Cable head manufacturing simulation method based on virtual-real space conversion

Abstract

The present invention proposes a simulation method for making a cable head based on virtual-real space conversion. The image of the cable head is collected by a binocular vision system and imported into the three-dimensional space of the OpenGL software, and the logical coordinates of the OpengGL three-dimensional space are established; the Laplace-Gaussian algorithm is used to extract the edges of the accessories required for the cable head from the image taken by the binocular camera, and a three-dimensional model framework is constructed by contour line fitting, and then a three-dimensional model of the accessories required for the cable head is constructed; the scene modeling built by Unity3D is used to form a digital model library of all elements of power cable operation; finally, the safety features in the power cable operation site are realized in the learning environment by combining virtual reality and multimedia interactive visualization technology, and the operation process is standardized and virtualized. It aims to achieve the ability to print out the model of the equipment used in the cable head production process at a ratio of 1:1 using 3D printing technology.

Description

Technical Field

[0001] The invention relates to the fields of electric power training tools and virtual reality technology, and in particular to a cable head manufacturing simulation method based on virtual-real space conversion. Background Art

[0002] Power cables are the carriers of power transmission. With the rapid development of clean energy in the country, the reliability of power cables used for ultra-high voltage, high voltage, medium voltage and low voltage is becoming more and more important. The quality of cable joints will affect the reliability of power transmission, so it is necessary to continuously strengthen the training of power employees on the production skills of power cables.

[0003] Traditional skill training for power cable connector production mainly involves offline learning methods such as playing videos or applying electronic courseware, or visiting training sites and work sites. These videos are tens of minutes long and contain many process requirements. If the trainees make a mistake, the cable heads worth tens of thousands of yuan may be scrapped. In addition, there is no guarantee that the cable connectors finally made by the trainees can be actually used (they may be unqualified, resulting in the cable heads being scrapped, and it is unknown which link has gone wrong, or the technology is not up to standard).

[0004] The current power cable simulation tools are developing towards 3D virtual simulation and virtual prototype technology. Virtual prototype technology is a technology that allows designers to use computer technology to build a mathematical model of a mechanical system before building the first physical prototype, conduct simulation analysis, and graphically display the various characteristics of the system under real engineering conditions, thereby modifying and obtaining the optimal design solution. Virtual prototype technology has given rise to the emergence of 3D printing technology, which can print the virtual prototype in the computer into a physical model.

[0005] The production of power cable heads requires the use of 1:1 real equipment to achieve better training results. Metaverse technology is a new type of virtual-real application and form that integrates multiple new technologies. It is based on extended reality technology to provide an immersive experience, and digital twin technology to generate a mirror image of the real world. The metaverse converts the real world into a "digital language" that can be recognized by computers, and on this basis, various virtual applications are superimposed at a 1:1 ratio. Through the construction of the metaverse, the information of the real world will be greatly supplemented by the virtual world, and the way humans interact with the virtual world will be completely improved. It can be seen from this that the real equipment in the cable head production process is put into the metaverse at a 1:1 ratio, which allows trainees to pre-practice in the virtual space, and to conduct practical exercises in a 1:1 real space through 3D printing technology.

[0006] However, in the specific implementation process, the three-dimensional space in the computer uses logical coordinates, and its coordinates can be arbitrary values. However, the equipment used in the production of cable heads measures the dimensions according to physical quantities, which makes it difficult to establish a 1:1 real space in the computer.

[0007] Cable operation skill training is a profession with strong practicality, application and engineering characteristics, with many models, complex processes, high and different process requirements. Most training centers are still based on the traditional indoctrination teaching concept, with "transmitting, helping and guiding" as the main teaching method. Training and assessment are carried out on-site, requiring personnel to concentrate or leave their jobs, which not only affects work but also increases corporate costs; in addition, traditional training methods mostly use multimedia courseware, video recordings, etc., and trainees passively and mechanically receive knowledge and methods. The form is single, the process is boring, and there is a lack of physical operation exercises. It is impossible to visually improve the level of cable accessory installation skills. In the end, the training process becomes a formality and is separated from production practice. The training results cannot reach the expected level; in addition, due to the particularity of the power industry, traditional cable operation training requires the use of a large amount of materials, and most of them are disposable consumable products, which will cause extremely high teaching costs, thus making do with what is available, losing sight of the big picture, and ultimately causing the one-sidedness of the education process. Summary of the invention

[0008] In view of the defects and shortcomings of the prior art, the present invention proposes a cable head production simulation method based on virtual-real space conversion, aiming to achieve the ability to print out models of equipment used in the cable head production process by 3D printing technology at a 1:1 ratio, so that trainees can not only save costs when making cable heads, but also replay and repeat the production process, thereby improving the cable head production skills of trainees.

[0009] The present invention specifically adopts the following technical solutions:

[0010] A cable head production simulation method based on virtual-real space conversion is characterized by: collecting images of the cable head through a binocular vision system and importing them into the three-dimensional space of the OpenGL software, and establishing the logical coordinates of the OpengGL three-dimensional space; using the Laplace-Gaussian algorithm to extract the edges of the accessories required for the cable head from the images taken by the binocular camera, constructing a three-dimensional model framework through contour line fitting, and then constructing a three-dimensional model of the accessories required for the cable head; using Unity3D to build scene modeling to form a digital model library of all elements of power cable operations; finally, combining virtual reality and multimedia interactive visualization technologies, the safety features in the power cable operation site are realized in the learning environment, and the operation process is standardized and virtualized.

[0011] Furthermore, when collecting the image of the cable head through the binocular vision system, a short section of the cable head with measured length, width and height is erected in front of the two cameras, and the center point of the cable head and the two cameras are in the same plane; then the two cameras are moved horizontally so that the lines connecting them and the center of the cable head are perpendicular in the same plane, and the positions of the two cameras are fixed, with one camera located directly in front of the cable head and the other located to the left side of the cable head, as well as the position of the cable head erection point.

[0012] Furthermore, in the process of establishing the logical coordinates of the OpengGL three-dimensional space, there are two steps from the screen coordinates to the OpenGL coordinates. The first step is the conversion of the screen coordinates to the view volume coordinates, and the second step is the conversion of the view volume coordinates to the OpenGL coordinates.

[0013] In the first step, the OpenGL software is initialized as follows: glViewport (0, 0, screenWidth, screenHeight), where screenWidth and screenHeight are the screen pixel width and pixel height of the client area respectively, and the coordinates of the lower left corner of the viewport are exactly (0, 0). No model transformation is done first to ensure that the viewport in OpenGL corresponds to the screen size of the student's computer, that is, for any pixel point P (x, y) on the screen, the corresponding point in the viewport is PV (x, screenHeight-y);

[0014] In the second step, the OpenGl function gluUnProject is used to complete the conversion of screen coordinates to view body coordinates, and the three-dimensional coordinates (posX, posY, posZ) of the point PS corresponding to the pixel point P in the three-dimensional space are obtained;

[0015] Then, the logical coordinates of the OpengGL three-dimensional space are established. The scaling ratio is S, and this scaling ratio S is applied to the collected cable head image to compress the image by S times. The corresponding relationship between the pixel height h of the cable head seen on the screen and the actual length L of the cable head is

[0016] L=h*S*scrLen / screenHeight (1)

[0017] Among them, S is the scaling ratio of the OpenGL software, scrLen is the physical height of the student's computer screen, and screenHeight is the screen pixel height;

[0018] When an accessory required for making a cable head is placed at the upright cable head position, a camera image of the accessory is collected, and then the image is reduced S times and displayed on a computer screen. By automatically recognizing the image of the accessory in the image, its true physical length can be calculated based on the above formula; then, based on the binocular cameras in front and on the left, the three-dimensional data of the accessories required for the cable head are automatically measured and modeled.

[0019] Furthermore, the Laplace Gaussian algorithm is used to extract the edges of the accessories required for the cable head from the image taken by the binocular camera, which specifically includes the following steps:

[0020] Step S1: Filtering: First, the image f(x, y) is smoothed and filtered, and the filter function is selected as a Gaussian function according to the characteristics of human vision, that is:

[0021]

[0022] Among them, G(x, y) is a circularly symmetric function, and its smoothing effect is controlled by σ; convolving the image G(x, y) with f(x, y) can obtain a smooth image, that is:

[0023] g(x,y)=f(x,y)*G(x,y);

[0024] Step S2: Enhancement: Perform Laplace operation on the smoothed image g(x,y), namely:

[0025]

[0026] In the formula is a LOG filter, which is:

[0027]

[0028] Step S3: contour extraction: the edge detection criterion is the zero crossing point of the second-order derivative, i.e., the point where h(x, y) = 0, and corresponds to the larger peak value of the first-order derivative; the Gaussian-Laplace operator is used to combine the Gaussian smoothing filter and the Laplace sharpening filter, firstly to flatten the noise, and then to perform edge detection, so as to extract the image contour curve of the accessories required for the cable head;

[0029] Step S4: Linear fitting of the contour: Since most accessories are cylinders, their regular projection is a rectangle, and the image contour curve of the accessories required for the cable head taken by the front camera is generally similar to a rectangle. The image contour curve is linearly fitted to maximize the overlap ratio of the rectangle area and the image contour curve; when the accessories required for the cable head are irregular shapes, multiple rectangles are used for fitting;

[0030] Step S5: constructing a three-dimensional model framework from the two images: through steps S1 to S4, the image contour curves of the accessories required for the cable head in the front and on the left are respectively extracted, and two rectangles are fitted, which are the front projection and the left projection of the accessories required for the cable head; a cube is constructed from the two projected rectangles, and the accessories required for the cable head are just wrapped therein; when the accessories required for the cable head are irregular shapes, a shape composed of multiple cubes is formed, which also just wraps the accessories required for the cable head therein;

[0031] Step S6: Automatically construct a three-dimensional model of accessories: generate an inscribed cubic column in the cube, and use this cubic column to automatically construct a three-dimensional model of the accessories required for the cable head; when the accessories required for the cable head are irregular shapes, a shape composed of multiple cubes is formed, each cube generates an inscribed cubic column, and these cubic columns are used to automatically construct a three-dimensional model of the accessories required for the cable head.

[0032] Furthermore, the specific process of scene modeling built with Unity3D is as follows: according to the specific content of power cable accessories installation including cable intermediate head production and GIS cable terminal production, the operation objects and operation scenes included in each operation training project are designed; then different object models are collected and established through the binocular vision system, and then combined with the scene modeling built with Unity3D, a digital model library of all elements of power cable operations is formed, including a typical operation scene library, a power equipment model library, an instrument model library, and a typical operation process library.

[0033] Furthermore, the three-dimensional model produced during the college assessment is printed into a solid model using a 3D printer.

[0034] The present invention and its preferred solution overcome the difficulty of establishing a 1:1 real space in a computer, and perform 1:1 three-dimensional modeling on the real equipment used in the power cable head production skill training, so that the existing power cable head three-dimensional virtual production simulation is closer to the real equipment size. Then, the digital model is printed as a physical model at a 1:1 ratio through 3D printing, which supports trainees to actually operate the printed real physical equipment, allowing trainees to repeat the actual operation at a relatively low economic cost, and even regress the previous operation.

[0035] This cable head production simulation method based on virtual-real space conversion has the following advantages:

[0036] 1. Through students' virtual operation in three-dimensional space, the system can automatically record students' operation process and judge whether their process is correct or not.

[0037] 2. Based on the students' familiarity with the skills, the 3D printing model can be made in proportion, allowing the students to make cable heads in proportion, which can reduce the cost of waste after errors.

[0038] 3. The tools used to make the cable head are captured into the three-dimensional space of the computer through the camera, and the correspondence between the world coordinates, logical coordinates and screen coordinates is constructed, so that the three-dimensional solid model can be measured based on binocular stereo vision.

[0039] 4. For the accessories used in the production of cable heads, their length, width and height parameters are identified through the two images of the front and back sides, so as to automatically establish the corresponding model of the accessories in the computer's three-dimensional virtual space, so as to achieve the purpose of building a three-dimensional model based on binocular stereo vision.

[0040] Therefore, the present invention simulates the production of cable heads in three-dimensional virtual space and simulates the production of cable heads in real physical space using 3D printed models of equal proportions, thereby meeting the requirement of allowing trainees to make mistakes, repeat, or even go back and do it again in cable head production training, thereby greatly saving the waste of cable head production materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0042] Figure 1 This is a schematic diagram of making a cable intermediate head according to an embodiment of the present invention.

[0043] Figure 2 The present invention is a schematic diagram of the GIS cable terminal manufacturing method according to an embodiment of the present invention.

[0044] Figure 3 A schematic diagram of the test levels for making a cable intermediate head according to an embodiment of the present invention.

[0045] Figure 4 A schematic diagram of the test levels for making a cable intermediate head according to an embodiment of the present invention.

[0046] Figure 5 It is a schematic diagram of the overall design key points of an embodiment of the present invention. DETAILED DESCRIPTION

[0047] Hereinafter, the specific embodiments of the present application will be described in detail with reference to the accompanying drawings. According to these detailed descriptions, those skilled in the art can clearly understand the present application and can implement the present application. Without violating the principles of the present application, the features in the various embodiments can be combined to obtain new implementations, or certain features in certain embodiments can be replaced to obtain other preferred implementations.

[0048] In order to make the features and advantages of this patent more obvious and easy to understand, the following embodiments are specifically described in detail with the accompanying drawings as follows:

[0049] This embodiment requires the use of a camera and other equipment to import the accessories used in the cable head production process into a computer three-dimensional scene and form a corresponding model. This requires the use of a binocular vision system that mimics the human eye, and by calculating two two-dimensional images of cable head production accessories with parallax information, a parallax map is obtained and the three-dimensional data of the scene is measured. The implementation process is divided into a calculation theory layer and an expression algorithm layer, wherein the calculation theory layer constructs a "primitive map" with basic features such as corners and edges of a two-dimensional image, and the expression algorithm layer uses the primitive map to restore the three-dimensional scene to obtain three-dimensional information such as depth and contours in the field of view.

[0050] Importing real objects into computer three-dimensional scenes through digital glasses is one of the research issues of augmented reality VR technology. Existing technologies include VR head-mounted displays, such as the HTC Vive virtual reality head-mounted display, but VR technology cannot perform computer-aided design and manufacturing like AutoCAD, because VR technology does not numerically determine the correspondence between world coordinates, screen coordinates and logical coordinates in three dimensions.

[0051] This first requires the use of a binocular vision system to establish the three-dimensional data space unit of the cable head accessories. Just like traditional computer-aided design and manufacturing software, users are required to define the size of the space before constructing the three-dimensional space, thereby establishing the correspondence between the world coordinates and the logical coordinates. To this end, it is necessary to establish the virtual and real space units for the production of the cable head.

[0052] 1. Establishment of virtual and real space units for cable head production

[0053] Two cameras are fixed next to each student's computer, and a short cable head with measured length, width and height is erected in front of the two cameras, with the center of the cable head approximately in the same plane as the two cameras. Then the two cameras are moved horizontally so that the lines connecting them and the center of the cable head are perpendicular in the same plane, and the positions of the two cameras (one camera is located directly in front of the cable head, and the other is located to the left of the cable head) and the position of the cable head erection point are fixed.

[0054] First, take an image of the cable head through the camera in front of you, and send it to the three-dimensional space in the OpenGL software through the USB port of the student's computer. There are two steps from screen coordinates to OpenGL coordinates. The first step is to convert screen coordinates to view body coordinates, and the second step is to convert view body coordinates to OpenGL coordinates.

[0055] In the first step, the OpenGL software is initialized as follows: glViewport (0, 0, screenWidth, screenHeight), where screenWidth and screenHeight are the screen pixel width and pixel height of the client area respectively. The coordinates of the lower left corner of the viewport are exactly (0, 0), and no model transformation is performed first. In this way, the viewport in OpenGL corresponds exactly to the screen size of the student's computer, that is, for any pixel point P (x, y) on the screen, the corresponding point in the viewport is PV (x, screenHeight-y).

[0056] In the second step, the OpenGl function gluUnProject can be used to complete the conversion of screen coordinates to view body coordinates, and obtain the three-dimensional coordinates (posX, posY, posZ) of the point PS corresponding to the pixel point P in the three-dimensional space.

[0057] Then we start to build the logical coordinates of the OpengGL three-dimensional space. The scaling ratio is S, and the scaling ratio S is applied to the cable head image collected by the USB to compress the image by S times. The corresponding relationship between the pixel height h of the cable head seen on the screen and the actual length L of the cable head is:

[0058] L=h*S*scrLen / screenHeight (1)

[0059] Among them, S is the scaling ratio of the OpenGL software, scrLen is the physical height of the student's computer screen (in centimeters), and screenHeight is the screen pixel height.

[0060] When an accessory required for making a cable head is placed at the above-mentioned upright cable head position, and the camera image of this accessory is collected through USB, and then the image is reduced by S times and displayed on the computer screen, its real physical length can be calculated according to the above formula by automatically identifying the image of the accessory in the image. Then, the three-dimensional data of the accessories required for the cable head are automatically measured and modeled based on the binocular cameras in front and on the left.

[0061] 2 Automatic 3D modeling of cylindrical equipment in cable head production

[0062] In this embodiment, the edge extraction of the accessories required for the cable head is performed on the image taken by the binocular camera. Marr and Hildreth proposed the Log (Laplacian of Gassian) algorithm based on the human visual characteristics, also known as the Laplace Gaussian algorithm. This method combines Gaussian filtering and Laplace detection operators to perform edge detection. The main ideas and steps are as follows:

[0063] ① Filtering: First, the image f(x, y) is smoothed and filtered. The filter function is selected as a Gaussian function according to the characteristics of human vision, that is:

[0064]

[0065] Among them, G(x, y) is a circularly symmetric function, and its smoothing effect can be controlled by σ.

[0066] By convolving the image G(x,y) with f(x,y), we can get a smooth image, namely:

[0067] g(x,y)=f(x,y)*G(x,y)

[0068] ② Enhancement: Perform Laplace operation on the smoothed image g(x,y), that is:

[0069]

[0070] In the formula It is called a LOG filter and is:

[0071]

[0072] ③Contour extraction: The edge detection criterion is the zero crossing point of the second-order derivative (i.e., the point where h(x,y)=0) and the corresponding large peak of the first-order derivative. The Gaussian-Laplace operator is used to combine the Gaussian smoothing filter and the Laplace sharpening filter, first smooth out the noise, then perform edge detection, and thus extract the image contour curve of the accessories required for the cable head.

[0073] ④ Linear fitting of the contour: The image contour curve of the accessories required for the cable head taken by the front camera is generally similar to a rectangle (accessories are mostly cylinders, and their regular projection is a rectangle). This requires linear fitting of the image contour curve to maximize the overlap ratio of the rectangle area and the image contour curve. When the accessories required for the cable head are irregular shapes, multiple rectangles can be used for fitting.

[0074] ⑤ Construct a 3D model framework from two images: After the first 4 steps, the image contour curves of the accessories required for the cable head in front and on the left are extracted respectively, and two rectangles are fitted, which are the front projection and left projection of the accessories required for the cable head. A cube can be constructed from these two projected rectangles, which just wraps the accessories required for the cable head. When the accessories required for the cable head are irregular shapes, a shape composed of multiple cubes is formed, which also just wraps the accessories required for the cable head.

[0075] ⑥ Automatically build the 3D model of accessories: Generate an inscribed cubic column in the above cube, and use this cubic column to automatically build the 3D model of the accessories required for the cable head. When the accessories required for the cable head are irregular shapes, a shape composed of multiple cubes is formed, and each cube generates an inscribed cubic column, and these cubic columns are used to automatically build the 3D model of the accessories required for the cable head.

[0076] 3. Make cable heads in three-dimensional digital space

[0077] Aiming at the specific contents of power cable accessories installation (including cable intermediate head production and GIS cable terminal production), we designed the operation objects and operation scenes included in each operation training project. Then, we used the binocular camera above to build different object models, and then combined them with scene modeling built with Unity3D to form a digital model library of all elements of power cable operations, which has a sense of reality on site and allows users to roam and interact with events. We formed a typical operation scene library, power equipment model library, instrument model library, typical operation process library, etc. Among them, the cable intermediate head production, such as Figure 1 As shown: GIS cable terminals are made as follows: Figure 2 shown.

[0078] Through interactive visualization technologies such as virtual reality and multimedia, the safety features of power cable operation sites are reflected as realistically as possible in the learning environment, and the operation process is standardized and virtualized, and the entire process of accessory installation and other work is realistically simulated, highlighting case teaching, improving immersion, perceptibility and naturalness, and cultivating students' on-site control capabilities. The operation process of cable intermediate head production is shown in Table 1; the operation process of GIS cable terminal production is shown in Table 2.

[0079] Table 1 The process of making the cable intermediate head

[0080]

[0081]

[0082] Table 2 GIS cable terminal production process

[0083]

[0084]

[0085]

[0086] 4. Print 3D models in proportion to students’ familiarity

[0087] According to the above cable intermediate head production process and GIS cable terminal production process, ten levels are extracted to assess the trainees' proficiency, such as Figure 3 and Figure 4 shown.

[0088] Each level corresponds to a model in three-dimensional space. Once a student makes an error in the assessment operation in three-dimensional space, the three-dimensional model corresponding to the test level can be printed as a solid model through a 3D printer (the 3D printing model can be scaled according to the student's skill level) so that the student can practice repeatedly. The instructor can also designate special training for a certain level and print the corresponding three-dimensional model as a solid model through a 3D printer multiple times (the 3D printing model can be scaled according to the student's skill level).

[0089] The main points of this embodiment can be summarized as follows: Figure 5 It can be seen that in power cable training, the use of 3D printers can achieve instant printing and batch production, which greatly reduces the storage, management and loss costs of cable training equipment, and has significant economic benefits.

[0090] The design scheme provided in this embodiment can be stored in a computer-readable storage medium in a coded form and implemented in the form of a computer program. The basic parameter information required for calculation is input through computer hardware, and the calculation results are output.

[0091] Portions of its computer program may also be loaded onto other programmable data processing devices so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions executed on the computer or other programmable device for implementing the process. Figure 1 The steps of a specified function in a process or multiple processes.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

[0093] This patent is not limited to the above-mentioned optimal implementation mode. Anyone can derive other forms of cable head production simulation methods based on virtual and real space conversion under the inspiration of this patent. All equal changes and modifications made according to the scope of the patent application of the present invention should be covered by this patent.

Claims

1. A cable head manufacturing simulation method based on virtual-real space conversion, characterized in that: The image of the cable head is collected by the binocular vision system and imported into the three-dimensional space of the OpenGL software, and the logical coordinates of the OpengGL three-dimensional space are established; the Laplace-Gaussian algorithm is used to extract the edges of the accessories required for the cable head from the image taken by the binocular camera, and the three-dimensional model framework is constructed through the line fitting of the contour, and then the three-dimensional model of the accessories required for the cable head is constructed; the scene modeling built by Unity3D is used to form a digital model library of all elements of power cable operation; finally, the safety features of the power cable operation site are realized in the learning environment by combining virtual reality and multimedia interactive visualization technology, and the operation process is standardized and virtualized; When collecting the image of the cable head through the binocular vision system, a short section of the cable head with measured length, width and height values ​​is erected in front of the two cameras, and the center point of the cable head and the two cameras are in the same plane; then the two cameras are moved horizontally so that the lines connecting them and the center of the cable head are perpendicular in the same plane, and the positions of the two cameras are fixed, with one camera located directly in front of the cable head and the other located to the left of the cable head, as well as the position of the erection point of the cable head; In the process of establishing the logical coordinates of the OpengGL three-dimensional space, there are two steps from the screen coordinates to the OpenGL coordinates. The first step is the conversion from the screen coordinates to the view volume coordinates, and the second step is the conversion from the view volume coordinates to the OpenGL coordinates. In the first step, the OpenGL software is initialized as follows: glViewport (0, 0, screenWidth, screenHeight), where screenWidth and screenHeight are the screen pixel width and pixel height of the client area respectively, and the coordinates of the lower left corner of the viewport are exactly (0, 0). No model transformation is done first to ensure that the viewport in OpenGL corresponds to the screen size of the student's computer, that is, for any pixel point P (x, y) on the screen, the corresponding point in the viewport is PV (x, screenHeight-y); In the second step, the OpenGl function gluUnProject is used to complete the conversion of screen coordinates to view body coordinates, and the three-dimensional coordinates (posX, posY, posZ) of the point PS corresponding to the pixel point P in the three-dimensional space are obtained; Then, the logical coordinates of the OpengGL three-dimensional space are established, and the scaling ratio is S. This scaling ratio S is applied to the collected cable head image, so that the image is compressed S times. The corresponding relationship between the pixel height h of the cable head seen on the screen and the actual length L of the cable head is L=h*S*scrLen / screenHeight (1) Among them, S is the scaling ratio of the OpenGL software, scrLen is the physical height of the student's computer screen, and screenHeight is the screen pixel height; When a component required for making a cable head is placed at the vertical position of the cable head, a camera image of the component is collected, and the image is reduced by S times and displayed on the computer screen, the actual length of the cable head is calculated according to formula (1) by automatically identifying the component image in the image; Then, based on the binocular cameras in front and on the left, the three-dimensional data of the accessories required for the cable head are automatically measured and modeled.

2. The cable head manufacturing simulation method based on virtual-real space conversion according to claim 1 is characterized in that: The Laplace Gaussian algorithm is used to extract the edges of the accessories required for the cable head from the image taken by the binocular camera, which specifically includes the following steps: Step S1: Filtering: First, the image f(x, y) is smoothed and filtered, and the filter function is selected as a Gaussian function according to the characteristics of human vision, that is: Among them, G(x, y) is a circularly symmetric function, and its smoothing effect is controlled by σ; convolving the image G(x, y) with f(x, y) can obtain a smooth image, that is: g(x,y)=f(x,y)*G(x,y); Step S2: Enhancement: Perform Laplace operation on the smoothed image g(x,y), namely: In the formula is a LOG filter, which is: Step S3: contour extraction: the edge detection criterion is the zero crossing point of the second-order derivative, i.e., the point where h(x, y) = 0, and corresponds to the larger peak value of the first-order derivative; the Gaussian-Laplace operator is used to combine the Gaussian smoothing filter and the Laplace sharpening filter, firstly to flatten the noise, and then to perform edge detection, so as to extract the image contour curve of the accessories required for the cable head; Step S4: Linear fitting of the contour: Since most accessories are cylinders, their regular projection is a rectangle, and the image contour curve of the accessories required for the cable head taken by the front camera is generally similar to a rectangle. The image contour curve is linearly fitted to maximize the overlap ratio of the rectangle area and the image contour curve; when the accessories required for the cable head are irregular shapes, multiple rectangles are used for fitting; Step S5: constructing a three-dimensional model framework from the two images: through steps S1 to S4, the image contour curves of the accessories required for the cable head in the front and on the left are respectively extracted, and two rectangles are fitted, which are the front projection and the left projection of the accessories required for the cable head; a cube is constructed from the two projected rectangles, and the accessories required for the cable head are just wrapped therein; when the accessories required for the cable head are irregular shapes, a shape composed of multiple cubes is formed, which also just wraps the accessories required for the cable head therein; Step S6: Automatically construct a three-dimensional model of accessories: generate an inscribed cubic column in the cube, and use this cubic column to automatically construct a three-dimensional model of the accessories required for the cable head; when the accessories required for the cable head are irregular shapes, a shape composed of multiple cubes is formed, each cube generates an inscribed cubic column, and these cubic columns are used to automatically construct a three-dimensional model of the accessories required for the cable head.

3. The cable head manufacturing simulation method based on virtual-real space conversion according to claim 2 is characterized in that: The specific process of scene modeling built with Unity3D is as follows: according to the specific content of power cable accessories installation including cable intermediate head production and GIS cable terminal production, the operation objects and operation scenes included in each operation training project are designed; then different object models are collected and established through the binocular vision system, and then combined with the scene modeling built with Unity3D, a digital model library of all elements of power cable operations is formed, including a typical operation scene library, a power equipment model library, an instrument model library, and a typical operation process library.

4. The cable head manufacturing simulation method based on virtual-real space conversion according to claim 3 is characterized in that: The three-dimensional model produced during the college assessment is printed into a solid model using a 3D printer.

Images