JPH10136263A - Thermal picture recording device/method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To grasp the thermal balance of an object as three-dimensional space distribution by executing one-dimensional scanning with a thermal picture recording point as a center and recording a picture as a global picture obtained by panning, tilting and globally enlarging it. SOLUTION: An infrared detection camera 3 is placed on the revolving panhead 19 of an electric stretching pole 18 erected on an outdoor environment observation vehicle 17. A display device containing a panhead control part 20 and the control part of a thermal picture recording device and the like are provided in the observation vehicle 17. The electric stretching pole 18 can be extended to the height of 7m at maximum for avoiding the visual obstacles of vehicles and fences at the time of observation and overlooking/photographing much more ground faces and the wall faces of buildings and it is extended by an electric remote controller at 10mm pitches. The revolving panhead 19 can be panned and tilted. The maximum rotary angle is set to be 330 degrees, maximum rotary speed to be 90 deg./sec and maximum load weight to be 10kg. The angle display resolution of the panhead control part 20 is 0.01 deg., angle display precision is ±0.08 and angle reproducibility is ±0.1 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal image recording device and a thermal image recording method for detecting and imaging infrared rays radiated from a three-dimensional space such as a ground surface or a building surface.

[0002]

2. Description of the Related Art Conventionally, in order to improve the thermal livability of cities and buildings, radiation temperature analysis of the effects of these buildings and the ground surface on the spatial composition has been widely performed. In such radiation temperature analysis, even if the temperature of the wall or ground surface of the building is measured using a globe thermometer or a radiation balance meter that measures pure radiation, the temperature of these objects depends on the surrounding air temperature. Due to the effects of radiation, convection, and conduction, it is difficult to measure the net radiation temperature of the wall or ground surface.

With the above-described globe thermometer or radiation balance meter, it is extremely difficult to measure a three-dimensional thermal environment because the temperature is measured pointwise.

[0004]

An infrared radiation camera is effective for measuring the surface temperature distribution of an object such as a wall surface of a building. However, a conventionally used infrared radiation camera has a measurement field of view that is too narrow to provide a thermal environment. However, there is a problem in that there is a limit as a means for capturing three-dimensionally comprehensively.

The present invention aims to provide a thermal image recording device and a thermal image recording method which have solved the above-mentioned problems.
An object of the present invention is to provide a thermal image measurement system capable of capturing the thermal balance of an object as a three-dimensional spatial distribution.

[0006]

SUMMARY OF THE INVENTION A thermal image recording apparatus according to the present invention detects infrared rays emitted from an object, and detects infrared rays emitted from the object in a thermal image recording apparatus for imaging. An infrared detection camera is one-dimensionally scanned around the thermal image recording point of the object, and is panned and tilted and recorded as a global thermal image enlarged to the whole world.

According to the thermal image recording method of the present invention, a temperature distribution on a ground surface or a building surface as an object is detected as a three-dimensional spatial distribution as an infrared global thermal image by an infrared detection camera.
The infrared thermal image is displayed as a planar thermal image.

According to the thermal image recording apparatus and the thermal image recording method of the present invention, it is possible to measure the radiation temperature environment around the observation point instead of the thermal environment information at a point or a narrow range.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermal image recording apparatus and a thermal image recording method according to the present invention will be described below in detail with reference to the drawings.

First, an overall system diagram of the thermal image recording apparatus of the present invention will be described with reference to FIG.

In FIG. 3, the intensity of infrared rays 2 radiated from an object 1 such as animals and plants and buildings is detected by an infrared detector 3 a in the infrared detection camera 3 via the infrared detection camera 3.

The infrared light 2 is cooled via a window 3b by a scanning optical system 3c such as a galvanometer mirror, a focusing objective lens 3d, a chopper 3e, a relay lens 3f, a coolant (such as liquid nitrogen or argon), or a cooling element. Hg
A scanning optical system 3c having an infrared detector 3a of CdTe or the like;
Is a galvano drive 3g, an objective lens 3d is a focus drive 3h, and a chopper 3e is a chopper motor 3j.
And the object 1 is usually a galvano driver 3g.
The two-dimensional line-sequential scanning is performed through the scanning optical system 3c to detect the intensity of the infrared temperature distribution image signal. In this example, the scanning is performed one-dimensionally.

The temperature distribution image signal detected by the infrared detector 3a in the infrared detection camera 3 is supplied to a preamplifier 4, and although not shown, emissivity correction, linearization,
Sampling and encoding are performed in an analog-to-digital converter (ADC) 5 through level adjustment, sense adjustment, and the like, and converted into digital-data.

The digital data from the ADC 5 is supplied to image memories 6a and 6b, and a color palette (memory) 7R of a pseudo color generation circuit 7 for generating red (R), green (G), and blue (B) signals. , 7G, 7B,
The coloring is determined according to the level (temperature) of the digital data.

Each data from the color pallets 7R, 7G, 7B is converted into a digital-analog conversion circuit (DAC).
8 (8R, 8G, 8B), which is converted into an analog temperature distribution color image signal, supplied to a monitor display device 9 such as a cathode ray tube (CRT), and the image of the object 1 is color-coded on the screen. It is displayed as a temperature distribution pattern.

The microcomputer (CPU) 10 is A
The DC 5, the image memories 6a and 6b, the pseudo color generator 7, and the DAC 8 are controlled, and the galvano drive 3g and the like of the infrared camera 3 are controlled via the interface 11 via the detection camera controller 12 and the like.

The ROM 13 and the RAM 14 are the CPU 10
Is a work memory normally provided, and the operation unit 15 is an input unit such as a keyboard.

The infrared detection camera 3 of the thermal image recording device 16 configured as described above is mounted on a rotating pan head 19 of an electric telescopic pole 18 erected on an outdoor environment observation vehicle 17 shown in FIG.

A display device 9 including a pan head control unit 20 and a control unit of the thermal image recording device 16 and the like are also provided in the observation vehicle 17. In addition, a meteorological observation device 21 such as a dry-wet bulb platinum thermometer with a ventilation tube, a propeller-type micro-wind anemometer, and a neo-pyrometer is provided by the observation vehicle
7 are located on the roof.

The optical scanning system of the infrared detection camera 3 has three wavelength bands 3 to 5 μm and 5.5 to 7.9 μ according to the purpose.
m, 8 to 13 μm is used. In a wavelength band of 3 to 5 μm, InSb is used for the infrared detector 3 a and a wavelength of 5.5 to 5.5 μm.
HgCdTe is used in the 7.9 μm and 8 to 13 μm bands.

The viewing angles are 30 °, 50 ° and 80 °.
You can select the type. Resolution is 0.1 ° C to 0.15 ° C, temperature measurement accuracy is ± 1.0 ° C, horizontal resolution is 344 or more, scanning angle is 30 ° horizontal x 28.5 ° vertical, and operating temperature range is 0 ° C
The instantaneous viewing angle is 1.5 mmrad, and the wavelength band to be used is determined by the spectral radiation characteristics of the material constituting the object 1 to be measured, the properties of the reflection components, the influence of the atmosphere, and the like.

The electric telescopic pole 18 avoids visual obstacles such as cars and fences at the time of observation, and allows the pole to be extended up to a height of 7 m above the ground in order to take a bird's eye view of more ground surfaces and building walls. It was expanded and contracted by an electric remote controller at a pitch of 10 mm, the elevating speed was 0.06 m / sec, and the swing angle of the pole was kept within ± 0.5 ° at the longest.

The rotating head 19 is capable of panning (horizontal rotation) and tilting (vertical rotation) in order to mount the infrared detection camera 3 and record a global thermal image.
0 °, the maximum rotation speed was 90 ° / sec, and the maximum loading weight was 10 kg.

The pan head controller 20 has an angle display resolution of 0.01 °, an angle display accuracy of ± 0.08, and an angle reproducibility of ± 0.1 °.

Since the thermal image recording device is mounted on the observation vehicle 17 as described above, for example, in a residential area,
It can be freely moved and measured in green areas and industrial areas.

FIG. 2 is a flow chart of an outdoor thermal environment measuring system showing recording, display and application examples of a global thermal image of the object 1 to be measured using the outdoor environment observation vehicle 17 described above.

[0027] First, in the recording step determines the measuring object 1 is performed in a first step ST _1, the selection of the thermal image recording method is performed in a second step ST _2. Usually, a swivel head 19 on which the infrared detection camera 3 is mounted to obtain a global thermal image.
There are two rotation methods. One is to rotate a scanning optical system 3c such as a galvanometer of an infrared detection camera in a tilt direction 25 while scanning a predetermined angle 24 in the horizontal direction as shown in FIG. FIG. 6 shows a tilt rotation method and a scanning optical system 3c for performing imaging while moving at a constant angle to each other.
Panning 26 while vertical scanning 27 in the vertical direction as shown in B
There is a pan rotation method in which the image is rotated while moving at a constant angle in the tilt direction 25.

If the rotation range of the revolving head 19 is ± 180 ° or more for both pan and tilt, 4πSr is included as a solid angle.

The recording of the global thermal image is possible by either rotation method. That is, choose the pan rotation method in the third step ST ₃ in FIG. 2, thermal image was recorded by selecting the tilt rotation method in the fourth step ST ₄ is the fifth or sixth step ST ₅ or ST ₆ The equirectangular projection and the horizontal equirectangular projection are as follows.

FIGS. 4 (A) and 4 (B) show the tilt rotation method of the swivel pan head 19. In this embodiment, as described above, the movable range of both pan and tilt is 330 °, and the swivel angle in one direction is as described above. ± 165 °, in which case FIGS. 4 (A) and (B)
As shown in FIGS. 6A and 6B, a range (shaded area) that forms a blind spot 23 occurs at the left and right ends in the tilt direction (downward) and the panning direction, and the downward direction is the roof of the observation vehicle 17. It can be considered that the left and right sides do not occur when the panning rotation angle is set to ± 180 ° or more.

FIG. 5 shows one of the global original images obtained by the tilt rotation method.
For example, FIG. 7 shows a global original image by the pan rotation method. In the tilt rotation method, the viewing angle of an optical scanning system (hereinafter referred to as a scanner) 3C is 50 ° in the horizontal direction (scanning direction), and the pan direction is And divided into 8 equal parts at 45 °.

Since such an original heat image is unsuitable for use in visual judgment, polygon drawing, etc., distortion correction by a wide-angle lens is performed, and then geometric transformation using a map projection method is performed. . The recorded global thermal image is geometrically corrected and represented by a map projection method adapted to the purpose of use. Since the global thermal image is originally a spherical image, the recorded image is
It can be regarded as a plane projection. Therefore the horizontal line and the equator, the zenith and the Arctic, expressed as a seventh step ST ₇ on map projection of the position of each pixel and latitude, and longitude.

[0033] Next, the information to be obtained from the eighth step ST ₈ in the heat image thinking of something, the azimuth angle of the object is in the way of the ninth step ST _9, when you want to know the zenith angle is the 10th step as of ST ₁₀ to display in equirectangular projection.

In the equirectangular projection, which is also a projection method of the original image by the pan rotation method shown in FIGS. 6 and 7, the meridians and the latitude lines are grids, and the height and horizontal angle of each pixel from the measurement point are measured. Visual judgment is possible. Therefore, by using this projection, it is possible to estimate the azimuth and altitude where the measurement target building or the like faces.

[0035] when the 11 step ST ₁₁ to be recorded solid angle like from the focal point of the object 1 in the twelfth step S
Mollweide like the T ₁₂ (MOLLWEIDE) projection or Sanson - Furamusuchido (SANSON-FLAMSTEED) to display in the projection.

The Mollweide projection is represented by an ellipse having a central meridian 28 and an equator-corresponding parallel 29 as major axes as shown in FIG. 8, and the Sanson-Flamsteed projection is represented by a central meridian 28.
Each of the parallel lines is divided into regular lengths with reference to, and the corresponding division points are connected by a curve. The recorded thermal image is as shown in FIG.

The Sanson-Flamsteed projection approximates the spherical surface of a global thermal image with a polyhedron having one pixel as a small plane, and is almost equivalent to a state in which all pixels on the surface are developed on a plane. This can be said to be the closest to a spherical surface as a projection in which both latitude and longitude lines are continuous. Therefore, if the reliability of the data must not be reduced by interpolation or duplication of pixels even when the original image is geometrically transformed, the Sanson-Flamsteed projection shown in FIG. 9 is used.

The Sanson-Flamsteed projection is an equal-area projection. However, since an object located farther from the central meridian 28 and the equator-corresponding parallel line 29 has a remarkably distorted shape, a polygon is drawn on a subject on an image and measurement is performed. When it is desired to measure a solid angle at a point, the Mollweide projection shown in FIG. 8 is more appropriate.

Alternatively, a division diagram of the GOODE projection, which has the advantages of the above-mentioned Sanson-Flamsteed projection and Mollweide projection, may be used.

[0040] Further, considering sky view factor of the measurement points as shown in the thirteenth step ST _13. When you want to know the thermal radiation and the like from the sky to as displayed using the orthographic projection as shown by the 14 step ST ₁₄ (FIG. 10). That is, on a global thermal image by the orthographic projection (orthogonal projection), the area of the object 1 represents a view factor with respect to a circular minute plane assumed to be a measurement point.

FIG. 2 shows an example of an application in which a global thermal image is recorded and displayed by the Mollweide projection in each step as described above.
It is described than the 15 step ST ₁₅ of.

The radiometric temperature distribution by Zentamanetsu image In a 15 step ST ₁₅ is associated with 3D geometric information. That is,
The three-dimensional geometric information of the recording target 1 is input by CAD and added to surface temperature information and the like.

Next processing, etc. to the net radiation amount calculation, or human MRT (mean radiant temperature) distribution from the measured object 1 as shown in the sixteenth step ST ₁₆ and 17 step ST ₁₇ is performed.

At the time of calculating the radiation balance described above, in order to obtain accurate information, it is necessary to consider attenuation due to the propagation of radiation in the atmosphere and reflection from the opposing surface, but all of them can be calculated from three-dimensional geometric information. is there. In addition, the spatial distribution of the MRT for the human body in the measurement area is processed into the spatial distribution of the heat load on the human body and the sensible temperature by using the measured data of other temperature elements together. At this time, if the radiation from the blind spot of the global thermal image greatly affects the human body on the ground, it will hinder the analysis, so global thermal images are recorded from several points to avoid this problem There is a need.

When the global original image was geometrically transformed and displayed by the map projection method, the nearest neighbor method was adopted as the interpolation method. for that reason,
Many interpolated pixels occur on the image, and cannot be ignored when analyzing data as a two-dimensional image. FIG.
1 shows a pixel to be interpolated by the Sanson projection, and FIG. 12 shows a pixel to be interpolated by the equirectangular projection. What is indicated by 30 in FIGS. 11 and 12 is an interpolation pixel.

Therefore, the state of pixel interpolation in each projection was examined. The following Table 1 shows the ratio of interpolated pixels to the total number of pixels (referred to as an interpolated ratio). Pixel size is equator
Defined by the length of the meridian (the size of the original image is 204
8 × 1024).

[0047]

[Table 1]

As a matter of course, the largest interpolated rate among the four projections studied in this study is as follows.
The equirectangular projection, which has a remarkable elongation near the pole, is 47.9% (1: 1), and the minimum is 18.5% in the Sanson projection, which roughly represents the spherical surface itself. Further, in the Sanson projection, pixels to be interpolated are distributed almost uniformly, and there is no danger that errors are concentrated in a part of the image. From the above examination results, it was confirmed that displaying the global thermal image by the Sanson projection is the most reliable display method as two-dimensional image data.

[0049] The Zentamanetsu image to associate the total Tamanetsu images and 3D geometric information in the fifteenth step ST ₁₅ described above 3
The measurement was performed by attaching the image to the corresponding coordinates in the dimensional geometric information and projecting it onto a two-dimensional image while performing texture mapping by the scan line method.

FIG. 13 is a projection of the global thermal image shown in FIG. 9 onto three-dimensional geometric information. In FIG. 13, the white portion visible in the courtyard is a blind spot space 31 when viewed from the recording point of the global thermal image.
It is. The triangle is the blind spot space 32 created by sculpture in the center of the square, and the white circle is the observation vehicle 17
Position. The position of the observation vehicle 17 is a white circle representing a blind spot, because it corresponds to the roof surface of the observation vehicle and there is no need to record a thermal image. Blind spot space is M
If the RT analysis is hindered, the number of measurement points must be increased. Note that FIG. 13 excludes 33 buildings in the front in the conceptual diagram of the actual example in FIG. 14.

Next, a method of calculating the spatial distribution of the MRT for the human body in the measurement target area (outdoor) will be described in detail. In this example, the spatial distribution of the MRT in the measurement target area is calculated after the shape of the human body model is determined. FIG. 15 shows an MRT distribution calculation result using such a method.

That is, the actual measurement day in the courtyard of the building shown in FIG. 13 was winter (January), the weather was fine, and the surrounding outside temperature was 9.3 ° C. In order to simplify the calculation, the shape of the human body model is
A facepiece was adopted. The number of radiation vectors divided into isomorphic coefficients is 98 × 6 per point. When a required object is hidden in a blind spot at a certain point and it is impossible to extract the radiation temperature from the global thermal image, interpolation may be sufficient instead of increasing the number of measurement points. This time, the surrounding air temperature is used for interpolation when the feature is not visible, and the sky radiation temperature in another direction is used for the interpolation when the sky is not visible.

FIG. 15 shows the calculation result of the MRT distribution.
The ground near the center of the courtyard is relatively uniform, but the MRT is not uniform near the buildings. There is a 4 ° C distribution throughout the courtyard. It is expected that the variation in the spatial distribution of the MRT will be even greater in summer.

In order to accurately calculate the MRT value at an arbitrary location, the surface temperature is estimated from the radiation temperature of the solid surface, or the radiation temperature of the sky is measured in the all infrared region (0.75 μm
(1 mm) must be corrected to a value reflecting the radiation amount.

Although the above-described infrared detection camera and weather observation device for recording a global thermal image were carried out on the observation vehicle 17, it is obvious that the measurement points can be fixed at places where the measurement points are fixed.

Further, the viewing angle of the infrared detection camera and the rotation angle of the revolving pan head 19 are not limited to the values described as one example, but can be appropriately selected depending on the measurement accuracy and the spatial resolution.

[0057]

According to the thermal image recording device and the thermal image recording method of the present invention, it is possible to measure the radiation environment of the entire sphere centering on an observation point in an outdoor environment, and to measure the heat balance of a terrestrial object or a human body. What can be grasped as a surface distribution or a spatial distribution where a human body exists can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an observation vehicle equipped with a thermal image recording device of the present invention.

FIG. 2 is a flowchart of an outdoor thermal environment measuring system of the thermal image recording device of the present invention.

FIG. 3 is a system diagram of the thermal image recording device of the present invention.

FIG. 4 is an explanatory diagram of a method of rotating a rotating head (tilt rotation method) used in the thermal image recording apparatus of the present invention.

FIG. 5 is an example of a global original image by the tilt rotation method used in the present invention.

FIG. 6 is an explanatory diagram of a method of rotating a pan head (pan rotation method) used in the thermal image recording apparatus of the present invention.

FIG. 7 is an example of a global original image by the pan rotation method used in the present invention.

FIG. 8 is an example of a global thermal image by the Mollweide projection method used in the present invention.

FIG. 9 is an example of a global thermal image by the Sanson-Flamsteed projection used in the present invention.

FIG. 10 is an example of a global thermal image by the orthographic projection method used in the present invention.

FIG. 11 is an example of a pixel to be interpolated by the Sanson projection.

FIG. 12 is an example of a pixel to be interpolated by the equidistant cylindrical projection.

FIG. 13 is an explanatory diagram of a link between a global thermal image and three-dimensional geometric information.

FIG. 14 is a conceptual diagram of actual measurement in FIG.

FIG. 15 is a pattern showing an MRT distribution calculation result according to the present invention.

[Explanation of symbols]

 3 Infrared detection camera 17 Outdoor environment observation vehicle 18 Electric telescopic pole 19 Spiral head 20 Head control unit

Claims (5)

[Claims] 1. detecting infrared light radiated from an object,
In the thermal image recording device for imaging, the infrared detection camera for detecting the infrared radiation emitted from the object is one-dimensionally scanned around the thermal image recording point of the object, and panned and tilted, and is globally. A thermal image recording device characterized in that the thermal image recording device is recorded as a global thermal image magnified in FIG. 2. The thermal image recording apparatus according to claim 1, wherein a global thermal image recorded by the infrared detection camera is converted into a planar thermal image by a map projection method and displayed. 3. The thermal image recording apparatus according to claim 2, wherein the map projection method is one of an equirectangular projection, an orthographic projection, a Sanson projection, and a Mollweide projection. 4. An infrared global thermal image is detected by an infrared detection camera as a three-dimensional spatial distribution of a density distribution on a ground surface or a building surface as an object, and the infrared global thermal image is displayed as a planar thermal image. A thermal image recording method, comprising: 5. The thermal image recording method according to claim 4, wherein a projection method with a small interpolated ratio at the time of geometric transformation of the infrared global thermal image into a planar thermal image is used.