Nuclear reactor underwater maintenance robot and use method thereof

Abstract

The invention discloses a nuclear reactor underwater maintenance robot and a use method thereof. The nuclear reactor underwater maintenance robot comprises a connecting mechanism, a telescopic positioning mechanism, a lifting mechanism, a rotating mechanism and a mechanical arm. The telescopic positioning mechanism of the nuclear reactor underwater maintenance robot has a telescopic function, the maintenance robot can be integrally positioned on the wall surface of a container through the telescopic positioning mechanism, and the posture of the underwater maintenance robot is adjusted through the multiple telescopic assemblies, so that the position of the underwater maintenance robot is conveniently calibrated; and the position of each telescopic assembly can be finely adjusted independently, and posture adjustment of the underwater maintenance robot is facilitated. Meanwhile, the lifting mechanism and the rotating mechanism are used for driving the mechanical arm to lift and rotate respectively, so that the mechanical arm can work better, the automatic replacement of the probe frame and the automatic replacement of the probe underwater calibration or maintenance tool frame can be realized through the mechanical arm, and the working efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of nuclear power plant reactor maintenance, and in particular to an underwater nuclear reactor maintenance robot and a use method thereof. Background Art

[0002] The inner cavity of cylindrical metal parts such as nuclear reactor pressure vessels and lower core components involves in-service inspection, maintenance, fastener replacement and other operations. Due to the presence of radioactivity, these operations are generally carried out underwater. The positioning accuracy and efficiency of underwater operation robots have always been a focus of attention.

[0003] The existing nuclear reactor pressure vessel in-service inspection equipment mainly includes bracket-type robots that use flange bolt holes for positioning, bracket-type robots that use keyways and support blocks for positioning, and wall-adsorption mobile robots, etc., which cannot simultaneously meet the requirements of equipment miniaturization and overall transportation, high underwater positioning accuracy, convenient detection signal calibration, equipment body not blocking the inspected area, and multiple robots being able to work in parallel. The related pressure vessel and lower reactor internal component inspection platforms mainly include some fixed lifting platforms, which are large in size and have relatively single functions, and cannot meet the needs of miniaturization and multi-function. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a nuclear reactor underwater maintenance robot and a method of using the same.

[0005] The technical solution adopted by the present invention to solve the technical problem is: constructing a nuclear reactor underwater maintenance robot, which includes a connecting mechanism, a telescopic positioning mechanism, a lifting mechanism, a rotating mechanism and a mechanical arm;

[0006] The telescopic positioning mechanism comprises a plurality of telescopic components, each of which comprises a support leg connected to the connecting mechanism, a telescopic driver mounted on the support leg, and a lead screw module connected to an output end of the telescopic driver;

[0007] The lead screw module comprises a slider connected to the output end of the telescopic driver, a lead screw positioning seat movably connected to the slider, and a lead screw driving motor connected to the lead screw positioning seat, wherein the wall surface of the lead screw positioning seat facing away from the slider abuts against the container wall surface of the nuclear reactor;

[0008] The lifting mechanism is connected to the connecting mechanism and is used to drive the mechanical arm to perform lifting and lowering movements; the rotating mechanism is connected to the connecting mechanism and is used to drive the mechanical arm to perform rotating movements; the mechanical arm is used for the operation of the underwater maintenance robot.

[0009] In some embodiments, the connecting mechanism includes a base and a connecting frame, one end of each of the plurality of supporting legs is connected to the base, the lifting mechanism is installed on the base, the output end of the lifting mechanism is connected to the connecting frame, the rotating mechanism is installed on the connecting frame, and the output end of the rotating mechanism is connected to the robotic arm.

[0010] In some embodiments, the connection mechanism further comprises a mounting frame, and the plurality of support legs are connected to the mounting frame;

[0011] The mounting frame is provided with a plurality of underwater thrusters and a plurality of buoyancy blocks.

[0012] In some embodiments, a tilt sensor is provided on the base.

[0013] In some embodiments, the nuclear reactor underwater maintenance robot further includes a plurality of functional component accommodating racks, wherein the functional component accommodating racks are connected to the supporting legs, and the functional component accommodating racks are provided with laser rangefinders, ultrasonic probes and maintenance tools.

[0014] In some embodiments, the lifting mechanism includes a lifting hollow motor, and the rotating mechanism includes a rotating hollow motor.

[0015] In this embodiment, a method for using the underwater maintenance robot for a nuclear reactor is also constructed, which is based on the underwater maintenance robot for a nuclear reactor and includes the steps of:

[0016] S1. Using a crane to allow the underwater nuclear reactor maintenance robot to enter a container of a nuclear reactor;

[0017] S2. With the assistance of a camera and a depth meter, the underwater nuclear reactor maintenance robot is suspended at a target depth by using an underwater thruster to achieve rough positioning;

[0018] S3, performing initial posture adjustment of the underwater nuclear reactor maintenance robot;

[0019] S4, calibrating the axial direction of the underwater nuclear reactor maintenance robot and the inspected object;

[0020] S5, calibrating the height and circumferential position of the underwater nuclear reactor maintenance robot;

[0021] S6, completing the coordinate mapping between the robot coordinates and the inspected object;

[0022] S7. Use the robotic arm to load the maintenance tool or calibrate the probe to perform the operation;

[0023] S8. Use the underwater thruster to move the nuclear reactor underwater maintenance robot as a whole and continue the next stage of work.

[0024] In some embodiments, step S3 includes:

[0025] S31, using a telescopic driver to extend the lead screw module to a first fixed position, so that the lead screw positioning seat contacts the container wall;

[0026] S32, according to the feedback of the inclination sensor, using the screw drive motor to adjust the position of the screw positioning seat relative to the container wall, until the nuclear reactor underwater maintenance robot is in a vertical position relative to the container of the nuclear reactor as a whole;

[0027] S33, using a telescopic driver to extend the lead screw module to a second fixed position for fixation.

[0028] In some embodiments, step S4 includes:

[0029] S41, using a mechanical arm to load a laser rangefinder, moving the laser rangefinder to a position close to the container wall and keeping the laser rangefinder perpendicular to the support leg;

[0030] S42, rotating the laser range finder 360 degrees around the central axis of the base to obtain a first curve measurement diagram between the laser range finder sensor data and the rotation angle;

[0031] S43. Compare the bottom structural features of the inspected object at different angles, and combine with the first curve measurement diagram. If the deviation exceeds the required range, adjust the position of the screw positioning seat until the data of the bottom structural features of the inspected object at different angles are within the deviation requirement range, so as to ensure that the nuclear reactor underwater maintenance robot is consistent with the axis of the inspected object.

[0032] In some embodiments, step S5 includes:

[0033] S51, rotating the laser range finder again by 360 degrees around the central axis of the base to obtain a second curve measurement diagram between the laser range finder sensor data and the rotation angle;

[0034] S52, using the distance data of the flat surface of the bottom structural features of the inspected object at different angles to calibrate the height direction of the inspection robot;

[0035] S53, using the rising edge or the falling edge of the second curve measurement diagram to calibrate the angle of the maintenance robot in the circumferential direction.

[0036] The implementation of the present invention has the following beneficial effects: the telescopic positioning mechanism of the underwater maintenance robot for a nuclear reactor has a telescopic function, and the maintenance robot can be positioned on the wall of the container as a whole through the telescopic positioning mechanism, and the posture of the underwater maintenance robot can be adjusted through multiple telescopic components to facilitate the calibration of the position of the underwater maintenance robot, and the position of each telescopic component can be fine-tuned individually to facilitate the posture adjustment of the underwater maintenance robot. At the same time, the lifting mechanism and the rotating mechanism respectively drive the mechanical arm to perform lifting and rotating movements, so that the mechanical arm can work better, and the mechanical arm can realize automatic replacement of the probe rack, underwater calibration of the probe or automatic replacement of the maintenance tool rack, thereby improving work efficiency. At the same time, the overall setting of the underwater maintenance robot occupies a small space, and multiple underwater maintenance robots can be operated in the nuclear reactor container at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work. In the drawings:

[0038] Figure 1 is a schematic diagram of the overall structure of a nuclear reactor underwater maintenance robot in some embodiments of the present invention;

[0039] Figure 2 is a schematic diagram of the application of the underwater maintenance robot for a nuclear reactor in some embodiments of the present invention;

[0040] Figure 3 It is a schematic diagram of the structure of the lead screw module in some embodiments of the present invention. DETAILED DESCRIPTION

[0041] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now 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", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0042] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0043] See also Figures 1 to 3 , is a nuclear reactor underwater maintenance robot in some embodiments of the present invention, the nuclear reactor underwater maintenance robot comprises a connection mechanism 1, a telescopic positioning mechanism 2, a lifting mechanism 3, a rotating mechanism 4 and a mechanical arm 5. The telescopic positioning mechanism 2 comprises a plurality of telescopic components, each of which comprises a support leg 21 connected to the connection mechanism 1, a telescopic driver 22 mounted on the support leg 21 and a lead screw module 23 connected to the output end of the telescopic driver 22. Figure 3 As shown, the lead screw module 23 includes a slider 231 connected to the output end of the telescopic driver 22, a lead screw positioning seat 232 movably connected to the slider 231, and a lead screw driving motor 233 connected to the lead screw positioning seat 232, and the wall of the lead screw positioning seat 232 facing away from the slider 231 abuts against the container wall 6 of the nuclear reactor. In addition, the lifting mechanism 3 is connected to the connecting mechanism 1, and is used to drive the mechanical arm 5 to perform lifting and lowering movements; the rotating mechanism 4 is connected to the connecting mechanism 1, and is used to drive the mechanical arm 5 to perform rotating movements; the mechanical arm 5 is used for the operation of the underwater maintenance robot. In this embodiment, the number of the telescopic components is three, and the three telescopic components are evenly distributed along the central axis of the connecting mechanism 1, and the telescopic components can be adjusted in posture.

[0044] It can be understood that the telescopic positioning mechanism 2 of the underwater maintenance robot for nuclear reactors has a telescopic function, and the maintenance robot can be positioned on the container wall 6 as a whole through this telescopic positioning mechanism 2, and the posture of the underwater maintenance robot can be adjusted through multiple telescopic components to facilitate the calibration of the position of the underwater maintenance robot. The position of each telescopic component can be fine-tuned individually to facilitate the posture adjustment of the underwater maintenance robot. At the same time, the lifting mechanism 3 and the rotating mechanism 4 respectively drive the mechanical arm 5 to perform lifting and rotating movements, so that the mechanical arm 5 can work better, and the mechanical arm 5 can realize automatic replacement of the probe rack, underwater calibration of the probe or automatic replacement of the maintenance tool rack, thereby improving work efficiency. At the same time, the overall setting of the underwater maintenance robot occupies a small space, and multiple underwater maintenance robots can be realized to work in the nuclear reactor container at the same time. If two underwater maintenance robots can work in parallel, it will help to improve work efficiency.

[0045] like Figure 1 As shown, the connection mechanism 1 includes a base 11 and a connecting frame 12, one end of each of the plurality of support legs 21 is connected to the base 11, a lifting mechanism 3 is mounted on the base 11, an output end of the lifting mechanism 3 is connected to the connecting frame 12, a rotating mechanism 4 is mounted on the connecting frame 12, and an output end of the rotating mechanism 4 is connected to a mechanical arm 5. The lifting mechanism 3 can simultaneously drive the rotating mechanism 4 and the mechanical arm 5 to perform lifting and lowering movements, and the rotating mechanism 4 drives the mechanical arm 5 to perform rotating movements, so that the mechanical arm 5 can better move according to different working environments. The mechanical arm 5 is specifically a multi-joint mechanical arm 5, the number of which can be one or more, and one end of the multi-joint mechanical arm 5 can be connected to a terminal quick-change device to achieve multifunctional operations, such as pressure vessel barrel girth weld inspection, pressure vessel nozzle safety end weld inspection, and underwater cutting of lower internal components, bolt replacement, underwater machining, etc.

[0046] The base 11 is also provided with an inclination sensor to cooperate with the movement of the telescopic positioning mechanism 2 to complete the posture adjustment of the underwater maintenance robot.

[0047] Furthermore, the mounting frame 13 is provided with a plurality of underwater thrusters 14 and a plurality of buoyancy blocks 15. In this embodiment, the number of the underwater thrusters 14 is three, and the three underwater thrusters 14 are evenly distributed along the central axis of the base 11. With a plurality of underwater thrusters 14, it is possible to achieve hovering in the water and stable lifting and lowering. The number of the buoyancy blocks 15 is multiple, and the main function of the buoyancy blocks 15 is to provide buoyancy to ensure the stability and reliability of the object in the water. By balancing the buoyancy blocks 15, the underwater maintenance robot can be in zero gravity underwater as a whole.

[0048] The nuclear reactor underwater maintenance robot also includes a plurality of function component storage racks 7, which are connected to the support legs 21. The function component storage racks 7 are provided with laser range finders, ultrasonic probes and maintenance tools. When different operations are required, the robot arm 5 can be used to load the tools in the function component storage racks 7.

[0049] The lifting mechanism 3 includes a lifting hollow motor, and the rotating mechanism 4 includes a rotating hollow motor. The cables can be built into the hollow motor, eliminating the need for a large number of coils, reducing radiation hot spots, and making it difficult to form high-dose areas.

[0050] In this embodiment, a method for using the underwater maintenance robot for a nuclear reactor is also constructed, which is based on the above-mentioned underwater maintenance robot for a nuclear reactor and includes the steps of:

[0051] S1. Using the crane to make the nuclear reactor underwater maintenance robot enter the container of the nuclear reactor;

[0052] S2. With the assistance of the camera and the depth meter, the underwater thruster 14 is used to suspend the nuclear reactor underwater maintenance robot at the target depth to achieve rough positioning;

[0053] S3, performing initial posture adjustment of the nuclear reactor underwater maintenance robot;

[0054] S4, calibrating the axial direction of the underwater nuclear reactor maintenance robot and the inspected object;

[0055] S5. Calibrate the height and circumferential position of the underwater nuclear reactor maintenance robot;

[0056] S6, completing the coordinate mapping between the robot coordinates and the inspected object;

[0057] S7, using the robot arm 5 to load the maintenance tool or calibrate the probe to perform the operation;

[0058] S8. Use the underwater thruster 14 to shift the nuclear reactor underwater maintenance robot as a whole and continue the next stage of work.

[0059] Specifically, in step S1, a crane is used to move the nuclear reactor underwater maintenance robot into a container of the nuclear reactor, and the maintenance robot enters the water and is unhooked.

[0060] The step S3 comprises:

[0061] S31, using the telescopic driver 22 to extend the lead screw module 23 to the first fixed position, so that the lead screw positioning seat 232 contacts the container wall 6;

[0062] S32, according to the feedback of the inclination sensor, the screw drive motor 233 is used to adjust the position of the screw positioning seat 232 relative to the container wall 6 until the nuclear reactor underwater maintenance robot is in a vertical position relative to the nuclear reactor container as a whole;

[0063] S33, using the telescopic driver 22 to extend the lead screw module 23 to the second fixed position for fixation.

[0064] Specifically, in step S31, when the screw positioning seat 232 contacts the container wall 6, the supporting force is relatively small, and the preliminary positioning is completed. In step S32, the slider 231 is driven to move by the screw drive motor 233, so that the screw positioning seat 232 can move up and down relative to the support leg 21 to adjust the position of the screw positioning seat 232 relative to the container wall 6, until the position of the three screw positioning seats 232 can make the nuclear reactor underwater maintenance robot as a whole in a vertical position relative to the container of the nuclear reactor. In step S33, when the screw module 23 is extended to the second fixed position for fixing, the supporting force between the screw positioning seat 232 and the container wall 6 is relatively large, completing the posture adjustment of the underwater maintenance robot and establishing a stable base point for the underwater maintenance robot.

[0065] Step S4 includes:

[0066] S41, using the robot arm 5 to load the laser rangefinder, moving the laser rangefinder to a position close to the container wall 6 and keeping the laser rangefinder perpendicular to the support leg 21;

[0067] S42, rotating the laser range finder 360 degrees around the central axis of the base 11, and obtaining a first curve measurement diagram between the laser range finder sensor data and the rotation angle;

[0068] S43. Compare the bottom structural features of the inspected object at different angles, and combine with the first curve measurement diagram. If the deviation exceeds the required range, adjust the position of the screw positioning seat 232 until the data of the bottom structural features of the inspected object at different angles are within the deviation requirement range, so as to ensure that the nuclear reactor underwater maintenance robot is consistent with the axis of the inspected object.

[0069] Specifically, in step S4, the axial direction of the nuclear reactor underwater maintenance robot and the inspected object is calibrated, and in step S43, the bottom structural features of the inspected object at different angles are based on the design drawing model of the inspected object as a reference. If the deviation exceeds the required range, a method similar to step S3 can be adopted to adjust the screw module 23 until the data of the bottom structural features of the inspected object at different angles are within the deviation requirement range to ensure that the nuclear reactor underwater maintenance robot and the inspected object are consistent in axis. The inspected object can be a support block or a core lower plate.

[0070] Step S5 includes:

[0071] S51, rotating the laser range finder again by 360 degrees around the central axis of the base 11, and obtaining a second curve measurement diagram between the laser range finder sensor data and the rotation angle;

[0072] S52, using the distance data of the flat surface of the bottom structural features of the inspected object at different angles to calibrate the height direction of the inspection robot;

[0073] S53, using the rising edge or the falling edge of the second curve measurement diagram to calibrate the angle of the maintenance robot in the circumferential direction.

[0074] Among them, the bottom structural features of the inspected object at different angles can be used as a reference based on the design drawing model of the inspected object, and the distance data of the flat surface of the bottom structural features of the inspected object at different angles can be used to calibrate the height direction of the maintenance robot, and the rising edge or falling edge of the second curve measurement diagram can be used to calibrate the angle of the maintenance robot in the circumferential direction.

[0075] In step S7, the robot arm 5 is used to load a maintenance tool or calibrate a probe to perform operations, and related non-destructive testing or maintenance and replacement operations can be performed.

[0076] In step S8, after the underwater maintenance robot completes the operation in the area, it uses the underwater propeller 14 to move, and repeats steps S2 to S6 to complete the position recalibration.

[0077] The beneficial effects of the nuclear reactor underwater maintenance robot and the use method thereof are:

[0078] 1. The underwater maintenance robot utilizes the underwater propeller 14 to facilitate underwater movement, reduce the use of crane resources, save time, avoid unnecessary partition detection work, help improve work efficiency, and save on-site resources;

[0079] 2. The overall configuration of the underwater maintenance robot takes up little space, and multiple underwater maintenance robots can be operated in the nuclear reactor vessel at the same time;

[0080] 3. Multiple lead screw modules 23 are used in conjunction with inclination sensors to adjust the posture of the underwater maintenance robot, and a laser rangefinder is used to calibrate the circumferential and height positions, thereby overcoming the problem of low positioning accuracy that may be caused by the lack of mechanical feature point support;

[0081] 4. The use of lifting hollow motors and rotating hollow motors can store cables without the need for a large number of coils. The built-in design of hollow cables in the equipment reduces the use of cable winding or drag chains and other components, and avoids the absorption of radioactive stains by a large number of cables, thereby reducing the collective radiation dose of operators and maintenance personnel, reducing radiation hotspots, and making it difficult to form high-dose areas;

[0082] 5. The underwater maintenance robot has a certain adaptability. By using the setting of the mechanical arm 5, it can be extended to a container with a similar structure to perform inspection and maintenance operations, such as inspection of the ring weld of the lower pile internal component hanging basket and replacement of the coaming bolts;

[0083] 6. The positioning method of the underwater maintenance robot is direct, fast and accurate, which overcomes the underwater maintenance robot's dependence on the specific installation position of the inspected object and achieves high-precision positioning.

[0084] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the scope covered by the claims of the present invention.

Claims

1. A nuclear reactor underwater maintenance robot, characterized in that: It comprises a connecting mechanism (1), a telescopic positioning mechanism (2), a lifting mechanism (3), a rotating mechanism (4) and a mechanical arm (5); The telescopic positioning mechanism (2) comprises a plurality of telescopic components, each of the telescopic components comprising a support leg (21) connected to the connecting mechanism (1), a telescopic driver (22) mounted on the support leg (21), and a lead screw module (23) connected to an output end of the telescopic driver (22); The lead screw module (23) comprises a slider (231) connected to the output end of the telescopic driver (22), a lead screw positioning seat (232) movably connected to the slider (231), and a lead screw driving motor (233) connected to the lead screw positioning seat (232), wherein the wall surface of the lead screw positioning seat (232) facing away from the slider (231) abuts against the container wall surface (6) of the nuclear reactor; The lifting mechanism (3) is connected to the connecting mechanism (1) and is used to drive the mechanical arm (5) to perform lifting movement; The rotating mechanism (4) is connected to the connecting mechanism (1) and is used to drive the mechanical arm (5) to perform a rotating motion; the mechanical arm (5) is used for the operation of the underwater maintenance robot.

2. The underwater nuclear reactor maintenance robot according to claim 1, characterized in that: The connecting mechanism (1) comprises a base (11) and a connecting frame (12); one end of each of the plurality of supporting legs (21) is connected to the base (11); the lifting mechanism (3) is mounted on the base (11); the output end of the lifting mechanism (3) is connected to the connecting frame (12); the rotating mechanism (4) is mounted on the connecting frame (12); and the output end of the rotating mechanism (4) is connected to the mechanical arm (5).

3. The underwater nuclear reactor maintenance robot according to claim 2, characterized in that: The connecting mechanism (1) further comprises a mounting frame (13), and the plurality of supporting legs (21) are all connected to the mounting frame (13); The mounting frame (13) is provided with a plurality of underwater thrusters (14) and a plurality of buoyancy blocks (15).

4. The underwater nuclear reactor maintenance robot according to claim 2, characterized in that: The base (11) is provided with an inclination sensor.

5. The underwater nuclear reactor maintenance robot according to claim 4, characterized in that: The nuclear reactor underwater maintenance robot further comprises a plurality of functional component accommodating racks (7), wherein the functional component accommodating racks (7) are connected to the supporting legs (21), and the functional component accommodating racks (7) are provided with laser rangefinders, ultrasonic probes and maintenance tools.

6. The underwater nuclear reactor maintenance robot according to claim 1, characterized in that: The lifting mechanism (3) comprises a lifting hollow motor, and the rotating mechanism (4) comprises a rotating hollow motor.

7. A method for using a nuclear reactor underwater maintenance robot, based on the nuclear reactor underwater maintenance robot according to any one of claims 1 to 6, characterized in that: Includes steps: S1. Using a crane to allow the underwater nuclear reactor maintenance robot to enter a container of a nuclear reactor; S2. With the assistance of a camera and a depth meter, the underwater nuclear reactor maintenance robot is suspended at a target depth position by using an underwater thruster (14) to achieve rough positioning; S3, performing initial posture adjustment of the underwater nuclear reactor maintenance robot; S4, calibrating the axial direction of the underwater nuclear reactor maintenance robot and the inspected object; S5, calibrating the height and circumferential position of the underwater nuclear reactor maintenance robot; S6, completing the coordinate mapping between the robot coordinates and the inspected object; S7, using the mechanical arm (5) to load the maintenance tool or calibrate the probe to perform the operation; S8. Use the underwater propeller (14) to shift the nuclear reactor underwater maintenance robot as a whole, and continue the work of the next stage.

8. The method for using the underwater nuclear reactor maintenance robot according to claim 7, characterized in that: Step S3 includes: S31, using the telescopic driver (22) to extend the lead screw module (23) to a first fixed position, so that the lead screw positioning seat (232) contacts the container wall (6); S32, according to the feedback of the inclination sensor, using the screw drive motor (233) to adjust the position of the screw positioning seat (232) relative to the container wall (6) until the nuclear reactor underwater maintenance robot as a whole is in a vertical position relative to the container of the nuclear reactor; S33, using the telescopic driver (22) to extend the lead screw module (23) to a second fixed position for fixation.

9. The method for using the underwater nuclear reactor maintenance robot according to claim 7, characterized in that: Step S4 includes: S41, using the mechanical arm (5) to load the laser rangefinder, moving the laser rangefinder to a position close to the container wall (6) and keeping the laser rangefinder perpendicular to the support leg (21); S42, rotating the laser rangefinder 360 degrees around the central axis of the base (11) to obtain a first curve measurement diagram between the laser rangefinder sensor data and the rotation angle; S43, comparing the bottom structural features of the inspected object at different angles, and combining the first curve measurement diagram, if the deviation exceeds the required range, adjusting the position of the screw positioning seat (232) until the data of the bottom structural features of the inspected object at different angles are within the required deviation range, so as to ensure that the nuclear reactor underwater maintenance robot is consistent with the axis of the inspected object.

10. The method for using the underwater nuclear reactor maintenance robot according to claim 7, characterized in that: Step S5 includes: S51, rotating the laser rangefinder again by 360 degrees around the central axis of the base (11), and obtaining a second curve measurement diagram between the laser rangefinder sensor data and the rotation angle; S52, using the distance data of the flat surface of the bottom structural features of the inspected object at different angles to calibrate the height direction of the inspection robot; S53, using the rising edge or the falling edge of the second curve measurement diagram to calibrate the angle of the maintenance robot in the circumferential direction.

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