Real-time Monitoring Method and Device for Cut Tobacco Based on High-speed Imaging of Lean-phase Pneumatic Conveying of Bent Pipes

Abstract

A real-time monitoring method and device for cut tobacco based on high-speed imaging of dilute-phase conveying in a bent pipe. The method is realized in the following way: A transparent bent pipe with an elliptical cross-section is connected to a branch line on the main cut tobacco conveying pipeline, and a vacuum dust-proof fan is connected to the other end of the transparent bent pipe, so that the cut tobacco reaches the fluidization velocity in the bent pipe for dilute-phase conveying, and generates wall-attached movement due to the action of centrifugal force, and the cut tobacco image close to the transparent pipe wall is obtained through a high-speed imaging system arranged outside the bent pipe, and finally the cut tobacco size distribution and the cut tobacco velocity distribution are obtained after image processing. The device includes an image acquisition system, a high-speed camera system, an image processing system, a cut tobacco recovery system, and a PLC control system. The advantages of the present invention are: It is applicable to the application scenarios of the tobacco industry and can be connected to the actual pneumatic conveying pipeline by a conventional connection method; it can quickly collect images of cut tobacco, calculate the size and velocity, and perform statistical analysis, and has good real-time performance.

Description

Technical Field

[0001] The present invention belongs to the field of tobacco processing, and particularly relates to a method and device for real-time monitoring of tobacco shred size and speed based on high-speed imaging of dilute-phase pneumatic conveying through a bent pipe. Background Art

[0002] The tobacco shred structure refers to the mass percentage of tobacco shreds in different length sections in the total tobacco shreds. Different tobacco shred sizes have an obvious impact on the amount of dropped tobacco shreds at the end of a cigarette. The difference in tobacco shred size not only affects the physical quality and smoking quality of the product, but may also affect the tipping and joining process. The tobacco industry standard YC / T 289-2009 stipulates a method for determining the structure of formulated tobacco shreds. This method uses 6 kinds of sieves with different specifications and a planar rotary eccentric detection sieve technology to obtain the mass proportion fractions of tobacco shreds in different size sections. Chinese Patent CN106370546A provides a sampling test method and sampling device for the whole tobacco shred rate and broken tobacco shred rate of tobacco shreds, which solves the problem of incomplete sampling in the process of detecting the whole tobacco shred rate and broken tobacco shred rate of tobacco shreds, making the detection result more accurate. Most traditional methods use the mass percentage of tobacco shreds on the sieve to measure the tobacco shred size. This method is labor-consuming, has low efficiency and poor objectivity, and can only obtain a discrete expression of the tobacco shred size.

[0003] In a dilute-phase negative-pressure pneumatic conveying system, the material moves at a high speed, and both the pipeline and the material will be worn due to friction and impact. Qiao Weibao et al. (Publication No.: CN204847397U) invented a tobacco shred speed detection and control device, which obtains the speed information of charged tobacco shreds through a charge detector.

[0004] Machine vision detection technology is a non-contact automatic detection technology, which has the advantages of safety and reliability, high detection accuracy, and can operate for a long time in a complex production environment. It is an effective method to realize factory production automation and intelligence and has a wide range of applications. Tian Binqiang et al. (Publication No.: CN106770303A) invented a method for characterizing the size of cigarette tobacco shreds based on image analysis, which performs image analysis on randomly sampled cigarette tobacco shreds to obtain a refined characterization of the tobacco shred size and visualizes the results. However, the above method also has defects. Since it requires manual sampling, it cannot be used for real-time monitoring of the continuous production process of tobacco shreds and has low efficiency. Summary of the Invention

[0005] Based on the problems existing in the above current methods, the object of the present invention is to propose a real-time monitoring method and device for the size and speed of cut tobacco based on high-speed imaging of dilute-phase pneumatic conveying in a bent pipe by using machine vision technology. The present invention utilizes machine vision technology to connect a transparent bent pipe to a branch line of the cut tobacco conveying pipeline. The cut tobacco reaches the fluidization speed in the bent pipe for dilute-phase conveying, and due to the centrifugal force, it moves along the wall. The cut tobacco image close to the transparent wall is obtained through a high-speed imaging system and processed, and finally the size distribution and speed distribution of the cut tobacco are obtained. The present invention is suitable for actual industrial scenarios and provides a method for characterizing the size and speed of cut tobacco in the pneumatic conveying process of cigarette production.

[0006] The object of the present invention is achieved by the following technical solutions:

[0007] A real-time monitoring method for the size and speed of cut tobacco based on high-speed imaging of dilute-phase pneumatic conveying in a bent pipe is realized in the following way: A transparent bent pipe with an elliptical cross-section is connected to a branch line on the main cut tobacco conveying pipeline, and the other end of the transparent bent pipe is connected to a vacuum dust-proof fan, so that the cut tobacco reaches the fluidization speed in the bent pipe for dilute-phase conveying, and due to the centrifugal force, it moves along the wall. The cut tobacco image close to the transparent pipe wall is obtained through a high-speed imaging system arranged outside the bent pipe, and finally the size distribution and speed distribution of the cut tobacco are obtained after image processing.

[0008] This method monitors the size and speed of cut tobacco by means of intermittent sampling through an access branch pipe. 。

[0009] A real-time monitoring device for the size and speed of cut tobacco based on high-speed imaging of dilute-phase pneumatic conveying in a bent pipe includes a dilute-phase cut tobacco conveying system, an image acquisition system, an image processing system, a cut tobacco recovery system, and a PLC control system;

[0010] The dilute-phase cut tobacco conveying system includes a transparent bent pipe with an elliptical cross-section connected to a branch line of the main cut tobacco conveying pipeline and a vacuum dust-proof fan arranged at the end of the bent pipe. A check valve is provided at the inlet end of the transparent bent pipe, and a funnel-shaped settling chamber for collecting cut tobacco is arranged on the pipeline near the position of the vacuum dust-proof fan; Since the check valve is installed at the inlet of the bent pipe, it opens when the cut tobacco enters the bent pipe under the action of negative pressure. The vacuum dust-proof fan is installed behind the funnel-shaped settling chamber to provide negative pressure for the image acquisition pipeline to make the cut tobacco flow in dilute phase, and its lift can be adjusted by a frequency converter.

[0011] The image acquisition system consists of a parallel supplementary light source, a high-speed camera, an image acquisition card, and a data transmission line. The parallel supplementary light source is arranged inside the bent pipe and parallel to the camera optical axis. The high-speed camera is arranged outside the bent pipe at a certain distance from the center of the outer side of the middle elliptical pipe section, and the optical axis is perpendicular to the outer wall of the elliptical pipe.

[0012] The PLC control system consists of two pressure sensors, an IO-LINK module, a PLC controller, and a frequency converter. The two pressure sensors are respectively arranged at the inlet and outlet ends of the transparent elbow pipe and are connected to the PLC controller through the IO-LINK module. The PLC controller controls the rotation speed of the vacuum dust-proof fan through the frequency converter;

[0013] The cut tobacco recovery system is arranged below the funnel-shaped sedimentation chamber. The cut tobacco recovery system is a rectangular recovery bin with a height of 300 - 800 mm and a length and width of 300 * 600 mm.

[0014] The image processing system includes a computer and an image acquisition and analysis program.

[0015] In the present invention, the selected elliptical pipe has a wall thickness of 1 - 5 mm, the ratio of the long axis to the short axis is 2 - 5, and the length dimension of the long axis is 100 - 300 mm; the length dimension of the inlet section pipeline is 400 - 800 mm; the lengths of the middle section and the outlet section pipelines are 200 - 400 mm; the inlet section pipeline and the outlet section pipeline form a 90° angle; the angle α between the inlet section pipeline and the cut tobacco pneumatic conveying pipeline is 90° - 150°; the gas velocity in the pipe is 30 - 50 m / s.

[0016] The elliptical pipe made of the transparent material refers to a glass elliptical pipe, a plexiglass elliptical pipe, or a polymer material elliptical pipe.

[0017] The high-speed camera is located 500 - 1500 mm from the outer side of the elbow pipe to the center of the outer side wall of the middle section elliptical pipe, and the optical axis is perpendicular to the outer side wall of the elliptical pipe; the image acquisition frame rate of the high-speed camera is greater than 500 fps, and the resolution is at least 1280×960. The high-speed camera can set the image acquisition frequency and the single acquisition duration, the sampling period interval is 10 - 30 min, and each sampling is 20 - 40 s.

[0018] The computer refers to an interactive hardware device that runs the image acquisition and analysis program and outputs the analysis result.

[0019] The image acquisition and analysis program has a cut tobacco morphology acquisition function and an image analysis function. The cut tobacco morphology acquisition function refers to the real-time acquisition of the cut tobacco morphology in the transparent pipeline through an image acquisition card and transmission to the computer storage address end; the image analysis function can call the real-time cut tobacco image data, perform preprocessing such as image correction, filtering, and enhancement on the image, perform gray-scale segmentation on the cut tobacco area in the image, extract and calculate the cut tobacco length parameters, and perform statistical analysis on the batch detection of cut tobacco sizes. Figure 2 Shown are the cut tobacco image and the preprocessed binary cut tobacco image. By processing the cut tobacco images within a unit time, a cut tobacco velocity vector field as shown in Figure 3 can be obtained, and the cut tobacco velocity is calculated through the position information of the cut tobacco at different times.

[0020] The specific process of using the above device to measure the size of cut tobacco is as follows:

[0021] (1) Connect the cut tobacco conveying system with a tee at the position where the size of cut tobacco needs to be measured on the main pipeline, check the operation of the equipment, and install other systems in sequence;

[0022] (2) Turn on the supplementary light source of the image acquisition system, set the acquisition frequency and single-sampling duration in the high-speed camera and the image analysis program, and set the PLC control period to be consistent with the image acquisition system period;

[0023] (3) After the main pipeline conveys stably, turn on the PLC controller;

[0024] (4) The PLC controller starts the fan according to the pressure difference between the two pressure sensors and adjusts the lift of the fan;

[0025] (5) The check valve opens under the action of negative pressure, and the cut tobacco enters the elbow. At this time, the cut tobacco is transported in dilute phase in the elbow, with a speed of 30 - 50 m / s. The cut tobacco in the camera's field of view adheres to the wall under the action of centrifugal force and has no overlap;

[0026] (6) The image acquisition system starts to acquire images, and the acquired images are stored in the computer through a data transmission line;

[0027] (7) The image acquisition and analysis program performs recognition, processing, statistical analysis on the cut tobacco images within the sampling duration, obtains the continuous distribution of cut tobacco length and the speed distribution of cut tobacco, and outputs them;

[0028] (8) The cut tobacco has a reduced speed in the funnel-shaped settling chamber due to the increase in pipe diameter. After settling and hitting the wall, it falls to the bottom of the funnel. The bottom valve is periodically opened to empty the cut tobacco into the cut tobacco recovery bin.

[0029] The advantages of the present invention are as follows:

[0030] (1) The present invention considers the application scenarios in the tobacco industry, and this device can be connected to the actual pneumatic conveying pipeline in a conventional connection manner;

[0031] (2) The present invention monitors the size of cut tobacco by means of intermittent sampling by connecting a branch pipe to the pneumatic conveying pipeline. High flow velocity can be adopted in the branch pipe to realize the dilute-phase fluidized transportation of cut tobacco, which is convenient for image acquisition, and has little influence on the size of cut tobacco and the material flow rate in the main pipeline.

[0032] (3) It can quickly acquire images of cut tobacco, calculate the size and speed, and perform statistical analysis, with good real-time performance. Description of the Drawings

[0033] Figure 1 It is the cut tobacco image and the preprocessed binary cut tobacco image. The left is the cut tobacco image, and the right is the preprocessed image;

[0034] Figure 2 is the tobacco shred velocity vector field;

[0035] Figure 3 is the structural schematic diagram of the device of the present invention,

[0036] In the figure: 1 - elbow pipe, 2 - check valve, 3 - funnel-shaped sedimentation chamber, 4 - vacuum dust-proof fan, 5 - high-speed camera, 6 - data transmission line, 7 - computer, 8 - image acquisition card, 9 - main tobacco shred conveying pipeline, 10 - tee, 11 - parallel supplementary light source, 12a - inlet pressure sensor, 12b - outlet pressure sensor, 13 - IO-LINK module, 14 - PLC controller, 15 - frequency converter, 16 - tobacco shred recycling bin, 17 - gate valve. Specific embodiments

[0037] The detection device and method of the present invention will be further described below with reference to the accompanying drawings:

[0038] A real-time monitoring method for the size and velocity of tobacco shreds based on high-speed imaging of dilute-phase pneumatic conveying in an elbow pipe is realized in the following way: A transparent elbow pipe with an elliptical cross-section is connected to a branch line on the main tobacco shred conveying pipeline, and the other end of the transparent elbow pipe is connected to a vacuum dust-proof fan, so that the tobacco shreds reach the fluidization velocity in the elbow pipe for dilute-phase conveying, and wall-attached movement is generated due to the centrifugal force. The tobacco shred images close to the transparent pipe wall are obtained through a high-speed imaging system arranged outside the elbow pipe, and finally the size distribution and velocity distribution of the tobacco shreds are obtained after image processing (see Figure 1 、 Figure 1 ).

[0039] This method monitors the size and velocity of tobacco shreds by means of intermittent sampling through an access branch pipe.

[0040] The structure of the real-time monitoring device designed by the present invention based on the above method is as Figure 3 shown, and it includes a dilute-phase tobacco shred conveying system, an image acquisition system, an image processing system, a tobacco shred recycling system, and a PLC control system;

[0041] The dilute-phase tobacco shred conveying system includes a transparent elbow pipe 1 with an elliptical cross-section connected to a branch line of the main tobacco shred conveying pipeline 9 and a vacuum dust-proof fan 4 arranged at the end of the elbow pipe. A check valve 2 is provided at the inlet end of the transparent elbow pipe, and the elbow pipe corner can be a straight corner or an arc corner. A funnel-shaped sedimentation chamber 3 for collecting tobacco shreds is arranged on the pipeline near the position of the vacuum dust-proof fan; Since the installation position of the check valve 2 is at the inlet of the elbow pipe 1, it opens when the tobacco shreds enter the elbow pipe under the action of negative pressure. The vacuum dust-proof fan 4 is installed behind the funnel-shaped sedimentation chamber 3 to provide negative pressure for the image acquisition pipeline to make the tobacco shreds flow in dilute phase, and its lift can be adjusted by the frequency converter 15.

[0042] The described image acquisition system consists of a parallel supplementary light source 11, a high-speed camera 5, an image acquisition card 8, and a data transmission line 6. The parallel supplementary light source 11 is arranged inside the elbow pipe and is parallel to the optical axis of the camera. The high-speed camera 5 is arranged outside the elbow pipe at a certain distance (500 - 1500 mm) from the center of the outer side of the elliptical pipe in the middle section, and its optical axis is perpendicular to the outer wall of the elliptical pipe. The image acquisition frame rate of the high-speed camera is greater than 500 fps, and the resolution is at least 1280×960. The high-speed camera can set the image acquisition frequency and the single acquisition duration. The sampling period interval is 10 - 30 min, and each sampling lasts for 20 - 40 s.

[0043] The described image processing system includes a computer 7 and an image acquisition and analysis program.

[0044] The tobacco shred recycling system is arranged below the funnel-shaped sedimentation chamber. The tobacco shred recycling system is a tobacco shred recycling bin 16 with a rectangular structure, with a height of 300 - 800 mm and a length and width of 300*600 mm.

[0045] The described PLC control system consists of two pressure sensors (12a, 12b), an IO-LINK module 13, a PLC controller 14, and a frequency converter 15. The two pressure sensors are respectively arranged at the inlet and outlet ends of the transparent elbow pipe and are connected to the PLC controller 14 through the IO-LINK module 13. The PLC controller 14 controls the rotation speed of the vacuum dust-proof fan 4 through the frequency converter 15; more specifically: the pressure sensors 12a and 12b are respectively located at the elbow pipe inlet end and the fan inlet, and are connected to the IO-LINK module 13 through signal lines. The IO-LINK module 13 converts the analog signal of the sensor into a digital signal and transmits it to the PLC controller 14. The PLC controller 14 adjusts the frequency of the frequency converter 13 according to the pressure sensor signal and can achieve cycle control. The frequency converter 13 is controlled by the PLC controller 14 and is connected to the fan.

[0046] In the present invention, the selected wall thickness of the elliptical pipe is 1 - 5 mm, the ratio of the long axis to the short axis is 2 - 5, and the length dimension of the long axis is 100 - 300 mm; the length dimension of the inlet section pipeline is 400 - 800 mm; the lengths of the middle section and the outlet section pipes are 200 - 400 mm; the inlet section pipeline and the outlet section pipeline form a 90° angle; the angle α between the inlet section pipeline and the tobacco shred pneumatic conveying pipeline is 90° - 150°; the gas velocity in the pipe is 30 - 50 m / s.

[0047] The described computer refers to an interactive hardware device that runs the image acquisition and analysis program and outputs the analysis result.

[0048] The image acquisition and analysis program has a function of collecting the tobacco shred morphology and a function of image analysis. The function of collecting the tobacco shred morphology refers to collecting the morphology of the tobacco shreds in the transparent pipeline in real time through an image acquisition card and transmitting it to the computer storage address end; the image analysis function can call the real-time image data of the tobacco shreds, perform preprocessing such as image correction, filtering, and enhancement on the image, perform gray-scale segmentation on the tobacco shred area in the image, extract and calculate the length parameters of the tobacco shreds, and perform statistical analysis on the sizes of the batch-detected tobacco shreds. Figure 2 Shown are the tobacco shred image and the binary image of the preprocessed tobacco shreds. By processing the tobacco shred images within a unit time, the tobacco shred velocity vector field as shown in Figure 3 can be obtained, and the tobacco shred velocity is calculated through the position information of the tobacco shreds at different times.

[0049] The specific process of the detection method using the above device is as follows:

[0050] 1) Connect the tobacco shred conveying system with a tee at the position where the tobacco shred size needs to be measured on the main pipeline, check the operating status of the equipment, and install other systems in sequence;

[0051] 2) Turn on the parallel supplementary light source 11 of the image acquisition system, set the acquisition frequency and single-sampling duration in the high-speed camera 5 and the image analysis program, set the PLC control period to be consistent with the image acquisition system period, and set the differential pressure rated value in the PLC control function;

[0052] 3) After the main pipeline conveys stably, turn on the PLC controller 14;

[0053] 4) The PLC controller 14 turns on the vacuum dust-proof fan 4 according to the differential pressure of the two pressure sensors and adjusts the fan lift;

[0054] 5) The check valve 2 is opened under the action of negative pressure, and the tobacco shreds enter the elbow 1. At this time, the tobacco shreds are in dilute-phase transportation in the elbow, with a speed of 30 - 50 m / s. The tobacco shreds in the camera field of view adhere to the wall under the action of centrifugal force and have no overlap;

[0055] 6) The image acquisition system starts to acquire images, and the acquired images are stored in the computer 7 through the data transmission line 6;

[0056] 7) The image acquisition and analysis program performs recognition, processing, and statistical analysis on the tobacco shred images within the sampling duration, obtains the continuous distribution of the tobacco shred lengths and the tobacco shred velocity distribution, and outputs them;

[0057] 8) The speed of the tobacco shreds decreases in the funnel-shaped sedimentation chamber 3, and after settling and hitting the wall, they fall to the bottom of the funnel. The bottom gate valve 17 is regularly opened to empty the tobacco shreds into the tobacco shred recovery bin 16.

[0058] Example 1

[0059] In order to enable those skilled in the art to better understand the tobacco shred size detection method and device provided by the present invention, the following describes the technical solutions in the present invention clearly and completely in combination with the following examples. Obviously, the described examples are only a part of the embodiments of the present invention, rather than all the embodiments of the present invention.

[0060] Turn on the fill light source of the high-speed imaging system, set the acquisition frequency in the high-speed camera 5 and the image acquisition and analysis program to be 30 min / time, the single sampling duration to be 20 s, and set the working cycle of the PLC control system to be the same as the camera image acquisition frequency. According to the above device and method, the continuous distribution of tobacco shred size and the tobacco shred speed distribution are obtained. The weight fraction information of the required tobacco shred size is obtained by using the continuous distribution of tobacco shred size to guide production.

[0061] To sum up, the present invention establishes a real-time monitoring device and method for tobacco shred size and speed based on high-speed imaging of dilute-phase pneumatic conveying in a bent pipe. The invention can obtain the continuous distribution of tobacco shred size and the tobacco shred speed information. The device is easy to install, suitable for actual industrial scenarios, and provides an idea for characterizing the tobacco shred size and speed in the pneumatic conveying process of cigarette production.

Claims

1. A real-time monitoring method for cut tobacco based on high-speed imaging of dilute-phase conveying in a bent pipe, characterized in that: it is implemented in the following way: A transparent bent pipe with an elliptical cross-section is branched into the main cut tobacco conveying pipeline. The other end of the transparent bent pipe is connected to a vacuum dust-proof fan and controlled by a PLC control system, so that the cut tobacco reaches the fluidization speed in the bent pipe for dilute-phase conveying, and wall-attached movement is generated due to the centrifugal force. The cut tobacco image close to the transparent pipe wall is obtained by a high-speed imaging system arranged outside the bent pipe, and finally the cut tobacco size distribution and the cut tobacco speed distribution are obtained through image processing; The ratio of the major axis to the minor axis of the elliptical pipe is 2-5, and the inlet section pipeline and the outlet section pipeline of the transparent bent pipe form a 90° angle; A check valve is provided at the inlet end of the transparent bent pipe, and a funnel-shaped settling chamber for collecting cut tobacco is arranged on the pipeline near the position of the vacuum dust-proof fan.

2. The real-time monitoring method for cut tobacco based on high-speed imaging of dilute-phase conveying in a bent pipe according to claim 1, characterized in that: This method monitors the cut tobacco size and speed by means of intermittent sampling through an access branch pipe.

3. A real-time monitoring device for cut tobacco based on high-speed imaging of dilute-phase conveying in a bent pipe, characterized in that: This device includes a dilute-phase cut tobacco conveying system, an image acquisition system, an image processing system, a cut tobacco recovery system, and a PLC control system; The dilute-phase cut tobacco conveying system includes a transparent bent pipe with an elliptical cross-section connected to the branch line of the main cut tobacco conveying pipeline and a vacuum dust-proof fan arranged at the end of the bent pipe. A check valve is provided at the inlet end of the transparent bent pipe, and a funnel-shaped settling chamber for collecting cut tobacco is arranged on the pipeline near the position of the vacuum dust-proof fan; The ratio of the major axis to the minor axis of the elliptical pipe is 2-5, and the inlet section pipeline and the outlet section pipeline of the transparent bent pipe form a 90° angle; The image acquisition system is composed of a parallel supplementary light source, a high-speed camera, an image acquisition card, and a data transmission line. The parallel supplementary light source is arranged inside the bent pipe and parallel to the camera optical axis. The high-speed camera is arranged at a certain distance from the center of the outer side of the middle section elliptical pipe outside the bent pipe and the optical axis is perpendicular to the outer wall of the elliptical pipe. During operation, the cut tobacco reaches the fluidization speed in the bent pipe for dilute-phase conveying, and wall-attached movement is generated due to the centrifugal force. The cut tobacco image close to the transparent pipe wall is obtained by a high-speed imaging system arranged outside the bent pipe, and finally the cut tobacco size distribution and the cut tobacco speed distribution are obtained through image processing; The PLC control system is composed of two pressure sensors, an IO-LINK module, a PLC controller, and an inverter. The two pressure sensors are respectively arranged at the inlet and outlet ends of the transparent bent pipe and are connected to the PLC controller through the IO-LINK module. The PLC controller realizes the speed control of the vacuum dust-proof fan through the inverter; The cut tobacco recovery system is arranged below the funnel-shaped settling chamber.

4. The real-time monitoring device for cut tobacco based on high-speed imaging of dilute-phase conveying in a bent pipe according to claim 3, characterized in that: The image processing system includes a computer and an image acquisition and analysis program.

5. The real-time monitoring device for cut tobacco based on high-speed imaging of dilute-phase conveying in a bent pipe according to claim 3, characterized in that: The shredded tobacco recovery system is a recovery bin with a rectangular structure, 300 - 800 mm in height, and 300 * 600 mm in length and width.

6. The real-time shredded tobacco monitoring device based on high-speed imaging of dilute-phase conveying through a bent pipe according to claim 3, characterized in that: The selected elliptical pipe has a wall thickness of 1 - 5 mm and a major axis length dimension of 100 - 300 mm; the length dimension of the inlet section pipeline is 400 - 800 mm; the lengths of the middle section and the outlet section pipelines are 200 - 400 mm; the included angle α between the inlet section pipeline and the shredded tobacco pneumatic conveying pipeline is 90° - 150°; the gas velocity in the pipe is 30 - 50 m / s.

7. The real-time shredded tobacco monitoring device based on high-speed imaging of dilute-phase conveying through a bent pipe according to claim 3, characterized in that: The high-speed camera is located 500 - 1500 mm from the outer side of the bent pipe to the center of the outer wall of the middle section elliptical pipe, and its optical axis is perpendicular to the outer wall of the elliptical pipe; the image acquisition frame rate of the high-speed camera is greater than 500 fps, and the resolution is at least 1280×960; the high-speed camera can set the image acquisition frequency and the single acquisition duration, the sampling period interval is 10 - 30 min, and each sampling is 20 - 40 s.

8. The real-time shredded tobacco monitoring device based on high-speed imaging of dilute-phase conveying through a bent pipe according to claim 4, characterized in that: The computer refers to an interactive hardware device that runs an image acquisition and analysis program and outputs an analysis result.

9. The real-time shredded tobacco monitoring device based on high-speed imaging of dilute-phase conveying through a bent pipe according to claim 4, characterized in that: The image acquisition and analysis program has a shredded tobacco morphology acquisition function and an image analysis function. The shredded tobacco morphology acquisition function refers to the real-time acquisition of the shredded tobacco morphology in the transparent pipeline through an image acquisition card and transmission to the computer storage address end; the image analysis function can call the real-time image data of the shredded tobacco, perform preprocessing such as image correction, filtering, and enhancement, perform gray-scale segmentation on the shredded tobacco area in the image, extract and calculate the shredded tobacco length parameters, and perform statistical analysis on the batch detection of shredded tobacco sizes.

Images