A method for testing the burning performance of dark cigarettes using dark cigarette paper

Abstract

The application discloses a method for testing the combustion performance of dark cigarettes using dark cigarette paper, wherein the dark cigarette paper refers to cigarette paper with a gray value less than 255; a mechanical arm is used to simulate the cigarette smoking process and the smoking environment, a full-vision camera system is used to collect the images of the carbon line and the ash column area of the cigarette combustion, then the coordinates of the carbon line and the ash column area are used to analyze the related index of the cigarette combustion. According to the surface reflection characteristics of the dark cigarette paper, the optical reflection principle is used, a light source is used to illuminate at a certain lateral angle, the color difference of the edge of the dark cigarette is highlighted, the cigarette positioning is obtained, and then the combustion index of the cigarette is detected.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of cigarette combustion performance, and particularly relates to a method for testing the combustion performance of dark cigarettes using dark cigarette paper. BACKGROUND

[0002] Cigarette combustion performance is used to characterize the combustion state of cigarettes during the combustion process, mainly focusing on consumer smoking experience related indicators during the smoking process, usually including indicators such as split rate, carbon line mass, ash color, fly ash and ash. Combining consumer experience needs, through targeted research on combustion performance related indicators, guiding the adjustment of cigarette raw material formula, optimizing cigarette product quality, can better meet the consumers' increasing demand for cigarette product quality in detail.

[0003] The above indicators are evaluated by visual method in the past, which is easily affected by the technical level, experience and subjective consciousness of the observer, thereby affecting the accuracy and objectivity of the evaluation results. At the same time, real-time data of cigarette combustion cannot be collected and digitized through visual method, which affects scientific statistics and research using data. At present, in order to solve the above problems, image acquisition is mainly carried out through machine vision, and quantitative analysis is completed. In the image acquisition process, in order to realize accurate acquisition and real-time analysis of the burned length part of the cigarette, carbon line positioning and image acquisition are adopted. At the same time, since the conventional cigarette product is generally white cigarette paper, in order to avoid the influence of the environment on the collected image and cause large experimental errors, the environment background is usually set to dark color, mainly black.

[0004] With the globalization of the consumer market, the quality of consumption is continuously improving, and the demand for consumption is diversified, and in addition to traditional white cigarette paper products, colored cigarette paper products have gradually appeared in cigarette products. The current market colored cigarette paper products are mainly dark colored cigarette paper, commonly known as brown, black and other colors, and according to the same color tone, they are divided into many products. With the emergence of colored cigarette paper, in the process of image processing by visual detection method for cigarettes, the detection method for conventional cigarettes (using white cigarette paper, white appearance) adopts the color difference method, which uses the color difference between the cigarette paper and the image processing environment background (usually black) to realize the positioning detection and processing of the cigarettes in the field of view. However, the color of the dark colored cigarette paper is different from the color of the market, and the appearance of the dark colored cigarette paper is dark (such as black, dark brown and light brown). Since the cigarette paper is dark, and the color of the image processing environment background is also dark, the color difference between the dark colored cigarette and the environment background cannot be formed, which leads to the fact that the picture collected by the camera system cannot distinguish the edge of the dark colored cigarette, so that the cigarette cannot be positioned by color difference, and there is currently no method and instrument to investigate the combustion performance of dark colored cigarettes using dark colored cigarette paper.

[0005] To solve the above problems, the present application is proposed. SUMMARY

[0006] The present application aims to provide a method for testing the burning performance of dark cigarettes using dark cigarette paper, adjusting the lighting system, using a camera system to collect the dark cigarette burning carbon line, and judging the burning performance of dark cigarette paper based on the burning carbon line; the lighting system includes multiple parallel light sources, and the lighting light source and camera position are adjusted to highlight the edge reflection light effect of the dark cigarette. The camera system includes multiple industrial cameras, and the exposure control of the industrial cameras is combined to distinguish the edge highlight part of the dark cigarette from the light dark background part when the industrial cameras collect and process images, so as to generate an edge peak with color difference, use the scanning line of the detection algorithm to scan and capture the edge peak, thereby real-time tracking and positioning the position coordinates of the dark cigarette in the image field of view collected, and real-time tracking and positioning the position of the dark cigarette burning carbon line. The present application solves the problem that the pictures collected by the camera system of the prior art cannot distinguish between dark cigarette paper and dark carbon line, cannot identify the position of the cigarette edge and the burning carbon line, and there is no method and instrument to investigate the burning performance of dark cigarettes using dark cigarette paper.

[0007] The evaluation indexes of cigarette burning performance usually include split rate, ash column deviation, ash column gray value, ash column length, ash column area, ash shrinkage rate, fly ash value, ash retention rate, carbon line width, carbon line uniformity, and burning speed. The meanings of the above-mentioned cigarette burning performance evaluation indexes are as follows: the split rate is the ratio of the area of the ash piece falling or cracking on the ash column to the overall surface area of the ash column; the ash column deviation refers to the maximum deviation angle of the cigarette ash column from the filter rod axis; the ash column gray value reflects the relative color difference of the remaining part after the cigarette burns under the same reference system, and the larger the value, the whiter the ash column; the ash column length is the length of the ash column formed after the cigarette burns; the ash column area is the width of the ash column formed after the cigarette burns; the ash shrinkage rate is the ratio of the ash column area after the cigarette burns to the area before the cigarette burns; the fly ash value is the ash area scattered outside the fixed ash point; the ash retention rate is the ratio of the longest value of the ash column that can be maintained during the cigarette burning process to the cigarette burning length; the carbon line width is the width of the carbon line at the bottom of the cigarette burning cone; the carbon line uniformity refers to the extreme difference value between the highest point and the lowest point of the carbon line at the bottom of the cigarette burning cone; and the burning speed is the ratio of the burning length to the burning time.

[0008] Specifically, the present application is realized by the following technical solutions:

[0009] The present application provides a method for testing the combustion performance of dark cigarettes using dark cigarette paper, wherein the dark cigarette paper refers to cigarette paper with a gray value less than 255; more preferably, the dark cigarette paper refers to cigarette paper with a gray value less than 200, and more preferably, the dark cigarette paper refers to cigarette paper with a gray value less than 180. In the present application, any cigarette made of non-white cigarette paper can be referred to as a dark cigarette, and more preferably, the dark cigarette refers to a cigarette with the appearance of black, dark brown, light brown and colored cigarette paper commonly used in the market. In the present application, the gray value represents the color depth of the cigarette paper under black and white conditions, ranging from 0 to 255, with white being 255 and black being 0, wherein the smaller the value, the darker the color.

[0010] The mechanical arm simulates the cigarette smoking process and the smoking environment, and a full-vision camera system is used to collect images of the carbon line and ash column area of the cigarette combustion, and then the coordinates of the carbon line and ash column area are analyzed to analyze the combustion-related indicators of the cigarette.

[0011] The specific method comprises the following steps:

[0012] 1) The sample dark cigarette is pretreated according to GB / T 16447 standard before determination;

[0013] 2) The sample dark cigarette is placed in the test position, and the axial direction of the cigarette in the determination position is perpendicular to the camera and the light source, and the light source is a strip light source, the angle A between the direction of the light emitted by the strip light source and the direction of the light received by the camera is greater than 90° and less than 150°;

[0014] 3) Start the software control system, the lighting system, the camera system and the mechanical arm movement system, take a picture of the sample before combustion, and then ignite the cigarette;

[0015] 4) Stop collecting the combustion images of the cigarette when the cigarette burns to 3mm from the tipping paper;

[0016] 5) During the test, the real-time combustion of the cigarette is calculated, and the combustion state of the cigarette is collected at the same time by the camera;

[0017] 6) During the real-time combustion detection, the axial edge of the dark cigarette is located and identified, the gray values of the adjacent coordinate pixels at the color difference junction are compared, the coordinate information of the carbon line and ash column area is obtained, and the combustion-related indicators of the cigarette are analyzed;

[0018] The method for identifying the axial edge of the dark cigarette in step (6) is: from top to bottom, the high-light edge of the cigarette is scanned by using pixel point scanning, when the gray value of the pixel point changes, the coordinate position of the pixel point is marked, and the edge of the cigarette is positioned according to the coordinate point.

[0019] Preferably, the mechanical arm simulates the cigarette smoking process and the smoking environment, and a full-vision camera system is used to collect the cigarette combustion carbon line image; the mechanical arm simulating the cigarette smoking process and the smoking environment, and the method of the full-vision camera system collecting the cigarette combustion carbon line image can refer to the series of patents of the applicant based on mechanical vision for cigarette combustion performance, application number: 2020103139473, name: a mechanical arm simulating the cigarette smoking process and the smoking environment of human body and a simulation method thereof; application number: 2020103234251, name: a smoking path simulation system based on a mechanical hand; application number: 2020106880405, name: a cigarette fly ash detection device and detection method based on machine vision; application number: 2020109761732, name: a cigarette fly ash detection device and detection method based on machine vision by using gray difference method, and the test device and test method of the above-mentioned patents are also incorporated into the present patent.

[0020] Preferably, in step 1), in order to investigate the cigarette combustion detection of different samples under specific conditions, the sample can be directly determined after pretreatment under the set equilibrium condition, so as to analyze the influence difference of different conditions on the cigarette combustion detection.

[0021] Preferably, in step 3), the camera system includes a plurality of cameras which are uniformly distributed in the direction perpendicular to the cigarette, so as to ensure that the cigarette ash column curved surface can be fully collected.

[0022] Preferably, in step 3), the lighting system includes a plurality of lighting sources, each lighting source corresponds to a camera, and the lighting source is a strip light source, and each group of lighting sources and cameras satisfies that the included angle A between the direction of the strip light source emitting light and the direction of the camera receiving light is greater than 90° and less than 150°.

[0023] Preferably, in step 3), after the sample cigarette is ignited, the cigarette should be kept in a vertical position without deviation.

[0024] Preferably, in step 4), the control system automatically collects images every 2s interval during the image collection of the sample in the test process. The collection time interval can be customized according to the test requirements, and the accuracy is 0.1s.

[0025] Preferably, in step 4), if the sample cigarette cannot be burned to the early fracture position of 3mm from the tipping paper during the test process, lower than the image determination collection requirement, the sample should be taken from the parallel sample for re-determination.

[0026] Preferably, step 4) is used to cut the image collection data in different burning length ranges, or the image collection data in different burning time ranges.

[0027] Compared with the prior art, the present application has the following beneficial effects:

[0028] 1. According to the surface reflection characteristics of dark cigarette paper, the present application uses optical reflection principle, adopts a light source to illuminate at a certain lateral angle, highlights the color difference of the edge of the dark cigarette, obtains the positioning of the cigarette, and further detects the cigarette burning index. Specifically, the light source is a bar light source, the angle A between the direction of the light emitted by the bar light source and the direction of the light received by the camera is greater than 90° and less than 150°, and the light angle and the camera angle can just illuminate the position of the edge of the dark cigarette, so that the reflection effect of the edge of the dark cigarette is highlighted. If the light source is not used, or the angle between the direction of the light emitted by the light source and the direction of the light received by the camera is not within the above range, the edge of the cigarette cannot be positioned on the collected image.

[0029] 2. The camera system includes a plurality of industrial cameras, and the exposure control of the industrial cameras can distinguish the high-light part of the edge of the dark cigarette from the dark background part of the light when the industrial cameras collect and process images, so as to generate an edge peak with color difference, and the scanning line of the detection algorithm is used to scan and capture the edge peak, so as to real-time track and locate the position coordinates of the dark cigarette in the field of view of the collected image, and real-time track and locate the position of the burning carbon line of the dark cigarette. Specifically, the method for identifying the color difference between the unburned dark cigarette paper and the burned cigarette ash column is as follows: the pixel point scanning mode is adopted to scan the high-light edge of the cigarette from top to bottom, and when the gray value of the pixel point changes, the coordinate position of the pixel point is marked, and the edge of the cigarette is positioned according to the coordinate point. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a schematic diagram of the light source, the camera and the cigarette test position;

[0031] Figure 2 It is a schematic diagram of the direction of the light emitted by the light source, the direction of the light received by the camera and the test angle of the cigarette;

[0032] Figure 3 It is a collected image of the black cigarette burning;

[0033] Figure 4 It is a black cigarette edge recognition result image;

[0034] Figure 5 Positioning diagram for black cigarette edge scanning;

[0035] Figure 6 Gray scale values for commonly used black, dark brown, light brown and colored cigarette paper;

[0036] Figures 7-16 Detection pictures corresponding to serial numbers 1-10 in Table 1-1 of Example 1;

[0037] Figures 17-26 Detection pictures corresponding to serial numbers 1-10 in Table 1-2 of Example 1;

[0038] Figures 27-36 Detection pictures corresponding to serial numbers 1-10 in Table 2-1 of Example 2;

[0039] Figures 37-46 Detection pictures corresponding to serial numbers 1-10 in Table 2-2 of Example 2;

[0040] Figures 47-56 Detection pictures corresponding to serial numbers 1-10 in Table 3-1 of Example 3;

[0041] Figures 57-66 Detection pictures corresponding to serial numbers 1-10 in Table 3-2 of Example 3. DETAILED DESCRIPTION

[0042] The present application will be described in detail below with reference to specific examples, but the embodiments of the present application are not limited thereto. In the examples, the experimental methods not specified for specific conditions are generally performed according to the conventional conditions and the conditions described in the manuals, or using the general equipment, materials, reagents, etc. recommended by the manufacturers, unless otherwise specified. The raw materials required in the following examples and comparative examples are commercially available.

[0043] Example 1

[0044] In this example, a black cigarette paper sample with a circumference of 22.0 mm was used as an example (cigarette paper gray scale value 79.08, see Figure 6 ), and the method of the present application was used to test the crack rate and ash column gray scale value during the combustion process.

[0045] The test method includes the following steps:

[0046] 1) The sample dark cigarette was pretreated according to GB / T 16447 standard before determination;

[0047] 2) Place the dark sample cigarette in the test position, with the axial direction of the cigarette in the test position perpendicular to the camera and the light source, and the light source being a strip-shaped light source, the angle A between the direction of the light emitted by the strip-shaped light source and the direction of the light received by the camera being greater than 90° and less than 150°;

[0048] 3) Start the software control system, the light system, the camera system, the mechanical hand movement system, take a picture of the sample before ignition, and then ignite the cigarette, after the sample cigarette is ignited, the camera system starts to collect the cigarette combustion image in real time;

[0049] 4) Stop collecting the cigarette combustion image when the cigarette burns to 3 mm from the tipping paper;

[0050] 5) During the test, calculate the real-time cigarette combustion, and collect the cigarette combustion state at the same time according to the camera;

[0051] 6) In the process of real-time combustion detection, the axial edge of the dark cigarette is positioned and recognized, the gray scale values of the adjacent coordinate pixels at the color difference junction are compared, the coordinate information of the carbon line and the gray column region is obtained, and then the cigarette combustion related index situation is analyzed;

[0052] The method for positioning and recognizing the axial edge of the dark cigarette in step (6) is: using the pixel point scanning method, scanning the cigarette highlight edge from top to bottom, marking the coordinate position of the pixel point when the gray scale value of the pixel point changes, and realizing the edge positioning of the cigarette according to the coordinate point.

[0053] Specifically: the system controls the light source to illuminate the camera field of view, and the camera starts to collect images. At this time, when the direction of the light emitted by the strip-shaped light source and the direction of the light received by the camera lens form an angle greater than 90° and less than 150°, the axial edge part of the cigarette concentrates more reflected light, the remaining curved surface part of the cigarette reflects the surface reflected light to the space that cannot be received by the camera field of view, only part of the weak scattered light will enter the camera field of view, but compared with the concentrated reflected highlight light of the edge part, under the condition of controlling the aperture of the lens and adjusting the exposure parameters of the camera, the weak scattered light can be ignored. The specific light incidence is shown in Figure 2 .

[0054] For step 6), the image processing link, first, the cigarette is positioned. After the image is grayed into a gray scale image through the above lightening method, the highlight part of the cigarette edge can produce obvious color difference with the environment background color, as shown in Figure 3 , the software recognition result is marked with a green straight line, as shown in Figure 4 .

[0055] According to the color difference, the cigarette position can be detected. The specific way is as follows: according to the region of interest in the image, the pixel point scanning mode is adopted to scan the cigarette highlight edge from top to bottom, as shown in Figure 5 When the gray value of the scanned pixel point changes, the coordinate position of the pixel point is marked, and the edge of the cigarette is positioned according to the coordinate point. In the later stage, the same image processing algorithm as the conventional cigarette is used to realize the detection and quantitative processing of various evaluation quality indexes of the cigarette.

[0056] The detection of the crack rate and the gray value index data of the black cigarette sample is as follows:

[0057] Table 1-1 is the crack rate index data table of the black cigarette sample. As can be seen from the table, the greater the crack rate detection value, the greater the crack rate of the cigarette occupies the area of the ash column, and the detection value is consistent with the actual observation value.

[0058] Table 1-1 is the crack rate index data table of the black cigarette sample. As can be seen from the table, the greater the crack rate detection value, the greater the crack rate of the cigarette occupies the area of the ash column, and the detection value is consistent with the actual observation value.

[0059]

[0060] Table 1-2 is the gray value data table of the black cigarette sample. The greater the gray value, the whiter the cigarette ash color. However, due to the influence of the burning cone spark during the detection process, the spark burns brightly when the cigarette is smoked, and the overall ash color of the cigarette is improved. Therefore, in order to characterize the cigarette ash color more accurately, it is suggested that the burning cone spark part should be removed when collecting and analyzing the pictures. As can be seen from the table, the gray value detection value of the black cigarette paper is consistent with the actual observation value.

[0061] Table 1-2 is the gray value data table of the black cigarette sample. The greater the gray value, the whiter the cigarette ash color. However, due to the influence of the burning cone spark during the detection process, the spark burns brightly when the cigarette is smoked, and the overall ash color of the cigarette is improved. Therefore, in order to characterize the cigarette ash color more accurately, it is suggested that the burning cone spark part should be removed when collecting and analyzing the pictures. As can be seen from the table, the gray value detection value of the black cigarette paper is consistent with the actual observation value.

[0062]

[0063] Example 2

[0064] In this embodiment, the brown cigarette paper cigarette sample with a cigarette circumference of 22.0 mm (the gray value of the cigarette paper is 150.84, see Figure 6 ) is taken as an example to test the crack rate and ash column gray value of the cigarette during the burning process. The test method is consistent with that of Example 1.

[0065] The crack rate and gray value index data of the brown cigarette sample (cigarette circumference 22.0 mm) are as follows:

[0066] Table 2-1 is the crack rate index data table of the brown cigarette sample. As can be seen from the table, the greater the crack rate detection value, the greater the crack rate of the cigarette occupies the area of the ash column, and the detection value is consistent with the actual observation value.

[0067] Table 2-1 Brown cigarette paper cigarette sample (cigarette circumference 22.0 mm) data table - crack rate index

[0068]

[0069] Table 2-2 is a data table for detecting the gray value of brown cigarette samples. The larger the gray value, the whiter the cigarette ash. As can be seen from the table, the detected value of the gray value of brown cigarette paper is consistent with the actual observation value.

[0070] Table 2-2 Brown cigarette paper cigarette sample (cigarette circumference 22.0 mm) data table - gray value index

[0071]

[0072] Example 3

[0073] This example takes brown cigarette paper cigarette samples (cigarette paper gray value 110.01, see Figure 6 ) with a cigarette circumference of 24.5 mm as an example to test the crack rate and ash column gray value during the combustion process. The test method is consistent with Example 1.

[0074] The crack rate and gray value index data of the brown cigarette sample (cigarette circumference 24.5 mm) are as follows:

[0075] Table 3-1 is a data table for detecting the crack rate index of different circumferences and brown cigarette samples. The larger the crack rate detection value, the larger the crack rate of the cigarette occupies the ash column area. The detection value is consistent with the actual observation value.

[0076] Table 3-1 Brown cigarette paper cigarette sample (cigarette circumference 24.5 mm) data table - crack rate index

[0077]

[0078]

[0079] Table 3-1 is a data table for detecting the crack rate index of different circumferences and brown cigarette samples. The larger the gray value, the whiter the cigarette ash. As can be seen from the table, the detected value of the gray value of brown cigarette paper is consistent with the actual observation value.

[0080] Table 3-2 Brown cigarette paper cigarette sample (cigarette circumference 24.5 mm) data table - gray value index

[0081]

Claims

1. A method for testing the combustion performance of dark cigarettes using dark cigarette paper, characterized in that, The dark cigarette paper refers to cigarette paper with a gray value of less than 255; the process and environment of cigarette smoking are simulated based on a robotic arm, and images of the char line and ash column areas of cigarette combustion are collected using a full vision camera system. Then, based on the coordinate information of the char line and ash column areas, the relevant indicators of cigarette combustion are analyzed. The specific method includes the following steps: 1) Before testing, dark-colored cigarette samples should be pretreated according to GB / T 16447 standard; 2) Place the dark-colored cigarette sample at the test position. The axial direction of the cigarette at the test position is perpendicular to the camera and the light source. The light source is a strip light source. The angle A between the direction of the light emitted by the strip light source and the direction of the light received by the camera is greater than 90° and less than 150°. 3) Start the software control system, lighting system, camera system, and robotic arm motion system. After taking pictures of the sample before combustion, ignite the cigarette. After the sample cigarette is ignited, the camera system begins to collect real-time images of the cigarette burning. 4) Stop acquiring images of the burning cigarette when it reaches 3mm from the tipping paper; 5) During the test, real-time cigarette combustion calculations were performed, and the combustion status of multiple cigarettes was collected simultaneously by the camera based on their combustion time. 6) During real-time combustion detection, the axial edge of dark cigarettes is located and identified, the gray values ​​of adjacent coordinate pixels at the intersection of color differences are compared, and the coordinate information of char lines and gray columns is obtained statistically, thereby analyzing the relevant indicators of cigarette combustion. The method for axial edge localization and recognition of dark cigarettes in step (6) is as follows: using pixel scanning, the bright edges of the cigarette are scanned from top to bottom. When the gray value of the scanned pixel changes, the coordinate position of the pixel is marked, and the edge localization of the cigarette is achieved based on the coordinate point.

2. The method of claim 1, wherein, In step 1), in order to examine the cigarette combustion detection of different samples under specific conditions, pretreatment can be carried out according to the set equilibrium conditions, or the samples can be directly measured to analyze the differences in the influence of different environmental conditions on cigarette combustion detection.

3. The method of claim 1, wherein, In step 3), the camera system includes multiple cameras, which are evenly distributed in the direction perpendicular to the cigarette to ensure that the curved surface of the cigarette ash column can be fully captured.

4. The method according to claim 3, characterized in that, In step 3), the lighting system includes multiple lighting sources, each lighting source corresponds to a camera, and the lighting source is a strip light source. Each group of lighting sources and cameras satisfies the following: the angle A between the direction of light emitted by the strip light source and the direction of light received by the camera is greater than 90° and less than 150°.

5. The method according to claim 1, characterized in that, In step 3), after the sample cigarette is lit, the cigarette should remain in a vertical position without shifting.

6. The method of claim 1, wherein, In step 4), the system automatically acquires an image every 2 seconds during the test; the acquisition time interval can be customized according to the test requirements, accurate to 0.1 seconds.

7. The method of claim 1, wherein, In step 4), if the sample cigarette fails to burn to 3mm from the tipping paper during the test, which is below the image acquisition requirement, a sample should be taken from a parallel sample for retesting.

8. The method of claim 1, wherein, Step 4) Capture image data within different burning length ranges, or capture image data within different burning time ranges.

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