A monitoring system and method for testing the full-bridge response based on limited sensors

Abstract

The present invention discloses a monitoring system and method for testing the full-bridge response based on limited sensors. The system includes: a radar positioning module for positioning the test position and the load position, determining the monitoring area where the test point is located and the distance from the sensor in the monitoring area; an optical fiber sensor for monitoring the bridge load under each monitoring area and outputting response data, and transmitting the response data to the central control module; a signal transmission optical cable for receiving the monitoring data and transmitting it to the central control module for data interaction; a central control module for controlling the radar positioning module and the optical fiber sensor, reading the monitoring information, monitoring the response state of the overall bridge, and judging the health state of the bridge structure; determining the amplification factor through the response transfer function, and obtaining the actual response value at the test position after correction, so as to realize the real-time monitoring of the full bridge by limited sensors, save costs, and at the same time can realize the monitoring of the state of any part of the full bridge. The processing method is simple and the result is reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge monitoring, and particularly relates to a monitoring system and method for testing the full-bridge response based on limited sensors. Background Art

[0002] Due to cost and structural strength considerations, bridge monitoring systems often only use limited sensors. For locations without sensors, the bridge conditions cannot be known. The commonly used method is the finite element method, which inversely deduces the response state of the entire bridge through data obtained from limited sensors. This method requires processing a large amount of data and has a large computational load, making it impossible to achieve good real-time monitoring. Moreover, after inversely deducing the response state of the entire bridge, the response data at the test locations cannot be directly read out. In summary, the bridge monitoring systems in the prior art process a large amount of data, have a large computational load, and cannot achieve good real-time monitoring. Summary of the Invention

[0003] The purpose of the present invention is to provide a monitoring system and method for testing the full-bridge response based on limited sensors, so as to achieve real-time monitoring of the health status of any point on the entire bridge.

[0004] The present invention provides a monitoring system for testing the full-bridge response based on limited sensors, including:

[0005] A radar positioning module, configured to position the test location and the load location, determine the monitoring area where the test point is located and the distance from the sensor in the monitoring area;

[0006] Optical fiber sensors, configured to monitor the bridge loads in each monitoring area and output response data under the action of the bridge loads, and transmit the response data to the central control module;

[0007] A signal transmission optical cable, configured to receive the monitoring data of the radar positioning module and the optical fiber sensors and transmit them to the central control module for data interaction;

[0008] A central control module, configured to control the radar positioning module and the optical fiber sensors, read the monitoring information of the radar positioning module and the optical fiber sensors, monitor the response state of the entire bridge, and judge the health state of the bridge structure; determine the amplification factor through the response transfer function, correct the response data by compensating the amplification factor, and obtain the actual response value at the test location, thereby realizing real-time monitoring of any point on the entire bridge by limited sensors.

[0009] Preferably, the width of the perimeter detection of the monitoring area by the optical fiber sensor is not greater than 90% of the maximum threshold of the detection distance of the optical fiber sensor.

[0010] Preferably, the central control module includes an alarm unit for warning the health status of the bridge structure, where the health status refers to the judgment on whether cracks occur in the bridge structure and whether the strength, stiffness, and stability of the bridge structure meet the usage requirements.

[0011] Preferably, the central control module further includes a software management unit for controlling the switch of the fiber optic sensors in any monitoring area and reading the historical data of any of the fiber optic sensors.

[0012] Preferably, fiber optic sensors are arranged on each of the monitoring areas for independently monitoring the strain signals of the bridge, continuously monitoring each monitoring area and returning response signals to the central control module for processing and analysis; when a single point fails or is damaged, only the corresponding single area will have a fault, while other areas except the faulty area will continue to work normally.

[0013] The present invention provides a monitoring method for applying the monitoring system based on finite sensor testing of the full-bridge response as described above, including:

[0014] Dividing the full bridge into monitoring areas and setting sensors at the centers of the monitoring areas;

[0015] Testing the position through radar positioning, establishing a plane rectangular coordinate system on the bridge deck, and obtaining the coordinates of the testing position;

[0016] Judging the monitoring area where the testing position is located and calculating the distance from the sensor at the center of the monitoring area, obtaining a compensation amplification coefficient through the response transfer relationship, compensating the response measured by the sensor, and obtaining the actual response value at the testing position after correction, and outputting the coordinate value of the testing point and the actual response value;

[0017] Wherein, in the coordinate system, the position where the radar is located is used as the origin, the transverse direction of the bridge is used as the x-axis, and the longitudinal direction of the bridge is used as the y-axis.

[0018] Preferably, the judging the monitoring area where the testing position is located and calculating the distance from the sensor at the center of the monitoring area includes:

[0019] Obtaining the coordinates of the sensor at the center of the monitoring area;

[0020] According to the coordinates of the sensor at the center of the monitoring area, calculating the distance from the testing position to the central sensor through the Euclidean distance calculation formula.

[0021] Preferably, the obtaining a compensation amplification coefficient through the response transfer relationship further includes:

[0022] Within the monitoring area where the sensor is located, continuously adjust and change the distance between the load and the sensor at the center of the monitoring area, and set a sensor at the position where the load is located to obtain the response values of the load center sensor and the actual position, and obtain the relationship between the distance from the load center sensor and the compensation amplification factor.

[0023] Preferably, the compensation for the response measured by the sensor and the further obtaining of the actual response value at the test position after correction include:

[0024] Measure the response value of the test point through the sensors in the monitoring area adjacent to the monitoring area where the test position is located. According to the distance between the test position and the sensors in the adjacent monitoring area and the force transmission relationship in the building materials, the actual response values of the test point obtained after correcting the data of each sensor are the same.

[0025] In view of the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides a monitoring system and method for testing the full-bridge response based on finite sensors, which realizes the real-time monitoring of the health status of any point on the full bridge, solves the problem of real-time testing of the full-bridge response based on finite sensors, and can analyze the structural deformation and damage conditions and locate them according to the actual response values; while saving costs, it can also monitor the status of any part of the full bridge, with a simple processing method and reliable results. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the erection of the monitoring system for testing the full-bridge response based on finite sensors in the embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of the connection of the monitoring system for testing the full-bridge response based on finite sensors in the embodiment of the present invention;

[0029] Figure 3 It is a working flow chart of the monitoring system for testing the full-bridge response based on finite sensors in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] Embodiment 1

[0032] As Figure 1 、2 As shown in the figure, the present invention provides a monitoring system for testing the full-bridge response based on limited sensors, including:

[0033] A radar positioning module 1, which is used to locate the test position and the load position, determine the monitoring area where the test point is located and the distance from the sensor in the monitoring area; considering the complex driving conditions of vehicles on the bridge, in order to accurately locate the load position, the radar is installed above the bridge deck. It can be installed on the truss or street lamp;

[0034] An optical fiber sensor 2, which is used to monitor the bridge load in each monitoring area and output the response data under the action of the bridge load, and transmit the response data to the central control module 4; comprehensively considering the sensor sensitivity and response transmission, the full bridge is reasonably divided into a finite number of monitoring areas, and sensors are arranged at the center of the area; the optical fiber sensor 2 is laid under the bridge deck, and the sheath is waterproof, which can play a protective role for the optical fiber sensor 2.

[0035] A signal transmission optical cable 3, which is used to receive the monitoring data of the radar positioning module 1 and the optical fiber sensor 2 and transmit them to the central control module 4 for data interaction; the transmission optical cable uses ordinary communication optical fiber cables, which mainly play the role of connecting monitoring areas. It is mostly a 2-to-48-core optical cable, and the specific number of cores is customized according to system requirements. The output of the monitoring area is the reading of the sensor. The signal transmission optical cable connects the sensor and the alarm host to realize data interaction. The transmission optical cable is directly buried underground. When the system fails or is damaged at a single point, only the corresponding single area will fail, while other areas will continue to work normally.

[0036] A central control module 4, which is used to control the radar positioning module 1 and the optical fiber sensor 2, read the monitoring information of the radar positioning module 1 and the optical fiber sensor 2, monitor the overall response state of the bridge, and judge the health state of the bridge structure; determine the amplification factor through the response transfer function, correct the response data through the compensation amplification factor, and obtain the actual response value of the test position, so as to realize the real-time monitoring of any point on the full bridge by limited measurement sensors.

[0037] Those skilled in the art can understand that the system includes a radar positioning module 1, an optical fiber sensor 2 and a signal transmission optical cable 3 connected in sequence. The optical fiber sensor 2 is laid under the bridge surface and can measure the pressure transmitted from the bridge deck. The width of the perimeter detection of the monitoring area by the optical fiber sensor 2 is not greater than 90% of the maximum threshold of the detection distance of the optical fiber sensor 2; the signal transmission optical cable 3 can read the sensor data and transmit it to the central control module 4 and is connected to the central control module 4.

[0038] Such as Figure 1As shown in the figure, the fiber optic sensor 2 is embedded in the concrete. The perimeter detection width H1 of the sensor monitoring area is not greater than 90% of the sensor detection limit distance. If it is necessary to improve the monitoring level, the perimeter detection width can be appropriately reduced. According to the divided monitoring areas on the surface of the bridge, the fiber optic sensor 2 is laid at the center of the monitoring area. The fiber optic sensor 2 should be straight and closely attached to the bridge surface, but deformation of the fiber optic sensor 2 caused by excessive pressure should be avoided. After fixing the sensor, the concrete is spread on it.

[0039] Furthermore, the central control module 4 includes an alarm unit for warning about the health status of the bridge structure. The health status refers to the judgment of whether cracks occur in the bridge structure and whether the strength, stiffness, and stability of the bridge structure meet the usage requirements.

[0040] Furthermore, the central control module 4 also includes a software management unit for controlling the switch of the fiber optic sensor 2 in any monitoring area and reading the historical data of any fiber optic sensor 2.

[0041] Furthermore, a fiber optic sensor 2 is set on each monitoring area for independently monitoring the strain signal of the bridge, continuously monitoring each monitoring area and returning a response signal to the central control module 4 for processing and analysis; when a single point fails or is damaged, only the corresponding single area will have a fault, while other areas except the faulty area will continue to work normally.

[0042] Those skilled in the art can understand that this monitoring system includes a positioning radar at the front end, a fiber optic sensor 2, an alarm unit and a software management unit at the back end. The front end is the site, and the back end is the control room, and data interaction is realized through the signal transmission optical cable 3. The alarm unit mainly realizes the early warning of the bridge health status, that is, whether cracks occur, and whether the strength, stiffness, and stability meet the usage requirements; the software management unit can realize functions such as switching the sensors in any monitoring area and reading the historical data of any sensor.

[0043] Analysis of each sensor module and back-end data: The bridge unit is divided into multiple monitoring areas, each area is an independent module, and each independent area can independently monitor the strain signal of the bridge, continuously monitor each area and return the signal to the device terminal for processing and analysis, monitor the overall response state of the bridge, and judge whether there are events that endanger the bridge. Users can individually modulate each independent area system to determine its working in the best state. This system uses interfaces such as serial ports and Ethernet ports to transmit alarm and system status information, and has an independent radio frequency port, which can facilitate users to calibrate through the dedicated software of the system.

[0044] The connection between the sensor and the signal transmission optical cable 3 is protected by a junction box. The junction box is used to protect each fiber optic fusion point and adopts an international standard interface.

[0045] During installation, first install the radar, fiber optic sensor 2 and communication optical fiber, and then carry out the line connection work. The connection adopts the fusion splicing method, and place the system host, terminal box, etc. in the cabinet.

[0046] Embodiment 2

[0047] As Figure 3 shown, based on the system of Embodiment 1, the present invention also provides a monitoring method for applying the monitoring system for testing the full-bridge response based on limited sensors, including:

[0048] Divide the monitoring area of the full bridge, and set sensors at the center of the monitoring area; considering the sensitivity of the sensors and calculation errors, the monitoring area can be refined at important positions of the bridge, namely at the bridge end supports, mid-span positions and positions prone to damage. Divide more monitoring areas and install more sensors to obtain more accurate data;

[0049] Locate the test position through the radar, establish a plane rectangular coordinate system on the bridge deck to obtain the coordinates of the test position; take the position where the radar is located as the origin, establish a plane rectangular coordinate system on the bridge deck, with the transverse direction of the bridge as the x-axis and the longitudinal direction of the bridge as the y-axis. Locate any test position through the radar to obtain the coordinates (x, y) of the test position P. Establish a coordinate system for the full bridge with the position where the radar is installed as the coordinate origin, and divide the area according to the monitoring range of the sensor. The monitoring range of the sensor: the sensor does not only respond when pressure is applied directly above the sensor. Due to the transmission of force in the paving layer and concrete, the sensor can also sense the change of force nearby. The range that can cause a significant change in the sensor reading is the monitoring range of the sensor. Bury sensors at the center of each area, number the limited sensors, locate the test position through the radar to obtain the coordinates (x, y) of the test position P.

[0050] Judge the monitoring area where the test position is located and calculate the distance from the sensor at the center of the monitoring area, obtain the compensation amplification coefficient through the response transfer relationship, compensate the response measured by the sensor, and obtain the actual response value at the test position after correction, and output the coordinate value of the test point and the actual response value; after obtaining the coordinates of the test position P, judge the monitoring area to which it belongs and obtain the coordinates (x i , y j ), and then calculate the distance from P to the sensor at the center of the area, obtain the compensation amplification coefficient through the response transfer relationship, and compensate the response measured by the sensor, so as to obtain the actual response value of the measured position. Locate the test position through the radar to obtain the monitoring area where the load is located and the length from the load to the measuring point in the area

[0051] Among them, in the coordinate system, the position where the radar is located is taken as the origin, the transverse direction of the bridge is taken as the x-axis, and the longitudinal direction of the bridge is taken as the y-axis.

[0052] If the force does not act directly on the sensor, but is transmitted to the sensor through media such as the paving layer and concrete, then the reading is obviously not the actual magnitude of the force. Multiple groups of tests are required to determine the relationship between the actual magnitude of the force, the sensor reading, and the distance from the force application point to the sensor. Usually, the sensor reading is less than the actual magnitude of the force, so the actual magnitude of the force is corrected by the compensation amplification factor. Since the bridge may be built with different materials, the response transmission relationship is not the same and needs to be determined by tests. Therefore, the compensation amplification factor in the system is not fixed and needs to be adjusted according to the bridge construction materials.

[0053] Further, the determining the monitoring area where the test position is located and calculating the distance from the sensor at the center of the monitoring area includes:

[0054] Obtaining the coordinates of the sensor at the center of the monitoring area;

[0055] According to the coordinates of the sensor at the center of the monitoring area, the distance from the test position to the center sensor is obtained through the Euclidean distance calculation formula.

[0056] Further, the obtaining the compensation amplification factor through the response transmission relationship further includes:

[0057] The method of real experiment or simulation can be used to continuously adjust and change the distance between the vehicle load and the sensor at the center of the monitoring area within the monitoring area where the sensor is located, and sensors are set at the positions where the load is located to obtain the response values between the load center sensor and the actual position, and the relationship between the distance from the load center sensor and the compensation amplification factor is obtained. The key to the full-bridge monitoring is the determination of the test position and the compensation amplification factor. The determination of the position can be carried out by radar positioning, while the determination of the compensation amplification factor is more complicated. The differences in the bridge construction materials used and the positions of the test positions on the bridge surface will cause changes in the compensation amplification factor.

[0058] Further, the compensating the response measured by the sensor and obtaining the actual response value at the test position after correction further includes:

[0059] The response value of the test point is measured by the sensors in the monitoring areas adjacent to the monitoring area where the test position is located. According to the distance between the test position and the sensors in the adjacent monitoring areas and the force transmission relationship in the building materials, the actual response value of the test point obtained after correcting the data of each sensor is the same.

[0060] To locate the test position, the coordinate system established on the bridge deck with the position of the radar as the origin, as described above, is required. After the radar scans the test position and obtains the azimuth and distance, the length of the test position from the origin can be obtained through the simple Pythagorean theorem, and the coordinates of the test position can be easily obtained based on the azimuth.

[0061] Determine the monitoring area to which it belongs. The monitoring area division rules are as follows: Assume that the sensor monitoring area is a square with a side length of 2 meters. Then we can number the area as follows, [-2,1], [-2,2], [-1,1,], [-1,2], [1,1], [1,2], [2,1], [2,2]... The first number in the array represents the x direction, and the positive and negative indicate the left and right sides of the radar, and the second number represents the y direction. After obtaining the coordinates of the test position, divide the x and y of the coordinates by 2 respectively, and perform a ceiling operation on the results. The obtained values are the corresponding monitoring area numbers. The coordinates of the central sensor in the area can also be easily obtained. Through the Euclidean distance calculation formula, it is easy to obtain the distance between the test position and the central sensor. According to the response transfer relationship, the sensor data is corrected to obtain the actual response value of the test position.

[0062] The present invention uses a radar for load positioning, proposes a compensation amplification factor to correct the data measured by the sensor, and obtains the actual strain value at the load position, thereby realizing the real-time monitoring of the strain state of the entire bridge.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A monitoring system for testing the full-bridge response based on limited sensors, characterized in that Comprising: A radar positioning module, configured to position the test location and the load location, determine the monitoring area where the test point is located and the distance from the fiber optic sensor in the monitoring area; Fiber optic sensors, configured to monitor the bridge load in each monitoring area and output response data under the action of the bridge load, and transmit the response data to the central control module; A signal transmission optical cable, configured to receive the monitoring data of the radar positioning module and the fiber optic sensors and transmit it to the central control module for data interaction; A central control module, configured to control the radar positioning module and the fiber optic sensors, read the monitoring information of the radar positioning module and the fiber optic sensors, monitor the overall response state of the bridge, and judge the health state of the bridge structure; Obtain a compensation amplification factor through the response transfer relationship, correct the response data with the compensation amplification factor to obtain the actual response value at the test location, thereby realizing real-time monitoring of any point on the entire bridge by the fiber optic sensor; The obtaining the compensation amplification factor through the response transfer relationship further includes: Within the range of the monitoring area where the fiber optic sensor is located, continuously adjust and change the distance between the load and the fiber optic sensor at the center of the monitoring area, and set a fiber optic sensor at the position where the load is located, obtain the response values of the fiber optic sensor at the load center and the actual position, and obtain the relationship between the distance from the fiber optic sensor at the load center and the compensation amplification factor.

2. The monitoring system for testing the full-bridge response based on limited sensors according to claim 1, wherein The width of the perimeter detection of the monitoring area by the fiber optic sensor is not greater than 90% of the maximum threshold of the detection distance of the fiber optic sensor.

3. The monitoring system for testing the full-bridge response based on limited sensors as claimed in claim 1, wherein The central control module includes an alarm unit, configured to give an early warning of the health state of the bridge structure, and the health state refers to the judgment of whether cracks occur in the bridge structure and whether the strength, stiffness, and stability of the bridge structure meet the use requirements.

4. The monitoring system for testing the full-bridge response based on limited sensors according to claim 1, characterized in that The central control module further includes a software management unit, configured to control the on / off of the fiber optic sensors in any monitoring area and read the historical data of any fiber optic sensor.

5. The monitoring system for testing the full-bridge response based on limited sensors according to claim 1, characterized in that, Fiber optic sensors are arranged on each monitoring area, configured to independently monitor the strain signal of the bridge, continuously monitor each monitoring area and return a response signal to the central control module for processing and analysis; when a single point fails or is damaged, only the corresponding single area will have a fault, and other areas except the faulty area will continue to work normally.

6. A monitoring method for a monitoring system that applies the full-bridge response based on limited sensor testing as described in any one of claims 1 to 5, characterized in that, Comprising: Divide the entire bridge into monitoring areas, and set fiber optic sensors at the centers of the monitoring areas; Position the test location through radar, establish a plane rectangular coordinate system on the bridge deck, and obtain the coordinates of the test location; Judge the monitoring area where the test location is located and calculate the distance from the fiber optic sensor at the center of the monitoring area, obtain a compensation amplification factor through the response transfer relationship, compensate the response measured by the fiber optic sensor, and after correction, obtain the actual response value at the test location, and output the coordinate value of the test point and the actual response value; Wherein, in the coordinate system, the position where the radar is located is used as the origin, the transverse direction of the bridge is used as the x-axis, and the longitudinal direction of the bridge is used as the y-axis.

7. The monitoring method for testing the full-bridge response based on limited sensors according to claim 6, characterized in that, The judging the monitoring area where the test location is located and calculating the distance from the fiber optic sensor at the center of the monitoring area includes: Obtain the coordinates of the fiber optic sensor at the center of the monitoring area; According to the coordinates of the central fiber optic sensor in the monitored area, the distance from the test position to the central fiber optic sensor is obtained through the Euclidean distance calculation formula.

8. The monitoring method for full-bridge response based on limited sensor testing according to claim 6, wherein The compensation for the response measured by the fiber optic sensor and the further obtaining of the actual response value at the test position after correction include: The response value of the test point is measured by the fiber optic sensor in the monitoring area adjacent to the monitoring area where the test position is located. According to the distance between the test position and the fiber optic sensor in the adjacent monitoring area and the force transmission relationship in the building material, the actual response value of the test point obtained after correcting the data of each fiber optic sensor is the same.

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