JPH0648187B2 - Sun tracking sensor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sun tracking sensor, for example, a sun tracking sensor used in a sunlight collecting device or the like.

(Prior Art) In general, a solar tracking device, for example, an underground facility such as an underground mall or a basement, or a place where sunlight is not directly exposed to light, such as the inside of a house in a densely populated area, is designed to guide the sunlight. In the sunlight collecting device, attitude control is performed according to the movement of the sun. That is, in the above-mentioned sunlight collecting device, the light collecting efficiency is improved.

As such a sunlight collecting device, for example, one shown in FIG. 10 is known. In FIG. 10, 1 is a condenser lens for converging the sunlight toward one point, and the converged sunlight is made into parallel rays by the control lens 2, and the parallel rays are directed by the reflecting mirror 3 to the light guide direction. It is reflected toward. The condenser lens 1 and the control lens 2 rotate the driven gear 5 attached to the rotating member 4 by the first electric motor 6 to rotate in the azimuth direction, and reciprocate the scanning load 7 by the second electric motor 8. It is moved and rotated in the elevation direction.

By the way, in order to improve the lighting efficiency of this sunlight collecting device, it is necessary for the condenser lens 1 and the control lens 2 to have their optical axis lines parallel to the sunlight. for that purpose,
The movement of the sun is tracked by a sun tracking sensor 9 mounted in the vicinity of the condenser lens 1, and based on a signal from the sun tracking sensor 9, the control unit 15 first
Controlling the drive of the electric motor 6 and the second electric motor 8;
The condenser lens 1 and the control lens 2 are rotated in the azimuth direction and the elevation angle direction.

As shown in FIGS. 11 and 12, the sun tracking sensor 9 is attached to the main body 10 having a substantially cylindrical shape, a base 11 provided at the base end of the main body 10, and the tip of the main body 10. It is composed of a rough adjustment photoelectric element 12 and a fine adjustment photoelectric element 13 attached to the side surface of the main body of the base 11. The rough-adjustment photoelectric element 12 comprises a main photoelectric element 12a attached to the center of the tip of the main body 10 and four sub-photoelements 12b attached to the inclined surface 14 formed at the tip. A difference in the amount of received light is caused by a change in the light receiving angle between the main photoelectric element 12a and the sub photoelectric element 12b, and this difference in the amount of received light is used as a signal for detecting the rough inclination direction of the main body 10 with respect to the sunlight S. Moreover, four photoelectric elements 13 for fine adjustment are attached to the base 11 so as to contact the side wall of the main body 10. A difference in the amount of received light is generated between the photoelectric elements 13 due to the shadow of the main body 10 due to the sunlight, and this difference in the amount of received light is used as a signal for detecting the accurate tilt direction of the main body 10 with respect to the sunlight.

(Problems to be Solved by the Invention) However, in such a non-adjustment photoelectric element 13 of the conventional sun tracking sensor 9, since the main body 10 has a columnar shape, the main body 10 is exposed to sunlight. The shadow edge of was unclear. Further, since the side surface of the main body 10 has a uniform outer diameter over the entire length, the sunlight is diffusely reflected by this side surface, and the edge of the shadow of the main body 10 due to the sunlight is unclear. For this reason, when the shadow edge of the main body 10 is located on the photoelectric element 13, the photoelectric element 13 moves with a small amount of light, that is, 3.0 mA to 4.5 mA, which may cause a malfunction. . Therefore, the sun tracking sensor 9 cannot accurately track the sun.

(Means for Solving Problems) In order to solve such problems, according to the present invention, a rectangular columnar shape having a taper so that the cross-sectional area increases from the distal end to the proximal end is formed. A main body, a rectangular piece-shaped guide member provided at the tip of the main body, a first guide groove formed at least in a pair on the side wall surface of the guide member, and the first guide groove.
A second guide groove is formed on a side wall surface of the base end of the main body so as to face the guide groove, and at least a pair of light receiving elements provided so that approximately half of the second guide groove is fitted into the second guide groove. The light receiving amount of the light receiving elements is compared by utilizing the shadow of the main body caused by sunlight, and the sun can be tracked.

(Operation) Due to the shadow of the main body caused by sunlight, a difference occurs in the amount of light received by the light receiving element of the fine adjustment sensor. At this time, the shaded edge of the square columnar body of the fine adjustment sensor is clearer than that of the columnar body. Further, since the side wall surface of the main body is formed with a taper, sunlight is prevented from being diffusely reflected by the taper, and therefore the shaded edge of the main body becomes clear. Therefore, the shaded edges of the main body due to sunlight are clear and clear, and there is no risk of malfunction of the light receiving element that moves with a small amount of light received. Further, since the sunlight incident on the light receiving element is guided to the first guide groove of the guide member and enters the light receiving element, this light receiving element can accurately receive parallel rays of sunlight.

(Example) Hereinafter, the present invention will be described with reference to the drawings. 1 to 9 are views showing an embodiment of a sun tracking sensor according to the present invention, and FIGS. 1 to 3 therein show a solar lighting device using the sun tracking sensor. It is a figure.

First, the configuration of the sunlight collecting device will be described. In FIG. 1 to FIG. 3, reference numeral 21 is an acridome which is composed of a regular hexahedron frame, and this acridome 21 is installed on the roof of a building through a support member 22. Acrydome 21
A rotary shaft 23 is mounted between the upper and lower frames 21a and 21b of the rotary gear 23, and the rotary gear 2 is provided above the rotary shaft 23.
4 and a slip ring 25 for preventing disconnection due to twisting of the electric wire. Also, the rotating shaft 23
Is rotated by the first step motor 20 via the rotation gear 24. A coarse adjustment sensor 26 is provided at the upper end of the slip ring 25. As shown in FIG. 4, the coarse adjustment sensor 26 includes a plate member 27 and the plate member 27.
And a pair of light receiving elements W and E (for example, photodiodes) attached to both side surfaces of the. The light receiving elements W and E have a light receiving angle of 120 degrees, and are mounted so that the center line of the light receiving angle is orthogonal to the center line of the plate member 27.

A central shaft 28 orthogonal to this axis is rotatably attached to the rotary shaft 23. On the left half and the right half of the central axis 28, a reflecting mirror 2 in which one long side of a substantially rectangular shape has an arc shape
A pair of 9 and 30 is rotatably attached. Further, two substantially L-shaped holding members 31 and 32 are rotatably attached to the central portion of the central shaft 28 so as to sandwich the rotating shaft 23. As shown in FIG. 1, fine adjustment sensors 33 and 34 are attached to the front end surfaces of the holding members 31 and 32 in a stepped manner.

As shown in FIG. 5 and FIG. 6, the fine adjustment sensors 33 and 34 have a rectangular columnar main body 35 which is tapered so that the cross-sectional area increases from the distal end to the proximal end, and the main body 35. The guide member is a square piece 36 provided at the tip and a base 37 provided at the base end of the guide member. A first guide groove 38 having a substantially arcuate cross section is formed in each of the four side walls of the guide member 36 in the axial direction, and each of the four side walls on the base end side of the main body 35 is opposed to the first guide groove 38. Is a second guide groove 3 having a substantially arcuate cross section.
9 is formed in the axial direction. Four second guide grooves 39
A light receiving element (for example, a photodiode) having a light receiving angle of 90 ° is half-fitted on each of the base ends of the and is attached to the main body 35. Four light receiving elements w, e, u
, D are a pair of the light receiving elements w, e and the light receiving elements u, d facing each other, and the shadow of the main body 35 caused by sunlight causes a difference in the amount of light received by the pair of light receiving elements w, e or u, d. Then, the difference in the amount of received light is used as a signal for detecting the accurate inclination direction of the main body 35 with respect to the sunlight.

Light receiving elements W and E of the coarse adjustment sensor 26 and the fine adjustment sensor 3
As shown in FIG. 7, the relationship between the light receiving angles of the light receiving elements w, e, u, d of the light receiving elements W, E, u, d of the light receiving elements W, E, u is as shown in FIG. , D is located at a 90 ° acceptance angle.

The portion from the central axis 28 of the holding member 31 to the base end side corresponds to the first link 41 as shown in FIGS. 2 and 8, and the base end portion of the first link 41 and With respect to the portion located at the same distance as the first link 41 from the central axis 28 of the moving shaft 23, one ends of the second link 42 and the third link 43 having the same length are rotatably connected, Further, the other end of each of the reflecting mirrors 29, 3 via the slider 44.
0 is slidably connected. The slider 44 has a bearing slidably fitted in a sliding groove 45 formed at the side end of the reflecting mirror 30. A second step motor 46 is attached to the rotating shaft 23 via a support member 47,
The step motor 46 is connected to a screw shaft 48 via a universal joint (not shown).
It is attached to the first link 41 via 9. In order to rotate the fine adjustment sensor 33 by a predetermined angle, the second step motor 46 is driven to move the first link 41 by a predetermined angle θ.
When it is swung only, the second link 42 and the third link 43 are simultaneously expanded or contracted to swing the reflecting mirrors 29 and 30 by an angle (1/2) × θ which is half the predetermined angle.

Here, the first step motor 20 rotates the reflecting mirrors 29 and 30 in the azimuth direction, and the second step motor 46 swings the reflecting mirrors 29 and 30 in the elevation direction via the link mechanism. It is a thing. The first step motor 20 and the second step motor 46 are the coarse adjustment sensor 4
6 is driven by the control unit 50 based on the signals output from the control unit 6 and the fine adjustment sensors 33 and 34, if necessary.

The operation of the sun tracking sensor according to the present invention will be described based on the flowchart shown in FIG. Note that P _{1 to} P ₁₄ in the figure
Shows each step of the flowchart.

First, when the power of the sun lighting device is turned on, step P
_{In step 1} , the sunlight on the sunrise is received by the coarse adjustment sensor 26, and the control unit 50 determines whether or not the received light amount is equal to or more than a predetermined received light amount capable of tracking the sun.

When the received light amount of sunlight is equal to or larger than the predetermined received light amount, a difference occurs in the received light amount of the light receiving elements W and E of the rough adjustment sensor 26 due to the shadow of the plate member 27 caused by the sunlight. In step P ₂ , the control unit 50 compares and calculates the difference in the amount of light received by the light receiving elements W and E, and the result of this comparison calculation is output to the first step motor 20 as a drive signal.

In Step P _3, when the first step motor 20 inputs the drive signal, on the basis of this drive signal is rotated toward the pivot shaft 23 the rough adjustment sensor 26 is attached to the sun in azimuth direction. At this time, the reflecting mirrors 29 and 30 are rotated toward the sun in the azimuth direction.

When the coarse adjustment sensor 26 roughly faces the sun, the sun is positioned within the light receiving angles of the light receiving elements w 1, e 2, u 3, and d 4 of the fine adjustment sensors 33 and 34. Therefore, the fine adjustment sensors 33, 3
4 becomes able to receive the sunlight, and in step P ₄ , the control unit 50 determines whether or not the amount of the received light is equal to or more than a predetermined amount of the received light capable of tracking the sun.

When the amount of received sunlight is equal to or more than the predetermined amount of received light, the amount of received light of the light receiving elements w 1 and e 2 of the fine adjustment sensors 33 and 34 is different due to the shadow of the main body 35 caused by the sunlight.
At this time, the rectangular columnar main body 3 of the fine adjustment sensors 33 and 34
The shadow edge of 5 is clearer than that of a cylinder. Further, since the side wall surface of the main body 35 is formed with a taper, it is possible to prevent the sunlight from being diffusely reflected by the taper, and therefore the shaded edge of the main body 35 becomes clear. Therefore, the shaded edges of the main body 35 due to sunlight become clear and clear, and there is no risk of malfunction of the light-receiving elements w and e that move with a slight amount of light received of 3.0 mA to 4.5 mA. Further, the sunlight incident on the light receiving elements w 1, e 2, u 2, and d 3 is guided to the first guide groove 38 of the guide member 36 and enters the light receiving elements w 1, e 2, u 3, and d 5, so that the light receiving elements w, e
, U, d can accurately receive parallel rays of sunlight. Furthermore, since the first guide groove 38 formed in the guide member 36 has a substantially arcuate cross-section, the guide groove 3 is different from the case where the guide groove is a guide hole formed in the guide member.
Even if the sunlight entering 8 is radiated obliquely, the light receiving element
It is possible to receive light without blocking one of w and e. In addition, the light receiving elements w 1, e 2, u 2, and d 3 are arranged in the second guide groove 39.
Since it is half exposed, the sunlight incident from the side of the main body 35 can be sufficiently received.

In step P ₅ , the control unit 50 compares and calculates the difference in the amount of light received by the light receiving elements w 1 and e 2, and the result of this comparison calculation is output to the first step motor 20 as a drive signal.

In step P ₆ , the first step motor 20 is driven based on this drive signal, the rotary shaft 23 is rotated by the first step motor 20, and the fine adjustment sensors 33, 34 are held via the holding members 31, 32. To rotate properly in the azimuth direction toward the sun. At this time, the reflector 2
9 and 30 are properly rotated toward the sun in the azimuth direction.

Whether or not the fine adjustment sensors 33, 34 are correctly oriented toward the sun in the azimuth direction is checked in Step P ₇ for the light receiving element w 1,
Comparing the difference in the amount of received light of e.

If there is no difference in the amount of light received by the light receiving elements w 1 and e 2, the fine adjustment sensors 33 and 34 are correctly oriented toward the sun,
Control unit 50 in step P ₈ stops the driving of the first stepping motor 20 and outputs a signal.

When the drive of the first stepping motor 20 is stopped, the light receiving element u fine adjustment sensor 33 in step P _9, the result of the comparison operation by the control unit 50 the difference between the amount of light received d, and the comparison operation first It is output as a drive signal to the two-step motor 46.

In step P ₁₀ , the second step motor 46 is driven based on this drive signal, and the fine adjustment sensors 33 and 34 attached to the holding members 31 and 32 are appropriately rotated toward the sun in the elevation angle direction. At this time, the fine adjustment sensor 3
When the mirrors 3, 34 are turned toward the sun by the angle θ, the reflecting mirrors 29, 30 are always rotated by the angle (1 /
2) Rotated by × θ. Therefore, the reflecting mirrors 29, 3
The sunlight reflected at 0 is always focused at a fixed position.

Whether or not the fine adjustment sensors 33 and 34 are correctly oriented toward the sun in the elevation direction is determined in Step P ₁₁ by the light receiving element u,
Comparing the difference in the amount of received light of d. If there is no difference in the amount of light received by the light receiving elements u and d, the fine adjustment sensors 33 and 34 are correctly oriented to the sun.

Here, it is necessary to control the fine adjustment sensors 33 and 34 in order to track the sun according to the movement of the sun for a predetermined time (for example,
Every 60 seconds). Therefore, step P ₁₂
Then, the timer provided in the control unit 50 determines whether a predetermined time has elapsed.

Further, since it is not necessary to control the fine adjustment sensors 33 and 34 after the sunset of the sun, it is necessary to stop them. Therefore, the control unit 50 receiving element w, e, u, or the amount of light received d is equal to or larger than the predetermined amount of received light in step P ₁₃
Judge by When the amount of light received by the light receiving elements w 1, e 2, u 3, and d 4 is equal to or greater than the predetermined amount of light received, the process returns to step P ₅ and the fine adjustment sensors 33, 34 are controlled again to track the sun according to the movement of the sun.

When the amount of light received by the light receiving elements w 1, e 2, u 3, and d 4 is equal to or less than the predetermined amount of received light, the second step motor 46 is stopped in step P ₁₄ because it is after sunset.

(Effects of the Invention) As described above, according to the present invention, the main body is formed into a square column shape with a taper, and the guide member having the first guide groove formed at the tip of the main body is formed in the main body. Since the light receiving element is provided in the second guide groove, the edge of the shadow of the main body due to sunlight becomes clear and clear, and the sunlight is guided by the first guide groove and accurately received by the light receiving element.
Therefore, the light receiving element does not malfunction. Therefore, the sun tracking sensor according to the present invention can accurately track the sun.

[Brief description of drawings]

1 to 9 are views showing an embodiment of the sun tracking sensor according to the present invention. FIG. 1 is a perspective view of a sunlight collecting device using this embodiment, and FIG. A front view of the sunlight collecting device, FIG. 3 is a sectional view taken along line III-III in FIG. 2, FIG. 4 (a) is a front view of the coarse adjustment sensor, and FIG. 4 (b) is a side view of the coarse adjustment sensor. Fig. 5 (a) is a front view of the fine adjustment sensor, Fig. 5 (b) is a side view of the fine adjustment sensor, Fig. 6 is a perspective view of the fine adjustment sensor, and Fig. 7 is a coarse adjustment sensor and a fine adjustment sensor. FIG. 8 is a view showing a light receiving angle of a light receiving element of the adjustment sensor, FIG. 8 is a perspective view showing a link mechanism of the sunlight collecting device, and FIG. 9 is a flowchart showing an operation of the sunlight collecting device. FIG. 10 is a perspective view showing a sunlight collecting device using a conventional sun tracking sensor, FIG. 11 is a side view of the conventional sun tracking sensor, and FIG. 12 is a plan view of the sun tracking sensor. 35 ... Main body, 36 ... Guide member 38 ... First guide groove, 39 ... Second guide groove w, e, u, d ... Photodetector

Claims (1)

[Claims] 1. A quadrangular prism-shaped main body provided with a taper so that its cross-sectional area increases from the tip to the base end, a quadrilateral piece-shaped guide member provided at the tip of the main body, and a guide member of this guide member. At least one pair of first guide grooves formed on the side wall surface, a second guide groove formed on the side wall surface of the base end portion of the main body facing the first guide groove, and the second guide groove At least one pair of light receiving elements provided so that half of them are fitted,
A sun tracking sensor, characterized in that it is possible to track the sun by comparing the amount of light received by the light receiving elements using the shadow of the main body caused by sunlight.