Cigarette clamp design method for CT scanning and cigarette clamp

Abstract

The invention discloses a cigarette clamp design method for CT scanning and a cigarette clamp, and the cigarette clamp design method comprises the following steps: S1, obtaining a scanning working surface of scanning equipment, and determining the radius of a clamp disc according to the scanning precision; s2, determining the circumference specification and the radius of the cigarette according to the cigarette sample; s3, the cigarettes in the ring A1 on the clamp disc are arranged with the center of the clamp disc as the circle center, the center of the cigarettes in the ring A1 falls on a circle with the radius being R1, and the initial value of the included angle needed by the arrangement space for arranging the single cigarettes is estimated; s4, the minimum distance between the cigarettes in the circle A1 is calculated, if the minimum distance is larger than 1 mm, arrangement of the cigarettes in the circle A1 is completed, and otherwise, the value of Y or / and the value of R0 are / is increased; applying a design method to obtain a cigarette clamp; and how to match the scanning precision, configure a cigarette gap and arrange the diameter of a cigarette ring are given.

Description

Technical Field

[0001] The invention belongs to the field of cigarette CT scanning in tobacco production, and in particular relates to a cigarette holder design method for CT scanning and the cigarette holder. Background Art

[0002] Computed Tomography (CT) is a non-destructive imaging technology that can generate detailed cross-sectional images of scanned objects by using X-rays and computer processing technology. It has been widely used in medical diagnosis, industrial non-destructive detection, precision machining and other fields.

[0003] Quality control and safety testing are crucial in the cigarette production process. Traditional testing methods may have limitations and cannot fully and accurately evaluate the quality and safety of cigarette products. In order to improve the quality management level of cigarette production, it is imperative to introduce advanced industrial non-destructive testing technology. Its main advantages include quality control and safety testing. Among them, quality control uses CT scanning technology to conduct comprehensive and three-dimensional testing of cigarette products without destroying the products, and realizes accurate evaluation of parameters such as the internal structure and density of cigarettes, which helps to find defects and problems in the production process; safety testing includes CT scanning, which can detect foreign matter, defects or unevenness that may exist in cigarette products, ensure that the quality and safety of the products meet the standard requirements, and effectively prevent product quality problems and safety hazards.

[0004] At the same time, due to the high accuracy of CT scanning, the requirements for the environment and samples are high. The sample will be fixed on a circular tray during the scanning process, and no displacement or vibration can occur during the scanning cycle. This is bound to have high requirements for the scanning fixture suitable for cigarettes of different circumferences. In order to balance the scanning efficiency and scanning rate, different samples have different suitable ranges of CT scanning accuracy. For cigarettes, the accuracy of CT scanning is generally 10um to 20um. Correspondingly, the scanning accuracy of 10um corresponds to a disc diameter of about 23mm; the scanning accuracy of 15um corresponds to a disc diameter of about 35mm; the scanning accuracy of 20um corresponds to a disc diameter of about 47mm. Finally, in order to facilitate image processing and data reorganization after scanning, the cigarettes need to be separated.

[0005] Publication number CN116008345A discloses a test fixture, including the following components: a hollow circular tube, which is fixedly placed on a test fixture bracket; a gap perpendicular to the axis of the hollow circular tube is provided on the middle wall of the hollow circular tube; a cylindrical slider is provided on each side of the gap, and the outer diameter of the cylindrical slider is slightly smaller than the inner diameter of the hollow circular tube; each cylindrical slider is connected to a slider moving screw extending out of the outside of the hollow circular tube.

[0006] In summary, applying CT scanning technology to non-destructive testing in cigarette production can improve the quality control level, ensure product safety, and bring more advantages and development opportunities to cigarette production. However, there are no effective technical measures to improve the utilization rate of CT equipment and to match appropriate cigarette fixtures for CT scanning of cigarettes. Summary of the Invention

[0007] In view of this, in the face of the deficiencies of the prior art, the purpose of this application is to provide a design method for a cigarette holder for CT scanning and a cigarette holder, which can stably fix cigarettes with different circumferences and dynamically adjust the number of cigarettes scanned each time according to the scanning accuracy requirements, and use the fixture to fix the cigarettes without damage and adjust the scanning accuracy according to the design requirements.

[0008] To achieve the above and other related purposes, this application provides a design method for a cigarette holder for CT scanning, including the following steps:

[0009] S1. Obtain the scanning working surface of the scanning device, and determine the radius R0 of the fixture disc based on the scanning accuracy.

[0010] S2. According to the cigarette samples, determine the cigarette circumference specification and the cigarette radius r0, where 2.0mm < r0 < 5.0mm, and the projection area of the cigarette on the fixture disc falls within a circle with a radius of r0.

[0011] S3. Arrange the cigarettes in the first circle A1 on the fixture disc. The cigarettes are arranged with the center of the fixture disc as the center of the circle, and the centers of the cigarettes in the first circle A1 fall on a circle with a radius of R1. Estimate the initial value of the included angle θ required for arranging the space of a single cigarette:

[0012]

[0013] R1 = R0 - r0

[0014] 2 ≤ Y ≤ 4

[0015] Or conservatively 2 ≤ Y ≤ 3;

[0016] The total number n of cigarettes arranged in the outer circle A1 is:

[0017]

[0018] That is, the calculated value Round down to obtain the number n of cigarettes arranged in the first circle A1, and adjust the value of Y so that 6 ≤ n;

[0019] S4. With the center of the fixture disc as the origin, in polar coordinates, obtain the polar angle θA1 of the center of the i-th cigarette in the first circle A1 i :

[0020]

[0021] Therefore, the polar coordinates of the center of the i-th cigarette on the clamp disk circle A1 are: (R1, θA1 i ), 1≦i≦

[0022] n, R1=R0-r0;

[0023] S4, calculate the minimum distance d between cigarettes in circle A1 min , the minimum distance between cigarettes d min Separate the scanned cigarette images into individual cigarettes;

[0024] Among them, when 1≦i≦n-1, the minimum distance d between the i-th cigarette and the i+1-th cigarette is i , calculated as follows:

[0025] Calculate the angle:

[0026]

[0027] Calculate using the sine function:

[0028]

[0029] After simplification, we get:

[0030]

[0031] The minimum distance d between the nth cigarette and the first cigarette n , calculated as follows:

[0032] Calculate the angle:

[0033]

[0034] Calculate using the sine function:

[0035]

[0036] After simplification, we get:

[0037]

[0038] Then we get:

[0039]

[0040] Substituting into the half-angle sine formula:

[0041] cos(2x)=1-2sin 2 x

[0042]

[0043] It can also be transformed into:

[0044]

[0045] If 1mm ≤ d min , complete the cigarette arrangement of circle A1;

[0046] Otherwise, d min < 1mm, increase the value of Y or / and increase the value of R0.

[0047] A technical solution for the design of a cigarette clamp for CT scanning provided by this application also has the following technical features:

[0048] Preferably, in an embodiment of this application, S5, for the cigarette arrangement of the inner circle A2 smaller than circle A1 on the clamp disc, in polar coordinates, for i taking odd sequences from 1 to n, the polar angle of the center of the jth cigarette in the inner circle A2 is correspondingly obtained, and the relationship between j and i is:

[0049]

[0050] According to d calculated by S4 min , the center of the cigarette arrangement of the inner circle A2 falls on a circle with a radius of R2;

[0051] The minimum distance between the jth cigarette in the inner circle A2 and the ith and (i + 1)th cigarettes in the adjacent circle A1 is equal to d A2min , under the condition of R2 < R1, the maximum value of R2 satisfies the following relationship:

[0052] d A2min = d min

[0053] Therefore, the centers of the jth cigarette in the inner circle A2, the ith cigarette in the adjacent circle A1, and the (i + 1)th cigarette form the three endpoints of an equilateral triangle:

[0054]

[0055] After simplification, it is obtained:

[0056]

[0057] Or using the Pythagorean theorem, it is equivalently satisfied:

[0058]

[0059] Substitute:

[0060]

[0061] It is obtained:

[0062]

[0063] Simplified to:

[0064]

[0065] Obtained:

[0066]

[0067] When 4 ≤ n, since 0 ≤ R2 < R1, the polar radius R2 of the inner circle A2 is:

[0068]

[0069] Therefore, if R2 satisfies the following relationship, the minimum distance between the cigarette rods in circle A2 and those in circle A1 is greater than or equal to d min :

[0070]

[0071] The polar coordinates of the center of the j-th cigarette rod in circle A2 are:

[0072]

[0073] When, the minimum distance d between the adjacent j-th and (j + 1)-th cigarette rods in circle A2 j , is greater than or equal to d min ;

[0074]

[0075] Calculate the included angle:

[0076]

[0077] Satisfy the condition:

[0078]

[0079] After simplification:

[0080]

[0081] After further simplification, obtained:

[0082]

[0083] Substitute into the double-angle sine formula:

[0084] sin(2x) = 2sinxcosx

[0085] Simplified to:

[0086]

[0087] The minimum distance d between the th cigarette adjacent to the first cigarette and the first cigarette A2 , according to the th cigarette, the angle formed by the first cigarette and the origin of the polar coordinates is greater than or equal to the angle between any other two adjacent cigarettes, and when the angle is less than a flat angle, the minimum distance d A2 ≧d j ;

[0088] Therefore, when 0 < R1, R2 satisfies the following relationship:

[0089]

[0090] And, when 0 < R2 < R1 and 6 ≦ n, take the maximum value of R2 to complete the cigarette arrangement of the cigarettes in circle A2;

[0091] According to the polar coordinates of the center of the jth cigarette in circle A2:

[0092]

[0093] Thus, the cigarette arrangement of the cigarettes in circle A2 is completed.

[0094] Preferably, in an embodiment of the present application, for the cigarette arrangement of circle A3 larger than circle A1 on the jig disc, corresponding to the relationship between the radius R3 of circle A3 larger than circle A1 and R1 of circle A1, one end point of the equilateral triangle constructed is outside circle A1, and according to symmetry:

[0095]

[0096] The polar angle sequence of the centers of the cigarettes in circle A3 is:

[0097]

[0098] 1 ≦ i ≦ n

[0099] 1 ≦ k ≦ n

[0100] The polar coordinates of the centers of the cigarettes in circle A3 are:

[0101] (R3, θA3 k ), 1 ≦ k ≦ n;

[0102] Since R1 < R3, therefore, the minimum distance between adjacent cigarettes in circle A3 is greater than d min .

[0103] Preferably, in an embodiment of the present application, the scanning accuracy of the inner circle is the same as that of the outermost circle, or the scanning accuracy of the inner circle is greater than that of the outermost circle.

[0104] Preferably, in one embodiment of the present application, in S1, the scanning accuracy is 10um~20um, 20mm≦R0≦50mm.

[0105] Preferably, in one embodiment of the present application, in S1, 11.5 mm <R0<23.5mm。

[0106] Preferably, in one embodiment of the present application, in S1, 15.75 mm≦R0≦19.25 mm.

[0107] Preferably, in an embodiment of the present application, in S1, based on a scanning accuracy of 15 um, the radius R0 of the fixture disk is determined to be 17.5 mm.

[0108] Preferably, in one embodiment of the present application, in S1, 2.7 mm≦r0≦3.9 mm.

[0109] Preferably, in one embodiment of the present application, in S1, Y=2.5.

[0110] Preferably, in one embodiment of the present application, in S1, a 15um scanning accuracy and a 10um scanning combination are designed, and the combined initial polar angle θ is:

[0111]

[0112] a=2r0+d

[0113] b=R0-r0

[0114] c=R0-2r0

[0115] d=1mm.

[0116] Preferably, in one embodiment of the present application, the offset angle θ between the 10um inner circle and the 15um outer circle is d :

[0117]

[0118] A cigarette holder for CT scanning is provided, which uses the above-mentioned design method for a cigarette holder for CT scanning, R0=17.5mm, 6≦n≦22.

[0119] The beneficial effects of this application are:

[0120] It provides how to match the scanning accuracy, configure the cigarette gap, and arrange the diameter of the cigarette ring to prepare for scanning, and to make the scanned result and the minimum spacing between adjacent cigarettes designed, so that the cigarettes in the scanned image can be separated for easy analysis without being interfered by other cigarettes.

[0121] This application applies CT scanning technology to non-destructive testing in cigarette production by carefully designing a fixture for cigarettes of different circumferences, which can improve the level of quality control, ensure product safety, and provide accurate scanning support for quality control of cigarette production. BRIEF DESCRIPTION OF THE DRAWINGS

[0122] Figure 1 It is a schematic diagram of the arrangement of cigarettes with a circumference of 24.5 mm in a cigarette holder for CT scanning of the present invention;

[0123] Figure 2 This is a schematic diagram of the arrangement of cigarettes on a 20 mm circumference of a cigarette holder for CT scanning of the present invention;

[0124] Figure 3 It is a schematic diagram of the arrangement of cigarettes with a 17 mm circumference in a cigarette holder for CT scanning of the present invention;

[0125] Figure 4 A scanning schematic diagram of a cigarette holder for CT scanning of the present invention; DETAILED DESCRIPTION

[0126] The specific implementation methods of the present application are further described in detail below in conjunction with the accompanying drawings. These implementation methods are only used to illustrate the present application, and are not intended to limit the present invention.

[0127] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0128] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0129] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0130] As Figure 1-4 , a design method for a cigarette holder for CT scanning, includes the following steps:

[0131] S1. Obtain the scanning working surface of the scanning device. Based on a scanning accuracy of 15 μm, determine the radius R0 of the fixture disk, where 11.5 mm < R0 < 23.5 mm;

[0132] S2. According to the cigarette sample, determine the cigarette circumference specification and the radius r0 of the cigarette, where 2.0 mm < r0 < 5.0 mm, and the projection area of the cigarette on the fixture disk falls within a circle with a radius of r0;

[0133] S3. Arrange the cigarettes in the first circle A1 on the fixture disk. The arrangement of the cigarettes is centered on the center of the fixture disk, and the centers of the cigarettes in the first circle A1 fall on a circle with a radius of R1. Estimate the initial value of the included angle θ required for arranging the space of a single cigarette:

[0134]

[0135] R1 = R0 - r0

[0136] 2 ≤ Y ≤ 3

[0137] The total number of cigarettes arranged in the outer circle A1 is:

[0138]

[0139] That is, the calculated value Round down to obtain the number n of cigarettes arranged in the first circle A1. By adjusting the value of Y or / and the value of R0, make 7 ≤ n ≤ 75;

[0140] S4. With the center of the fixture disk as the origin, in polar coordinates, obtain the polar angle θA1 of the center of the i-th cigarette in the first circle A1 i :

[0141]

[0142] Thus, the polar coordinates of the center of the i-th cigarette in the first circle A1 on the fixture disk are: (R1, θA1 i ), 1 ≤ i ≤

[0143] n, R1 = R0 - r0;

[0144] Calculate the minimum distance d between the cigarettes in the first circle A1 min , the minimum distance d between the cigarettes min makes the images of the cigarettes separated from each other after scanning;

[0145] Among them, when 1 ≤ i ≤ n - 1, the minimum distance d between the i-th cigarette and the (i + 1)-th cigarette i, calculated as follows:

[0146] The angle between the i-th cigarette and the i+1-th cigarette on the fixture disc:

[0147]

[0148] Using the relationship between the base and height of an isosceles triangle:

[0149]

[0150] in:

[0151] R1 is the waist of the triangle;

[0152] d i +2r0 is the base;

[0153] is the vertex angle of an isosceles triangle;

[0154] The minimum distance d between the nth cigarette and the first cigarette in circle A1 n , calculated as follows:

[0155] The angle between the nth cigarette and the first cigarette in circle A1 on the fixture disc:

[0156]

[0157] Similarly, using the relationship between the base and height of an isosceles triangle:

[0158]

[0159] in:

[0160] R1 is the length of the triangle’s waist;

[0161] d i +2r0 is the base length;

[0162] is the vertex angle of an isosceles triangle;

[0163] From this we get d n d i d min Relationship:

[0164]

[0165] According to the convenience of calculation, substitute the half-angle sine formula:

[0166] cos(2x)=1-2sin 2 x

[0167]

[0168] It can also be transformed into:

[0169]

[0170] If, 1mm ≤ d min , complete the cigarette arrangement of circle A1;

[0171] If, d min < 1mm, increase the value of Y or / and increase the value of R0, so that 1mm ≤ d min , complete the cigarette arrangement of circle A1;

[0172] This is because when 0.5mm < d min < 1mm, due to the too small gap, although CT scanning allows and two cigarettes can be distinguished, it is too fatiguing for the human eye to identify and read the image, and the requirement for the thin wall of the fixture design is too high. Therefore, for the working condition of d min < 1mm, all are discarded.

[0173] A technical solution for the design of a cigarette fixture for CT scanning provided by this application also has the following technical features:

[0174] Specifically, in an embodiment of this application, S5, for the cigarette arrangement of the inner circle A2 smaller than circle A1 on the fixture disc, in polar coordinates, for i taking an odd sequence from 1 to n, the polar angle of the center of the jth cigarette in the inner circle A2 is correspondingly obtained, and the relationship between j and i is:

[0175]

[0176] 2j - 1 = i;

[0177] 1 ≤ i ≤ n;

[0178] According to d calculated by S4 min , the center of the cigarette arrangement of the inner circle A2 falls on a circle with a radius of R2;

[0179] The minimum distance between the jth cigarette in the inner circle A2 and the ith cigarette and the (i + 1)th cigarette in the adjacent circle A1 is equal to d A2min , under the condition of R2 < R1, the maximum value of R2 satisfies the following relationship:

[0180] d A2min = d min

[0181] The significance of taking the maximum value of R2 is: to make the cigarettes in the inner circle A2 as far away from the center of the fixture disc as possible and as close to the cigarettes in circle A1 as possible, so that the cigarettes are tightly arranged, so that more cigarettes can be placed on the fixture disc;

[0182] Therefore, the centers of the j-th cigarette in the inner circle A2, the i-th cigarette and the (i + 1)-th cigarette in the adjacent circle A1 form the three endpoints of an equilateral triangle:

[0183]

[0184] d min + 2r0 is the side length of the equilateral triangle;

[0185] is the height of the equilateral triangle;

[0186] Or using the Pythagorean theorem, it satisfies:

[0187]

[0188] Substitute the condition for R2 to take the maximum value:

[0189]

[0190] Simplify to:

[0191]

[0192] Get

[0193]

[0194] When 4 ≤ n, since 0 ≤ R2 < R1, the polar radius R2 of the inner circle A2 is:

[0195]

[0196] And the other root of the equation can be understood as an arrangement under the condition of R2 > R1, that is, the working condition of arranging cigarettes outside the A1 circle;

[0197] Therefore, when R2 satisfies the following relationship, the minimum distance between the cigarettes in circle A2 and the cigarettes in circle A1 is greater than or equal to d min :

[0198]

[0199] The polar coordinates of the center of the j-th cigarette in circle A2 are:

[0200]

[0201] When, the minimum distance d j between the adjacent j-th cigarette and the (j + 1)-th cigarette is greater than or equal to d min ;

[0202]

[0203] After simplification, it is

[0204]

[0205] Substitute into the double - angle sine formula:

[0206] sin(2x) = 2sinxcosx

[0207] It simplifies to:

[0208]

[0209] The minimum distance d between the th cigarette and the first cigarette A2 , when 6 ≤ n, according to the angle formed by the

[0210] th cigarette, the first cigarette and the origin of the polar coordinates is greater than or equal to the angle between any other two adjacent cigarettes; A2 ≥ d j ;

[0211] The angle between the th cigarette in loop A2 and the first cigarette on the fixture disc:

[0212] When n is even:

[0213]

[0214] When n is odd:

[0215]

[0216] Therefore, when 0 < R1, R2 satisfies the following relationship:

[0217]

[0218] And, 0 < R2 < R1, when 6 ≤ n, take the maximum value of R2 to complete the cigarette arrangement of the cigarettes in loop A2;

[0219] According to the polar coordinates of the center of the j - th cigarette in loop A2 being:

[0220]

[0221] Thus, complete the cigarette arrangement of the cigarettes in loop A2.

[0222] Specifically, in an embodiment of the present application, in S6, for the cigarette arrangement in circle A3 on the fixture disc that is larger than circle A1, corresponding to the relationship between the radius R3 of circle A3 that is larger than circle A1 and the radius R1 of circle A1, outside one end point of the equilateral triangle constructed, according to symmetry:

[0223]

[0224] The polar angle sequence of the cigarette centers in circle A3 is:

[0225]

[0226] 1 ≤ i ≤ n

[0227] 1 ≤ k ≤ n

[0228] The polar coordinates of the centers of the cigarettes in circle A3 are:

[0229] (R3, θA3 k ), 1 ≤ k ≤ n;

[0230] The included angle between adjacent cigarettes in circle A3 is:

[0231]

[0232] Since R1 < R3, therefore, the minimum distance between adjacent cigarettes in circle A3 is greater than d min .

[0233] Specifically, in an embodiment of the present application, the scanning accuracy of the inner circle is the same as that of the outermost circle, or the scanning accuracy of the inner circle is greater than that of the outermost circle; that is, the accuracy of circles A2, A1, and A3 is the same, or the scanning accuracy of circles A2, A1, and A3 decreases from the inside to the outside. The area near the center of the fixture disc is used for high-precision scanning, and the scanning accuracy is reduced in the area far from the center.

[0234] Specifically, in an embodiment of the present application, in S1, according to the boundary conditions of R0 and r0, estimate θ and the value range of n.

[0235] Specifically, in an embodiment of the present application, in S1, the scanning accuracy is 10 um to 20 um, and 20 mm ≤ R0 ≤ 50 mm;

[0236] If 20 mm ≤ R0 ≤ 50 mm and 2.0 mm < r0 < 5.0 mm, according to the boundary conditions of R0 and r0, calculate the maximum and minimum values of the following fraction:

[0237]

[0238] When r0 is as large as possible and R0 is as small as possible, the maximum value is obtained:

[0239]

[0240] Angle corresponding to the maximum value:

[0241]

[0242] Make r0 as small as possible and R0 as large as possible to obtain the minimum value:

[0243]

[0244] Angle corresponding to the minimum value:

[0245]

[0246] Take 2 ≤ Y ≤ 3, from which we get:

[0247] 4.78° ≤ θ ≤ 55.32°

[0248] Generally, considering that the number of cigarettes placed should be greater than 6 to have design significance, and the number of cigarettes placed being 1, 2, 3, 4, 5, 6 is too intuitive and easy to calculate;

[0249] Round n to an integer, obtaining 7 ≤ n ≤ 75. In the corresponding calculations, generally take:

[0250]

[0251] This makes n rounded down.

[0252] Specifically, in an embodiment of the present application, in S1, 11.5mm < R0 < 23.5mm;

[0253] If 11.5mm < R0 < 23.5mm and 2.0mm < r0 < 5.0mm, according to the boundary conditions of R0 and r0, calculate the maximum and minimum values of the following fraction:

[0254]

[0255] Make r0 as large as possible and R0 as small as possible to obtain the maximum value:

[0256]

[0257] Angle corresponding to the maximum value

[0258]

[0259] Make r0 as small as possible and R0 as large as possible to obtain the minimum value:

[0260]

[0261] The angle corresponding to the minimum value is:

[0262]

[0263] Taking 2≦Y≦3, we get:

[0264] 10.62°≦θ≦112.71°

[0265] Generally, the number of cigarettes placed should be greater than 6 to make design sense, while the number of cigarettes placed is 1, 2, 3, 4, 5, which is too intuitive and easy to calculate;

[0266] Therefore, in the calculation, 10.62°≦θ≦60° is generally taken.

[0267] Rounding n, we get 6≦n≦33. In the corresponding calculation, we usually take:

[0268]

[0269] Specifically, in one embodiment of the present application, in S1, 15.75 mm≦R0≦19.25 mm.

[0270] Specifically, in one embodiment of the present application, in S1 , based on a scanning accuracy of 15 um, the radius R0 of the fixture disk is determined to be 17.5 mm.

[0271] Specifically, in one embodiment of the present application, in S1, 2.7 mm≦r0≦3.9 mm.

[0272] Specifically, in one embodiment of the present application, in S1, Y=2.5.

[0273] Specifically, in one embodiment of the present application, in S1, a 15um scanning accuracy and a 10um scanning combination are designed, and the combined initial polar angle θ is:

[0274]

[0275] a=2r0+d

[0276] b=R0-r0

[0277] c=R0-2r0

[0278] d=1mm.

[0279] Specifically, in one embodiment of the present application, the offset angle θ between the 10um inner circle and the 15um outer circle is d :

[0280]

[0281] Specifically, in one embodiment of the present application, a cigarette holder for CT scanning uses the above-mentioned cigarette holder design method for CT scanning, R0=17.5mm, 6≦n≦33.

[0282] like Figure 1-4 , a design method of a cigarette holder for CT scanning is as follows:

[0283] The first step is to determine the basic parameters of the fixture;

[0284] According to different scanning accuracies, the size specifications of the fixture need to be determined. For example, if the minimum scanning accuracy requirement is 20um, the radius R0 of the fixture disc is approximately 23.5mm. If the scanning accuracy is 15um, the radius of the fixture disc is 17.5mm. The same applies to other accuracies.

[0285] The second step is to determine the specifications of cigarette samples;

[0286] The common circumference specifications of cigarettes on the market are 24.5mm, 20mm and 17mm, which are converted into radii r0 of 3.90mm, 3.18mm and 2.70mm respectively.

[0287] The third step is to determine the minimum spacing between cigarettes;

[0288] The minimum spacing between cigarettes can ensure that the cigarettes are separated after scanning. Under this premise, the smaller the spacing, the more cigarettes can be scanned at the same time. The initial value is taken according to the coefficient Y, and the actual spacing is divided equally according to the principle of equal distance. The minimum spacing should not be less than 1mm.

[0289] If the size is less than 1mm, it will be difficult to read the scanned image, and the efficiency of distinguishing cigarettes will be low, making it difficult to scan, read and identify.

[0290] In addition, the requirements for fixture design and scanning equipment have been increased invisibly, so all working conditions less than 1mm are abandoned.

[0291] Step 4: Cigarette Arrangement Algorithm

[0292] First, arrange the cigarette circle A1 with a scanning accuracy of 15um. In the polar coordinate system, the initial polar angle of each cigarette is:

[0293]

[0294] 2.5 is a compromise coefficient, that is, considering the gap between cigarettes, if there is zero gap, then adjacent cigarettes are tangent; the total number of cigarettes arranged in the outer circle is approximately:

[0295]

[0296] Here, the calculation result of n is rounded down for simplicity;

[0297] The polar coordinates of the center of the i-th cigarette in the cigarette arrangement of circle A1 are determined as:

[0298] (R1, θA1 i )

[0299]

[0300] 1 ≤ i ≤ n

[0301] R1 = R0 - r0

[0302] The minimum distance d between cigarettes min is:

[0303]

[0304] Subsequently, arrange the cigarette circle with a scanning accuracy of about 10 μm in the inner circle A2. To ensure uniform arrangement of cigarettes;

[0305] The polar coordinates of the center of the j-th cigarette in circle A2 are:

[0306] (R2, θA2 j ) 2j - 1 = i, 1 ≤ i ≤ n;

[0307]

[0308] When 0 < R1, R2 satisfies the following relationship:

[0309]

[0310] And, 0 < R2 < R1, when 6 ≤ n, take the maximum value of R2 to complete the cigarette arrangement of circle A2.

[0311] Finally, place the cigarettes with a scanning accuracy of 20 μm in circle A3 that is larger than circle A1;

[0312] The radius R3 of circle A3 is as follows:

[0313]

[0314] The polar angle sequence of the centers of the cigarettes in circle A3 is:

[0315]

[0316] 1 ≤ k ≤ n

[0317] The polar coordinates of the centers of the cigarettes in circle A3 are: (R3, θA3 k )

[0318] If the area closer to the fixture disc is smaller than circle A2, only one cigarette can be placed, and the polar coordinates of the center of the circle are:

[0319] (0, 0)

[0320] If the area smaller than circle A2 close to the fixture disc can hold multiple cigarettes, a rectangular array or a circular array can be used for uniform arrangement. The center of the arranged cigarettes only needs to fall on circle A4 less than or equal to radius R4, or on A4:

[0321] 2r0+d min ≦R2-R4

[0322] Simplified to:

[0323] 0≦R4≦R2-(2r0+d min )

[0324] Substitute R2 and d min :

[0325]

[0326] Simplified to:

[0327]

[0328] n<12, R4 does not exist and cigarettes cannot be placed;

[0329] n=12,R4=0,only one can be placed;

[0330] 12 <n, The rectangular array or the circular array can be evenly arranged, and the center of the arranged cigarettes only needs to fall on a circle less than or equal to the radius R4, or within the circle of radius R4.

[0331] The cigarettes placed on the circle of radius R4 have the following relationship: the angle α between adjacent cigarettes is:

[0332]

[0333] Substituting in to simplify:

[0334]

[0335] Simplifying again:

[0336]

[0337] Taking n = 30 as an example, α ≈ 160°, and 2 can be placed;

[0338] Taking n = 25 as an example, α ≈ 161°, and 2 can be placed;

[0339] Specifically, in one embodiment of the present application, Figure 1-3 , cigarettes with circumference specifications of 24.5mm, 20mm and 17mm can be inserted into the corresponding circles according to the accuracy requirements;

[0340] In the figure, the disc is the disc fixture. According to the scanning accuracy of 20um, a total of 32 cigarettes can be inserted into the 20mm circumference cigarette.

[0341] In general, this application points out the maximum number of cigarettes that can be placed based on existing size specifications, such as scanning specifications, and cigarette specifications, calculates and solves the placement relationship of the inner and outer circles, and gives the optimal path, that is, the number of cigarettes in the outermost circle and the second inner circle is generally equal, and the number that can be placed is less than or equal to 33, and the number of cigarettes in the inner circle of the second inner circle will also decrease, and the number of cigarettes placed is less than or equal to half of the number that can be placed in the second inner circle, which is less than or equal to 16.

[0342] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for designing a cigarette holder for CT scanning, characterized in that: It includes the following steps: S1. Obtain the scanning working surface of the scanning device, and determine the radius R0 of the fixture disc based on the scanning accuracy; S2. Determine the cigarette circumference specification and the cigarette radius r0 according to the cigarette sample, where 2.0mm < r0 < 5.0mm, and the projection area of the cigarette on the fixture disc falls within a circle with a radius of r0; S3. Arrange the cigarettes in circle A1 on the fixture disc. The arrangement of the cigarettes is centered on the center of the fixture disc, and the centers of the cigarettes in circle A1 fall on a circle with a radius of R1. Estimate the initial value of the included angle θ required for the arrangement space of a single cigarette: R1 = R0 - r0 2≦Y≦3 The total number of cigarettes arranged in the outer circle A1 is n: Obtain the number n of cigarettes arranged in circle A1; S4. With the center of the fixture disc as the origin, in polar coordinates, the polar angle of the center of the i-th cigarette in circle A1: The polar coordinates of the center of the i-th cigarette in circle A1 are: (R1, θA1 i ), 1≦i≦n, R1=R0-r0; Calculate the minimum distance d between cigarettes in circle A1 min , the minimum distance between cigarettes d min Separate the scanned cigarette images into individual cigarettes; Among them, when 1≦i≦n-1, the minimum distance d between the i-th cigarette and the i+1-th cigarette in circle A1 is i : The minimum distance d between the nth cigarette and the first cigarette in circle A1 n , calculated as follows: Get n d i d min Relationship: If 1mm≦d min , complete the arrangement of cigarettes in circle A1; Otherwise, increase the value of Y or / and increase the value of R0 to make 1mm≦d min , complete the arrangement of cigarettes in circle A1.

2. The method for designing a cigarette holder for CT scanning according to claim 1, characterized in that: S5, the cigarette arrangement of the inner circle A2 smaller than the circle A1 on the fixture disc; the center of the cigarette arrangement of the inner circle A2 falls on a circle with a radius of R2; the minimum distance between the j-th cigarette of the inner circle A2 and the i-th and (i + 1)-th cigarettes of the adjacent circle A1 is equal to d A2min , under the condition of R2 < R1, the maximum value of R2 satisfies the following relationship: d A2min =d min According to the Pythagorean theorem: Substitute d A2min ,get: In polar coordinates, the polar coordinates of the center of the j-th cigarette in circle A2 are: R2 satisfies the following relationship, then the minimum distance between the cigarettes in circle A2 and the cigarettes in circle A1 is greater than or equal to d min : When the minimum distance d between the jth and j+1th adjacent cigarettes in circle A2 is j , greater than or equal to d min ; Substitute d min , which is simplified to: The adjacent The minimum distance d between the first cigarette and the second cigarette A2 , when 6≦n, the minimum spacing d A2 ≧d j ; Therefore, when 0 < R1, R2 satisfies the following relationship: And, when 0 < R2 < R1 and 6 ≤ n, take the maximum value of R2 to complete the arrangement of the cigarettes in circle A2.

3. The method for designing a cigarette holder for CT scanning according to claim 2, characterized in that: S6. Arrange the cigarettes in circle A3 on the fixture disc that is larger than circle A1. The radius R3 of circle A3 is as follows: The sequence of the polar angles of the centers of the cigarettes in circle A3 is: 1 ≤ k ≤ n The polar coordinates of the center of circle A3 are: (R3, θA3 k ), 1≦k≦n.

4. A method for designing a cigarette holder for CT scanning according to claim 3, characterized in that: The accuracy of circle A2, circle A1, and circle A3 is the same, or the scanning accuracy of circle A2, circle A1, and circle A3 decreases from the inside to the outside.

5. The method for designing a cigarette holder for CT scanning according to claim 1, characterized in that: In S1, 20mm ≤ R0 ≤ 50mm.

6. The method for designing a cigarette holder for CT scanning according to claim 1, characterized in that: In S1, 2.7mm ≤ r0 ≤ 3.9mm.

7. The method for designing a cigarette holder for CT scanning according to claim 1, characterized in that: In S1, Y = 2.

5.

8. The method for designing a cigarette holder for CT scanning according to claim 1, characterized in that: In S1, a combined design of a 15um scanning accuracy and a 10um scan, and the combined initial polar angle θ is: a = 2r0 + d b = R0 - r0 c = R0 - 2r0 d = 1mm.

9. The method for designing a cigarette holder for CT scanning according to claim 8, characterized in that: In S1, the offset angle θ between the 10um inner ring and the 15um outer ring d :

10. A cigarette holder for CT scanning, using the cigarette holder design method for CT scanning according to any one of claims 1 to 9, characterized in that: 6≦n≦33。

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