Tobacco leaf quality detection grading device and method

Abstract

A kind of tobacco quality detection grading device and method.The device includes sequentially connected conveying and shunting module, rolling and flattening module, detection module and grading and recycling module.Conveying and shunting module uses hopper, guide baffle and periodically oscillating shunting sweep bar to arrange disordered tobacco into at least one column;Rolling and flattening module adopts pre-rolling and two-stage rolling, and carries out flexible flattening on tobacco by support plate with pressure sensing and active avoidance function;Detection module combines ordinary conveyor belt, punched conveyor belt, negative pressure adsorption cavity, near-infrared spectrum assembly and machine vision assembly in dark box, so that tobacco completes internal quality detection, front and back appearance image acquisition and the like in continuous conveying process;Grading and recycling module guides tobacco into corresponding channel by roller conveyor belt, grading and poking rod and round corner collection channel.The present application can reduce the influence of conveyor belt shielding, leaf wrinkle, overlap and grading channel blockage on detection results, realize continuous, non-destructive detection and grading of tobacco.

Description

Technical Field

[0001] This invention belongs to the technical field of agricultural product quality testing and automatic grading equipment, specifically involving an intelligent tobacco leaf quality testing and grading device, testing and grading method, and its application in flue-cured tobacco purchasing and primary processing, which integrates near-infrared spectroscopy detection, machine vision recognition, negative pressure turning conveying, and mechanical lever grading. Background Technology

[0002] Tobacco leaves are the basic raw material for the tobacco industry, and their quality grade directly affects the quality of cigarette products, raw material utilization, and tobacco leaf transaction settlement. Tobacco leaf grading typically requires comprehensive consideration of appearance characteristics such as color, maturity, leaf structure, oil content, damage, and defects, as well as internal chemical components such as moisture, nicotine, total sugar, reducing sugar, total nitrogen, potassium, and chlorine. Current flue-cured tobacco grading still relies heavily on manual sensory evaluation, which is easily influenced by the experience, fatigue, ambient lighting, and subjective preferences of inspectors, resulting in poor consistency, low testing efficiency, and high labor intensity.

[0003] Near-infrared spectroscopy can rapidly acquire spectral information related to hydrogen-containing groups without damaging tobacco leaves, making it suitable for online detection of intrinsic quality parameters such as moisture, sugars, and nicotine. Machine vision can quantitatively identify the color, texture, shape, damaged area, and proportion of defects in tobacco leaves. Integrating these two technologies is beneficial for forming objective grading results that take into account both intrinsic and appearance quality.

[0004] However, existing intelligent tobacco leaf testing equipment generally still has the following shortcomings: First, the detection information is relatively simple, and relying solely on images or single-point spectra is insufficient to comprehensively reflect the quality of tobacco leaves; Second, ordinary conveyor belts can obscure the back of tobacco leaves, and the belt body and support structure of perforated conveyor belts may also create blind spots in detection; Third, the irregular shape, wrinkles, and overlaps of tobacco leaves, if not flattened, will affect spectral and image acquisition; Fourth, multiple tobacco leaves entering the testing station in an disorderly manner can easily cause blockages, and jamming may also occur at the grading outlet; Fifth, the integration of the various modules of the device and its continuous operation capability are insufficient, making it difficult to adapt to tobacco leaf purchasing stations and primary processing sites.

[0005] Therefore, there is a need for an intelligent tobacco quality detection and grading device that can perform orderly conveying, flexible flattening, unobstructed detection of both sides, integrated internal and external quality grading, and anti-blocking diversion and recycling. Summary of the Invention

[0006] To address the problems of incomplete detection information, easy obstruction of the back of tobacco leaves by the conveyor belt, interference from overlapping leaf folds affecting detection, and easy blockage during conveying and grading processes in existing tobacco leaf testing and grading devices, this invention proposes an intelligent tobacco leaf quality testing and grading device and method. This device adopts a technical approach of "diversion and sorting - two-stage flexible rolling - negative pressure flipping double-sided detection - spectral visual fusion grading - lever anti-blocking grading," achieving continuous online non-destructive testing and automatic recycling of tobacco leaves.

[0007] A tobacco leaf quality testing and grading device includes a conveying and diverting module, a rolling and leveling module, a testing module, and a grading and recycling module connected sequentially from front to back along the tobacco leaf flow direction; each module operates under the control of a control system.

[0008] (i) The conveying and diversion module is used to receive tobacco leaves and sort the disordered tobacco leaves into at least one column before outputting them.

[0009] The conveying and diversion module includes a hopper, a conveyor belt, guide baffles on both sides of the conveyor belt, a diversion sweeper at the outlet of the conveyor belt, and a conveyor frame. The hopper is located above the feed end of the conveyor belt, the guide baffles are used to gather the tobacco leaves to the middle of the conveyor belt, and the diversion sweeper swings periodically under the action of an independent drive mechanism to send the gathered tobacco leaves to different conveyor columns.

[0010] The drive mechanism of the diverting sweeper includes a sweeper drive motor, a transmission gear set, and a crank-rocker mechanism; the output shaft of the sweeper drive motor is connected to the transmission gear set, the output end of the transmission gear set is connected to the crank-rocker mechanism, and the rocker arm of the crank-rocker mechanism is connected to the diverting sweeper, causing the diverting sweeper to reciprocate around its root.

[0011] When implemented, the length of the diverting sweeper is 200mm, the swing angle is 20°, and the time to complete one reciprocating swing is 1s; the transmission gear set is a two-stage spur gear reduction mechanism with a total reduction ratio of 25, the number of teeth of the driving gear is 18, the number of teeth of the driven gear is 90, and the gear module is 1.5mm.

[0012] (ii) The rolling and leveling module is used to flexibly flatten the tobacco leaves through pre-rolling and secondary rolling.

[0013] The rolling and leveling module includes a support plate, pre-rolling rollers, secondary rolling rollers, limiters, a rolling conveyor belt, and an integrated frame. The pre-rolling rollers and secondary rolling rollers are sequentially positioned above the rolling conveyor belt along the tobacco leaf conveying direction. The support plate is positioned below the rolling conveyor belt and opposite the rolling rollers. The limiters are located at the secondary rolling rollers and have left and right openings for the rolling conveyor belt and tobacco leaves to pass through, as well as an upper opening for the secondary rolling rollers to move up and down. The support plate includes a base, a contact plate, multiple spring columns positioned between the base and the contact plate, telescopic modules positioned at corresponding positions on the spring columns, and a pressure sensor on the contact plate. When the pressure sensor detects that the force on the support plate exceeds a preset value, the telescopic module drives the spring columns to descend, moving the contact plate away from the rolling rollers to avoid tobacco leaf accumulation or hard foreign objects.

[0014] When the project is implemented, the support plate base is 400mm long, 300mm wide, and 20mm thick; the rolling width of the pre-rolling roller and the secondary rolling roller is 250mm; the limiter is 300mm long, 350mm wide, and 110mm high; and the running speed of the rolling conveyor belt is 0.2m / s.

[0015] (III) The detection module includes a dark box, a regular conveyor belt, a perforated conveyor belt, a negative pressure adsorption mechanism, a near-infrared spectroscopy detection component, a machine vision detection component, and a control box (the PLC of the control system and the host computer are installed in the control box. The host computer is equipped with machine vision detection software and near-infrared spectroscopy detection software). The regular conveyor belt and the perforated conveyor belt are arranged in coordination in the tobacco leaf conveying direction. The negative pressure adsorption mechanism is used to adsorb the tobacco leaves located on the regular conveyor belt to the perforated conveyor belt and release them at a predetermined position, so that the front and back sides of the tobacco leaves are exposed to the detection fields of the near-infrared spectroscopy detection component and the machine vision detection component in sequence.

[0016] The dark box has a rectangular structure, with the tobacco leaf inlet and outlet located at opposite ends of the dark box. The dark box is equipped with an observation window and an openable cover. Near-infrared spectroscopy detection station and machine vision detection station are set up inside the dark box along the tobacco leaf conveying direction. Each detection station has a detection area for front and back detection.

[0017] In the engineering implementation, the darkroom is 1200mm long, 400mm wide, and 350mm high; the ordinary conveyor belt and the perforated conveyor belt are arranged in two rows, with each row having an effective width of 150mm; the negative pressure adsorption mechanism includes a negative pressure machine, a negative pressure conduit, a negative pressure adsorption chamber, and a negative pressure release port. The distance between the lower surface of the negative pressure adsorption chamber and the ordinary conveyor belt below is 75mm, the working negative pressure is 15Pa, and the adsorption airflow velocity is 5m / s. The near-infrared spectroscopy detection component includes a near-infrared spectroscopy probe and a near-infrared light source. The distance between the near-infrared spectroscopy probe and the corresponding conveyor belt surface is 100-190mm; the machine vision inspection component includes an industrial camera, a shadowless ring light source, and a background plate. The distance between the lens of the industrial camera and the corresponding conveyor belt surface is 140-180mm, and the distance between the shadowless ring light source and the corresponding conveyor belt surface is 100mm.

[0018] (iv) The graded recycling module includes a roller conveyor belt, a grading lever and a collection channel. The control system generates a grading signal based on the near-infrared spectral detection results and the machine vision detection results, and controls the grading lever to guide the tobacco leaves into the corresponding collection channel.

[0019] The grading and recycling module includes at least one set of roller conveying units, each set of roller conveying units having a main track and a grading track smoothly connected to the main track with rounded corners; a grading lever is set at the connection between the main track and the grading track, and includes a grading drive motor, a sensing control module, a rotating bracket, a telescopic rod, and a lever body set at the end of the telescopic rod, with a flexible shovel section provided on the tobacco leaf contact side of the lever body.

[0020] When the project is implemented, the diameter of a single roller on the roller conveyor belt is 50mm, and the center distance between adjacent rollers is 60mm; the working radius of the grading lever is 200mm; the collection channel is a thin-walled inclined structure with a height of 1200mm and a width of 300mm, and is equipped with a collection port with a width of 200mm and a lower collection space with a length of 500mm.

[0021] The method using this device includes the following steps:

[0022] S1) Feeding and Diversion: The tobacco leaves are fed into the hopper, conveyed by the conveyor belt, collected by the guide baffle and sorted into at least one column by the diversion sweeper;

[0023] S2) Rolling and leveling: The tobacco leaves pass through the pre-rolling rollers and the secondary rolling rollers in sequence, and are flattened with the help of the support plate;

[0024] S3) Intrinsic quality inspection: Near-infrared spectroscopy detection station for tobacco leaves entering the dark chamber to collect near-infrared spectral information of tobacco leaves;

[0025] S4) Flipping and double-sided inspection: The negative pressure adsorption mechanism adsorbs the tobacco leaves from the ordinary conveyor belt to the perforated conveyor belt, exposing the other side of the tobacco leaves, and releases the tobacco leaves after the inspection is completed;

[0026] S5) Appearance quality inspection: The machine vision inspection component collects images of the front and back of the tobacco leaves and identifies the color, maturity, leaf shape, damage and injury characteristics of the tobacco leaves;

[0027] S6) Fusion Grading and Recycling: The control system fuses near-infrared spectroscopy detection results and machine vision detection results to generate a grading signal, and controls the grading lever to guide the tobacco leaves into the corresponding collection channel.

[0028] Near-infrared spectral information is used to determine at least one intrinsic quality parameter of tobacco leaves, including moisture, nicotine, total sugar, reducing sugar, total nitrogen, potassium, and chlorine. The machine vision inspection results are obtained by a lightweight artificial intelligence model, which fuses and judges the intrinsic quality parameters and appearance quality parameters according to preset grading rules.

[0029] This device and method are used in flue-cured tobacco purchasing, primary processing, raw material quality control, or grade verification.

[0030] The principle of this invention is explained as follows:

[0031] The tobacco leaf quality testing and grading device includes a conveying and diversion module, a rolling and leveling module, a testing module, and a grading and recycling module.

[0032] 1. The conveying and diversion module is located at the feed end of the device and is used to receive disordered tobacco leaves and arrange them into at least one column, preferably two columns. The conveying and diversion module includes a hopper, a conveyor belt, guide baffles, diversion sweepers, and a conveyor frame. The hopper is located above the feed end of the conveyor belt. After the tobacco leaves fall from the hopper onto the conveyor belt, they are gathered towards the center by the guide baffles. The diversion sweepers are located at the outlet of the conveyor belt and are periodically oscillating through an independent drive mechanism to gently guide the tobacco leaves to different conveyor columns.

[0033] The drive mechanism of the diverting sweeper includes a sweeper drive motor, a transmission gear set, and a crank-rocker mechanism. The sweeper drive motor drives the crank to rotate after being reduced in speed by a two-stage spur gear. The crank drives the rocker to oscillate reciprocally via a connecting rod, and the rocker is connected to the diverting sweeper. Preferably, the diverting sweeper is 200mm long, has a total oscillation angle of 20°, and an oscillation period of 1s; the total reduction ratio of the two-stage gear reduction mechanism is 25.

[0034] 2. The rolling and leveling module is connected to the discharge end of the conveying and diverting module, and includes a support plate, pre-rolling rollers, secondary rolling rollers, limiters, a rolling conveyor belt, and an integrated frame. The pre-rolling rollers initially flatten the tobacco leaves, and the secondary rolling rollers further reduce leaf wrinkles; the limiters laterally limit the tobacco leaves within the secondary rolling area. The support plate is positioned below the rolling conveyor belt, forming the tobacco leaf rolling gap together with the rolling rollers.

[0035] The support plate includes a base, a contact plate, spring columns, a telescopic module, and a pressure sensor. The contact plate is elastically supported on the base by multiple spring columns, and the pressure sensor is used to detect the rolling load. When the amount of tobacco leaves piled up is large or hard foreign objects enter the rolling area, causing the load to exceed a preset threshold, the telescopic module drives the spring columns to descend, widening the rolling gap to reduce tobacco leaf damage and the risk of mechanism jamming.

[0036] 3. The detection module is connected to the discharge end of the rolling and leveling module. The detection module includes a detection frame, a control box, a dark box, a regular conveyor belt, a perforated conveyor belt, a negative pressure machine, a negative pressure conduit, a negative pressure adsorption chamber, a near-infrared spectroscopy detection component, and a machine vision detection component. The tobacco leaves enter the dark box via the regular conveyor belt, where the first side is inspected in the front detection area. Subsequently, the negative pressure adsorption chamber applies an upward adsorption force to the tobacco leaves through the perforated conveyor belt, adsorbing the tobacco leaves onto the upper perforated conveyor belt, exposing the back side of the tobacco leaves to the detection field of view. After the back side inspection is completed, the tobacco leaves fall back onto the regular conveyor belt at the negative pressure release position and continue to be output.

[0037] 4. The near-infrared spectroscopy detection component is used to acquire at least one of the intrinsic quality parameters of tobacco leaves, such as moisture, nicotine, total sugar, reducing sugar, total nitrogen, potassium, and chlorine; the machine vision detection component is used to acquire the appearance quality parameters of tobacco leaves, such as color, maturity, leaf identity, oil content characterization, leaf morphology, damage, and defects. The intrinsic quality detection results and appearance quality detection results are fused together, and a comprehensive grade signal is output.

[0038] 5. The grading and recycling module is connected to the discharge end of the detection module, and includes a roller conveyor belt, a grading lever, and a collection channel. The roller conveyor belt has a main channel and a grading channel, which are connected by a smooth rounded corner. The grading lever is located at the connection between the main channel and the grading channel. When the corresponding grade of tobacco leaves arrives, the grading drive motor drives the lever to laterally pick up the tobacco leaves and push them into the grading channel. The tobacco leaf contact side of the lever has a flexible scooping part to reduce the impact on the tobacco leaves and prevent the tobacco leaves from getting stuck between the lever and the roller.

[0039] The steps of using the aforementioned detection and grading device to detect and grade tobacco leaves are illustrated below:

[0040] S1) Equipment preparation and feeding: Check the working status of each conveyor belt, negative pressure machine, detection component and grading lever, and set the conveying speed, rolling gap and negative pressure parameters according to the size and softness of the tobacco leaves; put the tobacco leaves to be tested into the hopper.

[0041] S2) Conveying and Diverting: The conveyor belt runs at a speed of about 0.2m / s, and the tobacco leaves are gathered in the middle by the guide baffle; the diverting sweeper swings at a period of about 1 second, sorting the tobacco leaves into two columns and conveying them to the rolling and leveling module.

[0042] S3) Rolling and leveling: The tobacco leaves first pass through the pre-rolling rollers, then through the limiter and the secondary rolling rollers. The support plate provides elastic support; when the pressure sensor detects an abnormal load, the telescopic module lowers the contact plate, and returns to the working position after the abnormality is resolved.

[0043] S4) Near-infrared spectroscopy detection: After the tobacco leaves enter the dark chamber, spectral and image acquisition is completed. Based on the calibration model, at least one intrinsic quality parameter from moisture, nicotine, total sugar, reducing sugar, total nitrogen, potassium, or chlorine is obtained;

[0044] After the tobacco leaves undergo the first inspection on a regular conveyor belt, they are drawn to a perforated conveyor belt by negative pressure and exposed to the second side.

[0045] The second-side spectrum and double-side image acquisition are completed under the action of the corresponding detection components at the upper and lower parts. Then the tobacco leaves fall back to the ordinary conveyor belt 303 at the negative pressure release port.

[0046] S5) Machine vision inspection and fusion grading: Based on images of the front and back of tobacco leaves collected by industrial cameras, a lightweight artificial intelligence model identifies features such as color, maturity, texture, leaf shape, damage and defects; the visual results are fused with near-infrared results to output the grade or qualification of the tobacco leaves.

[0047] S6) Grading and Recycling: When the tobacco leaves reach the corresponding grading lever position, the control system controls the grading lever to move according to the grading signal, sending the tobacco leaves into the main channel or grading channel, and the corresponding collection channel completes the recycling.

[0048] Explanation of the principles and beneficial effects of this invention:

[0049] 1) Near-infrared spectroscopy and machine vision are used to combine detection methods to obtain both the internal chemical quality and the physical quality of the tobacco leaves, thereby reducing the information loss caused by a single detection method.

[0050] 2) The combination of ordinary conveyor belt, perforated conveyor belt and negative pressure adsorption chamber allows the tobacco leaves to be exposed on both sides in sequence without manual turning, reducing conveyor belt obstruction and blind spots in detection.

[0051] 3) Pre-rolling and secondary rolling flatten the tobacco leaves step by step, and the adaptive support plate actively avoids overload, which can take into account the flatness, tobacco leaf integrity and equipment safety.

[0052] 4) The guide baffle and the periodic swing diversion sweeper organize the tobacco leaves into an orderly conveying column. The grading lever adopts a flexible shovel and rounded corner guide structure to reduce the risk of material blockage during the conveying, diversion and recycling process.

[0053] 5) The modules of the device are connected in sequence, which can realize continuous online operation of feeding, leveling, detection, grading and recycling. The structure is suitable for the layout of tobacco leaf purchasing stations and primary processing sites, and it is easy to expand the grading channels and detection sensors in the future. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the overall structure of the intelligent detection and grading device for tobacco leaf quality.

[0055] Figure 2 This is a structural diagram of the conveying and diversion module;

[0056] Figure 3(a) is a schematic diagram of the flow divider sweeper transmission mechanism;

[0057] Figure 3(b) is a schematic diagram of the crank-rocker mechanism.

[0058] Figure 4 This is a structural diagram of the roll forming and leveling module;

[0059] Figure 5 This is a schematic diagram of the adaptive support plate.

[0060] Figure 6 This is a schematic diagram of the overall structure of the detection module;

[0061] Figure 7 This is a structural diagram of the graded recycling module;

[0062] Figure 8 This is a schematic diagram of the graded lever structure.

[0063] Figures 1 to 8 middle:

[0064] 1. Conveying and diverting module; 2. Rolling and leveling module; 3. Detection module; 4. Grading and recycling module;

[0065] 101 hopper, 102 conveyor belt, 103 guide baffle, 104 diverting sweeper, 105 truss, 106 sweeper drive motor, 107 conveyor frame, 108 transmission gear set, 109 crank (its function is realized by the disc surface of the gear), 110 connecting rod, 111 frame rod, 112 rocker arm.

[0066] Support plate 201, pre-rolling roller 202, secondary rolling roller 203, limiter 204, rolling conveyor belt 205, support shaft 206, rolling motor 207, drive shaft 208, integrated frame 209, base 210, spring column 211, contact plate 212, pressure sensor 213, telescopic module 214;

[0067] Inspection frame 301, control box 302, ordinary conveyor belt 303, dark box 304, observation window 305, negative pressure conduit 306, perforated conveyor belt 307, inspection assembly 308 (second group of machine vision inspection assembly), negative pressure machine 309;

[0068] Roller conveyor belt 401, main track 402, grading track 403, grading lever 404, collection track 405, rotating bracket 406, telescopic rod 407, lever body 408, flexible shovel entry part 409. Detailed Implementation

[0069] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments described are for illustrative purposes only and are not intended to limit the scope of protection of the present invention; any equivalent substitutions made by those skilled in the art in terms of structural dimensions, component types, number of graded channels, and control parameters without departing from the technical concept of the present invention may fall within the scope of the technical solution of the present invention.

[0070] I. Overview

[0071] This invention discloses an intelligent tobacco leaf quality detection and grading device and method, and its application in flue-cured tobacco grading, belonging to the technical field of agricultural product quality detection and automatic grading equipment. The device includes a conveying and diversion module, a rolling and leveling module, a detection module, and a grading and recycling module connected in sequence. The conveying and diversion module uses a hopper, guide baffles, and periodically oscillating diversion sweepers to organize disordered tobacco leaves into at least one column; the rolling and leveling module employs pre-rolling and secondary rolling, and uses a support plate with pressure sensing and active avoidance functions to flexibly level the tobacco leaves; the detection module combines a conventional conveyor belt, a perforated conveyor belt, a negative pressure adsorption chamber, a near-infrared spectroscopy component, and a machine vision component within a dark chamber, enabling the tobacco leaves to complete internal chemical quality detection, front and back appearance image acquisition, and comprehensive grade determination during continuous conveying; the grading and recycling module guides the tobacco leaves into corresponding channels via a roller conveyor belt, grading levers, and rounded corner collection channels. This invention can reduce the impact of conveyor belt obstruction, leaf wrinkles, overlap, and grading channel blockage on the detection results, achieving continuous, non-destructive, objective detection and automatic grading of tobacco leaves, and is suitable for tobacco leaf purchasing stations and primary processing sites.

[0072] II. Description of this apparatus and method

[0073] A smart tobacco leaf quality detection and grading device is characterized by comprising a conveying and diverting module, a rolling and leveling module, a detection module, and a grading and recycling module connected sequentially from front to back along the tobacco leaf flow direction; each module operates under the control of a control system.

[0074] (i) The conveying and diversion module includes a hopper, a conveyor belt, a guide baffle, a diversion sweeper, and a conveyor frame;

[0075] The conveyor belt is on the conveyor frame; the hopper is above the feed end of the conveyor belt; guide baffles are connected to both sides of the conveyor belt, forming a trough-shaped material channel with a trapezoidal cross-section that is wider at the top and narrower at the bottom; a diverting sweeper is at the outlet of the conveyor belt and swings under the drive of an independent drive mechanism; the diverting sweeper faces the feed direction of the conveyor belt, and the projection of the diverting sweeper's swing trajectory on the surface of the conveyor belt is a fan shape, with the center of the fan shape close to the outlet of the conveyor belt; the two sides of the fan-shaped area are tobacco leaf channels; there is at least one diverting sweeper, and correspondingly, there are at least two parallel tobacco leaf channels;

[0076] (ii) The rolling and leveling module includes an integrated frame and a support plate, pre-rolling rollers, secondary rolling rollers and rolling conveyor belt installed on the integrated frame;

[0077] Pre-rolling rollers and secondary rolling rollers are sequentially connected above the rolling conveyor belt along the tobacco leaf conveying direction; two support plates are located below the rolling conveyor belt and correspond to the two rolling rollers respectively; the upper surface of the contact plate contacts the lower surface of the rolling conveyor belt; the support plate includes a base and a contact plate; the contact plate is connected to the base, and the base is connected to an integrated frame; both the pre-rolling rollers and the secondary rolling rollers rotate under the drive of a motor;

[0078] (iii) The detection module includes a detection frame and a dark box on the detection frame; inside the dark box are a regular conveyor belt, a perforated conveyor belt, a negative pressure adsorption mechanism, a near-infrared spectroscopy detection component, and a machine vision detection component; the two ends of the dark box are a tobacco leaf inlet and a tobacco leaf outlet, respectively;

[0079] The ordinary conveyor belt is divided into two sets, upstream and downstream. The perforated conveyor belt is located between the two sets of ordinary conveyor belts and above the dark box. There is one set of near-infrared spectroscopy detection components and two sets of machine vision detection components.

[0080] The upstream ordinary conveyor belt is located below inside the dark box, and the feed end of the upstream ordinary conveyor belt corresponds to the tobacco leaf inlet position; the probe of the infrared spectroscopy detection component and the lens of the first set of machine vision detection components face the bearing surface of the upstream ordinary conveyor belt; the discharge end of the upstream ordinary conveyor belt corresponds to the feed end of the perforated conveyor belt.

[0081] The perforated conveyor belt is connected to the negative pressure adsorption mechanism; the negative pressure adsorption mechanism includes a negative pressure adsorption chamber connected to the suction end of the negative pressure machine; the lower surface of the negative pressure adsorption chamber is flat and has air holes; the bearing surface of the perforated conveyor belt faces downward, and the lower surface of the negative pressure adsorption chamber is on the back of the bearing surface; the lens of the second set of machine vision inspection components faces the bearing surface of the perforated conveyor belt.

[0082] The discharge end of the perforated conveyor belt corresponds to the feed end of the downstream ordinary conveyor belt; the discharge end of the downstream ordinary conveyor belt corresponds to the tobacco leaf outlet.

[0083] (iv) The graded recycling module includes a roller conveyor belt, a grading lever, and a collection channel;

[0084] The number of roller conveyor belts corresponds to the number of tobacco leaf channels; for any roller conveyor belt, its feed end corresponds to the discharge end of the downstream ordinary conveyor belt. The roller conveyor belt serves as the main channel, and two collection channels are connected in sequence at its rear, corresponding to different grades of tobacco leaves; a grading lever is connected at the feed inlet of the collection channel; the grading lever is controlled by the bearing surface of the roller conveyor belt, and the fan-shaped area formed by its swing covers the main channel corresponding to the feed inlet of the collection channel.

[0085] As shown in Figures 3(a) and 3(b), the drive mechanism of the diverting sweeper includes a sweeper drive motor, a transmission gear set, and a crank-rocker mechanism.

[0086] The crank-rocker mechanism includes a crank 109 (capable of rotating a full revolution), a connecting rod 110 (connecting the rocker 112 and the frame rod 111), a fixed frame rod 111, and a rocker 112 (capable of swinging). The rocker is connected to the diverter sweeper, and their axes coincide. The output shaft of the sweeper drive motor drives the crank 109 through a transmission gear set 108 for speed reduction. The crank 109 drives the rocker 112 to swing back and forth through the connecting rod 110, thereby driving the diverter sweeper 104 to swing back and forth.

[0087] like Figure 4 The rolling conveyor belt is arranged in a trapezoidal shape: there are three support shafts 206 of the same height at the top and two drive shafts of the same height at the bottom, which are driven by motors respectively; there is a support shaft below the position between the pre-rolling rollers and the secondary rolling rollers of the rolling conveyor belt.

[0088] like Figure 5 The support plate also includes spring posts 211, telescopic modules 214, and pressure sensors 213; the pressure sensors sense the pressure on the contact plate; there are multiple spring posts, and each spring post is connected to a telescopic module between itself and the base; each spring post vertically supports the contact plate; the telescopic module is an electric miniature push rod; the telescopic module extends and retracts as the pressure sensor senses the pressure.

[0089] The rolling and leveling module also includes a box-type limiter; the left and right sides of the limiter have inlet and outlet ports respectively. The rolling conveyor belt enters the limiter from the inlet port, passes between the inner walls of the front and rear sides of the limiter, and then leaves the limiter from the outlet port; the top surface of the limiter has an upper opening, and the secondary rolling roller enters the limiter from the upper opening; the support plate corresponding to the secondary rolling roller is inside the limiter.

[0090] The design distance between the lower surface of the negative pressure adsorption chamber (the distance between the lower surface of the negative pressure adsorption chamber and the perforated conveyor belt is very small) and the ordinary conveyor belt is 75mm, the working negative pressure is 15Pa, and the airflow velocity in the adsorption area is preferably 5m / s.

[0091] like Figure 8 The graded lever 404 consists of a graded drive motor, a sensor control module, a rotating bracket 406, a telescopic rod 407, and a lever body 408, with an operating radius of about 200mm.

[0092] The sensing control module's sensing range is along the path of the tobacco leaves and corresponds to the collection channel;

[0093] The rotating bracket 406 is rotatably connected to the collection channel, and the rotating bracket is driven to rotate by a staged drive motor; a telescopic rod is connected between the rotating bracket and the lever body, so that the working radius is adjustable; a flexible shovel is connected to the bottom edge of the lever body; the flexible shovel rotates under the drive of the lever body, and the path of the flexible shovel is between the tobacco leaves and the rollers of the roller conveyor belt.

[0094] When the control system determines that the tobacco leaves continue to be conveyed along the main channel 402, the grading lever 404 remains in a position that does not obstruct the main channel 402; when the control system outputs a grading action signal, the telescopic rod 407 extends, the grading drive motor drives the lever body 408 to enter the main channel 402 laterally, the flexible shovel part 409 inserts between the tobacco leaves and the roller, and gently pushes the tobacco leaves into the grading channel 403.

[0095] The method for detecting and grading flue-cured tobacco using the above-mentioned device comprises the following steps:

[0096] S1) Feeding: The tobacco leaves to be tested are fed into the hopper;

[0097] S2) Conveying and Diverting: The conveyor belt runs, and the tobacco leaves are gathered in the middle by the guide baffle; the diverting sweeper swings periodically, sorting the tobacco leaves into multiple rows, forming a tobacco leaf channel, and conveying them to the rolling and leveling module;

[0098] S3) Rolling and leveling: The tobacco leaves are first rolled by the rolling conveyor belt through the pre-rolling rollers, and then through the limiter and the secondary rolling rollers;

[0099] Support plate 201 provides elastic support for the rolling conveyor belt; when pressure sensor 213 detects abnormal load, telescopic module 214 lowers contact plate 212, and returns to working position after the abnormality is resolved.

[0100] S4) Near-infrared spectroscopy detection: After the tobacco leaves enter the dark chamber 304, infrared spectra are collected by the infrared spectroscopy detection component on the upstream ordinary conveyor belt; and according to the calibrated spectral detection model, at least one intrinsic quality parameter among moisture, nicotine, total sugar, reducing sugar, total nitrogen, potassium or chlorine is obtained.

[0101] S5) Negative pressure flipping and double-sided detection: The first machine vision detection component acquires the front image of the tobacco leaf;

[0102] Then, the tobacco leaves are drawn into the perforated conveyor belt 307 by negative pressure and exposed on the second side; the second machine vision detection component collects the image of the reverse side of the tobacco leaves; the negative pressure is released and the tobacco leaves fall back onto the downstream ordinary conveyor belt;

[0103] S6) Machine vision inspection and fusion classification: Images of the front and back of tobacco leaves are used to identify the characteristics of color, maturity, texture, leaf shape, damage and injury through artificial intelligence models;

[0104] The machine vision inspection results are then fused with the near-infrared spectroscopy inspection results to obtain the grade or qualification of the tobacco leaves.

[0105] S7) Grading and recycling: When the tobacco leaves reach the corresponding grading lever 404 position along the main channel 402, the grading lever 404 is controlled to move according to the grade or qualification, so that the tobacco leaves are sent into the grading channel 403 and recycled by the corresponding collection channel 405.

[0106] The sensing and control module is a tobacco leaf arrival sensor used to detect the arrival of tobacco leaves. After completing the tobacco leaf quality inspection, the control system associates and stores the comprehensive grade signal of the tobacco leaves with their conveying sequence. When the tobacco leaf arrival sensor detects that the tobacco leaves have entered the working area of ​​the corresponding grading lever, the control system reads the grade signal of the tobacco leaves in the current sequence and compares it with the preset grade corresponding to the grading lever. When the two match, the control system moves the grading lever to move the tobacco leaves into the corresponding grading channel. When the two do not match, the grading lever remains in an avoidance position, allowing the tobacco leaves to continue to be conveyed along the main channel.

[0107] III. Specific structure of this device and its application in tobacco leaves

[0108] refer to Figure 1 The intelligent tobacco leaf quality detection and grading device in this embodiment includes a conveying and diversion module 1, a rolling and leveling module 2, a detection module 3, and a grading and recycling module 4 arranged in sequence. The height of the tobacco leaf conveying surface of each module is basically the same, so that the tobacco leaves can continuously pass through each station from the feeding end and enter the corresponding collection channel.

[0109] In this example, two tobacco leaf channels are created through a single diversion sweeper. These two channels share the same conveyor belt in both the rolling and leveling module and the detection module, until the tobacco leaves are further diverted to their corresponding two roller conveyor belts by the grading and recycling module.

[0110] 1. Conveying and Diverting Module

[0111] refer to Figure 2The conveying and diversion module 1 includes a hopper 101, a conveyor belt 102, a guide baffle 103, a diversion sweeper 104, a truss 105, a sweeper drive motor 106, and a conveyor frame 107. The conveyor belt 102 and its motor are bolted to the aluminum alloy conveyor frame 107. The side of the hopper 101 mates with the side plate of the conveyor frame 107. After the tobacco leaves enter the hopper 101, they are initially dispersed by the lower part of the hopper and the conveyor belt 102. The conveyor belt 102 has a pulley diameter of 100mm, a belt width of 300mm, and an operating speed of 0.2m / s, allowing two rows of tobacco leaves to pass through in parallel.

[0112] Guide baffles 103 are disposed above both sides of the conveyor belt 102, and their mounting plates also serve as side plates of the conveyor frame 107. A small gap is maintained between the guide baffles 103 and the conveyor belt 102 to prevent tobacco leaves from entering under the baffles; the arc-shaped guide radius of the guide baffles 103 is preferably 120mm, so that the tobacco leaves gradually converge towards the middle of the conveyor belt.

[0113] Referring to Figure 3, the diverting sweeper 104 is installed at the outlet of the conveyor belt 102 via a truss 105. The sweeper drive motor 106 drives the crank 109 via a transmission gear set 108. The crank 109 drives the rocker arm 112 to reciprocate via a connecting rod 110. The rocker arm 112 is integrally connected to the diverting sweeper 104. The preferred lengths of the crank 109, connecting rod 110, frame rod 111, and rocker arm 112 are 10mm, 35mm, 50mm, and 50mm, respectively. The rated speed of the sweeper drive motor 106 can be selected as 1500 r / min. The transmission gear set 108 adopts a two-stage reduction gear, with a transmission ratio of 5 for each stage and a total transmission ratio of 25, resulting in an output speed of 60 r / min. Both the high-speed and low-speed stages can use gear pairs with 18 and 90 teeth respectively, with a module of 1.5mm.

[0114] The conveyor belt 102 can be a food-grade matte PVC flat belt. The subsequent conveyor belt with a width of 0.15m can use a 60KTYZ synchronous geared motor, and the conveyor belt with a width of 0.30m can use a 70KTYZ synchronous geared motor; the speed range of both can be set to 0~38r / min.

[0115] 2. Roller flattening module

[0116] refer to Figure 4The rolling and leveling module 2 includes a support plate 201, pre-rolling rollers 202, secondary rolling rollers 203, a limiter 204, a rolling conveyor belt 205, a support shaft 206, a rolling motor 207, a drive shaft 208, and an integrated frame 209. The pre-rolling rollers 202 perform preliminary treatment on the tobacco leaves, while the secondary rolling rollers 203 further smooth the leaf surface. The effective rolling width of both sets of rolling rollers is 250mm, and their motors, couplings, and reduction mechanisms can be integrated behind the roller shaft and the back plate of the integrated frame 209.

[0117] To increase the installation spacing between the upper and lower parallel surfaces, the rolling conveyor belt 205 can be arranged in a trapezoidal shape, with three support shafts 206 at the top and two drive shafts 208 at the bottom. The two drive shafts 208 are driven by rolling motors 207 to ensure stable operation of the conveyor belt under conditions of a large center distance. The integrated frame 209 consists of a back plate, a front plate, and a bottom plate. The back plate has pre-drilled mounting holes for the rolling rollers, support plates, and transmission components, and a weight-reduction opening is provided near the bottom plate.

[0118] refer to Figure 5 The base 210 of the support plate 201 is 400mm long, 300mm wide, and 20mm thick, and is fixed to the back plate of the integrated frame 209 by bolts. The contact plate 212 is located below the rolling conveyor belt 205, and its upper surface contacts the lower surface of the rolling conveyor belt 205. Four spring columns 211 elastically support the contact plate 212 on the base 210, and telescopic modules 214 are provided at corresponding positions on the spring columns 211; pressure sensors 213 are provided on the contact plate 212 to form a sensing surface. When the sensed load exceeds the set value, the telescopic module 214 actively lowers the spring columns 211 and the contact plate 212 to widen the rolling gap.

[0119] The limiter 204 is 300mm long, 350mm wide, and 110mm high, with openings on the left, right, and top sides. The left and right openings allow the rolling conveyor 205 and tobacco leaves to pass through, while the top opening allows the secondary rolling rollers 203 to enter. The front and rear walls of the limiter 204 laterally restrict the tobacco leaves, and the inlet side can also be used to observe the pre-rolling effect.

[0120] 3. Detection Module

[0121] refer to Figure 6 The detection module 3 includes a detection frame 301, a control box 302, a regular conveyor belt 303, a dark box 304, an observation window 305, a negative pressure conduit 306, a perforated conveyor belt 307, a detection component 308, and a negative pressure machine 309. The dark box 304 is a cuboid with a length of 1200mm, a width of 400mm, and a height of 350mm. Tobacco leaves enter from the left inlet and exit from the right outlet. The dark box 304 has observation windows 305 with a length of approximately 300mm on the front and rear sides, and an openable dark box cover is provided on the top for easy installation, adjustment, and maintenance of the detection component.

[0122] The dark chamber 304 contains a lower ordinary conveyor belt 303 and an upper perforated conveyor belt 307. Tobacco leaves are first conveyed on the ordinary conveyor belt 303. After entering the negative pressure adsorption area, a negative pressure unit 309 creates negative pressure within the negative pressure adsorption chamber through a negative pressure conduit 306. The tobacco leaves are adsorbed upwards onto the lower surface of the perforated conveyor belt 307 and continue moving forward. When the tobacco leaves reach the negative pressure release port, the adsorption effect decreases, and the tobacco leaves fall back onto the downstream ordinary conveyor belt 303. The designed distance between the lower surface of the negative pressure adsorption chamber and the lower ordinary conveyor belt 303 is 75 mm. The preferred working negative pressure is 15 Pa, and the preferred airflow velocity in the adsorption area is 5 m / s.

[0123] Since the tobacco leaves are arranged into two columns in the conveying and diversion module 1, two corresponding conveying paths with a width of 150mm are set in the dark box 304. The perforated area of ​​the perforated conveyor belt 307 allows the side of the tobacco leaf that is being absorbed to still be subject to spectral or image detection, reducing belt occlusion.

[0124] The dark box 304 contains two sets of detection components 308 arranged along the conveying direction, namely a near-infrared spectroscopy station and a machine vision station. The near-infrared spectroscopy station includes a near-infrared spectral probe, a near-infrared light source, and a background plate; the machine vision station includes an industrial camera, a shadowless ring light source, and a background plate. Corresponding components can be installed at the upper and lower parts of the dark box 304 for both types of stations to accommodate the different postures of tobacco leaves on the ordinary conveyor belt 303 and the perforated conveyor belt 307.

[0125] The preferred working distance of the near-infrared spectroscopy probe is 120mm, adjustable within the range of 100-190mm; the distance between the near-infrared light source and the conveyor belt surface is approximately 110mm. The preferred distance between the bottom surface of the industrial camera lens and the conveyor belt surface is 160mm, adjustable within the range of 140-180mm; the distance between the shadowless ring light source and the conveyor belt surface is approximately 100mm.

[0126] In this example, the near-infrared spectrometer detector can be the Beijing Best ZN830 online near-infrared device, whose detection band covers characteristic areas such as moisture, sugar, and nicotine in tobacco leaves; the industrial camera can be the Hikvision MV-CS200-10UC color area array camera, with a resolution of 20 megapixels and a frame rate of 19.2fps. The negative pressure unit 309 can be an IP-L25 small low-noise Roots pump, and the actual negative pressure in the adsorption area can be adjusted to the range required for stable adsorption of tobacco leaves through a regulating valve.

[0127] The control box 302 (control system) is electrically connected to the conveyor motor, rolling motor, negative pressure machine 309, near-infrared spectral probe, industrial camera, pressure sensor 213, and grading drive mechanism. The control system receives near-infrared spectral data and tobacco leaf images. The host computer, with the help of corresponding detection model software, completes spectral preprocessing, quality parameter prediction, tobacco leaf target segmentation, and appearance feature recognition, and then generates a comprehensive grade signal according to the preset tobacco leaf grade rules.

[0128] Non-contact tobacco leaf inspection technologies based on spectral detection and machine vision can all utilize existing technologies.

[0129] 4. Tiered recycling module

[0130] refer to Figure 7 The grading and recycling module 4 is equipped with two sets of parallel roller conveyor units to correspond to the two columns of tobacco leaf conveying paths ahead. Each set of roller conveyor units includes a roller conveyor belt 401, a grading lever 404, and a collection channel 405. The main channel 402 of the roller conveyor belt 401 and the grading channel 403 have a smooth rounded corner transition. The diameter of a single roller is 50mm, and the center-to-center distance between adjacent rollers is 60mm.

[0131] The grade-degrading lever 404 is located at the connection point between the main lane 402 and the grade-degrading lane 403. (Reference) Figure 8 The grading lever 404 consists of a grading drive motor, a sensor control module, a rotating bracket 406, a telescopic rod 407, and a lever body 408, with an operating radius of approximately 200mm. When the control box 302 (control system) determines that the tobacco leaves will continue to be conveyed along the main path 402, the grading lever 404 remains in a position that does not obstruct the main path 402. When the control box 302 (control system) outputs a grading signal, the telescopic rod 407 extends, the grading drive motor drives the lever body 408 to laterally enter the main path 402, and the flexible shovel 409 inserts between the tobacco leaves and the rollers, gently guiding the tobacco leaves into the grading path 403. The collection path 405 has a thin-walled structure, 1200mm high and 300mm wide, with a collection opening 200mm wide that connects to the grading path 403. After entering the collection path 405, the tobacco leaves fall along an inclined slide into a lower collection space approximately 500mm long. The turning point of the collection channel 405 uses a large rounded corner to reduce jamming and breakage of tobacco leaves during the sliding process. By increasing the number of roller conveyor units, grading channels 403, and collection channels 405, it can be expanded to support multi-grade tobacco leaf grading.

[0132] 5. Methods for Grading and Testing Tobacco Leaf Quality

[0133] The specific steps for testing and grading flue-cured tobacco using the above-mentioned device are as follows:

[0134] S1) Equipment preparation and feeding: Check the working status of each conveyor belt, negative pressure machine 309, detection component 308 and grading lever 404, and set the conveying speed, rolling gap and negative pressure parameters according to the size and softness of the tobacco leaves; put the tobacco leaves to be tested into the hopper 101.

[0135] S2) Conveying and Diverting: The conveyor belt 102 runs at a speed of about 0.2 m / s, and the tobacco leaves are gathered in the middle by the guide baffle 103; the diverting sweeper 104 swings at a period of about 1 second, sorting the tobacco leaves into two columns and conveying them to the rolling and leveling module 2.

[0136] S3) Rolling and leveling: The tobacco leaves first pass through the pre-rolling roller 202, then through the limiter 204 and the secondary rolling roller 203.

[0137] The support plate 201 provides elastic support; when the pressure sensor 213 detects an abnormal load, the telescopic module 214 lowers the contact plate 212 and returns to the working position after the abnormality is resolved.

[0138] S4) Near-infrared spectroscopy detection: After the tobacco leaves enter the dark chamber 304, spectral acquisition is completed at the near-infrared spectroscopy station. Based on the calibrated spectral detection model, at least one intrinsic quality parameter from moisture, nicotine, total sugar, reducing sugar, total nitrogen, potassium, or chlorine is obtained.

[0139] S5) Negative pressure flipping and double-sided inspection: After the tobacco leaves complete the first side inspection on the ordinary conveyor belt 303, they are adsorbed by negative pressure to the perforated conveyor belt 307 and exposed to the second side.

[0140] The second-side spectrum and double-side image acquisition are completed under the action of the corresponding detection components at the upper and lower parts. Then the tobacco leaves fall back to the ordinary conveyor belt 303 at the negative pressure release port.

[0141] S6) Machine vision inspection and fusion grading: Industrial cameras collect images of the front and back of tobacco leaves, and lightweight artificial intelligence models (such as the YOLOv8n model) identify features such as color, maturity, texture, leaf shape, damage and defects; the visual results are fused with near-infrared results to output the grade or qualification of tobacco leaves.

[0142] S7) Grading and recycling: When the tobacco leaves reach the corresponding grading lever 404 position, the grading lever 404 is controlled to move according to the grading signal, so that the tobacco leaves are sent into the main channel 402 or the grading channel 403, and the corresponding collection channel 405 completes the recycling.

[0143] 6. Application in flue-cured tobacco grading

[0144] This device is suitable for conventional mature flue-cured tobacco leaves, preferably with a length of 180–350 mm, a maximum width of 100–220 mm, and a single leaf weight of 8–25 g. The device can be installed at tobacco purchasing stations, primary processing workshops, raw material quality control lines, or grading verification stations to perform internal quality testing, external quality testing, grading determination, and the diversion and recycling of tobacco leaves of corresponding grades. For tobacco leaves from different production areas, varieties, or with different moisture contents, the device can be adapted by adjusting the guide baffle spacing, rolling gap, negative pressure intensity, spectral calibration model, visual recognition model, and the number of grading channels.

Claims

1. A tobacco leaf quality testing and grading device, characterized in that, It includes a conveying and diversion module, a rolling and leveling module, a detection module, and a grading and recycling module connected sequentially from front to back along the tobacco leaf flow direction; each module operates under the control of the control system. (i) The conveying and diversion module includes a hopper, a conveyor belt, a guide baffle, a diversion sweeper, and a conveyor frame; The conveyor belt is on the conveyor frame; the hopper is above the feed end of the conveyor belt; guide baffles are connected to both sides of the conveyor belt, forming a trough-shaped material channel with a trapezoidal cross-section that is wider at the top and narrower at the bottom; a diverting sweeper is at the outlet of the conveyor belt and swings under the drive of an independent drive mechanism; the diverting sweeper faces the feed direction of the conveyor belt, and the projection of the diverting sweeper's swing trajectory on the surface of the conveyor belt is a fan shape, with the center of the fan shape close to the outlet of the conveyor belt; the two sides of the fan-shaped area are tobacco leaf channels; there is at least one diverting sweeper, and correspondingly, there are at least two parallel tobacco leaf channels; (ii) The rolling and leveling module includes an integrated frame and a support plate, pre-rolling rollers, secondary rolling rollers and rolling conveyor belt installed on the integrated frame; Pre-rolling rollers and secondary rolling rollers are sequentially connected above the rolling conveyor belt along the tobacco leaf conveying direction; two support plates are located below the rolling conveyor belt and correspond to the two rolling rollers respectively; the upper surface of the contact plate contacts the lower surface of the rolling conveyor belt; the support plate includes a base and a contact plate; the contact plate is connected to the base, and the base is connected to an integrated frame; both the pre-rolling rollers and the secondary rolling rollers rotate under the drive of a motor; (iii) The detection module includes a detection frame and a dark box on the detection frame; inside the dark box are a regular conveyor belt, a perforated conveyor belt, a negative pressure adsorption mechanism, a near-infrared spectroscopy detection component, and a machine vision detection component; the two ends of the dark box are a tobacco leaf inlet and a tobacco leaf outlet, respectively; The ordinary conveyor belt is divided into two sets, upstream and downstream. The perforated conveyor belt is located between the two sets of ordinary conveyor belts and above the dark box. There is one set of near-infrared spectroscopy detection components and two sets of machine vision detection components. The upstream ordinary conveyor belt is located below inside the dark box, and the feed end of the upstream ordinary conveyor belt corresponds to the tobacco leaf inlet position; the probe of the infrared spectroscopy detection component and the lens of the first set of machine vision detection components face the bearing surface of the upstream ordinary conveyor belt; The discharge end of the upstream ordinary conveyor belt corresponds to the feed end of the perforated conveyor belt; The perforated conveyor belt is connected to the negative pressure adsorption mechanism; the negative pressure adsorption mechanism includes a negative pressure adsorption chamber connected to the suction end of the negative pressure machine; the lower surface of the negative pressure adsorption chamber is flat and has air holes; the bearing surface of the perforated conveyor belt faces downwards, and the lower surface of the negative pressure adsorption chamber is on the back side of the bearing surface. The lens of the second set of machine vision inspection components is facing the bearing surface of the perforated conveyor belt; The discharge end of the perforated conveyor belt corresponds to the feed end of the downstream ordinary conveyor belt; the discharge end of the downstream ordinary conveyor belt corresponds to the tobacco leaf outlet. (iv) The graded recycling module includes a roller conveyor belt, a grading lever, and a collection channel; The number of roller conveyor belts corresponds to the number of tobacco leaf channels; for any roller conveyor belt, its feed end corresponds to the discharge end of the downstream ordinary conveyor belt. The roller conveyor belt serves as the main channel, and two collection channels are connected in sequence at its rear, corresponding to different grades of tobacco leaves; a grading lever is connected at the feed inlet of the collection channel; the grading lever is controlled by the bearing surface of the roller conveyor belt, and the fan-shaped area formed by its swing covers the main channel corresponding to the feed inlet of the collection channel.

2. The tobacco leaf quality detection and grading device according to claim 1, characterized in that, The drive mechanism of the diverter sweeper includes a sweeper drive motor, a transmission gear set, and a crank-rocker mechanism; The crank-rocker mechanism includes a crank, connecting rod, frame rod, and rocker arm; the rocker arm is connected to the flow divider sweeper, and their axes coincide; the output shaft of the sweeper drive motor drives the crank through a transmission gear set for speed reduction, and the crank drives the rocker arm to swing back and forth through the connecting rod, thereby driving the flow divider sweeper to swing back and forth.

3. The tobacco leaf quality detection and grading device according to claim 1, characterized in that, The rolling conveyor belt is arranged in a trapezoidal shape: there are three support shafts of the same height at the top and two drive shafts of the same height at the bottom, and the two drive shafts are driven by motors respectively; there is a support shaft below the position between the pre-rolling rollers and the secondary rolling rollers of the rolling conveyor belt; The support plate also includes spring columns, telescopic modules, and pressure sensors; the pressure sensors sense the pressure on the contact plate; there are multiple spring columns, each of which is connected to a telescopic module between itself and the base; each spring column vertically supports the contact plate; the telescopic module is an electric miniature push rod; the telescopic module extends and retracts as the pressure sensor senses the pressure. The rolling and leveling module also includes a box-type limiter; the left and right sides of the limiter have inlet and outlet ports respectively. The rolling conveyor belt enters the limiter from the inlet port, passes between the inner walls of the front and rear sides of the limiter, and then leaves the limiter from the outlet port; the top surface of the limiter has an upper opening, and the secondary rolling roller enters the limiter from the upper opening; the support plate corresponding to the secondary rolling roller is inside the limiter.

4. The tobacco leaf quality detection and grading device according to claim 1, characterized in that, The design spacing between the lower surface of the negative pressure adsorption chamber and the ordinary conveyor belt is 75mm, the working negative pressure is 15Pa, and the airflow velocity in the adsorption area is preferably 5m / s.

5. The tobacco leaf quality detection and grading device according to claim 1, characterized in that, The graded lever consists of a graded drive motor, a sensor control module, a rotating bracket, a telescopic rod, and the lever body; The sensing control module's sensing range is along the path of the tobacco leaves and corresponds to the collection channel; The rotating bracket 406 is rotatably connected to the collection channel, and the rotating bracket is driven to rotate by a grading drive motor; A telescopic rod connects the rotating bracket and the lever body; a flexible shovel is connected to the bottom edge of the lever body; the flexible shovel rotates under the drive of the lever body, and the path of the flexible shovel is between the tobacco leaf and the roller of the roller conveyor belt.

6. The tobacco leaf quality detection and grading device according to claim 1, characterized in that, The length of the diverting sweeper is 200mm, the swing angle is 20°, and the time to complete one reciprocating swing is 1s; the transmission gear set is a two-stage spur gear reduction mechanism with a total reduction ratio of 25, the number of teeth of the driving gear is 18, the number of teeth of the driven gear is 90, and the gear module is 1.5mm. The support plate base is 400mm long, 300mm wide, and 20mm thick; the rolling width of the pre-rolling roller and the secondary rolling roller is 250mm; the limiter is 300mm long, 350mm wide, and 110mm high; the running speed of the rolling conveyor belt is 0.2m / s; The dark box is 1200mm long, 400mm wide, and 350mm high; the ordinary conveyor belt and the perforated conveyor belt are set in two rows, with an effective width of 150mm for each row; The working distance of the near-infrared spectral probe of the infrared spectral detection component is 120mm, which is adjustable in the range of 100 to 190mm; the distance between the near-infrared light source of the infrared spectral detection component and the surface of the conveyor belt is 110mm. The distance between the surface of the industrial camera lens of the machine vision inspection component and the conveyor belt bearing surface is 160mm, and can be adjusted within the range of 140-180mm; the distance between the shadowless ring light source of the machine vision inspection component and the conveyor belt bearing surface is 100mm. The diameter of a single roller in the roller conveyor belt is 50mm, and the center-to-center distance between adjacent rollers is 60mm; the working radius of the grading lever is 200mm, which corresponds to the size of the feed inlet of the collection channel; the collection channel is a thin-walled inclined structure with a height of 1200mm and a width of 300mm, and is equipped with a collection inlet with a width of 200mm and a lower collection space with a length of 500mm.

7. A method for detecting and grading flue-cured tobacco using the apparatus described in any one of claims 1 to 6, characterized in that, The steps are as follows: S1) Feeding: The tobacco leaves to be tested are fed into the hopper; S2) Conveying and Diverting: The conveyor belt runs, and the tobacco leaves are gathered in the middle by the guide baffle; the diverting sweeper swings periodically, sorting the tobacco leaves into multiple rows, forming a tobacco leaf channel, and conveying them to the rolling and leveling module; S3) Rolling and leveling: The tobacco leaves are first rolled by the rolling conveyor belt through the pre-rolling rollers, and then through the limiter and the secondary rolling rollers; The support plate provides elastic support for the rolling conveyor belt; when the pressure sensor detects an abnormal load, the telescopic module lowers the contact plate and returns to the working position after the abnormality is resolved. S4) Near-infrared spectroscopy detection: After the tobacco leaves enter the dark chamber, infrared spectra are collected by the infrared spectroscopy detection component on the upstream ordinary conveyor belt; and according to the calibrated spectral detection model, at least one intrinsic quality parameter among moisture, nicotine, total sugar, reducing sugar, total nitrogen, potassium or chlorine is obtained. S5) Negative pressure flipping and double-sided detection: The first machine vision detection component acquires the front image of the tobacco leaf; Then, the tobacco leaves are drawn into the perforated conveyor belt by negative pressure and exposed on the second side; the second machine vision detection component captures the image of the reverse side of the tobacco leaves; the negative pressure is released and the tobacco leaves fall back onto the downstream ordinary conveyor belt; S6) Machine vision detection and fusion classification: Images of the front and back of tobacco leaves are used by an artificial intelligence model to identify features such as color, maturity, texture, leaf shape, damage and injury; The machine vision inspection results are then fused with the near-infrared spectroscopy inspection results to obtain the grade or qualification of the tobacco leaves. S7) Grading and Recycling: When the tobacco leaves reach the corresponding grading lever position along the main channel, the grading lever is controlled to send the tobacco leaves into the grading channel according to the grade or qualification, and the corresponding collection channel completes the recycling.

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