CN105354854A - Camera parameter dynamic united calibration method and system based on three-dimensional digital model - Google Patents

Abstract

The invention discloses a method and system for dynamic joint calibration of camera parameters based on a three-dimensional digital model. First, a high-precision three-dimensional digital model of a substation is established, and a visible light binocular camera and an infrared thermal imager camera are respectively installed in the substation to be monitored through mounting frames. secondly, two kinds of cameras are used to take the video photos of the substation site, and all the photos are transmitted to the image processor GPU through Ethernet, and finally the key points on the photos are compared with the three-dimensional coordinates of the corresponding key points on the three-dimensional digital model. For comparison, according to the results of the comparison, the parameters of the visible light binocular camera and the infrared thermal imaging camera are calibrated. The present invention utilizes the three-dimensional model and the image captured in real time to realize the dynamic calibration of the internal and external parameters of the camera, and solves the impact of changes in the internal and external parameters of the camera due to temperature, environment, etc. Very concise and efficient.

Description

Method and system for dynamic joint calibration of camera parameters based on 3D digital model

Technical field:

The invention relates to a camera calibration method, in particular to a camera parameter dynamic joint calibration method and system based on a three-dimensional digital model.

Background technique:

In applications such as multi-spectral photogrammetry, remote sensing, and target monitoring, in order to comprehensively obtain the spectral radiation information of an object, a method of multi-spectral joint measurement is often adopted. Among them, the visible light camera can obtain rich texture information, while the infrared thermal imager can obtain temperature information. Therefore, the joint measurement of visible light camera and infrared camera has been widely used. When the infrared camera and the visible light camera do not share the same lens or the same optical path, it is necessary to strictly calibrate their internal camera parameters and their relative position and attitude. The geometric model parameters that determine the relationship between the three-dimensional geometric position of a point on the surface of a space object and its corresponding point in the image are camera parameters. The process of using the calibration device and calibration method to determine these parameters is called camera calibration. Using the same calibration device and calibration method to determine the parameters of infrared and visible light cameras at the same time is called joint calibration. Using the camera parameters obtained through joint calibration, the spatial reference of the infrared thermal imager and the camera can be unified, and the foundation for multi-spectral fusion and joint measurement can be established.

Traditional camera calibration is carried out in the laboratory. In fact, after the camera is installed on site, the internal and external parameters of the camera will change due to the influence of the environment and temperature, which will affect the accuracy of visual measurement. Therefore, a In the method of on-site dynamic calibration, the internal and external parameters of the camera are regularly calibrated to ensure the measurement accuracy of the camera.

Invention content:

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method and system for dynamic joint calibration of camera parameters based on a three-dimensional digital model that is reasonable in design, easy to implement, and capable of simultaneously calibrating two cameras.

Technical scheme of the present invention is:

A method for dynamic joint calibration of camera parameters based on a three-dimensional digital model, comprising the following steps:

a. Establish a high-precision three-dimensional digital model of the substation, and set the visible light binocular camera and the infrared thermal imaging camera through the mounting bracket at the positions that need to be monitored in the substation;

b. Use the visible light binocular camera and the infrared thermal imager camera to take video photos of the substation site, and transmit all the photos to the image processor GPU through Ethernet, and the image processor GPU and the central processing unit CPU are connected to each other;

c. Compare the key points on the photo with the three-dimensional coordinates of the corresponding key points on the three-dimensional digital model, and perform parameter calibration on the visible light binocular camera and the infrared thermal imager camera according to the comparison results, so as to realize the joint dynamic parameters of the two cameras calibration.

The key points are equipment intersections, equipment signs, equipment clamps, casing tops, poles or towers; the comparison results and camera parameter adjustment results are transmitted to the host computer and personal information terminal respectively through the wireless communication network.

The visible light binocular camera and the infrared thermal imager camera are respectively arranged on the mounting frame, or are installed together on the same mounting frame; the high-precision three-dimensional digital model of the substation constitutes a standard library, and the standard library and the central processing unit CPU connect.

The mounting frame is a fixed structure, or a rotating structure capable of rotating in a vertical plane, or a rotating structure capable of rotating both in a vertical plane and in a horizontal plane.

The rotary structure includes an arc-shaped plate or an arc-shaped rack, and the arc-shaped plate or an arc-shaped rack is respectively connected with a fastening bolt or a gear of a driving motor.

A dynamic joint calibration system for camera parameters based on a three-dimensional digital model, including a visible light binocular camera, an infrared thermal imaging camera, an image processor GPU, and a central processing unit CPU. The visible light binocular camera and the infrared thermal imaging camera are installed The racks are respectively set on the on-site positions that need to be monitored in the substation. The images captured by the visible light binocular camera and the infrared thermal imaging camera are transmitted to the image processor GPU through Ethernet, and the image processor GPU is connected to the central The processor CPU is connected, and the central processing unit CPU compares the key points on the photo with the three-dimensional coordinates of the corresponding key points on the high-precision three-dimensional digital model of the substation, and compares the visible light binocular camera and the infrared thermal imager camera according to the result of the comparison. Perform parameter calibration to realize the joint calibration of the dynamic parameters of the two cameras.

The key points are equipment intersections, equipment signs, equipment clamps, casing tops, poles or towers; the comparison results and camera parameter adjustment results are transmitted to the host computer and personal information terminal respectively through the wireless communication network.

The visible light binocular camera and the infrared thermal imaging camera are respectively arranged on the mounting frame, or are installed together on the same mounting frame; the high-precision three-dimensional digital model of the substation constitutes a standard library, and the standard library and the described Central processing unit CPU connection.

The mounting frame is a fixed structure, or a rotating structure capable of rotating in a vertical plane, or a rotating structure capable of rotating both in a vertical plane and in a horizontal plane.

The rotary structure includes an arc-shaped plate or an arc-shaped rack, and the arc-shaped plate or an arc-shaped rack is respectively connected with a fastening bolt or a gear of a driving motor.

The beneficial effects of the present invention are:

1. The present invention utilizes the three-dimensional model and the images captured in real time to realize the dynamic calibration of the internal and external parameters of the camera, solve the impact on the equipment due to changes in the internal and external parameters of the camera due to temperature, environment, etc., and use the feature points on the three-dimensional model as marker points , the operation is very simple and efficient.

2. The present invention dynamically calibrates the camera in actual operation, and can also correct the camera pose. After taking enough photos, the center of the key point is used as the positioning point of the image point and the object point. Since the three-dimensional model corresponds to The actual coordinates of the object point are also known, so the current camera calibration method can be used to obtain the camera parameters of the visible light camera and the infrared thermal imager to improve the measurement accuracy.

3. The present invention can not only run in real time, but also can run at a certain cycle frequency, such as running a dynamic calibration once a week to determine the internal and external parameters of visible light and infrared cameras, which is convenient to use.

4. The fixing methods of the two cameras of the present invention can be either fixed installation, rotating installation in the vertical plane, or rotating installation in both the vertical plane and the horizontal plane, so as to achieve all-round monitoring and shooting and improve monitoring precision.

5. The rotation of the mounting frames of the two cameras of the present invention can be operated manually or electrically, and the electric operation can also be remotely controlled, which is convenient and quick.

6. The invention is reasonable in design, easy to implement, can calibrate two kinds of cameras at the same time, and reduces measurement accuracy errors caused by changes in internal and external parameters of the cameras after the cameras are deployed on site. It has a wide range of applications, is easy to popularize and implement, and has good economic benefits.

Description of drawings:

Figure 1 is a schematic structural diagram of a dynamic joint calibration system for camera parameters based on a three-dimensional digital model;

Fig. 2 is one of the structures of the mounting frame of the visible light binocular camera or the infrared thermal imager camera in Fig. 1;

Fig. 3 is the second structure of the mounting frame of the visible light binocular camera or the infrared thermal imaging camera in Fig. 1 .

detailed description:

Embodiment: See Fig. 1-Fig. 3, among the figure, 1-visible light binocular camera, 2-Ethernet, 3-image processor GPU, 4-standard library, 5-central processing unit CPU, 6-display, 7- Keyboard, 8-wireless communication network, 9-personal information terminal, 10-host computer, 11-infrared thermal imaging camera, 12-vertical frame, 13-hinge shaft, 14-clamp, 15-locking bolt, 16-arc Shaped plate, 17-horizontal frame, 18-turning disc, 19-base, 20-drive motor, 21-curved rack.

The dynamic joint calibration system of camera parameters based on a three-dimensional digital model includes a visible light binocular camera 1, an infrared thermal imaging camera 11, an image processor GPU and a central processing unit CPU, wherein: the visible light binocular camera 1 and the infrared thermal imaging camera 11 pass through The mounting brackets are respectively set on the sites where the substation needs to be monitored. The images captured by the visible light binocular camera 1 and the infrared thermal imaging camera 11 are transmitted to the image processor GPU through the Ethernet 2, and the image processor GPU is connected to the central processing unit CPU. , the central processing unit CPU compares the key points on the photo with the three-dimensional coordinates of the corresponding key points on the high-precision three-dimensional digital model of the substation, and performs parameter calibration on the visible light binocular camera 1 and the infrared thermal imager camera 11 according to the comparison result, Realize joint calibration of dynamic parameters of two kinds of cameras.

The key points are equipment intersections, equipment signs, equipment clamps, casing tops, benchmarks or towers; the results of the comparison and camera parameter adjustment are transmitted to the host computer 10 and the personal information terminal 9 through the wireless communication network 8 respectively.

Visible light binocular camera 1 and infrared thermal imager camera 11 are respectively installed on the mounting frame, or are installed together on the same mounting frame; the high-precision three-dimensional digital model of the substation forms a standard library 4, and the standard library 4 is connected to the central processing unit CPU.

The mounting frame is a fixed structure, or a rotating structure that can rotate in a vertical plane (as shown in Figure 2), or a rotating structure that can rotate in both a vertical plane and a horizontal plane (Figure 3 shown).

The rotary structure includes an arc-shaped plate 16 or an arc-shaped rack 21 , and the arc-shaped plate 16 or arc-shaped rack 21 is respectively connected with the fastening bolt 15 or the gear of the driving motor 20 .

When working, first establish a high-precision three-dimensional digital model of the substation to form a standard library 4, and then set the visible light binocular camera 1 and the infrared thermal imaging camera 11 respectively on the positions that need to be monitored in the substation through the mounting bracket; then use the visible light binocular camera 1 and the infrared thermal imager camera 11 respectively take video photos of the substation site, and transmit all the photos to the image processor GPU through the Ethernet 2, and the image processor GPU and the central processing unit CPU are connected to each other; finally, the key points on the photos are compared with the The three-dimensional coordinates of the corresponding key points on the three-dimensional digital model are compared, and the parameters of the visible light binocular camera and the infrared thermal imaging camera are calibrated according to the comparison results, and the joint calibration of the dynamic parameters of the two cameras is realized.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still belong to within the scope of the technical solutions of the present invention.

Claims (10)

1. A method for dynamic joint calibration of camera parameters based on a three-dimensional digital model, comprising the following steps: a. Establish a high-precision three-dimensional digital model of the substation, and set the visible light binocular camera and the infrared thermal imaging camera through the mounting bracket at the positions that need to be monitored in the substation; b. Use the visible light binocular camera and the infrared thermal imager camera to take video photos of the substation site, and transmit all the photos to the image processor GPU through Ethernet, and the image processor GPU and the central processing unit CPU are connected to each other; c. Compare the key points on the photo with the three-dimensional coordinates of the corresponding key points on the three-dimensional digital model, and perform parameter calibration on the visible light binocular camera and the infrared thermal imager camera according to the comparison results, so as to realize the joint dynamic parameters of the two cameras calibration. 2. The dynamic joint calibration method of camera parameters based on a three-dimensional digital model according to claim 1, wherein the key point is an intersection of equipment, equipment signs, equipment clamps, casing tops, benchmarks or towers; The comparison results and camera parameter adjustment results are transmitted to the host computer and the personal information terminal respectively through the wireless communication network. 3. The dynamic joint calibration method of camera parameters based on a three-dimensional digital model according to claim 1, wherein the visible light binocular camera and the infrared thermal imager camera are respectively arranged on a mounting frame, or are installed together on the same installation on the shelf; the high-precision three-dimensional digital model of the substation constitutes a standard library, and the standard library is connected to the central processing unit CPU. 4. The dynamic joint calibration method of camera parameters based on a three-dimensional digital model according to claim 3, characterized in that: the mounting frame is a fixed structure, or a rotating structure capable of rotating in a vertical plane, or a A rotary structure that can rotate both in the vertical plane and in the horizontal plane. 5. The dynamic joint calibration method of camera parameters based on a three-dimensional digital model according to claim 4, wherein the rotating structure includes an arc-shaped plate or an arc-shaped rack, and the arc-shaped plate or arc-shaped rack They are respectively connected with the fastening bolts or the gears of the drive motor. 6. A camera parameter dynamic joint calibration system based on a three-dimensional digital model, comprising a visible light binocular camera, an infrared thermal imager camera, an image processor GPU and a central processing unit CPU, characterized in that: the visible light binocular camera and the infrared camera The cameras of the thermal imager are respectively arranged on the on-site positions that need to be monitored in the substation through the installation frame, and the images captured by the visible light binocular camera and the infrared thermal imager camera are transmitted to the image processor GPU through Ethernet, and the image processing The device GPU is connected to the central processing unit CPU, and the central processing unit CPU compares the key points on the photo with the three-dimensional coordinates of the corresponding key points on the high-precision three-dimensional digital model of the substation, and compares the visible light binocular camera according to the result of the comparison. Perform parameter calibration with the infrared thermal imaging camera to realize the joint calibration of the dynamic parameters of the two cameras on site. 7. The dynamic joint calibration system of camera parameters based on a three-dimensional digital model according to claim 6, characterized in that: the key point is an intersection of equipment, equipment signs, equipment clamps, casing tops, benchmarks or towers; The comparison results and camera parameter adjustment results are transmitted to the host computer and the personal information terminal respectively through the wireless communication network. 8. The dynamic joint calibration system of camera parameters based on a three-dimensional digital model according to claim 6, characterized in that: the visible light binocular camera and the infrared thermal imaging camera are respectively set on the mounting frame, or are installed together on the on the same installation frame; the high-precision three-dimensional digital model of the substation constitutes a standard library, and the standard library is connected to the central processing unit CPU. 9. The dynamic joint calibration system of camera parameters based on a three-dimensional digital model according to claim 6, characterized in that: the mounting frame is a fixed structure, or a rotating structure capable of rotating in a vertical plane, or a A rotary structure that can rotate both in the vertical plane and in the horizontal plane. 10. The dynamic joint calibration system of camera parameters based on a three-dimensional digital model according to claim 9, wherein the rotating structure includes an arc-shaped plate or an arc-shaped rack, and the arc-shaped plate or arc-shaped rack They are respectively connected with the fastening bolts or the gears of the drive motor.