Coal bunker infrared annular panoramic temperature imaging method and system
Patent Information
- Application Number
- CN202610876698.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-17
- Publication Date
- 2026-10-20
Smart Images
Figure FT_1 
Figure FT_2 
Figure FT_3
Abstract
Description
Technical Field
[0001] This invention relates to the field of intelligent safety inspection technology for coal mine storage silos; specifically, this invention relates to a method and system for infrared annular panoramic temperature imaging of coal silos. Background Technology
[0002] In the field of intelligent safety inspection of coal mine storage silos, coal silos are closed cylindrical structures that store large quantities of raw coal. During the accumulation of raw coal, oxidation and poor heat dissipation can easily lead to localized high temperatures, which can then cause spontaneous combustion and fire hazards. Coal silos are characterized by high dust levels, low illumination, enclosed spaces, complex layers of raw coal accumulation, and extremely high risks associated with manual temperature measurement.
[0003] In existing coal bunker temperature monitoring technologies, infrared thermometers installed at fixed points have limited monitoring angles, only able to collect coal temperatures in localized areas, and cannot cover the entire coal seam inside the bunker. This results in numerous high-temperature blind spots, making it easy to miss hidden high-temperature hazards. Furthermore, existing technologies only output scattered local infrared images and lack the means to adapt to the circular coal storage space structure of the bunker and automatically generate a full-area annular coal temperature distribution map that matches the cross-section of the bunker, making it difficult to intuitively display the overall coal temperature distribution. Summary of the Invention
[0004] In view of this, the present invention provides a method and system for infrared annular panoramic temperature imaging of coal bunkers, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.
[0005] To achieve the aforementioned objective, a first aspect of the present invention provides a method for infrared annular panoramic temperature imaging of a coal bunker, comprising:
[0006] The gimbal installed on the top of the coal bunker is controlled to rotate step by step according to a preset angle sequence. The gimbal drives the infrared temperature measurement camera fixed to the gimbal to align with the raw coal area in different directions inside the coal bunker in turn. After the gimbal is stabilized, infrared temperature images are collected.
[0007] Trapezoidal perspective distortion correction was performed on the acquired multi-frame infrared temperature images to correct the edge temperature image distortion caused by the circular space of the coal bunker;
[0008] The corrected multi-frame infrared temperature images are subjected to fade-out weighted fusion processing to generate a continuous and complete rectangular global coal temperature image.
[0009] The rectangular global coal temperature image is transformed by polar coordinate mapping to generate an annular coal temperature distribution map adapted to the circular coal storage structure of the coal bunker.
[0010] The central area of the annular coal temperature distribution map is made transparent to remove invalid images of the central airspace of the coal bunker and retain the annular temperature distribution image of the raw coal accumulation area.
[0011] In the method described above, optionally, the preset angle sequence covers the 360° raw coal accumulation area of the coal bunker, the first angle deviates from the zero point of the gimbal reference, and the step size of the remaining angles is equal except for the first angle;
[0012] Before acquiring each frame of infrared temperature image, a preset time delay is performed to allow the dust in the chamber to settle and the gimbal to stabilize its mechanical attitude. The last frame of the stabilized video is then captured as the valid infrared temperature image.
[0013] In the method described above, optionally, the preset duration of the delayed stilling operation is between 10 and 20 seconds.
[0014] In the method described above, optionally, the trapezoidal perspective distortion correction maps the four vertices of the original rectangular image to trapezoidal target vertices, including:
[0015] The bottom left corner of the original image Map to target point ;
[0016] The bottom right corner of the original image Map to target point ;
[0017] The top left corner of the original image Map to target point ;
[0018] The top right corner of the original image Map to target point ;
[0019] in, The original image width, To correct the image height, To correct the width of the top edge of the image, This is the horizontal offset, and , This is the scaling factor.
[0020] In the method described above, optionally, the scaling factor is configured as follows:
[0021] For the inner ring raw coal area of the coal bunker, a first scaling factor is used to shrink the upper edge, and for the outer ring raw coal area of the coal bunker, a second scaling factor is used to shrink the upper edge. The first scaling factor is greater than the second scaling factor, and the value of the first scaling factor ranges from 2.6 to 3.2, while the value of the second scaling factor ranges from 1.6 to 2.2. The difference between the first scaling factor and the second scaling factor is controlled within the range of 0.9 to 1.1.
[0022] In the method described above, optionally, the fading weighted fusion process performs a weighted calculation on the pixels in the overlapping region of two adjacent infrared temperature images using a linear fading weight. The linear fading weight is dynamically determined based on the horizontal position coordinates of the pixels in the overlapping region, and the fusion formula is as follows:
[0023]
[0024] Among them, linear fading weights , This represents the pixel coordinates of the current pixel in the horizontal direction of the image. The starting horizontal pixel position of the merged region. This represents the total pixel width of the merged region.
[0025] In the method described above, optionally, the rectangular global coal temperature image is rotated 180° before polar coordinate mapping transformation.
[0026] In the method described above, optionally, the polar coordinate mapping transformation includes:
[0027] The position of each pixel in the rectangular global coal temperature image is converted from the Cartesian coordinate system to polar coordinates with the center of the annular coal temperature distribution map as the origin. The angle component adopts half-angle mapping to adapt to the 360° annular expansion. The angle calculation formula is as follows: In the formula, The coordinates of the current pixel in the rectangular global coal temperature image. The radius of the outer circle of the annular coal temperature distribution map. These are the transformed angular coordinates;
[0028] Calculate the radial distance from the current pixel to the center of the annular coal temperature distribution map: ;
[0029] The radial distance is normalized and mapped to the radial pixel coordinates of the annular coal temperature distribution map. The mapping formula is as follows: In the formula, For the mapped radial pixel coordinate index, The radius of the inner circle of the annular coal temperature distribution map. The height of the rectangular global coal temperature image.
[0030] In the method described above, optionally, a multi-layer center-aligned overlay is performed on the transparent annular coal temperature distribution map. The multi-layer includes a central ring, an inner ring, and an outer ring. The center-aligned overlay is performed by calculating the pixel offset of two images of different sizes and overlaying the smaller image onto the center of the larger image.
[0031]
[0032]
[0033] in, and These are the width and height of the larger image, respectively. and These represent the width and height of the smaller image, respectively.
[0034] To achieve the aforementioned objective, a second aspect of the present invention provides a coal bunker infrared annular panoramic temperature imaging system, comprising:
[0035] The pan-tilt control module includes a pan-tilt unit installed on the top of the coal bunker;
[0036] The infrared temperature measurement module includes an infrared temperature measurement camera that is fixedly installed on the pan-tilt unit;
[0037] The main control module is communicatively connected to the gimbal control module and the infrared temperature measurement module. It is used to control the gimbal to rotate step by step according to a preset angle sequence, so that the infrared temperature measurement camera is aligned with the raw coal area in different directions inside the coal bunker in sequence, and to control the infrared temperature measurement camera to collect infrared temperature images after the gimbal attitude is stable.
[0038] The image processing module is communicatively connected to the gimbal control module and the infrared temperature measurement module. It is used to perform trapezoidal perspective distortion correction on the acquired multi-frame infrared temperature images, perform fading weighted fusion processing on the corrected multi-frame infrared temperature images to generate a rectangular global coal temperature image, perform polar coordinate mapping transformation on the rectangular global coal temperature image to generate an annular coal temperature distribution map adapted to the circular coal storage structure of the coal bunker, and perform transparency processing on the central area of the annular coal temperature distribution map.
[0039] To achieve the foregoing objectives, a third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in any one of the first aspects above.
[0040] This invention utilizes a gimbal to rotate an infrared temperature measurement camera, covering different areas of raw coal accumulation inside the coal bunker, eliminating or reducing blind spots in traditional temperature measurement. Post-positioning and attitude stabilization ensure that each frame of infrared temperature image accurately corresponds to the corresponding coal seam location, resulting in high temperature data matching. Combined with trapezoidal deformation correction and fading weighted fusion algorithms, it eliminates or reduces image noise and splicing defects caused by coal dust. A centrally transparent annular coal temperature distribution map is generated, matching the raw coal distribution pattern of the coal bunker cross-section, providing a visual representation of the entire temperature field. Attached Figure Description
[0041] The disclosure of this invention will become more apparent from the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings:
[0042] Figure 1 A schematic block diagram of an infrared annular panoramic temperature imaging system for a coal bunker provided in an embodiment of the present invention;
[0043] Figure 2 This is a schematic diagram of the installation of a gimbal and an infrared temperature measuring camera in a coal bunker infrared annular panoramic temperature imaging system provided in an embodiment of the present invention.
[0044] Figure 3 This is a flowchart illustrating a method for infrared annular panoramic temperature imaging of a coal bunker, as provided in an embodiment of the present invention. Detailed Implementation
[0045] Referring to the accompanying drawings and specific embodiments, the structure, composition, features, and advantages of the coal bunker infrared annular panoramic temperature imaging method and system of the present invention will be described below by way of example. However, all descriptions should not be construed as limiting the present invention in any way.
[0046] Furthermore, for any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the various figures, the present invention still allows for any combination or deletion of these technical features (or their equivalents) without any technical obstacle, and thus these further embodiments according to the present invention should also be considered within the scope of this description.
[0047] It should also be noted that the use of terms such as “inner,” “outer,” “upper,” “lower,” “left,” “right,” and similar terms to indicate orientation or positional relationships is only for the convenience of describing this disclosure and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.
[0048] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; wired connections or wireless connections; direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention according to the specific circumstances.
[0049] It should be noted that the steps described in the method embodiments of this disclosure may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.
[0050] It should be noted that the system embodiments and method embodiments described herein can be referenced interchangeably. The actions performed by each module in the system of each embodiment of the present invention can correspond to the steps in the method of each embodiment of the present invention. For technical details not described in detail in the system embodiments, refer to the relevant descriptions in the method embodiments, and vice versa.
[0051] One or more embodiments of the present invention provide a coal bunker infrared annular panoramic temperature imaging system.
[0052] Please see Figure 1 The system includes a main control module, a gimbal control module, an infrared temperature measurement module, and an image processing module. The main control module is communicatively connected to the gimbal control module and the infrared temperature measurement module, and the image processing module is also communicatively connected to the gimbal control module and the infrared temperature measurement module. The gimbal control module includes a gimbal, and the infrared temperature measurement module includes an infrared temperature measurement camera.
[0053] Please see Figure 2 In this system, the pan-tilt unit is a rotating pan-tilt unit that can be mounted on the top of the coal bunker via a mounting bracket; the infrared temperature measuring camera is fixed to the pan-tilt unit and can rotate with it. Relying on the pan-tilt unit's 360° precise rotation scanning, the system provides comprehensive coverage of the raw coal accumulation area inside the coal bunker, helping to eliminate or reduce traditional temperature measurement blind spots and accurately detect various hidden high-temperature hazard points.
[0054] The hardware workflow of this system includes: the main control module establishing a communication connection with the pan-tilt unit and infrared temperature camera via the network, and issuing angle control and acquisition commands; the pan-tilt unit rotating step by step according to a preset precise angle, driving the infrared temperature camera to aim at the raw coal areas in different directions inside the coal bunker; the infrared temperature camera continuously outputting real-time infrared temperature video streams, accurately acquiring the temperature pixel information of the raw coal in each area; after rotating to a target angle, a certain delay is made to allow the dust inside the bunker to settle and the mechanical attitude of the pan-tilt unit to stabilize, avoiding interference from vibration and dust on temperature imaging; the last frame of the stabilized video is extracted as the effective infrared temperature image, automatically classified and saved to a designated path for subsequent panoramic coal temperature synthesis. Subsequent panoramic coal temperature synthesis is performed by the image processing module, and its implementation can be referred to one or more embodiments of the coal bunker infrared annular panoramic temperature imaging method of the present invention described below.
[0055] One or more embodiments of the present invention also provide a method for infrared annular panoramic temperature imaging of a coal bunker. Figure 3The following is a flowchart illustrating the method. The steps of the method will be described in detail below.
[0056] Before the method is executed, the system is initialized, the infrared temperature measurement video stream of the coal bunker and the communication link for gimbal control are established, and the temperature image storage path and temperature measurement parameters are configured.
[0057] Step S1: Automatic acquisition of coal temperature images in the coal bunker.
[0058] After system initialization, the angle sequence for full-area temperature measurement of the coal bunker is loaded; the main control drives the gimbal to rotate to each target angle in sequence, accurately locating the raw coal temperature measurement area in different directions; a certain period of time is executed for attitude stabilization and dust settling to eliminate or reduce environmental and mechanical interference, ensuring the clarity of temperature images and the accuracy of data; the infrared temperature video stream is read, and valid images with stable images and complete temperature data are selected and saved; the image acquisition of all angles in the angle sequence is completed in a loop, fully covering the 360° raw coal accumulation area of the coal bunker, and obtaining multi-dimensional coal seam temperature image materials.
[0059] For example, the angle sequence can be: [300, 3300, 6600, 9900, 13200, 16500, 19800, 23100, 26400, 29700, 33000]. These numbers in the sequence are the absolute position encoding values of the pan-tilt-zoom (PTZ) horizontal axis, which are internal coordinate values of the device, not physical angles. The complete 360° horizontal travel linearly mapped to an integer encoding range of 0-33000 is the factory-fixed coordinate mapping. The device's single-frame infrared field of view is approximately 36°, and a fixed step size of 3300 (corresponding to 36°) is set. The shooting angle of each image is completely consistent, and all original image distortion and perspective rules are uniform. This is a prerequisite for the normal operation of subsequent trapezoidal distortion correction algorithms and fading weighted fusion algorithms. If the step size is uneven, the image distortion will vary greatly, and the temperature data after stitching will be misaligned and discontinuous. Eleven sampling points are used to divide the area into 360° sections, completely covering the circular cross-section of the coal bunker with no blind spots.
[0060] Furthermore, although the gimbal device supports continuous 360° rotation horizontally without rigid mechanical jamming, the code 0 is the default reference zero point when the device powers on: it automatically returns to zero point during power-on, self-test, and reset. If the sampling starting point is set to 0 for a long time, it will frequently trigger gimbal reference calibration, increasing the probability of jitter and attitude instability. Therefore, based on the aforementioned uniform division of 360°, setting the first angle value to 300 (corresponding to approximately 3.27°) instead of 0, and using this small offset away from the reference zero point, can make the gimbal operation more stable and reduce invalid self-test actions.
[0061] For example, the duration of the delay operation can be set based on experience or experimentation, such as between 10 and 20 seconds, preferably 15 seconds. In one embodiment, a 15-second pause allows most of the suspended dust within the lens's field of view to settle to a safe concentration, balancing image quality and operational efficiency, and is the empirically optimal value under normal dust concentrations in coal bunkers. Actual tests show that when the delay is less than 10 seconds, a qualified annular temperature panoramic image cannot be generated in high-dust coal bunkers, and when the delay exceeds 15 seconds, the image quality and temperature measurement accuracy no longer improve significantly, and continuing to wait is an ineffective wait.
[0062] This step relies on the 360° precise rotation scanning of the gimbal to comprehensively cover all raw coal accumulation areas inside the coal bunker, eliminating or reducing blind spots in traditional temperature measurement and accurately capturing hidden high-temperature hazard points. It adopts strict timing control of angle positioning, dust settling and posture stabilization, and image acquisition to ensure that each frame of infrared temperature image accurately corresponds to the corresponding coal seam location, with extremely high temperature data matching degree.
[0063] Step S2: Adapting the trapezoidal deformation correction of the field of view for raw coal temperature measurement in the coal bunker.
[0064] Considering the circular space of the coal bunker and the morphological characteristics of the raw coal pile in the center, trapezoidal perspective distortion correction is performed on the collected rectangular infrared temperature images to correct edge temperature image distortion and ensure that coal seam temperature images from different angles can be accurately stitched and adapted.
[0065] For example, the coordinates of the lower left, lower right, upper left, and upper right vertices of the original infrared image before correction are as follows: , , , The coordinates of the four vertices of the corrected image are as follows: , , , .
[0066] in, This represents the pixel width of the original infrared image, i.e., the total horizontal pixels of the original image. The pixel height of the corrected image is the total vertical pixels of the output image. To correct the width of the top edge of the image, ( (where is the scaling factor), used to control the width of the upper edge of the trapezoid, and is the core parameter for achieving trapezoidal distortion correction; This is the overall horizontal offset (in pixels), used to control the horizontal translation of the entire image to fine-tune image centering and align stitching gaps. It can be set in typical scenarios. .
[0067] Specifically, in the vertex coordinates of the above-mentioned corrected image, the bottom edge of the image ( The top edge of the image corresponds to the coal seam area near the coal bunker. This corresponds to the distant view area deep within the center of the coal bunker. This is achieved by maintaining the bottom edge width as the original image width (…). This ensures that the imaging size of the near-field area of the coal bunker remains unchanged; at the same time, by controlling the width of the upper edge ( This causes the top edge of the image to converge towards the center, effectively simulating and correcting perspective distortion caused by an infrared thermometer camera shooting over a coal bunker, thus providing an accurate geometric basis for subsequent panoramic stitching.
[0068] Among them, the above scaling factor The scaling factor is divided into an inner ring scaling factor and an outer ring scaling factor. In one embodiment, for the inner ring of the coal bunker (i.e., the central raw coal accumulation area), the inner ring scaling factor is set to 2.9 to adapt to the temperature imaging of the central dense coal seam; for the outer ring of the coal bunker (i.e., the outer raw coal accumulation area), the outer ring scaling factor is set to 1.9 to adapt to the temperature imaging of the outer coal seam.
[0069] It should be noted that the specific values of the scaling factors mentioned above are not fixed restrictions, but rather optimal calibration values for the current standard operating conditions. These values can be fine-tuned within a reasonable range based on the actual scenario. For example, the standard adjustable range for the inner ring scaling factor is 2.6 to 3.2, and the standard adjustable range for the outer ring scaling factor is 1.6 to 2.2. During parameter adjustment, the constraint that the inner ring scaling factor must always be greater than the outer ring scaling factor must be met, and the difference between the two should be controlled between 0.9 and 1.1 to ensure a natural geometric transition between the inner and outer ring images during stitching.
[0070] In practical applications, the above scaling factor can be dynamically adjusted according to the changes in the coal bunker structure and equipment installation conditions. The specific adjustment strategies include: (1) When the equipment and coal bunker structure remain unchanged, maintain the above values (inner ring 2.9, outer ring 1.9); (2) When the coal bunker is raised or the camera installation position is raised, resulting in an enhanced overhead perspective effect, appropriately increase the inner ring scaling factor (e.g., adjust to 3.0 or 3.1), and simultaneously increase the outer ring scaling factor slightly; (3) When the coal bunker is lowered or the camera installation position is lowered, resulting in a weakened overhead perspective effect, appropriately decrease the inner ring scaling factor (e.g., adjust to 2.7 or 2.8), and simultaneously decrease the outer ring scaling factor slightly; (4) When the camera lens is replaced or the coal bunker structure is modified, calibration tests can be performed within the above standard adjustable range. The criteria for qualified calibration are: seamless panoramic image after splicing, continuous temperature data without breaks, and clear layering of inner and outer rings.
[0071] Step S3, Dust-resistant temperature image fusion
[0072] To address the issues of image stitching gaps and temperature data discontinuities caused by high dust levels in coal bunkers, a fading weighted fusion algorithm is employed to smoothly transition temperature pixels in overlapping areas, ensuring continuous and uninterrupted temperature images across the entire region.
[0073] The core of the fading weighted fusion algorithm includes the weight coefficients ( The calculation and pixel fusion calculation are used to smoothly transition the overlapping area of two adjacent infrared images, solving the problems of abrupt image stitching, temperature data discontinuity, and hard seams in high-dust environments like coal bunkers. The core formula is:
[0074]
[0075]
[0076] In the formula, coordinate variables The pixel coordinates of the current pixel in the horizontal direction of the image are used to identify the specific position of the current pixel in the stitching overlap area and serve as the basis for dynamically calculating the weights. The starting coordinates for fusion are the left boundary pixel positions where the two images begin to overlap and weighted fusion begins, used to define the starting point of the fusion interval; when When the current pixel is not in the overlapping and blending area, the pixel value of image 1 is directly used; when When the current pixel enters the overlapping area, the fade-out blending calculation begins. The fusion interval width, or the total pixel width of the horizontal fusion strip, represents the pixel span of the overlapping area of the two images. It is used to control the smoothness and gradation range of the fusion transition. The larger the value of the fusion interval width, the longer the transition interval and the more natural the seam. To integrate weighting coefficients This represents the weight proportion of image 2 in the current output pixels; within the fusion interval, as the pixel coordinates... The increase in weighting coefficient The data is linearly incremented from 0 to 1, thereby achieving pixel-level smooth transition between two adjacent infrared images in the overlapping area and continuous fusion of temperature data.
[0077] Optionally, before performing step S4, the fused rectangular full-area coal temperature image is rotated 180° for correction. This is because the actual installation posture of the infrared temperature camera (e.g., inverted mounting) or light path refraction may cause the fused rectangular full-area coal temperature image to be upside down or left-right inverted. Therefore, before performing polar coordinate mapping transformation, the rectangular full-area coal temperature image is first rotated 180° for correction to restore the true physical spatial orientation inside the coal bunker.
[0078] Step S4: Generation of the annular coal temperature distribution map
[0079] The calibrated and fused rectangular global coal temperature image is transformed into an annular temperature distribution map adapted to the circular structure of the coal bunker through polar coordinate mapping, accurately restoring the global temperature distribution of raw coal inside the coal bunker.
[0080] Specifically, the position of each pixel in the rectangular global coal temperature image is converted from a Cartesian coordinate system to a polar coordinate representation with the center of the annular coal temperature distribution map as the origin. The angle component uses a half-angle mapping to adapt to the 360° annular expansion, and the angle calculation formula is as follows:
[0081]
[0082] In the formula, The coordinates of the current pixel in the rectangular global coal temperature image. The radius of the outer circle of the annular coal temperature distribution map. These are the transformed angular coordinates;
[0083] The formula for calculating the radial distance from the current pixel to the center of the annular coal temperature distribution map is:
[0084]
[0085] The above radial distance is normalized and mapped to the radial pixel coordinates of the annular coal temperature distribution map. The mapping formula is as follows:
[0086]
[0087] In the formula, For the mapped radial pixel coordinate index, The radius of the inner circle of the annular coal temperature distribution map. The height of the rectangular global coal temperature image.
[0088] Step S5, making the center transparent
[0089] Considering the structural characteristics of the coal bunker center—which contains no raw coal and is an empty space—we take the image center as the center and divide the radius... The blank areas within the range are set to be completely transparent, invalid airspace images are eliminated, and only the annular temperature distribution image of the raw coal accumulation area is retained, improving imaging accuracy and intuitiveness.
[0090] Step S6: Center alignment of multi-layer images
[0091] Automatic alignment and layered fusion of multi-layered coal temperature images (e.g., center, inner ring, and outer ring) are achieved to ensure that the annular temperature maps of different layers accurately overlap in space.
[0092] Before image overlay, the sizes (e.g., pixel areas) of the two images to be overlaid are first compared. The image with the larger pixel size is used as the reference large image, and the image with the smaller pixel size is used as the small image to be overlaid. Then, the horizontal offset of the small image relative to the top-left vertex of the large image is calculated. ) and vertical offset ( The calculation formula is as follows:
[0093]
[0094]
[0095] In the above formula, and These represent the total horizontal pixel width and total vertical pixel height of the large-size image, respectively. and These represent the total horizontal pixel width and total vertical pixel height of the smaller image, respectively. By calculating half of the difference in width and half the difference in height between the two images, and using these as the horizontal and vertical offsets (the calculation results can be rounded down to the nearest pixel integer), the smaller image can be precisely aligned and superimposed onto the center of the larger image. Layer-by-layer superposition of multiple images based on these centering offsets effectively ensures that the temperature images of the coal bunker center, inner ring, and outer ring are centered and overlapped in the vertical and horizontal directions, providing an accurate spatial reference for subsequent panoramic temperature field construction.
[0096] After completing step S6, a standard annular panoramic view of coal temperature distribution is output, which can be directly used for coal bunker safety monitoring and high-temperature hazard investigation.
[0097] This invention also provides a computer-readable storage medium on which a computer program can be stored, wherein the computer program, when executed, implements the steps of the coal bunker infrared annular panoramic temperature imaging method as described in any of the foregoing embodiments.
[0098] It should be noted that the computer-readable storage medium described above in this invention can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory, read-only memory, erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this invention, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.
[0099] In summary, some embodiments of the present invention may have one or more of the following beneficial effects: (1) The gimbal provides 360° precise rotation scanning, covering all raw coal accumulation areas inside the coal bunker, which helps to eliminate or reduce blind spots in traditional temperature measurement and accurately capture hidden high-temperature hazard points; (2) By adopting strict timing control of angle positioning, dust settling posture stabilization, and image acquisition, each frame of infrared temperature image accurately corresponds to the corresponding coal seam position, and the temperature data matching degree is extremely high; (3) Through trapezoidal deformation correction and fading weighted fusion algorithm, image noise and splicing discontinuity caused by coal dust are effectively eliminated or reduced, ensuring continuous temperature images, true pixels, and no distortion of temperature data; (4) The entire process of coal temperature image acquisition, correction, splicing, and ring forming is automated, eliminating the need for manual down-to-the-box operations and avoiding the safety risks of manual temperature measurement; (5) Based on the circular coal storage structure of the coal bunker, an annular coal temperature distribution map with a transparent center and regular rings is automatically generated, matching the distribution pattern of raw coal in the cross section of the coal bunker, and intuitively presenting the temperature field of the entire domain; (6) The temperature images of the central, inner ring, and outer ring coal seams are automatically aligned and superimposed in the center, with clear layers, and can accurately distinguish the temperature differences of raw coal in different areas and different rings; (7) The temperature distribution of raw coal inside the coal bunker can be displayed in real time and intuitively, making it easy for staff to quickly locate high-temperature areas and predict the risk of spontaneous combustion, providing core data support for the fire prevention and explosion prevention safety management of the coal bunker.
[0100] The technical scope of this invention is not limited to the contents of the above specification. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the scope of this invention.
Claims
1. A method for infrared annular panoramic temperature imaging of a coal bunker, characterized in that, include: The gimbal installed on the top of the coal bunker is controlled to rotate step by step according to a preset angle sequence. The gimbal drives the infrared temperature measurement camera fixed to the gimbal to align with the raw coal area in different directions inside the coal bunker in turn. After the gimbal is stabilized, infrared temperature images are collected. Trapezoidal perspective distortion correction was performed on the acquired multi-frame infrared temperature images to correct the edge temperature image distortion caused by the circular space of the coal bunker; The corrected multi-frame infrared temperature images are subjected to fade-out weighted fusion processing to generate a continuous and complete rectangular global coal temperature image. The rectangular global coal temperature image is transformed by polar coordinate mapping to generate an annular coal temperature distribution map adapted to the circular coal storage structure of the coal bunker. The central area of the annular coal temperature distribution map is made transparent to remove invalid images of the central airspace of the coal bunker and retain the annular temperature distribution image of the raw coal accumulation area.
2. The method for infrared annular panoramic temperature imaging of a coal bunker according to claim 1, characterized in that, The preset angle sequence covers the 360° raw coal accumulation area of the coal bunker. The first angle deviates from the zero point of the gimbal reference, and the step size of the remaining angles is equal except for the first angle. Before acquiring each frame of infrared temperature image, a preset time delay is performed to allow the dust in the chamber to settle and the gimbal to stabilize its mechanical attitude. The last frame of the stabilized video is then captured as the valid infrared temperature image.
3. The method for infrared annular panoramic temperature imaging of a coal bunker according to claim 2, characterized in that, The preset duration of the delayed static operation is between 10 and 20 seconds.
4. The method for infrared annular panoramic temperature imaging of a coal bunker according to claim 1, characterized in that, The trapezoidal perspective distortion correction maps the four vertices of the original rectangular image to trapezoidal target vertices, including: The bottom left corner of the original image Map to target point ; The bottom right corner of the original image Map to target point ; The top left corner of the original image Map to target point ; The top right corner of the original image Map to target point ; in, The original image width, To correct the image height, To correct the width of the top edge of the image, This is the horizontal offset, and , This is the scaling factor.
5. The method for infrared annular panoramic temperature imaging of a coal bunker according to claim 4, characterized in that, The scaling factor is configured as follows: For the inner ring raw coal area of the coal bunker, a first scaling factor is used to shrink the upper edge, and for the outer ring raw coal area of the coal bunker, a second scaling factor is used to shrink the upper edge. The first scaling factor is greater than the second scaling factor, and the value of the first scaling factor ranges from 2.6 to 3.2, while the value of the second scaling factor ranges from 1.6 to 2.
2. The difference between the first scaling factor and the second scaling factor is controlled within the range of 0.9 to 1.
1.
6. The method for infrared annular panoramic temperature imaging of a coal bunker according to claim 1, characterized in that, The fading weighted fusion process calculates a weighted average of pixels in the overlapping region of two adjacent infrared temperature images using a linear fading weight. This linear fading weight is dynamically determined based on the horizontal coordinates of the pixels within the overlapping region. The fusion formula is as follows: Among them, linear fading weights , This represents the pixel coordinates of the current pixel in the horizontal direction of the image. The starting horizontal pixel position of the merged region. This represents the total pixel width of the merged region.
7. The method for infrared annular panoramic temperature imaging of a coal bunker according to claim 1, characterized in that, Before performing polar coordinate mapping transformation on the rectangular global coal temperature image, the rectangular global coal temperature image is first rotated and corrected by 180°.
8. The method for infrared annular panoramic temperature imaging of a coal bunker according to claim 1, characterized in that, The polar coordinate mapping transformation includes: The position of each pixel in the rectangular global coal temperature image is converted from the Cartesian coordinate system to polar coordinates with the center of the annular coal temperature distribution map as the origin. The angle component adopts half-angle mapping to adapt to the 360° annular expansion. The angle calculation formula is as follows: In the formula, Let be the coordinates of the current pixel in the rectangular global coal temperature image. The radius of the outer circle of the annular coal temperature distribution map. These are the transformed angular coordinates; Calculate the radial distance from the current pixel to the center of the annular coal temperature distribution map: ; The radial distance is normalized and mapped to the radial pixel coordinates of the annular coal temperature distribution map. The mapping formula is as follows: In the formula, For the mapped radial pixel coordinate index, The radius of the inner circle of the annular coal temperature distribution map. The height of the rectangular global coal temperature image.
9. The method for infrared annular panoramic temperature imaging of a coal bunker according to claim 1, characterized in that, The annular coal temperature distribution map after transparency processing is overlaid with multiple layers centered and aligned. These multiple layers include a central ring, an inner ring, and an outer ring. The center alignment and overlay is performed by calculating the pixel offset of two images of different sizes and overlaying the smaller image onto the center of the larger image. in, and These are the width and height of the larger image, respectively. and These represent the width and height of the smaller image, respectively.
10. A coal bunker infrared annular panoramic temperature imaging system, characterized in that, include: The pan-tilt control module includes a pan-tilt unit installed on the top of the coal bunker; The infrared temperature measurement module includes an infrared temperature measurement camera that is fixedly installed on the pan-tilt unit; The main control module is communicatively connected to the gimbal control module and the infrared temperature measurement module. It is used to control the gimbal to rotate step by step according to a preset angle sequence, so that the infrared temperature measurement camera is aligned with the raw coal area in different directions inside the coal bunker in sequence, and to control the infrared temperature measurement camera to collect infrared temperature images after the gimbal attitude is stable. The image processing module is communicatively connected to the gimbal control module and the infrared temperature measurement module. It is used to perform trapezoidal perspective distortion correction on the acquired multi-frame infrared temperature images, perform fading weighted fusion processing on the corrected multi-frame infrared temperature images to generate a rectangular global coal temperature image, perform polar coordinate mapping transformation on the rectangular global coal temperature image to generate an annular coal temperature distribution map adapted to the circular coal storage structure of the coal bunker, and perform transparency processing on the central area of the annular coal temperature distribution map.
11. A computer-readable storage medium, characterized in that, It stores a computer program, which, when executed by a processor, implements the coal bunker infrared annular panoramic temperature imaging method as described in any one of claims 1 to 9.