JPS6323482B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar direction sensor for detecting the direction of the sun, and in particular, to a solar direction sensor for detecting the direction of the sun, and particularly to a solar direction sensor for detecting the direction of the sun. The present invention relates to a sunlight direction sensor suitable for accurate tracking.

Recently, we have entered an era of energy conservation, and research and development is being conducted in various fields on the effective use of solar energy. It is important to collect solar energy, and for this purpose, it is necessary to make the solar energy collection device follow the movement of the sun and always collect solar energy in the most efficient state.

The present invention has been made in view of the above-mentioned demands, and particularly relates to a sunlight direction sensor suitable for being mounted on a solar energy collecting device and causing the solar energy collecting device to automatically track the movement of the sun. .

FIG. 1 is an overall perspective view of a sunlight direction sensor according to the present invention, and FIG. 2 is a cross-sectional view taken along the - line in FIG. 1.
3 is a plan view, and FIG. 4 is a sectional view taken along the line -2 in FIG. 2, in which 1 is a square or round cylinder, 2 is a flange provided at the upper end of the cylinder _X1 to _X4 and Xc are optical sensors, and a polygonal or circular window 3 is provided in the center of the flange 2. The optical sensors X ₁ to _{X 4} are arranged such that X ₁ and X ₂ and X ₃ and X ₄ form pairs and face each other as shown in FIG. The optical sensor
It is located approximately in the center of the top surface. Therefore, cylinder body 1
When A is facing the correct direction of the sun, in other words, when sunlight is coming from direction A, the light sensor
Direct sunlight D does not enter into _X1 to _X4 , but only indirect sunlight I enters, and direct sunlight D and indirect sunlight I enter into the optical sensor Xc. However, if the cylindrical body I is shifted from the direction of the sun and, for example, the sunlight comes from the direction B, then the optical sensor
X ₁ receives direct sunlight D at a portion α, receives indirect sunlight I throughout, and optical sensor X ₂ receives only indirect sunlight I. To explain in more detail, when the cylinder 1 is exactly aligned with the direction of the sun, the sunlight received by the optical sensors X ₁ and X ₂ (or X ₃ and X ₄ ) is equal, and the cylinder 1 is If the sunlight is shifted from the direction _of , the sunlight incident on the optical sensors X ₁ and X _{2 (} or
If the sunlight entering X ₁ and X ₂ is controlled to be equal, in other words, if the cylinder 1 is controlled to face in the direction A, the cylinder 1 will point exactly in the direction of the sun, and therefore , the sunlight collecting device equipped with the sunlight direction sensor will also accurately face the direction of the sun. However, in the sunlight direction sensor as described above, the distribution of indirect sunlight I inside the cylinder 1 is large in the center and small in the outer periphery, as shown in FIG. 5, so this difference must be corrected. , the position where the direct sunlight crosses the optical sensor, that is, the above α cannot be determined accurately.

In order to solve these drawbacks, the applicant first calculated the deviation between the direction of the sunlight direction sensor and the position of the sun by taking into account the distribution of indirect sunlight inside the cylinder as described above. We proposed a sunlight direction sensor that could accurately detect sunlight (Japanese Patent Application No. 1983-99993).

In the sunlight sensor shown in FIGS. 1 to 4, it is assumed that an optical sensor X ₀ is disposed on the upper surface of the flange 2, and the total amount of sunlight incident on this optical sensor X ₀ is S ₀ , Direct sunlight amount D ₀ , optical sensor
The electrical output signal of X ₀ is L ₀ , the photoelectric conversion coefficient of the optical sensor is δ ₀ (=S ₀ /L ₀ ), and the direct feed rate is β ₀ (D ₀ /S ₀ )
Then, S ₀ = δ ₀ L ₀ ...(1) D ₀ =β ₀ S ₀ =β ₀ δ ₀ L ₀ ...(2) holds true.

Similarly, for optical sensor Xc, Sc=δcLc...(3) Dc＝βcSc＝βcδcLc……(4) holds true.

In addition, regarding the optical sensor _{X 1} , the optical sensor
When direct sunlight hits the entire surface of the area, ₁ = _{1 1} ...(5) ₁ = _{1 1} = _{1 1 1} ...(6) holds true.

At this time, direct sunlight is not hitting the optical sensor X ₂ , so for the optical sensor X ₂ , S ₂ = δ ₂ L ₂ = I ₂ ...(7) D ₂ = 0 ... 8) holds true (where I ₂ is the amount of indirect sunlight incident on the optical sensor X ₂ ).

Here, if sunlight is currently shining on a part of _the optical _sensor
As shown in FIG. 2, when the ratio of the position that crosses the optical sensor _{X 1 to} the total length of the optical sensor , the total amount of sunlight entering the optical sensor X ₁ is S ₁ ,
If the electrical output signal at that time is L ₁ (mV) and the photoelectric conversion coefficient is δ ₁ , then S ₁ =δ ₁ L ₁ holds true. here,
Direct sunlight is incident only on the α _portion of _the optical sensor X ₁ , and indirect _sunlight is incident on _the entire surface _of the optical sensor _, I ₁ is the amount of indirect sunlight incident on _the optical sensor X ₁ , which is the amount of indirect sunlight incident on _the optical sensor
S ₂ ) is established, and by substituting equations (4) and (7) into equation (9), S ₁ =αβcδcLc+δ ₂ L ₂ ...(10) is obtained. Therefore, since S ₁ = δ ₁ L ₁ , the (10)
The formula is δ ₁ L ₁ =αβcδcLc+δ ₂ L ₂ (11).

On the other hand, Dc=Sc−Ic...(12), where _I2 (or _I1 )/Ic=λ...(13) (however, _I2 ≒ _I1 ), then (12) ) formula becomes Dc=ScI ₂ /λ ...(14), and from this, δcβcLc=δcLc−δ ₂ L ₂ /λ ...(15) is obtained.

Substituting this equation (15) into equation (11), δ ₁ L ₁ = α (δcLc−δ ₂ L ₂ /λ) + δ ₂ L ₂ ... (16) From this, α = δ ₁ L ₁ −δ ₂ L ₂ /δcLc−δ ₂ L ₂ /2 (17) can be obtained.

Here, once the shape and size of the cylindrical body 1 are determined, the relative distribution _of indirect sunlight that has entered the cylindrical body is constant.
If =I ₂ /Ic is determined in advance, λ becomes a constant. Since δ ₁ , δ ₂ , and δc are constants, if λ=I ₂ /Ic is calculated in advance as described above, α, that is, the solar The deviation between the light incident direction and the sunlight direction sensor can be quantitatively and accurately determined.

However, according to the sunlight direction sensor previously proposed by the applicant, when the sun is momentarily blocked by clouds etc., the sunlight is momentarily scattered.
The scattered light enters the optical sensors X ₁ to _{X 4} inside the cylinder unevenly in light quantity or with a time difference, and the sunlight collecting device sensitively follows this instantaneous imbalance, causing hunting. There were disadvantages such as causing

6 and 7 are diagrams showing an example of a sunlight direction sensor previously proposed by the applicant in order to solve the above-mentioned drawbacks. As shown in the figure, a perpendicular line drawn from the edge of the window 3 The optical sensors X ₁ -X ₄ are arranged such that the optical sensors X 1 -X 4 are located in the middle part (in the prior art shown in FIGS. 1 to 4, the ends) of the optical sensors X ₁ -X ₄ . That is, in the prior art, a virtual perpendicular line drawn from the edge of the window 3 of the flange 2 and an optical sensor
We tried to match the inner edges of X ₁ to _{X 4} , but it was very difficult to make the ends of the optical sensors X ₁ to _{X 4} exactly match the virtual perpendicular line drawn from the edge of window 3. In addition, it is very difficult to finish the ends of the optical sensors X ₁ to _{X 4} accurately in a straight line, and furthermore, since the ends of each optical sensor are on the boundary line that determines whether or not there is direct light, The starting point of the detector was very unstable, but with this arrangement, the virtual perpendicular line drawn from the edge of the window 3 is located at an arbitrary intermediate position between the optical sensors _X1 to _X4 . Therefore, there is no unstable material as in the prior art,
It is only necessary to accurately finish the width l of each sensor _X1 to _X4 , and therefore, the direction of sunlight can be determined accurately and without unstable operation such as hunting with a very simple configuration. can be detected. However, as shown in FIG. 6, the 0 position of α is the position where the virtual perpendicular line drawn from the edge of the window 3 hits. In addition, in this example, since the boundary line that determines the presence or absence of direct light is located at an intermediate position between the optical sensors _X1 to _X4 , the detection output of the optical sensor changes with respect to the movement of the boundary line. The linearity is improved, and since the detection output of the portion that is hit by the direct light is biased in advance, even if a disturbance occurs momentarily, it will not have a large effect. That is, there were advantages such as improved N/S and linearity, and much easier control.

However, in the sunlight direction sensor previously proposed by the applicant, sunlight is blocked by clouds or the like for a long time, and during that time the sun moves, and the incident angle of sunlight L ₁ changes to θ. If the deviation exceeds ₁ , sunlight will not hit any of the optical sensors X ₁ to _{X 4} ,
The sunlight direction sensor is no longer able to detect the direction of the sun, and therefore, once the angle of incidence of sunlight deviates beyond θ ₁ , it has the disadvantage that it loses its tracking function at all. Ta. In particular, if the light sensor X _{3 and} A large amount of scattered light enters the optical sensor located on the south side (generally the optical sensor on the south side), making it difficult to maintain balance in the north-south direction.

The present invention has been made to solve the drawbacks of the prior art as described above, and as shown in FIG. Elongated holes 11 and 21 are provided in the upper wall of each housing and extend in directions facing each other, and elongated holes 11 and 21 are provided in the upper wall of each housing, and elongated holes 11 and 21 are provided in the inner wall surface where the axes of the elongated holes are perpendicular to each other, and elongated holes 11 and 21 are provided in the upper wall of each casing. light sensor
It has X ₅ and X ₆ .

FIG. 9 is a sectional view taken along the line - in FIG. 8, and FIG. ₁₀ is _a sectional view taken along the line - in FIG. Even if the sun deviates by more than θ ₁ , the direction of the sun can be detected by optical sensor X ₅ or X ₆ within the range of θ ₂ - θ ₁ . The amount of incident light is small, and both optical sensors
Since scattered light is incident on X ₅ and X ₆ approximately equally, the sunlight tracking function is lost even if sunlight is blocked by clouds for a considerably longer period of time than in the prior art. As soon as the clouds clear and sunlight enters, the system starts solar tracking. Although FIG. 8 shows an example in which the casings 10 and 20 are attached to the east and west sides of the cylindrical body 1, as long as the positional relationship between the elongated hole and the optical sensor is as shown in FIG. It is easy to understand that it is not limited to the position and may be attached to any arbitrary position without necessarily being attached to the cylinder. If it is desired to further increase θ ₂ , holes 12, which are continuous with the elongated holes 11 and 21, and
22 may be provided. Further, although an example in which a pair of casings is used has been described above, it is not always necessary to use a pair of casings, and for example, as shown in FIG. 11, a single casing may be used. 30 is used, and elongated holes 11 and 21 are provided in the upper wall of the single housing 30 to extend in mutually opposing directions, and the axes of the elongated holes are arranged on the inner wall surface where the axes of the elongated holes are perpendicular to each other. The optical sensors X ₅ and X ₆ may be provided extending in the orthogonal horizontal direction, and in this case, the housing 30
As shown by a dotted line 31 in FIG. 12, a partition wall 31 may be provided to separate the elongated holes 11 and 21. In this way, the scattered light incident from the elongated hole 11 can be directed to the optical sensor. Scattered light incident on X ₆ and from the elongated hole 21 does not affect the optical sensor X ₅ .

As is clear from the above description, according to the present invention, it is possible to track sunlight over a wide range, and therefore, even after a long period of cloudy weather, sunlight can be immediately tracked in the direction of the sun. A direction sensor can be provided.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of the sunlight direction sensor previously proposed by the applicant, and FIG. 2 is the −-
3 is a plan view, FIG. 4 is a sectional view taken along the - line in FIG. 2, and FIG. 5 is a sectional view of the cylinder 1.
FIG. 6 is a side sectional view showing another example of the sunlight direction sensor previously proposed by the applicant, and FIG. 7 is a plan view of FIG. 6, and FIG. FIG. 8 is a schematic overall configuration diagram for explaining one embodiment of the sunlight direction sensor according to the present invention, and FIG.
8, FIG. 10 is a cross-sectional view taken along the line -- in FIG. 8, and FIGS. 11 and 12 are plan views for explaining other embodiments of the present invention. 1... Cylindrical body, 2... First flange, 3...
Window, 4...Bottom plate, 5...Window, 6...Second flange, _X1 to _X6 and Xc...Light sensor, 10, 20,
30... Housing, 11, 12, 21, 22... Long hole, 31... Partition wall.

Claims (1)

[Scope of Claims] 1. A cylindrical body, an opaque flange provided at the upper end of the cylindrical body and having a polygonal window smaller than the inner diameter of the cylindrical body; a first optical sensor provided at the center of the cylindrical body;
at least one pair of second and third optical sensors provided at the lower end of the cylindrical body and symmetrically disposed at positions where the inner end surface or intermediate position thereof intersects with an imaginary perpendicular line drawn from the edge of the window of the flange; The sunlight direction sensor further includes a casing, and the casing has two elongated holes extending in mutually opposing directions in the upper wall thereof, and the axis of each of the elongated holes is A sunlight direction sensor comprising an optical sensor extending in a horizontal direction perpendicular to the axis of the elongated hole on an orthogonal inner wall surface. 2. The sunlight direction sensor according to claim 1, further comprising a partition wall for separating the two elongated holes within the housing. 3. A cylindrical body, an opaque flange provided at the upper end of the cylindrical body and having a polygonal window smaller than the inner diameter of the cylindrical body, and a center portion of the cylindrical body at the lower end of the cylindrical body. a first optical sensor provided in;
at least one pair of second and third optical sensors provided at the lower end of the cylindrical body and symmetrically disposed at positions where the inner end surface or intermediate position thereof intersects with an imaginary perpendicular line drawn from the edge of the window of the flange; The sunlight direction sensor further includes a pair of housings, each housing having a long hole in its upper wall,
an optical sensor extending in a horizontal direction perpendicular to the axis of the elongated hole on an inner wall surface perpendicular to the axis of the elongated hole;
A sunlight direction sensor characterized in that a pair of housings is arranged so that the elongated holes are parallel to each other.