Non-contact temperature measurement system

Abstract

This reduces the effort required to carefully examine the output temperature. [Solution] The non-contact temperature measurement system measures the temperature of molten metal M in a non-contact manner. The imaging device 10 includes a solid-state image sensor 11 configured to receive radiant light emitted from the measurement target area A where the molten metal M appears at predetermined intervals and to image the measurement target area A. The information processing device 20 includes a histogram creation unit 21 that creates a brightness value histogram showing the distribution of brightness values ​​of pixels in the captured image data, a representative pixel count detection unit 22 that detects a representative pixel count based on the created brightness value histogram, a temperature calculation unit 23 that calculates the temperature of the measurement target area A based on the detected representative pixel count, and an output unit 24 that outputs the calculated temperature. The output unit 24 is configured to output the temperature when the representative pixel count is equal to or greater than a predetermined number of pixels, which is a value obtained when the molten metal M is imaged, but not to output the temperature when it is less than the predetermined number of pixels.

Description

Technical Field

[0001] The present invention relates to a non-contact temperature measurement system.

Background Art

[0002] Patent Document 1 discloses a temperature measurement system for non-contact measurement of the temperature of a heated measurement object. The temperature measurement system described in Patent Document 1 includes an imaging device and an information processing device. The imaging device is configured to receive radiation in the near-infrared band among the radiation emitted from the measurement object and image the measurement object. The information processing device includes a histogram creation unit, a representative pixel number detection unit, and a temperature calculation unit. The histogram creation unit creates a luminance value histogram showing the distribution of the luminance values of the pixels in the image data captured by the imaging device. The representative pixel number derivation unit derives the representative pixel number based on the luminance value histogram. The temperature calculation unit calculates the temperature of the measurement object based on the representative pixel number.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, in the casting process of pouring molten metal (hereinafter referred to as "molten metal"), when measuring the temperature of molten metal poured from a ladle into a mold, it is conceivable to image the molten metal flowing out of the ladle using an imaging device. In this case, it is conceivable to image the region from which the molten metal flows out using the imaging device at predetermined intervals from before the molten metal appears, and to calculate the temperature of the above region based on each of the captured image data. However, the temperature calculated before the molten metal appears in the above region is the temperature of something other than the molten metal, i.e., the temperature of something other than the object being measured. Therefore, if such temperatures other than the object being measured are output to a display device, a problem arises in that it becomes necessary to scrutinize the outputted temperature. [Means for solving the problem]

[0005] This document describes various embodiments of a non-contact temperature measurement system designed to solve the above problems. [Aspect 1] A non-contact temperature measurement system for measuring the temperature of a heated object without contact, Imaging device and Equipped with an information processing device, The imaging device includes a solid-state image sensor configured to receive synchrotron radiation emitted from the measurement target area where the object to be measured appears at predetermined intervals and to image the measurement target area. The aforementioned information processing device is A histogram creation unit creates a luminance value histogram showing the distribution of luminance values ​​of pixels in image data captured by the solid-state image sensor, A representative pixel count detection unit detects a representative pixel count based on the luminance value histogram created by the histogram creation unit, A temperature calculation unit that calculates the temperature of the measurement target area based on the representative pixel count detected by the representative pixel count detection unit, The system comprises an output unit that outputs the temperature calculated by the temperature calculation unit, The output unit is configured to output the temperature calculated by the temperature calculation unit when the representative number of pixels is equal to or greater than a predetermined number of pixels obtained when imaging the heated object to be measured, but not to output the temperature when it falls below the predetermined number of pixels. Non-contact temperature measurement system.

[0006] With this configuration, the temperature calculated by the temperature calculation unit is output when the number of representative pixels is equal to or greater than the predetermined number of pixels, while the temperature is not output when the number of representative pixels falls below the predetermined number of pixels. Therefore, the temperature is output only when the temperature of the measurement area is calculated based on the imaging data of the heated object being measured. As a result, the temperature is not output when the temperature of the measurement area is calculated based on imaging data when the heated object being measured is not being imaged, thus preventing, for example, the output of temperatures other than those of the object being measured.

[0007] Furthermore, when the measurement target area is constantly monitored, the load on the information processing device used in the output unit, specifically the CPU and memory load of the information processing device, is reduced, making it possible to quickly output the temperature when the object to be measured appears in the measurement target area. In addition, it is possible to suppress the output of the temperature of an object other than the object to be measured for which output is required. Moreover, in a state where temperature output is not performed because the number of representative pixels falls below a predetermined number, it is possible to resume temperature output when the number of representative pixels rises above the predetermined number again.

[0008] Therefore, the effort required to scrutinize the output temperature can be reduced. [Aspect 2] The temperature calculation unit is configured to calculate the temperature only when the number of representative pixels is equal to or greater than the predetermined number of pixels. A non-contact temperature measurement system according to Embodiment 1.

[0009] With this configuration, temperature calculation is performed only when the number of representative pixels exceeds the predetermined number of pixels. Therefore, when constantly monitoring the measurement target area, the load on the information processing device used in the temperature calculation unit, specifically the CPU and memory load of the information processing device, is reduced, making it possible to quickly start calculating and outputting the temperature when the object to be measured appears in the measurement target area. Furthermore, if the temperature calculation is stopped because the number of representative pixels falls below the predetermined number of pixels, it is possible to resume temperature calculation when the number of representative pixels exceeds the predetermined number of pixels again. Thus, when constantly monitoring the measurement target area, the load on the information processing device used in the temperature calculation unit is reduced, making it possible to increase the temperature calculation speed.

[0010] [Aspect 3] When the aforementioned predetermined time is set to the first predetermined time, The output unit is configured not to output the temperature during the period from when the number of representative pixels becomes equal to or greater than the predetermined number of pixels until a second predetermined time has elapsed. A non-contact temperature measurement system according to Embodiment 1 or Embodiment 2.

[0011] For example, in the melting process of casting, when measuring the temperature of molten metal contained in a container with the lid of the container open, or in the alloy addition process where an alloy such as a magnesium alloy is added to the molten metal, when the ladle is transported and reaches a predetermined position including the measurement target area, or in the pouring process when measuring the temperature of molten metal poured from the ladle into the mold, the following problems may occur if a large amount of steam or splashes are temporarily generated, or if the ladle is being transported. Specifically, if image data is obtained in an environment where a large amount of other substances that can hinder the detection of the measurement target are interposed between the imaging device and the measurement target due to steam, splashes, or the transport of the ladle, the temperature of the measurement target calculated based on the image data may deviate significantly from the actual temperature. Furthermore, if image data of something other than the measurement target, such as the furnace wall refractory material constituting the ladle, is obtained when the ladle is transported and appears in the measurement target area, the temperature of the measurement target calculated based on the image data may deviate significantly from the actual temperature. In other words, the temperature of the object being measured, calculated based on image data acquired immediately after the number of representative pixels exceeds the predetermined number of pixels, may deviate significantly from the actual temperature.

[0012] In this regard, with the above configuration, no temperature is output during the period from when the number of representative pixels exceeds the predetermined number of pixels until the second predetermined time has elapsed. As a result, the output of temperature is suppressed during the period until the influence of other substances that may be inhibiting factors, such as when the object to be measured is in focus, becomes negligibly small. In addition, even if the number of representative pixels exceeds the predetermined number of pixels due to the appearance of something other than the object to be measured, such as furnace wall refractory material, in the measurement area, no temperature is output during the period until the second predetermined time has elapsed. As a result, the output of temperatures of things other than the object to be measured, such as furnace wall refractory material, can be suppressed. Therefore, it is possible to suppress the output of image data in environments where the influence of other substances that may be inhibiting factors, such as when the object to be measured is not in focus, is significant, and to suppress the output of temperatures that deviate significantly from the actual temperature due to image data of things other than the object to be measured.

[0013] Furthermore, as a method for measuring the second predetermined time, the elapsed time after the number of representative pixels exceeds the predetermined number of pixels may be measured, or the number of temperature outputs after the number of representative pixels exceeds the predetermined number of pixels may be counted, and it may be determined that the second predetermined time has elapsed when the number of such outputs reaches a number corresponding to the second predetermined time.

[0014] [Aspect 4] The output unit is configured not to output the temperature after a third predetermined time, which is longer than the second predetermined time, has elapsed since the number of representative pixels reached or exceeded the predetermined number of pixels. A non-contact temperature measurement system as described in Embodiment 3.

[0015] For example, when measuring the temperature of molten metal poured from a ladle into a mold during the casting process, splashes of molten metal are likely to occur in the latter half of the pouring process, especially at the end. Because these splashes have a high contrast with their surroundings, the temperature of the object being measured, calculated based on imaging data including the splashes, may deviate significantly from the actual temperature. Furthermore, in the alloy addition process of casting, there is a risk that a temperature different from the one that should be measured may be output after the alloy addition or after the removal of impurities consisting of metal oxides called slag, which should be removed from the cast iron, known as slag removal.

[0016] In this regard, with the above configuration, after the number of representative pixels exceeds the predetermined number of pixels, and after a third predetermined time longer than the second predetermined time has elapsed, the temperature is not output. As a result, the temperature is not output in the latter half of the pouring process, especially at the end, when molten metal splashes are likely to occur. Furthermore, in the alloy addition process, it is possible to avoid outputting a temperature different from the temperature that should be measured after the alloy is added. Therefore, it is possible to suppress the output of a temperature that deviates significantly from the actual temperature.

[0017] As a method for measuring the third predetermined time, it is also possible to measure the elapsed time since the number of representative pixels has become equal to or greater than the predetermined number of pixels, or to count the number of times the temperature is output since the number of representative pixels has become equal to or greater than the predetermined number of pixels, and to determine that the third predetermined time has elapsed when the number of output times has reached the number corresponding to the third predetermined time.

[0018] [Aspect 5] The object to be measured is a molten metal in a predetermined process of casting or a metal plate in a predetermined process of hot rolling, The output unit is configured to be able to receive a signal from a control unit that controls the predetermined process of casting or the predetermined process of hot rolling so that the object to be measured appears in the measurement target region, and to output the temperature calculated by the temperature calculation unit in association with the signal after receiving the signal. The non-contact temperature measurement system according to any one of Aspects 1 to 5.

[0019] According to this configuration, after the output unit receives the above signal from the control unit that controls the predetermined process of casting or the predetermined process of hot rolling, the temperature calculated by the temperature calculation unit is output in association with the signal. Thereby, it is possible to suppress the correspondence relationship between the output temperature and the above predetermined process from becoming unclear.

[0020] [Aspect 6] The output unit is configured not to output the temperature when the temperature calculated by the temperature calculation unit is higher than or equal to an upper limit value higher than the maximum value of the temperature that the object to be measured can reach in the predetermined process of casting or the predetermined process of hot rolling. The non-contact temperature measurement system according to Aspect 5.

[0021] In the alloy addition process of casting, when measuring the temperature of molten metal contained in a container such as a ladle that has been transported to a predetermined position for alloy addition, or in the pouring process, when measuring the temperature of molten metal poured from the ladle into the mold, the following problems may occur. Specifically, if image data is obtained in an environment where a large amount of other substances that can hinder the detection of the object being measured are interposed between the imaging device and the object being measured, such as the movement of the molten metal due to the transport of the container, or steam or splashes causing the object to be out of focus, the temperature of the object being measured calculated based on the image data may deviate significantly from the actual temperature.

[0022] In particular, when measuring the temperature of molten metal poured from a ladle into a mold, splashes of molten metal are likely to occur in the latter half of the pouring process, especially at the very end. Because these splashes have a high contrast with their surroundings, the temperature of the object being measured, calculated based on imaging data including the splashes, may deviate significantly from the actual temperature.

[0023] In this regard, with the above configuration, if the calculated temperature is above an upper limit that is higher than the maximum temperature the molten metal can reach in the pouring process or alloy addition process, the temperature will not be output. Therefore, it is possible to suppress the output of a temperature that deviates significantly from the actual temperature.

[0024] [Aspect 7] The output unit is configured to output the temperature calculated by the temperature calculation unit to the control unit. A non-contact temperature measurement system according to embodiment 5 or embodiment 6.

[0025] With this configuration, if the representative number of pixels is equal to or greater than a predetermined number of pixels obtained when imaging molten metal or a metal sheet, the temperature calculated by the temperature calculation unit can be output to the control unit. This allows the control unit to utilize the temperature information of the molten metal or metal sheet when controlling a predetermined process of casting or a predetermined process of hot rolling. [Effects of the Invention]

[0026] According to the present invention, the effort required to carefully examine the output temperature can be reduced. [Brief explanation of the drawing]

[0027] [Figure 1] Figure 1 is a block diagram showing the electrical configuration of one embodiment of a non-contact temperature measurement system. [Figure 2] Figure 2 is a luminance value histogram showing the relationship between the luminance value gradation and the number of pixels. [Figure 3] Figure 3 is a graph showing the relationship between the temperature of the object being measured and the number of representative pixels. [Figure 4] Figure 4 shows the display screen of the device. [Figure 5] Figures 5(a) to 5(f) are timing charts showing an example of the time progression of imaging, pouring process execution signal, ladle orientation, representative pixel count, calculated temperature, and output temperature. [Modes for carrying out the invention]

[0028] An embodiment of a non-contact temperature measurement system will be described below with reference to Figures 1 to 5. As shown in Figure 1, the non-contact temperature measurement system of this embodiment measures the temperature of molten metal (hereinafter referred to as molten metal M) poured from a ladle 81 into a mold 90 during the casting pouring process in a non-contact manner, and comprises an imaging device 10, an information processing device 20, and a display device 30. The pouring process corresponds to a predetermined process in the section on means for solving the problem.

[0029] The molten metal M is cast iron in a molten state heated to over 1300°C and is contained in the ladle 81 of the pouring machine 80. <Pouring machine 80 and mold 90> As shown in Figure 1, the pouring machine 80 includes a ladle 81 that is tilted around a tilting axis 84 by an electric motor (not shown), and a control unit 85 that controls the tilting of the ladle 81 through the control of the electric motor.

[0030] The ladle 81 is configured to be tiltable between an upright position shown by the dashed line in Figure 1 and an inclined position shown by the solid line in Figure 1. A lid 82 is attached to the ladle 81. The lid 82 opens and closes the portion of the ladle 81's upper opening other than the spout 83 into which the molten metal M is poured.

[0031] In this embodiment, the pouring machine 80 is immovably positioned on the floor of the foundry. The control unit 85 controls the pouring process by the pouring machine 80 and is connected to the information processing device 20 (described later) by wire or wireless connection. The control unit 85 includes an industrial controller or repeater and is configured to communicate with the information processing device 20.

[0032] The mold 90 is provided so that it can be transported by a transport trolley (not shown). Multiple molds 90 are arranged side by side in the transport direction of the transport trolley. <Imaging device 10> As shown in Figure 1, the imaging device 10 includes a solid-state image sensor 11. The solid-state image sensor 11 is configured to receive synchrotron radiation emitted from the measurement target area A where molten metal M appears at first predetermined time intervals Δt1, and to image the measurement target area A. The imaging device 10 also includes a bandpass filter 12. The bandpass filter 12 blocks the transmission of synchrotron radiation in bands other than the near-infrared band from the synchrotron radiation emitted from the measurement target area A, thereby allowing the solid-state image sensor 11 to receive synchrotron radiation in the near-infrared band. The measurement target area A is set to include the molten metal M that appears from the spout 83 when the ladle 81 of the pouring machine 80 is tilted.

[0033] The imaging device 10 is a commercially available digital camera such as a CCD camera or a CMOS camera. The imaging device 10 is manually focused in advance so that it is in focus on the molten metal M that appears in the measurement target area A.

[0034] The imaging device 10 is fixed to the floor surface of the foundry. That is, the position of the imaging device 10 is fixed to the floor surface in a position where it can image the measurement target area A. <Information processing device 20, display device 30> As shown in Figure 1, the information processing device 20 is a computer equipped with a CPU, ROM, RAM, etc. Image data captured by the solid-state image sensor 11 is input to the information processing device 20.

[0035] The information processing device 20 includes, as functional units, a histogram creation unit 21, a representative pixel count detection unit 22, a temperature calculation unit 23, and an output unit 24. The histogram creation unit 21 creates a brightness value histogram that shows the distribution of brightness values ​​of pixels in the image data captured by the solid-state image sensor 11.

[0036] The area of ​​the image data being analyzed includes multiple pixels. Each of these multiple pixels has a brightness value. The luminance value histogram is a graph with the luminance value gradation on the horizontal axis and the number of pixels, which is the frequency of the luminance value gradation within the analysis range, on the vertical axis. In this embodiment, since it is 8-bit, the luminance value is represented by 256 gradations from 0 to 255.

[0037] As shown in Figure 2, the histogram creation unit 21 of this embodiment corrects the created luminance value histogram by performing a smoothing process using a Gaussian function on the luminance value histogram.

[0038] The luminance value histogram includes the first region R1, the second region R2, and the third region R3, in ascending order of luminance gradation. The first region R1 is the area where the luminance value gradation is L1 or greater and less than L2. In the first region R1, the number of pixels increases rapidly from 0 as the luminance value gradation increases.

[0039] The second region, R2, is the area where the luminance value gradation is L2 or higher and less than L3. In the second region, R2, the change in the number of pixels associated with an increase in the luminance value gradation is smaller compared to the first region, R1. The third region, R3, is the area where the luminance value gradation ranges from L3 to L4. In the third region, R3, the change in the number of pixels with increasing luminance value gradation is larger compared to the second region, R2. The number of pixels increases with increasing luminance value gradation, then rapidly decreases to 0.

[0040] The representative pixel count detection unit 22 detects the representative pixel count N based on the luminance value histogram created by the histogram creation unit 21. In this embodiment, the representative pixel count N is detected based on the luminance value histogram after correction as described above.

[0041] The representative pixel count detection unit 22 detects the representative pixel count N from the number of pixels in the second region R2 when the number of pixels in the range from the first region R1 to the third region R3 is equal to or greater than a predetermined number. Here, the predetermined number is a value smaller than a predetermined pixel count Nth, which will be described later. In this embodiment, the maximum value of the number of pixels in the second region R2 is detected as the representative pixel count N. Alternatively, the minimum or average value of the number of pixels in the second region R2 may be detected as the representative pixel count N.

[0042] The temperature calculation unit 23 calculates the temperature T of the object to be measured based on the representative pixel count N detected by the representative pixel count detection unit 22. If the number of pixels within the range from the first region R1 to the third region R3 is less than a predetermined number, the approximate temperature of the object to be measured may be derived based on the number of pixels within the range from the first region R1 to the third region R3. This approximate temperature is derived by a functional unit separate from the temperature calculation unit 23.

[0043] The ROM of the information processing device 20 stores a linear function that represents the relationship between the temperature T of the object being measured and the number of representative pixels N. This linear function is derived from a linear function that shows the relationship between temperature and brightness in the thermal radiation of a blackbody. This linear function can be calculated, for example, based on experiments or simulations using a blackbody furnace. The brightness of the synchrotron radiation increases in proportion to the temperature of the blackbody.

[0044] From this, as shown in Figure 3, the representative number of pixels N increases in proportion to the temperature T of the object being measured. The output unit 24 outputs the temperature T calculated by the temperature calculation unit 23. In this embodiment, the output unit 24 outputs the temperature T to the display device 30. The output unit 24 also outputs the temperature T to the control unit 85.

[0045] The display device 30 is electrically connected to the information processing device 20 or via a network. The display device 30 has a display screen 31. For example, if the information processing device 20 is configured as a laptop-type personal computer, the display of that personal computer functions as the display device 30.

[0046] Figure 4 shows the display screen 31 of the display device 30. As shown in Figure 4, the display screen 31 shows a start button 32, an end button 33, a video display unit 34, a temperature display unit 35, a measurement mode switching operation unit 36, a display mode switching operation unit 37, and a lower limit change operation unit 38.

[0047] When the start button 32 is operated, the input of image data captured by the imaging device 10 to the information processing device 20 begins, and a series of controls by the information processing device 20 are initiated.

[0048] When the termination button 33 is operated, the input of image data captured by the imaging device 10 to the information processing device 20 is terminated, and the series of controls performed by the information processing device 20 are terminated.

[0049] The video display unit 34 displays the latest image data captured by the imaging device 10, as well as the range of the image data used to calculate the temperature T. In this embodiment, the system is configured to allow selection of one measurement mode from two measurement modes ("center" and "line").

[0050] When "center" is selected, the center of the image displayed on the video display unit 34 is used to calculate the temperature T. When "Line" is selected, as shown by the dashed line in Figure 4, any portion of the straight line L in the image displayed on the video display unit 34 is used to calculate the temperature T. The position of the straight line L can be changed.

[0051] The measurement mode is switched using the measurement mode switching operation unit 36. The temperature display unit 35 displays the calculated temperature T.

[0052] In this embodiment, the system is configured to allow selection of one of two display modes (instantaneous value and maximum value hold). When an instantaneous value is selected, the latest temperature T, calculated based on image data captured at each predetermined time interval Δt1, is displayed.

[0053] When the maximum value hold option is selected, the maximum value Tmax of the calculated temperature T is displayed as the "highest temperature" after the output of temperature T to the temperature display unit 35 begins. In other words, the maximum value Tmax of temperature T is retained.

[0054] The display mode switching operation is performed through the operation of the display mode switching operation unit 37. The lower limit change operation unit 38 performs an operation to change the lower limit value (°C) of the temperature T displayed on the temperature display unit 35.

[0055] The start button 32, end button 33, measurement mode switching operation unit 36, display mode switching operation unit 37, and lower limit change operation unit 38 are configured to be operable by a keyboard or mouse connected to the information processing device 20 by wire or wireless connection. If the display screen 31 is a touch panel, the start button 32, etc., may be operated by touching the display screen 31.

[0056] Incidentally, the temperature T calculated before the molten metal M appears in the measurement target area A is a temperature other than that of the molten metal M. Therefore, when such a temperature other than that of the molten metal M is output to the temperature display unit 35, a problem arises in that it becomes necessary to scrutinize the outputted temperature T.

[0057] Therefore, the output unit 24 of this embodiment is configured to output the temperature T calculated by the temperature calculation unit 23 when the representative number of pixels N is equal to or greater than a predetermined number of pixels Nth, which is a value obtained when imaging the molten metal M, but not to output the temperature T when it falls below the predetermined number of pixels Nth.

[0058] It is preferable that the temperature calculation unit 23 is configured to calculate the temperature T only when the representative number of pixels N is equal to or greater than a predetermined number of pixels Nth, which is a value obtained when imaging the molten metal M.

[0059] Here, a linear relationship as shown in Figure 3 holds between a predetermined number of pixels Nth and the lower limit value (°C) of the temperature T displayed in the temperature display unit 35. When the lower limit value (°C) of the temperature T displayed in the temperature display unit 35 is changed by the lower limit value change operation unit 38, the predetermined number of pixels Nth is changed in conjunction with this.

[0060] It is preferable that the output unit 24 does not output the temperature T during the period from when the representative number of pixels N becomes equal to or greater than a predetermined number of pixels Nth until a second predetermined time Δt2 has elapsed. It is preferable that the second predetermined time Δt2 is set to a time longer than, for example, the time required for the imaging device 10 to focus on the molten metal M.

[0061] Furthermore, as a method for measuring the second predetermined time Δ, the elapsed time after the representative number of pixels N becomes equal to or greater than a predetermined number of pixels Nth may be measured. Alternatively, the number of times the temperature T is output after the representative number of pixels N becomes equal to or greater than a predetermined number of pixels Nth may be counted, and it may be determined that the second predetermined time Δt2 has elapsed when the number of such outputs reaches a number corresponding to the second predetermined time Δt2.

[0062] It is preferable that the output unit 24 is configured not to output the temperature T after a third predetermined time Δt3, which is longer than the second predetermined time Δt2, has elapsed since the representative number of pixels N became equal to or greater than a predetermined number of pixels Nth.

[0063] Furthermore, as a method for measuring the third predetermined time Δt3, the elapsed time after the representative number of pixels N becomes equal to or greater than a predetermined number of pixels Nth may be measured. Alternatively, the number of times the temperature T is output after the representative number of pixels N becomes equal to or greater than a predetermined number of pixels Nth may be counted, and it may be determined that the third predetermined time Δt3 has elapsed when the number of such outputs reaches a number corresponding to the third predetermined time Δt3.

[0064] The output unit 24 is configured to receive a pouring process execution signal from the control unit 85, which controls the pouring process. Preferably, the output unit 24 is configured to output the temperature T calculated by the temperature calculation unit 23 after receiving the pouring process execution signal, in association with the pouring process execution signal. Furthermore, it is preferable that the output unit 24 is configured to output the maximum value Tmax of the temperature T calculated by the temperature calculation unit 23 after receiving the pouring process execution signal. Here, the pouring process execution signal corresponds to a signal that causes the molten metal M to appear in the measurement target area A.

[0065] Preferably, the output unit 24 is configured not to output the temperature T if the temperature T calculated by the temperature calculation unit 23 is greater than or equal to an upper limit Th which is higher than the maximum temperature that the molten metal M can reach in the pouring process. In this embodiment, the upper limit Th is set to 1500°C.

[0066] The output unit 24 is configured to output the temperature T calculated by the temperature calculation unit 23 to the control unit 85. Next, with reference to Figure 5, an example of the time progression of (a) imaging, (b) pouring process execution signal, (c) ladle orientation, (d) representative number of pixels, (e) calculated temperature, and (f) output temperature will be described.

[0067] As shown in Figure 5(a), at timing t0, the start button 32 is operated, initiating imaging by the imaging device 10. Imaging by the imaging device 10 is repeatedly performed at first predetermined time intervals Δt1 until the stop button 33 is operated.

[0068] As shown in Figures 5(b) and 5(c), at timing t1, when the control unit 85 of the pouring machine 80 outputs a pouring process execution signal to the information processing device 20, the electric motor is controlled to tilt the ladle 81. This changes the position of the ladle 81 from an upright position to an inclined position.

[0069] As shown in Figures 5(d), 5(e), and 5(f), from timing t2 onward, as the ladle 81 tilts, molten metal M appears in the measurement target area A, causing the representative pixel count N detected based on the image data to be greater than or equal to a predetermined pixel count Nth. As a result, the temperatures T2 and T3 of the measurement target area A are calculated at timings t2 and t3 based on the representative pixel count N. However, at this time, since the second predetermined time Δt2 has not elapsed since timing t2 when the representative pixel count N became greater than or equal to the predetermined pixel count Nth, the calculated temperatures T2 and T3 are not output to the temperature display unit 35 of the display device 30.

[0070] At timing t4, a second predetermined time Δt2 has elapsed since timing t2. At timing t5, the temperature T5 of the measurement target area A is calculated based on the representative number of pixels N. At this time, since it is after timing t4, when the second predetermined time Δt2 has elapsed since the representative number of pixels N became equal to or greater than a predetermined number of pixels Nth, the calculated temperature T5 is output to the temperature display unit 35.

[0071] At timing t6, the temperature T6 of the measurement target area A is calculated based on the representative number of pixels N. At this time, the calculated temperature T6 is higher than the temperature T5 calculated immediately before, that is, it is the maximum value Tmax calculated by the temperature calculation unit 23 after receiving the pouring process execution signal, and is therefore output to the temperature display unit 35.

[0072] On the other hand, since the temperature T7 calculated at timing t7 is lower than the temperature T6, the temperature T6, which is the maximum value Tmax, is output to the temperature display unit 35 instead of the temperature T7. Furthermore, since the temperatures T calculated from timing t7 to just before timing t8 are all lower than temperature T6, the temperature T6, which is the maximum value Tmax, is displayed on the temperature display unit 35, rather than these temperatures T.

[0073] The temperature T8 calculated at timing t8 is an abnormally high temperature value that is higher than the upper limit Th (1500°C), therefore the temperature T8 is not displayed on the temperature display unit 35. On the other hand, from timing t9 onward, since a third predetermined time Δt3 has elapsed since the representative pixel count N reached a predetermined pixel count Nth or greater, the calculated temperature T (for example, the temperature T9 at timing t9) is not displayed on the temperature display unit 35. At this time, the temperature display unit 35 displays the maximum value Tmax, which is the temperature T6, as at timing t8. Also, at timing t9, since a third predetermined time Δt3 has elapsed since the representative pixel count N reached a predetermined pixel count Nth or greater, the maximum value Tmax, which is the temperature T6, is output to the control unit 85.

[0074] At timing t10, when the output of the pouring process execution signal is stopped, the electric motor is controlled to change the position of the ladle 81 from an inclined position to an upright position. From timing t11 onward, as the ladle 81 assumes an upright position, molten metal M no longer appears in the measurement target area A. As a result, the representative number of pixels N detected based on the image data falls below a predetermined number of pixels Nth. Consequently, the temperature T is no longer calculated based on the representative number of pixels N.

[0075] <Operation of this embodiment> The temperature calculation unit 23 outputs the calculated temperature T when the representative pixel count N is equal to or greater than a predetermined pixel count Nth, while it does not output the temperature T when the representative pixel count N is less than the predetermined pixel count Nth. Therefore, the temperature T is output only when the temperature T of the measurement target area A is calculated based on the imaging data of the molten metal M. As a result, when the temperature T of the measurement target area A is calculated based on imaging data when the molten metal M is not being imaged, the temperature T is not output, thus preventing, for example, the output of temperatures other than the molten metal M.

[0076] Furthermore, when the measurement target area A is constantly monitored, the load on the information processing device 20 used for the output unit 24, specifically the load on the CPU and memory of the information processing device 20, is reduced. This makes it possible to quickly output the temperature T for the entire measurement target area A when molten metal M appears in a part of the measurement target area A. It also prevents the output of the temperature T of something other than the molten metal M that needs to be output. Moreover, in a state where the output of the temperature T for the entire measurement target area A is not performed because the representative number of pixels N falls below a predetermined number of pixels Nth, it is possible to resume outputting the temperature T when the representative number of pixels N returns to or above the predetermined number of pixels Nth.

[0077] <Effects of this embodiment> (1) The output unit 24 outputs the temperature T calculated by the temperature calculation unit 23 when the representative number of pixels N is equal to or greater than a predetermined number of pixels Nth, which is the value obtained when imaging the molten metal M, but does not output the temperature T when it falls below the predetermined number of pixels Nth.

[0078] With this configuration, the effects of the above-described embodiment are achieved, thus reducing the effort required to scrutinize the output temperature T. (2) The temperature calculation unit 23 is configured to calculate the temperature T only when the representative number of pixels N is equal to or greater than a predetermined number of pixels Nth, which is a value obtained when imaging the molten metal M.

[0079] With this configuration, the temperature T is calculated only when the representative number of pixels N is equal to or greater than a predetermined number of pixels Nth. Therefore, when the measurement target area A is constantly monitored, the load on the information processing device 20 used for the temperature calculation unit 23, specifically the load on the memory of the information processing device 20, is reduced, making it possible to quickly start calculating and outputting the temperature T when molten metal M appears in the measurement target area A. Furthermore, in a state where the temperature T is not calculated because the representative number of pixels N is less than the predetermined number of pixels Nth, the calculation of the temperature T can be resumed when the representative number of pixels N becomes equal to or greater than the predetermined number of pixels Nth again. Thus, when the measurement target area A is constantly monitored, the load on the information processing device 20 used for the temperature calculation unit 23 is reduced, making it possible to increase the speed of temperature T calculation.

[0080] (3) The output unit 24 is configured not to output temperature T during the period from when the representative number of pixels N becomes equal to or greater than a predetermined number of pixels Nth until a second predetermined time Δt2 has elapsed.

[0081] When measuring the temperature of molten metal M poured from the ladle 81 into the mold 90 during the casting pouring process, the following problems may occur if a large amount of steam or splashes are temporarily generated. Specifically, if image data is obtained in an environment where a large amount of other substances that can interfere with the detection of the molten metal M, such as steam or splashes causing the molten metal M to be out of focus, are interposed between the imaging device 10 and the molten metal M, the temperature T of the molten metal M calculated based on the image data may deviate significantly from the actual temperature. In other words, the temperature of the molten metal M calculated based on image data acquired immediately after the representative number of pixels N becomes equal to or greater than the predetermined number of pixels Nth may deviate significantly from the actual temperature.

[0082] In this regard, with the above configuration, the temperature T is not output during the period from when the representative number of pixels N becomes equal to or greater than a predetermined number of pixels Nth until a second predetermined time Δt2 has elapsed. As a result, the output of temperature T is suppressed during the period until the influence of other substances that may be inhibiting factors, such as when the molten metal M is not in focus, becomes negligibly small. Therefore, it is possible to suppress the output of a temperature T that deviates significantly from the actual temperature due to image data in environments where the influence of other substances that may be inhibiting factors, such as when the molten metal M is not in focus, is significant.

[0083] (4) The output unit 24 is configured not to output temperature T after a third predetermined time Δt3, which is longer than the second predetermined time Δt2, has elapsed since the representative number of pixels N has reached a predetermined number of pixels Nth or more.

[0084] When measuring the temperature of molten metal M poured from the ladle 81 into the mold 90 during the casting pouring process, splashes of molten metal M are likely to occur in the latter half of the pouring process, especially at the end. Because the splashes have a high contrast with the surroundings, the temperature T of the molten metal M calculated based on imaging data including the splashes may deviate significantly from the actual temperature.

[0085] In this regard, with the above configuration, after the representative number of pixels N reaches a predetermined number of pixels Nth or more, and after a third predetermined time Δt3 that is longer than the second predetermined time Δt2 has elapsed, the temperature T is not output. As a result, the temperature T is not output in the latter half of the pouring process, especially at the end, when splashes of molten metal M are likely to occur. Therefore, it is possible to suppress the output of a temperature T that deviates significantly from the actual temperature.

[0086] (5) After the output unit 24 receives the pouring process execution signal from the control unit 85 which controls the pouring process, the temperature T calculated by the temperature calculation unit 23 is output in association with the pouring process execution signal. This prevents uncertainty regarding the correspondence between the output temperature T and the pouring process.

[0087] (6) The output unit 24 is configured to output the maximum value Tmax of the temperature T calculated by the temperature calculation unit 23 after receiving the execution signal. In the casting pouring process, when pouring molten metal M from the ladle 81 into the mold 90, the tilting motion of the ladle 81 may not be smooth due to mechanical snagging of the pouring machine 80. In this case, the pouring of molten metal from the ladle 81 into the mold 90 is performed intermittently multiple times in a single pouring process, resulting in so-called double or triple pouring.

[0088] In this case, the following problems may arise. Specifically, since the temperature T is output each time the pouring process is performed intermittently during a single pouring cycle, the relationship between the output temperature T and the pouring process becomes unclear.

[0089] In this regard, according to the above configuration, the maximum value Tmax of the temperature T calculated by the temperature calculation unit 23 is output after receiving the execution signal for the pouring process from the control unit 85. Therefore, even if pouring is performed intermittently multiple times in a single pouring process, the maximum value Tmax of the temperature T calculated in that pouring process is output. Thus, it is possible to suppress the uncertainty of the correspondence between the output temperature T and the pouring process.

[0090] (7) The output unit 24 is configured not to output the temperature T if the temperature T calculated by the temperature calculation unit 23 is greater than or equal to an upper limit Th which is higher than the maximum temperature that the molten metal M can reach in the pouring process.

[0091] When measuring the temperature of molten metal M poured from the ladle 81 into the mold 90 during the casting pouring process, the presence of steam or splashes may cause the following problems. Specifically, if image data is obtained in an environment where a large amount of other substances that can interfere with the detection of the molten metal M, such as steam or splashes causing the image to lose focus, are interposed between the imaging device 10 and the molten metal M, the temperature T of the molten metal M calculated based on the image data may deviate significantly from the actual temperature.

[0092] In particular, when measuring the temperature of molten metal M poured from ladle 81 into mold 90, splashes of molten metal M are likely to occur in the latter half of the pouring process, especially at the end. Because the splashes have a high contrast with the surroundings, the temperature of the molten metal M calculated based on imaging data including the splashes may deviate significantly from the actual temperature.

[0093] In this regard, with the above configuration, if the calculated temperature T is above the upper limit Th, which is higher than the maximum temperature that the molten metal M can reach during the pouring process, the temperature T will not be output. Therefore, it is possible to suppress the output of a temperature T that deviates significantly from the actual temperature.

[0094] (8) The output unit 24 is configured to output the temperature T calculated by the temperature calculation unit 23 to the control unit 85. With this configuration, when the representative number of pixels N is equal to or greater than a predetermined number of pixels Nth, the temperature T calculated by the temperature calculation unit 23 can be output to the control unit 85. This allows the control unit 85 to utilize the information on the temperature T of the molten metal M when controlling the pouring process.

[0095] (9) The solid-state image sensor 11 of the imaging device 10 receives near-infrared light emitted from the measurement target area A at first predetermined time intervals Δt1, and the measurement target area A is imaged. The histogram creation unit 21 creates a brightness value histogram showing the distribution of brightness values ​​of pixels in the image data captured by the solid-state image sensor 11. The representative pixel count detection unit 22 detects the representative pixel count N based on the brightness value histogram. The temperature calculation unit 23 calculates the temperature T of the measurement target area A based on the representative pixel count N.

[0096] With this configuration, the representative pixel count detection unit 22 detects the representative pixel count N based on the brightness value histogram, and the temperature calculation unit 23 calculates the temperature T based on the representative pixel count N, so that the temperature T can be calculated with high accuracy.

[0097] <Example of changes> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0098] In the above embodiment, the representative number of pixels N is detected from the number of pixels in the second region R2 of the luminance value histogram, but the method for detecting the representative number of pixels N is not limited to this. Alternatively, for example, the representative number of pixels N may be detected as the maximum number of pixels in all regions R1, R2, and R3 of the luminance value histogram.

[0099] In the imaging device 10 of the above embodiment, a bandpass filter 12 is provided so that the solid-state image sensor 11 receives only the near-infrared band of the synchrotron radiation emitted from the measurement target area A. However, by changing the bandpass filter 12, the solid-state image sensor 11 may receive synchrotron radiation in the visible light band, for example, between 550 nm and 650 nm.

[0100] • In the above embodiment, a configuration in which the measurement mode can be switched has been illustrated, but a configuration in which the measurement mode cannot be switched is also possible. In the above embodiment, a preset measurement target area A including both the molten metal M and the background is imaged. However, the measurement target area A may be variably set so that it includes only the molten metal M.

[0101] The first predetermined time Δt1 may be made variable. The output unit 24 in the above embodiment does not output the temperature T when the calculated temperature T is equal to or greater than the upper limit Th, but the present invention is not limited thereto. The output unit 24 may be configured to output the temperature T when the calculated temperature T is equal to or greater than the upper limit Th.

[0102] The display mode switching operation unit 37 may be configured to switch to a display mode that displays the average value Tave of the calculated temperature T. In this case, when calculating the average value Tave of temperature T, temperatures T2, T3, T8, and T9 in the above embodiment should be excluded.

[0103] • In the above embodiment, a configuration in which the temperature T display mode can be switched has been illustrated, but a configuration in which the display mode cannot be switched is also possible. • When measuring the temperature of molten metal contained in a ladle that has been transported to a predetermined position where an alloy such as a magnesium alloy is added to the molten metal M during the alloy addition process of casting, the following problems may occur. Specifically, if image data is obtained that is not in focus on the molten metal M due to the movement of the molten metal as the ladle is transported, the temperature T of the molten metal M calculated based on that image data may deviate significantly from the actual temperature.

[0104] Even in such cases, if the calculated temperature T is above an upper limit that is higher than the maximum temperature that the molten metal M can reach during the alloy addition process, the output of temperature T can be prevented from being significantly different from the actual temperature.

[0105] In the above embodiment, an example was given in which the pouring process execution signal is output over a period from timing t1 to timing t10. However, the pouring process execution signal may also be output only at timing t1. Even in this case, it is sufficient that the maximum value Tmax of the temperature T calculated by the temperature calculation unit 23 is output after receiving the pouring process execution signal.

[0106] In the alloy addition process of casting, when measuring the temperature of molten metal in a ladle that has been transported to a predetermined position for alloy addition, unnecessary temperature output is performed not only immediately after transport to that predetermined position, but also after the alloy addition and after the removal of impurities consisting of metal oxides called slag, which should be removed from the cast iron. Specifically, because heated molten metal is still present in the ladle after the alloy addition and slag removal, the temperature is calculated and output when the number of representative pixels exceeds a predetermined number of pixels.

[0107] In this case, since the temperature of the object being measured is output multiple times during a single alloy addition process, a problem arises in that the correspondence between the outputted temperature and the temperature of the molten metal in the ladle immediately after it is transported to the predetermined position becomes unclear.

[0108] Even in such cases, if the output unit is configured to output the temperature calculated by the temperature calculation unit after receiving the execution signal for the alloy addition process from the control unit that controls the alloy addition process, then even if operations such as slag removal are performed, the temperature calculation and output will cease. Therefore, it is possible to prevent uncertainty regarding the correspondence between the output temperature and the temperature of the molten metal in the ladle during the alloy addition process. Furthermore, even in this case, by having the output unit output the temperature T to the control unit, the control unit can utilize the information on the temperature T of the molten metal M when controlling the alloy addition process.

[0109] • In the alloy addition process during casting, there is a risk that the output temperature may differ from the temperature that should be measured after the alloy addition or after slag removal. Even in such cases, if the output unit 24 prevents the temperature T from being output after a third predetermined time Δt3, which is longer than the second predetermined time Δt2, has elapsed since the representative pixel count N reached or exceeded the predetermined pixel count Nth, it is possible to avoid outputting a temperature different from the temperature that should be measured after alloy addition, etc.

[0110] The temperature T output may be performed even after a third predetermined time Δt3, which is longer than the second predetermined time Δt2, has elapsed since the representative number of pixels N has reached a predetermined number of pixels Nth or more, or after the number of times the temperature T has been output has reached a predetermined number.

[0111] In the above embodiment, the second predetermined time Δt2 was set to a time longer than the time required for the imaging device 10 to focus on the molten metal M, but the method for setting the second predetermined time Δt2 is not limited to this.

[0112] For example, in the melting process of casting, if the temperature of the molten metal contained in a container is measured with the lid of the container open, or in the alloy addition process of casting, if a ladle is transported and reaches a predetermined position that includes the measurement target area, the following problems may occur if a large amount of steam or splashes are temporarily generated or if the ladle is being transported. Specifically, if image data is obtained that is not in focus on the object being measured due to steam, splashes, or the transport of the ladle, the temperature of the object being measured calculated based on that image data may deviate significantly from the actual temperature. Furthermore, if, when the ladle is transported and appears in the measurement target area, image data of something other than the molten metal M, such as the furnace wall refractory material that makes up the ladle, is obtained, the temperature of the object being measured calculated based on that image data may deviate significantly from the actual temperature.

[0113] In such cases, it is preferable to pre-set the second predetermined time Δt2 through experiments or other means so that the temperature of the object to be measured, calculated based on the image data, does not deviate significantly from the actual temperature.

[0114] In the above embodiment, the temperature T is not output during the period from when the representative number of pixels N becomes equal to or greater than a predetermined number of pixels Nth until a second predetermined time Δt2 has elapsed. However, the present invention is not limited thereto. The temperature T may be output even before the second predetermined time Δt2 has elapsed from when the representative number of pixels N becomes equal to or greater than a predetermined number of pixels Nth.

[0115] The imaging device 10 may also have an autofocus function that automatically adjusts the focus. In the above embodiment, a configuration was described in which the pouring machine 80 is immovably positioned on the floor of the foundry, while the mold 90 is transportable by a transport trolley. Alternatively, the present invention can also be applied to a configuration in which the mold 90 is immovably positioned on the floor, while the pouring machine 80 is transportable by a transport trolley. In this case, the imaging device 10 should be immovably positioned on the transport trolley on which the pouring machine 80 is mounted. In short, it is sufficient that the position of the imaging device 10 is fixed relative to the pouring machine 80.

[0116] In the above embodiment, the temperature of the molten metal M poured from the ladle 81 into the mold 90 during the casting pouring process is measured non-contact. However, the temperature of the molten metal M contained in a container during the casting melting process may also be measured non-contact. In this case, the imaging device 10 is provided above the container containing the molten metal M, and the molten metal M is imaged through the upper opening of the container while the lid of the container is open. Similarly, the temperature of the molten metal M contained in a container during the casting alloy addition process may also be measured non-contact.

[0117] The object to be measured according to the present invention is not limited to molten metal M, i.e., cast iron in a molten state. Metals such as aluminum and copper in a molten state can also be used as the object to be measured. Furthermore, metal plates such as steel plates used in the hot rolling process of a steel mill can also be used as the object to be measured. In other words, the object to be measured is not limited to metal in a molten state. [Explanation of symbols]

[0118] 10…Imaging device 11… Solid-state image sensor 12…Bandpass filter 20…Information Processing Devices 21... Histogram Creation Department 22... Representative pixel count detection unit 23...Temperature calculation section 24…Output section 30…Display device 31…Display screen 32... Start button 33... Exit button 34…Video display unit 35…Temperature display section 36...Measurement mode switching operation unit 37…Display mode switching operation unit 38... Lower limit change operation unit 80…Pouring machine 81...Ladle 82…Tilt axis 82…Lid 83... Spout 84…Tilt axis 85... Control Unit 90... Mold M...molten metal N... Representative number of pixels T…Temperature

Claims

1. A non-contact temperature measurement system for measuring the temperature of a heated object without contact, Imaging device and Equipped with an information processing device, The imaging device includes a solid-state image sensor configured to receive synchrotron radiation emitted from the measurement target area where the object to be measured appears at predetermined intervals and to image the measurement target area. The aforementioned information processing device is A histogram creation unit creates a luminance value histogram showing the distribution of luminance values ​​of pixels in image data captured by the solid-state image sensor, A representative pixel count detection unit detects a representative pixel count based on the luminance value histogram created by the histogram creation unit, A temperature calculation unit that calculates the temperature of the measurement target area based on the representative pixel count detected by the representative pixel count detection unit, The system comprises an output unit that outputs the temperature calculated by the temperature calculation unit, The output unit is configured to output the temperature calculated by the temperature calculation unit when the representative number of pixels is equal to or greater than a predetermined number of pixels obtained when imaging the heated object to be measured, but not to output the temperature when it falls below the predetermined number of pixels. Non-contact temperature measurement system.

2. The temperature calculation unit is configured to calculate the temperature only when the number of representative pixels is equal to or greater than the predetermined number of pixels. The non-contact temperature measurement system according to claim 1.

3. When the aforementioned predetermined time is set to the first predetermined time, The output unit is configured not to output the temperature during the period from when the number of representative pixels becomes equal to or greater than the predetermined number of pixels until a second predetermined time has elapsed. A non-contact temperature measurement system according to claim 1 or claim 2.

4. The output unit is configured not to output the temperature after a third predetermined time, which is longer than the second predetermined time, has elapsed since the number of representative pixels reached or exceeded the predetermined number of pixels. The non-contact temperature measurement system according to claim 3.

5. The object to be measured is molten metal in a predetermined casting process or a metal sheet in a predetermined hot rolling process. The output unit is configured to receive a signal from a control unit that controls the predetermined process of casting or the predetermined process of hot rolling, which causes the object to be measured to appear in the measurement target area, and is configured to output the temperature calculated by the temperature calculation unit after receiving the signal, in association with the signal. The non-contact temperature measurement system according to claim 1.

6. The output unit is configured not to output the temperature if the temperature calculated by the temperature calculation unit is above an upper limit that is higher than the maximum temperature that the object being measured can reach in the predetermined casting process or the predetermined hot rolling process. The non-contact temperature measurement system according to claim 5.

7. The output unit is configured to output the temperature calculated by the temperature calculation unit to the control unit. A non-contact temperature measurement system according to claim 5 or claim 6.

Images