A monitoring method and system for the slip of a composite saddle of a suspension bridge in mountainous areas

Abstract

The present application relates to a method and system for monitoring the slip of a composite saddle of a mountainous suspension bridge, belonging to the technical field of structural health monitoring of civil engineering, including collecting the overall displacement information of the saddle and taking digital images of the structural state of the saddle rollers; calculating the overall displacement of the saddle according to the displacement information, and calculating the rotational displacement of the saddle rollers according to the digital images of the structural state; calculating the saddle slip based on the overall displacement and the rotational displacement. It can be seen that the embodiment of the present application obtains the roller rotation information by taking digital images of the structural state of the saddle rollers, breaks through the space limitation at the rollers, and then calculates the saddle slip amount based on the overall displacement and the rotational displacement, realizing the real-time monitoring of the composite saddle slip, filling the blank of the slip monitoring of the composite saddle, a new component of the mountainous suspension bridge, and ensuring the long-term health and safety of the composite saddle.

Description

Technical Field

[0001] This application relates to the technical field of civil engineering structure health monitoring, and particularly to a method and system for monitoring the slip of a composite saddle of a mountainous suspension bridge. Background Art

[0002] Conventional suspension bridges generally have a main saddle and a dispersion saddle. However, to adapt to the mountain valley terrain in mountainous areas, avoid massive excavation of mountains, reduce project costs, and minimize damage to the environment, some highway bridges have cancelled one side of the pylon and directly anchored the main cable on that side to the mountain body, making it impossible to implement the conventional main saddle and dispersion saddle solutions. Therefore, to solve this problem, a composite saddle is used to replace the conventional main saddle and dispersion saddle in related technologies. Among them, the composite saddle integrates the functions of a conventional main saddle and a dispersion saddle, and a roller is installed at its bottom to bear the vertical force of the main cable. At the same time, the longitudinal displacement of the main cable is adapted by the rotation of the roller.

[0003] However, during the operation of the bridge, the longitudinal displacement of the main cable will be caused by vehicle loads and temperature changes, resulting in frequent rotation of the rollers of the composite saddle. And under the huge vertical force of the main cable, the rollers of the composite saddle are extremely prone to wear and poor rotation, which will further lead to the slip of the composite saddle, bringing great safety risks to the bridge operation. Therefore, to ensure the normal operation of the rollers of the composite saddle, it is necessary to monitor and warn of the slip of the composite saddle.

[0004] However, due to the narrow space at the roller of the composite saddle, it is difficult for conventional sensors to effectively monitor the rotational displacement of the roller, and thus it is impossible to effectively monitor the slip of the composite saddle, resulting in safety problems easily caused by the slip of the composite saddle. Summary of the Invention

[0005] The embodiments of this application provide a method and system for monitoring the slip of a composite saddle of a mountainous suspension bridge to solve the problem in related technologies that the slip of the composite saddle cannot be effectively monitored.

[0006] In a first aspect, a method for monitoring the slip of a composite saddle of a mountainous suspension bridge is provided, including the following steps:

[0007] Collect the overall displacement information of the saddle and capture the digital image of the structural state of the saddle roller;

[0008] Calculate the overall displacement of the saddle according to the displacement information, and calculate the rotational displacement of the saddle roller according to the digital image of the structural state;

[0009] Calculate the slip amount of the saddle based on the overall displacement and the rotational displacement.

[0010] In some embodiments, calculating the rotational displacement of the saddle roller shaft according to the structural state digital image includes:

[0011] Select a reference area in the first structural state digital image before the saddle roller shaft undergoes displacement. The reference area is a rectangle with a preset side length, and the center of the rectangle is the measurement point on the saddle.

[0012] Select M first search areas in the second structural state digital image after the saddle roller shaft undergoes displacement. The area of each first search area is equal to the area of the reference area, where M is a positive integer.

[0013] Determine a second search area from the M first search areas according to the pixel gray values of the reference area and each first search area.

[0014] Calculate the rotational displacement of the saddle roller shaft according to the center point coordinates of the second search area, the length represented by each pixel point in the second search area, and the center point coordinates of the reference area.

[0015] In some embodiments, before selecting the reference area in the first structural state digital image before the saddle roller shaft undergoes displacement, it further includes:

[0016] Convert the structural state digital image into a grayscale image.

[0017] Calibrate the length represented by each pixel point on the grayscale image.

[0018] In some embodiments, after calculating the saddle slip amount based on the overall displacement amount and the rotational displacement amount, it further includes:

[0019] Perform a saddle slip anomaly alarm according to the saddle slip amount and the saddle slip anomaly range.

[0020] In some embodiments, performing a saddle slip anomaly alarm according to the saddle slip amount and the saddle slip anomaly range includes:

[0021] Establish a saddle slip probability density function based on the calculated first N saddle slip amounts, where N is a positive integer.

[0022] Calculate the first rejection region of the saddle slip probability density function, and use the first rejection region as the slip anomaly range.

[0023] When the calculated saddle slip amount is within the slip anomaly range, perform an individual value anomaly alarm for the saddle slip.

[0024] In some embodiments, performing a saddle slip anomaly alarm according to the saddle slip amount and the saddle slip anomaly range includes:

[0025] Establish a periodic probability density function and a daily probability density function for each day within the previous period based on the saddle slip amount in the previous period;

[0026] Calculate the Euclidean distances between the periodic probability density function and each daily probability density function respectively to obtain a set of Euclidean distances;

[0027] Establish a distance probability density function based on the set of Euclidean distances, and calculate the second rejection region of the distance probability density function, using the second rejection region as the slip anomaly range;

[0028] When the Euclidean distance between the daily probability density function of a certain day in the next period and the periodic probability density function of the previous period is within the slip anomaly range, an alarm for abnormal daily probability distribution of the saddle slip amount is given.

[0029] In a second aspect, a monitoring system for the slip of a composite saddle of a mountain suspension bridge is provided, including a displacement acquisition module, a camera module, and a data processing module;

[0030] The displacement acquisition module is used to be arranged on the saddle and acquire the overall displacement information of the saddle;

[0031] The camera module is used to be arranged in the inspection hole of the pressing beam and capture a digital image of the structural state of the saddle roller shaft;

[0032] The data processing module is used to obtain the displacement information collected by the displacement acquisition module and the digital image of the structural state captured by the camera module, calculate the overall displacement amount of the saddle according to the displacement information, and calculate the rotational displacement amount of the saddle roller shaft according to the digital image of the structural state; calculate the saddle slip amount based on the overall displacement amount and the rotational displacement amount.

[0033] In some embodiments, the monitoring system further includes an early warning module, and the early warning module is used to give an alarm for abnormal saddle slip according to the saddle slip amount and the saddle slip anomaly range.

[0034] The beneficial effects brought by the technical solution provided in this application include: realizing real-time monitoring of the slip of the composite saddle and ensuring the long-term health and safety of the composite saddle.

[0035] The embodiment of the present application provides a method and system for monitoring the slip of a composite saddle of a mountainous suspension bridge, including collecting the overall displacement information of the saddle and taking a digital image of the structural state of the saddle roller shaft; calculating the overall displacement of the saddle according to the displacement information, and calculating the rotational displacement of the saddle roller shaft according to the digital image of the structural state; calculating the saddle slip based on the overall displacement and the rotational displacement. It can be seen that the embodiment of the present application obtains the acquisition of the rotational information of the roller shaft by taking a digital image of the structural state of the saddle roller shaft, breaks through the space limitation at the roller shaft, and then calculates the saddle slip amount based on the overall displacement and the rotational displacement, realizing the real-time monitoring of the composite saddle slip, solving the problem of limited internal monitoring space of the composite saddle roller shaft, filling the blank of the slip monitoring of the new component of the composite saddle of the mountainous suspension bridge, and ensuring the long-term health and safety of the composite saddle. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 It is a schematic flow chart of a method for monitoring the slip of a composite saddle of a mountainous suspension bridge provided by an embodiment of the present application;

[0038] Figure 2 It is a schematic structural diagram of a system for monitoring the slip of a composite saddle of a mountainous suspension bridge provided by an embodiment of the present application. Detailed Embodiments

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0040] The embodiment of the present application provides a method and system for monitoring the slip of a composite saddle of a mountainous suspension bridge to solve the problem that the slip of the composite saddle cannot be effectively monitored in the related art.

[0041] Figure 1 It is a schematic flow chart of a method for monitoring the slip of a composite saddle of a mountainous suspension bridge provided by an embodiment of the present application, including:

[0042] S1: Collect the overall displacement information of the saddle, and capture the digital image of the structural state of the saddle roller shaft;

[0043] Exemplarily, the acquisition of the overall displacement information of the saddle and the digital image of the structural state of the saddle roller shaft can be designed for the sampling rate according to the actual monitoring requirements. Among them, the overall displacement information of the saddle can be collected by a displacement sensor, or can be collected by a camera instrument and then corresponding image conversion is performed, which is not limited here; the digital image of the structural state of the saddle roller shaft can be captured by a high-definition camera.

[0044] S2: Calculate the overall displacement of the saddle according to the displacement information, and calculate the rotational displacement of the saddle roller shaft according to the digital image of the structural state;

[0045] The specific calculation method for calculating the rotational displacement of the saddle roller shaft according to the digital image of the structural state can be: select the reference area in the first digital image of the structural state before the saddle roller shaft is displaced. The reference area is a rectangle with a preset side length, and the center of the rectangle is the point to be measured on the saddle; select M first search areas in the second digital image of the structural state after the saddle roller shaft is displaced. The area of each first search area is equal to the area of the reference area, where M is a positive integer; determine the second search area from the M first search areas according to the pixel gray value of the reference area and the pixel gray values of each first search area; calculate the rotational displacement of the saddle roller shaft according to the center point coordinates of the second search area, the length represented by each pixel point in the second search area, and the center point coordinates of the reference area.

[0046] Exemplarily, convert the captured digital image of the structural state into a grayscale image; then select the first digital image of the structural state before the roller shaft is displaced as the reference image, select the point to be measured P(x, y) on the edge of the roller shaft, and select a (2b + 1)×(2b + 1) rectangular area as the reference area with this point to be measured as the center, where x and y are the horizontal and vertical coordinates of the pixel where the point to be measured is located respectively, and b is the number of pixels;

[0047] Select the second digital image of the structural state after the roller shaft is displaced as the target image, and divide the target image into M (2b + 1)×(2b + 1) rectangular areas, where each rectangular area represents a first search area, and b is the number of pixels.

[0048] Calculate the correlation coefficient c between the reference area and each first search area based on the gray value of the reference area and the gray values of each first search area. A first search area with the maximum correlation coefficient with the reference area can be obtained. This first search area is the search area that best matches the reference area. Therefore, select the first search area with the maximum correlation coefficient with the reference area as the second search area. The center point position of this second search area is P′(x′, y′), where x′ and y′ are the horizontal and vertical coordinates of the pixel where the center point of the second search area is located, respectively. The correlation coefficient c can be calculated by the following formula:

[0049]

[0050] Where f(x i , y j ) is the gray value of the measurement point (x i , y j ) in the reference area, g(x′ i , y′ j ) is the gray value of the center point (x′ i , y′ j ) of the second search area, i is the i-th pixel point, j is the j-th pixel point, is the average gray value of the reference area, is the average gray value of the second search area;

[0051] Then calculate the rotational displacement d of the composite saddle roller shaft according to the following formula:

[0052]

[0053] Where a is the length of the image pixel point.

[0054] S3: Calculate the saddle slip amount based on the overall displacement amount and the rotational displacement amount.

[0055] Exemplarily, by performing a difference operation on the overall displacement amount of the saddle and the rotational displacement amount of the saddle roller shaft, the saddle slip amount can be obtained. It can be seen that in the embodiment of the present application, the rotational information of the roller shaft is obtained by photographing the structural state digital image of the saddle roller shaft, breaking through the space limitation at the roller shaft. Then, based on the overall displacement amount and the rotational displacement amount, the saddle slip amount is calculated, realizing the real-time monitoring of the composite saddle slip, solving the problem of limited internal monitoring space of the composite saddle roller shaft, filling the blank of the slip monitoring of the new component of the composite saddle of the mountain suspension bridge, and ensuring the long-term health and safety of the composite saddle.

[0056] Further, in the embodiment of the present application, the monitoring method further includes calibrating the pixel equivalent of the high-definition camera used to capture the structural state digital image of the saddle roller. Specifically: the camera is used to capture the saddle roller with speckles sprayed and a scale posted thereon to obtain the structural state digital image of the saddle roller, and the structural state digital image is converted into a grayscale image; the length a represented by each pixel point on the grayscale image is calibrated through the scale.

[0057] Further, in the embodiment of the present application, after calculating the saddle slip amount based on the overall displacement amount and the rotational displacement amount, the following steps are further included: performing saddle slip anomaly alarm according to the saddle slip amount and the slip abnormal range of the saddle.

[0058] Specifically, a saddle slip probability density function is established based on the calculated first N saddle slip amounts, where N is a positive integer; the first rejection region of the saddle slip probability density function is calculated, and the first rejection region is used as the slip abnormal range; when the calculated saddle slip amount is within the slip abnormal range, an individual value anomaly alarm for the saddle slip is performed.

[0059] Exemplarily, assuming that the sampling quantity of the saddle slip amount per day is H, and it is necessary to perform early warning judgment on the Yth saddle slip amount collected on the Xth day. First, the probability distribution of the saddle slip amount is calculated using the previous N saddle slip amount data before this data, where N can be any positive integer greater than or equal to H and less than or equal to (X - 1)×H + Y, and no limitation is made here; and the probability distribution is fitted by the least squares method to obtain the saddle slip probability density function; taking the significance level as 0.05, the first rejection region of the saddle slip probability density function is calculated, and the first rejection region is used as the slip abnormal range; it is judged whether the Yth saddle slip amount collected on the Xth day is within the slip abnormal range. If so, an individual value anomaly of the saddle slip amount occurs, and a yellow early warning message is sent.

[0060] Specifically, a cycle probability density function and a daily probability density function for each day within the previous cycle are respectively established based on the saddle slip amounts of the previous cycle; the Euclidean distances between the cycle probability density function and each daily probability density function are respectively calculated to obtain a set of Euclidean distances; a distance probability density function is established based on the set of Euclidean distances, and the second rejection region of the distance probability density function is calculated, and the second rejection region is used as the slip abnormal range; when the Euclidean distance between the daily probability density function of a certain day in the next cycle and the cycle probability density function of the previous cycle is within the slip abnormal range, an alarm for abnormal daily probability distribution of the saddle slip amount is performed.

[0061] Exemplarily, the period can be annual, weekly, or within a custom time range. Taking the annual period as an example, the previous period is the previous year. The calculation method of the previous year can be the natural year (such as from January 1, 2020 to December 31, 2020), or a custom year (such as from March 10, 2020 to March 10, 2021), which is determined according to the specific monitoring and early warning situation and is not limited here.

[0062] Taking the natural year as the period as an example, assume that it is necessary to make an early warning judgment on the daily probability distribution of the saddle slip on a certain day (such as January 2, 2021): First, calculate the annual probability distribution of the saddle slip according to all the saddle slip amounts monitored from January 1, 2020 to December 31, 2020; then calculate the daily probability distribution of the saddle slip for each day according to the saddle slip amounts monitored every day in 2020; secondly, use the least squares method to fit the annual probability distribution and the daily probability distribution respectively to obtain the annual probability density function and the daily probability density function; then calculate the Euclidean distances between the annual probability density function and each daily probability density function respectively to obtain a set of Euclidean distances, and calculate the probability distribution of the Euclidean distances according to each Euclidean distance in the set of Euclidean distances; then use the least squares method to fit the probability distribution of the Euclidean distances to obtain the probability density function of the Euclidean distances; take the significance level as 0.05 and calculate the second rejection region of the probability density function of the Euclidean distances, and use the second rejection region as the slip anomaly range; establish the daily probability density function of the saddle slip on the day (January 2, 2021) according to the saddle slip amount monitored on January 2, 2021, and then calculate the Euclidean distance between the daily probability density function of the saddle slip on January 2, 2021 and the annual probability density function, and judge whether the Euclidean distance is within the slip anomaly range. If so, the daily probability distribution characteristics of the saddle slip amount are abnormal, and a red early warning message is sent.

[0063] It can be seen that the embodiment of the present application solves the problem of limited internal monitoring and control of the composite saddle roller shaft, fills the gap in the slip monitoring of the composite saddle, a new component of the mountain suspension bridge, and realizes multi-level early warning of the composite saddle slip by identifying the abnormality of individual values of the composite saddle slip amount and the abnormality of the daily probability distribution characteristics of the composite saddle slip, ensuring the long-term health and safety of the composite saddle.

[0064] See Figure 2As shown in the figure, the embodiment of the present application also provides a slip monitoring system for a composite saddle of a mountain suspension bridge, which includes a displacement acquisition module, a camera module, and a data processing module; the displacement acquisition module is used to be arranged on the saddle and acquire the overall displacement information of the saddle; the camera module is used to be arranged in the inspection hole of the pressing beam and capture the digital image of the structural state of the saddle roller shaft; the data processing module is used to obtain the displacement information acquired by the displacement acquisition module and the digital image of the structural state captured by the camera module, calculate the overall displacement of the saddle according to the displacement information, and calculate the rotational displacement of the saddle roller shaft according to the digital image of the structural state; calculate the saddle slip amount based on the overall displacement and the rotational displacement.

[0065] Exemplarily, the displacement acquisition module can be a displacement sensing unit or a camera instrument. Taking the displacement sensing unit as an example, it includes a displacement sensor and a signal converter. Specifically: one end of the displacement sensor is arranged on the stopper of the saddle, and the other end is arranged on the upper bearing plate of the saddle, which is used to measure the overall displacement of the saddle and obtain a displacement electrical signal. And this displacement electrical signal is transmitted to the signal converter through the monitoring field signal line. The signal converter will convert the displacement electrical signal into a displacement digital signal, and this displacement digital signal is then transmitted to the on-site optical-electric converter through the monitoring field network cable and converted into a displacement optical signal;

[0066] The camera module is preferably a high-definition camera, which is arranged in the inspection hole of the pressing beam of the saddle and is used to acquire the digital image of the structural state of the saddle roller shaft. This digital image of the structural state is transmitted to the on-site optical-electric converter through the monitoring field network cable and converted into a structural state optical signal;

[0067] Both the displacement optical signal and the structural state optical signal are transmitted to the optical-electric converter in the monitoring room through optical fibers and are respectively converted into a displacement digital signal and a digital image of the structural state again. This displacement digital signal and the digital image of the structural state are then transmitted to the data processing module through the monitoring room network cable; the data processing module includes a displacement solution operator module, a digital image solution operator module, and a slip solution operator module; among them, the displacement solution operator module is used to convert the displacement digital signal into the overall displacement of the saddle, the digital image solution operator module is used to convert the digital image of the structural state into the rotational displacement of the saddle roller shaft, and the slip solution operator module is used to calculate the saddle slip amount according to the overall displacement of the saddle and the rotational displacement of the saddle roller shaft.

[0068] It can be seen that the embodiment of the present application realizes the acquisition of the overall displacement information of the saddle and the rotational information of the roller shaft through the displacement acquisition module and the camera module, breaks through the space limitation at the roller shaft, and then calculates the saddle slip amount through the data processing module, thereby realizing the real-time monitoring of the composite saddle slip, solving the problem of limited internal monitoring space of the composite saddle roller shaft, filling the blank of the slip monitoring of the composite saddle of the mountain suspension bridge, and ensuring the long-term health and safety of the composite saddle.

[0069] Furthermore, in the embodiment of the present application, the monitoring system further includes an early warning module, and the early warning module is used to perform abnormal alarm for the saddle slip according to the saddle slip amount and the abnormal slip range of the saddle.

[0070] Specifically, a saddle slip probability density function is established based on the calculated saddle slip amounts of the first N saddles, where N is a positive integer; the first rejection region of the saddle slip probability density function is calculated, and the first rejection region is used as the abnormal slip range; when the calculated saddle slip amount is within the abnormal slip range, an individual value abnormal alarm for the saddle slip is performed.

[0071] Exemplarily, it is assumed that the number of saddle slip amount samples per day is H, and it is necessary to perform early warning judgment on the Yth saddle slip amount collected on the Xth day. First, the probability distribution of the saddle slip amount is calculated using the previous N saddle slip amount data before this data, where N can be any positive integer greater than or equal to H and less than or equal to (X - 1)×H + Y, and there is no limit here; and the least squares method is used to fit the probability distribution to obtain the saddle slip probability density function; taking the significance level as 0.05, the first rejection region of the saddle slip probability density function is calculated, and this first rejection region is used as the abnormal slip range; it is judged whether the Yth saddle slip amount collected on the Xth day is within this abnormal slip range. If so, an individual value abnormality of the saddle slip amount occurs, and a yellow early warning message is sent;

[0072] Specifically, a period probability density function and a daily probability density function for each day within the previous period are respectively established based on the saddle slip amounts of the previous period; the Euclidean distances between the period probability density function and each daily probability density function are respectively calculated to obtain a set of Euclidean distances; a distance probability density function is established based on the set of Euclidean distances, and the second rejection region of the distance probability density function is calculated, and the second rejection region is used as the abnormal slip range; when the Euclidean distance between the daily probability density function on the Kth day of the next period and the annual probability density function of the previous period is within the abnormal slip range, an abnormal alarm for the daily probability distribution of the saddle slip amount is performed, where K is a positive integer.

[0073] Exemplarily, the period can be annual, weekly, or within a custom time range. Taking the annual period as an example, the previous period is the previous year, and the calculation method of this previous year can be the natural year (such as from January 1, 2020 to December 31, 2020), or a custom year (such as from March 10, 2020 to March 10, 2021), which is determined according to the specific monitoring and early warning situation and is not limited here.

[0074] Taking the natural year by period as an example, assume that it is necessary to make a warning judgment on the probability distribution of the saddle slip date for a certain day (such as January 2, 2021): First, according to all the saddle slip amounts monitored from January 1, 2020 to December 31, 2020, calculate the annual probability distribution of the saddle slip; then, according to the saddle slip amounts monitored every day in 2020, calculate the daily probability distribution of the saddle slip for each day; secondly, use the least squares method to fit the annual probability distribution and the daily probability distribution respectively to obtain the annual probability density function and the daily probability density function; then calculate the Euclidean distances between the annual probability density function and each daily probability density function respectively to obtain a set of Euclidean distances, and calculate the probability distribution of the Euclidean distances according to each Euclidean distance in this set of Euclidean distances; then use the least squares method to fit this probability distribution of the Euclidean distances to obtain the probability density function of the Euclidean distances; take the significance level as 0.05, calculate the second rejection region of this probability density function of the Euclidean distances, and use the second rejection region as the slip abnormal range; establish the daily probability density function of the saddle slip on the day (January 2, 2021) according to the saddle slip amount monitored on January 2, 2021, and then calculate the Euclidean distance between the daily probability density function of the saddle slip on January 2, 2021 and the annual probability density function, and judge whether this Euclidean distance is within this slip abnormal range. If so, the daily probability distribution characteristics of the saddle slip amount are abnormal, and a red warning message is sent.

[0075] Furthermore, in the embodiment of the present application, the data processing module further includes an acquisition control sub-module, and this acquisition control sub-module is used to control the sampling rates of the displacement sensor and the high-definition camera.

[0076] Furthermore, in the embodiment of the present application, the data processing module further includes a calibration sub-module. This calibration sub-module is used for: calibrating the pixel equivalent of the high-definition camera used to capture the structural state digital image of the saddle roller shaft. Specifically: make the camera capture the saddle roller shaft with speckles sprayed and a scale posted to obtain the structural state digital image of the saddle roller shaft, and convert this structural state digital image into a grayscale image; calibrate the length a represented by each pixel point on the grayscale image through the scale.

[0077] Furthermore, in the embodiment of the present application, the data processing module further includes a display sub-module, and this display sub-module is used to display the saddle slip amount and specific warning information in real time, so that the monitoring personnel can view the saddle slip situation and abnormal state in real time, and then can take corresponding measures in time.

[0078] Furthermore, in the embodiment of the present application, the high-definition camera is a micro camera with a supplementary light function and is equipped with a short focal length lens, which can adapt to macro shooting of 2 cm to 5 cm.

[0079] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application. Unless otherwise clearly specified and defined, the terms "installed", "connected" and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0080] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for monitoring the slip of a composite saddle of a suspension bridge in mountainous areas, characterized in that, It includes the following steps: Collect the overall displacement information of the saddle and capture the digital image of the structural state of the saddle roller shaft; Calculate the overall displacement of the saddle according to the displacement information, and calculate the rotational displacement of the saddle roller shaft according to the digital image of the structural state; Calculate the saddle slip amount based on the overall displacement amount and the rotational displacement amount; Among them, calculating the rotational displacement of the saddle roller shaft according to the digital image of the structural state includes: Select the reference area in the first digital image of the structural state before the saddle roller shaft has displacement. The reference area is a rectangle with a preset side length, and the center of the rectangle is the measurement point on the saddle; Select M first search areas in the second digital image of the structural state after the saddle roller shaft has displacement. The area of each first search area is equal to the area of the reference area, where M is a positive integer; Determine the second search area from the M first search areas according to the pixel gray value of the reference area and the pixel gray values of each first search area; Calculate the rotational displacement of the saddle roller shaft according to the center point coordinates of the second search area, the length represented by each pixel point in the second search area, and the center point coordinates of the reference area.

2. The method for monitoring the slip of the composite saddle of the mountain suspension bridge according to claim 1, characterized in that, Before selecting the reference area in the first digital image of the structural state before the saddle roller shaft has displacement, it also includes: Convert the digital image of the structural state into a grayscale image; Calibrate the length represented by each pixel point on the grayscale image.

3. The method for monitoring the slip of the composite saddle of a mountain suspension bridge according to claim 1, characterized in that, After calculating the saddle slip amount based on the overall displacement amount and the rotational displacement amount, it also includes: Perform saddle slip abnormal alarm according to the saddle slip amount and the saddle slip abnormal range.

4. The slip monitoring method for the composite saddle of the mountainous suspension bridge according to claim 3, wherein Performing saddle slip abnormal alarm according to the saddle slip amount and the saddle slip abnormal range includes: Establish a saddle slip probability density function according to the calculated first N saddle slip amounts, where N is a positive integer; Calculate the first rejection region of the saddle slip probability density function, and use the first rejection region as the slip abnormal range; When the calculated saddle slip amount is within the slip abnormal range, perform individual value abnormal alarm for the saddle slip.

5. The method for monitoring the slip of the composite saddle of the mountain suspension bridge according to claim 3, characterized in that, Performing saddle slip abnormal alarm according to the saddle slip amount and the saddle slip abnormal range includes: Respectively establish a cycle probability density function and a daily probability density function for each day within the previous cycle according to the saddle slip amount of the previous cycle; Respectively calculate the Euclidean distances between the cycle probability density function and each daily probability density function to obtain a set of Euclidean distances; Establish a distance probability density function according to the set of Euclidean distances, and calculate the second rejection region of the distance probability density function, and use the second rejection region as the slip abnormal range; When the Euclidean distance between the daily probability density function of a certain day in the next cycle and the cycle probability density function of the previous cycle is within the slip abnormal range, perform abnormal alarm for the daily probability distribution of the saddle slip amount.

6. A slip monitoring system for a composite saddle of a mountainous area suspension bridge, characterized in that: It includes a displacement acquisition module, a camera module and a data processing module; The displacement acquisition module is used to be arranged on the saddle and collect the overall displacement information of the saddle; The camera module is used to be arranged in the overhaul hole of the pressing beam and capture the digital image of the structural state of the saddle roller shaft; The data processing module is used to obtain the displacement information collected by the displacement acquisition module and the digital structural state image captured by the imaging module, calculate the overall displacement of the saddle according to the displacement information, and calculate the rotational displacement of the saddle roller according to the digital structural state image; calculate the saddle slip amount based on the overall displacement and the rotational displacement; Among them, the data processing module is specifically used for: Select a reference area in the first digital structural state image before the saddle roller undergoes displacement. The reference area is a rectangle with a preset side length, and the center of the rectangle is the point to be measured on the saddle; Select M first search areas in the second digital structural state image after the saddle roller undergoes displacement. The area of each first search area is equal to the area of the reference area, where M is a positive integer; Determine the second search area from the M first search areas according to the pixel gray values of the reference area and each first search area; Calculate the rotational displacement of the saddle roller according to the center point coordinates of the second search area, the length represented by each pixel point in the second search area, and the center point coordinates of the reference area.

7. The slip monitoring system for the composite saddle of the mountainous suspension bridge according to claim 6, characterized in that: The monitoring system further includes an early warning module, and the early warning module is used to perform an abnormal saddle slip alarm according to the saddle slip amount and the abnormal saddle slip range.

Images