Self-cleaning system and method of an explosion-proof camera in a coal mine underground

Abstract

The application discloses a self-cleaning system and method of an explosion-proof camera in a coal mine. The pixel value of each pixel point in the image collected by the camera is used to determine whether the camera lens needs to be cleaned. When the number of pixel points with pixel values higher than the threshold value is too small, it is determined that the camera lens has been contaminated, and a cleaning action is performed. The cleaning process uses a film tearing method to remove contaminants in front of the explosion-proof camera lens. The front of the explosion-proof camera lens is covered with multiple layers of transparent film. When the surface of the film is contaminated and affects the camera image collection, the moving motor drives the gear rack mechanism to work, driving the cleaning module to move in a straight line. At the same time, the reel motor drives the reel to rotate, tearing off and storing the contaminated film, and exposing the uncontaminated film. The cleaning module completes a cleaning operation during the go and return. After the cleaning operation is completed, the number of layers of the remaining film is calculated. When the number of layers of the remaining film is less than the set value, the maintenance personnel replace the transparent film.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of camera cleaning, in particular to a self-cleaning system and method for an explosion-proof camera in a coal mine. BACKGROUND

[0002] With the continuous development of image processing technology, machine vision is widely used in various detection scenes, and has the advantages of high precision, low cost, high efficiency and strong adaptability. Therefore, the application of machine vision in the coal mine environment has also attracted widespread attention. However, due to the harsh environment in the coal mine, there are a large amount of coal dust, water mist and other pollutants in the air, which are easy to contaminate the camera lens, resulting in the camera being unable to collect effective image information. This poses a serious challenge to the application of machine vision in the coal mine.

[0003] At present, the methods for cleaning the camera mainly include three kinds of wiping method, water washing method and film replacement method. The wiping method is to wipe the camera lens or the transparent protective shell of the camera by a wiping device to remove the surface pollutants. For example, a Chinese patent with publication number CN219875896U discloses an automatic dust removal cleaning device suitable for industrial cameras in mine environment, which cleans the lens by rotating wiping and air blowing device at the lens of the protective shell. However, this method may scratch the lens or the protective shell, affecting the quality of the collected image, and the cleaning may not be complete. The water washing method is to realize self-cleaning by spraying cleaning liquid to the camera lens or the camera protective shell. For example, a Chinese patent application with publication number CN109249901A discloses a spherical rotary cleaning device for cameras or sensors. The camera is installed in a rotatable spherical transparent member, the side of the spherical member close to the lens is exposed to the external environment, and the rest is wrapped in the shell. When the spherical member is contaminated, it is rotated, the contaminated part enters the shell, and the spray head sprays cleaning liquid for cleaning. Then the wiping structure wipes the residual cleaning liquid on the outer surface of the spherical member. However, this method needs to be equipped with cleaning liquid, water pump, spray head and other devices, which on the one hand makes it difficult to provide enough cleaning liquid in the coal mine environment, and on the other hand the installation of water pump, spray head and other devices will make the cleaning system too complex and the cost is high.

[0004] The film replacement method is to arrange a transparent film in front of the camera lens, and the cleaning operation is realized by replacing the transparent film when the film is contaminated, such as the automatic cleaning device and method for monitoring the front glass of the camera disclosed in Chinese patent application CN116967242A, two spools are arranged on both sides of the camera, one is used for storing clean film, and the other is used for storing contaminated film; when the film in front of the lens is contaminated, the two spools rotate, one releases the clean film to cover the lens, and the other stores the contaminated film. However, in the coal mine environment, contaminants are normal, and the clean film will be contaminated during the process of being released from the spool to cover the lens. When the side of the film facing the lens is contaminated, the contaminants will directly contaminate the lens, resulting in incomplete cleaning. SUMMARY

[0005] In view of the above technical deficiencies, the purpose of the present application is to provide a self-cleaning system and method for a coal mine explosion-proof camera, which can solve the problems of incomplete cleaning, complex structure and difficulty in realizing in the coal mine environment.

[0006] To solve the above technical problems, the present application adopts the following technical scheme:

[0007] The present application provides a self-cleaning system for a coal mine explosion-proof camera, which comprises a plurality of layers of film covering the lens of the camera, a mounting plate fixed above the camera, and a cleaning module provided in front of the lens for winding the plurality of layers of film, the cleaning module comprising a barrel structure with a spool inside; the mounting plate is provided with a strip-shaped slot perpendicular to the direction of the lens; the upper end of the barrel structure is fixedly connected to a top platform through a plurality of connecting columns, the top platform is provided with a moving motor, the bottom of the barrel structure is provided with a spool motor for controlling the rotation of the spool, the connecting columns pass through the strip-shaped slot and are slidably matched with the strip-shaped slot to limit the movement of the barrel structure only in the direction of the strip-shaped slot, the output end of the moving motor is connected to a gear shaft, the other end of the gear shaft is rotatably connected to the upper end face of the barrel structure, and the gear shaft is provided with a gear below the strip-shaped slot, the bottom of the mounting plate is provided with a strip-shaped tooth engaged with the gear and consistent with the length direction of the strip-shaped slot; the gear shaft is provided with a shaft shoulder structure above the strip-shaped slot for limiting the downward displacement of the barrel structure, the gear limits the upward movement of the barrel structure, and the barrel structure is provided with a strip-shaped opening for the plurality of layers of film to pass through and a pressing device for pressing the plurality of layers of film to facilitate winding.

[0008] Preferably, the pressing device comprises four torsion springs, four connecting rods and two rollers coaxial with the reel; four boss structures are arranged near the two ends of the strip-shaped opening; the four connecting rods are respectively hingedly installed on the four boss structures; the torsion springs are respectively installed in the cavities formed by the boss structures and the connecting rods and are positioned by spring shafts, one spring head of the torsion spring is in contact with the boss structure, and the other spring head is in contact with the connecting rod; the upper end of the spring shaft is provided with a snap spring for pressing the connecting rod and the boss structure.

[0009] When the rollers are located on the upper surface of the multi-layer film, the torsion springs are in a twisted state, at this time, the torsion springs apply a torsional force to the connecting rods, so that the connecting rods have a tendency to rotate, further driving the rollers to press the multi-layer film; the end of the roller is hingedly connected with the two connecting rods on the same side, and the two rollers press the multi-layer film at the front and rear positions of the film tearing position respectively, and the multi-layer film passes between the two rollers and enters the reel in the barrel-shaped structure.

[0010] In order to prevent the pressing device from hindering the subsequent movement of the cleaning module when the cleaning module moves to the left and right limit positions, the connecting rod structure of the roller is arranged in a cross manner, and the roller can be automatically reset after being separated from the upper surface of the multi-layer film along with the movement of the cleaning module.

[0011] Preferably, the multi-layer film is folded from a transparent film, the film has adhesion, and is adhered to each other, one end of the film is fully covered and attached in front of the lens, and the other end of the film passes through the strip-shaped opening of the barrel-shaped structure and is wound on the reel.

[0012] Preferably, the barrel-shaped structure does not block the lens of the camera when it moves to the left and right maximum displacement positions.

[0013] Preferably, the mounting plate is fixed by a clamp installed on the camera, and a plurality of rib plates for strengthening the strength of the mounting plate are arranged on the mounting plate.

[0014] The application also provides a use method of the self-cleaning system, comprising the following steps:

[0015] S1, the camera transmits the pixel value of each pixel point in the collected image to the controller, and when the number of pixel points with pixel value higher than the threshold value is small, the controller determines that the lens has been contaminated and controls the cleaning module to perform cleaning operation;

[0016] S2, the initial position of the cleaning module is on the left side of the camera, the movement of the cleaning module from left to right is defined as the forward stroke, and the movement of the cleaning module from right to left is defined as the return stroke, and the forward stroke and the return stroke both complete a cleaning operation;

[0017] During the forward stroke, the moving motor and the reel motor work at the same time first, and when the contaminated multi-layer film is completely torn off, the reel motor stops rotating; in order to prevent the cleaning module from blocking the field of view of the camera, the moving motor continues to drive the cleaning module to move a distance L to the right;

[0018] When returning, the moving motor first drives the cleaning module to move left by a distance L, so that the film of the latest torn part of the multi-layer film is taut; then the moving motor and the reel motor work simultaneously until the cleaning module returns to the initial position;

[0019] S3, when the remaining multi-layer film layer number is less than the set layer number, the controller reminds the maintenance personnel to replace the transparent film.

[0020] Preferably, in step S1, a plurality of light sources are arranged in the camera field of view, to ensure that when the camera collects an effective image, the image contains at least A pixel points with pixel values higher than threshold B; the values of A and B are determined through a camera lens contamination simulation test, and in the process of determining whether the camera lens is contaminated, an image collected by the camera is detected every n seconds.

[0021] Preferably, in step S2, the moving speed of the cleaning module is the same as the film tearing speed, so in terms of rotating speed, the moving motor and the reel motor should satisfy the following relationship:

[0022] m·z·n1=(d+2h·i)·n2;

[0023] Where n1 is the rotating speed of the moving motor, n2 is the rotating speed of the reel motor, m is the modulus of the gear, z is the number of teeth of the gear, d is the diameter of the reel, h is the thickness of the film, and i is the number of turns of the reel motor since it started working, which is reset to zero after the film is replaced during maintenance.

[0024] Preferably, in step S2, the distance L is calculated as follows:

[0025]

[0026]

[0027]

[0028] s=s 初始 +j·h

[0029]

[0030] Where y is the distance from the center of the reel to the left side of the multi-layer film when the cleaning module is at the initial position, s 初始 is the distance from the center of the reel to the upper surface of the multi-layer film when the cleaning module is not performing cleaning, s is the distance from the center of the reel to the upper surface of the multi-layer film, j is the number of cleaning operations performed by the cleaning module, r is the radius of the reel after winding the film, and the meanings of α and β are shown in the schematic diagram.

[0031] Preferably, in step S3, the remaining number of multi-layer film layers X=C-j, where C is the initial number of layers of the transparent film.

[0032] The present application has the advantages that, compared with the water cleaning method, the present application uses the film tearing method to clean the contaminants of the camera lens, avoids the use of cleaning liquid, and does not need devices such as a water pump, greatly improving the practicability in the coal mine underground; compared with the film replacing method, the transparent film is pasted in front of the lens in the present application, avoiding the pollution of the clean film during the film replacing process, and ensuring the thoroughness of cleaning. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0034] Figure 1 A structural schematic diagram of a self-cleaning system of a coal mine underground explosion-proof camera provided by the present application;

[0035] Figure 2 A structure diagram of a reel shell of the present application;

[0036] Figure 3 A structure diagram of a pressing device of the present application;

[0037] Figure 4 An installation diagram of a torsion spring of the present application;

[0038] Figure 5 A structure diagram of a multi-layer film of the present application;

[0039] Figure 6 A principle diagram of a crossing arrangement of a pressing device of the present application;

[0040] Figure 7 A flow chart of a self-cleaning method of the present application;

[0041] Figure 8 A principle diagram of distance L calculation of the present application.

[0042] Explanation of reference signs:

[0043] 1, moving motor; 2, gear; 3, bearing; 4, camera; 5, mounting plate; 6, barrel structure; 7, reel; 8, multi-layer film; 9, pressing roller; 10, reel motor; 11, top platform; 12, connecting column; 14, strip-shaped port; 15, boss structure; 16, clamping spring; 17, torsion spring; 18, connecting rod; 19, spring head; 20, spring shaft; 21, strip-shaped tooth; 22, shaft shoulder structure. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0045] Please refer to Figures 1-2 The self-cleaning system of the explosion-proof camera underground coal mine disclosed in the embodiments of the present application comprises a plurality of thin films 8 covering the lens of the camera 4, a mounting plate 5 fixed above the camera 4, and a cleaning module arranged in front of the lens for winding the plurality of thin films 8. The cleaning module comprises a barrel-shaped structure 6 with a winding shaft 7 arranged inside. The mounting plate 5 is provided with a strip-shaped groove perpendicular to the direction of the lens. The upper end of the barrel-shaped structure 6 is fixedly connected to a top platform 11 through a plurality of connecting columns 12. The top platform 11 is provided with a moving motor 1. The bottom of the barrel-shaped structure 6 is provided with a winding shaft motor 10 for controlling the rotation of the winding shaft 7. The upper and lower ends of the winding shaft 7 are both provided with an adapted bearing 3.

[0046] The connecting columns 12 pass through the strip-shaped groove and are slidably matched with the strip-shaped groove to limit the barrel-shaped structure 6 to move only in the direction of the strip-shaped groove. The output end of the moving motor 1 is connected to a gear shaft. The other end of the gear shaft is rotatably connected to the upper end face of the barrel-shaped structure 6 through a bearing seat. The gear shaft is provided with a gear 2 below the strip-shaped groove. The bottom of the mounting plate 5 is provided with a strip-shaped tooth 21 engaged with the gear 2 and consistent with the length direction of the strip-shaped groove. The gear shaft is provided with a shaft shoulder structure 22 above the strip-shaped groove for limiting the downward displacement of the barrel-shaped structure 6. The gear limits the upward movement of the barrel-shaped structure. The barrel-shaped structure 6 is provided with a strip-shaped opening 14 for the plurality of thin films 8 to pass through and a pressing device for pressing the plurality of thin films 8 to facilitate winding the plurality of thin films 8. The winding shaft motor 10 and the moving motor 1 are respectively electrically connected to a controller.

[0047] Please refer to Figures 3-4 The pressing device comprises four torsional springs 17, four connecting rods 18, and two pressure rollers 9 coaxial with the winding shaft 7. Four boss structures 15 are correspondingly arranged near the two ends of the strip-shaped opening 14. The four connecting rods 18 are respectively hingedly mounted on the four boss structures 15. The torsional springs 17 are respectively mounted in the cavities formed by the boss structures 15 and the connecting rods 18 and are positioned by spring shafts 20. One spring head 19 of the torsional spring 17 is in contact with the boss structure 15, and the other spring head 19 is in contact with the connecting rod 18. The spring shaft 20 is provided with a clamping spring 16 for pressing the connecting rod 18 and the boss structure 15.

[0048] When the pressing roller 9 is located on the upper surface of the multi-layer film 8, the torsion spring 17 is in a state of being twisted, at this time, the torsion spring 17 applies a torsion force to the connecting rod 18, so that the connecting rod 18 has a tendency to rotate, further driving the pressing roller 9 to press the multi-layer film 8; the end of the pressing roller 9 is hinged to the two connecting rods 18 on the same side, and the two pressing rollers 9 press the multi-layer film 8 at the front and rear positions of the film tearing position respectively, and the multi-layer film 8 passes between the two pressing rollers 9 and enters the reel 7 of the barrel structure 6.

[0049] Please refer to Figure 6 In order to prevent the pressing device from hindering the subsequent movement of the cleaning module when the cleaning module moves to the left and right limit positions, the connecting rod structure of the pressing roller is arranged in a cross manner, and the pressing roller can be automatically reset after being separated from the upper surface of the multi-layer film. When a non-cross arrangement is used, the movement direction of the connecting rod is opposite to the reset direction, which will hinder the movement of the cleaning module; when a cross arrangement is used, the movement direction of the connecting rod is the same as the reset direction, which will not hinder the movement of the cleaning module, and the pressing roller separated from the upper surface of the multi-layer film will return to the surface.

[0050] Please refer to Figure 5 The multi-layer film 8 is folded from a transparent film, and the film has adhesion, so that the films adhere to each other, one end of the film is fully covered and attached in front of the lens, and the other end of the film passes through the strip-shaped opening 14 of the barrel structure 6 and is wound on the reel 7.

[0051] The barrel structure 6 does not block the lens of the camera 4 when it moves to the left and right maximum displacement positions.

[0052] The mounting plate 5 is fixed by the clamp installed on the camera 4, and a plurality of rib plates for strengthening the strength of the mounting plate 5 are arranged on the mounting plate 5.

[0053] Please refer to Figure 7 The application also provides a use method of the self-cleaning system, which comprises the following steps:

[0054] S1, the camera 4 transmits the pixel value of each pixel point in the collected image to the controller, and when the number of pixel points with pixel value higher than the threshold value is small, the controller determines that the lens has been contaminated and controls the cleaning module to perform cleaning operation;

[0055] S2, the initial position of the cleaning module is on the left side of the camera 4, and the movement of the cleaning module from left to right is defined as the forward stroke, and the movement of the cleaning module from right to left is defined as the return stroke, and the forward stroke and the return stroke each complete a cleaning operation;

[0056] During the forward stroke, the motor 1 and the reel motor 10 are first moved and work at the same time, and when the contaminated multi-layer film 8 is completely torn off, the reel motor 10 stops rotating; in order to prevent the cleaning module from blocking the field of view of the camera, the motor 1 continues to drive the cleaning module to move a distance L to the right;

[0057] When returning, the moving motor 1 first drives the cleaning module to move left by a distance L, so that the film of the latest torn part of the multi-layer film 8 is taut; then the moving motor 1 and the reel motor 10 work simultaneously until the cleaning module returns to the initial position;

[0058] S3, when the remaining multi-layer film 8 layer number is less than the set layer number, the controller reminds the maintenance personnel to replace the transparent film.

[0059] In step S1, a plurality of light sources are arranged in the field of view of the camera 4, so that when the camera 4 collects an effective image, the image contains at least A pixel points with pixel values higher than threshold B; the values of A and B are determined through a camera 4 lens contamination simulation test, and in the process of determining whether the camera 4 lens is contaminated, an image collected by the camera 4 is detected every n seconds.

[0060] In step S2, the moving speed of the cleaning module is the same as the film tearing speed, so in terms of rotating speed, the moving motor 1 and the reel motor 10 should satisfy the following relationship:

[0061] m·z·n1=(d+2h·i)·n2;

[0062] Where n1 is the rotating speed of the moving motor 1, n2 is the rotating speed of the reel motor 10, m is the modulus of the gear 2, z is the number of teeth of the gear 2, d is the diameter of the reel 7, h is the thickness of the film, and i is the number of turns of the reel motor 10 since it started working, which is reset to zero after the film is replaced during maintenance.

[0063] Referring to Figure 8 , in step S2, the calculation formula of the distance L is as follows:

[0064]

[0065]

[0066]

[0067] s=s 初始 +j·h

[0068]

[0069] Where y is the distance from the center of the reel 7 to the left side of the multi-layer film 8 when the cleaning module is at the initial position, s 初始 is the distance from the center of the reel 7 to the upper surface of the multi-layer film 8 when the cleaning module is not performing cleaning, s is the distance from the center of the reel 7 to the upper surface of the multi-layer film 8, j is the number of cleaning operations of the cleaning module, r is the radius of the reel 7 after winding the film, and the meanings of α and β are shown in the schematic diagram.

[0070] In step S3, the number of layers X of the multilayer film 8 remaining is X = C - j, where C is the initial number of layers of the transparent film.

[0071] It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application cover modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

Claims

1. A self-cleaning system for an explosion-proof camera in a coal mine underground, characterized by, The application relates to a cleaning module for a camera, which comprises a multi-layer film (8) covering the lens of the camera (4), a mounting plate (5) fixed above the camera (4), and a cleaning module arranged in front of the lens for winding the multi-layer film (8), wherein the cleaning module comprises a barrel-shaped structure (6) with a winding shaft (7) arranged inside; the mounting plate (5) is provided with a strip-shaped slot perpendicular to the direction of the lens; the upper end of the barrel-shaped structure (6) is fixedly connected with a top platform (11) through a plurality of connecting columns (12); the top platform (11) is provided with a moving motor (1); the bottom of the barrel-shaped structure (6) is provided with a winding shaft motor (10) for controlling the rotation of the winding shaft (7); the connecting columns (12) pass through the strip-shaped slot and are slidably matched with the strip-shaped slot so as to limit the barrel-shaped structure (6) to move only along the direction of the strip-shaped slot; the output end of the moving motor (1) is connected with a gear shaft, the other end of the gear shaft is rotationally connected with the upper end face of the barrel-shaped structure (6), the gear shaft is provided with a gear (2) below the strip-shaped slot, and the bottom of the mounting plate (5) is provided with a strip-shaped gear (21) engaged with the gear (2) and consistent with the length direction of the strip-shaped slot; the gear shaft is provided with a shaft shoulder structure (22) above the strip-shaped slot for limiting the downward displacement of the barrel-shaped structure (6); the barrel-shaped structure (6) is provided with a strip-shaped opening (14) for the multi-layer film (8) to pass through and a pressing device for pressing the multi-layer film (8) to facilitate winding of the multi-layer film (8); the winding shaft motor (10) and the moving motor (1) are electrically connected with a controller respectively. The pressing device comprises four torsion springs (17), four connecting rods (18) and two pressure rollers (9) coaxial with the winding shaft (7); the strip-shaped opening (14) is provided with four boss structures (15) near both ends of the strip-shaped opening (14); the four connecting rods (18) are respectively hingedly arranged on the four boss structures (15); the torsion springs (17) are respectively arranged in cavities formed by the boss structures (15) and the connecting rods (18) and are positioned by spring shafts (20), one spring head (19) of the torsion spring (17) is in contact with the boss structure (15), and the other spring head (19) is in contact with the connecting rod (18); the connecting rods (18) of the two pressure rollers (9) are cross arranged; the spring shaft (20) is provided with a clamping spring (16) for pressing the connecting rod (18) and the boss structure (15) on the upper end. When the pressure roller (9) is located on the upper surface of the multi-layer film (8), the torsion spring (17) is in a twisted state, at this time, the torsion spring (17) applies a torsional force to the connecting rod (18), so that the connecting rod (18) has a tendency to rotate, and further drives the pressure roller (9) to press the multi-layer film (8); the end of the pressure roller (9) is hingedly connected with two connecting rods (18) on the same side, and the two pressure rollers (9) respectively press the multi-layer film (8) at the front and rear positions of the film tearing position, and the multi-layer film (8) passes through the two pressure rollers (9) and enters the winding shaft (7) of the barrel-shaped structure (6). The multi-layer film (8) is folded from a transparent film, the film has adhesion, and is adhered to each other, one end of the film is fully covered and attached in front of the lens, and the other end of the film passes through the strip-shaped opening (14) of the barrel-shaped structure (6) and is wound on the winding shaft (7).

2. The self-cleaning system of an explosion-proof camera in a coal mine underground according to claim 1, characterized in that, The barrel structure (6) does not block the lens of the camera (4) when moving to the left and right maximum displacement.

3. The self-cleaning system of an explosion-proof camera in a coal mine underground according to claim 1, characterized in that, The mounting plate (5) is fixed by a clamp mounted on the camera (4), and a plurality of rib plates for strengthening the strength of the mounting plate (5) are further arranged on the mounting plate (5).

4. A method of using the self-cleaning system of the explosion-proof camera for use in coal mines according to any one of claims 1-3, characterized in that, The method comprises the following steps: S1, the camera (4) transmits the pixel value of each pixel point in the collected image to the controller, and when the number of pixel points with pixel value higher than the threshold value is small, the controller determines that the lens has been contaminated and controls the cleaning module to perform cleaning operation; S2, the initial position of the cleaning module is on the left side of the camera (4), and the movement of the cleaning module from left to right is defined as the forward stroke, and the movement of the cleaning module from right to left is defined as the return stroke, and the forward stroke and the return stroke each complete a cleaning operation; During the forward stroke, the motor (1) and the reel motor (10) work at the same time, and when the contaminated multilayer film (8) is completely torn off, the reel motor (10) stops rotating; In order to prevent the cleaning module from blocking the camera view, the motor (1) continues to drive the cleaning module to move to the right by a distance L; During the return stroke, the motor (1) first drives the cleaning module to move to the left by a distance L, so that the newly torn part of the multilayer film (8) is taut; then the motor (1) and the reel motor (10) work at the same time until the cleaning module returns to the initial position; S3, when the number of layers of the remaining multilayer film (8) is less than the set number of layers, the controller reminds the maintenance personnel to replace the transparent film.

5. The method of claim 4, wherein, In step S1, a plurality of light sources are arranged in the field of view of the camera (4) to ensure that the camera (4) includes at least A pixel points with pixel value higher than threshold value B in the image when collecting effective image; the values of A and B are determined through camera (4) lens contamination simulation test, and in the process of determining whether the camera (4) lens is contaminated, an image collected by the camera (4) is detected every n seconds.

6. The method of claim 4, wherein, In step S2, the moving speed of the cleaning module is the same as the film tearing speed, so in terms of rotating speed, the motor (1) and the reel motor (10) should satisfy the following relationship: ； wherein is the rotational speed of the mobile motor (1), is the rotational speed of the reel motor (10), m is the module of the gear (2), z is the number of teeth of the gear (2), d is the diameter of the reel (7), h is the thickness of the film, i is the number of revolutions of the reel motor (10) from the start of the work, the value of i is zeroed after the film is replaced during the repair work.

7. The method of claim 5, wherein, In step S2, the calculation formula of the distance L is as follows: ; wherein, y is the distance from the center of the reel (7) to the left side of the multi-layer film (8) when the cleaning module is in the initial position, s is the distance from the center of the reel (7) to the upper surface of the multi-layer film (8) when the cleaning module does not perform the cleaning action, j is the number of times the cleaning module performs the cleaning operation, and r is the radius of the reel (7) after winding the film.

8. The method of claim 7, wherein, In step S3, the number of layers of the multilayer film (8) remaining where C is the initial number of layers of the transparent film.

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