JP5977721B2 - Spatial temperature estimation method and apparatus - Google Patents

Description

  The present invention relates to a space temperature estimation method and apparatus for estimating the temperature of a space. More specifically, the present invention relates to a smoke body (aerosol: aerosol), which is irradiated with a laser beam, to form a smoke body (fine particles (smoke) The present invention relates to a method and an apparatus for imaging a laser beam reflected by the quality or air quality)) and estimating a temperature in the space using an image of the laser beam.

  Measuring and knowing the characteristics of airflow in real space is necessary and important for reducing energy consumption in air conditioners and servers. There are temperature, velocity, and pressure as the basic characteristics of the airflow, and a special measuring instrument can be used to measure their three-dimensional spatial distribution (see Non-Patent Document 1).

Suzuki Yasutoshi, Trends in Automotive Semiconductor Sensor Technology, Denso Technical Review, Vol. 9, no. 2, P10-18, 2004

  However, in the spatial temperature measurement, in order to increase the spatial resolution (or resolution), it has been pointed out that many measuring instruments are required to be arranged, which causes an increase in cost. The temperature distribution has been widely measured near the floor, ceiling, or casing surface, but the spatial distribution measurement has often been limited to a special experimental environment. A low-priced temperature sensor can be obtained for each unit, but only 10 pieces are required along the one axis in the space. In the case of sensor power supply or IP (Internet protocol) connection, there is a problem that an ether cable changes the flow of airflow in the space and a problem of complicated installation. There also arises a problem that power consumption increases due to an increase in the number of sensors. For this reason, the sensor installation in the space may be reduced as much as possible. However, it leads to a decrease in spatial resolution, making it difficult to know the dynamics of airflow details. The thermal fluid phenomenon often shows a non-uniform temperature distribution, so there is a limit in accuracy in using a small number of sensor data by simple linear interpolation or the like.

As described above, the space temperature measurement has the following problems.
The first problem is that the three-dimensional temperature cannot be measured with a small number of sensors with high resolution.
The second problem is that a special device is required for highly accurate measurement.
The third problem is that it is difficult to measure a wide range with a small number of wires and electric power.

  The present invention has been made in view of such problems. The object of the present invention is to use a small number of sensors, a small number of wires, and a small amount of power and power without using a special device. It is an object of the present invention to provide a method and apparatus for estimating temperature with high resolution.

  In order to achieve such an object, the present invention provides a method for measuring (estimating) the temperature of an imaging data obtained by an imaging device such as a camera in a wide space through image processing. The temperature is estimated from the relationship with the apparent density in the book. More specifically, applying an optical model to efficiently measure a wide range, utilizing the relationship between temperature and smoke, performing nonlinear data interpolation, and / or image processing via imaging data Including.

  An apparatus for estimating a three-dimensional temperature distribution in a space, which is an aspect of the present invention, includes a storage unit that stores a relationship between a temperature measured in advance and a density of a smoke body, and a smoke body generation unit that generates a smoke body. A laser beam irradiating means for irradiating the smoke body with a laser beam, an imaging means for imaging the laser beam reflected by the smoke body and outputting imaging data, and a means for estimating the intensity of the reflected laser beam from the imaging data And means for estimating the density of the smoke body in the space reflecting the laser light from the estimated intensity of the laser light, the estimated density of the smoke body, and the pre-measured stored in the storage means Means for estimating the temperature distribution of the space based on the relationship between the temperature and the density of the smoke body.

  In one embodiment, the laser beam irradiation means may be a plurality of laser light sources arranged in a matrix. The image processing apparatus further includes an interpolation processing unit that performs nonlinear interpolation processing using a nonlinear function on the imaging data.

  According to another aspect of the present invention, a method for estimating a three-dimensional temperature distribution in a space includes a storage unit that stores a relationship between a temperature measured in advance and a density of a smoke body, and a smoke body generation unit that generates a smoke body. This is a method for estimating a three-dimensional temperature distribution in a space in an apparatus including a laser beam irradiation unit that irradiates the smoke body with a laser beam, an imaging unit, and a processing unit. In the method, the imaging unit images the laser beam reflected by the smoke body and outputs imaging data, and the processing unit estimates the intensity of the reflected laser beam from the imaging data. A step of estimating the density of the smoke body in the space where the laser light is reflected from the estimated intensity of the laser light, and the processing means comprising the estimated density of the smoke body And estimating the temperature distribution of the space based on the relationship between the pre-measured temperature stored in the storage means and the density of the smoke body. In one embodiment, the method further includes a step of performing a nonlinear interpolation process using a nonlinear function on the imaging data.

  As described above, according to the present invention, there is provided a method and apparatus for estimating a wide range of temperatures in a space with high resolution by using a small number of sensors, a small number of wires and power without using a special apparatus. It becomes possible to provide.

It is a flowchart which shows the method of calculating | requiring in advance the relationship with the temperature for the spatial density of a smoke body for using for the spatial temperature estimation method concerning one Embodiment of this invention. It is a flowchart which shows the space temperature estimation method concerning one Embodiment of this invention. It is a figure for demonstrating the space temperature estimation method and apparatus concerning one Embodiment of this invention, (a) is a figure which shows schematic structure of the space temperature estimation apparatus arrange | positioned in a measurement environment, (b) is a laser beam. The figure which shows schematic structure of an irradiation apparatus, (c) is a figure which shows the image of the laser beam imaged by the imaging device. It is a graph which shows the density of a smoke body and the relationship of temperature. It is a figure which illustrates the user interface which displays the temperature estimated by the space temperature estimation method and apparatus concerning one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 3A is a diagram illustrating a schematic configuration of the space temperature estimation device according to the embodiment. The space temperature estimation device according to the present embodiment includes a laser beam irradiation device 302 that emits a laser beam 304, a smoke body generator 308 that generates a smoke body 310, and smoke in the smoke body, which are installed in a dark room 300. An imaging device 306 that images the laser beam reflected by the quality and outputs imaging data. In FIG. 3A, the direction in which the laser beam irradiation device 302 emits a laser beam is the x axis, the direction orthogonal to the x axis of the horizontal plane including the x axis is the y axis, and is perpendicular to the horizontal plane (xy plane). This direction is the z-axis.

  FIG. 3B is a diagram illustrating a schematic configuration of the laser beam irradiation apparatus 302. The laser beam irradiation device 302 is provided with 5 × 5 laser light sources arranged in a lattice pattern in the yz plane. The laser beam irradiation device 302 and the smoke body generation device 308 are arranged with their positions adjusted so that the laser beam emitted by the laser beam irradiation device is irradiated onto the smoke body 310 generated by the smoke body generation device. The number of laser light sources arranged in the laser beam irradiation apparatus 302 is not limited to 5 × 5, and the arrangement method is not limited to a lattice shape. The smoke generator 308 generates a smoke in the z-axis direction. The smoke generator 308 generates a plate-like (or belt-like or rod-like) smoke body. Desirably, the smoke generator 308 generates a smoke having a width (density (concentration) in space) such that the image of the reflected laser beam is captured by the imaging device 306.

  The imaging device 306 images the laser beam irradiated to the smoke body 310 and reflected by the smoke quality of the smoke body, and outputs imaging data. FIG. 3A shows an example in which the imaging device 306 is disposed at a position adjacent to the smoke generator 308 in a direction orthogonal to the direction in which the laser beam is emitted. However, the present invention is not limited to this. Absent. The imaging device 306 may be arranged at a position and an angle at which the images of 5 × 5 laser beams do not overlap and at a position where the laser beam reflected by the smoke quality of the smoke body can be imaged. A computer (not shown) having a database and a processing device (processor) is connected to the imaging device 306. The imaging device images the laser beam reflected by the smoke quality of the smoke body continuously in time or at predetermined intervals, and outputs the imaging data to the computer.

  FIG. 3C shows an example of an image of the laser beam reflected by the smoke quality of the smoke body represented by the imaging data output from the imaging device 306. As shown in FIG. 3C, the image of the laser beam reflected by the fumes distributed in the space is captured in a straight line extending in the x-axis direction. When the density (concentration) of fumes distributed in space is sufficiently low, a maximum of 5 × 5 linear images can be observed in this embodiment. On the other hand, when there is a large amount of fumes distributed between the position where the laser beam is reflected and the imaging device (when high-density fumes are present locally, or over a wide area in the optical path of the reflected laser beam). In the case of low-density smoke), the reflected laser light is attenuated by absorption and reflection (dispersion), and is extinguished before being imaged by the imaging device. This is why a part of the linear imaging extending in the x-axis direction appears to be cut off in the middle in FIG.

  It is known that the absorption, reflection, and attenuation of light traveling in a smoke body distributed in space can be expressed using an optical model. Therefore, by using this optical model, the intensity of the laser beam and the density of the smoke body can be estimated from the image of the laser beam captured by the imaging device.

  In the embodiment of the present invention, the density of the smoke body is estimated from the image of the laser light reflected by the actually measured smoke quality using an optical model. On the other hand, using the temperature as a parameter, the relationship between the density of the smoke body and the temperature is measured in advance and stored in a database. Determine the density of the smoke body stored in the database that matches the density of the smoke body estimated from the image of the laser light obtained in the actual measurement, and measure the temperature associated with the determined density of the smoke body Estimated temperature of

  FIG. 1 is a diagram for explaining a method for measuring the density and temperature of a smoke body in advance and storing these relationships in a database. This method can be implemented using the space temperature estimation apparatus described with reference to FIG.

  In step 102, the laser beam from the laser beam irradiation device 302 is irradiated onto the smoke body 310 generated by the smoke body generation device 308, and the imaging device 306 images the laser beam reflected by the smoke quality in the smoke body. Data is output to a computer, stored in a database, and stored. At this time, the temperature distribution of the smoke body is measured by a thermometer, stored in a database, and stored. It is desirable to measure the temperature distribution of the smoke body including the surroundings of the smoke body.

  In step 104, the laser beam (light intensity) reflected from the imaging data is estimated.

  In step 106, an optical model is applied to the estimated laser beam (light intensity) to estimate the density of the smoke body in space.

  In step 108, the estimated density of the smoke body and the measured temperature are associated and stored in the database.

  After repeating steps 102 to 108 a plurality of times, it is desirable to statistically process the relationship between the estimated laser beam (light intensity) and the measured temperature. Further, if necessary, the imaging data may be smoothed, interpolated, or extrapolated by an interpolation function. For various temperatures, it is desirable to obtain the relationship between the density of the smoke body and the temperature and store it in a database.

  FIG. 4 is a diagram showing the relationship between the density of the smoke body obtained by the method described with reference to FIG. 1 and the temperature. The relationship between the spatial density of the smoke body and the temperature is non-uniform. FIG. 4 shows an example in which a nonlinear function is applied to points plotted by the nonlinear least square method.

  Next, with reference to FIG. 2, the space temperature estimation method of this embodiment will be described. It can be implemented using the space temperature estimation apparatus described with reference to FIG.

  In step 202, similarly to step 102, the laser beam from the laser beam irradiation device 302 is applied to the smoke body 310 generated by the smoke body generation device 308, and is reflected by the smoke quality in the smoke body by the imaging device 306. The laser beam is imaged, and the imaging data is output to a computer, stored in a database, and stored. At this time, the temperature is not actually measured with a thermometer.

  In step 204, as in step 104, the laser beam (light intensity) reflected from the imaging data is estimated. In order to increase the apparent spatial resolution in the imaging data, a nonlinear interpolation method using a nonlinear function may be applied.

  In step 206, as in step 106, an optical model is applied to the estimated laser beam (light intensity) to estimate the density of the smoke body in the space.

  In step 208, matching processing between the density of the smoke body in the space estimated in step 206 and the density of the smoke body stored in the database in step 108 is performed.

  In step 210, the temperature associated with the density of the smoke body stored in the database matched with the density of the smoke body in the space estimated in step 206 is the position at which the laser beam estimated in step 204 is reflected by the smoke quality. Determine as temperature.

  By executing steps 204 to 210 for each pixel of the imaging data output in step 202, the temperature distribution in the space can be determined.

  In addition, by performing steps 204 to 210 for imaging data output from the imaging device 306 continuously in time or at predetermined intervals, it is possible to estimate a temporal change in temperature distribution in the space.

  FIG. 5 shows an example of a user interface (GUI) that displays the temperature estimated by the space temperature estimation method and apparatus of the present embodiment. The estimated temperature at any point in space can be displayed selectively and / or in time series. In the example of FIG. 5, the GUI displays estimated temperatures of points (T1, T2, T3, T4) at arbitrarily selected x coordinates for four selected 4 × 5 laser beams. Yes. However, the position and the number of positions for estimating the temperature are not limited to this, and can be estimated for an arbitrary point.

DESCRIPTION OF SYMBOLS 300 Dark room 302 Laser beam irradiation apparatus 304 Laser beam 306 Imaging apparatus 308 Smoke body generator 310 Smoke body

Claims (5)

An apparatus for estimating a three-dimensional temperature distribution in space,
Storage means for storing the relationship between the temperature measured in advance and the density of the smoke body,
A smoke generating means for generating a smoke,
A laser beam irradiation means for irradiating the smoke body with a laser beam;
Imaging means for imaging the laser beam reflected by the smoke body and outputting imaging data;
Means for estimating the intensity of the reflected laser beam from imaging data;
Means for estimating the density of the smoke bodies in the space reflecting the laser light from the estimated intensity of the laser light;
Means for estimating the temperature distribution of the space based on the estimated density of the smoke body and the relationship between the pre-measured temperature stored in the storage means and the density of the smoke body. Features device.   The apparatus according to claim 1, wherein the laser beam irradiation means is a plurality of laser light sources arranged in a matrix.   The apparatus according to claim 1, further comprising an interpolation processing unit configured to perform nonlinear interpolation processing using a nonlinear function on the imaging data. Storage means for storing the relationship between the temperature measured in advance and the density of the smoke body, a smoke body generating means for generating the smoke body, a laser beam irradiation means for irradiating the smoke body with a laser beam, an imaging means, and a processing means A method for estimating a three-dimensional temperature distribution in a space in an apparatus comprising:
The imaging means images the laser beam reflected by the smoke body, and outputs imaging data;
The processing means estimating an intensity of the reflected laser beam from the imaging data;
Estimating the density of the smoke body in the space where the processing means has reflected the laser light from the estimated intensity of the laser light;
The processing means estimating the temperature distribution of the space based on the estimated density of the smoke body and the relationship between the pre-measured temperature stored in the storage means and the density of the smoke body; A method comprising the steps of:   The method according to claim 4, further comprising a step of performing nonlinear interpolation processing using a nonlinear function on the imaging data.

Images