Fabricated steel structure intelligent bolt screwing robot

Abstract

The invention discloses an intelligent bolt screwing robot for a fabricated steel structure, and relates to the technical field of steel structures. Comprising a trolley, a mechanical arm, a bolt operation module and a visual system, the mechanical arm is installed on the trolley, the visual system identifies and positions a bolt hole site in a steel structure, the bolt operation module is installed on the mechanical arm, and the mechanical arm sends the bolt operation module to the bolt hole site under the action of the visual system. And the bolt operation module automatically tightens a bolt connected with the steel structure. The assembling task of the high-strength bolt is completed through automatic operation instead of manual operation, stable operation in the complex construction site environment can be achieved, the efficiency of the steel structure assembling process can be improved, and the safety of workers is protected.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel structures, and more specifically, relates to an intelligent bolt tightening robot for assembled steel structures. Background Art

[0002] With the rapid development of building industrialization and steel structure housing industrialization, the trend of building industrialization, standardization and greening represented by prefabricated steel structures is leading the development direction of the construction industry. Among various types of prefabricated steel structure buildings, steel structures using bolts as anchors have many advantages such as fast assembly and disassembly speed, low difficulty, high efficiency, small component size, high standardization level, high repeatability, and green construction process. A large number of torsion shear type high-strength bolt connection auxiliary anchors are usually required at the assembly nodes of such buildings. Therefore, how to accurately, quickly and firmly install bolts is an important issue of concern to people.

[0003] At present, bolt assembly is still mainly done manually, with low work efficiency, high labor costs, and potential safety hazards in construction. In aerial work, bolt assembly carries a high risk, and workers must be equipped with comprehensive safety protection measures, but it is still difficult to completely avoid the occurrence of safety accidents. Therefore, how to use robots to improve the bolt anchoring efficiency of prefabricated steel structure buildings, reduce labor costs, and improve construction safety has become an urgent problem to be solved in the construction industry. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an intelligent bolt tightening robot for assembled steel structures, which can replace manual work to complete the assembly task of high-strength bolts through automated operations. It can not only operate stably in complex construction site environments, but also improve the efficiency of the steel structure assembly process and protect the safety of workers.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: An intelligent bolt tightening robot for assembled steel structures comprises a trolley, a mechanical arm, which is mounted on the trolley, a bolt operating module, and a visual system. The visual system identifies and locates bolt holes on the steel structure. The bolt operating module is mounted on the mechanical arm. The mechanical arm sends the bolt operating module to the bolt hole under the action of the visual system, and the bolt operating module automatically tightens the bolts connecting the steel structure.

[0006] Preferably, the bolt operating module includes a bolt seat, a linear motion pair, a bolt operating mechanism, a motor support, and a second motor. The bolt seat is installed on the robotic arm, the bolt is vertically placed on the bolt seat and can rotate on the bolt seat, one end of the linear motion pair is connected to the bolt seat, the bolt operating mechanism is installed on the linear motion pair and the linear motion pair drives the bolt operating mechanism to move up and down relative to the bolt seat, the second motor is fixedly connected to the bolt operating mechanism through the motor support, the head of the bolt can be inserted into the bolt operating mechanism for sliding movement and can rotate under the drive of the second motor.

[0007] Preferably, the bolt seat includes an end cover, a base plate, a bolt bowl, a first bearing, and a first magnet. The base plate is fixedly connected to the linear motion pair, the first bearing is installed on the base plate, the bolt bowl is rotatably connected to the base plate through the first bearing, the end cover is connected to the bottom of the bolt bowl and is rotatably connected to the base plate through the first bearing, and the first magnet is arranged in the end cover, and the first magnet adsorbs the bottom of the bolt in the bolt bowl.

[0008] Preferably, a groove for placing the first magnet is provided on the upper surface of the end cover, and the first magnet is adsorbed on the lower surface of the bolt bowl.

[0009] Preferably, the bolt operating mechanism includes an outer sleeve, a middle sleeve, an inner sleeve, a second bearing, a spring, and a second magnet. The outer sleeve is fixedly connected to the motor support, the middle sleeve is sleeved in the outer sleeve and rotatably connected to the outer sleeve through the second bearing, the output shaft of the second motor is connected to the top of the middle sleeve to drive the middle sleeve to rotate, a cavity with an opening at one end is provided in the middle sleeve, a spring is provided in the cavity, one end of the spring is connected to the bottom surface of the cavity, and the other end is connected to the upper end surface of the inner sleeve, the inner sleeve can slide and move in the cavity and rotate synchronously with the middle sleeve; the head of the bolt can slide into the inner sleeve and rotate synchronously with the inner sleeve, and a second magnet is provided at the bottom end of the outer sleeve, and the second magnet attracts the washer and the nut.

[0010] Preferably, a plurality of latch teeth are provided at intervals along the circumference of the bottom end surface of the outer sleeve, wherein the latch teeth are arc-shaped protrusions, the inner diameter of the latch teeth matches the outer diameter of the gasket, and the latch teeth limit the gasket.

[0011] Preferably, the vision system includes a binocular camera, a monocular camera, and a host computer. The binocular camera and the monocular camera are electrically connected to the host computer. The binocular camera is installed on the trolley, and the monocular camera is installed on the bolt operating module. The host computer uses the binocular camera to scan the environment to obtain the bolt hole position information to complete the rough positioning of the robotic arm, and also uses the image taken by the monocular camera to perform the fine positioning of the robotic arm, and finally aligns the bolt operating module with the target hole position.

[0012] Preferably, the linear motion pair includes a guide rail, a lead screw, a slider, and a first motor; the guide rail is arranged vertically, and one end is fixedly connected to a bolt bowl; the lead screw is arranged parallel to the guide rail, and both ends are rotatably connected to the guide rail; the first motor drives the lead screw to rotate, the slider is screwed to the lead screw and slides along the guide rail as the lead screw rotates, and the bolt operating mechanism is fixedly connected to the slider.

[0013] The beneficial effects of adopting the above technical solution are: 1. The robot in this application can assemble steel structures in complex building environments and can automatically tighten bolts, effectively replacing manual operations. In particular, it significantly improves safety and efficiency in high-altitude operations and large-scale assembly, meeting the current needs of green buildings and intelligent construction.

[0014] 2. The robot's core mechanism, the bolt operating module, innovatively adopts a three-layer sleeve structure bolt operating mechanism, integrating the bolt positioning and tightening functions into a compact module, achieving a high degree of integration and structural compactness. It not only improves operational efficiency, but also significantly reduces the size and complexity of the equipment, reduces costs, and can adapt to the operational needs of various steel structure nodes.

[0015] 3. The robot in this application adopts a "coarse positioning + fine positioning" machine vision solution, achieves global positioning through a binocular camera, and uses a monocular camera on the bolt operation module to accurately align the bolt holes. Combining vision and motion control, it effectively improves positioning accuracy and assembly efficiency, ensuring that the robot can operate efficiently in a dynamic and complex construction environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the bolt operation module. Figure 3 It is a schematic diagram of the structure of the bolt seat; Figure 4 It is a structural schematic diagram of the bolt operating mechanism; Figure 5 It is a schematic diagram of the working process of the bolt operating mechanism tightening the bolt; Figure 6 It is a schematic diagram of the principle of bolt tightening; Figure 7 This is a schematic diagram of the robot's information architecture; Figure 8 It is a schematic diagram of the robot’s workflow; In the figure: 1. bolt operating module; 11. bolt seat, 111. end cover, 112. bottom plate, 113. bolt bowl, 114. first bearing, 115. first magnet; 12. linear motion pair, 121. guide rail, 122. lead screw, 123. slider, 124. first motor; 13. bolt operating mechanism, 131. outer sleeve, 132. middle sleeve, 133. inner sleeve, 1331. bolt receiving groove, 134. second bearing, 135. spring, 14. motor support, 15. second motor; 2. robotic arm; 3. trolley; 4. binocular camera; 5. steel structure; 6. monocular camera; 7. bolt; 8. nut; 9. washer. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] like Figure 1 As shown, the bolt tightening robot includes a trolley 3, a mechanical arm 2, a bolt operation module 1, and a visual system. The visual system identifies and locates the bolt hole position on the steel structure. The bolt operation module 1 is installed on the mechanical arm 2. The mechanical arm 2 sends the bolt operation module 1 to the bolt hole position under the action of the visual system, and the bolt operation module 1 automatically tightens the bolt 7 connecting the steel structure.

[0019] The trolley 3 may be a Mecanum wheel trolley or a crawler trolley, which is indicated by a plate in the figure.

[0020] The robot arm 2 is the core part of the robot to achieve high-precision operation. The robot arm 2 consists of five parts: base, turntable, upper arm, lower arm, and load interface. The robot arm 2 has three revolute pairs and is a three-degree-of-freedom robot arm. Each revolute pair is driven by a motor with a reduction gearbox. The three revolute pairs control the angles between the base and the turntable, the turntable and the upper arm, and the upper arm and the lower arm respectively.

[0021] In order to achieve high-precision automatic positioning, the robot in this application is equipped with a binocular camera 4 and a monocular camera 6 as the core components of the machine vision system. The binocular camera 4 is the main camera mounted on the top of the connecting rod outside the robot arm 2, and the monocular camera 6 is the auxiliary camera installed on the bolt operation module 1 at the top of the robot arm 2. By acquiring images from the two, the host computer can accurately identify and locate the bolt hole position. The QR code mark is pre-pasted on the flange of the steel structure and the first section of the arm of the robot close to the end effector. The robot obtains the three-dimensional spatial position of the target object and its own initial position and joint angle by identifying the QR code, and combines the real-time image processing algorithm to ensure that each operation can accurately align with the target hole position.

[0022] The bolt operation module 1 is the core actuator of the present invention, and its design directly affects the overall operation effect of the robot. Figure 2 As shown, the bolt operating module includes a bolt seat 11, a linear motion pair 12, a bolt operating mechanism 13, a motor support 14, and a second motor 15. The bolt seat 11 is mounted on the robot arm 2, and the bolt 7 is vertically placed on the bolt seat 11 and can rotate on the bolt seat 11. One end of the linear motion pair 12 is connected to the bolt seat 11, and the bolt operating mechanism 13 is mounted on the linear motion pair 12, and the linear motion pair 12 drives the bolt operating mechanism 13 to move up and down relative to the bolt seat 11. The second motor 15 is fixedly connected to the bolt operating mechanism 13 through the motor support 14, and the head of the bolt 7 can be inserted into the bolt operating mechanism 13 to slide and move and can rotate under the drive of the second motor 15.

[0023] The function of the bolt seat 11 is to place the bolts to ensure that the bolt connection pair is tightened smoothly. Figure 3 As shown, the bolt seat 11 includes an end cover 111, a base plate 112, a bolt bowl 113, a first bearing 114, and a first magnet 115. The base plate 112 is fixedly connected to the robot arm 2, and the first bearing 114 is installed on the base plate 112. The bolt bowl 113 is rotatably connected to the base plate 112 through the first bearing 114. The end cover 111 is connected to the bottom of the bolt bowl 113 and is rotatably connected to the base plate 112 through the first bearing 114. The upper surface of the bolt bowl 113 is provided with a receiving groove with an opening upward that is adapted to the bottom of the bolt 7, and the bottom of the bolt 7 is just placed in the receiving groove. A groove is provided on the upper surface of the end cover 111, and the first magnet 115 is placed in the groove. The first magnet 115 adsorbs the bottom of the bolt 7 in the bolt bowl 113 to prevent the bolt 7 from shifting or falling. When the bolt operation module 1 is working, the base plate 1 is in close contact with the steel member 5. The first bearing 114 allows the bolt bowl 113 and the bolt 7 to rotate freely. The relative height of the bolt bowl 113 is just enough to leave a certain gap between the bolt 7 and the steel member 5 when the bolt connection pair is not tightened, thereby ensuring that the bolt 7 can be screwed smoothly.

[0024] The bolt operating mechanism 13 is the main device for tightening the bolts. Figure 4 As shown. The bolt operating mechanism 13 includes an outer sleeve 131, a middle sleeve 132, an inner sleeve 133, a second bearing 134, a spring 135, and a second magnet. The top of the outer sleeve 131 is fixedly connected to the motor support 14, and the middle sleeve 132 is sleeved in the outer sleeve 131 and rotatably connected to the outer sleeve 131 through the second bearing 134. The output shaft of the second motor 15 is connected to the top of the middle sleeve 132 to drive the middle sleeve 132 to rotate. A cavity with an open end is provided in the middle sleeve 132, and a spring 135 is provided in the cavity. One end of the spring 135 is connected to the bottom surface of the cavity, and the other end is connected to the upper end surface of the inner sleeve 133. The design of the spring 135 enables the inner sleeve 133 to move up and down, can accommodate bolts of different lengths, and can press the plum head of the bolt as much as possible, play a limiting role, and can also meet the installation requirements of bolts of different specifications during construction. The inner sleeve 133 can slide and move in the cavity and rotate synchronously with the middle sleeve 132. A bolt receiving groove 1331 is provided at the bottom end of the inner sleeve 133. The shape of the bolt receiving groove 1331 is adapted to the plum blossom head of the bolt 7, so as to facilitate the tightening of the bolt 7. The plum blossom head of the bolt 7 can slide into the bolt receiving groove 1331 and rotate synchronously with the inner sleeve 133. Two grooves are provided on the bottom end surface of the outer sleeve 131. A second magnet is installed in one groove. The second magnet attracts the washer 9 and the nut 8 on the bottom end surface of the outer sleeve 131. Four arc-shaped teeth are also provided along the circumference of the bottom end surface of the outer sleeve 131. The four teeth are spaced apart. The inner diameter of the teeth is adapted to the outer diameter of the washer. After the washer is attracted by the second magnet, it is stuck between the four teeth to prevent the teeth from being misaligned.

[0025] like Figure 2 As shown, the linear motion pair 12 includes a guide rail 121, a lead screw 122, a slider 123, and a first motor 124; the guide rail 121 is arranged vertically, and one end is fixedly connected to the bolt bowl 113. The lead screw 122 is arranged parallel to the guide rail 121, and both ends of the lead screw 122 are rotatably connected to the guide rail 121. The first motor 124 drives the lead screw 122 to rotate, and the slider 123 is screwed to the lead screw 122 and slides along the guide rail 121 as the lead screw 122 rotates. The outer sleeve 131 of the bolt operating mechanism 13 is fixedly connected to the slider 12. The first motor 124 rotates, driving the lead screw 122 to rotate, and the lead screw 122 drives the slider 123 to slide up and down, and the slider 123 drives the bolt operating mechanism 13 to move up and down.

[0026] like Figure 5 As shown, the workflow of bolt operation module 1 is as follows (taking M16 torsion shear type high-strength bolt as an example): The outer sleeve 131 in the bolt operation module 1 has a strong magnet embedded at the bottom, which can attract the nut 8 and the washer 9. At the beginning of the operation, the outer sleeve 131 moves downward through the linear motion pair 12, driving the nut 8 and the washer 9 to be squeezed downward. When the connection pair of the M16 bolt completely passes through the washer 9, the washer 9 fits the building component completely, and the upper end of the bolt head protrudes a small section (about 3mm) from the nut 8 and penetrates into the inner sleeve 133. The inner cavity shape of the inner sleeve 133 matches the bolt head, which can tightly bite the upper end of the head for the next tightening action.

[0027] Subsequently, the second motor 15 is started, driving the middle sleeve 132 and the inner sleeve 133 connected thereto to rotate together. Since the inner sleeve 133 has been engaged with the upper end of the bolt's plum head, the bolt 7 also rotates accordingly and begins to tighten the nut 8. During the rotation of the bolt 7, the nut 8 does not rotate, but gradually moves down along the thread to compress the washer 9 and the building component. As the nut 8 moves downward, the part of the plum head that penetrates into the inner sleeve 133 gradually increases, the inner sleeve 133 engages more tightly with the plum head, and the torque that can be provided also gradually increases. As the bolt 7 continues to rotate, the nut 8 is continuously tightened, so that the connection pair gradually reaches the required degree of tightening.

[0028] like Figure 6 As shown, during the tightening process, the bolt operating mechanism 13 continuously applies torque to the plum head until the preset torque value is reached. When this critical point is reached, the plum head of the bolt will be twisted off from the V-groove. The design of this breaking point ensures that the applied torque meets the standard requirements and ensures that the anchoring torque of the connection pair meets the regulations.

[0029] Finally, the linear motion pair 12 drives the outer sleeve 131 to lift upwards, and the bolt operation is completed. At this time, the nut 8 is tightly fixed on the washer 9 and the member, and the process of tightening the whole bolt ends smoothly.

[0030] In the actual application process of the robot on the construction site, a series of task steps need to be completed, from positioning to bolt assembly, all operations are performed by the robot autonomously or under the instruction of the operator. The main working process of the robot is as follows: 1. Self-positioning: At the work site, the robot first scans the environment through the main camera, obtains image information of the surrounding environment, identifies the QR code on the component flange and the robotic arm, and uses the QR code information to calculate the joint angle and plane position of the robotic arm. It further calculates the rough relative position between itself and the target bolt hole, and makes adjustments to ensure that the robotic arm can operate within the correct range.

[0031] 2. Bolt hole identification and alignment: After completing self-positioning, the robot obtains rough information about the bolt hole position of the flange through the binocular camera 4 vision and moves to the vicinity of the bolt hole. This process is called coarse positioning. The monocular camera 6 visual image is captured, and the monocular camera image is subjected to Hough transform to identify the boundary and center position of the hole position. This process is repeated many times until the position difference between the hole position and the axis of the bolt operating head is less than the threshold. This process is called fine positioning. Based on the image feedback, the control system calculates the relative displacement between the bolt operating module 1 and the hole position, and plans the path. The robot arm 2 moves on the path to accurately align the bolt operating module 1 with the target hole position.

[0032] 3. Bolt anchoring: When the bolt operating module 1 reaches the designated hole position, the bolt operating module 1 starts to perform the bolt assembly task. The bolt operating module 1 first clamps the nut 8 with the outer sleeve 131 of the bolt operating mechanism to ensure that the nut 8 does not rotate during the tightening process. Subsequently, the second motor 15 drives the inner sleeve 133 to rotate through the middle sleeve 132, so that the bolt 7 and the nut 8 are tightened with each other until the bolt 7 reaches the preset torque standard.

[0033] 4. Withdrawal and repeat operation: After completing the tightening of a bolt, the robot arm 2 withdraws the bolt operation module 1 from the hole position and prepares for the assembly of the next bolt. The entire operation process can be repeated as many times as needed until all bolts are tightened.

[0034] In summary, the robot's control system combines machine vision feedback to achieve efficient and automated assembly of steel structure nodes through self-positioning, rough positioning, fine positioning and bolt tightening processes. In actual operation, it ensures that each bolt can be installed accurately and firmly in place.

[0035] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An assembled steel structure intelligent bolt tightening robot, comprising a trolley and a mechanical arm, wherein the mechanical arm is mounted on the trolley, and is characterized in that: It also includes a bolt operation module and a visual system. The visual system identifies and locates the bolt holes on the steel structure. The bolt operation module is installed on a robotic arm. Under the action of the visual system, the robotic arm sends the bolt operation module to the bolt hole. The bolt operation module automatically tightens the bolts connecting the steel structure.

2. The intelligent bolt tightening robot for assembled steel structures according to claim 1, characterized in that: The bolt operating module includes a bolt seat, a linear motion pair, a bolt operating mechanism, a motor support, and a second motor. The bolt seat is installed on the robotic arm, the bolt is vertically placed on the bolt seat and can rotate on the bolt seat, one end of the linear motion pair is connected to the bolt seat, the bolt operating mechanism is installed on the linear motion pair and the linear motion pair drives the bolt operating mechanism to move up and down relative to the bolt seat, the second motor is fixedly connected to the bolt operating mechanism through the motor support, the head of the bolt can be inserted into the bolt operating mechanism for sliding movement and can rotate under the drive of the second motor.

3. The intelligent bolt tightening robot for assembled steel structure according to claim 2, characterized in that: The bolt seat includes an end cover, a base plate, a bolt bowl, a first bearing, and a first magnet. The base plate is fixedly connected to the linear motion pair, the first bearing is installed on the base plate, the bolt bowl is rotatably connected to the base plate through the first bearing, the end cover is connected to the bottom of the bolt bowl and is rotatably connected to the base plate through the first bearing, and the first magnet is arranged in the end cover, and the first magnet adsorbs the bottom of the bolt in the bolt bowl.

4. The intelligent bolt tightening robot for assembled steel structure according to claim 3 is characterized in that: Described, the upper surface of end cover is provided with the groove for placing the first magnet, and the first magnet is adsorbed on the lower surface of bolt bowl.

5. The intelligent bolt tightening robot for assembled steel structure according to claim 2, characterized in that: The bolt operating mechanism includes an outer sleeve, a middle sleeve, an inner sleeve, a second bearing, a spring, and a second magnet. The outer sleeve is fixedly connected to the motor support, the middle sleeve is sleeved in the outer sleeve and rotatably connected to the outer sleeve through the second bearing, the output shaft of the second motor is connected to the top of the middle sleeve to drive the middle sleeve to rotate, a cavity with an open end is provided in the middle sleeve, a spring is provided in the cavity, one end of the spring is connected to the bottom surface of the cavity, and the other end is connected to the upper end surface of the inner sleeve, the inner sleeve can slide and move in the cavity and rotate synchronously with the middle sleeve; the head of the bolt can slide into the inner sleeve and rotate synchronously with the inner sleeve, a second magnet is provided at the bottom end of the outer sleeve, and the second magnet attracts the washer and the nut.

6. The intelligent bolt tightening robot for assembled steel structure according to claim 5, characterized in that: A plurality of latch teeth are arranged at intervals along the circumference of the bottom end surface of the outer sleeve. The latch teeth are arc-shaped protrusions. The inner diameter of the latch teeth matches the outer diameter of the gasket. The latch teeth limit the gasket.

7. The intelligent bolt tightening robot for assembled steel structures according to claim 1, characterized in that: The visual system includes a binocular camera, a monocular camera, and a host computer. The binocular camera and the monocular camera are electrically connected to the host computer. The binocular camera is installed on the trolley, and the monocular camera is installed on the bolt operation module. The host computer uses the binocular camera to scan the environment to obtain bolt hole position information to complete the rough positioning of the robotic arm, and also uses the image taken by the monocular camera to perform fine positioning of the robotic arm, and finally aligns the bolt operation module with the target hole position.

8. The intelligent bolt tightening robot for assembled steel structures according to claim 2, characterized in that: The linear motion pair includes a guide rail, a lead screw, a slider, and a first motor; the guide rail is arranged vertically, and one end is fixedly connected to a bolt bowl; the lead screw is arranged parallel to the guide rail, and both ends are rotatably connected to the guide rail; the first motor drives the lead screw to rotate, the slider is screwed to the lead screw and slides along the guide rail as the lead screw rotates, and the bolt operating mechanism is fixedly connected to the slider.

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