A device for detecting the curvature of a large-span fish-belly steel structure truss

Abstract

The present invention discloses a radian detection device for a large-span fish-belly steel structure truss, which belongs to the technical field of fish-belly steel structure trusses and solves the problem that the radian of a large-span fish-belly steel structure truss is difficult to measure and inconvenient to ensure the radian accuracy; the device includes two pipeline welding fixtures, a steel cable inspection robot, a guide telescopic rod and a measuring instrument. The present invention can limit the welding deformation of two adjacent welding sections by adjusting the tension of the steel cable, and at the same time use the steel cable as a guide rail of the steel cable inspection robot to guide the steel cable inspection robot to move along the welding section, so that the measuring instrument can obtain the radian shape of each welding section under the drive of the steel cable inspection robot, and the controller obtains the radian of each welding section through the radian shape, thereby facilitating the construction personnel to monitor the position of the welding section and improving the radian accuracy of the large-span fish-belly steel structure truss.

Description

Technical Field

[0001] The present invention relates to the technical field of fish-belly steel structure trusses, and particularly to a radian detection device for a long-span fish-belly steel structure truss. Background Art

[0002] With the rapid development of high-speed railway station buildings, the structural design forms are becoming more and more novel and changeable, and long-span special-shaped curved steel structures are constantly being promoted and applied. Due to the excellent tensile, compressive and torsional properties of the steel pipe section, and the connection between steel pipes is crucial in the overall structure. Considering the convenience of fabrication and installation, the connection is often made in the form of a connecting plate. The common fabrication method is to groove the steel pipe section and insert the connecting plate into the pre-grooved slot for welding. This connection is called the inserted plate connection. In actual engineering, there are various forms of inserted plates, and the common ones are single inserted plates, U-shaped inserted plates, cross inserted plates and T-shaped inserted plates. No matter what form of inserted plate, because it is partially connected to the steel pipe, under the action of tension, shear lag and local buckling are very likely to occur at the cross section of the inserted plate and the steel pipe. In severe cases, it can cause early failure of the joint.

[0003] Especially in a truss with a long-span spatial special-shaped curved surface in the shape of a fish belly, referring to Figure 1 and Figure 2 , the fish-belly steel structure truss includes an upper chord and a lower chord with inverted equilateral triangle and triangle cross sections respectively. The upper chord and the lower chord are connected by multiple vertical connecting web members. The bottom rod of the upper chord is multiple arc-shaped welding segments 1. Each welding segment 1 not only needs to be welded to the adjacent two welding segments 1, but also the middle part of the welding segment 1 needs to be inserted into the upper inserted plate 2 of the connecting web member for welding. Therefore, during the construction process, it is not only inconvenient to measure the curved surface radian of the upper chord due to its complex structure, but also due to the large number of inserted plates on the multiple welding segments 1 and large welding deformation, it is inconvenient to ensure the radian accuracy of the curved surface. Summary of the Invention

[0004] Aiming at the above problems in the prior art, the present invention provides a radian detection device for a long-span fish-belly steel structure truss, which solves the problems that it is difficult to measure the radian of a long-span fish-belly steel structure truss and it is inconvenient to ensure the radian accuracy.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] Provided is a radian detection device for a long-span fish-belly steel structure truss, including: two pipe welding jigs, which are respectively fixed on two adjacent welding sections on the bottom rod of the fish-belly steel structure truss. A steel cable is arranged between the two pipe welding jigs, and the axis of the steel cable coincides with the center line connecting the tops of two upper inserting plates in the two welding sections; a steel cable inspection robot, which is movably arranged on the steel cable. A cable force sensor for measuring the tension of the steel cable is arranged on the steel cable inspection robot, and a limiting rod is horizontally arranged at the bottom of the steel cable inspection robot; a guiding telescopic rod, one end of the guiding telescopic rod is vertically hinged on the upper inserting plate in the middle of a welding section, the other end of the guiding telescopic rod is sleeved on the limiting rod, and a first position sensor for detecting the sliding distance relative to the limiting rod is arranged on the sleeved end of the guiding telescopic rod. The first position sensor is electrically connected to the controller of the steel cable inspection robot; a measuring instrument, which is fixed on the steel cable inspection robot and electrically connected to the controller, and the measuring instrument is used to measure the arc surface shape of each welding section; wherein, the steel cable inspection robot moves horizontally along the steel cable under the restriction of the guiding telescopic rod, the measuring instrument obtains the arc surface shape of each welding section driven by the steel cable inspection robot, and the controller obtains the radian of each welding section through the arc surface shape.

[0007] The beneficial effects of this solution are as follows: The setting of the two pipe welding jigs facilitates the crane to insert the two welding sections into the upper inserting plates on the two connecting web members respectively and perform welding. Moreover, the steel cable between the two pipe welding jigs connects the two welding sections. By adjusting the tension of the steel cable, the welding deformation of the adjacent two welding sections is restricted. At the same time, the steel cable serves as the guide rail of the steel cable inspection robot to guide the steel cable inspection robot to move along the welding section, so that the measuring instrument obtains the arc surface shape of each welding section driven by the steel cable inspection robot, and the controller obtains the radian of each welding section through the arc surface shape, thereby facilitating the construction personnel to monitor the position of the welding section and improving the radian accuracy of the long-span fish-belly steel structure truss.

[0008] Among them, the beneficial effect of setting the axis of the steel cable to coincide with the center line connecting the tops of the two upper inserting plates in the two welding sections is as follows: Considering that there may be a certain torsional angle or deviation between the two adjacent welding sections due to installation errors or welding deformation between the two welding sections. And the two upper inserting plates are welding positioning parts located on the center line of the two welding sections. The deviation degree of the center line connecting the tops of the two upper inserting plates is not only the smallest, but also can best reflect the torsional degree of the welding deformation of the two welding sections. Therefore, by setting the axis direction of the steel cable in this way, not only can the welding deformation of the two welding sections be restricted, but also by obtaining the deviation distance of the two ends of the steel cable in the top view projection direction, the torsional angle between the two welding sections can be obtained, so as to obtain a more accurate radian.

[0009] The beneficial effects of the guiding telescopic rod are as follows: Since the cable inspection robot may twist during the process of traveling along the cable, which affects the measurement effect of the measuring instrument, one end of the guiding telescopic rod is vertically hinged to one of the upper inserting plates, so that the guiding telescopic rod can only rotate and expand and contract in the vertical plane. Thus, by sleeving the guiding telescopic rod on the limiting rod of the cable inspection robot, the cable inspection robot can always travel horizontally on the cable, ensuring the measurement effect of the measuring instrument. At the same time, the sliding distance of the guiding telescopic rod on the limiting rod is the deviation distance of the cable, so that the torsional degree of the welding deformation of the two welding sections can be reflected by the sliding distance of the guiding telescopic rod on the limiting rod through the first position sensor.

[0010] The beneficial effects of the cable inspection robot are as follows: The cable inspection robot can not only inspect the tension and damage conditions of the cable to ensure the construction quality, but also drive the measuring instrument to move and scan the arc surface shape of the welding section. The cable inspection robot can calculate the installation radian of the welding section in three-dimensional space by combining the design parameters of the welding section, the moving distance of the first position sensor and the arc surface shape of the welding section, ensuring the construction quality.

[0011] Further, a distance sensor for measuring the length of the guiding telescopic rod is arranged inside the guiding telescopic rod, and an inclination sensor is arranged at the hinged end of the guiding telescopic rod and the upper inserting plate. Both the distance sensor and the inclination sensor are communicatively connected to the controller. A three-dimensional coordinate axis is established at the hinge between the upper inserting plate and the guiding telescopic rod, and the vertically upward direction is taken as the Z axis, and the horizontal line in the length direction of the welding section is taken as the X axis. Considering that due to the deformation of the welding section, the top view projection of the cable is not a horizontal line, so the moving distance of the cable inspection robot on the cable cannot be used as the X-axis position coordinate. Therefore, the length and inclination of the guiding telescopic rod are obtained through the distance sensor and the inclination sensor, and the X-axis position coordinate of the cable inspection robot is obtained by multiplying the length by the cosine of the inclination. Combining the Z-axis coordinate change of the elastic telescopic distance measuring rod, the radian of the welding section can be obtained more accurately. At the same time, the sliding distance of the guiding telescopic rod on the limiting rod is used as the coordinate of the Y axis, so that the three-axis coordinates of the top arc surface of the welding section can be obtained.

[0012] Further, the measuring instrument is a three-dimensional lidar, a laser distance sensor or a contact rangefinder for scanning and obtaining the arc surface shape of each welding section. The laser distance sensor or the contact rangefinder obtains the arc surface shape of each welding section by measuring the shortest vertical distance between the cable inspection robot and each welding section during the movement process. The three-dimensional lidar can directly scan and obtain the three-dimensional shape of the welding section, which is convenient and fast, but requires high measurement accuracy and high use cost. The laser distance sensor and the contact rangefinder can obtain the arc surface shape of each welding section by using the change of the shortest vertical distance on the horizontal plane, and the cost is lower.

[0013] Furthermore, the laser distance sensor includes a plurality of laser emitting ends longitudinally distributed. The welding section is tubular and has a curved surface in the cross-sectional direction. Thus, by comparing multiple sets of distance data of the plurality of laser emitting ends, not only can the shortest vertical distance between the cable inspection robot and each welding section during movement be obtained, but also the controller can comprehensively restore the three-dimensional shape of the welding section through multiple sets of distance data, the offset data of the first position sensor, and the moving distance of the cable inspection robot.

[0014] Furthermore, the contact rangefinder includes an elastic telescopic distance measuring rod. A contact plate perpendicular to the extending direction of the upper chord frame is fixed on the measuring end of the elastic telescopic distance measuring rod, and the bottom of the contact plate contacts the top of the welding section. The elastic telescopic distance measuring rod obtains the shortest vertical distance through the contact plate, with low cost and high precision ensured through physical contact.

[0015] Furthermore, a chute perpendicular to the welding section is provided at the bottom of the contact plate. A sliding table is slidably arranged in the chute, and a rotating shaft is arranged on the sliding table. The rotating shaft is fixedly connected to the top of a positioning block in an inverted V shape, and both side surfaces of the positioning block contact both sides of the welding section respectively; a damper for resetting the rotation angle of the rotating shaft is arranged at the rotating connection of the rotating shaft and the sliding table. The inverted V-shaped positioning block can position the center of the welding section under the extrusion of the elastic telescopic distance measuring rod. No matter how the welding section deforms or twists, the height change of the center line of the welding section on the horizontal plane can be directly obtained, which can more intuitively reflect the arc of the welding section and reduce the data processing workload. The settings of the rotating shaft and the chute provide the positioning block with the freedom of movement to adapt to the shape of the welding section, and the setting of the damper can limit and reset the rotation angle of the positioning block to prevent the positioning block from tilting excessively under the pressure of the elastic telescopic distance measuring rod and separating from the welding section.

[0016] Furthermore, the distance between the inner top of the positioning block and the wall surface of each welding section is greater than the distance between the top of the upper insertion plate and each welding section. Setting the height of the positioning block in this way enables the positioning block to pass through the upper insertion plate of the welding section to avoid interference.

[0017] Furthermore, an industrial camera is arranged at the inner top of the positioning block. The industrial camera is electrically connected to the controller and is used for detecting the welding quality. The industrial camera on the positioning block can detect the welding quality between the upper insertion plate and the welding section during the movement of the positioning block.

[0018] Furthermore, a second position sensor for detecting the sliding position of the rotating shaft is arranged in the chute, and a rotation sensor for measuring the rotation angle of the rotating shaft is arranged on the rotating shaft. Both the second position sensor and the rotation sensor are communicatively connected to the controller. The controller can obtain the shape of the center line of the welding section in the three-dimensional space through the data of the second position sensor and the rotation sensor.

[0019] Furthermore, a cable fixator and a positioning clamping plate in the radial direction of the cable fixator are provided on each pipeline welding fixture, and the positioning clamping plate is clamped and connected with the upper insertion plate on the welding section. The setting of the positioning clamping plate facilitates the coincidence of the axis of the cable with the center line connecting the tops of the two upper insertion plates in the two welding sections. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of a long-span fish-belly steel structure truss;

[0021] Figure 2 It is a front view of the connection between the welding section and the upper insertion plate;

[0022] Figure 3 It is a schematic diagram of the deformation in the top view projection direction of the welding section;

[0023] Figure 4 It is a schematic structural diagram of the radian detection device;

[0024] Figure 5 It is a schematic connection diagram of the cable inspection robot, the guiding telescopic rod and the measuring instrument;

[0025] Figure 6 It is a front view of the connection between the cable inspection robot and the guiding telescopic rod;

[0026] Figure 7 It is a schematic diagram of the movement of the guiding telescopic rod on the limiting rod;

[0027] Figure 8 It is a schematic structural diagram of the measuring instrument being a contact distance measuring instrument;

[0028] Figure 9 It is a front view structural diagram of the positioning plate;

[0029] Figure 10 It is a front view structural diagram of the positioning plate moving and rotating;

[0030] Figure 11 It is a schematic connection diagram of the cable force sensor and the cable inspection robot;

[0031] Wherein: 1. Welding section; 2. Upper insertion plate;

[0032] 100. Pipeline welding fixture; 11. Cable;

[0033] 200. Cable inspection robot; 21. Limiting rod; 22. Clamping arm; 221. Cable force sensor;

[0034] 300. Guiding telescopic rod;

[0035] 400, Measuring instrument; 41, Elastic telescopic distance measuring rod; 42, Contact plate; 43, Chute; 44, Positioning block. Specific embodiments

[0036] The following describes the specific embodiments of the present invention to facilitate those skilled in the art of this technical field to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of this technical field, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions created using the concept of the present invention are within the scope of protection.

[0037] In the prior art, referring to Figure 1 and Figure 2 , the upper chord of the long-span fish-belly steel structure truss is in the shape of a fish-belly arc. Since the bottom rod in the upper chord includes multiple welding segments 1, each welding segment 1 not only needs to be welded to the adjacent two welding segments 1, but also the middle part of the welding segment 1 needs to be inserted into the upper inserting plate 2 of the connecting web member and welded. The existence of multiple welding surfaces causes a certain amount of torsional deformation of the welding segment 1, deviating from the designed circular arc curve (referring to Figure 3 , Figure 3 where S is the deviation distance), resulting in the problem that it is inconvenient to measure the curved surface radian of the long-span fish-belly steel structure truss and it is inconvenient to ensure the accuracy of the curved surface radian. To solve this problem in this application, the welding deformation of the welding segment 1 is restricted by the steel cable 11, and the axis of the steel cable 11 is set to coincide with the center line connecting the tops of the two upper inserting plates 2 in the two welding segments 1, so that the steel cable 11 serves as the moving track of the steel cable inspection robot 200. The steel cable inspection robot 200 can not only obtain the torsional degree of the adjacent two welding segments 1 through the tension of the steel cable 11 and the offset distance of the steel cable 11, but also move horizontally along the steel cable 11 under the restriction of the guiding telescopic rod 300. The measuring instrument 400 obtains the arc surface shape and radian of each welding segment 1 under the drive of the steel cable inspection robot 200, thus facilitating the construction personnel to monitor the position of the welding segment 1, improving the radian accuracy of the long-span fish-belly steel structure truss, and solving the problem that it is difficult to measure the radian of the long-span fish-belly steel structure truss and it is inconvenient to ensure the radian accuracy.

[0038] A radian detection device for a long-span fish-belly steel structure truss provided in this embodiment, referring to Figure 4 , includes two pipeline welding jigs 100, a steel cable inspection robot 200, a guiding telescopic rod 300, and a measuring instrument 400.

[0039] Specifically, two pipe welding jigs 100 are respectively fixed on two welding sections 1 on the bottom rod of the fish-belly steel structure truss. A steel cable 11 is arranged between the two pipe welding jigs 100, and the axis of the steel cable 11 coincides with the connecting line of the centers of the tops of the two upper plug plates 2 in the two welding sections 1. As a specific structure for setting the axis of the steel cable 11 to coincide with the connecting line of the centers of the tops of the two upper plug plates 2 in the two welding sections 1, a steel cable fixator and a positioning clamping plate (not shown in the figure) in the radial direction of the steel cable fixator are arranged on each pipe welding jig 100, and the positioning clamping plate is tightly connected with the upper plug plate 2 on the welding section 1.

[0040] The function of setting the axis of the steel cable 11 to coincide with the connecting line of the centers of the tops of the two upper plug plates 2 in the two welding sections 1 is as follows: Considering that there is a certain torsional angle or deviation between the two adjacent welding sections 1 due to installation errors or welding deformations between the two welding sections 1, and the two upper plug plates 2 are welding positioning parts located on the center connecting line of the two welding sections 1, the deviation degree of the connecting line of the centers of the tops of the two upper plug plates 2 is not only the smallest, but also can best reflect the torsional degree of the welding deformation of the two welding sections 1. Therefore, by setting the axis direction of the steel cable 11 in this way, not only can the welding deformation of the two welding sections 1 be restricted, but also the torsional angle between the two welding sections 1 can be obtained by getting the deviation distance of the two ends of the steel cable 11 in the top view projection direction, so as to obtain a more accurate radian.

[0041] Specifically, referring to Figure 5 , the steel cable inspection robot 200 is movably arranged on the steel cable 11, and a limiting rod 21 is horizontally arranged at the bottom of the steel cable inspection robot 200. In this embodiment, the steel cable inspection robot 200 can be a cable inspection robot or a wire climbing robot. Referring to Figure 11 , a cable force sensor 221 for measuring the tension of the steel cable 11 is arranged on the steel cable inspection robot 200. In this embodiment, the cable force sensor 221 is a contact type cable force sensor, and the contact type cable force sensor is arranged on the clamping arm 22 of the steel cable inspection robot 200. The clamping arm 22 drives itself and the contact type cable force sensor to always keep in contact with the steel cable 11 through a spring. Preferably, the contact type cable force sensor is a vibrating wire type cable force sensor, which has a vibrating wire inside. The tension of the steel cable is transmitted to the vibrating wire, and the vibrating wire is vibrated by an internal excitation device, and the vibration frequency of the vibrating wire is measured by a vibration pickup device, and the tension of the steel cable is calculated by using the calibrated frequency-tension relationship curve and the vibration frequency of the vibrating wire.

[0042] The function of the wire rope inspection robot 200 is: the wire rope inspection robot 200 can not only inspect the tension and damage of the wire rope 11 to ensure the construction quality, but also drive the measuring instrument 400 to move and scan the arc shape of the welding section 1. The wire rope inspection robot 200 can calculate the installation arc of the welding section 1 in three-dimensional space based on the design parameters of the welding section 1, the moving distance of the first position sensor and the arc shape of the welding section 1 to ensure the construction quality.

[0043] Specifically, one end of the guide telescopic rod 300 is vertically hinged on the upper plug plate 2 in the middle of a welding section 1, and the other end of the guide telescopic rod 300 is sleeved on the limit rod 21, and a first position sensor (not shown in the figure) for detecting the sliding distance relative to the limit rod 21 is provided on the sleeved end of the guide telescopic rod 300, and the first position sensor is electrically connected to the controller of the wire rope inspection robot 200.

[0044] In this embodiment, in order to more accurately obtain the curvature of the welding section 1, a distance sensor (not shown in the figure) for measuring the length of the guide telescopic rod 300 is provided in the guide telescopic rod 300, and a tilt sensor (not shown in the figure) is provided at the hinged end of the guide telescopic rod 300 and the upper plug plate 2. Both the distance sensor and the tilt sensor are connected to the controller for communication. A three-dimensional coordinate axis is established at the hinge of the above plug plate 2 and the guide telescopic rod 300, and the vertical upward direction is used as the Z axis, and the horizontal line in the length direction of the welding section 1 is used as the X axis. Considering that due to the deformation of the welding section 1, the top view projection of the steel cable 11 is not a horizontal line, so the moving distance of the steel cable inspection robot 200 on the steel cable 11 cannot be used as the X-axis position coordinate. Therefore, the length and tilt of the guide telescopic rod 300 are obtained by the distance sensor and the tilt sensor, and the X-axis position coordinate of the steel cable inspection robot 200 is obtained by multiplying the length by the cosine of the tilt angle. Combined with the change of the Z-axis coordinate of the elastic telescopic distance measuring rod 41, the curvature of the welding section 1 can be obtained more accurately.

[0045] The function of the guide telescopic rod 300 is: since the wire rope inspection robot 200 may twist while traveling along the wire rope 11, which may affect the measurement effect of the measuring instrument 400, one end of the guide telescopic rod 300 is vertically hinged on one of the upper plug plates 2, so that the guide telescopic rod 300 can only rotate and telescope in the vertical plane, so that the guide telescopic rod 300 is sleeved on the limit rod 21 of the wire rope inspection robot 200, so that the wire rope inspection robot 200 can always maintain horizontal travel on the wire rope 11, ensuring the measurement effect of the measuring instrument 400. At the same time, the sliding distance of the guide telescopic rod 300 on the limit rod 21 is the deviation distance of the wire rope 11, refer to Figure 3 、 Figure 6 and Figure 7, so that the sliding distance of the telescopic rod 300 guided by the first position sensor on the limit rod 21 can reflect the torsional degree of the welding deformation of the two welding segments 1.

[0046] Specifically, the measuring instrument 400 is fixed on the cable inspection robot 200 and electrically connected to the controller. The measuring instrument 400 is used to measure the arc surface shape of each welding segment 1. In this embodiment, the specific structure of the measuring instrument 400 can be a 3D lidar, a laser distance sensor or a contact rangefinder. The 3D lidar is used to scan and obtain the arc surface shape of each welding segment 1. The laser distance sensor or the contact rangefinder obtains the arc surface shape of each welding segment 1 by measuring the shortest vertical distance between the cable inspection robot 200 and each welding segment 1 during the movement process.

[0047] As a further solution when the measuring instrument 400 is a laser distance sensor, refer to Figure 5 , the laser distance sensor includes a plurality of longitudinally distributed laser emission ends. The welding segment 1 is tubular and has a curved surface in the cross-sectional direction. Therefore, through the comparison of multiple sets of distance data by the plurality of laser emission ends, not only can the shortest vertical distance between the cable inspection robot 200 and each welding segment 1 be obtained during the movement process, but also the controller can comprehensively restore the three-dimensional shape of the welding segment 1 through multiple sets of distance data, the offset data of the first position sensor, and the moving distance of the cable inspection robot 200.

[0048] As a further solution when the measuring instrument 400 is a contact rangefinder, refer to Figure 8 , the contact rangefinder includes an elastic telescopic distance measuring rod 41. A contact plate 42 perpendicular to the extension direction of the upper chord frame is fixed on the measuring end of the elastic telescopic distance measuring rod 41, and the bottom of the contact plate 42 contacts the top of the welding segment 1. The elastic telescopic distance measuring rod 41 obtains the shortest vertical distance through the contact plate 42, with low cost and high accuracy can be ensured through physical contact.

[0049] In order to more intuitively reflect the radian of the welding segment 1 and reduce the data processing workload, a sliding groove 43 perpendicular to the welding segment 1 is provided at the bottom of the contact plate 42. A sliding table is slidably arranged in the sliding groove 43, a rotating shaft is arranged on the sliding table, and the rotating shaft is fixedly connected to the top of a positioning block 44 in an inverted V shape. The two side surfaces of the positioning block 44 are respectively in contact with the two sides of the welding segment 1. A damper for resetting the rotation angle of the rotating shaft is arranged at the rotation connection of the rotating shaft and the sliding table. Refer to Figure 9 and Figure 10, the inverted V-shaped positioning block 44 can position the center of the welding section 1 under the extrusion of the elastic telescopic distance measuring rod 41. Whether the welding section 1 is deformed or twisted, the height change of the center line of the welding section 1 on the horizontal plane can be directly obtained, which can more intuitively reflect the radian of the welding section 1 and reduce the workload of data processing. The setting of the rotating shaft and the sliding groove 43 provides the positioning block 44 with the freedom of movement to adapt to the shape of the welding section 1. The setting of the damper can limit and reset the rotation angle of the positioning block 44 to prevent the positioning block 44 from tilting excessively under the pressure of the elastic telescopic distance measuring rod 41 and separating from the welding section 1. In this embodiment, the damper limits the angle between the positioning block 44 and the horizontal plane to between -15° and 15°, ensuring that the positioning block 44 is always on the welding section 1. To prevent the positioning block 44 from getting stuck due to excessive torsion of the welding section 1, the length of the positioning block 44 can be appropriately reduced according to the diameter of the welding section 1 itself, and a smooth layer is provided on the inner surface of the positioning block 44 to reduce friction.

[0050] To further obtain the shape of the center line of the welding section 1 in three-dimensional space, a second position sensor (not shown in the figure) for detecting the sliding position of the rotating shaft is provided in the sliding groove 43, and a rotation sensor for measuring the rotation angle of the rotating shaft is provided on the rotating shaft. Both the second position sensor and the rotation sensor are communicatively connected to the controller.

[0051] To enable the positioning block 44 to pass through multiple welding sections 1 and avoid interference. The distance between the inner top of the positioning block 44 and the wall surface of each welding section 1 is greater than the distance between the top of the upper insertion plate 2 and each welding section 1. Setting the height of the positioning block 44 in this way enables the positioning block 44 to pass through the upper insertion plate 2 of the welding section 1.

[0052] To detect the welding quality between the upper insertion plate 2 and the welding section 1 during the movement of the positioning block 44, an industrial camera (not shown in the figure) can be provided on the inner top of the positioning block 44 in this embodiment. The industrial camera is electrically connected to the controller and is used to detect the welding quality.

[0053] Although the specific embodiments of the invention have been described in detail with reference to the accompanying drawings, it should not be construed as a limitation on the protection scope of the present application. Within the scope described in the claims, various modifications and deformations that can be made by those skilled in the art without creative efforts still fall within the protection scope of the present application.

Claims

1. A device for detecting the curvature of a large-span fish-belly steel structure truss, characterized in that: include: Two pipe welding clamps (100), the two pipe welding clamps (100) being respectively fixed on two adjacent welding sections (1) on the bottom rod of the fish-belly steel structure truss, a steel cable (11) being arranged between the two pipe welding clamps (100), the axis of the steel cable (11) being coincident with a center line connecting the tops of two upper plug plates (2) in the two welding sections (1); A wire rope inspection robot (200), the wire rope inspection robot (200) being movably arranged on the wire rope (11), the wire rope inspection robot (200) being provided with a wire force sensor (221) for measuring the tension of the wire rope (11), and a limit rod (21) being horizontally arranged at the bottom of the wire rope inspection robot (200); a guide telescopic rod (300), one end of the guide telescopic rod (300) being vertically hinged on an upper plug plate (2) in the middle of the welding section (1), the other end of the guide telescopic rod (300) being sleeved on the limit rod (21), and a first position sensor for detecting a sliding distance relative to the limit rod (21) being provided on the sleeved end of the guide telescopic rod (300), the first position sensor being electrically connected to a controller of the wire rope inspection robot (200); a measuring instrument (400), the measuring instrument (400) being fixed on the wire rope inspection robot (200) and electrically connected to the controller, the measuring instrument (400) being used to measure and obtain the arc surface shape of each welding segment (1); The wire rope inspection robot (200) moves horizontally along the wire rope (11) under the restriction of the guide telescopic rod (300), the measuring instrument (400) obtains the arc surface shape of each welding segment (1) under the drive of the wire rope inspection robot (200), and the controller obtains the curvature of each welding segment (1) through the arc surface shape.

2. The arc detection device according to claim 1, characterized in that: A distance sensor for measuring the length of the guide telescopic rod (300) is arranged inside the guide telescopic rod (300), and an inclination sensor is arranged at the hinged end between the guide telescopic rod (300) and the upper plugboard (2), and both the distance sensor and the inclination sensor are in communication connection with the controller.

3. The arc detection device according to claim 1, characterized in that: The measuring instrument (400) is a laser distance sensor, a contact distance meter or a three-dimensional laser radar for scanning to obtain the arc shape of each welding segment (1); the laser distance sensor or the contact distance meter obtains the arc shape of each welding segment (1) by measuring the shortest vertical distance between the wire rope inspection robot (200) and each welding segment (1) during movement.

4. The arc detection device according to claim 3, characterized in that: The laser distance sensor comprises a plurality of laser emitting ends distributed longitudinally.

5. The arc detection device according to claim 3, characterized in that: The contact distance meter comprises an elastic telescopic distance measuring rod (41), a contact plate (42) perpendicular to the extension direction of the upper chord frame being fixed to the measuring end of the elastic telescopic distance measuring rod (41), and the bottom of the contact plate (42) is in contact with the top of the welding section (1).

6. The arc detection device according to claim 5, characterized in that: A slide groove (43) perpendicular to the welding section (1) is provided at the bottom of the contact plate (42); a slide table is slidably provided in the slide groove (43); a rotating shaft is provided on the slide table; the rotating shaft is fixedly connected to the top of an inverted V-shaped positioning block (44); two side surfaces of the positioning block (44) are respectively in contact with two sides of the welding section (1); a damper for resetting the rotation angle of the rotating shaft is provided at the rotation connection between the rotating shaft and the slide table.

7. The arc detection device according to claim 6, characterized in that: The distance between the top of the positioning block (44) and the wall surface of each welding section (1) is greater than the distance between the top of the upper insert plate (2) and each welding section (1).

8. The arc detection device according to claim 7, characterized in that: An industrial camera is arranged on the inner top of the positioning block (44); the industrial camera is electrically connected to the controller and is used to detect welding quality.

9. The arc detection device according to claim 6, characterized in that: A second position sensor for detecting the sliding position of the rotating shaft is arranged in the sliding groove (43), and a rotation sensor for measuring the rotation angle of the rotating shaft is arranged on the rotating shaft. Both the second position sensor and the rotation sensor are in communication connection with the controller.

10. The arc detection device according to claim 1, characterized in that: Each of the pipeline welding clamps (100) is provided with a steel cable fixer and a positioning clamp plate located in the radial direction of the steel cable fixer, and the positioning clamp plate is clamped and connected to the upper plug plate (2) on the welding section (1).

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