A box girder bottom plate maintenance robot and a maintenance method

Abstract

A box girder bottom plate maintenance robot includes two storage areas and a robot body. The robot body includes an installation frame, first, second, and third connecting arms. There are two rows of support wheels arranged in the installation frame. The first connecting arm is fixed to the top of the installation frame, wound with a coil and electrically connected to a power source to form a first electromagnet. The second connecting arm is in a U-shaped structure, with the horizontal section clamped between the two rows of support wheels, and the two vertical sections extending out of the installation frame, each wound with a coil and electrically connected to the power source to form a second electromagnet. The third connecting arm is in an L-shaped structure, with the vertical section arranged at the bottom of the installation frame, and the extending end of the horizontal section exceeding the projection range of the installation frame and provided with a camera. The storage area includes a belt conveying mechanism, and the extending direction is perpendicular to the length direction of the box girder. The belt of the belt conveying mechanism is flush with the bottom of the installation frame. The structure of the present invention is simple and the maintenance cost is low, which can effectively meet the maintenance requirements for maintaining the bottom plate of the box girder.

Description

Technical Field

[0001] The present invention relates to the field of municipal bridges, and particularly to a maintenance robot for the bottom plate of a box girder and a maintenance method therefor. Background Art

[0002] A steel box girder is a commonly used structural form for long-span bridges. It is integrally welded by a top plate, a bottom plate, webs, transverse diaphragms, longitudinal diaphragms, and stiffeners, and has advantages such as good mechanical properties, reasonable weight, convenient construction, and prefabrication in a factory, and is widely used.

[0003] The steel box girder needs to be regularly maintained. For the maintenance operation of the bottom plate of the steel box girder, currently, it is usually that workers are hoisted manually under the steel box girder and towed by others for maintenance. Due to the large span of the steel box girder, the length of the suspension rope used is long, resulting in a large height interval between the middle section of the suspension rope and the bottom of the steel box girder, reducing the manual maintenance accuracy, and requiring multiple reciprocating movements, with high labor intensity and difficult to conduct reasonable detection. In addition, the steel box girder is relatively high, and there is also a risk of falling from a height.

[0004] Therefore, designing a bottom plate maintenance robot that can replace manual labor to solve the above problems is an urgent problem for those skilled in the art. Summary of the Invention

[0005] One of the purposes of the present invention is to provide, in view of the deficiencies of the prior art, a maintenance robot for the bottom plate of a box girder, which has a simple structure and low maintenance cost, and can effectively meet the maintenance requirements for the bottom plate of the box girder.

[0006] The second purpose of the present invention is to provide a method for maintaining the bottom plate of a box girder using the above-mentioned maintenance robot, which is simple and convenient to operate, can achieve the purpose of automatic maintenance, greatly reduces the manual labor intensity, ensures the safety of personnel, and can also avoid detection blind spots.

[0007] One of the technical solutions to achieve the purpose of the present invention is: a maintenance robot for the bottom plate of a box girder, including two storage areas and a robot body. A power supply is provided in the robot body. The robot body includes an installation frame, a first connecting arm, a second connecting arm, and a third connecting arm. Two rows of support wheels are provided in the installation frame. The number of support wheels in the same row is at least two and they are at the same height. At least one support wheel is driven to rotate by a first motor. The first connecting arm is fixed to the top of the installation frame and extends vertically upward. A coil is wound on the first connecting arm and is electrically connected to the power supply to form a first electromagnet. The second connecting arm has a U-shaped structure. The horizontal section of the second connecting arm is clamped between the two rows of support wheels. The two vertical sections of the second connecting arm extend out of the installation frame and have the same height as the first connecting arm. Coils are wound on the two vertical sections of the second connecting arm respectively and are electrically connected to the power supply to form a second electromagnet. The third connecting arm has an L-shaped structure. The vertical section of the third connecting arm is arranged at the bottom of the installation frame and is driven to rotate by a second motor. The extending end of the horizontal section of the third connecting arm extends beyond the projection range of the installation frame and is provided with a camera. The storage area includes a belt conveyor mechanism. The two belt conveyor mechanisms are respectively suspended at both ends of the bottom plate of the box girder, extend horizontally, and the extending direction is perpendicular to the length direction of the box girder. The belt of the belt conveyor mechanism is flush with the bottom of the installation frame.

[0008] The horizontal section of the second connecting arm is strip-shaped, and two strip-shaped grooves extending along the length direction are provided on both the top surface and the bottom surface. The number of support wheels in the same row is two pairs, which are respectively arranged at both ends of the installation frame and rollingly cooperate in the corresponding strip-shaped grooves.

[0009] The driving wheel of the belt conveyor mechanism is driven to rotate by a stepping motor, and the first motor uses a servo motor.

[0010] The horizontal section of the third connecting arm is an electric telescopic rod.

[0011] One of the technical solutions to achieve the second purpose of the present invention is: a method for maintaining the bottom plate of a box girder using any of the above maintenance robots, including the following steps:

[0012] 1) In the initial state, the robot body is supported on the belt conveyor mechanism at the first end through the installation frame, and the installation frame is away from the second vertical section of the second connecting arm;

[0013] 2) The first electromagnet is energized to adsorb on the bottom of the box girder, the second electromagnet is de-energized, and the first motor is energized to drive the support wheels to rotate, so that the second connecting arm translates towards the belt conveyor mechanism at the second end until the installation frame is away from the first vertical section of the second connecting arm;

[0014] 3) The second electromagnet is energized and adsorbed on the bottom of the box girder. The first electromagnet is de-energized, and the first motor is energized to drive the supporting wheels to rotate, causing the installation frame to translate towards the belt conveyor at the second end until the installation frame is close to the second vertical section of the second connecting arm.

[0015] 4) Repeat steps 2) and 3) to support the robot body on the belt conveying mechanism at the second end through the installation frame, and the installation frame is close to the first vertical section of the second connecting arm.

[0016] 5) The belt conveying mechanism at the second end drives the robot body to move vertically along the length direction of the box girder.

[0017] 6) The first electromagnet is energized and adsorbed on the bottom of the box girder. The second electromagnet is de-energized, and the first motor is energized to drive the supporting wheels to rotate, causing the second connecting arm to translate towards the belt conveyor at the first end until the installation frame is close to the second vertical section of the second connecting arm.

[0018] 7) The second electromagnet is energized and adsorbed on the bottom of the box girder. The first electromagnet is de-energized, and the first motor is energized to drive the supporting wheels to rotate, causing the installation frame to translate towards the belt conveyor at the first end until the installation frame is close to the first vertical section of the second connecting arm.

[0019] 8) Repeat steps 6) and 7) to make the robot body in the initial position and the vertical position change.

[0020] 9) The belt conveying mechanism at the first end drives the robot body to move vertically along the length direction of the box girder. The robot body reciprocates and translates on the belt conveying mechanisms at the first end and the second end. During the translation process of the robot body, the third connecting arm rotates, and the camera captures the area passing by the bottom of the box girder and synthesizes an image of the bottom of the box girder through an image algorithm for manual inspection to complete the maintenance work.

[0021] Specifically, the image algorithm in step 9) includes the following steps:

[0022] 1) The width of the annular area scanned by the camera rotating one week is s. After the camera rotates one week, the horizontal section length of the third connecting rod extends outward by s, and it is scanned n times. The width of the scanned annular area is denoted as S = n * s.

[0023] 2) During the alternating movement of the robot, the single movement distance is k, and it alternates m times. The translation distance is denoted as K = m * k.

[0024] 3) Establish a coordinate system based on the annular area width S and the translation distance K.

[0025] 4) Intercept the effective area within the fixed coordinates in the annular area with a width of S obtained in step 1).

[0026] 5) Fade - in processing is performed on the overlapping regions of the intercepted valid regions along the K coordinate;

[0027] 6) Stack the images to form a rectangular image for manual inspection.

[0028] In step 4), the valid region is a right - angled trapezoid or an isosceles trapezoid with an arc - shaped hypotenuse.

[0029] Adopting the above - mentioned technical solution has the following beneficial effects:

[0030] 1. The inspection robot for the box - girder bottom plate includes two storage areas and a robot body, and a power supply is arranged in the robot body. The robot body includes a mounting frame, a first connecting arm, a second connecting arm, and a third connecting arm. Among them, the mounting frame is used to install each connecting arm. Two rows of support wheels are arranged in the mounting frame. The number of support wheels in the same row is at least two and they are at the same height. At least one support wheel is driven to rotate by a first motor. The first connecting arm is fixed on the top of the mounting frame and extends vertically upward. A coil is wound on the first connecting arm and is electrically connected to the power supply to form a first electromagnet. When the first electromagnet is energized, it can be adsorbed on the box - girder bottom plate, making the mounting frame suspended under the box - girder bottom plate. The second connecting arm has a U - shaped structure. The horizontal section of the second connecting arm is clamped between the two rows of support wheels. The two vertical sections of the second connecting arm extend out of the mounting frame and have the same height as the first connecting arm. Coils are wound on the two vertical sections of the second connecting arm respectively and are electrically connected to the power supply to form a second electromagnet. The second connecting arm and the mounting bracket cooperate through the support wheels and the horizontal section, enabling the second connecting arm and the mounting bracket to move relative to each other horizontally and stably. When the second electromagnet is energized, it can be adsorbed on the box - girder bottom plate, making the mounting frame suspended under the box - girder bottom plate. The third connecting arm has an L - shaped structure. The vertical section of the third connecting arm is arranged at the bottom of the mounting frame and is driven to rotate by a second motor. The extending end of the horizontal section of the third connecting arm extends beyond the projection range of the mounting frame and is provided with a camera. The camera is driven by the mounting frame to translate and rotates along the translation trajectory during the translation process, achieving a larger camera coverage range. The storage area includes a belt conveyor mechanism. The two belt conveyor mechanisms are respectively suspended at both ends of the box - girder bottom plate, extending horizontally, and the extending direction is perpendicular to the length direction of the box - girder. The belt of the belt conveyor mechanism is flush with the bottom of the mounting frame. The robot body is supported on the belt conveyor mechanism through the mounting frame, and by controlling the position of the second connecting arm, the center of gravity of the robot body is located on the belt conveyor mechanism, ensuring the stability of the robot body on the belt conveyor mechanism, which is used for charging and maintenance, can effectively reduce the manual labor intensity, and ensure the safety of workers.

[0031] 2. The horizontal section of the second connecting arm is strip-shaped, and two strip-shaped grooves extending along the length direction are provided on both the top surface and the bottom surface. The number of support wheels in the same row is two pairs, which are respectively arranged at both ends of the installation frame and are in rolling fit in the corresponding strip-shaped grooves to ensure the relative stability between the second connecting arm and the installation frame and the supporting strength between them.

[0032] 3. In the maintenance method of the present invention, the camera makes a circular motion during translation, and a relatively large-area circular image is obtained by extending outward from the horizontal section of the third connecting arm, improving the scanning efficiency of the maintenance robot and reducing the number of reciprocating motions of the robot. By cutting the effective area from the circular scanned image and splicing it to form a rectangular image, the problem of inaccurate damage positioning caused by the horizontal stretching deformation of a single image can be avoided, and the weld blind area of the stiffener can also be eliminated, and the inspection image of the stiffener on the bottom plate of the box girder can be accurately obtained.

[0033] The following is a further description in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of the present invention;

[0035] Figure 2 is a schematic diagram of the robot body staying in the storage area of the present invention;

[0036] Figure 3 is a view of step 1) in the image algorithm of the present invention;

[0037] Figure 4 is a view of step 2) in the image algorithm of the present invention;

[0038] Figure 5 is a view of step 3) in the image algorithm of the present invention;

[0039] Figure 6 is a view of step 4) in the image algorithm of the present invention;

[0040] Figure 7 is a view of step 5) in the image algorithm of the present invention;

[0041] Figure 8 is a view of step 6) in the image algorithm of the present invention.

[0042] In the drawings, 1 is the storage area, 2 is the robot body, 3 is the installation frame, 4 is the first connecting arm, 5 is the second connecting arm, 6 is the third connecting arm, 7 is the support wheel, 8 is the first motor, 9 is the first electromagnet, 10 is the second electromagnet, 11 is the second motor, 12 is the camera, and 13 is the belt conveyor mechanism. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] Embodiment

[0044] See Figure 1 and Figure 2 Figure 2 , the box girder bottom plate maintenance robot includes two storage areas 1 and a robot body 2. A power supply is provided in the robot body 2, and generally, a rechargeable lithium battery is used as the power supply. The robot body 2 includes a mounting frame 3, a first connecting arm 4, a second connecting arm 5, and a third connecting arm 6. Generally, the mounting frame 3 is set as a cubic frame. Two rows of support wheels 7 are provided in the mounting frame 3. The number of support wheels 7 in the same row is at least two and they are at the same height. At least one support wheel is driven to rotate by a first motor 8. In this embodiment, the number of support wheels 7 in the same row is two pairs, which are respectively arranged at both ends of the mounting frame 3, and the first motor 8 is a servo motor. The first connecting arm 4 is fixed to the top of the mounting frame 3 and extends vertically upward. A coil is wound on the first connecting arm and is electrically connected to the power supply to form a first electromagnet 9. The second connecting arm 5 has a U-shaped structure. The horizontal section of the second connecting arm 5 is clamped between the two rows of support wheels 7. The two vertical sections of the second connecting arm 5 extend out of the mounting frame 3 and have the same height as the first connecting arm 4. Coils are respectively wound on the two vertical sections of the second connecting arm and are electrically connected to the power supply to form a second electromagnet 10. In this embodiment, the horizontal section of the second connecting arm 4 is strip-shaped, and two strip-shaped grooves extending along the length direction are provided on both the top surface and the bottom surface, and it is in rolling fit with the corresponding strip-shaped grooves. The third connecting arm 6 has an L-shaped structure. The vertical section of the third connecting arm 6 is arranged at the bottom of the mounting frame 3 and is driven to rotate by a second motor 11. The extending end of the horizontal section of the third connecting arm 6 extends beyond the projection range of the mounting frame 3 and is provided with a camera 12. In this embodiment, the horizontal section of the third connecting arm 6 is an electric telescopic rod, so that the camera can be translated outward. The storage area 1 includes a belt conveying mechanism 13. The driving wheel of the belt conveying mechanism 13 is driven to rotate by a stepping motor. The two belt conveying mechanisms 13 are respectively suspended at both ends of the box girder bottom plate, extend horizontally, and the extending direction is perpendicular to the length direction of the box girder. The belt of the belt conveying mechanism 13 is flush with the bottom of the mounting frame.

[0045] To ensure safety, a safety rope is further included. The two ends of the safety rope are respectively fixedly connected to both ends of the box girder, and a safety support arm is provided on the mounting frame. The extending end of the safety support arm is sleeved on the safety rope.

[0046] Embodiment

[0047] The method for maintaining the box girder bottom plate by using the maintenance robot of Embodiment 1 includes the following steps:

[0048] 1) In the initial state, the robot body is supported on the belt conveying mechanism at the first end through the mounting frame, and the mounting frame is away from the second vertical section of the second connecting arm;

[0049] 2) The first electromagnet is energized and adsorbed on the bottom of the box girder. The second electromagnet is de-energized. The first motor is energized to drive the support wheels to rotate, causing the second connecting arm to translate towards the belt conveyor mechanism at the second end until the first vertical section of the installation frame is away from the second connecting arm.

[0050] 3) The second electromagnet is energized and adsorbed on the bottom of the box girder. The first electromagnet is de-energized. The first motor is energized to drive the support wheels to rotate, causing the installation frame to translate towards the belt conveyor at the second end until the second vertical section of the installation frame is away from the second connecting arm.

[0051] 4) Repeat steps 2) and 3) to support the robot body on the belt conveyor mechanism at the second end through the installation frame, and the first vertical section of the installation frame is away from the second connecting arm.

[0052] 5) The belt conveyor mechanism at the second end drives the robot body to move vertically along the length direction of the box girder.

[0053] 6) The first electromagnet is energized and adsorbed on the bottom of the box girder. The second electromagnet is de-energized. The first motor is energized to drive the support wheels to rotate, causing the second connecting arm to translate towards the belt conveyor mechanism at the first end until the second vertical section of the installation frame is away from the second connecting arm.

[0054] 7) The second electromagnet is energized and adsorbed on the bottom of the box girder. The first electromagnet is de-energized. The first motor is energized to drive the support wheels to rotate, causing the installation frame to translate towards the belt conveyor mechanism at the first end until the first vertical section of the installation frame is away from the second connecting arm.

[0055] 8) Repeat steps 6) and 7) to place the robot body in the initial position with a change in the vertical position.

[0056] 9) The belt conveyor mechanism at the first end drives the robot body to move vertically along the length direction of the box girder. The robot body reciprocates and translates between the belt conveyor mechanisms at the first end and the second end. During the translation process of the robot body, the third connecting arm rotates, and the camera captures the area passing by the bottom of the box girder and synthesizes an image of the bottom of the box girder through an image algorithm for manual inspection to complete the maintenance work. The image algorithm includes the following steps:

[0057] 1) The width of the annular area scanned by the camera rotating one week is s. After the camera rotates one week, the horizontal section length of the third connecting rod extends outward by s. Scanning n times, the width of the scanned annular area is recorded as S = n * s. See Figure 3 ;

[0058] 2) During the alternating movement of the robot, the single movement distance is k. Alternating m times, the translation distance is recorded as K = m * k. See Figure 4 ;

[0059] 3) Establish a coordinate system based on the width S of the annular region and the translation distance K, see Figure 5 ;

[0060] 4) Intercept the effective region within the fixed coordinates in the annular region with width S obtained in step 1). Specifically, the effective region is a right trapezoid or an isosceles trapezoid with an arc as the hypotenuse, see Figure 6 ;

[0061] 5) Fade out the overlapping regions of the intercepted effective regions along the K coordinate, see Figure 7 ;

[0062] 6) Superimpose the images to form a rectangular image for manual inspection, see Figure 8 .

[0063] There is currently a long-span steel box girder in a certain area, with a span of 50 m. Its main function is for vehicle traffic. The connected area is the urban road separated by the Third Ring Road, spanning across the Third Ring Road Expressway. The width of the bottom plate of each bridge is 10 m, and the upper width is 15 m.

[0064] According to the conventional method, the steel box girder needs to be closed for maintenance, which causes problems such as high risk and long cycle. It needs to be maintained once every two years. During maintenance, workers need to use a jacking vehicle to lift it to the bottom of the steel box girder and rely on manual vision for discrimination. For manual inspection, each of the six lanes of the Third Ring Road Expressway needs to be closed. Starting from the preparatory work for each lane (which means that first, a long-distance diversion warning device needs to be set up, such as a warning sign for construction ahead, then the personnel jacking vehicle needs to be driven under the steel box girder, and then under the management of on-site supervisors, the jacking operation is carried out. Therefore, each shift operation requires no less than 3 - 5 workers, drivers, on-site supervisors, etc.), it takes 2.5 days to close the lane, and a total of no less than 15 days of maintenance time is required, which has a greater impact on vehicle speed and traffic flow.

[0065] Robot inspection is for daily random inspection and has no such problems. For some existing municipal bridges, for safety considerations, height limit warnings need to be set during the inspection period to avoid the risk of large vehicles colliding with the robot.

Claims

1. A maintenance robot for the bottom plate of a box girder, characterized in that: It includes two storage areas (1) and a robot body (2). A power supply is arranged in the robot body (2). The robot body (2) includes a mounting frame (3), a first connecting arm (4), a second connecting arm (5), and a third connecting arm (6). Two rows of support wheels (7) are arranged in the mounting frame (3). The number of support wheels (7) in the same row is at least two and they are at the same height. At least one support wheel is driven to rotate by a first motor (8). The first connecting arm (4) is fixed to the top of the mounting frame (3) and extends vertically upward. A coil is wound around the first connecting arm and is electrically connected to the power supply to form a first electromagnet (9). The second connecting arm (5) has a U-shaped structure. The horizontal section of the second connecting arm (5) is clamped between the two rows of support wheels (7). The two vertical sections of the second connecting arm (5) extend out of the mounting frame (3) and have the same height as the first connecting arm (4). Coils are wound around the two vertical sections of the second connecting arm respectively and are electrically connected to the power supply to form a second electromagnet (10). The third connecting arm (6) has an L-shaped structure. The vertical section of the third connecting arm (6) is arranged at the bottom of the mounting frame (3) and is driven to rotate by a second motor (11). The extending end of the horizontal section of the third connecting arm (6) extends beyond the projection range of the mounting frame (3) and is provided with a camera (12). The storage area (1) includes a belt conveying mechanism (13). The two belt conveying mechanisms (13) are respectively suspended at both ends of the box girder bottom plate, extend horizontally, and the extending direction is perpendicular to the length direction of the box girder. The belt of the belt conveying mechanism (13) is flush with the bottom of the mounting frame.

2. The box girder bottom plate maintenance robot according to claim 1, characterized in that: The horizontal section of the second connecting arm (5) is strip-shaped, and two strip-shaped grooves extending along the length direction are provided on both the top surface and the bottom surface. The number of support wheels (7) in the same row is two pairs, which are respectively arranged at both ends of the mounting frame (3) and rollingly cooperate in the corresponding strip-shaped grooves.

3. The box girder bottom plate maintenance robot according to claim 1, characterized in that: The driving wheel of the belt conveying mechanism (13) is driven to rotate by a stepping motor, and the first motor (8) is a servo motor.

4. The box girder bottom plate maintenance robot according to claim 1, characterized in that: The horizontal section of the third connecting arm (6) is an electric telescopic rod.

5. The method for maintaining the bottom slab of a box girder using the maintenance robot according to any one of claims 1-4, characterized in that, It includes the following steps: 1) In the initial state, the robot body is supported on the belt conveying mechanism at the first end through the mounting frame, and the mounting frame is away from the second vertical section of the second connecting arm. 2) The first electromagnet is energized to adsorb on the bottom of the box girder. The second electromagnet is de-energized. The first motor is energized to drive the support wheels to rotate, so that the second connecting arm translates towards the belt conveying mechanism at the second end until the mounting frame is away from the first vertical section of the second connecting arm. 3) The second electromagnet is energized to adsorb on the bottom of the box girder. The first electromagnet is de-energized. The first motor is energized to drive the support wheels to rotate, so that the mounting frame translates towards the belt conveyor at the second end until the mounting frame is away from the second vertical section of the second connecting arm. 4) Repeat step 2) and step 3) to make the robot body supported on the belt conveying mechanism at the second end through the mounting frame, and the mounting frame is away from the first vertical section of the second connecting arm. 5) The belt conveying mechanism at the second end drives the robot body to move vertically in the length direction of the box girder. 6) The first electromagnet is energized and adsorbed on the bottom of the box girder. The second electromagnet is de-energized. The first motor is energized to drive the support wheels to rotate, causing the second connecting arm to translate towards the belt conveyor mechanism at the first end until it reaches the second vertical section of the mounting frame away from the second connecting arm. 7) The second electromagnet is energized and adsorbed on the bottom of the box girder. The first electromagnet is de-energized. The first motor is energized to drive the support wheels to rotate, causing the mounting frame to translate towards the belt conveyor mechanism at the first end until it reaches the first vertical section of the mounting frame away from the second connecting arm. 8) Repeat steps 6) and 7) to place the robot body in the initial position and change its vertical position. 9) The belt conveyor mechanism at the first end drives the robot body to move vertically along the length direction of the box girder. The robot body reciprocates and translates between the belt conveyor mechanism at the first end and the belt conveyor mechanism at the second end. During the translation process of the robot body, the third connecting arm rotates, and the camera captures the area passed by the bottom of the box girder, and synthesizes an image of the bottom of the box girder through an image algorithm for manual inspection to complete the maintenance work.

6. The method according to claim 5, characterized in that, The image algorithm in step 9) includes the following steps: 1) The width of the annular area scanned by the camera rotating one week is s. After the camera rotates one week, the horizontal section length of the third connecting rod extends outward by s, and it is scanned n times. The width of the scanned annular area is denoted as S = n*s. 2) During the alternating movement of the robot, the single movement distance is k, and it alternates m times. The translation distance is denoted as K = m*k. 3) Establish a coordinate system based on the annular area width S and the translation distance K. 4) Intercept the effective area within the fixed coordinates in the annular area with a width of S obtained in step 1). 5) Fade-out processing is performed on the overlapping areas of the intercepted effective areas along the K coordinate. 6) Superimpose the images to form a rectangular image for manual inspection.

7. The method according to claim 6, wherein In step 4), the effective area is a right trapezoid or an isosceles trapezoid with an arc as the hypotenuse.

Images