阅读说明：本技术 一种水上水下一体化分布式高速视频测量系统的实现方法 (Method for realizing overwater and underwater integrated distributed high-speed video measurement system ) 是由 童小华 陈鹏 高飒 谢欢 冯永玖 刘世杰 金雁敏 叶真 许雄 柳思聪 王超 于 2021-07-27 设计创作，主要内容包括：本发明涉及一种水上水下一体化分布式高速视频测量系统的实现方法,该方法包括：1)分布式高速视频传感器组网方法,采用多节点数据存储传输,用于获取目标结构的高速视频影像序列；2)分布式高速序列影像目标识别与三维重建方法,采用分布式并行计算,用于解析已获取的高速视频影像序列中目标结构的动态形变参数。与现有技术相比,本发明具有精度高、实时性高、鲁棒性能强、可靠性高优点。(The invention relates to a method for realizing an overwater and underwater integrated distributed high-speed video measurement system, which comprises the following steps: 1) the networking method of the distributed high-speed video sensor adopts multi-node data storage transmission and is used for acquiring a high-speed video image sequence of a target structure; 2) the distributed high-speed sequence image target identification and three-dimensional reconstruction method adopts distributed parallel computation and is used for analyzing dynamic deformation parameters of a target structure in an acquired high-speed video image sequence. Compared with the prior art, the method has the advantages of high precision, high real-time performance, strong robust performance and high reliability.)

1. An implementation method of an overwater and underwater integrated distributed high-speed video measurement system is characterized by comprising the following steps:

step 1) a networking method of a distributed high-speed video sensor, which adopts multi-node data storage and transmission and is used for acquiring a high-speed video image sequence of a target structure;

and step 2) a distributed high-speed sequence image target identification and three-dimensional reconstruction method adopts distributed parallel computation and is used for analyzing dynamic deformation parameters of a target structure in the obtained high-speed video image sequence.

2. The method for realizing the above-water and underwater integrated distributed high-speed video measurement system according to claim 1, wherein the distributed high-speed video sensor networking in the step 1) comprises a high-speed imaging system, a synchronous control system, a high-speed acquisition and storage system and a lighting system; the high-speed imaging system is combined with the lighting system to collect high-speed video sequence images of a target structure, the high-speed video sequence images are stored through the high-speed collecting and storing system, and the synchronous control system is used for transmitting and processing high-speed sequence image information.

3. The method for realizing the above-water and underwater integrated distributed high-speed video measurement system according to claim 2, wherein the high-speed imaging system comprises high-speed cameras, the synchronous control system comprises industrial personal computers and a main control computer, the main control computer is connected with the industrial personal computers, and each industrial personal computer corresponds to one high-speed camera.

4. The implementation method of the above-water and underwater integrated distributed high-speed video measurement system according to claim 3, wherein the distributed high-speed video sensor networking method in the step 1) comprises setting up a three-layer node control, and the three-layer node control comprises the following parts:

11) the high-speed camera is a layer of nodes and collects high-speed sequence images of the target object at different shooting visual angles;

12) the industrial personal computer is a two-layer node and stores high-speed sequence images acquired by the plurality of high-speed cameras in real time;

13) the main control computer is three layers of nodes and displays and manages the high-speed sequence images of the industrial control computers;

the main control machine completes the processes of communication control, target identification, stereo matching, three-dimensional reconstruction and deformation analysis; each industrial personal computer synchronously finishes data acquisition and storage and sequence image matching tasks; and the transmission of processing instructions and the transmission of data results between the main control computer and the industrial control computer are executed through a distributed data transmission network and a synchronous control network.

5. The implementation method of the above-water and underwater integrated distributed high-speed video measurement system according to claim 4, wherein the distributed data transmission network specifically comprises: the exchanger is connected with the main control machine and each industrial control machine through a data connecting line to transmit data and instructions in real time.

6. The method for implementing the above-water and underwater integrated distributed high-speed video measurement system according to claim 4, wherein the synchronous control network specifically comprises: the synchronous controller is respectively connected with the main control computer and each industrial control computer through a synchronous control line to transmit synchronous control signals, and each high-speed camera synchronously stores high-speed sequence images.

7. The implementation method of the above-water and underwater integrated distributed high-speed video measurement system according to claim 1, wherein the distributed high-speed sequence image target identification and three-dimensional reconstruction method comprises high-speed video measurement sequence image processing, high-speed video measurement space geometric analysis and structural deformation parameter estimation which are sequentially performed.

8. The implementation method of the above-water and underwater integrated distributed high-speed video measurement system according to claim 7, wherein the high-speed video measurement sequence image processing is used for obtaining sequence image coordinates of target points with the same name, and specifically comprises automatic target identification and positioning, multi-target stereo matching, and target tracking and matching.

9. The implementation method of the above-water and underwater integrated distributed high-speed video measurement system according to claim 8, wherein the target tracking and matching adopts a distributed parallel processing method.

10. The implementation method of the above-water and underwater integrated distributed high-speed video measurement system according to claim 7, wherein the high-speed video measurement space geometric analysis is used for obtaining deformation parameter estimation of a target object, and the deformation parameter estimation comprises a high-speed camera calibration, camera pose estimation and a three-dimensional reconstruction process.

Technical Field

The invention relates to the field of high-speed video measurement, in particular to a method for realizing an overwater and underwater integrated distributed high-speed video measurement system.

Background

With the continuous expansion and extension of the application field, the high-speed video measurement method is continuously improved. The massive image data collected by the high-speed camera brings huge computational burden, and in the current research situation at home and abroad, the main data processing mode of high-speed video measurement is a centralized post-processing mode (Liu et al, 2015; Ye et al, 2018). The traditional data processing mode has the problems of low data processing efficiency, low automation degree and the like, and cannot meet the requirements of field calculation. The distributed parallel computing method greatly improves the data processing efficiency, but the research aiming at distributed high-speed video measurement is not systematic and deep at present.

Along with large-scale ocean development and utilization engineering activities, precise three-dimensional measurement of underwater target structures is a leading-edge research problem of current video photogrammetry. Aiming at the requirement of precise measurement of the structure of an overwater and underwater engineering experiment, a high-precision and high-efficiency measurement method is urgently needed; different from high-speed video measurement of general waterborne target objects, underwater illumination has certain interference on an identification algorithm; the installation options of the equipment are also greatly limited; furthermore, for the above-water and underwater engineering test, the measurement of real-time is an important requirement.

Through retrieval, the chinese patent CN201810540437.2 discloses a distributed analysis-based high-speed video measurement method for multi-layer frame earthquake-resistant experiments, which comprises the following steps: 1) constructing a distributed stereo photogrammetry network and acquiring a structure sequence image; 2) and tracking and matching a target point on the structure to be detected by adopting a distributed type parallel processing strategy through a distributed type stereo photogrammetry network, resolving the three-dimensional space coordinates of the target point sequence image through the adjustment of a light beam method, and further calculating the vibration parameters of the resolved target point. Compared with the prior art, the method has the advantages of reducing data processing time, improving processing efficiency and the like. However, the method only considers deformation measurement of the target object on the water, and does not consider factors such as actual underwater measurement illumination, limited acquisition of high-speed video sequences and the like.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a method for realizing an overwater and underwater integrated distributed high-speed video measurement system.

The purpose of the invention can be realized by the following technical scheme:

an implementation method of an overwater and underwater integrated distributed high-speed video measurement system comprises the following steps:

step 1) a networking method of a distributed high-speed video sensor, which adopts multi-node data storage and transmission and is used for acquiring a high-speed video image sequence of a target structure;

and step 2) a distributed high-speed sequence image target identification and three-dimensional reconstruction method adopts distributed parallel computation and is used for analyzing dynamic deformation parameters of a target structure in the obtained high-speed video image sequence.

Preferably, the distributed high-speed video sensor networking in the step 1) comprises a high-speed imaging system, a synchronous control system, a high-speed acquisition and storage system and a lighting system; the high-speed imaging system is combined with the lighting system to collect high-speed video sequence images of a target structure, the high-speed video sequence images are stored through the high-speed collecting and storing system, and the synchronous control system is used for transmitting and processing high-speed sequence image information.

Preferably, the high-speed imaging system comprises high-speed cameras, the synchronous control system comprises industrial personal computers and a main control computer, the main control computer is connected with each industrial personal computer, and each industrial personal computer corresponds to one high-speed camera.

Preferably, the distributed high-speed video sensor networking method in the step 1) comprises setting up a three-layer node control, wherein the three-layer node control comprises the following parts:

11) the high-speed camera is a layer of nodes and collects high-speed sequence images of the target object at different shooting visual angles;

12) the industrial personal computer is a two-layer node and stores high-speed sequence images acquired by the plurality of high-speed cameras in real time;

13) the main control computer is three layers of nodes and displays and manages the high-speed sequence images of the industrial control computers;

the main control machine completes the processes of communication control, target identification, stereo matching, three-dimensional reconstruction and deformation analysis; each industrial personal computer synchronously finishes data acquisition and storage and sequence image matching tasks; and the transmission of processing instructions and the transmission of data results between the main control computer and the industrial control computer are executed through a distributed data transmission network and a synchronous control network.

Preferably, the distributed data transmission network specifically includes: the exchanger is connected with the main control machine and each industrial control machine through a data connecting line to transmit data and instructions in real time.

Preferably, the synchronization control network specifically includes: the synchronous controller is respectively connected with the main control computer and each industrial control computer through a synchronous control line to transmit synchronous control signals, and each high-speed camera synchronously stores high-speed sequence images.

Preferably, the distributed high-speed sequence image target identification and three-dimensional reconstruction method comprises high-speed video measurement sequence image processing, high-speed video measurement space geometric analysis and structural deformation parameter estimation which are sequentially carried out.

Preferably, the high-speed video measurement sequence image processing is used for acquiring sequence image coordinates of a target point with the same name, and specifically comprises automatic target identification and positioning, multi-target stereo matching and target tracking and matching.

Preferably, the target tracking and matching adopts a distributed parallel processing method.

Preferably, the high-speed video measurement space geometric analysis is used for obtaining deformation parameter estimation of the target object, including high-speed camera calibration, camera pose estimation and three-dimensional reconstruction processes.

Compared with the prior art, the invention has the following advantages:

1) the method for realizing the overwater and underwater integrated distributed high-speed video measurement system realizes the distributed processing and high-precision three-dimensional deformation calculation of the overwater and underwater high-speed sequence images, and synchronously improves the efficiency and the precision;

2) the method for realizing the overwater and underwater integrated distributed high-speed video measurement system is not only suitable for the overwater target, but also suitable for the accurate deformation measurement of the underwater target, meets the structural accurate measurement of overwater and underwater engineering tests, can realize the high-precision measurement of deformation parameters such as instantaneous three-dimensional point coordinates, displacement, speed, acceleration and the like of rigid body and flexible body structural objects in different places, and has stronger applicability;

2) the framework of the distributed high-speed video measurement system provided by the invention meets the deformation monitoring requirement of a large-scale structure, the multi-node data storage and transmission distributed sensor networking method realizes the real-time storage and management of multi-camera high-speed image sequences, the constructed data transmission network realizes the real-time transmission of data and instructions, and the constructed synchronous control network enables all joint-measuring cameras to synchronously store high-speed sequence images;

4) a distributed computing method is adopted to complete a field resolving task, a main control computer is utilized to complete algorithm steps such as communication control, target identification, stereo matching, three-dimensional reconstruction and deformation analysis, and all the industrial control computers synchronously complete data acquisition and storage and sequence image matching tasks, so that the high-speed image processing efficiency is improved.

Drawings

FIG. 1 is a method for implementing an overwater and underwater integrated distributed high-speed video measurement system;

FIG. 2 is a method for networking an overwater and underwater integrated distributed high-speed video sensor;

FIG. 3 illustrates a distributed high-speed video sensor networking and data processing task collaborative division of work;

FIG. 4 is a structural dimension diagram (front view) (unit: mm) of a multi-layer frame;

FIG. 5 is a structural dimension diagram (left side view) (unit: mm) of a multi-layer frame;

FIG. 6 is an original image captured by a multi-layer frame vibration table experimental environment-high speed camera;

FIG. 7 is a graph of displacement time course of a target tracking point;

FIG. 8 is a graph of velocity time course of a target tracking point;

FIG. 9 is a graph of acceleration time course of a target tracking point;

fig. 10 is a graph of the vibration spectrum of the target tracking point.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

The embodiment is directed to the requirement of precise measurement of a structure of an overwater and underwater engineering experiment, and the implementation method of the overwater and underwater integrated distributed high-speed video measurement system provided by the invention is used for carrying out deformation measurement analysis on a multilayer frame structure vibration table and realizing high-precision measurement on deformation parameters such as instantaneous three-dimensional point coordinates, displacement, speed, acceleration and the like of rigid body and flexible body structural objects, and specifically comprises the following aspects:

1) experimental background and model

The frame structure is a structure in which a plurality of beams and columns are connected by reinforcing bars to bear the entire load of a house. In recent years, multi-storey frame structures have become more conventional building structures because large civil and industrial buildings cannot be built solely with brick walls to meet load bearing requirements. The frame model of the experiment is a double-cylinder 5-layer reinforced concrete core cylinder structure, and the scale of the model is 1/5. As shown in FIGS. 4 and 5, the model has a plan size of 2420mm x 1620mm, an elevation height of 4500mm (300 mm without base plate), and a layer height of 900mm for all five-layer frames.

2) Video measurement network deployment

In the distributed high-speed video measurement network layout, six high-speed cameras surround the whole frame to shoot the vibration process of the frame, wherein every two high-speed cameras form a pair of stereo observation. The experiment used a model CL600X2 camera, manufactured by Optronis, germany, which captured images of 1280 × 1024 pixels in size and at a frame rate of 200 fps. To enlarge the measurement field of view, each high-speed camera is equipped with a 20mm fixed-focus lens to increase the angle of view, and is mounted on a tripod to be kept in a stable and stationary state. On the target structure, a circular artificial target with a diameter of 50mm is uniformly stuck on the key measuring points of the structure model. Each layer selects a target tracking point to measure its dynamic variation. In addition, in the control network, the control points are uniformly stuck on the stable scaffolding around the model. The three dimensional spatial seating of these stable control points will be provided by a NET05AX total station, which is able to provide point location measurement accuracy better than 0.5 mm.

3) Technical scheme

As shown in fig. 1, the framework for integrated distributed high-speed video measurement on water and underwater provided by the invention comprises two parts, namely a networking method of integrated distributed high-speed video sensors on water and underwater and a target identification and three-dimensional reconstruction method of integrated distributed high-speed sequence images on water and underwater.

As shown in fig. 2 and fig. 3, the distributed high-speed video sensor networking method refers to an optical measurement hardware building method around a target structure, and is mainly used for obtaining a high-quality image sequence of the target structure. The distributed sensor networking method for multi-node data storage and transmission is provided for the deformation monitoring requirement of a large structure, and real-time storage and management of multi-camera high-speed image sequences are achieved.

As shown in fig. 2, in the distributed sensor networking scheme, three layers of node control are set up:

1) the high-speed camera is a layer of nodes and collects high-speed sequence images of the target object at different shooting visual angles;

2) the industrial personal computer is a two-layer node and stores high-speed sequence images acquired by the plurality of high-speed cameras in real time;

3) the main control computer is three layers of nodes and displays and manages the high-speed sequence images of the industrial control computers.

The three layers of nodes respectively complete image capture, image storage and image control, and real-time storage and management of high-speed sequence images are realized.

And a data transmission network and a synchronous control network are established among the nodes of each layer to uniformly manage and coordinate tasks such as image acquisition, data storage, data transmission, data processing and the like.

The data transmission network is constructed by connecting an exchanger with a main control computer and each industrial control computer through a data connecting line, and the main function of the data transmission network is to realize real-time transmission of data and instructions.

The synchronous control network is constructed by connecting a synchronous controller with a master control machine and each industrial control machine through a synchronous control line respectively, and the main function of the synchronous control network is to transmit synchronous control signals so that each joint measuring camera can synchronously store high-speed sequence images.

The method mainly aims to analyze dynamic deformation parameters of a target structure from a high-speed image sequence, and relates to contents of high-speed video measurement sequence image processing, high-speed video measurement space geometric analysis, structural deformation parameter estimation and the like.

In the high-speed video measurement data processing, the matching process of mass sequence images is the most time-consuming, and the traditional centralized post-processing method needs to copy the sequence image data of each industrial personal computer for centralized calculation, so that a large amount of time is consumed, and the requirement of field processing cannot be met. To avoid the cumbersome steps and time consumption of data copying, distributed computing methods are proposed herein to accomplish the field solution task.

As shown in fig. 3, the main control computer and the industrial control computer are all small computers, and have certain complex computing power. The main control computer completes the algorithm steps of communication control, target identification, stereo matching, three-dimensional reconstruction, deformation analysis and the like, and each industrial control computer completes the tasks of data acquisition and storage and sequence image matching.

In the task division mechanism, a plurality of computing nodes (industrial personal computers) synchronously complete the sequence image matching task, so that the high-speed image processing efficiency is improved. And finally, the transmission of processing instructions and the transmission of data results between the main control computer and the industrial computer are executed through a distributed data transmission network.

The networking method of the distributed high-speed video sensor mainly comprises the design of an overwater and underwater high-speed imaging system, the design of a high-speed acquisition and storage system, the design of a synchronous control system, the design of a lighting system, the layout scheme of a video measurement network and the like.

The method mainly aims to analyze dynamic deformation parameters of a target structure from a high-speed image sequence, and relates to contents of high-speed video measurement sequence image processing, high-speed video measurement space geometric analysis, structural deformation parameter estimation and the like.

3) Results and analysis of the experiments

The average back projection error of the high-speed camera in the image space is about 0.05-0.1 pixel through the calibration of the high-speed camera. In order to evaluate the space point position measurement accuracy of the distributed high-speed video measurement method, the control point can be divided into two parts, one part is used as a stable control point to participate in adjustment calculation of a beam method, and the other part is used as a check point to participate in accuracy evaluation. As shown in table 1, in the high-speed video measurement, three-dimensional coordinates of the check points can be reconstructed by the forward intersection algorithm, and the three-dimensional coordinates of the check points can be directly measured and acquired by the high-precision total station. The results of the two measurement modes were analyzed in comparison, and the root mean square error of the coordinate difference was 0.29mm, 0.18mm and 0.20mm in the X, Y and Z directions, respectively. Therefore, through the precision evaluation, the millimeter-scale point position measurement precision can meet the precision requirement of the experiment.

TABLE 1 coordinate deviation between calculated value of high-speed video measurement method and measured value of high-precision total station

In this experiment, seismic waves in the Y direction were input into the vibration table. Fig. 7 shows the displacement results of the target tracking points of different layers in the Y direction (main direction), and these displacement time course curves describe the three-dimensional morphological response of the structure during the vibration process. As shown in fig. 8 and 9, the velocity and acceleration time-course curves of the target tracking point can be obtained by time-series analysis. From the results, it can be seen that the spatial motion trends of the target tracking points of the respective layers are almost the same. Further, as shown in fig. 10, by further performing spectrum analysis on the displacement data, it was obtained that the main vibration frequency of the present experiment was about 1.42 Hz. Therefore, based on the distributed high-speed video measurement method provided by the text, the obtained structural deformation result can provide an important basis for subsequent structural mechanics analysis.

The embodiment introduces the application of the overwater and underwater integrated distributed high-speed video measurement method in the dynamic monitoring of a multi-layer frame structure, and verifies the robustness of the high-speed video measurement method in the three-dimensional vibration response monitoring. In this embodiment, six high-speed cameras with a frame rate of 200fps are able to observe dynamic changes in the target structure synchronously. Compared with the measurement result of a high-precision total station, the high-speed video measurement method provided by the invention can provide the positioning precision of the sub-millimeter-level point. In addition, the displacement, the speed, the acceleration and the vibration frequency spectrum of the target tracking point can be obtained through the structural deformation parameter estimation, and the three-dimensional dynamic response in the structural vibration process is reflected in detail. Experimental results show that the overwater and underwater integrated distributed high-speed video measurement method is a reliable measurement method for monitoring a large-scale structure vibration table experiment.

While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.