Coal gangue recognition device and method based on resistive inversion imaging

Abstract

This invention relates to the field of coal gangue identification technology, specifically to a coal gangue identification device and method based on resistance inversion imaging; the coal gangue identification device includes a supporting side plate, a power supply upper plate, and a power measurement lower plate, wherein retractable injection pens are arranged in a matrix on the power supply upper plate; sampling electrodes are arranged in a matrix on the power measurement lower plate; each sampling electrode is connected to a short-circuit protection resistor. R The system includes an ammeter and a central processor and display. Through an array of injection pens and corresponding sampling electrodes, a multi-parallel resistance detection circuit is established in the vertical direction of the coal gangue material. This enables simultaneous adaptive full-envelope power feeding of a large number of irregular coal gangue materials. Based on resistance, a large number of coal gangue materials are identified simultaneously, and resistance and coal gangue image displays are displayed. This solves the problems of inaccurate monitoring when the surface of coal gangue materials is contaminated and the low efficiency of single-point identification, achieving a highly reliable and efficient identification technology for the resistance sensing and intuitive monitoring (display) of coal gangue materials.

Description

Technical Field

[0001] This invention relates to the field of coal gangue identification technology, and specifically to a coal gangue identification device and method based on resistivity inversion imaging. Background Technology

[0002] During raw coal mining, due to geological constraints and the influence of mechanized mining techniques, a large amount of gangue inevitably mixes into the raw coal. Effective separation of coal and gangue can significantly improve the calorific value of clean coal and reduce subsequent transportation costs, while also substantially reducing sulfur dioxide and dust emissions during coal combustion. Currently, mainstream coal and gangue identification technologies mainly include natural gamma-ray radiation intensity identification, machine vision identification, and vibration spectrum identification. However, in the complex operating environment of underground coal mines, these technologies all face severe engineering challenges. For example, the receiver for natural gamma-ray radiation intensity identification is too expensive; machine vision identification requires high image clarity and has limited effectiveness under low illumination and high dust conditions; and vibration spectrum identification is easily affected by on-site noise.

[0003] In essence, the most fundamental and stable physical difference between coal and gangue lies in their electrical properties: coal, as a carbonaceous organic material, exhibits significant semiconductor or weak conductor characteristics with low resistivity; while gangue, mainly composed of silicates, alumina, and other minerals, is a typical electrical insulator, with a resistivity several orders of magnitude higher than that of coal. Traditional point-to-point conductivity detection technology can utilize this difference, but due to the highly irregular shape of the materials and the presence of localized surface contamination, single-point measurements are prone to errors due to poor contact. Furthermore, single-point measurements can only measure and identify coal and gangue materials one by one, resulting in low identification efficiency. Therefore, developing a highly reliable and efficient identification technology that can overcome surface contamination interference, achieve coal and gangue impedance sensing, and possess intuitive monitoring capabilities has become an urgent need for realizing intelligent top coal caving and intelligent coal and gangue separation in underground mines.

[0004] It should be noted that the information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a coal gangue identification device based on resistance inversion imaging, comprising a supporting side plate, a power supply upper plate, and a power measurement lower plate; the power supply upper plate and the power measurement lower plate are arranged opposite each other; retractable injection pens are arranged in a matrix on the lower plate of the power supply upper plate, and the injection pens are connected to the positive terminal of the power supply; sampling electrodes are arranged in a matrix on the upper plate of the power measurement lower plate, and the matrix arrangement of sampling electrodes corresponds one-to-one with the matrix arrangement of injection pens; each sampling electrode is connected to a short-circuit protection resistor R0 and an ammeter, and then independently connected to the negative terminal of the power supply.

[0006] It also includes a central processor and a display. The central processor records the coordinates of each sampling electrode and its corresponding ammeter. The current value of the ammeter is collected by a current network collector and mapped one-to-one with the sampling electrode. The resistance calculation unit of the central processor can calculate the resistance value of the coal and gangue material at each sampling electrode based on Ohm's law. The resistance display interface of the display can display the resistance value of the coal and gangue material at each sampling electrode at the corresponding coordinate position on the resistance display interface based on the coordinates of each sampling electrode. The coal and gangue image display interface of the display can display the display point with a resistance value of gangue as a gangue image, and the display point with a resistance value of coal as a coal image. When the resistance values ​​of adjacent display points are the same, they are displayed as a gangue image or a coal image. When the resistance value is 0, it is displayed as empty.

[0007] Preferably, the rear sides of the upper power supply plate and the lower power measurement plate are both slidably connected to the front side of the support side plate via sliding rails.

[0008] Preferably, the injection pen stops extending downwards after touching an object during its downward extension.

[0009] Preferably, the power supply is located in the support side plate, and the voltage of the power supply is maintained at a safe explosion-proof threshold of 24-48V.

[0010] Preferably, the diameter of each sampling electrode 203 is designed to be 2-5 mm, and the physical center distance between the sampling electrodes 203 is set to 10 mm.

[0011] Preferably, the coal and gangue image display interface of the display uses grayscale pixel values, and a multi-order logarithmic transformation function is used to nonlinearly enhance the contrast of the resistance value. By adjusting the logarithmic base and contrast factor, the huge difference in resistance value is mapped to a standard grayscale level space. Coal with extremely low resistance value will be represented as a deep black block with rich texture depth, while gangue with extremely high resistance value will be represented as a bright white or grayish-white block with sharp edges, and the air area without material coverage will be marked as a specific background color.

[0012] Preferably, it also includes a controller for controlling the operation of each part of the coal gangue identification device.

[0013] A method for identifying coal gangue based on resistivity inversion imaging, using the coal gangue identification device based on resistivity inversion imaging described above, includes the following steps:

[0014] S1: Match the lower platen of the electrical measuring device with the feeding height of the feeder, and feed the coal and gangue material evenly and without overlap into the area of ​​the lower platen of the electrical measuring device through the feeding mechanism. Drive the upper platen of the power supply to move downward to the appropriate position; control the injection pen to extend downward. Stop extending downward after touching irregular coal and gangue material or sampling electrode during the downward movement.

[0015] S2: Power is on;

[0016] S3: The current value of the ammeter is collected by the current network collector and corresponds one-to-one with the sampling electrodes; the resistance calculation unit calculates the resistance value of the coal and gangue material at each sampling electrode based on Ohm's law; the identification unit accurately determines whether the coal and gangue material above each sampling electrode is coal or gangue based on the magnitude of the resistance value R.

[0017] S4: The resistance display interface of the display shows the resistance value of the coal and gangue material at each sampling electrode at the corresponding coordinate position on the resistance display interface based on the coordinates of each sampling electrode; the coal and gangue image display interface of the display shows the display point with a resistance value of gangue as a gangue image, the display point with a resistance value of coal as a coal image, when the resistance values ​​of adjacent display points are the same, they are displayed as a gangue image or a coal image, and when the resistance value is 0, it is displayed as empty.

[0018] Beneficial Effects: The coal gangue identification device based on resistance inversion imaging of this invention establishes a multi-parallel resistance detection circuit in the vertical direction of the coal gangue material through an array of injection pens and corresponding sampling electrodes. This enables simultaneous adaptive full-envelope power feeding of a large number of irregular coal gangue materials, converting weak electrical signals into resistance characteristics. Based on this resistance, a large number of coal gangue materials are identified simultaneously, and the resistance and coal gangue image are displayed. This solves the problems of inaccurate monitoring when the surface of the coal gangue material is contaminated and the low efficiency of single-point identification, achieving a highly reliable and efficient identification technology for the resistance sensing and intuitive monitoring (display) of coal gangue materials. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural schematic diagram of the coal gangue identification device based on resistance inversion imaging according to the present invention;

[0020] Figure 2 This is a side view of the coal gangue identification device based on resistivity inversion imaging according to the present invention;

[0021] Figure 3 This is the display of the coal gangue identification device based on resistance inversion imaging according to the present invention.

[0022] In the diagram, 101 is the upper power supply plate, 102 is the injection pen, 103 is the sliding track, 104 is the supporting side plate, 105 is the power supply, 201 is the lower measuring plate, 202 is the coal and gangue material, 203 is the sampling electrode, 204 is the current network collector, and 3 is the display. Detailed Implementation

[0023] 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.

[0024] like Figure 1-3 As shown, this invention provides a coal gangue identification device based on resistance inversion imaging. This device uses a servo-driven array injection pen 102 to achieve adaptive full-envelope power supply to irregular coal gangue material 202. Combined with a bottom measuring plate 201, a vertical resistance detection loop is established for the coal gangue material 202, converting weak electrical signals into resistance characteristics. Based on the resistance value, the coal gangue material 202 is identified, and a two-dimensional pseudo-color distribution map distinguishing the coal gangue material 202 is generated using a logarithmic enhancement algorithm. This solves the problems of inaccurate monitoring when the surface of the coal gangue material 202 is contaminated, and low efficiency of single-point identification, achieving a highly reliable and efficient identification technology for the resistance sensing and intuitive monitoring of coal gangue material 202.

[0025] Specifically, the coal gangue identification device includes a supporting side plate 104, a power supply upper plate 101, and a voltage measuring lower plate 201. Both the power supply upper plate 101 and the voltage measuring lower plate 201 are rectangular plates arranged vertically opposite each other, and their rear sides are slidably connected to the front side plate of the supporting side plate 104 via sliding rails 103. An injection pen 102 is arranged in an M×N matrix on the lower plate of the power supply upper plate 101. The injection pen 102 is retractable in the vertical direction and stops extending downwards after touching an object. Each injection pen 102 is connected (in parallel) to the positive terminal of a power supply 105 via an independent wire. The power supply 105 is located in the supporting side plate 104, and its voltage is maintained at a safe explosion-proof threshold of 24-48V. The upper surface of the measuring plate 201 is made of epoxy resin with excellent insulation, wear resistance and impact resistance. The sampling electrodes 203 are arranged in an M×N matrix inside. The sampling electrodes 203 arranged in an M×N matrix correspond one-to-one with the injection pens 102 arranged in an M×N matrix. That is, there is a sampling electrode 203 directly below each injection pen 102. Each sampling electrode 203 is connected to a short-circuit protection resistor R0 and an ammeter through an independent wire, and then independently connected to the negative terminal of the power supply 105 (in parallel). That is, each injection pen 102, its corresponding sampling electrode 203 and short-circuit protection resistor R0 form a circuit (when there is no coal gangue material 202). All circuits are set in parallel.

[0026] Preferably, the diameter of each sampling electrode 203 is designed to be 2-5 mm, and the physical center distance between the sampling electrodes 203 is set to 10 mm, that is, the row spacing and column spacing of the M×N matrix are both 10 mm; thus, each coal gangue material 202 can correspond to multiple sampling electrodes 203 and the injection pen 102 to form a full-envelope power supply. The short-circuit protection resistor R0 has the characteristics of low temperature drift and high precision.

[0027] It also includes a central processor, a display, and a controller. The central processor includes a current network acquisition unit 204, a resistance calculation unit, and an identification unit. The central processor records the coordinates (x, y, y) of each sampling electrode 203. i ,y i The current value of the coal and gangue material 202 at each sampling electrode 203 is collected by the current network collector 204 and corresponds one-to-one with the sampling electrode 203. The resistance calculation unit can calculate the resistance value R(x) of the coal and gangue material 202 at each sampling electrode 203 based on Ohm's law. i ,y i The resistivity of coal is approximately 10⁻⁶. 2 -10 5 The resistivity of gangue can reach up to 10 Ω·m. 8 The difference between Ω·m and the two spans several orders of magnitude, therefore the identification unit can determine the resistance value R(x) based on the resistance value. i ,y i The size of R(x) accurately determines whether the coal or gangue material 202 above each sampling electrode 203 is coal or gangue. i ,y i When the value is 0, it indicates that there is no coal gangue material 202 above the sampling electrode 203.

[0028] Among them, the resistance value R(x) of coal gangue material 202 i ,y i The calculation formula is as follows:

[0029]

[0030] In the formula: R(x) i ,y j ) is the coordinate (x i ,y j The resistance value of the coal and gangue material at the sampling electrode; V in I(x) is the injection voltage value of power supply 105. i ,y j ) is the coordinate (x i ,y j The current value of the ammeter in the circuit where the sampling electrode is located.

[0031] The display 3 has a resistance display interface, which can display the resistance based on the coordinates (x, y) of each sampling electrode 203.i ,y i The resistance value R(x) of the coal and gangue material at each sampling electrode 203 is displayed at the corresponding coordinate position on the resistance display interface. i ,y i That is, the resistance display interface is set with a number of display points corresponding to the sampling electrode 203 and their corresponding positions. Each display point can display the resistance value R(x) of the coal and gangue material 202 at the corresponding sampling electrode 203. i ,y i When the resistance value R(x) of the coal gangue material 202 at the adjacent sampling electrode 203 is... i ,y i When R(x) is the same, it means that the coal and gangue material 203 on adjacent sampling electrodes 203 are the same coal and gangue material. i ,y i A value of 0 indicates that there is no coal or gangue material 202 above the sampling electrode 203. The display 3 also has a coal and gangue image display interface, which can be switched between a coal and gangue image display interface and a resistance display interface. The coal and gangue image display interface can display the resistance value R(x) from the resistance display interface. i ,y i The display point for gangue is shown as a gangue image, with resistance value R(x). i ,y i The display point for coal is shown as a coal image, and when the resistance value R(x) of an adjacent display point is equal to the value of the coal image, the display point is equal to the value of the coal image. i ,y i When the resistance value R(x) is the same, it is displayed as a gangue image or a coal image. i ,y i When the value is 0, it will be displayed as empty.

[0032] The coal gangue image display interface of the display 3 can also be represented using grayscale pixel values. Specifically, a multi-order logarithmic transformation function is used to represent the resistance value R(x). i ,y i Nonlinear contrast enhancement is performed by adjusting the logarithmic base and contrast factor to reduce the large resistance value R(x). i ,y i The difference is mapped to a standard grayscale level space of 0-255. For the resistance value R(x) i ,y i Extremely low resistivity coal will appear as a deep black mass with rich texture depth, for a resistivity R(x) i ,y i Extremely high levels of gangue appear as sharp-edged bright white or grayish-white blocks, while areas of air without material cover are designated as a specific background color. The formula for converting grayscale pixel values ​​based on a multi-order logarithmic transformation function is as follows:

[0033]

[0034] In the formula: L(i,j) represents the coordinates of (x... i ,y j The image grayscale pixel value of the coal gangue material at the sampling electrode; R max and R min These are the upper and lower limits for the set resistance, used to lock the dynamic range of the image.

[0035] The controller is used to control the operation of each part of the coal gangue identification device.

[0036] This invention provides a method for coal gangue identification based on resistivity inversion imaging, employing the coal gangue identification device based on resistivity inversion imaging described above, and includes the following steps:

[0037] S1: The lower measuring plate 201 is adjusted to a suitable height by the controller to match the feeding height of the feeder. After the coal gangue material 202 is fed into the area of ​​the lower measuring plate 201 evenly and without overlap by the feeding mechanism, the upper feeding plate 101 is driven to move downward to a suitable position by the controller. Then, the injection pen 102 is controlled to extend downward. When it touches the irregular coal gangue material 202 or the sampling electrode 203 during the downward movement, it will stop extending downward. The injection pen 102 stably contacts the surface of the coal gangue material 202 or the sampling electrode 203.

[0038] S2: After the power supply 105 is powered on, the current flows through the injection pen 102, the coal gangue material 202, the sampling electrode 203, the short-circuit protection resistor R0 and the ammeter in sequence to form a circuit; or, it flows through the injection pen 102, the sampling electrode 203, the short-circuit protection resistor R0 and the ammeter in sequence to form a circuit.

[0039] S3: The central processor contains the coordinates (x, y) of each sampling electrode 203. i ,y i The current value of the coal and gangue material 202 at each sampling electrode 203 is collected by the current network acquisition unit 204 and corresponds one-to-one with the sampling electrode 203. The resistance calculation unit calculates the resistance value R(x) of the coal and gangue material 202 at each sampling electrode 203 based on Ohm's law. i ,y i The identification unit is based on the resistance value R(x). i ,y i The size of R(x) accurately determines whether the coal or gangue material 202 above each sampling electrode 203 is coal or gangue. i ,y i When the value is 0, it indicates that there is no coal gangue material 202 above the sampling electrode 203.

[0040] S4: The resistance display interface of display 3 is based on the coordinates (x, y) of each sampling electrode 203. i ,yi The resistance value R(x) of the coal and gangue material at each sampling electrode 203 is displayed at the corresponding coordinate position on the resistance display interface. i ,y i When display 3 switches to the coal gangue image display interface, the coal gangue image display interface will display the resistance value R(x) from the resistance display interface. i ,y i The display point for gangue is shown as a gangue image, with resistance value R(x). i ,y i The display point for coal is shown as a coal image, and when the resistance value R(x) of an adjacent display point is equal to the value of the coal image, the display point is equal to the value of the coal image. i ,y i When the resistance value R(x) is the same, it is displayed as a gangue image or a coal image. i ,y i When the value is 0, it will be displayed as empty.

[0041] Preferably, the coal gangue image display interface of the display 3 can also be represented using grayscale pixel values, and the resistance value R(x) can be represented using a multi-order logarithmic transformation function. i ,y i Nonlinear contrast enhancement is performed by adjusting the logarithmic base and contrast factor to reduce the large resistance value R(x). i ,y i The difference is mapped to a standard grayscale level space of 0-255; for the resistance value R(x) i ,y i Extremely low resistivity coal will appear as a deep black mass with rich texture depth, for a resistivity R(x) i ,y i Extremely high levels of gangue appear as sharp-edged bright white or grayish-white blocks, while air areas without material coverage are marked with a specific background color.

[0042] The above description of the disclosed embodiments is presented in a progressive manner to enable those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A coal gangue identification device based on resistivity inversion imaging, characterized in that, The system includes a support side plate, a power supply upper plate, and a current measuring lower plate. The power supply upper plate and the current measuring lower plate are arranged opposite each other. Retractable injection pens are arranged in a matrix on the lower surface of the power supply upper plate, and each injection pens is connected to the positive terminal of the power supply. Sampling electrodes are arranged in a matrix on the upper surface of the current measuring lower plate, with each sampling electrode corresponding to a single injection pen. Each sampling electrode is connected to a short-circuit protection resistor. R 0 and the ammeter are then connected independently to the negative terminal of the power supply; It also includes a central processor and a display. The central processor records the coordinates of each sampling electrode and its corresponding ammeter. The current value of the ammeter is collected by the current network collector and matched one by one with the sampling electrode. The resistance calculation unit of the central processor can calculate the resistance value of the coal and gangue material at each sampling electrode based on Ohm's law. The resistance display interface of the display can display the resistance value of the coal and gangue material at each sampling electrode at the corresponding coordinate position on the resistance display interface based on the coordinates of each sampling electrode. The display interface for coal and gangue images can display gangue images when the resistance value of the display point in the resistance display interface is gangue, and coal images when the resistance value of the display point is coal. When adjacent display points have the same resistance value, they are displayed as a gangue image or a coal image. When the resistance value is 0, it is displayed as empty.

2. The coal gangue identification device based on resistivity inversion imaging according to claim 1, characterized in that, The upper power supply plate and the lower power measurement plate are both connected to the front of the support side plate via sliding rails.

3. The coal gangue identification device based on resistivity inversion imaging according to claim 1, characterized in that, The injection pen will stop extending downwards after it touches an object during its downward extension.

4. The coal gangue identification device based on resistivity inversion imaging according to claim 1, characterized in that, The power supply is located in the supporting side plate, and the voltage of the power supply is maintained at the safe explosion-proof threshold of 24-48V.

5. The coal gangue identification device based on resistivity inversion imaging according to any one of claims 1-4, characterized in that, The diameter of each sampling electrode 203 is designed to be 2-5 mm, and the physical center distance between sampling electrodes 203 is set to 10 mm.

6. The coal gangue identification device based on resistivity inversion imaging according to claim 1, characterized in that, The coal and gangue image display interface of the display uses grayscale pixel values. A multi-order logarithmic transformation function is used to nonlinearly enhance the contrast of the resistance values. By adjusting the logarithmic base and contrast factor, the huge difference in resistance values ​​is mapped to a standard grayscale level space. Coal with extremely low resistance values ​​will be represented as a deep black block with rich texture depth, while gangue with extremely high resistance values ​​will be represented as a bright white or grayish-white block with sharp edges. Air areas without material coverage are marked with a specific background color.

7. The coal gangue identification device based on resistivity inversion imaging according to claim 1, characterized in that, It also includes a controller, which is used to control the operation of each part of the coal gangue identification device.

8. A method for identifying coal gangue based on resistivity inversion imaging, using the coal gangue identification device based on resistivity inversion imaging as described in any one of claims 1-7, comprising the following steps: S1: Match the lower platen of the electrical measuring device with the feeding height of the feeder, and feed the coal and gangue material evenly and without overlap into the area of ​​the lower platen of the electrical measuring device through the feeding mechanism. Drive the upper platen of the power supply to move downward to the appropriate position; control the injection pen to extend downward. Stop extending downward after touching irregular coal and gangue material or sampling electrode during the downward movement. S2: Power is on; S3: The current value of the ammeter is collected by the current network collector and mapped one-to-one with the sampling electrodes; the resistance calculation unit calculates the resistance value of the coal and gangue material at each sampling electrode based on Ohm's law; the identification unit determines the resistance value based on the resistance value. R The size accurately determines whether the coal or gangue material above each sampling electrode is coal or gangue; S4: The resistance display interface of the display shows the resistance value of the coal and gangue material at each sampling electrode at the corresponding coordinate position on the resistance display interface based on the coordinates of each sampling electrode; The display interface for coal and gangue images shows gangue images for display points with resistance values ​​of gangue and coal images for display points with resistance values ​​of coal. When adjacent display points have the same resistance value, they are displayed as either a gangue image or a coal image. When the resistance value is 0, the display is empty.

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