Array workpiece laser welding control method and welding device

Abstract

The invention discloses an array workpiece laser welding control method and a welding device. The method comprises the steps that S1, a control system is initialized; s2, array workpiece placing parameters are set; s3, a welding track is selected; s4, configuring a three-color light source, and setting paraxial image recognition parameters; s5, laser welding parameters are set; s6, the laser head is controlled to conduct welding; s7, whether batch welding is completed or not is judged; and if welding is completed, the welding process is ended, and if welding is not completed, the laser head continues to be controlled for welding. The array workpiece welding device has the advantages of being easy to operate, stable in running, high in automation degree and the like, array workpiece welding is completed through one key, and the welding efficiency of batch array workpieces is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of laser welding, and in particular relates to a laser welding control method and a welding device for array workpieces. Background Art

[0002] Laser welding is a method of metal processing using lasers. By focusing the laser beam on the surface of the material, the metal is locally melted and solidified instantly, thus connecting the metals together. Laser welding technology has the characteristics of non-contact welding and no need for pressurization during the operation process. It has excellent welding effect and good product quality. The metal shell of the microwave component is hermetically packaged in an inert atmosphere. Not only is the welding strong and airtight, but it can also be filled with inert gas in the workpiece shell, effectively protecting the components inside the component. Therefore, laser welding has become the preferred packaging method for microwave component welding. The sealed welding of microwave components has very high requirements on the fit of the track and the weld. Usually, if the deviation exceeds 0.1mm, the welding seal is prone to be loose.

[0003] The existing component welding method requires manual placement of workpieces on the welding workpiece table one by one, and then calibrating the trajectory one by one to complete the welding. The existing manual welding method is inefficient, which seriously limits the output of component welding and is increasingly unsuitable for the growing demand for component welding. In addition, the manual operation method is labor-intensive and requires operators to always focus on the welding operation. Any negligence will lead to welding deviation. In addition, the workpiece needs to be manually pressed down during spot welding, which is very easy to cause laser damage under fatigue conditions. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a laser welding control method and a welding device for array workpieces with simple operation, stable operation, high degree of automation and high welding efficiency in view of the deficiencies in the prior art.

[0005] To achieve the above object, the present invention can adopt the following technical solutions:

[0006] A laser welding control method for array workpieces comprises the following steps:

[0007] Step S1, control system initialization;

[0008] Step S2, setting array workpiece placement parameters;

[0009] Step S3, selecting a welding track;

[0010] Step S4, configuring a three-color light source and setting paraxial image recognition parameters;

[0011] Step S5, setting laser welding parameters;

[0012] Step S6, controlling the laser head to perform welding;

[0013] Step S7, determine whether the batch welding is completed; if the welding is completed, end the welding process; if the welding is not completed, continue to control the laser head to perform welding.

[0014] As a further improvement of the present invention, in step S4, the setting of the paraxial image recognition parameters includes the following steps:

[0015] Step S41, placing the workpiece in the field of view of the paraxial vision camera and focusing;

[0016] Step S42, adjusting relevant parameters of the three-color light source;

[0017] Step S43, adjusting camera related parameters;

[0018] Step S44, obtaining a welding trajectory graph;

[0019] Step S45, adjusting image feature parameters, generating features, and identifying workpiece welds;

[0020] Step S46, adjusting the welding trajectory graphic position to match the identified workpiece weld;

[0021] Step S47, setting a matching threshold. If the matching threshold is exceeded, the recognition is determined to be successful, and the recognition parameters are saved; if the matching threshold is lower than the threshold, the recognition is determined to be unsuccessful.

[0022] Step S48, repeating steps S41 to S47 on the remaining workpieces in the array to perform recognition verification and fine-tune the recognition parameters.

[0023] As a further improvement of the present invention, step S6 further comprises:

[0024] Step S61, placing the workpieces to be welded arranged in an array on a workpiece table and under a laser head;

[0025] Step S62, moving the workpiece stage and ensuring that the first workpiece of the array appears in the field of view of the coaxial camera;

[0026] Step S63, automatically measuring the distance by a laser rangefinder, and ensuring that the laser focus appears on the surface of the first workpiece;

[0027] Step S64, the capping device automatically presses each workpiece placed in the array;

[0028] Step S65, moving the workpiece stage, and scanning and identifying the workpieces in the array one by one through a paraxial camera;

[0029] Step S66, starting the spot welding program, spot welding the workpieces in the array one by one;

[0030] Step S67, the capping device is released and moved out of the welding area;

[0031] Step S68, moving the workpiece stage, and scanning and identifying the workpieces in the array one by one by the rangefinder camera again;

[0032] Step S69, start the sealing welding procedure to complete the welding of the workpieces in the array one by one.

[0033] As a further improvement of the present invention, in step S62, the coaxial camera displays the conditions below the laser head in real-time video.

[0034] As a further improvement of the present invention, in step S63, the laser rangefinder measures the distance between the laser head and the workpiece and feeds back the distance to the control system, and the control system adjusts the height of the laser head according to the distance feedback value.

[0035] As a further improvement of the present invention, in step S65, the rangefinder camera takes a picture of any workpiece in the array and identifies the weld position through an image processing algorithm to obtain the deviation between the actual weld trajectory and the standard weld trajectory, providing positioning information for executing spot welding and sealing procedures.

[0036] As a further improvement of the present invention, in the process of identifying the weld position by the image processing algorithm, if the identification is successful, the rangefinder camera transmits the actual weld trajectory of the workpiece and the acquired welding trajectory position deviation to the control system; if the identification is unsuccessful, the workpiece is skipped and no welding is performed.

[0037] As a general technical concept, the present invention also provides a welding device for implementing the above-mentioned array workpiece laser welding control method, including a mobile module, and a laser head, a coaxial camera, a laser rangefinder, a paraxial camera and a workpiece table arranged on the mobile module; the laser head, the coaxial camera, the laser rangefinder and the paraxial camera are all located above the workpiece table; a plurality of workpieces to be welded are arranged in an array on the workpiece table, and a pressure covering device for pressing the workpieces is provided on the workpiece table.

[0038] As a further improvement of the present invention, the workpiece has a movable space of 1 mm to 2 mm on the workpiece table.

[0039] As a further improvement of the present invention, the moving module includes an X-axis moving module, a Y-axis moving module and a Z-axis moving module. The workpiece table is arranged on the Y-axis moving module, and the Y-axis moving module is arranged on the X-axis moving module, so that the workpiece table drives the workpiece to move along the X-axis direction and the Y-axis direction; the laser head, coaxial camera, laser rangefinder and paraxial camera are all arranged on the Z-axis moving module.

[0040] Compared with the prior art, the advantages of the present invention are:

[0041] 1. The array workpiece laser welding control method of the present invention first sets the array workpiece placement parameters, welding trajectory, paraxial image recognition parameters, laser welding parameters and other related control programs in the control system, and then calls the relevant control programs according to the specific needs of the array workpiece. It only needs to place the array workpiece on the workpiece table, and the entire array welding process can be executed by one button in the control system, which greatly improves the welding efficiency of the array workpiece.

[0042] 2. The array workpiece laser welding control method of the present invention first places the arranged array workpiece under the laser head, and then moves the workpiece table so that the first workpiece in the array appears in the field of view of the coaxial camera. The coaxial camera can be used to grasp the status of the workpiece under the laser head in real time, and then use a laser rangefinder to measure the distance between the laser head and the workpiece, and adjust the height of the laser head according to the distance measurement result, ensuring that the laser head is in a better welding position, and using a cover device to automatically press the array workpiece to avoid warping of the workpiece during welding and ensure welding quality, and then use a rangefinder camera to identify the weld seam of the workpiece before and after spot welding, thereby improving the controllability of welding, combining spot welding with full welding, and finally realizing one-click fully automatic completion of array workpiece welding, which significantly improves welding efficiency.

[0043] 3. The welding device of the present invention is used to implement the above method and thus also has the above advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the overall process of laser welding control of array workpieces in a specific embodiment of the present invention;

[0045] Figure 2 It is a schematic diagram of a specific process of laser welding of array workpieces in a specific embodiment of the present invention;

[0046] Figure 3 It is a schematic diagram of the process of setting paraxial image recognition parameters in a specific embodiment of the present invention;

[0047] Figure 4 A schematic diagram of image recognition of a weld in a specific embodiment of the present invention;

[0048] Figure 5 It is a schematic diagram of the structural principle of a welding device in a specific embodiment of the present invention;

[0049] Legend: 1. Workpiece; 2. Laser head; 3. Coaxial camera; 4. Laser rangefinder; 5. Rangefinder camera; 6. Capping device; 7. Workpiece table; 8. X-axis moving module; 9. Y-axis moving module; 10. Z-axis moving module; 100. Base plate; 200. Support frame. DETAILED DESCRIPTION

[0050] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0051] In the description of the present invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0052] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0053] Example

[0054] like Figure 1 As shown, the array workpiece laser welding control method of the present invention comprises the following steps:

[0055] Step S1, system initialization;

[0056] Step S2, setting the array workpiece placement parameters; such as the number of rows and columns of the array, the size of the workpiece in the X direction, the size in the Y direction, the interval in the X direction, and the interval in the Y direction; if the array workpieces are not full, you can also set the position where the workpiece is not placed to be unavailable to skip the position to save time.

[0057] Step S3, selecting a welding track;

[0058] Step S4, configuring a three-color light source and setting paraxial image recognition parameters;

[0059] Step S5, setting laser welding parameters, such as welding energy, waveform, etc.;

[0060] Step S6, controlling the laser head to perform welding; that is, after the various parameter adjustments and settings are completed, it is only necessary to place the array workpiece on the workpiece table, and the entire array welding process can be executed with one click in the monitoring software;

[0061] Step S7, determine whether the batch welding is completed; if the welding is completed, end the welding process; if the welding is not completed, continue to control the laser head to perform welding.

[0062] For a certain type of batch workpieces, array placement parameters, welding trajectories, image recognition parameters, and laser welding parameters can all be saved and can be directly called when batch welding is required. You only need to place the array workpieces on the workpiece table, and the entire array welding process can be executed with one click in the control system.

[0063] like Figure 3 As shown, in step S4 of this embodiment, the setting of the paraxial image recognition parameters includes the following steps:

[0064] Step S41, placing the workpiece in the field of view of the paraxial vision camera and focusing;

[0065] Step S42, adjusting the relevant parameters of the three-color light source, such as light source color, brightness, etc.;

[0066] Step S43: adjusting camera-related parameters, such as camera exposure and gain, to ensure that more interference can be removed during the photo-taking process;

[0067] Step S44, obtaining a welding trajectory graph;

[0068] Step S45, adjusting image feature parameters, generating features, and identifying workpiece welds;

[0069] Step S46, adjusting the welding trajectory graphic position to match the identified workpiece weld;

[0070] Step S47, set the matching threshold. If it exceeds the threshold, it is determined that the recognition is successful and the recognition parameters are saved; if it is lower than the threshold, it is determined that the recognition fails. The weld image recognition result is as follows: Figure 4 as shown in .

[0071] Step S48, repeating steps S41 to S47 on the remaining workpieces in the array to perform recognition verification, and fine-tune the recognition parameters to ensure that the parameters have better adaptability.

[0072] like Figure 2 As shown, step S6 of this embodiment further includes:

[0073] Step S61: Place the workpieces to be welded arranged in an array on a workpiece table and under a laser head.

[0074] Step S62: Move the workpiece stage to ensure that the first workpiece of the array appears in the field of view of the coaxial camera.

[0075] Step S63, automatically measure the distance by using a laser rangefinder to ensure that the laser focus appears on the surface of the first workpiece. The array workpieces are generally placed on a specific workpiece table, and the height of the workpieces is basically the same. In order to improve welding efficiency, the focusing action using the laser rangefinder only needs to be performed once.

[0076] Step S64: The capping device automatically presses each workpiece placed in the array.

[0077] Step S65, move the workpiece stage, and use the rangefinder camera to scan and identify the workpieces in the array one by one.

[0078] Step S66, start the spot welding program and perform spot welding on the workpieces in the array one by one.

[0079] Step S67: the capping device is released and moved out of the welding area.

[0080] Step S68, move the workpiece stage, and scan and identify the workpieces in the array one by one using the rangefinder camera again.

[0081] Step S69, start the sealing welding procedure to complete the welding of the workpieces in the array one by one.

[0082] Generally, the workpieces for array welding are of the same model, with basically the same size and weld size, and the same welding trajectory and welding procedure can be used.

[0083] In step S62 of this embodiment, the coaxial camera displays the situation below the laser head in real time video to observe the welding status. The coaxial vision coincides with the laser focus, and the laser light point is marked with a cursor on the coaxial vision software. After the paraxial vision recognition is completed, the coaxial camera and the laser head can move in an empty track (no laser is emitted during the movement process), which can conveniently and clearly observe whether the welding movement track and the weld are overlapped.

[0084] In step S63 of this embodiment, the laser rangefinder measures the distance between the laser head and the workpiece and feeds back the distance to the CNC interpolation control system. The control system adjusts the height of the laser head according to the distance feedback value to ensure that the laser focus is exactly on the workpiece surface.

[0085] In step S65 of this embodiment, the rangefinder camera takes a picture of any workpiece in the array, and identifies the weld position through an image processing algorithm to obtain the deviation between the actual weld trajectory and the standard weld trajectory, and provide positioning information for executing the spot welding and sealing welding procedures. It can be seen that when the capping device is pressing the workpiece, the pressure strip will partially block the workpiece welding trajectory, so only spot welding can be performed when the workpiece is pressed; when sealing welding, the capping device needs to be removed; the capping device will move the workpiece to a certain extent when pressing and releasing the workpiece, so the weld position needs to be identified before spot welding and sealing welding.

[0086] Furthermore, in the process of the image processing algorithm identifying the weld position, if the recognition is successful, the rangefinder camera transmits the actual weld trajectory of the workpiece and the acquired welding trajectory position deviation to the control system. If the recognition is unsuccessful, the workpiece is skipped and no welding is performed.

[0087] like Figure 5 As shown, the welding device of the present invention is used to implement the above-mentioned array workpiece laser welding control method, including a mobile module, and a laser head 2, a coaxial camera 3, a laser rangefinder 4, a paraxial camera 5 and a workpiece stage 7 arranged on the mobile module. The laser head 2, the coaxial camera 3, the laser rangefinder 4 and the paraxial camera 5 are all located above the workpiece stage 7, and the laser head 2, the coaxial camera 3 and the paraxial camera 5 are in the same focal plane. A plurality of workpieces 1 to be welded are arranged in an array on the workpiece stage 7, and a capping device 6 for pressing the workpiece 1 is provided on the workpiece stage 7. When the laser head 2 is welding, a certain stress will be generated, which will cause the workpiece 1 to be easily warped at the diagonal part of the welding, affecting the welding quality. Therefore, generally before the sealing welding, the workpiece 1 will be pressed by the capping device 6, and the workpiece 1 will be fixed by interval spot welding along the weld. In this embodiment, the capping device 6 can adopt conventional technical means in the field, as long as the workpiece 1 can be pressed and fixed.

[0088] In this embodiment, in order to improve the applicability of the workpiece table 7, a fixture can also be set on the workpiece table 7 to place the workpiece 1, and a corresponding fixture is selected according to the size and structure of the workpiece 1. Since the workpiece table 7 has a certain applicability, the workpiece 1 has a 1mm to 2mm activity space on the workpiece table 7, which is enough to cause welding deviation, so before each welding, it is necessary to take a picture with the rangefinder camera 5 to identify the precise position of the weld of the workpiece 1.

[0089] In this embodiment, the mobile module includes an X-axis mobile module 8, a Y-axis mobile module 9 and a Z-axis mobile module 10. The workpiece stage 7 is arranged on the Y-axis mobile module 9, the Y-axis mobile module 9 is arranged on the X-axis mobile module 8, and the X-axis mobile module 8 is arranged on the bottom plate 100, so that the workpiece stage 7 drives the workpiece 1 to move along the X-axis direction and the Y-axis direction. The laser head 2, the coaxial camera 3, the laser rangefinder 4 and the paraxial camera 5 are all arranged on the Z-axis mobile module 10, the Z-axis mobile module 10 is arranged on the support frame 200, and the support frame 200 is arranged on the bottom plate 100. Specifically, the X-axis mobile module 8, the Y-axis mobile module 9 and the Z-axis mobile module 10 can all adopt conventional technical means in this field, as long as they can drive the workpiece stage 7, the laser head 2, the coaxial camera 3, the laser rangefinder 4 and the paraxial camera 5 to move smoothly. In this embodiment, the laser head 2 is fixed on the lifting Z-axis moving module 10, and the Z-axis height can be adjusted. By adjusting the installation height, it is ensured that the paraxial vision, coaxial vision and laser focus are basically in the same plane, that is, after the workpiece 1 is focused by laser ranging, the workpiece 1 is moved to the paraxial camera 5 and the coaxial camera 3, and the clearest image can be seen. If welding, the laser focus is also on the surface of the workpiece 1. The workpiece 1 is placed on the workpiece table 7, and the workpiece table 7 is on the XY axis plane. During welding, it moves along the set trajectory through three-axis interpolation, and the laser head 2 emits light to complete the welding process.

[0090] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any technician familiar with the art can use the above disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the spirit and technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention still fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A laser welding control method for array workpieces, characterized in that: The following steps are involved: Step S1, control system initialization; Step S2, setting array workpiece placement parameters; Step S3, selecting a welding track; Step S4, configuring a three-color light source and setting paraxial image recognition parameters; Step S5, setting laser welding parameters; Step S6, controlling the laser head to perform welding; Step S7, determine whether the batch welding is completed; if the welding is completed, end the welding process; if the welding is not completed, continue to control the laser head to perform welding.

2. The array workpiece laser welding control method according to claim 1, characterized in that: In step S4, the setting of paraxial image recognition parameters includes the following steps: Step S41, placing the workpiece in the field of view of the paraxial vision camera and focusing; Step S42, adjusting relevant parameters of the three-color light source; Step S43, adjusting camera related parameters; Step S44, obtaining a welding trajectory graph; Step S45, adjusting image feature parameters, generating features, and identifying workpiece welds; Step S46, adjusting the welding trajectory graphic position to match the identified workpiece weld; Step S47, setting a matching threshold. If the matching threshold is exceeded, the recognition is determined to be successful, and the recognition parameters are saved; if the matching threshold is lower than the threshold, the recognition is determined to be unsuccessful. Step S48, repeating steps S41 to S47 on the remaining workpieces in the array to perform recognition verification and fine-tune the recognition parameters.

3. The array workpiece laser welding control method according to claim 1, characterized in that: The step S6 further comprises: Step S61, placing the workpieces to be welded arranged in an array on a workpiece table and under a laser head; Step S62, moving the workpiece stage and ensuring that the first workpiece of the array appears in the field of view of the coaxial camera; Step S63, automatically measuring the distance by a laser rangefinder, and ensuring that the laser focus appears on the surface of the first workpiece; Step S64, the capping device automatically presses each workpiece placed in the array; Step S65, moving the workpiece stage, and scanning and identifying the workpieces in the array one by one through a paraxial camera; Step S66, starting the spot welding program, spot welding the workpieces in the array one by one; Step S67, the capping device is released and moved out of the welding area; Step S68, moving the workpiece stage, and scanning and identifying the workpieces in the array one by one by the rangefinder camera again; Step S69, start the sealing welding procedure to complete the welding of the workpieces in the array one by one.

4. The array workpiece laser welding control method according to claim 3, characterized in that: In step S62, the coaxial camera displays the situation below the laser head in real-time video.

5. The array workpiece laser welding control method according to claim 3, characterized in that: In step S63, the laser rangefinder measures the distance between the laser head and the workpiece and feeds back the distance to the control system, and the control system adjusts the height of the laser head according to the distance feedback value.

6. The array workpiece laser welding control method according to claim 3, characterized in that: In step S65, the rangefinder camera takes a picture of any workpiece in the array and identifies the weld position through an image processing algorithm to obtain the deviation between the actual weld trajectory and the standard weld trajectory, providing positioning information for executing spot welding and sealing welding procedures.

7. The array workpiece laser welding control method according to claim 6, characterized in that: In the process of the image processing algorithm identifying the weld position, if the recognition is successful, the rangefinder camera transmits the actual weld trajectory of the workpiece and the acquired welding trajectory position deviation to the control system. If the recognition is unsuccessful, the workpiece is skipped and no welding is performed.

8. A welding device for implementing the array workpiece laser welding control method according to any one of claims 1 to 7, characterized in that: The invention comprises a mobile module, and a laser head (2), a coaxial camera (3), a laser rangefinder (4), a paraxial camera (5) and a workpiece table (7) arranged on the mobile module; the laser head (2), the coaxial camera (3), the laser rangefinder (4) and the paraxial camera (5) are all located above the workpiece table (7); a plurality of workpieces (1) to be welded are arranged in an array on the workpiece table (7), and a pressure cover device (6) for pressing the workpieces (1) is provided on the workpiece table (7).

9. The welding device according to claim 8, characterized in that: The workpiece (1) has a movable space of 1 mm to 2 mm on the workpiece platform (7).

10. The welding device according to claim 8, characterized in that: The movable module comprises an X-axis movable module (8), a Y-axis movable module (9) and a Z-axis movable module (10); the workpiece table (7) is arranged on the Y-axis movable module (9), and the Y-axis movable module (9) is arranged on the X-axis movable module (8), so that the workpiece table (7) drives the workpiece (1) to move along the X-axis direction and the Y-axis direction; and the laser head (2), the coaxial camera (3), the laser rangefinder (4) and the paraxial camera (5) are all arranged on the Z-axis movable module (10).

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