Gantry type profile steel arch frame automatic positioning and cutting special machine and control system

Abstract

The invention relates to the technical field of mechanical arms, in particular to a gantry type profile steel arch frame automatic positioning cutting special machine and a control system, and the gantry type profile steel arch frame automatic positioning cutting special machine comprises a gantry welding frame, and an edge searching positioning mechanism and a cutting execution mechanism which are mounted on the gantry welding frame. By integrating the edge searching positioning mechanism and the cutting executing mechanism on the gantry welding frame, the edge searching, rotating and cutting processes are continuously completed under the same equipment standard, and before cutting, an edge searching feeding lead screw is used for driving the cutting frame to integrally move; the edge of the profile steel arch frame is positioned through the edge finding laser generator mounted below the cutting frame, so that the cutting reference does not depend on manual measurement and scribing operation any more, and the influence of manual measurement errors and inconsistent manual operation on the cutting precision is effectively reduced; and the reliability and repeatability of profile steel arch frame broken material positioning are improved from the structure and process levels.

Description

Technical Field

[0001] This invention relates to the field of positioning and cutting technology for steel arch frames, specifically to a gantry-type automatic positioning and cutting machine and control system for steel arch frames. Background Technology

[0002] With the rapid development of highway, railway, and water conservancy networks both domestically and internationally, the processing of steel arch frames is particularly important in tunnel construction in mountainous areas, especially in the cutting process. This requires flat cross-sections that are perpendicular to the web of the steel arch frame, and the variety of steel arch frame types and material thicknesses is significant. Currently, there are two methods for cutting steel arch frames: one is manual gas cutting using acetylene and oxygen, which has low production efficiency and produces low-quality cut surfaces; the second is plasma cutting, which uses ionized gas to melt and cut the steel arch frame.

[0003] Currently, products manufactured using these two methods have various problems, including the inability to guarantee specifications and dimensions, and the impact on subsequent welding and processing.

[0004] (a) Manual method:

[0005] The steel arch frame is manually placed on a tooling support. Measuring tools such as a tape measure are used to determine the length of the steel arch frame to be cut. A cutting path is then marked using tools such as a square, and the flame temperature of the cutting tool is adjusted before starting work. Due to inconsistent operator skill levels and variations in cutting machine parameters, the material produced using this method has a curved and uneven cross-section, and the cutting path deviates from the theoretically required parameters. This results in a high scrap rate for subsequent welded products and low production efficiency.

[0006] (II) Automatic Plasma Cutting Method:

[0007] Plasma cutting guns are used to cut structural steel sections using articulated robotic arms or linear modules. However, articulated robotic arms require programming instruction or the purchase of welding software packages. This presents several challenges: firstly, it demands a certain level of electromechanical expertise from the operators; secondly, malfunctions prevent rapid production recovery; and thirdly, the entire system requires numerous parameter adjustments, including for the robotic arm and plasma cutter. While the cutting straightness may meet requirements, the excessive parameter adjustments and inconsistent material thickness mean the plasma cutting depth cannot cover the entire cross-section of the I-beam, resulting in compromised flatness and perpendicularity between the cut surface and the web. Furthermore, slag often remains on the back side of the plasma cutter. If this slag is not blown away during cutting or removed promptly after cutting, it poses a significant hazard during subsequent welding, as the weld pool can become contaminated with slag, leading to insufficient strength. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides an automatic positioning and cutting machine and control system for gantry-type steel arch frames.

[0009] The present invention adopts the following technical solution: an automatic positioning and cutting machine for gantry steel arch frames, including a gantry welding frame, and an edge-finding positioning mechanism and a cutting execution mechanism installed on the gantry welding frame;

[0010] The edge-finding and positioning mechanism includes an edge-finding and positioning frame, which is fixedly installed on the gantry welding frame by locking screws. An edge-finding guide rail is fixed on the edge-finding and positioning frame by bolts. An edge-finding feed screw is also rotatably connected to the edge-finding and positioning frame and arranged parallel to the edge-finding guide rail. A first slider is provided on the edge-finding guide rail, and a rotary table connecting seat is fixed to the lower surface of the first slider by bolts.

[0011] The lower surface of the rotary table connecting seat is rotatably connected to a rotary table, and the lower surface of the rotary table is fixed with a cutting frame by bolts. The lower surface of the cutting frame is equipped with an edge-finding laser generator.

[0012] As a further description of the above technical solution: an edge-finding drive motor is installed on the edge-finding positioning frame, and the output shaft of the edge-finding drive motor is fixedly connected to one end of the edge-finding feed screw through a coupling for driving the screw to rotate. A first screw nut seat is welded and fixed on the rotary table connecting seat, and the first screw nut seat is threadedly connected to the edge-finding feed screw.

[0013] As a further description of the above technical solution: an edge-finding drag chain bracket is fixed to the edge-finding positioning frame by bolts, and the edge-finding drag chain bracket is connected to the edge-finding drag chain by bolts, which is used to provide follow-up protection for cables and signal lines.

[0014] A rotary table drive motor is installed on the rotary table connecting seat. A rotary table drive gear is fixedly connected to the output shaft of the rotary table drive motor. A gear ring is welded onto the rotary table, and the rotary table drive gear meshes with the gear ring.

[0015] As a further description of the above technical solution: along the length direction, the lower surface of the cutting frame is bolted with two parallel cutting guide rails.

[0016] A cutting feed drive motor is bolted to the center line of the lower surface of the cutting frame, and a cutting feed screw is rotatably connected to the center line of the lower surface of the cutting frame. The output shaft of the cutting feed drive motor is fixedly connected to the cutting feed screw through a coupling.

[0017] As a further description of the above technical solution: the cutting actuator includes a cutting machine connecting seat, which is mounted on a second slider that is slidably connected to the cutting guide rail by fixing screws. A cutting machine connecting plate is fixed to the lower surface of the cutting machine connecting seat by bolts. A cutting machine support and a cutting machine drive motor are fixed to the cutting machine connecting plate by bolts. A drive pulley is fixed to the output shaft of the cutting machine drive motor. A driven shaft is rotatably connected inside the cutting machine support. A driven pulley is fixed to one end of the driven shaft. A cutting machine belt is wound between the drive pulley and the driven pulley. A cutting saw blade is fixed to the other end of the driven shaft by bolts. A second lead screw nut seat is fixed to the cutting machine connecting seat by bolts. The second lead screw nut seat is threadedly connected to the cutting feed lead screw.

[0018] As a further description of the above technical solution: a cutting drag chain is connected to the cutting frame by screws, the cutting drag chain is connected to the cutting drag chain connecting plate by bolts, and the cutting drag chain connecting plate is connected to the cutting machine connecting seat by screws.

[0019] A control system for a gantry-type automatic positioning and cutting machine for steel arch frames includes: a gantry-type automatic positioning and cutting machine for steel arch frames and a control unit, wherein the control unit includes:

[0020] The multi-axis spatial coordinate system construction module establishes a composite coordinate system by using the gantry welding frame as a fixed reference benchmark after the steel arch frame enters the processing station, and by establishing the edge-finding linear coordinate system, the rotary table angle coordinate system, and the cutting feed coordinate system.

[0021] The boundary data acquisition module controls the edge-finding drive motor, which moves the rotary table and cutting execution mechanism along the edge-finding guide rail. During the movement, the edge-finding laser generator installed below the cutting frame continuously scans the outer contour of the steel arch frame to obtain a set of boundary space point data.

[0022] The real boundary model generation module fits the boundary space point data set to generate a real boundary model of the steel arch frame in the current clamping state. Based on the geometric model of the steel arch frame design drawings, it calculates the spatial offset of the frame at the ideal position under the gantry welded frame.

[0023] The cutting control module inputs the acquired translational offset and attitude offset angle, as well as the dimensions of the steel arch frame, into the pre-built cutting control parameter prediction model, and outputs cutting control parameters, including the rotary table rotation angle and the cutting machine connecting seat movement length.

[0024] The cutting execution module first controls the rotary table drive motor (10) based on the rotation angle of the rotary table (9) to drive the rotary table (9) to rotate to the target angle, then controls the cutting saw blade (23) to work, and then controls the cutting feed drive motor (27) to work based on the moving length of the cutting machine connecting seat (18), driving the cutting machine connecting seat (18) to move and complete the cutting.

[0025] As a further description of the above technical solution: the boundary data acquisition module is configured as follows:

[0026] Step Sa1: After the steel arch frame enters the processing station and completes the initial clamping, the edge-finding drive motor is controlled to drive the edge-finding feed screw to rotate, so that the rotary table and the cutting execution mechanism are as a whole execution unit and make linear feed motion along the edge-finding guide rail, thereby forming an active edge-finding scanning trajectory covering the length direction of the steel arch frame.

[0027] Based on the active scanning trajectory for edge finding, the edge finding laser generator installed below the cutting frame is controlled to continuously emit a ranging laser beam, and synchronously ranging and sampling are performed on the outer edge of the steel arch frame located below the scanning trajectory at a preset sampling period to obtain edge finding data.

[0028] Based on the fixed installation position of the edge-finding laser generator in the equipment coordinate system, each set of edge-finding data is converted into the boundary space point corresponding to the outer edge of the steel arch frame in the composite coordinate system.

[0029] Multiple boundary space points distributed along the length of the steel arch frame are obtained, and the boundary space points are collected in the sampling order to form a boundary space point data set of the outer edge contour of the steel arch frame.

[0030] As a further description of the above technical solution: the real boundary model generation module is configured as follows:

[0031] The acquired set of boundary space point data is preprocessed to obtain a set of valid boundary points;

[0032] Using the direction of the edge-finding linear coordinate system as the length direction of the steel arch frame, the effective boundary point set is divided into multiple cross-sectional intervals according to the preset cross-sectional spacing. Within each cross-sectional interval, the corresponding boundary space point subset is extracted to obtain the cross-sectional point set.

[0033] For each set of cross-sectional points, at a fixed cross-sectional position, the two-dimensional coordinates of the boundary points are projected onto the corresponding cross-sectional plane to obtain a two-dimensional point set. The least squares method is used to perform curve fitting on the two-dimensional point set to obtain the cross-sectional boundary profile curve corresponding to the cross-section.

[0034] Based on the boundary contour curves of all sections, spatial interpolation is performed on each contour curve along the direction of the edge-finding linear coordinate system in the order of sections to construct a three-dimensional real boundary model that reflects the actual spatial form of the steel arch frame in the current clamping state.

[0035] As a further description of the above technical solution: the real boundary model generation module is also configured as follows:

[0036] Obtain the geometric model corresponding to the design drawings of the steel arch frame, and place the geometric model in an ideal installation position with the gantry welded frame coordinate system as the reference datum according to the equipment design requirements to obtain the reference model under ideal conditions;

[0037] The real boundary model is spatially registered with the reference model. By minimizing the overall distance between corresponding boundary points of the two models, the rigid spatial transformation parameters that make the two models best coincide are solved. The rigid spatial transformation parameters include rotation matrix and translation vector.

[0038] Based on the translation vector, the translation offset of the steel arch frame relative to the coordinate system of the gantry welded frame is obtained, and based on the rotation matrix... The attitude offset angle relative to the coordinate system of the gantry welding frame is obtained.

[0039] As a further description of the above technical solution: the control unit also includes:

[0040] The cutting execution module first controls the rotary table drive motor based on the rotary table rotation angle, driving the rotary table to rotate to the target angle. Then, it controls the cutting saw blade to work. Based on the moving length of the cutting machine connecting seat, it controls the cutting feed drive motor to work, driving the cutting machine connecting seat to move and complete the cutting.

[0041] The beneficial effects of this invention are as follows:

[0042] This invention provides an automatic positioning and cutting machine and control system for gantry-type steel arch frames. By integrating an edge-finding positioning mechanism and a cutting execution mechanism on the gantry welding frame, the edge-finding, rotation, and cutting processes are completed continuously under the same equipment reference. Before cutting, the edge-finding feed screw drives the entire cutting frame to move, and the edge-finding laser generator installed below the cutting frame positions the edge of the steel arch frame. This eliminates the need for manual measurement and scribing of the cutting reference, effectively reducing the impact of manual measurement errors and inconsistent human operation on cutting accuracy. It improves the reliability and repeatability of steel arch frame material cutting and positioning from both structural and process perspectives.

[0043] By spatially registering the real boundary model with the ideal reference model established based on the design drawings, the translational offset and attitude offset angle of the steel arch frame relative to the gantry welding frame datum are automatically solved, realizing a quantitative description of the clamping state of the steel arch frame. This method avoids unstable operations such as manual alignment and experience correction, and enables the clamping error to participate in subsequent control calculations in the form of clear spatial parameters, providing a reliable data basis for cutting accuracy. Attached Figure Description

[0044] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0045] Figure 1 This is a structural schematic diagram of an automatic positioning and cutting machine for gantry-type steel arch frames provided in Embodiment 1 of the present invention;

[0046] Figure 2 This is a schematic diagram of the edge-finding and positioning frame provided in Embodiment 1 of the present invention;

[0047] Figure 3 This is a schematic diagram of the cutting frame provided in Embodiment 1 of the present invention;

[0048] Figure 4 This is a schematic diagram of the structure of the cutting machine connecting plate provided in Embodiment 1 of the present invention;

[0049] Figure 5 This is a schematic diagram of the connection structure between the driving pulley and the driven pulley provided in Embodiment 1 of the present invention;

[0050] Figure 6 This is a module connection diagram of the control system of an automatic positioning and cutting machine for gantry steel arch frames provided in Embodiment 2 of the present invention;

[0051] Figure 7 The configuration flowchart of the boundary data acquisition module provided in Embodiment 2 of the present invention;

[0052] Figure 8 This is a flowchart illustrating the configuration of the real boundary model generation module provided in Embodiment 2 of the present invention.

[0053] Reference numerals: 1. Gantry welding frame; 2. Edge-finding positioning frame; 3. Edge-finding guide rail; 31. First slider; 4. Edge-finding feed screw; 5. Edge-finding drive motor; 6. Edge-finding drag chain bracket; 7. Edge-finding drag chain; 8. Rotary table connecting seat; 9. Rotary table; 91. Gear ring; 10. Rotary table drive motor; 11. Rotary table drive gear; 12. Cutting frame; 13. Cutting guide rail; 131. Second slider; 14. Edge-finding laser generator; 15. Cutting feed screw; 16. Cutting drag chain; 17. Cutting drag chain connecting plate; 18. Cutting machine connecting seat; 19. Cutting machine connecting plate; 20. Cutting machine belt; 21. Cutting machine drive motor; 22. Cutting machine support; 23. Cutting saw blade; 24. Drive pulley; 25. Driven pulley; 26. Driven shaft; 27. Cutting feed drive motor. Detailed Implementation

[0054] To make the technical means, creative features, objectives, and effects of this invention readily understandable, the invention is further described below with reference to specific illustrations. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0055] Example 1

[0056] Please see Figures 1-5 The present invention provides a technical solution: a gantry-type steel arch frame automatic positioning and cutting machine, including a gantry welding frame 1 for supporting and installing various functional components, and an edge-finding positioning mechanism and a cutting execution mechanism installed on the gantry welding frame 1;

[0057] The edge-finding positioning mechanism includes an edge-finding positioning frame 2, which is fixedly installed on the gantry welding frame 1 by locking screws and serves as the mounting base for the various edge-finding components. An edge-finding guide rail 3 is fixedly mounted on the edge-finding positioning frame 2 by bolts. An edge-finding feed screw 4 is also rotatably connected to the edge-finding positioning frame 2 and arranged parallel to the edge-finding guide rail 3. An edge-finding drive motor 5 is mounted on the edge-finding positioning frame 2. The output shaft of the edge-finding drive motor 5 is fixedly connected to one end of the edge-finding feed screw 4 through a coupling and is used to drive the screw to rotate.

[0058] An edge-finding positioning frame 2 is fixed with an edge-finding drag chain bracket 6 by bolts. The edge-finding drag chain bracket 6 is connected to the edge-finding drag chain 7 by bolts and is used to provide follow-up protection for cables and signal lines.

[0059] The edge-finding guide rail 3 is provided with a first slider 31. A rotary table connecting seat 8 is bolted to the lower surface of the first slider 31. The rotary table connecting seat 8 can move synchronously with the first slider 31 under the guidance of the edge-finding guide rail 3. A first lead screw nut seat is welded and fixed on the rotary table connecting seat 8, and the first lead screw nut seat is threadedly connected to the edge-finding feed screw 4.

[0060] A rotary table 9 is rotatably connected to the lower surface of the rotary table connecting seat 8. A rotary table drive motor 10 is mounted on the rotary table connecting seat 8. A rotary table drive gear 11 is fixedly connected to the output shaft of the rotary table drive motor 10. A gear ring 91 is welded onto the rotary table 9. The rotary table drive gear 11 and the gear ring 91 are meshed together. By controlling the forward and reverse rotation of the rotary table drive motor 10, the rotary table drive gear 11 is driven to rotate the gear ring 91, thereby allowing the rotary table 9 to adjust its angle around the vertical axis.

[0061] The lower surface of the rotary table 9 is fixed with a cutting frame 12 by bolts. The lower surface of the cutting frame 12 is equipped with an edge-finding laser generator 14 for assisting in cutting position calibration.

[0062] Along the length direction, two parallel cutting guide rails 13 are bolted to the lower surface of the cutting frame 12.

[0063] A cutting feed drive motor 27 is bolted to the center line along the length direction of the lower surface of the cutting frame 12. A cutting feed screw 15 is rotatably connected to the center line of the lower surface of the cutting frame 12. The output shaft of the cutting feed drive motor 27 is fixedly connected to the cutting feed screw 15 through a coupling.

[0064] A cutting drag chain 16 is connected to the cutting frame 12 by screws. The cutting drag chain 16 is connected to the cutting drag chain connecting plate 17 by bolts. The cutting drag chain connecting plate 17 is connected to the cutting machine connecting seat 18 by screws. A second lead screw nut seat is fixed on the cutting machine connecting seat 18 by bolts. The second lead screw nut seat is threadedly connected to the cutting feed lead screw 15.

[0065] The cutting actuator includes a cutting machine connecting seat 18, which is mounted on a second slider 131 slidably connected to the cutting guide rail 13 by fixing screws. A cutting machine connecting plate 19 is fixed to the lower surface of the cutting machine connecting seat 18 by bolts. A cutting machine support 22 and a cutting machine drive motor 21 are fixed to the cutting machine connecting plate 19 by bolts. A drive pulley 24 is fixed to the output shaft of the cutting machine drive motor 21. A driven shaft 26 is rotatably connected inside the cutting machine support 22. A driven pulley 25 is fixed to one end of the driven shaft 26. A cutting machine belt 20 is wound between the drive pulley 24 and the driven pulley 25. A cutting saw blade 23 is fixed to the other end of the driven shaft 26 by bolts.

[0066] The cutting machine drive motor 21 drives the drive pulley 24, which in turn drives the driven pulley 25 and driven shaft 26 to rotate at high speed via belt transmission, thereby driving the cutting saw blade 23 to cut the steel arch frame; at the same time, the cutting feed drive motor 27 controls the cutting machine to feed along the cutting guide rail 13 to achieve a stable and continuous cutting process.

[0067] In this embodiment, the specifications and dimensions of the steel arch frame to be cut are first input into the control system. The edge-finding drive motor 5 is controlled by the human-machine interface platform. The rotation of the edge-finding drive motor 5 drives the edge-finding feed screw 4 to rotate. Through the mechanical transmission characteristics of the edge-finding feed screw 4, the rotary motion is converted into the linear motion of the cutting frame 12, which in turn drives the edge-finding laser generator 14 to move laterally. By determining whether the edge-finding laser generator 14 coincides with the specified edge of the steel arch frame, the operating system records the relevant parameters of the current position. These position parameters can be used as reference point values ​​for cutting the steel arch frame material.

[0068] If the cutting task continues, the operating system will execute the next action. By controlling the rotation of the rotary table drive motor 10, it drives the rotary table drive gear 11, which in turn drives the rotary table 9 through gear meshing, thus rotating the cutting frame 12. This adjusts the rotation of components such as the cutting machine connecting seat 18 and the cutting saw blade 23 to the required cutting angle. Simultaneously, the operating system controls the rotation of the cutting feed drive motor 27, which in turn drives the cutting feed screw 15, forming a mechanical engagement between the screw and the screw nut, which drives the cutting machine connecting seat 18 to feed. The cutting machine drive motor 21 drives the drive pulley 24 to rotate. The drive pulley 24, driven pulley 25, and cutting machine belt 20 form a belt drive that drives the driven shaft 26 to rotate. The cutting saw blade 23 is fixed on the driven shaft 26, thus achieving synchronous speed with the cutting machine drive motor 21. The cutting saw blade 23 cuts the steel arch material at the corresponding position.

[0069] In this embodiment, the present invention integrates an edge-finding positioning mechanism and a cutting execution mechanism on the gantry welding frame 1, so that the edge-finding, rotation and cutting processes are completed continuously under the same equipment reference. Before cutting, the edge-finding feed screw 4 drives the cutting frame 12 to move as a whole, and the edge-finding laser generator 14 installed below the cutting frame 12 positions the edge of the steel arch frame. This makes the cutting reference no longer dependent on manual measurement and scribing operations, effectively reducing the impact of manual measurement errors and inconsistent human operations on the cutting accuracy. It improves the reliability and repeatability of the steel arch frame material cutting positioning from the structural and process levels.

[0070] Furthermore, by setting a rotary table 9 structure between the edge-finding positioning mechanism and the cutting execution mechanism, the cutting frame 12 and the cutting components can be angled around the vertical axis. After the edge-finding positioning is completed, the angle position of the cutting frame 12 can be adjusted by the rotary table drive motor 10, and then the cutting execution mechanism can perform straight cutting, so that the cutting direction matches the actual clamping posture of the steel arch frame. This avoids the problem of section tilting that is easy to occur when there is a deviation in the posture of the steel in the traditional fixed-angle cutting method, and makes the cutting section closer to the angle state required by the design.

[0071] Example 2

[0072] Please see Figures 1-8 This invention provides a technical solution: a control system for an automatic positioning and cutting machine for gantry-type steel arch frames, comprising an automatic positioning and cutting machine for gantry-type steel arch frames and a control unit, wherein the control unit includes:

[0073] The multi-axis spatial coordinate system construction module establishes a composite coordinate system by taking the gantry welding frame 1 as a fixed reference datum after the steel arch frame enters the processing station and establishing the edge-finding linear coordinate system, the rotary table angle coordinate system, and the cutting feed coordinate system.

[0074] The edge-finding linear coordinate system is used as the global reference coordinate system, the rotary table angular coordinate system is defined as a rotating sub-coordinate system attached to the edge-finding axis coordinate system, and the cutting feed coordinate system is defined as a linear sub-coordinate system attached to the rotary table angular coordinate system, thus forming a composite coordinate system.

[0075] Specifically, the multi-axis spatial mapping relationship is used as a unified coordinate constraint for subsequent edge finding, rotation and cutting actions. It is not just about establishing a CNC coordinate system, but about pre-constructing a multi-axis mapping relationship for subsequent "boundary drive control".

[0076] Optionally, the method for constructing the coordinate system for finding the edge includes:

[0077] The edge-finding drive motor 5 drives the edge-finding feed screw 4 to move in the opposite direction until the rotary table connecting seat 8 triggers the origin limit signal of the edge-finding guide rail 3; the limit trigger position is defined as the origin of the linear coordinate system of the edge-finding axis, and one end of the axial direction of the edge-finding feed screw 4 is taken as the positive direction of the linear coordinate system of the edge-finding axis.

[0078] The method for constructing the rotary table angular coordinate system includes:

[0079] After the linear coordinate system for edge finding is constructed, the rotary table angular coordinate system is constructed: the rotary table drive motor 10 is controlled to drive the rotary table 9 to rotate until the rotary table 9 reaches the mechanical angular reference position. This reference position is defined as the zero angular position of the rotary table angular coordinate system. The counterclockwise rotation direction when viewed from top to bottom along the central axis of the rotary table is taken as the positive direction of the rotary table angular coordinate system, and the rotation angle of the rotary table is limited to a preset safe angle range.

[0080] The method for constructing the cutting feed coordinate system includes:

[0081] After the rotary table angle coordinate system is constructed, the cutting feed coordinate system is constructed. The cutting feed drive motor 27 is controlled to drive the cutting machine connecting seat 18 to move in the opposite direction along the cutting guide rail 13. When the cutting machine connecting seat 18 reaches the origin limit position, this position is set as the origin of the cutting feed coordinate system. One end of the axis of the cutting feed screw 15 is taken as the positive direction of the cutting feed coordinate system.

[0082] It should be noted that after the above three coordinate systems are constructed, the linear coordinate system of the edge-finding axis is used as the global reference coordinate system, the rotary table angle coordinate system is defined as a rotating sub-coordinate system attached to the edge-finding axis coordinate system, and the cutting feed coordinate system is defined as a linear sub-coordinate system attached to the rotary table angle coordinate system. This forms a composite coordinate system with a nested hierarchy of linear-rotating-linear. The position of any cutting point can be represented as a composite function of the three coordinate systems, realizing a calculable and closed-loop control path for edge-finding results, angle back-calculation, and feed generation.

[0083] The boundary data acquisition module controls the edge-finding drive motor 5 to make the rotary table 9 and the cutting execution mechanism move along the edge-finding guide rail 3. During the movement, the edge-finding laser generator 14 installed below the cutting frame 12 continuously scans the outer edge contour of the steel arch frame to obtain the boundary space point data set.

[0084] The boundary data acquisition module is configured as follows:

[0085] Step Sa1: After the steel arch frame enters the processing station and completes the initial clamping, the edge-finding drive motor 5 is controlled to drive the edge-finding feed screw 4 to rotate, so that the rotary table 9 and the cutting execution mechanism are as a whole execution unit and make linear feed motion along the edge-finding guide rail 3, thereby forming an active edge-finding scanning trajectory covering the length direction of the steel arch frame.

[0086] Step Sa2: Based on the edge-finding active scanning trajectory, control the edge-finding laser generator 14 installed below the cutting frame 12 to continuously emit a ranging laser beam, and synchronously measure the distance of the outer edge of the steel arch frame located below the scanning trajectory at a preset sampling period.

[0087] Specifically, during the execution of the scanning trajectory, the edge-finding laser generator 14 installed below the cutting frame 12 continuously emits a ranging laser beam, and performs ranging sampling on the outer edge contour of the steel arch frame at a preset sampling period to obtain edge-finding data, which is expressed as: In the formula, For the first Each laser ranging sampling data, The coordinates of the edge to be found are the coordinates of the current sampling point. This is the measured distance from the laser generator to the outer edge of the steel arch frame;

[0088] Step Sa3: Based on the fixed installation position of the edge-finding laser generator 14 in the equipment coordinate system, each set of edge-finding data obtained in step Sa2 is converted into the boundary space point corresponding to the outer edge of the steel arch frame in the composite coordinate system.

[0089] Specifically, the boundary space points are represented as: ;

[0090] in, For the first The outer spatial boundary point of the individual steel arch frame Based on distance measurement values The installation height, installation angle, and relative position of the edge-finding laser generator to the edge-finding guide rail are used to calculate the first... The lateral and vertical coordinates of the spatial boundary points on the outer edge of each type of steel arch frame;

[0091] For example, the laser rangefinder is fixed below the cutting frame 12, with a mounting height relative to the edge-finding axis reference plane of [missing information]. ， Distance measured by edge-finding laser generator 14 It is the distance measured along the laser emission direction to the outer edge of the steel profile, and the laser installation angle relative to the horizontal plane is... So for the first The conversion method for the outer spatial boundary points of individual steel arch frames is as follows:

[0092] ;

[0093] in, and It refers to the lateral and vertical offsets of the laser mounting center point relative to the edge-finding linear coordinate system. It is a cosine function. It is a sine function.

[0094] Step Sa4 involves sequentially executing steps Sa2 and Sa3 to obtain multiple boundary space points distributed along the length of the steel arch frame. These boundary space points are then aggregated according to the sampling order to form a boundary space point data set of the outer edge contour of the steel arch frame.

[0095] Specifically, the boundary space point data set is represented as follows: ; The number of valid boundary space points obtained during a complete edge-finding active scan is used as the sole input data source for subsequent real boundary model generation steps, which are used to perform boundary fitting, spatial offset analysis and cutting path generation.

[0096] The real boundary model generation module fits the boundary space point data set to generate a real boundary model of the steel arch frame in the current clamping state. Based on the geometric model of the steel arch frame design drawings, it calculates the spatial offset of the ideal position under the gantry welded frame 1. Specifically, by obtaining the real boundary model, the model can reflect non-design factors such as actual clamping errors and deformation.

[0097] The real boundary model generation module is configured as follows:

[0098] Step Sb1: Preprocess the acquired boundary space point data set to obtain a valid boundary point set. The preprocessing includes outlier removal and boundary continuity smoothing.

[0099] Specifically, outlier removal is achieved by calculating the Euclidean distance between adjacent boundary spatial points. When the distance between a boundary spatial point and its adjacent points exceeds a preset threshold, the boundary spatial point is identified as an outlier and removed.

[0100] Boundary continuity smoothing includes: arranging the remaining boundary space points sequentially along the coordinate system of the edge-finding line, and using moving average or local least squares methods to smooth the boundary space points in order to eliminate the influence of laser ranging noise on the boundary profile.

[0101] In this embodiment, by continuously acquiring boundary space points of the outer edge of the steel arch frame during the edge-finding process, and performing outlier removal, continuity smoothing, and cross-section fitting on the boundary data, this invention can generate a three-dimensional boundary model that reflects the true spatial form of the steel arch frame in the current clamping state. This realistic boundary model not only includes the design contour information of the steel arch frame, but also accurately reflects non-ideal factors such as clamping deviations and material deformation, thereby overcoming the problem of existing technologies that rely solely on theoretical dimensions for cutting and are difficult to adapt to changes in actual working conditions.

[0102] Step Sb2: Using the direction of the linear coordinate system for edge finding as the length direction of the steel arch frame, the effective boundary point set is divided into multiple cross-sectional intervals according to a preset cross-sectional spacing. Within each cross-sectional interval, the corresponding subset of boundary space points is extracted to obtain the cross-sectional point set. ;

[0103] Specifically, the subset of boundary space points corresponding to this interval is represented as follows:

[0104] ;

[0105] In the formula, To indicate the first A subset of boundary points corresponding to each cross section. Indicates the first The starting position of each cross section in the edge-finding direction. For the preset cross-sectional spacing, These represent the spatial coordinates of the boundary points in the horizontal and vertical directions, respectively, forming a two-dimensional coordinate pair. To find the position along the edge direction;

[0106] Step Sb3, for each set of cross-section points In a fixed cross-section In this position, the two-dimensional coordinates of the boundary points are paired. Projecting the data onto the corresponding cross-sectional plane yields a two-dimensional point set. Using the least squares method, spline curve, or polynomial fitting method, curve fitting is performed on the two-dimensional point set to obtain the cross-sectional boundary profile curve corresponding to the cross-section.

[0107] Specifically, the cross-sectional boundary profile curve is represented as follows: ;

[0108] In the formula, Indicates the first The cross-sectional boundary profile curve of each section. The fitting function relationship represents the boundary profile of the cross section below the cross section; Z represents the vertical position, and Y represents the horizontal position of the boundary point;

[0109] Step Sb4: Based on the contour curves of all cross sections, spatial interpolation is performed on each contour curve along the direction of the edge-finding linear coordinate system in the order of the cross sections to construct a three-dimensional real boundary model that reflects the actual spatial form of the steel arch frame in the current clamping state.

[0110] The real boundary model generation module is also configured to:

[0111] Step SC1: Obtain the geometric model corresponding to the steel arch frame design drawings, and place the geometric model in the ideal installation position with the gantry welded frame 1 coordinate system as the reference reference according to the equipment design requirements, so as to obtain the reference model in the ideal state.

[0112] Step SC2 involves spatially registering the real boundary model with the reference model. By minimizing the overall distance between corresponding boundary points of the two models, the rigid spatial transformation parameters that optimally coincide between the two models are solved. These rigid spatial transformation parameters include the rotation matrix. Translation vector ;

[0113] It should be noted that the rotation matrix Used to describe the pose deviation between models; translation vector Used to describe the spatial offset between models;

[0114] ;in, Characterizing the clamping position deviation of the steel arch frame in the length direction. The clamping offset of the characterizing steel arch frame in the lateral direction. The installation error of the steel arch frame in the height direction is characterized;

[0115] The registration relationship is expressed as follows:

[0116] ;

[0117] In the formula, Represents any boundary point in the real boundary model. This represents the boundary point of the reference model corresponding to any boundary point in the real boundary model.

[0118] Step SC3: Based on the translation vector, obtain the translation offset of the steel arch frame relative to the coordinate system of the gantry welded frame 1, and then use the rotation matrix... The attitude offset angle relative to the coordinate system of the gantry welding frame 1 is obtained.

[0119] It should be noted that the coordinate system of gantry welded frame 1 is defined with the length direction of the crossbeam of gantry welded frame 1 as the X-axis direction of the gantry reference coordinate system, the width direction between the columns of gantry welded frame 1 as the Y-axis direction, the height direction of the columns of gantry welded frame 1 as the Z-axis direction, and the center point of gantry welded frame 1 as the origin of the coordinate system.

[0120] The rotation matrix R is analyzed according to a preset coordinate axis rotation sequence, decomposing the overall rotation relationship into independent rotation components around each reference coordinate axis, thereby obtaining the attitude offset angles of the steel arch frame relative to the gantry welding frame reference in each direction. These attitude offset angles describe the angular deviation of the steel arch frame from its ideal installation posture in the clamping state, providing a basis for subsequent rotary table angle reverse calculations and cutting posture compensation.

[0121] The attitude offset angles represent the angular deviations of the steel arch frame relative to the gantry welding frame reference in the corresponding directions when the frame is clamped, reflecting the tilting, twisting, or swaying state of the steel arch frame in space. The above-mentioned configuration process based on rotation matrix analysis of attitude angles is a common technique in robot kinematics, CNC equipment, and multi-axis machining control. This invention introduces this technique into an automatic steel arch frame cutting device, achieving automatic acquisition and control compensation of the actual attitude deviation of the steel arch frame, which will not be elaborated further here.

[0122] The cutting control module inputs the acquired translational offset and attitude offset angle, as well as the dimensions of the steel arch frame, into the pre-built cutting control parameter prediction model, and outputs cutting control parameters, including the rotation angle of the rotary table 9 and the moving length of the cutting machine connecting seat 18.

[0123] The training method for the cutting control parameter prediction model includes:

[0124] Acquire historical data on the successful cutting of steel arch frames, which are recorded as historical cutting data. The historical cutting data includes the dimensions of the steel arch frame, the translational offset and attitude offset angle of the steel arch frame, and the cutting control parameters, including the rotation angle of the rotary table 9 and the moving length of the cutting machine connecting seat 18. Construct a dataset from the acquired historical cutting data, and randomly divide the dataset into a training set, a test set, and a validation set according to a preset ratio (7:2:1).

[0125] A multi-output gradient boosting regression tree was selected as the prediction model for the control parameters.

[0126] Model initialization involves setting initial hyperparameters, including: number of decision trees: 150-200, maximum depth of a single tree: 6-8, minimum number of samples for node splitting: 8-12, maximum number of features considered during splitting: 3, learning rate: 0.05-0.1, regularization coefficient (L2): 0.1-0.2, and the loss function is mean squared error. The splitting criterion for a single tree is also mean squared error.

[0127] The initial prediction value is set as the mean of the two labels (rotation angle and movement length) in the training set to provide a benchmark for subsequent iterative training.

[0128] For each sample in the training set, calculate the residuals between the current model's predicted turntable rotation angle and connecting seat movement length and the true values, and integrate the two residuals into a residual vector; construct a new decision tree with the goal of minimizing the sum of squares of the residual vectors, select the optimal splitting feature based on the mean square error, such as prioritizing the attitude offset angle, and divide the samples into different sub-nodes until the stopping condition is met, such as reaching the maximum depth or the number of sub-node samples < the minimum number of samples.

[0129] The weights of the leaf nodes of the new tree are optimized by gradient descent. The learning rate controls the contribution of the new tree to the dual-output prediction results, avoiding the dominance of a single tree. The new tree is then integrated into the existing model. At the same time, the prediction bias of the rotation angle and the movement length are corrected. The process is repeated iteratively until the preset number of trees is built or the early stopping mechanism is triggered.

[0130] The early stopping mechanism calculates the mean root mean square error (RMSE) of the validation set (RMSE of rotation angle + RMSE of movement length) / 2 every 20 iterations. When the mean RMSE of the validation set decreases by less than 0.001 after 3 consecutive iterations and a total of 60 trees, training stops and the model parameters with the lowest mean RMSE of the validation set are saved.

[0131] The Bayesian optimization method is used to search for the optimal combination of hyperparameters within a preset range. The optimization objective is to minimize the mean root mean square error of the validation set. The optimization range includes: number of decision trees: 120-250, maximum depth of a single tree: 5-9, learning rate: 0.03-0.12, minimum number of samples for node splitting: 8-20, and regularization coefficient (L2): 0.05-0.25.

[0132] The trained model is evaluated using a test set. If the root mean square error of the rotation angle is ≤0.5°, the root mean square error of the movement length is ≤1mm, and the mean coefficient of determination (R²) is ≥0.95, the model performance evaluation is considered satisfactory and it can be deployed and applied.

[0133] The cutting execution module first controls the rotary table drive motor 10 based on the rotation angle of the rotary table 9, driving the rotary table 9 to rotate to the target angle, then controls the cutting saw blade 23 to work, and then controls the cutting feed drive motor 27 to work based on the moving length of the cutting machine connecting seat 18, driving the cutting machine connecting seat 18 to move and complete the cutting.

[0134] In this embodiment, by spatially registering the real boundary model with the ideal reference model established based on the design drawings, the translational offset and attitude offset angle of the steel arch frame relative to the gantry welding frame reference are automatically solved, realizing a quantitative description of the clamping state of the steel arch frame. This method avoids unstable operations such as manual alignment and experience correction, and enables the clamping error to participate in subsequent control calculations in the form of clear spatial parameters, providing a reliable data basis for cutting accuracy.

[0135] Furthermore, this invention does not simply generate cutting actions directly based on geometric relationships. Instead, it inputs the acquired translational offset, attitude offset angle, and steel arch frame dimensions into a pre-constructed cutting control parameter prediction model. The model outputs the rotary table rotation angle and the cutting axis feed length. By introducing a multi-output regression model trained based on historical benchmark data, the cutting control parameters can comprehensively consider the influence of different specifications of steel, different clamping states, and different attitude deviations. This significantly reduces the dependence on operator experience and equipment debugging level, and improves the equipment's adaptability to multiple specifications and working conditions.

[0136] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A gantry-type automatic positioning and cutting machine for steel arch frames, characterized in that, It includes a gantry welding frame (1), and an edge-finding positioning mechanism and a cutting execution mechanism installed on the gantry welding frame (1); The edge-finding positioning mechanism includes an edge-finding positioning frame (2), which is fixedly installed on the gantry welding frame (1) by locking screws. An edge-finding guide rail (3) is fixed on the edge-finding positioning frame (2) by bolts. An edge-finding feed screw (4) is also rotatably connected to the edge-finding positioning frame (2) and arranged parallel to the edge-finding guide rail (3). A first slider (31) is provided on the edge-finding guide rail (3), and a rotary table connecting seat (8) is fixed to the lower surface of the first slider (31) by bolts. The lower surface of the rotary table connecting seat (8) is rotatably connected to a rotary table (9), and the lower surface of the rotary table (9) is fixed with a cutting frame (12) by bolts. The lower surface of the cutting frame (12) is equipped with an edge-finding laser generator (14).

2. The gantry-type steel arch frame automatic positioning and cutting machine according to claim 1, characterized in that, The edge-finding positioning frame (2) is equipped with an edge-finding drive motor (5). The output shaft of the edge-finding drive motor (5) is fixedly connected to one end of the edge-finding feed screw (4) through a coupling, which is used to drive the screw to rotate. The rotary table connecting seat (8) is welded and fixed with a first screw nut seat, and the first screw nut seat is threadedly connected to the edge-finding feed screw (4).

3. The gantry-type steel arch frame automatic positioning and cutting machine according to claim 2, characterized in that, The edge-finding positioning frame (2) is fixed with an edge-finding drag chain bracket (6) by bolts, and the edge-finding drag chain bracket (6) is connected to the edge-finding drag chain (7) by bolts; A rotary table drive motor (10) is installed on the rotary table connecting seat (8). A rotary table drive gear (11) is fixedly connected to the output shaft of the rotary table drive motor (10). A gear ring (91) is welded on the rotary table (9). The rotary table drive gear (11) meshes with the gear ring (91).

4. The gantry-type steel arch frame automatic positioning and cutting machine according to claim 3, characterized in that, Along the length direction, the lower surface of the cutting frame (12) is bolted with two parallel cutting guide rails (13). A cutting feed drive motor (27) is bolted to the center line of the lower surface of the cutting frame (12), and a cutting feed screw (15) is rotatably connected to the center line of the lower surface of the cutting frame (12). The output shaft of the cutting feed drive motor (27) is fixedly connected to the cutting feed screw (15) through a coupling.

5. The gantry-type steel arch frame automatic positioning and cutting machine according to claim 4, characterized in that, The cutting actuator includes a cutting machine connecting seat (18), which is mounted on a second slider (131) slidably connected to the cutting guide rail (13) by fixing screws. A cutting machine connecting plate (19) is fixed to the lower surface of the cutting machine connecting seat (18) by bolts. A cutting machine support (22) and a cutting machine drive motor (21) are fixed to the cutting machine connecting plate (19) by bolts. A drive pulley (24) is fixed to the output shaft of the cutting machine drive motor (21). A driven shaft (26) is rotatably connected inside the cutting machine support (22). A driven pulley (25) is fixed to one end of the driven shaft (26). A cutting machine belt (20) is wound between the drive pulley (24) and the driven pulley (25). A cutting saw blade (23) is fixed to the other end of the driven shaft (26) by bolts. A second lead screw nut seat is fixed to the cutting machine connecting seat (18) by bolts. The second lead screw nut seat is threadedly connected to the cutting feed lead screw (15).

6. The gantry-type steel arch frame automatic positioning and cutting machine according to claim 5, characterized in that, A cutting drag chain (16) is connected to the cutting frame (12) by screws. The cutting drag chain (16) is connected to the cutting drag chain connecting plate (17) by bolts. The cutting drag chain connecting plate (17) is connected to the cutting machine connecting seat (18) by screws.

7. A control system for an automatic positioning and cutting machine for gantry-type steel arch frames, characterized in that, include: The gantry-type steel arch frame automatic positioning and cutting machine and control unit according to any one of claims 5-6, wherein the control unit comprises: The multi-axis spatial coordinate system construction module establishes a composite coordinate system by taking the gantry welding frame (1) as a fixed reference benchmark after the steel arch frame enters the processing station and establishing the edge-finding linear coordinate system, the rotary table angle coordinate system and the cutting feed coordinate system. The boundary data acquisition module controls the edge-finding drive motor (5) to make the rotary table (9) and the cutting execution mechanism move along the edge-finding guide rail (3). During the movement, the edge-finding laser generator (14) installed under the cutting frame (12) continuously scans the outer edge contour of the steel arch frame to obtain the boundary space point data set. The real boundary model generation module fits the boundary space point data set to generate the real boundary model of the steel arch frame in the current clamping state. Based on the geometric model of the steel arch frame design drawings, the spatial offset is calculated at the ideal position under the gantry welded frame (1). The cutting control module inputs the acquired translational offset and attitude offset angle, as well as the dimensions of the steel arch frame, into the pre-built cutting control parameter prediction model and outputs the cutting control parameters, which include the rotation angle of the rotary table (9) and the moving length of the cutting machine connecting seat (18). The cutting execution module first controls the rotary table drive motor (10) based on the rotation angle of the rotary table (9) to drive the rotary table (9) to rotate to the target angle, then controls the cutting saw blade (23) to work, and then controls the cutting feed drive motor (27) to work based on the moving length of the cutting machine connecting seat (18), driving the cutting machine connecting seat (18) to move and complete the cutting.

8. The control system of the gantry-type steel arch frame automatic positioning and cutting machine according to claim 7, characterized in that, The boundary data acquisition module is configured as follows: After the steel arch frame enters the processing station and completes the initial clamping, the edge-finding drive motor (5) is controlled to drive the edge-finding feed screw (4) to rotate, so that the rotary table (9) and the cutting execution mechanism are as a whole execution unit and make linear feed motion along the edge-finding guide rail (3), thereby forming an active edge-finding scanning trajectory covering the length direction of the steel arch frame. Based on the active scanning trajectory for edge finding, the edge finding laser generator (14) installed below the cutting frame (12) is controlled to continuously emit a ranging laser beam, and synchronously ranging and sampling are performed on the outer edge of the steel arch frame located below the scanning trajectory at a preset sampling period to obtain edge finding data. Based on the fixed installation position relationship of the edge-finding laser generator (14) in the equipment coordinate system, each set of edge-finding data obtained is converted into the boundary space point corresponding to the outer edge of the steel arch frame in the composite coordinate system; Multiple boundary space points distributed along the length of the steel arch frame are obtained, and the boundary space points are collected in the sampling order to form a boundary space point data set of the outer edge contour of the steel arch frame.

9. The control system of the gantry-type steel arch frame automatic positioning and cutting machine according to claim 7, characterized in that, The real boundary model generation module is configured as follows: The acquired set of boundary space point data is preprocessed to obtain a set of valid boundary points; Using the direction of the edge-finding linear coordinate system as the length direction of the steel arch frame, the effective boundary point set is divided into multiple cross-sectional intervals according to the preset cross-sectional spacing. Within each cross-sectional interval, the corresponding boundary space point subset is extracted to obtain the cross-sectional point set. For each set of cross-sectional points, at a fixed cross-sectional position, the two-dimensional coordinates of the boundary points are projected onto the corresponding cross-sectional plane to obtain a two-dimensional point set. The least squares method is used to perform curve fitting on the two-dimensional point set to obtain the cross-sectional boundary profile curve corresponding to the cross-section. Based on the boundary contour curves of all sections, spatial interpolation is performed on each contour curve along the direction of the edge-finding linear coordinate system in the order of sections to construct a three-dimensional real boundary model that reflects the actual spatial form of the steel arch frame in the current clamping state.

10. The control system of the gantry-type steel arch frame automatic positioning and cutting machine according to claim 9, characterized in that, The real boundary model generation module is also configured to: Obtain the geometric model corresponding to the design drawings of the steel arch frame, and place the geometric model in the ideal installation position with the gantry welded frame (1) coordinate system as the reference reference according to the equipment design requirements, so as to obtain the reference model in the ideal state; The real boundary model is spatially registered with the reference model. By minimizing the overall distance between corresponding boundary points of the two models, the rigid spatial transformation parameters that make the two models best coincide are solved. The rigid spatial transformation parameters include rotation matrix and translation vector. Based on the translation vector, the translation offset of the steel arch frame relative to the coordinate system of the gantry welded frame (1) is obtained, and the attitude offset angle relative to the coordinate system of the gantry welded frame (1) is obtained based on the rotation matrix.

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