JP7769945B2 - Equipment temperature control system, equipment temperature control program, marker material for equipment temperature control system - Google Patents

Description

The present invention relates to an equipment temperature control system and an equipment temperature control program for controlling the surface temperature of equipment.

Conventionally, equipment such as paint drying ovens is used to dry paint applied to workpieces such as automobile bodies. For this reason, hot air is constantly supplied to the oven to ensure the paint dries reliably. However, due to oven deterioration or other reasons, cracks can develop in the exhaust duct (not shown) installed in the oven or in the oven walls, causing the hot air inside the oven to leak to the outside through the cracks. Therefore, technology has been proposed to detect hot air leaks by periodically capturing images of the oven surface with a thermal camera to check the surface temperature (see, for example, Patent Documents 1 and 2).

JP-A-10-111714 (Fig. 1, etc.) JP-A-6-138003 (Fig. 1 etc.)

However, the ambient temperature around the drying oven (equipment) changes with the seasons. As a result, the surface temperature of the drying oven measured by a thermal camera also changes, so even if the surface temperature is checked, it may not be possible to accurately detect abnormal temperature changes.

The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide an equipment temperature management system and an equipment temperature management program that can detect abnormal temperature changes with high accuracy without being affected by the ambient temperature.

In order to solve the above problem, the invention described in claim 1 is an equipment temperature management system comprising: a first marker for measuring the equipment surface temperature, which is provided in contact with the surface of the equipment; and a second marker for measuring the ambient temperature, which is provided at a distance from the surface of the equipment, the first marker and the second marker having different, identifiable geometric characteristics; an imaging means for capturing images of a first area including the first marker and a second area including the second marker to obtain visible images and thermal images; a marker discrimination means for discriminating the type of marker captured by the imaging means based on the geometric characteristics captured in the visible images; an equipment surface temperature calculation means for calculating the surface temperature of the equipment based on the thermal image in which the first marker is captured if the marker is determined to be the first marker; an ambient temperature determination means for calculating the surface temperature of the second marker based on the thermal image in which the second marker is captured if the marker is determined to be the second marker, and determining the ambient temperature based on the calculated surface temperature; and a temperature difference calculation means for calculating the temperature difference between the surface temperature of the equipment and the ambient temperature.

In the invention described in claim 1, the surface temperature of the equipment is calculated based on the thermal image showing the first marker, the ambient temperature is determined based on the thermal image showing the second marker, and then the temperature difference between the surface temperature and the ambient temperature is calculated, thereby canceling out changes in surface temperature caused by changes in ambient temperature. Therefore, by measuring the surface temperature in this state, abnormal temperature changes can be detected with high accuracy without being affected by the ambient temperature.

While imaging means can be fixed or non-fixed, it is preferable to use non-fixed imaging means. Non-fixed imaging means are generally cheaper than fixed ones, making it possible to manage the surface temperature of equipment at low cost. Furthermore, when using non-fixed imaging means, it is possible to image all markers with a single imaging means by moving the imaging location. This eliminates the need to install multiple imaging means to image each marker. Therefore, the cost required to manage the surface temperature of equipment can be significantly reduced compared to when fixed imaging means are used.

The invention described in claim 2 is based on claim 1, and the ambient temperature determination means calculates the average value of temperatures at multiple points on one second marker and determines the calculated average value as the ambient temperature.

In the invention described in claim 2, the average value of the temperatures at multiple points on one second marker is used as the ambient temperature. Therefore, even if there is variation in the surface temperature of that second marker, that variation is averaged out, allowing the ambient temperature to be calculated with high accuracy.

The invention described in claim 3 is based on claim 1, and is characterized in that the second markers are provided at multiple locations, and the ambient temperature determination means calculates the average value of the surface temperatures of the multiple second markers and determines the calculated average value as the ambient temperature.

In the invention described in claim 3, second markers are placed at multiple locations around the equipment, and the average surface temperature of each second marker is calculated, thereby obtaining the ambient temperature of the entire equipment, rather than just the ambient temperature near a single second marker. Therefore, even if there is variation in the temperature around the equipment, that variation is averaged out, and the ambient temperature can be calculated with high accuracy.

The invention described in claim 4 is based on any one of claims 1 to 3 and further includes a display means for displaying the visible image and the thermal image, and the display means displays an image indicating a temperature obtained by subtracting the ambient temperature from the surface temperature of the equipment as a corrected visible image.

In the invention described in claim 4, the display means displays not an image showing the surface temperature of the equipment, but an image showing the temperature obtained by subtracting the ambient temperature from the surface temperature of the equipment, i.e., an image in which changes in surface temperature caused by changes in ambient temperature are canceled out. This allows the operator to accurately recognize which parts of the equipment's surface have experienced large temperature changes, i.e., which parts of the equipment's surface are experiencing abnormal temperature changes.

The invention described in claim 5 is based on any one of claims 1 to 4, and is characterized in that the second marker is a marker member having a geometric pattern made of multiple colors with different brightnesses displayed on the surface of a base made of a highly thermally conductive material.

In the invention described in claim 5, the base constituting the second marker is made of a material with high thermal conductivity, so the surface temperature of the second marker easily follows the ambient temperature of the surrounding area. As a result, by capturing an image of the second marker with an imaging device, the surface temperature of the second marker can be accurately calculated based on the image of the second marker captured in the thermal image. Furthermore, because the geometric pattern displayed on the surface of the base is made up of multiple colors with different brightness levels, the geometric pattern is easy to recognize, and therefore easy to distinguish from other markers with different geometric characteristics.

The highly thermally conductive material that makes up the base is preferably a metal or other material, such as copper (thermal conductivity: 403 W/m·K), aluminum (thermal conductivity: 236 W/m·K), zinc (thermal conductivity: 116 W/m·K), iron (thermal conductivity: 83.5 W/m·K), nickel (thermal conductivity: 91 W/m·K), cobalt (thermal conductivity: 69 W/m·K), magnesium (thermal conductivity: 156 W/m·K), chromium (thermal conductivity: 90.3 W/m·K), or alloys of these. In other words, the thermal conductivity of the material that makes up the base is preferably 50 W/m·K or higher, and more preferably 100 W/m·K or higher.

The invention described in claim 6 is the same as claim 5, except that the second marker has an anti-reflection treatment applied to the surface of the base.

For example, if the second marker reflects ambient heat, the amount of heat reflection varies depending on the imaging angle relative to the second marker. Therefore, even if the second marker is imaged with an imaging device, it may not be possible to accurately calculate the surface temperature of the second marker reflected in the thermal image. Therefore, the invention described in claim 6 applies an anti-reflection treatment to the surface of the base that constitutes the second marker. In this way, the second marker is less likely to reflect heat and is less affected by the amount of heat reflection, making it possible to accurately calculate the surface temperature of the second marker reflected in the thermal image. Examples of anti-reflection treatments include applying a matte paint to the surface of the base or increasing the surface roughness of the base.

The invention described in claim 7 is based on any one of claims 1 to 6 and further comprises a warning means for issuing a warning if the temperature difference range is outside a predetermined range.

The invention described in claim 7 warns that the temperature difference range is outside a specified range, ensuring that workers are aware that the change in the equipment's surface temperature is too large. As a result, it becomes possible to respond quickly to abnormalities in the surface temperature.

Examples of warning means include light-emitting means such as a lamp that emits light (lights up, flashes, etc.) to warn that the temperature difference is outside the specified range, audio output means such as an alarm that emits audio (beep, etc.) to warn that the temperature difference is outside the specified range, and display means such as a liquid crystal display device that displays (letters, symbols, pictures, etc.) to warn that the temperature difference is outside the specified range.

The invention described in claim 8 is an equipment temperature management program that causes a processor controlling an equipment temperature management system having imaging means that captures visible and thermal images of a first area including a first marker for measuring equipment surface temperature that is provided in contact with the surface of the equipment and a second area including a second marker for measuring ambient temperature that is provided away from the surface of the equipment. The processor then executes the following steps: a marker determination step that determines the type of marker captured by the imaging means based on geometric features that appear in the visible image; an equipment surface temperature calculation step that calculates the surface temperature of the equipment based on the thermal image in which the first marker appears, if the marker is determined to be the first marker; an ambient temperature determination step that calculates the surface temperature of the second marker based on the thermal image in which the second marker appears, if the marker is determined to be the second marker, and determines the ambient temperature based on the calculated surface temperature; and a temperature difference calculation step that calculates the temperature difference between the surface temperature of the equipment and the ambient temperature.

In the invention described in claim 8, in the equipment surface temperature calculation step, the surface temperature of the equipment is calculated based on the thermal image showing the first marker, and in the ambient temperature determination step, the ambient temperature is determined based on the thermal image showing the second marker. Then, in the temperature difference calculation step, the temperature difference between the equipment surface temperature and the ambient temperature is calculated, thereby canceling out changes in surface temperature caused by changes in ambient temperature. Therefore, by measuring the surface temperature in this state, abnormal temperature changes can be detected with high accuracy without being affected by the ambient temperature.

Furthermore, the reference invention relating to the marker member for the equipment temperature control system is a marker member used in an equipment temperature control system that is imaged by an imaging means and controls the surface temperature of the equipment, and its gist is that a geometric pattern consisting of multiple colors with different brightnesses is displayed on the surface of a base made of a material with high thermal conductivity, and an anti-reflection treatment is applied.

In the reference invention, the base of the marker member is made of a material with high thermal conductivity, which allows the surface temperature of the marker member to easily follow the ambient temperature. As a result, by capturing an image of the marker member with an imaging device and acquiring a thermal image, the surface temperature of the marker member, and therefore the ambient temperature, can be accurately calculated based on the marker member captured in the thermal image. Then, by calculating the temperature difference between the surface temperature of the equipment and the ambient temperature, changes in the surface temperature of the equipment due to changes in ambient temperature are canceled out. Therefore, by measuring the surface temperature of the equipment in this state, abnormal temperature changes can be detected with high accuracy without being affected by the ambient temperature. Furthermore, because the geometric pattern displayed on the surface of the base is made up of multiple colors with different brightness levels, the geometric pattern is easy to recognize and, ultimately, can be easily distinguished from other markers with different geometric features.

As described above in detail, according to the inventions set forth in claims 1 to 8 , abnormal temperature changes can be detected with high accuracy without being affected by the ambient temperature.

1 is a schematic configuration diagram showing an equipment temperature management system according to an embodiment of the present invention; Photograph showing a first visible image of a first area including a first marker. Photograph showing a second visible image showing a second area including a second marker. Photograph showing the first thermal image. Photograph showing a second thermal image. 10 is a flowchart showing a process for managing the surface temperature of a drying furnace. Photograph showing the corrected visible image. 10 is a table showing the measurement results of the temperature of each part and the calculation results of the temperature difference.

An embodiment of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, the equipment temperature management system 1 of this embodiment is a system that manages the surface temperature of a drying furnace 10 (equipment). The drying furnace 10 is used to dry paint applied to the surface of workpiece W1 (in this embodiment, an automobile body) that has passed through a paint booth (not shown). The drying furnace 10 is formed in a roughly rectangular parallelepiped shape using a wall material such as steel plate, and includes a ceiling 11, a floor 12, and a pair of side walls 13. Furthermore, the entire inner surface of the drying furnace 10 is covered with heat insulating material (not shown). A conveyor 21 is provided on the floor 12 of the drying furnace 10. The conveyor 21 is a device that transports multiple carts 22 carrying the workpiece W1 along a transport direction (to the right in FIG. 1).

As shown in Figures 1 and 2, multiple first markers 31 for measuring equipment surface temperature are provided along the conveying direction on the sidewall 13 of the drying oven 10. Each first marker 31 is provided at a specific measurement point A1 to A13 in the drying oven 10. Each first marker 31 has a different, identifiable geometric feature for each measurement point A1 to A13, and is a two-dimensional plate-like member affixed to the surface 10a of the drying oven 10. In other words, each first marker 31 is provided in contact with the surface 10a of the drying oven 10. In this embodiment, the first marker 31 is a marker member (ArUco marker) that has a geometric pattern 34 made of two colors (white and black) of different brightness displayed on the surface 33 of a rectangular base 32 made of a material with high thermal conductivity (aluminum).

Furthermore, as shown in Figures 1 and 3, a second marker 41 for measuring ambient temperature is provided on the side wall 13 of the drying oven 10. The second marker 41 is provided in a location within the factory that is not affected by sunlight, specifically, at a specific measurement point A0 in the drying oven 10. The second marker 41 has identifiable geometric characteristics different from those of each of the first markers 31, and is a two-dimensional plate-like member suspended from the beam 15 of the marker support frame 14 installed near the side wall 13. The second marker 41 is provided at a position 100 mm or more away from the surface 10a of the drying oven 10.

The second marker 41 of this embodiment is a marker component (ArUco marker) that has a geometric pattern 44 made of two colors (white and black) of different brightness displayed on the surface 43 of a rectangular base 42 made of a material with high thermal conductivity (aluminum). Furthermore, the surface 43 of the base 42 is treated with an anti-reflection coating (specifically, a matte finish). In this embodiment, the surface 33 of the base 32 of the first marker 31 is not treated with an anti-reflection coating, but it may be treated with an anti-reflection coating. If the first marker 31 is treated with an anti-reflection coating, the first marker 31 can be used as both the first marker 31 and the second marker 41.

As shown in FIG. 1, the facility temperature management system 1 includes a thermal camera 50, which is a non-fixed (i.e., portable) imaging device. The thermal camera 50 simultaneously acquires a first visible image 51a (see FIG. 2) and a first thermal image 52a (see FIG. 4) by capturing an image of a first region 31a (see FIG. 2) including a first marker 31. The thermal camera 50 also simultaneously acquires a second visible image 51b (see FIG. 3) and a second thermal image 52b (see FIG. 5) by capturing an image of a second region 41a (see FIG. 3) including a second marker 41. The thermal camera 50 then outputs image data of the captured visible images 51a, 51b and thermal images 52a, 52b. Note that the visible images 51a, 51b are color images, and the thermal images 52a, 52b are infrared images.

Next, we will explain the electrical configuration of the equipment temperature control system 1.

As shown in FIG. 1, the facility temperature control system 1 includes a personal computer (not shown), which includes a control device 60 (processor) that controls the entire system. The control device 60 is a well-known computer consisting of a CPU 61, ROM 62, RAM 63, etc. The CPU 61 is electrically connected to the computer's keyboard 64, display 65 (display means), and alarm 66. In this embodiment, the thermal camera 50 is electrically connected to the CPU 61 by connecting it to the control device 60 via a USB (Universal Serial Bus) cable. The RAM 63 stores visible images 51a, 51b and thermal images 52a, 52b captured by the thermal camera 50. The ROM 62 stores a program (facility temperature control program) for controlling the facility temperature control system 1.

Next, we will explain how to control the temperature of the drying oven 10.

First, the worker holds the thermal camera 50 and captures images of the surface 10a of the drying oven 10 at each of the measurement points A0 to A13, acquiring visible images 51a, 51b and thermal images 52a, 52b at each of the measurement points A0 to A13. In other words, the thermal camera 50 of this embodiment is a handheld camera that simultaneously captures visible images 51a, 51b and thermal images 52a, 52b using a common optical axis. The worker periodically captures images of each of the measurement points A0 to A13 (for example, once a month).

Then, each time imaging of each measurement point A0-A13 is completed, the operator connects the thermal camera 50 to the PC's control device 60 using a USB cable. At this point, the thermal camera 50 outputs the image data of the acquired visible images 51a, 51b and thermal images 52a, 52b to the CPU 61. The CPU 61 then stores the visible images 51a, 51b and thermal images 52a, 52b represented by the input image data in RAM 63. Furthermore, the CPU 61 controls the display 65 to display the visible images 51a, 51b and thermal images 52a, 52b stored in RAM 63.

Next, the CPU 61 controls the surface temperature of the drying oven 10 based on the equipment temperature management program stored in the ROM 62. First, the CPU 61 performs a marker discrimination step, determining the type of marker 31, 41 captured by the thermal camera 50 based on the geometric features captured in the visible images 51a, 51b. In other words, the CPU 61 functions as a "marker discrimination means."

Specifically, in step S10 shown in FIG. 6, the CPU 61 performs processes such as binarization, contour extraction, and intersection calculation on all visible images 51a, 51b stored in RAM 63, and controls the extraction of markers 31, 41 within each visible image 51a, 51b. In the following step S20, the CPU 61 calculates the ID numbers (0-13) of the extracted markers 31, 41 from the shapes of the geometric patterns 34, 44. The ID numbers (0-13) are numbers associated with each measurement point A0-A13.

If the calculated ID number is any one of "1" to "13," the CPU 61 determines that the captured marker is the first marker 31. In this case, the CPU 61 performs processing in step S30 (equipment surface temperature calculation step) and calculates the surface temperature of the drying oven 10 based on the first thermal image 52a in which the first marker 31 appears. More specifically, the CPU 61 measures the temperature of pixels (points) located on the surface 33 of the first marker 31 among the pixels of the first thermal image 52a. The CPU 61 then determines the temperature of the measured pixel as the surface temperature of the drying oven 10. In other words, the CPU 61 functions as an "equipment surface temperature calculation means."

Furthermore, if the calculated ID number is "0," the CPU 61 determines that the captured marker is the second marker 41. In this case, the CPU 61 performs the process of step S40 (ambient temperature determination step), calculates the surface temperature of the second marker 41 based on the second thermal image 52b in which the second marker 41 is captured, and determines the ambient temperature based on the calculated surface temperature. More specifically, the CPU 61 measures the temperature of each of multiple pixels (points) located on the surface 43 of the second marker 41 among the pixels of the second thermal image 52b. The CPU 61 then calculates the average value of the measured temperatures of each pixel and determines the calculated average value as the ambient temperature. In other words, the CPU 61 functions as an "ambient temperature determination means." Furthermore, in this embodiment, the captured marker is determined to be the second marker 41 if the calculated ID number is "0." However, it is also possible to set the system to determine that the captured marker is the second marker 41 if the ID number is other than "0."

The CPU 61 then performs step S50 (temperature difference calculation step) and calculates the temperature difference between the surface temperature of the drying oven 10 calculated in step S30 and the ambient temperature determined in step S40. In other words, the CPU 61 functions as a "temperature difference calculation means." Note that the temperature difference is calculated when the surface temperature of the drying oven 10 is higher than the ambient temperature. The CPU 61 also sequentially executes steps S10 to S30 and S50 at all measurement points A1 to A13 to calculate the temperature difference between the surface temperature of the drying oven 10 and the ambient temperature.

In the next step S60, the CPU 61 controls the display 65 to display an image showing the temperature obtained by subtracting the ambient temperature from the surface temperature of the drying oven 10. In other words, the image shows an image in which changes in surface temperature due to changes in ambient temperature have been canceled out. This image is then displayed as a corrected visible image 53 (see FIG. 7). The CPU 61 also compares the current corrected visible image 53 with a corrected visible image 53 acquired previously (e.g., three months ago). Specifically, the CPU 61 calculates the difference between the temperature at each pixel of the current corrected visible image 53 and the temperature at each pixel of the previously acquired corrected visible image 53. The CPU 61 then determines whether to set color images 54 and 55 based on the level (magnitude) of the difference. Specifically, if the temperature shown in the current corrected visible image 53 is higher than the temperature shown in the previously acquired corrected visible image 53, e.g., if the temperature rise is 50°C or more, the image 54 is displayed as red. If the temperature rise is 10°C or more but less than 50°C, the image 55 is displayed as blue. On the other hand, if the temperature rise is less than 10°C, or if the temperature indicated by the current corrected visible image 53 is lower than the temperature indicated by the previously acquired corrected visible image 53, color images 54 and 55 will not be set.

Next, the CPU 61 controls the display 65 to display the set color images 54, 55. Specifically, the CPU 61 controls the display 65 to superimpose the color images 54, 55 on the corresponding locations (pixels) on the corrected visible image 53. As a result, the areas on the surface 10a of the drying oven 10 at the corresponding measurement points where a large temperature rise has been determined are displayed in different colors. This allows the operator to accurately recognize which areas on the surface 10a of the drying oven 10 have experienced a large temperature rise, i.e., which areas on the surface 10a of the drying oven 10 are leaking hot air.

Furthermore, if it is determined that the temperature difference range is outside the specified range (higher than 10°C in this embodiment), the CPU 61 determines that an abnormality has occurred and outputs a drive signal to the alarm 66, thereby controlling the alarm 66 to activate as a warning means. This warns the operator that there is a high possibility that hot air is leaking from the drying oven 10 due to the high temperature of the surface 10a of the drying oven 10.

Next, we will explain the method for verifying temperature control of the drying oven 10 and the results.

First, the surface temperature of the drying oven 10 was measured in winter, mid-season, and summer (see the "Surface Temperature (Measured Value)" column in Figure 8). After measuring the ambient temperature in winter, mid-season, and summer, the temperature difference between the surface temperature of the drying oven 10 and the ambient temperature, i.e., the corrected surface temperature, was calculated (see the "Surface Temperature (Corrected)" column in Figure 8). The temperature inside the drying oven 10 (inside the equipment) was always kept at 250°C. Figure 8 is a table showing the temperature measurement results for each part and the calculation results for the temperature difference.

As a result, it was confirmed that the seasonal temperature difference (summer - winter) for the surface temperature (measured value) before correction reached 29.1°C. On the other hand, the seasonal temperature difference (summer - winter) for the surface temperature after correction was reduced to 0.9°C, confirming that the true surface temperature of the drying oven 10 could be measured. Therefore, it was confirmed that hot air leakage can be accurately detected by checking whether the range of the corrected surface temperature (i.e., the temperature difference between the surface temperature of the drying oven 10 and the ambient temperature) is outside a specified range (e.g., 10°C or more). The temperature values for each part shown in Figure 8 may also be displayed on the screen of the display 65.

Therefore, this embodiment provides the following advantages:

(1) In this embodiment, the equipment temperature management system 1 calculates the surface temperature of the drying oven 10 based on the first thermal image 52a that shows the first marker 31, determines the ambient temperature based on the second thermal image 52b that shows the second marker 41, and then calculates the temperature difference between the surface temperature and the ambient temperature. This cancels out changes in the surface temperature caused by changes in the ambient temperature, so by measuring the change in surface temperature in this state, it is possible to detect hot air leaks within the drying oven 10 with high accuracy without being affected by the ambient temperature.

(2) In this embodiment, the base 32 constituting the first marker 31 is made of aluminum, which has high thermal conductivity and heat resistance capable of withstanding temperatures of several hundred degrees Celsius (at least 100 degrees Celsius or higher). This allows the surface temperature of the first marker 31 to easily follow the surface temperature of the drying oven 10. Similarly, the base 42 constituting the second marker 41 is also made of aluminum, so the surface temperature of the second marker 41 easily follows the ambient temperature. As a result, by capturing images of the markers 31, 41 with a thermal camera 50, the surface temperature and ambient temperature can be accurately calculated based on the markers 31, 41 captured in the thermal images 52a, 52b. Furthermore, because the bases 32, 42 are not made of flammable materials such as resin, the markers 31, 41 can be suitably used in a drying oven 10 that uses hot air.

(3) For example, if the second marker 41 reflects ambient heat, even if the second marker 41 is imaged by an imaging device, it may not be possible to accurately calculate the surface temperature of the second marker 41 reflected in the second thermal image 52b. Furthermore, the calculated surface temperature of the second marker 41 may change depending on the angle at which the thermal camera 50 images the second marker 41. Therefore, in this embodiment, an anti-reflection treatment is applied to the surface of the base that constitutes the second marker 41. This makes the second marker 41 less likely to reflect heat. Furthermore, even if the angle at which the second marker 41 is imaged changes, the error in the obtained surface temperature is reduced. Therefore, the surface temperature of the second marker 41 reflected in the second thermal image 52b can be accurately calculated.

(4) In this embodiment, the second marker 41 is located at a distance of 100 mm or more from the surface 10a of the drying oven 10, making it less susceptible to the influence of the surface temperature of the drying oven 10. Therefore, the surface temperature of the second marker 41, and therefore the ambient temperature, can be accurately calculated.

(5) For example, it is possible to install a temperature sensor at each measurement point A0 to A13 and use each temperature sensor to measure the surface temperature and ambient temperature of the drying oven 10. However, in this case, each temperature sensor must be electrically connected to the personal computer (CPU 61). Furthermore, the temperature sensors may be up to several hundred meters away from the personal computer. Therefore, the task of installing each temperature sensor at each measurement point A0 to A13 is tedious.

In contrast, in this embodiment, the markers 31 and 41 installed at each measurement point A0 to A13 are imaged with a thermal camera 50, and the surface temperature and ambient temperature of the drying oven 10 are calculated based on the imaged markers 31 and 41. In this case, the unfixed thermal camera 50 simply needs to be connected to a PC via a USB cable, eliminating the need to electrically connect multiple markers 31 and 41 to the PC, making it easy to obtain the surface temperature and ambient temperature. Furthermore, in this embodiment, the CPU 61 automatically reads the ID numbers of the markers 31 and 41 imaged with the thermal camera 50, automatically determines whether they are first markers 31 for measuring the equipment surface temperature or second markers 41 for measuring the ambient temperature, and automatically calculates the surface temperature and ambient temperature. This eliminates the need for the operator to manually identify the markers or calculate the surface temperature and ambient temperature. This further reduces the operator's workload.

The above embodiment may be modified as follows:

- In the above embodiment, the CPU 61 calculates the average temperature of multiple pixels (points) on one second marker 41 and determines the calculated average as the ambient temperature. However, the second markers 41 may be provided at multiple locations around the drying oven 10, and the CPU 61 may calculate the average surface temperature of each second marker 41 and determine the calculated average as the ambient temperature. In this way, it is possible to obtain the ambient temperature for the entire drying oven 10, rather than the ambient temperature near one second marker 41. Therefore, even if there is variation in the temperature around the drying oven 10, the variation is averaged out, and the ambient temperature can be calculated with high accuracy.

- In the above embodiment, the CPU 61 calculates the average value of the temperatures of multiple pixels (points) in one second marker 41 and determines this calculated average value as the ambient temperature. However, the CPU 61 may also determine the maximum or minimum value of the temperatures of each pixel in one second marker 41 as the ambient temperature. Furthermore, the CPU 61 may calculate the temperature of one point (e.g., a pixel) in one second marker 41 and determine this calculated temperature as the ambient temperature.

- In the above embodiment, the markers 31, 41 displayed geometric patterns 34, 44 made up of two colors (white and black) with different brightness levels, but geometric patterns made up of three or more colors may also be displayed.

- In the above embodiment, the markers 31 and 41 were two-dimensional ArUco markers, but other two-dimensional markers such as QR Code (a registered trademark of Denso Wave Inc.) or AprilTag may also be used. Other two-dimensional objects such as pictures, letters, and symbols may also be used as markers. Furthermore, three-dimensional objects such as parts present on the surface of equipment may also be used as markers.

- In the above embodiment, if the surface temperature of the drying furnace 10 exceeds a predetermined range (here, 10°C) above the ambient temperature, the alarm 66 is activated to warn the operator. However, if the surface temperature exceeds a predetermined range (for example, -10°C) below the ambient temperature, the alarm 66 may also be activated to warn the operator. In this way, it is possible to detect cold air leaks within equipment, for example, in chemical plants.

- In the above embodiment, a thermal camera 50 was used as the imaging means, capturing images of the first region 31a including the first marker 31 and the second region 41a including the second marker 41 to obtain visible images 51a, 51b and thermal images 52a, 52b. However, the imaging means may also be composed of a visible image imaging camera (imaging means) that captures visible images 51a, 51b, and a thermal image imaging camera (imaging means) that is provided separately from the visible image imaging camera and captures thermal images 52a, 52b. It is preferable that the visible image imaging camera and thermal image imaging camera be positioned as close together as possible.

- In the above embodiment, all measurement points A0 to A13 were imaged by a non-fixed thermal camera 50. However, some of the measurement points A0 to A13 may be imaged by a fixed thermal camera, or all of the measurement points A0 to A13 may be imaged by a fixed thermal camera.

- In the above embodiment, the thermal camera 50 transmits image data to the control device 60 via a USB cable, but the image data may be transmitted to the control device 60 using other means. For example, the thermal camera 50 may transmit image data to the control device 60 via communication means such as Bluetooth (a registered trademark of Bluetooth SIG, Inc.), infrared communication, or an internet line (such as a telephone line).

- The equipment temperature management system 1 in the above embodiment was a system that managed the surface temperature of the drying furnace 10, but it may also be a system that manages the surface temperature of other equipment, such as production equipment, utility equipment, or chemical plants, that perform heating and cooling.

Next, in addition to the technical ideas set forth in the claims, the technical ideas grasped by the above-described embodiments are listed below.

(1) An equipment temperature management system according to any one of claims 1 to 7, wherein the temperature difference is a temperature difference calculated when the surface temperature of the equipment is higher than the ambient temperature.

(2) An equipment temperature system according to any one of claims 1 to 7, wherein the first marker is a marker member having a geometric pattern made of multiple colors of different brightness displayed on the surface of a base made of a highly thermally conductive material.

(3) In the technical concept (2), the first marker is characterized in that the surface of the base is subjected to an anti-reflection treatment.

(4) An equipment temperature management system according to any one of claims 1 to 7, wherein the first marker and the second marker are provided at each specific measurement point in the equipment, and the first marker and the second marker are assigned an ID number associated with each measurement point.

DESCRIPTION OF SYMBOLS 1...Facility temperature management system 10...Drying furnace 10a as facility...Surface 31 of facility...First marker 31a...First region 41...Second marker 41a...Second region 42...Base 43...Surface 44 of base...Geometric pattern 50...Thermal camera 51a as imaging means...First visible image 51b as visible image...Second visible image 52a as visible image...First thermal image 52b as thermal image...Second thermal image 53 as thermal image...Corrected visible image 60...Control device 61 as processor...CPU as marker discrimination means, facility surface temperature calculation means, ambient temperature determination means, and temperature difference calculation means
65: Display as display means 66: Alarm as warning means

Claims (8)

A system for managing the surface temperature of equipment,
a first marker for measuring a surface temperature of the equipment, the first marker being in contact with the surface of the equipment; and a second marker for measuring an ambient temperature, the second marker being spaced apart from the surface of the equipment, the first marker and the second marker having different identifiable geometric features;
an imaging unit that captures an image of a first region including the first marker and a second region including the second marker to obtain a visible image and a thermal image;
a marker discrimination means for discriminating the type of the marker captured by the imaging means based on the geometric features shown in the visible image;
an equipment surface temperature calculation means for calculating a surface temperature of the equipment based on the thermal image in which the first marker appears when the equipment is determined to be the first marker; and an ambient temperature determination means for calculating a surface temperature of the second marker based on the thermal image in which the second marker appears when the equipment is determined to be the second marker, and determining an ambient temperature based on the calculated surface temperature.
An equipment temperature management system comprising a temperature difference calculation means for calculating a temperature difference between the surface temperature of the equipment and the ambient temperature. The equipment temperature management system described in claim 1, characterized in that the ambient temperature determination means calculates the average value of temperatures at multiple points on one of the second markers and determines the calculated average value as the ambient temperature. The second markers are provided at a plurality of locations,
2. The equipment temperature management system according to claim 1, wherein the ambient temperature determining means calculates an average value of surface temperatures of a plurality of the second markers and determines the calculated average value as the ambient temperature. a display means for displaying the visible image and the thermal image,
4. The equipment temperature management system according to claim 1, wherein the display means displays an image indicating a temperature obtained by subtracting the ambient temperature from the surface temperature of the equipment as a corrected visible image. An equipment temperature management system according to any one of claims 1 to 4, characterized in that the second marker is a marker member having a geometric pattern made of multiple colors of different brightness displayed on the surface of a base made of a highly thermally conductive material. The equipment temperature management system described in claim 5, characterized in that the second marker has an anti-reflection coating applied to the surface of the base. The equipment temperature management system described in any one of claims 1 to 6, further comprising a warning means for issuing a warning if the temperature difference range is outside a predetermined range. a processor for controlling an equipment temperature management system including an imaging means for capturing visible and thermal images of a first area including a first marker for measuring the equipment surface temperature that is provided in contact with the surface of the equipment and a second area including a second marker for measuring the ambient temperature that is provided apart from the surface of the equipment;
a marker discrimination step of discriminating the type of the marker imaged by the imaging means based on geometric features shown in the visible image;
an equipment surface temperature calculation step of calculating a surface temperature of the equipment based on the thermal image in which the first marker appears when the marker is determined to be the first marker; and an ambient temperature determination step of calculating a surface temperature of the second marker based on the thermal image in which the second marker appears when the marker is determined to be the second marker, and determining an ambient temperature based on the calculated surface temperature.
an equipment temperature management program for executing a temperature difference calculation step of calculating a temperature difference between the surface temperature of the equipment and the ambient temperature;