Automatic monitoring system and monitoring method for fastening degree

Abstract

The invention provides an automatic monitoring system and monitoring method for the fastening degree. The method comprises the following steps: acquiring image information of a gasket area; background removal is carried out on the photographing area image, and a gasket image is segmented from the obtained area image; performing standardized sampling on the obtained gasket image to obtain a standard gasket image with a unified pixel size; calculating an average color vector by adopting sliding sampling based on the obtained standard gasket image; counting the color type distribution of the average color vector obtained by calculation after each sliding of the window in the standard gasket image, and marking the color type with the largest distribution number as the color of the standard gasket image; comparing whether the color of the standard gasket image is within the upper and lower limit thresholds of the color plate of the piezochromic material of which the fastening degree is in a safe state or not; based on the comparison result, further control is performed. According to the invention, real-time monitoring of the fastening degree of the nut is realized, the purpose of real-time control of the fastening degree of the nut is effectively achieved, and ACM safety accidents are prevented.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft, and in particular to an automatic monitoring system and a monitoring method for the tightening degree of an ACM connecting rod nut. Background Art

[0002] With the rapid development and technological advancement of the aircraft manufacturing industry, aircraft are flying higher and higher. The low temperature, low pressure, and low oxygen environment at high altitudes pose a great threat to the human body. Therefore, the aircraft environmental control system has become an indispensable system in aircraft. There are two main types of refrigeration systems in aircraft environmental control systems: air cycle refrigeration systems and steam cycle refrigeration systems. Among them, the air cycle refrigeration system dissipates heat based on the principle of converting thermal energy into mechanical work. The core component of the aircraft air cycle refrigeration system is the air cycle machine (ACM). The ACM is a coaxial component in which the turbine, compressor, and fan are fastened to the same connecting rod 4 by nuts. The nut 1 is installed in the same position as shown in the figure. Figure 1 As shown. During the operation of the ACM, due to the rotation and vibration of the connecting rod 4, the nut 1 used to fix the connecting rod 4 may be easy to fall off and loose, affecting the normal operation of the ACM. Therefore, how to solve the problem of monitoring the tightness of the ACM connecting rod nut is an urgent problem to be solved in this field.

[0003] The prior art discloses a solution for monitoring the tightness of nuts and bolts, which adds a gasket 3 of a piezochromic material between the nut 1 and the bolt, and uses the compression force between the nut 1 and the bolt to change the color of the gasket 3 to judge the tightness.

[0004] The applicant has found that the prior art has at least the following technical problems: this method does not take into account the stress distribution of the clamping force between the bolt and the nut 1, and requires manual inspection, and its effectiveness and convenience need to be improved.

[0005] Therefore, it is necessary to develop an automatic method for detecting the tightness of the nut, which can be used to monitor the tightness of the nut during normal operation of the ACM, reduce management and maintenance work, and save manpower. Summary of the invention

[0006] The purpose of the present invention is to provide an automatic monitoring system and method for the tightness of an ACM connecting rod nut, so as to solve the technical problems in the prior art that the tightness monitoring scheme does not take into account the stress distribution of the clamping force between the bolt and the nut, requires manual inspection, and the effectiveness and convenience need to be improved.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a method for fully automatic monitoring the tightness of an ACM connecting rod nut, the method comprising the following steps:

[0009] Get the gasket area image information;

[0010] De-backgrounding is performed on the photographed area image, and the gasket image is segmented from the acquired area image;

[0011] Performing standardized sampling on the obtained gasket image to obtain a standard gasket image with uniform pixel size;

[0012] Based on the obtained standard gasket image, the average color vector is calculated by sliding sampling;

[0013] Count the color type distribution of the average color vector calculated after each sliding of the window in the standard gasket image, and mark the color type with the largest distribution as the color of the standard gasket image;

[0014] Comparing whether the color of the standard gasket image is within the upper and lower limit thresholds of the color plate of the piezochromic material with a secure tightening degree;

[0015] Based on the comparison result, further control is performed.

[0016] The fully automatic monitoring method for the tightness of an ACM connecting rod nut provided by the present invention obtains a standard gasket image by taking photos, removing background and standardizing sampling, makes the gasket image pixel size uniform for later processing, performs sliding sampling on the gasket image, and performs average color vector calculation based on RGB value; counts the number distribution of color categories corresponding to the average color vector of each sliding window in the gasket image, and takes the color type with the largest distribution number as the color of the entire piezochromic gasket; finally, compares whether the color of the piezochromic gasket is within the color change range of the tightness in a safe state; if the color does not reach the corresponding color range of the tightness in a safe state, sends information to the maintenance personnel terminal to remind them to tighten the nuts. Under the premise of not affecting the normal operation of the ACM, the tightness of the nuts can be monitored in real time, and a high recognition accuracy and a fast recognition speed are maintained. Monitoring record query is supported, and the purpose of real-time control of the tightness of the nuts is effectively achieved to prevent ACM safety accidents.

[0017] As a further improvement of the present invention, the further control is performed based on the comparison result, including:

[0018] If the color does not reach the corresponding color range for a safe tightening state, a message is sent to the maintenance personnel terminal to remind them to tighten the equipment;

[0019] If the color is within the corresponding color range of the secure tightening state, it is determined to be secure, and the next gasket area image is captured.

[0020] As a further improvement of the present invention, the step of removing the background of the photographed area image and segmenting the gasket image from the acquired area image includes:

[0021] In the RGB color space, pixels within the color change range are extracted from the gasket area image according to the determined RGB threshold range;

[0022] Add a mask on top of the irrelevant pixels of the original image, segmenting the pad image.

[0023] As a further improvement of the present invention, the method of calculating the average color vector by sliding sampling based on the obtained standard gasket image includes:

[0024] Select a fixed-size window;

[0025] Select the step size for each slide to define the step size;

[0026] Starting from the upper left corner of the image, place the window on the image, and then gradually move the window until the entire image is covered to complete the sliding window process;

[0027] The average color vector is calculated for each pixel within the window for color analysis.

[0028] As a further improvement of the present invention, the average color vector is calculated according to the following formula:

[0029] In RGB space, the average color vector of pixels in each window is:

[0030] Where: T is the transpose,

[0031]

[0032] Where R i , G i , B i Respectively represent the values ​​of the RGB components of the i-th pixel in each window, and m is the number of pixels in the given sliding window.

[0033] As a further improvement of the present invention, the step of obtaining the gasket area image information includes:

[0034] Use an industrial camera to continuously capture images of the gasket area at 10-second intervals until the color fails or the ACM operation ends;

[0035] After the industrial camera captures the gasket area image, the captured gasket area image is uploaded to the image processing module for processing.

[0036] As a further improvement of the present invention, the step size is equal to the window size, or the step size is smaller than the window size.

[0037] As a further improvement of the present invention, the pressing force when the fastening degree is in a safe state is 80-100% of the maximum pressing force; and the pressing force when the fastening degree is in an unsafe state is 0-80% of the maximum pressing force.

[0038] The present invention provides an automatic monitoring system for tightening degree, comprising a tightening color display device, an image acquisition module, an image processing module, and an early warning module; wherein:

[0039] The fastening color display device is installed at the position to be monitored;

[0040] The image acquisition module is installed on the outside of the fastening color development device;

[0041] The image processing module and the early warning module are arranged in a server of an aircraft environmental control system.

[0042] As a further improvement of the present invention, the fastening display device comprises a nut, a transparent plastic ring and a piezochromic gasket; wherein:

[0043] The piezochromic gasket is sleeved on the outside of the connecting rod and abuts against the bolt;

[0044] The nut is threaded on the connecting rod and abuts against the piezochromic gasket;

[0045] The transparent plastic ring is sleeved on the outside of the nut and abuts against the piezochromic gasket.

[0046] As a further improvement of the present invention, the image acquisition module includes an industrial camera installed on the ram air valve.

[0047] The automatic monitoring system of the tightness of the present invention is firmly adhered to the nut by a transparent plastic ring, so that the stress of the nut when pressing the piezochromic gasket is evenly distributed, so that the color change of the gasket is uniform, and it is more convenient to observe the tightness of the nut. The gasket image is obtained by removing the background of the photographed area image, and standardized sampling is performed to make the gasket image pixel size uniform for later processing. Sliding sampling is performed on the gasket image, and the average color vector calculation and classification based on the RGB value are performed; the number distribution of color categories corresponding to the average color vector of each sliding window in the gasket image is counted, and the color type with the largest distribution number is used as the color of the piezochromic gasket; finally, the color of the piezochromic gasket is compared to see whether it is within the color change range of the tightness in a safe state; if the color does not reach the corresponding color range of the tightness in a safe state, a message is sent to the maintenance personnel terminal to remind tightening. 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0049] Figure 1 It is a structural schematic diagram of the automatic monitoring system of the tightening degree of the present invention;

[0050] Figure 2 yes Figure 1 Middle A is a partial enlarged view;

[0051] Figure 3 It is a flow chart of the fully automatic monitoring method of the tightening degree of the ACM connecting rod nut of the present invention;

[0052] Figure 4 It is a control flow chart of an embodiment of a method for fully automatic monitoring the tightness of an ACM connecting rod nut of the present invention.

[0053] In the figure, 1. nut; 2. transparent plastic ring; 3. piezochromic gasket; 4. connecting rod; 5. ram air valve; 6. industrial camera; 7. bracket connection; 8. standard light source. DETAILED DESCRIPTION

[0054] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0055] like Figure 3 As shown, the present invention provides a method for fully automatic monitoring of the tightness of an ACM connecting rod nut, the method comprising the following steps:

[0056] Step S1, obtaining gasket area image information;

[0057] As a further improvement of the present invention, obtaining the gasket area image information includes:

[0058] Step S11, using an industrial camera to continuously capture images of the gasket area at intervals of 10 seconds until the color fails or the ACM operation ends;

[0059] Step S12: After the industrial camera captures the gasket area image, the captured gasket area image is uploaded to the image processing module for processing.

[0060] Step S2, removing the background of the photographed area image, and segmenting the gasket image from the acquired area image;

[0061] As a further improvement of the present invention, background removal is performed on the photographed area image, and a gasket image is segmented from the acquired area image, including:

[0062] Step S21, in the RGB color space, extracting pixels within the color change range of the gasket area image according to the determined RGB threshold range;

[0063] Step S22: adding a mask on top of irrelevant pixels of the original image to segment the gasket image.

[0064] Step S3, performing standardized sampling on the obtained gasket image to obtain a standard gasket image with a uniform pixel size;

[0065] Step S4, based on the obtained standard gasket image, using sliding sampling to calculate the average color vector;

[0066] As a further improvement of the present invention, based on the obtained standard gasket image, sliding sampling is used to calculate the average color vector, including:

[0067] Step S41, selecting a window of a fixed size;

[0068] Step S42: Select the step size of each slide to define the step size; the step size can be equal to the window size (no overlap), or the step size can be smaller than the window size (with overlap).

[0069] Step S43, starting from the upper left corner of the image, placing the window on the image, and then gradually moving the window until the entire image is covered to complete the sliding window process;

[0070] Step S44: Calculate the average color vector for the pixels in each window to perform color analysis.

[0071] As a further improvement of the present invention, the average color vector is calculated according to the following formula:

[0072] In RGB space, the average color vector of pixels in each window is:

[0073] Where: T is the transpose,

[0074]

[0075] Where R i , G i , B iRespectively represent the values ​​of the RGB components of the i-th pixel in each window, and m is the number of pixels in the given sliding window.

[0076] Step S5, counting the color type distribution of the average color vector calculated after each sliding of the window in the standard gasket image, and marking the color type with the largest distribution as the color of the standard gasket image;

[0077] Step S6, comparing the color of the standard gasket image to see whether it is within the upper and lower limit thresholds on the color plate of the piezochromic material with a secure tightening degree;

[0078] Step S7: Based on the comparison result, further control is performed.

[0079] As an optional implementation of the present invention, further control is performed based on the comparison result, including:

[0080] Step S71: If the color does not reach the corresponding color range of the tightening degree to be a safe state, a message is sent to the maintenance personnel terminal to remind tightening;

[0081] Step S72: If the color is within the corresponding color range of the secure tightening state, it is determined to be secure, and the next gasket area image is captured.

[0082] The fully automatic monitoring method for the tightness of an ACM connecting rod nut provided by the present invention obtains a standard gasket image by taking photos, removing background and standardizing sampling, makes the gasket image pixel size uniform for later processing, performs sliding sampling on the gasket image, and performs average color vector calculation based on RGB value; counts the number distribution of color categories corresponding to the average color vector of each sliding window in the gasket image, and takes the color type with the largest distribution number as the color of the entire piezochromic gasket; finally, compares whether the color of the piezochromic gasket is within the color change range of the tightness in a safe state; if the color does not reach the corresponding color range of the tightness in a safe state, sends information to the maintenance personnel terminal to remind them to tighten the nuts. Under the premise of not affecting the normal operation of the ACM, the tightness of the nuts can be monitored in real time, and a high recognition accuracy and a fast recognition speed are maintained. Monitoring record query is supported, and the purpose of real-time control of the tightness of the nuts is effectively achieved to prevent ACM safety accidents.

[0083] It should be noted that the pressing force when the tightening degree is in a safe state is 80-100% of the maximum pressing force; and the pressing force when the tightening degree is in an unsafe state is 0-80% of the maximum pressing force.

[0084] Embodiment 1:

[0085] like Figure 4As shown, in this embodiment, the fully automatic monitoring method of the tightness of the ACM connecting rod nut is specifically embodied in the image processing and early warning module.

[0086] When the tightening nut 1 is rotated and tightened, the transparent plastic ring 2 firmly attached to the nut 1 will exert an axial compression force on the piezochromic gasket 3. The more turns are tightened, the greater the compression force. The piezochromic material in the piezochromic gasket 3 will change color when subjected to the compression force. The color of the piezochromic gasket 3 is observed and compared with the standard chromatogram, and the observation can be divided into three situations:

[0087] The clamping force is 80%-100% of the maximum clamping force, and the tightness is in a safe state. Record the color change range in this case.

[0088] The clamping force is 50%-80% of the maximum clamping force, the tightness is in a warning state, and the color change range in this case is recorded.

[0089] The clamping force is 0%-50% of the maximum clamping force, and the tightness is in a dangerous state. Record the color change range in this case.

[0090] Among them, the piezochromic material is a reversible piezochromic material with high sensitivity. The range of color change pressure can be experimented, adjusted and controlled according to actual needs. When the tightness is in a safe state, a piezochromic material that changes color under pressure to a relatively mild and comfortable color such as green can be selected; when the tightness is in a warning and dangerous state, a piezochromic material that changes color to a more eye-catching color such as yellow or red when not under pressure can be selected.

[0091] In the RGB color space, the color picking library function is used to determine the upper and lower thresholds of the color plate according to the color change range of the piezochromic gasket in three cases and import them into the database.

[0092] Color Type RGB Low Threshold RGB high threshold red (150,0,0) (255,100,100) green (0,150,0) (100,255,100) yellow (150,150,0) (255,255,100)

[0093] The image acquisition module comprises an industrial camera 6 mounted on the ram air valve 5, coupled to a standard light source 8 for illuminating the piezochromic gasket.

[0094] The fully automatic monitoring method comprises the following steps:

[0095] S1: Use an industrial camera to take pictures of the gasket to obtain the image information of the gasket area. Use the industrial camera to continuously take pictures of the gasket area at intervals of 10 seconds until the color fails or the ACM operation ends;

[0096] After the industrial camera captures the gasket area image, it uploads the captured gasket area image to the image processing module for processing;

[0097] S2: De-background the photographed area image and segment the gasket image from the acquired area image. The specific steps are as follows:

[0098] S21: In the RGB color space, extract pixels within the color change range of the gasket area image according to the determined RGB threshold range

[0099] S22: adding a mask on top of irrelevant pixels of the original image to segment the pad image;

[0100] S3: performing standardized sampling on the gasket image obtained in S2 to obtain a standard gasket image with uniform pixel size;

[0101] S4: Based on the standard gasket image obtained in S3, the average color vector is calculated using sliding sampling. The specific steps are as follows:

[0102] S41: Select a window of a fixed size. The window size can be adjusted according to specific needs.

[0103] S42: Define step size: Select the step size for each slide. The step size can be equal to the window size (no overlap) or smaller than the window size (with overlap).

[0104] S43: Sliding Window: Starting from the upper left corner of the image, place the window on the image and then move the window step by step until the entire image is covered.

[0105] S44: Color analysis: Calculate the average color vector for the pixels in each window. In the RGB space, the color vector of the i-th pixel in each window of the color image is: f i =(R i , G i , B i ) T , where R i , G i , B i Respectively represent the values ​​of the RGB components of the i-th pixel in each window, and T is the transpose. If the window for each sliding is composed of m pixels, the average color component value of the pixels in each window is defined as: And determine the average color vector The color type.

[0106] S5: Counting the color type distribution of the average color vector calculated after each sliding of the window in the standard gasket image, and marking the color type with the largest distribution as the color of the standard gasket image.

[0107] S6: comparing whether the color of the standard gasket image is within the upper and lower limit thresholds of the color plate of the piezochromic material with a secure tightening degree;

[0108] S7: Based on the comparison results, further control is performed; the specific steps are as follows:

[0109] S71. If the color does not reach the corresponding color range of the tightening degree for a safe state, a message is sent to the maintenance personnel terminal to remind them to tighten the parts.

[0110] S72: If the color in S6 is within the corresponding color range of the secure tightening state, it is determined to be secure, and then the next gasket area image is captured.

[0111] like Figure 1 and Figure 2 As shown, the present invention provides an automatic monitoring system for the degree of tightening, including a tightening color display device, an image acquisition module, an image processing module, and an early warning module; wherein:

[0112] Fasten the color display device and install it at the location to be monitored;

[0113] The image acquisition module is installed on the outside of the fastening color development device;

[0114] The image processing module and the early warning module are arranged in the server of the aircraft environmental control system.

[0115] As a further improvement of the present invention, the fastening display device comprises a nut 1, a transparent plastic ring 2 and a piezochromic gasket 3; wherein:

[0116] The piezochromic gasket 3 is sleeved on the outside of the connecting rod 4 and abuts against the bolt;

[0117] The nut 1 is screwed onto the connecting rod 4 and abuts against the piezochromic gasket 3;

[0118] The transparent plastic ring 2 is sleeved on the outside of the nut 1 and abuts against the piezochromic gasket 3. It should be noted that, in order to facilitate pressure transmission, in this embodiment, the transparent plastic ring 2 is firmly adhered to the nut 1, so that the stress when the nut 1 presses the piezochromic gasket 3 is evenly distributed, so that the color change of the gasket is uniform, which makes it easier to observe the tightness of the nut.

[0119] As a further improvement of the present invention, the image acquisition module includes an industrial camera 6 mounted on the ram air valve 5;

[0120] Furthermore, the ram air valve 5 is a structural component of the aircraft air conditioner, and in the present invention, it mainly plays a role in supporting and placing the industrial camera 6;

[0121] Specifically, the industrial camera 6 is suspended on the ram air valve 5 through the bracket connection 7 in the acquisition auxiliary module;

[0122] The standard light source 8 in the acquisition auxiliary module is installed on the industrial camera 6 .

[0123] Embodiment 2:

[0124] In this embodiment, the automatic monitoring system for tightening degree includes a tightening color display device, an image acquisition module, an acquisition auxiliary module, an image processing module, and an early warning module;

[0125] The fastening color display device includes a nut 1, a transparent plastic ring 2 and a piezochromic gasket 3. Among them, the nut 1 is a HB5636 M8 model nut installed on the ACM connecting rod 4 before improvement. The transparent plastic ring 2 is sleeved on the outside of the nut 1 and is firmly bonded to the nut 1 by super glue. The transparent plastic ring 2 is made of transparent plastic material in order to observe the color change of the bottom side piezochromic gasket 3. The piezochromic gasket 3 is also a ring component, and the inner diameter of the ring is the diameter of the ACM connecting rod 4. The piezochromic gasket 3 is located on the bottom side of the nut 1 and the transparent plastic ring 2, and is also tightly connected to the two by super glue. The piezochromic material is a reversible piezochromic material with high sensitivity. The range of the color changing pressure can be experimented, adjusted and controlled according to actual needs. When the tightness is in a safe state, a piezochromic material that changes color under pressure to a relatively mild and comfortable color such as green can be selected; when the tightness is in a warning and dangerous state, a piezochromic material that changes color without pressure to a more eye-catching color such as yellow or red can be selected.

[0126] The image acquisition module includes an industrial camera 6 mounted on the ram air valve 5. The industrial camera 6 is installed in the ram air valve 5. During the monitoring process, the gasket area image is continuously captured at intervals of 10 seconds until the color fails or the ACM operation ends. After capturing the gasket area image, the industrial camera 6 uploads the image to the image processing module.

[0127] The acquisition auxiliary module includes a bracket connection 7 between the ram air valve 5 and the industrial camera 6, and a standard light source 8 installed on the ram air valve 5. The bracket connection 7 plays a role of connection and fixed support. The standard light source 8 is used to maintain the light conditions of the shooting environment. The standard light source 8 illuminates the surface of the nut and the gasket at a normal angle.

[0128] The image processing module is located in the server responsible for the aircraft environmental control system. It is used to perform image segmentation, standardized sampling, sliding sampling, average color vector calculation, and classification statistics on the images collected by the image acquisition module, so as to finally realize the gasket color recognition and store the image processing results in the server. When the judgment result is unqualified, the image processing module will remind the maintenance personnel to tighten.

[0129] The automatic monitoring system of the tightness of the present invention is firmly adhered to the nut 1 by the transparent plastic ring 2, so that the stress of the nut 1 when pressing the piezochromic gasket 3 is evenly distributed, so that the color change of the gasket is uniform, and it is more convenient to observe the tightness of the nut. The gasket image is obtained by removing the background of the photographed area image, and standardized sampling is performed to make the gasket image pixel size uniform for post-processing. The gasket image is subjected to sliding sampling, and the average color vector calculation and classification based on the RGB value are performed; the number distribution of color categories corresponding to the average color vector of each sliding window in the gasket image is counted, and the color type with the largest number of distributions is used as the color of the piezochromic gasket; finally, the color of the piezochromic gasket is compared to see whether it is within the color change range of the tightness in a safe state; if the color does not reach the corresponding color range of the tightness in a safe state, a message is sent to the maintenance personnel terminal to remind the tightening.

[0130] First of all, it should be explained here that “inward” refers to the direction toward the center of the accommodating space, and “outward” refers to the direction away from the center of the accommodating space.

[0131] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate directions or positional relationships based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0132] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0133] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0134] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0135] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0136] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for fully automatic monitoring of the tightness of an ACM connecting rod nut, characterized in that: The method comprises the following steps: Get the gasket area image information; De-backgrounding is performed on the photographed area image, and the gasket image is segmented from the acquired area image; Performing standardized sampling on the obtained gasket image to obtain a standard gasket image with uniform pixel size; Based on the obtained standard gasket image, the average color vector is calculated by sliding sampling; Count the color type distribution of the average color vector calculated after each sliding of the window in the standard gasket image, and mark the color type with the largest distribution as the color of the standard gasket image; Comparing whether the color of the standard gasket image is within the upper and lower limit thresholds of the color plate of the piezochromic material with a secure tightening degree; Based on the comparison result, further control is performed.

2. The method according to claim 1, characterized in that Based on the comparison result, further control is performed, including: If the color does not reach the corresponding color range for a safe tightening state, a message is sent to the maintenance personnel terminal to remind them to tighten the equipment; If the color is within the corresponding color range of the secure tightening state, it is determined to be secure, and the next gasket area image is captured.

3. The method according to claim 1, characterized in that The step of removing the background of the photographed area image and segmenting the gasket image from the acquired area image comprises: In the RGB color space, pixels within the color change range are extracted from the gasket area image according to the determined RGB threshold range; Add a mask on top of the irrelevant pixels of the original image, segmenting the pad image.

4. The method according to claim 1, characterized in that The method of calculating the average color vector based on the obtained standard gasket image by sliding sampling includes: Select a fixed-size window; Select the step size for each slide to define the step size; Starting from the upper left corner of the image, place the window on the image, and then gradually move the window until the entire image is covered to complete the sliding window process; The average color vector is calculated for each pixel within the window for color analysis.

5. The method according to claim 4, characterized in that The average color vector is calculated according to the following formula: In RGB space, the average color vector of pixels in each window is: Where: T is the transpose, Where R i , G i , B i Respectively represent the values ​​of the RGB components of the i-th pixel in each window, and m is the number of pixels in the given sliding window.

6. The method according to claim 1, characterized in that The step of obtaining the gasket area image information includes: Use an industrial camera to continuously capture images of the gasket area at 10-second intervals until the color fails or the ACM operation ends; After the industrial camera captures the gasket area image, the captured gasket area image is uploaded to the image processing module for processing.

7. The method according to claim 1, characterized in that The step size is equal to the window size, or the step size is smaller than the window size.

8. The method according to claim 1, characterized in that: The clamping force when the tightening degree is in a safe state is 80-100% of the maximum clamping force; the clamping force when the tightening degree is in an unsafe state is 0-80% of the maximum clamping force.

9. An automatic monitoring system for tightening degree, characterized in that: It includes a fastening color display device, an image acquisition module, an image processing module, and an early warning module; wherein: The fastening color display device is installed at the position to be monitored; The image acquisition module is installed on the outside of the fastening color development device; The image processing module and the early warning module are arranged in a server of an aircraft environmental control system.

10. The automatic monitoring system for tightening degree according to claim 9, characterized in that: The fastening display device comprises a nut, a transparent plastic ring and a piezochromic gasket; wherein: The piezochromic gasket is sleeved on the outside of the connecting rod and abuts against the bolt; The nut is threaded on the connecting rod and abuts against the piezochromic gasket; The transparent plastic ring is sleeved on the outside of the nut and abuts against the piezochromic gasket.

11. The automatic monitoring system for tightening degree according to claim 9, characterized in that: The image acquisition module includes an industrial camera mounted on the ram air valve.

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