CN113654476B - Irradiation-resistant underwater deformation vision measurement unit and measurement method - Google Patents

Abstract

The invention provides a radiation-resistant underwater deformation vision measurement unit and a measurement method, comprising: an image acquisition module and a laser module, the outer side is shielded from nuclear radiation by a tungsten alloy shielding layer; after the data lines of the image acquisition module and the laser module are integrated It is connected to the external controller through a watertight connector; the reflective part used to ensure the effective working distance of the measuring unit; the base used to install the image acquisition module and the laser module; the shell that is connected with the base to form a sealed space, the image acquisition module, the laser module And the reflective parts are located in the sealed space, wherein two reflective parts are located near both ends of the sealed space, and the image acquisition module and the laser module are located between the two reflective parts. The invention not only has anti-irradiation performance, but also has the effect of deep water waterproofing. It is installed on the stainless steel connecting pipe through the clamp connection block, and integrates multiple sets of visual measurement units, so that the transient non-contact deformation of the fuel assembly in deep water and irradiation environment can be carried out. Measurement.

Description

Irradiation-resistant underwater deformation vision measurement unit and measurement method

technical field

The invention relates to the field of deformation measurement of nuclear power plant fuel assemblies, in particular to a non-contact visual measurement unit and measurement method based on the principle of double-light knife line laser triangulation.

Background technique

The fuel assembly is composed of control rod, upper tube seat, upper grid, guide tube, fuel rod, middle grid, lower grid, lower tube seat and other components. It is the core component of nuclear energy system to generate energy. It works at high temperature for a long time , high pressure, high radiation circulating water, affected by many factors such as assembly stress and thermal stress, prone to bending deformation, twisting deformation, etc., when the deformation is serious, it will affect the normal insertion of fuel rods and endanger the safe operation of the reactor.

In order to ensure the safety in the process of nuclear energy development, nuclear power plants need to conduct regular maintenance operations on the fuel assemblies and other components in the core, and assess whether the deformation is within a safe range through the test results, so as to remind the staff to replace the fuel assemblies in time. Because the fuel assembly works in the radiation environment for a long time, the contact measurement method for it will be greatly restricted, which urgently requires the non-contact detection technology of the fuel assembly.

In foreign countries, the visual measurement unit developed and designed by Swedish Mabema company based on the principle of single-light knife line laser triangulation mainly includes industrial cameras, lenses, lasers, housings, etc. The measurement system adopts a modular design concept, and 8 sets of visual measurement units are installed in the pipeline to align. When the fuel assembly and the measurement system are suspended, the system measures the fuel assembly in about 3 seconds, and then rotates 90 degrees three times to complete the four-sided measurement of the fuel assembly. The total time is about 40 seconds, and the overall accuracy is better than 0.5mm, but the measurement accuracy of this measuring unit is low, and the measurement efficiency needs to be improved.

Domestically, the binocular radiation-resistant camera module designed by the Institute of Optoelectronic Technology of the Chinese Academy of Sciences mainly includes four parts: radiation-resistant lens, sensor, control transmission unit and mechanical main body. However, the underwater camera module based on binocular vision has higher requirements for camera calibration, the epipolar geometric constraints are no longer accurate, the measurement distance is short, and the measurement accuracy is low.

SUMMARY OF THE INVENTION

In view of the defects in the prior art, the purpose of the present invention is to provide a radiation-resistant underwater deformation visual measurement unit and a measurement method, which have certain radiation-resistant performance and deep-water waterproof effect, and can carry out deep-water and irradiation environments for fuel assemblies. The transient non-contact deformation measurement under the control of the nuclear power plant helps the nuclear power plant to regularly perform maintenance operations on the fuel assemblies and other components in the core, and assists in screening and judging the safety risk level of the fuel assemblies.

A first aspect of the present invention provides a radiation-resistant underwater deformation vision measurement unit, comprising:

Laser module, the module emits two laser stripes, and the outer side is shielded from nuclear radiation by a tungsten alloy shielding layer;

an image acquisition module, which collects the calibration plate image and the laser stripe image of the laser module for camera calibration and light plane calibration, and the outside of the image acquisition module is shielded from nuclear radiation by a tungsten alloy shielding layer; the image After the data lines of the acquisition module and the laser module are integrated, they are connected to the external controller through watertight connectors;

a reflection part, which is used to reflect the laser stripes of the laser module and the camera field of view of the image acquisition module, so as to ensure the effective working distance of the measurement unit;

a base for installing and fixing the image acquisition module, the laser module and the reflection component;

a shell, which is matched and connected with the base to form a sealed space, the image acquisition module, the laser module and the reflective component are located in the sealed space, wherein the two reflective components are located near the two ends of the sealed space, The image acquisition module and the laser module are located between the two reflection parts.

Preferably, the angle between the reflection part near the image acquisition module and the base is 75°, and the angle between the reflection part near the laser module and the base is 45°.

Preferably, the image acquisition module adopts an industrial camera, a lens and an optical filter are mounted on the industrial camera, and the industrial camera is mounted on a camera support frame; the outer sides of the industrial camera, the lens and the optical filter pass through a tungsten alloy The shielding layer performs nuclear radiation shielding.

Preferably, the laser module includes two lasers, the lasers are installed on a laser fixing block, the laser fixing block is fixed on the laser support frame, and the outer sides of the laser and the laser fixing block are shielded by a tungsten alloy shielding layer. Radiation shielding; one of the industrial cameras and two of the lasers constitute a dual-knife line laser triangulation.

Preferably, the reflecting component adopts a silver-coated mirror, two silver-coated mirrors are respectively fixed on the camera support frame and the laser support frame, the camera support frame and the base have an angle of 75°, and the laser The angle between the support frame and the base is 45° to ensure the effective working distance of the industrial camera and the laser.

Preferably, the radiation-resistant underwater deformation vision measurement unit further comprises: a sealing member, the sealing member is located between the base and the casing, and is used to ensure the sealing connection between the two.

Preferably, the radiation-resistant underwater deformation vision measurement unit further comprises: lead glass, the lead glass is embedded in the outer casing of the vision measurement unit and pressed by a lead glass fixing frame.

A second aspect of the present invention provides a measurement method for a fuel assembly grid or base, which is realized by the above-mentioned radiation-resistant underwater deformation visual measurement unit, including:

The laser modules of multiple groups of vision measurement units emit laser stripes at the same time, and after being reflected by the reflective parts, they are projected onto the fuel assembly grid or base;

The image acquisition modules of multiple groups of visual measurement units are reflected by the reflective parts at the same time to capture and obtain laser fringe images;

Perform image segmentation and optical center extraction on the captured laser fringe image to obtain upper and lower laser fringe centers;

Based on the underwater multi-medium refraction model and the upper and lower light plane equations, 3D reconstruction is performed to obtain the 3D point cloud data of the fuel assembly grid or base, which is used for subsequent bending and torsional deformation calculations to realize the measurement of the fuel assembly grid or base.

Compared with the prior art, the embodiments of the present invention have at least one of the following beneficial effects:

The above-mentioned measuring unit and measuring method of the present invention use a reflective component, two lasers, and an industrial camera to cooperate, benefiting from the design and installation of a reflective structure and the principle of laser triangulation with a double-beam knife line, which can realize a long measurement distance and high measurement accuracy. Measurement is fast.

The measurement unit and measurement method provided above in the present invention have certain radiation resistance and deep water waterproof effect, and can be used for transient non-contact deformation measurement of fuel assemblies in deep water and irradiation environments.

The above-mentioned measuring unit and measuring method of the present invention can help the nuclear power station to regularly perform maintenance operations on the fuel assemblies and other components in the core, and assist in screening and judging the safety risk level of the fuel assemblies.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

1 is a schematic structural diagram of an underwater deformation vision measurement unit in a preferred embodiment of the present invention;

2 is a schematic diagram of the tungsten alloy shielding layer of the underwater deformation visual measurement unit in a preferred embodiment of the present invention;

3 is a front view of the structure of the underwater deformation vision measurement unit in a preferred embodiment of the present invention;

4 is a top view of the structure of the underwater deformation vision measurement unit in a preferred embodiment of the present invention;

In the figure: 11 is an industrial camera, 12 is a lens, 13 is a filter, 14 is a camera support frame, 21 is a laser, 22 is a laser fixing block, 23 is a laser support frame, 31 is a base, 32 is a mechanical seal, 4 is a watertight connector, 5 is a reflector, 61 is a shell, 62 is a lead glass, 63 is a lead glass fixing frame, and 7 is a tungsten alloy shielding layer.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

As shown in FIG. 1 to FIG. 4 , it is the radiation-resistant underwater deformation vision measurement unit according to the embodiment of the present invention. Specifically, it includes: an image acquisition module, a laser module, a reflection component, a base and a casing, wherein: the laser module emits There are two laser stripes, and the outer side is shielded from nuclear radiation by the tungsten alloy shielding layer 7; the image acquisition module collects the calibration plate image and the laser stripe image emitted by the laser module, and transmits it to the computer through the data line for camera calibration and light plane calibration, and the outer side passes through The tungsten alloy shielding layer 7 performs nuclear radiation shielding; the data lines of the image acquisition module and the laser module are integrated and connected to the external controller through the watertight connector 4; the reflection part reflects the laser stripes of the laser module and the camera field of view of the image acquisition module, so Ensure the effective working distance of the measuring unit; preferably, the angle between the reflection part near the image acquisition module and the base 31 is 75°, and the angle between the reflection part near the laser module and the base 31 is 45°; the base 31 is used to install a fixed image The acquisition module, the laser module and the reflective part; the housing 61 and the base 31 are cooperatively connected to form a sealed space, the image acquisition module, the laser module and the reflective part are located in the sealed space, wherein the two reflective parts are located near the two ends of the sealed space, The image acquisition module and the laser module are located between the two reflective parts.

The visual measurement unit of the above-mentioned embodiment of the present invention adopts the principle of double-knife line laser triangulation, and integrates one industrial camera 11 and two lasers 21, which has certain radiation resistance and deep water waterproof effect, and can be used for deep water of fuel assemblies. , Transient non-contact deformation measurement in irradiation environment.

In this embodiment, the image acquisition module adopts an industrial camera 11, the lens 12 and the filter 13 are mounted on the industrial camera 11, the industrial camera 11 is mounted on the camera support frame 14; the industrial camera 11, the lens 12 and the filter 13 are mounted After forming a whole, a tungsten alloy shielding layer 7 is arranged on the outer periphery of the whole, and the whole is wrapped inside to shield the nuclear radiation.

1 and 2, in this embodiment, the laser module includes two lasers 21, the two lasers 21 are mounted on the laser fixing block 22, the laser fixing block 22 is fixed on the laser support frame 23, the lasers 21 and After the laser fixing block 22 is installed, it forms a whole, and a tungsten alloy shielding layer 7 is arranged on the outer periphery of the whole, and the whole is wrapped in it for nuclear radiation shielding; an industrial camera 11 and two lasers 21 form a double-knife line laser triangulation measurement . In a specific embodiment, after the lens 12 and the filter 13 are installed on the industrial camera 11, they are fixed to the camera support frame 14 through screw connections, and the outside is shielded from nuclear radiation by a customized tungsten alloy shielding layer 7; the two lasers 21 pass through The screw connection is installed on the laser fixing block 22, the laser fixing block 22 is fixed to the laser support frame 23 by screw connection, and the outer side is shielded by the tungsten alloy shielding layer 7 for nuclear radiation shielding; 4 Connect to an external controller. Further, the camera support frame 14 and the laser support frame 23 are fixed on the base 31 , and the reflection component adopts two silver-coated mirrors 5 , and the two silver-coated mirrors 5 are respectively fixed on the camera support frame 14 and the laser support frame 23 .

3 and 4, in a preferred embodiment, the vision measurement unit further includes: lead glass 62 and a lead glass fixing frame 63, two pieces of lead glass 62 are embedded in the vision measurement unit casing 61 and fixed by the lead glass The frame 63 is pressed tightly, and it has a certain degree of anti-radiation performance while ensuring that the industrial camera and the laser are sealed and light-transmitting.

In order to better achieve the sealing effect, in one embodiment, the base 31 is grooved, the mechanical sealing ring 32 is placed in the groove, the mechanical sealing ring 32 is used for physical sealing, and the base 31 and the shell 61 are fastened by screw connection, so as to ensure the sealing Effect. Specifically, the casing 61 and the base 31 are made of corrosion-resistant stainless steel processed by an electropolishing process, which can effectively reduce the retention of pollutants.

In some embodiments, the industrial camera 11 adopts Basler's acA1920-48gm area scan camera model, with a resolution of 2.3 million pixels, a pixel size of 4.8 μm, and a frame rate of 50fps, and the lens 12 adopts Ricoh's FL-CC1614-2M fixed-focus lens model. The focal length is 16mm. The laser 21 is a red laser with a wavelength of 650 nm and a power of 150 mW. Of course, in other embodiments, other types of industrial cameras and lasers may also be used.

In some embodiments, two pieces of lead glass 62 with a thickness of 5 mm are embedded in the casing 61 of the vision measurement unit, and are pressed by the lead glass fixing frame 63 . Of course, in other embodiments, lead glass with other thicknesses can also be used.

In some embodiments, two silver-coated mirrors 5 with a thickness of 2 mm are respectively fixed to the camera support frame 14 and the laser support frame 23 to emit laser stripes emitted by the laser 21 to ensure the working field of view of the industrial camera 11 . Of course, in other embodiments, silver-coated mirrors with other thicknesses may also be used.

The underwater working distance of the visual measurement unit in the above-mentioned embodiments of the present invention can be 900±100 mm, the measurement distance is long, the measurement accuracy is high, and the measurement speed is fast.

In the above-mentioned embodiment of the present invention, the industrial camera 11 and the laser 21 are isolated by the tungsten alloy shielding layer 7, and the industrial camera 11 and the laser 21 are installed by means of a reflective structure design. , projected onto the calibration plate, the post-industrial camera 11 is reflected by the mirror 5 and passed through the lead glass 62 to capture and obtain the laser fringe image for subsequent computer processing. The visual measurement unit can reduce the loss of nuclear radiation to the electronic components while ensuring the working field of view of the electronic components.

In the above-mentioned embodiment of the present invention, the mechanical sealing ring 32 is used for physical sealing, and the deep waterproof watertight connector 4 is used to connect the external controller. The visual measurement unit can satisfy the deep water waterproof effect for a certain period of time.

In another embodiment, the present invention employs the visual measurement unit of the above-described embodiments to perform measurements on fuel assembly grids or bases. Among them, before the measurement, the visual measurement unit is installed to the stainless steel connecting pipe through the clamp connection block, and multiple sets of visual measurement units are integrated to measure the fuel assembly grid or base within the underwater working distance range. The specific number of visual measurement unit groups is determined according to the specific size, quantity and measurement requirements of the actually measured fuel assembly grid or base.

During the measurement, the lasers 21 of the multiple groups of visual measurement units simultaneously emit laser stripes, which are reflected by the reflector 5, pass through the lead glass 62, and project to the fuel assembly grid or base. Then, the industrial cameras 11 of the multiple groups of visual measurement units are reflected by the mirror 5 at the same time, and then pass through the lead glass 62 to capture and obtain the laser fringe image. Then, image segmentation and optical center extraction are performed on the captured laser fringe image to obtain the upper and lower laser fringe centers. Finally, 3D reconstruction is performed based on the underwater multi-media refraction model and the upper and lower light plane equations, and the 3D point cloud data of the fuel assembly grid or base is obtained for subsequent bending and torsional deformation calculations to achieve final measurement.

The above embodiment of the present invention not only has certain radiation resistance performance, but also has certain deep water waterproof effect. It is installed to the stainless steel connecting pipe through the clamp connection block, and integrates multiple sets of visual measurement units, so that the fuel assembly can be carried out in deep water and irradiation environment. Transient non-contact deformation measurement.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and those skilled in the art can make various variations or modifications within the scope of the claims, which do not affect the essential content of the present invention. The above-mentioned preferred features can be used in any combination as long as they do not conflict with each other.

Claims (8)

1. a radiation-resistant underwater deformation vision measurement unit, is characterized in that, comprises: Laser module, the module emits two laser stripes, and the outer side is shielded from nuclear radiation by a tungsten alloy shielding layer; an image acquisition module, which collects the calibration plate image and the laser stripe image of the laser module for camera calibration and light plane calibration, and the outside of the image acquisition module is shielded from nuclear radiation by a tungsten alloy shielding layer; the image After the data lines of the acquisition module and the laser module are integrated, they are connected to the external controller through watertight connectors; a reflection part, which is used to reflect the laser stripes of the laser module and the camera field of view of the image acquisition module, so as to ensure the effective working distance of the measurement unit; a base for installing and fixing the image acquisition module, the laser module and the reflection component; a shell, which is matched and connected with the base to form a sealed space, the image acquisition module, the laser module and the reflective component are located in the sealed space, wherein the two reflective components are located near the two ends of the sealed space, The image acquisition module and the laser module are located between the two reflection parts; The angle between the reflection part near the image acquisition module and the base is 75°, and the angle between the reflection part near the laser module and the base is 45°; It also includes: lead glass, the lead glass is embedded in the outer casing of the vision measurement unit, and is pressed by the lead glass fixing frame; The measuring unit adopts the principle of double-knife line laser triangulation, and integrates one industrial camera and two lasers. It has anti-irradiation performance and deep water waterproof effect. deformation measurement; The reflecting component adopts two silver-coated reflecting mirrors. 2. The radiation-resistant underwater deformation vision measurement unit according to claim 1, wherein the image acquisition module adopts an industrial camera, a lens and a filter are installed on the industrial camera, and the industrial camera is installed on the camera support frame; the industrial camera, the lens and the optical filter form a whole after being installed, and a tungsten alloy shielding layer is arranged on the outer periphery of the whole, and the whole is wrapped inside for nuclear radiation shielding. 3. The radiation-resistant underwater deformation vision measurement unit according to claim 2, wherein the laser module comprises two lasers, and the lasers are installed on a laser fixing block, and the laser fixing block is fixed on the laser fixing block. On the laser support frame, the laser and the laser fixing block form a whole after being installed, and a tungsten alloy shielding layer is arranged on the outer periphery of the whole, and the whole is wrapped inside for nuclear radiation shielding; one of the industrial cameras and two The lasers constitute a double-knife line laser triangulation. 4. The radiation-resistant underwater anamorphic vision measurement unit according to claim 3, wherein the reflecting member adopts a silver-coated mirror, and two silver-coated mirrors are respectively fixed on the camera support frame and the camera support frame. On the laser support frame, the included angle between the camera support frame and the base is 75°, and the included angle between the laser support frame and the base is 45°, so as to ensure the effective working distance of the industrial camera and the laser. 5. The radiation-resistant underwater deformation visual measurement unit according to any one of claims 1-4, characterized in that, further comprising: a sealing member, the sealing member is located between the base and the housing, Used to ensure a sealed connection between the two. 6. A radiation-resistant underwater deformation vision measurement method is characterized in that, using the radiation-resistant underwater deformation vision measurement unit described in any one of claims 1-5 to realize, comprising: The laser modules of multiple groups of vision measurement units emit laser stripes at the same time, and after being reflected by the reflective parts, they are projected onto the fuel assembly grid or base; The image acquisition modules of multiple groups of visual measurement units are reflected by the reflective parts at the same time to capture and obtain laser fringe images; Perform image segmentation and optical center extraction on the captured laser fringe image to obtain upper and lower laser fringe centers; Based on the underwater multi-medium refraction model and the upper and lower light plane equations, 3D reconstruction is performed to obtain the 3D point cloud data of the fuel assembly grid or base, which is used for subsequent bending and torsional deformation calculations to realize the measurement of the fuel assembly grid or base. 7. The radiation-resistant underwater deformation visual measurement method according to claim 6, wherein the visual measurement unit is installed on the stainless steel connecting pipe through the clamp connection block, and multiple groups of visual measurement units are integrated to be installed in the water. Measure the fuel assembly grid or base within the lower working distance. 8. The radiation-resistant underwater deformation vision measurement method according to claim 7 is characterized in that, the laser modules of multiple groups of vision measurement units emit laser stripes at the same time, and after being reflected by the reflective component, pass through lead glass and project to the surface. fuel assembly grids or bases; The image acquisition modules of multiple sets of visual measurement units are reflected by the reflective components at the same time, and pass through the lead glass to capture and obtain the laser fringe image.

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