A real-time monitoring system for bridge cable tension

Abstract

The present application relates to the technical field of bridge structure safety monitoring, and relates to a real-time monitoring system for bridge cable force. According to the vibration frequency signal of the bridge cable, the initial cable force is determined, the cable force compensation value of the environment temperature where the bridge is located is combined, the real-time cable force of the bridge cable is obtained, when the real-time cable force is in a safe state, the correlation coefficient between each cable and the cable on the same side is obtained based on the historical cable force time sequence vector of the cable, the corresponding cable on the same side of each cable is determined, the cable force time sequence synchronization degree between the cables on the same side and the cable force time sequence deviation value and deviation direction between the symmetric cables are obtained, whether each cable has the cable force cooperation on the same side and the symmetric cable force cooperation is judged, the overall safety performance of the bridge cable is diagnosed based on the judgment result, the reliability of the overall safety performance diagnosis of the bridge cable is improved by comprehensively evaluating the stress balance state of the bridge cable group, and data support is provided for the preventive operation and maintenance of the bridge.

Description

Technical Field

[0001] This invention relates to the field of bridge structural safety monitoring technology, and specifically to a real-time monitoring system for bridge cable tension. Background Technology

[0002] As a key load-bearing component of cable-stayed bridges, cables endure alternating loads and environmental erosion over long periods, and changes in their stress state directly reflect the health of the bridge structure. With the increasing service life of bridges, cables face the effects of material aging and environmental temperature variations. Real-time monitoring of cable stress and assessment of its overall safety performance are of significant engineering value for preventing bridge structural accidents and guiding maintenance and repair decisions.

[0003] In the prior art, Chinese Patent Publication No. CN115931199A discloses a method for measuring the cable force of bridge cables based on radar-visual integration. This method acquires radar vibration information of multiple cables within the radar coverage area and video vibration information of a certain cable. Through vibration information matching and position determination, and combined with Fourier transform to extract the fundamental frequency of vibration, the cable force of each cable is finally determined, thus realizing the synchronous measurement of the cable force of each cable.

[0004] The existing technology has the following problems: 1. The existing technology directly calculates the cable force based on the vibration frequency without considering the influence of the change in ambient temperature on the elastic modulus and thermal expansion and contraction effect of the cable material. This results in temperature drift error in the cable force calculation results, which affects the accuracy of cable force monitoring and may lead to misjudgment or omission of the cable force safety status, thus reducing the reliability of bridge safety assessment.

[0005] 2. Existing technologies measure the cable force of each cable through a combination of radar and visual methods, but can only obtain the independent cable force values ​​of each cable. They lack analysis of the temporal correlation of cable forces between cables on the same side and between symmetrical cables, and cannot assess the collaborative performance of the cable group. This makes it difficult to diagnose the overall safety status of the bridge cables, and can only detect cable force anomalies in a single cable, and cannot provide early warning of the overall structural risks of the bridge caused by the collaborative failure of multiple cables. Summary of the Invention

[0006] This invention aims to overcome the deficiencies in the prior art and provide a real-time monitoring system for bridge cable tension. It improves the accuracy of cable tension monitoring through temperature compensation and achieves overall safety performance diagnosis by combining cable synergy analysis, thereby ensuring the overall structural safety of the bridge.

[0007] The technical solution adopted by the present invention to solve its technical problem is: a real-time monitoring system for bridge cable force, including a real-time cable force acquisition module, a cable force safety judgment module, a cable correlation determination module, a historical cable force comparison module, and a cable collaborative analysis module.

[0008] The connections between the modules are as follows: the real-time cable force acquisition module is connected to the cable force safety judgment module; the cable association determination module is connected to both the cable force safety judgment module and the historical cable force comparison module; and the cable collaborative analysis module is connected to the historical cable force comparison module.

[0009] The real-time cable force acquisition module determines the initial cable force based on the vibration frequency signal of the bridge cable, and obtains the real-time cable force of the bridge cable by combining the cable force compensation value based on the ambient temperature of the bridge.

[0010] The cable force safety judgment module determines whether the real-time cable force is in a safe state. When it is in a safe state, it retrieves the historical cable force data of the bridge cables and generates a historical cable force time series vector.

[0011] The cable association determination module obtains the correlation coefficient between each cable and its corresponding cable on the same side based on the historical cable force time series vector of each cable of the bridge, and determines the corresponding cable on the same side based on the correlation coefficient.

[0012] The historical cable force comparison module compares the historical cable force time sequence vectors of each cable with those of the associated cables on the same side and the symmetrical cables, and obtains the cable force time sequence synchronization degree between cables on the same side and the cable force time sequence deviation value and deviation direction between symmetrical cables.

[0013] The cable coordination analysis module determines whether each cable has symmetric cable force coordination and synergy, and diagnoses the overall safety performance of the bridge cables based on the judgment results.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention extracts the maximum natural vibration frequency by collecting the vibration frequency signal of the bridge cable to calculate the initial cable force, and obtains the real-time cable force of the bridge cable by combining the cable force compensation value of the ambient temperature of the bridge, thereby eliminating the influence of ambient temperature factors on cable force measurement, improving the accuracy of cable force monitoring, reducing the possibility of misjudging the safety status of the bridge cable force, and improving the reliability of bridge safety assessment.

[0015] (2) Based on the historical cable force time series vector of each cable of the bridge, the present invention calculates the correlation coefficient between each cable and the cable on the same side, determines the corresponding cable on the same side of each cable, and can accurately identify the cable group on the same side with similar cable force patterns, providing related data for subsequent cable force coordination judgment and ensuring the effectiveness of cable relationship determination.

[0016] (3) The present invention obtains the synchronization degree of cable force timing between cables on the same side and the cable force timing deviation value and deviation direction between symmetrical cables, and determines whether each cable has the same-side cable force synergy and symmetrical cable force synergy. By using the same-side and symmetrical synergy judgment, the force synergy state of the cable group can be fully captured, the overall force imbalance risk can be accurately identified, and the comprehensiveness of bridge safety performance diagnosis can be improved.

[0017] (4) Based on the judgment results of whether each cable has the same-side cable force coordination and symmetrical cable force coordination, the present invention diagnoses the overall safety performance of bridge cables. By comprehensively evaluating the force balance state of the bridge cable group, it effectively avoids the overall safety misjudgment caused by single-dimensional judgment, improves the reliability of the overall safety performance diagnosis of bridge cables, and provides data support for bridge preventive operation and maintenance. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the system module connections of the present invention.

[0020] Figure 2 This is a schematic diagram illustrating the implementation steps of the real-time cable force acquisition module in this invention.

[0021] Figure 3 This is a schematic diagram illustrating the implementation steps of the cable force safety judgment module in this invention. Detailed Implementation

[0022] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. Furthermore, it should be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale.

[0023] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification.

[0024] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0025] Please see Figure 1 As shown, the present invention provides a real-time monitoring system for bridge cable force, including a real-time cable force acquisition module, a cable force safety judgment module, a cable correlation determination module, a historical cable force comparison module, and a cable collaborative analysis module.

[0026] The connections between the modules are as follows: the real-time cable force acquisition module is connected to the cable force safety judgment module; the cable association determination module is connected to both the cable force safety judgment module and the historical cable force comparison module; and the cable collaborative analysis module is connected to the historical cable force comparison module.

[0027] The real-time cable force acquisition module determines the initial cable force based on the vibration frequency signal of the bridge cable, and obtains the real-time cable force of the bridge cable by combining the cable force compensation value based on the ambient temperature of the bridge.

[0028] Considering that changes in ambient temperature can affect the elastic modulus of cable materials and cause thermal expansion and contraction, which directly leads to temperature drift errors in cable force calculation, it is necessary to establish a mapping relationship between temperature and cable force compensation value through historical data, and to accurately correct the initial cable force to ensure the accuracy of real-time cable force.

[0029] Based on this, such as Figure 2 As shown, this module calculates the initial cable force through vibration frequency and obtains the real-time cable force by combining temperature compensation value. The specific implementation method includes: S1, collecting the real-time vibration frequency signal of each monitoring point on the bridge cable, filtering and denoising the real-time vibration frequency signal, extracting the natural vibration frequency from the processed real-time vibration frequency signal, and screening the maximum natural vibration frequency.

[0030] Preferably, in one embodiment of the present invention, vibration sensors are deployed at different length divisions along each cable of the bridge, such as... The length position is divided, real-time vibration frequency signals are collected, and low-pass filtering algorithm is used to filter out interference such as wind noise and traffic vibration. The time domain signal is converted into a frequency domain signal through Fourier transform to extract all inherent vibration frequencies. The low-pass filtering algorithm and Fourier transform technology are existing technologies, and will not be described in detail in this invention.

[0031] S2. Based on the maximum natural vibration frequency and the structural parameters of the cable, the initial cable force is calculated using cable force theory. The cable force theory calculation is based on the existing string vibration theory formula, used to calculate the initial cable force using the vibration frequency method. The string vibration theory formula is: .

[0032] In the formula, The initial cable force, The linear density of the cables in the cable structure parameters. The vibration length, cable linear density, and vibration length parameters in the cable structure were all retrieved from the bridge design documents. The maximum natural vibration frequency, This represents the vibration order corresponding to the maximum natural vibration frequency.

[0033] S3. Extract historical monitoring data of cable force from the bridge's historical database, determine the mapping relationship between ambient temperature and cable force compensation value, and obtain the corresponding cable force compensation value based on the ambient temperature of the bridge.

[0034] It should be noted that the mapping relationship between the ambient temperature and the cable force compensation value is determined as follows: First, all recent historical monitoring data of cable force are extracted from the bridge's historical database, and the natural vibration frequency of the cable, historical cable force, and historical ambient temperature are obtained from the historical monitoring data. In this embodiment, "recent" can be set to the past year, but the implementer can also adjust the recent time period as needed.

[0035] Secondly, based on historical cable force and the natural vibration frequency of the cable, the cable force compensation value affected by temperature is obtained through reverse analysis. The reverse analysis process is as follows: based on the natural vibration frequency of the cable, the historical theoretical cable force is derived using the calculation formula of string vibration theory, and the difference between the historical cable force and the historical theoretical cable force is used as the cable force compensation value affected by temperature.

[0036] Then, the 3σ criterion was used to remove outliers from the cable force compensation values ​​affected by temperature under each historical ambient temperature, and the average cable force compensation value was obtained by averaging the remaining cable force compensation values.

[0037] Finally, a mapping database between ambient temperature and cable force compensation value is established, with ambient temperature as the independent variable and average cable force compensation value as the dependent variable. For example, in this embodiment of the invention, the average cable force compensation value corresponding to a temperature of 25°C is 5.2 kN, and the average cable force compensation value corresponding to a temperature of 30°C is 6.8 kN.

[0038] The step of obtaining the corresponding cable force compensation value based on the ambient temperature of the bridge specifically includes: after collecting the ambient temperature of the bridge, if the ambient temperature of the bridge matches a certain ambient temperature point in the mapping relationship database, then the cable force compensation value of that ambient temperature point is retrieved as the cable force compensation value corresponding to the ambient temperature of the bridge.

[0039] If the ambient temperature of the bridge falls between two adjacent ambient temperature points in the mapping database, then linear interpolation is used to calculate the cable force compensation value corresponding to the adjacent ambient temperature points, thus obtaining the cable force compensation value corresponding to the ambient temperature of the bridge. Linear interpolation is existing technology and will not be elaborated upon in this invention.

[0040] S4. Combine the initial cable force with the cable force compensation value to calculate the real-time cable force of the bridge cable.

[0041] Considering that under actual bridge conditions, the thermal expansion and contraction of cables is restricted by the fixed constraints at both ends and cannot be realized freely, additional stress is generated inside. The total cable force is obtained by superimposing the additional stress with the original cable force. When the cable temperature rises, the cable force decreases, and when the temperature drops, the cable force increases. Therefore, the real-time cable force is obtained by calculating the difference between the initial cable force and the cable force compensation value.

[0042] This invention calculates the initial cable force by collecting the vibration frequency signal of bridge cables, extracting the maximum natural vibration frequency, and combining the cable force compensation value with the ambient temperature of the bridge to obtain the real-time cable force. This eliminates the influence of ambient temperature on cable force measurement, improves the accuracy of cable force monitoring, reduces the possibility of misjudging the safety status of bridge cables, and enhances the reliability of bridge safety assessment.

[0043] The cable force safety judgment module determines whether the real-time cable force is in a safe state. When it is in a safe state, it retrieves the historical cable force data of the bridge cables and generates a historical cable force time series vector.

[0044] Considering that real-time cable force must first meet the safety threshold requirements before subsequent collaborative analysis can be carried out, abnormal cable force data should be avoided from interfering with the determination of correlation. At the same time, the historical cable force time series vector can fully reflect the trend of cable force change, providing basic data for determining cable correlation.

[0045] Based on this, such as Figure 3 As shown, the specific implementation of this module includes: if the real-time cable force of the bridge cable is greater than the rated safe cable force, the rated safe cable force is retrieved from the bridge design documents, and it is determined that the real-time cable force of the bridge cable is in a dangerous state. At the same time, an early warning message (including the cable number and real-time cable force) is generated and pushed to the bridge operation and maintenance personnel.

[0046] Conversely, if the preset time period is set to 3 months, the historical cable force data of the bridge cables within the preset time period is retrieved from the bridge history database, and the historical cable force data is sorted according to the timestamp order to form a historical cable force time series vector.

[0047] The cable association determination module obtains the correlation coefficient between each cable and its corresponding cable on the same side based on the historical cable force time series vector of each cable of the bridge, and determines the corresponding cable on the same side based on the correlation coefficient.

[0048] Considering that the stress environment of cables on the same side is similar and the cable force change patterns are correlated, it is necessary to calculate the correlation coefficient of historical cable force time series vectors to screen cables on the same side with synchronous cable force changes, and to delineate the related groups for synergy analysis.

[0049] Based on this, this module uses Pearson correlation coefficient calculation and screening to determine the ipsilateral associated cables. Specific implementation methods include:

[0050] First, the historical cable force time series vectors of each cable and its corresponding cable on the same side are selected from the bridge history database. The Pearson correlation coefficient is then used to calculate the correlation coefficient between the historical cable force time series vectors of each cable and its corresponding cable on the same side. The correlation coefficient ranges from [-1, 1], with a value closer to 1 indicating a stronger linear correlation.

[0051] Secondly, if the correlation coefficient of the historical cable force time series vector between a cable and its cable on the same side is greater than the set correlation coefficient, then the cable on the same side is recorded as the cable on the same side, and the cable on the same side corresponding to each cable is counted.

[0052] In one embodiment of the present invention, the correlation coefficient can be set to the value corresponding to the strong correlation strength in the Pearson correlation coefficient. For example, the correlation coefficient can be set to 0.8. When the correlation coefficient is greater than 0.8, it indicates that the cable force change pattern between the cable and the cable on the same side is the same or similar. The implementer can also customize it.

[0053] This invention calculates the correlation coefficient between each cable and its corresponding cable on the same side based on the historical time-series vector of each cable in a bridge, and determines the corresponding cable on the same side for each cable. It can accurately identify groups of cables on the same side with similar cable force patterns, providing associated data for subsequent judgment of cable force synergy and ensuring the effectiveness of cable correlation determination.

[0054] The historical cable force comparison module compares the historical cable force time sequence vectors of each cable with those of the associated cables on the same side and the symmetrical cables, and obtains the cable force time sequence synchronization degree between cables on the same side and the cable force time sequence deviation value and deviation direction between symmetrical cables.

[0055] Considering that the changes in cable force of multiple cables on the same side should be coordinated, insufficient synchronization in timing may lead to local stress concentration or overall force imbalance. Therefore, it is necessary to quantitatively evaluate the reliability of the coordinated operation of the cable group by using node matching and deviation analysis of historical cable force data.

[0056] Based on this, the method for obtaining the synchronization of cable force time sequence between cables on the same side in this module is as follows: A11, extract the time and cable force change amplitude of all cable force change nodes in the historical cable force time sequence vector of each cable and its associated cables on the same side, match all cable force change nodes, calculate the time difference between each cable force change node, and calculate the average of all time differences.

[0057] It should be noted that the cable force change nodes mentioned above include, but are not limited to: cable force peak node, cable force valley node, and cable force stable segment start node. The maximum and minimum values ​​in the historical cable force time series vector are used as cable force peak node and cable force valley node, respectively; when the cable force remains unchanged for a preset number of consecutive timestamps (e.g., 3 consecutive times), the start timestamp is used as the cable force stable segment start node.

[0058] The magnitude of the cable force change at the cable force change node represents the absolute value of the difference between the cable force at the cable force change node and the cable force at the previous node.

[0059] A12. Obtain the ratio of cable force change amplitude at each cable force change node, and filter the cable force change nodes whose ratio of cable force change amplitude matches the set ratio of cable force amplitude between the corresponding cable and its associated cable on the same side, and record them as matching cable force change nodes.

[0060] Preferably, considering that the cables on the same side share the vertical and horizontal loads of the bridge frame, the force ratio of each cable to its corresponding cable on the same side is distributed through mechanical calculations during bridge design to ensure uniform load transfer and structural stress balance. Therefore, the set cable force amplitude ratio between each cable and its corresponding cable on the same side can be retrieved from the bridge design documents. If the ratio of the cable force variation amplitude of the cables on the same side deviates from the set cable force amplitude ratio, it will lead to local cable overload or structural stress imbalance, indicating that the ratio of the cable force variation amplitude of the cables on the same side does not conform to the set cable force amplitude ratio.

[0061] A13. Statistically determine the proportion of nodes with consistent cable force changes to the total number of nodes with changes in cable force, and combine this with the average time difference to comprehensively evaluate the cable force timing synchronization.

[0062] It should be noted that the weighted summation method is used to calculate the cable force timing synchronization. The weight allocation of the proportion of nodes with matching cable force changes to the total number of nodes with cable force changes and the mean of time difference is adjusted according to the dominant factor of cable co-force. The proportion of nodes with matching cable force changes to the total number of nodes with cable force changes reflects the consistency of cable force response, and the mean of time difference reflects the timeliness of cable force changes. If cable force co-force is dominant, the weight of the proportion of nodes with matching cable force changes to the total number of nodes with cable force changes can be increased. If timing response is dominant, the weight of the mean of time difference can be increased, and the sum of the weights is always 1.

[0063] In a specific embodiment of the present invention, the proportion of nodes with matching cable force changes to the total number of nodes with cable force changes and the weight of the average time difference are set to 0.7 and 0.3, respectively, and the formula for calculating the cable force timing synchronization is as follows: .

[0064] in, For cable timing synchronization, To match the proportion of nodes with varying cable force to the total number of nodes with varying cable force, The mean of the time difference. For the set unit cable force monitoring interval, such as 1 hour, ensure that the normalized range of the mean time difference is [0, 1]. The smaller the average time difference, the higher the synchronization of the cable timing.

[0065] Considering that symmetrical cables are the core support for the stress balance of bridge structures, the deviation of cable force directly reflects the stress imbalance state of the structure. However, asynchronous timestamps can lead to distortion in deviation calculations. The direction of deviation can clearly indicate the trend of imbalance. Therefore, it is necessary to ensure the reliability of deviation indicators through precise alignment and quantitative calculation.

[0066] Based on this, the method for obtaining the cable force time sequence deviation value and deviation direction between symmetrical cables in this module is as follows: A21, select the historical cable force time sequence vector of each cable and its symmetrical cable, align all instantaneous cable forces in the two historical cable force time sequence vectors according to the timestamp, and calculate the cable force time sequence deviation value of each timestamp.

[0067] A22. Based on the sign of the instantaneous deviation value of cable force at each timestamp, determine the direction of the cable force deviation between each cable and its symmetrical cable at each timestamp. For example, if the instantaneous deviation value of cable force is greater than zero, it is determined that the current cable force is greater than that of its symmetrical cable, and the deviation direction points to the side of the symmetrical cable; if the instantaneous deviation value of cable force is less than zero, it is determined that the current cable force is less than that of its symmetrical cable, and the deviation direction points to the side of the current cable; if the instantaneous deviation value of cable force is zero, there is no clear deviation direction.

[0068] The cable coordination analysis module determines whether each cable has symmetric cable force coordination and synergy, and diagnoses the overall safety performance of the bridge cables based on the judgment results.

[0069] Considering that the coordination of cables on the same side needs to be determined by the degree of synchronization between individuals and the group, a single synchronization value cannot reflect whether it conforms to the force law of the group; the imbalance risk of symmetrical cables is a continuous deviation rather than an accidental fluctuation, and it is necessary to combine the dual constraints of deviation range and continuous direction to ensure the accuracy of coordination judgment and engineering rationality.

[0070] Based on this, this module determines whether each cable has symmetric cable force coordination and symmetrical cable force coordination. Specific implementation methods include:

[0071] The first step is to extract the temporal synchronization degree of cable force between each cable and its corresponding cables on the same side, and construct a synergy analysis matrix. The specific construction process is as follows: using each cable as the row vector and the corresponding cables on the same side as the column vector, the temporal synchronization degree of cable force between each cable and its corresponding cables on the same side is used as the matrix elements to form the synergy analysis matrix; combined with the average temporal synchronization degree of cable force of the cable group on the same side... and standard deviation This involves determining a reasonable distribution range for the timing synchronization of cable forces within a group of cables on the same side. For example, in this embodiment of the invention, the reasonable distribution range is... It covers more than 95% of the normal synchronization data and conforms to the normal distribution law.

[0072] In other embodiments, the implementer may adjust the standard deviation multiple of a reasonable distribution range as needed.

[0073] Step 2: If the cable force time series synchronization degree of a certain cable and all its同侧 associated cables is within the reasonable distribution range, it is determined that the cable has同侧 cable force synergy; otherwise, it is determined that the cable does not have同侧 cable force synergy.

[0074] Step 3: If the cable force time series deviation values of a certain cable and its symmetric cable at each time stamp are all within the corresponding allowable cable force deviation value range, it is determined that the cable has symmetric cable force synergy; if the cable force time series deviation values of a certain cable and its symmetric cable at consecutive time stamps are outside the corresponding allowable cable force deviation value range and the cable force deviation directions at consecutive time stamps are the same, it is determined that the cable does not have symmetric cable force synergy.

[0075] It should be supplemented that if the cable force time series deviation values of a certain cable and its symmetric cable at consecutive time stamps are outside the corresponding allowable cable force deviation value range and the cable force deviation directions at consecutive time stamps are not the same, it indicates that the cable is an accidental fluctuation and still has symmetric cable force synergy.

[0076] In a specific embodiment of the present invention, for example, the allowable cable force deviation value range is determined based on ±2% of the rated safe cable force of the cable, and the number of consecutive time stamps can be adjusted according to the monitoring sampling interval. When the sampling interval is 1 hour, the number of consecutive time stamps can be 5, and the implementer can also adjust the allowable cable force deviation value range and the number of consecutive time stamps by himself.

[0077] It should be noted that the steps for diagnosing the overall safety performance of the bridge cable are as follows: when a certain cable does not have同侧 cable force synergy or does not have symmetric cable force synergy, the cable is recorded as an abnormal cable, and the number of abnormal cables is counted.

[0078] If the number of abnormal cables is unique, it is determined that the overall safety performance of the bridge cable is qualified, and the location number of the abnormal cable is pushed for warning.

[0079] On the contrary, when there are multiple abnormal cables that do not have同侧 cable force synergy and there is no同侧 association between the multiple abnormal cables, it is determined that the overall safety performance of the bridge cable is qualified, and the location number warning information of each abnormal cable is pushed respectively, and it is recommended to check one by one; when there are multiple abnormal cables that do not have同侧 cable force synergy and there is an同侧 association between the multiple abnormal cables, it is determined that the overall safety performance of the bridge cable is unqualified, and an同侧 force imbalance warning is generated.

[0080] When there are multiple abnormal cables that do not have symmetric cable force synergy, it is determined that the overall safety performance of the bridge cable is unqualified, and a structural overall imbalance warning is pushed.

[0081] This invention diagnoses the overall safety performance of bridge cables based on the judgment results of whether each cable has synergy of cable forces on the same side and symmetry of cable forces. By comprehensively evaluating the force balance state of the bridge cable group, it effectively avoids misjudgment of overall safety caused by single-dimensional judgment, improves the reliability of the overall safety performance diagnosis of bridge cables, and provides data support for preventive operation and maintenance of bridges.

[0082] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0083] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0084] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0085] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0086] Finally, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A real-time monitoring system for bridge cable tension, characterized in that, include: The real-time cable force acquisition module determines the initial cable force based on the vibration frequency signal of the bridge cable, and obtains the real-time cable force of the bridge cable by combining the cable force compensation value of the ambient temperature of the bridge. The cable force safety judgment module determines whether the real-time cable force is in a safe state. When it is in a safe state, it retrieves the historical cable force data of the bridge cables and generates a historical cable force time-series vector. The cable association determination module obtains the correlation coefficient between each cable and its corresponding cable on the same side based on the historical cable force time series vector of each cable of the bridge, and determines the corresponding cable on the same side based on the correlation coefficient; The historical cable force comparison module compares the historical cable force time series vectors of each cable with those of the same-side associated cables and symmetrical cables to obtain the cable force time series synchronization degree between cables on the same side and the cable force time series deviation value and deviation direction between symmetrical cables; The cable coordination analysis module determines whether each cable has symmetric cable force coordination and is on the same side, and diagnoses the overall safety performance of the bridge cables based on the judgment results. The method for obtaining the cable force timing synchronization between cables on the same side is as follows: Extract the time and magnitude of all cable force change nodes from the historical cable force time series vector of each cable and its associated cable on the same side. Match all cable force change nodes, calculate the time difference between each cable force change node, and calculate the average of all time differences. Obtain the ratio of cable force change amplitude at each cable force change node, and filter the cable force change nodes whose ratio of cable force change amplitude matches the set ratio of cable force amplitude between the corresponding cable and its associated cable on the same side, and record them as matching cable force change nodes; The proportion of nodes with consistent cable force changes to the total number of nodes with changes in cable force is statistically analyzed, and the cable force timing synchronization degree is obtained by combining the average time difference. The method for obtaining the timing deviation value and direction of the cable force between the symmetrical cables is as follows: Select the historical cable force time series vectors of each cable and its symmetrical cable, align all instantaneous cable forces in the two historical cable force time series vectors according to the timestamp, and calculate the cable force time series deviation value at each timestamp; Based on the sign of the instantaneous deviation value of cable force at each timestamp, determine the direction of the cable force deviation between each cable and its symmetrical cable at each timestamp; The determination of whether each cable has symmetric cable force coordination and symmetrical cable force coordination specifically includes: Extract the cable force temporal synchronization degree of each cable and its related cables on the same side, construct a synergy analysis matrix, and combine the mean and standard deviation of the cable force temporal synchronization degree of the cable group on the same side to determine the reasonable distribution range of the cable force temporal synchronization degree of the cable group on the same side. If the cable tension timing synchronization degree of a certain cable and all its related cables on the same side is within a reasonable distribution range, then the cable is judged to have the same-side cable tension coordination; otherwise, the cable is judged not to have the same-side cable tension coordination. If the cable force timing deviation values ​​at each time point between a cable and its symmetrical cable are all within the corresponding allowable cable force deviation value range, then the cable is judged to have symmetrical cable force coordination. If the cable force timing deviation values ​​at consecutive time points between a cable and its symmetrical cable are outside the corresponding allowable cable force deviation value range, and the cable force deviation directions at consecutive time points are consistent, then the cable is judged not to have symmetrical cable force coordination.

2. The real-time monitoring system for bridge cable tension according to claim 1, characterized in that: The specific contents of the real-time cable force acquisition module are as follows: Real-time vibration frequency signals from various monitoring points on the bridge cables are collected, and the real-time vibration frequency signals are filtered and noise-reduced. The natural vibration frequencies are extracted from the processed real-time vibration frequency signals, and the maximum natural vibration frequency is selected. The initial cable force is calculated based on the maximum natural vibration frequency and the structural parameters of the cable through cable force theory. Extract historical monitoring data of cable force from the bridge historical database, determine the mapping relationship between ambient temperature and cable force compensation value, and obtain the corresponding cable force compensation value based on the ambient temperature of the bridge. The initial cable force and the cable force compensation value are combined for calculation to obtain the real-time cable force of the bridge cable.

3. The real-time monitoring system for bridge cable tension according to claim 2, characterized in that: The mapping relationship between ambient temperature and cable force compensation value is determined as follows: Extract all recent historical monitoring data of cable tension from the bridge historical database, and obtain the natural vibration frequency of the cable, historical cable tension and historical ambient temperature from the historical monitoring data; Based on historical cable force and the natural vibration frequency of the cable, the cable force compensation value affected by temperature is obtained by back-analysis. Outliers were removed from the cable force compensation values ​​affected by temperature under various historical environmental temperatures, and the average cable force compensation value was calculated by averaging the remaining cable force compensation values. Using ambient temperature as the independent variable and average cable force compensation value as the dependent variable, a mapping relationship database between ambient temperature and cable force compensation value is established.

4. The real-time monitoring system for bridge cable tension according to claim 3, characterized in that: The process of obtaining the corresponding cable force compensation value based on the ambient temperature of the bridge specifically includes: Once the ambient temperature of the bridge is collected, if the ambient temperature of the bridge matches a certain ambient temperature point in the mapping relationship database, the cable force compensation value of that ambient temperature point is retrieved as the cable force compensation value corresponding to the ambient temperature of the bridge. If the ambient temperature of the bridge is between two adjacent ambient temperature points in the mapping database, then the linear interpolation method is used to calculate the cable force compensation value corresponding to the adjacent ambient temperature points, thus obtaining the cable force compensation value corresponding to the ambient temperature of the bridge.

5. The real-time monitoring system for bridge cable tension according to claim 1, characterized in that: The specific content of the cable safety judgment module is as follows: If the real-time cable tension of the bridge cable exceeds the rated safe cable tension, the real-time cable tension of the bridge cable is judged to be in a dangerous state, and an early warning message is generated and pushed out simultaneously. Conversely, historical cable force data of bridge cables within a preset time period is retrieved, and the historical cable force data is sorted according to timestamp order to form a historical cable force time series vector.

6. The real-time monitoring system for bridge cable tension according to claim 5, characterized in that: The method for determining the corresponding associated cables on the same side for each cable is as follows: Historical cable force time series vectors of each cable and its corresponding cable on the same side are selected from the bridge history database, and the correlation coefficient between the historical cable force time series vectors of each cable and its corresponding cable on the same side is calculated using the Pearson correlation coefficient. If the correlation coefficient of the historical cable force time series vector between a cable and its corresponding cable on the same side is greater than the set correlation coefficient, then the cable on the same side is recorded as the corresponding cable on the same side, and the corresponding cables on the same side for each cable are counted.

7. The real-time monitoring system for bridge cable tension according to claim 1, characterized in that: The steps for diagnosing the overall safety performance of bridge cables are as follows: When a cable does not have the same-side cable force coordination or does not have the symmetrical cable force coordination, the cable is recorded as an abnormal cable, and the number of abnormal cables is counted. If the number of abnormal cables is unique, the overall safety performance of the bridge cables is deemed to be qualified, and the location number of the abnormal cable is sent as an early warning. Conversely, if multiple abnormal cables do not have synergistic force on the same side and there is no synergistic relationship between the multiple abnormal cables, the overall safety performance of the bridge cable is deemed to be qualified; if multiple abnormal cables do not have synergistic force on the same side and there is a synergistic relationship between the multiple abnormal cables, the overall safety performance of the bridge cable is deemed to be unqualified. When multiple abnormal cables lack symmetrical cable force coordination, the overall safety performance of the bridge cables is deemed unqualified.

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