A robot for grabbing foreign matter from the bottom of a pressure vessel

Abstract

The present invention relates to a method for grasping foreign objects, and more specifically, to a robot for grasping foreign objects at the bottom of a pressure vessel. A robot for grasping foreign objects at the bottom of a pressure vessel comprises a soft robotic arm, which is wrapped around a feed cylinder, two gripper motors respectively fixed on both sides of a gripper motor box, the output shaft of the gripper motor is wrapped around a gripper motor wire, the gripper motor wire is connected to the soft robotic arm, a feed ball screw and a ball screw nut form a ball screw mechanism, the feed ball screw is driven by a feed motor reducer, the feed ball screw is fixedly connected to the gripper motor box, the feed cylinder is fixedly connected to the gripper motor box, the ball screw nut is fixed to a feed bottom plate, a slideway corresponding to the feed motor is provided on the ball screw nut, and the feed motor is slidably connected to the ball screw nut in a horizontal direction; the robot can enter the lower part of the lower grid plate of the pressure vessel to grasp foreign objects.

Description

Technical Field

[0001] The present invention relates to a foreign body grabbing method, and more particularly to a foreign body grabbing robot at the bottom of a pressure vessel. Background Art

[0002] As the only non-replaceable component during the life of a nuclear power plant, the lower internals of the pressure vessel represent the lowest point in the primary circuit system. Therefore, inspection for foreign matter in this area is essential. During operation or during maintenance outages, foreign matter can be introduced into the internals due to various operating factors, inadequate foreign matter protection during pressure vessel maintenance, or improper operation. If these foreign matter are not promptly detected and removed, they can migrate with the medium during operation, potentially damaging fuel assemblies and primary circuit system equipment, and potentially compromising the safe operation of the nuclear power plant.

[0003] The lower reactor internals and the entire pressure vessel lower head form a complex, enclosed area. To inspect and remove foreign objects, tools must pass through the water holes in the lower grid plate above the core support plate. Most of these holes are inaccessible to the pressure vessel bottom. With the reactor internals located 20-25 meters underwater, remote inspection tools are required for comprehensive inspection. Therefore, a remotely operated, radiation-resistant robot is required to remove foreign objects beneath the pressure vessel's lower grid plate. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a foreign body grabbing robot at the bottom of a pressure vessel, which has the beneficial effect of being able to enter the lower part of the lower grid plate of the pressure vessel to grab foreign bodies.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A foreign body grabbing robot for the bottom of a pressure vessel, comprising a soft robotic arm, the soft robotic arm being wound around a feed cylinder, two gripper motors being fixed on either side of a gripper motor box, the gripper motor output shaft being wound around a gripper motor cable, the gripper motor cable being connected to the soft robotic arm, a feed ball screw and a ball screw nut forming a ball screw mechanism, the feed ball screw being driven by a feed motor reducer, the feed ball screw being fixedly connected to the gripper motor box, the feed cylinder being fixedly connected to the gripper motor box, the ball screw nut being fixed to a feed bottom plate, a slideway corresponding to the feed motor being provided on the ball screw nut, and the feed motor being slidably connected to the ball screw nut in a horizontal direction;

[0007] The structural form of the soft robotic arm is:

[0008] The tip of the soft robotic arm is connected to a joint segment formed by gluing a bellows and a joint partition, and the three joint segments are connected to a non-joint segment formed by gluing a bellows and a non-joint partition.

[0009] The tip of the robotic arm is provided with a camera, a mechanical gripper, a suction pipe and a negative pressure gripper.

[0010] The feed tube is connected to the opening at the bottom of the gripper motor box, the hole of the feed tube is connected to the starting position of the soft robotic arm, the feed tube is fixedly connected to the starting end of the soft robotic arm, and the gripper motor wire wrapped around the gripper motor passes through the hole of the feed tube and the gripper motor box, and penetrates into the soft robotic arm to connect the mechanical gripper.

[0011] The feed motor reducer provides power to the ball screw, and the feed motor drives the ball screw to rotate on the ball screw nut, driving the feed cylinder to rotate and translate. A spiral groove is pre-set on the feed cylinder, and the pitch of the spiral groove is consistent with the ball screw. The soft robotic arm is wound around the spiral groove to control the soft robotic arm to be retracted or released on the feed cylinder to achieve rotary fixed-point feeding; the soft robotic arm hangs down and passes through the water flow hole. When the soft robotic arm is in the zero point state, the three joint segments have passed through the feed base plate.

[0012] The joint motor base is equipped with nine joint motors. The soft robotic arm passes through the center of the joint motor base, which is fixed to the feed base. Each joint motor is connected to nine joint wires. Each joint wire passes through a hole in the joint separator and is then tied to the top of the corresponding joint segment. The holes in the non-joint segments are replaced with slots to prevent the joint wires from interacting with the non-joint segments during the soft robotic arm's descent. Each joint is connected to three joint wires, separated by 120 degrees. The joint motors pull the joint wires to control the joint's bending.

[0013] The lower side of the feed base plate is fixedly connected to the movable end of the guide rail mechanism; a foreign matter collection box is fixed under the guide rail mechanism, and the guide rail mechanism is fixed on the rotating base;

[0014] The rotating base is provided with a rotating motor, which drives the guide rail mechanism to rotate via a worm gear reducer.

[0015] The guide rail mechanism includes a movable end of the guide rail mechanism and an advance and retreat base plate. The movable end of the guide rail mechanism is slidably connected to the advance and retreat base plate. The advance and retreat motor is fixed to the advance and retreat base plate. The advance and retreat motion is transmitted to the advance and retreat trapezoidal lead screw by the advance and retreat motor. The advance and retreat trapezoidal lead screw cooperates with a nut, and the nut is connected to the advance and retreat base plate to realize the relative translation of the movable end of the guide rail mechanism and the advance and retreat base plate.

[0016] The suction tube and the negative pressure gripper are provided with negative pressure by an air pump on the ground. The mechanical gripper is driven by two gripper motors to rotate and grasp. The rotation is pulled by the gripper motor line, and the grasping is a biopsy forceps structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0018] Figure 1 This is a schematic diagram of the overall structure of a robot for grabbing foreign matter from the bottom of a pressure vessel according to the present invention;

[0019] Figure 2 Schematic diagram of the structure of the soft robotic arm of the present invention;

[0020] Figure 3 It is a schematic structural diagram of the tip of the soft robotic arm of the present invention;

[0021] Figure 4 It is a structural diagram of the positioning subsystem of the present invention;

[0022] Figure 5 It is a structural schematic diagram of the feeding subsystem of the present invention;

[0023] Figure 6 Schematic diagram of the joints of the soft robotic arm of the present invention;

[0024] Figure 7 Schematic diagram of the rear structure of the tip of the soft robotic arm of the present invention;

[0025] In the figure: feed cylinder 1; soft robotic arm 2; gripper motor box 3; gripper motor 4; feed ball screw 5; ball screw nut 6; feed motor 7; advance and retreat motor 8; rotating base 9; foreign matter collection box 10; guide rail mechanism 11; advance and retreat base plate 12; advance and retreat trapezoidal screw 13; feed base plate 14; joint motor 15; rotating motor 16; robotic arm tip 17; joint partition 18; non-joint partition 19; bellows 20; robotic gripper 21; suction pipe 22; negative pressure gripper 23; camera 24; joint line 25; gripper motor line 26. DETAILED DESCRIPTION

[0026] like Figure 1-7 As shown, a foreign body grasping robot at the bottom of a pressure vessel includes a soft robotic arm 2, which is wrapped around a feed cylinder 1, and two gripper motors 4 are respectively fixed on both sides of a gripper motor box 3. The output shaft of the gripper motor 4 is wrapped around a gripper motor line 26, and the gripper motor line 26 is connected to the soft robotic arm 2. The feed ball screw 5 and the ball screw nut 6 form a ball screw mechanism. The feed ball screw 5 is driven by a reducer of a feed motor 7. The feed ball screw 5 is fixedly connected to the gripper motor box 3, and the feed cylinder 1 is fixedly connected to the gripper motor box 3. The ball screw nut 6 is fixed on a feed base plate 14, and a slide corresponding to the feed motor 7 is provided on the ball screw nut 6. The feed motor 7 is slidably connected to the ball screw nut 6 in the horizontal direction.

[0027] The feed motor 7 can drive the feed ball screw 5 to rotate. When the feed ball screw 5 rotates on the ball screw nut 6, it will also move left and right, thereby driving the gripper motor box 3 and the feed cylinder 1 to move left and right while rotating. The forward and reverse rotation of the feed cylinder 1 drives the soft robotic arm 2 to be released from the feed cylinder 1 or wound around the feed cylinder 1; when the two gripper motors 4 rotate, they can drive the gripper motor wires 26 thereon to be released or retracted, and then the two gripper motors 4 can control the mechanical gripper 21 on the soft robotic arm 2 through the two gripper motor wires 26.

[0028] The structural form of the soft robotic arm 2 is:

[0029] The tip 17 of the soft robotic arm is connected to a joint segment formed by gluing a bellows 20 and a joint partition 18 , and the three joint segments are connected to a non-joint segment formed by gluing a bellows 20 and a non-joint partition 19 .

[0030] In this way, three joint segments are formed, and the three joint segments are connected by non-joint segments, so that the soft robotic arm 2 can bend and perform various movements.

[0031] The tip of the robotic arm 17 is provided with a camera 24 , a robotic gripper 21 , a suction pipe 22 and a negative pressure gripper 23 .

[0032] The camera 24 can provide images to find and locate foreign objects; the mechanical gripper 21 can grab foreign objects, and the straw 22 can suck up foreign objects; the negative pressure gripper 23 can grab foreign objects, and then different tools can be selected as needed to pick up foreign objects at the bottom of the pressure vessel.

[0033] The feed tube 1 is connected to the opening at the bottom of the gripper motor box 3. The hole of the feed tube 1 is connected to the starting position of the soft robotic arm 2. The feed tube 1 is fixedly connected to the starting end of the soft robotic arm 2. The gripper motor wire 26 wound around the gripper motor 4 passes through the hole of the feed tube 1 and the gripper motor box 3, and penetrates into the soft robotic arm 2 to connect the mechanical gripper 21.

[0034] The gripper motor wire 26 wound on the gripper motor 4 can be conveniently passed through the holes of the feed tube 1 and the gripper motor box 3, and penetrated into the soft robotic arm 2 to connect to the mechanical gripper 21, so as to facilitate the control of the mechanical gripper 21 to grab foreign objects.

[0035] The reducer of the feed motor 7 provides power to the ball screw 5, and the feed motor 7 drives the ball screw 5 to rotate on the ball screw nut 6, driving the feed cylinder 1 to rotate and translate. A spiral groove is pre-set on the feed cylinder 1, and the pitch of the spiral groove is consistent with the ball screw 5. The soft robotic arm 2 is wound around the spiral groove to control the soft robotic arm 2 to be retracted or released on the feed cylinder 1, realizing rotary fixed-point feeding; the soft robotic arm 2 hangs down through the water flow hole, and the soft robotic arm 2 is in the zero point state, and the three joint segments have passed through the feed base plate 14.

[0036] Nine joint motors 15 are provided on the joint motor seat, and the soft robotic arm 2 passes through the center of the joint motor seat, and the joint motor seat is fixed on the feed base plate 14; the nine joint motors 15 are respectively connected to nine joint lines 25, and each joint line 25 passes through the hole of the joint partition plate 18, passes through the top of the corresponding joint segment, and is tied and fixed to the joint. The hole of the non-joint segment is changed to a groove, so that the joint line 25 does not interact with the non-joint segment when the soft robotic arm 2 descends; each joint is fixed with three joint lines 25, and the fixed joint lines 25 are separated by one hundred and twenty degrees. The joint motor 15 pulls the joint line 25 to control the bending of the joint.

[0037] The lower side of the feed base plate 14 is fixedly connected to the movable end of the guide rail mechanism 11 ; a foreign matter collection box 10 is fixed below the guide rail mechanism 11 , and the guide rail mechanism 11 is fixed on the rotating base 9 .

[0038] The rotating base 9 is provided with a rotating motor 16 , which drives the guide rail mechanism 11 to rotate via a worm gear reducer.

[0039] The guide rail mechanism 11 includes a movable end of the guide rail mechanism and an advance and retreat base plate 12. The movable end of the guide rail mechanism is slidably connected to the advance and retreat base plate 12. The advance and retreat motor 8 is fixed to the advance and retreat base plate 12. The advance and retreat motion is transmitted by the advance and retreat motor 8 to the advance and retreat trapezoidal lead screw 13. The advance and retreat trapezoidal lead screw 13 cooperates with the nut, and the nut is connected to the advance and retreat base plate 12 to realize the relative translation of the movable end of the guide rail mechanism and the advance and retreat base plate 12.

[0040] The suction tube 22 and the negative pressure gripper 23 are provided with negative pressure by an air pump on the ground. The mechanical gripper 21 is driven by two gripper motors 4 to rotate and grasp, wherein the rotation is pulled by the gripper motor line 26, and the grasping is a biopsy forceps structure.

[0041] The following are the steps for routine inspection of pressure vessels:

[0042] During routine inspection of the pressure vessel, the structure above the lower grid plate has been completely dismantled;

[0043] The pressure vessel bottom foreign body grabbing robot is hoisted as a whole above the lower grid plate, and the four fixing feet of the pressure vessel bottom foreign body grabbing robot are passed through the water flow holes to fix the robot as a whole;

[0044] By rotating and translating, the camera 24 on the soft robotic arm 2 is positioned so that the soft robotic arm 2 is perpendicular to the target water flow hole;

[0045] Make the soft robotic arm 2 fall vertically and stop between a certain plate of the pressure vessel;

[0046] The soft robotic arm 2 consists of a tip and three joint segments. Joint motors 15 drive the movement of the joint segments. Each joint is connected to three joint lines 25, which are spaced 120 degrees apart. The joint motors 15 pull the joint lines 25 to control joint bending. The tip carries a camera 24 to search for and locate foreign objects.

[0047] The mechanical gripper 21, the negative pressure gripper 23, and the suction pipe 22 use appropriate gripping mechanisms to grab foreign objects according to their size, shape, and weight;

[0048] After the foreign object is captured, the soft robot arm 2 returns to its original path, places the foreign object into the foreign object collection box 10 for temporary storage, and repeats the above process between other boards;

[0049] After the inspection is completed, the overall lifting robot moves out of the pressure vessel.

Claims

1. A robot for grabbing foreign matter from the bottom of a pressure vessel, comprising a soft robotic arm (2), characterized in that: The soft robotic arm (2) is wound on the feed cylinder (1), and two gripper motors (4) are respectively fixed on both sides of the gripper motor box (3). The output shaft of the gripper motor (4) is wound around the gripper motor line (26), and the gripper motor line (26) is connected to the soft robotic arm (2). The feed ball screw (5) and the ball screw nut (6) form a ball screw mechanism. The feed ball screw (5) is driven by the feed motor (7) reducer. The feed ball screw (5) is fixedly connected to the gripper motor box (3). The feed cylinder (1) is fixedly connected to the gripper motor box (3). The ball screw nut (6) is fixed on the feed base plate (14). A slideway corresponding to the feed motor (7) is provided on the ball screw nut (6). The feed motor (7) is slidably connected to the ball screw nut (6) in the horizontal direction.

2. The robot for grabbing foreign matter from the bottom of a pressure vessel according to claim 1, characterized in that: The structural form of the soft robotic arm (2) is: The tip of the soft robotic arm (17) is connected to a joint segment formed by bonding a bellows (20) and a joint partition (18), and the three joint segments are connected to a non-joint segment formed by bonding a bellows (20) and a non-joint partition (19).

3. The robot for grabbing foreign matter from the bottom of a pressure vessel according to claim 2, characterized in that: A camera (24), a mechanical gripper (21), a suction pipe (22) and a negative pressure gripper (23) are provided on the tip of the mechanical arm (17).

4. The robot for grabbing foreign matter from the bottom of a pressure vessel according to claim 2, characterized in that: The feed cylinder (1) is connected to the opening at the bottom of the gripper motor box (3), the hole of the feed cylinder (1) is connected to the starting position of the soft robotic arm (2), the feed cylinder (1) and the starting end of the soft robotic arm (2) are fixedly connected, and the gripper motor wire (26) wound around the gripper motor (4) passes through the hole of the feed cylinder (1) and the gripper motor box (3), penetrates into the soft robotic arm (2) and connects to the mechanical gripper (21).

5. The robot for grabbing foreign matter from the bottom of a pressure vessel according to claim 2, characterized in that: The feed motor (7) reducer provides power to the ball screw (5), and the feed motor (7) drives the ball screw (5) to rotate on the ball screw nut (6), driving the feed cylinder (1) to rotate and translate. A spiral groove is pre-set on the feed cylinder (1), and the pitch of the spiral groove is consistent with that of the ball screw (5). The soft robotic arm (2) is wound around the spiral groove to control the soft robotic arm (2) to be retracted or released on the feed cylinder (1), thereby realizing rotary fixed-point feeding; the soft robotic arm (2) hangs down and passes through the water flow hole. When the soft robotic arm (2) is in a zero-point state, the three joint segments have passed through the feed base plate (14).

6. The robot for grabbing foreign matter from the bottom of a pressure vessel according to claim 5, characterized in that: Nine joint motors (15) are arranged on the joint motor seat, the soft robot arm (2) passes through the center of the joint motor seat, and the joint motor seat is fixed on the feed base plate (14); the nine joint motors (15) are respectively connected to nine joint lines (25), each joint line (25) passes through the hole of the joint partition plate (18), passes through the top of the corresponding joint segment, and is then tied to the joint, and the hole of the non-joint segment is changed into a groove, so that the joint line (25) does not interact with the non-joint segment when the soft robot arm (2) descends; each joint is fixedly connected to three joint lines (25), and the fixed joint lines (25) are separated by 120 degrees. The joint motor (15) pulls the joint line (25) to control the bending of the joint.

7. The robot for grabbing foreign matter from the bottom of a pressure vessel according to claim 1, characterized in that: The lower side of the feed base plate (14) is fixedly connected to the movable end of the guide rail mechanism (11); a foreign matter collection box (10) is fixed below the guide rail mechanism (11), and the guide rail mechanism (11) is fixed on the rotating base (9).

8. The robot for grabbing foreign matter from the bottom of a pressure vessel according to claim 7, characterized in that: A rotating motor (16) is provided on the rotating base (9), and the rotating motor (16) drives the guide rail mechanism (11) to rotate via a worm gear reducer.

9. The robot for grabbing foreign matter from the bottom of a pressure vessel according to claim 8, characterized in that: The guide rail mechanism (11) comprises a movable end of the guide rail mechanism and an advance and retreat base plate (12); the movable end of the guide rail mechanism is slidably connected to the advance and retreat base plate (12); the advance and retreat motor (8) is fixed to the advance and retreat base plate (12); the advance and retreat motion is transmitted by the advance and retreat motor (8) to the advance and retreat trapezoidal lead screw (13); the advance and retreat trapezoidal lead screw (13) cooperates with a nut, and the nut is connected to the advance and retreat base plate (12), thereby realizing relative translation between the movable end of the guide rail mechanism and the advance and retreat base plate (12).

10. The robot for grabbing foreign matter from the bottom of a pressure vessel according to claim 3, characterized in that: The suction tube (22) and the negative pressure gripper (23) are provided with negative pressure by an air pump on the ground. The mechanical gripper (21) is driven by two gripper motors (4) to rotate and grasp, wherein the rotation is pulled by the gripper motor line (26), and the grasping is a biopsy forceps structure.

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