A method for detecting and removing defects of blank packaging bags

Abstract

The present invention relates to the technical field of quality inspection of packaging bags, and provides a method for detecting and removing defects of blank packaging bags, which includes the following steps: obtaining the captured image of a visual image acquisition device, and determining whether there are defects in the objects in the captured image. Among them, in the running direction of the bag making machine, the length of the defect recognition area is L1, the length of the blank packaging bag is L2, and nL1≤L2, where n≥3; in the case that there are defects in the objects, obtaining the running position of the defective object recorded by the first encoder; when the defective object runs to the removal device, the control module sends a removal signal to the removal device; the removal device removes the blank packaging bag where the defect recognition area is located, the blank packaging bag where the first adjacent area is located, and the blank packaging bag where the second adjacent area is located, where the first adjacent area and the second adjacent area are two adjacent defect recognition areas of the defect recognition area in the running direction of the bag making machine.

Description

Technical Field

[0001] The invention belongs to the technical field of packaging bag quality inspection, and in particular relates to a blank packaging bag defect inspection and rejection method. Background Art

[0002] At present, when making blank packaging bags, the installation positions of defect detection equipment are usually divided into two types. One is to set the detection equipment behind the floating roller of the bag making machine and perform detection when the bag is intermittently feeding. For linear array cameras, the image will shake and deform when the camera captures the picture, but blank packaging bags have no printed patterns and no shaking can be seen. The detection equipment cannot determine the relative position of the defect and the edge of the packaging bag, and can only remove the front and back two packaging bags. Moreover, when the packaging bag passes the floating roller, the general process has been completed, such as folding, slitting, inserting the bottom and connecting the bottom. At this time, the detection equipment cannot detect the inner defects after folding. If it is not a transparent product, it cannot even detect the defects on the back of the packaging bag.

[0003] Another method is to set the detection equipment at the unwinding end of the bag making machine. Blank packaging bags (transparent packaging bags, solid color packaging bags) do not need to be calibrated during the bag making process. You only need to set the feeding length of the packaging bags to produce products. However, the detection software templates on the market today need to set the detection range, that is, the boundary range of the packaging bags. Blank packaging bags do not have any printed patterns. The detection range of the detection software and the boundary of the finished product made by the actual bag making machine cannot be the same boundary. Even if there is a very small possibility that they are the same boundary, there is no electric eye tracking during the bag making process of the blank packaging bag of the bag making machine, and there will be deviations. There will still be deviations, and the boundary cannot be unified, resulting in the need to remove the front and back two rows of products to ensure that the defects are removed. In addition, the setting of the floating roller makes the length of the coil in the floating roller area affect the determination of the product tracking distance, which will cause inaccurate removal of the front and back. The front and back three rows of products need to be removed to ensure that the defective packaging bags are removed. In this way, the scrap rate of the product will increase exponentially, and most of the rejected packaging bags are good products. If the good products are selected from them, it will take a lot of manpower and time. If they are directly discarded, it will be a great waste of resources.

[0004] In order to solve the above technical problems, the present invention designs a method for detecting and removing defects of blank packaging bags. Summary of the invention

[0005] The present invention provides a method for detecting and rejecting defects of blank packaging bags, aiming to solve the problems that defects of blank packaging bags are difficult to detect and the scrap rate is high when the bags are rejected after defect detection.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a method for detecting and rejecting defects in blank packaging bags, comprising the following steps: obtaining a capture screen of a visual image capture device, and judging whether an object in the capture screen has defects, wherein in the running direction of the bag making machine, the length of the defect recognition area is L1, and the length of the blank packaging bag is L2, nL1≤L2, wherein n≥3; in the case that the object has defects, obtaining the running position of the defective object recorded by the first encoder; when the defective object runs to a rejection device, the control module sends a rejection signal to the rejection device; the rejection device rejects the blank packaging bag where the defect recognition area is located, the blank packaging bag where the first adjacent area is located, and the blank packaging bag where the second adjacent area is located, wherein the first adjacent area and the second adjacent area are two adjacent defect recognition areas of the defect recognition area in the running direction of the bag making machine.

[0007] On the basis of the above technical solution, the rejection signal includes a first rejection signal, a second rejection signal and a third rejection signal. When the defective object runs to the rejection device, the control module sends the rejection signal to the rejection device and further includes: judging whether the blank packaging bags in the corresponding areas of the first rejection signal, the second rejection signal and the third rejection signal in the rejection signal are in the same blank packaging bag; when the blank packaging bags in the corresponding areas of the first rejection signal, the second rejection signal and the third rejection signal are the same blank packaging bag, the rejection device rejects the blank packaging bag; when the blank packaging bags in the corresponding areas of the first rejection signal, the second rejection signal and the third rejection signal are two adjacent blank packaging bags, the rejection device rejects the two adjacent blank packaging bags.

[0008] On the basis of the above technical solution, the rejection device includes a hot knife mechanism, a rejection mechanism and a proximity switch. When the blank packaging bags in the areas corresponding to the first rejection signal, the second rejection signal and the third rejection signal are the same blank packaging bag, the rejection device rejects the blank packaging bag including: obtaining the first action moment and the second action moment of the hot knife mechanism detected by the proximity switch; when the first rejection signal, the second rejection signal and the third rejection signal are simultaneously received between the first action moment and the second action moment, the rejection mechanism rejects the blank packaging bag passing between the first action moment and the second action moment.

[0009] On the basis of the above technical solution, when the blank packaging bags in the areas corresponding to the first rejection signal, the second rejection signal and the third rejection signal are two adjacent blank packaging bags, the rejection device rejects the two adjacent blank packaging bags including: obtaining the third action moment and the fourth action moment of the proximity switch detecting the hot knife mechanism; when the first rejection signal is received between the third action moment and the fourth action moment or the first rejection signal and the second rejection signal are received at the same time, obtaining the fifth action moment of the proximity switch detecting the hot knife mechanism; when the second rejection signal and the third rejection signal are received between the fourth action moment and the fifth action moment or only the third rejection signal is received, the rejection mechanism rejects the blank packaging bags passing between the third action moment and the fourth action moment and the blank packaging bags passing between the fourth action moment and the fifth action moment.

[0010] Based on the above technical solution, the bag making machine includes a floating roller assembly and a second encoder. The floating roller assembly includes a loading roller, a unloading roller, a floating roller and a rotating member. The rotating member is connected to the floating roller to drive the floating roller to swing. The second encoder is arranged on the rotating member.

[0011] On the basis of the above technical solution, when there is a defect in the object, obtaining the running position of the defective object recorded by the first encoder includes: when there is a defect in the object, obtaining the current running distance Pc of the defective object recorded by the first encoder, the corresponding distance Pp when the object passes through the visual image acquisition device, and the distance De from the visual image acquisition device to the rejection module; when Pc=Pp+De, the control module sends a rejection signal to the rejection device.

[0012] On the basis of the above technical solution, when Pc=Pp+De, the control module sends a rejection signal to the rejection device, including: obtaining the floating roller swing angle data measured by the second encoder, and calculating the coil length Df in the floating roller area; when Pc=Pp+De+Df, the control module sends a rejection signal to the rejection module.

[0013] On the basis of the above technical solution, in the case of Pc=Pp+De+Df, the control module sends a reject signal to the reject module, including: in the case of Pc=Pp+De+Df-L1, the control module sends a first reject signal to the reject module; in the case of Pc=Pp+De+Df, the control module sends a second reject signal to the reject module; in the case of Pc=Pp+De+Df+L1, the control module sends a third reject signal to the reject module.

[0014] On the basis of the above technical scheme, the floating roller swing angle data measured by the second encoder is obtained, and the coil length Df in the floating roller area is calculated, which includes: obtaining the initial data measured by the second encoder; calculating the reference angle of the floating roller through basic parameters and the initial data; obtaining the real-time swing angle data of the floating roller measured by the second encoder again; and calculating the coil length Df in the floating roller area through the reference angle and real-time swing angle data of the floating roller.

[0015] On the basis of the above technical scheme, the coil length Df in the floating roller area is calculated by using the reference angle and real-time swing angle data of the floating roller, including: calculating the distance between the loading roller and the floating roller and the distance between the lower loading roller and the floating roller by using the reference angle and real-time swing angle of the floating roller; calculating the coil length Df in the floating roller area by using the distance between the loading roller and the floating roller, the distance between the lower loading roller and the floating roller, the distance between the loading roller and the lower loading roller, and the diameters of the loading roller, the lower loading roller and the floating roller.

[0016] Based on the above technical solution, the coil length Df in the floating roller area includes the first section, the second section, the third section, the fourth section and the fifth section. The first section is the winding part of the feeding roller, the second section is the suspended part from the feeding roller to the floating roller, the third section is the winding part of the floating roller, the fourth section is the suspended part from the floating roller to the unloading roller, and the fifth section is the winding part of the unloading roller.

[0017] Compared with the related art, the beneficial effects of the present invention are as follows:

[0018] The present invention collects blank packaging bag images by setting a visual image acquisition device, so as to judge whether the blank packaging bag in the acquisition image has defects. When it is detected that the blank packaging bag has defects, the first encoder determines that the defective blank packaging bag runs to the rejection device, and the rejection device rejects the blank packaging bag with defects. When the length of the defect recognition area is L1, the length of the blank packaging bag is L2, nL1≤L2, and n≥3, when the rejection device rejects the blank packaging bag where the defect recognition area is located, the blank packaging bag where the first adjacent area is located, and the blank packaging bag where the second adjacent area is located, the lengths of the defect recognition area, the first adjacent area, and the second adjacent area are all L1. In the running direction, the sum of the lengths of the three areas 3L1 is also less than or equal to the length L2 of the blank packaging bag. Therefore, the defect recognition area, the first adjacent area and the second adjacent area are very likely to correspond to the same blank packaging bag. At this time, the rejection device only needs to reject the blank packaging bag. The defect recognition area, the first adjacent area and the second adjacent area also have a certain probability of corresponding to two adjacent blank packaging bags. The rejection device only needs to reject these two adjacent blank packaging bags. However, the situation where the defect recognition area, the first adjacent area and the second adjacent area correspond to three blank packaging bags will not occur. In this way, the scrap rate of blank packaging bags can be reduced and unnecessary resource consumption can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0020] Figure 1 It is a flow chart of a method for detecting and rejecting defects of blank packaging bags provided by the present invention;

[0021] Figure 2 is a flow chart of another blank packaging bag defect detection and rejection method provided by the present invention;

[0022] Figure 3 It is a structural schematic diagram of a floating roller assembly of a soft package precision rejection system provided by the present invention;

[0023] Figure 4 It is a structural schematic diagram of a floating roller assembly of another soft package precision rejection system provided by the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings and examples:

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0026] 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 directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations 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 should not be understood as a limitation on the present invention.

[0028] Combination Figure 1 As shown, the embodiment of the present disclosure provides a method for detecting and rejecting defects of blank packaging bags, comprising the following steps:

[0029] S101, obtaining a captured image of a visual image acquisition device, and determining whether an object in the captured image has defects, wherein in the running direction of the bag making machine, the length of the defect recognition area is L1, the length of the blank packaging bag is L2, nL1≤L2, wherein n≥3;

[0030] S102, when the object has a defect, obtaining a running position of the defective object recorded by the first encoder;

[0031] S103, when the defective object moves to the rejection device, the control module sends a rejection signal to the rejection device;

[0032] S104, the rejection device rejects the blank packaging bags where the defect recognition area is located, the blank packaging bags where the first adjacent area is located, and the blank packaging bags where the second adjacent area is located, wherein the first adjacent area and the second adjacent area are two adjacent defect recognition areas of the defect recognition area in the running direction of the bag making machine.

[0033] By adopting the blank packaging bag defect detection and rejection method provided by the embodiment of the present disclosure, a visual image acquisition device is set to capture the blank packaging bag screen, so as to determine whether the blank packaging bag in the captured screen has defects. When it is detected that the blank packaging bag has defects, the first encoder is used to determine that the defective blank packaging bag runs to the rejection device, and the rejection device rejects the blank packaging bag with defects. When the length of the defect recognition area is L1, the length of the blank packaging bag is L2, nL1≤L2, and n≥3, the rejection device rejects the blank packaging bag where the defect recognition area is located, the blank packaging bag where the first adjacent area is located, and the blank packaging bag where the second adjacent area is located, the defect recognition area, the first adjacent area, and the second adjacent area are removed. The lengths of the three areas are all L1. In the running direction of the bag making machine, the sum of the lengths of the three areas, 3L1, is also less than or equal to the length L2 of the blank packaging bag. Therefore, the defect recognition area, the first adjacent area, and the second adjacent area are very likely to correspond to the same blank packaging bag. At this time, the rejection device only needs to reject the blank packaging bag. The defect recognition area, the first adjacent area, and the second adjacent area also have a certain probability of corresponding to two adjacent blank packaging bags. The rejection device only needs to reject the two adjacent blank packaging bags. However, the defect recognition area, the first adjacent area, and the second adjacent area will not correspond to three blank packaging bags. In this way, the scrap rate of blank packaging bags can be reduced and unnecessary resource consumption can be avoided.

[0034] It can be understood that in the running direction of the bag making machine, the smaller the length of the defect identification area is or the larger the length of the blank packaging bag is, the greater the probability that the defect identification area, the first adjacent area and the second adjacent area correspond to the same blank packaging bag, and the probability that the rejection device only needs to reject one blank packaging bag increases.

[0035] Specifically, the maximum value of the value range of L1 can be set according to the actual situation of defect detection, and there is no limit on the maximum value. The minimum value of L1 is determined according to the pixel height of the defect recognition area in the acquisition screen. Since the defect types presented by the normal printed packaging bag material include ink spots, mosquitoes, knife lines, overprinting, etc., the length or area of ​​the defect is relatively large. Taking the length of the defect recognition area as 256 pixels and the height of a pixel as 0.195mm as an example, L1 is 50mm, where the number of pixels and the height of the pixel can be adjusted according to actual needs. Blank packaging bag products, such as transparent or solid color packaging bags, have mostly black spots and mosquitoes, and the length or area of ​​the defects is very small. The number of pixels in the defect recognition area can be reduced to make L1 smaller, thereby increasing the probability of only rejecting one packaging bag. In theory, the smaller L1 is, the more accurate the rejection can be achieved, but the actual defects have area and size, so the value of L1 cannot be too small, which will affect the accuracy of defect recognition. It needs to be adjusted according to actual production needs to make the method more widely applicable.

[0036] On the basis of the above technical solution, the rejection signal includes a first rejection signal, a second rejection signal and a third rejection signal. When the defective object runs to the rejection device, the control module sends the rejection signal to the rejection device and further includes: judging whether the blank packaging bags in the corresponding areas of the first rejection signal, the second rejection signal and the third rejection signal in the rejection signal are in the same blank packaging bag; when the blank packaging bags in the corresponding areas of the first rejection signal, the second rejection signal and the third rejection signal are the same blank packaging bag, the rejection device rejects the blank packaging bag; when the blank packaging bags in the corresponding areas of the first rejection signal, the second rejection signal and the third rejection signal are two adjacent blank packaging bags, the rejection device rejects the two adjacent blank packaging bags.

[0037] On the basis of the above technical solution, the rejection device includes a hot knife mechanism, a rejection mechanism and a proximity switch. When the blank packaging bags in the areas corresponding to the first rejection signal, the second rejection signal and the third rejection signal are the same blank packaging bag, the rejection device rejects the blank packaging bag including: obtaining the first action moment and the second action moment of the hot knife mechanism detected by the proximity switch; when the first rejection signal, the second rejection signal and the third rejection signal are simultaneously received between the first action moment and the second action moment, the rejection mechanism rejects the blank packaging bag passing between the first action moment and the second action moment.

[0038] Specifically, one bag can be made between two action moments of the ironing knife mechanism. When the first rejection signal, the second rejection signal and the third rejection signal are all received between these two action moments, it means that the blank packaging bags in the corresponding areas of the three signals are the same blank packaging bag. The rejection mechanism only needs to reject the blank packaging bags passing between these two action moments. Avoiding the rejection of excess blank packaging bags can reduce the scrap rate.

[0039] On the basis of the above technical solution, when the blank packaging bags in the areas corresponding to the first rejection signal, the second rejection signal and the third rejection signal are two adjacent blank packaging bags, the rejection device rejects the two adjacent blank packaging bags including: obtaining the third action moment and the fourth action moment of the proximity switch detecting the hot knife mechanism; when the first rejection signal is received between the third action moment and the fourth action moment or the first rejection signal and the second rejection signal are received at the same time, obtaining the fifth action moment of the proximity switch detecting the hot knife mechanism; when the second rejection signal and the third rejection signal are received between the fourth action moment and the fifth action moment or only the third rejection signal is received, the rejection mechanism rejects the blank packaging bags passing between the third action moment and the fourth action moment and the blank packaging bags passing between the fourth action moment and the fifth action moment.

[0040] Specifically, one bag can be made between two action moments of the ironing knife mechanism. When the first rejection signal, the second rejection signal and the third rejection signal are received twice by the rejection device between the three action moments, it means that the blank packaging bags in the areas corresponding to the three signals are two adjacent blank packaging bags. The rejection mechanism only needs to reject the two blank packaging bags that pass through the three action moments, and there is no need to reject the first, middle and last three packaging bags.

[0041] Based on the above technical solution, the bag making machine includes a floating roller assembly and a second encoder. The floating roller assembly includes a loading roller, a unloading roller, a floating roller and a rotating member. The rotating member is connected to the floating roller to drive the floating roller to swing. The second encoder is arranged on the rotating member.

[0042] On the basis of the above technical solution, when there is a defect in the object, obtaining the running position of the defective object recorded by the first encoder includes: when there is a defect in the object, obtaining the current running distance Pc of the defective object recorded by the first encoder, the corresponding distance Pp when the object passes through the visual image acquisition device, and the distance De from the visual image acquisition device to the rejection module; when Pc=Pp+De, the control module sends a rejection signal to the rejection device.

[0043] On the basis of the above technical solution, when Pc=Pp+De, the control module sends a rejection signal to the rejection device, including: obtaining the floating roller swing angle data measured by the second encoder, and calculating the coil length Df in the floating roller area; when Pc=Pp+De+Df, the control module sends a rejection signal to the rejection module.

[0044] Combination Figure 2 As shown, the embodiment of the present disclosure provides another method for detecting and rejecting defects of blank packaging bags, comprising the following steps:

[0045] S201, obtaining a captured image of a visual image acquisition device, and determining whether an object in the captured image has defects, wherein in the running direction of the bag making machine, the length of the defect recognition area is L1, the length of the blank packaging bag is L2, nL1≤L2, wherein n≥3;

[0046] S202, when there is a defect in the object, obtain the current running distance Pc of the defective object recorded by the first encoder, the corresponding distance Pp when the object passes through the visual image acquisition device, and the distance De from the visual image acquisition device to the rejection module;

[0047] S203, obtaining the swing angle data of the floating roller measured by the second encoder, and calculating the coil length Df in the floating roller area;

[0048] S204, when Pc=Pp+De+Df, the control module sends a rejection signal to the rejection module;

[0049] S205, the rejection device rejects the blank packaging bags where the defect recognition area is located, the blank packaging bags where the first adjacent area is located, and the blank packaging bags where the second adjacent area is located, wherein the first adjacent area and the second adjacent area are two adjacent defect recognition areas of the defect recognition area in the running direction of the bag making machine.

[0050] Specifically, if an object has defects, in the absence of a floating roller, when Pc=Pp+De, a rejection signal can be issued. When there is a floating roller in the object's forward path, the object needs to advance by the length of the coil in the floating roller area to reach the predetermined rejection position. The length of the coil when the floating roller swings to the shortest length is recorded as Df. Then, when Pc=Pp+De+Df, a rejection signal can be issued. When the floating roller runs to the shortest coil length, it means that a bag on the flexible packaging bag making machine has run to the cutter or ironing knife position and stopped. Then, as the unwinding end continues to unwind, the coil in the floating roller area begins to extend, while the bag at the cutter or ironing knife position remains stationary. When the cutter or ironing knife completes an action, the bag making machine quickly pulls the material, and the length of the coil in the floating roller area gradually shrinks to the shortest position, completing a cycle of action. As long as the rejection signal is issued within one cycle, the rejection command can be matched with the cut bag.

[0051] On the basis of the above technical solution, in the case of Pc=Pp+De+Df, the control module sends a reject signal to the reject module, including: in the case of Pc=Pp+De+Df-L1, the control module sends a first reject signal to the reject module; in the case of Pc=Pp+De+Df, the control module sends a second reject signal to the reject module; in the case of Pc=Pp+De+Df+L1, the control module sends a third reject signal to the reject module.

[0052] On the basis of the above technical scheme, the floating roller swing angle data measured by the second encoder is obtained, and the coil length Df in the floating roller area is calculated, which includes: obtaining the initial data measured by the second encoder; calculating the reference angle of the floating roller through basic parameters and the initial data; obtaining the real-time swing angle data of the floating roller measured by the second encoder again; and calculating the coil length Df in the floating roller area through the reference angle and real-time swing angle data of the floating roller.

[0053] Specifically, the basic parameters include the distance L between the rotating member and the feeding roller. AB , the distance between the rotating part and the unloading roller L AC , the distance between the rotating part and the floating roller L AD , the distance between the upper and lower rollers L BC , the distance L between the loading roller and the floating roller in the initial state BD , and the diameters d of the feed roller, the feed roller and the floating roller. ∠BAC=arccos[(L AB 2 +L AC 2 -L BC 2 ) / 2*L AB *L AC ], ∠BAD=arccos[(L AB 2 +L AD 2 -L BD 2 ) / 2*L AB *L AD ], calculate the reference angle Angle = encoder initial data / 4096*360°+∠BAD through the basic parameters and the initial data measured by the absolute encoder.

[0054] On the basis of the above technical scheme, the coil length Df in the floating roller area is calculated by using the reference angle and real-time swing angle data of the floating roller, including: calculating the distance between the loading roller and the floating roller and the distance between the lower loading roller and the floating roller by using the reference angle and real-time swing angle of the floating roller; calculating the coil length Df in the floating roller area by using the distance between the loading roller and the floating roller, the distance between the lower loading roller and the floating roller, the distance between the loading roller and the lower loading roller, and the diameters of the loading roller, the lower loading roller and the floating roller.

[0055] Combination Figure 3 As shown, the reference angle Angle of the floating roller calculated by the above embodiment and the real-time data of the encoder are used to calculate ∠BAD=Angle-(real-time data of the encoder / 4096*360°), ∠CAD=Angle-(real-time data of the encoder / 4096*360°)-∠BAC, and the distance L between the feeding roller and the floating roller is obtained according to ∠BAD and ∠CAD. BD 2 =L AB 2 +L AD 2 -2*L AB *L AD *cos∠BAD, distance L between unloading roller and floating roller CD 2 =L AC 2 +L AD 2 -2*L AC *L AD cos∠CAD.

[0056] Based on the above technical solution, the coil length Df in the floating roller area includes the first section, the second section, the third section, the fourth section and the fifth section. The first section is the winding part of the feeding roller, the second section is the suspended part from the feeding roller to the floating roller, the third section is the winding part of the floating roller, the fourth section is the suspended part from the floating roller to the unloading roller, and the fifth section is the winding part of the unloading roller.

[0057] like Figure 4 As shown, the distance L between the feeding roller and the floating roller is calculated from the above embodiment. BD And the distance L between the unloading roller and the floating roller CD , and the distance L between the upper and lower rollers is known BC And the diameter d of the loading roller, the lower roller and the floating roller.

[0058] First, calculate ∠BCD, ∠CBD and ∠CDB according to the cosine theorem. Taking ∠BCD as an example, ∠BCD=arccos[(L BC 2 +LCD 2 -L BD 2 ) / 2*L BC *L CD ], the calculation of ∠CBD and ∠CDB is the same as ∠BCD, and ∠DCH=arccos(d / L CD ), and obtain the suspended part L from the second feeding roller to the floating roller HJ =L CD *sin(∠DCH).

[0059] Knowing that ∠BCG=45°, ∠GCH=45°-(∠DCH-∠BCD), we can get the winding part L of the first section of the feeding roller. GH =π*d*(∠GCH / 360).

[0060] From ∠DBL=arccos(d / BD), ∠JDK=360°-∠CDJ-∠BDK-∠BDC=360°-∠DCH-∠DBL-∠BDC, we can get the winding part L of the third floating roller: JK =π*d*(∠JDK / 360), the suspended part L from the fourth floating roller to the unloading roller KL =L BD *sin(∠DBL).

[0061] Knowing that ∠CBM=45°, ∠LBM=45°-(∠DBL-∠CBD), we can get the winding part L of the fifth section of the unloading roller. LM =π*d*(∠LBM / 360).

[0062] Get the coil length Df=L in the floating roller area GH +L HJ +L JK +L KL +L LM .

[0063] Optionally, when two floating rollers are arranged in the floating roller area, the area may be divided into two and the calculation in the above embodiment may be performed to obtain the coil length in the floating roller area.

[0064] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments, and any changes or modifications made based on the present invention belong to the scope of protection claimed by the present invention.

Claims

1. A method for detecting and removing defects in blank packaging bags, characterized in that: The following steps are involved: Obtain the captured image of the visual image acquisition device, and determine whether the object in the captured image has defects, wherein in the running direction of the bag making machine, the length of the defect recognition area is L1, the length of the blank packaging bag is L2, nL1≤L2, where n≥3; In the case where the object has a defect, obtaining the running position of the defective object recorded by the first encoder; When the defective object runs to the rejection device, the control module sends a rejection signal to the rejection device; The rejection signal includes a first rejection signal, a second rejection signal and a third rejection signal, and it is determined whether the blank packaging bags in the areas corresponding to the first rejection signal, the second rejection signal and the third rejection signal in the rejection signal are in the same blank packaging bag; In the case where the blank packaging bag in the areas corresponding to the first rejection signal, the second rejection signal and the third rejection signal is the same blank packaging bag, the rejection device includes a hot knife mechanism, a rejection mechanism and a proximity switch, and obtains a first action time and a second action time of the hot knife mechanism detected by the proximity switch; When the first rejection signal, the second rejection signal and the third rejection signal are simultaneously received between the first action moment and the second action moment, the rejection mechanism rejects the blank packaging bag passing between the first action moment and the second action moment.

2. The method for detecting and removing defects of blank packaging bags according to claim 1, characterized in that: Also includes: When the blank packaging bags in the areas corresponding to the first rejection signal, the second rejection signal and the third rejection signal are two adjacent blank packaging bags, the rejection device rejects the two adjacent blank packaging bags.

3. The method for detecting and removing defects of blank packaging bags according to claim 2, characterized in that: In the case where the blank packaging bags in the areas corresponding to the first rejection signal, the second rejection signal and the third rejection signal are two adjacent blank packaging bags, the rejection device rejects the two adjacent blank packaging bags including: Obtaining the third action time and the fourth action time of the proximity switch detecting the hot knife mechanism; When the first rejection signal is received between the third action moment and the fourth action moment, or the first rejection signal and the second rejection signal are received simultaneously, obtaining the fifth action moment of the proximity switch detecting the hot knife mechanism; When the second rejection signal and the third rejection signal are received simultaneously between the fourth action moment and the fifth action moment, or when only the third rejection signal is received, the rejection mechanism rejects the blank packaging bags passing between the third action moment and the fourth action moment and the blank packaging bags passing between the fourth action moment and the fifth action moment.

4. The method for detecting and removing defects of blank packaging bags according to any one of claims 1 to 3, characterized in that: The bag making machine comprises a floating roller assembly and a second encoder. The floating roller assembly comprises a feeding roller, a feeding roller, a floating roller and a rotating member. The rotating member is connected to the floating roller to drive the floating roller to swing. The second encoder is arranged on the rotating member.

5. The method for detecting and removing defects of blank packaging bags according to claim 4, characterized in that: In the case where the object has a defect, obtaining the running position of the defective object recorded by the first encoder includes: In the case of defects in the object, obtain the current running distance Pc of the defective object recorded by the first encoder, the corresponding distance Pp when the object passes through the visual image acquisition device, and the distance De from the visual image acquisition device to the rejection module; When Pc=Pp+De, the control module sends a rejection signal to the rejection device.

6. The method for detecting and removing defects of blank packaging bags according to claim 5, characterized in that: In the case of Pc=Pp+De, the control module sends a rejection signal to the rejection device including: Obtain the floating roller swing angle data measured by the second encoder, and calculate the coil length Df in the floating roller area; When Pc=Pp+De+Df, the control module sends a rejection signal to the rejection module.

7. The method for detecting and removing defects of blank packaging bags according to claim 6, characterized in that: In the case of Pc=Pp+De+Df, the control module sends a rejection signal to the rejection module including: In the case of Pc=Pp+De+Df-L1, the control module sends a first rejection signal to the rejection module; In the case of Pc=Pp+De+Df, the control module sends a second rejection signal to the rejection module; When Pc=Pp+De+Df+L1, the control module sends a third reject signal to the reject module.

8. The method for detecting and removing defects of blank packaging bags according to claim 6, characterized in that: Obtaining the floating roller swing angle data measured by the second encoder and calculating the coil length Df in the floating roller area includes: Acquire initial data measured by the second encoder; Calculate the reference angle of the floating roller through basic parameters and initial data; again obtaining the real-time swing angle data of the floating roller measured by the second encoder; The web length Df in the dancing roller area is calculated by the reference angle of the dancing roller and the real-time swing angle data.

9. The method for detecting and removing defects of blank packaging bags according to claim 8, characterized in that: The web length Df in the floating roller area is calculated by using the reference angle and real-time swing angle data of the floating roller, including: The distance between the loading roller and the floating roller and the distance between the unloading roller and the floating roller are calculated by the reference angle and the real-time swing angle of the floating roller; The web length Df in the floating roller area is calculated by the distance between the upper and lower rollers, the distance between the lower and upper rollers, the distance between the upper and lower rollers, and the diameters of the upper, lower and upper rollers.

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