JP2022063622A - Measurement device and measurement method - Google Patents

Abstract

To improve the measurement accuracy of the temperature measured by a thermography device.SOLUTION: A thermography device (100) pertaining to the present application includes an acquisition unit (41) for acquiring distance information that indicates the distance from a measurement object (IT) to an infrared camera (50) that measures electromagnetic waves radiated from the measurement object (IT). The thermography device (100) also includes a calculation unit (42) for calculating the temperature of the measurement object (IT) on the basis of the result of measurement by the infrared camera (50). Furthermore, the thermography device 100 includes a correction unit (43) for correcting the temperature calculated by the calculation unit (42), on the basis of the distance indicated by the distance information.SELECTED DRAWING: Figure 3

Description

The present invention relates to a measuring device and a measuring method for measuring the temperature of a measurement target, such as a thermography device.

Conventionally, there is known a technique for inspecting various processes and products by using a thermography device that captures a thermal image showing a thermal distribution of an imaging target. As an example of such a technique, a technique for inspecting an adhesive state by hot melt using a thermography device is known. For example, there is known one that determines the amount, position, splattering or elongation of hot melt based on a thermal image taken by using a thermography device, and determines the adhesion state of hot melt based on the determination result. ..

Japanese Unexamined Patent Publication No. 2015-034778

Since such a thermography device measures the temperature in the measurement target based on the radiance of infrared rays emitted from the measurement target, it is necessary to calibrate the correspondence between the radiance and the temperature. In such calibration, for example, the correspondence between the temperature of the measurement target and the shooting brightness acquired by the thermography device is calibrated while the distance from the measurement target to the thermography device is fixed.

However, in a thermography device that has been calibrated in this way, if the distance between the measurement target and the thermography device at the time of measurement is different from that at the time of calibration, the correspondence between the shooting brightness and the temperature changes, so the correct temperature is used. It becomes impossible to measure.

The present application is to solve such a problem, and aims to improve the measurement accuracy of the temperature measured by a thermography apparatus.

The measuring device according to the present application is a measuring unit that measures an electromagnetic wave radiated from a measuring object, an acquisition unit that acquires distance information indicating a distance between the measuring object, and a measuring unit based on the measurement results of the measuring unit. It is provided with a calculation unit for calculating the temperature and a correction unit for correcting the temperature calculated by the calculation unit based on the distance indicated by the distance information.

In the above measuring device, the acquisition unit may acquire distance information indicating the distance between the measurement unit that measures infrared rays emitted from the measurement target and the measurement target.

Further, in the above measuring device, the acquisition unit acquires distance information indicating the distance between the measurement unit that measures the radiation brightness of the infrared rays emitted from the measurement target and the measurement target, and the calculation unit is the measurement unit. The temperature of the object to be measured may be calculated based on the measured infrared radiation brightness.

Further, in the above-mentioned measuring device, the acquisition unit may acquire distance information indicating the distance between the measurement surface on which the measurement unit measures electromagnetic waves and the measurement target.

Further, in the above measuring device, the acquisition unit determines the distance between the measuring surface and the measuring object based on the distance between the lens and the measuring surface when the image of the measuring object is formed on the measuring surface in a predetermined mode. You may estimate.

Further, in the above measuring device, the acquisition unit may acquire the distance information input by the user.

Further, in the above measuring device, the acquisition unit may acquire distance information indicating the distance between the measuring unit and the measurement target measured by the predetermined distance measuring device.

Further, in the above measuring device, the correction unit is a distance between a predetermined measurement target having a predetermined temperature and a measurement surface for measuring electromagnetic waves in the predetermined measurement device, a temperature of the predetermined measurement target, or a predetermined measurement. A correction formula generated based on the temperature measured by the predetermined measuring device while changing at least one of the distances between the lens and the measuring surface of the device, and forming an image with a predetermined measurement target. The temperature calculated by the calculation unit may be corrected by using a correction formula for correcting the temperature measured by a predetermined measuring device to the temperature of a predetermined measurement target based on the distance from the surface.

Further, in the above measuring device, the correction unit may correct the temperature calculated by the calculation unit by using a linear polynomial that corrects the temperature based on the distance from the measurement target to the measurement unit.

Further, in the above measuring device, the correction unit may use a correction formula corresponding to the temperature calculated by the calculation unit among a plurality of correction formulas for correcting the temperature in different ranges.

Further, in the above measuring device, the calculation unit may use the correction formula having the lowest error rate in the range including the temperature calculated by the calculation unit among the plurality of correction formulas.

Further, in the above measuring device, the acquisition unit acquires the focal distance of the lens of the measurement unit and the distance information indicating the distance from the measurement target to the measurement surface where the electromagnetic wave is measured in the measurement unit, and the correction unit obtains the focal distance. And the temperature calculated by the calculation unit may be corrected based on the distance information.

Further, in the measuring device, the correction unit may correct the temperature calculated by the calculation unit based on the distance indicated by the distance information and the characteristics of the lens possessed by the measurement unit.

Further, in the above-mentioned measuring device, the acquisition unit may further acquire the measurement result from the photographing apparatus operating as the measuring unit.

Further, the measuring device may further have a photographing unit that operates as a measuring unit.

According to the above-mentioned measuring device, distance information indicating the distance between the measuring unit for measuring electromagnetic waves such as infrared rays emitted from the measuring target and the measuring target is acquired. For example, the measuring device may acquire the distance information input by the user, and acquires the distance information indicating the distance measured by a predetermined distance measuring device that measures the distance between the measuring unit and the measurement target. You may. Then, the measuring device calculates the temperature of the measurement target from the measurement result of the measuring unit, and corrects the calculated temperature based on the distance indicated by the distance information. As a result of such processing, the measuring device can accurately measure the temperature of the measurement target even when the distance to the measurement target changes from the time of calibration. Further, the measuring device can measure the temperature of the measurement target without performing calibration again when the distance to the measurement target changes from the time of calibration.

FIG. 1 is a diagram showing an example of the principle of processing executed by the thermography apparatus according to the embodiment. FIG. 2 is a diagram showing an outline of the thermography device according to the embodiment. FIG. 3 is a diagram showing an example of a functional configuration of the thermography apparatus according to the first embodiment. FIG. 4 is a diagram showing an example of correction data according to the embodiment. FIG. 5 is a flowchart showing an example of the measurement process executed by the controller according to the embodiment. FIG. 6 is a flowchart showing an example of the creation process executed by the controller according to the embodiment.

Next, an embodiment will be described with reference to the drawings. In the following description, the same reference numerals will be given to the components common to each embodiment, and the repeated description will be omitted.

[principle]
The thermography device uses an image pickup element to measure the radiance of infrared rays generated from the measurement target, and measures the temperature of the measurement target according to the measured radiance. For example, the thermography apparatus calibrates the correspondence information indicating the correspondence between the radiance and the temperature by measuring the radiance of infrared rays generated from the blackbody furnace while changing the temperature of the blackbody furnace. Then, the thermography device calculates the temperature of the measurement target from the radiance generated from the measurement target based on the calibrated correspondence information (hereinafter, referred to as “calibration information”).

Hereinafter, with reference to FIG. 1, the principle of the process in which the thermography apparatus according to the present embodiment measures the temperature of the measurement target will be described. FIG. 1 is a diagram showing an example of the principle of processing executed by the thermography apparatus according to the embodiment. Note that FIG. 1 shows an infrared camera 2 that measures the radiance of infrared rays emitted from the measurement target among the blackbody furnace 1 as the measurement target and the thermography device.

In the example shown in FIG. 1, the infrared camera 2 is an image pickup element that captures an image of the lens 3 emitted from the blackbody furnace 1 and the blackbody furnace 1 imaged by the lens 3, that is, measurement for measuring electromagnetic waves. It has an FPA (Focal Plane Array) 4 which is a surface. Further, in the following description, the distance from the blackbody furnace 1 to FPA4 is defined as the measurement distance “d”, and the distance from the lens 3 to FPA4 is defined as the lens distance “f”. Further, in the following description, the temperature of the blackbody furnace 1 is defined as "x".

Here, when calibrating the corresponding information, the radiance is measured while keeping the focus on the FPA4 constant by fixing the measurement distance “d” and the lens distance “f”. For example, in the thermography apparatus, the radiation luminance measured when the temperature of the blackbody furnace 1 is set to "x1", that is, the photographing brightness is "y1", and the temperature of the blackbody furnace 1 is set to "x2". When the shooting brightness measured at this time is "y2", the formula for calculating the temperature "x1" from the shooting brightness "y1" and the temperature "x2" from the shooting brightness "y2" (hereinafter, "temperature calculation"). It may be described as "formula") as calibration information. Then, the thermography apparatus calculates the temperature of the measurement target from the measured value of the photographing brightness by using the temperature calculation formula.

However, when the measurement distance "d" changes, the shooting brightness of the infrared rays measured by the FPA 4 changes even if the temperature "x" of the blackbody furnace 1 does not change. Further, when the lens distance "f" changes, the focus on the FPA4 changes, so that the infrared shooting brightness measured by the FPA4 changes even if the temperature "x" of the blackbody furnace 1 does not change. .. Therefore, if the distance from the FPA 4 to the measurement target is different from that at the time of calibration, it takes time and effort to recalibrate the corresponding information.

Therefore, the thermography device according to the present embodiment calculates the temperature of the measurement target from the radiance of infrared rays emitted from the measurement target, and corrects the calculated temperature based on the distance between the measurement target and the thermography device. do. As a result of such processing, the thermography apparatus according to the present embodiment can improve the temperature measurement accuracy while saving the trouble of recalibrating the calibration information even when the distance between the thermography apparatus and the measurement target changes. Can be improved.

For example, the thermography apparatus uses calibration information to change the temperature based on the shooting brightness while changing at least one of the measurement distance “d” or the lens distance “f” and the temperature “x” of the blackbody furnace 1. Calculate "t". The thermography device is a correction formula that corrects the temperature "t" calculated using the calibration information to the actual temperature "X", and has the temperature "t" calculated using the calibration information and the measurement distance "d". , And a correction formula with the lens distance "f" as parameters.

For example, the thermography device holds calibration information with the measurement distance as "d" and the lens distance as "f". In such a case, the thermography apparatus measures the photographing brightness "y3" in a state where the temperature of the blackbody furnace 1 is "X" and the measurement distance is "d3". Then, the thermography apparatus calculates the temperature "t3" of the blackbody furnace 1 from the photographing brightness "y3" by using the calibration information. Further, the thermography apparatus measures the shooting brightness “y4” in a state where the temperature of the blackbody furnace 1 is “X” and the measurement distance is “d4”. Then, the thermography apparatus calculates the temperature "t4" of the blackbody furnace 1 from the photographing brightness "y4" by using the calibration information.

Here, when the measurement distances "d3" and "d4" are different from the measurement distances "d", the temperature "t3" and the temperature "t4" deviate from the temperature "X" of the blackbody furnace 1. Therefore, the thermography apparatus generates a correction formula for correcting the temperature "t3" and the temperature "t4" to the temperature "X" of the blackbody furnace 1 with the measurement distance as a parameter. Similarly, the thermography device measures the radiance of infrared rays emitted from the blackbody furnace 1 while changing the lens distance and temperature, and is calculated from the measured radiance (that is, the shooting brightness) using the calibration information. Generate a correction formula that changes the temperature to the actual temperature.

For example, the correction formula T (x, f, d) having the temperature “x” of the object, the measurement distance “d”, and the lens distance “f” as parameters can be approximated by the following formula (1). .. Here, in the equation (1), X (x) is a function having the temperature “x” as a parameter, and F (f) is a function having the lens distance “f” as a parameter, and D (d). ) Is a function having the measurement distance “d” as a parameter, and k is a predetermined variable.

(Number 1)
T (x, f, d) = X (x) x F (f) x D (d) + k ... (1)

Here, when the focus in the FPA 4 is appropriate, the lens distance "f" is determined by the measurement distance "d". Therefore, the equation (1) can be converted into the following equation (2). Here, in the equation (2), D'(d) is a predetermined function in which the measurement distance "d" is used as a parameter and the lens distance "f" based on the measurement distance "d" and the measurement distance "d" is taken into consideration. Is.

(Number 2)
T (x, d) = X (x) x D'(d) + k ... (2)

Here, when the measurement distance "d" is a specific distance and the FPA is in focus, when the function X (x) is approximated by a linear expression of x, the temperature "t" output by the thermography device is obtained. It can be expressed by the following equation (3). Here, in the formula (3), a and b are predetermined constants determined based on the measurement distance "d".

(Number 3)
t = ax + b

As a result, the temperature x of the object can be expressed by the following equation (4). In addition, in the formula (4), a'and b'are predetermined constants determined based on the a and b of the formula (3).

(Number 4)
x = a'xt + b'... (4)

The thermography apparatus calculates the values of the constants a'and b'in the above-mentioned equation (4) for each measurement distance "d" while changing the temperature "t", the measurement distance "d", and the lens distance "f". do. Then, when measuring the temperature of the measurement target, the thermography device determines and determines the values of the constants a'and b'based on the value of the measurement distance "d" between the measurement target and the thermography device. The temperature "t" calculated from the shooting brightness is corrected based on the values of the constants a'and b'. The thermography apparatus may generate an approximate expression for calculating the constants a'and b'according to the measurement distance "d".

[Embodiment]
Hereinafter, the outline of the embodiment will be described with reference to FIG. FIG. 2 is a diagram showing an outline of the thermography device according to the embodiment. In the example shown in FIG. 2, the thermography device 100 includes a controller 10 and an infrared camera 50. Further, the controller 10 is connected to the terminal device 200.

The infrared camera 50 measures the radiance of infrared rays emitted from the inspection target IT flowing through the inspection line IL1 using an FPA such as a thermopile array sensor composed of a plurality of thermopile, and transmits the measurement result to the controller 10. .. The infrared camera 50 may use various thermal infrared sensors such as a microbolometer and a charcoal sensor, or may use various quantum infrared sensors.

In such a case, the controller 10 measures the temperature of the IT to be inspected based on the measurement result. More specifically, the controller 10 measures the temperature distribution on the surface of the measurement target IT by measuring the temperature of each region on the surface of the measurement target IT. Then, the controller 10 generates a thermal image showing the measured temperature distribution. For example, the controller 10 generates data as a thermal image associated with a signal value indicating the amount of infrared rays and the temperature measured for each pixel. Then, the controller 10 provides the generated thermal image to the terminal device 200.

In such a process, the controller 10 acquires distance information indicating the distance between the measurement target IT and the infrared camera 50. For example, the operator OP measures the distance between the surface of the measurement target IT and the FPA 4 in the infrared camera 50, and inputs the distance information indicating the measured distance to the terminal device 200. In such a case, the controller 10 acquires the distance information from the terminal device 200.

Further, the controller 10 calculates the temperature on the surface of the measurement target IT from the measurement result of the infrared camera 50 by using the calibration information calibrated in advance. Then, the controller 10 corrects the calculated temperature based on the distance indicated by the distance information by using the correction formula generated in advance. Then, the controller 10 generates a thermal image showing the corrected temperature (hereinafter, referred to as “corrected temperature”), and provides the generated thermal image to the operator OP.

[Example of functional configuration in the first embodiment]
Subsequently, an example of the functional configuration of the controller 10 of the thermography apparatus 100 and the infrared camera 50 will be described with reference to FIG. FIG. 3 is a diagram showing an example of a functional configuration of the thermography apparatus according to the first embodiment. In the following description, the functional configuration of the infrared camera 50 will be described, and then the functional calibration of the controller 10 will be described.

The infrared camera 50 included in the thermography device 100 has a cylindrical portion 51 and a housing 52. Further, the cylindrical portion 51 has a lens 53. Further, the housing 52 has an image pickup element 54. The lens 53 is a lens having a predetermined focal length, and for example, collects infrared rays emitted from the measurement target IT. Further, the image pickup element 54 is an element for measuring the radiance of infrared rays collected by the lens 53, and provides the controller 10 with a value indicating the radiance measured by each pixel.

Here, the cylindrical portion 51 may be capable of appropriately changing the distance between the image pickup device 54 and the lens 53. Although the description is omitted in the example shown in FIG. 3, the infrared camera 50 may be an infrared camera 50 having a shutter or a shutterless infrared camera. For example, the infrared camera 50 has various known autofocus functions, and for example, has a function of adjusting the position of the lens 53 so as to be in focus on the image pickup device 54.

On the other hand, the controller 10 included in the thermography device 100 has a communication unit 20, a storage unit 30, and a control unit 60.

The communication unit 20 controls communication with the infrared camera 50 and the terminal device 200 that obtain a thermal image showing the heat distribution of the object to be photographed. For example, the communication unit 20 is realized by a NIC (Network Interface Card), a USB (Universal Serial Bus) port, or the like, and controls communication with the infrared camera 50 or the terminal device 200.

The storage unit 30 is a storage device for storing various types of information, and is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory (Flash Memory), or a storage device such as a hard disk or an optical disk. .. For example, the calibration data 31 and the correction data 32 are registered in the storage unit 30.

The calibration data 31 is information for calculating the temperature of the measurement target from the radiance of infrared rays emitted from the measurement target IT, and is, for example, a temperature calculation formula created in advance as calibration information. For example, the calibration data 31 has a measurement distance “d” which is a distance between the blackbody furnace 1 and the image pickup element 54 and a lens distance “f” which is a distance between the lens 53 and the image pickup element 54. It is realized by a temperature calculation formula in which various coefficients are set so as to convert the radiance measured while changing the temperature of the blackbody furnace 1, that is, the shooting brightness, into the temperature of the blackbody furnace 1 in a fixed state. To.

The correction data 32 is a correction formula for correcting the calculated temperature calculated by the temperature calculation formula based on the value of the measurement distance “d” and the value of the lens distance “f”. For example, FIG. 4 is a diagram showing an example of correction data according to an embodiment. In the example shown in FIG. 4, the correction data 32 includes a plurality of information having items such as “temperature range” and “correction formula”.

The "temperature range" is information indicating the range of the calculated temperature. Further, the "correction formula" is information indicating a correction formula adopted when the calculated temperature is included in the associated "temperature range". As described above, the controller 10 corrects the calculated temperature from the distance information by using the correction formula. For example, in the example shown in FIG. 4, when the temperature range is included in "T1 to T2", the correction data 32 is corrected by using "correction formula # 1", and the temperature range is included in "T2 to T3". If so, it indicates that the correction is performed using "correction formula # 2".

Here, it will be described that different correction formulas are used for each temperature range. As a result of the applicant generating a correction formula for correcting the calculated temperature to the temperature "X" of the blackbody furnace 1 while changing the measurement range "d", it was found that the correction formula is a multi-order equation according to the temperature. rice field. However, when such a multi-order equation is used, it takes time to calculate the correction temperature. Therefore, the controller 10 has come up with the idea of reducing the order of the correction formula and reducing the processing load required for calculating the correction temperature by setting the correction formula for each range of the calculated temperature. As a result, in the correction data 32, for example, a correction formula approximated by a linear formula for each range of the calculated temperature, and a correction formula having a different coefficient is registered.

Returning to FIG. 3, the explanation will be continued. The control unit 40 is realized by executing various programs stored in the storage device inside the thermography device 100 by a processor such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit) using the RAM or the like as a work area. Will be done. Further, the control unit 60 may be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

As shown in FIG. 3, the control unit 40 includes an acquisition unit 41, a calculation unit 42, a correction unit 43, a provision unit 44, and a creation unit 45.

The acquisition unit 41 acquires distance information indicating the distance between the measuring device that measures the electromagnetic wave radiated from the measurement target IT and the measurement target. More specifically, the acquisition unit 41 acquires distance information indicating the distance between the infrared camera 50 that measures the radiance of infrared rays emitted from the measurement target IT and the measurement target. For example, the acquisition unit 41 measures the distance via the terminal device 200 and acquires distance information indicating the value of the distance input to the terminal device 200.

Here, the distance indicated by the distance information may be the distance between the image pickup device 54 as the FPA of the infrared camera 50 and the measurement target IT. Here, when the image pickup element 54 is fixed to the housing 52 of the infrared camera 50, for example, the distance indicated by the distance information is an arbitrary position of the infrared camera 50 (for example, the end of the cylindrical portion 51 or the housing 52). It may be the distance from the end of the image to the measurement target IT.

The calculation unit 42 calculates the temperature of the measurement target based on the measurement result by the measurement unit. For example, the calculation unit 42 acquires the value of the radiance measured by each pixel of the image pickup element 54 of the infrared camera 50, that is, the value of the shooting brightness. In such a case, the calculation unit 42 converts the value of the photographing luminance measured for each pixel into the calculated temperature by using the temperature calculation formula registered in the storage unit 30 as the calibration data 31.

The correction unit 43 corrects the calculated temperature calculated by the calculation unit 42 based on the distance indicated by the distance information. Specifically, the correction unit 43 performs the following processing for each pixel of the image sensor 54. First, the correction unit 43 refers to the correction data 32 and specifies the correction formula corresponding to the temperature range including the calculated temperature. Then, the correction unit 43 calculates the corrected correction temperature based on the distance indicated by the distance information by inputting the calculated temperature and the distance indicated by the distance information into the correction formula.

The providing unit 44 generates a thermal image using the correction temperature calculated for each pixel by the correction unit 43, and provides the generated thermal image to the operator OP. For example, the providing unit 44 generates an image in which colors corresponding to the correction temperature are added to the pixels on the image in each pixel of the image pickup device 54 as a thermal image. Then, the providing unit 44 provides the generated thermal image to the terminal device 200 and displays it.

The creating unit 45 creates a temperature calculation formula as the calibration data 31 and a correction formula as the correction data 32. It should be noted that the creation of such a correction formula may be performed at the time of calibration of the thermography device 100, or may be performed at an arbitrary timing instructed by the operator OP.

Hereinafter, an example of the process executed by the creating unit 45 will be described. First, the creating unit 45 performs a calibration process for creating a temperature calculation formula for calculating the temperature from the measured infrared radiance. In such a calibration process, the operator OP changes the measurement target IT and installs the blackbody furnace 1 whose temperature can be changed at a position where the infrared camera 50 can take a picture. In such a case, the infrared camera 50 focuses on the blackbody furnace 1.

Further, the operator OP sets the temperature of the blackbody furnace 1 to a predetermined temperature, and inputs the set temperature to the controller 10 via the terminal device 200. In such a case, the controller 10 controls the infrared camera 50 to measure the radiance of infrared rays emitted from the blackbody furnace 1. Further, the operator OP causes the controller 10 to perform the same process while appropriately changing the temperature of the blackbody furnace 1 without changing the distance between the infrared camera 50 and the blackbody furnace 1. As a result of such processing, the creating unit 45 obtains a correspondence between the temperature of the blackbody furnace 1 and the photographing brightness measured at that temperature.

Then, the creating unit 45 generates a mathematical formula for converting the value of the photographing luminance into the temperature of the corresponding blackbody furnace 1. For example, the creating unit 45 uses the value of the photographing luminance as a parameter based on the value of each temperature of the blackbody furnace 1 and the value of the photographing luminance measured when the blackbody furnace 1 was at that temperature. Set the coefficients of the multidimensional equation. Then, the creating unit 45 registers the multi-order equation in which the coefficient is set as the calibration data 31 in the storage unit 30.

Subsequently, an example of the process in which the creating unit 45 generates the correction data 32 will be described. First, the operator OP is the temperature of the blackbody furnace 1, the distance between the blackbody furnace 1 and the infrared camera 50 (that is, the measurement distance), or the distance between the lens 3 and the image pickup element 54 (that is, the lens). Distance) is used as a parameter, and at least one of the parameters is appropriately changed. Then, the operator OP inputs the changed parameter value to the controller 10 via the terminal device 200.

In such a case, the creating unit 45 causes the infrared camera 50 to measure the value of the infrared radiance. Then, the creating unit 45 creates the calculated temperature from the radiance using the temperature calculation formula that becomes the calibration data 31. Further, the creating unit 45 measures the radiance every time the operator OP changes various parameters, and calculates the calculated temperature from the measured shooting brightness using the calibration data 31.

As a result of such processing, the creating unit 45 determines the calculated temperature “t” based on the calibration information for each combination of the actual temperature “X”, the measurement distance “d”, and the lens distance “f” of the blackbody furnace 1. Can be obtained. Then, the creating unit 45 generates a correction formula for correcting the calculated temperature "t" to the actual temperature "X" of the blackbody furnace 1 with the measurement distance "d" and the lens distance "f" as parameters. That is, the creating unit 45 is a correction formula generated based on the temperature "t" measured by the controller 10 while changing at least one of the measurement distance "d", the temperature "X", and the lens distance "f". Therefore, a correction formula for correcting the temperature "t" to the temperature "X" is generated based on the measurement distance "d".

For example, the creating unit 45 sets the coefficient of the polynomial that outputs the temperature “X” when the measurement distance “d” and the calculated temperature “t” are input by using various known regression analysis methods. Then, the creating unit 45 registers the polynomial in which the coefficient is set in the storage unit 30 as a correction formula.

Here, the creating unit 45 may generate a plurality of polynomials having a predetermined degree, and among the generated polynomials, the polynomial having the lowest error rate in each temperature region may be used as a correction formula in the temperature region. For example, in a correction expression whose accuracy satisfies a predetermined condition, it is considered that the value of the order is larger than the predetermined value. Therefore, for example, the creating unit 45 creates a plurality of polynomials having a degree lower than a predetermined value (for example, a first-order polynomial) and having different coefficients, and calculates the error rate in each temperature region. do. Then, the creating unit 45 may use the polynomial having the lowest error rate in a certain temperature region as a correction formula in that temperature region. By performing such processing, the creating unit 45 can prevent a decrease in correction accuracy while reducing the amount of calculation associated with the correction.

[Example of operation in the embodiment]
Next, an example of the operation timing of the controller 10 according to the embodiment will be described with reference to the drawings. FIG. 5 is a flowchart showing an example of the measurement process executed by the controller according to the embodiment.

For example, the controller 10 determines whether or not the shooting result has been acquired from the infrared camera 50 (step S101), and if not (step S101: No), waits. Then, when the controller 10 acquires the shooting result (step S101: Yes), the controller 10 calculates the temperature from the shooting result (step S102).

Further, the controller 10 acquires the distance to the measurement target (step S103). It should be noted that step S102 and step S103 may be executed in any order or may be executed at the same time. Then, the controller 10 corrects the temperature based on the distance (step S104), provides information such as a thermal image showing the corrected temperature (step S105), and ends the process.

Subsequently, an example of the process of creating the correction formula will be described with reference to FIG. FIG. 6 is a flowchart showing an example of the creation process executed by the controller according to the embodiment. For example, when the controller 10 acquires the imaging result (step S201), the controller 10 calculates the temperature from the imaging result using the calibration information (temperature calculation formula) calibrated in advance (step S202).

Subsequently, the controller 10 acquires the measurement distance, the lens distance, and the temperature (step S203). Then, the controller 10 determines whether or not a predetermined number of sets of parameters of the measurement distance, the lens distance, the temperature to be measured, and the calculated distance are obtained (step S204), and if not (step S204). S204: No), the process is repeated from step S201. In such repetition, the measurement distance, the lens distance, or the temperature of the measurement target is appropriately changed by the operator OP.

On the other hand, when a predetermined number of parameter sets are obtained (step S204: Yes), the controller 10 generates a correction formula based on the parameters (step S205) and ends the process. The correction formula thus generated will be used in step S104 shown in FIG.

[Extension of Embodiment]
In the above, an example of the measurement process and the creation process executed by the thermography apparatus 100 has been described. However, the embodiments are not limited to this. Hereinafter, variations in the processing executed by the thermography apparatus 100 and variations in the measurement processing and the creation processing will be described.

(1. About distance)
In the above-mentioned example, in the thermography apparatus 100, the distance from the FPA 4 or the image pickup device 54 (hereinafter, simply collectively referred to as “measurement surface”) to the surface of the measurement target such as the measurement target IT or the blackbody furnace 1 is defined as the measurement distance. .. However, the embodiments are not limited to this. For example, the thermography device 100 may use the distance from the end of the cylindrical portion 51 of the infrared camera 50 on the surface side of the measurement target to the measurement target as the measurement distance instead of the measurement surface.

Further, in the above-mentioned example, the thermography apparatus 100 uses the distance information input by the operator OP as the measurement distance. However, the embodiments are not limited to this. For example, when the infrared camera 50 of the thermography device 100 has an autofocus function, the lens distance is automatically controlled so as to be in focus on the measurement surface. In other words, the lens distance is automatically controlled to a value according to the measurement distance. Therefore, the thermography apparatus 100 may estimate the measurement distance based on the value of the lens distance, and may create a correction formula or correct the calculated temperature based on the estimated estimated distance.

Further, the thermography apparatus 100 may estimate the lens distance based on the measurement distance and create a correction formula using the estimated lens distance as a parameter. By performing such processing, the thermography apparatus 100 may save the trouble of inputting the lens distance.

Further, the thermography device 100 may acquire the measured distance measured by various distance measuring sensors. For example, the thermography device 100 may have a range-finding sensor in the infrared camera 50, and may create a correction formula or correct the calculated temperature based on the measurement distance measured by the range-finding sensor.

(2. About infrared rays)
In the above example, the thermography apparatus 100 calculates the calculated temperature based on the radiance of infrared rays emitted from the measurement target. However, the embodiments are not limited to this. For example, the thermography apparatus 100 may calculate the temperature of the measurement target based on the radiance of electromagnetic waves having various arbitrary wavelengths.

(3. Correction timing)
The thermography apparatus 100 described above corrected the calculated temperature when the measurement target was photographed. However, the embodiments are not limited to this. For example, the thermography apparatus 100 may correct the calculated temperature after the fact.

For example, the thermography apparatus 100 calculates the calculated temperature from the radiance of infrared rays using the calibration information (calibration data 31) calibrated in advance at a predetermined measurement distance and lens distance, and outputs information indicating the calculated temperature. .. Here, the operator OP determines whether or not there is a deviation between the actual measured distance and the measured distance at the time of calibration after the measurement, and if there is a deviation, the actual measurement distance is passed through the terminal device 200. Enter the measurement distance and the focal length of the lens.

For example, the operator OP inputs the actual measurement distance and the focal length of the lens, and specifies the thermal image to be corrected after the fact. For example, the operator OP specifies the date and time to be corrected. In such a case, the terminal device 200 transmits the thermal image included in the correction target to the thermography device 100.

In such a case, the thermography apparatus 100 corrects the calculated temperature calculated in the past based on the actual measurement distance and the focal length of the lens. For example, the thermography apparatus 100 calculates the lens distance based on the actual measurement distance and the focal length of the lens. Then, the thermography apparatus 100 may use a correction formula to correct the calculated temperature ex post facto from the actual measurement distance and the lens distance, and output a thermal image or the like showing the corrected correction temperature.

(4. Correction formula)
In the above description, the thermography apparatus 100 has created the correction formula used by itself. However, the embodiments are not limited to this. For example, the thermography device 100 may correct the calculated temperature by using a correction formula created in advance by another thermography device 100. Such a correction formula is registered in the thermography apparatus 100 in advance at the time of shipment from the factory, for example.

The correction formula calculates the correction temperature from the measurement distance, the lens distance, and the calculated temperature, and the coefficient of such a correction formula depends on the characteristics of the lens. For example, the coefficient of the correction formula appropriately changes depending on the lens itself, the structure of the lens, etc., such as the diameter of the lens, the focal length, the transmittance, the thickness, the material, and the presence / absence of temperature control. Therefore, when the correction formula is registered in advance in the thermography device 100 at the time of shipment from the factory or the like, the correction formula created by the thermography device equipped with the lens of the same model number as the thermography device 100 is registered.

The thermography apparatus 100 may adopt a correction formula having such a lens characteristic as a parameter. For example, a creating device for creating such a correction formula acquires a calculated temperature while changing not only the measurement distance, the lens distance, or the temperature of the measurement target but also the characteristics of the various lenses described above. Then, the creating device creates a correction formula for calculating the temperature of the measurement target when the measurement distance, the calculated distance, and the characteristics of the lens are input. By using such a correction formula, the thermography apparatus 100 may be able to correct the calculated temperature even when the lens is changed without creating the correction formula again.

Further, when creating the correction formula, the thermography apparatus 100 may generate the correction formula from an arbitrary number of parameter sets. For example, when the thermography apparatus 100 creates a first-order correction formula, the correction formula may be calculated using at least a set of two parameters.

Further, in the above-mentioned example, the thermography apparatus 100 uses the polynomial as calibration information (temperature calculation formula) or correction formula. However, the embodiments are not limited to this. For example, the thermography apparatus 100 may use a table in which the temperature of the measurement target and the radiance of infrared rays measured when the measurement target person is at that temperature are associated with each other as calibration information. Further, the thermography apparatus 100 uses a correction formula as a table in which the measurement distance and the correction value to be applied to the calculated temperature (for example, the coefficient to be integrated, the constant to be added, etc.) are associated with the measurement distance. It may be used differently.

(5. Execution subject)
In the above-mentioned example, the controller 10 included in the thermography device 100 performs the above-mentioned correction process from the measurement result by the photographing device that operates as the measuring unit, that is, the infrared camera 50. However, the embodiments are not limited to this. For example, the thermography device 100 may have an infrared camera 50 capable of exhibiting the same functions as the controller 10 described above. For example, such an infrared camera 50 calculates the calculated temperature from the measurement result, measures the measured distance using a distance measuring sensor or the like, and corrects the calculated temperature based on the measured distance. It becomes.

Further, for example, the above-mentioned correction process and creation process may be realized by various information processing devices such as the terminal device 200.

[Effect in the embodiment]
As described above, the thermography apparatus 100 calculates the temperature of the measurement target based on the radiance of the infrared rays radiated from the measurement target, and also calculates the temperature based on the distance between the measurement target and the infrared camera 50. Correct the temperature. As a result of such processing, the thermography apparatus 100 can measure an appropriate temperature without performing calibration again even if the distance to the measurement target is different from the distance at the time of calibration. ..

Although examples of the embodiments have been described above, these are examples, and the present embodiment is not limited to the above description. The configurations and details of the embodiments, including the embodiments described in the disclosure column of the invention, can be implemented in other embodiments with various modifications and improvements based on the knowledge of those skilled in the art. In addition, each embodiment can be implemented in any combination within a consistent range.

1 Blackbody furnace 2,50 Infrared camera 3,53 Lens 4 FPA
10 Controller 20 Communication unit 30 Storage unit 31 Calibration data 32 Correction data 40 Control unit 41 Acquisition unit 42 Calculation unit 43 Correction unit 44 Providing unit 45 Creation unit 51 Cylindrical unit 52 Housing 54 Image sensor 100 Thermography device 200 Terminal device IT measurement Target IL1 inspection line

Claims (16)

An acquisition unit that acquires distance information indicating the distance between the measurement unit that measures the electromagnetic waves radiated from the measurement target and the measurement target, and the acquisition unit.
A calculation unit that calculates the temperature of the measurement target based on the measurement results of the measurement unit, and a calculation unit.
A measuring device having a correction unit that corrects the temperature calculated by the calculation unit based on the distance indicated by the distance information. The measuring device according to claim 1, wherein the acquiring unit acquires distance information indicating a distance between a measuring unit that measures infrared rays emitted from the measuring object and the measuring object. The acquisition unit acquires distance information indicating the distance between the measurement unit that measures the radiance of infrared rays emitted from the measurement target and the measurement target.
The measuring device according to claim 2, wherein the calculating unit calculates the temperature of the measurement target based on the radiance of infrared rays measured by the measuring unit. The acquisition unit is described in any one of claims 1 to 3, wherein the measurement unit acquires distance information indicating a distance between a measurement surface for measuring an electromagnetic wave and the measurement target. Measuring device. The acquisition unit determines the distance between the measurement surface and the measurement target based on the distance between the lens and the measurement surface when an image of the measurement target is formed on the measurement surface in a predetermined manner. The measuring device according to claim 4, wherein the measuring device is estimated. The measuring device according to any one of claims 1 to 4, wherein the acquisition unit acquires distance information input by a user. The invention according to any one of claims 1 to 4, wherein the acquisition unit acquires distance information indicating a distance between the measurement unit and the measurement target measured by a predetermined distance measuring device. Measuring device. The correction unit is a distance between a predetermined measurement target having a predetermined temperature and a measurement surface for measuring electromagnetic waves in the predetermined measuring device, the temperature of the predetermined measurement target, or a lens included in the predetermined measuring device. It is a correction formula generated based on the temperature measured by the predetermined measuring device while changing at least one of the distance between the measuring surface and the measuring surface, and is a correction formula generated based on the temperature measured by the predetermined measuring device. A claim characterized in that the temperature calculated by the calculation unit is corrected by using a correction formula for correcting the temperature measured by the predetermined measuring device to the temperature of the predetermined measurement target based on the distance between the two and the above. Item 6. The measuring apparatus according to any one of Items 1 to 7. Of claims 1 to 8, the correction unit corrects the temperature calculated by the calculation unit by using a linear polynomial that corrects the temperature based on the distance from the measurement target to the measurement unit. The measuring device according to any one. The measuring device according to claim 9, wherein the correction unit uses a correction formula corresponding to the temperature calculated by the calculation unit among a plurality of correction formulas for correcting temperatures in different ranges. The measuring device according to claim 10, wherein the calculation unit uses the correction formula having the lowest error rate in the range including the temperature calculated by the calculation unit among the plurality of correction formulas. The acquisition unit acquires the focal length of the lens of the measurement unit and the distance information indicating the distance from the measurement target to the measurement surface on which the electromagnetic wave is measured in the measurement unit.
The measuring device according to any one of claims 1 to 11, wherein the correction unit corrects the temperature calculated by the calculation unit based on the focal length and the distance information. One of claims 1 to 12, wherein the correction unit corrects the temperature calculated by the calculation unit based on the distance indicated by the distance information and the characteristics of the lens possessed by the measurement unit. The measuring device according to one. The measuring device according to any one of claims 1 to 13, wherein the acquiring unit further acquires a measurement result from a photographing device that operates as the measuring unit. The measuring device according to any one of claims 1 to 13, wherein the measuring device has a photographing unit that operates as the measuring unit. It is a measurement method performed by a measuring device.
An acquisition step for acquiring distance information indicating the distance between the measurement unit that measures the electromagnetic wave radiated from the measurement target and the measurement target, and the acquisition step.
A calculation step for calculating the temperature of the measurement target based on the measurement result of the measurement step, and a calculation step.
A measurement method comprising a correction step of correcting the temperature calculated by the calculation step based on the distance indicated by the distance information.

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