A method and system for controlling the cutting speed of a boom-type roadheader

Abstract

The application provides a kind of cutting speed control method and system of cantilever type heading machine, belong to coal mine cutting field, cutting speed control method includes: obtaining the image of coal wall to be cut;The edge of the image of coal wall to be cut is detected, and the gray value of edge pixel point is set to 255, the gray value of non-edge pixel point is set to 0, to obtain edge image;The edge image is grid processed, to obtain grid image;For any grid in grid image, according to the gray value of each pixel point in the grid, the geological intensity index value in the grid is determined, which can quantitatively represent the stability of each position of coal rock mass;The preset cutting path of cantilever type heading machine on the coal wall to be cut is obtained;Based on the preset cutting path, according to the geological intensity index value of each grid in the grid image, the rotating speed of the cutting head of the cantilever type heading machine is automatically adjusted, the adaptive energy-saving control of the cutting head of the cantilever type heading machine is realized, and the cutting efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of coal mine cutting, and in particular to a cutting speed control method and system for a cantilever tunneling machine. Background Technology

[0002] Cantilever roadheaders cut the coal face using a high-speed rotating cutting head, continuously transporting coal to the surface. They are one of the most widely used mining equipment in coal mines. Cantilever roadheaders can significantly improve fully mechanized mining efficiency, reduce labor costs, lower labor intensity, and provide better mining conditions for coal miners. Therefore, cantilever roadheaders have a promising future.

[0003] Currently, cantilever tunneling machines are mainly operated manually, and the positioning accuracy and automatic cutting technology are not yet mature. Although most cantilever tunneling machines are equipped with frequency converters, the cutting head still runs at a constant speed and does not automatically adjust the speed according to the strength of the coal and rock, resulting in a huge waste of electrical energy. Summary of the Invention

[0004] The purpose of this invention is to provide a cutting speed control method and system for a cantilever tunneling machine, which can automatically adjust the rotation speed of the cutting head according to the geological strength index value of the cutting path, thereby realizing adaptive energy-saving control of the cutting head of the cantilever tunneling machine.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A method for controlling the cutting speed of a cantilever tunneling machine includes:

[0007] Obtain an image of the coal face to be cut;

[0008] Edge detection is performed on the coal wall image to be cut, and the gray value of edge pixels is set to 255, while the gray value of non-edge pixels is set to 0, to obtain the edge image;

[0009] The edge image is processed into a grid to obtain a gridded image; the gridded image includes multiple grids.

[0010] For any grid in the gridded image, the geological intensity index value within the grid is determined based on the grayscale value of each pixel within the grid.

[0011] Obtain the preset cutting path of the cantilever tunneling machine on the coal face to be cut;

[0012] Based on the preset cutting path, the rotational speed of the cutting head of the cantilever tunneling machine is adjusted according to the geological strength index value of each grid in the gridded image.

[0013] Optionally, acquiring the image of the coal face to be cut specifically includes:

[0014] Acquire initial images of the coal face to be cut;

[0015] The initial image is subjected to dark channel prior dehazing to obtain a clear image;

[0016] The clear image is then subjected to image enhancement processing to obtain an enhanced image;

[0017] The enhanced image is subjected to guided filtering to obtain an image of the coal face to be cut.

[0018] Optionally, acquiring the initial image of the coal face to be cut specifically includes:

[0019] The initial image of the coal face to be cut is acquired by a monocular camera on the cantilever tunneling machine.

[0020] Optionally, the initial image can be subjected to dark channel prior dehazing using the following formula:

[0021]

[0022] Where J(x,y) is the intensity value of pixel (x,y) in the clear image, I(x,y) is the intensity value of pixel (x,y) in the initial image, t(x,y) is the transmittance at pixel (x,y) in the initial image, t0 is a preset threshold used to limit the exposure range, and A is the global atmospheric light composition.

[0023] Optionally, edge detection is performed on the coal face image to be cut, and the grayscale value of edge pixels is set to 255, while the grayscale value of non-edge pixels is set to 0, to obtain an edge image, specifically including:

[0024] For any pixel in the coal face image to be cut, determine the gradient in the x-direction and the gradient in the y-direction based on the coordinates of the pixel.

[0025] Calculate the gradient magnitude and gradient direction of the pixel based on the gradient in the x-direction and the gradient in the y-direction;

[0026] Non-maximum suppression is applied to the gradient magnitude of each pixel, and the gray value of the non-maximum pixel is set to 0 to obtain a preliminary edge image;

[0027] For any pixel in the preliminary edge image, determine whether the pixel is a preliminary edge pixel based on the gray value of the pixel and the gray values ​​of each neighboring pixel to obtain a preliminary edge pixel set; the neighboring pixels are pixels within a defined neighborhood along the gradient direction of the pixel.

[0028] For any initial edge pixel, determine the relationship between the gradient magnitude of the initial edge pixel and a set high threshold and a set low threshold.

[0029] If the gradient magnitude of the preliminary edge pixel is greater than a set high threshold, then the preliminary edge pixel is an edge pixel.

[0030] If the gradient value of the preliminary edge pixel is less than a set low threshold, then the preliminary edge pixel is a non-edge pixel.

[0031] If the gradient value of the preliminary edge pixel is less than or equal to a set high threshold and greater than or equal to a set low threshold, then the preliminary edge pixel is determined to be an edge pixel based on the gradient magnitude of each pixel in the set neighborhood of the preliminary edge pixel.

[0032] The gray values ​​of non-edge pixels in the preliminary edge image are set to 0, and the gray values ​​of edge pixels are set to 1 to obtain the edge image.

[0033] Optionally, determining whether a pixel is a preliminary edge pixel based on its grayscale value and the grayscale values ​​of its neighboring pixels specifically includes:

[0034] Determine whether the gray value of the pixel is greater than the gray values ​​of its neighboring pixels. If so, the pixel is a preliminary edge pixel; otherwise, the pixel is a non-edge pixel.

[0035] Optionally, the geological strength index value within grid i can be calculated using the following formula:

[0036]

[0037] Among them, GSI i G represents the geological intensity index value within grid i. i,b N represents the number of pixels with a grayscale value of 255 within grid i. i Let f be the total number of pixels in grid i, and f be a coefficient.

[0038] Optionally, based on the preset cutting path and according to the geological strength index values ​​of each grid in the gridded image, the rotational speed of the cutting head of the cantilever tunneling machine is adjusted, specifically including:

[0039] The preset cutting path is mapped onto the gridded image to obtain multiple cutting segments; each cutting segment corresponds to a grid.

[0040] For any given grid, the rotational speed of the cutting head at the corresponding cutting section of that grid is adjusted based on the geological strength index value of that grid.

[0041] Optionally, the rotational speed of the cutting head at the cutting section corresponding to the grid is adjusted according to the geological strength index value of the grid, specifically including:

[0042] Determine whether the geological strength index value of the grid is greater than a first set threshold. If the geological strength index value of the grid is greater than the first set threshold, control the cutting head to cut at the cutting section of the coal wall corresponding to the grid at a first rotation speed.

[0043] If the geological strength index value of the grid is less than or equal to the first set threshold, then it is determined whether the geological strength index value of the grid is greater than the second set threshold. If the geological strength index value of the grid is greater than the second set threshold, then the cutting head is controlled to cut at the cutting section of the coal wall corresponding to the grid at the second rotation speed.

[0044] If the geological strength index value of the grid is less than or equal to the second set threshold, the cutting head is controlled to cut at the cutting section of the coal wall corresponding to the grid at the third rotation speed; first set threshold > second set threshold; first rotation speed > second rotation speed > third rotation speed.

[0045] To achieve the above objectives, the present invention also provides the following solution:

[0046] A cutting speed control system for a cantilever tunneling machine includes: an image acquisition unit and a processor;

[0047] The image acquisition unit is used to acquire images of the coal face to be cut.

[0048] The processor includes:

[0049] An edge detection unit, connected to the image acquisition unit, is used to perform edge detection on the coal wall image to be cut, and set the gray value of edge pixels to 255 and the gray value of non-edge pixels to 0 to obtain an edge image;

[0050] A meshing unit, connected to the edge detection unit, is used to perform meshing processing on the edge image to obtain a meshed image; the meshed image includes multiple meshes;

[0051] An intensity calculation unit, connected to the gridding unit, is used to determine the geological intensity index value within any grid in the gridded image based on the grayscale value of each pixel within the grid.

[0052] The path acquisition unit is used to acquire the preset cutting path of the cantilever tunneling machine on the coal face to be cut;

[0053] The control unit is connected to the path acquisition unit, the strength calculation unit, and the cantilever tunneling machine, respectively, and is used to adjust the rotation speed of the cutting head of the cantilever tunneling machine based on the preset cutting path and the geological strength index value of each grid in the gridded image.

[0054] According to specific embodiments provided by the present invention, the following technical effects are disclosed: Edge detection is performed on the image of the coal face to be cut, and the edge image is meshed. The geological strength index value within each mesh is calculated, which can quickly and effectively quantitatively represent the stability of the coal and rock mass at the corresponding location. Furthermore, based on the different geological strength index values ​​at different locations along the cutting path, the rotational speed of the cutting head is automatically adjusted, enabling the cutting head of the cantilever roadheader to achieve energy-saving operation of "accelerating in hard rock and decelerating in soft rock," thereby improving the cutting efficiency of the cantilever roadheader. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This is a flowchart of the cutting speed control method for the cantilever tunneling machine of the present invention;

[0057] Figure 2 This is a schematic diagram of an edge image;

[0058] Figure 3 This is a schematic diagram of the grid and geological strength index values;

[0059] Figure 4 This is a schematic diagram illustrating the relationship between geological strength index values ​​and fracture joints.

[0060] Figure 5 This is a schematic diagram of the truncation path;

[0061] Figure 6 A schematic diagram illustrating the mapping of the truncated path to a meshed image;

[0062] Figure 7 A schematic diagram of the process for adjusting the cutting head speed;

[0063] Figure 8 This is a schematic diagram of the cutting speed control system of the cantilever tunneling machine of the present invention.

[0064] Figure 9 This is a schematic diagram of a cantilever tunneling machine.

[0065] Symbol explanation:

[0066] Image acquisition unit-1, processor-2, edge detection unit-21, meshing unit-22, intensity calculation unit-23, path acquisition unit-24, control unit-25, cantilever tunneling machine-3, frequency converter-31. Detailed Implementation

[0067] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] The purpose of this invention is to provide a cutting speed control method and system for a cantilever tunneling machine. By performing gridding processing on the edge image, the geological strength index value within each grid is calculated, which quickly and effectively quantitatively represents the stability of the coal and rock mass at the corresponding location. Furthermore, based on the different geological strength index values ​​at different locations along the cutting path, the rotational speed of the cutting head can be automatically adjusted.

[0069] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0070] Example 1

[0071] like Figure 1 As shown, the cutting speed control method for the cantilever tunneling machine provided in this embodiment includes:

[0072] S1: Acquire images of the coal face to be cut. Specifically, an image of the coal face to be cut is acquired using a camera.

[0073] Because cantilever tunneling machines generate a large amount of coal dust during operation, the video images captured by the mine cameras are affected by the coal dust, resulting in unclear images. Furthermore, the limited and uneven lighting in the tunnel face significantly impacts the quality of the video images. Therefore, it is necessary to perform image enhancement processing to improve image detection accuracy. Specifically, an industrial Ethernet network is used to transmit the image of the coal face to be cut to the industrial control computer of the cantilever tunneling machine. The computer software first preprocesses the image to obtain the image of the coal face to be cut, thus improving image clarity.

[0074] S2: Perform edge detection on the coal face image to be cut, set the grayscale value of edge pixels to 255, and set the grayscale value of non-edge pixels to 0 to obtain the edge image, such as... Figure 2 As shown.

[0075] The coal wall image to be cut output in step S1 clearly shows the coal fractures and joints, which need to be further extracted. In this embodiment, an edge detection algorithm is used to extract the fractures and joints in the coal wall image to be cut.

[0076] S3: Perform gridding processing on the edge image to obtain a gridded image. The gridded image includes multiple grids.

[0077] In this embodiment, fractal dimension theory is used to analyze the fracture joints of the coal face in the tunneling face. The edge image is meshed into a 9×9 grid. Fracture features within each grid are extracted, and the geological strength index value for each grid is calculated and displayed in the grid, such as... Figure 3 As shown, the geological strength index value characterizes the rock mass strength at the corresponding location, thereby obtaining the rock mass strength distribution of the entire coal face, which can quickly and effectively quantitatively represent the stability of the coal rock mass at the corresponding location.

[0078] S4: For any grid in the gridded image, determine the geological intensity index value within the grid based on the grayscale value of each pixel within the grid.

[0079] Specifically, for each grid i, black pixels (grayscale value 255) represent fractures and joints, and white pixels (grayscale value 0) represent smooth rock surfaces. This process iterates through all pixels within grid i, resulting in a total of N pixels. i The number of black pixels is G i,b By calculating the ratio of black pixels to total pixels in grid i and multiplying it by the corresponding coefficient, the geological intensity index value of grid i can be obtained.

[0080]

[0081] Among them, GSI i G represents the geological intensity index value within grid i. i,b N represents the number of pixels with a grayscale value of 255 within grid i. i Let f be the total number of pixels within grid i, and f be a coefficient. In this embodiment, f = 855. The calculation result is when GSI i When the value is greater than 100, take GSI. i The value is 100.

[0082] The relationship between geological strength index values ​​and fracture joints is as follows: Figure 4 As shown, the fewer the fissures and joints, the higher the geological strength index value; the more the fissures and joints, the lower the geological strength index value.

[0083] S5: Obtain the preset cutting path of the cantilever tunneling machine on the coal face to be cut.

[0084] The cutting arm of a cantilever roadheader has two swing modes: horizontal and vertical. Horizontal swing is driven by rotary cylinders on both sides. When the roadheader swings to the left, the left cylinder extends and the right cylinder retracts; when it swings to the right, the left cylinder retracts and the right cylinder extends. Vertical swing is driven by a pair of lifting cylinders. When the cutting arm swings upward, both lifting cylinders extend simultaneously; when it swings downward, both cylinders retract simultaneously. The cutting head rotates counterclockwise, and its speed is controlled by the roadheader's frequency converter. Changing the frequency of the frequency converter adjusts the rotation speed of the cutting head.

[0085] The cutting process of the tunneling machine is as follows: the lifting cylinder drives the cutting arm to swing vertically, and the rotary cylinder drives the cutting arm to swing horizontally. At the same time as the cutting arm swings, the cutting head rotates at high speed to cut the coal wall. The coal falls below the cutting head and is transported by a belt conveyor.

[0086] The cutting path is as follows: Starting from the lower left corner, the cutting arm swings horizontally to the right until it reaches the predetermined boundary on the right side of the coal face. Then, it cuts vertically upwards to a certain height, followed by a horizontal reverse cut to the predetermined boundary on the left side, and then another vertical upward cut. This process is repeated multiple times to cut the cross-section of the tunnel face. The cutting path is as follows: Figure 5 As shown.

[0087] S6: Based on the preset cutting path, adjust the rotation speed of the cutting head of the cantilever tunneling machine according to the geological strength index value of each grid in the gridded image.

[0088] Specifically, the preset truncation path is mapped onto the gridded image to obtain multiple truncation segments. Each truncation segment corresponds to a grid, such as... Figure 6 As shown. For any given grid, the rotational speed of the cutting head at the corresponding cutting section of that grid is adjusted based on the geological strength index value of that grid.

[0089] Further, step S1 includes:

[0090] (11) Acquire initial images of the coal face to be cut. In this embodiment, initial images of the coal face to be cut are acquired by a monocular camera on the cantilever tunneling machine.

[0091] As one specific implementation method, an explosion-proof camera is installed on the body of the cantilever roadheader, facing the coal face (the coal face to be cut). A high-intensity light source is installed at the head of the roadheader to illuminate the entire coal face, enabling the camera to acquire images of the coal face with clearly visible fractures and joints.

[0092] (12) Perform dark channel prior dehazing on the initial image to obtain a clear image. The dark channel prior principle algorithm is used to effectively sharpen the initial image.

[0093] In this embodiment, the following formula is used to perform dark channel prior dehazing on the initial image:

[0094]

[0095] Where J(x,y) is the intensity value of pixel (x,y) in the clear image, I(x,y) is the intensity value of pixel (x,y) in the initial image, t(x,y) is the transmittance (atmospheric transmission coefficient) at pixel (x,y) in the initial image, t0 is a preset threshold used to limit the exposure range, and A is the global atmospheric light composition, which is a known quantity in the initial image. In this embodiment, t0 = 0.1.

[0096] (13) Perform image enhancement processing on the clear image to obtain an enhanced image.

[0097] To highlight the characteristics of fracture joints, a suitable masking algorithm is needed to sharpen the clear image. Sharpening enhances the edges and areas of abrupt grayscale transitions. Specifically, sharpening can be performed using the Laplace operator in image enhancement algorithms. The following formula is used to enhance the clear image:

[0098] L(J(x,y))=J(x+1,y)+J(x-1,y)+J(x,y+1)+J(x,y-1)-4×J(x,y);

[0099] Where J(x,y) is the intensity value of pixel (x,y) in the clear image, and L(J(x,y)) is the intensity value of pixel (x,y) after Laplace transform.

[0100] The above expression is equivalent to a convolution operation with J(x,y), which can be expressed as:

[0101]

[0102] Where g(x,y) is the intensity value of pixel (x,y) in the enhanced image obtained after sharpening.

[0103] (14) The enhanced image is subjected to guided filtering to obtain the coal wall image to be cut.

[0104] Guided filtering is a linear shift-varying filter, derived from the local linear model, primarily used to filter images and eliminate impurities and noise. In this embodiment, guided filtering is used to eliminate pixel impurities and noise interference from redundant cracks in the enhanced image.

[0105] Guided filtering mainly consists of a guide image, an input image (enhanced image), and an output image (image of the coal face to be cut), and its expression is:

[0106]

[0107] Where q(x,y) is the intensity value of pixel (x,y) in the image of the coal face to be cut, g(x,y) is the intensity value of pixel (x,y) in the enhanced image, x and y are the positions of the pixels, I is the guide map, and W xy () is the filtering function for the guide graph.

[0108] Compared to traditional filters, guided filters can effectively improve image clarity and have a faster processing speed in grayscale and high-dimensional images, showing good performance in improving the clarity of mine images.

[0109] Further, step S2 includes:

[0110] (21) For any pixel in the coal wall image to be cut, determine the gradient in the x-direction and the gradient in the y-direction according to the coordinates of the pixel.

[0111] (22) Calculate the gradient magnitude and gradient direction of the pixel based on the gradient in the x-direction and the gradient in the y-direction.

[0112] (23) Non-maximum suppression is applied to the gradient magnitude of each pixel, and the gray value of the non-maximum pixel is set to 0 to obtain the preliminary edge image.

[0113] In steps (21)-(23), the gradient value and angle of the pixel are calculated first. The gradient in the x and y directions can be obtained based on the coordinate pixel. Then, the gradient magnitude and angle of the pixel can be calculated based on the gradient in the x and y directions. Next, non-maximum suppression is performed on the gradient magnitude to find the local maximum value of the pixel and set the gray value corresponding to the non-maximum point to 0 in order to eliminate the influence of some non-edge pixels.

[0114] (24) For any pixel in the preliminary edge image, determine whether the pixel is a preliminary edge pixel based on the gray value of the pixel and the gray values ​​of each neighboring pixel, so as to obtain a preliminary edge pixel set. The neighboring pixels are pixels within a defined neighborhood along the gradient direction of the pixel.

[0115] Specifically, it is determined whether the grayscale value of the pixel is greater than the grayscale values ​​of its neighboring pixels. If so, the pixel is a preliminary edge pixel; otherwise, the pixel is a non-edge pixel. In this embodiment, within a 3×3 neighborhood, the center pixel is compared with two pixels along the gradient direction. If the grayscale value of the center pixel is greater than that of the pixel, it is an edge pixel; if the grayscale value of the center pixel is less than that of the pixel, it is not an edge pixel.

[0116] (25) Due to the influence of noise, edges that should be continuous may become broken. To address this problem, the present invention uses a dual threshold method to detect edge pixels and connect them.

[0117] For any initial edge pixel, determine the relationship between the gradient magnitude of the initial edge pixel and the set high threshold and the set low threshold.

[0118] If the gradient magnitude of the preliminary edge pixel is greater than the set high threshold, then the preliminary edge pixel is an edge pixel.

[0119] If the gradient value of the initial edge pixel is less than a set low threshold, then the initial edge pixel is a non-edge pixel.

[0120] If the gradient value of the preliminary edge pixel is less than or equal to a set high threshold and greater than or equal to a set low threshold, then the preliminary edge pixel is determined to be an edge pixel based on the gradient magnitude of each pixel in the set neighborhood of the preliminary edge pixel.

[0121] Specifically, the process involves detecting eight pixels in the neighborhood of the initial edge pixel. If one or more of these eight pixels have a gradient magnitude exceeding a set high threshold, then the initial edge pixel is considered an edge pixel; otherwise, it is not.

[0122] (26) Set the gray values ​​of non-edge pixels in the preliminary edge image to 0 and the gray values ​​of edge pixels to 1 to obtain the edge image.

[0123] Furthermore, in step S6, to reduce the error of the geological strength index values ​​and increase the robustness of the method, this invention uses mean filtering to smooth the geological strength index values ​​of each grid. By detecting the target grid coordinates and the mean of the geological strength index values ​​within the surrounding 8 grids, the geological strength index values ​​of the target grid are assigned values, transforming the grid's geological strength index values ​​into a corresponding 9×9 matrix A. Matrix A is represented as follows:

[0124]

[0125] The elements in the matrix represent the geological intensity index values ​​of the corresponding grid.

[0126] In this embodiment, the geological strength index value along the cutting path is: a 82 →a 83 →a 84 →a 85 →a 86 →a 87 →a 88 →a 78 →a 68 →a 67 →a 66 →a 65 →a 64 →a 63 →a 62 →a 52 →a 42 →a 43 →a 44 →a 45 →a 46 →a 47 →a 48 →a 38 →a 28 →a 27 →a 26 →a 25 →a 24 →a 23 →a 22 .

[0127] Specifically, it is determined whether the geological strength index value of the grid is greater than a first set threshold. If the geological strength index value of the grid is greater than the first set threshold, the cutting head is controlled to cut at a first rotation speed at the cutting section of the coal wall corresponding to the grid.

[0128] If the geological strength index value of the grid is less than or equal to the first set threshold, then it is determined whether the geological strength index value of the grid is greater than the second set threshold. If the geological strength index value of the grid is greater than the second set threshold, then the cutting head is controlled to cut at the cutting section of the coal wall corresponding to the grid at the second rotation speed.

[0129] If the geological strength index value of the grid is less than or equal to the second preset threshold, the cutting head is controlled to cut at the cutting section of the coal face corresponding to the grid at a third rotation speed. First preset threshold > Second preset threshold; First rotation speed > Second rotation speed > Third rotation speed.

[0130] In one specific implementation, the first set threshold is 70, and the second set threshold is 35.

[0131] The cutting head oscillates along a planned path, passing through different grids. The cutting head's rotation speed is adjusted according to the geological strength index value within each grid. The tunneling machine's cutting head has three speed modes: high, medium, and low. These modes are switched by adjusting the frequency of the tunneling machine's inverter, thus achieving automatic speed adjustment of the cutting head. When the geological strength index value is in the range of 0-35, the cutting head rotates at low speed (inverter frequency 30Hz); when the value is in the range of 35-70, it rotates at medium speed (inverter frequency 40Hz); and when the value is in the range of 70-100, it rotates at high speed (inverter frequency 50Hz). The speed adjustment process is as follows: Figure 7 As shown.

[0132] This invention introduces a visual measurement method. A monocular vision camera installed in front of the cantilever tunneling machine photographs and analyzes the coal face, extracting fracture and joint features to quickly and efficiently quantify geological strength indicators. By using fractal dimension to display the geological strength indicators along the cutting path in a grid, the geological strength indicator value within each grid is calculated. The cutting head automatically adjusts its rotation speed based on the coal and rock geological strength indicators along the cutting path, enabling the cantilever tunneling machine's cutting head to achieve an energy-saving operating condition of "accelerating in hard rock and decelerating in soft rock," thus realizing adaptive energy-saving control of the cantilever tunneling machine's cutting head.

[0133] Example 2

[0134] In order to implement the method corresponding to Embodiment 1 above and achieve the corresponding functions and technical effects, a cutting speed control system for a cantilever tunneling machine is provided below.

[0135] like Figure 8 and Figure 9 As shown, the cutting speed control system of the cantilever tunneling machine provided in this embodiment includes: an image acquisition unit 1 and a processor 2.

[0136] The image acquisition unit 1 is used to acquire images of the coal face to be cut. Specifically, the image acquisition unit is a monocular camera, which is mounted on the cantilever tunneling machine.

[0137] The processor 2 includes: an edge detection unit 21, a meshing unit 22, an intensity calculation unit 23, a path acquisition unit 24, and a control unit 25.

[0138] The edge detection unit 21 is connected to the image acquisition unit 1. The edge detection unit 21 is used to perform edge detection on the coal wall image to be cut, and set the gray value of the edge pixels to 255 and the gray value of the non-edge pixels to 0 to obtain the edge image.

[0139] The meshing unit 22 is connected to the edge detection unit 21. The meshing unit 22 is used to perform meshing processing on the edge image to obtain a meshed image. The meshed image includes multiple meshes.

[0140] The intensity calculation unit 23 is connected to the gridding unit 22. The intensity calculation unit 23 is used to determine the geological intensity index value of any grid in the grid based on the gray value of each pixel in the grid.

[0141] The path acquisition unit 24 is used to acquire the preset cutting path of the cantilever tunneling machine on the coal face to be cut.

[0142] The control unit 25 is connected to the path acquisition unit 24, the strength calculation unit 23 and the cantilever tunneling machine 3 respectively. The control unit 25 is used to adjust the rotation speed of the cutting head of the cantilever tunneling machine 3 based on the preset cutting path and the geological strength index value of each grid in the gridded image.

[0143] Specifically, the control unit 25 is connected to the explosion-proof frequency converter 31 of the cantilever tunneling machine 3, and the rotation speed of the cutting head is controlled by controlling the frequency of the frequency converter 31.

[0144] like Figure 9 As shown, an explosion-proof camera (image acquisition unit 1) is installed on the body of the cantilever tunneling machine 3, facing the coal face (coal face to be cut).

[0145] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0146] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for controlling the cutting speed of a cantilever tunneling machine, characterized in that, The cutting speed control method of the cantilever tunneling machine includes: Acquiring an image of the coal face to be cut specifically includes: acquiring an initial image of the coal face to be cut; performing dark channel prior dehazing on the initial image to obtain a clear image; performing image enhancement processing on the clear image to obtain an enhanced image; and performing guided filtering on the enhanced image to obtain the image of the coal face to be cut. Edge detection is performed on the coal wall image to be cut, and the gray value of edge pixels is set to 255, while the gray value of non-edge pixels is set to 0, to obtain the edge image; The edge image is processed into a grid to obtain a gridded image; the gridded image includes multiple grids. For any grid in the gridded image, the geological intensity index value within the grid is determined based on the grayscale value of each pixel within the grid. Obtain the preset cutting path of the cantilever tunneling machine on the coal face to be cut; Based on the preset cutting path, and according to the geological strength index values ​​of each grid in the gridded image, the rotational speed of the cutting head of the cantilever tunneling machine is adjusted. Specifically, this includes: mapping the preset cutting path onto the gridded image to obtain multiple cutting segments; each cutting segment corresponding to a grid; for any grid, determining whether the geological strength index value of the grid is greater than a first preset threshold; if the geological strength index value of the grid is greater than the first preset threshold, controlling the cutting head to cut at the cutting segment corresponding to the grid on the coal face to be cut at a first rotational speed; if the geological strength index value of the grid is greater than the first preset threshold, then... If the geological strength index value is less than or equal to a first set threshold, then it is determined whether the geological strength index value of the grid is greater than a second set threshold. If the geological strength index value of the grid is greater than the second set threshold, then the cutting head is controlled to cut at a second rotation speed at the cutting section of the coal wall corresponding to the grid. If the geological strength index value of the grid is less than or equal to the second set threshold, then the cutting head is controlled to cut at a third rotation speed at the cutting section of the coal wall corresponding to the grid. First set threshold > second set threshold; first rotation speed > second rotation speed > third rotation speed.

2. The cutting speed control method for a cantilever tunneling machine according to claim 1, characterized in that, The acquisition of the initial image of the coal face to be cut specifically includes: The initial image of the coal face to be cut is acquired by a monocular camera on the cantilever tunneling machine.

3. The cutting speed control method for a cantilever tunneling machine according to claim 1, characterized in that, Edge detection is performed on the coal face image to be cut, and the grayscale value of edge pixels is set to 255, while the grayscale value of non-edge pixels is set to 0, to obtain the edge image. Specifically, this includes: For any pixel in the image of the coal face to be cut, determine the coordinates of the pixel. x Directional gradient and y Orientation gradient; According to the above x Directional gradient and the y Orientation gradient: Calculate the gradient magnitude and gradient direction of the pixel. Non-maximum suppression is applied to the gradient magnitude of each pixel, and the gray value of the non-maximum pixel is set to 0 to obtain a preliminary edge image; For any pixel in the preliminary edge image, determine whether the pixel is a preliminary edge pixel based on the gray value of the pixel and the gray values ​​of each neighboring pixel to obtain a preliminary edge pixel set; the neighboring pixels are pixels within a defined neighborhood along the gradient direction of the pixel. For any initial edge pixel, determine the relationship between the gradient magnitude of the initial edge pixel and a set high threshold and a set low threshold. If the gradient magnitude of the preliminary edge pixel is greater than a set high threshold, then the preliminary edge pixel is an edge pixel. If the gradient value of the preliminary edge pixel is less than a set low threshold, then the preliminary edge pixel is a non-edge pixel. If the gradient value of the preliminary edge pixel is less than or equal to a set high threshold and greater than or equal to a set low threshold, then the preliminary edge pixel is determined to be an edge pixel based on the gradient magnitude of each pixel in the set neighborhood of the preliminary edge pixel. The gray values ​​of non-edge pixels in the preliminary edge image are set to 0, and the gray values ​​of edge pixels are set to 1 to obtain the edge image.

4. The cutting speed control method for a cantilever tunneling machine according to claim 3, characterized in that, Determining whether a pixel is a preliminary edge pixel based on its grayscale value and the grayscale values ​​of its neighboring pixels specifically includes: Determine whether the gray value of the pixel is greater than the gray values ​​of its neighboring pixels. If so, the pixel is a preliminary edge pixel; otherwise, the pixel is a non-edge pixel.

5. A cutting speed control system for a cantilever tunneling machine, applied to the cutting speed control method of the cantilever tunneling machine according to any one of claims 1-4, characterized in that, The cutting speed control system of the cantilever tunneling machine includes: an image acquisition unit and a processor; The image acquisition unit is used to acquire images of the coal face to be cut. The processor includes: An edge detection unit, connected to the image acquisition unit, is used to perform edge detection on the coal wall image to be cut, and set the gray value of edge pixels to 255 and the gray value of non-edge pixels to 0 to obtain an edge image; A meshing unit, connected to the edge detection unit, is used to perform meshing processing on the edge image to obtain a meshed image; the meshed image includes multiple meshes; An intensity calculation unit, connected to the gridding unit, is used to determine the geological intensity index value within any grid in the gridded image based on the grayscale value of each pixel within the grid. The path acquisition unit is used to acquire the preset cutting path of the cantilever tunneling machine on the coal face to be cut; The control unit is connected to the path acquisition unit, the strength calculation unit, and the cantilever tunneling machine, respectively, and is used to adjust the rotation speed of the cutting head of the cantilever tunneling machine based on the preset cutting path and the geological strength index value of each grid in the gridded image.

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