Method for correcting the precision of multiple light recoats based on additive and subtractive equipment

Abstract

The application belongs to the technical field of laser processing, and relates to a multi-light coincidence precision correction method based on additive and subtractive equipment, which comprises the following steps: generating and storing a corresponding first correction file for additive laser; generating and storing a corresponding second correction file for subtractive laser; and calling and loading the first correction file or the second correction file according to a printing stage. The application provides a multi-light coincidence precision correction method based on additive and subtractive equipment, which can improve forming quality and forming efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser processing, and relates to a light source coincidence precision correction method, in particular to a multi-light coincidence precision correction method based on an additive and subtractive equipment. BACKGROUND

[0002] In the invention application with the application number CN202110297092.4, a femtosecond laser additive and subtractive machining system and machining method are disclosed, which belong to the technical field of laser processing and include a laser emission unit and a laser working unit. The laser working unit includes a laser light path adjustment assembly, a light path integration assembly, and a workpiece machining assembly. The laser emitted by the laser emission module passes through the light path adjustment assembly and the light path integration assembly in turn to reach the machining assembly to perform laser processing on the internal region to be processed of the workpiece. However, the coincidence precision of the light beams of different wavelengths in the additive and subtractive integrated forming equipment in the focal plane is low, which further affects the forming quality. In order to solve the problem of the coincidence precision of the light beams of different wavelengths in the focal plane in the additive and subtractive integrated forming equipment, the additive and subtractive laser beams share the same set of galvanometer control parameters. For example, in the invention application with the application number 202111543604.7, a sub-region scanning large-format galvanometer correction system based on an A3 format scanner is disclosed, which includes marking a circular array file according to the size of the format to be corrected, marking array points on the first correction target A and the correction target B using the galvanometer to be corrected, scanning the maximum width by the two-dimensional scanner, correcting the actual coordinates of each point of the correction target A and the target B, and finally generating a correction file to realize galvanometer correction. However, in the high-precision forming scene, due to the different wavelengths of the additive and subtractive laser beams, if only the same set of galvanometer control parameters is used, there will be a coincidence error in the forming plane, which further leads to forming failure. SUMMARY

[0003] In order to solve the above technical problems in the background art, the application provides a multi-light coincidence precision correction method based on an additive and subtractive equipment, which can improve the forming quality and efficiency.

[0004] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0005] A multi-light coincidence precision correction method based on an additive and subtractive equipment, the method comprising: generating and storing a corresponding first correction file for additive laser; generating and storing a corresponding second correction file for subtractive laser; calling and loading the first correction file or the second correction file according to the stage of printing.

[0006] According to the stage of printing, the first correction file or the second correction file is called and loaded, including: if the stage of printing is an additive manufacturing stage, the first correction file is called and loaded; if the stage of printing is a subtractive manufacturing stage, the second correction file is called and loaded.

[0007] Generating and storing the corresponding first correction file for the additive laser specifically includes: sintering a plurality of cross intersections on the forming plane using a small-power additive laser, obtaining the actual coordinates of the plurality of cross intersections in the galvanometer coordinate system, and generating and storing the first correction file by subtracting the actual coordinates from the preset standard coordinates; and generating and storing the corresponding second correction file for the subtractive laser specifically includes: sintering a plurality of cross intersections on the forming plane using a small-power subtractive laser, obtaining the actual coordinates of the plurality of cross intersections in the galvanometer coordinate system, and generating and storing the second correction file by subtracting the actual coordinates from the preset standard coordinates.

[0008] The additive-subtractive equipment-based multi-light coincidence precision correction method further includes: calibrating the initial coordinate system of the additive laser to be consistent with the initial coordinate system of the subtractive laser. Calibrating the initial coordinate system of the additive laser to be consistent with the initial coordinate system of the subtractive laser includes: calibrating the initial coordinate system of the subtractive laser to coincide with the reference coordinate system of the initial coordinate system of the additive laser.

[0009] Calibrating the initial coordinate system of the subtractive laser to coincide with the reference coordinate system of the initial coordinate system of the additive laser includes the following steps:

[0010] a) controlling the additive laser to emit light scanning at a specified position, obtaining the first actual position coordinates of the additive laser on the focal plane corresponding to the specified position, and obtaining the additive laser beam coordinate system XOY according to the first actual position coordinates; the additive laser beam coordinate system XOY is the reference coordinate system;

[0011] b) controlling the subtractive laser to emit light scanning at the specified position, obtaining the second actual position coordinates of the subtractive laser on the focal plane corresponding to the specified position, and obtaining the subtractive laser beam coordinate system X'O'Y' according to the second actual position coordinates;

[0012] c) coinciding the subtractive laser beam coordinate system X'O'Y' with the reference established coordinate system, and obtaining the rotation offset parameters of the subtractive laser beam coordinate system X'O'Y' and the reference established coordinate system;

[0013] d) setting the control software parameter configuration file according to the rotation offset parameters calculated in step c), and calibrating the initial coordinate system of the subtractive laser to coincide with the reference coordinate system by loading the control software parameter configuration file.

[0014] The above step a) is specifically: controlling the additive laser to emit light scanning at the feature point O and the feature point P, and obtaining the actual position coordinates of the additive laser on the focal plane corresponding to the feature point O and the feature point P and Taking the actual position coordinates of the feature point O as the coordinate system origin and combining the actual position coordinates of the feature point P, the additive laser beam coordinate system XOY is obtained.

[0015] The step b) is specifically: controlling the subtractive laser to emit light scanning at the feature point O and the feature point P, and obtaining the second actual position coordinates of the subtractive laser corresponding to the feature point O and the feature point P on the focal plane And Taking the second actual position coordinates of the feature point O as the coordinate system origin, and combining the second actual position coordinates of the feature point P, the subtractive laser beam coordinate system X'O'Y' is obtained.

[0016] In the step c), the rotation offset parameter includes an offset value and an offset angle, and the offset value is calculated in the following manner:

[0017]

[0018]

[0019] Wherein:

[0020] X offset is the offset value of the subtractive laser beam coordinate system X'O'Y' relative to the X direction of the additive laser beam coordinate system XOY;

[0021] Y offset is the offset value of the subtractive laser beam coordinate system X'O'Y' relative to the Y direction of the additive laser beam coordinate system XOY;

[0022] The offset angle is calculated in the following manner:

[0023]

[0024] Wherein:

[0025] abs() is an absolute value function;

[0026] θ is the offset angle of the subtractive laser beam coordinate system X'O'Y' relative to the additive laser beam coordinate system XOY.

[0027] The advantages of the present application are:

[0028] The application provides a multi-light coincidence precision correction method based on an additive and subtractive equipment, which controls a galvanometer deflection by respectively obtaining scanning position data through light scanning in two kinds of incident states of additive and subtractive laser beams and then obtaining two different correction files; in an additive and subtractive integrated forming process, different beam corresponding coordinate system transformation parameters and correction files are loaded according to requirements in the control software, so that the scanning point height coincidence on the forming plane in different forming modes is ensured. At the same time, a coordinate system is established with the center of the additive laser beam on the forming plane as a reference, the rotation and translation of the subtractive laser beam on the forming plane relative to the additive laser beam are calculated, and then the coordinate system position of the subtractive laser beam on the forming plane is corrected, so that the additive and subtractive laser beams on the forming plane tend to be completely coincident. The application can realize that the scanning positions of different wavelength additive and subtractive laser beams in the additive and subtractive integrated equipment after passing through the same galvanometer deflection can be one-to-one corresponding and highly coincident on the forming plane. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Fig. 1 is a flowchart of the multi-light coincidence precision correction method based on the additive and subtractive equipment provided by the application;

[0030] Figure 2 Fig. 2 is a schematic diagram of the equipment used in the additive and subtractive laser beam forming plane correction;

[0031] Figure 3 Fig. 3 is a schematic diagram of the coordinate system conversion in the additive and subtractive laser beam forming plane correction;

[0032] Figure 4 Fig. 4 is a schematic diagram of the simplified model of the multi-light coincidence precision correction method based on the additive and subtractive equipment provided by the application. DETAILED DESCRIPTION

[0033] Since the optical system of the SLM equipment adopts a scanning galvanometer to deflect the laser beam, the deflection angle of the scanning lens is nonlinearly mapped on the plane coordinate, but the control system uses a continuous function approximation method to fit the nonlinear relationship, and this nonlinear distortion will produce pillow distortion or barrel distortion, so currently laser additive manufacturing or subtractive manufacturing needs to be calibrated before the galvanometer. At present, in the additive and subtractive equipment, the same set of galvanometer calibration files is usually used for additive laser and subtractive laser, and since the wavelength of the additive laser and the subtractive laser is quite different, the use of the same set of galvanometer calibration files will cause coincidence error, which will affect the final part forming.

[0034] The application provides a multi-light coincidence precision correction method based on additive and subtractive equipment, correction files of additive laser and subtractive laser are obtained respectively, and then in the additive and subtractive printing process, the equipment can call the appropriate correction file according to the current printing state (in the additive manufacturing process, the equipment calls the first correction file corresponding to the additive laser; in the subtractive manufacturing process, the equipment calls the second correction file corresponding to the subtractive laser), so as to avoid the error caused by using the same galvanometer correction file for different wavelength lasers, and realize high-precision coincidence of scanning points of lasers with different wavelengths after the same galvanometer.

[0035] It should be noted that the present scheme is not only suitable for double laser, but also suitable for three laser or more laser. In order to facilitate description, the following will be described by taking additive and subtractive double laser as an example.

[0036] Referring to Figure 1 In the embodiment of the present application, the additive laser beam corresponds to the correction file (the first correction file) of the additive laser, and the subtractive laser beam corresponds to the correction file (the second correction file) of the subtractive laser. In the forming process, the equipment can call and load the appropriate correction file as needed according to the current printing stage, so as to ensure the forming precision.

[0037] Specifically, if the printing stage is the additive manufacturing stage, the first correction file is called and loaded; if the printing stage is the subtractive manufacturing stage, the second correction file is called and loaded.

[0038] In the embodiment of the present application, the method for generating the first correction file for the additive laser and the second correction file for the subtractive laser is the same, and specifically as follows:

[0039] A small-power laser is used to sinter a plurality of cross intersection points on the forming plane, the actual coordinates of the plurality of cross intersection points in the galvanometer coordinate system are obtained, the actual coordinates are subtracted from the preset standard coordinates, the correction file corresponding to the laser is generated and stored.

[0040] In addition, since there may be deviation in the initial coordinate system of different lasers, that is, if the initial coordinate systems of the two lasers do not coincide, it will also affect the subsequent printing precision. Therefore, before generating the first correction file and the second correction file, the application further includes: calibrating the initial coordinate system of the additive laser to be consistent with the initial coordinate system of the subtractive laser. It can also be understood that the initial coordinate system of the subtractive laser is calibrated to coincide with the reference coordinate system of the initial coordinate system of the additive laser. Of course, the initial coordinate system of the subtractive laser can also be taken as the reference coordinate, which is not limited in the present application.

[0041] For the convenience of description, the initial coordinate system of the additive laser is taken as the reference coordinate system in the following. The initial coordinate system of the subtractive laser is calibrated to coincide with the reference coordinate system, which specifically includes (see Figure 2 and Figure 3 ):

[0042] a) control the additive laser to emit light scanning at the feature point O and the feature point P, and obtain the actual position coordinates of the additive laser corresponding to the feature point O and the feature point P on the focal plane and take the actual position coordinates of the feature point O as the origin of the coordinate system, and combine the actual position coordinates of the feature point P to obtain the additive laser beam coordinate system XOY;

[0043] b) control the subtractive laser to emit light scanning at the feature point O and the feature point P, and obtain the second actual position coordinates of the subtractive laser corresponding to the feature point O and the feature point P on the focal plane and take the second actual position coordinates of the feature point O as the origin of the coordinate system, and combine the second actual position coordinates of the feature point P to obtain the subtractive laser beam coordinate system X'O'Y';

[0044] c) coincide the subtractive laser beam coordinate system X'O'Y' with the reference coordinate system to obtain the rotation offset parameters of the subtractive laser beam coordinate system X'O'Y' relative to the reference coordinate system; the rotation offset parameters include an offset value and an offset angle, and the offset value is calculated as follows:

[0045]

[0046]

[0047] wherein:

[0048] X offset is the offset value of the X direction of the subtractive laser beam coordinate system X'O'Y' relative to the additive laser beam coordinate system XOY;

[0049] Y offset is the offset value of the Y direction of the subtractive laser beam coordinate system X'O'Y' relative to the additive laser beam coordinate system XOY;

[0050] the offset angle is calculated as follows:

[0051]

[0052] wherein:

[0053] abs() is an absolute value function;

[0054] θ is the offset angle of the subtractive laser beam coordinate system X'O'Y' relative to the additive laser beam coordinate system XOY.

[0055] d) setting the control software parameter configuration file according to the rotation offset number calculated in step c), and aligning the initial coordinate system of the subtractive laser to coincide with the reference coordinate system by loading the control software parameter configuration file.

[0056] Wherein, for steps a) and b), the corresponding data collection can be performed by the device as shown in Figure 2 The correction plate as shown in the application number 202111277275.6 can also be used. Figure 2 For example, place the laser position correction plate equipped with a photodiode in the scanning area below the galvanometer, and use the sensor of the specific position of the correction plate to collect position data.

[0057] Please continue to see Figure 2 The coordinate collection method in steps a) and b) is as follows: adjust the position of the correction plate so that the red light origin of the additive and subtractive laser is located at the center position of the sensor 0 (feature point), and then move the machining platform so that the light receiving plane of the sensor is at the device forming plane (focal plane) position. Control the additive laser to emit light scanning at the specified position, and transfer the position data fed back by the sensor to the host computer through the data acquisition card for processing and recording to obtain the actual position data of the additive laser (sensor 0 Sensor 1 Two identical sensors can be equivalent to two feature points). Then switch to the incident state of the subtractive laser, keep the position of the correction plate unchanged, control the subtractive laser beam to emit light scanning at the same position as the additive laser beam, and obtain the position data of the subtractive laser (sensor 0 Sensor 1 ).

[0058] See Figure 4 A multi-angle correction model as shown in Figure 4 including the first correction file and the second correction file as previously described and the control software parameter configuration file can be constructed. In the actual processing process, first align the initial coordinate system of the laser by loading the control software parameter configuration file, and then selectively call the first correction file or the second correction file according to the stage of printing to improve the scanning accuracy of different lasers and better realize the high-precision coincidence of the scanning points of different beams after the galvanometer.

[0059] In addition, in Figure 4In the model shown, especially in the section file, the additive / subtractive scanning state trigger switch is introduced. During the operation of the device, when the next layer of scanning path is loaded, if it is found that the layer has laser beam switching requirement, a separate thread is started in the software to load and cache the control parameters of the corresponding light beam, so that the additive / subtractive scanning switching process is more efficient.

[0060] It should be noted that for additive manufacturing of different wavelengths of laser, a correction file can also be generated for each additive laser according to the present scheme.

Claims

1. A multi-light coincidence accuracy correction method based on additive and subtractive equipment, characterized by: The method comprises: The initial coordinate system of the additive laser is used as a reference coordinate system, and the initial coordinate system of the subtractive laser is calibrated to coincide with the reference coordinate system, and the additive laser and the subtractive laser are deflected by the same galvanometer; Generate and store a corresponding first calibration file for the additive laser; specifically, use a low-power additive laser to sinter multiple cross points on the forming plane, obtain the actual coordinates of the multiple cross points in the galvanometer coordinate system, subtract the actual coordinates from the preset standard coordinates, and generate and store the first calibration file; Generate and store a corresponding second calibration file for the subtractive laser; specifically, use a low-power subtractive laser to sinter multiple cross points on the forming plane, obtain the actual coordinates of the multiple cross points in the galvanometer coordinate system, subtract the actual coordinates from the preset standard coordinates, and generate and store the second calibration file; Depending on the printing stage, the first correction file or the second correction file is called and loaded; if the printing stage is the additive manufacturing stage, the first correction file is called and loaded; if the printing stage is the subtractive manufacturing stage, the second correction file is called and loaded.

2. The multi-light coincidence accuracy correction method based on additive and subtractive material equipment according to claim 1, characterized in that: The method of calibrating the initial coordinate system of the subtractive laser to coincide with the reference coordinate system using the initial coordinate system of the additive laser as the reference coordinate system includes the following steps: a) controlling the additive laser to emit light and scan at a specified position, obtaining a first actual position coordinate of the additive laser corresponding to the specified position on the focal plane, and obtaining an additive laser beam coordinate system XOY based on the first actual position coordinate; the additive laser beam coordinate system XOY is a reference coordinate system; b) Controlling the subtractive laser to scan at a specified position, obtaining a second actual position coordinate of the subtractive laser corresponding to the specified position on the focal plane, and obtaining a subtractive laser beam coordinate system based on the second actual position coordinate ; c) Subtractive laser beam coordinate system The reference coordinate system coincides and the subtractive laser beam coordinate system is obtained Rotation offset parameters of the coordinate system established with the reference; d) Setting a control software parameter configuration file according to the rotation offset calculated in step c), and calibrating the initial coordinate system of the subtractive laser to coincide with the reference coordinate system by loading the control software parameter configuration file.

3. The multi-light coincidence accuracy correction method based on additive and subtractive material equipment according to claim 2, characterized in that: The step a) specifically includes: controlling the additive laser to emit light and scan at the feature point O and the feature point P, and obtaining the actual position coordinates of the additive laser corresponding to the feature point O and the feature point P on the focal plane ( and( , ), taking the actual position coordinates of the feature point O as the origin of the coordinate system and combining the actual position coordinates of the feature point P, the additive laser beam coordinate system XOY is obtained.

4. The multi-light coincidence accuracy correction method based on additive and subtractive material equipment according to claim 3, characterized in that: The step b) specifically includes: controlling the subtractive laser to scan at the feature point O and the feature point P, and obtaining the second actual position coordinates of the subtractive laser corresponding to the feature point O and the feature point P on the focal plane ( and( , ), take the second actual position coordinate of the feature point O as the origin of the coordinate system, and combine the second actual position coordinate of the feature point P to obtain the subtractive laser beam coordinate system .

5. The multi-light coincidence accuracy correction method based on additive and subtractive material equipment according to claim 4, characterized in that: In step c), the rotation offset parameter includes an offset value and an offset angle. The offset value is calculated as follows: in: is the subtractive laser beam coordinate system The offset value in the X direction relative to the additive laser beam coordinate system XOY; is the subtractive laser beam coordinate system The Y-axis offset relative to the additive laser beam coordinate system XOY; The offset angle is calculated as follows: in: abs is the absolute value function; θ is the subtractive laser beam coordinate system The offset angle relative to the additive laser beam coordinate system XOY.

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