Optical field-of-view calibration device for pipeline

Abstract

The utility model discloses an optical field calibration device for a pipeline, which comprises a connecting body, a plurality of calibration bodies and two cameras, the connecting body is used for connecting the inner wall of the pipeline, at least one first calibration surface is formed on the surface of the connecting body, the plurality of calibration bodies are distributed in an array mode along the center line of the connecting body and are all detachably connected with the connecting body, and the two cameras are arranged on the connecting body. A second calibration surface is formed on the surface of the calibration body, the color of the second calibration surface is different from that of the first calibration surface, and the two cameras are arranged on the two sides of the pipeline, are arranged opposite to the connector and are used for focusing and calibrating the connector. According to the utility model, the problem of low measurement precision caused by the fact that the result of the calibration outside the pipeline and then the test experiment is easily influenced by the external environment in the prior art can be effectively solved.

Description

Technical Field

[0001] The utility model relates to the technical field of camera calibration, in particular to an optical field calibration device for pipelines. Background Art

[0002] Three-dimensional Particle Image Velocimetry (PIV) is a non-invasive flow field measurement technology, which is crucial for measuring the variation law of the flow field in pipelines.

[0003] However, most of the current calibration methods are to use a calibration plate in an open space for calibration outside the pipeline and then conduct a test experiment. Such a measurement environment is easily affected by the outside world and changes. At the same time, the curvature of the circular pipeline will cause optical distortion, thus affecting the calibration structure and resulting in low measurement accuracy.

[0004] Therefore, there is an urgent need for an optical field calibration device for pipelines to solve the problem that the results of the existing technology, which first calibrate outside the pipeline and then conduct a test experiment, are easily affected by the external environment, resulting in low measurement accuracy. Summary of the Utility Model

[0005] The purpose of the utility model is to overcome the above technical deficiencies and propose an optical field calibration device for pipelines to solve the technical problem that the results of the existing technology, which first calibrate outside the pipeline and then conduct a test experiment, are easily affected by the external environment, resulting in low measurement accuracy.

[0006] To achieve the above technical purpose, the utility model adopts the following technical solutions:

[0007] In a first aspect, the utility model provides an optical field calibration device for pipelines, including:

[0008] A connecting body for connecting the inner wall of the pipeline, and at least one first calibration surface is formed on the surface of the connecting body;

[0009] A plurality of calibration bodies, which are arranged in an array along the center line of the connecting body and are all detachably connected to the connecting body. A second calibration surface is formed on the surface of the calibration body, and the color of the second calibration surface is different from that of the first calibration surface; and

[0010] Two cameras, which are arranged on both sides of the pipeline relative to the connecting body and are used for focusing and calibrating the connecting body and the plurality of calibration bodies.

[0011] In some embodiments, the color of the first calibration surface is black, and the color of the second calibration surface is white.

[0012] In some embodiments, the connector is disc-shaped, the axis of the pipeline is collinear with the axis of the connector, and the cross-sectional area of the connector is equal to the cross-sectional area of the inner section of the pipeline.

[0013] In some embodiments, the number of the calibration bodies is nine, and the nine calibration bodies are distributed in a 3×3 array along the center line of the connector.

[0014] In some embodiments, the connector is provided with nine calibration holes, the calibration bodies are cylindrical and elastic, the calibration bodies are arranged in one-to-one correspondence with the calibration holes, and the calibration bodies are elastically clamped in the calibration holes.

[0015] In some embodiments, the length of the calibration body is equal to the depth of the calibration hole.

[0016] In some embodiments, the material of the calibration body is polyethylene plastic.

[0017] In some embodiments, the optical field calibration device for pipelines further includes an optical correction box, and the optical correction box is arranged opposite to the connector.

[0018] In some embodiments, the fluid medium in the optical correction box is the same as that in the pipeline.

[0019] In some embodiments, both side walls of the connector can form the first calibration surface.

[0020] Compared with the prior art, the beneficial effects of the optical field calibration device for pipelines provided by the present utility model include: a connector and a plurality of calibration bodies, the plurality of calibration bodies are connected to the inner wall of the pipeline through the connector, and the plurality of calibration bodies are distributed in an array along the center line of the connector, wherein at least one first calibration surface is formed on the connector, a second calibration surface is formed on the calibration body, and there is a color difference between the color of the second calibration surface and the color of the first calibration surface. Two cameras are respectively distributed on both sides of the pipeline opposite to the connector for focusing and calibrating the connector and the plurality of calibration bodies. Compared with the prior art, in this device, the calibration bodies are arranged inside the pipeline and are connected to the inner wall of the pipeline through the connector. The binocular cameras are used to focus and calibrate the connector and the calibration bodies. The color difference between the first calibration surface on the connector and the second calibration surface on the calibration body is used to assist the binocular cameras to complete the precise calibration of the pipeline cross-section, and it can solve the technical problem that in the prior art, the results of calibration outside the pipeline and then testing experiments are easily affected by the external environment, resulting in low measurement accuracy. Description of the Drawings

[0021] Figure 1 is a schematic diagram of an optical field calibration device for pipelines provided by an embodiment of the present utility model;

[0022] Figure 2 It is a cross-sectional schematic diagram of the connection of the pipeline, the connecting body and the calibration body provided by the embodiment of the present utility model;

[0023] Figure 3 It is a schematic diagram of the connecting body provided by the embodiment of the present utility model;

[0024] Figure 4 It is a schematic diagram of the calibration body provided by the embodiment of the present utility model.

[0025] Explanation of the reference numerals in the drawings:

[0026] Connecting body 1;

[0027] First calibration surface 11;

[0028] Calibration body 2;

[0029] Second calibration surface 21;

[0030] Camera 3;

[0031] Pipeline 4;

[0032] Optical correction box 5. Specific implementation manners

[0033] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0034] In order to solve the technical problem that in the prior art, the results of calibration outside the pipeline and then testing experiments are easily affected by the external environment, resulting in low measurement accuracy, the present utility model provides an optical field calibration device for pipelines, which can achieve accurate calibration when using three-dimensional PIV technology to measure the internal flow field of circular pipelines.

[0035] It should be noted that the optical field calibration device for pipelines described in the present utility model is used in but not limited to the technical field of camera calibration, etc. For the convenience of description, in the present utility model, only the case where the optical field calibration device for pipelines is applied to the technical field of camera calibration is taken as an example for description, and the principle of the optical field calibration device for pipelines applied to other types of equipment is substantially the same as that applied to the technical field of camera calibration, and will not be elaborated herein one by one.

[0036] Please refer to Figures 1 to 4 , Figure 1The figure is a schematic structural diagram of an optical field calibration device for pipelines in an embodiment of the present utility model. An optical field calibration device for pipelines includes: a connecting body 1, a plurality of calibration bodies 2, and two cameras 3. The connecting body 1 is used to connect to the inner wall of the pipeline 4. At least one first calibration surface 11 is formed on the surface of the connecting body 1. The plurality of calibration bodies 2 are distributed in an array along the central axis of the connecting body 1 and are all detachably connected to the connecting body 1. A second calibration surface 21 is formed on the surface of the calibration body 2, and there is a color difference between the color of the second calibration surface 21 and that of the first calibration surface 11. The two cameras 3 are arranged on both sides of the pipeline 4 and are both arranged relative to the connecting body 1 for focusing and calibrating the connecting body 1.

[0037] In this device, the connecting body 1 and the plurality of calibration bodies 2 are such that the plurality of calibration bodies 2 are connected to the inner wall of the pipeline 4 via the connecting body 1, and the plurality of calibration bodies 2 are distributed in an array along the central axis of the connecting body 1. At least one first calibration surface 11 is formed on the connecting body 1, and a second calibration surface 21 is formed on the calibration body 2, and there is a color difference between the color of the second calibration surface 21 and that of the first calibration surface 11. The two cameras 3 are respectively distributed on both sides of the pipeline 4 relative to the connecting body 1 for focusing and calibrating the connecting body 1 and the plurality of calibration bodies 2.

[0038] Compared with the prior art, in this device, the calibration body 2 is arranged inside the pipeline 4 and is connected to the inner wall of the pipeline 4 through the connecting body 1. The binocular cameras 3 are used to focus and calibrate the connecting body 1 and the calibration body 2. The color difference between the first calibration surface 11 on the connecting body 1 and the second calibration surface 21 on the calibration body 2 is utilized to assist the binocular cameras 3 to complete the precise calibration of the cross-section of the pipeline 4, which can solve the technical problem in the prior art that the result of calibration outside the pipeline 4 and then testing is easily affected by the external environment, resulting in low measurement accuracy.

[0039] Furthermore, this device is also assisted by a laser. The laser, the camera 3, and the focusing calibration are all conventional settings well-known to those skilled in the art and will not be elaborated further.

[0040] In this embodiment, the color of the first calibration surface 11 is black, and the color of the second calibration surface 21 is white.

[0041] By respectively setting the colors of the first calibration surface 11 and the second calibration surface 21 to black and white with obvious color differences, it is beneficial to improve the calibration accuracy.

[0042] In one of the embodiments, please refer to Figure 2 、 Figure 3 , the connecting body 1 is in a disc shape, the axis of the pipeline 4 is collinear with the axis of the connecting body 1, and the cross-sectional area of the connecting body 1 is equal to the cross-sectional area of the inner section of the pipeline 4.

[0043] By providing a connecting body 1 in the shape of a disc, and making the cross-sectional area of the connecting body 1 equal to the inner cross-sectional area of the pipe 4, the connecting body 1 can be clamped to the inner wall of the pipe 4.

[0044] In another embodiment, please refer to Figure 3 , the number of the calibration bodies 2 is nine, and the nine calibration bodies 2 are distributed in a 3×3 array along the center line of the connecting body 1.

[0045] The 3×3 array distribution is used to improve the calibration accuracy.

[0046] In another embodiment, please refer to Figure 3 , Figure 4 , the connecting body 1 is provided with nine calibration holes, the calibration bodies 2 are cylindrical and elastic, the calibration bodies 2 are arranged in one-to-one correspondence with the calibration holes, and the calibration bodies 2 are elastically clamped in the calibration holes.

[0047] The calibration bodies 2 and the connecting body 1 are elastically clamped through the calibration holes and the elastic calibration bodies 2 to realize the detachable connection between the calibration bodies 2 and the connecting body 1.

[0048] As a preferred embodiment, the length of the calibration body 2 is equal to the depth of the calibration hole.

[0049] The length of the calibration body 2 is equal to the depth of the calibration hole so that the surface of the calibration body 2 and the connecting body 1 remains flat after the calibration body 2 is inserted into the calibration hole.

[0050] Specifically, in this device, the calibration holes penetrate through the two side walls of the connecting body 1, the calibration bodies 2 are clamped in the calibration holes, and the height of the calibration bodies 2 is equal to the depth of the calibration holes.

[0051] In this embodiment, the material of the calibration body 2 is polyethylene plastic.

[0052] In this embodiment, this device further includes an optical correction box 5, and the optical correction box 5 is arranged opposite to the connecting body 1.

[0053] By providing the optical correction box 5 outside the pipe 4, the optical distortion of the circular pipe 4 on the calibration plate can be prevented.

[0054] As a preferred embodiment, the fluid medium in the optical correction box 5 is the same as that in the pipe 4.

[0055] During the calibration process, both the correction box and the inside of the pipe 4 are filled with the same kind of liquid.

[0056] Furthermore, when testing the gaseous flow field in the pipe, calibration can be directly carried out without installing an additional correction box.

[0057] Wherein, as another preferred embodiment, both side walls of the connecting body 1 can form the first calibration surface 11.

[0058] Further, the camera 3 focuses on the surface of the calibration plate illuminated by the laser, captures the boundary position coordinates of the bottom surface of the white polyethylene plastic cylinder (i.e., the white characteristic circle), and obtains and converts the positions through the positions of the cameras 3 at different angles, thereby completing the calibration.

[0059] To better understand the present invention, the technical solution of the present invention will be described in detail below with reference to the drawings: a connecting body 1 and a plurality of calibration bodies 2, the plurality of calibration bodies 2 are connected to the inner wall of the pipeline 4 through the connecting body 1, and the plurality of calibration bodies 2 are arranged in an array along the center line of the connecting body 1. At least one first calibration surface 11 is formed on the connecting body 1, and a second calibration surface 21 is formed on the calibration body 2, and a color difference is formed between the color of the second calibration surface 21 and the color of the first calibration surface 11. Two cameras 3 are respectively distributed on both sides of the pipeline 4 relative to the connecting body 1 for focusing and calibrating the connecting body 1 and the plurality of calibration bodies 2. Compared with the prior art, the device sets the calibration body 2 in the pipeline 4, forms a connection with the inner wall of the pipeline 4 through the connecting body 1, uses the binocular cameras 3 to focus and calibrate the connecting body 1 and the calibration body 2, and uses the color difference between the first calibration surface 11 on the connecting body 1 and the second calibration surface 21 on the calibration body 2 to assist the binocular cameras 3 to complete the precise calibration of the cross-section of the pipeline 4.

[0060] The specific working process of the present invention is as follows: when in use, the calibration body 2 is connected to the connecting body 1 and is built into the pipeline 4 through the connecting body 1. Under the auxiliary action of the laser, the camera 3 focuses on the surface of the calibration plate illuminated by the laser, captures the boundary position coordinates of the bottom surface of the white polyethylene plastic cylinder (i.e., the white characteristic circle), and obtains and converts the positions through the positions of the cameras 3 at different angles, thereby completing the calibration.

[0061] Through the above structure, the device can solve the technical problem in the prior art that the result of calibration outside the pipeline 4 and then testing and experimenting is easily affected by the external environment, resulting in low measurement accuracy.

[0062] The above specific embodiments of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An optical field calibration device for a pipeline, characterized in that: include: A connector, used to connect to the inner wall of the pipeline, wherein at least one first calibration surface is formed on the surface of the connector; a plurality of calibration bodies, the plurality of calibration bodies are distributed in an array along the center line of the connecting body and are all detachably connected to the connecting body, a second calibration surface is formed on the surface of the calibration body, and the color of the second calibration surface is different from the color of the first calibration surface; and Two cameras are arranged on two sides of the pipeline relative to the connecting body, and are used for focusing and calibrating the connecting body and the plurality of calibration bodies.

2. The optical field calibration device for pipelines according to claim 1, characterized in that: The first calibration surface is black, and the second calibration surface is white.

3. The optical field calibration device for pipelines according to claim 2, characterized in that: The connector is disc-shaped, the axis of the pipeline is colinear with the axis of the connector, and the cross-sectional area of ​​the connector is equal to the cross-sectional area of ​​the inner section of the pipeline.

4. The optical field calibration device for pipelines according to claim 3, characterized in that: The number of the calibration bodies is nine, and the nine calibration bodies are distributed in a 3×3 array along the center line of the connector.

5. The optical field calibration device for pipelines according to claim 4, characterized in that: The connecting body is provided with nine calibration holes. The calibration body is cylindrical and elastic. The calibration bodies are arranged in one-to-one correspondence with the calibration holes, and the calibration bodies are elastically clamped in the calibration holes.

6. The optical field calibration device for pipelines according to claim 5, characterized in that: The length of the calibration body is equal to the depth of the calibration hole.

7. The optical field of view calibration device for pipelines according to claim 6, characterized in that: The material of the calibration body is polyethylene plastic.

8. The optical field calibration device for pipelines according to claim 7, characterized in that: It also includes an optical correction box, which is arranged relative to the connector.

9. The optical field of view calibration device for pipelines according to claim 8, characterized in that: The optical correction box and the fluid medium in the pipeline are the same.

10. The optical field calibration device for pipelines according to claim 9, characterized in that: Both side walls of the connector can form the first calibration surface.

Images