A stress monitoring method and system for emergency rescue cableway bridge

Abstract

The present application provides a stress monitoring method and system for an emergency cableway bridge, relating to the field of stress detection technology. This method detects current cable body stress detection data while simultaneously monitoring current temperature data, current cable body vibration acceleration data, and current cable body vibration-strain transfer coefficient. The current cable body stress detection data is first corrected using the temperature data to determine current temperature-corrected stress data. The current temperature-corrected stress data is then corrected using previous cable body vibration acceleration data and the current cable body vibration-strain transfer coefficient to obtain current vibration-corrected stress data. Finally, the current vibration-corrected stress data is denoised using small packet denoising, thereby improving the accuracy of cableway bridge stress monitoring.

Description

Technical Field

[0001] The present application relates to the field of stress detection technology, and in particular to a stress monitoring method and system for an emergency rescue cableway bridge. Background Art

[0002] Conducting stress and strain testing on cableway bridges is an important technical means to ensure their safety and durability. In the existing technology, bridge stress and strain testing is mainly aimed at cableway bridges that are put into use for a long time. Therefore, before the bridge is put into use, it is necessary to monitor the various parameters of the bridge for a period of time. It will only be put into use if the design requirements of the bridge can be maintained during the monitoring process. However, emergency cableway bridges are more likely to be put into use quickly. After the bridge is built, it is quickly put into use. In the early stage of use, the residual stress and foundation structure of the bridge are still in a relatively unstable state. Therefore, traditional dynamic load tests and static load tests can no longer meet the requirements for rapid testing of emergency cableway bridges.

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

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

[0005] The present application provides a stress monitoring method for an emergency cableway bridge, comprising: obtaining bridge status monitoring data, the bridge status monitoring data including current cable body stress detection data, current temperature data, current cable body vibration acceleration data, and current cable body vibration-strain transfer coefficient; determining current temperature-corrected stress data based on the current cable body stress detection data and the current temperature data; determining current vibration-corrected stress data based on the current temperature-corrected stress data, current cable body vibration acceleration data, and the vibration-strain transfer coefficient; and performing small packet denoising on the current vibration-corrected stress data to determine current target stress data.

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

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

[0008] In some embodiments, the stress detection sensor is a dual-wavelength fiber Bragg grating, and the bridge state monitoring data also includes the strain sensitivity coefficient and temperature sensitivity coefficient of the stress detection sensor. Obtaining the bridge state monitoring data, which includes current cable body stress detection data, current temperature data, current cable body vibration acceleration data, and current cable body vibration-strain transfer coefficient, includes: obtaining a first drift and a second drift of the current stress detection sensor, wherein the first drift is the drift of light of a first wavelength propagating within the detection sensor, and the second drift is the drift of light of a second wavelength propagating within the detection sensor, and during the propagation of the first and second wavelengths of light within the detection sensor, one is sensitive to light and the other is sensitive to strain; and determining the current cable body stress detection data and the current stress detection sensor temperature data based on the strain sensitivity coefficient, the temperature sensitivity coefficient, the first drift, and the second drift.

[0009] In some embodiments, obtaining bridge status monitoring data, which includes current cable body stress detection data, current temperature data, current cable body vibration acceleration data, and current cable body vibration-strain transfer coefficient, also includes: obtaining historical bridge status monitoring data, which 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; and determining the current cable body vibration-strain transfer coefficient based on the historical cable body vibration acceleration data and the historical cable body stress detection data.

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

[0011] In some embodiments, 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. Obtaining the bridge state monitoring data, which includes current cable body stress detection data, current temperature data, current cable body vibration acceleration data, and current cable body vibration-strain transfer coefficient, includes: determining a vehicle-free period in the historical bridge state monitoring data based on the historical live load data, and determining the historical cable body temperature distribution data and historical cable body stress detection data corresponding to the vehicle-free period as first stress data; and determining a current temperature gradient compensation coefficient based on the historical cable body stress detection data and historical cable body temperature distribution data of the first stress data.

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

[0013] In some embodiments, before the step of obtaining historical bridge status monitoring data, the historical bridge status 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 also includes: obtaining structural information of the emergency rescue cableway bridge; determining the preset time period for obtaining the historical bridge status monitoring data based on the service time of the emergency rescue cableway bridge and the structural information of the emergency rescue cableway bridge.

[0014] The present application also provides an emergency rescue cableway bridge stress monitoring system. The emergency rescue cableway bridge stress monitoring system includes: a bridge state monitoring data acquisition module, a temperature correction stress data determination module, a vibration correction stress data determination module, and a target stress data determination module. Among them, the beam state monitoring data acquisition module is used to acquire 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. The temperature correction stress data determination module is used to determine the current temperature correction stress data based on the current cable body stress detection data and the current temperature data. The vibration correction stress data determination module is used to determine the current vibration correction stress data based on the current temperature correction stress data, the current cable body vibration acceleration data, and the vibration-strain transfer coefficient. The target stress data determination module is used to perform small packet denoising on the current vibration correction stress data to determine the current target stress data.

[0015] This application also provides a method for controlling stress in an emergency cableway bridge. The method comprises: using the emergency cableway bridge stress monitoring method provided in this application to monitor target stress data of the cableway bridge. The method also comprises: determining the current remaining load capacity of the bridge based on the target stress data; and closing the gates at both ends of the cableway bridge if the current remaining load capacity is less than or equal to a preset value.

[0016] In some embodiments, the method for controlling stress of an emergency cableway bridge further includes: obtaining the natural frequency of the current bridge and the load data of the current passing vehicles, and determining the speed of the current passing vehicles based on the natural frequency of the current bridge and the load data of the current passing vehicles.

[0017] As described above, the present application provides a stress monitoring method and system for an emergency cableway bridge, which has the following beneficial effects:

[0018] The present application discloses an emergency cableway bridge stress monitoring method that uses bridge temperature data and cable vibration acceleration data to correct the detected cable stress detection data, thereby improving the accuracy of cable stress detection when the bridge structure is vibrating. Furthermore, the bridge temperature data must be used to correct the cable stress detection data before the cable vibration acceleration data, which further improves the accuracy of cable stress detection. Small packet denoising is useful for filtering out residual random noise in the corrected data and improving the signal-to-noise ratio. Furthermore, small packet denoising first corrects the cable stress detection data to ensure that the data is closer to the actual strain. Denoising can more accurately retain the effective signal, thus more accurately retaining the target stress data that can reflect the actual stress and strain of the bridge.

[0019] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are incorporated into and constitute a part of the specification, illustrating embodiments consistent with the present application and, together with the specification, serving to explain the principles of the present application. It is obvious that the drawings described below are merely some embodiments of the present application, and a person of ordinary skill in the art can derive other drawings based on these drawings without inventive effort. In the drawings:

[0021] Figure 1 is a flow chart of a stress monitoring method for an emergency cableway bridge shown in an exemplary embodiment of the present application;

[0022] Figure 2 1 is a structural block diagram of a stress monitoring device for an emergency cableway bridge shown in an exemplary embodiment of the present application;

[0023] Figure 3 1 is a front view of an emergency rescue cableway bridge shown in an exemplary embodiment of the present application;

[0024] Figure 4 is a top view of an emergency rescue cableway bridge shown in an exemplary embodiment of the present application;

[0025] Figure 5 It is a cross-sectional view in the width direction of an emergency rescue cableway bridge shown in an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0026] The following will describe the embodiments of the present application with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand the other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through different specific embodiments, and the details in this specification can also be modified or changed in various ways 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 the purpose of illustrating the present application and are not intended to limit the scope of protection of the present application.

[0027] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. Therefore, the illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0028] 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.

[0029] See also Figure 1 , Figure 1 FIG1 is a flow chart of a stress monitoring method for an emergency cableway bridge according to an exemplary embodiment of the present application. Figure 1 It can be seen that the stress monitoring method for the emergency rescue cableway bridge can include:

[0030] Step 100: Acquire bridge status monitoring data.

[0031] Exemplarily, 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.

[0032] Reference Figures 3 to 5In some embodiments, the emergency rescue cableway bridge includes a bridge deck 51, a plurality of bridge deck cables 52, a plurality of stabilizing cables 53, a rotating cable saddle 54, a cable saddle foundation beam 55, and a stabilizing crossbeam 56. It should be noted that the cable body described herein can be the main structure of various types of cable structures in the exemplary emergency rescue cableway bridge structure described herein. Exemplarily, the emergency rescue cableway bridge adopts modular steel strand bridge deck cables 52, and the effective width of the bridge deck 51 is 3.8m. Specifically, the bridge deck cables 52 are composed of 21 bundles of 5×Φ15.24 high-strength and low-relaxation steel strands, and the single-side ground anchor is provided with 3 rows of 23 bundles of prestressed anchor cables, and the anchoring section length is ≥15m.

[0033] Exemplarily, cable body stress detection data includes deck cable strain data and stabilizing cable strain data. Specifically, strain sensors can be arranged along the deck cables and stabilizing cables to detect the stress and strain data of each deck cable and each stabilizing cable, thereby obtaining current cable body stress detection data. Optionally, the strain sensors can be fiber grating sensors, such as dual-wavelength fiber grating sensors. Optionally, to better reflect the stress and strain data of the cable body, strain sensors can be arranged every 2 meters along the extension direction of the cable body. Of course, the arrangement and spacing of the strain sensors can be adjusted according to the specific type of stress sensor. Therefore, this embodiment does not limit the arrangement of the strain sensors.

[0034] In some embodiments, an accelerometer can be arranged at a position adjacent to the strain sensor to detect vibration acceleration, thereby obtaining the current cable body vibration acceleration data. Exemplarily, the strain sensor and the accelerometer can be installed in a one-to-one correspondence. In some embodiments, the accelerometer and the strain sensor can be monitored synchronously. It should be noted that the synchronous monitoring described in the present application can be synchronous sampling between different sensors, that is, multiple parameters can be monitored through 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 is preset with a time shift to ensure synchronous monitoring. Of course, in some embodiments, it is also possible to achieve synchronous monitoring between different physical quantities by continuous sampling and then reading data in the continuously sampled data according to the time shift between different physical quantities.

[0035] In some embodiments, temperature sensors can be deployed at various locations on the bridge to detect and obtain current temperature data. Specifically, the temperature sensor locations can be set as needed to determine current temperature data. For example, the temperature sensor can be monitored synchronously with an accelerometer and a strain sensor. Specifically, the monitoring data from the strain sensor, temperature sensor, and accelerometer can be read synchronously using an FPGA.

[0036] The vibration-strain transfer coefficient can be used to reflect the proportional relationship between vibration characteristics and strain interference. For example, the current cable body vibration-strain transfer coefficient can be determined through a sweep frequency test on a vibration table. The vibration characteristics may include vibration displacement and / or vibration velocity.

[0037] In some embodiments, the steps of the emergency rescue cableway bridge stress monitoring method provided in the embodiments of the present application can be executed by a terminal, a server, or a server cluster.

[0038] Step 200: determining current temperature-corrected stress data based on current cable body stress detection data and current temperature data.

[0039] In some embodiments, a temperature sensor may be arranged every 2 meters along the extension direction of the cable body to obtain current temperature data through the temperature sensor. Of course, the arrangement and spacing of the temperature sensors can be adjusted based on the specific type of temperature sensor. Therefore, this embodiment does not limit the arrangement of the temperature sensors. Of course, in some embodiments, temperature data can also be obtained indirectly through other sensors.

[0040] For example, the temperature compensation correction formula is as follows:

[0041] ;

[0042] in, Correct stress data for current temperature, is the current cable stress detection data, that is, the detection data directly obtained by the strain sensor, It is the additional strain for detecting the stress and strain of the cable body due to temperature change.

[0043] In some embodiments, The temperature strain characteristics of the cable structure can be determined based on temperature data, the temperature sensor's temperature strain characteristics, and the cable structure's temperature strain characteristics. If the structure and materials of the emergency cableway bridge's components are known, the temperature strain characteristics of the cable structure corresponding to the emergency cableway bridge can be pre-calibrated based on the structure and materials of the components. If the temperature sensor type is known, the temperature strain characteristics of the temperature sensor can be pre-calibrated based on the temperature sensor type.

[0044] In some embodiments, step 200, determining current temperature-corrected stress data based on current cable-body stress detection data and current temperature data, includes: step 210, determining a current temperature-gradient-compensated stress value based on current cable-body temperature distribution data and a current temperature gradient compensation coefficient; and step 220, determining current temperature-corrected stress data based on the current cable-body stress detection data and the current temperature gradient-compensated stress value. This embodiment can correct for additional strain caused by non-uniform temperature distribution along the cable length. Therefore, cable stress and strain data for each cable structure in a cableway bridge can be measured even when the bridge is exposed to uneven sunlight.

[0045] For example, the temperature gradient of the cable body along the extension direction of the cable body is monitored in real time by temperature sensors arranged every 2 meters along the cable body. For example, the temperature gradient compensation formula is:

[0046] ;

[0047] in, is the additional strain value caused by uneven temperature distribution of the cable body. is the thermal expansion strain term caused by uniform temperature change, is the thermal expansion coefficient of the cable material, is the temperature change, specifically, It is the change of local or overall temperature relative to the reference temperature. It should be noted that the reference temperature can be set according to the environment of the location of the cableway bridge. In some embodiments, the reference temperature can be adjusted seasonally, and the temperature gradient compensation coefficient can be adaptively adjusted after the reference temperature is adjusted. For example, in winter, the change of the reference temperature can be reset or calibrated to the temperature gradient compensation coefficient. This embodiment can make the reference temperature closer to the temperature at the time of monitoring, which is beneficial to reducing the compensation value and improving the accuracy of cable body stress and strain monitoring. Specifically, The real-time temperature can be measured by a temperature sensor and determined based on the difference between the temperature sensor measurement value and the reference temperature.

[0048] is the temperature gradient along the spatial direction of the bridge structure (such as the direction of the cable length) (unit: °C / m).

[0049] For example, The temperature gradient along the length of the cable structure can be obtained by, but is not limited to, collecting data using distributed temperature sensors, infrared thermal imagers, fiber Bragg gratings, and other sensors, and by calculating the ratio of the temperature difference between adjacent measurement points to their distance. In some embodiments, the surface temperature field can be acquired using thermal imaging technology, and the spatial gradient can be calculated by interpolation.

[0050] is the temperature gradient strain coefficient (unit: με·m / °C), which can be used to reflect the contribution of temperature gradient to additional strain. For example, Apply a known temperature gradient in the laboratory or on site, measure the strain response, and use linear regression to fit the temperature gradient. .

[0051] In some embodiments, temperature compensation only includes temperature gradient compensation, i.e. .

[0052] In some embodiments, the current cable body stress detection data is detected by a stress detection sensor. The current temperature data also includes the current temperature data of the stress detection sensor. Exemplarily, the current temperature data of the stress detection sensor may be a temperature change of the stress detection sensor.

[0053] In some embodiments, step 220, determining current temperature-corrected stress data based on current cable body stress detection data and current temperature gradient compensation stress value, includes: step 221, determining current static temperature-corrected stress data based on current cable body stress detection data and temperature data of current stress detection sensor; and step 222, determining current temperature-corrected stress data based on current static temperature-corrected stress data and current temperature gradient compensation stress value.

[0054] In the above embodiment, additional strain caused by sensor temperature changes can also be obtained by detecting sensor temperature data. Specifically, a mapping table between sensor temperature and additional strain caused by sensor temperature changes can be obtained based on the sensor type. For example, the mapping table between sensor temperature and additional strain caused by sensor temperature changes can be calibrated in a laboratory or on-site by applying a known temperature and measuring the strain response.

[0055] For example, the temperature compensation may include cable body temperature gradient compensation and / or sensor temperature compensation.

[0056] In some embodiments, temperature compensation includes cable body temperature gradient compensation and sensor temperature compensation, then:

[0057] ;

[0058] in, It is the additional strain on the stress and strain detection of the cable body due to the temperature change of the temperature sensor.

[0059] ;

[0060] in, Correct the stress data for the current static temperature, is the current cable body stress detection data, that is, the detection data directly obtained by the strain sensor.

[0061] In some embodiments, the stress detection sensor is a dual-wavelength fiber Bragg grating. The bridge state monitoring data also includes a strain sensitivity coefficient and a temperature sensitivity coefficient of the stress detection sensor.

[0062] Step 100: Acquire bridge condition monitoring data. The bridge condition 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. The process includes: Step 110: Acquire a first drift and a second drift of the current stress detection sensor. Step 120: Determine the current cable body stress detection data and the current stress detection sensor temperature data based on the strain sensitivity coefficient, the temperature sensitivity coefficient, the first drift, and the second drift.

[0063] The first drift is the drift of light of the first wavelength propagating within the detection sensor. The second drift is the drift of light of the second wavelength propagating within the detection sensor. During the propagation of the first wavelength light and the second wavelength light within the detection sensor, one is sensitive to light and the other is sensitive to strain.

[0064] Specifically, the temperature data, i.e., the temperature change of the stress detection sensor, can be determined according to the dual-wavelength fiber Bragg grating decoupling formula. For example, the dual-wavelength fiber Bragg grating decoupling formula is as follows:

[0065] ;

[0066] in, is the first drift, is the second drift, The strain sensitivity coefficient of the dual-wavelength fiber Bragg grating (unit: nm / με) represents the wavelength change caused by unit strain;

[0067] 、 is the temperature sensitivity coefficient of the fiber Bragg grating (unit: nm / °C);

[0068] is the temperature change of the fiber Bragg grating sensor (unit: °C);

[0069] : Stress and strain detected by the dual-wavelength fiber Bragg grating sensor (unit: με).

[0070] It should be noted that, during the detection process, the dual-wavelength fiber Bragg grating sensor has achieved decoupling of sensor detection stress and sensor temperature.

[0071] Step 300 : determining current vibration-corrected stress data according to current temperature-corrected stress data, current cable body vibration acceleration data, and vibration-strain transfer coefficient.

[0072] Exemplarily, the vibration compensation correction formula is as follows:

[0073] ε 振动修正 =ε 温度修正 -Δε 振动补偿；

[0074] Among them, ε 温度修正 Correct stress data for current temperature, ε 振动修正 Correct stress data for current vibration, Δε 振动补偿 is the impact value of vibration on the stress and strain detection of the cable body.

[0075] In some optional embodiments, the real-time measurement of vibration acceleration a(t) can be used to compensate for the strain signal. Alternatively, in the case of low-frequency vibration, the cable body vibration displacement is determined by integrating the cable body vibration acceleration a(t) and combining it with the vibration-strain transfer coefficient k d Correct the strain measurement value to eliminate the interference of base strain caused by vibration. For example, Δε 振动补偿 The calculation formula is:

[0076] ;

[0077] Among them, k d : The vibration-strain transfer coefficient of the cable body under low-frequency vibration can be calibrated by a vibration table; specifically, k can be calibrated based on the displacement when the vibration frequency is less than 1 Hz. d .

[0078] Vibration time history data measured by accelerometer.

[0079] In some optional embodiments, when the vibration frequency is greater than or equal to 1 Hz, the cable body vibration velocity is determined by integrating the cable body vibration acceleration a(t) and combining the vibration-strain transfer coefficient k v Correct the strain measurement value to eliminate the interference of base strain caused by vibration. For example, Δε 振动补偿 The calculation formula is:

[0080] ;

[0081] Among them, k v : The vibration-strain transfer coefficient of the cable body under high-frequency vibration can be calibrated by a vibration table; for example, when the vibration frequency is less than or equal to 1 Hz, the speed is used as the reference to calibrate k d .

[0082] Vibration time history data measured by accelerometer.

[0083] Although emergency cableway bridges are equipped with stabilizing cables, they are still susceptible to vibration, and the intensity of this vibration is more intense than that of other non-cableway bridges. Bridge vibration directly causes mechanical vibration in the sensor itself, which in turn affects measurement results. Step 300 effectively compensates for the impact of bridge vibration on stress and strain detection, thereby improving stress and strain detection accuracy.

[0084] In some embodiments, the vibration-strain transfer coefficient includes a vibration displacement-strain transfer coefficient and a vibration velocity-strain coefficient. Step 300, determining current vibration-corrected stress data based on current temperature-corrected stress data, current cable body vibration acceleration data, and the vibration-strain transfer coefficient, includes:

[0085] Obtaining the vibration frequency of the cable body;

[0086] When the cable body vibration frequency is less than a preset value, current vibration correction stress data is determined according to current temperature correction stress data, current cable body vibration acceleration data and vibration displacement-strain transfer coefficient;

[0087] When the cable body vibration frequency is greater than or equal to a preset value, current vibration correction stress data is determined according to current temperature correction stress data, current cable body vibration acceleration data and vibration velocity-strain transfer coefficient.

[0088] The above embodiment can make the factors affecting the vibration-strain transfer coefficient different in different frequency bands during the stress and strain detection process. The above method of calculating the vibration-strain transfer coefficient can be adjusted according to the vibration frequency to adapt to the different factors affecting the vibration-strain transfer coefficient in different frequency bands. Specifically, during high-frequency vibration, the vibration velocity-strain transfer coefficient can be used to effectively adapt to the situation where the 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 be used to 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 and strain detection process and improving detection accuracy.

[0089] Step 400, perform wavelet packet denoising on the current vibration correction 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 by performing multi-resolution analysis on the signal, and then removes the noise component through threshold processing. The steps of wavelet packet denoising will not be described in detail here. During the strain detection process, noise may come from high-frequency electromagnetic interference or low-frequency drift. For example, the 0.1Hz-100Hz frequency band can be retained by wavelet packet denoising, and high-frequency noise greater than 100Hz and low-frequency drift less than 0.1Hz can be eliminated.

[0090] In some embodiments, as a bridge ages, its structure may undergo significant changes. In some embodiments, the cable body vibration-strain transfer coefficient may be updated at specific time points based on the structural characteristics of the bridge. For example, step 100 acquires bridge status monitoring data, which 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 also includes:

[0091] Step 130 : Acquire historical bridge status monitoring data, where the historical bridge status 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.

[0092] For example, sensors can be installed on the cable bridge to monitor physical parameters that can characterize the bridge's condition, thereby obtaining historical bridge condition monitoring data. For example, the physical parameters that can characterize the bridge's condition can include, but are not limited to, cable body vibration acceleration and cable body stress and strain.

[0093] Step 140 : determining the current cable body vibration-strain transfer coefficient based on the historical cable body vibration acceleration data and the historical cable body stress detection data.

[0094] Illustratively, the above embodiment can recalibrate the cable body vibration-strain transfer coefficient through historical cable body vibration acceleration data and historical cable body stress detection data, which can improve environmental adaptability and maintenance convenience, and is beneficial to automatically updating the cable body vibration-strain transfer coefficient.

[0095] In some embodiments, historical bridge condition monitoring data can be analyzed in real time based on machine learning (such as recurrent neural network RNN) to predict the drift trend of the cable body vibration-strain transfer coefficient, and then the measured data can be input into the digital twin model to reversely deduce and correct the cable body vibration-strain transfer coefficient.

[0096] In some embodiments, step 140 of determining the current cable body vibration-strain transfer coefficient based on historical cable body vibration acceleration data and historical cable body stress detection data includes:

[0097] Step 141, time-aligning historical cable body vibration acceleration data and historical cable body stress detection data;

[0098] Step 142: performing band-pass filtering on the historical cable body vibration acceleration data, retaining the historical cable body vibration acceleration data having a vibration frequency within a first preset range, and determining it as the first historical cable body vibration acceleration data;

[0099] Step 143, determining historical cable body vibration characteristic data based on the first historical cable body vibration acceleration data and the first historical cable body stress detection data;

[0100] Step 144 , performing detrending processing on the historical cable body stress detection data to determine the historical cable body strain noise;

[0101] Step 145 : determining the current cable body vibration-strain transfer coefficient based on the historical cable body vibration characteristic data and the historical cable body strain noise.

[0102] In some embodiments, the FFT transform can also be used to obtain historical cable-body vibration characteristic data through frequency domain integration. By using frequency domain integration to process noise-shifted acceleration signals, the cumulative error problem encountered in time domain integration can be effectively avoided. Frequency domain integration methods for processing noise-shifted acceleration signals are known techniques, so this embodiment will not further elaborate 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.

[0103] In some embodiments, the historical cable body vibration characteristic data includes historical cable body vibration displacement data.

[0104] Specifically, the historical cable body vibration displacement data can be obtained by performing a second-order integration of the first historical cable body vibration acceleration data. Specifically, the data is as follows:

[0105] ,in is the historical cable body vibration displacement data, It is the first historical cable body vibration acceleration data measured by the accelerometer.

[0106] Exemplarily, when the vibration frequency of the first historical cable-body vibration acceleration data is less than a preset value, the historical cable-body vibration characteristic data is 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 historical cable-body vibration displacement data.

[0107] In some embodiments, when the vibration frequency of the first historical cable-body vibration acceleration data is less than a preset value, the historical cable-body vibration displacement data may be obtained by frequency domain integration.

[0108] In some embodiments, the historical cable body vibration characteristic data includes historical cable body vibration velocity data. Specifically,

[0109] ,in, Historical cable body vibration velocity data, It is the first historical cable body vibration acceleration data measured by the accelerometer.

[0110] Exemplarily, when the vibration frequency of the first historical cable-body vibration acceleration data is greater than or equal to a preset value, the historical cable-body vibration characteristic data is 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 historical cable-body vibration displacement data.

[0111] In some embodiments, historical bridge condition monitoring data also includes historical cable temperature distribution data, historical cable stress detection data, and historical live load data. Live load data refers to temporarily applied, movable, or variable loads during the use of the bridge. Exemplary live load data may include, but is not limited to, vehicle loads, pedestrian loads, and heavy object loads. It should be noted that live loads do not include loads caused by environmental changes, such as wind loads. Historical cable stress detection data may be obtained by measuring strain data detected by stress and strain sensors. Historical cable temperature distribution data may be obtained by recording distributed temperature sensor data.

[0112] In some embodiments, step 100 of acquiring bridge state monitoring data, wherein 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, further includes: step 150 of determining a vehicle-free period in the historical bridge state monitoring data based on historical live load data, and determining the historical cable body temperature distribution data and historical cable body stress detection data corresponding to the vehicle-free period as first stress data; and step 160 of determining a current temperature gradient compensation coefficient based on the historical cable body stress detection data and historical cable body temperature distribution data of the first stress data. For example, a period of time when the historical live load data is less than a preset value may be determined as a vehicle-free period.

[0113] In some embodiments, step 160 of determining a current temperature gradient compensation coefficient based on historical cable body stress detection data and historical cable body temperature distribution data of the first stress data includes:

[0114] Step 161: Bandpass filter the historical cable-body stress detection data, retaining historical cable-body stress detection data with strain frequencies within a second preset range and determining this data as second historical cable-body stress detection data. Exemplarily, low-frequency temperature strain signals are extracted from the historical cable-body stress detection data through bandpass filtering (0.001 Hz - 0.1 Hz) and determined as the second historical cable-body stress detection data.

[0115] Step 162: Determine the current temperature gradient compensation coefficient based on the second historical cable body stress detection data and the historical cable body temperature distribution data. For example, the current temperature gradient compensation coefficient can be determined by, but not limited to, linear regression fitting.

[0116] Exemplarily, all sensors are synchronized to ensure that time stamps are aligned. Specifically, cable body temperature distribution data and cable body stress detection data are collected synchronously.

[0117] In some embodiments, linear or spline interpolation may be performed on historical cable body stress detection data and / or historical cable body temperature distribution data, and the time axis may be aligned.

[0118] The time shift Δt is determined, and the first historical cable body temperature distribution data and the third historical cable body stress detection data of the alignment signal are determined based on Δt. It should be noted that since heat conduction requires time, temperature changes will not cause an instantaneous strain response. Therefore, the time shift Δt can be pre-set as needed. Of course, the time shift Δt can also be determined by calculating the cross-correlation function between the temperature gradient integral and the strain. Specifically, the time shift Δt can be determined in combination with the thermal inertia compensation method in the prior art. Exemplarily, the time shift Δt can be determined by pre-calibration. Exemplarily, a mapping relationship table between ambient temperature and time shift Δt can be established by pre-calibration. Specifically, the ambient temperature over a certain time period can be collected. The time shift Δt is then determined based on the mapping relationship table between ambient temperature and time shift Δt and the collected ambient temperature. In some embodiments, the time shift Δt can also be determined by phase difference analysis, optimization search, feature point matching, and cross-correlation function methods. Exemplarily, the time shift Δt can be determined by frequency domain methods.

[0119] Real-time integration of temperature gradients along structural paths ,in It can be obtained by the ratio of the temperature difference to the distance between adjacent measuring points in the first historical cable body temperature distribution data.

[0120] For example, the cross-correlation function between the temperature gradient integral and the strain is as follows:

[0121] ;

[0122] in, is the third historical cable stress detection data; β is the current temperature gradient compensation coefficient. Specifically, the slope β can be fitted by the least squares method to obtain the current temperature gradient compensation coefficient.

[0123] In some embodiments, before step 100, obtaining historical bridge status monitoring data, where the historical bridge status 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 emergency rescue cableway bridge stress monitoring method further includes:

[0124] Step 500, obtaining structural information of the emergency cableway bridge;

[0125] Step 600: determining a preset time period for acquiring historical bridge status monitoring data based on the service life of the emergency rescue cableway bridge and the structural information of the emergency rescue cableway bridge.

[0126] Exemplarily, the preset time period can also be determined based on the service time of the emergency rescue cableway bridge, and the preset time period is positively correlated with the service time of the emergency rescue cableway bridge. After the emergency rescue cableway bridge is put into use, the longer it is used, the smaller the influence of factors such as the settlement of the cable saddle and the saddle foundation beam, and the release of residual stress in the cable structure on the temperature gradient compensation coefficient and the cable body vibration-strain transfer coefficient. Exemplarily, the slight settlement of the cable saddle and the saddle foundation beam is mainly concentrated in the early stage of being put into use. That is, the settlement of the cable saddle and the saddle foundation beam changes rapidly in the early 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.

[0127] In some embodiments, the preset time period for acquiring historical bridge condition monitoring data may be determined based on changes in ambient temperature. For example, the preset time period for acquiring historical bridge condition monitoring data may be determined based on changes in seasons.

[0128] In some embodiments, the emergency rescue cableway bridge stress monitoring method further includes:

[0129] Step 700, determining the current remaining load capacity of the bridge according to the target stress data;

[0130] Step 800: When the current remaining load capacity of the bridge is less than or equal to a preset value, the gates at both ends of the cableway bridge are closed.

[0131] The above embodiment accurately monitors the stress data on the cable body, and then uses existing bridge health assessment methods to determine the current remaining load capacity of the bridge. This can then be used to control the opening or closing of gates based on the remaining load capacity of the bridge, thereby regulating the vehicle load on the bridge. Therefore, this embodiment is beneficial in preventing overloads on emergency cableway bridges and ensuring their safe operation.

[0132] In some embodiments, such as Figure 2 This is a block diagram of the stress monitoring system for emergency cableway bridges provided by this application. Figure 2 As shown, the exemplary emergency rescue cableway bridge stress monitoring system 20 includes:

[0133] The bridge state monitoring data acquisition module 21 is used to acquire bridge state monitoring data, which includes current cable body stress detection data, current temperature data, current cable body vibration acceleration data and current cable body vibration-strain transfer coefficient;

[0134] The temperature-corrected stress data determining module 22 is used to determine the current temperature-corrected stress data according to the current cable body stress detection data and the current temperature data;

[0135] a vibration correction stress data determination module 23, configured to determine current vibration correction stress data based on current temperature correction stress data, current cable body vibration acceleration data, and vibration-strain transfer coefficient;

[0136] The target stress data determination module 24 is used to perform small packet denoising on the current vibration-corrected stress data to determine the current target stress data.

[0137] In some embodiments, gates are provided at both ends of the emergency rescue cableway bridge. The present application also provides a control method based on stress monitoring of the emergency rescue cableway bridge. The method includes:

[0138] Step 101: monitor target stress data of the cable body of the cableway bridge.

[0139] Exemplarily, the target stress data includes but is not limited to cable body stress and strain data.

[0140] Step 102, determining the current remaining load capacity of the bridge based on the target stress data;

[0141] Step 103: When the current remaining load capacity of the bridge is less than or equal to a preset value, the gates at both ends of the cableway bridge are closed.

[0142] The control method based on stress monitoring of the emergency rescue cableway bridge also includes: when the current remaining load capacity of the bridge is greater than a preset value, opening the gates at both ends of the cableway bridge.

[0143] The above embodiment accurately monitors the stress data of the cable body, and then uses some bridge health assessment methods in the existing technology to obtain the current residual load capacity of the bridge. Then, the opening or closing of the gate can be controlled according to the residual load capacity of the bridge to regulate the vehicle load on the bridge.

[0144] In some embodiments, the control method based on stress monitoring of an emergency cableway bridge further includes:

[0145] Step 104: Obtain the natural frequency of the current bridge and the current vehicle load data.

[0146] Step 105 : determining the current speed of the passing vehicle based on the natural frequency of the current bridge and the current load data of the passing vehicle.

[0147] In the above embodiment, since resonance between the vehicle and the bridge is prevented during the vehicle's travel, it is beneficial to reduce the shaking of the bridge.

[0148] In some embodiments, the tension of different cables in the bridge can be adjusted so that the vibrations between the different cables can be mutually offset, thereby reducing the shaking of the bridge.

[0149] It should be noted that the emergency rescue cableway bridge stress monitoring system provided in the above embodiment and the emergency rescue cableway bridge stress monitoring method provided in the above embodiment belong to the same concept, wherein the specific manner in which each module and unit performs operations has been described in detail in the method embodiment and will not be repeated here. In actual applications, the emergency rescue cableway bridge stress monitoring system provided in the above embodiment can allocate the above functions to different functional modules as needed, that is, divide the internal structure of the system into different functional modules to complete all or part of the functions described above, and this is not limited here.

[0150] An embodiment of the present application also provides an electronic device, comprising: one or more processors; a storage device for storing one or more programs, wherein when the one or more programs are executed by one or more processors, the electronic device implements the emergency rescue cableway bridge stress monitoring method provided in the above-mentioned embodiments.

[0151] Another aspect of the present application provides a computer-readable storage medium storing a computer program. When executed by a computer processor, the computer program causes the computer to perform the emergency cableway bridge stress monitoring methods provided in the aforementioned embodiments. The computer-readable storage medium may be included in the electronic device described in the aforementioned embodiments, or may exist independently and not be incorporated into the electronic device.

[0152] Another aspect of the present application provides a computer program product or 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 executes the computer instructions, causing the computer device to perform the emergency cableway bridge stress monitoring method provided in each of the above embodiments.

[0153] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance. Throughout the specification and claims, the terms "including" and "comprising" are open-ended terms and should be interpreted as "including but not limited to."

[0154] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, any equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concepts disclosed in this application shall be covered by the claims of this application.

Claims

1. A stress monitoring method for an emergency cableway bridge, characterized in that: include: Acquiring bridge status monitoring data, the bridge status monitoring data including current cable body stress detection data, current temperature data, current cable body vibration acceleration data, and current cable body vibration-strain transfer coefficient, the current temperature data including current cable body temperature distribution data and current temperature gradient compensation coefficient, and the vibration-strain transfer coefficient including vibration displacement-strain transfer coefficient and vibration velocity-strain coefficient; Determine current temperature-corrected stress data based on current cable body stress detection data and current temperature data; Wherein, determining the current temperature-corrected stress data includes determining the current temperature gradient compensation stress value according to the current cable body temperature distribution data and the current temperature gradient compensation coefficient; determining the current temperature-corrected stress data according to the current cable body stress detection data and the current temperature gradient compensation stress value; determining current vibration-corrected stress data according to current temperature-corrected stress data, current cable body vibration acceleration data, and the vibration-strain transfer coefficient; Wherein, determining the current vibration-corrected stress data includes: obtaining the vibration frequency of the cable body; when the vibration frequency of the cable body is less than a preset value, determining the current vibration-corrected stress data based on the current temperature-corrected stress data, the current cable body vibration acceleration data, and the vibration displacement-strain transfer coefficient; when the vibration frequency of the cable body is greater than or equal to the preset value, determining the current vibration-corrected stress data based on the current temperature-corrected stress data, the current cable body vibration acceleration data, and the vibration velocity-strain transfer coefficient; Perform small packet denoising on the current vibration-corrected stress data to determine the current target stress data.

2. The stress monitoring method for an emergency cableway bridge according to claim 1, characterized in that: The current cable body stress detection data is detected by the stress detection sensor, and the current temperature data also includes the temperature data of the current stress detection sensor; Determining the current temperature-corrected stress data based on the current cable body stress detection data and the current temperature gradient compensation stress value includes: Determine current static temperature corrected stress data based on current cable body stress detection data and current temperature data of the stress detection sensor; The current temperature-corrected stress data is determined according to the current static temperature-corrected stress data and the current temperature gradient-compensated stress value.

3. The stress monitoring method for an emergency cableway bridge according to claim 1, characterized in that: Acquire bridge status monitoring data, including current cable body stress detection data, current temperature data, current cable body vibration acceleration data, and current cable body vibration-strain transfer coefficient, including: Acquiring historical bridge state monitoring data, wherein 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 current cable body vibration-strain transfer coefficient is determined according to the historical cable body vibration acceleration data and the historical cable body stress detection data.

4. The stress monitoring method for an emergency cableway bridge according to claim 3, characterized in that: Determining a current cable body vibration-strain transfer coefficient according to the historical cable body vibration acceleration data and the historical cable body stress detection data includes: Time-align the historical cable body vibration acceleration data and the historical cable body stress detection data; performing band-pass filtering on the historical cable body vibration acceleration data, retaining the historical cable body vibration acceleration data having a vibration frequency within a first preset range, and determining the historical cable body vibration acceleration data as first historical cable body vibration acceleration data; determining historical cable body vibration characteristic data according to the first historical cable body vibration acceleration data and the first historical cable body stress detection data; Detrending the historical cable stress detection data to determine the historical cable strain noise; The current cable body vibration-strain transfer coefficient is determined based on the historical cable body vibration characteristic data and historical cable body strain noise.

5. The stress monitoring method for an emergency cableway bridge according to claim 3, characterized in that: The historical bridge condition monitoring data also includes historical cable body temperature distribution data, historical cable body stress detection data and historical live load data; Acquiring bridge status monitoring data, the bridge status monitoring data including current cable body stress detection data, current temperature data, current cable body vibration acceleration data, and current cable body vibration-strain transfer coefficient, and also including: Determine a period of no vehicle traffic in the historical bridge state monitoring data according to the historical live load data, and determine the historical cable body temperature distribution data and the historical cable body stress detection data corresponding to the period of no vehicle traffic as first stress data; The current temperature gradient compensation coefficient is determined according to the historical cable body stress detection data and the historical cable body temperature distribution data of the first stress data.

6. The stress monitoring method for an emergency cableway bridge according to claim 5, characterized in that: Determining a current temperature gradient compensation coefficient based on historical cable body stress detection data and historical cable body temperature distribution data of the first stress data includes: performing band-pass filtering on the historical cable body stress detection data, retaining the historical cable body stress detection data whose strain frequency is within a second preset range and determining it as the second historical cable body stress detection data; The current temperature gradient compensation coefficient is determined according to the second historical cable body stress detection data and the historical cable body temperature distribution data.

7. The stress monitoring method for an emergency cableway bridge according to any one of claims 3 to 6, characterized in that: Before step 100 of acquiring historical bridge state monitoring data, wherein 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 structural information of emergency cableway bridges; The preset time period for acquiring the historical bridge status monitoring data is determined according to the service time of the emergency rescue ropeway bridge and the structural information of the emergency rescue ropeway bridge.

8. The stress monitoring method for an emergency cableway bridge according to claim 7, characterized in that: Also includes: determining the current remaining load capacity of the bridge according to the target stress data; When the current remaining load capacity of the bridge is less than or equal to the preset value, the gates at both ends of the cableway bridge will be closed.

9. An emergency rescue cableway bridge stress monitoring system, characterized in that: The stress monitoring method for an emergency rescue cableway bridge according to any one of claims 1 to 8, wherein the stress monitoring system for an emergency rescue cableway bridge comprises: A bridge state monitoring data acquisition module is used to acquire bridge state monitoring data, wherein 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 is used to determine current temperature-corrected stress data based on current cable body stress detection data and current temperature data; a vibration correction stress data determination module, configured to determine current vibration correction stress data based on current temperature correction stress data, current cable body vibration acceleration data, and the vibration-strain transfer coefficient; The target stress data determination module is used to perform small packet denoising on the current vibration-corrected stress data to determine the current target stress data.

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