Laser cutting apparatus and method for complex shaped metal conduit

Abstract

The application discloses a kind of complex shape metal conduit laser cutting equipment and method.The equipment includes laser cutting device, measuring machine and robot;Laser cutting device is matched by rotating shaft, swing shaft and servo shaft equipped with capacitive gap sensor, realizes three-dimensional posture adjustment and non-contact height tracking of spray head;Measuring machine includes binocular vision system, scans conduit and obtains three-dimensional point coordinate data;Robot utilizes multi-axis collaborative motion to realize end clamp spatial arbitrary position and attitude control.The method includes: importing theoretical three-dimensional numerical model and presetting path;Binocular vision scans conduit and reconstructs three-dimensional numerical model;Compare reconstructed numerical model with theoretical numerical model, calculate overall deviation to determine the eligibility of shape;For qualified conduit, generate robot motion path and simulate optimization;After trial cutting, measure cutting numerical model again for verification, and correct deviation value when unqualified.The application is suitable for high-precision automatic cutting of complex spatial curved surface, special-shaped structure metal conduit.

Description

Technical Field

[0001] This invention relates to the field of laser cutting technology, specifically to a laser cutting device and method for complex-shaped metal conduits, which is particularly suitable for processing metal tubes with multi-dimensional bending and variable cross-section characteristics in fields such as aerospace and automobile manufacturing. Background Technology

[0002] With the increasing demand for complex-shaped metal conduits in aerospace, automotive manufacturing, and precision instrumentation industries, traditional cutting techniques are no longer sufficient to meet the industry requirements of high precision, high efficiency, and green manufacturing. Currently, laser cutting technology, with its advantages of non-contact processing, high energy density, and flexibility, is gradually becoming the mainstream choice for metal conduit processing. Laser cutting is a technology that uses a high-energy-density laser beam to precisely cut materials, and it can be used for both metal and non-metal processing. Compared to traditional cutting techniques, laser-cut metal conduits have smoother cut edges and lower roughness, reducing subsequent grinding work.

[0003] However, existing laser cutting technology still faces many bottlenecks when dealing with metal conduits with complex shapes. Current laser cutting technology cannot achieve high-precision cutting of complex-shaped metal conduits and is highly dependent on the operator's experience and skills. Before cutting begins, operators need to perform extensive preparation work. They must manually place the metal conduit to be cut at the cutting station and select suitable clamps to fix it in place to prevent movement during the cutting process. After pre-cutting preparation, the operator must operate the laser cutting machine to plan the cutting path on the metal conduit, input the corresponding cutting parameters to generate cutting process data, and finally perform the actual cutting.

[0004] Patent application CN118559237A discloses a metal pipe cutting tool that can effectively fix multiple pipes and simultaneously cut them axially. However, this tool is only suitable for cutting straight pipes and not for metal conduits with complex shapes. Patent application CN118513693A discloses a laser cutting intelligent control system that can perform laser control judgment based on the cutting parameters of the cutting trajectory and analyze the cutting depth and width. However, the system does not clearly explain how to identify and judge complex-shaped metal conduits. Summary of the Invention

[0005] The purpose of this invention is to provide a laser cutting device and method for complex-shaped metal conduits, which can perform high-precision laser cutting of complex spatial curved surfaces and irregular structures of metal conduits in three-dimensional space, thereby improving automation, reducing manual intervention, and increasing production efficiency.

[0006] To achieve the above objectives, the present invention employs the following technical solution: A laser cutting device for complex-shaped metal conduits includes a laser cutting unit, a measuring machine, and a robot; The laser cutting device includes a connecting rod, a rotating shaft, a swing shaft, a follower shaft, and a nozzle. The connecting rod is connected between the rotating shaft and the swing shaft. The rotating shaft is used to drive the entire laser cutting device to rotate to adjust the orientation of the nozzle in the horizontal plane. The swing shaft cooperates with the rotating shaft to enable the nozzle to adjust its posture in three-dimensional space. The nozzle is mounted on the end of the swing shaft. The follower shaft is mounted on the nozzle and equipped with a capacitive gap sensor to detect the distance between the nozzle and the surface of the metal conduit in real time during the cutting process and to achieve non-contact automatic height tracking through closed-loop control so that the nozzle and the surface of the metal conduit maintain a constant preset distance. The measuring machine includes a guide rail, a first camera, a semiconductor laser, a second camera, a motor, a mounting platform, and a measuring platform. The measuring platform is used to support the metal conduit. The guide rail is mounted above the measuring platform and driven by the motor. The mounting platform is mounted on the guide rail and can move horizontally back and forth along the guide rail under the drive of the motor. The first camera, the semiconductor laser, and the second camera are all fixed on the mounting platform. The first camera and the second camera constitute a binocular vision system for synchronously acquiring images of the surface of the metal conduit. The semiconductor laser is used to project laser light onto the surface of the metal conduit to assist in obtaining three-dimensional point coordinates. The robot, used to grip a metal conduit and deliver it below the nozzle of the laser cutting device, includes a base, an upper arm, a forearm, a wrist joint, J1 axes, J2 axes, J3 axes, J4 axes, J5 axes, J6 axes, and an end effector. The base is a fixed base. The J1 axis is mounted on the base to drive the robot to rotate horizontally around the Z-axis. The J2 axis connects the base to the upper arm to drive the upper arm to swing back and forth around the Y-axis. The upper arm is connected to the forearm via the J3 axis, which drives the forearm to swing up and down around the Y-axis. The wrist joint is connected to the end of the forearm and includes the J4, J5, and J6 axes. The J4 axis enables the wrist joint to rotate around the forearm axis. The J5 axis controls the vertical tilt of the end effector. The J6 axis enables the rotation of the end effector, which is mounted at the end of the J6 axis and used to grip the metal conduit.

[0007] Furthermore, the axes of the rotating shaft and the swing shaft are perpendicular, and the axis of the nozzle is perpendicular to the axis of the swing shaft; the follower shaft detects the distance between the nozzle and the surface of the metal conduit in real time through a capacitive gap sensor mounted on it, and automatically adjusts the position of the follower shaft to adapt to the irregular changes in the shape of the metal conduit, ensuring that the laser focus always accurately acts on the surface of the metal conduit.

[0008] Furthermore, in the measuring machine, the guide rail extends along the length of the measuring platform; the first camera and the second camera are respectively fixed on both sides of the semiconductor laser, and their optical axes intersect; the motor is electrically connected to the control console, and drives the guide rail to move according to control commands to control the moving speed and scanning range of the mounting platform; when the measuring machine is working, the image data collected by the first camera and the second camera are processed by analysis software to obtain the three-dimensional point coordinate data of the surface of the metal conduit and the coordinate data of the position to be cut.

[0009] Furthermore, the J1 to J6 axes of the robot, through coordinated motion, enable the end effector to achieve precise control of any position and orientation in three-dimensional space; the end effector can be replaced or adjusted according to the shape and size of the metal conduit to adapt to the clamping requirements of metal conduits of different specifications.

[0010] A method for laser cutting complex-shaped metal conduits, based on the aforementioned laser cutting equipment for complex-shaped metal conduits, includes the following steps: Step 1: Equipment inspection, confirming that the laser cutting device, measuring machine, and robot equipment are in good condition and functioning normally; Step 2: Import the theoretical 3D model file of the metal conduit to be cut into the modeling software. In the software, pre-set the cutting position path and the position of the robot holding the metal conduit as a reference benchmark for subsequent measurement and path planning. Step 3: Place the metal conduit on the measuring platform. The motor drives the guide rail to move the mounting platform horizontally. The first camera and the second camera scan the metal conduit throughout its entire length. Based on the binocular vision 3D reconstruction method, obtain the 3D point coordinate data of the surface of the metal conduit and the coordinate data of each cutting position. Feed the coordinate data back to the analysis software to complete the 3D digital model reconstruction of the metal conduit. Step 4: Align and match the reconstructed 3D digital model with the theoretical 3D digital model of the metal conduit, and calculate the overall deviation between the two models. ,like If the diameter is within millimeters, the metal conduit is deemed to be in good shape and proceeds to the next cutting step; otherwise, the metal conduit is deemed to be in bad shape and the cutting process is terminated. Step 5: Combining the theoretical three-dimensional digital model parameters of the metal conduit with the three-dimensional point coordinate data and cutting position point coordinate data obtained by the measuring machine, the spatial relative position of the metal conduit and the robot, the precise coordinates of each cutting position, and the relative positional relationship between the nozzle, the end clamp and the cutting position point are calculated through coordinate transformation. Based on this, the robot motion path is generated by solving the calculation, and the motion path is simulated, checked and optimized in the modeling software to eliminate interference or collision risks. Step Six: Send the optimized motion path to the robot and the laser cutting device. The robot moves while holding the metal conduit, and the laser cutting device performs a trial cut. After the trial cut, place the metal conduit back on the measurement platform and repeat the scanning and measurement work of Step Three to obtain the three-dimensional model data of the cut metal conduit. Compare and verify the three-dimensional model data of the cut conduit with the theoretical three-dimensional model. If the deviation is within the allowable range, the cut is deemed qualified and the next conduit is cut. Otherwise, the cut is deemed unqualified, and the robot motion path is corrected according to the measured deviation value. Steps Five and Six are repeated until the cut is qualified.

[0011] Furthermore, the binocular vision 3D reconstruction method described in step three specifically includes: Let the point to be measured in space be... The coordinates of the projection point on the image plane of the first camera are: The coordinates of the projection point on the image plane of the second camera are: ; Like a dot The three-dimensional coordinates in the first camera coordinate system are represented as follows: ,in , for Physical coordinates in the left image plane The focal length of the first camera. , , , The coordinate compensation amount obtained from pre-calibration; Like a dot The three-dimensional coordinates in the second camera coordinate system are represented as follows: ,in , for Physical coordinates in the right image plane The focal length of the second camera; Set the point to be measured The three-dimensional coordinates in the first camera coordinate system are The three-dimensional coordinates in the second camera coordinate system are Based on the perspective projection relationship satisfying the proportional relationship, and through the rigid body transformation relationship between the first camera coordinate system and the second camera coordinate system, the measurement point is obtained by solving the simultaneous equations. The three-dimensional coordinates.

[0012] Furthermore, the overall deviation described in step four The calculation formula is: ,in The number of corresponding point pairs involved in the deviation calculation. For the first Spatial Euclidean distance between corresponding point pairs.

[0013] Furthermore, the step five, which involves solving and generating the robot's motion path, refers to automatically generating the robot's continuous motion trajectory by performing spatial coordinate transformation and kinematic calculations based on the spatial relative position of the metal conduit and the robot, the precise coordinates of the cutting position point, and the relative positional relationship data in the modeling software.

[0014] Furthermore, in the trial cutting verification process described in step six, deviation correction refers to correcting the coordinates of the corresponding points in the robot's motion path in reverse, based on the spatial deviation between the measured 3D model data and the theoretical 3D digital model at each cutting position point, when the 3D model data exceeds the allowable deviation range after cutting.

[0015] Compared with the prior art, the present invention has the following technical features: Currently, laser cutting technology cannot achieve high-precision cutting of complex-shaped metal conduits and is highly dependent on the operator's experience and skills. Before cutting, operators need to perform extensive preparation. They must manually place the metal conduit to be cut at the cutting station and select suitable clamps to secure it, preventing movement during the cutting process. After preparation, the operator must use the laser cutting machine to plan the cutting path on the metal conduit, input the corresponding cutting parameters to generate cutting process data, and finally perform the actual cutting. This invention designs a cutting method for complex-shaped metal conduits, expanding the applicability of laser cutting to complex-shaped metal conduits; this method can improve work efficiency and reduce the difficulty of cutting complex conduit parts. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the laser cutting head structure; Figure 2 This is a 3D schematic diagram of a laser cutting head; Figure 3 This is a schematic diagram of the principle and structure of the measuring machine; Figure 4 This is a schematic diagram of three-dimensional reconstruction of spatial points measured by a measuring machine; Figure 5 This is a 3D schematic diagram of the robot's structure; Figure 6 This is a flowchart of the cutting and assembly method for complex-shaped metal conduits.

[0017] Explanation of reference numerals in the attached drawings: 1-connecting rod, 2-rotation axis, 3-swing axis, 4-follower axis, 5-nozzle, 6-guide rail, 7-first camera, 8-semiconductor laser, 9-second camera, 10-motor, 11-mounting platform, 12-measuring platform, 13-base, 14-upper arm, 15-forearm, 16-wrist joint, 17-J1 axis, 18-J2 axis, 19-J3 axis, 20-J4 axis, 21-J5 axis, 22-J6 axis, 23-end clamp. Detailed Implementation

[0018] This invention provides a laser cutting device and method for complex-shaped metal conduits, enabling laser cutting to be used on complex-shaped metal conduits, and achieving high-precision laser cutting of metal conduits with complex spatial curved surfaces and irregular structures.

[0019] Part 1: Laser cutting equipment for complex-shaped metal conduits.

[0020] like Figures 1 to 5 As shown, this invention provides a laser cutting device for cutting complex-shaped metal conduits. The device mainly consists of three parts: a laser cutting unit, a measuring machine, and a robot. These three components work together to achieve high-precision automated cutting of metal conduits with complex spatial curved surfaces and irregular structural features.

[0021] I. Laser cutting equipment.

[0022] like Figure 1 and Figure 2 As shown, the laser cutting device is the cutting execution unit of the equipment, used to generate a high-energy-density laser beam and precisely cut the metal conduit; the laser cutting device specifically includes a connecting rod 1, a rotating shaft 2, a swing shaft 3, a follower shaft 4, and a nozzle 5, wherein: Link 1 is the connecting component between the rotating shaft 2 and the swing shaft 3, and the axes of the rotating shaft 2 and the swing shaft 3 are perpendicular to each other; the rotating shaft 2 is used to drive the laser cutting device to achieve rotational movement, thereby adjusting the orientation angle of the nozzle 5 in the horizontal plane to adapt to the cutting requirements in different directions in the conduit cutting path.

[0023] The coordinated movement of the swing axis 3 and the rotation axis 2 allows the nozzle 5 to adjust its posture at any angle in three-dimensional space. The combined movement of the rotation axis 2 and the swing axis 3 enables the laser cutting device to adapt to the complex spatial curvature changes of the guide tube surface and always keep the nozzle 5 aligned with the normal of the cutting point.

[0024] The nozzle 5 is installed at the end of the swing shaft 3, with its axis perpendicular to the swing shaft 3. It is used to focus and spray the laser beam and is the final output port of the laser energy. The follower shaft 4 is installed on the nozzle 5 and is equipped with a capacitive gap sensor. During the cutting process, the gap sensor detects the distance between the nozzle 5 and the surface of the metal guide tube in real time, and automatically adjusts the position of the follower shaft 4 through closed-loop control to achieve a non-contact height automatic tracking function. This ensures that the nozzle 5 and the surface of the metal guide tube always maintain a constant preset distance during processing, thereby adapting to the irregular changes in the shape of the metal guide tube and ensuring that the laser focus always accurately acts on the surface of the metal guide tube, ensuring the uniformity and consistency of the cutting quality.

[0025] II. Measuring machine.

[0026] like Figure 3 and Figure 4 As shown, the measuring machine is the vision measurement unit of the equipment, used to perform 3D scanning of the metal conduit to be cut placed on it, and to obtain the point cloud data of the metal conduit's shape and the coordinates of the cutting position; the measuring machine specifically includes a guide rail 6, a first camera 7, a semiconductor laser 8, a second camera 9, a motor 10, a mounting platform 11, and a measuring platform 12, wherein: The measuring platform 12 is the base platform of the measuring machine, used to support and place the metal conduit to be measured.

[0027] The guide rail 6 is installed above the measuring platform 12 and extends along the length of the measuring platform 12. The guide rail 6 is driven by the motor 10, which can drive the mounting platform 11 mounted on it to move horizontally back and forth along the measuring platform 12. The mounting platform 11 is equipped with a first camera 7, a semiconductor laser 8, and a second camera 9. When the measuring platform 12 moves, it can perform a full-range scan of the metal conduit placed on the measuring platform 12. The first camera 7 and the second camera 9 constitute a binocular vision system, which serves as the left camera and the right camera, respectively. The first camera 7 and the second camera 9 are fixedly installed on both sides of the semiconductor laser 8 on the mounting platform 11, and their optical axes intersect. During the scanning process, the first camera 7 and the second camera 9 simultaneously acquire image information of the conduit surface. The semiconductor laser 8 is used to project laser light onto the surface of the metal conduit to enhance the recognizability of the conduit surface features in the image and assist the binocular vision system in obtaining high-precision three-dimensional point coordinate data.

[0028] The motor 10 is the drive device for the guide rail 6 and is electrically connected to the control console. It can drive the guide rail 6 to move according to the control command, thereby controlling the moving speed and scanning range of the mounting platform 11.

[0029] When the measuring machine is working, the image data collected by the first camera 7 and the second camera 9 are processed by the analysis software to obtain the three-dimensional point coordinate data of the surface of the metal conduit and the coordinate data of the position to be cut.

[0030] III. Robots.

[0031] like Figure 5 As shown, the robot is the spatial motion execution unit of the device, used to grip the metal conduit and deliver it to the nozzle 5 of the laser cutting device according to the planned motion path, thus completing the cutting action. The robot has six degrees of freedom, specifically including a base 13, an upper arm 14, a forearm 15, a wrist joint 16, and J1 axes 17, J2 axes 18, J3 axes 19, J4 axes 20, J5 axes 21, and J6 axes 22 distributed at each joint, and an end effector 23 mounted at the end. The base 13 serves as the robot's fixed base, mounted on the work surface or frame, providing stable support for the entire robot. The J1 axis 17 is the first axis, mounted on the base 13, driving the robot to rotate horizontally around the Z-axis, determining the horizontal coverage area of ​​the robot's working range. The J2 axis 18 is the second axis, connecting the base 13 and the upper arm 14 via the J1 axis, driving the upper arm 14 to swing back and forth around the Y-axis, controlling the robot's end effector's main vertical movement range. The upper arm 14 is the robot's main support arm, connected to the forearm 15 via the J3 axis 19. The J3 axis 19 is the third axis, connecting the upper arm 14 and the forearm 15, driving the forearm 15 to swing up and down around the Y-axis, further expanding the end effector's vertical workspace. The forearm 15 is the robot's... The auxiliary support arm has a wrist joint 16 at its end. The wrist joint 16 includes three joint axes: J4 axis 20, J5 axis 21, and J6 axis 22, which are used to achieve fine adjustment of the end-effector posture. J4 axis 20 is installed at the end of the forearm 15 and is used to realize the rotational movement of the wrist joint 16 around the axis of the forearm 15, adjusting the orientation of the wrist end. J5 axis 21, J6 axis 22, and end clamp 23 are connected in sequence. J5 axis 21 is the pitch axis, which controls the up and down tilt of the end clamp 23. J6 axis 22 is the deflection axis, which realizes the rotation of the end clamp 23. The end clamp 23 is used to firmly clamp the metal conduit during the cutting process. The end clamp 23 can be replaced or adjusted according to the shape and size of the metal conduit to adapt to the clamping requirements of different specifications of metal conduits.

[0032] The robot's coordinate system is established with the mounting surface of base 13 as the horizontal reference plane. Specifically: the Z-axis is perpendicular to the mounting surface of the base and points upwards, coinciding with the rotation axis of J1 axis 17; the Y-axis is parallel to the mounting surface of the base and parallel to the swing axes of J2 axis 18 and J3 axis 19, pointing directly forward of the robot; the X-axis is determined according to the right-hand rule and is perpendicular to the plane containing the Y-axis and Z-axis.

[0033] Through the coordinated movement of six joint axes from J1 axis 17 to J6 axis 22, the robot can achieve precise control of the end effector 23 in any position and orientation in three-dimensional space, thereby delivering the clamped metal conduit to the nozzle 5 of the laser cutting device at any angle and position, and completing the cutting path execution of the complex-shaped conduit.

[0034] Part Two: Laser Cutting Methods for Complex Shaped Metal Conduits

[0035] Based on the aforementioned laser cutting equipment, this invention further provides a method for laser cutting complex-shaped metal conduits. This method acquires the actual shape data of the metal conduit using a measuring machine and compares it with a theoretical numerical model, automatically generating a robot motion path to achieve high-precision automated cutting of the metal conduit. Figure 6 As shown, the method specifically includes the following steps: Step 1: Equipment inspection.

[0036] Before use, conduct a visual inspection of the laser cutting device, measuring machine, robot, and other equipment to ensure that the equipment labels are complete and the appearance is intact. After powering on, check and verify the continuity of the circuits of each device to confirm that the equipment is operating normally.

[0037] Step 2: Import the theoretical mathematical model and preset the path.

[0038] Import the theoretical 3D model file of the catheter to be cut into the modeling software, and pre-set the cutting position path and the position of the robot holding the metal catheter in the software as a reference benchmark for subsequent measurement and path planning.

[0039] Step 3: 3D scanning and reconstruction of the catheter shape.

[0040] The metal conduit is placed on the measuring platform 12 of the measuring machine. Then, the motor 10 starts operating, driving the guide rail 6 to move the mounting platform 11 horizontally. The semiconductor laser 8, the first camera 7, and the second camera 9 on the mounting platform 11 move along the length of the metal conduit to scan its entire length. After the first camera 7 and the second camera 9 acquire images of the conduit surface, the three-dimensional point coordinate data of the metal conduit surface are obtained using the following binocular vision 3D reconstruction method: Suppose there is a point to be measured in the space. Its image plane (left image plane) of the first camera 7 The coordinates of the projection point on ) are In the image plane (right image plane) of the second camera 9 The coordinates of the projection point on ) are .

[0041] Image points First camera coordinate system The three-dimensional coordinates below are represented as ,in , For image points Physical coordinates in the left image plane The focal length of the first camera (7) , , , The coordinate compensation amount is obtained through pre-calibration.

[0042] Similarly, like a dot Second camera coordinate system The three-dimensional coordinates below are represented as ,in , For image points Physical coordinates in the right image plane The focal length of the second camera (9).

[0043] Set the point to be measured The three-dimensional coordinates in the first camera coordinate system are The three-dimensional coordinates in the second camera coordinate system are According to perspective projection, the coordinates of the image point and the coordinates of the spatial point satisfy the following proportional relationship: ; There is a rigid body transformation relationship between the first camera coordinate system and the second camera coordinate system, which can be achieved through a rotation matrix. Translation vector Description, namely: ; in It is a translation vector. for The orthogonal rotation matrix.

[0044] Combining formulas (1) and (2), since in each formula, except for the coordinates of spatial points... and Apart from the fact that all other parameters are known, the measurement point can be solved. The three-dimensional coordinate values ​​in the first camera coordinate system or the second camera coordinate system.

[0045] Using the above method, the measuring machine processes each pair of images acquired during the scanning process to obtain the three-dimensional point coordinate data of the duct surface and the coordinate data of each cutting position point; all the acquired coordinate data are fed back to the analysis software to complete the three-dimensional digital model reconstruction of the metal duct.

[0046] Step 4: Determine the conformity of the catheter shape.

[0047] Computer analysis software acquires the 3D digital model reconstructed by the measuring machine, and simultaneously imports the theoretical 3D digital model of the metal conduit. After aligning and matching the theoretical 3D digital model with the reconstructed 3D digital model, the overall deviation between the two models is calculated using the following formula. : ; in, The number of corresponding point pairs involved in the deviation calculation. For the first Spatial Euclidean distance between corresponding point pairs.

[0048] If the calculation yields (Unit: mm) indicates that the overall deviation between the reconstructed 3D digital model and the theoretical 3D digital model is within the allowable range, thus the metal conduit is deemed to have a qualified shape and can proceed to the subsequent cutting step; if If the shape of the metal conduit is deemed unqualified, the cutting process is terminated, and the next metal conduit is used for measurement and evaluation.

[0049] Step 5: Motion path generation and simulation.

[0050] For a metal conduit with a qualified shape, the measuring machine has acquired its three-dimensional point coordinate data and the coordinate data of the cutting position point; combined with the theoretical three-dimensional digital model parameters of the metal conduit, the following spatial relationship data are calculated through coordinate transformation: The spatial relative position of the metal conduit and the robot; the precise coordinates of each cutting position on the metal conduit in space; the relative positional relationship between the laser cutting device nozzle 5, the robot end clamp 23, and the cutting position point on the metal conduit, thereby determining the positional relationship between the robot and the laser cutting device.

[0051] The spatial relationship data is solved to generate the robot's motion path. The generated motion path is then simulated in the modeling software to check for any interference or collision risks between the robot and the laser cutting device and the guide tube. The motion path is then optimized and adjusted to eliminate potential collision hazards.

[0052] Step Six: Trial Cutting and Verification.

[0053] The optimized motion path is sent to the robot and the laser cutting device; the robot moves while holding the metal conduit, and the laser cutting device performs trial cuts in coordination.

[0054] After the trial cut is completed, the cut metal conduit is placed back on the measuring platform 12 of the measuring machine, and the scanning measurement work in step three is repeated to obtain the three-dimensional model data of the cut metal conduit.

[0055] The cut 3D model data is compared and verified with the corresponding theoretical 3D digital model to determine whether each cut position is within the allowable deviation range. If the measured data is within the allowable deviation range, the metal conduit is deemed to be cut successfully, and the cutting of the next conduit continues. If it exceeds the allowable deviation range, the metal conduit is deemed to be cut unsuccessfully, and the robot's motion path is corrected according to the measured deviation value. Steps five and six are then repeated until a qualified metal conduit is cut.

[0056] By combining the aforementioned equipment structure and cutting method, this invention achieves high-precision laser cutting of metal conduits with complex spatial curved surfaces and irregular structures. The method acquires the actual shape of the conduit through binocular vision measurement, compares it with the theoretical three-dimensional digital model to determine its conformity, automatically generates and simulates the robot's motion path, and completes precise cutting after trial cutting verification. The entire process is highly automated, reduces manual intervention, improves production efficiency and cutting accuracy, and expands the application scope of laser cutting technology in the processing of complex-shaped metal conduits.

[0057] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A laser cutting device for complex-shaped metal conduits, characterized in that, This includes laser cutting equipment, measuring machines, and robots; The laser cutting device includes a connecting rod (1), a rotating shaft (2), a swing shaft (3), a follower shaft (4), and a nozzle (5). The connecting rod (1) is connected between the rotating shaft (2) and the swing shaft (3). The rotating shaft (2) is used to drive the laser cutting device to rotate as a whole to adjust the orientation of the nozzle (5) in the horizontal plane. The swing shaft (3) cooperates with the rotating shaft (2) to enable the nozzle (5) to adjust its posture in three-dimensional space. The nozzle (5) is installed at the end of the swing shaft (3). The follower shaft (4) is installed on the nozzle (5) and equipped with a capacitive gap sensor, which is used to detect the distance between the nozzle (5) and the surface of the metal conduit in real time during the cutting process and realize non-contact height automatic tracking through closed-loop control so that the nozzle (5) and the surface of the metal conduit maintain a constant preset distance. The measuring machine includes a guide rail (6), a first camera (7), a semiconductor laser (8), a second camera (9), a motor (10), a mounting platform (11), and a measuring platform (12). The measuring platform (12) is used to support the metal conduit. The guide rail (6) is mounted on the measuring platform (12) and driven by the motor (10). The mounting platform (11) is mounted on the guide rail (6) and can move horizontally back and forth along the guide rail (6) under the drive of the motor (10). The first camera (7), the semiconductor laser (8), and the second camera (9) are all fixed on the mounting platform (11). The first camera (7) and the second camera (9) constitute a binocular vision system for synchronously acquiring images of the surface of the metal conduit. The semiconductor laser (8) is used to project laser light onto the surface of the metal conduit to assist in obtaining three-dimensional point coordinates. The robot is used to grip the metal conduit and deliver it to the nozzle (5) of the laser cutting device. It includes a base (13), upper arm (14), forearm (15), wrist joint (16), J1 axis (17), J2 axis (18), J3 axis (19), J4 axis (20), J5 axis (21), J6 axis (22), and end effector (23). The base (13) is a fixed base. The J1 axis (17) is mounted on the base (13) to drive the robot to rotate horizontally around the Z-axis. The J2 axis (18) connects the base (13) and the upper arm (14) to drive the upper arm (14) to swing back and forth around the Y-axis. (14) The forearm (15) is connected to the J3 axis (19). The J3 axis (19) drives the forearm (15) to swing up and down around the Y axis. The wrist joint (16) is connected to the end of the forearm (15) and includes the J4 axis (20), the J5 axis (21) and the J6 axis (22). The J4 axis (20) realizes the rotation of the wrist joint (16) around the axis of the forearm (15). The J5 axis (21) controls the up and down tilt of the end clamp (23). The J6 axis (22) realizes the rotation of the end clamp (23). The end clamp (23) is installed at the end of the J6 axis (22) and is used to clamp the metal conduit.

2. The laser cutting equipment for complex-shaped metal conduits according to claim 1, characterized in that, The axial directions of the rotating shaft (2) and the swing shaft (3) are perpendicular, and the axial direction of the nozzle (5) is perpendicular to the axial direction of the swing shaft (3). The follower shaft (4) detects the distance between the nozzle (5) and the surface of the metal conduit in real time through a capacitive gap sensor installed on it, and automatically adjusts the position of the follower shaft (4) to adapt to the irregular changes in the shape of the metal conduit, so as to ensure that the laser focus always acts precisely on the surface of the metal conduit.

3. The laser cutting equipment for complex-shaped metal conduits according to claim 1, characterized in that, In the measuring machine, the guide rail (6) extends along the length direction of the measuring platform (12); the first camera (7) and the second camera (9) are respectively fixed on both sides of the semiconductor laser (8), and their optical axes intersect. The motor (10) is electrically connected to the control console and drives the guide rail (6) to move according to the control command to control the moving speed and scanning range of the mounting platform (11); when the measuring machine is working, the image data collected by the first camera (7) and the second camera (9) are processed by the analysis software to obtain the three-dimensional point coordinate data of the surface of the metal conduit and the coordinate data of the position to be cut.

4. The laser cutting equipment for complex-shaped metal conduits according to claim 1, characterized in that, The robot's J1 axis (17) to J6 axis (22) move in coordination, enabling the end effector (23) to achieve precise control of any position and posture in three-dimensional space; the end effector (23) can be replaced or adjusted according to the shape and size of the metal conduit to adapt to the clamping requirements of metal conduits of different specifications.

5. A method for laser cutting complex-shaped metal conduits, characterized in that, The laser cutting equipment for complex-shaped metal conduits as described in any one of claims 1 to 4 includes the following steps: Step 1: Equipment inspection, confirming that the laser cutting device, measuring machine, and robot equipment are in good condition and functioning normally; Step 2: Import the theoretical 3D model file of the metal conduit to be cut into the modeling software. In the software, pre-set the cutting position path and the position of the robot holding the metal conduit as a reference benchmark for subsequent measurement and path planning. Step 3: Place the metal conduit on the measuring platform (12). The motor (10) drives the guide rail (6) to move the mounting platform (11) horizontally. The first camera (7) and the second camera (9) scan the metal conduit throughout the entire process. The three-dimensional point coordinate data of the surface of the metal conduit and the coordinate data of each cutting position point are obtained according to the binocular vision three-dimensional reconstruction method. The coordinate data is fed back to the analysis software to complete the three-dimensional digital model reconstruction of the metal conduit. Step 4: Align and match the reconstructed 3D digital model with the theoretical 3D digital model of the metal conduit, and calculate the overall deviation between the two models. ,like If the diameter is within millimeters, the metal conduit is deemed to be in good shape and proceeds to the next cutting step; otherwise, the metal conduit is deemed to be in bad shape and the cutting process is terminated. Step 5: Combining the theoretical three-dimensional numerical model parameters of the metal conduit with the three-dimensional point coordinate data and cutting position point coordinate data obtained by the measuring machine, the spatial relative position of the metal conduit and the robot, the precise coordinates of each cutting position, and the relative positional relationship between the nozzle (5), the end clamp (23) and the cutting position point are calculated through coordinate transformation. Based on this, the robot motion path is generated by solving the calculation, and the motion path is simulated, checked and optimized in the modeling software to eliminate interference or collision hazards. Step 6: Send the optimized motion path to the robot and the laser cutting device. The robot clamps the metal conduit and moves, and the laser cutting device cooperates to perform a trial cut. After the trial cut is completed, place the metal conduit back on the measurement platform (12) and repeat the scanning measurement work of step 3 to obtain the three-dimensional model data of the cut metal conduit. Compare and verify the three-dimensional model data after cutting with the theoretical three-dimensional model. If the deviation is within the allowable range, the cutting is deemed qualified and the next conduit is cut. Otherwise, the cutting is deemed unqualified and the robot motion path is corrected according to the measured deviation value. Steps 5 and 6 are executed again until the cutting is qualified.

6. The laser cutting method for complex-shaped metal conduits according to claim 5, characterized in that, The binocular vision 3D reconstruction method described in step three specifically includes: Let the point to be measured in space be... The coordinates of the projection point on the image plane of the first camera (7) are: The coordinates of the projection point on the image plane of the second camera (9) are: ; Like a dot The three-dimensional coordinates in the first camera coordinate system are represented as follows: ,in , for Physical coordinates in the left image plane The focal length of the first camera (7) , , , The coordinate compensation amount obtained from pre-calibration; Like a dot The three-dimensional coordinates in the second camera coordinate system are represented as follows: ,in , for Physical coordinates in the right image plane The focal length of the second camera (9); Set the point to be measured The three-dimensional coordinates in the first camera coordinate system are The three-dimensional coordinates in the second camera coordinate system are Based on the perspective projection relationship satisfying the proportional relationship, and through the rigid body transformation relationship between the first camera coordinate system and the second camera coordinate system, the measurement point is obtained by solving the simultaneous equations. The three-dimensional coordinates.

7. The laser cutting method for complex-shaped metal conduits according to claim 5, characterized in that, The overall deviation described in step four The calculation formula is: ,in The number of corresponding point pairs involved in the deviation calculation. For the first Spatial Euclidean distance between corresponding point pairs.

8. The laser cutting method for complex-shaped metal conduits according to claim 5, characterized in that, The step five, which involves solving and generating the robot's motion path, refers to automatically generating the robot's continuous motion trajectory by performing spatial coordinate transformation and kinematic calculations based on the spatial relative position of the metal conduit and the robot, the precise coordinates of the cutting position point, and the relative positional relationship data in the modeling software.

9. The laser cutting method for complex-shaped metal conduits according to claim 5, characterized in that, In the trial cutting verification process described in step six, deviation correction refers to the process of correcting the coordinates of the corresponding points in the robot's motion path in reverse, based on the spatial deviation between the measured 3D model data and the theoretical 3D digital model at each cutting position point, when the 3D model data exceeds the allowable deviation range after cutting.

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