A method and system for measuring the distance between a spray gun and a melt surface in a blowing furnace

Abstract

The present invention provides a distance measurement method and system between a spray gun and a melt surface in a blowing furnace, the method comprising: when the furnace body is not in operation, the spray gun is brought into contact with the melt surface to obtain an original image and a liquid level calibration line, the original image including a guide contour area corresponding to a guide object; when the furnace body is in operation, a real-time image is obtained, and the real-time image is converted into a binary image; the binary image is converted into a negative image, and a minimum circumscribed rectangular frame is obtained; a first circumscribed rectangular frame corresponding to the spray gun and a second circumscribed rectangular frame corresponding to the guide object are selected; a correction image is obtained through the guide contour area and the second circumscribed rectangular frame, and the liquid level calibration line is calibrated into the correction image; the distance between the spray gun and the melt surface is determined based on the first circumscribed rectangular frame and the liquid level calibration line. Replacing manual observation with automated and intelligent observation not only allows real-time observation when the furnace body is in operation, and real-time adjustment of the spray gun, but also significantly reduces the error rate, thereby improving the blowing efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of image processing, and in particular to a method and system for measuring the distance between a spray gun and a melt surface in a blowing furnace. Background Art

[0002] The copper pyrometallurgical molten pool smelting currently mainly adopts the blowing process. The blowing process is a blowing technology that uses multiple spray guns. Through multiple upright non-submerged spray guns, oxygen-enriched air is blown into the melt in the furnace to make the oxygen-enriched air react with the white copper matte.

[0003] Under ideal production conditions, the spray gun is suspended about 200mm above the melt surface to feed oxygen-rich air for reaction. However, in actual production, due to the violent reaction of the air supply process in the furnace, the spray gun will suffer losses such as partial melting of the nozzle during the blowing process, causing the spray gun to be suspended above 200mm above the melt surface. If the suspension position of the spray gun is not adjusted in time, the blowing efficiency and production capacity will be affected.

[0004] Currently, the suspension height of the spray gun in the furnace above the melt surface is generally confirmed by manual observation. However, if the observation is carried out during blowing, it is difficult to accurately judge whether the suspension height of the spray gun meets the requirements due to the large amount of smoke and dust in the furnace and the local slight positive pressure state. The error rate is large, and stopping the blowing for observation will affect the blowing efficiency and it is difficult to meet the demand for real-time adjustment of the suspension position of the spray gun. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method and system for measuring the distance between the spray gun and the melt surface in a blowing furnace, aiming to solve the technical problem that in the prior art, the suspension height of the spray gun above the melt surface in the furnace body is confirmed by manual observation. The observation is performed during the blowing state. Due to the complex internal environment of the furnace body, it is difficult to accurately judge whether the suspension height of the spray gun meets the requirements, and the error rate is large. Stopping the blowing for observation will lead to a decrease in the blowing efficiency, and the suspension position of the spray gun cannot be adjusted in real time.

[0006] In order to achieve the above objectives, in a first aspect, an embodiment of the present application provides a method for measuring the distance between a spray gun and a melt surface in a blowing furnace, comprising the following steps:

[0007] When the furnace body provided with the guide object is not in operation, the air outlets of several spray guns are brought into contact with the melt surface, and an original image of the interior of the furnace body is obtained, wherein the original image includes a guide contour area corresponding to the guide object, and a liquid level calibration line is obtained in the original image;

[0008] When the furnace body is in operation, a real-time image of the interior of the furnace body is obtained, grayscale processing is performed on the real-time image to obtain a grayscale image, and binarization processing is performed on the grayscale image to obtain a binarized image;

[0009] Converting the binary image into a negative image, performing contour detection in the negative image to obtain a plurality of contour graphics, and obtaining a minimum circumscribed rectangular frame of the contour graphics;

[0010] Selecting a first circumscribed rectangular frame corresponding to the spray gun and a second circumscribed rectangular frame corresponding to the guide from among the plurality of minimum circumscribed rectangular frames;

[0011] Adjusting the negative film image by means of the guide contour area and the second circumscribed rectangular frame to form a correction image, and calibrating the liquid level calibration line into the correction image;

[0012] The distance between the air outlet of the spray gun and the melt surface is determined based on the first circumscribed rectangular frame and the liquid level calibration line.

[0013] Compared with the prior art, the beneficial effect of the present invention is that: when the furnace body is not in operation, the spray gun is brought into contact with the melt surface, and then the liquid surface line of the melt surface, i.e., the liquid level calibration line, can be fitted through the air outlet position of the spray gun; when the furnace body is in operation, the real-time image is acquired, and the real-time image is processed in a series of ways to acquire the correction image including the first circumscribed rectangular frame, so that the position of the air outlet of the spray gun in the furnace body can be grasped in real time, and then combined with the liquid level calibration line, the distance between the air outlet of the spray gun and the melt surface can be automatically and intelligently acquired, so as to replace manual observation in this way, and not only real-time observation can be performed when the furnace body is in operation, and the suspension position of the spray gun can be adjusted in real time, but also the error rate is significantly reduced compared with manual observation, so as to effectively improve the blowing efficiency; by setting the guide, the guide contour area and the second circumscribed rectangular frame are compared, so that the position deviation between the real-time image and the original image caused by the operation of the furnace body can be corrected to a certain extent, so as to further improve the accuracy of observation and reduce the error.

[0014] Furthermore, the step of obtaining a liquid level calibration line in the original image includes:

[0015] Calibrate the positions of a plurality of air outlets of the spray gun in the original image to obtain a plurality of calibration points;

[0016] A straight line fitting is performed on a plurality of the calibration points to obtain a liquid level calibration line.

[0017] Furthermore, the step of binarizing the grayscale image to obtain a binary image includes:

[0018] Obtaining a maximum pixel value and a minimum pixel value from all pixels in the grayscale image, and determining an initial threshold value based on the maximum pixel value and the minimum pixel value;

[0019] Performing threshold segmentation on the grayscale image using the initial threshold to obtain a first image and a second image;

[0020] Iteratively updating the initial threshold based on average pixel values ​​of the first image and the second image to obtain an optimal threshold;

[0021] The grayscale image is binarized using the optimal threshold to obtain a binarized image.

[0022] Furthermore, the step of converting the binary image into a negative image is specifically as follows:

[0023] Perform an inversion operation on all the pixels in the binary image to obtain a negative image.

[0024] Furthermore, the step of obtaining the minimum circumscribed rectangular frame of the contour graphic is specifically as follows:

[0025] Acquire the coordinates of all pixel points in the contour graphic to form a contour coordinate set, and acquire the centroid coordinates of the contour graphic based on the contour coordinate set to calibrate the centroid point in the contour graphic;

[0026] Generating a horizontal axis and a vertical axis in the contour figure based on the calibrated centroid point, and forming an initial circumscribed rectangular frame surrounding the contour figure through the horizontal axis and the vertical axis;

[0027] The horizontal axis and the vertical axis are rotated several times with the centroid point as the axis to obtain several stage circumscribed rectangular frames, and a minimum circumscribed rectangular frame is determined from the initial circumscribed rectangular frame and the several stage circumscribed rectangular frames.

[0028] Furthermore, the step of selecting a first circumscribed rectangular frame corresponding to the spray gun and a second circumscribed rectangular frame corresponding to the guide from the plurality of the minimum circumscribed rectangular frames comprises:

[0029] Comparing the plurality of minimum circumscribed rectangular frames with a first threshold range to separate the plurality of minimum circumscribed rectangular frames into a first rectangular frame to be eliminated, a first rectangular frame to be selected, and a second rectangular frame to be selected;

[0030] Compare the x-axis coordinate value of the center point of the lower frame of the first rectangular frame to be selected with the first coordinate range to separate the first rectangular frames to be selected into a third rectangular frame to be selected and a second rectangular frame to be removed;

[0031] Comparing the y-axis coordinate value of the center point of the lower frame of the third rectangular frame to be selected with the second coordinate range to separate the plurality of the third rectangular frames to be selected into a first circumscribed rectangular frame corresponding to the spray gun and a third rectangular frame to be removed;

[0032] The plurality of second rectangular frames to be selected are compared with a second threshold range to separate the plurality of second rectangular frames to be selected into a second circumscribed rectangular frame corresponding to the guide and a fourth rectangular frame to be eliminated.

[0033] Furthermore, the step of adjusting the negative image by using the guide contour area and the second circumscribed rectangular frame is specifically as follows:

[0034] Adjusting the position of the negative film image based on the relative position relationship between the guide contour area and the second circumscribed rectangular frame;

[0035] The negative film image is scaled based on the areas of the guide contour area and the second circumscribed rectangular frame.

[0036] Furthermore, the step of determining the distance between the air outlet of the spray gun and the melt surface based on the first circumscribed rectangular frame and the liquid level calibration line is specifically:

[0037] The center point of the lower frame of the first circumscribed rectangular frame is obtained, and the vertical distance between the center point and the liquid level calibration line is calculated to determine the distance between the air outlet of the spray gun and the melt surface.

[0038] In a second aspect, an embodiment of the present application provides a distance measurement system between a spray gun and a melt surface in a blowing furnace, which is applied to the distance measurement method between a spray gun and a melt surface in a blowing furnace as described in the first aspect above, and the system comprises:

[0039] A driving module, used for making the air outlets of a plurality of spray guns contact the melt surface when the furnace body provided with the guide object is not in operation, obtaining an original image of the interior of the furnace body, the original image including a guide contour area corresponding to the guide object, and obtaining a liquid level calibration line in the original image;

[0040] An acquisition module, used for acquiring a real-time image of the interior of the furnace body when the furnace body is in operation, performing grayscale processing on the real-time image to acquire a grayscale image, and performing binarization processing on the grayscale image to acquire a binarized image;

[0041] A processing module, used for converting the binary image into a negative image, performing contour detection in the negative image to obtain a plurality of contour graphics, and obtaining a minimum circumscribed rectangular frame of the contour graphics;

[0042] A selection module, used for selecting a first circumscribed rectangular frame corresponding to the spray gun and a second circumscribed rectangular frame corresponding to the guide from a plurality of the minimum circumscribed rectangular frames;

[0043] An adjustment module, used for adjusting the negative film image through the guide contour area and the second circumscribed rectangular frame to form a correction image, and calibrating the liquid level calibration line into the correction image;

[0044] An execution module is used to determine the distance between the air outlet of the spray gun and the melt surface based on the first circumscribed rectangular frame and the liquid level calibration line.

[0045] In a third aspect, an embodiment of the present application provides a computer, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for measuring the distance between the spray gun and the melt surface in the blowing furnace as described in the first aspect above is implemented.

[0046] In a fourth aspect, an embodiment of the present application provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for measuring the distance between a spray gun and a melt surface in a blowing furnace as described in the first aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flow chart of a method for calculating the distance between a spray gun and a melt surface in a blowing furnace in the first embodiment of the present invention;

[0048] Figure 2 It is a structural block diagram of a distance measurement system between a spray gun and a melt surface in a blowing furnace in a second embodiment of the present invention;

[0049] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0050] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0051] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0053] See also Figure 1 The method for measuring the distance between the spray gun and the melt surface in the blowing furnace provided by the first embodiment of the present invention comprises the following steps:

[0054] S10: when the furnace body provided with the guide object is not in operation, the air outlets of a plurality of spray guns are brought into contact with the melt surface, and an original image of the interior of the furnace body is obtained, wherein the original image includes a guide contour area corresponding to the guide object, and a liquid level calibration line is obtained in the original image;

[0055] In this embodiment, the furnace body is a top-blown furnace, and the guide is arranged on the inner wall of the furnace body. An industrial camera is arranged on the outer wall of the furnace body, and a shooting port corresponding to the position of the industrial camera is provided on the furnace body, and the image of the interior of the furnace body can be obtained through the industrial camera. When the furnace body is not in operation, there is no interference such as smoke inside the furnace body, and at this time, it is convenient to determine the liquid level of the melt surface in the furnace body. However, the melt surface is difficult to accurately distinguish in the image, so the position of the spray gun can be adjusted so that the air outlet of the spray gun abuts the melt surface to complete the acquisition of the liquid level calibration line. Before obtaining the original image, the actual height of the melt surface in the furnace body is determined, all the spray guns on the furnace body are replaced, and the replaced spray guns are lowered to the inside of the furnace body, and the position encoder provided on the spray gun is used to determine that the air outlet of the spray gun abuts the melt surface.

[0056] Specifically, the step S10 includes:

[0057] S110: Calibrate the positions of a plurality of air outlets of the spray guns in the original image to obtain a plurality of calibration points;

[0058] S120: performing straight line fitting on a plurality of the calibration points to obtain a liquid level calibration line.

[0059] In this embodiment, a linear fitting is performed on a plurality of the calibration points by using the least square method, which will not be described in detail here.

[0060] Preferably, after the step of acquiring the liquid level calibration line in the original image, the method further includes acquiring a plurality of calibration lines by adjusting the suspension height of the spray gun, and calibrating the liquid level calibration line based on the plurality of calibration lines.

[0061] It can be understood that the positions of several spray guns can be adjusted synchronously, such as making several spray guns synchronously suspended at 200 mm, 400 mm above the melt surface, etc. The method of obtaining the calibration line is consistent with the steps S110 to S120, and will not be repeated here. The calibration line is compared with the liquid level calibration line to obtain several deflection angles, and the several deflection angles are averaged to obtain the adjustment angle. The liquid level calibration line is calibrated based on the adjustment angle to improve the accuracy of subsequent distance acquisition.

[0062] S20: when the furnace body is in operation, obtaining a real-time image of the interior of the furnace body, performing grayscale processing on the real-time image to obtain a grayscale image, and performing binarization processing on the grayscale image to obtain a binarized image;

[0063] It can be understood that the real-time image and the original image are acquired by the same industrial camera, and the positions where the two are photographed are substantially the same. When the real-time image is gray-scaled by weighted average method.

[0064] The step S20 comprises:

[0065] S210: Obtaining a maximum pixel value and a minimum pixel value from all pixel points in the grayscale image, and determining an initial threshold value based on the maximum pixel value and the minimum pixel value;

[0066] The maximum pixel value and the minimum pixel value are both grayscale values. Initial threshold = (maximum pixel value + minimum pixel value) / 2.

[0067] S220: performing threshold segmentation on the grayscale image using the initial threshold to obtain a first image and a second image;

[0068] After threshold segmentation of the grayscale image using the initial threshold, the first image corresponding to the background area and the second image corresponding to the target area can be obtained. However, this threshold segmentation cannot clearly separate the background area from the target area, and is insufficient to support subsequent capture of the spray gun.

[0069] S230: iteratively updating the initial threshold based on average pixel values ​​of the first image and the second image to obtain an optimal threshold;

[0070] Specifically, the second threshold is obtained by the average pixel value of the first image and the second image, and the second threshold = (average pixel value of the first image + average pixel value of the second image) / 2. After obtaining the second threshold, the grayscale image is threshold segmented by the second threshold to obtain a third image and a fourth image, and the above steps are repeated until a certain threshold is the same as the previous threshold, that is, the optimal threshold is obtained.

[0071] S240: Binarizing the grayscale image using the optimal threshold to obtain a binary image.

[0072] S30: converting the binary image into a negative image, performing contour detection in the negative image to obtain a plurality of contour graphics, and obtaining a minimum circumscribed rectangular frame of the contour graphics;

[0073] The step S30 comprises:

[0074] S310: performing an inversion operation on all pixels in the binary image to obtain a negative image;

[0075] The essence of the binary image is a black and white image, that is, a white image representing the background area and a black image representing the target area, and the pixel values ​​in the image are 0 and 1 respectively. Through the inversion operation, the pixel value of the pixel point with a pixel value of 0 is converted to 1, and the pixel value of the pixel point with a pixel value of 1 is converted to 0, that is, the white image representing the background area is converted to a black image, and the black image representing the target area is converted to a white image. By obtaining the negative image, the subsequent contour detection can be ensured to be more accurate.

[0076] In this embodiment, after acquiring the negative film image, the contour graphic is acquired by using an edge detection algorithm. The edge detection algorithm has many applications and will not be described in detail here.

[0077] S320: Acquire coordinates of all pixel points in the contour graphic to form a contour coordinate set, and acquire centroid coordinates of the contour graphic based on the contour coordinate set to calibrate a centroid point in the contour graphic;

[0078] The calculation formula of the centroid coordinates is:

[0079] ,

[0080] in, represents the abscissa of the centroid point, represents the ordinate of the centroid point, Represents the horizontal coordinate of the i-th pixel point in the contour graph, Represents the ordinate of the i-th pixel in the contour graph, Represents the horizontal coordinate of the i-1th pixel point in the contour graphic, Represents the ordinate of the i-1th pixel point in the contour graphic, Indicates the number of pixels in the contour graphic. Represents the set of pixels in the contour graphic, , All represent calculation parameters.

[0081] S330: generating a horizontal axis and a vertical axis in the contour figure based on the centroid point, and forming an initial circumscribed rectangular frame surrounding the contour figure through the horizontal axis and the vertical axis;

[0082] The horizontal axis is moved parallel to the direction of the vertical axis. When the horizontal axis intersects with the last point at the top of the contour figure, the top side of the initial circumscribed rectangular frame is formed. When the horizontal axis intersects with the last point at the bottom of the contour figure, the bottom side of the initial circumscribed rectangular frame is formed. The vertical axis is moved parallel to the direction of the horizontal axis. When the vertical axis intersects with the last point at the opposite ends of the contour figure respectively, the two side sides of the initial circumscribed rectangular frame are formed, thereby enclosing the initial circumscribed rectangular frame.

[0083] S340: taking the centroid point as the axis, rotating the horizontal axis and the vertical axis several times to obtain several stage circumscribed rectangular frames, and determining a minimum circumscribed rectangular frame from the initial circumscribed rectangular frame and the several stage circumscribed rectangular frames;

[0084] The sum of the angles of several rotations is 90°. By rotating the horizontal axis and the vertical axis, the stage circumscribed rectangular frame can be obtained in the same way as step S330. The areas of the initial circumscribed rectangular frame and several stage circumscribed rectangular frames are compared, and the one with the smallest area is selected as the minimum circumscribed rectangular frame.

[0085] S40: selecting a first circumscribed rectangular frame corresponding to the spray gun and a second circumscribed rectangular frame corresponding to the guide from among the plurality of minimum circumscribed rectangular frames;

[0086] The step S40 comprises:

[0087] S410: comparing the plurality of minimum circumscribed rectangular frames with a first threshold range to separate the plurality of minimum circumscribed rectangular frames into a first rectangular frame to be eliminated, a first rectangular frame to be selected, and a second rectangular frame to be selected;

[0088] When the shooting position and the shooting angle remain unchanged, the overall range of the spray gun is relatively stable. Therefore, the minimum circumscribed rectangular frame can be preliminarily screened through the first threshold range. When the sum of the side lengths of the minimum circumscribed rectangular frame is greater than the first threshold range, it is determined to be the first rectangular frame to be selected. When the sum of the side lengths of the minimum circumscribed rectangular frame falls within the first threshold range, it is determined to be the first rectangular frame to be selected. When the sum of the side lengths of the minimum circumscribed rectangular frame is less than the first threshold range, it is determined to be the second rectangular frame to be selected.

[0089] S420: comparing the x-axis coordinate value of the center point of the lower frame of the first candidate rectangular frame with the first coordinate range to separate the first candidate rectangular frames into a third candidate rectangular frame and a second candidate rectangular frame;

[0090] S430: comparing the y-axis coordinate value of the center point of the lower frame of the third rectangular frame to be selected with the second coordinate range, so as to separate the third rectangular frames to be selected into a first circumscribed rectangular frame corresponding to the spray gun and a third rectangular frame to be removed;

[0091] After obtaining the first selected rectangular box, if its selection range is the spray gun, the center point of its lower frame is the air outlet of the spray gun. By comparing it with the first coordinate range and the second coordinate range, it can be determined whether the position of the first selected rectangular box is compatible with the position of the spray gun, thereby more accurately screening out the first external rectangular box.

[0092] S440: Compare the plurality of second rectangular frames to be selected with a second threshold range to separate the plurality of second rectangular frames to be selected into a second circumscribed rectangular frame corresponding to the guide and a fourth rectangular frame to be eliminated.

[0093] The screening rule of the second rectangular box to be selected is consistent with the screening rule of the first rectangular box to be selected, and will not be described in detail here.

[0094] S50: adjusting the negative film image through the guide contour area and the second circumscribed rectangular frame to form a correction image, and calibrating the liquid level calibration line into the correction image;

[0095] The step S50 comprises:

[0096] S510: adjusting the position of the negative film image based on the relative position relationship between the guide contour area and the second circumscribed rectangular frame;

[0097] Respectively obtain two corresponding corner points of the guiding contour area and the second circumscribed rectangular frame, perform a primary adjustment on the negative image through the two corner points, obtain two corresponding side lines of the guiding contour area and the second circumscribed rectangular frame, determine a rotation angle based on the two corner points and the two side lines, and perform a secondary adjustment on the negative image through the rotation angle.

[0098] S520: scaling the negative image based on the guide contour area and the area of ​​the second circumscribed rectangular frame;

[0099] The scaling adjustment is to enlarge or reduce the negative film image, and the adjustment coefficient is determined by the area ratio of the guide contour area and the second circumscribed rectangular frame.

[0100] By setting the guide object and comparing the guide contour area and the second circumscribed rectangular frame, it is possible to avoid slight deviations of the industrial camera caused by vibrations during operation of the furnace, which in turn causes position deviations between the acquired real-time image and the original image. Correcting the real-time image to a certain extent can further improve the accuracy of observation and reduce errors.

[0101] S60: Determine the distance between the air outlet of the spray gun and the melt surface based on the first circumscribed rectangular frame and the liquid level calibration line.

[0102] The center point of the lower frame of the first circumscribed rectangular frame is obtained, and the vertical distance between the center point and the liquid level calibration line is calculated to determine the distance between the air outlet of the spray gun and the melt surface. It can be understood that different first circumscribed rectangular frames represent different spray guns. By obtaining the distance between the center point of the lower frame of the first circumscribed rectangular frame and the melt surface, the distance between the air outlet of different spray guns and the melt surface can be obtained, and then the lifting parameters can be set respectively, and the suspension height of different spray guns can be adjusted separately to ensure that they are always at the optimal suspension height.

[0103] When the furnace body is not operating, the spray gun is brought into contact with the melt surface, and the liquid surface line of the melt surface, i.e., the liquid level calibration line, can be fitted through the air outlet position of the spray gun. When the furnace body is operating, the real-time image is acquired, and a series of processes are performed on the real-time image to acquire the corrected image including the first circumscribed rectangular frame. The position of the air outlet of the spray gun in the furnace body can be grasped in real time, and then combined with the liquid level calibration line, the distance between the air outlet of the spray gun and the melt surface can be acquired automatically and intelligently. In this way, manual observation can be replaced, and not only real-time observation can be performed when the furnace body is operating, and the suspension position of the spray gun can be adjusted in real time, but also the error rate is significantly reduced compared with manual observation, thereby effectively improving the blowing efficiency.

[0104] See also Figure 2 The second embodiment of the present invention provides a distance measurement system between a spray gun and a melt level in a blowing furnace. The system is applied to the distance measurement method between a spray gun and a melt level in a blowing furnace described in the above embodiment. The description has been made and will not be repeated. As used below, the terms "module", "unit", "subunit" and the like can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation in hardware, or a combination of software and hardware, is also possible and conceivable.

[0105] The system comprises:

[0106] The driving module 10 is used to make the air outlets of several spray guns abut against the melt surface when the furnace body provided with the guide object is not in operation, obtain an original image of the interior of the furnace body, the original image includes a guide contour area corresponding to the guide object, and obtain a liquid level calibration line in the original image;

[0107] The driving module 10 comprises:

[0108] The first unit is used to calibrate the positions of the air outlets of the spray guns in the original image to obtain a plurality of calibration points;

[0109] The second unit is used to perform straight line fitting on a plurality of the calibration points to obtain a liquid level calibration line;

[0110] An acquisition module 20, used for acquiring a real-time image of the interior of the furnace body when the furnace body is in operation, performing grayscale processing on the real-time image to acquire a grayscale image, and performing binarization processing on the grayscale image to acquire a binarized image;

[0111] The acquisition module 20 includes:

[0112] A third unit is used to obtain a maximum pixel value and a minimum pixel value from all pixel points in the grayscale image, and determine an initial threshold value based on the maximum pixel value and the minimum pixel value;

[0113] A fourth unit is used to perform threshold segmentation on the grayscale image by using the initial threshold to obtain a first image and a second image;

[0114] A fifth unit, configured to iteratively update the initial threshold based on an average pixel value of the first image and the second image to obtain an optimal threshold;

[0115] A sixth unit is used to perform binarization processing on the grayscale image by using the optimal threshold value to obtain a binarized image;

[0116] A processing module 30 is used to convert the binary image into a negative image, perform contour detection in the negative image to obtain a plurality of contour graphics, and obtain a minimum circumscribed rectangular frame of the contour graphics;

[0117] The processing module 30 includes:

[0118] The seventh unit is used to perform an inversion operation on all the pixels in the binary image to obtain a negative image;

[0119] An eighth unit is used to obtain the coordinates of all pixel points in the contour graphic to form a contour coordinate set, and obtain the centroid coordinates of the contour graphic based on the contour coordinate set to calibrate the centroid point in the contour graphic;

[0120] A ninth unit, configured to generate a horizontal axis and a vertical axis in the contour figure based on the centroid point, and form an initial circumscribed rectangular frame surrounding the contour figure through the horizontal axis and the vertical axis;

[0121] A tenth unit is used to rotate the horizontal axis and the vertical axis several times with the centroid point as the axis center to obtain several stage circumscribed rectangular frames, and determine a minimum circumscribed rectangular frame from the initial circumscribed rectangular frame and the several stage circumscribed rectangular frames;

[0122] A selection module 40, for selecting a first circumscribed rectangular frame corresponding to the spray gun and a second circumscribed rectangular frame corresponding to the guide from among the plurality of minimum circumscribed rectangular frames;

[0123] The selection module 40 comprises:

[0124] The eleventh unit is used to compare the plurality of the minimum circumscribed rectangular frames with a first threshold range to separate the plurality of the minimum circumscribed rectangular frames into a first rectangular frame to be eliminated, a first rectangular frame to be selected and a second rectangular frame to be selected;

[0125] A twelfth unit is used to compare the x-axis coordinate value of the center point of the lower frame of the first rectangular frame to be selected with the first coordinate range to separate the first rectangular frames to be selected into a third rectangular frame to be selected and a second rectangular frame to be removed;

[0126] The thirteenth unit is used to compare the y-axis coordinate value of the center point of the lower frame of the third rectangular frame to be selected with the second coordinate range to separate the plurality of the third rectangular frames to be selected into a first circumscribed rectangular frame corresponding to the spray gun and a third rectangular frame to be removed;

[0127] The fourteenth unit is used to compare the plurality of the second rectangular frames to be selected with a second threshold range to separate the plurality of the second rectangular frames to be selected into a second circumscribed rectangular frame corresponding to the guide and a fourth rectangular frame to be eliminated;

[0128] An adjustment module 50, configured to adjust the negative film image through the guide contour area and the second circumscribed rectangular frame to form a correction image, and to calibrate the liquid level calibration line into the correction image;

[0129] The adjustment module 50 includes:

[0130] A fifteenth unit, configured to adjust the position of the negative film image based on the relative position relationship between the guide contour area and the second circumscribed rectangular frame;

[0131] A sixteenth unit, configured to scale the negative image based on the areas of the guide contour area and the second circumscribed rectangular frame;

[0132] An execution module 60 is used to determine the distance between the air outlet of the spray gun and the melt surface based on the first circumscribed rectangular frame and the liquid level calibration line;

[0133] The execution module 60 is specifically used to obtain the center point of the lower frame of the first circumscribed rectangular frame, calculate the vertical distance between the center point and the liquid level calibration line, so as to determine the distance between the air outlet of the spray gun and the melt surface.

[0134] The present invention also provides a computer, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for measuring the distance between the spray gun and the melt surface in the blowing furnace as described in the above technical solution is implemented.

[0135] The present invention also provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for measuring the distance between the spray gun and the melt surface in the blowing furnace as described in the above technical solution is implemented.

[0136] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0137] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for measuring the distance between a spray gun and a melt surface in a blowing furnace, characterized in that: The following steps are involved: When the furnace body provided with the guide object is not in operation, the air outlets of several spray guns are brought into contact with the melt surface, and an original image of the interior of the furnace body is obtained, wherein the original image includes a guide contour area corresponding to the guide object, and a liquid level calibration line is obtained in the original image; When the furnace body is in operation, a real-time image of the interior of the furnace body is obtained, grayscale processing is performed on the real-time image to obtain a grayscale image, and binarization processing is performed on the grayscale image to obtain a binarized image; Converting the binary image into a negative image, performing contour detection in the negative image to obtain a plurality of contour graphics, and obtaining a minimum circumscribed rectangular frame of the contour graphics; Selecting a first circumscribed rectangular frame corresponding to the spray gun and a second circumscribed rectangular frame corresponding to the guide from among the plurality of minimum circumscribed rectangular frames; The step of selecting a first circumscribed rectangular frame corresponding to the spray gun and a second circumscribed rectangular frame corresponding to the guide from the plurality of the minimum circumscribed rectangular frames comprises: Comparing the plurality of minimum circumscribed rectangular frames with a first threshold range to separate the plurality of minimum circumscribed rectangular frames into a first rectangular frame to be eliminated, a first rectangular frame to be selected, and a second rectangular frame to be selected; Compare the x-axis coordinate value of the center point of the lower frame of the first rectangular frame to be selected with the first coordinate range to separate the first rectangular frames to be selected into a third rectangular frame to be selected and a second rectangular frame to be removed; Comparing the y-axis coordinate value of the center point of the lower frame of the third rectangular frame to be selected with the second coordinate range to separate the plurality of the third rectangular frames to be selected into a first circumscribed rectangular frame corresponding to the spray gun and a third rectangular frame to be removed; Comparing the plurality of second rectangular frames to be selected with a second threshold range to separate the plurality of second rectangular frames to be selected into a second circumscribed rectangular frame corresponding to the guide and a fourth rectangular frame to be eliminated; Adjusting the negative film image by means of the guide contour area and the second circumscribed rectangular frame to form a correction image, and calibrating the liquid level calibration line into the correction image; The distance between the air outlet of the spray gun and the melt surface is determined based on the first circumscribed rectangular frame and the liquid level calibration line.

2. The method for calculating the distance between the spray gun and the melt surface in the blowing furnace according to claim 1, characterized in that: The step of obtaining a liquid level calibration line in the original image comprises: Calibrate the positions of a plurality of air outlets of the spray gun in the original image to obtain a plurality of calibration points; A straight line fitting is performed on a plurality of the calibration points to obtain a liquid level calibration line.

3. The method for calculating the distance between the spray gun and the melt surface in a blowing furnace according to claim 1, characterized in that: The step of performing binarization processing on the grayscale image to obtain a binary image comprises: Obtaining a maximum pixel value and a minimum pixel value from all pixels in the grayscale image, and determining an initial threshold value based on the maximum pixel value and the minimum pixel value; Performing threshold segmentation on the grayscale image using the initial threshold to obtain a first image and a second image; Iteratively updating the initial threshold based on average pixel values ​​of the first image and the second image to obtain an optimal threshold; The grayscale image is binarized using the optimal threshold to obtain a binarized image.

4. The method for calculating the distance between the spray gun and the melt surface in a blowing furnace according to claim 1, characterized in that: The step of converting the binary image into a negative image is specifically as follows: Perform an inversion operation on all the pixels in the binary image to obtain a negative image.

5. The method for calculating the distance between the spray gun and the melt surface in a blowing furnace according to claim 1, characterized in that: The step of obtaining the minimum circumscribed rectangular frame of the contour graphic is specifically as follows: Acquire the coordinates of all pixel points in the contour graphic to form a contour coordinate set, and acquire the centroid coordinates of the contour graphic based on the contour coordinate set to calibrate the centroid point in the contour graphic; Generating a horizontal axis and a vertical axis in the outline figure based on the centroid point, and forming an initial circumscribed rectangular frame surrounding the outline figure through the horizontal axis and the vertical axis; The horizontal axis and the vertical axis are rotated several times with the centroid point as the axis to obtain several stage circumscribed rectangular frames, and a minimum circumscribed rectangular frame is determined from the initial circumscribed rectangular frame and the several stage circumscribed rectangular frames.

6. The method for calculating the distance between the spray gun and the melt surface in a blowing furnace according to claim 1, characterized in that: The step of adjusting the negative image by using the guide contour area and the second circumscribed rectangular frame is specifically as follows: Adjusting the position of the negative film image based on the relative position relationship between the guide contour area and the second circumscribed rectangular frame; The negative film image is scaled based on the areas of the guide contour area and the second circumscribed rectangular frame.

7. The method for calculating the distance between the spray gun and the melt surface in a blowing furnace according to claim 1, characterized in that: The step of determining the distance between the air outlet of the spray gun and the melt surface based on the first circumscribed rectangular frame and the liquid level calibration line is specifically: The center point of the lower frame of the first circumscribed rectangular frame is obtained, and the vertical distance between the center point and the liquid level calibration line is calculated to determine the distance between the air outlet of the spray gun and the melt surface.

8. A system for measuring the distance between a spray gun and a melt surface in a converting furnace, applied to the method for measuring the distance between a spray gun and a melt surface in a converting furnace as claimed in any one of claims 1 to 7, characterized in that: The system comprises: A driving module, used for making the air outlets of a plurality of spray guns contact the melt surface when the furnace body provided with the guide object is not in operation, obtaining an original image of the interior of the furnace body, the original image including a guide contour area corresponding to the guide object, and obtaining a liquid level calibration line in the original image; An acquisition module, used for acquiring a real-time image of the interior of the furnace body when the furnace body is in operation, performing grayscale processing on the real-time image to acquire a grayscale image, and performing binarization processing on the grayscale image to acquire a binarized image; A processing module, used for converting the binary image into a negative image, performing contour detection in the negative image to obtain a plurality of contour graphics, and obtaining a minimum circumscribed rectangular frame of the contour graphics; A selection module, used for selecting a first circumscribed rectangular frame corresponding to the spray gun and a second circumscribed rectangular frame corresponding to the guide from a plurality of the minimum circumscribed rectangular frames; The selection module comprises: The eleventh unit is used to compare the plurality of the minimum circumscribed rectangular frames with a first threshold range to separate the plurality of the minimum circumscribed rectangular frames into a first rectangular frame to be eliminated, a first rectangular frame to be selected and a second rectangular frame to be selected; A twelfth unit is used to compare the x-axis coordinate value of the center point of the lower frame of the first rectangular frame to be selected with the first coordinate range to separate the first rectangular frames to be selected into a third rectangular frame to be selected and a second rectangular frame to be removed; The thirteenth unit is used to compare the y-axis coordinate value of the center point of the lower frame of the third rectangular frame to be selected with the second coordinate range to separate the plurality of the third rectangular frames to be selected into a first circumscribed rectangular frame corresponding to the spray gun and a third rectangular frame to be removed; The fourteenth unit is used to compare the plurality of the second rectangular frames to be selected with a second threshold range to separate the plurality of the second rectangular frames to be selected into a second circumscribed rectangular frame corresponding to the guide and a fourth rectangular frame to be eliminated; An adjustment module, used for adjusting the negative film image through the guide contour area and the second circumscribed rectangular frame to form a correction image, and calibrating the liquid level calibration line into the correction image; An execution module is used to determine the distance between the air outlet of the spray gun and the melt surface based on the first circumscribed rectangular frame and the liquid level calibration line.

9. A computer comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for measuring the distance between the spray gun and the melt surface in the blowing furnace according to any one of claims 1 to 7 is implemented.

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