A laser-arc hybrid welding optical wire spacing positioning system and its positioning method

Abstract

A laser-arc hybrid welding optical wire spacing positioning system and its positioning method according to the present invention include a welding robot, a laser, a robot teaching pendant, a robot control cabinet, an arc welding torch, an optical wire spacing sensor, a wire feeder, and an arc welding machine. The welding robot and the robot teaching pendant are respectively connected to the robot control cabinet, and the arc welding torch and the wire feeder are respectively connected to the arc welding machine. A laser is provided on the welding robot, and an optical wire spacing sensor is provided on the arc welding torch, and the spot position of the optical wire spacing sensor coincides with the tip of the welding wire. The present invention enables the optical wire spacing to always remain constant, thereby ensuring heat source coupling and improving the stability of the welding process.

Description

Technical Field

[0001] The present invention relates to the technical field of laser-arc hybrid welding, and particularly to a laser-arc hybrid welding optical wire spacing positioning system and a positioning method thereof. Background Art

[0002] The laser-arc hybrid welding method that combines the advantages of high penetration of laser welding and high bead width of arc welding has been applied in the industrial field. The laser-arc hybrid welding combines two different heat sources, laser and arc, and acts on the same position of the workpiece together. The laser beam and the arc are simultaneously superimposed in a common interaction zone, effectively utilizing the advantages of the laser and arc heat sources. It is a new type of high-efficiency welding method and one of the research directions of welding technology at home and abroad. Compared with traditional welding processes, the main advantages of laser-arc hybrid welding lie in its high welding speed, high penetration depth, good bridging performance, low assembly accuracy, and process stability. Therefore, it is widely applied to various engineering fields and can play its unique advantages in pipeline construction, shipbuilding, automotive tracks, aerospace, etc.

[0003] The optical wire spacing refers to the straight-line distance from the center of the laser spot to the point where the welding wire is perpendicular to the plate. The size of the optical wire spacing determines whether the laser and the arc jointly form a molten pool, and also has a certain influence on the coupling effect of the two heat sources. It is one of the key process parameters in laser-arc hybrid welding and plays a crucial role in the cooperation effect of the two heat sources.

[0004] Nowadays, various sensors have been widely used in robotic welding systems, such as infrared sensors, photosensitive sensors, etc. The optical wire spacing sensor system mainly includes sensors, controllers, servo systems, and actuators. The stability of the optical wire spacing during the welding process poses higher requirements for robotic automated welding. Due to the high precision requirements of the optical wire spacing, slight differences will affect the coupling effect of the laser and the arc, and manual calibration is relatively difficult. At the same time, the error of manual measurement of the optical wire spacing and the differences between individual workpieces will lead to errors in the optical wire spacing during the welding process, thereby affecting the energy coupling of the laser and the arc, and further affecting the stability of the welding process and the quality of the welded joint. Therefore, a system that can achieve optical wire spacing positioning and adjustment is needed, which is of great significance for the control of welding quality. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above deficiencies and provide a laser-arc hybrid welding optical wire spacing positioning system and a positioning method thereof. By using an optical wire spacing sensor, the relative positions of the laser and the arc during the laser-arc hybrid welding process are mutually adjusted, effectively controlling the distance between the laser and the arc, so that the optical wire spacing always remains constant, thereby ensuring heat source coupling and improving the stability of the welding process.

[0006] The object of the present invention is achieved as follows:

[0007] A positioning system for the light wire spacing in laser-arc hybrid welding, which comprises a welding robot, a laser, a robot teach pendant, a robot control cabinet, an arc welding torch, a light wire spacing sensor, a wire feeder and an arc welding machine. The welding robot and the robot teach pendant are respectively connected to the robot control cabinet, and the arc welding torch and the wire feeder are respectively connected to the arc welding machine. A laser is provided on the welding robot, and a light wire spacing sensor is arranged on the arc welding torch, and the spot position of the light wire spacing sensor coincides with the tip of the welding wire. The light wire spacing sensor captures the position of the guiding laser spot and transmits the generated data to the robot control cabinet, thereby obtaining the size of the current light wire spacing.

[0008] Further, the light wire spacing sensor is arranged on the arc welding torch through a tooling fixture.

[0009] A positioning method for a positioning system of the light wire spacing in laser-arc hybrid welding, comprising the following contents:

[0010] S1. Start the welding robot, edit the laser-arc hybrid welding program on the control panel of the robot teach pendant, and respectively set the positions of the welding starting point and the welding ending point;

[0011] S2. Move the laser to the welding starting point position, and turn on the guiding laser of the laser through the teach pendant;

[0012] S3. Touch the button of the wire feeder to feed the welding wire outwards, so that the tip of the arc welding wire slightly contacts the welding base material;

[0013] S4. The spot emitted by the light wire spacing sensor should coincide with the tip of the welding wire and remain fixed throughout the welding process;

[0014] S5. The light wire spacing sensor scans the guiding laser point at the welding starting point set on the control panel of the teach pendant, and detects the relative distance between the guiding laser point and the spot of the light wire spacing sensor;

[0015] S6. Use the I / O board in the robot control cabinet to detect the output signal of the light wire spacing sensor, obtain the distance distribution between the guiding laser and the spot of the light wire spacing sensor during the whole welding process, ensure that the light wire spacing remains unchanged during the welding process, view and determine the initial value of the light wire spacing;

[0016] S7. The robot control cabinet adjusts the lead screw knob according to the size of the scanned light wire spacing to change the light wire spacing in real time;

[0017] S8. The teaching pendant feeds back the size of the required optical wire spacing during the actual welding process, and the welding robot and the laser weld from the starting point to the ending point according to the corrected optical wire spacing.

[0018] Further, before step S1, there are also the following preparatory works S01. Install the optical wire spacing sensor on the side of the arc welding torch through a tooling fixture, so that the light spot of the optical wire spacing sensor coincides with the position of the wire tip. At the same time, ensure that the connection line between its light spot and the guiding laser light spot is on a horizontal straight line and parallel to the weld seam.

[0019] Further, before step S1, there are also the following preparatory works S02. Adjust the laser to be at a right angle to the welded base material, and respectively obtain the TCPs of the optical wire spacing sensor, the laser, and the arc welding torch through the TCP calibration program of the robot itself, and obtain the conversion relationship between the sensor and the robot laser coordinate system.

[0020] Further, before step S1, there are also the following preparatory works S03. Process and clean the welded base material, and fix it on the welding platform through a fixture.

[0021] Further, the above step S5 specifically includes the following steps:

[0022] S50. Install the optical wire spacing sensor on the arc welding torch through a tooling fixture, and adjust it so that the light spot position of the optical wire spacing sensor coincides with the wire tip, and ensure that the connection line between the light spot position of the optical wire spacing sensor and the guiding laser position of the laser is on a horizontal straight line;

[0023] S51. Measure the angle of the laser with a level to make the laser perpendicular to the position of the welded base material;

[0024] S52. Respectively obtain the TCPs of the optical wire spacing sensor and the laser through the TCP calibration program of the robot itself, so as to obtain the conversion relationship between the optical wire spacing sensor and the laser coordinate system;

[0025] S53. Open the welding program panel of the teaching pendant and position the welding starting point and the ending point;

[0026] S54. Edit the welding program through the teaching pendant and check whether there are errors;

[0027] S55. Start the power supply and run the robot welding program, so that the laser and the arc scan from the starting point to the ending point at the same time;

[0028] S56. View the information fed back by the robot control cabinet through the teaching pendant panel.

[0029] Further, the above step S6 specifically includes the following steps:

[0030] S60. The robot control cabinet obtains the distribution of the original path and the welded base material surface along the entire weld seam.

[0031] S61. Compare the coordinate values of the points on the preset segments of this weld seam with the required welding positions of the target to obtain the deviation values and the actual welding positions, convert them into robot coordinates, and generate the actual welding path.

[0032] S63. Debug and weld the laser and arc with the set wire-light spacing on the actual welding path.

[0033] Further, in step S7, determine the robot's posture and mode according to the actual welding path, and adjust the posture during the robot welding process to keep the laser perpendicular to the base material all the time as the workpiece changes during welding.

[0034] Further, the TCP height of the laser during the actual welding process is adjustable. By adjusting the reference value given by the wire-light spacing sensor, the change of the points on the path is realized.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] By installing a wire-light spacing sensor on the arc welding torch, the present invention perceives the external welding environment information, converts it into information data and transmits it to the robot control cabinet, and assists the welding robot to accurately control the relative position of the laser and the arc, so that the guiding laser and the tip of the welding wire are always on a straight line, and the wire-light spacing always remains constant, thereby ensuring the heat source coupling and improving the stability of the welding process.

[0037] The present invention can change the postures of the laser and the welding torch during the welding process, thereby affecting the stability of the welding process and the quality of the welding joint. It is used for the precise adjustment of the distance between the laser and the arc in laser-arc hybrid welding, which can avoid the error of manual measurement with a tool scale, and greatly improve the stability of the welding joint quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the system structure of the present invention.

[0039] Figure 2 It is a schematic diagram of the path during the welding process of the present invention.

[0040] Figure 3 It is a schematic diagram of the method flow of the present invention. EMBODIMENT

[0041] To better understand the technical solution of the present invention, the following will be described in detail with reference to relevant drawings. It should be understood that the following specific embodiments are not intended to limit the specific implementation modes of the technical solution of the present invention, but are only implementation modes that the technical solution of the present invention can adopt. It should be noted first that the description of the positional relationship of each component herein, such as component A is located above component B, is based on the relative positions of the components in the drawings and is not intended to limit the actual positional relationship of the components. Embodiment

[0042] See Figure 1-2 , Figure 1 , a schematic diagram of the system structure of the present invention is drawn. As shown in the figure, a laser-arc hybrid welding optical wire spacing positioning system of the present invention is applied to the laser-arc hybrid welding process. It includes a welding robot, a laser, a robot teach pendant, a robot control cabinet, an arc welding torch, an optical wire spacing sensor, a wire feeder, and an arc welding machine. The welding robot and the robot teach pendant are respectively connected to the robot control cabinet, and the arc welding torch and the wire feeder are respectively connected to the arc welding machine.

[0043] A laser is provided on the flange of the welding robot, and the laser is connected to a power source through a cable; an optical wire spacing sensor is arranged on the arc welding torch through a tooling fixture, and the light spot position of the optical wire spacing sensor coincides with the tip of the welding wire.

[0044] In the actual operation process, first start the robot, open the robot program editor, edit the robot welding program according to the actual welding path, determine the workpiece coordinate and the tool coordinate, teach and position the starting point and the ending point of the welding path, and move the welding program to the routine program and start it.

[0045] At the control panel of the robot teach pendant, make a note of the laser light-emitting program to prevent the laser from emitting light, and at the same time lock the arc.

[0046] Modify the robot welding speed in the welding program and set the wire feeding speed on the control panel of the wire feeder. The relative distance between the light spot of the guiding laser emitted by the laser and the light spot of the optical wire spacing sensor under the path is obtained by distance sensing of the guiding laser light spot emitted by the laser through the optical wire spacing sensor installed on the side of the arc welding torch. Divide the actual welding path into M segments, adjust the coordinate values (X, Y, Z) at each point on the path according to the corresponding distance, adjust the TCP point to a suitable position at the center of the weld seam, and generate a new working path according to the new coordinate points so that the welding path is on the same straight line as the weld seam.

[0047] At the same time, the filament spacing sensor will capture the position of the guide laser spot and transmit the generated data to the robot control cabinet to obtain the current filament spacing. According to the filament spacing required by the welding test, the filament spacing is controlled by adjusting the lead screw knob. At this time, the information will be immediately transmitted to the robot teaching pendant through the robot control cabinet, so that the filament spacing sensor will maintain the best distance from the guide laser spot.

[0048] See also Figure 2 The present invention relates to a positioning method of a laser-arc hybrid welding wire spacing positioning system, comprising the following contents:

[0049] S1. Install the light filament spacing sensor and adjust the light spot;

[0050] Install the wire spacing sensor on the side of the arc welding gun through a fixture, so that the light spot of the wire spacing sensor coincides with the tip of the welding wire, and at the same time ensure that the line connecting it and the guide laser spot is on a horizontal straight line and parallel to the weld;

[0051] S2, adjust the laser and obtain the conversion relationship between the sensor and the robot laser coordinate system;

[0052] Adjust the laser to be at right angles to the welding base material, obtain the TCP of the filament spacing sensor, laser and arc welding gun respectively through the TCP calibration program provided by the robot, and obtain the conversion relationship between the sensor and the robot laser coordinate system;

[0053] S3, fix the welding base material;

[0054] Process and clean the welding base material and fix it on the welding platform with a clamp;

[0055] S4, start the welding robot;

[0056] Start the welding robot and edit the welding program through the robot teaching pendant;

[0057] S41, edit welding program: edit the laser-arc hybrid welding program on the robot teaching pendant control panel, and set the welding start point and welding end point positions respectively;

[0058] S5, turn on the laser guide laser;

[0059] Move the laser to the welding starting point, turn on the laser guide laser through the teach pendant, move to the starting point and the end point on the weld, modify the position on the teach pendant, use these two points as the two ends of the original position, and divide this line segment into M equal parts;

[0060] S6, running the robot welding program;

[0061] Touch the wire feeder button to feed the welding wire outwards, making the tip of the arc welding wire slightly contact the base metal to be welded; run the robot welding program, and let the sensor installed on one side of the arc welding torch scan from the starting point to the ending point, obtaining the distribution on the entire line segment on the surface of the original path and the base metal to be welded to see if the light spots of both and the weld seam are on the same straight line; the light spot emitted by the light-wire distance sensor should coincide with the tip of the welding wire and remain fixed throughout the welding process;

[0062] S7. Keep the laser perpendicular to the weld seam all the time; according to the actual welding situation, by selecting a certain posture change mode, keep the laser perpendicular to the weld seam all the time during the welding process;

[0063] S8. Adjust and calibrate the light-wire distance;

[0064] The initial light-wire distance information will be fed back to the robot teach pendant through the robot control cabinet. According to the pre-set light-wire distance, by adjusting the lead screw knob, the light-wire distance changes, and the robot control cabinet receives the information, thereby adjusting and calibrating the light-wire distance.

[0065] The specific steps of S8 are as follows:

[0066] S81. The light-wire distance sensor scans the guiding laser point at the welding starting point set on the teach pendant control panel, and detects the relative distance between the guiding laser point and the light spot of the light-wire distance sensor;

[0067] S82. Use the I / O board in the robot control cabinet to detect the output signal of the light-wire distance sensor, obtain the distance distribution between the guiding laser and the light spot of the light-wire distance sensor during the entire welding process, ensure that the light-wire distance remains unchanged during the welding process, and check and determine the initial value of the light-wire distance;

[0068] S83. The robot control cabinet adjusts the lead screw knob in real time according to the scanned light-wire distance;

[0069] S84. The teach pendant feeds back the required light-wire distance during the actual welding process, and the welding robot and the laser weld from the starting point to the ending point according to the corrected light-wire distance.

[0070] The specific steps of S81 are as follows:

[0071] S811. Install the light-wire distance sensor on the arc welding torch through a tooling fixture, and by adjusting, make the light spot position of the light-wire distance sensor coincide with the tip of the welding wire, and ensure that the connection line between the light spot position of the light-wire distance sensor and the position of the guiding laser of the laser is on a horizontal straight line;

[0072] S812. Measure the angle of the laser with a level to make the laser perpendicular to the position of the welded base material;

[0073] S813. Obtain the TCPs of the optical wire spacing sensor and the laser respectively through the TCP calibration program of the robot, so as to obtain the conversion relationship between the coordinate systems of the optical wire spacing sensor and the laser;

[0074] S814. Open the welding program panel of the teach pendant, and position the starting point and the ending point of the welding;

[0075] S815. Edit the welding program through the teach pendant and check whether there are errors;

[0076] S816. Start the power supply and run the robot welding program, so that the laser and the arc scan from the starting point to the ending point simultaneously;

[0077] S817. View the information feedback by the robot control cabinet through the teach pendant panel.

[0078] The specific steps of S82 are as follows:

[0079] S821. The robot control cabinet obtains the distribution of the original path and the surface of the welded base material on the entire weld seam;

[0080] S822. Compare the coordinate values of the points on the set segments of this weld seam with the required welding positions of the target, obtain the deviation value and the actual welding position, convert them into robot coordinates, and generate the actual welding path;

[0081] S823. Debug and weld the laser and the arc with the set optical wire spacing on the actual welding path.

[0082] In step S83: Determine the posture and mode of the robot according to the actual welding path, and adjust the posture during the robot welding process to make the laser always keep perpendicular to the base material during the welding process as the workpiece changes.

[0083] The TCP height of the laser during the actual welding process is adjustable. By adjusting the reference value given by the optical wire spacing sensor, the change of the points on the path is realized.

[0084] Before welding, it is necessary to first determine the actual welding path and then determine the size of the optical wire spacing between the laser and the arc.

[0085] In step S811, for the conversion between coordinate systems, through the original tool coordinate system tool0 of the robot as a medium, the TCP of the laser and the TCP of the optical wire spacing sensor are set respectively to realize the coordinate conversion between the laser and the optical wire spacing sensor.

[0086] Regarding the actual welding working mode: The optical wire spacing sensor scans in advance according to the path set by the program. By perceiving external information, it checks whether the light spot is on the same straight line as the weld seam, and calculates the mutual distance between the optical wire spacing light spot and the guiding laser light spot, so as to perform feedback, adjustment and correction.

[0087] The adjustment of the laser posture during the welding process mainly refers to the change of the posture values of the existing points on the path, and realizes the posture change during the welding process by assigning the posture values of relevant positions.

[0088] See Figure 2 , Figure 2 is the path schematic diagram during the welding process. As Figure 2 shown, P10 is the starting point of the teaching positioning, P30 is the ending point of the teaching positioning, and P20 is at the center point of the path.

[0089] Through robot teaching, during the teaching process, check the initial optical wire spacing value. According to the test requirements, control the relative distance between the laser and the arc by adjusting the lead screw knob. At this time, the signal transmitted by the robot control cabinet will be synchronized in real time on the robot teach pendant panel. If the weld seam path is too long, start the welding program, and the welding program can be stopped at the center point P20 of the weld seam path. By checking whether the optical wire spacing value on the control panel is equal to the value at the starting point, this is because during the welding process, the optical wire spacing may change slightly due to various factors, such as the tightness of the fixture, etc. The change of the optical wire spacing will cause different welding qualities at different positions on the weld seam, and welding defects will be generated, such as incomplete penetration, undercut, weld bead, etc. Therefore, the adjustment and correction of the optical wire spacing before the welding process are crucial.

[0090] After debugging and correcting the optical wire spacing, move the laser head to the initial welding point P10, start the welding program, and start welding along the actual path until reaching the ending point P30 and stop working.

[0091] The above is only a specific application example of the present invention, and does not constitute any limitation to the protection scope of the present invention. Any technical solutions formed by equivalent transformation or equivalent substitution fall within the scope of the protection of the present invention.

Claims

1. A positioning method for a laser-arc hybrid welding wire spacing positioning system, characterized in that: A laser-arc hybrid welding wire spacing positioning system includes a welding robot, a laser, a robot teaching pendant, a robot control cabinet, an arc welding gun, a wire spacing sensor, a wire feeder and an arc welding machine, wherein the welding robot and the robot teaching pendant are respectively connected to the robot control cabinet, and the arc welding gun and the wire feeder are respectively connected to the arc welding machine; the welding robot is provided with a laser, the arc welding gun is provided with a wire spacing sensor, and the spot position of the wire spacing sensor coincides with the tip of the welding wire; the wire spacing sensor captures the position of the guide laser spot, and transmits the generated data to the robot control cabinet, thereby obtaining the current size of the wire spacing; the wire spacing sensor is provided on the arc welding gun through a fixture; Positioning methods include the following: S1. Start the welding robot, edit the laser-arc hybrid welding program on the robot teaching pendant control panel, and set the welding start point and welding end point positions respectively; S2. Move the laser to the welding starting point and turn on the laser guide through the teaching pendant; S3, trigger the wire feeder button to feed the welding wire outward, so that the tip of the arc welding wire slightly contacts the welding base material; S4. The light spot emitted by the wire spacing sensor should overlap with the tip of the welding wire and remain fixed during the welding process; S5, the light wire spacing sensor scans the guide laser point at the welding starting point set on the teaching pendant control panel, and detects the relative distance between the guide laser point and the light wire spacing sensor spot; S6. Use the I / O board in the robot control cabinet to detect the output signal of the light wire spacing sensor to obtain the distance distribution between the guide laser and the light spot of the light wire spacing sensor during the entire welding process, ensure that the light wire spacing remains unchanged during the welding process, and check and determine the initial value of the light wire spacing; S7, the robot control cabinet adjusts the lead screw knob in the robot control cabinet to change the optical filament spacing in real time according to the size of the optical filament spacing scanned; S8. The teaching pendant feeds back the required filament spacing in the actual welding process, and the welding robot and the laser weld from the starting point to the end point according to the corrected filament spacing.

2. The positioning method of a laser-arc hybrid welding optical wire spacing positioning system according to claim 1, characterized in that: Before step S1, there are the following preparations S01, install the wire spacing sensor on the side of the arc welding gun through a fixture, so that the wire spacing sensor spot coincides with the tip of the welding wire, and at the same time ensure that the line connecting it and the guide laser spot is on a horizontal straight line and parallel to the weld.

3. The positioning method of a laser-arc hybrid welding optical wire spacing positioning system according to claim 1, characterized in that: Before step S1, there are the following preparations S02, adjusting the laser to be at a right angle to the welding base material, obtaining the TCP of the filament spacing sensor, laser and arc welding gun respectively through the robot's own TCP calibration program, and obtaining the conversion relationship between the sensor and the robot laser coordinate system.

4. The positioning method of a laser-arc hybrid welding optical wire spacing positioning system according to claim 1, characterized in that: Before step S1, there are the following preparations S03, processing and cleaning the welding base material, and fixing it on the welding platform by a clamp.

5. The positioning method of a laser-arc hybrid welding optical wire spacing positioning system according to claim 1, characterized in that, The above step S5 specifically includes the following steps: S50, installing the wire spacing sensor on the arc welding gun through a fixture, adjusting the wire spacing sensor spot position and the tip of the welding wire to coincide with each other, and ensuring that the line connecting the wire spacing sensor spot position and the laser guide laser position is on a horizontal straight line; S51. Use a level to measure the angle of the laser so that the laser and the welding base material are perpendicular to each other; S52, respectively obtaining the TCP of the optical filament spacing sensor and the laser through the TCP calibration program provided by the robot, thereby obtaining the conversion relationship between the optical filament spacing sensor and the laser coordinate system; S53, open the welding program panel of the teaching pendant, and locate the welding starting point and end point; S54, edit the welding program through the teaching pendant and check whether there is any error; S55, start the power supply and run the robot welding program so that the laser and the arc scan from the starting point to the ending point at the same time; S56. Check the information fed back by the robot control cabinet through the teach pendant panel.

6. The positioning method of a positioning system for the laser-arc hybrid welding optical wire spacing according to claim 1, characterized in that The above step S6 specifically includes the following steps: S60, the robot control cabinet obtains the distribution of the original path and the surface of the welding base material on the entire weld; S61, comparing the coordinate values of the points on the set segments of the weld with the target welding positions, obtaining the deviation values and the actual welding positions, converting them into robot coordinates, and generating the actual welding path; S63, debug the laser and arc with the set filament spacing on the actual welding path.

7. The positioning method of a laser-arc hybrid welding optical wire spacing positioning system according to claim 1, characterized in that: In step S7, the posture and mode of the robot are determined according to the actual welding path, and the posture of the robot during welding is adjusted so that the laser always remains perpendicular to the base material as the workpiece changes during the welding process.

8. The positioning method of a laser-arc hybrid welding optical wire spacing positioning system according to claim 1, characterized in that: The TCP height of the laser in the actual welding process is adjustable, and the change of the point position on the path is achieved by adjusting the reference value given by the filament spacing sensor.

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