An end-effector positioning platform for replacing reactor siding bolts

Abstract

This invention belongs to the field of reactor siding bolt replacement, specifically relating to an end-effector positioning platform for reactor siding bolt replacement. The platform includes a vertical conveying platform, an end-effector mounting platform, and a visual monitoring and auxiliary positioning system. The end-effector mounting platform is slidably mounted on the vertical conveying platform, the visual monitoring and auxiliary positioning system is mounted on the end-effector mounting platform, and the end-effector execution module is mounted on the end-effector mounting platform. The vertical conveying platform enables the end-effector mounting platform to move vertically. The visual monitoring and auxiliary positioning system is used for visual identification and assisted positioning of bolt holes or bolts. The end-effector mounting platform is used to deliver the end-effector execution module to the target working position within the reactor, enabling tool head replacement of each module and achieving precise positioning with the siding bolts. This invention effectively reduces positioning errors and lowers the risk of bolt replacement failure.

Description

Technical Field

[0001] This invention belongs to the field of reactor cofferdam bolt replacement, and specifically relates to an end-effector positioning platform for reactor cofferdam bolt replacement. Background Technology

[0002] The cofferdam bolts of the lower in-reactor components of M310 and CPR1000 nuclear power units are exposed to high stress and high corrosion, and are subjected to repeated loads for extended periods, leading to corrosion and cracking. This bolt deterioration directly impacts the safe operation of the nuclear power unit, necessitating timely replacement of deteriorated cofferdam bolts.

[0003] The current process for replacing baffle bolts involves first locating them and removing the anti-loosening devices, then removing the deteriorated bolts, installing new bolts, and finally applying anti-loosening treatment to the newly installed bolts. This repair process is characterized by its complexity, involving multiple action requirements and various tool heads; its long-distance underwater operation with high radiation doses; its high bolt installation accuracy requirements; and its excessive reliance on manual labor in the positioning process. Achieving consistent positioning accuracy across different tool heads during baffle bolt replacement places high demands on the system. In underwater and highly radioactive environments, the equipment's radiation resistance, corrosion resistance, and signal transmission stability face significant challenges. High bolt alignment and positioning accuracy is required; otherwise, bolt replacement failures may occur, or even damage to the replacement tools. Summary of the Invention

[0004] The purpose of this invention is to provide an end-effector positioning platform for reactor cofferdam bolt replacement, which enables precise underwater positioning of the end-effector and the cofferdam bolts, reduces positioning errors, and thus lowers the risk of bolt replacement failure.

[0005] Technical solution to achieve the purpose of this invention:

[0006] An end-effector positioning platform for reactor cofferdam bolt replacement includes a vertical transport platform, an end-effector mounting platform, and a visual monitoring and auxiliary positioning system. The end-effector mounting platform is slidably mounted on the vertical transport platform, the visual monitoring and auxiliary positioning system is mounted on the end-effector mounting platform, and the end-effector module is mounted on the end-effector mounting platform. The vertical transport platform enables the end-effector mounting platform to move vertically. The visual monitoring and auxiliary positioning system is used to visually identify bolt holes or bolts, and then calculate the positional deviation between the tool head and the bolt hole or bolt based on the hand-eye calibration results to achieve auxiliary positioning. The end-effector mounting platform is used to deliver the end-effector module to the target working position inside the reactor, and to perform tool head replacement of each module underwater as needed, achieving precise positioning with the cofferdam bolts.

[0007] The vertical conveying platform includes: a basic frame, linear slide rails, and a transmission rack. The basic frame is symmetrically equipped with linear slide rails along the vertical direction. The end-mounted platform is slidably installed on the linear slide rails and moves along the vertical direction on the linear slide rails. The transmission rack is installed on the back of one side of the linear slide rails and cooperates with the end-mounted platform to ensure that the end-mounted platform moves along the vertical direction on the linear slide rails.

[0008] The vertical conveying platform is connected to an operating platform at the top, which is used to realize movement in the X direction, movement in the Y direction, and vertical lifting and rotation.

[0009] An angle sensor is installed above the basic frame to ensure the verticality of the vertical conveying platform.

[0010] The vertical conveying platform also includes: a tool head storage rack and a temporary storage container for waste bolts. The tool head storage rack and the temporary storage container for waste bolts are respectively installed on the basic frame and are used to store tool heads and waste bolts.

[0011] The end effector module includes a rotary operation end and an EDM processing end.

[0012] The end-mounted platform includes: a lifting frame, a linear sliding base bearing, a lifting drive, a transverse screw assembly, a rotary table, and an integrated frame for the end-effector module. The linear sliding base bearing is installed on the rear side of the lifting frame and cooperates with the linear slide rail on the vertical conveying platform for guidance, enabling the end-mounted platform to move vertically. The lifting drive is installed on the rear side of the lifting frame and is connected to the transmission rack and pinion on the vertical conveying platform to provide lifting drive power for the end-mounted platform. The transverse screw assembly is installed below the lifting frame, and the rotary table is installed below the transverse screw assembly. The integrated frame for the end-effector module is installed below the rotary table, and the rotary end-working end and the EDM processing end are installed on the integrated frame for the end-effector module. The transverse screw assembly provides lateral movement for the rotary end-working end and the EDM processing end, and the rotary table provides rotational movement for the rotary end-working end and the EDM processing end when positioning the bolt to be replaced.

[0013] The end-mounted platform also includes a filter and suction device, which is installed at the front end of the lifting frame. A suction device inlet is provided next to both the rotating end and the EDM processing end to absorb the dust and foreign objects generated during the operation of the rotating end and the EDM processing end.

[0014] The visual monitoring and assisted positioning system includes a visual assisted positioning camera, which is installed on the end-mounted platform and faces the bolt holes and threaded holes of the enclosure. By visually recognizing the bolt holes and bolts, the system calculates the positional deviation between the optical center of the camera and the center of the extracted threaded hole in a unified coordinate system. Then, based on the hand-eye calibration results, it calculates the positional deviation between the tool head and the center of the bolt hole or bolt head to achieve assisted positioning.

[0015] The visual monitoring and assisted positioning system also includes a visual monitoring camera, which is installed on the end-effector module integration frame to monitor the working process and status of the end-effector module.

[0016] The beneficial technical effects of this invention are as follows:

[0017] 1. The present invention provides an end-effector positioning platform for replacing reactor cofferdam bolts. The vertical conveying platform has translational movements in the X, Y, and Z directions, enabling automatic positioning. It also has a rotation function, allowing for angle adjustment to ensure the end-effector on the vertical conveying platform is aligned with the target bolt hole. Through X, Y, Z directional and rotational movements, after position calibration, it can automatically carry the tool head to complete the initial positioning of the designated bolt hole.

[0018] 2. The end-effector positioning platform for reactor cofferdam bolt replacement provided by the present invention has lifting, lateral movement and rotation functions. It is driven by a servo motor driving a lead screw nut. With encoder feedback and vision-assisted positioning, it can achieve automatic and accurate positioning, meeting the accuracy requirements when replacing cofferdam bolts.

[0019] 3. In the end-positioning platform for replacing reactor cofferdam bolts provided by the present invention, all drive motors of the end-mounted platform adopt an underwater air-filled sealing structure design, which has good sealing performance.

[0020] 4. In the end-positioning platform for replacing reactor cofferdam bolts provided by the present invention, the end-mounted platform frame is made of stainless steel welded together to ensure sufficient rigidity and strength, and to ensure its parallelism and perpendicularity requirements during the design, processing and manufacturing process.

[0021] 5. The end-effector positioning platform for reactor cofferdam bolt replacement provided by the present invention is equipped with a visual monitoring, observation and auxiliary positioning camera, which can accurately realize the positioning and centering of the target position during the end-effector operation, and monitor the operation process throughout.

[0022] 6. The present invention provides an execution end positioning platform for replacing reactor cofferdam bolts. The end platform is equipped with an underwater filtration and suction system, which can completely absorb the dust and foreign objects generated during the operation of the end tool. The suction and filtration system works together to prevent foreign objects such as cutting materials from contaminating the water quality of the pool during the entire bolt replacement process. Moreover, a logical protection relationship is set between the loading platform and the execution end module, so the bolt replacement process has a high degree of safety.

[0023] 7. In the end-effector positioning platform for reactor cofferdam bolt replacement provided by this invention, the visual monitoring and auxiliary positioning system has good radiation resistance and can meet the replacement and maintenance needs of multiple bolts; the camera has good underwater sealing performance, adopts explosion-proof design, can withstand large water pressure, has its own high-brightness LED lighting, the light source brightness is adjustable, and the camera focal length is adjustable to ensure good image acquisition. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the vertical conveying platform structure in an end-positioning platform for replacing reactor cofferdam bolts provided by the present invention.

[0025] Figure 2 This is a schematic diagram of the end-mounted platform structure in an end-positioning platform for reactor coaxial plate bolt replacement provided by the present invention.

[0026] Figure 3 This is a schematic diagram of the assembly of an end-effector positioning platform and an end-effector module for replacing reactor coaxial bolts, as provided by the present invention.

[0027] Figure 4 This is a schematic diagram of the filter suction device in the end-mounted platform of the present invention;

[0028] Figure 5 This is a schematic diagram of the rotary table structure in the end-mounted platform of the present invention;

[0029] Figure 6 This is a schematic diagram of the visual-assisted positioning camera structure of the present invention;

[0030] Figure 7 This is a flowchart illustrating the positioning bolt positioning of the visual-assisted positioning camera according to the present invention.

[0031] In the diagram: 1-1, Basic frame; 1-2, Tool head storage rack; 1-3, End-effector mounting platform; 1-4, End-effector module; 1-5, Temporary storage container for waste bolts; 3-1, Lifting frame; 3-2, Filtering and suction device; 3-3, Transverse lead screw assembly; 3-4, Visual monitoring camera; 3-5, Rotary end-effector; 3-6, EDM processing end-effector; 3-7, Filtering and suction device inlet; 3-8, Visual auxiliary positioning camera; 3-9, End-effector module integrated frame; 3-10, Rotary table; 3-11, Lifting drive; 3-12, Linear sliding base bearing. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0033] like Figure 1-3 As shown, this invention provides an end-effector positioning platform for reactor cofferdam bolt replacement, comprising a vertical transport platform, an end-effector mounting platform 1-3, and a visual monitoring and auxiliary positioning system. The end-effector mounting platform 1-3 is slidably mounted on the vertical transport platform, the visual monitoring and auxiliary positioning system is mounted on the end-effector mounting platform 1-3, and the end-effector module 1-4 is mounted on the end-effector mounting platform 1-3. The vertical transport platform is used for horizontal or vertical movement, and the direction is adjusted by rotating the vertical transport platform to initially position the end-effector module 1-4, ensuring it is aligned with the template screw holes. The visual monitoring and auxiliary positioning system visually identifies the bolt holes or bolts, and then calculates the positional deviation between the tool head and the bolt holes or bolts based on hand-eye calibration results, achieving auxiliary positioning. The end-effector mounting platform 1-3 delivers the end-effector module 1-4 to the target working position inside the reactor. As needed, the tool heads of each module are replaced underwater, achieving precise positioning with the cofferdam bolts.

[0034] like Figure 1 As shown, the vertical conveying platform includes: a base frame 1-1, linear guide rails, a transmission rack, a tool head storage rack 1-2, and a temporary storage container for waste bolts 1-5. The top of the vertical conveying platform is connected to the operating platform, enabling movement in the X and Y directions, as well as vertical lifting and rotation. The base frame 1-1 is constructed from welded stainless steel sheets. An angle sensor is installed above the base frame 1-1 to ensure the verticality of the conveying platform. Linear guide rails are symmetrically arranged along the vertical direction on the base frame 1-1. The end-mounted platform 1-3 is slidably mounted on these linear guide rails and moves vertically along them. The transmission rack, made of purchased stainless steel, is installed on the back of one side of the linear guide rail. The transmission rack cooperates with the end-mounted platform 1-3 to ensure its vertical movement along the linear guide rails.

[0035] like Figure 1-2 As shown, the end effector module 1-4 includes a rotary operation end 3-5 and an EDM processing end 3-6.

[0036] like Figure 2 As shown, the visual monitoring and assisted positioning system includes visual monitoring camera 3-4 and visual assisted positioning camera 3-8.

[0037] like Figure 2 As shown, the end-mounted platform 1-3 includes: a lifting frame 3-1, a linear sliding base bearing 3-12, a lifting drive 3-11, a transverse screw assembly 3-3, a rotary table 3-10, an end-actuator module integrated frame 3-9, and a filter suction device 3-2. The lifting frame 3-1 is made of welded stainless steel plates and serves as the structural foundation of the entire end-mounted platform 1-3. The linear sliding base bearing 3-12 is installed on the rear side of the lifting frame 3-1 and cooperates with the linear slide rail on the vertical conveying platform for guidance, enabling the end-mounted platform 1-3 to move vertically. The lifting drive 3-11 is installed on the rear side of the lifting frame 3-1 and uses a gear and rack transmission method, connecting with the transmission rack and rack on the vertical conveying platform. The motor reducer is designed with an underwater sealed structure to provide lifting drive power for the end-mounted platform 1-3. The transverse screw assembly 3-3 is installed below the lifting frame 3-1 and uses a screw drive structure. The rotary table 3-10, as shown... Figure 5 As shown, a gear-supported bearing structure is adopted, and the motor reducer is designed with an underwater sealing structure. The rotary table 3-10 is installed below the transverse lead screw assembly 3-3. The end effector module integrated frame 3-9 is made of stainless steel sheet welded together and is installed below the rotary table 3-10. The rotary operation end effector 3-5 and the EDM processing end effector 3-6 are installed on the end effector module integrated frame 3-9. The transverse lead screw assembly 3-3 provides lateral movement function for the rotary operation end effector 3-5 and the EDM processing end effector 3-6, and the rotary table 3-10 provides rotational movement function for the rotary operation end effector 3-5 and the EDM processing end effector 3-6 when positioning with the bolt to be replaced. A visual monitoring camera 3-4 is also installed on the end effector module integrated frame 3-9 to monitor the working process and working status of the end effector module 1-4.

[0038] Filter suction device 3-2, such as Figure 4 As shown, a suction device inlet 3-7 is installed at the front end of the lifting frame 3-1, next to the rotating end 3-5 and the EDM processing end 3-6, to absorb the dust and foreign objects generated during the operation of the rotating end 3-5 and the EDM processing end 3-6.

[0039] Visual-assisted positioning cameras 3-8, such as Figure 6As shown, this is an underwater radiation-resistant camera. The visual-assisted positioning camera 3-8 is installed on the end-mounted platform 1-3, facing the bolt holes and threaded holes of the enclosure. By visually recognizing the bolt holes and bolts, it calculates the positional deviation between the camera's optical center and the extracted center of the threaded hole in a unified coordinate system. Then, based on the hand-eye calibration results, it calculates the positional deviation between the tool head and the center of the bolt hole or bolt head, thus achieving assisted positioning.

[0040] like Figure 7 As shown, the bolt replacement is performed using an end-effector positioning platform for reactor coaxial plate bolt replacement provided by this invention, specifically including the following steps:

[0041] S1: Determine the exact location of the reactor coaxial plate bolts that need to be replaced;

[0042] S2: By controlling the horizontal, vertical and longitudinal directions, the vertical conveyor platform is transported to the target position and orientation to achieve initial positioning;

[0043] S3: Obtain an image of the bolt to be replaced by the visual monitoring and auxiliary positioning system 3-8 installed on the end-mounted platform 1-3;

[0044] S4: By visually recognizing bolt holes and bolts, the positional deviation between the camera optical center and the center of the bolt hole to be replaced in a unified coordinate system is calculated. Then, based on the hand-eye calibration results, the positional deviation between the tool head (the tool head and the camera are installed with an offset, and the offset is obtained through hand-eye calibration) and the center of the bolt hole or bolt head is calculated to achieve auxiliary positioning.

[0045] S5: After converting the position deviation into motion parameters, it feeds them back to the end-mounted platform 1-3 to guide it in position compensation;

[0046] S6: The end-mounted platform 1-3 provides lifting drive power through the lifting drive 3-11 and lateral movement of the transverse lead screw assembly 3-3 to control the movement of the end-acting tool 1-4, so that it moves to the spatial position of the bolt to be replaced;

[0047] S7: Controls the rotary table 3-10 of the end-effector platform, and through its rotational motion function, controls the rotation angle of the end-effector tool head to correspond to the spatial posture of the bolt to be replaced, thereby achieving precise positioning;

[0048] S8: Automatically replace the target bolts using the execution terminals 1-4 after positioning is completed.

[0049] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. All contents not described in detail in the present invention can be derived from existing technologies.

Claims

1. An end-effector positioning platform for replacing reactor siding bolts, characterized in that, The system includes a vertical conveying platform, an end-effector platform (1-3), and a visual monitoring and auxiliary positioning system. The end-effector platform (1-3) is slidably mounted on the vertical conveying platform. The visual monitoring and auxiliary positioning system is mounted on the end-effector platform (1-3), and the end-effector execution module (1-4) is mounted on the end-effector platform (1-3). The vertical conveying platform enables the end-effector platform (1-3) to move vertically. The visual monitoring and auxiliary positioning system is used to visually identify bolt holes or bolts, and then calculate the positional deviation between the tool head and the bolt hole or bolt based on the hand-eye calibration results to achieve auxiliary positioning. The end-effector platform (1-3) is used to deliver the end-effector execution module (1-4) to the target working position inside the stack, and to enable the tool head replacement of each module underwater as needed. The top of the vertical conveying platform is connected to an operating platform, which is used to realize movement in the X direction, movement in the Y direction, and vertical lifting and rotation; The vertical conveying platform includes: a base frame (1-1), linear slide rails, and a transmission rack. The base frame (1-1) is symmetrically equipped with linear slide rails along the vertical direction. The end-mounted platform (1-3) is slidably mounted on the linear slide rails and moves along the vertical direction on the linear slide rails. The transmission rack is mounted on the back of one side of the linear slide rail and cooperates with the end-mounted platform (1-3) to ensure that the end-mounted platform (1-3) moves along the vertical direction on the linear slide rails. The end-effector platform (1-3) includes: a lifting frame (3-1), a linear sliding base bearing (3-12), a lifting drive (3-11), a transverse lead screw assembly (3-3), a rotary table (3-10), and an end-effector module integrated frame (3-9). The linear sliding base bearing (3-12) is installed on the rear side of the lifting frame (3-1) and cooperates with the linear slide rail on the vertical conveying platform for guidance, realizing the vertical movement of the end-effector platform (1-3). The lifting drive (3-11) is installed on the rear side of the lifting frame (3-1) and is connected to the transmission rack and pinion on the vertical conveying platform. The system provides lifting drive power to the end-mounted platform (1-3); the transverse screw assembly (3-3) is installed below the lifting frame (3-1), and the rotary table (3-10) is installed below the transverse screw assembly (3-3); the end-execution module integration frame (3-9) is installed below the rotary table (3-10), and the end-execution module (1-4) is installed on the end-execution module integration frame (3-9); the transverse screw assembly (3-3) provides lateral movement function for the end-execution module (1-4), and the rotary table (3-10) provides rotational movement function for the end-execution module (1-4) when positioning with the bolt to be replaced.

2. The end-effector positioning platform for replacing reactor cofferdam bolts according to claim 1, characterized in that, An angle sensor is installed above the basic frame (1-1) to ensure the verticality of the vertical conveying platform.

3. The end-effector positioning platform for replacing reactor cofferdam bolts according to claim 1, characterized in that, The vertical conveying platform also includes: a tool head storage rack (1-2) and a waste bolt temporary storage container (1-5). The tool head storage rack (1-2) and the waste bolt temporary storage container (1-5) are respectively installed on the basic frame (1-1) for storing tool heads and waste bolts.

4. The end-effector positioning platform for replacing reactor cofferdam bolts according to claim 1, characterized in that, The end effector module (1-4) includes a rotary operation end (3-5) and an EDM processing end (3-6).

5. The end-effector positioning platform for replacing reactor cofferdam bolts according to claim 4, characterized in that, The rotary working end (3-5) and EDM processing end (3-6) are mounted on the end-effector module integrated frame (3-9); the transverse lead screw assembly (3-3) provides lateral movement function for the rotary working end (3-5) and EDM processing end (3-6), and the rotary table (3-10) provides rotational movement function for the rotary working end (3-5) and EDM processing end (3-6) when positioning with the bolt to be replaced.

6. The end-effector positioning platform for replacing reactor cofferdam bolts according to claim 5, characterized in that, The end-mounted platform (1-3) also includes a filter suction device (3-2). The filter suction device (3-2) is installed at the front end of the lifting frame (3-1). A suction device inlet (3-7) is provided next to the rotating working end (3-5) and the EDM processing end (3-6) to absorb the dust and foreign objects generated during the operation of the rotating working end (3-5) and the EDM processing end (3-6).

7. The end-effector positioning platform for replacing reactor cofferdam bolts according to claim 1, characterized in that, The visual monitoring and assisted positioning system includes a visual assisted positioning camera (3-8). The visual assisted positioning camera (3-8) is installed on the end-mounted platform (1-3) and faces the bolt holes and threaded holes of the enclosure. By visually recognizing the bolt holes and bolts, the system calculates the positional deviation between the optical center of the camera and the center of the extracted threaded hole in a unified coordinate system. Then, based on the hand-eye calibration results, it calculates the positional deviation between the tool head and the center of the bolt hole or bolt head to achieve assisted positioning.

8. The end-effector positioning platform for replacing reactor siding bolts according to claim 5, characterized in that, The visual monitoring and assisted positioning system also includes a visual monitoring camera (3-4), which is installed on the end-effector module integration frame (3-9) to monitor the working process and working status of the end-effector module (1-4).

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