Automatic light beam centering method and system based on laser cutting, laser cutting machine and storage medium

Abstract

The invention provides an automatic light beam centering method and system based on laser cutting, a laser cutting machine and a storage medium, and belongs to the technical field of laser cutting. The laser cutting head is controlled to move above the light source; turning on a light source, shooting a nozzle image, and analyzing the nozzle image to obtain the center and radius of the nozzle; executing a laser cutting process, acquiring a molten pool center position in real time, and monitoring a relative position of the molten pool center and a nozzle center; if the offset distance between the center of the molten pool and the center of the nozzle is larger than a preset offset threshold value, it is judged that the center of the nozzle is not centered and recorded in a storage, and a lens is controlled to move to achieve centering. Automatic centering can be achieved, the laser centering efficiency is improved, and errors caused by manual operation are reduced. And when deviation occurs, automatic adjustment and centering are performed in real time, so that the consistency of cutting quality is ensured, and the phenomena of dregs, burrs and the like of parts during cutting are effectively prevented.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser cutting, and in particular relates to a method and system for automatic centering of a light beam based on laser cutting, a laser cutting machine and a storage medium. Background Art

[0002] Laser cutting refers to the process of cutting by focusing the laser beam through the internal lens of the laser cutting head and projecting it from the nozzle of the laser cutting head to the surface of the material to produce a thermal effect. During the cutting process, in order to ensure the cutting quality, the laser should normally be located at the center of the nozzle, which is the centering in the field of laser cutting. If the laser deviates from the center of the nozzle, the service life of the nozzle will be reduced, and in severe cases, the nozzle will be burned, and problems such as slag and burrs will occur on the processed parts. Therefore, it is necessary to monitor the laser centering in real time during the cutting process and make timely adjustments if the laser is offset from the center of the nozzle.

[0003] In the prior art, adhesive tape is pasted on the surface of the nozzle, and low-power laser is used to spot-shoot the adhesive tape, and the position of the hole formed by spot-shooting in the nozzle is observed to determine whether the laser is centered. This method needs to be performed before cutting, and it is impossible to monitor the laser centering during the cutting process in real time, which affects the laser cutting quality and cutting accuracy. Summary of the invention

[0004] The present invention provides a method for automatic centering of a light beam based on laser cutting, which can ensure that the light beam in the laser cutting process is always kept in an optimal centering state, ensure that the laser is located at the center of a nozzle, thereby improving cutting accuracy and processing quality.

[0005] Methods include:

[0006] S101, before performing laser cutting, installing a nozzle and configuring nozzle information;

[0007] S102, controlling the laser cutting head to move above the light source, and lowering the laser cutting head to a preset height position from the light source;

[0008] S103, turning on the light source, photographing the nozzle image, analyzing the nozzle image, obtaining the center and radius of the nozzle, moving the laser cutting head above the plate, and preparing to perform the cutting operation;

[0009] S104, executing the laser cutting process, obtaining the center position of the molten pool in real time, and monitoring the relative position between the center of the molten pool and the center of the nozzle;

[0010] S105. If the offset distance between the center of the molten pool and the center of the nozzle is greater than a preset offset threshold, it is determined that the nozzle center is not centered, and the information is recorded in the memory, and a misalignment prompt message is issued.

[0011] It should be further explained that, in step S103, the nozzle image is analyzed in the following manner: image enhancement is performed on the nozzle image, and the brightness and contrast of the nozzle image are adjusted;

[0012] The nozzle image is converted into a grayscale image, and edge detection is performed on the grayscale image to obtain the nozzle edge contour information;

[0013] Circular curve fitting is performed based on the contour information to obtain the center and radius of the nozzle.

[0014] It should be further explained that, in the method, grayscale conversion is performed based on the HSV color space to segment the molten pool area, and the head position and tail position of the molten pool area are determined;

[0015] Get the center of the molten pool head position as the molten pool center.

[0016] It should be further explained that, in the method, a coordinate system is defined in the laser cutting area, and the coordinates of the center of the molten pool and the center of the nozzle are obtained based on the coordinate system;

[0017] Determine whether the coordinate values ​​(x, y) of the center of the molten pool are both greater than 0;

[0018] If both are greater than 0, it is judged that the offset distance between the center of the molten pool and the center of the nozzle is greater than the preset offset threshold.

[0019] It should be further explained that the offset distance between the center of the molten pool and the center of the nozzle is determined based on the following formula:

[0020]

[0021] Among them, A(x1,y1) represents the coordinates of the center of the molten pool, and B(x2,y2) represents the coordinates of the center of the nozzle.

[0022] It should be further explained that, in the method, the number of times the offset distance between the center of the molten pool and the center of the nozzle is greater than a preset offset threshold is recorded;

[0023] If the number is greater than or equal to the preset number, it is determined that the cutting position of the current laser cutting head is deviated, and a correction process is performed to adjust the nozzle center coordinate position so that the offset distance between the molten pool center and the nozzle center is within the preset offset threshold range.

[0024] It should be further explained that in the method, the average value of the center coordinate of the molten pool in the N laser misalignment records is calculated as the starting coordinate for adjusting the alignment. The calculation formula is:

[0025]

[0026] Among them, x avgIndicates the average x-axis coordinate of the center of the molten pool, y avg represents the average value of the y-axis coordinate of the center of the molten pool, x i ,y i Indicates the coordinates of the center of the molten pool in N laser misalignment records.

[0027] The present application also provides a beam automatic centering system based on laser cutting, the system comprising: a nozzle installation device, a laser head control module, a shooting analysis module, a position monitoring module, a centering judgment module and a memory;

[0028] A nozzle installation device, used to install a nozzle on the laser cutting machine and configure nozzle information before performing laser cutting;

[0029] The laser head control module is used to control the laser cutting head to move above the light source and to lower the laser cutting head to a preset height from the light source;

[0030] The shooting and analysis module is used to control the light source to turn on, and control the industrial camera to shoot the nozzle image, analyze the nozzle image, obtain the center and radius of the nozzle, move the laser cutting head above the plate, and prepare to perform the cutting operation;

[0031] The position monitoring module is used to execute the laser cutting process, obtain the center position of the molten pool in real time, and monitor the relative position between the center of the molten pool and the center of the nozzle;

[0032] The centering judgment module is used to judge that when the offset distance between the center of the molten pool and the center of the nozzle is greater than a preset offset threshold, it is determined that the nozzle center is not centered, and the information is recorded in the memory, and a misalignment prompt message is issued at the same time.

[0033] According to another embodiment of the present application, a laser cutting machine is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of an automatic beam centering method based on laser cutting when executing the program.

[0034] According to another embodiment of the present application, a storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the automatic beam centering method based on laser cutting are implemented.

[0035] It can be seen from the above technical solutions that the present invention has the following advantages:

[0036] The automatic beam centering method based on laser cutting involved in the present application obtains the center position of the molten pool in real time when executing the laser cutting process, and monitors the relative position of the molten pool center and the nozzle center. If the offset distance between the molten pool center and the nozzle center is greater than the preset offset threshold, it is judged that the nozzle center is not centered, and it is recorded in the memory, and a misalignment prompt message is issued. In this way, by monitoring the relative position of the molten pool center and the nozzle center in real time, and recording and prompting when the offset exceeds the preset threshold, it can ensure that the beam in the laser cutting process is always kept in the best centering state, and ensure that the laser is located at the center of the nozzle, thereby improving the cutting accuracy and processing quality.

[0037] The present application can timely detect and correct the deviation of the light beam, thus reducing the waste caused by inaccurate cutting, improving production efficiency and material utilization. It also reduces the need for manual intervention through automatic monitoring and adjustment, and improves the automation level of the production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0039] Figure 1 A flow chart of a beam automatic centering method based on laser cutting;

[0040] Figure 2 It is a schematic diagram of a ring-shaped LED light source;

[0041] Figure 3 This is an example of a nozzle image;

[0042] Figure 4 This is an example diagram of nozzle calibration;

[0043] Figure 5 It is a schematic diagram of the process of an embodiment of automatic centering of a light beam during laser cutting;

[0044] Figure 6 This is an example of a normal cutting melt pool image;

[0045] Figure 7 It is a schematic diagram of the molten pool image during the perforation process;

[0046] Figure 8 Schematic diagram of abnormal cutting melt pool image. DETAILED DESCRIPTION

[0047] The following describes in detail the steps of the automatic centering method for laser cutting provided by the present application. For the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are provided to facilitate a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application can also be implemented in other embodiments without these specific details.

[0048] In the automatic beam centering method based on laser cutting provided by the present application, when used in the specification, the term "include" indicates the existence of the described features, wholes, steps, operations, elements and / or components, but does not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. The terms "include", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0049] It should be understood that the "one or more" mentioned in this application refers to one, two or more than two, and the "multiple" mentioned in this application refers to two or more. In the description of this application, unless otherwise specified, " / " means or, for example, A / B can mean A or B. The "and / or" in this article is just a way to describe the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0050] The phrases such as "one embodiment" or "some embodiments" described in the present application mean that the specific features, structures or characteristics described in the embodiment are included in one or more embodiments of the present application. Therefore, the phrases such as "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments" etc. that appear in different places in the present application do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways.

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] See also Figure 1 The figure is a flow chart of a method for automatic centering of a beam based on laser cutting in a specific embodiment, the method comprising:

[0053] S101. Before performing laser cutting, install the nozzle and configure the nozzle information.

[0054] In some embodiments, according to the cutting process parameter requirements, a nozzle is installed on the laser cutting head of the laser cutting machine. The nozzle information is configured into the laser cutting machine. The nozzle information may include but is not limited to the nozzle model, the nozzle center and the radius.

[0055] S102, controlling the laser cutting head to move above the light source, and lowering the laser cutting head to a preset height position from the light source.

[0056] In some embodiments, the laser cutting head is precisely moved to the position directly above the light source by using the mechanical positioning system of the laser cutting machine. Then, according to the design parameters of the nozzle and the light source, the control system is used to set the laser cutting head to descend to a preset height position, which can ensure that the light source can illuminate the inside of the nozzle.

[0057] S103, turn on the light source, take a picture of the nozzle, analyze the nozzle image, obtain the center and radius of the nozzle, move the laser cutting head above the plate, and prepare to perform the cutting operation.

[0058] In this embodiment, the laser or light source can be turned on, and then the high-resolution camera can be turned on. The camera can take a clear image of the nozzle, ensuring that the image includes the entire outline of the nozzle.

[0059] Optionally, this embodiment uses an image processing algorithm to analyze the nozzle image and extract the center coordinates and radius of the nozzle. The image processing algorithm may use an edge detection algorithm or a Hough transform algorithm.

[0060] In the embodiment, the laser cutting head is controlled to move above the plate to be cut and adjusted to a suitable cutting height according to the nozzle position information obtained through analysis.

[0061] S104, executing the laser cutting process, obtaining the center position of the molten pool in real time, and monitoring the relative position between the center of the molten pool and the center of the nozzle.

[0062] According to the embodiment of the present application, the laser cutting process can be performed according to preset parameters such as cutting power, cutting speed, gas flow rate, etc. The center position of the molten pool formed during the cutting process is monitored in real time by a high-speed camera or an infrared sensor. The center position of the molten pool obtained in real time is compared with the center position of the nozzle obtained by analysis in step S103, and the relative offset between the center of the molten pool and the center of the nozzle is calculated.

[0063] S105. If the offset distance between the center of the molten pool and the center of the nozzle is greater than a preset offset threshold, it is determined that the nozzle center is not centered, and the information is recorded in the memory, and a misalignment prompt message is issued.

[0064] This embodiment compares the calculated offset distance with a preset offset threshold. If the offset distance is greater than the threshold, it is considered that the nozzle center is not centered and the position needs to be adjusted so that the offset distance between the molten pool center and the nozzle center is within the preset offset threshold.

[0065] This embodiment can also record the misalignment situation in the memory of the laser cutting machine for subsequent analysis and improvement. At the same time, the operator is prompted to check and adjust by display screen, sound alarm or other means.

[0066] In some specific embodiments, monitoring the relative position of the molten pool center and the nozzle center is an important step that affects the cutting quality. The relative position of the molten pool center and the nozzle center is within a preset range, which can ensure the cutting quality and stability. The following is a detailed method for specific monitoring:

[0067] This embodiment uses a high-speed camera to monitor the process of the molten pool center and the nozzle center in real time.

[0068] Specifically, cameras with high frame rates ranging from tens of thousands of fps to millions of fps and high resolution can be used to ensure that the rapidly changing state information of the molten pool can be clearly captured.

[0069] In this embodiment, the light source is turned on, the nozzle image is photographed, the nozzle image is analyzed, the center and radius of the nozzle are obtained, and the laser cutting head is moved above the plate to prepare for the cutting operation;

[0070] Optionally, a high-speed camera can be installed at an appropriate position of the laser cutting machine, usually near the nozzle and in an area where the molten pool can be clearly photographed. The camera lens maintains a certain angle and distance with the molten pool area to obtain the best imaging effect.

[0071] In this embodiment, a semi-transparent mirror or a beam splitter is arranged in the optical path of the laser beam, so that the reflected light signal of the molten pool area is transmitted back while the laser light source passes through, and the molten pool image is captured by a coaxially placed high-speed camera. This can reduce the image distortion caused by the shooting angle and position and improve the monitoring accuracy.

[0072] Optionally, a suitable filter type and wavelength range are selected according to the radiation characteristics of the molten pool.

[0073] This embodiment can continuously capture images of the molten pool area.

[0074] The collected nozzle images and melt pool images are preprocessed, including denoising, contrast enhancement, background subtraction, etc., to improve the image quality and highlight the center and radius of the nozzle and the melt pool characteristics.

[0075] In this embodiment, image processing algorithms such as edge detection, threshold segmentation, and morphological processing can be used to extract the center and radius of the nozzle and the molten pool characteristics.

[0076] According to the extracted coordinate positions of the molten pool center and the nozzle center, the relative position relationship between the two is calculated. Optionally, image processing software or a self-written algorithm can be used to implement the position calculation.

[0077] This embodiment can display the calculated offset in real time on the interface for operator monitoring. The interface can be designed as an intuitive chart or digital display. Of course, the monitoring data can also be sent to the user terminal based on the communication module.

[0078] In this embodiment, a deviation threshold value can be set according to the cutting process. When the deviation exceeds the threshold value, an alarm is automatically issued to prompt the operator to pay attention.

[0079] In this embodiment, according to the real-time monitored deviation, the operator can timely adjust the position of the nozzle or the parameters of the laser cutting to ensure that the center of the molten pool is aligned with the center of the nozzle circle. The nozzle can also be realigned by adjusting the position of the laser cutting head based on the automatic adjustment method to ensure that the center of the molten pool is aligned with the center of the nozzle circle.

[0080] The automatic beam centering method based on laser cutting provided in this embodiment obtains the center position of the molten pool in real time and monitors the relative position between the center of the molten pool and the center of the nozzle when executing the laser cutting process. If the offset distance between the center of the molten pool and the center of the nozzle is greater than the preset offset threshold, it is judged that the nozzle center is not centered, and it is recorded in the memory, and a misalignment prompt message is issued. In this way, during the laser cutting process, the laser alignment is monitored in real time, and the alignment adjustment is performed in real time in the case of laser offset to ensure that the laser is located at the center of the nozzle, thereby effectively improving the quality of laser cutting.

[0081] Furthermore, as a refinement and extension of the specific implementation of the above embodiment, in order to fully illustrate the specific implementation process in this embodiment, the automatic beam centering method based on laser cutting includes the following specific steps: before performing laser cutting, install the nozzle and configure the nozzle information.

[0082] S2001. Move the laser cutting head above the light source, and control the laser cutting head to descend to a distance of 2 cm to 3 cm above the light source.

[0083] Optionally, the light source is a ring-shaped LED light source, as shown in the attached Figure 2 As shown, it is fixed at the edge of the machine tool head and is used to illuminate the nozzle.

[0084] S2002, turn on the light source.

[0085] S2003, start the industrial camera, set the camera exposure to 100000μs, the gain to 10dB, and take a picture of the nozzle, as shown in the attached figure. Figure 3 shown.

[0086] S2004, performing image enhancement on the nozzle image, improving the image brightness and contrast, and converting the image into a grayscale image.

[0087] Perform edge detection on the grayscale image to obtain the nozzle edge contour, perform circular curve fitting on the nozzle edge contour to obtain the center and radius of the nozzle. The recognition results are shown in the attached figure. Figure 4 shown.

[0088] S2005. Turn off the light source and move the laser cutting head over the plate to prepare for cutting. The cutting can be batch cutting or individual cutting of the plate.

[0089] It should be noted that each time the nozzle is replaced, the nozzle needs to be recalibrated to determine the center coordinates and radius size of the new nozzle.

[0090] S2006. During the laser cutting process, the center of the molten pool is detected in real time, and the relative position of the molten pool relative to the center of the nozzle is monitored. When the offset distance between the center of the molten pool and the center of the nozzle is greater than a threshold, automatic centering is performed. The specific steps are as follows: Figure 5 shown.

[0091] S2007. Set the exposure of the industrial camera to 5000μs and the gain to 0db.

[0092] S2008, set cutting parameters and start cutting process.

[0093] S2009. During the cutting process, the molten pool image is acquired in real time, the normal cutting molten pool image is screened out, and the molten pool image during the perforation process and the abnormal cutting molten pool image are filtered out.

[0094] In this embodiment, the molten pool image is intercepted based on the nozzle center and radius, as shown in the attached figure. Figure 6 , Figure 7 as well as Figure 8 The molten pool area image shown is used to identify the normal cutting molten pool image, the molten pool image during the perforation process and the abnormal cutting molten pool image through the image classification algorithm.

[0095] Optionally, in order to meet real-time requirements, a lightweight mobilenet convolutional neural network, or a mobileone model, or a shufflenet model can be used to implement the image classification algorithm.

[0096] In this embodiment, for a normal cutting molten pool image, as shown in the attached Figure 6As shown in the figure, the accurate molten pool area can be segmented based on the HSV color space extraction, grayscale conversion, and contour extraction operations. Then, the head and tail positions of the molten pool are determined, and the center of the molten pool head is obtained, thereby obtaining the coordinates of the molten pool center. For the molten pool image during the perforation process, as shown in the attached figure, Figure 7 As shown in the figure, and the abnormal cutting molten pool image, as shown in the attached Figure 8 As shown, no processing is performed and this step continues.

[0097] In some embodiments, the molten pool region is extracted based on the HSV color space, grayscale conversion is performed, and contour extraction operations are performed to segment the precise molten pool region, and the head position and tail position of the molten pool are determined, and the center of the head position of the molten pool is obtained, thereby obtaining the coordinates of the center of the molten pool. The following is an exemplary description of the process of extracting the molten pool region based on the HSV color space.

[0098] The HSV color space involved in this embodiment consists of three components: hue (Hue, H), saturation (Saturation, S) and brightness (Value, V). Compared with the RGB color space, HSV more intuitively reflects the essential attributes of color and facilitates color segmentation.

[0099] This embodiment converts the melt pool image from the RGB color space to the HSV color space. In the HSV space, appropriate threshold ranges of hue (H), saturation (S), and brightness (V) can be set according to the color characteristics of the melt pool in the melt pool image (such as red, orange, etc.). Use these threshold ranges to create a mask in the HSV image, and the mask only contains pixels that meet the conditions.

[0100] The mask is applied to the original melt pool image and the melt pool area is extracted through bitwise operation.

[0101] The grayscale conversion in this embodiment can be achieved by a weighted average method.

[0102] Optionally, a grayscale conversion formula is: Gray=0.3R+0.6G+0.116B.

[0103] This embodiment can also use the findContours contour detection function in OpenCV in the image processing library to extract the contour on the binary image of the molten pool area. After the contour is extracted, the boundary information of the molten pool area can be obtained.

[0104] This embodiment pre-processes the contour through morphological operations to more accurately identify the head position and the tail position of the molten pool.

[0105] The head position and tail position of the molten pool are determined based on the aspect ratio, area, convex hull shape characteristics and position information of the molten pool. The head position and tail position can be determined based on the geometric characteristics of the contour.

[0106] To obtain the center coordinates of the molten pool head, the outline of the molten pool head can be determined first, and its center of gravity can be obtained by calculating the weighted average position of all pixel points within the outline. The center of gravity coordinates are the center coordinates of the molten pool head, which is also an approximate value of the center coordinates of the entire molten pool.

[0107] S2010. Determine whether the coordinate values ​​(x, y) of the center of the molten pool are both greater than 0. If they are both greater than 0, execute step S2011; otherwise, continue to execute step S2009.

[0108] S2011. Calculate the offset distance between the center of the molten pool and the center of the nozzle. The distance formula is:

[0109]

[0110] Among them, A(x1,y1) represents the coordinates of the center of the molten pool, and B(x2,y2) represents the coordinates of the center of the nozzle.

[0111] S2012. If the offset distance between the center of the molten pool and the center of the nozzle is greater than a threshold, it is determined that the laser is not centered and is recorded in the memory.

[0112] As an embodiment of the present application, the offset distance threshold can be set according to the cutting requirements and cutting accuracy, etc. Within the threshold range, even if the laser has a certain degree of offset, there will be no cutting quality problems.

[0113] The contents recorded in the memory include the coordinates of the center of the molten pool and the offset distance between the center of the molten pool and the center of the nozzle.

[0114] During the cutting process, if the offset distance is greater than the threshold once, it may not affect the cutting quality. If the offset distance is greater than the threshold once or multiple times, it will only be recorded and the adjustment process will not be performed.

[0115] In this embodiment, a preset number of laser misalignments can be set to be recorded. If the preset number of misalignments is reached, it is considered to have an impact on the cutting quality, and an adjustment process needs to be performed to ensure that the offset distance between the center of the molten pool and the center of the nozzle is within a threshold range.

[0116] For example, the preset number of misalignment can be set to 6 times. When it is greater than 6 times, it is confirmed that there is indeed a laser misalignment phenomenon and a centering operation needs to be performed.

[0117] S2013. Calculate the average value of the center coordinate of the molten pool in the six laser misalignment records as the starting coordinate for adjusting the alignment. The calculation formula is:

[0118]

[0119] Among them, x avg Indicates the average x-axis coordinate of the center of the molten pool, y avg represents the average value of the y-axis coordinate of the center of the molten pool, x i ,y i (i=1, 2, 3, 4, 5, 6) represents the coordinates of the center of the molten pool in the six laser misalignment records. The coordinates of the end point of the adjustment are the coordinates of the center of the nozzle.

[0120] S2014, adjusting the moving position of the lens inside the laser cutting head by controlling the centering device inside the laser cutting head, and moving the laser beam from the starting coordinate to the nozzle center coordinate so that the laser is located at the nozzle center, and clearing the laser misalignment record stored in the memory.

[0121] It should be noted that during the adjustment of the laser beam, the laser cutting head does not need to be stopped and the operator does not need to be involved, and the laser cutting head performs the cutting task normally.

[0122] In this embodiment, the operator can reasonably set the number of laser misalignment records according to the cutting system, laser cutting head model, cutting quality requirements, etc.

[0123] S2015. If the offset distance between the center of the molten pool and the center of the nozzle is less than the threshold, clear the laser misalignment record in the memory and execute step S2009.

[0124] During the batch cutting process, steps S2009 to S2015 are continuously executed until the cutting is completed.

[0125] The entire cutting process does not require operator intervention. The method of the present invention is used to monitor the laser centering status during cutting, and automatically adjust the laser beam when the offset distance is exceeded to make it located at the center of the nozzle.

[0126] The automatic beam centering method based on laser cutting provided in this embodiment obtains the center position of the molten pool in real time and monitors the relative position between the center of the molten pool and the center of the nozzle when executing the laser cutting process. If the offset distance between the center of the molten pool and the center of the nozzle is greater than the preset offset threshold, it is judged that the nozzle center is not centered, and it is recorded in the memory, and a misalignment prompt message is issued. In this way, during the laser cutting process, the laser alignment is monitored in real time, and the alignment adjustment is performed in real time in the case of laser offset to ensure that the laser is located at the center of the nozzle, thereby effectively improving the quality of laser cutting.

[0127] The following is an embodiment of the automatic beam centering system based on laser cutting provided in the embodiments of the present disclosure. The system and the automatic beam centering method based on laser cutting in the above-mentioned embodiments belong to the same inventive concept. For details not described in detail in the embodiment of the automatic beam centering system based on laser cutting, please refer to the embodiment of the automatic beam centering method based on laser cutting.

[0128] The system includes: a nozzle installation device, a laser head control module, a shooting analysis module, a position monitoring module, a centering judgment module and a memory;

[0129] The nozzle installation device is used to install the nozzle to the laser cutting machine and configure the nozzle information before performing laser cutting.

[0130] The laser head control module is used to control the laser cutting head to move above the light source and to lower the laser cutting head to a preset height position from the light source.

[0131] The shooting and analysis module is used to control the light source to turn on, and control the industrial camera to shoot the nozzle image, analyze the nozzle image, obtain the center and radius of the nozzle, move the laser cutting head above the plate, and prepare to perform the cutting operation.

[0132] The position monitoring module is used to execute the laser cutting process, obtain the center position of the molten pool in real time, and monitor the relative position between the center of the molten pool and the center of the nozzle.

[0133] The centering judgment module is used to judge that when the offset distance between the center of the molten pool and the center of the nozzle is greater than a preset offset threshold, it is determined that the nozzle center is not centered, and the information is recorded in the memory, and a misalignment prompt message is issued at the same time.

[0134] The automatic beam centering method based on laser cutting involved in the present application can also be applied to a specific laser cutting machine.

[0135] The laser cutting machine may include a processor, a memory interface, a memory, a universal serial bus interface, a wireless communication module, an audio module, a speaker, a sensor, a button, a display screen, etc.

[0136] The processor may include one or more processing units, for example, the processor may include a central processing unit (CPU), an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), etc. Different processing units may be independent devices or integrated into one or more processors.

[0137] The processor can be the nerve center and command center of the laser cutting machine. The controller can generate operation control signals according to the instruction operation code and timing signal to complete the control of fetching and executing instructions.

[0138] The memory can be used to store computer executable program codes, which include instructions. The processor executes various functional applications and data processing of the laser cutting machine by running the instructions stored in the internal memory.

[0139] The automatic beam centering method based on laser cutting involved in the present application is a combination of the units and algorithm steps of each example described in the embodiments disclosed herein, which can be implemented by electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0140] The steps of the automatic centering method of the laser beam based on laser cutting can also be stored in a storage medium. In some possible implementations, various aspects of the present disclosure can also be implemented in the form of a program product, which includes a program code. When the program product is run on a terminal device, the program code is used to enable the terminal device to execute the steps according to various exemplary implementations of the present disclosure described in the above "Exemplary Method" section of this specification.

[0141] The storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0142] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for automatic beam centering based on laser cutting, characterized in that: Methods include: S101, before performing laser cutting, installing a nozzle and configuring nozzle information; S102, controlling the laser cutting head to move above the light source, and lowering the laser cutting head to a preset height position from the light source; S103, turning on the light source, photographing the nozzle image, analyzing the nozzle image, obtaining the center and radius of the nozzle, moving the laser cutting head above the plate, and preparing to perform the cutting operation; S104, executing the laser cutting process, obtaining the center position of the molten pool in real time, and monitoring the relative position between the center of the molten pool and the center of the nozzle; S105. If the offset distance between the center of the molten pool and the center of the nozzle is greater than a preset offset threshold, it is determined that the nozzle center is not centered, and the information is recorded in the memory, and a misalignment prompt message is issued.

2. The method for automatic beam centering based on laser cutting according to claim 1, characterized in that: In step S103, the nozzle image is analyzed in a manner including: performing image enhancement on the nozzle image and adjusting the brightness and contrast of the nozzle image; The nozzle image is converted into a grayscale image, and edge detection is performed on the grayscale image to obtain the nozzle edge contour information; Circular curve fitting is performed based on the contour information to obtain the center and radius of the nozzle.

3. The method for automatic beam centering based on laser cutting according to claim 1, characterized in that: In the method, grayscale conversion is performed based on the HSV color space to segment the molten pool area, and the head position and tail position of the molten pool area are determined; Get the center of the molten pool head position as the molten pool center.

4. The automatic beam centering method based on laser cutting according to claim 3 is characterized in that: In the method, a coordinate system is defined in the laser cutting area, and the coordinates of the center of the molten pool and the center of the nozzle are obtained based on the coordinate system; Determine whether the coordinate values ​​(x, y) of the center of the molten pool are both greater than 0; If both are greater than 0, it is judged that the offset distance between the center of the molten pool and the center of the nozzle is greater than the preset offset threshold.

5. The method for automatic beam centering based on laser cutting according to claim 4, characterized in that: Based on the following formula, the offset distance between the center of the molten pool and the center of the nozzle is determined: Among them, A(x1,y1) represents the coordinates of the center of the molten pool, and B(x2,y2) represents the coordinates of the center of the nozzle.

6. The method for automatic beam centering based on laser cutting according to claim 4, characterized in that: In the method, the number of times the offset distance between the center of the molten pool and the center of the nozzle is greater than a preset offset threshold is recorded; If the number is greater than or equal to the preset number, it is determined that the cutting position of the current laser cutting head is deviated, and a correction process is performed to adjust the nozzle center coordinate position so that the offset distance between the molten pool center and the nozzle center is within the preset offset threshold range.

7. The method for automatic beam centering based on laser cutting according to claim 4, characterized in that: In the method, the average coordinate of the center of the molten pool in the N laser misalignment records is calculated as the starting coordinate for adjusting the alignment. The calculation formula is: Among them, x avg Indicates the average x-axis coordinate of the center of the molten pool, y avg represents the average value of the y-axis coordinate of the center of the molten pool, x i ,y i Indicates the coordinates of the center of the molten pool in N laser misalignment records.

8. A beam automatic centering system based on laser cutting, characterized in that: The system is used to implement the automatic beam centering method based on laser cutting as described in any one of claims 1 to 7; The system includes: a nozzle installation device, a laser head control module, a shooting analysis module, a position monitoring module, a centering judgment module and a memory; A nozzle installation device, used to install a nozzle on the laser cutting machine and configure nozzle information before performing laser cutting; The laser head control module is used to control the laser cutting head to move above the light source and to lower the laser cutting head to a preset height from the light source; The shooting and analysis module is used to control the light source to turn on, and control the industrial camera to shoot the nozzle image, analyze the nozzle image, obtain the center and radius of the nozzle, move the laser cutting head above the plate, and prepare to perform the cutting operation; The position monitoring module is used to execute the laser cutting process, obtain the center position of the molten pool in real time, and monitor the relative position between the center of the molten pool and the center of the nozzle; The centering judgment module is used to judge that when the offset distance between the center of the molten pool and the center of the nozzle is greater than a preset offset threshold, it is determined that the nozzle center is not centered, and the information is recorded in the memory, and a misalignment prompt message is issued at the same time.

9. A laser cutting machine, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the automatic beam centering method based on laser cutting as described in any one of claims 1 to 7 are implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the automatic beam centering method based on laser cutting according to any one of claims 1 to 7 are implemented.

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