JPH06229754A - Sensor and method for tracing solar beam - Google Patents

Abstract

PURPOSE:To allow highly accurate tracing of solar beam while suppressing shift of optical axis by providing a light receiving sensor for correction which receives only scattered solar beam thereby eliminating the effect of scattered light from the light arriving directly. CONSTITUTION:When a light from the sun arrives directly in L0 direction, a main optical sensor MM1 receives the light arriving directly from L0 direction and a scattered light from the direction of incident angle A deg. (between L2-L4). On the contrary, a light receiving sensor SS1 for correction receives scattered light only from the direction of incident angle B deg. (between L1-L3)Since the scattered lights from the directions of incident angles A deg. and B deg. have substantially same intensity, a signal obtained by subtracting the output signal of the sensor SS1 from the output signal of the sensor MM1 is substantially equal to the output signal only of the directly arriving solar beam incident from the L0 direction. Four sets of light receiving sensors, each comprising sensors of same type as the sensors MM1, SS1, are disposed on a circle at an interval of 90 deg. and a solar beam collecting section is driven with output signals only of the directly arriving solar beam obtained through the four sets of sensors thus tracing the solar beam highly accurately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar tracking sensor and a solar tracking method for detecting and tracking the position of the sun, and more particularly to a solar tracking sensor and a solar provided in a solar concentrator. The present invention relates to a light condensing device.

[0002]

2. Description of the Related Art In the past, direct light from a window or a skylight was generally used as a method of collecting sunlight and taking it into a room. However, with the recent increase in the density of houses, an indoor space has emerged that prevents direct sunlight from entering even during the day. Therefore, a lot of sunlight concentrators including a condensing component for concentrating sunlight and a transport path for transferring the concentrator have been proposed recently. In order to collect sunlight more efficiently, it is necessary to accurately track the sunlight by the sunlight concentrator according to the movement of the sun. Therefore, in the sunlight concentrator, for example, as a sunlight tracking sensor for detecting the direction of the sun, JP-A-57-67814 and JP-A-59-18414 are used.
An optical sensor was provided as shown in No. These photosensors receive both the direct light from the sun and the scattered light scattered by the atmosphere or clouds, and electrically process the photosensor signal to track the sun. However, if the scattered light is not symmetrical with respect to the sun, that is, if the altitude of the sun is low, or if the cloud is not symmetrical with respect to the sun, there will be a deviation between the direction of the sun and the direction of the sun tracking sensor. It had a problem that it would occur.

[0003]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems of the prior art, and newly provides a solar tracking sensor and a solar tracking method which have not been known so far. It is intended to be provided.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and includes a sunlight concentrating section, a conveying section,
In a sunlight concentrating device including a drive unit, a sunlight tracking sensor, a circuit unit, and the like, the sunlight tracking sensor outputs a signal of a direct light component of the sun and an aggregate of scattered light components, and a main light sensor of the sun. A sunlight tracking sensor provided with a correction optical sensor that outputs only a signal of a scattered light component.

Further, according to the present invention, only the signal of the direct light component of the sun is taken out from the output signal of the main light sensor and the correction light sensor, and the drive unit is operated by the signal of the direct light component to collect the sunlight. Provided is a solar light tracking sensor characterized in that a light unit tracks the sun.

The present invention also provides an opaque tubular body, a donut-shaped opaque lid provided on the upper end of the tubular body, and
A main optical sensor arranged so that a line drawn vertically from the inner peripheral portion of the donut to the lid falls on the light receiving surface of the sensor, and a correction provided adjacent to the outside of the main optical sensor. One set of optical sensors including optical sensors, and at least two sets of the optical sensors are arranged at the lower end portion of the cylindrical body at symmetrical positions equal to the inner diameter of the donut. Provide a solar tracking sensor that operates.

[0007]

EXAMPLES The present invention will be described below with reference to examples. FIG. 1 is a schematic configuration diagram showing an embodiment of a sunlight tracking sensor provided in the sunlight concentrating device of the present invention. FIG. 2 is a sectional view taken along the line A--A in FIG. FIG. 3 shows an embodiment of an electric circuit using the solar light tracking sensor according to the present invention. 1
Is an opaque tubular body, 2 is a donut-shaped opaque lid having a circular hole, and 3 is the edge of the hole (the inner periphery of the donut) is vertically lowered to the lower end of the tubular body (to the lid). It is a virtual line that came. Optical sensor MS1, MS2, MS3, M
S4 is set so that the virtual line 3 passes through the center of the light receiving surface.
The optical sensors S are arranged at 0 ° division, and are arranged in such a positional relationship that the light receiving surfaces of the respective optical sensors are not covered with the outside of each of the optical sensors S.
S1, SS2, SS3 and SS4 are optical sensors MS1 and MS1, respectively.
It is arranged so as to be adjacent to the outside of MS2, MS3, MS4. When the direct light from the sun is in the direction of L ₀ , the optical sensor MS1 detects the direct light coming from the direction of L ₀ and the scattered light coming from the direction between L ₂ and L ₄ , that is, the scattered light of the incident angle A °. Will be received. On the other hand, the optical sensor SS1 receives only the scattered light coming from the direction between L ₁ and L ₃ , that is, the scattered light at the incident angle B °. Since the intensity of the scattered light at the incident angle A ° and the intensity of the scattered light at the incident angle B ° are approximately equal, the output signal of the optical sensor SS1 is converted from the output signal of the optical sensor MS1 to the differential amplifier OP1.
The signal SG1 subtracted by is almost equal to the output signal of only the sun direct light incident from the direction of L ₀ . Similarly, the signal SG
2, SG3 and SG4 are also substantially equal to the output signals of only the sun direct light incident from the direction L ₀ . When the direct light from the sun is in the direction of L ₀ , the signals SG1 and SG3 are substantially equal, and the signals SG2 and SG4 are also approximately equal. That is, the values of the signals SG1 and SG3 are set to the differential amplifier OP.
Drive motor M so as to make them equal
When X is controlled, the values of the signal SG2 and the signal SG4 are compared at the same time by the differential amplifier OP5, and the drive motor MY is controlled so that the values are equal to each other to drive the sunlight converging unit. The concentrator performs highly accurate sun tracking. It can be arranged so that the axis of the cylinder of the sunlight tracking sensor and the axis of an optical system such as a lens forming the sunlight condensing unit are parallel or shared.

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. The length of the opaque columnar cylinder 1 is 50
mm, the diameter of the hole of the opaque lid 2 is 25 mm, and the light receiving surfaces are 2.4 mm × 2.4 mm, and the optical sensors MS1 to MS4 are arranged in 90 ° division on a circle having a diameter of 25 mm. The optical sensors SS1 to SS4 having the same light receiving surface as these sensors are arranged on a circle having a diameter of 30 mm. When solar tracking was performed using this sensor when the sun altitude was about 15 ° and it was in a clear sky, the deviation between the direction of the sun and the direction of this solar tracking sensor was within 0.05 °.

[Second Embodiment] A solar tracking sensor was assembled in the same manner as in the first embodiment, and an electric circuit as shown in FIG. 4 was provided. The signal from the photosensor is amplified by the amplifier circuit 4, digitized by the A / D converter circuit 5, and then sent to the central arithmetic circuit unit 6. Appropriate gains are given to the signals of the optical sensors MS1 to MS4 and SS1 to SS4 in the central processing unit 6 for parameters such as the altitude of the sun and weather conditions, and the signals are subtracted. By controlling the drive motors MX and MY using these values, highly accurate sun tracking was possible even in a weather condition where the influence of sun scattered light was great.

[Comparative Example 1] The same solar tracking sensor as in Example 1 was used, the optical sensors SS1 to SS4 were covered, and solar tracking was performed with the output signals of only the optical sensors MS1 to MS4. When the sun altitude was about 15 ° and the weather was fine, the deviation between the direction of the sun and this solar tracking sensor was about 2 °.

[Comparative Example 2] Example 1 in a light cloudy evening.
The sun tracking by the same solar tracking sensor and the optical sensors SS1 to SS4 of the solar height tracking sensor were covered, and the sun tracking was performed by the output signals of only the optical sensors MS1 to MS4. Further, at this time, in order to clarify the direction of the sun and the amount of deviation of the solar light tracking sensor, a convex lens was attached to the solar light tracking sensor, and the optical fiber was attached so that the focal position thereof coincided with the incident end face of the optical fiber. The direction of the sunlight tracking sensor and the optical axis of the convex lens were matched. The measurement result is shown in a graph in FIG. The horizontal axis represents time, and the vertical axis represents the amount of light at the fiber output end. A is the change in light amount due to solar tracking similar to that in the first embodiment, and B is the change in light amount due to sun tracking with the output signals of only the optical sensors MS1 to MS4. There is almost no difference in the amount of emitted light until around 16:30, but thereafter, as the sun's altitude becomes lower and the influence of scattered light increases, B causes axial misalignment and the amount of emitted light decreases. On the other hand, A has almost no axis misalignment and is tracking near the sunset time.

[0012]

As described above, according to the present invention, by providing the sensor for receiving only the sun scattered light, the influence of the sun scattered light which is a disturbance in the tracking of the sunlight is canceled, and only the sun direct light is emitted. Since tracking can be performed with a signal, it is possible to perform highly accurate sunlight tracking with a very small optical axis shift due to sun scattered light. Therefore, by providing the solar light tracking sensor of the present invention, it is possible to obtain a solar light concentrating device having an extremely high solar light concentrating efficiency. In addition, the effect that the sunlight trackable range is expanded by optimizing the algorithm in the central processing unit is also recognized. Further, the solar light tracking method of the present invention is not limited to the solar light concentrating device and can be used independently.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 shows an embodiment of an electric circuit using the sun tracking sensor according to the present invention.

FIG. 4 is another embodiment of an electric circuit using the sun tracking sensor according to the present invention.

FIG. 5 is a graph showing tracking accuracy of the sun tracking sensor according to the present invention.

[Explanation of symbols]

 1: Opaque cylindrical body 2: Opaque lid having a circular hole 3: Virtual line 4: Amplifying circuit 5: A / D converter circuit 6: Central arithmetic circuit unit MS1 to MS4, SS1 to SS4: Optical sensor OP1 to OP6 : Differential amplifier circuit MX, MY: Drive motor

Claims (5)

[Claims] 1. A solar light concentrating device comprising a solar light concentrating part, a conveying part, a driving part, a solar light tracking sensor, a circuit part, and the like, wherein the solar light tracking sensor has a signal of a direct light component of the sun and scattered light. A sun tracking sensor, comprising: a main optical sensor that outputs a component signal and a correction optical sensor that outputs only a scattered light component signal of the sun. 2. A signal of only the direct light component of the sun is taken out from the output signal of the main light sensor and the correction light sensor, and the drive unit is operated by the signal of the direct light component and the sunlight collecting unit is The solar tracking sensor according to claim 1, which tracks the sun. 3. An opaque tubular body, a donut-shaped opaque lid provided on an upper end portion of the tubular body, and a line extending vertically from the inner peripheral portion of the donut to the lid to receive light from the sensor. At least two sets of the above-mentioned optical sensors, each of which is composed of a main optical sensor arranged so as to fall on the surface and a correction optical sensor arranged adjacent to the outside of the main optical sensor. The solar tracking sensor according to claim 1, wherein is arranged at the lower end of the cylindrical body at a symmetrical position equal to the inner diameter of the donut. 4. A sunlight concentrating device comprising the sunlight tracking sensor according to claim 1. 5. A signal of the direct light component of the sun from a main light sensor which outputs a signal of the direct light component of the sun and a signal of the scattered light component and a correction optical sensor which outputs only a signal of the scattered light component of the sun. A solar light tracking method, wherein only the light is extracted and the sun is tracked using the signal of the direct light component.