A testing device and simulation method for bending life of membrane material

Abstract

The present invention relates to the field of flexible membrane testing technology, and specifically to a testing device and simulation method for the bending life of membrane materials, including obtaining all pores and corner pores between the current simulation test and the next simulation test; obtaining the degree of membrane material offset based on the positional analysis of the corner pores relative to the four corners of the membrane material; obtaining the wrinkle edges and their direction vectors of each pore in the image of the membrane material to be tested; quantifying the consistency of the direction vectors of the wrinkle edges to obtain the consistency of the force direction of the membrane material; obtaining the force coefficient of the pores based on the morphology of the wrinkle edges; obtaining the degree of negative pressure imbalance based on the consistency of the force direction of the membrane material; and using the degree of membrane material offset and the degree of negative pressure imbalance to obtain the adjustment feedback parameters of the current simulation test to adjust the preset negative pressure of the next simulation test. The present invention implements a life test of the flexible membrane material by proposing a testing device for the bending life of the membrane material to bend and dislocate the flexible membrane material.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible film material testing, and in particular to a testing device and a simulation method for the bending life of a film material. Background Art

[0002] With the widespread use of electronic products such as mobile phones, laptops, and tablets, products have also appeared in various forms. The durability of their screens and film materials has become an important indicator of concern to users. Currently, most of the products on the market are bendable, and there is still a gap in the field of bending and displacement testing. The existing bending life test of film materials uses the gluing method to fix the film material on the test instrument, and perform a bending test on the part that needs to bend life test. However, the gluing method can only bend a single area of ​​the film material at a time, ignoring the influence of displacement bending when the film material moves as a whole. In addition, the gluing method adheres the entire film material to the test instrument, so that the stress of the entire film material is affected by the gluing, resulting in problems such as insufficient comprehensiveness of the test and inaccurate results.

[0003] There is an existing method of fixing the membrane material by using pore negative pressure. However, in actual application, the size of the negative pressure is affected by the different rigidity of the membrane material. Excessive negative pressure will pull the membrane material, causing the membrane material rigidity to be inconsistent with the actual rigidity, resulting in errors beyond the life test. Excessive negative pressure will cause the membrane material to be unable to be adsorbed on the test equipment, reducing the success rate of the bending life test. Summary of the Invention

[0004] The present invention provides a testing device and a simulation method for the bending life of a membrane material to solve the existing problems.

[0005] The testing equipment and simulation method for the bending life of a membrane material of the present invention adopt the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a method for testing and simulating the bending life of a film material, the method comprising the following steps:

[0007] The film material is adsorbed and bent by an adsorption plate to obtain an original film material image of the current simulation test and an image of the film material to be tested; the adsorption plate includes a fixed adsorption plate and a movable adsorption plate;

[0008] Between the current simulation test and the next simulation test, the edge images of the original film material image and the film material image to be tested are obtained; all pores and corner holes in the original film material image and the film material image to be tested are obtained; based on the positions of the corner holes in the original film material image and the film material image to be tested relative to the four corners of the film material, the offset of the film material image to be tested relative to the original film material image is analyzed to obtain the degree of film material offset; according to the connection between other edges in the edge image of the film material image to be tested and the edges of the pores, the wrinkle edges and their direction vectors of each pore in the film material image to be tested are obtained; the consistency of the direction vectors of the wrinkle edges generated by the force on the film material in the film material image to be tested in different regions is quantified to obtain the consistency of the force direction of the film material; according to the morphology of the wrinkle edges of each pore in the film material image to be tested, the force coefficient of each pore in the film material image to be tested is obtained; the degree of negative pressure mismatch is obtained by combining the force coefficients of all pores in the film material image to be tested and the consistency of the force direction of the film material;

[0009] The adjustment feedback parameters of the current simulation test are obtained using the degree of membrane material deviation and the degree of improper negative pressure; and the preset negative pressure of the next simulation test is adjusted using the adjustment feedback parameters of the current simulation test.

[0010] Preferably, the step of acquiring all pores and corner holes in the original film material image and the image of the film material to be tested comprises:

[0011] All circular areas in the edge images of the original film material image and the film material image to be tested are obtained, each circular area is recorded as a pore, the pore center of each pore is obtained, and the pore corresponding to the pore center with the closest Euclidean distance to the film material corner point in the original film material image and the film material image to be tested is recorded as a corner pore.

[0012] Preferably, the specific steps of obtaining the degree of film material deviation include:

[0013] The corresponding corner holes in the original film material image and the film material image to be tested are recorded as a set of corner hole pairs. The corner hole pair in the upper left corner of the original film material image is recorded as the first set of corner hole pairs. The four sets of corner hole pairs are obtained by sorting them in a clockwise order.

[0014] The calculation method of the membrane material deviation degree D in the current simulation test is:

[0015]

[0016] in, is the positioning vector of the corner holes of the i-th group of corner holes in the original film material image, is the positioning vector of the corner holes of the i-th group of corner holes in the image of the film to be tested; cos( ) is the function for calculating the cosine similarity of the orientation vector, and exp( ) represents the exponential function with a natural constant as the base.

[0017] Preferably, the specific steps of obtaining the positioning vector include:

[0018] In the original film material image, with the center of each corner hole as the origin, construct a vector from each origin to the nearest film material corner point, which is recorded as the positioning vector of each corner hole in the original film material image;

[0019] Get the positioning vector of each corner hole in the film material image to be tested.

[0020] Preferably, the specific steps of obtaining the consistency of the force direction of the membrane material include:

[0021] The image of the film to be tested is equally divided along the direction perpendicular to the fixed adsorption plate and pointing to the movable adsorption plate. The area of ​​the image of the film to be tested on the fixed adsorption plate is recorded as the fixed adsorption area, and the area on the movable adsorption plate is recorded as the movable adsorption area.

[0022] In the active adsorption region, for each pore, the direction vectors of all wrinkle edges of each pore are vector-fitted to obtain the pull fitting vector of each pore;

[0023] The pull-fitting vectors of all pores in the active adsorption area are averaged to obtain the vector mean of the pull-fitting vectors of all pores in the active adsorption area. The mean of the cosine similarity between the pull-fitting vector of each pore in the active adsorption area and the vector mean of the pull-fitting vectors of all pores is calculated and recorded as the force consistency of the active adsorption area.

[0024] Preferably, obtaining the wrinkle edge and direction vector of each pore in the image of the film material to be tested according to the connection between other edges in the edge image of the film material to be tested and the edge of the pore comprises:

[0025] In the edge image of the film material image to be measured, the edge connected to the edge of each pore is recorded as the wrinkle edge of each pore in the film material image to be measured;

[0026] The point where each wrinkle edge of each pore in the film material image to be tested is connected to the edge of the pore is recorded as the end point, the other end of the wrinkle edge is recorded as the starting point, and the vector formed by the starting point pointing to the end point is recorded as the direction vector of each wrinkle edge of each pore in the film material image to be tested.

[0027] Preferably, the specific steps of obtaining the stress coefficient include:

[0028] For the mth pore, the stress coefficient C of the mth pore is m The calculation method is:

[0029]

[0030] in, is the direction vector of the qth wrinkle edge of the mth pore, Q m is the number of wrinkle edges of the mth pore, L m,q is the number of pixels at the qth wrinkle edge of the mth pore, σ(L) m is the standard deviation of the number of pixels at the edges of all wrinkles of the mth pore;

[0031] || ||2 is the function for finding the second norm, || is the function for finding the absolute value, exp( ) is the exponential function with a natural constant as the base, and σ( ) is the function for finding the standard deviation.

[0032] Preferably, the specific steps of obtaining the degree of improper negative pressure include:

[0033] The consistency of the force direction of the membrane material is recorded as S;

[0034] The calculation method of the negative pressure improper degree F in the current simulation test is:

[0035]

[0036] Where M is the number of pores, C m is the force coefficient of the mth pore; sigmoid{} represents the sigmoid function.

[0037] Preferably, the specific steps of obtaining the adjustment feedback parameters include:

[0038] The calculation method of the adjustment feedback parameter W of the current simulation test is:

[0039]

[0040] Wherein, D is the degree of membrane material deviation in the current simulation test, and F is the degree of improper negative pressure in the current simulation test.

[0041] In a second aspect, another embodiment of the present invention further provides a device for testing the bending life of a film material, the device comprising:

[0042] The bending and dislocation testing unit is used to absorb the film material through the adsorption plate and bend it to obtain the original film material image and the film material image to be tested in the current simulation test;

[0043] A film material offset degree acquisition unit is used to obtain edge images of the original film material image and the image of the film material to be tested between the current simulation test and the next simulation test; obtain all pores and corner holes in the original film material image and the image of the film material to be tested; and analyze the offset of the image of the film material to be tested relative to the original film material image based on the positions of the corner holes in the original film material image and the image of the film material to be tested relative to the four corners of the film material to obtain the film material offset degree;

[0044] A negative pressure mismatch degree acquisition unit is configured to obtain the wrinkle edge and direction vector of each pore in the film material image to be tested based on the connection between other edges in the edge image of the film material image to be tested and the edges of the pores; quantify the consistency of the direction vectors of the wrinkle edges generated by the film material under stress in different regions in the film material image to be tested, and obtain the consistency of the stress direction of the film material; obtain the stress coefficient of each pore in the film material image to be tested based on the morphology of the wrinkle edge of each pore in the film material image to be tested; and obtain the negative pressure mismatch degree by combining the stress coefficients of all pores in the film material image to be tested and the consistency of the stress direction of the film material;

[0045] The adjustment feedback parameter acquisition unit is used to obtain the adjustment feedback parameters of the current simulation test by using the degree of membrane material deviation and the degree of negative pressure imbalance;

[0046] The negative pressure adjustment unit is used to adjust the preset negative pressure of the next simulation test by using the current simulation test adjustment feedback parameter.

[0047] The beneficial effects of the technical solution of the present invention are as follows: the present invention absorbs the film material through the adsorption plate and bends it to obtain the original film material image of the current simulation test and the film material image to be tested; between the current simulation test and the next simulation test, the edge image of the original film material image and the film material image to be tested is obtained; all pores and corner holes in the original film material image and the film material image to be tested are obtained; the pores of the film material and the adsorption plate are positioned; based on the positions of the corner holes in the original film material image and the film material image to be tested relative to the four corners of the film material, the displacement of the film material image to be tested relative to the original film material image is analyzed to obtain the degree of displacement of the film material; the position change of the film material corner point and the pore of the adsorption plate before and after bending is used to reflect the displacement of the film material due to too small negative pressure during the test process; the wrinkle edge and direction vector of each pore in the film material image to be tested are obtained according to the connection between other edges in the edge image of the film material image to be tested and the edge of the pore; the consistency of the direction vectors of the wrinkle edges generated by the force on the film material in the film material image to be tested in different areas is quantified, Obtain the consistency of the force direction of the membrane material; analyze the direction of the wrinkle edge of the membrane material after bending due to excessive negative pressure, and reflect the deformation of the membrane material; obtain the force coefficient of each pore in the image of the membrane material to be tested according to the shape of the wrinkle edge of each pore in the image of the membrane material to be tested; quantify the force degree of the wrinkle edge corresponding to the position of the membrane material by analyzing the shape of the wrinkle edge; obtain the degree of improper negative pressure in combination with the force coefficient of all pores in the image of the membrane material to be tested and the consistency of the force direction of the membrane material; use the degree of membrane material offset and the degree of improper negative pressure to obtain the adjustment feedback parameters of the current simulation test; use the current simulation test adjustment feedback parameters to adjust the preset negative pressure of the next simulation test; through the testing equipment for the bending life of membrane material proposed by the present invention, the bending and dislocation life test of the membrane material is realized, and the negative pressure adjustment method provided in the test simulation method for the bending life of membrane material is used to avoid pressure discomfort caused by different rigidity of the membrane material during the bending process, and solve the problem that the test results of the membrane material are interfered by improper negative pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0049] Figure 1 A flowchart of a method for testing and simulating the bending life of a membrane material provided by one embodiment of the present invention;

[0050] Figure 2 A schematic diagram of a film material bending life testing device provided by one embodiment of the present invention;

[0051] Figure 3 A schematic diagram of a bending dislocation testing unit of a film material bending life testing device provided by one embodiment of the present invention;

[0052] Figure 4 A schematic diagram of a fixed adsorption plate 5, a movable adsorption plate 6, a film 8, and a lifting platform 3 in a preparation state in a bending dislocation test unit of a film bending life test device provided by one embodiment of the present invention;

[0053] Figure 5 A schematic diagram of a fixed adsorption plate 5 and a movable adsorption plate 6 in a bending dislocation test unit of a film bending life test device provided by one embodiment of the present invention;

[0054] Figure 6 A schematic diagram of a bending simulation state of a bending misalignment test unit of a film material bending life test device provided by one embodiment of the present invention when the bending misalignment test unit is at 90 degrees;

[0055] Figure 7 A schematic diagram of a bending simulation state of a bending misalignment test unit of a film material bending life test device provided by one embodiment of the present invention when the bending misalignment test unit is at a 45-degree bending angle;

[0056] Figure 8 A schematic diagram of a bending simulation state of a bending misalignment test unit of a film material bending life test device provided by one embodiment of the present invention when the bending misalignment test unit is at 0 degrees;

[0057] Figure 9 A schematic diagram of a bending dislocation test unit of a film material bending life test device provided by one embodiment of the present invention in a first stage post-bending dislocation simulation state;

[0058] Figure 10 A schematic diagram of a bending dislocation test unit of a film material bending life test device provided by one embodiment of the present invention in a second stage post-bending dislocation simulation state;

[0059] Figure 11 A schematic diagram of a bending dislocation test unit of a film material bending life test device provided by one embodiment of the present invention in a third stage of post-bending dislocation simulation state;

[0060] Figure 12 A block diagram of a film material bending life testing device provided by one embodiment;

[0061] In the figure: 1. Lifting shaft; 2. Support rod; 3. Lifting platform; 4. Hydraulic rod; 5. Fixed adsorption plate; 6. Movable adsorption plate; 7. Rotating shaft; 8. Membrane material; 9. Sensor; 10. Slide rail. DETAILED DESCRIPTION

[0062] To further illustrate the technical means and effectiveness of the present invention in achieving its intended objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effectiveness of a membrane flexure life testing device and simulation method proposed in accordance with the present invention. In the following description, references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0063] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0064] The following describes in detail a specific solution of a testing device and simulation method for the bending life of a membrane material provided by the present invention in conjunction with the accompanying drawings.

[0065] On the one hand, see Figure 1 , which shows a flowchart of a test simulation method for the bending life of a membrane material provided by an embodiment of the present invention, the method comprising the following steps:

[0066] Step S001: Adsorbing a film material by an adsorption plate and bending the film material to obtain an image of the original film material of the current simulation test and an image of the film material to be tested.

[0067] Among them, the adsorption plate uses negative pressure to adsorb the film material through the pores. Step S001 is specifically as follows: after fixing the film material by two adsorption plates, the film material is bent and restored to its original shape by adjusting the spatial position of the adsorption plates, and the sensor installed above the adsorption plate is used to collect the film material images before bending and after recovery, respectively, to obtain the original film material image and the film material image to be tested.

[0068] More specifically, by Figure 3The bending dislocation test unit of the testing equipment for the bending life of a membrane material shown in the figure performs a bending test on the membrane material. First, two slide rails 10 are installed in parallel on the cabinet, and two lifting shafts 1 are installed vertically on the slide rails 10. The two lifting shafts 1 can move synchronously along the slide rails; the horizontally placed rotating shaft 7 is connected to the two lifting shafts 1 through a transmission mechanism, etc., which can realize the up and down movement of the rotating shaft 7. The movable adsorption plate 6 is fixed on the rotating shaft 7 through a connecting device such as a slot and a bolt. The lifting shaft 1 can make the rotating shaft 7 move up and down; the rotation of the rotating shaft 7 means that the movable adsorption plate 6 rotates synchronously, combined with the sliding of the two lifting shafts 1 and the height increase and decrease of the rotating shaft 7, so that the movable adsorption plate 6 is flipped with one end as the fulcrum, so that the membrane material adsorbed on the movable adsorption plate 6 is bent; the two support rods 2 are fixed vertically, and the fixed adsorption plate 5 is fixed by The connecting devices such as the card slot and the bolt are fixed to the support rod 2, which are used to keep half of the membrane material from being bent during the bending test; when the fixed adsorption plate 5 is stationary and the movable adsorption plate 6 is flipped, the membrane material can be bent. After the movable adsorption plate 6 is flipped and kept at a certain distance and parallel to the fixed adsorption plate, the hydraulic rod 4 of the hydraulic device is used to lift the lifting platform 3 to the same plane as the fixed adsorption plate 5, so as to support the membrane material during the dislocation process, and change the bending position of the membrane material by moving the lifting shaft 1 to realize the dislocation test of the membrane material; further, the sensor 9 installed just above the middle of the fixed adsorption plate 5 and the movable adsorption plate 6 is used to collect the original membrane material image and the membrane material image to be tested for each simulation test.

[0069] Among them, the bending test unit includes a preparation state, bending simulation states at several angles, and several dislocation simulation states after bending at different stages when performing bending dislocation tests on the film material. It should be noted that after each bending simulation state or each stage of dislocation simulation state after bending, it is necessary to restore to the preparation state before performing the next bending simulation state or dislocation simulation state after bending.

[0070] See also Figure 4 , which shows a schematic diagram of the fixed adsorption plate 5, the movable adsorption plate 6, the membrane material 8 and the lifting platform 3 in a ready state;

[0071] See also Figure 5 , which shows a schematic diagram of a fixed adsorption plate 5 and a movable adsorption plate 6, wherein each of the fixed adsorption plate 5 and the movable adsorption plate 6 has two adsorption areas, which are respectively marked as adsorption area 1, adsorption area 2, adsorption area 3 and adsorption area 4 from the fixed adsorption plate to the movable adsorption plate. Each adsorption area has a number of circular air holes for adsorbing the film material through negative pressure;

[0072] See also Figure 6, which shows the simulated bending state at 90 degrees. At this time, adsorption areas 1 and 2 generate negative pressure to adsorb the film material, while adsorption areas 3 and 4 do not generate negative pressure. The movable adsorption plate is perpendicular to the fixed adsorption plate after moving through the lifting axis and the rotating axis.

[0073] See also Figure 7 , which shows the bending simulation state at 45 degrees. At this time, adsorption areas 1 and 2 generate negative pressure to adsorb the film material, while adsorption areas 3 and 4 do not generate negative pressure. The minimum angle between the movable adsorption plate and the fixed adsorption plate after moving through the lifting axis and the rotating axis is 45 degrees.

[0074] See also Figure 8 , which shows the bending simulation state at 0 degrees. At this time, adsorption areas 1 and 2 generate negative pressure to adsorb the film material, while adsorption areas 3 and 4 do not generate negative pressure. The movable adsorption plate and the fixed adsorption plate are moved by the lifting axis and the rotating axis and are parallel to the fixed adsorption plate at a certain distance. The lifting platform and the movable adsorption plate are not in the same plane.

[0075] See also Figure 9 , which shows the first stage of the post-bending dislocation simulation state. The positions of the movable adsorption plate and the fixed adsorption plate are consistent with the bending simulation state at 0 degrees. At this time, all adsorption areas generate negative pressure to adsorb the film material, and the lifting platform is at the same level as the adsorption plate through the hydraulic device;

[0076] See also Figure 10 , which shows the simulation state of post-bending dislocation in the second stage. At this time, all adsorption areas generate negative pressure to adsorb the film material, and the movable adsorption plate moves in the direction from the fixed adsorption plate to the lifting platform, so that one end of the movable adsorption plate and one end of the lifting platform are in the same vertical plane;

[0077] See also Figure 11 , which shows the simulation state of post-bending dislocation in the third stage. At this time, all adsorption areas generate negative pressure to adsorb the membrane material, and the movable adsorption plate moves a certain distance in the direction from the fixed adsorption plate to the lifting platform, so that one end of the movable adsorption plate exceeds the longitudinal plane of the other end of the lifting platform that is not adjacent to the fixed adsorption plate.

[0078] More specifically, the above illustrates the bending and dislocation test unit in different states. Each time a simulation test of the bending life of a membrane is performed, the membrane is first placed on the surfaces of the fixed adsorption plate and the movable adsorption plate in the preparation state. Negative pressure is generated by the pores on the adsorption areas corresponding to the working state on the fixed adsorption plate and the movable adsorption plate, adsorbing the membrane on the fixed adsorption plate and the movable adsorption plate. This allows the membrane to be fixed on the fixed adsorption plate and the movable adsorption plate in different states, and the corresponding required simulation test is then performed.

[0079] It should be noted that the shape of the membrane material described in this embodiment is described using a rectangle as an example. In this embodiment, in order to ensure that the adsorption of the membrane material by the adsorption plate is not affected by the shape of the membrane material and the position of the pores, the pores on all adsorption plates are arranged in a matrix shape, the aperture of each pore is 1 mm, and the distance between the pores is 5 mm.

[0080] Furthermore, each time a simulation test of the bending life of the membrane material is performed, each time the bending dislocation test unit starts from the preparation state, reaches the bending simulation state or the bending dislocation simulation state, and finally returns to the preparation state is recorded as a simulation test. In each simulation test, the sensor 9 collects images of the membrane material once for the fixed adsorption plate and the movable adsorption plate in the two preparation states respectively. The image of the membrane material collected in the first preparation state is recorded as the original membrane material image of the simulation test, and the image of the membrane material collected in the second preparation state is recorded as the image of the membrane material to be tested in the simulation test.

[0081] It should be noted that the original film material image and the film material image to be tested described in this embodiment are both grayscale images. Grayscale conversion of images is a well-known technique and will not be described in detail in this embodiment.

[0082] Step S002: Between the current simulation test and the next simulation test, obtain the edge images of the original film material image and the image of the film material to be tested; obtain all pores and corner holes in the original film material image and the image of the film material to be tested; based on the positions of the corner holes in the original film material image and the image of the film material to be tested relative to the four corners of the film material, analyze the offset of the image of the film material to be tested relative to the original film material image to obtain the degree of film material offset.

[0083] It should be noted that the main reason affecting the life of the membrane material is that the flexible membrane material cannot be restored to a flat state due to pressure and other reasons during use. Therefore, the life test of the membrane material is mainly based on the bending test; the membrane material to be tested is fixed on the adsorption plate by negative pressure through the adsorption area. Due to the different rigidity and elasticity of different membrane materials, there are differences in the adsorption effect when adsorbed with the same negative pressure; when the negative pressure is too small, the elasticity of the membrane material after bending will cause the membrane material on the movable adsorption plate to shift; therefore, this embodiment first obtains the degree of membrane material offset in the current simulation test based on the offset of the image of the membrane material to be tested relative to the original membrane material image.

[0084] Preferably, between the current simulation test and the next simulation test, edge images of the original film material image and the image of the film material to be tested are obtained; all pores and corner holes in the original film material image and the image of the film material to be tested are obtained; based on the positions of the corner holes in the original film material image and the image of the film material to be tested relative to the four corners of the film material, the offset of the image of the film material to be tested relative to the original film material image is analyzed, and the specific steps of obtaining the degree of film material offset include:

[0085] Between the current simulation test and the next simulation test, circle detection is performed on the original film material image and the film material image to be tested, all pores and the pore center of each pore in the original film material image and the film material image to be tested are obtained, and corner holes are obtained according to the positions of the pores;

[0086] According to the positions of the corner holes and the corner points of the original film material image and the film material image to be tested, the positioning vectors of the corner holes in the original film material image and the positioning vectors of the corner holes in the film material image to be tested are constructed;

[0087] The degree of film material deviation is obtained according to the difference between the positioning vectors of each corner hole in the original film material image and the positioning vectors of each corner hole in the film material image to be measured.

[0088] Specifically, between the current simulation test and the next simulation test, circle detection is performed on the original film material image and the film material image to be tested, and all pores and the pore center of each pore in the original film material image and the film material image to be tested are obtained. The specific steps for obtaining the corner pores according to the positions of the pores are as follows:

[0089] Between the current simulation test and the next simulation test, the Canny edge detection operator is used to perform edge detection on the original film material image and the film material image to be tested, and edge images of the original film material image and the film material image to be tested are obtained respectively;

[0090] Hough circle detection is used to obtain all circular areas in the edge images of the original film material image and the film material image to be tested, each circular area is recorded as a pore, the pore center of each pore is obtained, and the pore corresponding to the pore center with the closest Euclidean distance to the film material corner point in the original film material image and the film material image to be tested is recorded as a corner pore;

[0091] It should be noted that the corner points of the film material are the four vertices of the film material. Since the film material is rectangular, the four corners of the film material are known and can be obtained through a corner point detection algorithm such as the Harris algorithm; among them, the Canny edge detection operator, Hough circle detection and Harris algorithm are all existing well-known technologies and will not be repeated in this embodiment.

[0092] Specifically, according to the positions of the corner holes and the corner points of the original film material image and the film material image to be tested, the specific steps of constructing the positioning vectors of each corner hole in the original film material image and the positioning vectors of each corner hole in the film material image to be tested are as follows:

[0093] In the original film material image, with the center of each corner hole as the origin, construct a vector from each origin to the nearest film material corner point, which is recorded as the positioning vector of each corner hole in the original film material image;

[0094] Similarly, the positioning vector of each corner hole in the film material image to be tested is obtained.

[0095] Furthermore, according to the difference between the positioning vectors of each corner hole in the original film material image and the positioning vectors of each corner hole in the film material image to be measured, the specific method for obtaining the degree of film material deviation is as follows:

[0096] It should be noted that during the simulation test, the position of the edge pores is fixed. When the membrane is subjected to bending force, it will produce elastic displacement, so the positioning vectors of the four corners of the membrane relative to the corner holes will change. The positions of the corner holes in the original membrane image and the image of the membrane to be tested correspond one to one.

[0097] The corresponding corner holes in the original film material image and the film material image to be tested are recorded as a set of corner hole pairs. The corner hole pair in the upper left corner of the original film material image is recorded as the first set of corner hole pairs. The four sets of corner hole pairs are obtained by sorting them in a clockwise order.

[0098] The calculation method of the membrane material deviation degree D in the current simulation test is:

[0099]

[0100] in, is the positioning vector of the corner holes of the i-th group of corner holes in the original film material image, is the positioning vector of the corner holes of the i-th group of corner holes in the image of the film to be tested; cos( ) is the function for calculating the cosine similarity of the orientation vector, and exp( ) represents the exponential function with a natural constant as the base.

[0101] At this point, the degree of membrane material displacement in the current simulation test is obtained, which is used to determine whether there is a situation where the negative pressure is too small, causing the membrane material to shift.

[0102] Step S003: Between the current simulation test and the next simulation test, the wrinkle edge and its direction vector of each pore in the film material image to be tested are obtained based on the connection between other edges in the edge image of the film material image to be tested and the edges of the pores; the consistency of the direction vectors of the wrinkle edges generated by the film material under stress in different regions in the film material image to be tested is quantified to obtain the consistency of the stress direction of the film material; the stress coefficient of each pore in the film material image to be tested is obtained based on the morphology of the wrinkle edge of each pore in the film material image to be tested; and the degree of negative pressure mismatch is obtained by combining the stress coefficients of all pores in the film material image to be tested and the consistency of the stress direction of the film material.

[0103] It should be noted that the simulation test described in this embodiment requires multiple bending simulations and multiple dislocation simulations. When the negative pressure of the adsorption plate is too large, the flexible membrane material is squeezed by the atmospheric pressure and deformed and sucked into the pores, and the membrane material cannot produce the expected deformation when bending, resulting in the membrane material being stretched and wrinkled. The membrane material on the movable adsorption plate close to the fixed adsorption plate is more likely to be stretched and wrinkled than the membrane material far away from the fixed adsorption plate because it serves as the tested area.

[0104] It should be further explained that when the membrane material in other areas is bent and deformed accordingly, the membrane material at the pores is sucked into the pores by the high negative pressure and fixed, and wrinkles are generated due to the different displacements between different areas, and the wrinkles are derived around the pores. Therefore, this embodiment obtains the consistency of the force direction of the membrane material based on the directional consistency of the wrinkle texture around the pores, and obtains the force degree of the membrane material by combining the edge shape and number of the wrinkle texture, and comprehensively obtains the degree of negative pressure imbalance simulated by the current test.

[0105] Preferably, between the current simulation test and the next simulation test, the specific steps of quantifying the direction consistency of the wrinkles generated by the pulling of the film material corresponding to the pore edge texture in the image of the film material to be tested and obtaining the consistency of the force direction of the film material include:

[0106] In the edge image of the film material image to be measured, the edge connected to the edge of each pore is recorded as the wrinkle edge of each pore in the film material image to be measured;

[0107] Obtaining a direction vector of each wrinkle edge of each pore in the image of the film material to be tested according to the direction of each wrinkle edge of each pore in the image of the film material to be tested;

[0108] The image of the film to be tested is divided into a fixed adsorption area and an active adsorption area, and the direction vectors of all wrinkle edges of the same pore in the fixed adsorption area and the active adsorption area are decomposed to obtain the consistency of the force direction of the film material;

[0109] Specifically, the specific method of obtaining the direction vector of each wrinkle edge of each pore in the image of the film to be tested according to the direction of each wrinkle edge of each pore in the image of the film to be tested is:

[0110] It should be noted that each wrinkle edge of each pore in the image of the film material to be tested is a pixel sequence segment composed of pixel points;

[0111] The point where each wrinkle edge of each pore in the film material image to be tested connects with the edge of the pore is recorded as the end point, the other end of the wrinkle edge is recorded as the starting point, and the vector formed by the starting point pointing to the end point is recorded as the direction vector of each wrinkle edge of each pore in the film material image to be tested;

[0112] Specifically, the image of the film to be tested is divided into a fixed adsorption area and an active adsorption area, and the direction vectors of all wrinkle edges of the same pore in the fixed adsorption area and the active adsorption area are decomposed to obtain the consistency of the force direction of the film material in the following manner:

[0113] It should be noted that when the membrane is bent, stress is generated from the bending part to the two ends of the membrane. Therefore, the direction of the wrinkles generated by the pulling of the membrane is symmetrical with the bending part of the membrane as the center. In this embodiment, the image of the membrane to be tested is first divided into a fixed adsorption area and an active adsorption area based on the bending part, and then the direction vectors of the wrinkle edges of each area are analyzed to obtain the consistency of the force direction of the membrane.

[0114] The image of the film to be tested is equally divided along the direction perpendicular to the fixed adsorption plate and pointing to the movable adsorption plate. The area of ​​the image of the film to be tested on the fixed adsorption plate is recorded as the fixed adsorption area, and the area on the movable adsorption plate is recorded as the movable adsorption area.

[0115] In the active adsorption area, for the kth pore, the orthogonal decomposition method is used to perform vector fitting on the direction vectors of all the wrinkle edges of the kth pore to obtain the pull fitting vector of the kth pore;

[0116] Furthermore, the pull fitting vectors of all pores in the active adsorption region are averaged to obtain the vector mean of the pull fitting vectors of all pores in the active adsorption region. The mean of the cosine similarities between the pull fitting vector of each pore in the active adsorption region and the vector mean of the pull fitting vectors of all pores is calculated and recorded as the force consistency of the active adsorption region.

[0117] Similarly, the force consistency of the fixed adsorption area is obtained; the mean of the force consistency of the active adsorption area and the force consistency of the fixed adsorption area are normalized using a linear normalization algorithm, and the result is recorded as the force direction consistency of the membrane material.

[0118] It should be noted that the above-mentioned linear normalization algorithm is an existing well-known technology, and the maximum and minimum value normalization algorithm is used as an example for processing, which will not be described in detail in this embodiment.

[0119] It should be noted that the above-mentioned force consistency refers to the consistency of the direction of wrinkles generated by the membrane material after being pulled by the pores in the fixed adsorption area or the active adsorption area. If the adsorption force generated by the pores is too large, the membrane material will not be able to produce corresponding deformation, resulting in excessive deformation of the membrane material in all pore areas, resulting in longer wrinkle edges, that is, the direction vector of the wrinkle edge is larger, so the force direction consistency of the membrane material is greater; on the contrary, if the adsorption force of the pores is normal, then the farther away from the bending area, the smaller the deformation, that is, the wrinkle edge of the pore farther away from the bending area of ​​the membrane material is greater than the wrinkle edge of the pore close to the bending area, and at this time the force direction consistency of the membrane material is smaller.

[0120] It should be noted that when the flexible membrane material is wrinkled by adsorption force, the greater the force it is subjected to, the more edge wrinkles are likely to be left on the surface of the membrane material, and the greater the force it is subjected to, the straighter the shape of the edge wrinkles, forming a tight, straight edge at the edge of the pore. Therefore, this embodiment obtains the degree of negative pressure mismatch based on the wrinkle edge shape of the pore and the consistency of the force direction of the membrane material.

[0121] Preferably, the force coefficient of each pore in the image of the film material to be tested is obtained according to the shape of the wrinkle edge of each pore in the image of the film material to be tested; and the specific steps of obtaining the degree of negative pressure mismatch by combining the force coefficients of all pores in the image of the film material to be tested and the consistency of the force direction of the film material are as follows:

[0122] Obtaining the force coefficient of each pore in the image of the film material to be tested according to the shape of the wrinkle edge of each pore in the image of the film material to be tested;

[0123] The degree of negative pressure mismatch is obtained by combining the stress coefficients of all pores in the image of the film to be tested and the consistency of the stress direction of the film;

[0124] Specifically, the specific method for obtaining the force coefficient of each pore in the image of the film to be tested is:

[0125] For the mth pore, the stress coefficient C of the mth pore is m The calculation method is:

[0126]

[0127] in, is the direction vector of the qth wrinkle edge of the mth pore, Q m is the number of wrinkle edges of the mth pore, L m,q is the number of pixels of the qth wrinkle edge of the mth pore, indicating the length of the qth wrinkle edge of the mth pore, σ(L) m is the standard deviation of the number of pixels of all wrinkle edges of the mth pore; || ||2 is the function for obtaining the second norm, | | is the function for obtaining the absolute value, exp( ) is the exponential function with a natural constant as the base, and σ( ) is the function for obtaining the standard deviation.

[0128] in, Represents the number of pixels and the modulus of the direction vector of the qth wrinkle edge of the mth pore When the value is closer to 1, it means that the actual length of the wrinkle edge is more consistent with the length of the direction vector, that is, the wrinkle edge is straighter; σ(L) m is the standard deviation of the number of pixels of all wrinkle edges of the mth pore, which is used to reflect the consistency of different wrinkle edges. The better the consistency, the greater the stress on the pore.

[0129] Specifically, the specific method for obtaining the degree of negative pressure mismatch by combining the force coefficients of all pores in the image of the film to be tested and the consistency of the force direction of the film is as follows:

[0130] The consistency of the force direction of the membrane material is recorded as S;

[0131] The calculation method of the negative pressure improper degree F in the current simulation test is:

[0132]

[0133] Where M is the number of pores, C m is the stress coefficient of the mth pore; sigmoid{} represents the sigmoid function, which is used to normalize the product of the consistency of the stress direction of the membrane material and the mean of the stress coefficient, and the normalized result is 0-1.

[0134] Step S004: obtaining adjustment feedback parameters for the current simulation test using the degree of membrane material deviation and the degree of improper negative pressure; and adjusting the preset negative pressure for the next simulation test using the adjustment feedback parameters for the current simulation test.

[0135] It should be noted that when the membrane material is offset, it means that the negative pressure applied by the adsorption plate to the membrane material is too small, which in turn causes the movement of the membrane material. Therefore, it is necessary to increase the adsorption force of the adsorption plate according to the degree of membrane material offset. At this time, there is no need to adjust the adsorption force according to the degree of improper negative pressure. When the membrane material offset is zero, it proves that there is no membrane material offset due to too small a negative pressure. At this time, it is necessary to judge the pulling of the membrane material due to excessive negative pressure. Therefore, this embodiment uses the degree of membrane material offset and the degree of improper negative pressure to obtain the adjustment feedback parameters of the current simulation test; and uses the current simulation test adjustment feedback parameters to adjust the preset negative pressure of the next simulation test.

[0136] Specifically, the calculation method of the adjustment feedback parameter W in the current simulation test is:

[0137]

[0138] Wherein, D is the degree of membrane material deviation in the current simulation test, and F is the degree of improper negative pressure in the current simulation test.

[0139] Furthermore, the product of the adjustment feedback parameter of the current simulation test and the preset negative pressure is used as the preset negative pressure of the next simulation test, which is used for the adsorption of the membrane material by all adsorption plates in the next simulation test.

[0140] It should be noted that the exp(-x) model used in this embodiment only indicates that the negative correlation and the result of the constraint model output are in the interval (0,1], where x is the input of this model. In specific implementation, it can be replaced with other models with the same purpose. This embodiment only uses the exp(-x) model as an example for description without specific limitation.

[0141] On the other hand, see Figure 12 , which also shows a film bending life testing device provided by another embodiment of the present invention, please refer to Figure 2 The testing equipment for the bending life of a film material includes a display, a cabinet, a safety shield, and a dislocation bending test module, wherein the dislocation bending test module includes the following units:

[0142] The bending and dislocation testing unit 101 is used to absorb the film material through the adsorption plate and bend it to obtain the original film material image and the film material image to be tested in the current simulation test;

[0143] The film material offset degree acquisition unit 102 is used to obtain edge images of the original film material image and the film material image to be tested between the current simulation test and the next simulation test; obtain all pores and corner holes in the original film material image and the film material image to be tested; and analyze the offset of the film material image to be tested relative to the original film material image based on the positions of the corner holes in the original film material image and the film material image to be tested relative to the four corners of the film material to obtain the film material offset degree;

[0144] The negative pressure mismatch degree acquisition unit 103 is configured to obtain the wrinkle edge and direction vector of each pore in the film material image to be tested based on the connection between other edges in the edge image of the film material image to be tested and the edges of the pores; quantify the consistency of the direction vectors of the wrinkle edges generated by the film material under stress in different regions in the film material image to obtain the consistency of the stress direction of the film material; obtain the stress coefficient of each pore in the film material image to be tested based on the shape of the wrinkle edge of each pore in the film material image to be tested; and obtain the negative pressure mismatch degree by combining the stress coefficients of all pores in the film material image to be tested and the consistency of the stress direction of the film material;

[0145] The adjustment feedback parameter acquisition unit 104 is used to obtain the adjustment feedback parameters of the current simulation test using the degree of membrane material deviation and the degree of negative pressure inappropriateness;

[0146] The negative pressure adjustment unit 105 is used to adjust the preset negative pressure of the next simulation test by using the adjustment feedback parameters of the current simulation test.

[0147] like Figure 3 As shown, it shows a schematic diagram of a bending dislocation test unit of a film bending life test device, specifically, Figure 3a shows a schematic diagram of the bending and dislocation test unit in a 90-degree bending simulation state. The bending and dislocation test unit is installed on two parallel slide rails 10 of the cabinet, and two lifting shafts 1 are respectively installed vertically on the slide rails 10. The horizontally arranged rotating shaft 7 is connected to the two lifting shafts 1 through a transmission mechanism, etc. The movable adsorption plate 6 is fixed to the rotating shaft 7 by connecting devices such as a slot and a bolt. The fixed adsorption plate 5 is connected to two support rods 2 vertically installed on the cabinet by connecting devices such as a slot and a bolt to prevent the fixed adsorption plate 5 from being displaced. There is a certain distance between the fixed adsorption plate 5 and the movable adsorption plate 6 to leave space required for the movable adsorption plate to rotate. Figure 3 b shows a schematic diagram of the bending dislocation test unit in a ready state. When in the ready state, the movable adsorption plate 6 and the fixed adsorption plate 5 are in the same horizontal plane; the hydraulic device is tightly installed under the movable adsorption plate 6, and the hydraulic device includes a hydraulic rod 4 and a lifting platform 3 connected to one end of the hydraulic rod, and the other end of the hydraulic rod is fixed on the cabinet. The hydraulic device can move the lifting platform 3 from under the movable adsorption plate 6 to the same plane as the fixed adsorption plate 5, and one end of the lifting platform 3 is in the same longitudinal plane as the fixed adsorption plate 5 when in the ready state; a sensor 9 is installed directly above the center position of the fixed adsorption plate 5 and the movable adsorption plate 6, and the sensor is installed on the safety protective cover, wherein the sensor 9 is used to collect the image to be tested after each bending dislocation test of the membrane material.

[0148] It should be noted that the order in which the embodiments of the present invention are described above is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0149] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A test simulation method for the bending life of a membrane material, characterized in that: The method comprises the following steps: The film material is adsorbed and bent by an adsorption plate to obtain an original film material image of the current simulation test and an image of the film material to be tested; the adsorption plate includes a fixed adsorption plate and a movable adsorption plate; Between the current simulation test and the next simulation test, the edge images of the original film material image and the film material image to be tested are obtained; all pores and corner holes in the original film material image and the film material image to be tested are obtained; based on the positions of the corner holes in the original film material image and the film material image to be tested relative to the four corners of the film material, the offset of the film material image to be tested relative to the original film material image is analyzed to obtain the degree of film material offset; according to the connection between other edges in the edge image of the film material image to be tested and the edges of the pores, the wrinkle edges and their direction vectors of each pore in the film material image to be tested are obtained; the consistency of the direction vectors of the wrinkle edges generated by the force on the film material in the film material image to be tested in different regions is quantified to obtain the consistency of the force direction of the film material; according to the morphology of the wrinkle edges of each pore in the film material image to be tested, the force coefficient of each pore in the film material image to be tested is obtained; the degree of negative pressure mismatch is obtained by combining the force coefficients of all pores in the film material image to be tested and the consistency of the force direction of the film material; The specific steps for obtaining the degree of film material deviation include: The corresponding corner holes in the original film material image and the film material image to be tested are recorded as a set of corner hole pairs. The corner hole pair in the upper left corner of the original film material image is recorded as the first set of corner hole pairs. The four sets of corner hole pairs are obtained by sorting them in a clockwise order. The degree of membrane material deviation in the current simulation test The calculation method is: ； in, For the The positioning vector of the corner holes in the original film material image. For the Positioning vectors of the corner holes of the group corner holes in the image of the film material to be measured; is the function for finding the cosine similarity of the orientation vector, represents an exponential function with a natural constant as its base; The specific steps for obtaining the degree of improper negative pressure include: The consistency of the force direction of the membrane material is recorded as ; The degree of improper negative pressure in the current simulation test The calculation method is: ； in, is the number of pores, For the The stress coefficient of each pore; Represents the sigmoid function; The adjustment feedback parameters of the current simulation test are obtained by using the degree of membrane material deviation and the degree of improper negative pressure; the preset negative pressure of the next simulation test is adjusted by using the adjustment feedback parameters of the current simulation test; The specific steps of obtaining the adjustment feedback parameters include: Adjustment feedback parameters of the current simulation test The calculation method is: ； in, is the degree of membrane material deviation in the current simulation test, It is the degree of improper negative pressure in the current simulation test.

2. A test simulation method for the bending life of a membrane material according to claim 1, characterized in that: The obtaining of all pores and corner holes in the original film material image and the film material image to be tested comprises: Acquire all circular areas in the edge images of the original film material image and the film material image to be tested, record each circular area as a pore, and obtain the pore center of each pore; The film material corner point is obtained, and the pores corresponding to the pore circle centers with the closest Euclidean distance to the film material corner point in the original film material image and the film material image to be measured are recorded as corner pores.

3. A test simulation method for the bending life of a membrane material according to claim 1, characterized in that: The specific steps of obtaining the positioning vector include: In the original film material image, with the center of each corner hole as the origin, construct a vector from each origin to the nearest film material corner point, which is recorded as the positioning vector of each corner hole in the original film material image; Get the positioning vector of each corner hole in the film material image to be tested.

4. A test simulation method for the bending life of a membrane material according to claim 1, characterized in that: The specific steps for obtaining the consistency of the force direction of the membrane material include: The image of the film to be tested is equally divided along the direction perpendicular to the fixed adsorption plate and pointing to the movable adsorption plate. The area of ​​the image of the film to be tested on the fixed adsorption plate is recorded as the fixed adsorption area, and the area on the movable adsorption plate is recorded as the movable adsorption area. In the active adsorption region, for each pore, the direction vectors of all wrinkle edges of each pore are vector-fitted to obtain the pull fitting vector of each pore; The pull-fitting vectors of all pores in the active adsorption area are averaged to obtain the vector mean of the pull-fitting vectors of all pores in the active adsorption area. The mean of the cosine similarity between the pull-fitting vector of each pore in the active adsorption area and the vector mean of the pull-fitting vectors of all pores is calculated and recorded as the force consistency of the active adsorption area.

5. A test simulation method for the bending life of a membrane material according to claim 1, characterized in that: The method of obtaining the wrinkle edge and direction vector of each pore in the image of the film material to be tested according to the connection between other edges in the edge image of the film material to be tested and the edge of the pore comprises: In the edge image of the film material image to be measured, the edge connected to the edge of each pore is recorded as the wrinkle edge of each pore in the film material image to be measured; The point where each wrinkle edge of each pore in the film material image to be tested is connected to the edge of the pore is recorded as the end point, the other end of the wrinkle edge is recorded as the starting point, and the vector formed by the starting point pointing to the end point is recorded as the direction vector of each wrinkle edge of each pore in the film material image to be tested.

6. A test simulation method for the bending life of a membrane material according to claim 1, characterized in that: The specific steps of obtaining the force coefficient include: For the pores, The stress coefficient of each pore The calculation method is: ； in, For the The first pore The direction vector of the wrinkle edge, For the The number of wrinkled edges of each pore, For the The first pore The number of pixels along the edge of the wrinkle, For the The standard deviation of the number of pixels at the edges of all wrinkles of each pore; To find the second norm of the function, To find the absolute value of a function, is an exponential function with a natural constant as its base, To obtain the standard deviation function.

7. A testing device for the bending life of a membrane material, characterized in that: The device comprises: The bending and dislocation testing unit is used to absorb the film material through the adsorption plate and bend it to obtain the original film material image and the film material image to be tested in the current simulation test; A film material offset degree acquisition unit is used to obtain edge images of the original film material image and the image of the film material to be tested between the current simulation test and the next simulation test; obtain all pores and corner holes in the original film material image and the image of the film material to be tested; and analyze the offset of the image of the film material to be tested relative to the original film material image based on the positions of the corner holes in the original film material image and the image of the film material to be tested relative to the four corners of the film material to obtain the film material offset degree; The specific steps for obtaining the degree of film material deviation include: The corresponding corner holes in the original film material image and the film material image to be tested are recorded as a set of corner hole pairs. The corner hole pair in the upper left corner of the original film material image is recorded as the first set of corner hole pairs. The four sets of corner hole pairs are obtained by sorting them in a clockwise order. The degree of membrane material deviation in the current simulation test The calculation method is: ； in, For the The positioning vector of the corner holes in the original film material image. For the Positioning vectors of the corner holes of the group corner holes in the image of the film material to be measured; is the function for finding the cosine similarity of the orientation vector, represents an exponential function with a natural constant as its base; A negative pressure mismatch degree acquisition unit is configured to obtain the wrinkle edge and direction vector of each pore in the film material image to be tested based on the connection between other edges in the edge image of the film material image to be tested and the edges of the pores; quantify the consistency of the direction vectors of the wrinkle edges generated by the film material under stress in different regions in the film material image to be tested, and obtain the consistency of the stress direction of the film material; obtain the stress coefficient of each pore in the film material image to be tested based on the morphology of the wrinkle edge of each pore in the film material image to be tested; and obtain the negative pressure mismatch degree by combining the stress coefficients of all pores in the film material image to be tested and the consistency of the stress direction of the film material; The specific steps for obtaining the degree of improper negative pressure include: The consistency of the force direction of the membrane material is recorded as ; The degree of improper negative pressure in the current simulation test The calculation method is: ； in, is the number of pores, For the The stress coefficient of each pore; Represents the sigmoid function; The adjustment feedback parameter acquisition unit is used to obtain the adjustment feedback parameters of the current simulation test by using the degree of membrane material deviation and the degree of negative pressure imbalance; The specific steps of obtaining the adjustment feedback parameters include: Adjustment feedback parameters of the current simulation test The calculation method is: ； in, is the degree of membrane material deviation in the current simulation test, is the degree of improper negative pressure in the current simulation test; The negative pressure adjustment unit is used to adjust the preset negative pressure of the next simulation test by using the current simulation test adjustment feedback parameter.

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