Underwater multifunctional detection device for reactor in-vessel core plate and positioning method

Abstract

The application discloses a reactor in-core component core upper plate underwater multifunctional detection device and a positioning method. The detection device comprises an omnidirectional moving chassis and an action mechanism detachably carried on the omnidirectional moving chassis. The action mechanism comprises a video lifting inspection module, a fuel positioning pin verticality inspection module, an in-situ ultrasonic inspection module of the fuel positioning pin and the split pin, and a pin hole emergency inspection module. The detection device is used for video imaging inspection of components in the core upper plate area through the video lifting inspection module, measures the inclination angle of the fuel positioning pin through the fuel positioning pin verticality inspection module, detects defects in the typical failure area of the split pin and potential cracks in the thread area and the light rod area of the fuel positioning pin through the in-situ ultrasonic inspection module of the fuel positioning pin and the split pin, and realizes in-situ emergency inspection of the pin hole of the core upper plate through the pin hole emergency inspection module, thereby solving the industry problem that there is a lack of comprehensive detection means in the core upper plate area.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of in-service inspection of reactor internals of nuclear power plants, and in particular to a reactor internals core deck underwater multifunctional detection device and positioning method. BACKGROUND

[0002] The existing video detection of the core deck related components of nuclear power plants mainly uses long rod type tools to carry cameras for video detection from the periphery of the upper internals, however, the cotter nuts, support column bolts, and fuel positioning pin nuts are located inside the core deck, and there are a large number of unreachable areas; the patent CN107731329B needs to add high internals to implement cotter ultrasonic inspection; the fuel positioning pin is positioned by observing the video to check the neatness of the pin arrangement, but it cannot measure the suspected inclined target, nor can it detect internal potential cracks.

[0003] In terms of robot positioning, the detection robot of the patent CN107731329B only realizes local positioning of a single target, and the macro positioning of the robot still needs manual judgment; the patent CN113917920B performs robot positioning and map construction based on VSLAM, but under the condition that the internals are not added, the height space is narrow, the camera field of view is limited, and it is difficult to implement; the patent CN117649956A realizes in-situ emergency inspection of the pin hole, but uses laser radar to realize positioning, but the laser attenuates quickly underwater, and cannot overcome the problem of long-distance positioning. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a reactor internals core deck underwater multifunctional detection device and positioning method.

[0005] The technical solution adopted by the present application to solve the technical problem is: a reactor internals core deck underwater multifunctional detection device is constructed, which comprises an omnidirectional mobile chassis and an action mechanism detachably carried on the omnidirectional mobile chassis, the action mechanism comprises a video lifting inspection module, a fuel positioning pin perpendicularity inspection module, a fuel positioning pin and cotter in-situ ultrasonic inspection module, and a pin hole emergency inspection module;

[0006] The video lifting inspection module is used for video imaging inspection of the components in the core deck area;

[0007] The fuel positioning pin perpendicularity inspection module is used for measuring the inclination angle of the fuel positioning pin;

[0008] The fuel positioning pin and cotter in-situ ultrasonic inspection module is used for detecting defects in the typical failure area of the cotter and potential cracks in the intersection area of the fuel positioning pin thread area and the light rod area;

[0009] The pin hole emergency inspection module is used for realizing in-situ emergency inspection of the pin hole of the upper core plate.

[0010] In some embodiments, the omnidirectional mobile chassis comprises a base body, a positioning camera assembly mounted on the base body, and a radiation sensor built in the base body, the positioning camera assembly comprising an optical zoom high-definition camera module, a camera rotating motor, and an encoder.

[0011] The base body adopts a hollow design and is provided with a plurality of watertight joints.

[0012] The optical zoom high-definition camera module is used for capturing images of column members in the upper core plate area through zoom adjustment; and the camera rotating motor is used for driving the optical zoom high-definition camera module to rotate.

[0013] The encoder is used for recording the rotation angle of the optical zoom high-definition camera module.

[0014] The radiation sensor is used for collecting the radiation dose rate of the underwater detection environment.

[0015] In some embodiments, the video lifting inspection module comprises, in sequence, a base, a first video lifting translation driving module, a second video lifting translation driving module, a video lifting lifting module, a telescopic mounting rack, and a gimbal camera.

[0016] The first video lifting translation driving module is mounted on the base, and is used for driving the gimbal camera to move along the width direction of the base.

[0017] The second video lifting translation driving module is used for driving the gimbal camera to move along the length direction of the base.

[0018] The video lifting lifting module and the telescopic mounting rack are used for driving the gimbal camera to move along the height direction of the base.

[0019] The gimbal camera is mounted on the telescopic mounting rack, and is used for video imaging inspection of members in the upper core plate area.

[0020] In some embodiments, the gimbal camera is sealed by an organic glass cover, and the outer side of the gimbal camera is arranged with an annular underwater light belt.

[0021] In some embodiments, the fuel positioning pin perpendicularity inspection module comprises a positioning table, a first perpendicularity inspection translation driving module, a second perpendicularity inspection translation driving module, a first perpendicularity inspection lifting module, a second perpendicularity inspection lifting module, a perpendicularity inspection rotating module, a perpendicularity mounting seat, and a plurality of perpendicularity detection sensors connected in sequence.

[0022] The first perpendicularity inspection translation driving module is installed on the positioning table, and is used to drive the plurality of perpendicularity detection sensors to move along the width direction of the positioning table.

[0023] The second perpendicularity inspection translation driving module is used to drive the plurality of perpendicularity detection sensors to move along the length direction of the positioning table.

[0024] The first perpendicularity inspection lifting module and the second perpendicularity inspection lifting module are used to drive the plurality of perpendicularity detection sensors to move along the height direction of the positioning table.

[0025] The perpendicularity inspection rotating module is used to drive the plurality of perpendicularity detection sensors to rotate.

[0026] The plurality of perpendicularity detection sensors are installed on the perpendicularity mounting seat.

[0027] In some embodiments, the perpendicularity detection sensors are LVDT sensors, the number of the LVDT sensors is eight, and the eight LVDT sensors are installed on the perpendicularity mounting seat in two layers, and the LVDT sensors in each layer are arranged uniformly along the circumferential direction of the perpendicularity mounting seat.

[0028] In some embodiments, the fuel positioning pin and split pin in-situ ultrasonic inspection module comprises a support table, a first ultrasonic inspection translation driving module, a second ultrasonic inspection translation driving module, a first ultrasonic inspection lifting module, a second ultrasonic inspection lifting module, an ultrasonic inspection rotating module, and an ultrasonic detection probe connected in sequence.

[0029] The first ultrasonic inspection translation driving module is installed on the support table, and is used to drive the ultrasonic detection probe to move along the width direction of the support table.

[0030] The second ultrasonic inspection translation driving module is used to drive the ultrasonic detection probe to move along the length direction of the support table.

[0031] The first ultrasonic inspection lifting module and the second ultrasonic inspection lifting module are used to drive the ultrasonic detection probe to move along the height direction of the support table.

[0032] The ultrasonic inspection rotating module is used to drive the ultrasonic detection probe to rotate.

[0033] In some embodiments, the ultrasonic testing probe is a four-element ultrasonic probe or a positioning pin ultrasonic probe.

[0034] In this embodiment, a positioning method for an underwater multi-functional detection device for the reactor core upper plate of reactor internal components is also constructed, which is applied to the underwater multi-functional detection device for the reactor core upper plate of reactor internal components, and includes the following steps:

[0035] S1. System initialization and parameter calibration: Establish the global coordinate system of the reactor core upper plate, input the global coordinate information of the column in the operation scene into the software in advance, calibrate the core optical parameters of the optical zoom high-definition camera module, initialize the motion axis of the optical zoom high-definition camera module to be consistent with the forward direction of the omnidirectional moving chassis, control the omnidirectional moving chassis to move to the center of the reactor core upper plate and face the 0° direction of the component pool, and perform initial position calibration.

[0036] S2. Adaptive visual scanning and feature extraction: The camera rotation motor drives the optical zoom high-definition camera module to perform a 360° continuous scan of the workspace. After identifying and locking the target column, the focal length is automatically adjusted according to the imaging size of the column in the image. The image processing algorithm is used to extract the center line of the column and perform sub-pixel level optimization. The optical zoom high-definition camera module is rotated to adjust the center line of the column to be located in the center of the screen, and the encoder value is recorded at this time.

[0037] S3. Based on the pose calculation of the two columns, observe at least two columns and obtain the corresponding encoder angle information. Combine the known global coordinates of the columns, the initial position of the optical zoom high-definition camera module and the relative coordinates of the omnidirectional moving chassis, and the angle information obtained by the encoder, and solve the geometric constraint equations together to obtain the position (x, y) and heading angle θ of the omnidirectional moving chassis in the global coordinate system.

[0038] S4. Based on cross-validation and accuracy improvement of three pillars, when three or more pillars are observed, two pillars are randomly selected to form multiple independent observation pairs. Each pair performs pose calculation in step S3 to obtain multiple independent pose results. The results are then fused using a weighted average or optimal filtering algorithm to remove abnormal results with large deviations and output the final pose estimate.

[0039] In some embodiments, in step S3, if it is a three-dimensional positioning scenario, a perspective N-point model needs to be established based on the three-dimensional coordinates of the upper and lower edge points of the column and the corresponding horizontal rotation angle and pitch angle, and the three-dimensional position (x, y, z) and three-dimensional attitude of the omnidirectional moving chassis need to be calculated. The three-dimensional attitude includes pitch angle α, roll angle β, and yaw angle γ.

[0040] The reactor core plate underwater multifunctional detection device for the reactor in-core component has the following beneficial effects: the video lifting inspection module is arranged to perform video imaging inspection on the components in the core plate region, the fuel positioning pin verticality inspection module is arranged to measure the inclination angle of the fuel positioning pin, the fuel positioning pin and open pin in-situ ultrasonic inspection module is arranged to detect defects in the typical failure region of the open pin and potential cracks in the joint region of the fuel positioning pin thread region and the light rod region, and the pin hole emergency inspection module is arranged to realize in-situ emergency inspection of the core plate pin hole, thereby solving the industry problems of a large number of inspection blind areas and lack of comprehensive detection means in the core plate region of the reactor due to limited space, greatly improving the on-site detection efficiency and reducing the radiation exposure risk. The action mechanisms and the omnidirectional mobile chassis can be detachably carried, facilitating later maintenance and function expansion, and through the cooperation of the action mechanisms, the comprehensiveness of the inspection can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the present application, the present application will be further described below in conjunction with the drawings and examples. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings:

[0042] Figure 1 is a structural schematic diagram of the omnidirectional mobile chassis in some embodiments of the present application;

[0043] Figure 2 is a structural schematic diagram of the positioning camera assembly in some embodiments of the present application;

[0044] Figure 3 is a structural schematic diagram of the video lifting inspection module in some embodiments of the present application;

[0045] Figure 4 is a structural schematic diagram of the omnidirectional mobile chassis cooperating with the video lifting inspection module in some embodiments of the present application;

[0046] Figure 5 is a structural schematic diagram of the fuel positioning pin verticality inspection module in some embodiments of the present application;

[0047] Figure 6 is a structural schematic diagram of the omnidirectional mobile chassis cooperating with the fuel positioning pin verticality inspection module in some embodiments of the present application;

[0048] Figure 7 is a structural schematic diagram of the fuel positioning pin and open pin in-situ ultrasonic inspection module in some embodiments of the present application;

[0049] Figure 8is a structural schematic view of another embodiment of the fuel dowel pin and split pin in-situ ultrasonic inspection module in some embodiments of the present application;

[0050] Figure 9 is a structural schematic view of the omnidirectional mobile chassis cooperating with the fuel dowel pin and split pin in-situ ultrasonic inspection module in some embodiments of the present application;

[0051] Figure 10 is a structural schematic view of the omnidirectional mobile chassis cooperating with the pin hole emergency inspection module in some embodiments of the present application. DETAILED DESCRIPTION

[0052] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "upper", "lower", "left", "right", "vertical", "horizontal", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail" and the like are based on the directions or positional relationships shown in the drawings, constructed and operated in a particular direction, and are only for the convenience of describing the technical solutions, and should not be understood as indicating that the devices or elements referred to must have a particular direction, and therefore should not be understood as limiting the present application.

[0053] It should also be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing", "setting" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. When an element is referred to as "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there can be one or more intermediate elements. The terms "first", "second", "third" and the like are only for the convenience of describing the technical solutions, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features with "first", "second", "third" and the like can explicitly or implicitly include one or more of the features. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0054] Please refer to Figures 1 to 10The reactor in-vessel component core upper plate underwater multifunctional detection device is one of the reactor in-vessel component core upper plate underwater multifunctional detection devices in some embodiments of the present application, which comprises an omnidirectional mobile chassis 1 and an action mechanism detachably carried on the omnidirectional mobile chassis 1, and the action mechanism comprises a video lifting inspection module 2, a fuel positioning pin verticality inspection module 3, a fuel positioning pin and open pin in-situ ultrasonic inspection module 4 and a pin hole emergency inspection module 5. The video lifting inspection module 2 is used for video imaging inspection of components in the core upper plate region; the fuel positioning pin verticality inspection module 3 is used for measuring the inclination angle of the fuel positioning pin; the fuel positioning pin and open pin in-situ ultrasonic inspection module 4 is used for detecting defects in the typical failure region of the open pin and potential cracks in the intersection region of the fuel positioning pin thread region and the light rod region; and the pin hole emergency inspection module 5 is used for realizing in-situ emergency inspection of the pin hole of the core upper plate. The action mechanism can be fixed with the omnidirectional mobile chassis 1 through screws, and can realize plug and play by connecting an underwater connector.

[0055] It can be understood that the reactor in-vessel component core upper plate underwater multifunctional detection device is used for video imaging inspection of components in the core upper plate region by setting the video lifting inspection module 2, is used for measuring the inclination angle of the fuel positioning pin by setting the fuel positioning pin verticality inspection module 3, is used for detecting defects in the typical failure region of the open pin and potential cracks in the intersection region of the fuel positioning pin thread region and the light rod region by setting the fuel positioning pin and open pin in-situ ultrasonic inspection module 4, and is used for realizing in-situ emergency inspection of the pin hole of the core upper plate by setting the pin hole emergency inspection module 5, thereby solving the industry problems of a large number of inspection blind areas and lack of comprehensive detection means in the reactor core upper plate region due to limited space, greatly improving the on-site detection efficiency and reducing the radiation exposure risk. The action mechanism and the omnidirectional mobile chassis 1 are detachably carried, which is convenient for later maintenance and function expansion, and the comprehensiveness of inspection can be improved through the cooperation of the action mechanism.

[0056] As Figure 1 and Figure 2As shown, the omnidirectional mobile chassis 1 includes a base body 11, a positioning camera assembly mounted on the base body 11, and a radiation sensor built in the base body 11, the positioning camera assembly including an optical zoom high-definition camera module 12, a camera rotating motor 13, and an encoder. The base body 11 adopts a hollow design and is provided with a plurality of watertight joints 14; the optical zoom high-definition camera module 12 is used to capture the image of the column member in the core upper plate area through zoom adjustment; the camera rotating motor 13 is used to drive the optical zoom high-definition camera module 12 to rotate; the encoder is used to record the rotation angle of the optical zoom high-definition camera module 12; and the radiation sensor is used to collect the radiation dose rate of the underwater detection environment. The optical zoom high-definition camera module 12 can automatically extract the column center line by vision, and calculate the position and angle of the omnidirectional mobile chassis 1 by using the angle information of multiple columns. The combination of the optical zoom high-definition camera module 12, the camera rotating motor 13 and the encoder solves the problems of underwater imaging blur at different distances and inaccurate angle measurement, and provides reliable data source for subsequent high-precision positioning. The base body 11 adopts a hollow design, which can reduce underwater flow resistance, facilitate impurity discharge, and avoid the influence of foreign matter accumulation on equipment operation; the base body 11 is provided with a plurality of standardized watertight joints 14, which can realize quick waterproof electrical connection with each action mechanism, ensure the safety of underwater operation, and ensure the stability and safety of the chassis under water, reduce flow resistance and foreign matter interference. The radiation sensor can measure the environmental radiation dose rate, and the integral cumulative dose can be obtained. According to the maximum cumulative dose of the key components of the omnidirectional mobile chassis 1, the remaining life of the omnidirectional mobile chassis 1 can be calculated, which effectively guarantees the reliability of the omnidirectional mobile chassis 1 in the radioactive environment. In addition, the base body 11 adopts a foreign matter prevention design, which greatly reduces the number of loose parts of the omnidirectional mobile chassis 1 and reduces the foreign matter prevention workload of the omnidirectional mobile chassis 1 in the field operation. In addition, the omnidirectional mobile chassis 1 is equipped with Mecanum wheels to realize omnidirectional movement. The optical zoom high-definition camera module 12 can be connected with a pitch platform to realize the pitch action of the optical zoom high-definition camera module 12.

[0057] As Figure 3 and Figure 4As shown, the video lifting inspection module 2 comprises a base station 21, a first video lifting translation driving module 22, a second video lifting translation driving module 23, a video lifting lifting module 24, a telescopic mounting rack 25 and a gimbal camera 26 connected in sequence. The first video lifting translation driving module 22 is installed on the base station 21, and the first video lifting translation driving module 22 is used to drive the gimbal camera 26 to move along the width direction of the base station 21; the second video lifting translation driving module 23 is used to drive the gimbal camera 26 to move along the length direction of the base station 21; the video lifting lifting module 24 and the telescopic mounting rack 25 are used to drive the gimbal camera 26 to move along the height direction of the base station 21; the gimbal camera 26 is installed on the telescopic mounting rack 25; the gimbal camera 26 is used for video imaging inspection of the components in the core upper plate region. In this embodiment, the first video lifting translation driving module 22 and the second video lifting translation driving module 23 are driven by servo motors, the video lifting lifting module 24 is driven by a gas cylinder, and the telescopic mounting rack 25 can be driven by multiple gas cylinders. The first video lifting translation driving module 22 and the second video lifting translation driving module 23 realize the horizontal full-range movement of the gimbal camera 26, and the video lifting lifting module 24 and the telescopic mounting rack 25 realize the height adjustment of the gimbal camera 26, which can accurately send the gimbal camera 26 to any detection point of the core upper plate, especially to a position higher than the support column bolt, avoiding the obstruction of the components, solving the problem of limited view of the traditional long rod tool. Multi-drive module cooperative control can quickly adjust the camera posture according to the detection target position, without the need to move the omnidirectional mobile chassis 1 as a whole, which improves the operation efficiency and reduces the positioning error caused by frequent movement of the omnidirectional mobile chassis 1.

[0058] The gimbal camera 26 is sealed by an organic glass cover, and the outer side of the gimbal camera 26 is provided with an annular underwater light band 27. The organic glass cover sealing design ensures that the gimbal camera 26 works normally under high pressure underwater environment, avoids water seepage damage to the equipment, improves the underwater operation reliability of the device, and adapts to the underwater detection scene of the core upper plate of the nuclear power plant. The annular underwater light band 27 provides uniform light supplement, solves the imaging blur problem caused by insufficient underwater light, ensures that the details of the support column bolt and the open pin nut (such as surface scratches and looseness) can be clearly captured, and improves the defect recognition rate of video inspection.

[0059] As Figure 5 and Figure 6As shown, the fuel positioning pin perpendicularity inspection module 3 comprises a positioning table 31, a first perpendicularity inspection translation driving module 32, a second perpendicularity inspection translation driving module 33, a first perpendicularity inspection lifting module 34, a second perpendicularity inspection lifting module 35, a perpendicularity inspection rotating module 36, a perpendicularity mounting seat 37, and a plurality of perpendicularity detection sensors 38 connected in sequence. The first perpendicularity inspection translation driving module 32 is installed on the positioning table 31, and is used to drive the plurality of perpendicularity detection sensors 38 to move along the width direction of the positioning table 31; the second perpendicularity inspection translation driving module 33 is used to drive the plurality of perpendicularity detection sensors 38 to move along the length direction of the positioning table 31; the first perpendicularity inspection lifting module 34 and the second perpendicularity inspection lifting module 35 are used to drive the plurality of perpendicularity detection sensors 38 to move along the height direction of the positioning table 31; the perpendicularity inspection rotating module 36 is used to drive the plurality of perpendicularity detection sensors 38 to rotate; and the plurality of perpendicularity detection sensors 38 are installed on the perpendicularity mounting seat 37. In this embodiment, the first perpendicularity inspection translation driving module 32, the second perpendicularity inspection translation driving module 33, the second perpendicularity inspection lifting module 35, and the perpendicularity inspection rotating module 36 are all driven by servo motors, and the first perpendicularity inspection lifting module 34 is driven by a pneumatic cylinder. The first perpendicularity inspection translation driving module 32 and the second perpendicularity inspection translation driving module 33 realize full-range horizontal movement of the perpendicularity detection sensors 38, the first perpendicularity inspection lifting module 34 and the second perpendicularity inspection lifting module 35 realize height adjustment of the perpendicularity detection sensors 38, and the perpendicularity inspection rotating module 36 realizes rotational movement of the perpendicularity detection sensors 38.

[0060] The perpendicularity detection sensors 38 are LVDT sensors, and the number of the LVDT sensors is eight. The eight LVDT sensors are installed in two layers on the perpendicularity mounting seat 37, and the LVDT sensors in each layer are uniformly arranged along the circumferential direction of the perpendicularity mounting seat 37. The LVDT sensors have high-precision displacement measurement capability, and the eight LVDT sensors arranged in two layers can simultaneously collect displacement data of eight points of the positioning pin, and calculate the inclination angle through multi-point data fitting. Compared with traditional single-point measurement, the perpendicularity measurement precision is greatly improved, and misjudgment caused by single-point data deviation is avoided. The two-layer layout can cover the upper and lower regions of the positioning pin, capture the inclination angle and inclination direction of the full height of the positioning pin, and solve the problem that the traditional single-layer measurement cannot reflect the overall inclination state of the positioning pin.

[0061] As shown in FIG. 4, the fuel positioning pin perpendicularity inspection module 3 is used to inspect the perpendicularity of the fuel positioning pin 2. The fuel positioning pin perpendicularity inspection module 3 comprises a positioning table 31, a first perpendicularity inspection translation driving module 32, a second perpendicularity inspection translation driving module 33, a first perpendicularity inspection lifting module 34, a second perpendicularity inspection lifting module 35, a perpendicularity inspection rotating module 36, a perpendicularity mounting seat 37, and a plurality of perpendicularity detection sensors 38 connected in sequence. The first perpendicularity inspection translation driving module 32 is installed on the positioning table 31, and is used to drive the plurality of perpendicularity detection sensors 38 to move along the width direction of the positioning table 31; the second perpendicularity inspection translation driving module 33 is used to drive the plurality of perpendicularity detection sensors 38 to move along the length direction of the positioning table 31; the first perpendicularity inspection lifting module 34 and the second perpendicularity inspection lifting module 35 are used to drive the plurality of perpendicularity detection sensors 38 to move along the height direction of the positioning table 31; the perpendicularity inspection rotating module 36 is used to drive the plurality of perpendicularity detection sensors 38 to rotate; and the plurality of perpendicularity detection sensors 38 are installed on the perpendicularity mounting seat 37. In this embodiment, the first perpendicularity inspection translation driving module 32, the second perpendicularity inspection translation driving module 33, the second perpendicularity inspection lifting module 35, and the perpendicularity inspection rotating module 36 are all driven by servo motors, and the first perpendicularity inspection lifting module 34 is driven by a pneumatic cylinder. The first perpendicularity inspection translation driving module 32 and the second perpendicularity inspection translation driving module 33 realize full-range horizontal movement of the perpendicularity detection sensors 38, the first perpendicularity inspection lifting module 34 and the second perpendicularity inspection lifting module 35 realize height adjustment of the perpendicularity detection sensors 38, and the perpendicularity inspection rotating module 36 realizes rotational movement of the perpendicularity detection sensors 38. Figures 7 to 9As shown, the in-situ ultrasonic inspection module 4 for fuel positioning pins and cotter pins includes a support platform 41, a first ultrasonic inspection translational drive module 42, a second ultrasonic inspection translational drive module 43, a first ultrasonic inspection lifting module 44, a second ultrasonic inspection lifting module 45, an ultrasonic inspection rotation module 46, and an ultrasonic detection probe 47, connected in sequence. The first ultrasonic inspection translational drive module 42 is mounted on the support platform 41 and is used to drive the ultrasonic detection probe 47 to move along the width direction of the support platform 41; the second ultrasonic inspection translational drive module 43 is used to drive the ultrasonic detection probe 47 to move along the length direction of the support platform 41; the first ultrasonic inspection lifting module 44 and the second ultrasonic inspection lifting module 45 are used together to drive the ultrasonic detection probe 47 to move along the height direction of the support platform 41; the ultrasonic inspection rotation module 46 is used to drive the ultrasonic detection probe 47 to rotate. In this embodiment, the first ultrasonic examination translation drive module 42, the second ultrasonic examination translation drive module 43, the second ultrasonic examination lifting module 45, and the ultrasonic examination rotation module 46 are all driven by servo motors, while the first ultrasonic examination lifting module 44 is driven by a cylinder. The first ultrasonic examination translation drive module 42 and the second ultrasonic examination translation drive module 43 enable the ultrasonic testing probe 47 to move across its entire horizontal range, the first ultrasonic examination lifting module 44 and the second ultrasonic examination lifting module 45 enable the height adjustment of the ultrasonic testing probe 47, and the ultrasonic examination rotation module 46 enables the rotational movement of the ultrasonic testing probe 47.

[0062] The ultrasonic testing probe 47 is either a four-element ultrasonic probe or a positioning pin ultrasonic probe. For example... Figure 7 As shown, the in-situ ultrasonic inspection module 4 for fuel positioning pins and cotter pins is equipped with a four-element ultrasonic probe for cotter pin detection. The four-element probe can simultaneously cover three typical failure areas of the cotter pin: the head fracture area, the pin wear area, and the tail deformation area. Full coverage scanning can be completed without multiple probe angle adjustments, avoiding missed detections caused by repeated adjustments. Figure 8 As shown, the in-situ ultrasonic inspection module 4 for fuel positioning pins and cotter pins is equipped with an ultrasonic probe for positioning pin detection. The ultrasonic probe can perform a spiral scan along the junction of the threaded area and the smooth rod area to ensure no missed detections.

[0063] like Figure 10 As shown, the pin hole emergency inspection module 5 is used to perform in-situ emergency inspections of the pin holes on the reactor core upper plate, responding to emergencies such as damage to the inner wall of the pin hole or blockage by foreign objects. It includes a telescopic inspection arm 51, a visual inspection camera 52, and an illumination unit. The telescopic inspection arm 51 can extend horizontally, allowing the visual inspection camera 52 to extend into the pin hole. The illumination unit provides localized strong light illumination to ensure that the visual inspection camera 52 clearly captures images of the inner wall of the pin hole. Image analysis is then used to quickly determine the condition of the pin hole, providing a basis for emergency response.

[0064] In the present embodiment, a positioning method of the reactor in-vessel component core upper plate underwater multifunctional detection device is also constructed, which comprises the following steps:

[0065] S1, system initialization and parameter calibration, establish the global coordinate system of the core upper plate, pre-input the global coordinate information of the column in the work scene into the software, calibrate the core optical parameters of the optical zoom high-definition camera module 12, initialize the motion axis of the optical zoom high-definition camera module 12 to be consistent with the forward direction of the omnidirectional mobile chassis 1, control the omnidirectional mobile chassis 1 to move to the center of the core upper plate and to the 0° direction of the component pool, and perform initial position calibration;

[0066] S2, adaptive visual scanning and feature extraction, continuously scan the working space by the camera rotating motor 13 driving the optical zoom high-definition camera module 12, after recognizing and locking the target column, automatically adjust the focal length according to the imaging size of the column in the image, extract the column center line and perform sub-pixel level optimization by using image processing algorithm, adjust the optical zoom high-definition camera module 12 to the column center line located at the center of the screen by rotating, and record the value of the encoder at this time;

[0067] S3, pose solving based on two columns, observe at least two columns and obtain the corresponding encoder angle information, combine the known column global coordinates, the relative coordinates of the initial position of the optical zoom high-definition camera module 12 and the omnidirectional mobile chassis 1, and the angle information obtained by the encoder, and solve jointly by geometric constraint equation to obtain the position (x, y) and heading angle θ of the omnidirectional mobile chassis 1 in the global coordinate system;

[0068] S4, cross verification and precision improvement based on three columns, when three or more columns are observed, form multiple independent observation pairs from any two of them, each group performs the pose solving of step S3 to obtain multiple independent pose results, performs weighted average or optimal filtering algorithm data fusion on each result, removes abnormal results with large deviation, and outputs the final pose estimation value.

[0069] The positioning method of the reactor in-vessel component core upper plate underwater multifunctional detection device combines intelligent visual algorithm and encoder, and solves by double column geometric constraint, which improves the positioning accuracy, and based on the cross verification and abnormal removal of three columns, can effectively eliminate accidental errors such as shielding and recognition error, ensure the robustness of the positioning result, and solve the problem of low reliability caused by single feature dependence of the existing positioning method. The method does not need manual intervention throughout the process, and automatically completes scanning, feature extraction and solving, reduces the manual operation intensity and human error, and improves the positioning efficiency.

[0070] In step S2, the optical zoom high-definition camera module 12 is driven by the camera rotating motor 13 to continuously scan the working space at 360°, automatically identify and lock the target column; the system adjusts the focal length according to the imaging size of the column in the image, so that the column image is clear and the size is moderate, which is convenient for subsequent feature extraction; the adaptive threshold edge detection algorithm is used to process the column image, which can exclude the interference of underwater impurities and light reflection, and the least square method can be used to perform linear fitting on the edge points to extract the column center line and perform sub-pixel level optimization; the angle of the optical zoom high-definition camera module 12 is adjusted by the camera rotating motor 13 until the column center line is located at the center of the screen, and the rotation angle value of the encoder at this time is recorded to provide the basis for the angle calculation. In the three-dimensional positioning scene, the two-degree-of-freedom holder needs to be controlled to adjust the pitch angle, scan the column at different heights, and use the sub-pixel level edge detection algorithm combined with gray gradient analysis to extract the accurate image coordinates of the upper and lower edge points of the column, and record the values of the horizontal rotation encoder and the pitch encoder synchronously to obtain three-dimensional feature data.

[0071] In step S3, if it is a three-dimensional positioning scene, a perspective N-point model is established based on the three-dimensional coordinates of the upper and lower edge points of the column and the corresponding horizontal rotation angle and pitch angle, and the three-dimensional position (x, y, z) and three-dimensional attitude of the omnidirectional mobile chassis 1 are calculated. The three-dimensional attitude includes pitch angle a, roll angle β and yaw angle γ. Specifically, based on the three-dimensional coordinates of the upper and lower edge points of the column and the corresponding horizontal rotation angle and pitch angle, a perspective N-point (PnP) model is established, and the EPnP algorithm can be used for calculation. The EPnP algorithm reduces the calculation complexity by decomposing the space points into linear combinations of virtual control points, and meets the real-time positioning requirements. At the same time, the RANSAC algorithm is introduced to remove abnormal feature points, and the anti-interference ability is improved. By fusing the three-dimensional feature point observations of multiple targets, the six-degree-of-freedom (6-DOF) pose of the omnidirectional mobile chassis 1 is solved, and the three-dimensional position (x, y, z) and three-dimensional attitude (pitch, roll, yaw) of the omnidirectional mobile chassis 1 are obtained. This step can meet the complex task requirements of three-dimensional inspection and wall-following navigation.

[0072] In step S4, in specific embodiments, any two of the three posts are optionally combined into three independent observation pairs (e.g., posts A&B, A&C, B&C). The pose solving in step S3 is performed for each group, and three independent pose solving results (x1, y1, θ1), (x2, y2, θ2) and (x3, y3, θ3) are obtained. Data fusion and error rejection: the three pose solving results are weighted averaged or data fusion is performed using an optimal filtering algorithm to obtain a final, more accurate pose estimation value. If one of the solving results deviates greatly from the other two, the system can determine that there is a large error in the observation of this group (e.g., a post is blocked or misidentified), and it is rejected, thereby effectively suppressing accidental errors and ensuring the robustness of the positioning result.

[0073] The positioning method effectively suppresses the noise and accidental errors of a single sensor by fusing multi-source information of vision and encoders and using geometric constraints between multiple posts for cross-validation. The optical zoom function enables the omnidirectional mobile chassis 1 to adapt to different distances and scales of the working environment within the visible range, and always maintains optimal observation accuracy. Compared with acoustic or laser radar systems, the optical zoom high-definition camera module 12 and the encoder used in the present application have lower cost and do not require additional deployment of beacons in the environment, but only need to use the existing post structure, and are more practical.

[0074] It can be understood that the above embodiments only express the preferred embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present application; it should be noted that for ordinary skilled in the art, the above technical features can be freely combined without departing from the concept of the present application, and some modifications and improvements can be made, which all belong to the protection scope of the present application; therefore, any equivalent transformation and modification within the scope of the claims of the present application shall belong to the scope of the claims of the present application.

Claims

1. A multi-functional underwater detection device for the reactor core upper plate of reactor internals, characterized in that, It includes an omnidirectional mobile chassis (1) and a detachable action mechanism mounted on the omnidirectional mobile chassis (1). The action mechanism includes a video lifting inspection module (2), a fuel positioning pin verticality inspection module (3), a fuel positioning pin and cotter pin in-situ ultrasonic inspection module (4), and a pin hole emergency inspection module (5). The video lifting inspection module (2) is used to perform video imaging inspection of components in the core upper plate area; The fuel positioning pin verticality inspection module (3) is used to measure the tilt angle of the fuel positioning pin. The in-situ ultrasonic inspection module (4) for fuel positioning pin and cotter pin is used to detect defects in typical failure areas of cotter pin and potential cracks in the junction area of ​​the threaded area and the smooth rod area of ​​fuel positioning pin. The pin hole emergency inspection module (5) is used to realize in-situ emergency inspection of the pin holes on the core upper plate; The fuel positioning pin verticality inspection module (3) includes a positioning table (31), a first verticality inspection translation drive module (32), a second verticality inspection translation drive module (33), a first verticality inspection lifting module (34), a second verticality inspection lifting module (35), a verticality inspection rotation module (36), a verticality mounting base (37), and multiple verticality detection sensors (38) connected in sequence. The first verticality check translation drive module (32) is installed on the positioning stage (31). The first verticality check translation drive module (32) is used to drive the multiple verticality detection sensors (38) to move along the width direction of the positioning stage (31). The second verticality inspection translation drive module (33) is used to drive the plurality of verticality detection sensors (38) to move along the length direction of the positioning stage (31); The first verticality inspection lifting module (34) and the second verticality inspection lifting module (35) are used together to drive the multiple verticality detection sensors (38) to move along the height direction of the positioning platform (31); The verticality inspection rotation module (36) is used to drive the multiple verticality detection sensors (38) to rotate. Multiple verticality detection sensors (38) are mounted on the verticality mounting base (37).

2. The underwater multi-functional detection device for the reactor core upper plate of reactor internals according to claim 1, characterized in that, The omnidirectional mobile chassis (1) includes a base (11), a positioning camera assembly mounted on the base (11), and a radiation sensor built into the base (11). The positioning camera assembly includes an optical zoom high-definition camera module (12), a camera rotation motor (13), and an encoder. The substrate (11) adopts a hollow design and is provided with multiple watertight joints (14). The optical zoom high-definition camera module (12) is used to capture images of columnar components within the core plate area by zoom adjustment; the camera rotation motor (13) is used to drive the optical zoom high-definition camera module (12) to rotate. The encoder is used to record the rotation angle of the optical zoom high-definition camera module (12); The radiation sensor is used to collect the radiation dose rate of the underwater detection environment.

3. The underwater multi-functional detection device for the reactor core upper plate of reactor internals according to claim 1, characterized in that, The video lifting inspection module (2) includes a base (21), a first video lifting and translation drive module (22), a second video lifting and translation drive module (23), a video lifting and raising module (24), a telescopic mounting frame (25), and a PTZ camera (26) connected in sequence. The first video lifting and translation driving module (22) is mounted on the base (21), and the first video lifting and translation driving module (22) is used to drive the gimbal camera (26) to move along the width direction of the base (21); The second video lifting and translation drive module (23) is used to drive the gimbal camera (26) to move along the length direction of the base (21); The video lifting module (24) and the telescopic mounting bracket (25) are used to drive the gimbal camera (26) to move along the height direction of the base (21); The PTZ camera (26) is mounted on the telescopic mounting frame (25) and is used to perform video imaging inspection of components in the core plate area.

4. The underwater multi-functional detection device for the reactor core upper plate of reactor internals according to claim 3, characterized in that, The gimbal camera (26) is sealed with an organic glass cover, and an annular underwater light strip (27) is arranged on the outside of the gimbal camera (26).

5. The underwater multi-functional detection device for the reactor core upper plate of reactor internals according to claim 1, characterized in that, The verticality detection sensor (38) is an LVDT sensor. There are eight LVDT sensors. The eight LVDT sensors are installed on the verticality mounting base (37) in two separate upper and lower layers. The LVDT sensors in each layer are evenly arranged along the circumferential direction of the verticality mounting base (37).

6. The underwater multi-functional detection device for the reactor core upper plate of reactor internals according to claim 1, characterized in that, The in-situ ultrasonic inspection module (4) for fuel positioning pin and cotter pin includes a support platform (41), a first ultrasonic inspection translation drive module (42), a second ultrasonic inspection translation drive module (43), a first ultrasonic inspection lifting module (44), a second ultrasonic inspection lifting module (45), an ultrasonic inspection rotation module (46), and an ultrasonic detection probe (47) connected in sequence. The first ultrasonic examination translation drive module (42) is mounted on the support platform (41) and is used to drive the ultrasonic detection probe (47) to move along the width direction of the support platform (41). The second ultrasonic examination translation drive module (43) is used to drive the ultrasonic detection probe (47) to move along the length direction of the support platform (41); The first ultrasound examination lifting module (44) and the second ultrasound examination lifting module (45) are used together to drive the ultrasound detection probe (47) to move along the height direction of the support platform (41). The ultrasonic examination rotating module (46) is used to drive the ultrasonic detection probe (47) to rotate.

7. The underwater multi-functional detection device for the reactor core upper plate of reactor internals according to claim 6, characterized in that, The ultrasonic testing probe (47) is a four-element ultrasonic probe or a positioning pin ultrasonic probe.

8. A positioning method for an underwater multi-functional detection device for the reactor core upper plate of reactor internals, applicable to the underwater multi-functional detection device for the reactor core upper plate of any one of claims 1 to 7, characterized in that, Including the following steps: S1. System initialization and parameter calibration: Establish the global coordinate system of the reactor core plate, input the global coordinate information of the column in the operation scene into the software in advance, calibrate the core optical parameters of the optical zoom high-definition camera module (12), initialize the motion axis of the optical zoom high-definition camera module (12) to be consistent with the forward direction of the omnidirectional moving chassis (1), control the omnidirectional moving chassis (1) to move to the center of the reactor core plate and face the 0° direction of the component pool, and perform initial position calibration. S2. Adaptive visual scanning and feature extraction: The optical zoom high-definition camera module (12) is driven by the camera rotation motor (13) to perform a 360° continuous scan of the workspace. After identifying and locking the target column, the focal length is automatically adjusted according to the imaging size of the column in the image. The center line of the column is extracted by the image processing algorithm and optimized at the sub-pixel level. The optical zoom high-definition camera module (12) is rotated to adjust the center line of the column to be located in the center of the screen, and the encoder value is recorded at this time. S3. Based on the pose calculation of the two columns, observe at least two columns and obtain the corresponding encoder angle information. Combine the known global coordinates of the columns, the initial position of the optical zoom high-definition camera module (12) with the relative coordinates of the omnidirectional moving chassis (1) and the angle information obtained by the encoder, and solve the geometric constraint equations together to obtain the position (x, y) and heading angle θ of the omnidirectional moving chassis (1) in the global coordinate system. S4. Based on cross-validation and accuracy improvement of three pillars, when three or more pillars are observed, two pillars are randomly selected to form multiple independent observation pairs. Each pair performs pose calculation in step S3 to obtain multiple independent pose results. The results are then fused using a weighted average or optimal filtering algorithm to remove abnormal results with large deviations and output the final pose estimate.

9. The positioning method of the underwater multi-functional detection device for the reactor core upper plate of reactor internal components according to claim 8, characterized in that, In step S3, if it is a three-dimensional positioning scenario, a perspective N-point model needs to be established based on the three-dimensional coordinates of the upper and lower edge points of the column and the corresponding horizontal rotation angle and pitch angle, and the three-dimensional position (x, y, z) and three-dimensional attitude of the omnidirectional moving chassis (1) are calculated. The three-dimensional attitude includes pitch angle α, roll angle β and yaw angle γ.

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