Underwater non-contact measurement device and method for inner surface defects of pressure vessels

Abstract

The invention discloses an underwater non-contact measurement device and method for inner surface defects of pressure vessels, the device comprises: a power supply component; a mechanical arm; a probe frame component; a data processing component; a laser three-dimensional probe comprises a support shell capable of shielding, a laser for generating laser, a three-dimensional receiving camera and several cameras for collecting reflected lasers, and a control circuit for controlling the laser, the receiving camera and several cameras, the laser, the three-dimensional receiving camera, the camera and the control circuit are all installed in the support shell, and the angle between the laser emitted by the laser and the center line of the three-dimensional receiving camera is 45°-80°. The data measurement has high accuracy and good detail restoration; it is dustproof and moisture-proof, and has good compatibility with different water environments; it has an anti-radiation shielding design to prevent radiation damage to cameras and other equipment; it has a high degree of automation, reduces the radiation dose of personnel and the large workload of underwater operations; and overcomes the problems of refraction and scattering in underwater measurement.

Description

Technical Field

[0001] The invention belongs to the field of nuclear power detection equipment, and in particular relates to an underwater non-contact measurement device and method for inner surface defects of a pressure vessel. Background Art

[0002] The reactor pressure vessel is one of the most important main equipment in the nuclear island. Whether it can maintain a good condition is the key to the safe and reliable operation of the nuclear power plant. The reactor may cause scratches on the inner wall of the vessel during operation and refueling maintenance in the nuclear power plant, which may cause safety hazards during the service of the pressure vessel. There are two main difficulties in evaluating and measuring the scratch defects on the inner surface of the pressure vessel: underwater operations and high radioactive environments.

[0003] At present, the commonly used method is to observe and take pictures of the inner surface of the pressure vessel through a single camera, obtain the ratio of the number of pixels and the size through the analysis of the two-dimensional picture, quantitatively analyze the defects, or use the artificial coating method to use plasticine, colloidal resin, etc. to make an impression of the defect to indirectly measure the size of the defect. However, the disadvantages of the two-dimensional image analysis method are obvious: the measurement efficiency is low, the measured size is a two-dimensional size, the accuracy is low, and the depth direction cannot be measured; and the artificial coating method: mainly has the following limitations: high requirements for operators, poor consistency of coating data; the completed impression mold is radioactive, and there are many inconveniences in further analysis and long-term storage; the inspection range is small, and only the inner wall operation very shallow below the flange surface can be performed; the safety risk is high, there is a risk of personnel falling and foreign objects falling into the reactor, and the risk of personnel being exposed to high radiation. Summary of the invention

[0004] The purpose of the present invention is to provide an underwater non-contact measuring device for inner surface defects of pressure vessels, which can solve the problems of accurate identification and precise three-dimensional measurement and analysis of internal defects of underwater pressure vessels in a nuclear radiation environment, improve detection efficiency, and has radiation protection, anti-collision protection and measurement positioning.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: an underwater non-contact measuring device for inner surface defects of a pressure vessel, comprising:

[0006] A power supply component for providing power to the device;

[0007] A data acquisition component, which is used to collect defects on the inner surface of the pressure vessel, and includes a laser three-dimensional probe;

[0008] A mechanical arm, which is used to deliver the data acquisition component to one side of the inner surface of the pressure vessel;

[0009] A probe holder assembly, which is mounted on the mechanical arm, and includes a probe for ultrasonic scanning and / or eddy current scanning, and a bracket for mounting the probe, wherein the bracket is mounted on the mechanical arm;

[0010] A data processing component, which is used to receive the data collected by the data collection component and make analysis and calculation, and includes a data analysis component and a collection control component;

[0011] The laser three-dimensional measuring head includes a shield-proof bracket shell, a laser for generating laser, a three-dimensional receiving camera and several cameras for collecting reflected laser, and a control circuit for controlling the laser, the receiving camera and the several cameras. The laser, the three-dimensional receiving camera, the camera and the control circuit are all installed in the bracket shell. The angle between the laser emitted by the laser and the center line of the three-dimensional receiving camera is 45°-80°.

[0012] Optimally, the cameras are evenly distributed around the three-dimensional receiving camera.

[0013] Optimized, the camera includes a first camera for inspecting the inner wall, bottom head and bottom penetration of the container, a second camera for video inspection of the container nozzle, and the remaining cameras are a third camera for assisting the probe to enter the container nozzle for scanning.

[0014] Optimally, an exit is provided on the side wall of the bracket shell at a position corresponding to the laser emission of the laser, and an entrance is provided on the side wall of the bracket shell at a position corresponding to the laser injection of the laser, and both the exit and the entrance are made of lead-containing radiation-proof glass.

[0015] Optimally, the exit and the entrance are arranged on the right side wall of the bracket shell, the right side wall includes a vertically arranged upper right side wall, a lower right side wall located below the upper right side wall, and a V-shaped right middle side wall connected between the upper right side wall and the lower right side wall, the right middle side wall includes an upper middle right side wall connected to the upper right side wall and inclined downward, and a lower middle right side wall connected between the upper middle right side wall and the lower right side wall, the laser is installed opposite to the exit, and the three-dimensional receiving camera and a plurality of cameras are installed opposite to the entrance.

[0016] Optimized, the length of the lower right side wall in the right direction exceeds the length of the upper right side wall in the right direction, an upper mounting ring for mounting the radiation-proof glass is provided on the entrance, a lower mounting ring for mounting the radiation-proof glass is provided on the entrance, and the vertical downward projection of the upper right side wall covers the uppermost inner side wall edge of the lower mounting ring. The upper right side wall is flush with the uppermost inner side wall edge of the lower mounting ring in the vertical direction, which can block part of the interfering light while ensuring that the three-dimensional receiving camera can normally receive the laser signal. The inward angle formed by the right middle side wall can absorb the interfering optical fiber near the three-dimensional receiving camera, further reducing the reception of the normal laser signal of the three-dimensional receiving camera by other optical fibers.

[0017] Optimally, the angle between the laser emitted by the laser and the center line of the three-dimensional receiving camera is 55°-70°.

[0018] Optimally, the laser source of the laser is a green laser source.

[0019] The present invention also provides a measurement method based on the above-mentioned measurement device, characterized in that it comprises the following steps:

[0020] a. Device connection

[0021] The laser three-dimensional probe is installed at the end of the mechanical arm of the eleven-axis reactor pressure vessel inspection machine, connected to the control computer through a network cable, and powered by a power interface reserved by the eleven-axis reactor pressure vessel inspection machine;

[0022] b. Probe calibration

[0023] Use a fixed calibration stand to place the probe and calibration block in water for calibration; the calibration block is made of ceramic material with a stable expansion coefficient and its size has been verified and certified;

[0024] c. Data collection

[0025] The eleven-axis reactor pressure vessel inspection uses a video camera to first conduct a visual inspection of the inner wall of the nuclear reaction pressure vessel, and record the coordinates of the confirmed and suspected scratch defect positions; the eleven-axis reactor pressure vessel inspection machine control system accurately sends the laser three-dimensional probe to the vertical direction of the object to be measured according to the recorded coordinate position, turns on the laser, and the laser projects the laser to the target position; the three-dimensional receiving camera is used to capture the image of the target on the inner wall of the pressure vessel after the laser is projected; the eleven-axis reactor pressure vessel inspection machine is used to control the laser three-dimensional probe to move along the central axis of the object to be measured, and to trigger the camera and the laser three-dimensional probe; each time a position is moved, a pair of laser projection images are triggered to be collected; and multiple continuous images of the target position on the inner wall of the pressure vessel are obtained;

[0026] d. Data analysis

[0027] Based on the acquired image information, the three-dimensional geometric dimensions of the pressure vessel at the target position are calculated; based on the motion coordinate parameters and cross-sectional data of the eleven-axis reactor pressure vessel inspection machine, the global measurement data of the inner wall of the pressure vessel can be spliced ​​together; based on the initial geometric parameter characteristics of the inner wall of the pressure vessel and the comparison with the global point cloud data, it can be determined whether there are defects in the area; when it is confirmed that there are defects in the area, the length and height analysis of the cross-sectional data of the area can be performed to obtain the defect size of the area.

[0028] Optimized, in step d, the three-dimensional geometric dimensions of the pressure vessel at the photographed target position are calculated using the principle of triangulation.

[0029] The beneficial effects of the present invention are: high data measurement accuracy and good detail restoration; dustproof, moisture-proof, and good compatibility with different water environments; radiation shielding design to prevent cameras and other equipment from being damaged by radiation; high degree of automation to reduce personnel exposure dose and large underwater work workload; and overcoming the problems of refraction and scattering in underwater measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the principle of the present invention;

[0031] Figure 2 It is a stereogram of the laser 3D probe;

[0032] Figure 3 This is the right view of the laser 3D probe;

[0033] Figure 4 This is the main view of the laser 3D probe;

[0034] Figure 5 It is a schematic diagram of calculation based on the principle of trigonometric method. DETAILED DESCRIPTION

[0035] The present invention is described in detail below in conjunction with the embodiments shown in the accompanying drawings:

[0036] like Figure 1 As shown, the underwater non-contact measuring device for inner surface defects of a pressure vessel comprises:

[0037] A power supply component is used to provide power to the device.

[0038] A data acquisition component is used to collect defects on the inner surface of a pressure vessel, and includes a laser three-dimensional probe 1; the laser three-dimensional probe 1 includes a support shell 2 that can prevent shielding, a laser 3 for generating laser, a three-dimensional receiving camera 4 and several cameras 5 for collecting reflected laser light, and a control circuit for controlling the laser 3, the receiving camera and the several cameras 5. The laser 3, the three-dimensional receiving camera, the camera 5 and the control circuit are all installed in the support shell 2, and the laser source of the laser 3 is a green laser source. The angle between the laser emitted by the laser 3 and the center line of the three-dimensional receiving camera 4 is 45°-80°, and the optimized angle is 55°-70°, and the optimal angle is 64°. The cameras 5 are evenly distributed around the three-dimensional receiving camera 4. The cameras 5 include a first camera 5 for inspecting the inner wall, bottom head and bottom penetration of the container, a second camera 5 for video inspection of the container nozzle, and the remaining cameras 5 are third cameras 5 for assisting the probe to enter the container nozzle for scanning. An exit is provided on the side wall of the support housing 2 at a position corresponding to the laser emission of the laser 3, and an entrance is provided on the side wall of the support housing 2 at a position corresponding to the laser emission of the laser 3, and both the exit and the entrance are made of lead-containing radiation-proof glass. The exit and the entrance are provided on the right side wall of the support housing 2, and the right side wall includes an upper right side wall 21 arranged vertically, a lower right side wall 22 located below the upper right side wall 21, and a right middle side wall 23 connected between the upper right side wall 21 and the lower right side wall 22 in a V shape, and the right middle side wall 23 includes a middle upper right side wall 231 connected to the upper right side wall and arranged obliquely downward, and a middle lower right side wall 232 connected between the middle upper right side wall 231 and the lower right side wall, and the laser 3 is installed facing the exit 211, and the three-dimensional receiving camera 4 and a plurality of cameras 5 are installed facing the entrance 221. The length of the lower right side wall 22 in the right direction exceeds the length of the upper right side wall 21 in the right direction. The entrance is provided with an upper mounting ring 212 for mounting the radiation-proof glass, and the entrance 221 is provided with a lower mounting ring 222 for mounting the radiation-proof glass. The vertical downward projection of the upper right side wall covers the uppermost inner side wall edge of the lower mounting ring 222. The upper right side wall 21 is flush with the uppermost inner side wall edge of the lower mounting ring 222 in the vertical direction, which can block part of the interfering light while ensuring that the three-dimensional receiving camera 4 can normally receive the laser signal. The angle formed by the right middle side wall 23 is inwardly drawn to absorb the interfering optical fiber near the three-dimensional receiving camera 4, further reducing the reception of the normal laser signal of the three-dimensional receiving camera 4 by other optical fibers.

[0039] The robot arm is used to deliver the data acquisition component to one side of the inner surface of the pressure vessel.

[0040] The probe holder assembly is installed on the mechanical arm, and comprises a probe for ultrasonic scanning and / or eddy current scanning, and a bracket for mounting the probe, wherein the bracket is installed on the mechanical arm.

[0041] The data processing component is used to receive the data collected by the data collection component and make analysis and calculations, and includes a data analysis component and a collection control component.

[0042] The measuring method based on the above measuring device comprises the following steps:

[0043] a. Device connection

[0044] The laser three-dimensional probe is installed at the end of the mechanical arm of the eleven-axis reactor pressure vessel inspection machine, connected to the control computer through a network cable, and powered by a power interface reserved by the eleven-axis reactor pressure vessel inspection machine;

[0045] b. Probe calibration

[0046] Use a fixed calibration stand to place the probe and calibration block in water for calibration; the calibration block is made of ceramic material with a stable expansion coefficient and its size has been verified and certified;

[0047] c. Data collection

[0048] The eleven-axis reactor pressure vessel inspection uses a video camera to first conduct a visual inspection of the inner wall of the nuclear reaction pressure vessel, and record the coordinates of the confirmed and suspected scratch defect positions; the eleven-axis reactor pressure vessel inspection machine control system accurately sends the laser three-dimensional probe to the vertical direction of the object to be measured according to the recorded coordinate position, turns on the laser, and the laser projects the laser to the target position; the three-dimensional receiving camera is used to capture the image of the target on the inner wall of the pressure vessel after the laser is projected; the eleven-axis reactor pressure vessel inspection machine is used to control the laser three-dimensional probe to move along the central axis of the object to be measured, and to trigger the camera and the laser three-dimensional probe; each time a position is moved, a pair of laser projection images are triggered to be collected; and multiple continuous images of the target position on the inner wall of the pressure vessel are obtained;

[0049] d. Data analysis

[0050] According to the acquired image information, the three-dimensional geometric dimensions of the pressure vessel at the target position are calculated using the principle of triangulation; the laser emission beam is focused on the object to be measured through the transmission mirror, and after being reflected by the inner surface of the pressure vessel, it is imaged on the three-dimensional receiving camera through the receiving lens. The movement of the object to be measured or the deformation of the surface causes the incident light point to move along the incident light axis, resulting in a displacement x' of the light point on the imaging surface. The displacement (or deformation) x of the measured surface is calculated, such as Figure 5 As shown, first, the angles α and β satisfy the following relationship: cosβ=n / x, and cosβ=cos[180°-θ-90°-α]=sinθcosα-cosθsinα. From the relationship between similar triangles, we can get: The relationship between the displacement of the 3D receiving camera surface and the actual moving distance of the object, combined with the above equations, the displacement (or deformation) x is: Wherein β is the complementary angle between the incident light of the laser on the undeformed inner wall of the pressure vessel and the reflected light reflected into the three-dimensional receiving camera, θ is the angle between the incident light of the laser on the deformed inner wall of the pressure vessel and the reflected light reflected into the three-dimensional receiving camera, α is the angle between the reflected light of the laser on the undeformed inner wall of the pressure vessel and the reflected light on the deformed inner wall of the pressure vessel, a is the distance between the reflection point of the laser on the deformed inner wall of the pressure vessel and the focus of the receiving lens of the three-dimensional receiving camera, and b is the distance between the receiving point of the reflected light of the laser on the deformed inner wall of the pressure vessel on the three-dimensional receiving camera and the focus of the receiving lens of the three-dimensional receiving camera;

[0051] The motion coordinate parameters and cross-sectional displacement of the eleven-axis reactor pressure vessel inspection machine can be spliced ​​into global measurement data of the inner wall of the pressure vessel. By comparing the initial geometric parameter characteristics of the inner wall of the pressure vessel with the global point cloud data, it can be determined whether there are defects in the area. When it is confirmed that there are defects in the area, the length and height of the cross-sectional data of the area are analyzed to obtain the defect size of the area.

[0052] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A measurement method based on an underwater non-contact measurement device for inner surface defects of a pressure vessel, the device comprising: A power supply component for providing power to the device; A data acquisition component, which is used to collect defects on the inner surface of the pressure vessel, and includes a laser three-dimensional probe; A mechanical arm, which is used to deliver the data acquisition component to one side of the inner surface of the pressure vessel; A probe holder assembly, which is mounted on the mechanical arm, and includes a probe for ultrasonic scanning and / or eddy current scanning, and a bracket for mounting the probe, wherein the bracket is mounted on the mechanical arm; A data processing component, which is used to receive the data collected by the data collection component and make analysis and calculation, and includes a data analysis component and a collection control component; The laser three-dimensional measuring head comprises a support shell capable of shielding, a laser for generating laser light, a three-dimensional receiving camera and several cameras for collecting reflected laser light, and a control circuit for controlling the laser, the receiving camera and the several cameras. The laser, the three-dimensional receiving camera, the camera and the control circuit are all installed in the support shell. The angle between the laser emitted by the laser and the center line of the three-dimensional receiving camera is 45°-80°. Characterized in that the measuring method comprises the following steps: a. Device connection The laser three-dimensional probe is installed at the end of the mechanical arm of the eleven-axis reactor pressure vessel inspection machine, connected to the control computer through a network cable, and powered by a power interface reserved by the eleven-axis reactor pressure vessel inspection machine; b. Probe calibration Use a fixed calibration stand to place the probe and calibration block in water for calibration; the calibration block is made of ceramic material; c. Data collection The eleven-axis reactor pressure vessel inspection machine uses a video camera to first visually inspect the inner wall of the nuclear reaction pressure vessel, and records the coordinates of the confirmed and suspected scratch defect positions; the control system of the eleven-axis reactor pressure vessel inspection machine accurately sends the laser three-dimensional probe to the vertical direction of the object to be measured according to the recorded coordinate position, turns on the laser, and the laser projects the laser to the target position; the three-dimensional receiving camera is used to capture the image of the target on the inner wall of the pressure vessel after the laser is projected; the eleven-axis reactor pressure vessel inspection machine is used to control the laser three-dimensional probe to move along the central axis of the object to be measured, and to trigger the camera and the laser three-dimensional probe; each time a position is moved, a pair of laser projection images are triggered to be collected; and multiple continuous images of the target position on the inner wall of the pressure vessel are obtained; d. Data analysis The three-dimensional geometric dimensions of the pressure vessel at the target position are calculated based on the acquired image information; the global measurement data of the inner wall of the pressure vessel are spliced ​​based on the motion coordinate parameters and cross-sectional data of the eleven-axis reactor pressure vessel inspection machine; the initial geometric parameter characteristics of the inner wall of the pressure vessel are compared with the global point cloud data to determine whether there is a defect at the target position; when it is confirmed that there is a defect at the target position, the length and height of the cross-section data of the target position are analyzed to obtain the defect size at the target position.

2. The measurement method based on the underwater non-contact measurement device for inner surface defects of pressure vessels according to claim 1 is characterized in that: The cameras are evenly distributed around the three-dimensional receiving camera.

3. The measurement method based on the underwater non-contact measurement device for inner surface defects of pressure vessels according to claim 2 is characterized in that: The cameras include a first camera for inspecting the inner wall, bottom head and bottom penetration of the container, a second camera for video inspection of the container nozzle, and the remaining cameras are a third camera for assisting the probe to enter the container nozzle for scanning.

4. The measurement method based on the underwater non-contact measurement device for inner surface defects of pressure vessels according to claim 1 is characterized in that: An exit is provided on the side wall of the support shell at a position corresponding to the laser emission of the laser, and an entrance is provided on the side wall of the support shell at a position corresponding to the laser injection of the laser, and both the exit and the entrance are made of lead-containing radiation-proof glass.

5. The measuring method based on the underwater non-contact measuring device for inner surface defects of pressure vessels according to claim 4 is characterized in that: The exit and the entrance are arranged on the right side wall of the bracket shell, and the right side wall includes a vertically arranged upper right side wall, a lower right side wall located below the upper right side wall, and a V-shaped right middle side wall connected between the upper right side wall and the lower right side wall. The right middle side wall includes an upper middle right side wall connected to the upper right side wall and inclined downward, and a lower middle right side wall connected between the upper middle right side wall and the lower right side wall. The laser is installed facing the exit, and the three-dimensional receiving camera and a plurality of cameras are installed facing the entrance.

6. The measurement method based on the underwater non-contact measurement device for inner surface defects of pressure vessels according to claim 5 is characterized in that: The length of the lower right side wall in the right direction exceeds the length of the upper right side wall in the right direction, an upper mounting ring for mounting the radiation-proof glass is provided on the outlet, and a lower mounting ring for mounting the radiation-proof glass is provided on the entrance, and a vertical downward projection of the upper right side wall covers the uppermost inner wall edge of the lower mounting ring.

7. The measuring method based on the underwater non-contact measuring device for inner surface defects of pressure vessels according to claim 5 is characterized in that: The angle between the laser emitted by the laser and the center line of the three-dimensional receiving camera is 55°-70°.

8. The measurement method based on the underwater non-contact measurement device for inner surface defects of pressure vessels according to claim 5 is characterized in that: The laser source of the laser is a green laser source.

9. The method according to claim 1, characterized in that: In step d, the three-dimensional geometric dimensions of the pressure vessel at the photographed target position are calculated using the principle of triangulation.

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