JP2011013036A - Device for determining presence or absence of direct light, device for controlling electric blind, method for determining presence or absence of direct light and method for controlling electric blind - Google Patents

Abstract

There is provided a direct light presence / absence judgment device that is easy to maintain and can accurately judge the presence or absence of direct light.
Imaging means 2, 3 and 4 for taking a sky image of the whole sky at regular intervals, a luminance distribution calculating means 5 for calculating a luminance distribution of the sky image, and a sun for calculating a sun position on the luminance distribution Position calculating means 5 and determining means 5 for determining the presence or absence of direct light based on the luminance distribution are provided.
[Selection] Figure 1

Description

  The present invention relates to a determination device that determines the presence or absence of direct light and a blind control device that controls a slat based on a determination result of the determination device.

Taking sunlight into the room and using it as illumination light reduces the power consumption required for illumination and is also effective in reducing CO ₂ emissions.
However, the brightness by direct sunlight of the sun greatly exceeds the level required for normal illumination. In addition, if direct light is introduced, useless radiant heat is introduced in the summer, which reduces the air conditioning effect.

  Therefore, when the sunlight to be taken into the room is controlled by an electric blind, it is necessary to efficiently take in the outdoor light while controlling the slat angle so as to block the direct light in fine weather.

  Some control devices for electric blinds have data on the altitude and azimuth of the sun for one year in advance, and a control device that automatically controls the slat angle to an angle that blocks direct light based on that data. Yes (see Patent Document 1). In such a control device, it is possible to prevent the direct light from entering the room by automatically controlling the slat at an angle that blocks direct light at each time.

  However, the angle of the slats is the same even during clear or overcast weather. It will be uncomfortable for you.

  Therefore, Patent Document 2 includes a first illuminometer that tracks the sun and a second illuminometer that measures illuminance at a position away from the sun by a predetermined angle, and the detected illuminance of the first and second illuminometers. There has been proposed a control device that calculates a difference to detect whether the sky is clear or cloudy, and controls the slats based on the detection result.

Japanese Patent No. 2618274 Japanese Patent No. 4216130

In the control device as shown in Patent Document 2, an automatic tracking device that drives the first illuminometer so as to automatically track the sun becomes a large-scale and costs increase.
In addition, when the sun is lowered, the difference between the detected illuminances of the first and second illuminometers becomes smaller, and the slats may not be rotated to an angle that blocks direct light despite the presence of direct light. For example, there is a problem that satisfactory detection accuracy is not ensured.

Moreover, even if the detection accuracy at that time is high, the presence or absence of direct light frequently fluctuates depending on the weather conditions, and if the slats are rotated frequently, it is uncomfortable for the resident.
An object of the present invention is to provide a direct light presence / absence determination device that can appropriately determine the presence or absence of direct light. It is another object of the present invention to provide an electric blind control device that can appropriately block direct light without causing the occupant to feel uncomfortable.

  In Claim 1, the imaging means which images the sky image of the whole sky for every fixed time, the luminance distribution calculation means for calculating the luminance distribution of the sky image, and the solar position calculating means for calculating the sun position on the luminance distribution And determination means for determining the presence or absence of direct light based on the luminance distribution.

According to a second aspect of the present invention, the determination means includes first determination means for determining the presence or absence of the direct light based on a difference between the luminance at the sun position and the luminance at a position other than the sun position.
According to a third aspect of the present invention, the determination means directly emits when the difference between the luminance at the solar position and the luminance at a position other than the solar position is continuously equal to or less than a first threshold value in a luminance distribution based on a plurality of sky images. There is provided a second determination unit that determines that there is no light and determines that there is direct light when the luminance distribution based on a plurality of sky images is not continuously below the threshold value.

  In Claim 4, the said determination means calculates the raise total brightness | luminance on the solar locus after the said sun position, judges that there is direct light when this raise total brightness exceeds a 2nd threshold value, and raises total Third determining means for determining that there is no direct light when the luminance does not exceed the second threshold value is provided.

In Claim 5, said 1st judgment means compares the brightness | luminance of the said solar position, and the brightness | luminance on the solar locus after the said solar position.
According to a sixth aspect of the present invention, the first determination means compares the luminance at the solar position with the luminance on a line segment connecting the solar position and the zenith.

According to a seventh aspect of the present invention, the first determination unit compares an average luminance of a circular luminance distribution image centered on the sun position with an average luminance on a circle centered on the sun position.
The determination means determines that there is direct light when detecting a luminance exceeding a third threshold from the luminance distribution, and direct light when detecting no luminance exceeding the third threshold. A fourth judging means for judging that there is none is provided.

In a ninth aspect, the fourth determination means lowers the third threshold value when the solar altitude of the solar position is low.
According to a tenth aspect of the present invention, in the fifth aspect, the determining means determines that there is direct light when the sun position and a position where the luminance reaches a peak in the luminance distribution match, and determines that there is no direct light when they do not match. Judgment means was provided.

  In claim 11, the determination means calculates the total number of increases in luminance on the solar trajectory after the sun position, and determines that there is direct light when the total number of increases exceeds a fourth threshold value, Sixth determination means is provided for determining that there is no direct light when the total number of increases does not exceed the fourth threshold value.

  In Claim 12, the said judgment means calculates the raise total brightness | luminance of the brightness | luminance on the sun locus | trajectory after the said sun position, and the total number of the rises, and there is direct light when this raise total brightness exceeds a 2nd threshold value And a seventh determination means for determining that there is no direct light when the total increase brightness does not exceed the second threshold value and the total number of increases does not exceed the fourth threshold value. .

  According to a thirteenth aspect of the present invention, the determination signal output from the direct light presence / absence determination device according to any one of the first to ninth aspects is received, and the slat is formed at an angle that blocks the direct light based on the determination signal that the direct light is present. And a controller that rotates the slat to an angle that allows external light to be taken in based on a determination signal that there is no direct light.

  In claim 14, when the first determining means for determining the presence or absence of the present direct light and when the first determining means determines that the current direct light is not present, when the brightness fluctuations other than the sun position are large, semi-clear weather And a third judging means for judging.

  In the fifteenth aspect, the first determination unit includes an imaging unit that captures a sky image of the whole sky at regular intervals, a luminance distribution calculation unit that calculates a luminance distribution of the sky image, and a sun on the luminance distribution. A solar position calculating means for calculating a position; and determining the presence or absence of the current direct light based on the luminance distribution, wherein the third determining means is a total rising luminance on a solar trajectory after the sun position. Calculating a semi-sunny sky when the increased total luminance exceeds a second threshold, and determining that there is no direct light when the increased total luminance does not exceed the second threshold. Prepared.

  In Claim 16, the sky image of the whole sky is imaged for every fixed time, the luminance distribution of the sky image is calculated, the sun position and the sun locus on the luminance distribution are calculated, and the direct light is calculated based on the luminance distribution. Determine the presence or absence.

In the seventeenth aspect, the presence / absence of the direct light is determined based on the difference between the luminance at the solar position and the luminance at a position other than the solar position.
In claim 18, it is determined that there is no direct light when the difference between the luminance at the sun position and the luminance at a position other than the sun position is continuously below a first threshold in a luminance distribution based on a plurality of sky images. When the luminance distribution based on a plurality of sky images is not continuously below the threshold value, it is determined that there is direct light.

  In claim 19, the rising total luminance on the solar trajectory after the sun position is calculated, it is determined that there is direct light when the rising total luminance exceeds a second threshold, and the rising total luminance is the second When the threshold is not exceeded, it is determined that there is no direct light.

  In claim 20, when it is determined that there is direct light based on the first determination means for determining the presence or absence of current direct light, the slat is rotated to an angle that blocks direct light, and the first determination means When it is determined that there is no direct light, the slat is rotated to an angle that blocks the direct light when the third determining means determines that the luminance fluctuation other than the sun position is large.

  According to a twenty-first aspect of the present invention, when the third determination means determines that the luminance variation on the solar locus after the sun position is large, the slat is rotated to an angle that blocks direct light.

  According to the present invention, it is possible to provide a direct light presence / absence determination device that is easy to maintain and can accurately determine the presence or absence of direct light.

It is a schematic diagram which shows the control apparatus of the electric blind of one Embodiment. It is explanatory drawing which shows a luminance distribution image and a sun locus. It is a flowchart which shows operation | movement of the direct light presence determination apparatus. It is explanatory drawing which shows a luminance distribution image. (A)-(c) is explanatory drawing which shows the brightness | luminance on a solar locus. (A) (b) is explanatory drawing which shows an example of a raise total brightness | luminance and the frequency | count of a brightness rise. (A) (b) is explanatory drawing which shows the malfunction rate of the direct light presence determination. It is explanatory drawing which shows operation | movement of 2nd embodiment. It is explanatory drawing which shows operation | movement of 2nd embodiment. It is explanatory drawing which shows operation | movement of another example. It is explanatory drawing which shows a sky image. It is explanatory drawing which shows a luminance distribution image.

(First embodiment)
Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings. FIG. 1 shows a blind control device including a direct light presence / absence determination device. In the direct light presence / absence determination device 1, a shutter unit 3 is disposed below a fisheye lens 2 installed toward the sky, and an image sensor 4 of, for example, a CCD element is disposed below the shutter unit 3. The direct light presence / absence determination device 1 includes a CPU 5 and a memory 6.

  The CPU 5 operates based on a preset program, and drives the shutter unit 3 to open and close at regular intervals. When the shutter unit 3 is opened and closed, a sky image captured via the fisheye lens 2 and the shutter unit 3 is captured by the image sensor 4, and the CPU 5 stores the sky image data in the memory 6. The fisheye lens 2 is equipped with a neutral density filter 2a that prevents overexposure of a sky image to be captured.

  The CPU 5 calculates a luminance distribution image from the sky image data. Then, the presence / absence of direct light, that is, whether it is clear or cloudy, is determined based on the luminance distribution image, and the determination signal is output to the electric blind system 7.

  In the electric blind system 7, a large number of electric blinds 10 are connected to a main controller 8 via a communication line 9. Each electric blind 10 is provided with a blind controller 11 that drives a motor based on a control signal output from the main controller 8 to control the height and angle of the slats.

  Then, the determination signal output from the CPU 5 is input to the main controller 8, and the main controller 8 controls each electric blind 10 based on the determination signal.

  Specifically, when a determination signal indicating clear sky is input from the CPU 5 to the main controller 8, the slats of each electric blind 10 are rotated to an angle that blocks direct light. When a determination signal indicating cloudy weather is input to the main controller 8, the slats of the electric blinds 10 are rotated in the horizontal direction, or the slats are pulled up and controlled so that external light can be taken in.

  The fisheye lens 2 is an all-around fisheye lens having an imaging circle whose diameter is smaller than the diagonal line of the screen, and images a sky image by, for example, an equisolid angle projection method. The equisolid angle projection method is a method in which the solid angle of each part of the celestial sphere with respect to the center of the celestial sphere is proportional to the projected area of that part.

  The CPU 5 calculates the luminance for each pixel of the imaged sky image data, and generates a luminance distribution image P as shown in FIG. Further, the CPU 5 has a calendar function and a function for calculating a sun locus for each sky image capturing date. Then, the sun trajectory corresponding to the date and time when the sky image was captured is superimposed on the luminance distribution image, and the presence or absence of direct light on the imaging date is determined based on the luminance distribution on the sun trajectory.

  In FIG. 2, the sun locus A indicates the summer solstice, the sun locus B indicates the spring and autumn minutes, and the sun locus C indicates the winter solstice. The sun trajectory for each imaging day of the year sequentially moves from sun trajectory A to C.

Next, the operation of the CPU 5 of the direct light presence / absence determination device 1 will be described with reference to FIG.
Based on the start of the operation of the CPU 5, the count value N of the counter built in the CPU 5 is first reset to “0” (step 1). Next, the shutter unit 3 is opened and closed, and a sky image is captured by the image sensor 4 (step 2). This imaging operation is performed every predetermined time (for example, every 10 minutes) set in advance, and the captured sky image data is stored in the memory 6.

  Next, a brightness distribution image is created based on the sky image data (step 3), and the sun locus corresponding to the shooting date and the sun position corresponding to the shooting time are calculated (step 4). Here, the luminance distribution image P at the shooting time as shown in FIG. 4, the sun locus SO of the shooting date, and the sun position S at the shooting time are obtained. The sun locus SO and the sun position S may be calculated at the start of the operation on each shooting day, or may be calculated, for example, every week and stored in the memory 6 and read from the memory 6 at each shooting time.

  Next, the brightness of the sun position S is compared with the brightness of all other parts on the brightness distribution image P (step 5). Then, when the brightness of the sun position S is higher than the preset threshold value than the brightness of all other parts, it is judged as sunny (steps 6 and 7), and a judgment signal indicating sunny is sent to the main controller 8. It outputs and returns to step 1, and the operation | movement of step 1-6 is repeated.

  Here, the brightness at the sun position S is the average brightness of pixels corresponding to the sun diameter. Further, the threshold value in Step 5 is a value that makes the luminance of other portions 80 or less, that is, 1.25, assuming that the luminance of the solar position S is 100.

  In Step 6, when there is at least one other portion where the luminance at the solar position S is equal to or less than the threshold value, that is, when there is a portion having a small luminance difference from the solar position S, the processing proceeds to Step 8. .

  In step 8, the counter count value N is incremented by “1”, and then it is determined whether or not the count value N is less than a preset upper limit value X (step 9). Here, it is assumed that the upper limit value X is set to “3”, for example.

  If the count value N has not reached the upper limit value X in step 9, it is determined that it is clear and a determination signal indicating clear is output to the main controller 8 (step 10), and the process returns to step 2.

  If it is determined that the weather is sunny in step 10, the brightness of the sun position S and the brightness of all other parts on the brightness distribution image P are compared for the sky image at the next time in steps 2-6.

  And when the brightness | luminance difference of the sun position S and another part is small, it transfers to step 8 and 9, and when the count value N becomes equal to the upper limit X by repetition of such operation | movement, it transfers to step 11.

In step 11, the total rising brightness on the solar locus SO from the current sun position to the sunset position of the brightness distribution data is calculated. This increased total luminance will be described.
FIG. 11 shows an example of a captured sky image, and FIG. 12 shows an example of a luminance distribution image calculated from the sky image data.

FIG. 5A is a graph showing the luminance distribution on the solar locus SO of the luminance distribution image P at 9 o'clock, 11 o'clock, 13 o'clock and 15 o'clock on a cloudy day when the sky is almost covered with clouds. In the figure, the vertical axis represents the luminance per unit area of the sky (unit cd / m ² , cd is candela), and the horizontal axis represents the pixel (pixel) position in the X-axis direction on the sun locus SO. As shown in the figure, the brightness fluctuation on the sun trajectory is relatively small during cloudy weather.

  The increased total luminance is a luminance obtained by adding only the amount of increase in luminance after the current sun position on the sun trajectory SO, and the increased total luminance after the current solar position during cloudy weather shown in FIG. 5A is small. Become.

  FIG. 5B is a graph showing the luminance distribution on the solar locus SO of the luminance distribution image P at 9 o'clock, 11 o'clock, 13 o'clock, and 15 o'clock on clear days with almost no clouds in the sky. As shown in the figure, the peak value PC increases at the sun position during fine weather, and the luminance on the sun locus SO decreases almost smoothly toward the sunset position after the current sun position. Therefore, when the weather is fine, the increased total luminance is small.

  FIG. 5C is a graph showing the luminance distribution on the sun locus SO of the luminance distribution image P at 9 o'clock, 11 o'clock, 13 o'clock, and 15 o'clock on a semi-clear day in which clouds are scattered in the sky. As shown in the figure, since the sun appears and disappears depending on the time in semi-fine weather, there are a time when the peak value PC is high at the solar position, that is, a time when direct light is present, and a time when the peak value PC is not high, that is, a time when there is no direct light. And even if it is the time when the peak value PC becomes high in the solar position (time when the direct light exists) at the solar position SO, the brightness fluctuation on the solar locus SO increases at a position other than the solar position. Since there is a spot (cloud) where the brightness increases, the total brightness increases when the weather is semi-clear.

Fig.6 (a) shows an example of the change for every time of the raise total brightness | luminance from the sun position of a clear day and a semi-fine day to the sunset position. Increasing the total brightness Q1 of sunny day, almost while 2000 cd / ^{m 2} is stable below, elevated total luminance Q2 day semi sunny in the range from around 2000 cd / ^{m 2} to around 12000 cd / ^{m 2} It changes a lot.

  In step 11, based on the luminance distribution image P calculated in steps 3 and 4 and the sun trajectory SO, the total increase brightness from the sun position to the sunset position on the sun trajectory SO is calculated, and the process proceeds to step 12.

In step 12, it is determined whether or not the increased total luminance exceeds a preset lower limit value Y. Here, the lower limit value Y is set to 4000 cd / ^{m 2,} if increasing the total brightness exceeds 4000 cd / ^{m 2} outputs a determination signal indicating the sunny to the main controller 8 determines that the clear, step 1 Return to.

In step 12, if the total increase brightness does not exceed 4000 cd / m ² , it is determined that the cloud is uniformly covered with clouds from the sun position to the sunset position, and a determination signal indicating cloudiness to the main controller 8 And return to step 1.

With the direct light presence / absence determination device 1 and the electric blind control device configured as described above, the following operational effects can be obtained.
(1) On the brightness distribution image of the whole sky, it is possible to determine the presence or absence of direct light, that is, whether it is sunny or cloudy, by comparing the ratio of the brightness of the other part with respect to the brightness of the sun position S. Therefore, since the presence or absence of direct light can be detected without requiring a solar tracking device, maintenance management costs can be reduced.
(2) When a determination signal indicating clearness is output from the CPU 5 of the direct light presence / absence determination device 1 to the main controller 8, the slats of the electric blinds 10 are controlled by a control signal output from the main controller 8 to the electric blinds 10. It can be rotated to an angle that blocks direct light. Further, when a determination signal indicating cloudy weather is output from the CPU 5 of the direct light presence / absence determination device 1 to the main controller 8, the slats of the electric blinds 10 are horizontally leveled by a control signal output from the main controller 8 to the electric blinds 10. It can be controlled to rotate in the direction, or pull up the slats to incorporate external light.
(3) When the difference between the brightness of the sun position S and the brightness of other parts is small, only when a similar determination result is obtained with a brightness distribution image based on three or more consecutive imagings, cloudy weather is indicated A determination signal can be output. Therefore, even when the difference between the brightness of the sun position S and the brightness of other portions becomes small, it is possible to control so that the slat is not immediately opened. As a result, in the case of semi-clear weather dotted with clouds, the slats are not rotated horizontally even when there is no direct light temporarily, and frequent rotation of the slats can be prevented. .
(4) When the difference between the luminance at the sun position S and the luminance at other portions is small, the total increase luminance on the solar trajectory SO after the solar position S is calculated, and the total increase luminance is higher than the lower limit Y Can determine that the sky is semi-sunny with dots and output a determination signal indicating the clear sky. Therefore, it is possible to prevent the slats from being frequently rotated in the case of semi-fine weather dotted with clouds.
(5) When the total increase brightness is lower than the lower limit value Y, it is possible to output a judgment signal indicating cloudy weather and control the slats so as to incorporate outside light.
(Second embodiment)
In the first embodiment, in step 6 shown in FIG. 3, when the brightness at the sun position S is higher than the threshold value set in advance by the brightness of all other portions, it is determined that the weather is sunny. Such a comparison process may be performed.

The average brightness W within a circle having a radius of 7.5 degrees centered on the sun position S is calculated, and the average brightness V on a circle having a radius of 17.5 degrees centered on the sun position S is calculated. . Then, W−V is compared with a threshold value. For example, when the threshold value is 100 cd / m ² , if W−V is equal to or greater than the threshold value, it is determined to be sunny, and if less than the threshold value, step 8 to move.

  FIG. 7A shows the malfunction rate with respect to each threshold value when the presence / absence of direct light based on the luminance difference is determined. In the figure, the malfunction rate E1 indicates the malfunction rate when the slat opens during clear weather, and the malfunction rate E2 indicates the malfunction rate when the slat closes during cloudy weather.

As indicated by the malfunction rate E1, the lower the threshold value, the lower the malfunction rate at which the slats open in fine weather, but it can be suppressed to about 5% as a whole. Further, as shown in the malfunction rate E2, the lower the threshold value, the higher the malfunction rate that causes the slats to close during cloudy weather. However, if the threshold value is set to 100 cd / m ² or more, malfunction will occur. Can be substantially prevented.

  Incidentally, FIG.7 (b) shows the malfunction rate when determining the presence or absence of direct light using an illuminance difference like the prior art example. In this case, as shown in the malfunction rate E1, as the threshold value is set lower, the malfunction rate at which the slat opens in fine weather can be lowered, but the malfunction rate as a whole increases to about 20%. .

  When the solar altitude in the morning or evening is low, as shown in FIG. 8, the average brightness W is within a range of a radius of 7.5 degrees centered on the sun position S and the brightness of the range AR1 in the circular brightness distribution image. The average of is calculated.

  Similarly, the average luminance V is a radius of 17.5 degrees centered on the sun position S, and the average luminance on the circle of the circular luminance distribution image AR2 is calculated. With such a calculation method, an accurate luminance difference can be calculated. Moreover, when the building B shown in FIG.11 and FIG.12 overlaps in a circle, the part which overlaps in a circle is excluded beforehand.

  Further, as shown in FIG. 9, the average luminance W in a circle in a range AR3 having a radius of 7.5 degrees centered on the sun position S and a radius 7.5 centered on a position away from the sun position S by a predetermined angle. The average luminance V within the circle of the degree range AR4 may be calculated, and these luminance differences may be compared with a threshold value.

In this embodiment, in addition to the operational effects obtained in the first embodiment, the following operational effects can be obtained.
(1) By comparing the luminance difference between the average luminance W and the average luminance V with a threshold value, it is possible to improve the accuracy of determining the presence or absence of direct light.
(2) When the solar altitude is low, the average luminance W and the average luminance V are calculated using only the luminance values within the range of the luminance distribution image, so that the accuracy of the average luminance W and the average luminance V can be improved.

You may implement the said embodiment in the following aspects.
-In step 6 of 1st embodiment, the brightness | luminance of the sun position S and the brightness | luminance on the solar locus SO may be compared, and the presence or absence of direct light may be judged. Compared with step 6 of the first embodiment, the load on the CPU 5 can be reduced.
-It replaces with step 5 of 1st embodiment, and when the brightness | luminance more than the preset threshold value is detected from the brightness | luminance data on the solar locus SO calculated at step 4, it will judge that there exists direct light. You may do it. The threshold value is, for example, a luminance value of 100,000 when the luminance value on the solar locus SO is displayed on a logarithmic scale as shown in FIG. In such a process, it is not necessary to calculate the sun position, so the load on the CPU 5 can be reduced. Furthermore, it may be determined that the process is cloudy at the time of transition from step 6 to step 8, and step 9 and subsequent steps may be omitted.
When the solar altitude in the morning and evening is low, the luminance peak on the solar locus SO is low. Therefore, as shown in FIG. 10, the threshold value T may be changed in proportion to the solar altitude in the morning and evening.
In step 3 of the first embodiment, the sky luminance distribution image is calculated. However, the luminance distribution image is not generated, the coordinates where the luminance value reaches the peak are obtained, and the coordinates and the coordinates of the sun position S are obtained. It may be determined whether or not there is direct light by determining whether or not they match. If the coordinates where the luminance value reaches the peak and the coordinates of the sun position S match, it is determined that there is direct light, and if it does not match, it is determined that there is no direct light. Furthermore, it may be determined that the process is cloudy at the time of transition from step 6 to step 8, and step 9 and subsequent steps may be omitted.
-Although the increase total brightness | luminance was calculated in step 11 of 1st embodiment, it may replace with a raise total brightness | luminance and may calculate the number of total increase. FIG. 6B shows the total number of rises Q3 and Q4 after the sun position on the same day as the day when the total rise brightness shown in FIG. 6A is calculated.

As shown in FIG. 6 (a), the judgment of only the total number of rises is 9 o'clock, 11 o'clock, and 15 o'clock, and the rise total luminance is 4000 cd / m ² or less. is there. Therefore, it is determined whether or not the total number of ascents (see FIG. 6B) exceeds a threshold value (for example, 17 times) between step 12 and step 13; If not, it is judged cloudy. Then, based on the number of times of brightness increase Q4 on a semi-clear day, it can be determined that it is sunny (half-sky weather with a mixture of clouds and sunny) at 9 o'clock, 11 o'clock, and 15 o'clock, so the accuracy can be further improved. it can. Further, the threshold value may be lowered toward sunset. In this way, if the number of brightness increases is large, it can be determined that the weather is semi-sunny with dotted clouds.
-You may reduce the lower limit Y of a raise total brightness | luminance toward sunset time.
The processing operation of the CPU 5 and the memory 6 of the direct light presence / absence determination device 1 according to the first embodiment may be performed by the main controller 8 constituted by a personal computer or the like.
The fisheye lens 2, the shutter unit 3, and the image sensor 4 of the direct light presence / absence determination device 1 of the first embodiment may be configured by a digital camera, and the processing operations of the CPU 5 and the memory 6 may be performed by a personal computer.
-In 1st and 2nd embodiment, it may judge that it is cloudy at the time of transfering from step 6 to step 8, and you may abbreviate | omit step 9 and subsequent steps.
In the embodiment including step 4 and step 11, the luminance value on the line segment L 1 connecting the solar position S and the zenith Z shown in FIG. May be calculated and compared with a threshold value. In the season when the solar altitude is low, comparison with luminance other than the sun position and luminance variation can be identified in a relatively wide range than the solar trajectory. Alternatively, both the brightness calculation of the sun locus and the brightness calculation of the line segment L1 connecting the zenith may be performed, and when both threshold values are satisfied in step 6, it may be determined that the sky is clear.
In the embodiment including Step 4 and Step 11, instead of the sun trajectory, the luminance value on the line segment L1 connecting the sun position S and the zenith Z shown in FIG. 12 and the luminance on the line segment L2 orthogonal to the line segment L1 Based on the values, the brightness difference between the brightness value at the sun position S and the brightness values on the line segments L1 and L2, the total rise brightness and the total number of rises from the sun position on the line segment L1 to the zenith Z are calculated. In addition, the total rise brightness and the total number of rises from the end of the line segment L2 toward the zenith Z are calculated. Each of these may be compared with a threshold value.

Comparison with brightness other than the sun position and brightness fluctuation can be identified in a wider range than the sun trajectory. Furthermore, in addition to the line segment L2, a line segment that intersects the line segment L1 at an angle of 45 degrees or 135 degrees is added, and the total rise brightness and the total number of rises from the end toward the zenith Z are calculated for the line segment. Then, by comparing them with the threshold value, it is possible to further take the determination accuracy.
In Step 3 of the first embodiment, the sky brightness distribution image is calculated, but the brightness distribution image is not generated, and brightness higher than a preset threshold is detected from the sky sky brightness data. Sometimes, it may be determined that there is direct light. At this time, as shown in FIG. 10, the threshold value is, for example, a luminance value of 250,000 cd / m ^{2 at} which the image is overexposed. In such a process, it is not necessary to calculate the sun position, so the load on the CPU 5 can be reduced. And the calculation process of the sun position in step 4 and the brightness | luminance comparison process of step 5 can be abbreviate | omitted.

  Further, in addition to this processing, instead of the sun trajectory after step 8, the total brightness and the total number of times of the increase from the solar position S toward the zenith Z are calculated by the luminance value on the line segment L1 connecting the solar position S and the zenith Z. It may be calculated and compared with a threshold value after step 12. By such processing, it is possible to determine whether the sky is cloudy or cloudy from the current sun position and brightness without calculating the sun trajectory.

  DESCRIPTION OF SYMBOLS 1 ... Direct light presence determination apparatus, 2 ... Imaging means (fisheye lens), 3 ... Imaging means (shutter unit), 4 ... Imaging means (image sensor), 5 ... Luminance distribution calculation means, solar position calculation means, 1st-1st Seven judgment means (CPU), 8 ... main controller, 11 ... blind controller.

Claims (21)

Imaging means for capturing a sky image of the whole sky at regular intervals;
A luminance distribution calculating means for calculating a luminance distribution of the sky image;
Solar position calculating means for calculating the solar position on the luminance distribution;
A direct light presence / absence determining apparatus comprising: a determination unit that determines presence / absence of direct light based on the luminance distribution. The determination means includes
The direct light presence / absence judgment device according to claim 1, further comprising first judgment means for judging the presence / absence of the direct light based on a difference between the brightness of the sun position and the brightness other than the sun position. The determination means includes
When the difference between the brightness of the sun position and the brightness other than the sun position is continuously below the first threshold in the brightness distribution based on a plurality of sky images, it is determined that there is no direct light, and a plurality of sky images 3. The direct light presence / absence judging device according to claim 2, further comprising a second judging means for judging that there is direct light when the luminance distribution based on is not continuously below the threshold value. The determination means includes
Calculate the total rising brightness on the solar trajectory after the sun position, and determine that there is direct light when the total rising brightness exceeds the second threshold, and the total rising brightness exceeds the second threshold. The direct light presence / absence judging device according to claim 3, further comprising third judging means for judging that there is no direct light when not exceeding.   5. The presence / absence of direct light according to claim 2, wherein the first determination unit compares the brightness of the sun position with the brightness on a solar locus after the sun position. 6. Judgment device.   5. The direct irradiation according to claim 2, wherein the first determination unit compares the brightness of the sun position with the brightness on a line segment connecting the sun position and the zenith. 6. Light presence / absence judgment device.   The first determination means compares an average luminance of a circular luminance distribution image centered on the sun position with an average luminance on a circle centered on the sun position. The direct light presence / absence determination device according to any one of 4.   The determining means determines that there is direct light when detecting a luminance exceeding a third threshold from the luminance distribution, and determines that there is no direct light when detecting no luminance exceeding the third threshold. The direct light presence / absence judgment device according to claim 1, further comprising four judgment means.   The direct light presence / absence judging device according to claim 8, wherein the fourth judging means lowers the third threshold value when the solar altitude at the sun position is low.   The determination means includes fifth determination means for determining that there is direct light when the position of the sun matches the position where the luminance reaches a peak in the luminance distribution, and for determining that there is no direct light when the positions do not match. The direct light presence / absence judgment device according to claim 1. The determination means includes
Calculate the total number of rises in luminance on the solar trajectory after the sun position, and determine that there is direct light when the total number of rises exceeds the fourth threshold, and the total number of rises is the fourth threshold. The direct light presence / absence judging device according to claim 3, further comprising sixth judgment means for judging that there is no direct light when the value is not exceeded. The determination means includes
Calculate the total increase in luminance and the total number of increases on the solar trajectory after the sun position, determine that there is direct light when the total increase luminance exceeds a second threshold, and the total increase luminance is The seventh determination means for determining that there is no direct light when the second threshold value is not exceeded and the total number of rises does not exceed the fourth threshold value. Direct light presence / absence judgment device.   Receiving the determination signal output from the direct light presence / absence determination device according to any one of claims 1 to 9, rotating the slat to an angle that blocks direct light based on the determination signal that there is direct light, A control device for an electric blind, comprising a controller for rotating a slat to an angle at which outside light is taken in based on a determination signal that there is no direct light. A first determination means for determining the presence of current direct light;
When the first determining means determines that there is no current direct light, it comprises third determining means for determining that the sky is semi-sunny when the luminance fluctuations other than the sun position are large. apparatus. The first determination means includes
Imaging means for capturing a sky image of the whole sky at regular intervals;
A luminance distribution calculating means for calculating a luminance distribution of the sky image;
Solar position calculating means for calculating the solar position on the luminance distribution;
Determining the presence or absence of current direct light based on the luminance distribution,
The third determination means includes
Calculate the total rising brightness on the solar trajectory after the sun position, determine that the total rising brightness exceeds a second threshold value, and that the total rising brightness exceeds the second threshold value. The direct light presence / absence judgment device according to claim 14, further comprising: determining that there is no direct light when not exceeding. Take a sky image of the whole sky at regular intervals,
Calculating the luminance distribution of the sky image;
Calculate the sun position and sun trajectory on the luminance distribution,
A method for determining the presence / absence of direct light based on the luminance distribution.   The direct light presence / absence determination method according to claim 16, wherein the presence / absence of the direct light is determined based on a difference between the brightness at the sun position and the brightness at a position other than the sun position.   When the difference between the brightness of the sun position and the brightness other than the sun position is continuously below the first threshold in the brightness distribution based on a plurality of sky images, it is determined that there is no direct light, and a plurality of sky images The direct light presence / absence determination method according to claim 17, wherein it is determined that there is direct light when the luminance distribution based on is not continuously below the threshold value.   Calculate the total rising brightness on the solar trajectory after the sun position, and determine that there is direct light when the total rising brightness exceeds the second threshold, and the total rising brightness exceeds the second threshold 19. The method according to claim 18, wherein when there is no direct light, it is determined that there is no direct light.   When it is determined that there is direct light based on the first determination means for determining the presence or absence of the current direct light, the slat is rotated to an angle that blocks the direct light, and the first determination means determines that there is no current direct light. When this is done, when the third determining means determines that the brightness fluctuations other than the sun position are large, the slat is rotated to an angle that blocks direct light.   21. The electric blind according to claim 20, wherein when the third determination means determines that the luminance fluctuation on the solar locus after the sun position is large, the slat is rotated to an angle that blocks direct light. Control method.

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