WO2020147639A1 - Method for real-time tracking and detection of weld bead trajectory and attitude, electronic device and medium - Google Patents

Abstract

A method for real-time tracking and detection of a weld bead trajectory and attitude, comprising: using a uniform diffusion light source (7) and a multi-line laser light source (5) to synchronously irradiate a region in the periphery of a fine-porous groove (81) of the surface of a workpiece to be welded (8), and obtaining an original image with appropriate gray level by adjusting the exposure time of an imaging member (4); determining two thresholds by calculating and analyzing a gray level frequency histogram of the original image; performing binaryzation on the original image by using the two thresholds respectively, and extracting a groove region and a laser projection region; calculating the three-dimensional position of the center of the groove and a normal vector of the surface of said workpiece based on the groove region and the laser projection region. According to the method, the surface of the workpiece is synchronously irradiated with dual light sources to obtain an image with unsaturated gray level. The method is applicable to special occasions of high-speed welding, long-distance detecting and the like, the speed of an image processing method is fast, and the demands of welding real-time tracking can be met. Also provided are an electronic device and a non-transient computer readable storage medium.

Description

Real-time tracking detection method for welding bead trajectory and posture, electronic equipment and medium

cross reference

This application refers to the Chinese patent application No. 2019100373796 with the patent titled "Real-time tracking and detecting method for welding bead trajectory and posture, electronic equipment and medium" filed on January 15, 2019, which is fully incorporated into this application by reference.

Technical field

The embodiments of the present application relate to the field of welding automation, and more specifically, to a method for real-time tracking and detection of weld bead trajectory and posture, electronic equipment, and media.

Background technique

In the field of welding, automatic welding seam detection is of great significance for automatic teaching before welding and automatic tracking during welding. Visual inspection has become an important method of automatic welding seam detection because it can provide a wealth of information about welds.

At present, the structured light method is commonly used in weld inspection. This method projects structured light onto the groove, and obtains the position information of the groove through the deformation of the structured light. However, when the groove gap is extremely small, the deformation of the structured light in the image is difficult to distinguish, and This method can only detect the three-dimensional coordinates of the groove, and it is difficult to detect the posture of the workpiece surface, so the welding gun cannot be guided to adjust the posture during the welding process.

Chinese Patent Literature (Publication No. CN103954216A) discloses a device and method for detecting narrow bevels of a strongly specularly reflective workpiece based on a spherical light source. The sensor alternately lights and projects a laser array and a spherical light source on the surface of the workpiece and synchronizes with an imaging element. Shoot images when different light sources are lit, obtain the pose of the workpiece surface near the projection point of the laser array through the images when the laser array is lit, and obtain the two-dimensional information of the groove through the image with uniform brightness when the spherical light source is lit. The two are combined to determine the three-dimensional pose of the groove. However, this method has two shortcomings: First, there is a time difference between the image lit by the laser array and the image lit by the spherical light source collected by the imaging element. The detection caused by the time difference during high-speed welding or when the surface pose of the workpiece to be welded changes drastically The error is obvious; second, this method requires that the image grayscale when the spherical light source is lit is close to saturation, so as to quickly and accurately extract the center position of the groove. In the application of groove real-time tracking, the detection device is often fixedly connected to the welding torch. In some occasions where long-distance welding is required, such as laser welding in some occasions, the welding torch is difficult to approach the workpiece. In order to make the image gray scale close to saturation, a more powerful spherical light source is required. The larger the power of the light source, the larger the volume will usually be. The larger the size, the larger the volume of the detection device.

Summary of the invention

The embodiments of the present application provide a real-time tracking detection method, electronic equipment and medium for the trajectory and posture of the weld bead, so as to solve the existing technology that is difficult to adapt to high-speed welding, long-distance detection and other occasions when real-time detection of small gap grooves exists in the prior art. The problem.

In the first aspect, the embodiments of the present application provide a method for real-time tracking and detection of weld bead trajectory and posture, including:

Use uniform diffuse light source and multi-line laser light source to simultaneously illuminate the area near the surface of the workpiece to be welded with the grooves, and obtain the original image with appropriate gray scale by adjusting the exposure time of the imaging element;

Calculating and analyzing the gray frequency histogram of the original image, and determining the first threshold for extracting the groove area and the second threshold for extracting the laser projection area;

Binarize the original image by using the first threshold and the second threshold respectively, and perform morphological operations on the original image after the binarization process and the preservation of connected domains to obtain the groove area and laser projection area;

Based on the groove area and the laser projection area, the three-dimensional position of the groove center and the normal vector of the surface of the workpiece to be welded are calculated.

In the second aspect, an embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor. The processor executes the program as described in the first aspect. Provides the steps of the real-time tracking detection method of the weld bead trajectory and attitude.

In the third aspect, the embodiments of the present application provide a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, real-time tracking of the weld bead trajectory and posture provided in the first aspect is realized Steps of the detection method.

The real-time tracking detection method, electronic equipment and medium of weld bead trajectory and posture provided by the embodiments of this application can be applied to high-speed welding and long-distance detection of fine groove grooves, and broaden the application scenarios of the method of fine groove groove detection. And the image processing method is fast, which can meet the requirements of welding real-time tracking.

BRIEF DESCRIPTION

In order to more clearly describe the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description These are some embodiments of the application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

FIG. 1 is a schematic diagram of the structural principle of a detection device adopting the detection method proposed in an embodiment of the present application;

Figure 2 is a schematic diagram of a multi-line laser light source projected on the surface of the workpiece to be welded;

FIG. 3 is a schematic flow diagram of a method for real-time tracking and detection of weld bead trajectory and posture provided by an embodiment of the application;

Figure 4 is a schematic diagram of an original image collected by an imaging element;

Figure 5 is a gray frequency histogram of the original image collected by the imaging element.

6 is a schematic diagram of the physical structure of an electronic device provided by an embodiment of the application;

Description of reference signs: 1-control unit; 2-welding gun; 3-sensor housing; 4-imaging element; 5-multi-line laser light source; 6-filter element; 7-uniform diffusion light source; 8-workpiece to be welded; 81- bevel.

detailed description

To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of this application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

Fig. 1 is a schematic diagram of the structure and principle of a detection device for real-time tracking and detecting of weld bead trajectory and posture provided by an embodiment of the present application, including: a control unit 1, a sensor housing 3, and an imaging element 4 fixed in the sensor housing 3, and a filter Element 6, multi-line laser light source 5, and uniform diffusion light source 7. Among them, the control unit 1 and the imaging element 4 are connected by a control line; the multi-line laser light source 5 can emit at least two laser lines to project on the surface of the workpiece 8 to be welded, as shown in FIG. Schematic diagram on the surface of the welding workpiece; the uniformly diffused light source 7 can emit diffused light with uniform brightness to project on the surface of the workpiece to be welded 8; the reflected light from the surface of the workpiece to be welded 8 passes through the filter element 6 and enters the imaging element 4 for imaging.

During the welding process, the welding torch needs to be aligned with the welding bead, and at the same time, the welding torch needs to maintain a certain attitude relationship with the surface of the workpiece to be welded (for example, the torch axis should be perpendicular to the surface of the workpiece) to ensure welding quality. Therefore, the welding trajectory and attitude are tracked in real time The goal of detection is to track and detect the three-dimensional position of the groove center and the normal vector of the workpiece surface in real time. The three-dimensional position of the groove center and the normal vector information of the workpiece surface can provide a reference for the adjustment of the welding gun pose and welding process parameters during the welding process.

Fig. 3 is a schematic flow chart of a method for real-time tracking and detecting weld bead trajectory and posture provided by an embodiment of the present application, including:

Step 100: Use a uniform diffused light source and a multi-line laser light source to simultaneously illuminate the area near the crevice groove on the surface of the workpiece to be welded, and obtain an original image with a suitable gray scale by adjusting the exposure time of the imaging element;

The fine gap groove on the surface of the workpiece to be welded refers to the groove with a very small gap, generally not exceeding 0.1mm.

The embodiment of the application uses a uniform diffused light source and a multi-line laser light source to simultaneously irradiate the area near the fine groove on the surface of the workpiece to be welded, so that the three-dimensional position of the groove and the normal vector of the workpiece surface can be calculated according to the same frame of image, which avoids the existing The method uses the detection error caused by the time difference when the two frames of images are calculated, and the grayscale of the image does not have to be close to saturation, which reduces the requirement for uniform diffused light source illumination brightness.

Adjust the exposure time of the imaging element to obtain an original image with a suitable gray scale, where the gray scale refers to that the gray scale of the image obtained by the imaging element meets the preset gray scale range.

Specifically, the multi-line laser light source 5 and the uniformly diffused light source 7 are simultaneously lit to illuminate the area near the groove 81 on the surface of the workpiece 8 to be welded, and the control unit 1 controls the imaging element 4 to take the original image I of the area, as shown in FIG. 4 In the figure, a represents the groove, b represents the two laser lines, and the small squares and ellipses in the figure show the traces of the workpiece surface. After that, the control unit 1 calculates the average gray level _{rave of the} original image I, if _rave ∈[r _min ,r _max ], then enters the next step, otherwise the control unit 1 adjusts the exposure time of the imaging element 4 to obtain the original image I again, until r _ave ∈[r _min ,r _max ], where [r _min ,r _max ] is a preset gray scale range, here is to make the surface of the workpiece 8 to be welded in the original image I have a moderate gray scale for subsequent follow-up In the step, the groove area and the laser projection area are extracted. For example, when the average gray level of the original image I is 128, it can be considered that the gray level of the original image is moderate.

In order to achieve real-time tracking and detection of the weld bead trajectory and posture, before step 100, a three-dimensional rectangular coordinate system {C} of the imaging element is established, where the origin of {C} is the optical center of the imaging element 4, {C} The z-axis direction is the same as the optical axis direction of the imaging element 4; a two-dimensional pixel coordinate system {P} is established on the image collected by the imaging element 4;

Calibrate the imaging element 4 to obtain the conversion relationship between corresponding points between the three-dimensional rectangular coordinate system {C} of the imaging element and the two-dimensional coordinate system {P} of the pixel;

The multi-line laser light source 5 is calibrated to obtain the equation of each light plane of the multi-line laser light source in the three-dimensional rectangular coordinate system {C} of the imaging element.

Step 200: Calculate and analyze the gray frequency histogram of the original image, and determine a first threshold for extracting the groove area and a second threshold for extracting the laser projection area;

After obtaining the original image I whose average gray level meets the requirements, calculate its gray frequency histogram p(r).

The determination of the first threshold for extracting the groove area and the second threshold for extracting the laser projection area by analyzing the gray frequency histogram of the original image specifically includes:

Calculate the first threshold t _low used to extract the groove area according to the following formula:

t _low =max r,

s,t.

Among them, r is the gray value in the gray frequency histogram, p(i) is the frequency of the gray value i, and a is a preset value, 0<a<1.

Since the gray level of the laser line in the original image I is much higher than other areas, there will be a peak in the high gray area in the gray frequency histogram. As shown in Figure 5, the gray value corresponding to the trough in front of the peak can be taken as Threshold to extract the laser projection area.

Specifically, the gray frequency histogram p(r) is smoothed first to remove random fluctuations in it, and after the smoothed gray frequency histogram p _s (r) is obtained, the maximum gray scale in p _s (r) is found A minimum point of, and the gray level corresponding to the minimum point is used as the second threshold t _high for extracting the laser projection area.

It should be noted that since the groove 81 may be relatively narrow, there may be no valleys in the low grayscale area of the gray frequency histogram, so a similar method cannot be used to determine the threshold t _low for extracting the groove area.

Gaussian filtering method or average filtering method may be used to smooth the gray frequency histogram.

Step 300: Binarize the original image by using the first threshold and the second threshold respectively, and perform a morphological operation on the original image after the binarization process and the preservation of connected domains to obtain a groove area And laser projection area;

Specifically, the original image is binarized by using the first threshold and the second threshold respectively, two binarized images can be obtained, and the binarized image obtained by the binarization operation using the first threshold is performed The morphology and the connected domain are retained to obtain the groove area; the morphology and the connected domain are retained on the binarized image obtained by the binarization operation using the second threshold to obtain the laser projection area.

Step 300 includes the following steps:

Using the first threshold t _low to perform binarization processing on the original image I, and keep the points in the original image I whose grayscale is less than or equal to the first threshold t _low to obtain the first binarized image I _low ;

Due to noise or the like, a first binarized image I _low in the groove region may be slight gaps and holes, so the first binarized image I _low morphological closing operation once, so that the gaps and holes which are closed.

Because there may be some low-reflection areas on the surface of the workpiece 8 to be welded, as shown in Figure 4, the gray level in the original image I is low, and it is retained in the middle after the binarization process, and these low-reflection areas are generally small or The shape is not as slender as the groove 81, so the connected domain is extracted again, and the connected domain with large enough area and slender shape is retained.

That is, the connected domains whose area and roundness ratio meet the first preset condition are reserved, and the first preset condition is specifically:

Among them, A represents the area of the connected component, A _min1 represents the preset first area threshold of the connected component, R _c represents the roundness rate of the connected _component , and R _cmax1 represents the preset first roundness threshold of the connected component ；

Among them, the roundness rate R _{c of the} connected domain is defined as:

Among them, P represents the perimeter of the connected domain.

The connected domain remaining in the first binarized image I _low is used as the groove area, and the coordinates of the groove center in the pixel two-dimensional coordinate system {P} are obtained based on the groove area.

The specific steps of obtaining the coordinates of the groove center in the pixel two-dimensional coordinate system may be: taking the middle column in the first binarized image I _low , and finding the two intersection points between this column and the remaining connected domains, The midpoint of the two intersections is regarded as the center of the groove, and the coordinates of the intersection are obtained, that is, the coordinates of the center of the groove in the pixel two-dimensional coordinate system {P} are obtained. If the connected domain is discontinuous, after the connected domain is fitted with a straight line, the middle column of the first binarized image I _{low is} taken, and the intersection of this column and the fitted connected domain is regarded as the center of the groove, and then Get the coordinates of the groove center in the pixel two-dimensional coordinate system {P}.

Perform binarization processing on the original image I by using the second threshold value t _high , and keep the points in the original image I whose grayscale is greater than or equal to the second threshold value t _high to obtain a second binarized image I _high ;

Due to laser speckle and other reasons, there are a large number of tiny low-gray areas in the laser projection area of the original image I, which become tiny gaps and holes after binarization. Therefore, a morphological closing operation is performed on I _high to eliminate the laser projection area. Tiny gaps and holes.

Since there may be some high-reflection areas on the surface of the workpiece 8 to be welded, the gray level is higher in the original image I, and is retained in I _high after the binarization process, and these high-reflection areas are generally small in area or not shaped like a laser The projection area is the same slender, so the connected domain is extracted again, and the connected domain with large enough area and long enough shape is reserved.

That is, the connected domains whose area and roundness ratio meet the second preset condition are reserved, and the second preset condition is specifically:

Among them, A represents the area of the connected component, A _min2 represents the preset second area threshold of the connected component, R _c represents the roundness rate of the connected _component , and R _cmax2 represents the preset second roundness threshold of the connected component . R _{c is} defined as described above.

The connected domain remaining in the second binary image I _high is taken as the laser projection area, where the laser projection area refers to the surface area of the workpiece where the multi-line laser projection is located.

Obtain the coordinates of a series of points on the laser projection line in the pixel two-dimensional coordinate system {P} based on the laser projection area.

Step 400: Based on the groove area and the laser projection area, calculate and obtain the three-dimensional position of the groove center and the normal vector of the surface of the workpiece to be welded.

Specifically, according to the coordinates of a series of points on the laser projection line obtained in step 300 in the pixel two-dimensional coordinate system {P}, combined with the three-dimensional rectangular coordinate system {C} of the imaging element obtained by the previous calibration and the pixel The conversion relationship of the corresponding points between the two-dimensional coordinate systems {P} and the equations of each light plane of the multi-line laser light source in the three-dimensional rectangular coordinate system {C} of the imaging element, calculate a series of the laser projection lines The coordinates of the point in the three-dimensional rectangular coordinate system {C} of the imaging element;

The surface area of the workpiece 8 where multiple laser projection lines are located is regarded as a plane W, and based on the coordinates of a series of points on the laser projection line in the three-dimensional rectangular coordinate system {C} of the imaging element, the The equation of the workpiece plane W where the multi-line laser projection is located in the three-dimensional rectangular coordinate system {C} of the imaging element.

The fitting method can adopt the least square method.

And calculate and obtain the normal vector of the workpiece plane W according to the equation.

According to the coordinates of the groove center in the pixel two-dimensional coordinate system {P}, the equation of the workpiece plane W where the multi-line laser projection is located in the imaging element three-dimensional rectangular coordinate system {C}, the The conversion relationship of corresponding points between the imaging element three-dimensional rectangular coordinate system {C} and the pixel two-dimensional coordinate system {P} is calculated to obtain the coordinates of the groove center in the three-dimensional rectangular coordinate system {C}.

According to the three-dimensional position of the groove center and the normal vector of the workpiece surface, it can provide a reference for the adjustment of the welding gun's pose and welding process parameters during the welding process.

The real-time tracking detection method for the trajectory and posture of the weld bead provided by the embodiments of the application detects the three-dimensional coordinates of the groove and the posture of the workpiece surface, which can be applied to high-speed welding of fine groove grooves, long-distance detection and other occasions, and widens the fine gap The application scenarios of the groove detection method and the fast image processing method can meet the requirements of welding real-time tracking.

FIG. 6 is a schematic diagram of the physical structure of an electronic device provided by an embodiment of the application. As shown in FIG. 6, the electronic device may include: a processor 610, a communication interface 620, a memory (memory) 630, and communication The bus 640, wherein the processor 610, the communication interface 620, and the memory 630 communicate with each other through the communication bus 640. The processor 610 can call a computer program stored on the memory 630 and running on the processor 610 to execute the real-time tracking and detection method of the weld bead trajectory and posture provided by the foregoing method embodiments, for example, including: using a uniformly diffused light source Simultaneously irradiate the area near the gap groove on the surface of the workpiece to be welded with the multi-line laser light source, and obtain the original image with appropriate gray scale by adjusting the exposure time of the imaging element; calculate and analyze the gray frequency histogram of the original image to determine the The first threshold for extracting the groove area and the second threshold for extracting the laser projection area; the first threshold and the second threshold are used to binarize the original image, and the binarized The original image is subjected to morphological operations and connected domains to obtain the groove area and the laser projection area; based on the groove area and the laser projection area, the three-dimensional position of the groove center and the surface of the workpiece to be welded are calculated and obtained Normal vector.

In addition, the aforementioned logic instructions in the memory 630 can be implemented in the form of software functional units and when sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application essentially or contribute to the existing technology or parts of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium. A number of instructions are included to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program code .

The embodiments of the present application also provide a non-transitory computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the method for real-time tracking and detection of weld bead trajectory and posture provided by the foregoing method embodiments is implemented. For example, it includes: using a uniform diffuse light source and a multi-line laser light source to simultaneously illuminate the area near the crevice groove on the surface of the workpiece to be welded, and adjusting the exposure time of the imaging element to obtain an original image with a suitable gray level; calculating and analyzing the original image Gray frequency histogram, determining the first threshold for extracting the groove area and the second threshold for extracting the laser projection area; using the first threshold and the second threshold to binarize the original image, Morphological operations and the preservation of connected domains are performed on the original image after the binarization process to obtain the groove area and the laser projection area; based on the groove area and the laser projection area, the three-dimensional position of the groove center is calculated And the normal vector of the surface of the workpiece to be welded.

The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in One place, or it can be distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement without creative work.

Through the description of the above implementation manners, those skilled in the art can clearly understand that each implementation manner can be implemented by software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions can be embodied in the form of software products in essence or part of the contribution to the existing technology, and the computer software products can be stored in computer-readable storage media, such as ROM/RAM, magnetic Discs, optical discs, etc., include several instructions to enable a computer device (which may be a personal computer, server, or network device, etc.) to perform the methods described in the various embodiments or some parts of the embodiments.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the application, not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: The technical solutions recorded in the foregoing embodiments are modified, or some of the technical features are equivalently replaced; these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims (10)

1. A real-time tracking and detecting method for weld bead trajectory and posture, which is characterized in that it comprises:

   Use uniform diffuse light source and multi-line laser light source to simultaneously illuminate the area near the surface of the workpiece to be welded with the grooves, and obtain the original image with appropriate gray scale by adjusting the exposure time of the imaging element;

   Calculating and analyzing the gray frequency histogram of the original image, and determining the first threshold for extracting the groove area and the second threshold for extracting the laser projection area;

   Binarize the original image by using the first threshold and the second threshold respectively, and perform morphological operations on the original image after the binarization process and the preservation of connected domains to obtain the groove area and laser projection area;

   Based on the groove area and the laser projection area, the three-dimensional position of the groove center and the normal vector of the surface of the workpiece to be welded are calculated.
2. The method according to claim 1, wherein the uniform diffused light source and the multi-line laser light source are used to simultaneously irradiate the area near the crevice groove on the surface of the workpiece to be welded, and the gray scale is obtained by adjusting the exposure time of the imaging element Before the steps of the original image, also include:

   Establish a three-dimensional rectangular coordinate system of the imaging element, and establish a two-dimensional coordinate system of pixels on the image collected by the imaging element;

   Calibrating the imaging element to obtain a conversion relationship between corresponding points between the three-dimensional rectangular coordinate system of the imaging element and the two-dimensional coordinate system of the pixel;

   The multi-line laser light source is calibrated to obtain the equation of each light plane of the multi-line laser light source in the three-dimensional rectangular coordinate system of the imaging element.
3. The method according to claim 1, wherein the step of obtaining the original image with suitable gray scale by adjusting the exposure time of the imaging element is specifically:

   Calculating the average gray level of the image of the area near the groove on the surface of the workpiece to be welded taken by the imaging element;

   If the average gray level is not within the preset gray level range, adjust the exposure time of the imaging element until the average gray level of the image in the area near the slit groove on the surface of the workpiece to be welded meets the preset gray level range.
4. The method according to claim 1, wherein the calculation and analysis of the gray frequency histogram of the original image determine the first threshold for extracting the groove area and the second threshold for extracting the laser projection area. The threshold steps are as follows:

   Calculating the gray frequency histogram of the original image;

   The first threshold t _low is calculated according to the following formula:

   t _low =max r,

   

   Among them, r is the gray value in the gray frequency histogram, p(i) is the frequency of gray value i, a is a preset value, 0<a<1;

   Perform smoothing processing on the gray frequency histogram of the original image to obtain the smoothed gray frequency histogram p _s (r), obtain a minimum point with the largest gray in p _s (r), and The gray level of the minimum value point is used as the second threshold t _high .
5. The method according to claim 2, wherein the first threshold and the second threshold are used to binarize the original image, and the original image after the binarization process is morphologically processed. The steps to learn the operation and the preservation of connected domains to obtain the groove area and the laser projection area are as follows:

   Perform binarization processing on the original image by using the first threshold, and retain points whose grayscale is less than or equal to the first threshold, to obtain a first binarized image;

   Perform a morphological closing operation on the first binarized image, and then extract connected domains, retain connected domains that meet the first preset condition, and use the remaining connected domains in the first binarized image as slope Mouth area, obtaining the coordinates of the groove center in the pixel two-dimensional coordinate system based on the groove area;

   Performing binarization processing on the original image by using the second threshold, and retaining points whose grayscale is greater than or equal to the second threshold, to obtain a second binarized image;

   Perform a morphological closing operation on the second binarized image, and then extract connected domains, retain connected domains that meet the second preset condition, and use the remaining connected domains in the second binarized image as a laser The projection area, based on the laser projection area, obtains the coordinates of a series of points on the laser projection line in the pixel two-dimensional coordinate system.
6. The method according to claim 5, wherein the step of calculating the three-dimensional position of the groove center and the normal vector of the surface of the workpiece to be welded based on the groove area and the laser projection area is specifically:

   According to the coordinates of a series of points on the laser projection line in the pixel two-dimensional coordinate system, the conversion relationship between corresponding points between the imaging element three-dimensional rectangular coordinate system and the pixel two-dimensional coordinate system, and the multi-line laser light source The equation of each light plane in the three-dimensional rectangular coordinate system of the imaging element, calculating the coordinates of a series of points on the laser projection line in the three-dimensional rectangular coordinate system of the imaging element;

   Based on the coordinates of a series of points on the laser projection line in the three-dimensional rectangular coordinate system of the imaging element, the equation of the workpiece plane on which the multi-line laser projection is located in the three-dimensional rectangular coordinate system of the imaging element is fitted, and according to the Calculating the normal vector of the workpiece plane by the equation;

   According to the coordinates of the groove center in the pixel two-dimensional coordinate system, the equation of the workpiece plane where the multi-line laser projection is located in the imaging element three-dimensional rectangular coordinate system, the imaging element three-dimensional rectangular coordinate system and The conversion relationship of corresponding points between the pixel two-dimensional coordinate systems is calculated to obtain the coordinates of the groove center in the three-dimensional rectangular coordinate system.
7. The method according to claim 4, wherein the step of smoothing the gray frequency histogram is specifically:

   A Gaussian filtering method or an average filtering method is used to smooth the gray frequency histogram.
8. The method according to claim 5, wherein the first preset condition is specifically:

   

   Among them, A represents the area of the connected component, A _min1 represents the preset first area threshold of the connected component, R _c represents the roundness rate of the connected _component , and R _cmax1 represents the preset first roundness threshold of the connected component ；

   Among them, R _{c is} defined as:

   

   Among them, P represents the perimeter of the connected domain;

   Correspondingly, the second preset condition is:

   

   Among them, A represents the area of the connected component, A _min2 represents the preset second area threshold of the connected component, R _c represents the roundness rate of the connected _component , and R _cmax2 represents the preset second roundness threshold of the connected component .
9. An electronic device, characterized in that it comprises:

   At least one processor; and

   At least one memory connected in communication with the processor, wherein:

   The memory stores program instructions that can be executed by the processor, and the processor can execute the method according to any one of claims 1 to 8 by calling the program instructions.
10. A non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions that cause the computer to execute the method according to any one of claims 1 to 8 .

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