Emergency rescue cableway bridge stress monitoring method and system

Abstract

The invention provides a stress monitoring method and system for an emergency rescue cableway bridge, and relates to the technical field of stress detection.The method comprises the steps that current temperature data, current cable body vibration acceleration data and a current cable body vibration-strain transfer coefficient are monitored while current cable body stress detection data are detected; and correcting the current cable body stress detection data through the temperature data to determine the current temperature correction stress data. And then correcting the current temperature correction stress data through the front cable body vibration acceleration data and the current cable body vibration-strain transfer coefficient to obtain current vibration correction stress data. And finally, the current vibration correction stress data is denoised through packet wave denoising, so that the improvement of the cableway bridge stress monitoring precision is facilitated.

Description

Technical Field

[0001] The present application relates to the technical field of stress detection, and particularly to a stress monitoring method and system for an emergency rescue cable bridge. Background Art

[0002] Stress and strain detection of a cable bridge is an important technical means to ensure its safety and durability. In the prior art, the stress and strain detection of a bridge mainly targets cable bridges that have been in long-term use. Therefore, before the bridge is put into use, various parameters of the bridge need to be monitored for a period of time. Only when the bridge can meet the design requirements during the monitoring process will it be put into use. However, for an emergency rescue cable bridge, it is more desirable to be quickly put into use. After the bridge is built and quickly put into use, in the early stage of use, the residual stress, foundation structure, etc. of the bridge are still in a relatively unstable state. Therefore, the traditional dynamic load test and static load test can no longer meet the requirements of the emergency rescue cable bridge for rapid detection.

[0003] Bridge stress and strain detection is an important parameter for bridge health detection, and its detection accuracy directly affects the accuracy of bridge health detection results. Therefore, there is an urgent need to provide a stress monitoring scheme that can adapt to the emergency rescue cable bridge. Summary of the Invention

[0004] The present application provides a stress monitoring method and system for an emergency rescue cable bridge, which can improve the accuracy of bridge stress and strain detection.

[0005] A stress monitoring method for an emergency rescue cable bridge provided by the present application includes: obtaining bridge state monitoring data, where the bridge state monitoring data includes current cable stress detection data, current temperature data, current cable vibration acceleration data, and current cable vibration-strain transfer coefficient; determining current temperature-corrected stress data according to the current cable stress detection data and the current temperature data; determining current vibration-corrected stress data according to the current temperature-corrected stress data, the current cable vibration acceleration data, and the vibration-strain transfer coefficient; and performing wavelet denoising on the current vibration-corrected stress data to determine the current target stress data.

[0006] In some embodiments, the current temperature data includes current cable temperature distribution data and current temperature gradient compensation coefficient. Determining the current temperature-corrected stress data according to the current cable stress detection data and the current temperature data includes: determining the current temperature gradient compensation stress value according to the current cable temperature distribution data and the current temperature gradient compensation coefficient; and determining the current temperature-corrected stress data according to the current cable stress detection data and the current temperature gradient compensation stress value.

[0007] In some embodiments, the current cable stress detection data is detected by a stress detection sensor. The current temperature data further includes the temperature data of the current stress detection sensor. Determining the current temperature-corrected stress data based on the current cable stress detection data and the current temperature gradient-compensated stress value includes: determining the current static temperature-corrected stress data based on the current cable stress detection data and the temperature data of the current stress detection sensor; and determining the current temperature-corrected stress data based on the current static temperature-corrected stress data and the current temperature gradient-compensated stress value.

[0008] In some embodiments, the stress detection sensor is a dual-wavelength fiber Bragg grating, and the bridge condition monitoring data further includes the strain sensitivity coefficient and the temperature sensitivity coefficient of the stress detection sensor. Obtaining the bridge condition monitoring data, which includes the current cable stress detection data, the current temperature data, the current cable vibration acceleration data, and the current cable vibration-strain transfer coefficient, includes: obtaining a first drift amount and a second drift amount under the current stress detection sensor, where the first drift amount is the drift amount of the first-wavelength light propagating in the detection sensor, and the second drift amount is the drift amount of the second-wavelength light propagating in the detection sensor. During the propagation of the first-wavelength light and the second-wavelength light in the detection sensor, one is sensitive to light and the other is sensitive to strain; determining the current cable stress detection data and the temperature data of the current stress detection sensor based on the strain sensitivity coefficient, the temperature sensitivity coefficient, the first drift amount, and the second drift amount.

[0009] In some embodiments, obtaining the bridge condition monitoring data, which includes the current cable stress detection data, the current temperature data, the current cable vibration acceleration data, and the current cable vibration-strain transfer coefficient, further includes: obtaining historical bridge condition monitoring data, which includes the historical cable vibration acceleration data and the historical cable stress detection data corresponding to each time point within a preset time period before the current time point; and determining the current cable vibration-strain transfer coefficient based on the historical cable vibration acceleration data and the historical cable stress detection data.

[0010] In some embodiments, determining the current cable vibration-strain transfer coefficient based on the historical cable vibration acceleration data and the historical cable stress detection data includes: time-aligning the historical cable vibration acceleration data and the historical cable stress detection data; performing band-pass filtering on the historical cable vibration acceleration data, retaining the historical cable vibration acceleration data with vibration frequencies within a first preset range, and determining it as the first historical cable vibration acceleration data; determining the historical cable vibration characteristic data based on the first historical cable vibration acceleration data and the first historical cable stress detection data; performing detrending processing on the historical cable stress detection data to determine the historical cable strain noise; and determining the current cable vibration-strain transfer coefficient based on the historical cable vibration characteristic data and the historical cable strain noise.

[0011] In some embodiments, the historical bridge condition monitoring data further includes historical cable temperature distribution data, historical cable stress detection data, and historical live load data. Obtaining the bridge condition monitoring data, where the bridge condition monitoring data includes current cable stress detection data, current temperature data, current cable vibration acceleration data, and current cable vibration-strain transfer coefficient, includes: determining, according to the historical live load data, a period without vehicle passage in the historical bridge condition monitoring data, and determining the historical cable temperature distribution data and historical cable stress detection data corresponding to the period without vehicle passage as the first stress data; determining the current temperature gradient compensation coefficient according to the historical cable stress detection data and historical cable temperature distribution data of the first stress data.

[0012] In some embodiments, determining the current temperature gradient compensation coefficient according to the historical cable stress detection data and historical cable temperature distribution data of the first stress data includes: performing band-pass filtering on the historical cable stress detection data, retaining the historical cable stress detection data with the strain frequency in the second preset range and determining it as the second historical cable stress detection data; determining the current temperature gradient compensation coefficient according to the second historical cable stress detection data and historical cable temperature distribution data.

[0013] In some embodiments, before the step of obtaining the historical bridge condition monitoring data, where the historical bridge condition monitoring data includes historical cable vibration acceleration data and historical cable stress detection data corresponding to each time point within a preset time period before the current time point, the method further includes: obtaining the structural information of the emergency rescue cable bridge; determining the preset time period for obtaining the historical bridge condition monitoring data according to the service time of the emergency rescue cable bridge and the structural information of the emergency rescue cable bridge.

[0014] This application also provides an emergency rescue cable bridge stress monitoring system. The emergency rescue cable bridge stress monitoring system includes: a bridge condition monitoring data acquisition module, a temperature-corrected stress data determination module, a vibration-corrected stress data determination module, and a target stress data determination module. Among them, the bridge condition monitoring data acquisition module is used to acquire the bridge condition monitoring data. The bridge condition monitoring data includes current cable stress detection data, current temperature data, current cable vibration acceleration data, and current cable vibration-strain transfer coefficient. The temperature-corrected stress data determination module is used to determine the current temperature-corrected stress data according to the current cable stress detection data and current temperature data. The vibration-corrected stress data determination module is used to determine the current vibration-corrected stress data according to the current temperature-corrected stress data, current cable vibration acceleration data, and vibration-strain transfer coefficient. The target stress data determination module is used to perform wavelet packet denoising on the current vibration-corrected stress data to determine the current target stress data.

[0015] The present application also provides a method for controlling the stress of an emergency rescue cable bridge. The method includes: monitoring the target stress data of the cable body of the cable bridge by using the emergency rescue cable bridge stress monitoring method provided by the present application. The method further includes: determining the current remaining load capacity of the bridge according to the target stress data; and closing the access gates at both ends of the cable bridge when the current remaining load capacity of the bridge is less than or equal to a preset value.

[0016] In some embodiments, the method for controlling the stress of the emergency rescue cable bridge further includes: obtaining the natural frequency of the current bridge and the current passing vehicle load data. Determining the driving speed of the current passing vehicle according to the natural frequency of the current bridge and the current passing vehicle load data.

[0017] As described above, an emergency rescue cable bridge stress monitoring method and system provided by the present application have the following beneficial effects: In the emergency rescue cable bridge stress monitoring method of the present application, the detected cable body stress detection data is corrected by the bridge temperature data and the cable body vibration acceleration data respectively. Thus, it is beneficial to improve the accuracy of the cable body stress detection when the bridge structure is vibrating. In addition, the bridge temperature data corrects the cable body stress detection data prior to the cable body vibration acceleration data, which is beneficial to further improving the accuracy of the cable body stress detection. The wavelet packet denoising is beneficial to filtering out the residual random noise in the corrected data and improving the signal-to-noise ratio. In addition, after the wavelet packet denoising corrects the cable body stress detection data first, it can ensure that the data is closer to the true strain, and the denoising can more accurately retain the effective signal, that is, it can more accurately retain the target stress data that can reflect the true stress and strain of the bridge.

[0018] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts. In the drawings: Figure 1 is a flowchart of an emergency rescue cable bridge stress monitoring method shown in an exemplary embodiment of the present application; Figure 2 is a structural block diagram of an emergency rescue cable bridge stress monitoring device shown in an exemplary embodiment of the present application; Figure 3 is a front view of an emergency rescue cable bridge shown in an exemplary embodiment of the present application; Figure 4 It is a top view of an emergency rescue cableway bridge shown in an exemplary embodiment of the present application; Figure 5 It is a cross-sectional view in the width direction of the emergency rescue cableway bridge shown in an exemplary embodiment of the present application. Detailed implementation manners

[0020] The following will describe the implementation manners of the present application with reference to the drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for explaining the present application, rather than for limiting the protection scope of the present application.

[0021] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner. Therefore, only the components related to the present application are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0022] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the present application. However, it is obvious to those skilled in the art that the embodiments of the present application can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present application difficult to understand.

[0023] Please refer to Figure 1 , Figure 1 It is a flowchart of a stress monitoring method for an emergency rescue cableway bridge shown in an exemplary embodiment of the present application. Referring to Figure 1 it can be seen that the stress monitoring method for the emergency rescue cableway bridge may include: Step 100, obtaining bridge state monitoring data.

[0024] Exemplarily, the bridge state monitoring data includes current cable stress detection data, current temperature data, current cable vibration acceleration data, and current cable vibration-strain transfer coefficient.

[0025] Referring to Figures 3 to 5, in some embodiments, the emergency rescue cable bridge includes a bridge deck 51, multiple bridge deck cables 52, multiple stabilizing cables 53, a rotating saddle 54, a saddle foundation beam 55, and a stabilizing crossbeam 56. It should be noted that the cable body described in this article can be the main structure of various types of cable structures in the exemplary emergency rescue cable bridge structure of this article. Exemplarily, the emergency rescue cable bridge adopts a modular steel strand bridge deck cable 52, and the effective width of the bridge deck 51 is 3.8 m. Specifically, the bridge deck cable 52 is composed of 21 bundles of 5×Φ15.24 high-strength low-relaxation steel strands, and 3 rows of 23 bundles of prestressed anchor cables are arranged on one-sided ground anchors, and the anchorage section length ≥ 15 m.

[0026] Exemplarily, the cable body stress detection data includes bridge deck cable strain data and stabilizing cable strain data. Specifically, strain sensors can be arranged along the bridge deck cables and stabilizing cables to detect the stress and strain data of each bridge deck cable and each stabilizing cable, and then obtain the current cable body stress detection data. Optionally, the strain sensor can be a fiber Bragg grating sensor, such as a dual-wavelength fiber Bragg grating sensor. Optionally, in order to better reflect the stress and strain data of the cable body, a strain sensor can be arranged every 2 meters along the extension direction of the cable body. Of course, the arrangement method and the spacing of the strain sensors can be adjusted according to the specific type of the stress sensor. Therefore, the arrangement method of the strain sensors is not limited in this embodiment.

[0027] In some embodiments, accelerometers can be arranged at positions adjacent to the strain sensors to detect vibration acceleration and then obtain the current cable body vibration acceleration data. Exemplarily, the strain sensors and the accelerometers can be installed in one-to-one correspondence. In some embodiments, the accelerometers and the strain sensors can be synchronously monitored. It should be noted that the synchronous monitoring described in this application can be synchronous sampling between different sensors, that is, multiple parameters can be monitored for different sensors at the same time node. It can also be based on the hysteresis between different physical quantities, so that the detection time interval between the two physical quantities has a preset time shift amount to ensure synchronous monitoring. Of course, in some embodiments, it is also possible to perform continuous sampling, and then read the data according to the time shift amount between different physical quantities in the continuous sampling data, so as to achieve synchronous monitoring between different physical quantities.

[0028] In some embodiments, temperature sensors can be arranged at different positions of the bridge body to detect and obtain the current temperature data. Specifically, the positions of the temperature sensors can be set as needed to obtain the current temperature data through the temperature sensors. Exemplarily, the temperature sensors can be synchronously monitored with the accelerometers and the strain sensors. Specifically, the monitoring data of the strain sensors, the temperature sensors, and the accelerometers can be synchronously read through the FPGA.

[0029] The vibration-strain transfer coefficient can be used to reflect the proportional relationship between vibration characteristics and strain interference. Exemplarily, the current cable vibration-strain transfer coefficient can be determined by a vibration table sweep frequency test. The vibration characteristics may include vibration displacement and / or vibration velocity.

[0030] In some embodiments, the steps of the emergency rescue cableway bridge stress monitoring method provided by the embodiments of the present application can be executed by a terminal, a server, or a server cluster.

[0031] Step 200, determine the current temperature-corrected stress data according to the current cable stress detection data and the current temperature data.

[0032] In some embodiments, a temperature sensor can be arranged every 2 meters along the extension direction of the cable to obtain the current temperature data through the temperature sensor. Of course, the arrangement method and the spacing of the temperature sensors can be adjusted according to the specific type of the temperature sensor. For this reason, the arrangement method of the temperature sensors is not limited in this embodiment. Of course, in some embodiments, the temperature data can also be indirectly obtained through other sensors.

[0033] Exemplarily, the temperature compensation correction formula is as follows: ; Wherein, is the current temperature-corrected stress data, is the current cable stress detection data, that is, the detection data directly obtained through the strain sensor, is the additional strain of the cable stress and strain detection caused by the temperature change.

[0034] In some embodiments, can be determined according to the temperature data, the temperature strain characteristics of the temperature sensor, and the temperature strain characteristics of the cable structure. When the structure of the emergency rescue cableway bridge and the materials of each component are known, the temperature strain characteristics of the corresponding cable structure of the emergency rescue cableway bridge can be pre-calibrated by the structure of the emergency rescue cableway bridge and the materials of each component. When the type of the temperature sensor is determined, the temperature strain characteristics of the temperature sensor can be pre-calibrated according to the type of the temperature sensor.

[0035] In some embodiments, in step 200, determining the current temperature-corrected stress data based on the current cable stress detection data and the current temperature data includes: step 210, determining the current temperature gradient compensation stress value according to the current cable temperature distribution data and the current temperature gradient compensation coefficient; step 220, determining the current temperature-corrected stress data based on the current cable stress detection data and the current temperature gradient compensation stress value. This embodiment can correct the additional strain caused by the non-uniform temperature distribution along the cable length. Therefore, in the case of uneven sunlight covering the bridge, the cable stress and strain data of each cable structure in the cable-stayed bridge can be detected.

[0036] Exemplarily, the temperature gradient of the cable along the cable extension direction is monitored in real time by temperature sensors arranged every 2 meters along the cable. Exemplarily, the temperature gradient compensation formula is: ; where is the additional strain value caused by the uneven temperature distribution of the cable. is the thermal expansion strain term caused by uniform temperature change, is the thermal expansion coefficient corresponding to the material of the cable, is the temperature change amount. Specifically, is the change of the local or overall temperature relative to the reference temperature. It should be noted that the reference temperature can be set according to the environment where the cable-stayed bridge is located. In some embodiments, the reference temperature can be adjusted seasonally, and the temperature gradient compensation coefficient can be adaptively adjusted after adjusting the reference temperature. Exemplarily, in winter, the change of the reference temperature can be used to re-set or calibrate the temperature gradient compensation coefficient. This embodiment can make the reference temperature closer to the temperature at the monitoring moment, thereby helping to reduce the compensation value and improve the monitoring accuracy of the cable stress and strain. Specifically, the real-time temperature can be measured by a temperature sensor, and determined according to the difference between the measured value of the temperature sensor and the reference temperature.

[0037] is the gradient of the temperature in the spatial direction of the bridge structure (such as the cable length direction) (unit: °C / m).

[0038] Exemplarily, is the gradient of the temperature along the length direction of the cable structure. It can be obtained by collecting through, but not limited to, distributed temperature sensors or sensors such as infrared thermal imagers and fiber Bragg gratings, and calculating the ratio of the temperature difference between adjacent measurement points to the distance. In some embodiments, the surface temperature field can be obtained by thermal imaging technology, and the spatial gradient can be interpolated and calculated.

[0039] is the temperature gradient strain coefficient (unit: με·m / °C), which can be used to reflect the contribution of the temperature gradient to the additional strain. Exemplarily, Apply a known temperature gradient in the laboratory or on-site, measure the strain response, and fit by linear regression .

[0040] In some embodiments, the temperature compensation only includes temperature gradient compensation, that is .

[0041] In some embodiments, the current cable stress detection data is detected by a stress detection sensor. The current temperature data also includes the temperature data of the current stress detection sensor. Exemplarily, the temperature data of the current stress detection sensor can be the temperature change amount of the stress detection sensor.

[0042] In some embodiments, step 220, determining the current temperature corrected stress data according to the current cable stress detection data and the current temperature gradient compensated stress value includes: step 221, determining the current static temperature corrected stress data according to the current cable stress detection data and the temperature data of the current stress detection sensor; step 222, determining the current temperature corrected stress data according to the current static temperature corrected stress data and the current temperature gradient compensated stress value.

[0043] In the above embodiments, the additional strain caused by the temperature change of the sensor can also be obtained through the temperature data of the detection sensor. Specifically, a mapping table of the temperature of the sensor and the additional strain caused by the temperature change of the sensor can be obtained according to the type of the sensor. Exemplarily, the mapping table of the temperature of the sensor and the additional strain caused by the temperature change of the sensor can be calibrated by applying a known temperature in the laboratory or on-site to measure the strain response.

[0044] Exemplarily, the temperature compensation can include cable temperature gradient compensation and / or sensor temperature compensation.

[0045] In some embodiments, the temperature compensation includes cable temperature gradient compensation and sensor temperature compensation, then ; wherein is the additional strain on the cable stress and strain detection due to the temperature change of the temperature sensor.

[0046] ; wherein is the current static temperature corrected stress data, is the current cable stress detection data, that is, the detection data directly obtained by the strain sensor.

[0047] In some embodiments, the stress detection sensor is a dual-wavelength fiber Bragg grating. The bridge condition monitoring data also includes the strain sensitivity coefficient and the temperature sensitivity coefficient of the stress detection sensor.

[0048] Step 100: Obtain bridge status monitoring data. The bridge status monitoring data includes current cable stress detection data, current temperature data, current cable vibration acceleration data, and current cable vibration-strain transfer coefficient, including: Step 110: Obtain the first drift amount and the second drift amount under the current stress detection sensor. Step 120: Determine the current cable stress detection data and the current stress detection sensor temperature data according to the strain sensitivity coefficient, the temperature sensitivity coefficient, the first drift amount, and the second drift amount.

[0049] Among them, the first drift amount is the drift amount of the first wavelength light propagating in the detection sensor. The second drift amount is the drift amount of the second wavelength light propagating in the detection sensor. During the propagation of the first wavelength light and the second wavelength light in the detection sensor, one is sensitive to light and the other is sensitive to strain.

[0050] Specifically, the temperature data, that is, the temperature change amount of the stress detection sensor, can be determined according to the dual-wavelength fiber Bragg grating decoupling formula. Exemplarily, the dual-wavelength fiber Bragg grating decoupling formula is as follows: ; Among them, is the first drift amount, is the second drift amount, The strain sensitivity coefficient (unit: nm / με) of the dual-wavelength fiber Bragg grating represents the wavelength change caused by unit strain; 、 is the temperature sensitivity coefficient (unit: nm / °C) corresponding to the fiber Bragg grating; is the temperature change amount (unit: °C) of the fiber Bragg grating sensor; : is the stress strain (unit: με) detected by the dual-wavelength fiber Bragg grating sensor.

[0051] It should be noted that during the detection process of the dual-wavelength fiber Bragg grating sensor, the decoupling of the sensor detected stress and the sensor temperature has been realized.

[0052] Step 300: Determine the current vibration corrected stress data according to the current temperature corrected stress data, the current cable vibration acceleration data, and the vibration-strain transfer coefficient.

[0053] Exemplarily, the vibration compensation correction formula is as follows: ε 振动修正 =ε 温度修正 -Δε 振动补偿； Among them, ε 温度修正 is the current temperature corrected stress data, ε 振动修正is the current vibration correction stress data, Δε 振动补偿 is the influence value of vibration on the stress and strain detection of the cable body.

[0054] In some alternative embodiments, the vibration acceleration a(t) can be measured in real time for strain signal compensation. Optionally, in the case of low-frequency vibration, the vibration displacement of the cable body is determined by integrating the vibration acceleration a(t) of the cable body, and combined with the vibration-strain transfer coefficient k d to correct the strain measurement value and eliminate the base strain interference caused by vibration. Exemplarily, Δε 振动补偿 The calculation formula is: ; where k d : the vibration-strain transfer coefficient of the cable body under low-frequency vibration, which can be calibrated by a shaking table; specifically, in the case where the vibration frequency is less than 1 Hz, based on displacement, k d .

[0055] is the vibration time history data measured by the accelerometer.

[0056] In some alternative embodiments, in the case where the vibration frequency is greater than or equal to 1 Hz, the vibration velocity of the cable body is determined by integrating the vibration acceleration a(t) of the cable body, and combined with the vibration-strain transfer coefficient k v to correct the strain measurement value and eliminate the base strain interference caused by vibration. Exemplarily, Δε 振动补偿 The calculation formula is: ; where k v : the vibration-strain transfer coefficient of the cable body under high-frequency vibration, which can be calibrated by a shaking table; exemplarily, in the case where the vibration frequency is less than greater than or equal to 1 Hz, based on velocity, k d .

[0057] is the vibration time history data measured by the accelerometer.

[0058] Although the emergency rescue cable bridge is provided with stabilizing cables, the emergency rescue cable bridge is still prone to vibration, and the vibration intensity is more intense than that of other non-cable bridges. The vibration of the bridge body will directly cause mechanical vibration of the sensor itself, thereby affecting the measurement result. Step 300 can effectively compensate for the influence value of the vibration of the bridge body on the stress and strain detection, which is beneficial to improving the stress and strain detection accuracy.

[0059] In some embodiments, the vibration-strain transfer coefficient includes a vibration displacement-strain transfer coefficient and a vibration velocity-strain coefficient. Step 300 of determining the current vibration-corrected stress data based on the stress data corrected according to the current temperature, the current cable vibration acceleration data, and the vibration-strain transfer coefficient includes: Obtain the cable vibration frequency; When the cable vibration frequency is less than a preset value, determine the current vibration-corrected stress data based on the stress data corrected according to the current temperature, the current cable vibration acceleration data, and the vibration displacement-strain transfer coefficient; When the cable vibration frequency is greater than or equal to the preset value, determine the current vibration-corrected stress data based on the stress data corrected according to the current temperature, the current cable vibration acceleration data, and the vibration velocity-strain transfer coefficient.

[0060] In the above embodiments, during the stress-strain detection process, the factors affecting the vibration-strain transfer coefficient are different in different frequency bands. The above can adjust the calculation method of the vibration-strain transfer coefficient according to the vibration frequency to adapt to different factors affecting the vibration-strain transfer coefficient in different frequency bands. Specifically, during high-frequency vibration, the vibration velocity-strain transfer coefficient can effectively adapt to the situation where damping effect and inertial force are the main influencing factors under high-frequency vibration. During low-frequency vibration, the vibration displacement-strain transfer coefficient can effectively adapt to the situation where elastic deformation is the main influencing factor under low-frequency vibration. Therefore, this embodiment is beneficial to reducing the noise in the stress-strain detection process and improving the detection accuracy.

[0061] Step 400 of performing wavelet packet denoising on the current vibration-corrected stress data to determine the current target stress data. Wavelet packet denoising is an existing signal processing technology. Specifically, wavelet packet denoising decomposes the signal into different frequency bands through multi-resolution analysis of the signal, and then removes the noise components through threshold processing. The steps of wavelet packet denoising will not be elaborated here. During the strain detection process, the noise may come from high-frequency electromagnetic interference or low-frequency drift. Exemplarily, wavelet packet denoising can retain the frequency band of 0.1 Hz - 100 Hz, and remove high-frequency noise greater than 100 Hz and low-frequency drift less than 0.1 Hz.

[0062] In some embodiments, as the bridge is used over time, the bridge structure will change significantly. In some embodiments, the cable vibration-strain transfer coefficient can be updated at specific time nodes according to the structural characteristics of the bridge. Exemplarily, step 100 of obtaining the bridge condition monitoring data, where the bridge condition monitoring data includes the current cable stress detection data, the current temperature data, the current cable vibration acceleration data, and the current cable vibration-strain transfer coefficient, further includes: Step 130: Obtain historical bridge condition monitoring data, which includes historical cable vibration acceleration data and historical cable stress detection data corresponding to each time point within a preset time period before the current time point.

[0063] Exemplarily, sensors can be installed on the cable-stayed bridge to monitor physical parameters that can characterize the bridge condition, so as to obtain historical bridge condition monitoring data. Exemplarily, the physical parameters that can characterize the bridge condition can be, but are not limited to, cable vibration acceleration and cable stress and strain.

[0064] Step 140: Determine the current cable vibration-strain transfer coefficient based on the historical cable vibration acceleration data and the historical cable stress detection data.

[0065] Exemplarily, in the above embodiment, the cable vibration-strain transfer coefficient can be recalibrated through the historical cable vibration acceleration data and the historical cable stress detection data, which can improve the environmental adaptability and maintenance convenience, and is beneficial to realizing the automatic update of the cable vibration-strain transfer coefficient.

[0066] In some embodiments, the historical bridge condition monitoring data can also be analyzed in real time based on machine learning (such as a recurrent neural network RNN) to predict the drift trend of the cable vibration-strain transfer coefficient, and then the measured data is input into the digital twin model to inversely deduce and correct the cable vibration-strain transfer coefficient.

[0067] In some embodiments, Step 140: Determine the current cable vibration-strain transfer coefficient based on the historical cable vibration acceleration data and the historical cable stress detection data, including: Step 141: Align the historical cable vibration acceleration data and the historical cable stress detection data in terms of time; Step 142: Perform band-pass filtering on the historical cable vibration acceleration data, retain the historical cable vibration acceleration data with the vibration frequency within the first preset range, and determine it as the first historical cable vibration acceleration data; Step 143: Determine the historical cable vibration characteristic data based on the first historical cable vibration acceleration data and the first historical cable stress detection data; Step 144: Perform detrending processing on the historical cable stress detection data to determine the historical cable strain noise; Step 145: Determine the current cable vibration-strain transfer coefficient based on the historical cable vibration characteristic data and the historical cable strain noise.

[0068] In some embodiments, for the FFT transform: the historical cable body vibration characteristic data can also be obtained by frequency-domain integration. By using frequency-domain integration to process the noise-offset acceleration signal, the cumulative error problem in time-domain integration can be effectively avoided. The method of using frequency-domain integration to process the noise-offset acceleration signal is a prior art. Therefore, in this embodiment, no further elaboration will be made on how to perform frequency-domain integration on the first historical cable body vibration acceleration data to obtain the historical cable body vibration characteristic data.

[0069] In some embodiments, the historical cable body vibration characteristic data includes historical cable body vibration displacement data.

[0070] Specifically, the historical cable body vibration displacement data can be obtained by second-order integration of the first historical cable body vibration acceleration data. Specifically as follows: , where is the historical cable body vibration displacement data, is the first historical cable body vibration acceleration data measured by the accelerometer.

[0071] Exemplarily, when the vibration frequency of the first historical cable body vibration acceleration data is less than the preset value, the historical cable body vibration characteristic data is the historical cable body vibration displacement data. Specifically, when the vibration frequency of the first historical cable body vibration acceleration data is less than 1 Hz, the historical cable body vibration characteristic data is the historical cable body vibration displacement data.

[0072] In some embodiments, when the vibration frequency of the first historical cable body vibration acceleration data is less than the preset value, the historical cable body vibration displacement data can also be obtained by frequency-domain integration.

[0073] In some embodiments, the historical cable body vibration characteristic data includes historical cable body vibration velocity data. Specifically as follows: , where, is the historical cable body vibration velocity data, is the first historical cable body vibration acceleration data measured by the accelerometer.

[0074] Exemplarily, when the vibration frequency of the first historical cable body vibration acceleration data is greater than or equal to the preset value, the historical cable body vibration characteristic data is the historical cable body vibration velocity data. Specifically, when the vibration frequency of the first historical cable body vibration acceleration data is greater than or equal to 1 Hz, the historical cable body vibration characteristic data is the historical cable body vibration displacement data.

[0075] In some embodiments, the historical bridge condition monitoring data further includes historical cable temperature distribution data, historical cable stress detection data, and historical live load data. Among them, the live load data refers to the loads that are temporarily applied, movable, or variable during the use of the bridge. Exemplarily, the live load data may be, but is not limited to, vehicle loads, pedestrian loads, and heavy object loads. It should be noted that the live load does not include the loads caused by environmental changes, such as wind loads. The historical cable stress detection data can be the strain data detected by a stress-strain sensor. The historical cable temperature distribution data can be obtained by recording the data of a distributed temperature sensor.

[0076] In some embodiments, in step 100, bridge condition monitoring data is acquired. The bridge condition monitoring data includes current cable stress detection data, current temperature data, current cable vibration acceleration data, and current cable vibration-strain transfer coefficient, and further includes: in step 150, the time periods without vehicle passage in the historical bridge condition monitoring data are determined according to the historical live load data, and the historical cable temperature distribution data and historical cable stress detection data corresponding to the time periods without vehicle passage are determined as the first stress data; in step 160, the current temperature gradient compensation coefficient is determined according to the historical cable stress detection data and historical cable temperature distribution data of the first stress data. Exemplarily, the time period when the historical live load data is less than a preset value can be determined as the time period without vehicle passage.

[0077] In some embodiments, in step 160, determining the current temperature gradient compensation coefficient according to the historical cable stress detection data and historical cable temperature distribution data of the first stress data includes: Step 161, perform band-pass filtering on the historical cable stress detection data, retain the historical cable stress detection data with the strain frequency located in the second preset range, and determine it as the second historical cable stress detection data. Exemplarily, the low-frequency temperature strain signal in the historical cable stress detection data is extracted through band-pass filtering (0.001 Hz - 0.1 Hz) and determined as the second historical cable stress detection data.

[0078] Step 162, determine the current temperature gradient compensation coefficient according to the second historical cable stress detection data and historical cable temperature distribution data. Exemplarily, the current temperature gradient compensation coefficient can be determined by, but is not limited to, linear regression fitting.

[0079] Exemplarily, all sensors are synchronized to ensure the alignment of timestamps. Specifically, the cable temperature distribution data and cable stress detection data are synchronously acquired.

[0080] In some embodiments, linear or spline interpolation can also be performed on the historical cable stress detection data and / or historical cable temperature distribution data, and the time axes are aligned.

[0081] Determine the time shift amount Δt, and determine the first historical cable body temperature distribution data and the third historical cable body stress detection data of the alignment signal according to Δt. It should be noted that since heat conduction takes time, the temperature change will not instantaneously cause a strain response. Therefore, the time shift amount Δt can be preset as needed. Of course, the time shift amount Δt can also be determined by calculating the cross-correlation function of the temperature gradient integral and the strain. Specifically, the time shift amount Δt can be determined in combination with the thermal inertia compensation method in the prior art. Exemplarily, the time shift amount Δt can be determined by prior calibration. Exemplarily, a mapping relationship table between the ambient temperature and the time shift amount Δt can be established by prior calibration. Specifically, the ambient temperature for a certain period can be collected, and then the time shift amount Δt can be determined according to the mapping relationship table between the ambient temperature and the time shift amount Δt and the collected ambient temperature. In some embodiments, it can also be determined by the phase difference analysis method, the optimization search method, the feature point matching method, and the cross-correlation function method. Exemplarily, the time shift amount Δt can be determined by the frequency domain method.

[0082] Integrate the temperature gradient along the structural path in real time , where can be obtained by the ratio of the temperature difference between adjacent measurement points in the first historical cable body temperature distribution data to the distance.

[0083] Exemplarily, the cross-correlation function of the temperature gradient integral and the strain is as follows: ; where is the third historical cable body stress detection data; β is the current temperature gradient compensation coefficient. Specifically, the slope β can be fitted by the least squares method, and then the current temperature gradient compensation coefficient can be obtained.

[0084] In some embodiments, before step 100 of obtaining the historical bridge state monitoring data, where the historical bridge state monitoring data includes the historical cable body vibration acceleration data and the historical cable body stress detection data corresponding to each time point within a preset time period before the current time point, the stress monitoring method for the emergency rescue cable bridge further includes: Step 500, obtain the structural information of the emergency rescue cable bridge; Step 600, determine the preset time period for obtaining the historical bridge state monitoring data according to the service time of the emergency rescue cable bridge and the structural information of the emergency rescue cable bridge.

[0085] Exemplarily, the preset time period can also be determined according to the usage time of the emergency rescue cableway bridge, and the preset time period is positively correlated with the usage time of the emergency rescue cableway bridge. Since after the emergency rescue cableway bridge is put into use, the longer the usage time, the smaller the influence of factors such as the settlement of the rotating saddle and the saddle foundation beam, and the release of the residual stress of the cable structure on the temperature gradient compensation coefficient and the cable vibration-strain transfer coefficient. Exemplarily, the slight settlement of the rotating saddle and the saddle foundation beam mainly occurs in the early stage of being put into use. That is, the settlement of the rotating saddle and the saddle foundation beam changes rapidly in the initial stage and slows down in the later stage. Therefore, in the early stage of the bridge's use, the preset time period can be shorter, such as 15 days. In the later stage of the bridge's use, the preset time period can be longer, such as 1 month.

[0086] In some embodiments, the preset time period for obtaining the historical bridge state monitoring data can also be determined according to the change of the environmental temperature. Exemplarily, the preset time period for obtaining the historical bridge state monitoring data can be determined according to the alternation of seasons.

[0087] In some embodiments, the stress monitoring method for the emergency rescue cableway bridge further includes: Step 700, determining the current remaining load capacity of the bridge according to the target stress data; Step 800, closing the access gates at both ends of the cableway bridge when the current remaining load capacity of the bridge is less than or equal to a preset value.

[0088] Through accurately monitoring the stress data received by the cable body in the above embodiments, the current remaining load capacity of the bridge can be obtained through some bridge health assessment methods in the prior art, and then the opening or closing of the gate can be controlled according to the remaining load capacity of the bridge to regulate the vehicle load received by the bridge. Therefore, this embodiment is beneficial to preventing the emergency rescue cableway bridge from being overloaded and ensuring the safe operation of the emergency rescue cableway bridge.

[0089] In some embodiments, as Figure 2 is a block diagram of the stress monitoring system for the emergency rescue cableway bridge provided by the present application. As Figure 2 shown, the exemplary stress monitoring system 20 for the emergency rescue cableway bridge includes: A bridge state monitoring data acquisition module 21, configured to acquire bridge state monitoring data, where the bridge state monitoring data includes current cable body stress detection data, current temperature data, current cable body vibration acceleration data, and current cable vibration-strain transfer coefficient; A temperature-corrected stress data determination module 22, configured to determine current temperature-corrected stress data according to the current cable body stress detection data and the current temperature data; A vibration-corrected stress data determination module 23, configured to determine current vibration-corrected stress data according to the current temperature-corrected stress data, the current cable body vibration acceleration data, and the vibration-strain transfer coefficient; The target stress data determination module 24 is configured to perform small packet wave denoising on the current vibration corrected stress data to determine the current target stress data.

[0090] In some embodiments, gateways are further provided at both ends of the emergency rescue cable bridge. The present application also provides a control method for stress monitoring of an emergency rescue cable bridge. The method includes: Step 101, monitoring the target stress data of the cable body of the cable bridge.

[0091] Exemplarily, the target stress data includes but is not limited to the stress and strain data of the cable body.

[0092] Step 102, determining the current remaining load capacity of the bridge according to the target stress data; Step 103, closing the access gateways at both ends of the cable bridge when the current remaining load capacity of the bridge is less than or equal to a preset value.

[0093] The control method for stress monitoring of an emergency rescue cable bridge further includes: opening the access gateways at both ends of the cable bridge when the current remaining load capacity of the bridge is greater than the preset value.

[0094] Through the above embodiments, by accurately monitoring the stress data received by the cable body, the current remaining load capacity of the bridge can be obtained through some bridge health assessment methods in the prior art, and then the opening or closing of the gateway can be controlled according to the remaining load capacity of the bridge to regulate the vehicle load received by the bridge.

[0095] In some embodiments, the control method for stress monitoring of an emergency rescue cable bridge further includes: Step 104, obtaining the natural frequency of the current bridge and the current passing vehicle load data, Step 105, determining the driving speed of the current passing vehicle according to the natural frequency of the current bridge and the current passing vehicle load data.

[0096] In the above embodiments, since resonance between the vehicle and the bridge is prevented during the vehicle driving process, it is beneficial to reduce the shaking of the bridge.

[0097] In some embodiments, the tension of different cable bodies in the bridge can also be adjusted so that the vibrations between different cable bodies can cancel each other out to reduce the shaking of the bridge.

[0098] It should be noted that the emergency rescue cable bridge stress monitoring system provided in the above embodiments and the emergency rescue cable bridge stress monitoring method provided in the above embodiments belong to the same concept. The specific ways in which each module and unit perform operations have been described in detail in the method embodiments and will not be elaborated here. In practical applications, the emergency rescue cable bridge stress monitoring system provided in the above embodiments can, according to needs, allocate the above functions to different functional modules, that is, divide the internal structure of the system into different functional modules to complete all or part of the functions described above. This will not be limited here either.

[0099] An embodiment of the present application also provides an electronic device, including: one or more processors; a storage device for storing one or more programs, and when the one or more programs are executed by the one or more processors, the electronic device implements the emergency rescue cable bridge stress monitoring method provided in each of the above embodiments.

[0100] On the other hand, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor of the computer, the computer executes the emergency rescue cable bridge stress monitoring method provided in each of the above embodiments. The computer-readable storage medium may be included in the electronic device described in the above embodiments or may exist separately without being assembled into the electronic device.

[0101] On the other hand, the present application also provides a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the emergency rescue cable bridge stress monitoring method provided in each of the above embodiments.

[0102] In the embodiments of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. The terms "comprising" and "including" mentioned throughout the specification and claims are open-ended terms and should be interpreted as "including but not limited to".

[0103] The above embodiments are only used to exemplarily illustrate the principles and effects of the present application and are not used to limit the present application. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present application should still be covered by the claims of the present application.

Claims

1. A stress monitoring method for an emergency rescue cableway bridge, characterized in that Including: Obtaining bridge status monitoring data, where the bridge status monitoring data includes current cable stress detection data, current temperature data, current cable vibration acceleration data, and current cable vibration-strain transfer coefficient; Determining current temperature-corrected stress data based on the current cable stress detection data and the current temperature data; Determining current vibration-corrected stress data based on the current temperature-corrected stress data, the current cable vibration acceleration data, and the vibration-strain transfer coefficient; Performing wavelet denoising on the current vibration-corrected stress data to determine the current target stress data.

2. The stress monitoring method of the emergency rescue cable bridge according to claim 1, wherein The current temperature data includes current cable temperature distribution data and current temperature gradient compensation coefficient; Determining current temperature-corrected stress data based on the current cable stress detection data and the current temperature data includes: Determining the current temperature gradient compensation stress value based on the current cable temperature distribution data and the current temperature gradient compensation coefficient; Determining the current temperature-corrected stress data based on the current cable stress detection data and the current temperature gradient compensation stress value.

3. The stress monitoring method of the emergency rescue cableway bridge according to claim 2, characterized in that The current cable stress detection data is detected by a stress detection sensor, and the current temperature data further includes the temperature data of the current stress detection sensor; Determining the current temperature-corrected stress data based on the current cable stress detection data and the current temperature gradient compensation stress value includes: Determining the current static temperature-corrected stress data based on the current cable stress detection data and the temperature data of the current stress detection sensor; Determining the current temperature-corrected stress data based on the current static temperature-corrected stress data and the current temperature gradient compensation stress value.

4. The emergency rescue cableway bridge stress monitoring method according to claim 2, characterized in that Obtaining bridge status monitoring data, where the bridge status monitoring data includes current cable stress detection data, current temperature data, current cable vibration acceleration data, and current cable vibration-strain transfer coefficient, including: Obtaining historical bridge status monitoring data, where the historical bridge status monitoring data includes historical cable vibration acceleration data and historical cable stress detection data corresponding to each time point within a preset time period before the current time point; Determining the current cable vibration-strain transfer coefficient based on the historical cable vibration acceleration data and the historical cable stress detection data.

5. The emergency rescue cableway bridge stress monitoring method according to claim 4, characterized in that Determining the current cable vibration-strain transfer coefficient based on the historical cable vibration acceleration data and the historical cable stress detection data includes: Performing time alignment on the historical cable vibration acceleration data and the historical cable stress detection data; Performing band-pass filtering on the historical cable vibration acceleration data, retaining the historical cable vibration acceleration data with vibration frequencies within a first preset range, and determining it as the first historical cable vibration acceleration data; Determining historical cable vibration characteristic data based on the first historical cable vibration acceleration data and the first historical cable stress detection data; Performing detrending processing on the historical cable stress detection data to determine historical cable strain noise; Determining the current cable vibration-strain transfer coefficient based on the historical cable vibration characteristic data and the historical cable strain noise.

6. The stress monitoring method for the emergency rescue cable - way bridge according to claim 4, characterized in that the historical bridge state monitoring data further includes historical cable body temperature distribution data, historical cable body stress detection data, and historical live load data; obtain bridge state monitoring data, the bridge state monitoring data includes current cable body stress detection data, current temperature data, current cable body vibration acceleration data, and current cable body vibration - strain transfer coefficient, and further includes: determine the period without vehicle passage in the historical bridge state monitoring data according to the historical live load data, and determine the historical cable body temperature distribution data and historical cable body stress detection data corresponding to the period without vehicle passage as the first stress data; determine the current temperature gradient compensation coefficient according to the historical cable body stress detection data and historical cable body temperature distribution data of the first stress data.

7. The stress monitoring method for the emergency rescue cable - way bridge according to claim 6, characterized in that determine the current temperature gradient compensation coefficient according to the historical cable body stress detection data and historical cable body temperature distribution data of the first stress data, including: perform band - pass filtering on the historical cable body stress detection data, retain the historical cable body stress detection data with the strain frequency in the second preset range and determine it as the second historical cable body stress detection data; determine the current temperature gradient compensation coefficient according to the second historical cable body stress detection data and historical cable body temperature distribution data.

8. The stress monitoring method for the emergency rescue cable - way bridge according to any one of claims 4 to 7, characterized in that before the step of obtaining historical bridge state monitoring data, the historical bridge state monitoring data includes historical cable body vibration acceleration data and historical cable body stress detection data corresponding to each time point within a preset time period before the current time point, the method further includes: obtain the structural information of the emergency rescue cable - way bridge; determine the preset time period for obtaining historical bridge state monitoring data according to the service time of the emergency rescue cable - way bridge and the structural information of the emergency rescue cable - way bridge.

9. The stress monitoring method of the emergency rescue cableway bridge according to claim 8, characterized in that, It further includes: determine the current remaining load - bearing capacity of the bridge according to the target stress data; in the case where the current remaining load - bearing capacity of the bridge is less than or equal to the preset value, close the access gates at both ends of the cable - way bridge.

10. An emergency rescue cableway bridge stress monitoring system, characterized in that, Includes: a bridge state monitoring data acquisition module, used to obtain bridge state monitoring data, the bridge state monitoring data includes current cable body stress detection data, current temperature data, current cable body vibration acceleration data, and current cable body vibration - strain transfer coefficient; a temperature - corrected stress data determination module, used to determine the current temperature - corrected stress data according to the current cable body stress detection data and current temperature data; a vibration - corrected stress data determination module, used to determine the current vibration - corrected stress data according to the current temperature - corrected stress data, current cable body vibration acceleration data, and the vibration - strain transfer coefficient; a target stress data determination module, used to perform wavelet packet denoising on the current vibration - corrected stress data to determine the current target stress data.

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