JP4583253B2 - Heat detector - Google Patents

Description

  The present invention relates to a heat detection device, and more particularly, to a heat detection device that performs sensitivity correction on a collected heat source image of a heat source to be measured with reference to a plurality of reference heat sources.

  In recent years, heat detection devices that detect infrared rays emitted from a heat source to be measured and display the detection signal as a heat source image of the heat source to be measured are used in, for example, surveillance cameras, night vision devices, thermography, remote sensing, vehicles, and aircraft. Widely used as an on-board monitoring device. Thermal detectors that detect infrared rays include single detection elements, one-dimensional array detection elements, and two-dimensional array detection element configurations. In a heat detector having a multi-element configuration such as a one-dimensional array element and a two-dimensional array element, the sensitivity characteristics of each element are not necessarily uniform. An error also occurs in pixels detected by the same element depending on the measurement conditions. Therefore, in order to accurately measure the temperature of the heat source to be measured, it is necessary to correct the sensitivity of each pixel.

Conventional example (1)
A conventional heat detection device (infrared imaging device), for example, an infrared imaging device described in JP-A-10-111172 (Patent Document 1) collects infrared rays from an imaging target (measurement target heat source) and heat detector The scanning optical system for scanning the field of view includes two reference heat sources, and when the sensing element expects both reference heat sources in the invalid scanning period of the sensing element constituting the thermal detector with respect to the heat source to be measured In the infrared imaging device that corrects the sensitivity of the detection element from the output, the intermediate value of the output of the detection element with respect to the two reference heat sources is calculated, and the intermediate value images the target object (measurement target heat source) Then, the temperature of the first reference heat source and the temperature of the second reference heat source are controlled with a predetermined temperature difference so as to coincide with the average value of the output of the sensing element. Then, sensitivity correction based on these two temperatures is performed. Thereby, the temperature of the first and second reference heat sources can be set close to the temperature of the measurement target heat source, and accurate sensitivity correction can be performed.

Conventional example (2)
Further, another conventional heat detection device (infrared imaging device), for example, an infrared imaging device described in Japanese Patent Application Laid-Open No. 2001-8100 (Patent Document 2), an infrared detector composed of a plurality of elements, and a high-temperature Equipped with a reference heat source and a normal temperature reference heat source, the reference heat source control circuit controls the temperature of the reference heat source between the high temperature and the normal temperature, and the optical system scans infrared rays in the direction of the target (measurement target heat source) during the effective scanning period. The signal processing circuit scans the infrared rays from the reference heat source at the high temperature and the normal temperature and enters the infrared detector during the invalid scanning period, and takes in the invalid scanning period. Based on the high temperature data by the high temperature reference heat source and the room temperature data by the room temperature reference heat source, the sensitivity correction corresponding to the element is performed, and the defect of each element constituting the infrared detector is determined, and the defect element Signal by normal element Perform the replacement process.
Japanese Patent Laid-Open No. 10-111172 (page 3-4, FIG. 1) JP 2001-8100 (page 3-4, FIG. 1)

As described above, in the heat detectors of the conventional examples (1) and (2), the temperature of the two reference heat sources having a temperature difference is controlled to be close to the temperature of the heat source to be measured, and these two temperatures are used. As a reference, variations in sensitivity of the detection element of the heat detector are accurately corrected.
However, in the conventional examples (1) and (2), no consideration is given to the case where the heat detection device moves. That is, there is no consideration for the case where the heat detection device moves from outside the shielding space into the shielding space.

In view of the above, an object of the present invention is to provide a method for controlling a reference heat source when a heat detection device moves from outside a shielded space (tunnel as a typical example) into the shielded space and measures the temperature of the inner wall of the shielded space. And
It is another object of the present invention to provide an efficient method for controlling a reference heat source when moving intermittently in a shielded space.

  For example, when the temperature of the inner wall of a tunnel is measured from outside the tunnel where the temperature of the heat source to be measured enters from a low temperature tunnel (closed space), the reference heat source is quickly adjusted to the optimum temperature and the temperature near the heat source to be measured is tracked. I can't let you. This is a temperature control delay caused by the size of the heat capacity of the reference heat source. For example, this delay may be about 30 seconds. That is, in order to perform accurate sensitivity correction, it is necessary to set the set temperature of the reference heat source in the vicinity of the inner wall temperature of the tunnel. However, when entering the tunnel, a delay occurs in this control, and the sensitivity correction becomes inaccurate. .

  In addition, when measuring the inner walls of multiple tunnels sequentially and recording the heat source image, the heat source image outside the tunnel (outside the shielding space) that is not originally measured is also recorded in the heat source image recording unit. A limited amount of storage capacity was wasted. In other words, more than necessary recording media had to be prepared for unnecessary heat source images outside the tunnel.

  Accordingly, an object of the present invention is to extract and record a measurement target heat source image in a shielded space.

In order to solve the above problems, in the present invention, a heat detection device that performs sensitivity correction of an infrared detector using a reference heat source includes a plurality of reference heat sources and a measurement object temperature that measures the temperature of the measurement target heat source. The measuring unit, the outside temperature measuring unit for measuring the outside air temperature, the determining unit for determining whether or not the own device is in the shielded space, and the determining unit moving the own device from the outside of the shielded space into the shielded space and upon detecting that was the control of the plurality of reference heat source, the outside air temperature the measurement target temperature measuring portion from the measurement result based on the control of the outside air temperature when measuring section by that the own device is not in the shielding space It is characterized by comprising a control unit for switching the measurement result based on the control of the temperature of the measurement target heat source that by the.

That is, the heat detection apparatus includes a plurality of (usually two) reference heat sources, a measurement object temperature measurement unit, an outside air temperature measurement unit, a determination unit, and a control unit. The measurement object temperature measurement unit measures the temperature of the measurement target heat source, the outside air temperature measurement unit measures the outside air temperature, and the discrimination unit discriminates whether or not the own device is in a shielded space (for example, a tunnel). When the control unit detects that the determination unit has moved from the outside of the shielded space to the inside of the shielded space, the control unit controls the plurality of reference heat sources to the outside air temperature measuring unit when the device is not in the shielded space. wherein the control based on Ru good measurement result measured object temperature measuring unit by that measured the heat source temperature of the measurement result of the switch to control based on the (temperature of the wall of the tunnel).

  Thus, the reference heat source can be controlled when the heat detection device moves from the outside of the shielded space (tunnel as a representative example) to the shielded space and measures the temperature of the inner wall of the shielded space.

In the above, in the present invention, by the determination unit, when it is detected that the own device is moved to the closed space outside the shielded space, the plurality based on the temperature measurement result of the measurement target heat source in the shielded space the temperature of the reference heat source, is characterized by further comprising a control unit for holding a temperature of said plurality of reference heat source until then moves to shield the space.

That is, the measurement object temperature measurement unit measures the temperature of the measurement target heat source, the outside air temperature measurement unit measures the outside air temperature, and the determination unit determines whether or not the own device is in the shielded space, When the control unit detects a movement from the inside of the shielded space to the outside of the shielded space, the control unit performs temperature control of the plurality of reference heat sources based on the measurement result of the temperature of the heat source to be measured in the shielded space, The temperature of the plurality of reference heat sources is maintained until it moves into the shielded space.

  Generally, the outside air outside the tunnel is continuous with the outside air inside the tunnel, so the outside air temperature near the tunnel entrance and the temperature of the tunnel inner wall near the tunnel entrance (in contact with the outside air inside the tunnel) Are almost equal. Therefore, when the reference heat source temperature setting unit performs the temperature control of each reference heat source as described above, without performing control to give each reference heat source a steep temperature change that cannot be followed by each reference heat source, that is, the reference heat source It becomes possible to perform temperature control that the heat source can follow. This enables efficient control of the reference heat source when intermittently moving in the shielded space.

The above-mentioned control unit, by the determination unit, when the own device is determined to be within shielded space, the control such infrared detectors for recording measured heat source image acquired, shielded space outside If it is determined that the measurement target heat source image acquired by the infrared detector is not recorded, control can be performed. Thereby, it becomes possible to extract and record the measurement target heat source image in the shielded space.

  In addition, when the control unit moves from the inside of the shielded space to the outside of the shielded space, the temperature of each reference heat source is set based on the outside air temperature instead of maintaining the temperature at which the measurement target heat source is detected in the shielded space. Can be controlled.

  According to this, for example, when the distance between the shielded space and the next shielded space is long, the temperature of the inner wall of the exit of the previous shielded space and the temperature of the inner wall of the entrance of the next shielded space may greatly differ, In this case, if the temperature is controlled while maintaining the last detected temperature, the delay of the reference heat source becomes a problem. Therefore, if the outside air temperature gradually changes from the temperature of the inner wall of the outlet of the shielded space to the temperature of the inner wall of the inlet of the next shielded space, if the temperature control of the reference heat source is performed based on the outside air temperature, there will be a problem of delay. Is resolved.

  In addition, the determination unit includes a GPS receiver. When the GPS receiver fails to receive all GPS signals, the determination unit determines that it is within the shielded space and receives at least one GPS signal. , It can be determined that it is outside the shielding space. This makes it possible to determine whether or not the heat detection device is in the shielded space.

  The measurement object temperature measuring unit may be a radiation thermometer using a thermopile.

  In addition, the outside air temperature measurement unit may be a temperature sensor using a platinum resistance.

  Further, in the present invention, when one of the reference heat sources is a high temperature side reference heat source and the other is a low temperature side reference heat source, the heat source of the high temperature side reference heat source detected by the infrared detector. The difference between the average value of all the pixel data of the image and the average value of all the pixel data of the heat source image of the low-temperature side reference heat source is obtained by calculating each pixel data of the heat source image of the high-temperature side reference heat source and the heat source image of the low-temperature side reference heat source. The product of the average value of all pixel data of the heat source image of the low temperature side reference heat source and each pixel data of the heat source image of the high temperature side reference heat source is defined as the gain coefficient of each pixel. Difference between the average value of all pixel data of the heat source image of the high temperature side reference heat source and the product of each pixel data of the heat source image of the low temperature side reference heat source, and each pixel data of the heat source image of the high temperature side reference heat source The value divided by the difference from each pixel data of the heat source image of the low-temperature side reference heat source is the value of each pixel. It may comprise a signal processing unit for the photosensitive degree correction as set coefficient. Note that this sensitivity correction can be performed more accurately by using pixel data of three or more reference heat sources.

  Further, each pixel data described above can be an average value of a plurality of pixel data in the vicinity of each pixel. Thereby, it is possible to eliminate the influence of noise included in each pixel data of the heat detector 12.

  The shielded space can be a tunnel.

ADVANTAGE OF THE INVENTION According to this invention, the efficient control method of the reference | standard heat source in case a heat | fever detection apparatus moves into the enclosed space from the shielding space is provided.
In addition, according to the present invention, an efficient method for controlling a reference heat source is provided when moving in a shielded space intermittently.
Further, according to the present invention, it is possible to extract and record the measurement target heat source image in the shielded space.

Configuration Example FIG. 1 shows a configuration example of the heat detection apparatus 100 of the present invention. This heat detection apparatus 100 includes an optical system unit 10, an optical path selection unit 11, a heat detector (infrared detector) 12, an amplifier 13, an A / D converter 14, a signal processing unit 15, a D / A converter 16, a monitor 17, a heat source image recording unit 18, and a reference heat source incident selection unit 19 are provided. Furthermore, the heat detection device 100 includes a measurement object temperature measurement unit 21, an outside air temperature measurement unit 22, a shielded space operation determination unit 23, a reference heat source temperature setting unit 24, a reference heat source 25, a reference heat source 26, and a reference heat source selection unit. 27. Among these, the optical path selection unit 11, the reference heat source selection unit 27, and the reference heat source incidence selection unit 19 constitute a selection unit 31.

Operation Example In the operation, the optical system unit 10 gives the infrared ray received from the measurement target heat source 30 to the optical path selection unit 11. The reference heat source selection unit 27 selects infrared rays from one of the reference heat source 25 and the reference heat source 26 and supplies the selected infrared rays to the optical path selection unit 11. The optical path selection unit 11 selects one of the infrared rays from the measurement target heat source 30 and the infrared rays from the reference heat source 25 or the reference heat source 26 and supplies the selected one to the heat detector 12. The heat detector (infrared detector) 12 converts the applied infrared light into an electric signal, and the electric signal is amplified by the amplifier 13 and supplied to the A / D converter 14. The A / D converter 14 converts the supplied electric signal into a digital signal and supplies it to the signal processing unit 15. The digital signals are sequentially configured and output as image frames 800_1, 800_2,..., 800_n,.

  FIG. 2 shows an example of an image frame 800, and the image frame 800 includes a measurement target heat source image 800a and a reference heat source image 800b. The reference heat source image 800b includes a low temperature side reference heat source image or a high temperature side reference heat source image. In the reference heat source image 800b, 128 data is acquired for each pixel. The reference heat source image 800b is used for calculating the sensitivity correction coefficient. The sensitivity correction coefficient is normally updated every frame.

  The signal processing unit 15 is caused by, for example, variations in sensitivity of the detection elements of the heat detector 12 based on the low-temperature side reference heat source image and the high-temperature side reference heat source image of the reference heat source image 800b corresponding to the reference heat source 25 and the reference heat source 26. The sensitivity of each pixel to be corrected is corrected. Furthermore, the signal processing unit 15 converts the heat source image of the measurement target heat source 30 into a data format that can be recorded in the heat source image recording unit 18 and gives the data to the heat source image recording unit 18 and also converts the data format to be displayed on the monitor 17 Digital data is supplied to the D / A converter 16. The D / A converter 16 converts this digital data into an analog signal and supplies it to the monitor 17. The monitor 17 displays a heat source image of the measurement target heat source 30 based on the analog signal.

  The reference heat source incidence selection unit 19 controls the reference heat source selection unit 27 and the optical path selection unit 11, and respectively detects infrared rays from the reference heat source 25 or the reference heat source 26 set to the high temperature side and the low temperature side temperature as the heat detector 12. To enter. Further, the reference heat source incident selection unit 19 notifies the signal processing unit 15 of a reference heat source incident notification 704 indicating which infrared ray of the reference heat source 25 and the reference heat source 26 is currently incident on the heat detector 12. . The heat source image recording unit 18 records a heat source image in a given data format. As this recording medium, for example, a hard disk is used. Recording start and recording stop of the heat source image recording unit 18 are performed based on the in-shielded space operation determination information 702 output from the in-shielded space operation determination unit 23. As a result, it is possible to record only the heat source image outside the shielded space and the measurement target heat source image within the shielded space among the target heat source images within the shielded space.

  The measurement object temperature measurement unit 21 measures the surface temperature of the measurement target heat source 30, for example, a radiation thermometer using a thermopile as a sensor, and the error in the surface temperature of the measurement target heat source 30 obtained is Keep the temperature approximately within ± 1 ° C. The measuring object temperature measuring unit 21 may include a calibration circuit for improving the accuracy. The range of the heat source 30 to be measured which is measured by the radiation thermometer is made to overlap the range which the heat detector 12 measures. The obtained surface temperature of the heat source 30 to be measured is sent to the reference heat source temperature setting unit 24 in an analog or digital format.

  The outside air temperature measurement unit 22 measures the outside air temperature around the heat detection apparatus 100 of the present invention, and is configured using, for example, a platinum resistor as a sensor. A current of about 1 mA is passed through the platinum resistor, and the voltage drop at that time is amplified to obtain an outside temperature at which the error is about ± 1 ° C. or less. The obtained outside air temperature is sent to the reference heat source temperature setting unit 24 in an analog or digital format.

  The shielded space operation determining unit 23 determines whether or not the heat detection device 100 of the present invention is in the shielded space (in the tunnel), and includes, for example, a GPS receiver. In general, a GPS receiver has a status output function using RS232C or the like. Among the status outputs, information on the number of GPS satellites currently received is used. Since the radio wave emitted from the GPS satellite can be received when the heat detection apparatus 100 of the present invention is outside the shielded space (tunnel), the “number of GPS satellites currently received” indicated by the status output by the GPS receiver ≧ “ 1 ".

  On the other hand, since the radio wave emitted from the GPS satellite cannot be received when the heat detection apparatus 100 of the present invention is in the shielded space, “the number of GPS satellites currently received” indicated by the status output by the GPS receiver = “0 "Become. That is, when “the number of GPS satellites currently received” indicated by the status output by the GPS receiver ≧ “1”, the heat detection device 100 of the present invention is outside the shielded space, and “the GPS satellites that can be received now” When the number is “0”, it is determined that the heat detection device 100 of the present invention is in the shielded space. The operation determination information 702 in the shielded space is a 1-bit logic signal and is sent to the reference heat source temperature setting unit 24 and the heat source image recording unit 18.

  The reference heat source temperature setting unit 24 is constituted by, for example, a logic circuit, the measurement object temperature 703 output from the measurement object temperature measurement unit 21, the outside air temperature 701 output from the outside air temperature measurement unit 22, and the operation determination unit in the shielded space The temperatures of the reference heat source 25 and the reference heat source 26 are set on the basis of the operation determination information 702 in the shielded space output from 23.

Reference Heat Source Temperature Setting Example FIG. 3 shows an operation procedure example of the reference heat source temperature setting unit 24. In this operation procedure, the reference heat source temperature setting unit 24 sets the temperatures of the reference heat source 25 and the reference heat source 26. The operation procedure of the setting unit 24 will be described below.

Step S100 : The heat detection apparatus 100 is turned on, and the operation of the heat detection apparatus 100 is started.

Step S110 : The reference heat source temperature setting unit 24 determines whether or not the heat detection device 100 is in the shielded space, that is, the reference heat source temperature setting unit 24 is the shielded space from the operation determination unit 23 in the shielded space. When the internal operation determination information 702 = “0: NO (outside shielded space)”, the process proceeds to step S120, and when “1: YES (inside shielded space)”, the process proceeds to step S130.

Step S120 : The reference heat source temperature setting unit 24 sets the temperatures of the reference heat source 25 and the reference heat source 26 based on the outside air temperature 701 measured by the outside air temperature measuring unit 22. For example, after setting the reference heat source 25 = “outside air temperature 701 + 5 ° C.” and the reference heat source 26 = “outside air temperature 701-5 ° C.”, the process returns to step S110.

When the reference heat sources 25 and 26 are controlled using the measurement result of the measurement object temperature measurement unit 21 when the measurement object is outside the shielding space, for example, if the measurement object is set on the upper side, the radiation temperature of the sky And the reference heat source is controlled in accordance with a temperature lower than the temperature of the inner wall of the shielded space. Therefore, when moving into a shielded space, the temperature of the reference heat source must be greatly changed, and the infrared detector correction is performed due to a temperature control delay (for example, about 30 seconds) caused by the heat capacity of the reference heat source. This increases the period during which the normal operation cannot be performed.
However, in this embodiment, the reference heat sources 25 and 26 are controlled based on the outside air temperature measured by the outside air temperature measuring unit 22. The temperature of the inner wall near the entrance to the shielded space is close to the outside air temperature, and when moving into the shielded space, the reference heat source is controlled based on the temperature as close as possible to the inner wall temperature to be measured. is there.

Step S130 : The reference heat source temperature setting unit 24 sets the temperatures of the reference heat source 25 and the reference heat source 26 based on the temperature of the measurement target heat source (tunnel inner wall) 30 measured by the measurement target temperature measurement unit 21. For example, the reference heat source 25 = “temperature of the measurement target heat source 30 + 5 ° C.” and the reference heat source 26 = “temperature of the measurement target heat source 30−5 ° C.” are set.

Step S140 : The heat detection apparatus 100 again determines whether or not the operation is in the shielded space. If “YES (in the shielded space)”, the process returns to step S130 and is measured in step S130. Based on the temperature of the heat source 30 to be measured, the set temperatures of the reference heat source 25 and the reference heat source 26 are updated. If “NO (out of shielding space)”, the process proceeds to step S150.

Step S150 : The set temperatures of the reference heat source 25 and the reference heat source 26 are maintained without being updated. The process returns to step S140. When the operation outside the shielded space continues, the set temperatures of the reference heat source 25 and the reference heat source 26 are maintained without being updated.

  FIG. 4 shows a temperature setting example of the reference heat source 25 and the reference heat source 26 in the heat detection apparatus 100 of the present invention. FIG. 1 (1) shows the operation determination information 702 in the shielded space. The horizontal axis represents time, the vertical axis represents the determination information 702 = “1: YES (in the shielded space)”, and the operation determination information 702 = “0: “NO (outside shielding space)”. In (2) to (5), the horizontal axis represents time, and the vertical axis represents the outside air temperature 701, the measurement object temperature 703, the set temperature of the reference heat source 25, and the set temperature of the reference heat source 26, respectively. ing.

  The temperature setting operation of the reference heat source 25 and the reference heat source 26 shown in FIG. 4 will be described below with reference to FIG.

Section T1 : The power source of the heat detection device 100 is turned on outside the shielded space, and the operation of the heat detection device 100 is started (see step S100 in FIG. 3). At this time, since the operation is not performed in the shielded space (see step S110), the temperature of the reference heat source 25 is set to “outside temperature 701 + 5 ° C.”, and the temperature of the reference heat source 26 is set to “outside temperature 701-5 ° C.”. (Refer to step S120).

Section T2 : When the heat detection device 100 enters the shielded space (inside the tunnel), the operation determination information in the shielded space 702 = “1: YES (in the shielded space)” (see step S110), and the reference heat source 25 Temperature = “measurement object temperature 703 + 5 ° C.” and reference heat source 26 temperature = “measurement object temperature 703-5 ° C.” (see step S130). That is, it is set based on the inner wall temperature in the shielded space (= temperature of the heat source to be measured).

Section T3 : Further, when the heat detection device 100 goes out of the shielded space (see “NO” in step S140), the operation determination information in the shielded space 702 = “0: NO (outside shielded space)”, and the reference heat source 25 temperature = “maintains the measurement object temperature 703 + 5 ° C. in the shielded space”, the temperature of the reference heat source 26 = “maintains the measurement object temperature 703−5 ° C. in the shielded space”, that is, the reference heat sources 25, 26 The set temperature is maintained (see step S150).

Section T4 : Furthermore, when the heat detection apparatus 100 enters the shielded space (see “YES” in step S140), the operation determination information in the shielded space 702 = “1: YES (within the shielded space)”, and the reference heat source The temperature of 25 = “measurement object temperature 703 + 5 ° C.” and the temperature of the reference heat source 26 = “measurement object temperature 703-5 ° C.” (see step S130).

Section T5 : Further, when the heat detection apparatus 100 goes out of the shielded space, similarly to the section T3, the operation determination information 702 in the shielded space becomes “0: NO (outside the shielded space)”, and the temperature of the reference heat source 25 = “ The measurement object temperature 703 + 5 ° C. in the shielded space is set, and the temperature of the reference heat source 26 is set to “hold the measurement object temperature 703-5 ° C. in the shielded space”.

  In section T3, the temperature of the heat source to be measured (tunnel inner wall) in section T2 was maintained, but the distance to the next tunnel was long, and the inner wall temperature at the exit of the previous tunnel and the inner wall temperature of the entrance of the next tunnel were When there is a possibility that the temperature is greatly different, delay of the reference heat source becomes a problem when temperature control is performed while maintaining the temperature detected last. Therefore, the temperature control of the reference heat source may be performed based on the outside air temperature, assuming that the outside air temperature gradually changes from the temperature of the inner wall of the outlet of the shielded space to the temperature of the inner wall of the inlet of the next shielded space. (See the flow of the wavy line from “NO” in step S140 to step S120 in FIG. 3).

  As described above, the infrared rays from the set reference heat source 25, the infrared rays from the reference heat source 26, and the infrared rays from the measurement target heat source 30 are selected by the reference heat source selection unit 27 and the optical path selection unit 11, and are supplied to the heat detector 12. Reach alternately. The reference heat source incidence selection unit 19 performs the selection control of these infrared rays. That is, the reference heat source incidence selection unit 19 performs infrared switching by providing the switching control signals 705 and 706 to the reference heat source selection unit 27 and the optical path selection unit 11, respectively. Further, the reference heat source incident selection unit 19 performs reference heat source incident notification 704 indicating whether the infrared light incident on the heat detector 12 is the infrared light emitted from the reference heat source 25, the reference heat source 26, or the measurement target heat source 30. Is given to the signal processing unit 15. As a result, the signal processing unit 15 allows the heat source image transmitted from the heat detector 12 via the amplifier 13 and the A / D converter 14 to be one of the reference heat source 25, the reference heat source 26, and the measurement target heat source 30. Can be determined.

  Since each pixel detected by the heat detector 12 has variations in gain and offset, the signal processing unit 15 needs to calculate a correction coefficient in order to obtain an accurate heat source image of the heat source 30 to be measured. There are two types of correction coefficients, a gain coefficient ai and an offset coefficient bi. These coefficients are the reference heat source image 800b of the heat detector 12 when the infrared rays of the reference heat sources 25 and 26 are detected (FIG. 2). ).

  In this calculation example, in order to eliminate the influence of noise included in the output data of the heat detector 12, the output data of the heat detector 12 is 16 image frames for each of the low-temperature side reference heat source 26 and the high-temperature side reference heat source 25. Minutes and averages are used. That is, 128 pieces of data are acquired per image frame for each pixel. It is collected and averaged for another 16 frames. The calculation formula for calculating the coefficient is shown below.

The gain coefficient ai and the offset coefficient bi can be obtained by the following expressions (1) and (2), respectively.

  Here, i = pixel number, Hm = average value of all pixels of high-temperature data, Lm = average value of all pixels of low-temperature data, Hi = average value of each pixel of high-temperature data, Li = each value of low-temperature data Average value at pixel, Di = corrected output of each pixel, di = heat detector output of each pixel.

The heat detector output can be corrected by the following equation (3) using the gain coefficient ai and the offset coefficient bi obtained for each pixel number i.

Thereby, accurate sensitivity correction of each pixel becomes possible.
According to the above embodiment, (1) it is possible to control the temperature of the reference heat source to be close to the temperature of the heat source to be measured, and the correction (sensitivity correction) of the detection element constituting the heat detector can be accurately performed. It becomes possible to do. This eliminates the need to manually measure the temperature of the inner wall at a plurality of locations in advance, and manually set the temperature of the reference heat source based on the average value. Disappear.

 (2) Outside the shielded space, the set temperature of the reference heat source is maintained at the temperature of the heat source to be measured in the previous shielded space, so even when measuring continuously in multiple shielded spaces, each shielded space When the temperature of the heat source to be measured is the same, a heat source image whose sensitivity is correctly corrected can be obtained from the time when it enters the shielded space.

 (3) For example, after the power of the heat detection device is turned on, the temperature of the reference heat source is set and controlled in advance based on the outside air temperature, thereby entering the shielded space and based on the temperature of the measurement target heat source at a temperature close to the outside air temperature. When the temperature control of the reference heat source is performed, the time when the temperature of the reference heat source approaches the temperature of the heat source to be measured is shortened, and the error of sensitivity correction of the detection element of the heat detector and the time when the error occurs can be reduced.

 (4) When heat detection is not used outside the shielded space, unnecessary heat source image recording is automatically stopped to save recording media and reduce costs, and to analyze recorded heat source images. This eliminates unnecessary heat source image removal work and speeds up the analysis. That is, it is determined whether or not it is outside the tunnel, and when it is outside the tunnel, unnecessary time and manpower for manually and temporarily stopping recording of the heat source image are not required.

(Appendix 1)
In a heat detection device that performs sensitivity correction of an infrared detector using a reference heat source,
Multiple reference heat sources;
A measurement object temperature measurement unit for measuring the temperature of the measurement target heat source;
An outside temperature measuring unit for measuring outside temperature;
A discriminator for discriminating whether or not the own device is in the shielding space;
When the discriminating unit detects that it is in a shielded space, the control of the plurality of reference heat sources is changed from the control based on the measurement result in the outside air temperature measurement unit to the control based on the measurement result in the measurement object temperature measurement unit. A control unit for switching;
A heat detection apparatus comprising:
(Appendix 2)
In a heat detection device that performs sensitivity correction of an infrared detector using a reference heat source,
Multiple reference heat sources;
A measurement object temperature measurement unit for measuring the temperature of the measurement target heat source;
An outside temperature measuring unit for measuring outside temperature;
A discriminator for discriminating whether or not the own device is in the shielding space;
When the change from the inside of the shielded space to the outside of the shielded space is detected by the discriminating unit, the control unit that holds the temperature control of the plurality of reference heat sources in the shielded space until the next movement into the shielded space;
A heat detection apparatus comprising:
(Appendix 3)
The control unit controls to record the measurement target heat source image when the determination unit determines that the measurement target heat source image is within the shielded space, and not to record the measurement target heat source image when the determination unit determines that the measurement target heat source image is outside the shielded space. The heat detection device according to appendix 1 or 2, wherein:
(Appendix 4)
When the control unit moves from the inside of the shielded space to the outside of the shielded space, the temperature of each reference heat source is controlled based on the outside air temperature instead of maintaining the temperature at which the heat source to be measured in the shielded space is detected. The heat detection apparatus according to appendix 1 or 2, characterized by:
(Appendix 5)
The determination unit includes a GPS receiver,
When the GPS receiver is unable to receive all GPS signals, it is determined that the GPS receiver is inside the shielded space, and when at least one GPS signal is received, the GPS receiver is determined to be outside the shielded space. Supplementary note 1 or 2 described above.
(Appendix 6)
The heat detection apparatus according to appendix 1 or 2, wherein the measurement object temperature measurement unit is a radiation thermometer using a thermopile.
(Appendix 7)
The heat detection apparatus according to appendix 1 or 2, wherein the outside air temperature measurement unit is a temperature sensor using a platinum resistance.
(Appendix 8)
When one of the reference heat sources is a high temperature side reference heat source and the other is a low temperature side reference heat source,
The difference between the average value of all pixel data of the heat source image of the high temperature side reference heat source detected by the infrared detector and the average value of all pixel data of the heat source image of the low temperature side reference heat source is determined as the high temperature side reference heat source. The value obtained by dividing the pixel data of each heat source image by the difference between the pixel data of the heat source image of the low-temperature side reference heat source is the gain coefficient of each pixel, and the average value of all pixel data of the heat source image of the low-temperature side reference heat source And the product of each pixel data of the heat source image of the high temperature side reference heat source, and the product of the average value of all the pixel data of the heat source image of the high temperature side reference heat source and each pixel data of the heat source image of the low temperature side reference heat source A signal processing unit that corrects the sensitivity using a value obtained by dividing the difference by the difference between each pixel data of the heat source image of the high temperature side reference heat source and each pixel data of the heat source image of the low temperature side reference heat source as an offset coefficient of each pixel Heat detection according to supplementary note 1 or 2, characterized by comprising Location.
(Appendix 9)
The heat detection apparatus according to appendix 8, wherein each pixel data is an average value of a plurality of pixel data in the vicinity of each pixel.
(Appendix 10)
The heat detection apparatus according to appendix 1 or 2, wherein the shielding space is a tunnel.

It is the block diagram which showed the structure Example of the heat detection apparatus which concerns on this invention. It is the figure which showed the example of the image frame input into the signal processing part in the heat detection apparatus which concerns on this invention. It is the flowchart figure which showed the example of the operation | movement procedure of the reference | standard heat source temperature setting part in the heat detection apparatus which concerns on this invention. It is the figure which showed the temperature setting example of the reference | standard heat source in the heat detection apparatus which concerns on this invention.

Explanation of symbols

100 heat detector
10 Optics 11 Optical path selector
12 Thermal detector 13 Amplifier
14 A / D converter 15 Signal processor
16 D / A converter 17 Monitor
18 Heat source image recording unit 19 Reference heat source incident selection unit
21 Measurement object temperature measurement unit 22 Outside air temperature measurement unit
23 Operation discrimination section in shielded space 24 Reference heat source temperature setting section
25, 26 Reference heat source 27 Reference heat source selector
30 Heat source to be measured 31 Selection section
701 Outside air temperature 702 Operation discrimination information in shielded space
703 Measurement target temperature 704 Reference heat source incident notification
705, 706 Switching control signal 800, 800_n to 800_n + 2 Image frame
800a Heat source image to be measured 800b Reference heat source image (low temperature side or high temperature side)
i Pixel number ai Gain coefficient of each pixel
bi Offset coefficient for each pixel
Hm Average value of all pixels of high temperature data Lm Average value of all pixels of low temperature data
Hi Average value of each pixel of high temperature data Li Average value of each pixel of low temperature data
Di Corrected output of each pixel di Heat detector output of each pixel In the figure, the same reference numerals indicate the same or corresponding parts.

Claims (5)

In a heat detection device that performs sensitivity correction of an infrared detector using a reference heat source,
Multiple reference heat sources;
A measurement object temperature measurement unit for measuring the temperature of the measurement target heat source;
An outside temperature measuring unit for measuring outside temperature;
A discriminator for discriminating whether or not the own device is in the shielding space;
The該判specific unit, when the information processing apparatus 100 detects that it has moved from outside the shielded space to shield the space, the control of the plurality of reference heat source, wherein when the outside air temperature measurement unit by that the own device is not in the shielding space and a control section for switching from the measurement result based on the control of the outside air temperature control based on temperature measurements of by that measured the heat source to the measurement target temperature measuring section,
A heat detection apparatus comprising: By the determination unit, when it is detected that the own device is moved to the closed space outside the shielded space, the temperature of the plurality of reference heat source based on the temperature measurement result of the measurement target heat source in the shielding space, then A control unit that holds the temperature of the plurality of reference heat sources until moving into the shielded space ;
The heat detection apparatus according to claim 1 , further comprising: Wherein the control unit, by the determination unit, when the own device is determined to be within shielded space, the control such infrared detectors for recording measured heat source image obtained, if it is outside the shielded space If determined, control to not record the measurement target heat source image acquired by the infrared detector ,
The heat detection apparatus according to claim 1 or 2, wherein The determination unit includes a GPS receiver,
When the GPS receiver is unable to receive all GPS signals, it is determined that the GPS receiver is inside the shielded space, and when at least one GPS signal is received, the GPS receiver is determined to be outside the shielded space. The heat detection device according to any one of claims 1 to 3 . When one of the reference heat sources is a high temperature side reference heat source and the other is a low temperature side reference heat source,
The difference between the average value of all pixel data of the heat source image of the high temperature side reference heat source detected by the infrared detector and the average value of all pixel data of the heat source image of the low temperature side reference heat source is determined as the high temperature side reference heat source. The value obtained by dividing the pixel data of each heat source image by the difference between the pixel data of the heat source image of the low-temperature side reference heat source is the gain coefficient of each pixel, and the average value of all pixel data of the heat source image of the low-temperature side reference heat source And the product of each pixel data of the heat source image of the high temperature side reference heat source, and the product of the average value of all the pixel data of the heat source image of the high temperature side reference heat source and each pixel data of the heat source image of the low temperature side reference heat source A signal processing unit that corrects the sensitivity using a value obtained by dividing the difference by the difference between each pixel data of the heat source image of the high temperature side reference heat source and each pixel data of the heat source image of the low temperature side reference heat source as an offset coefficient of each pixel any one of claims 1 to 4 which is characterized in that it comprises a Thermal detector according to One.

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