Bridge frequency monitoring system based on low frame rate video

Abstract

The utility model discloses a bridge frequency monitoring system based on a low frame rate video, comprising a plurality of sub-control stations and a remote master control station, each sub-control station is provided with a video signal acquisition unit and a monitoring early warning unit, the video signal acquisition unit is used for acquiring a vibration image of a bridge and sending the vibration image to the monitoring early warning unit, and the monitoring early warning unit is used for monitoring the vibration image of the bridge. The early warning device is installed on a computer mainboard, the data processing module is connected with the frequency identification module and used for receiving and processing vibration images, generating structure displacement signals and transmitting the structure displacement signals to the frequency identification module, and the frequency identification module is connected with the early warning signal generation module and used for processing the structure displacement signals. The early warning signal generation module is connected with the early warning device to give an alarm, the remote master control station is in network connection with the sub-control stations, the bridge frequency is received in real time to achieve remote monitoring, and the system is suitable for different construction environments and is simple in structure and low in cost.

Description

Technical Field

[0001] The utility model relates to the field of monitoring and early warning, in particular to a bridge frequency monitoring system based on low frame rate video. Background Art

[0002] Computer vision, as a new technology that can achieve long-distance, non-contact and multi-point synchronous monitoring, has received close attention from scholars in the field of structural health monitoring as soon as it was proposed. Existing studies have used computer vision technology to measure the vibration of engineering structures, and then identify the natural frequency of the structure and evaluate the structural state, and have achieved relatively successful engineering applications. Most practices use high-performance industrial cameras or SLR cameras to shoot vibration videos of the structure to be measured at a high frame rate, and then identify the structural frequency through an offline video vibration analysis system. This approach is inefficient and costly, and it is obviously impossible to extend it to a large number of small and medium-span bridges, and it cannot achieve the goal of real-time structural monitoring and early warning. On the other hand, although low-cost cameras have been widely deployed on smart highway bridges, the video frame rate they shoot is too low (30-60Hz), which cannot meet the requirements of vibration monitoring of small and medium-span bridges to cover the 0-100Hz frequency range.

[0003] In view of the above situation, there is an urgent need to develop a simple, efficient, economical and real-time bridge frequency monitoring system suitable for small and medium span bridges. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings of the prior art and provide a bridge frequency monitoring system based on low frame rate video. The system can extract the vibration frequency of the bridge in real time when the camera price is low and the sampling rate is 30-60Hz. The system can be applied to different construction environments and can identify the structural frequency conveniently, efficiently, accurately and at low cost, and can achieve real-time monitoring and early warning.

[0005] In order to achieve the above objectives, the technical solution of the utility model is:

[0006] A bridge frequency monitoring system based on low frame rate video, including several sub-control stations and a remote master control station, wherein the sub-control stations are provided with a video signal acquisition unit and a monitoring and early warning unit, wherein the video signal acquisition unit includes an industrial camera lens and a high-definition camera, wherein the industrial camera lens is mounted on the high-definition camera and is used to acquire a vibration image of the bridge and send it to the monitoring and early warning unit, wherein the monitoring and early warning unit includes a computer mainboard, an early warning device, a data processing module, a frequency identification module and an early warning signal generation module, wherein the early warning device is mounted on the computer mainboard, the data processing module is connected to the frequency identification module, and the data processing module is used to receive and process The vibration image is processed to generate a structural displacement signal and transmit it to the frequency identification module. The frequency identification module is connected to the early warning signal generation module. The frequency identification module is used to process the structural displacement signal, identify the bridge frequency and transmit it to the early warning signal generation module. The early warning signal generation module is connected to the early warning device. The early warning signal generation module is used to generate an early warning signal when the received bridge frequency is higher than a threshold value and transmit it to the early warning device. The early warning device is used to issue an alarm after receiving the early warning signal. The remote master control station is connected to each sub-control station network and receives the bridge frequency in real time to achieve remote monitoring.

[0007] Preferably, the data processing module identifies pixel changes of the vibration image by Lucas-Kanade optical flow method to obtain the structural displacement signal.

[0008] Preferably, the data processing module is connected to the computer mainboard and the frequency identification module respectively via USB interfaces.

[0009] Preferably, the frequency identification module uses a characteristic system implementation algorithm to process the structural displacement signal to identify the bridge frequency.

[0010] Preferably, the monitoring and early warning unit further comprises a TF card, and the TF card is installed on and connected to the computer mainboard.

[0011] Preferably, the computer mainboard is connected to the Internet via a network cable or a wireless network card, and the remote master control station is provided with a computer, which is remotely connected to and controls the computer mainboard of each sub-control station.

[0012] Preferably, the early warning device includes a buzzer or a warning light.

[0013] Preferably, the industrial camera lens comprises a zoom lens or a fixed-focus lens, which is connected to the high-definition camera via a C / CS interface and is aimed at the structure to be monitored on the bridge.

[0014] Preferably, the high-definition camera is connected to the computer mainboard via a USB interface or a CSI interface.

[0015] Preferably, the sub-control station also includes an external protection device, which includes a shell, a cavity for accommodating the video signal acquisition unit and the monitoring and early warning unit is provided inside the shell, and the industrial camera lens is exposed, and the shell is fixed around the bridge.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] The bridge frequency monitoring system based on low frame rate video proposed in the utility model can extract the vibration frequency of the bridge in real time when the camera price is low and the sampling rate is 30-60Hz. It can be applied to different construction environments, has a simple structure and low cost. The sub-control station is provided with a video signal acquisition unit and a monitoring and early warning unit, which can integrate vibration image acquisition, transmission, data processing, vibration frequency recognition and early warning. It is easy to operate and can conveniently, efficiently, accurately and at low cost identify the structural frequency and achieve real-time monitoring and early warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and together with the description are used to explain the principles of the utility model. It will be easy to recognize other embodiments and many expected advantages of the embodiments as they become better understood by reference to the following detailed description.

[0019] Figure 1 A schematic diagram of a sub-control station of a bridge frequency monitoring system based on low frame rate video according to an embodiment of the present application;

[0020] Figure 2 A schematic diagram of a bridge frequency monitoring system based on low frame rate video according to an embodiment of the present application;

[0021] Attached figure numbers: 1. structure to be monitored; 2. video signal acquisition unit; 21. industrial camera lens; 22. high-definition camera; 3. monitoring and early warning unit; 31. frequency identification module; 32. data processing module; 33. TF card; 34. computer motherboard; 35. early warning device; 36. early warning signal generating module; 4. remote master control station; 5. sub-control station No. 1; 6. sub-control station No. 2; 7. sub-control station No. 3; 8. sub-control station No. 4. DETAILED DESCRIPTION

[0022] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It is also necessary to explain that, for ease of description, only the parts related to the relevant utility model are shown in the accompanying drawings.

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] refer to Figure 1 and Figure 2 In the embodiment of the utility model, a bridge frequency monitoring system based on low frame rate video is proposed, including several sub-control stations and a remote master control station 4, and the remote master control station 4 remotely controls each sub-control station. The sub-control station is provided with a video signal acquisition unit 2 and a monitoring and early warning unit 3. The video signal acquisition unit 2 is used to collect the vibration image of the bridge and send it to the monitoring and early warning unit 3. Specifically, the vibration image of the structure to be monitored 1 on the bridge is collected. The structure to be monitored 1 should have known dimensions or known partial dimensions. The video signal acquisition unit 2 includes an industrial camera lens 21 and a high-definition camera 22. The industrial camera lens 21 is installed on the high-definition camera 22. Specifically, the industrial camera lens 21 includes a zoom lens or a fixed focus lens, which is connected to the high-definition camera 22 through a C / CS interface. The industrial camera lens 21 can select a lens with a suitable focal length according to the actual on-site conditions, aim at the structure to be monitored 1, and then be installed on the high-definition camera 22. The high-definition camera 22 directly affects the accuracy of the monitoring results. The video signal acquisition unit 2 can freely change the sampling frequency between 30-60Hz.

[0025] Further, the monitoring and early warning unit 3 includes a computer motherboard 34, an early warning device 35, a TF card 33, a data processing module 32, a frequency identification module 31 and an early warning signal generation module 36. The high-definition camera 22 is connected to the computer motherboard 34 via a USB interface or a CSI interface to realize information exchange between the video signal acquisition unit 2 and the monitoring and early warning unit 3. The TF card 33 is installed on the computer motherboard 34 and connected to the computer motherboard 34. The TF card 33 can burn the image file in advance for storing files. The early warning device 35 is installed on the computer motherboard 34 and connected to the early warning signal generation module 36 to receive the early warning signal generated by the early warning signal generation module 36 to monitor the real-time alarm. The data processing module 32 is connected to the frequency identification module 31. The data processing module 32 is used to receive and process the vibration image, generate a structural displacement signal and transmit it to the frequency identification module 31. Specifically, the data processing module 32 identifies the pixel changes of the vibration image through the Lucas-Kanade optical flow method to obtain the structural displacement signal. The Lucas-Kanade optical flow method is an existing algorithm, which will not be repeated here, and does not involve the improvement of the computer program. The frequency identification module 31 is connected to the early warning signal generation module 36. The frequency identification module 31 is used to process the structural displacement signal, identify the bridge frequency and transmit it to the early warning signal generation module 36. Specifically, the frequency identification module 31 uses a characteristic system implementation algorithm to process the structural displacement signal and identify the bridge frequency. The characteristic system implementation algorithm is an existing algorithm and will not be repeated here. It does not involve the improvement of the computer program. The early warning signal generation module 36 is used to generate an early warning signal and transmit it to the early warning device 35 when the received bridge frequency is higher than the threshold. The early warning device 35 is used to issue an alarm after receiving the early warning signal. When the bridge frequency changes significantly, the early warning signal generation module 36 generates an early warning signal, causes the early warning device 35 to operate, and issues an alarm. The early warning signal can be further sent to a remote total air station for real-time monitoring and early warning. In a specific embodiment, the early warning device 35 includes a buzzer or a warning light.

[0026] Specifically, the remote master control station 4 is connected to each sub-control station network and receives the bridge frequency in real time to realize remote monitoring. The computer motherboard 34 is connected to the Internet through a network cable or a wireless network card. The remote master control station 4 is equipped with a computer, and the computer is remotely connected to and controlled by the computer motherboard 34 of each sub-control station. The computer motherboard 34 is powered by a power cord or a battery to achieve the effect of independent operation; a USB wireless network card or a network cable is added to the computer motherboard 34, and the IP address of the computer motherboard 34 can be obtained after networking. The remote master control station 4 can be installed with a tablet computer or an ordinary computer to remotely control the computer motherboard 34; the data processing module 32 and the computer motherboard 34, and the frequency identification and warning module and the data processing module 32 are all connected through a USB interface to realize information interaction.

[0027] In a specific embodiment, the sub-control station also includes an external protection device for windproof, waterproof, anti-static, etc., to prevent the extreme environment from affecting the monitoring process. The external protection device includes a shell, and a cavity for accommodating the video signal acquisition unit 2 and the monitoring and early warning unit 3 is provided inside the shell, and the industrial camera lens 21 is exposed, and the exposed industrial camera lens 21 is aimed at the structure to be monitored 1. An external protection device is added to the outside of the video signal acquisition unit 2 and the monitoring and early warning unit 3 to prevent them from being disturbed by the environment. The external protection device is fixed around the bridge by welding, riveting or bolting to ensure that the detection result is not disturbed by the displacement of the camera.

[0028] refer to Figure 2 , the remote master control station 4 can be connected to several sub-control stations to achieve multi-region global monitoring. Taking four sub-control stations and one remote master control station 4 as an example, sub-control station 1 5, sub-control station 2 6, sub-control station 3 7, and sub-control station 4 8 are connected to the remote master control station 4 through network cables, USB wireless network cards, local area networks or wide area networks.

[0029] The above describes the specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A bridge frequency monitoring system based on low frame rate video, characterized in that: It includes several sub-control stations and a remote master control station. The sub-control station is provided with a video signal acquisition unit and a monitoring and early warning unit. The video signal acquisition unit includes an industrial camera lens and a high-definition camera. The industrial camera lens is installed on the high-definition camera and is used to collect the vibration image of the bridge and send it to the monitoring and early warning unit. The monitoring and early warning unit includes a computer mainboard, an early warning device, a data processing module, a frequency identification module and an early warning signal generation module. The early warning device is installed on the computer mainboard. The data processing module is connected to the frequency identification module. The data processing module is used to receive and process the vibration image, generate a structural displacement signal and transmit it to the frequency identification module. The frequency identification module is connected to the early warning signal generation module. The frequency identification module is used to process the structural displacement signal, identify the bridge frequency and transmit it to the early warning signal generation module. The early warning signal generation module is connected to the early warning device. The early warning signal generation module is used to generate an early warning signal when the received bridge frequency is higher than a threshold and transmit it to the early warning device. The early warning device is used to issue an alarm after receiving the early warning signal. The remote master control station is connected to each sub-control station network and receives the bridge frequency in real time to realize remote monitoring.

2. The bridge frequency monitoring system based on low frame rate video according to claim 1 is characterized in that: The data processing module identifies pixel changes of the vibration image through the Lucas-Kanade optical flow method to obtain the structural displacement signal.

3. The bridge frequency monitoring system based on low frame rate video according to claim 1 is characterized in that: The data processing module is connected to the computer mainboard and the frequency identification module respectively through a USB interface.

4. The bridge frequency monitoring system based on low frame rate video according to claim 1 is characterized in that: The frequency identification module uses a characteristic system implementation algorithm to process the structural displacement signal and identify the bridge frequency.

5. The bridge frequency monitoring system based on low frame rate video according to claim 1 is characterized in that: The monitoring and early warning unit also includes a TF card, which is installed on the computer mainboard and connected to the computer mainboard.

6. The bridge frequency monitoring system based on low frame rate video according to claim 1 is characterized in that: The computer mainboard is connected to the Internet via a network cable or a wireless network card. The remote master control station is provided with a computer, and the computer is remotely connected to and controlled by the computer mainboard of each sub-control station.

7. The bridge frequency monitoring system based on low frame rate video according to claim 1 is characterized in that: The early warning device includes a buzzer or a warning light.

8. The bridge frequency monitoring system based on low frame rate video according to claim 1, characterized in that: The industrial camera lens includes a zoom lens or a fixed-focus lens, which is connected to the high-definition camera via a C / CS interface and is aimed at the structure to be monitored on the bridge.

9. The bridge frequency monitoring system based on low frame rate video according to claim 1, characterized in that: The high-definition camera is connected to the computer mainboard via a USB interface or a CSI interface, and the computer mainboard is connected to the high-definition camera via a USB interface or a CSI interface.

10. The bridge frequency monitoring system based on low frame rate video according to claim 1, characterized in that: The sub-control station also includes an external protection device, which includes a shell. A cavity for accommodating the video signal acquisition unit and the monitoring and early warning unit is provided inside the shell, and the industrial camera lens is exposed. The shell is fixed around the bridge.

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