Irregular welding seam polishing speed regulation method, controller and polishing system

Abstract

The invention relates to an irregular weld joint polishing speed regulation method, a controller and a polishing system. The method comprises the steps that a polishing target image of a welded object is obtained; wherein the polishing target image comprises a to-be-polished weld joint and a set shape calibration object arranged on the to-be-welded object; according to the shape and the actual size of the set-shape calibration object, the area expansion and contraction proportion of an actual object in the polishing target image is determined; collecting height information of the welding seam; determining the volume of the welding seam according to the area expansion and contraction proportion and the height information; and the moving speed of the grinding device is set according to the volume. The moving speed of the grinding device in the grinding system can be automatically adjusted according to the size of the irregular welding seam, and the welding seam grinding efficiency and the welding seam quality can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal surfacing in nuclear power plants, and particularly to a method for adjusting the speed of grinding irregular welds, a controller, and a grinding system. Background Art

[0002] There are a large number of pipes and equipment in nuclear power plants that are connected by surfacing. After welding the pipes and equipment, the shapes and sizes of their welds are uneven or even defective. To ensure that the tightness, integrity, and reliability of the welds meet safety requirements, it is necessary to grind the welds through a grinding device to reduce the risk of stress concentration.

[0003] To improve work efficiency and safety, currently, nuclear power plants usually use a grinding system or a grinding robot to remotely grind welds. However, due to the uneven size and path distribution of the welds, different requirements are imposed on the moving speed of the grinding device in the grinding system. If the speed is inappropriate, it is easy to cause insufficient grinding and excessive grinding, affecting the quality of the welds. Currently, during the process of grinding welds, it is necessary for workers to remotely adjust the moving speed of the grinding device by visually observing the actual situation of the welds through a camera. There are problems such as insufficient intelligence, poor efficiency, and the actual grinding effect being affected by the actual experience of the workers. There is also a risk of human error, which is not conducive to the safety of nuclear power plants. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for adjusting the speed of grinding irregular welds, a controller, and a grinding system.

[0005] The technical solution adopted by the present invention to solve its technical problem is to construct a method for adjusting the speed of grinding irregular welds, including:

[0006] Obtaining a grinding target image of the welded object; wherein, the grinding target image includes the weld to be ground and a set-shaped calibration object arranged on the welded object;

[0007] Determining the area scaling ratio of the actual object in the grinding target image according to the shape and actual size of the set-shaped calibration object;

[0008] Collecting the height information of the weld;

[0009] Determining the volume of the weld according to the area scaling ratio and the height information;

[0010] Setting the moving speed of the grinding device according to the volume.

[0011] Preferably, in the step of setting the moving speed of the grinding device according to the volume, it includes:

[0012] Determine the volume interval in which the volume is located according to a preset set of volume intervals, so as to determine the speed value corresponding to the volume interval, and denote it as the speed to be set; wherein, the set of volume intervals includes multiple volume intervals and multiple speed values corresponding to each volume interval one by one;

[0013] Set the moving speed of the grinding device to the speed to be set.

[0014] Preferably, the multiple volume intervals in the set of volume intervals include: (0, Φ1), [Φ1, Φ2), [Φ2, Φ3), and [Φ3, +∞); wherein, Φ1 < Φ2 < Φ3.

[0015] Preferably, the range of Φ1 is 0.8mm 3 to 1.2mm 3 ; and / or

[0016] The range of Φ2 is 5.5mm 3 to 6.5mm 3 ; and / or

[0017] The range of Φ2 is 8mm 3 to 10mm 3 .

[0018] Preferably, the multiple speed values in the set of volume intervals include the first speed value, the second speed value, the third speed value, and the fourth speed value corresponding to (0, Φ1), [Φ1, Φ2), [Φ2, Φ3), and [Φ3, +∞) in sequence and arranged from small to large; wherein, the first speed value is the minimum moving speed of the grinding device, and the fourth speed value is the maximum moving speed of the grinding device.

[0019] Preferably, the set shape calibration object is a square sheet structure.

[0020] Preferably, in the step of determining the area scaling ratio of the actual object in the grinding target image according to the shape and actual size of the set shape calibration object, it includes:

[0021] Based on the shape of the set shape calibration object, determine the pixel region corresponding to the set shape calibration object in the grinding target image;

[0022] Determine the pixel length and pixel width of the pixel region, and calculate the pixel area of the pixel region;

[0023] Calculate the actual area of the set shape calibration object according to the actual size of the set shape calibration object;

[0024] Calculate the quotient of the actual area divided by the pixel area to obtain the area scaling ratio.

[0025] Preferably, the height information includes a plurality of pixel heights corresponding to each pixel of the weld seam in the grinding target image;

[0026] In the step of determining the volume of the weld seam according to the area scaling ratio and the height information, the expression of the volume is:

[0027] Φ=ρs∑ i,j h i,j ; Φ represents the volume, ρ represents the area scaling ratio, s is equal to 1 pix 2 ,h i,j represents the pixel height of the pixel in the i-th row and j-th column of each pixel of the weld seam in the grinding target image.

[0028] Preferably, in the step of obtaining the grinding target image of the object to be welded, it includes: shooting the grinding target image through a depth camera;

[0029] In the step of collecting the height information of the weld seam, it includes: collecting the distance information between the object to be welded and the depth camera through the depth camera, and analyzing the distance information to obtain the height information.

[0030] The present invention also constructs a controller, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned irregular weld seam grinding speed regulation method are realized.

[0031] The present invention also constructs a grinding system, including:

[0032] A set shape calibration object, which is used to be set at a position close to the weld seam;

[0033] A depth camera, which is set facing the set shape calibration object, and is used to simultaneously shoot the set shape calibration object and the weld seam and output a grinding target image;

[0034] A fill light, which is used to fill light for the depth camera;

[0035] A grinding device, which is used to grind the weld seam;

[0036] A moving mechanism, which is used to move the grinding device; and

[0037] The above-mentioned controller.

[0038] Implementing the technical solution of the present invention can automatically adjust the moving speed of the grinding device in the grinding system according to the volume of the irregular weld, which can not only avoid insufficient grinding and over-grinding, improve the weld quality, but also help improve the weld grinding efficiency and the intelligent process, reduce the risk of human error, and play a positive role in saving the human resources of nuclear power plants and improving the safety of nuclear power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0040] Figure 1 is a schematic structural diagram of a grinding system in the related art;

[0041] Figure 2 is a program flow chart of a method for adjusting the speed of grinding an irregular weld in some embodiments of the present invention;

[0042] Figure 3 is a program flow chart of step S5 in some embodiments of the present invention;

[0043] Figure 4 is a circuit structure block diagram of a controller in some embodiments of the present invention;

[0044] Figure 5 is a schematic structural diagram of a part of the grinding system in some embodiments of the present invention;

[0045] Figure 6 is Figure 5 a schematic structural diagram of another part of the grinding system in the embodiments of DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] In order to have a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the drawings.

[0047] It should be noted that the flow charts shown in the drawings are only illustrative descriptions, and do not necessarily include all the contents and operations / steps, nor do they necessarily need to be executed in the described order. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined. Therefore, the actual execution order may be changed according to the actual situation.

[0048] The block diagrams shown in the drawings are only functional entities, and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0049] It should be noted that, for the convenience of understanding, the working principle of the present invention will be described below with the object to be welded being a pipeline. It should be understood that the object to be welded can also be other metal objects, which also fall within the protection scope of the present invention.

[0050] The grinding system is the existing grinding equipment in the nuclear power plant, such as Figure 1 As shown, the grinding system includes a grinding device 4 (i.e., a grinding wheel), a moving mechanism 5 for controlling the movement of the grinding device 4, and a controller (not shown) for controlling the operation of the grinding device 4 and the moving mechanism 5. Among them, the moving mechanism 5 can include a moving track or a robotic arm. The electric track or the robotic arm is mechanically connected to the grinding device 4 and can drive the grinding device to move. When welding a pipeline, an electric track is preferably used. Please refer to Figure 1 , the electric track includes a circular track and a moving device that is mechanically connected to the grinding device 4 and can slide on the circular track. The circular track can surround the pipeline 20 completely or partially ( Figure 1 belongs to complete surrounding). The moving device is composed of a motor and can drive the grinding device 4 to move circumferentially along the pipeline 10 according to the control of the controller. For specific implementation schemes, please refer to the prior art and will not be elaborated here. It can be understood that if the object to be ground is a plane, an electric track can also be used, and the circular track can be replaced with a linear track. For an object to be ground with an irregular shape, it is preferably to use an existing robotic arm to control the movement of the grinding device 4.

[0051] Figure 2 is the program flow chart of the grinding speed regulation method for irregular welds in some embodiments of the present invention. The grinding speed regulation method for irregular welds can automatically adjust the moving speed of the grinding device in the grinding system according to the volume of the irregular weld. Please refer to Figure 2 , the grinding speed regulation method for irregular welds can include step S1, step S2, step S3, step S4 and step S5.

[0052] Step S1 includes: obtaining a grinding target image of the object to be welded; wherein, the grinding target image includes the weld to be ground and a set shape calibration object provided on the object to be welded. In this step, a set shape calibration object is provided on the object to be welded near the weld, and the set shape calibration object is simultaneously captured in the grinding target image, that is, the grinding target image simultaneously includes part or all of the weld to be ground and the whole picture of the set shape calibration object, and the shape and size of the set shape calibration object are both established and are the reference objects for determining the volume ratio of the weld in the grinding target image to the actual weld.

[0053] In some embodiments, the grinding target image can be captured by a camera (such as a depth camera). To ensure that the shape of the set shape calibrator in the grinding target image is as consistent as possible with the shape of the set shape calibrator when viewed from above, the camera is preferably directly opposite the surface of the set shape calibrator when viewed from above, that is, the lens axis of the camera is perpendicular to the surface of the set shape calibrator when viewed from above (i.e., the surface opposite to the pipe surface).

[0054] Furthermore, the set shape calibrator is preferably a square sheet-like structure. Of course, the sheet-like structure can also be other shapes, such as oval, etc. However, the advantage of using a square sheet-like structure is that the square shape is simple but has obvious characteristics (the length and width are the same), which is easy to identify, and the method of calculating the pixel area in subsequent steps is simple, which helps to simplify the algorithm and save the computing power resources of the processor.

[0055] In some embodiments, the set shape calibrator can be a square sheet-like structure with a side length of 10 mm.

[0056] To improve the accuracy of identifying the set shape calibrator in the grinding target image, the color of the surface of the set shape calibrator when viewed from above is preferably set to a color different from the colors of the pipe surface and the weld.

[0057] Step S2 includes: determining the area scaling ratio of the actual object in the grinding target image according to the shape and actual size of the set shape calibrator.

[0058] In some embodiments, the area scaling ratio can be determined in the following manner: determining the pixel region corresponding to the set shape calibrator in the grinding target image based on the shape of the set shape calibrator; determining the pixel length and pixel width of the pixel region, and calculating the pixel area of the pixel region; calculating the actual area of the set shape calibrator according to the actual size of the set shape calibrator; calculating the quotient of the actual area divided by the pixel area to obtain the area scaling ratio.

[0059] In this embodiment, since the shape of the set shape calibrator is known, the region consistent with the shape of the set shape calibrator can be extracted from the grinding target image through an existing algorithm (such as a trained square image recognition model) to obtain the pixel region; then, after determining the pixel length and pixel width of the pixel region, the product of the pixel length and pixel width can be calculated to obtain the pixel area.

[0060] Step S3 includes: collecting the height information of the weld. Among them, the height information includes the multiple pixel heights corresponding to each pixel of the weld in the grinding target image.

[0061] In some embodiments, the height information can be obtained in the following manner: The depth camera collects the distance information between the object to be welded and the depth camera, and analyzes the distance information to obtain the height information. In this embodiment, since the depth camera has a ranging function, it can collect the pixel distances from each pixel in the grinding target image to the depth camera, thereby obtaining the distance information. Considering that the set shape calibration object has a certain thickness, the set shape calibration object can be first identified using step S2, and through existing algorithms, the pixel regions similar or even identical in shape to the set shape calibration object are extracted to obtain the remaining image. For the remaining image, since the height of the weld seam is significantly higher than that of the pipe body, the pixel point farthest from the depth camera can be regarded as the pixel corresponding to the pipe body. That is, the farthest pixel distance in the remaining image can be determined as the pipe pixel distance between the pipe and the depth camera. Then, by subtracting the distance information of each pixel in the remaining image from the pipe pixel distance respectively, the pixel height corresponding to each pixel in the remaining image can be obtained to form the height information. It should be noted that although the pipe has a certain curvature and the actual surface of the pipe is not a plane, due to the limited frame that the depth camera can capture and the large radius of the nuclear power plant pipe, the actual height change range of the pipe body in the grinding target image is small, and the curvature change can be ignored. Therefore, the surface of the pipe in the grinding target image can be regarded as a plane. Of course, in order to obtain the height information more accurately, the pipe pixel distance can also be compensated in combination with the outer diameter of the pipe. For example, the staff can set the compensation value according to the empirical value, and add the compensation value (the compensation value decreases as the pipe diameter increases) to the pipe pixel distance to achieve compensation and reduce the error of the height information.

[0062] Step S4 includes: determining the volume of the weld seam according to the area scaling ratio and the height information.

[0063] In some embodiments, the expression of the volume can be represented as: Φ = ρs∑ i,j h i,j ; Φ represents the volume, ρ represents the area scaling ratio, s is equal to 1 pix 2 ,h i,j represents the pixel height of the pixel at the i-th row and j-th column among the pixels of the weld seam in the grinding target image.

[0064] Step S5 includes: setting the moving speed of the grinding device according to the volume. In this step, the moving speed of the grinding device is set by sending a control command to the moving mechanism.

[0065] As Figure 3 shown, in some embodiments, the moving speed of the grinding device can be set by executing step S51 and step S52.

[0066] Step S51 includes: determining the volume interval in which the volume is located according to a preset set of volume intervals, so as to determine the speed value corresponding to the volume interval, and recording it as the speed to be set; wherein, the set of volume intervals includes a plurality of volume intervals and a plurality of speed values corresponding to each volume interval one by one.

[0067] In some embodiments, the plurality of volume intervals in the set of volume intervals may include: (0, Φ1), [Φ1, Φ2), [Φ2, Φ3), and [Φ3, +∞), where Φ1 < Φ2 < Φ3. Among them, the range of Φ1 may be 0.8 mm 3 to 1.2 mm 3 , preferably 1 mm 3 ; the range of Φ2 may be 5.5 mm 3 to 6.5 mm 3 , preferably 6 mm 3 . The range of Φ3 may be 8 mm 3 to 10 mm 3 , preferably 9 mm 3 .

[0068] Step S52 includes: setting the moving speed of the grinding device to the speed to be set. Among them, the plurality of speed values in the set of volume intervals may include a first speed value, a second speed value, a third speed value, and a fourth speed value corresponding to (0, Φ1), [Φ1, Φ2), [Φ2, Φ3), and [Φ3, +∞) in sequence and arranged from small to large; wherein, the first speed value is the minimum moving speed that the grinding device can set, and the fourth speed value is the maximum moving speed that the grinding device can set.

[0069] Furthermore, the hardness of grinding targets made of different materials is different. To avoid insufficient grinding and excessive grinding, different grinding speeds should be configured for different hardnesses. For this, in some embodiments, this method for adjusting the speed of irregular weld grinding may further include: obtaining the material type, and setting the first speed value, the second speed value, the third speed value, and the fourth speed value according to the material type. Specifically, the corresponding relationship between different material types and the first to fourth speed values can be pre-stored in a storage device. The staff can input the material type by operating a human-computer interaction unit (such as a mouse, keyboard, etc.). When the material type is obtained, the corresponding first speed value, second speed value, third speed value, and fourth speed value will be automatically set based on the material type. Of course, the staff can also customize and set any one of the first to fourth speed values according to the actual situation by operating the human-computer interaction unit. It can be understood that implementing the technical solution of the present invention can automatically adjust the moving speed of the grinding device in the grinding system according to the volume of the irregular weld, which can not only avoid insufficient grinding and excessive grinding, improve the weld quality, but also help to improve the weld grinding efficiency and the intelligentization process, reduce the risk of human error, and play a positive role in saving human resources in nuclear power plants and improving the safety of nuclear power plants.

[0070] Figure 4 It is a circuit structure block diagram of a controller in some embodiments of the present invention. The controller may include a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the irregular weld grinding speed regulation method provided by the embodiments of the present invention.

[0071] The present invention also provides a grinding system, as Figure 5 and Figure 6 shown. The grinding system may include a set - shape calibration object 1, a depth camera 2, a fill light 3, a grinding device 4, a moving mechanism 5, and a controller 6 provided by the embodiments of the present invention.

[0072] The set - shape calibration object 1 is used to be set at a position close to the weld. The set - shape calibration object 1 can be directly placed on the pipeline, or can be fixed on the surface of the pipeline by means of magnetic attraction, pasting, etc.

[0073] The depth camera 2 is set facing the set - shape calibration object 1 to simultaneously capture the set - shape calibration object 1 and the weld 7 and output a grinding target image.

[0074] The fill light 3 is used to supplement light for the depth camera 2 to improve the shooting quality of the grinding target image.

[0075] The grinding device 4 is used to grind the weld 7. Specifically, the grinding device 4 can be a grinding wheel.

[0076] The moving mechanism 5 is mechanically connected to the grinding device 4 and can move the grinding device 4 under the control of the controller 6.

[0077] In some embodiments, the grinding system may further include a human - machine interaction unit. The human - machine interaction unit is used to input the material type according to the operation.

[0078] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and reference can be made to the description in the method part for related parts.

[0079] Those skilled in the art may further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0080] The steps of the methods or algorithms described in combination with the embodiments disclosed herein can be directly implemented by hardware, software modules executed by a processor, or a combination of the two. The software modules can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the technical field.

[0081] It can be understood that the above embodiments only represent the preferred embodiments of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can also be made, all of which belong to the protection scope of the present invention. Therefore, all equivalent transformations and modifications made to the scope of the claims of the present invention shall fall within the scope covered by the claims of the present invention.

Claims

1. A method for speed regulation of irregular weld grinding, characterized in that: include: Acquire a grinding target image of the object to be welded; wherein the grinding target image includes a grinded weld and a set shape calibration object disposed on the object to be welded; Determining the area expansion ratio of the actual object in the polishing target image according to the shape and actual size of the set shape calibration object; Collecting height information of the weld; Determining the volume of the weld according to the area expansion ratio and the height information; The moving speed of the grinding device is set according to the volume.

2. The irregular weld grinding speed regulation method according to claim 1, characterized in that: The step of setting the moving speed of the grinding device according to the volume includes: Determine the volume interval in which the volume is located according to a preset volume interval set, so as to determine a speed value corresponding to the volume interval and record it as the to-be-set speed; wherein the volume interval set includes a plurality of volume intervals and a plurality of speed values ​​corresponding to each volume interval one by one; The moving speed of the grinding device is set to the to-be-set speed.

3. The irregular weld grinding speed regulation method according to claim 2, characterized in that: The multiple volume intervals in the volume interval set include: (0, Φ1), [Φ1, Φ2), [Φ2, Φ3) and [Φ3, +∞); wherein Φ1<Φ2<Φ3.

4. The irregular weld grinding speed regulation method according to claim 3, characterized in that: The range of Φ1 is 0.8mm 3 Up to 1.2mm 3 ; and / or The range of Φ2 is 5.5mm 3 Up to 6.5mm 3 ; and / or The range of Φ2 is 8mm 3 Up to 10mm 3 .

5. The irregular weld grinding speed regulation method according to claim 3, characterized in that: The multiple speed values ​​concentrated in the volume interval include a first speed value, a second speed value, a third speed value and a fourth speed value which correspond to (0, Φ1), [Φ1, Φ2), [Φ2, Φ3) and [Φ3, +∞) in sequence and are arranged from small to large; wherein the first speed value is the minimum moving speed of the grinding device, and the fourth speed value is the maximum moving speed of the grinding device.

6. The irregular weld grinding speed regulation method according to any one of claims 1 to 5, characterized in that: The set shape calibration object is a square sheet structure.

7. The irregular weld grinding speed regulation method according to claim 6, characterized in that: The step of determining the area scaling ratio of the actual object in the polishing target image according to the shape and actual size of the set shape calibration object includes: Determining a pixel area corresponding to the calibration object of the set shape in the polishing target image based on the shape of the calibration object of the set shape; Determine the pixel length and pixel width of the pixel region, and calculate the pixel area of ​​the pixel region; Calculating the actual area of ​​the calibration object of the set shape according to the actual size of the calibration object of the set shape; The quotient of the actual area divided by the pixel area is calculated to obtain the area expansion ratio.

8. The irregular weld grinding speed regulation method according to claim 7, characterized in that: The height information includes a plurality of pixel heights corresponding to each pixel of the weld in the grinding target image; In the step of determining the volume of the weld according to the area expansion ratio and the height information, the expression of the volume is: Φ=ρs∑ i,j h i,j Φ represents the volume, ρ represents the area expansion ratio, and s is equal to 1pix 2 ,h i,j Represents the pixel height of the pixel in the i-th row and j-th column in each pixel of the weld in the grinding target image.

9. The irregular weld grinding speed regulation method according to claim 6, characterized in that: The step of obtaining the polishing target image of the object to be welded includes: photographing the polishing target image by a depth camera; The step of collecting the height information of the weld includes: collecting distance information between the object to be welded and the depth camera by the depth camera, and analyzing the distance information to obtain the height information.

10. A controller 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 computer program, the steps of the irregular weld grinding speed regulation method according to any one of claims 1 to 9 are implemented.

11. A grinding system, characterized in that: include: A shape calibration object is set to be placed near the weld; A depth camera is arranged opposite to the set shape calibration object, and is used to simultaneously photograph the set shape calibration object and the weld and output a grinding target image; A fill light, used to provide fill light to the depth camera; A grinding device, used for grinding the weld; A moving mechanism, used for moving the grinding device; as well as A controller as claimed in claim 10.

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