stable quality.

[0005] Selection is to conduct a refined classification operation on the teas in the blended tea according to technical indicators such as size, shape, color, luster, and cleanliness. The finished Longjing tea has six grades, namely super-grade and grades one to five. Among the super-grade standards, the shape requirements are: flat, smooth, straight, pointed, and sharp; tender green and fresh; even, heavy, and solid; clean.

[0006] Therefore, in order to improve the quality of Longjing tea and conduct a refined selection and classification operation on it, better research and application are needed to make it more accurate, standardized, and efficient. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for selecting high-quality Longjing tea based on image contour analysis and a blending equipment, which is used to improve the blending efficiency of Longjing tea, accurately sort it through efficient blending and image recognition, and at the same time reduce the damage to Longjing tea during the sorting process.

[0008] In order to achieve the above purpose, the technical solution of the present invention is as follows: A blending equipment, comprising: A feeding mechanism for corresponding feeding operations of multiple categories of preliminary selected Longjing tea; A mixing mechanism for evenly mixing and spreading out the preliminary selected Longjing tea from the multiple feeding mechanisms; The impurity removal mechanism is used to remove impurities from the initially selected Longjing tea processed by the mixing mechanism; The selection mechanism finely sorts the initially selected Longjing tea by means of visual photography; The feeding mechanism includes a plurality of feeding hoppers. A feeding conveyor belt is correspondingly arranged below the feeding hoppers. A vibrating conveying mechanism is arranged at the front end of the feeding conveyor belt. The front end of the vibrating conveying mechanism has a 45-degree beveled outlet. The mixing mechanism includes a transverse conveyor belt, which is arranged below the beveled outlet of the vibrating conveying mechanism. The width of the transverse conveyor belt matches the size of the beveled outlet. The impurity removal mechanism is arranged at the rear end of the transverse conveyor belt and includes a plurality of electrostatic adsorption components and an impurity removal conveyor belt. The impurity removal conveyor belt is arranged below the electrostatic adsorption components. The selection mechanism includes a plurality of selection conveyor belts. The front end of the selection conveyor belt is used to receive the initially selected Longjing tea from the rear end of the impurity removal conveyor belt. A camera is fixedly arranged directly above the selection conveyor belt. The camera is used to photograph the Longjing tea directly below it. The camera is connected to a control host. A jet nozzle is fixedly arranged on one side of the selection conveyor belt behind the camera. A first collection box is arranged on the opposite side of the jet nozzle. The jet nozzle is connected to a gas source and a valve. The valve is connected to the control host. A second collection box is arranged at the end of the selection conveyor belt.

[0009] Further, the feeding conveyor belt is made of a flexible material, and its conveying surface has a plurality of grooves. A leveling mechanism is arranged at the middle position of the feeding conveyor belt.

[0010] Further, the leveling mechanism is used to evenly spread the initially selected Longjing tea on the conveying surface of the feeding conveyor belt. The leveling mechanism includes a horizontal cross bar and a plurality of staggered roller bars arranged on the cross bar. One end of the horizontal cross bar is provided with a motor, and a flexible scraper is arranged at the end of the cross bar.

[0011] Further, the vibrating conveying mechanism includes a vibrating plate and a vibrating mechanism arranged below the vibrating plate. The vibrating plate is connected to the frame through a plurality of elastic members. The rear end of the vibrating plate matches the output port of the feeding conveyor belt. The front end of the vibrating plate is a 45-degree beveled outlet.

[0012] Further, the electrostatic adsorption component includes an electrostatic adsorption roller spanning above the impurity removal conveyor belt and an electrostatic adsorption roller motor. The electrostatic adsorption roller is connected to a high-voltage electrostatic generator, and the surface of the electrostatic adsorption roller is uniformly charged with static electricity. Sliders are arranged at both ends of the electrostatic adsorption roller. The sliders are provided with vertical chutes in a matching manner. The sliders are connected to a servo cylinder. The servo cylinder is used to drive the sliders and the electrostatic adsorption roller to lift along the chutes and to adjust the distance between the electrostatic adsorption roller and the upper surface of the impurity removal conveyor belt.

[0013] Further, a foreign object collecting mechanism is arranged behind the electrostatic adsorption roller in the rotation direction. The foreign object collecting mechanism includes a scraper attached to the surface of the electrostatic adsorption roller, and a U-shaped groove located on one side below the scraper and connected to the slider. A screw conveyor is arranged in the U-shaped groove, and the screw conveyor is used to continuously discharge the impurities accumulated in the U-shaped groove along its axis.

[0014] Further, a plurality of funnel-shaped material receiving structures are arranged at the rear end of the impurity removal conveyor belt. An inclined guide plate is arranged in front of the funnel-shaped material receiving structure. The lower end of the guide plate is arranged above the front end of the selection conveyor belt. The running speed of the selection conveyor belt is greater than that of the impurity removal conveyor belt, and the selection conveyor belt is a conveyor belt structure with a light-colored bottom plate.

[0015] A method for selecting high-quality Longjing tea based on image contour analysis, which is applied to the above-mentioned even-piling equipment, includes the following steps: S1: Photograph the Longjing tea at the current position on the selection conveyor belt through the camera, obtain the current image and send it to the control host; S2: Perform pixel positioning on the Longjing tea image in the current photo. According to the number of pixels in the X-axis direction and the Y-axis direction, calculate the pixel number value corresponding to the longest diagonal. Through the pixel number value, determine the length value of the current Longjing tea according to the preset relationship between pixels and length. If the length value is not within the set length range, mark the current Longjing tea as "no"; S3: If the length value of the current Longjing tea is within the set length range, perform sub-pixel edge detection on the current photo. Construct and sample at specific pixel points at intervals, connect adjacent pixel sampling points, construct a closed figure composed of pixel sampling points and connecting lines. Take the longest diagonal of this figure as the Y-axis and the rear end of the Y-axis as the coordinate origin, and place all pixel sampling points into this coordinate system. Connect several adjacent pixel sampling points on the left and right at the vertex of the Y-axis and fit them into a triangular structure. If the angle of the apex of this triangular structure is greater than the preset value, mark the current Longjing tea as "no"; S4: If the angle of the apex of this triangular structure is less than or equal to the preset value, perform an acute angle search process on at least three adjacent current pixel sampling points, and determine the current acute angle point. Connect the acute angle point with the coordinate origin, divide the closed figure into two parts on the left and right, and perform an area calculation process on the enclosed intervals of the corresponding pixel sampling points. If the area ratio of the small area part to the large area part is greater than the preset value, mark the current Longjing tea as "no"; S5 If the area ratio of the small area part to the large area part is less than or equal to a preset value, find the endpoints of the longest side in the contour of the small area part as vertices, connect the vertex to the origin. If the angle between the connection line and the Y-axis is greater than a set value, mark the current Longjing tea as "No". S6 Mark the current Longjing tea as "Yes", calculate the distance deviation value between the current position of the Longjing tea and the air jet position of the air jet nozzle, calculate the time required for the Longjing tea to move this distance based on the running speed value of the selection conveyor belt, and when the time value is reached, perform an air jet operation on the air jet nozzle by controlling the valve, and drive the current Longjing tea marked as "Yes" to the first collection box.

[0016] Furthermore, in step S5, if the ratio of the length of the diagonal of the small area part to the length of the longest diagonal is greater than the preset value, mark the current Longjing tea as "No".

[0017] Furthermore, in any one of steps S2 to S5, if the current Longjing tea has been marked as "No", return to step S1, and use the next Longjing tea to be identified on the selection conveyor belt as the current Longjing tea.

[0018] Adopting this solution, compared with the prior art, it has the following advantages: This solution is a uniform stacking device. Through the feeding mechanism, the primary selected Longjing tea of multiple categories can be fed, and according to the corresponding characteristics of these Longjing teas, reasonable, orderly, and differential feeding operations can be carried out at a set mixing ratio. At the same time, this solution has multiple feeding mechanisms, and various combined feeding and uniform stacking operations can be carried out according to the set requirements. Finally, the uniform stacking operation of Longjing tea can be implemented flexibly and efficiently; In order to make the uniform stacking operation more uniform, this solution adopts the method of secondary vibration conveying, and through the transverse conveyor belt, the primary selected Longjing tea conveyed by all feeding mechanisms is evenly stacked and vibration mixed, so the final product has excellent consistency; This solution uses the method of electrostatic adsorption to remove foreign matters such as dust, dust, fluff, or fine particles in the primary selected Longjing tea, which can improve the purity of Longjing tea, reduce the influence of such foreign matters on subsequent selection operations, and also improve the stability of equipment operation; The main body of the selection operation of this solution uses the image contour analysis method of visual recognition. Since Longjing tea is a flat tea and is always arranged on the conveyor belt with the front and back sides, the characteristics of flat tea can be fully utilized, which can greatly improve the recognition efficiency and accuracy, reduce the system calculation amount, and improve the overall recognition efficiency; As the visual recognition method of this solution, the Longjing tea is photographed vertically downward by a camera. Since a fixed height is adopted, the length of the current Longjing tea can be quickly deduced through the number of pixels corresponding to the current Longjing tea in the image. Therefore, according to the Longjing tea grade standard, the current Longjing tea can be quickly predicted, thus greatly improving the efficiency. This solution will also adopt sub-pixel edge detection operations and, through pixel sampling, polygonize the contour of the current Longjing tea, and then various subsequent recognition and comparison operations can be realized. In this solution, through the feature analysis of super-grade Longjing tea, technical features including length, top shape, enclosed area ratio, included angle, and branch length can accurately distinguish and identify super-grade Longjing tea, solve the problem that traditional methods require manual participation, and reduce the damage to Longjing tea during the selection operation. Brief Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the overall structure of the preferred embodiment.

[0020] Figure 2 It is a layout diagram of the rear-end structure of six feeding mechanisms.

[0021] Figure 3 It is a schematic diagram of the structure of the feeding mechanism.

[0022] Figure 4 It is a schematic diagram of the overall structure of the impurity removal mechanism and the selection mechanism.

[0023] Figure 5 It is an exploded view of the structure of the electrostatic adsorption component.

[0024] Figure 6 It is a schematic diagram of the structure of the selection mechanism.

[0025] Figure 7 It is a schematic side view of the selection mechanism.

[0026] Figure 8 It is a layout diagram of the structure of a single selection mechanism.

[0027] Figure 9 It is a table diagram of the Longjing tea grading standard.

[0028] Figure 10 It is a physical diagram of the dry and wet products of a typical super-grade Longjing tea.

[0029] Figure 11 It is a schematic diagram of the Longjing tea image recognition and processing.

[0030] Figure 12 It is a schematic diagram of the difference structure of the Longjing tea. Detailed Description of the Preferred Embodiment

[0031] West Lake Longjing tea, especially the Longjing tea picked and processed before the Tomb-Sweeping Festival, is the highest-grade and quite precious Longjing tea. The Xihu District of Hangzhou City is the most important origin of West Lake Longjing tea. The strict standardized production, blending, and selection of West Lake Longjing tea are the embodiment of its value. West Lake Longjing tea is a product that emphasizes grades. The applicant of this solution is committed to promoting and selling Longjing tea domestically and internationally. In order to better achieve the consistency of Longjing tea products, the original intention of this solution is to standardize the operations of its production, blending, and selection. On the basis of inheriting and developing historical techniques, modern scientific and technological means are used to ensure that details such as the shape and appearance of the tea are not damaged during the selection process, and the grades are more standardized and accurate.

[0032] Reference Figure 1 (In this drawing, in order to make the image clearer, the support wheels, support structures, drive structures, and other accessory structures of the conveyor belt and transmission belt have been hidden), a blending device for intelligent selection of Longjing tea, comprising: A feeding mechanism 1, which is used for corresponding feeding operations of primary-selected Longjing tea of multiple categories; A mixing mechanism 2, which is used for uniformly mixing and spreading out the primary-selected Longjing tea from the multiple feeding mechanisms; An impurity removal mechanism 3, which is used for removing impurities from the primary-selected Longjing tea processed by the mixing mechanism; A selection mechanism 4, and the selection mechanism 4 conducts fine sorting operations on the primary-selected Longjing tea by means of visual photography; A control host, connected to the above electrical equipment, capable of analyzing and processing images, controlling the corresponding electrical components, and realizing overall coordinated and precise operations.

[0033] Reference Figure 2 Figure 3 , the feeding mechanism 1 includes a plurality of feeding hoppers 11, and a feeding conveyor belt 12 is correspondingly arranged below the feeding hoppers 11. In this embodiment, by arranging six feeding mechanisms 1 side by side, the primary-selected Longjing tea of the same grade but different in origin, picking time, and batch can be respectively arranged in different feeding hoppers 11 according to different indicators such as taste, aroma, and color for uniform mixing, so as to reduce the quality differences between different batches of tea and achieve relative stability in quality. The six feeding ports of this blending device can independently control the speed and can set blending data according to different requirements to meet the blending needs of different products. It should be noted that when the primary-selected Longjing tea is placed into the feeding hoppers 11, operations such as multi-layer screen and blowing stratification impurity removal have been carried out, and impurities such as dust, mud blocks, or tea stalks can be removed, so as to improve the subsequent processing efficiency.

[0034] Specifically, the feeding conveyor belt 12 is in an inclined upward conveying state. To improve the conveying capacity, the feeding conveyor belt 12 is made of flexible material, and its conveying surface has a plurality of grooves 13. The grooves 13 can increase the friction for conveying the initially selected Longjing tea upward and make the conveying more balanced. At the front end of the feeding hopper 11, that is, at the middle position of the feeding conveyor belt 12, a leveling mechanism is provided. The leveling mechanism is used to evenly spread the initially selected Longjing tea on the conveying surface of the feeding conveyor belt 12 and keep it at a reasonable thickness. The leveling mechanism includes a horizontal cross bar 14 and a plurality of staggered roller bars 15 arranged on the cross bar. One end of the horizontal cross bar 14 is provided with a motor, and the motor realizes its corresponding rotation speed under the control of the control host. To protect the initially selected Longjing tea from being damaged, a flexible sheet 141 is arranged at the end of the cross bar 14.

[0035] The front end of the feeding conveyor belt 12 is provided with a vibrating conveying mechanism. The vibrating conveying mechanism includes a vibrating flat plate 16 and a vibrating mechanism arranged under the vibrating flat plate. The vibrating flat plate 16 is connected to the framework through a plurality of elastic members 17. In some embodiments, the elastic member can be a flexible connecting rubber cylinder or a pneumatic cylinder structure, or can also be a spring limit support structure (such as Figure 3 shown). A vibrating unit is arranged under the vibrating flat plate 16. In some embodiments, the vibrating unit can be an eccentric wheel structure driven by a motor. When the motor drives the eccentric wheel to rotate, according to the rotation speed of the eccentric wheel, a specific frequency and amplitude vibration of the vibrating flat plate 16 can be realized. Therefore, the initially selected Longjing tea (in a flat state) on the vibrating flat plate 16 can be vibrated and conveyed forward, and during the vibrating conveying process, the initially selected Longjing tea is spread more evenly and consistently. The front end of the vibrating flat plate is a 45-degree beveled outlet.

[0036] The mixing mechanism 2 is arranged at the position below the front end of the vibrating flat plate 16. The mixing mechanism 2 includes a transverse conveyor belt 21. The transverse conveyor belt 21 is arranged below the opening of the vibrating flat plate 16, and the width of the transverse conveyor belt 16 matches the size of the opening of the vibrating flat plate 16. Therefore, at the opening in front of the vibrating flat plate 16, the initially selected Longjing tea after vibrating conveying can be transferred onto the transverse conveyor belt 21, and due to the 45-degree opening, when the initially selected Longjing tea is transferred onto the transverse conveyor belt 21, it can maintain the original even and flat state without stacking or other situations; The transverse conveyor belt 21 can receive the different Longjing teas conveyed by six feeding mechanisms 1 arranged side by side. After passing through the six feeding mechanisms 1, at the rear end of the transverse conveyor belt 21, the initially selected Longjing teas conveyed by the six feeding mechanisms 1 are evenly stacked and mixed.

[0037] A second vibrating conveying mechanism 22 is arranged at the rear end of the transverse conveyor belt 21. The second vibrating conveying mechanism 22 can have a similar structure to the vibrating conveying mechanism. The front end of the second vibrating conveying mechanism 22 is a straight output port. When the mixed primary Longjing tea is conveyed to the second conveying member 22, during its vibrating conveying process, the primary Longjing tea can be more evenly mixed and staggered to achieve even distribution operation.

[0038] refer to Figure 4 Figure 5 The impurity removal mechanism 3 is arranged at the rear end of the second vibrating conveying mechanism 22. The impurity removal mechanism 3 includes multiple electrostatic adsorption components 31 and an impurity removal conveyor belt 30. It removes dust, powder, lint or fine particles in the pre-selected Longjing tea by electrostatic adsorption, making the finished Longjing tea cleaner and facilitating subsequent selection operations. The electrostatic adsorption component 31 includes an electrostatic adsorption roller 32 and an electrostatic adsorption roller motor 33 that spans the top of the dust removal conveyor belt 31. The electrostatic adsorption roller 33 is electrically connected to the electrostatic generating unit, and its surface has a coating or outer ring layer that can accommodate static electricity, so the surface of the electrostatic adsorption roller 33 can be uniformly provided with static electricity. Sliders 34 are arranged at both ends of the electrostatic adsorption roller 33. The slider 34 is equipped with a vertical slide groove 35. A servo cylinder 36 is provided on the slider 35. The servo cylinder 36 can adjust the vertical height of the slider 35 and the electrostatic adsorption roller 33, and is used to adjust the distance between the electrostatic adsorption roller 33 and the upper surface of the dust removal conveyor belt 30, thereby realizing the adsorption and transfer operation of foreign matter such as dust, dust, lint or fine particles on the dust removal conveyor belt 30, so that it is adsorbed and adsorbed to the surface of the electrostatic adsorption roller 33.

[0039] In order to collect foreign matter on the surface of the electrostatic adsorption roller 33, enable it to operate continuously and efficiently, and prevent secondary pollution, a foreign matter collection mechanism is arranged at the rear end of the rotation of the electrostatic adsorption roller 33. The foreign matter collection mechanism includes a scraper 37 attached to the surface of the electrostatic adsorption roller 33 and a U-shaped groove 38 arranged on one side below the scraper. The U-shaped groove 38 is integrally connected to the slider 35 through a connecting piece, and can realize synchronous up and down displacement movement with the electrostatic adsorption roller 33 under the action of the servo cylinder 36. A screw conveyor 39 is arranged in the U-shaped groove. Under the action of the motor on one side of the screw conveyor 39, through its own rotation, the impurities and foreign matter collected by the scraper 33 in the U-shaped groove 38 can be output from the continuous output pipe at one end thereof.

[0040] In actual operation, multiple electrostatic adsorption components 31 can be arranged side by side, and differentiated heights and electrostatic voltages can be set to make the collection of foreign matter and impurities more complete and efficient.

[0041] refer to Figure 6 Figure 7 Figure 8, the selection mechanism 4 includes multiple selection conveyor belts 40, and the selection conveyor belts 40 are used to receive the preliminarily selected Longjing tea from the impurity removal conveyor belt 30. To reduce external influence, the selection mechanism 4 is provided with a shielding cover 401. As a single selection conveyor belt 40, a camera 41 is arranged at a fixed position directly above the front end thereof. The camera 41 is used to photograph the Longjing tea on the selection conveyor belt 40 directly below it. The camera 41 is connected to the control host. The control host receives the images taken by the camera 41, analyzes and processes them, and configures the corresponding results to the corresponding devices. On one side of the selection conveyor belt 40 at the rear end of the camera 41, a jet nozzle 45 is provided at a fixed position. On the opposite side of the jet nozzle 45, a first collection box 44 is provided. To prevent the interference of air flow, a ventilation net is provided on the side wall of the first collection box 44. The jet nozzle 45 is connected to a gas source and a valve. The valve is connected to the control host and, under the control of the control host, realizes precise jetting operation. A second collection box is provided at the rear end of the selection conveyor belt 40.

[0042] At the rear end of the impurity removal conveyor belt 30, multiple funnel-shaped material receiving structures 301 are arranged. The material receiving structures 301 correspond to the selection conveyor belts 40 one by one. A guide plate 302 is arranged between the material receiving structures 301 and the selection conveyor belts 40. The front end of the guide plate 302 is fitted to the turning point of the impurity removal conveyor belt 30, and can receive the preliminarily selected Longjing tea on the impurity removal conveyor belt 30 and transfer it to the front end of the selection conveyor belt 40 in a translational manner. At the same time, under the control of the control host, the running speed of the selection conveyor belt 40 is greater than that of the impurity removal conveyor belt 30, so as to control the conveying of the preliminarily selected Longjing tea and make it in a flat structure at the selection conveyor belt 40, and there will be no situation where two pieces of Longjing tea are stacked.

[0043] To improve the recognition efficiency of the camera 41, soft light lamp assemblies 42 are arranged on both sides of the camera 41 to provide shadowless soft light illumination for the camera. To make the green Longjing tea better appear at the selection conveyor belt 40, the selection conveyor belt 40 is a conveyor belt structure with a light-colored bottom plate. To reduce the adhesion of sundries, a blowing component 43 is arranged at the position below the turning of the selection conveyor belt 40 to make the surface of the selection conveyor belt 40 clean and free of foreign objects by using the blowing air flow.

[0044] To improve the imaging comparison efficiency of the camera 41 and facilitate the distance calibration of the current Longjing tea, at the position directly below the camera 41, and on both sides or below the selection conveyor belt 40, there is a substrate 47. At the midline position of the substrate 47, there is a mark 48. The mark is a fixed physical mark drawn or pasted on the substrate 47. The mark 48 is vertically aligned with the camera 41. The mark 48 can be a line segment structure. The length of the line segment of the mark 48 is a fixed value for reference comparison during imaging. To reduce the interference between adjacent selection conveyor belts 40, partition plates 49 are provided on both sides of the substrate 47.

[0045] On the other hand, this solution also includes a method for selecting premium Longjing tea based on image contour analysis, which is applied to the above-mentioned even-piling equipment.

[0046] Reference Figure 9 Figure 10 , as the grading standard for West Lake Longjing tea, the quality of fresh leaves, where the special grade is: the first unfolding of one bud and one leaf, the included angle between the bud and the leaf is small, the bud is longer than the leaf, the bud and the leaf are uniform and plump, and the length of the bud and the leaf does not exceed 2.5 cm; the first grade: from one bud and one leaf to the first unfolding of one bud and two leaves, mainly one bud and one leaf, the first unfolding of one bud and two leaves is below 10%, the bud is slightly longer than the leaf, clean, and the length of the bud and the leaf does not exceed 3 cm. In the special grade standard of Longjing tea (finished product), the appearance requirements are: flat, smooth, straight, pointed and sharp; light green and fresh; uniform, heavy and solid; clean. A typical special grade Longjing tea (finished product) is as shown in Figure 12 M1 in

[0047] Based on the above standards, this solution realizes the selection operation of special grade Longjing tea for Longjing tea by means of image contour analysis, including the following steps: S1 Take a photo of the current Longjing tea at the current position through a camera, obtain the current photo image, and send it to the control host.

[0048] S2 Perform pixel positioning on the Longjing tea image in the current photo image. According to the number of pixels in the X-axis direction and the Y-axis direction, calculate the pixel number value corresponding to the longest diagonal. Through the pixel number value, determine the length value of the current Longjing tea according to the preset relationship between pixels and length. If the length value is not within the set length interval, mark the current Longjing tea as "no"; Specifically, referring to Figure 11 area one in

[0049] S3 If the length value of the current Longjing tea is within the set length interval, perform sub-pixel edge detection operation on the current photo image, construct and sample at specific pixel points at intervals, and connect adjacent pixel sampling points to construct a closed figure composed of pixel sampling points and connecting lines; Specifically, referring to Figure 11In the second and third regions, in the second-region diagram, through sub-pixel edge detection operations, 13 pixel sampling points (from P01 to P13) are sampled on the edge of the current Longjing tea. (The 13 sampling points are for making the image clearer. In actual sampling, the number of pixel samplings can far exceed 13.) Then, these P01 - P13 sampling points are placed in the coordinate system. To make the calculation clearer and more convenient, P01 can be set as the coordinate origin, so the respective coordinates of the P01 - P13 sampling points can be obtained.

[0050] To improve the calculation and processing efficiency, in some embodiments, the graphic space can use the longest diagonal as the Y-axis, with the rear end of the Y-axis as the coordinate origin. All pixel sampling points are placed in this coordinate system. At the vertex of the Y-axis, several adjacent pixel sampling points on the left and right are connected and fitted into a triangular structure. If the angle of the apex of this triangular structure is greater than the preset value, the current Longjing tea is marked as "no"; Specifically, the P01 - P13 sampling points are connected in sequence to form a vector contour diagram in the third region. In this step, the key is to detect whether there is any missing or broken situation at the tip of the bud of the current Longjing tea. A typical situation is as shown in Figure 12 M2 in. The red line represents the defect at the tip of the bud. Although M2 in step S2 meets the length range of super-grade Longjing tea, it does not belong to super-grade Longjing tea. In this step, the P07 sampling point is selected, and the corresponding P06 and P08 sampling points are connected in sequence. By calculating the included angle formed by P06 - P07 - P08, if this included angle is less than 65 degrees, the tip is considered complete; otherwise, the current Longjing tea is marked as "no".

[0051] S4 If the angle of the apex of this triangular structure is less than or equal to the preset value (which can be 65 degrees), an acute-angle search process is performed on at least three adjacent pixel sampling points. This operation is used in the third-region diagram to find the P09 sampling point. The acute-angle point is connected to the coordinate origin, and the closed figure is divided into two parts on the left and right (the yellow part and the purple part in the third-region diagram). By calculating the area of the enclosed interval of the corresponding pixel sampling points, specifically, in the yellow part, 7 triangular structures are constructed by connecting P03, P04, P05, P06, P07, P08 to P01. Since all sampling points have corresponding coordinates, the area of the yellow part can be quickly calculated. Similarly, the area of the purple part can also be quickly calculated. If the area ratio of the purple part (the small-area part) to the yellow part (the large-area part) is greater than the preset value, the preset value can be, for example, 40%. A typical situation is as shown in Figure 12 M3 in, then the current Longjing tea is marked as "no".

[0052] S5 If the area ratio of the small area to the large area is less than or equal to the preset value, find the vertex of the longest side in the small area, connect the vertex with the origin, and as described by the L2 line segment in the three-area diagram, if the angle A between the connecting line and the Y axis (or the L1 in the yellow part) is greater than the set value, the preset value can be 45 degrees, and the typical case also corresponds to Figure 12 As shown in M3, the current Longjing tea is marked as "No".

[0053] In order to prevent the typical situation Figure 12 As shown in M4, that is, the leaf area is small, the angle is small, but the leaf is thin and long, in S5, if the ratio of the length of the diagonal line L2 of the small area part to the length of the longest diagonal line L1 is greater than the preset value, the preset value can be such as 0.75, then the current Longjing tea is marked as "No".

[0054] S6, under the control of the control host, marks the current Longjing tea as "yes". So far, this method has visually identified the special-grade Longjing tea that meets the requirements through image contour analysis.

[0055] In order to improve efficiency, in any step of steps S2 to S5, if the current Longjing tea has been marked as "no", the process returns to step S1 and the Longjing tea at the next position on the selection conveyor belt 40 is set as the current Longjing tea.

[0056] When the current Longjing tea is identified as "yes", the current position deviation value is calculated. The distance deviation value can be the distance from the current position to the standard position of the air nozzle 45 based on the position distance of the mark 48, and the time value of the distance value is calculated based on the running speed value of the selection conveyor belt 40. When the time value is reached, under the control of the control host, the air nozzle 45 is operated to spray in a point-like manner through the control valve, so that the current Longjing tea marked as "yes" is driven to the first collection box 44, and the other Longjing tea marked as "no" is transported to the second collection box 46.

[0057] At this point, this solution is based on the Longjing tea grading standards and uses image contour analysis to achieve the selection operation of special-grade Longjing tea. On the other hand, through differentiated parameter requirements, corresponding selection operations can also be implemented for first-grade or other grades of Longjing tea, and it is efficient and accurate.

[0058] In summary, the present solution is a heap equalizing device. The feeding mechanism can feed the initially selected Longjing tea of multiple categories, and according to the characteristics of these Longjing teas, perform differential feeding operations in a reasonable, orderly and set mixing ratio on time. At the same time, the present solution has multiple feeding mechanisms and can perform various combined feeding and heap equalizing operations according to the set requirements, and finally can flexibly and efficiently implement the heap equalizing operation of Longjing tea; In order to make the heap equalizing operation more uniform, the present solution adopts the method of secondary vibration conveying, and uses the horizontal conveyor belt to perform flat spreading, heap equalizing and vibration mixing operations on the initially selected Longjing tea conveyed by all feeding mechanisms, so the final product has excellent consistency; The present solution uses the method of electrostatic adsorption to remove foreign matters such as dust, dust, fluff or fine particles in the initially selected Longjing tea, which can improve the purity of Longjing tea, reduce the influence of such foreign matters on subsequent selection operations, and also improve the stability of equipment operation; The main body of the selection operation in the present solution adopts the image contour analysis method of visual recognition. Since Longjing tea is flat tea and is always arranged on the conveyor belt with the front and back sides, the characteristics of flat tea can be fully utilized, and the recognition efficiency and accuracy can be greatly improved, and the system calculation amount can also be reduced, improving the overall recognition efficiency; As the visual recognition method of the present solution, the Longjing tea is photographed vertically downward by a camera. Since a fixed height is adopted, the length of the current Longjing tea can be quickly deduced through the number of pixels corresponding to the current Longjing tea in the image. Therefore, according to the Longjing tea grade standard, the current Longjing tea can be quickly judged, and the efficiency can be greatly improved; The present solution will also adopt sub-pixel edge detection operations and, through pixel sampling, polygonize the contour of the current Longjing tea, and then various subsequent recognition and comparison operations can be realized; In the present solution, through the feature analysis of super-grade Longjing tea, technical features including length, top shape, enclosed area ratio, included angle and branch length can accurately distinguish and identify super-grade Longjing tea, solve the problem that traditional methods require manual participation, and reduce the damage to Longjing tea in the selection operation.

Claims

1. A uniform stacking device, characterized in that: Including: A loading mechanism for correspondingly loading the primary Longjing tea of multiple categories; A mixing mechanism for uniformly mixing and spreading out the primary Longjing tea from the multiple loading mechanisms; An impurity removal mechanism for removing impurities from the primary Longjing tea processed by the mixing mechanism; A selection mechanism that finely sorts the primary Longjing tea by means of visual photography; The loading mechanism includes a plurality of loading hoppers, a loading conveyor belt is correspondingly arranged below the loading hoppers, a vibrating conveying mechanism is arranged at the front end of the loading conveyor belt, and the front end of the vibrating conveying mechanism has a 45-degree beveled outlet; the mixing mechanism includes a transverse conveyor belt, the transverse conveyor belt is arranged below the beveled outlet of the vibrating conveying mechanism, and the width of the transverse conveyor belt matches the size of the beveled outlet; the impurity removal mechanism is arranged at the rear end of the transverse conveyor belt and includes a plurality of electrostatic adsorption components and an impurity removal conveyor belt, and the impurity removal conveyor belt is arranged below the electrostatic adsorption components; the selection mechanism includes a plurality of selection conveyor belts, the selection conveyor belt, the front end of which is used to receive the primary Longjing tea from the rear end of the impurity removal conveyor belt, a camera is arranged at a fixed position directly above the selection conveyor belt, the camera is used to photograph the Longjing tea directly below it, the camera is connected to a control host, a jet nozzle is arranged at a fixed position on one side of the selection conveyor belt behind the camera, a first collection box is arranged on the opposite side of the jet nozzle, the jet nozzle is connected to a gas source and a valve, the valve is connected to the control host, and a second collection box is arranged at the end of the selection conveyor belt.

2. The equalizing heap device according to claim 1, wherein: The loading conveyor belt is made of a flexible material, and its conveying surface has a plurality of grooves, and a leveling mechanism is arranged at the middle position of the loading conveyor belt.

3. The equalizing stacker according to claim 2, characterized in that: The leveling mechanism is used to evenly spread out the primary Longjing tea on the conveying surface of the loading conveyor belt. The leveling mechanism includes a horizontal cross bar and a plurality of staggered roller bars arranged on the horizontal cross bar. One end of the horizontal cross bar is provided with a motor, and a flexible scraping blade is arranged at the end of the cross bar.

4. The equalizing heap device according to claim 1, wherein: The vibrating conveying mechanism includes a vibrating plate and a vibrating mechanism arranged below the vibrating plate. The vibrating plate is connected to a frame through a plurality of elastic members. The rear end of the vibrating plate matches the output port of the loading conveyor belt, and the front end of the vibrating plate is a 45-degree beveled outlet.

5. A uniform stacking device according to claim 1, characterized in that: The electrostatic adsorption component includes an electrostatic adsorption roller spanning above the impurity removal conveyor belt and an electrostatic adsorption roller motor. The electrostatic adsorption roller is connected to a high-voltage electrostatic generator and makes the surface of the electrostatic adsorption roller uniformly have static electricity. Sliders are arranged at both ends of the electrostatic adsorption roller, and vertical chutes are provided for the sliders to cooperate with. The sliders are connected to a servo cylinder. The servo cylinder is used to drive the sliders and the electrostatic adsorption roller to lift along the chute and is used to adjust the distance between the electrostatic adsorption roller and the upper surface of the impurity removal conveyor belt.

6. The equal heap device according to claim 5, characterized in that: A foreign object collection mechanism is arranged behind the electrostatic adsorption roller in the rotation direction. The foreign object collection mechanism includes a scraper attached to the surface of the electrostatic adsorption roller, and a U-shaped groove located on one side below the scraper and fixedly connected to the slider. A screw conveyor is arranged in the U-shaped groove, and the screw conveyor is used to continuously discharge the impurities accumulated in the U-shaped groove along its axis.

7. A kind of average stacking device according to claim 5, characterized in that: A plurality of funnel-shaped material collection structures are arranged at the rear end of the impurity removal conveyor belt. An inclined deflector is arranged in front of the funnel-shaped material collection structures. The lower end of the deflector is arranged above the front end of the selection conveyor belt. The running speed of the selection conveyor belt is greater than that of the impurity removal conveyor belt. The selection conveyor belt is a conveyor belt structure with a light-colored bottom plate.

8. A method for selecting high-quality Longjing tea based on image contour analysis, which is applied to a blending device as described in any one of claims 1 to 7, characterized in that: It includes the following steps: S1: Use the camera to take pictures of the Longjing tea at the current position on the selection conveyor belt, obtain the current image and send it to the control host; S2: Perform pixel positioning on the Longjing tea image in the current photo. According to the number of pixels in the X-axis direction and the Y-axis direction, calculate the pixel number value corresponding to the longest diagonal. Through the pixel number value, determine the length value of the current Longjing tea according to the preset relationship between pixels and length. If the length value is not within the set length interval, mark the current Longjing tea as "no"; S3: If the length value of the current Longjing tea is within the set length interval, perform sub-pixel edge detection on the current photo, construct and sample at specific pixel points at intervals, connect adjacent pixel sampling points, construct a closed figure composed of pixel sampling points and connecting lines. Take the longest diagonal of this figure as the Y-axis and the rear end of the Y-axis as the coordinate origin, place all pixel sampling points into this coordinate system, connect several adjacent pixel sampling points on the left and right at the vertex of the Y-axis, and fit them into a triangular structure. If the angle of the top angle of this triangular structure is greater than the preset value, mark the current Longjing tea as "no"; S4: If the angle of the top angle of this triangular structure is less than or equal to the preset value, perform an acute angle search process on at least three adjacent pixel sampling points of the current one, and determine the current acute angle point. Connect this acute angle point with the coordinate origin, divide the closed figure into left and right parts, calculate the area of the corresponding pixel sampling points by enclosing intervals. If the area ratio of the small area part to the large area part is greater than the preset value, mark the current Longjing tea as "no"; S5: If the area ratio of the small area part to the large area part is less than or equal to the preset value, find the end point of the longest side in the contour of the small area part as the vertex, connect this vertex with the origin. If the included angle between this connection line and the Y-axis is greater than the set value, mark the current Longjing tea as "no"; S6: Mark the current Longjing tea as "yes", calculate the distance deviation value between the current position of the Longjing tea and the jet position of the jet nozzle, and calculate the time required for the Longjing tea to move this distance based on the running speed value of the selection conveyor belt. When reaching this time value, perform a jet operation on the jet nozzle by controlling the valve, and drive the current Longjing tea marked as "yes" to the first collection box.

9. The method for selecting premium Longjing tea based on image contour analysis according to claim 8, characterized in that: In step S5, if the ratio of the length of the diagonal of the small area part to the length of the longest diagonal is greater than a preset value, then mark the current Longjing tea as "No".

10. A method for selecting high-quality Longjing tea based on image contour analysis according to claim 8, characterized in that: In any one of steps S2 to S5, if the current Longjing tea has been marked as "No", then return to step S1, and use the next Longjing tea to be identified on the selected conveyor belt as the current Longjing tea.

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