TWI383170B - Incident light direction and power detecting apparatus and application thereof - Google Patents

Description

Light incident azimuth and power judging device and application thereof

The present invention is a device for tracking the direction of incidence of light, and more particularly to a device that can be used to track the direction of incident light and the power output of light.

Solar energy is a clean, zero-pollution energy source that has been found to be sustainable in recent years. The abundant solar radiation energy is an inexhaustible, inexhaustible, non-polluting and easily accessible natural energy source. Solar energy does not require any fuel to generate electricity. It converts electromagnetic radiation emitted by the sun into electricity that can be used. The power generation process is noise-free, produces no waste and pollution, and is therefore one of the mainstream developments of renewable energy in the future.

The solar energy conversion device is a modular finished product, which is a non-light collecting type (also called a flat type solar panel, which is usually arranged in an array type when used), and a non-light collecting solar panel is manufactured by a factory, and a certain The fixed area can produce a specific power output, so the user can cascade or connect to obtain the required power (voltage, power) output according to the demand. In addition, the durability, reliability and durability of solar panels are very good, and the maintenance costs are very low. It is also the main reason why countries are competing to adopt and develop this technology.

Although solar panels have many of the above advantages, solar energy is similar to wind power generation, and the stability of power conversion sources (solar radiation, wind generation) is not artificially controllable, so it is impossible to sustain power generation throughout the day. If the factors such as climate, air quality, and environmental variation (shading) are excluded, the photoelectric conversion efficiency of solar panels fixed at a specific angle and position depends on the angular relationship between the earth and the sun. In short, due to the rotation and revolution of the earth, the solar panels installed at a certain point on the earth cannot sustain the state of direct sunlight. Therefore, the solar radiation absorbed by the solar panels follows. The time continues to mutate and cannot be in a highly efficient photoelectric conversion state for a long time.

In order to solve the situation that the photoelectric conversion efficiency of fixed solar panels is limited by the rotation and revolution of the earth, many manufacturers and research institutes are rushing to introduce a chasing solar device that can track the sun's position, so that the solar panels can continue to maintain the sun. The incident direction is vertical to improve energy conversion efficiency. At present, the common chasing solar device mainly utilizes a chasing sensing element, which is usually mounted on a mechanical rotating platform, and the mechanical rotating platform can operate the position of the chasing sensing element to receive light. Thereby, the tracking sensor element continuously tracks the direct direction of the sunlight to achieve the chasing function through the adjustment of the mechanical rotating platform.

However, although the aforementioned chasing solar device can achieve the performance of chasing light, its structure or use has its drawbacks. For example, the aforementioned tracking sensor component must use the mechanical rotating platform to achieve the function of chasing light. However, since the mechanical rotating platform is exposed to the outside for a long time, it is very likely that various weather factors cause rust, thereby increasing the operation and maintenance of the overall system. cost.

In order to solve the problems of high maintenance cost and inconvenient use of the existing mechanical chasing inductive element, the present invention utilizes a plurality of sensing elements fixedly mounted at different azimuth angles to calculate the coordinate conversion (vector geometric space) and the optical power comparison judgment. The method of estimating the incident direction of the light and the maximum optical output power solves the shortcomings of the prior art that requires a complicated mechanical structure, and achieves the purpose of reducing the cost and improving the convenience of use.

The present invention provides a light incident azimuth and power judging device, which comprises a body, a plurality of light sensors and an operation module, wherein: the base body is a stereo body. The plurality of illumination surfaces are non-coplanar, and there is an angle conversion relationship between the adjacent illumination surfaces; each of the light sensors is correspondingly and fixedly disposed on the surface of the illumination surface, and each light sensor receives one When the incident light source is illuminated, an electrical signal is generated and outputted to the computing module; the computing module receives the electrical signals received by the optical sensors and the angular conversion relationship of the optical sensors, and obtains the incident light source by a comparison and calculation means. Maximum light output power and light incident direction.

The seat is in the shape of a hemisphere, a hemispherical polyhedron, a polygonal pyramid, a cone or a stereoscopic ladder.

The seat body is a four-sided flat-topped cone, which comprises a top surface and four side wall surfaces, and the top surface and the four side wall surfaces are respectively fixed with a light sensor.

The optical sensors are connected in series with an operational amplifier circuit, and are electrically connected to the computing module. The magnification of the operational amplifier circuit is used to adjust the electrical signal output consistency of each optical sensor under the same optical input intensity. .

The computing module is a single chip or a programmable logic circuit chip, and the single chip or the programmable logic circuit chip stores and executes the comparison calculation means.

The comparison calculation means includes the steps of: setting the base body to a standard system; obtaining a spatial relationship between the illumination surfaces of the base body and the angle conversion relationship; and calculating each light induction according to the angle conversion relationship. The relationship between the received optical power and a maximum optical output power, wherein the maximum optical output power is the optical power in the incident direction of the vertical light source; and the incident angle and the azimuth angle of the incident light source are estimated according to the angle conversion relationship and the optical power comparison calculation result.

The invention further provides a tracking solar energy conversion system, comprising: a body, a plurality of light sensors, a computing module, a solar photovoltaic panel and a control terminal, wherein: the base body is a stereo body, which comprises a plurality of The illumination surface is non-coplanar, and there is an angle conversion relationship between the adjacent illumination surfaces; each of the light sensors is correspondingly and fixedly disposed on the surface of the illumination surface, and each light sensor is irradiated by an incident light source. Generating a signal output to the computing module; the computing module receives the electrical signals received by the optical sensors and the angle conversion relationship of the optical sensors, and obtains the maximum optical output power of the incident light source by a comparison calculation means. And the light incident direction; the computing module outputs the light incident direction to the solar photovoltaic panel, so that the solar photovoltaic panel is adjusted to face the incident direction of the light; and the control terminal receives and compares the maximum optical output power signal of the computing module And the solar photovoltaic panel receives the power output converted by the incident light source, thereby determining whether the working state of the solar photovoltaic panel is normal.

Thereby, the present invention can achieve the following technical effects:

1. The light incident azimuth and power judging device can eliminate the mechanical structure that can be moved, and only needs to pass the simple comparison and mathematical operation to obtain the incident direction and the output optical power of the incident light, thereby solving the problems of the prior art and achieving the reduction. The technical effect of cost and convenience.

2. When the aforementioned light incident azimuth and power judging device is connected to the solar photovoltaic panel, not only can the solar photovoltaic panel know the incident direction thereby improving the energy conversion efficiency, but also let the overall system compare the final energy conversion of the solar photovoltaic panel. In line with expectations, maintenance personnel can remotely monitor the normal operation of solar photovoltaic panels, which greatly saves labor costs.

Please refer to the first figure and the second figure, which are preferred embodiments of the light incident orientation and power judging device of the present invention, comprising a body (10), a plurality of light sensors (20) and an operation module ( 30).

The base body (10) is a three-dimensional seat body, and the plurality of illumination surfaces are non-coplanar, and the base body (10) receives at least one illumination surface to receive the incident sunlight when the white light has solar rays. Since each illumination surface is non-coplanar, that is, there is an angle conversion relationship between two adjacent illumination surfaces, wherein the angle conversion relationship includes at least an azimuth angle and a tilt angle relationship, and the angle conversion relationship can utilize a transposed matrix. Said. The shape of the seat body (10) is not limited, and may be a hemispherical seat body, a hemispherical polyhedron, a polygonal pyramid, a cone, a stereoscopic ladder type or the like. The seat body (10) of the embodiment is a four-sided flat-topped cone, which comprises a top surface and four side wall surfaces, and each of the side wall surfaces has an angular conversion relationship with the top surface.

Each of the light sensors (20) is correspondingly and fixedly disposed on the surface of the illumination surface, and each of the light sensors (20) generates an electrical signal output to the computing module (30) when receiving sunlight, wherein the wireless signal The number contains information about the power of the incident sun. In this embodiment, five light sensors (20) are respectively fixed on the top surface and the four side wall surfaces. Since the light sensors (20) are respectively disposed on different illumination surfaces (side wall surface, top surface), each The optical power received by the light sensor (20) and the maximum light output power that can be received when facing vertically in the incident direction are related to the aforementioned angular conversion relationship. In other words, the angle between the illuminated surface of each light sensor (20) and the incident light is also the amount of optical power that affects the electrical signal output by each light sensor (20).

The operation module (30) receives the electrical signals from the light sensors (20), and cooperates with the angle conversion relationship of the light sensors (20) to obtain the direct direction of the light by a comparative calculation means. Since the angle conversion relationship of each light sensor (20) is known, when the daylight time (in the case of sunlight), more than two of the light sensors (20) can be illuminated by a certain incident angle of sunlight. The operation module (30) can obtain the maximum light output power and the light incident direction by comparing the electrical signal values and the angle conversion relationship output by the two or more light sensors (20). Taking the embodiment as an example, as shown in the first figure, the light may only be irradiated to the light sensor (20) numbered T (horizontal, top), F (front, Front), and therefore, the operation module (30) The maximum light output power and incident angle of the incident light can be obtained by calculating and comparing the angle conversion relationship and the electrical signal of the numbered T and F light sensors (20).

For a more detailed description of the process of translating the angle conversion relationship and the optical power operation, the present embodiment is described as an example. First, the orientation vector of the embodiment is divided into four quadrants (I, II, III, IV). As shown in the first figure, wherein the light sensors (20) of the numbers F, R (rear, Rear) and T have an electrical signal output when the light incident direction is toward the first quadrant (I), similarly, The light sensors (20) with numbers F, L (left, Left) and T have electrical signal output when the light incident direction is toward the second quadrant (II), and the light sensors (20) B, L, T are in the incident direction of the light. The electrical signal is outputted toward the third quadrant (III), and the optical sensors (20) B, R, T have electrical signals output when the light incident direction is toward the fourth quadrant (IV).

In the practice process, the direction vector of the incident light of the sun must be within four quadrants (I to IV), and the direction of the incident light can be determined by comparing the optical power information of the electrical signals output by the optical sensors (20) of each position. (the quadrant where the light source is located): When P _R >P _L , P _F >P _B , the operation module (30) can determine that the incident direction of the light source is in the first quadrant (I); when P _L >P _R , P _F >P _B , which can determine that the light source is in the second quadrant (II); when P _L >P _R , P _B >P _F , the computing module (30) can determine that the incident direction of the light source is in the third quadrant; When P _R >P _L and P _B >P _F , the operation module (30) can determine that the incident direction of the light source is in the fourth quadrant (IV).

If the third-order vector space is used to define the right side of the first graph as the X-axis (+), the rear-side is the Y-axis (+), and the upper is the Z-axis (+), and by the coordinate conversion method (ie, the aforementioned transpose) Matrix operation), deriving the equation between the light sensor (20) of each position and the incident light direction (the incident direction of the sunlight), and obtaining the solar azimuth angle, an elevation angle, and the maximum optical power output.

Referring to the third figure, in the flat-topped quadrangular pyramid body (10) of the present embodiment, the operational angle conversion relationship can be defined and operated as follows:

(1) Obtain the incident light direction vector: the vector geometric space coordinate between the light sensor (20) at the top of the horizontal and the incident direction vector (x, y, z) of the light source (S) is as shown in the third figure, where the incident direction vector (x, y, z) can be expressed as follows:

Where φ is the angle between the incident direction of the light source (S) and the Z axis; α is the angle between the incident direction vector (x, y, z) projected on the XY plane and the X axis; r is the light source (S) and the origin (ie The distance of the light sensor T).

As can be seen from the third figure, the angle between the light sensor (20) and the incident direction of the light source (S) is different, wherein the light sensor (20) T is exposed to the light power and the vertical direction of the light source ( The cosine of the Z-axis is proportional to the angle φ of the plane normal of each light sensor.

(2) Define the coordinate transfer formula: Please refer to the fourth figure. When the position of the light source is unchanged, use the coordinate conversion method to obtain the coordinate axis system of the light sensor (20) of each illumination surface. The fourth figure shows the definition of the rotation direction θ of each plane coordinate. Taking the light sensor (20) in front (F) as an example, the coordinate axis is converted to horizontal, and the light sensor (20) T is rotated by θ angle around the Y axis. θ is the rotation angle; after the coordinate axis conversion, the installation position and angle relationship of different light sensors (20) can be obtained, and then the relationship between each light sensor (20) and the incident light direction vector is analyzed. The following formulas (2) to (4) are the coordinate axes conversion formulas and results of the X, Y, and Z axes of the present embodiment:

(i) Rotating the angle θ around the X axis to obtain a new coordinate axis x ₁ , y ₁ , z ₁

(ii) Rotating the angle θ around the Y axis to obtain a new coordinate axis x ₂ , y ₂ , z ₂

(iii) Rotating the angle θ around the Z axis to obtain a new coordinate axis x ₃ , y ₃ , z ₃

(3) Obtain the maximum optical output power of each light sensor and incident light (P) _Max Relationship:

The embodiment comprises five light sensors (20) disposed on different illumination surfaces of the base body (10). By using the formula derived above, the vector geometry between the illumination surface and the light source of each light sensor (20) can be separately obtained. The relationship of space. By rotating the θ angle with respect to the X, Y, and Z axes, the left (L) and right (R) light sensors (20) can be derived from the geometric space equation of the light source vector:

(i) Rotating the θ angle with respect to the X-axis, and deriving the geometric space equation of the light source vector of the light sensor (20) R, L:

● The right (east) light sensor (20) R is horizontally rotated by θ angle around the X axis, and the geometric space equation of the sensor (20) R to the source vector is obtained:

P _{Z R} = P _max (sinφsinαSinθ+cosφcosθ)= P _max cosφ _R (5)

● The left light sensor (20) is rotated horizontally around the X axis by the angle θ, and the relationship between the light sensor (20) L and the light source is obtained:

P _{Z L} = P _max (-sinφsinαsinθ+cosφcosθ)= P _max cosφ _L (6)

(ii) Rotating the θ angle with respect to the Y-axis, and deriving the geometric space equation of the light source vector of the light sensor (20) F, B:

● The rear light sensor (20) rotates the angle θ clockwise around the Y axis horizontally to obtain the equation of the relationship between the light sensor (20) B and the light source:

P _{Z B} = P _max (-sinφcosαsinθ+cosφcosθ)= P _max cosφ _B (7)

● The front light sensor (20) rotates the angle θ counterclockwise horizontally around the Y axis to obtain the equation of the relationship between the light sensor (20) F and the light source:

P _{Z F} =P _max (sinφcosαsinθ+cosφcosθ)=P _max cosφ _F (8)

(iii) Rotating the θ angle with respect to the Z axis, and deriving the geometric space equation of the light sensor (20) T to the light source vector:

P _{Z T} = P _max cosφ = P _max cosφ _T ... (9)

(4) Estimate the incident angle φ by using the relationship of the received optical power of each light sensor :

(i) If the light source is in the I and IV quadrants, use equations (5) and (9) to find φ:

(ii) If the light source is in the III and IV quadrants, use equations (7) and (9) to find φ:

(iii) If the light source is in the I and II quadrants, use equations (8) and (9) to find φ:

(iv) If the light source is in the quadrants II and III, use equations (8) and (9) to find φ:

(5) Use the above formula _to derive α, where α may fall in four quadrants ( α _I~IV ) and have different derivation processes, such as after:

(i) If the light source is in the IVth quadrant, it can be substituted into (5)/(7) by equation (10) or (12) to obtain α _IV.

(ii) If the light source is in the first quadrant, it can be obtained by substituting equation (10) or equation (13) into (5)/(8) for α _I

(iii) If the light source is in the IIth quadrant, it can be substituted into (6)/(8) by equation (11) or (13) for α _II

(iv) If the light source is in the IIth quadrant, it can be substituted into (6)/(7) by equation (11) or (12) to obtain α _III.

(6) Angle conversion type:

The solar azimuth is defined as 0° in the south. Therefore, the four quadrants can be divided into rear (south), right (east), and front (north): 0°~180°; rear (south), left (west), and front. (North): 0°~-180°, and redefine the azimuth and elevation angles of each quadrant:

Based on the foregoing formula, the computing module (30) can determine the maximum light output power (P _max ) of the light source (S) and the incident angle of incidence (φ) according to the light sensing result of each light sensor (20). With azimuth (α).

Please refer to the fifth picture. In use, the computing module (30) of the embodiment can be combined with a solar photovoltaic panel (40) and a control terminal (50), wherein the control terminal (50) and the solar photovoltaic panel (40) Electrically connected to form a chasing solar energy conversion system. In this way, the solar photovoltaic panel (40) can be outputted by the incident angle (φ) and the azimuth angle (α) of the computing module (30) to track the incident direction of the sunlight, thereby giving the solar photovoltaic panel (40) a chance. The maximum photoelectric conversion efficiency is continuously maintained; moreover, the control terminal (50) can check whether the photoelectric conversion efficiency of the solar photovoltaic panel (40) matches the maximum light output power (P _max ) result at any time, thereby judging the solar photovoltaic Whether the board (40) is working properly. For example, the solar photovoltaic panel (40) may be contaminated on the surface or because of the shading relationship of the building or the tree, so that although the incident direction of the sunlight is not able to produce equivalent electric energy, the control terminal (50) The power output (P _max ) induced by the computing module (30) and the power output of the solar photovoltaic panel (40) can be checked to determine whether the surface contamination and the shading condition are present. Appropriate time to inform personnel to eliminate the aforementioned conditions, so that the solar photovoltaic panel (40) maintains the best energy conversion efficiency.

Further, in order to avoid a slight difference between the employed light sensors (20), resulting in a large difference in the final result of the angle calculation and the optical power calculation, the reliability and practicability of the present invention are reduced, and the light sensors can be used in each light sensor ( 20) The output terminals are respectively connected to an operational amplifier circuit, and by adjusting the magnification of each operational amplifier circuit, the output of the optical signals produced by the respective light sensors (20) under the same light intensity is corrected to improve the amount of the present invention. The accuracy of the azimuth (latitude angle) and elevation angle (time angle) of the sun (light source) is measured; the operational amplification circuit can be as shown in the example of the sixth figure.

In practice, the computing module (30) can use the technology of integrating a single chip or a programmable logic circuit to burn the aforementioned optical power, angle conversion formula, equation and control circuit to a single chip or programmable logic circuit. Chips (CPLD, FPGA, etc.) and output the results by liquid crystal display or similar display. Table 1 is a measurement result of a group of the present embodiment from 8:00 am to 6:00 pm. It can be seen from Table 1 that each of the light sensors (20) of the front (F), the rear (B), the left (L), the right (R), and the horizontal plane (T) has a different angle of incidence due to sunlight, resulting in each The azimuth light sensor (20) differs in the degree of light received and the optical power varies. Therefore, the optical power sensed by the different azimuth light sensors (20) of Table 1 is substituted into the aforementioned angle and optical power conversion equation. And compared with the actual solar azimuth (latitude angle) and altitude angle (time angle), verify the solar azimuth (latitude angle) and elevation angle (time angle) equations deduced in this embodiment, as shown in Tables 2 and 3. Show. From the comparison results of Table 2, it can be found that the azimuth measured by the present embodiment is very close to the angle of the actual solar azimuth. The comparison results of Table 3 show that the angles measured by the height angle of the present embodiment are very close to the angles of the actual solar elevation angles.

Based on the foregoing description, the structure of the embodiment is simple, and the angle of incidence and the optical power conversion formula can be used to obtain the incident direction and the light output power of the sunlight, so that the connected solar photovoltaic panel (40) can continue to work at the most efficient. State, thereby obtaining maximum photoelectric conversion efficiency.

(10). . . Seat

(20). . . Light sensor

(30). . . Computing module

(40). . . Solar photovoltaic panel

(50). . . Control terminal

The first figure is a perspective perspective view of a preferred embodiment of the invention.

The second figure is a block diagram of a circuit according to a preferred embodiment of the present invention.

The third figure is a schematic diagram of a coordinate system in accordance with a preferred embodiment of the present invention.

The fourth figure is a schematic diagram of the conversion angle of the preferred embodiment of the present invention.

Figure 5 is a block diagram showing the circuit of the second embodiment of the present invention.

The sixth figure is a schematic diagram of an operational amplifier circuit of the present invention.

(20). . . Light sensor

(30). . . Computing module

(40). . . Solar photovoltaic panel

(50). . . Control terminal

Claims (14)

A light incident azimuth and power judging device comprises a body, a plurality of light sensors and an operation module, wherein: the base body is a stereo body, and the plurality of illumination surfaces are non-coplanar, two and two phases There is an angle conversion relationship between the adjacent illumination surfaces; each of the light sensors is correspondingly and fixedly disposed on the surface of the illumination surface, and each of the light sensors generates an electrical signal output to the operation module when receiving an incident light source. The computing module receives the electrical signals received by the optical sensors and the angular conversion relationship of the optical sensors, and obtains a maximum optical output power and a light incident direction of the incident light source by a comparison calculation means. The light incident azimuth and power judging device according to claim 1, wherein the seat body has a shape of a hemispherical body, a hemispherical polyhedron, a polygonal pyramid, a cone or a stereoscopic ladder. The light incident azimuth and power judging device according to claim 1 or 2, wherein the seat body is a four-sided flat-topped cone comprising a top surface and four side wall surfaces, and the top surface and the fourth surface A light sensor is fixed to each of the side wall surfaces. The optical incident azimuth and optical power judging device according to claim 1 or 2, wherein each optical sensor is connected in series with an operational amplifying circuit, and is electrically connected to the computing module, and the operating magnification of the operational amplifying circuit It is used to adjust the electrical signal output consistency of each light sensor under the same light input intensity. The optical incident azimuth and power judging device according to claim 3, wherein each of the optical sensors is connected in series with an operational amplifying circuit, and is electrically connected to the computing module, wherein the magnification of the operational amplifying circuit is used for adjusting The electrical signal output consistency of each light sensor at the same optical input intensity. The light incident orientation and power judging device according to claim 5, wherein the computing module is a single chip or a programmable logic circuit chip, and the single chip or the programmable logic circuit chip stores and performs the comparison. Means of calculation. The light incident azimuth and power judging device according to claim 6, wherein the comparing calculating means comprises the steps of: setting the seat body to a standard system; and obtaining a spatial relationship between the irradiated surfaces of the seat body and the coordinate system; And the angle conversion relationship; calculating, according to the angle conversion relationship, a relationship between the received optical power of each optical sensor and a maximum optical output power, wherein the maximum optical output power is the optical power of the incident direction of the vertical light source; and the relationship according to the angle conversion The calculation result of the comparison with the optical power is used to estimate the incident angle and the azimuth angle of the incident light source. A tracking solar energy conversion system comprising a body, a plurality of light sensors, an operation module, a solar photovoltaic panel and a control terminal, wherein: the base body is a stereo body, and the plurality of illumination surfaces are Non-coplanar, there is an angle conversion relationship between two adjacent illumination surfaces; each of the light sensors is correspondingly and fixedly disposed on the surface of the illumination surface, and each light sensor generates a telecommunications when receiving an incident light source The output is output to the computing module; the computing module receives the electrical signals received by the optical sensors and the angular conversion relationship of the optical sensors, and obtains the maximum optical output power and the incident direction of the incident light source by a comparison calculation means. The computing module outputs the light incident direction to the solar photovoltaic panel, so that the solar photovoltaic panel is adjusted to face the incident direction of the light; and the control terminal receives and compares the maximum optical output power signal of the computing module with the solar photovoltaic The board receives the power output converted by the incident light source, thereby determining whether the working state of the solar photovoltaic panel is normal. The tracking solar energy conversion system according to claim 8, wherein the seat body has a shape of a hemispherical body, a hemispherical polyhedron, a polygonal pyramid, a cone or a stereoscopic ladder. The tracking solar energy conversion system of claim 8 or 9, wherein the base is a four-sided flat-topped cone comprising a top surface and four side wall surfaces, and the top surface and the four sides A light sensor is fixed on the wall surface. The light-sensing solar energy conversion system according to claim 8 or 9, wherein each of the light sensors is connected in series with an operational amplifier circuit, and is electrically connected to the operation module, and the magnification of the operational amplifier circuit is used for adjustment. The electrical signal output consistency of each light sensor at the same optical input intensity. The light-sensing solar energy conversion system according to claim 10, wherein each of the light sensors is connected in series with an operational amplifier circuit, and is electrically connected to the operation module, wherein the magnification of the operational amplifier circuit is used to adjust each light. The electrical signal output consistency of the sensor at the same optical input intensity. The tracking solar energy conversion system of claim 12, wherein the computing module is a single chip or a programmable logic circuit chip, and the single chip or the programmable logic circuit chip stores and executes the comparison calculation means . The tracking solar energy conversion system according to claim 13 , wherein the comparison calculation means comprises the steps of: setting the base body to a standard system; obtaining a spatial relationship between the illumination surfaces of the base body and the coordinate system; An angle conversion relationship; calculating, according to the angle conversion relationship, a relationship between a received optical power of each optical sensor and a maximum optical output power, wherein the maximum optical output power is an optical power in a direction in which the vertical light source is incident; and the light is converted according to an angle The power comparison calculation results estimate the incident angle and azimuth of the incident light source.