A method, device and medium for compensating focal offset of laser cutting head

Abstract

This application discloses a method, device, and medium for focal offset compensation of a laser cutting head. The method includes: controlling a light source group to emit a light beam, so that the beam reaches a pre-set image acquisition area after passing through one or more semi-reflective mirrors; analyzing the beam image to obtain the contour size of the beam-forming shape in the beam image; obtaining the actual focal position in the current working state based on a pre-tested mapping relationship, according to the contour size of the beam-forming shape and the current focal setting value; and performing focal offset compensation based on the difference between the current target focal position and the actual focal position. Compared with timed compensation methods, the focal offset compensation process can be automated through a pre-obtained mapping relationship, without requiring a high level of operator skill, resulting in more accurate and stable compensation results.

Description

[0001] This application claims priority to Chinese patent application CN 2024107237134, filed on June 5, 2024.

[0002] This application incorporates the full text of the aforementioned Chinese patent application. Technical Field

[0003] This application relates to the field of laser cutting, specifically to a method, device, and medium for compensating for focus offset of a laser cutting head. Background Technology

[0004] With the development of technology, laser processing power is constantly increasing in the laser cutting industry.

[0005] During high-power laser cutting, as processing time increases, the heat absorbed and accumulated by components such as lenses and barrels will continue to increase. The resulting "thermal lensing effect" of the lens itself and the deformation caused by uneven heating of the barrel can easily cause the focal position to shift, making the cutting parameters no longer objective. This situation will seriously affect the cutting quality and reduce the cutting performance.

[0006] Traditional solutions address this type of focus shift by using timed compensation. This involves adjusting the focus within a pre-defined time period and manually optimizing the focus compensation parameters based on the cutting effect.

[0007] The aforementioned traditional methods require a high level of operator skill, are difficult for ordinary employees to master, and are easily affected by various objective factors, making it difficult to achieve accurate and real-time compensation. Furthermore, timed compensation methods are not based on real-time compensation according to actual changes in optical focus, making them unsuitable for various working conditions. Summary of the Invention

[0008] To address the aforementioned problems, this application proposes a focal offset compensation method for laser cutting heads, comprising:

[0009] The light source group set inside the laser cutting head is controlled to emit a light beam, so that the light beam reaches a pre-set image acquisition area after passing through one or more semi-reflective mirrors;

[0010] Acquire the beam image generated by the beam in the image acquisition area;

[0011] The beam image is analyzed to obtain the outline size of the beam forming shape in the beam image;

[0012] Based on the mapping relationship between the profile size, focus setting value, and actual focus position generated by pre-testing, the actual focus position in the current working state is obtained according to the profile size of the beam forming shape and the focus setting value in the current working state.

[0013] Focus offset compensation is performed based on the difference between the target focus position and the actual focus position in the current operation.

[0014] On the other hand, this application also proposes a focus offset compensation device for a laser cutting head, comprising:

[0015] At least one processor; and,

[0016] A memory communicatively connected to the at least one processor; wherein,

[0017] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform, for example, the focus offset compensation method for a laser cutting head described in the above example.

[0018] On the other hand, this application also proposes a non-volatile computer storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured as: the focus offset compensation method for the laser cutting head described in the above example.

[0019] The focal offset compensation method for laser cutting heads proposed in this application can bring the following beneficial effects:

[0020] Compared to timed compensation methods, the focus offset compensation process can be automated by using a pre-obtained mapping relationship, without requiring any skill level from the employee, resulting in more accurate and stable compensation results.

[0021] Furthermore, variations in ambient light intensity and focal position significantly impact the contour recognition of individual light spot images, but have a smaller impact on the center point recognition. Moreover, the large contour of a light source group, compared to the beam of a single laser module, makes it easier to achieve a larger contour, thus improving the recognition of image changes under the same lens distortion and focal shift conditions. In other words, during image acquisition and analysis, the center position of each light spot is relatively less affected by changes in ambient light, sharpness, spot size, and beam intensity.

[0022] Compared to the variation in the contours of individual light spots, the positions of the center points of each light spot are relatively easy to analyze and calculate visually. The overall graphic contour fitted using the center points of each light spot is relatively stable and clear. Therefore, the method of using light sources to form an image, fitting the contour size, and then inferring the actual focal position and focal offset based on the contour size, calibration data model, or calculation, and performing focal compensation, has better stability and recognition accuracy. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0024] Figure 1 This is a flowchart illustrating the focal offset compensation method for a laser cutting head in an embodiment of this application.

[0025] Figure 2 This is a schematic diagram of focus offset in an embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the structure of the light source group and the semi-reflective mirror in one scenario of this application embodiment;

[0027] Figure 4 This is a schematic diagram illustrating the interaction between the industrial control computer and the image acquisition device in the first scenario of this application embodiment;

[0028] Figure 5 This is a schematic diagram illustrating the interaction between the industrial control computer and the image acquisition device under the second scenario in the embodiments of this application;

[0029] Figure 6 This is a schematic diagram of the contour generation of the beam image in an embodiment of this application;

[0030] Figure 7 This is a schematic diagram illustrating the duration of periodic light emission in an embodiment of this application;

[0031] Figure 8 This is a schematic diagram illustrating the process of obtaining the actual focus position in an embodiment of this application;

[0032] Figure 9 This is a schematic diagram illustrating the process of obtaining the focus offset in an embodiment of this application;

[0033] Figure 10 This is a schematic diagram illustrating the determination of the geometric center in an embodiment of this application;

[0034] Figure 11 This is a schematic diagram of a focus offset compensation device for a laser cutting head in an embodiment of this application. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0037] like Figure 1 As shown in the figure, this application provides a focal offset compensation method for a laser cutting head, including:

[0038] S101: Control the light source group set inside the laser cutting head to emit a light beam so that the light beam reaches the preset image acquisition area after passing through one or more semi-reflective mirrors.

[0039] like Figure 2 As shown, focal shift may occur during the actual use of a laser cutting head. Essentially, focal shift is caused by heat accumulation in the lenses, leading to an increase in lens temperature and an increase in the curvature of the entire lens assembly (collimating lens, focusing lens, etc.) exhibiting convex lens characteristics. When focal shift occurs, the focal point changes towards the positive focal direction. The greater the increase in curvature, the greater the shift of the focal point towards the positive focal direction.

[0040] exist Figure 2 In the diagram, position 1 is the theoretical focal position, and position 2 is the actual focal position after lens deformation (focal point shift). To address issues in timing compensation, a camera or image sensor can be installed inside the laser cutting head to estimate the focal point shift by observing changes in the size of the indicator light spot emitted from the laser fiber optic head. Alternatively, matching lenses and filters can be added to filter out light from non-light source spectrum bands and eliminate the influence of scattered light, allowing the camera or image sensor's photosensitive element to observe the entire light spot image more completely from its current position.

[0041] However, during the observation of a single indicator light source spot, it is easily affected by factors such as unclear spot boundaries, the spot image being greatly affected by ambient scattered light, the original indicator light source spot being irregular, and the spot size being inconsistent. It is difficult to effectively determine the change in focus offset by observing the outline change of an original indicator light spot.

[0042] Furthermore, when setting the focal position, the position of the collimating lens or focusing lens of the laser cutting head is adjustable and variable, so the size of the observed spot itself varies. From an image perspective, the edge (also known as the contour) of a single spot is easily affected by factors such as the irregularity of the original indicator light source spot, its own stray light, and variations in the intensity of ambient scattered light, making it difficult to define the edge changes.

[0043] Based on this, setting up a light source group and relying on the light source group to complete the focus shift calculation can solve the problems caused by a single indicator light source.

[0044] The light source group contains multiple active light sources, which can actively emit corresponding beams of light under control. The active light sources are arranged based on a preset shape, which can be a ring, multiple parallel lines, or other irregular shapes. When the shape is a ring, it can be a circular ring, a fan-shaped ring, or a rectangular ring, and the multiple active light sources in the light source group can be evenly distributed. For example, there can be multiple active light sources distributed in a ring, emitting multiple beams of parallel light to form a ring-like beam combination.

[0045] Variations in ambient light intensity and focus position significantly impact the contour recognition of individual light spot images, but have a smaller impact on the center point recognition. Furthermore, the large contour of a light source group, compared to the beam of a single laser module, makes it easier to achieve a larger contour, thus improving the recognition of image changes under the same lens distortion and focus shift conditions. In other words, during image acquisition and analysis, the center position of each light spot is relatively less affected by changes in ambient light, sharpness, spot size, and beam intensity.

[0046] Compared to the variation in the contours of individual light spots, the positions of the center points of each light spot are relatively easy to analyze and calculate visually. The overall graphic contour fitted using the center points of each light spot is relatively stable and clear. Therefore, the method of using light sources to form an image, fitting the contour size, and then inferring the actual focal position and focal offset based on the contour size, calibration data model, or calculation, and performing focal compensation, has better stability and recognition accuracy.

[0047] Furthermore, the brightness and output power of each active light source in the light source group are relatively consistent. The brightness of the active light sources can be designed to be fixed or adjustable. The light emitted by the light source group can be parallel or regularly angled indicator laser light, or it can be a non-laser beam.

[0048] By setting the position and angle of the light source group accordingly, the light beam can pass through lenses that may cause focus shift (such as collimating lenses and focusing lenses), and be reflected by a semi-reflecting mirror, thereby reaching the image acquisition area.

[0049] Specifically, it can be like Figure 3 As shown, the light source group is set around the output end of the processing laser light source. When the light source group is ring-shaped, it can be set around the processing laser light source, and the beam is emitted from top to bottom and enters the laser processing channel.

[0050] At this point, there can be one semi-reflective mirror, positioned below the focusing lens and at a preset angle to it, such as 45 degrees. Alternatively, another semi-reflective mirror can be placed below the light source group and above the collimating lens; its addition can be determined based on requirements. Figure 3 The multiple mirrors in the image, from top to bottom, are: a semi-reflecting mirror, a collimating mirror, a focusing mirror, and another semi-reflecting mirror.

[0051] The image acquisition area is set on the side of the lower semi-reflecting mirror. When the upper semi-reflecting mirror is not set, the light beam emitted by the light source group passes through the collimating mirror and the focusing mirror, and is reflected by the semi-reflecting mirror before entering the image acquisition area. The image acquisition device acquires the light beam image in the image acquisition area.

[0052] certainly, Figure 3 The structure described is merely an example; other implementations readily conceived by those skilled in the art can also be included within the scope of protection of this application's embodiments. For instance, increasing the number of semi-reflective mirrors, such that they are positioned on one side of the laser light source, allows light beams entering from the side to pass through the collimating lens and focusing lens before entering the image acquisition area. In this case, the light source group can remain positioned above, with the image acquisition area remaining below; alternatively, the two can be interchanged, with the light source group positioned below and the image acquisition area remaining above.

[0053] In addition, the light beams emitted by the light source group can be a set of parallel beams or non-parallel beams. For example, they can be at a certain angle to the central axis and diverge inward or outward.

[0054] S102: Acquire the beam image generated by the beam in the image acquisition area using an image acquisition device.

[0055] Once the light beam from the light source reaches the image acquisition area, the corresponding beam image is acquired by the image acquisition device (which can be a camera or an image sensor). The beam can directly enter the photosensitive element of the camera or image sensor for image capture. Alternatively, a screen or projection screen (made of a semi-transparent screen, double-sided projection screen, semi-transparent PVC board, etc.) can be placed in the image acquisition area. The beam forms an image on this screen or projection screen, and the image acquisition device observes the light spot created by the beam on the screen or projection screen to acquire the image. The image acquisition device and the screen or projection screen can be located on the same side of the semi-reflective mirror, or on different sides of the semi-reflective mirror; both locations can achieve beam image acquisition.

[0056] Furthermore, when a screen or projection screen is provided, the light beam illuminating the screen or projection screen can be an image before the beam group-focal point (meaning the focal point of the beam is located outside the semi-reflecting mirror and the screen), or an image after the beam group-focal point (meaning the focal point of the beam is located between the semi-reflecting mirror and the screen). There are no restrictions here, as long as the position of the screen or projection screen is fixed and the outline size of the image on the screen or projection screen is greater than a preset value. This ensures that when measuring the outline size, the image on the screen will not alternate between the two states of before and after the beam group-focal point due to changes in the actual focal point position, thus preventing errors in the calculation of the outline size.

[0057] S103: Analyze the beam image to obtain the outline size of the beam forming shape in the beam image.

[0058] An image processing unit is pre-installed. After the image acquisition device acquires the image of the beam, it sends the image of the beam to the image processing unit for processing.

[0059] like Figure 4 As shown, the image processing unit is a module in the industrial control computer, mainly used for image processing and calculating contour size. In addition, the industrial control computer also includes other modules, such as the focus compensation calculation module, which is used to calculate the focus offset that needs to be compensated and send control commands to the laser cutting head to perform focus offset compensation.

[0060] like Figure 5 As shown, the image processing unit can also be the hardware and software processing part integrated into the embedded programmable camera, or an embedded module integrated with the image sensor. It is a module in the image acquisition device. When transmitting data to the industrial control computer, it no longer transmits the beam image, but transmits the calculated contour size.

[0061] The industrial computer and the image acquisition device communicate via a bus to transmit image data, for example, by using an Ethernet bus to transmit data via the GigE interface.

[0062] Each beam of light is represented as a spot in the beam image. Typically, the preset shape corresponding to the light source group can also be represented in the beam image. Therefore, the preset shapes in this preset image are usually regular shapes. For example... Figure 6 As shown, taking a pre-defined ring shape as an example, during image analysis, the position of the center point of each light spot is obtained. Then, the positions of the center points of each light spot are used to fit a general contour. When the pre-defined shape is a ring, the final contour is a circle. At this point, its contour size is calculated. The contour size is related not only to the installation position and angle of the light source group, but also to the individual lenses inside the laser cutting head.

[0063] S104: Based on the mapping relationship between the contour size, focus setting value, and actual focus position generated by the pre-test, the actual focus position in the current operation is obtained according to the contour size of the beam forming shape and the focus setting value in the current operation.

[0064] Generally speaking, when there is no focus shift (i.e., the focus setting value and the actual focus position are the same), the outline size will change accordingly as the focus setting value changes. However, when there is a focus shift, the actual focus position will also change as the focus setting value changes. In this case, the outline size will also change due to the change in the actual focus position. Therefore, there is a corresponding mapping relationship among the three, and the other can be obtained based on two of them.

[0065] The mapping relationship between the contour size, focus setting value, and actual focus position is generated in advance. In the current working process, the contour size of the beam formation has been obtained based on image analysis, and the focus setting value is used to set in advance before the work. Therefore, the actual focus position can be inferred based on the mapping relationship.

[0066] Specifically, the mapping relationship can be generated through multiple rounds of testing. In each round of testing, the emission duration and interval duration corresponding to the periodic emission are first set for a single focus value. Periodic emission refers to continuous emission of light during the emission duration and then stopping emission during the interval duration, thus completing one cycle of emission.

[0067] Laser processing tests are conducted by processing a laser source and periodically emitting light to simulate actual working conditions until the test parameters stabilize. These parameters include lens temperature (including issues corresponding to collimating and focusing lenses), lens deformation, and focal point shift. Stable test parameters mean that when periodic light emission continues, the test parameters no longer change, or the change is very small, below a preset range.

[0068] Obtain the actual focal position and outline size in the current state. The outline size has already been obtained above, while the actual focal position can be obtained in various ways. For example, under the above conditions, during the multi-cycle "periodic" light emission process, a corresponding measure can be briefly inserted to determine the actual focal position.

[0069] Specifically, the corresponding measures may include:

[0070] Measure 1, Blue Spark Spotting Method. When the laser is in focus, the nozzle can be removed, and air is blown to direct the pulsed laser onto the stainless steel plate, causing the cutting head to move up and down until the blue spark becomes the focal point.

[0071] Method 2, thin plate kerf method. By cutting a thin plate to create the smallest kerf that can be obtained, the focal point position can be determined. This method can only be used for negative focus cutting calibration.

[0072] Measure 3, beam analysis method. A beam analyzer is used to observe the beam and obtain the focal point. During observation, the nozzle, ceramic ring, and even the bottom module can be removed to facilitate observation of the entire beam.

[0073] Measure 4: Plastic Plate Inclined Pulling Method. Use a plastic plate at a certain angle to the vertical axis to pull horizontally, and find the minimum point of the beam as the focal point.

[0074] Measure 5, Plastic Plate Printing Method. The laser cutting head is moved up and down, and the beam is printed onto a plastic plate, with the smallest printing diameter as the focal point. This method can only be used for negative focus cutting calibration.

[0075] At this point, a focus setting value is established. When light is emitted periodically, and the continuous light emission duration within each cycle is fixed, the interval duration within each cycle remains constant. After several cycles, the focus offset tends to stabilize. Gradually adjusting the interval duration of the periodic light emission output allows the focus offset to change gradually. After changing the interval duration, the laser processing test is repeated until the actual focus position and contour size corresponding to all focus offsets (from 0 to the maximum value) under the current single focus setting value are obtained, in order to generate the mapping relationship corresponding to the current single focus setting value.

[0076] In the mapping relationship, the focus offset increases as the duration of light emission in periodic light emission increases and the duration of the interval decreases.

[0077] Specifically, when the duration of periodic light output is short and the interval is long enough, the lens temperature remains low, and there is usually no focus shift. When the duration of periodic light output is fixed and the interval is short enough, after several cycles, heat accumulates in the lens, the lens temperature rises, and focus shift occurs—that is, an increase from nothing to something.

[0078] When the interval duration is zero (at this time, the laser cutting head is in a state of continuous light emission), after multiple cycles, the lens temperature can rise to the highest level, the lens curvature changes to the maximum, and the focal offset increases to the maximum.

[0079] With a fixed focus setting and interval duration, after multiple cycles, the lens temperature and deformation tend to stabilize, and the focus shift becomes basically stable. For each focus setting, a fixed interval duration is maintained. After multiple cycles, a stable profile size can be obtained, along with the corresponding actual focus position and focus shift for that focus setting.

[0080] For example, such as Figure 7 As shown, the continuous light emission time T1 and the interval duration T2 are given. One cycle T = T1 + T2. Under the current focus setting and interval duration, a sufficient number of consecutive tests are conducted, as the lens temperature tends to stabilize and the focus shift tends to stabilize. Under this focus setting, as long as the number of test cycles is sufficient, the larger the interval duration T2, the closer the focus shift is to the minimum value of 0; the smaller the interval duration T2, the closer the focus shift is to the maximum value.

[0081] Therefore, by adjusting the value of the interval duration T2, the focus offset can be gradually changed from 0 to its maximum value. Furthermore, this can be extended to allow for gradual changes in focus offset at all focus settings by adjusting the value of the interval duration T2.

[0082] Finally, the focus setting value is changed and calibration continues until the mapping relationship corresponding to all focus settings is generated. This gives us the mapping relationship between focus setting value, outline size, and actual focus position. The relationship is then generated into an association list and stored.

[0083] S105: Perform focus offset compensation based on the difference between the target focus position and the actual focus position in the current operation.

[0084] like Figure 8 As shown, based on the mapping relationship (also known as the calibration relationship) mentioned above, the actual focus position has been obtained based on the focus setting value and the contour size.

[0085] At this point, based on the user's processing parameters, obtain the desired target focus position (that is, the actual focus position under the user's processing parameters, assuming no focus shift occurs), such as... Figure 9 As shown, the offset that needs to be compensated (also the focus offset) is calculated based on the difference between the target focus position and the actual focus position.

[0086] Based on the focus setting value, the difference between it and the focus offset is calculated to obtain the focus setting value that needs to be updated next, thus completing the update of the focus setting value. The updated focus setting value is used as the user processing parameter for readjustment, thereby realizing focus offset compensation.

[0087] During real-time compensation, the current focus setting is used as input, and the current outline size is used as feedback to infer the current actual focus position and focus compensation value.

[0088] During the dynamic adjustment process, the current focus setting value is used as an intermediate process debugging quantity, the current contour size and the current actual focus position are used as feedback quantities, and the target focus position required by the user's processing parameters is used as the target quantity.

[0089] In one embodiment, the active light source and the processing laser light source belong to different spectral bands, and the spectral band of the processing laser light source is higher than that of the active light source. In this case, the beam emitted by the light source group has a certain transmittance to the aligning mirror and focusing mirror, and the semi-reflective mirror has high transmittance to the processing laser, which is higher than a first preset threshold and will not affect the operation of the processing laser. It also has a certain reflectance to the active light source, which is higher than a second preset threshold, and can reflect the beam of the active light source.

[0090] In one embodiment, when analyzing the beam image, the image is preprocessed, for example, by image filtering. Median filtering sorts the gray values ​​of all pixels within a certain region centered on any given pixel in ascending order, using the median value as the gray value of that pixel. Applying non-linear stretching, background interference pixels often have a large difference in gray value compared to their neighboring pixels. Taking the median value after sorting can make the interference pixel's gray value consistent with its neighboring pixels, thereby removing interference and better preserving image edges.

[0091] Based on a binarization threshold, the preprocessed beam image is binarized, and the light spot image is processed using threshold processing region segmentation technology. By fully utilizing the data difference in grayscale values ​​between the background and the light spot in the image, and according to the binarization threshold, it is determined whether the grayscale characteristics of each pixel in the beam image meet the requirements, thereby identifying whether the pixel belongs to the light spot region or the background region, thus generating a binarized image.

[0092] Morphological processing, such as dilation, erosion, opening and closing operations, is performed on the binarized beam image to remove large noise at the edges of the binarized image and smooth the edges of the light spot.

[0093] For the morphologically processed beam image, determine the center position of the light spot presented by each beam in the image. For example... Figure 10 As shown, the minimum bounding rectangle of each light spot profile is calculated, and the center coordinates of this rectangle are taken as the geometric center of the light spot, that is, the center position.

[0094] By fitting the center positions of all light spots, the corresponding contours are obtained, and the size of the corresponding contours is determined.

[0095] Based on the center points of each light spot, the overall contour is fitted to infer the current focal position. Although changes in the position of the collimating or focusing lens cause focal shift, or lens distortion due to high temperature causes focal shift, the contour of each light spot's image will change. The geometric center points of each light spot are relatively clear in the visual image and can be effectively observed. Extracting the center points of the light spots from the visual image is less affected by ambient light, focusing, and other interference factors than extracting the light spot contours.

[0096] In a visual image, the total contour size fitted from the center points of each light spot (e.g., the total ring contour of the ring light spot group generated by the ring light source group in the visual image) is valid data. Based on the contour size fitted from the center points of each light spot and the current set focus value, the actual focus position and focus offset can be inferred according to the mapping relationship, thereby enabling focus compensation. Figure 6 As shown, when the light source group is a ring, the diameter of the final ring is the outline size. Of course, the area can also be calculated from the diameter and used as the outline size.

[0097] Furthermore, in order to better analyze the spot imaging of the light source group, a light intensity sensor can be installed inside the laser cutting head, near the image acquisition area, to collect the intensity of scattered light inside the laser cutting head cavity in real time.

[0098] The intensity of scattered light within the laser cutting head cavity is collected by a light intensity sensor, and the corresponding binarization threshold is determined based on this intensity. A data model of processing status, scattered light intensity, and average image brightness is pre-established before the laser cutting head leaves the factory. This data model distinguishes between laser processing and non-processing states. By incorporating the scattered light intensity values ​​collected inside the laser cutting head, batch acquisition of beam image data from the light source group is performed to obtain image brightness values, thereby establishing the data model of processing status, scattered light intensity, and average image brightness.

[0099] At this point, using this data model, the average brightness value of the image can be obtained based on the scattered light intensity value. Generally speaking, the higher the scattered light intensity, the higher the average brightness of the image. Therefore, in the beam image before binarization processing, a binarization threshold needs to be set based on the average brightness of the image. When the average brightness of the image is high, the binarization threshold should retain as many pixels as possible as black, while when the brightness is low, it should retain as many pixels as possible as white, thereby achieving automatic adjustment of the image brightness.

[0100] like Figure 11 As shown in the illustration, this application also provides a focus offset compensation device for a laser cutting head, comprising:

[0101] At least one processor; and,

[0102] A memory communicatively connected to the at least one processor; wherein,

[0103] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform a focus offset compensation method for a laser cutting head, as described in any of the above embodiments.

[0104] This application also provides a non-volatile computer storage medium storing computer-executable instructions, characterized in that the computer-executable instructions are configured as: the focus offset compensation method for laser cutting heads described in any of the above embodiments.

[0105] The various embodiments in this application are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the device and medium embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the description of the method embodiments.

[0106] The devices and media provided in this application are one-to-one with the methods. Therefore, the devices and media also have similar beneficial technical effects as their corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the devices and media will not be repeated here.

[0107] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0108] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0109] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0110] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0111] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0112] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0113] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0114] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0115] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for compensating for focus offset in a laser cutting head, characterized in that, include: The light source group set inside the laser cutting head is controlled to emit a light beam, so that the light beam reaches a pre-set image acquisition area after passing through one or more semi-reflective mirrors; Acquire the beam image generated by the beam in the image acquisition area; The beam image is analyzed to obtain the outline size of the beam forming shape in the beam image; Based on the mapping relationship between the profile size, focus setting value, and actual focus position generated by pre-testing, the actual focus position in the current working state is obtained according to the profile size of the beam forming shape and the focus setting value in the current working state. Based on the difference between the current target focus position and the actual focus position, focus offset compensation is performed; Before controlling the light source assembly located inside the laser cutting head to emit a light beam, the method further includes: A light source group installed inside the laser cutting head is identified, the light source group containing multiple active light sources arranged according to a preset shape.

2. The method according to claim 1, characterized in that, The active light source and the processing laser source belong to different spectral bands, and the spectral band of the processing laser source is higher than that of the active light source; The semi-reflective mirror has a transmittance of processing laser higher than a first preset threshold and a reflectance of the active light source higher than a second preset threshold.

3. The method according to claim 1, characterized in that, The mapping relationship between the pre-tested generated outline size, focus setting value, and actual focus position includes: For a single focus setting, set the corresponding light emission duration and interval duration during periodic light emission; Laser processing tests are conducted by processing a laser light source and using the periodic light emission method until the test parameters stabilize. The test parameters include lens temperature, lens deformation degree, and focal offset. Get the actual focus position and outline size in the current state; After changing the interval duration, the laser processing test is repeated until the actual focus position and contour size corresponding to all focus offsets under the current single focus setting value are obtained, so as to generate the mapping relationship corresponding to the current single focus setting value. Change the focus setting value until all mappings are generated.

4. The method according to claim 3, characterized in that The mapping relationship is such that as the duration of light emission in the periodic light emission increases and the duration of the intermittent emission decreases, the focus offset increases.

5. The method according to claim 1, characterized in that, Based on the difference between the current target focus position and the actual focus position, focus offset compensation is performed, specifically including: Based on the processing parameters set by the user, obtain the target focus position in the current working process; The focus offset is obtained based on the difference between the target focus position and the actual focus position; The focus offset is used as the offset to be compensated. The focus setting value is updated according to the focus offset, and the updated focus setting value is used for focus offset compensation.

6. The method according to claim 1, characterized in that, Analyzing the beam image to obtain the outline size of the beam forming shape in the beam image specifically includes: The beam image is preprocessed, and the preprocessing includes at least image filtering. Based on the binarization threshold, the preprocessed beam image is binarized, and the binarized beam image is then subjected to morphological processing. For the morphologically processed beam image, determine the center position of the light spot presented by each beam in the image; By fitting the center positions of all light spots, the corresponding contours are obtained, and the contour size is determined.

7. The method according to claim 6, characterized in that, Before performing binarization processing on the preprocessed beam image based on a binarization threshold, the method further includes: The light intensity sensor installed inside the laser cutting head is identified; The intensity of scattered light inside the laser cutting head cavity is collected by the light intensity sensor, and the corresponding binarization threshold is determined by the intensity of the scattered light.

8. A focal offset compensation device for a laser cutting head, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform, for example, the focus offset compensation method for a laser cutting head as described in any one of claims 1 to 7.

9. A non-volatile computer storage medium storing computer-executable instructions, characterized in that, The computer-executable instructions are configured as follows: the focus offset compensation method for a laser cutting head as described in any one of claims 1 to 7.

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