JP5160833B2 - Light incident direction sensor - Google Patents

Description

  The present invention relates to a light incident direction sensor used for detecting the incident direction of other light in order to detect the incident direction of sunlight in a solar light tracking device or the like.

  Some solar power generation devices attempt to improve power generation efficiency by attaching a solar tracking device to track sunlight. And the sunlight tracking device generally generates a tracking control signal using the incident direction detection signal from the sunlight incident direction sensor, and controls and drives the direction conversion mechanism.

  A conventional sunlight incident direction sensor uses a part of a power generation solar panel as a light receiving element for a sensor (a) and a part using a solar panel for detection of incident light intensity different from the power generation solar panel (b) (C) is known in which a light receiving element such as a phototransistor is arranged at a position partitioned in four directions by a light shielding plate at the bottom of the light shielding plate having a required cross section and a letter-shaped height.

Since the sunlight incident direction sensor (a) uses a part of the power generation solar panel as the light receiving element for the sensor, naturally, the power generation capability of the power generation apparatus is reduced. Therefore, in order to ensure the required power generation, it is necessary to increase the panel size, which is not suitable for a power generator that is reduced in size and requires portability. The solar incident direction sensor of (b) uses a solar panel for detecting the amount of incident light different from that for power generation. Therefore, the area of the entire panel increases and the size of the panel increases. Does not fit. Furthermore, since the sunlight incident direction sensor (c) is formed by arranging a light receiving element at the bottom of an open type light shielding plate having a cross-section + character, the sensitivity of the sensor is unstable, and a unique incident direction detection signal. Therefore, the solar tracking control of the solar tracking device cannot be performed accurately. The prior art has the above problems.
nothing special.

  The present invention has been made in view of the above points, and an object thereof is to provide a light incident direction sensor capable of outputting an accurate and unique incident direction detection signal.

In order to achieve the above object, the inventor of the present application is centered on a cylinder having a transparent top wall and side walls, two straight lines perpendicular to each other at the center of the cylinder inside the bottom of the cylinder, and the center of the cylinder. A light receiving element disposed at four intersections with the circle and a center of the upper surface wall of the cylinder, and has a size capable of shielding two adjacent light receiving elements at the maximum among the four light receiving elements. A light-shielding mark; an incident light quantity measuring unit that receives the output of each light receiving element and measures the incident light quantity at four intersections; and an incident direction determining unit that determines an incident direction based on an output value of the incident light quantity measuring unit. In addition, a sunlight incident direction sensor has been devised in which at least the cylinder, the light-shielding mark, and the light-receiving element constitute one unit of sensor body.
The light-shielding mark is provided at the center of the top wall of the cylinder, and the two light receiving elements that are adjacent to each other at the maximum of the four light receiving elements disposed at the intersection of two straight lines orthogonal to the center of the cylinder and a circle centered on the center of the cylinder. Since each light receiving element has a size capable of shielding light, depending on the direction of incidence on the light cylinder, (a) a state in which all the light receiving elements receive light, that is, a state in which the shadow of the mark is inscribed in all the light receiving elements, (B) a state where none of the light receiving elements receives light, (c) a state where any one light receiving element is shielded, that is, a state where a shadow of the mark can be formed on any one light receiving element, (d) any one The two adjacent light receiving elements are shielded from light. The incident light amount measuring means measures the incident light amount in each light receiving element from the output of each light receiving element in each state. The incident direction determining means determines the incident direction based on the output value of the incident light quantity measuring means. This determination result can be used to change the direction of the cylinder so that the central axis of the cylinder coincides with the light incident direction.

However, the sunlight incident direction sensor does not directly detect sunlight, but as a specific problem caused by detecting a shadow by a light shielding mark, the light incident on the cylinder is reflected from the side wall. because it can irradiate the light receiving element shadow of the light blocking mark occurs, there is a problem of low reliability of the incident direction detection, also, when the sunlight dawn when is incident at a large angle to the axis of the cylinder line In addition, there is a problem that it is difficult to detect the presence or absence of the incident light.
To solve this problem, the sunlight incident direction sensor according to the present invention, wherein said cylinder have a transparent top wall and side walls and blackout mark the center of the upper wall is provided And

  In a further preferred embodiment of the present invention, the incident light amount measured by the incident light amount measuring means is compared to detect the incident direction, and an incident direction detection signal is output, or further, a cylinder corresponding to the detected incident direction is output. It is characterized in that determination means for outputting a rotation direction signal indicating the direction in which the direction of the cylinder should be changed so that the central axis coincides with the incident direction of sunlight is added.

According to the present invention, since the light shielding mark has a size capable of shielding two adjacent light receiving elements among the four light receiving elements, the state in which only one of the light receiving elements is shielded; Since any two adjacent light receiving elements can be shielded from light, it is possible to accurately detect the incident directions in the east, west, south, and north directions. Further, the incident direction determination signal can be used to change the direction of the cylinder so as to coincide with the light incident direction. Further, the size can be reduced, and a small solar tracking device can be manufactured. In addition, since the top and side walls of the cylinder are transparent, the light incident on the cylinder is transmitted through the cylinder, preventing a decrease in detection reliability due to light reflected from the inner wall surface of the cylinder entering the light receiving element. can do. Furthermore, when the side wall is opaque, it is difficult to detect the presence or absence of incident light when sunlight enters at a large angle with respect to the axis of the cylinder at dawn, but the side wall is transparent. Therefore, it is possible to detect the dawn and detect the incident direction.

  Further, according to the present invention, the incident light amount measured by the incident light amount measuring means is compared to detect the incident direction and output the incident direction detection signal, or further, the cylinder corresponding to the detected incident direction. Since the determination means for outputting the rotation direction signal indicating the direction in which the direction of the cylinder should be changed is added so that the central axis of the solar light coincides with the incident direction of sunlight, the sunlight incident direction sensor of the present invention is used as it is. It can be attached to a light tracking device and used for control for sunlight tracking. Therefore, the solar light tracking device can be downsized and portable.

  Next, embodiments of the present invention will be described with reference to the drawings.

  1 is a perspective view of a sunlight incident direction sensor according to the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a sectional view taken along line XX of FIG. 2, and FIG. 4 is a circuit diagram mainly showing an example of a configuration of a determination circuit. FIG. 5 is an explanatory diagram for explaining the relationship between the light receiving states of the four light receiving elements, the determination reference table for determining the incident direction, and the determination of the incident direction.

As shown in FIGS. 1 to 3, the sunlight incident direction sensor A according to the present invention is provided on a cylinder 1 having a transparent upper surface wall and side walls and capable of receiving light, and on the inner side of the bottom of the cylinder. The light receiving elements 2 1, 2 2, 2 3, 2 4 and the light shielding mark 3 provided at the center of the upper wall of the cylinder.

  The light receiving elements 2 1, 2 2, 2 3, and 2 4 are composed of phototransistors and the like, respectively, at two positions that are perpendicular to each other passing through the center of the bottom surface of the cylinder and at a position close to the inner peripheral surface of the cylinder centered on the center of the bottom surface Arranged on four intersections with the circle.

As long as the light-shielding mark 3 has light-shielding performance, the material and the kind of the material are not limited, and the means provided at the center of the upper surface wall of the cylinder 1 is not limited. Preferably, an opaque paint may be circularly applied to the center of the upper surface wall formed of a transparent disk 3a made of synthetic resin or glass, or an opaque cloth or seal may be attached. The important point is that the shading mark 3 has a size that can circumscribe the four light receiving elements 21, 22, 23, and 24, and can shield any two adjacent light receiving elements. It is. That is, the shadow caused by the incident light of the light shielding mark 3 exists in the center of the four light receiving elements 2 1, 2 2, 2 3, 2 4, and no light receiving element is shielded, and only one light receiving element is The size of the light shielding mark 3 and the size and arrangement position of the light receiving elements are set so that the light shielding state and the state of shielding the two adjacent light receiving elements occur.

The side wall of the cylinder 1 is transparent . One of the reasons is to avoid the light incident on the cylinder from being reflected from the side wall and irradiating the light receiving element in which the shadow of the light shielding mark is generated, and the other reason is that the side wall is opaque. If it is, when sunlight dawn when is incident at a large angle to the axis of the cylinder line, it is difficult to detect the presence or absence of the incident light, when the transparent side wall, this will be possible Because. In other words, it becomes possible to detect the incident direction by detecting dawn.

This sunlight incident direction sensor A detects the incident direction of light by detecting which one of the light receiving elements 2 1, 2 2, 2 3, 2 4 is shaded by the light shielding mark 3 provided at the center of the upper wall of the cylinder. Therefore, the depth (height) of the cylinder 1 is blocked when the axial direction of the cylinder 1 is directed to the direction in which sunlight is irradiated as a result of measurement as shown in FIG. It is set to such an extent that the shadow of the mark 3 can be formed on the upper surface of the bottom of the cylinder 1.

  As shown in FIG. 3, each light receiving element 2 1, 2 2, 2 3, 2 4 is attached to a container 4 provided on the lower side of the bottom of the cylinder 1, and each light receiving element 2 1, 2 2, 2 3, 2 4 is generated when receiving light The voltage is supplied to a determination circuit 5 provided in the container 4 as shown as a preferred example in FIG. As illustrated in FIG. 4, the determination circuit 5 includes an incident light amount measurement circuit 51-54 and a comparison circuit 55. Each of the incident light amount measurement circuits 51 to 54 outputs the voltage when the voltage input from the light receiving element is equal to or greater than a predetermined threshold value. The comparison circuit 55 compares the combination of the output states (presence / absence) of the incident light amount measurement circuits 51-54 with a preset determination criterion table, and, for example, sunlight is cylindrical depending on which determination criterion table matches. The incident direction determination signal a corresponding to the determination result is output.

  The sunlight incident direction sensor A is a light receiving element 21, 2 2, 2 3, 2 4 with an arbitrary set of light receiving elements existing on opposite sides of the center of the cylinder in the north-south direction, and another set of light receiving elements. Used according to the east-west direction. In the example shown in FIG. 2, the light receiving elements 2 1 and 2 2 are associated with the west and the north, and the light receiving elements 2 3 and 2 4 are associated with the east and the south. Further, in the preferred embodiment, as shown in FIG. 2, in order to clearly show which light receiving element corresponds to which direction, in the vicinity of each light receiving element 21, 2 2, 23, 24, , North, East, South or W, N, E, S are desirable. The display of this direction is also effective to prevent the wrong connection partner of each light receiving element 21, 2 2, 2 3, 2 4 and the judgment circuit.

  FIG. 5 shows an example of a determination criterion table used for incident direction determination used in the comparison circuit 55. W, N, E, and S in the upper column of the figure indicate light receiving elements in each direction, the left end of the table indicates a light receiving state number, ● in the table indicates no light reception, and ◯ indicates light reception. Further, a is an incident direction determination signal representing the light incident direction output as a determination result by the comparison circuit 55.

  In the case of this invention, the incident direction determination signal a means the direction in which the cylinder should be rotated so that the central axis of the cylinder 1 coincides with the light incident direction.

  The determination reference table will be further described. The light receiving state number 1 indicates that all the light receiving elements 21, 22, 23, and 24 are receiving sunlight, that is, the sensor detection direction (cylinder axis) is the light incident direction. This is the case. Accordingly, the incident direction determination signal a at this time outputs “0” indicating that it coincides with the current direction of the cylinder 1. For example, the light receiving state number 2 is a state in which only the light receiving element 21 in the W direction is shielded by the light shielding mark 3. Therefore, the incident direction determination signal a at this time indicates that the incident direction is determined to be E.

Next, an example in which the light incident direction determination result of the sunlight incident direction sensor A is used for control driving of the solar light tracking device or the solar power generation device will be described.
6 is a front view conceptually showing the configuration of the solar light tracking device, FIG. 7 is a front view showing an example of a specific configuration of the solar light tracking device, FIG. 8 is a side view, and FIG. A front view showing another example of the specific configuration, FIG. 10 is a side view of the same.

As shown in FIG. 6, the solar tracking device B conceptually includes a sunlight incident direction sensor A and rotates the cylinder 1 around two axes P1 and P2 orthogonal to each other in a required direction. The cylindrical rotation mechanism 10 is controlled based on the mechanism 10 and the incident direction determination signal a output from the determination circuit 5 of the sunlight incident direction sensor A, and the direction of the central axis 1c of the cylinder 1 coincides with the sunlight incident direction. And a control unit 20 that rotates in a predetermined direction until the operation is performed.
The cylinder 1 and the determination circuit 5 of the sunlight incident direction sensor A may be integrally coupled as shown in FIG. 3, or the determination circuit 5 may be separated from the cylinder 1. The control unit 20 is preferably accommodated in the bottom container 4 of the cylinder 1 together with the determination circuit 5 for maintenance and the like.

  For convenience of explanation, it is assumed that the determination circuit 5 of the sunlight incident direction sensor A outputs a rotation direction signal. The cylinder rotation mechanism 10 can be composed of a first motor M1 and a second motor M2 for rotating the cylinder 1 around two axes P1 and P2 orthogonal to each other. For example, when the determination circuit 5 outputs the N-direction rotation direction signal, the control unit 20 causes the first motor M1 to rotate the first shaft P1 forward, and the determination circuit 5 outputs the S-direction rotation direction signal. When output, the first motor M1 is configured to reverse the first axis P1. When the determination circuit 5 outputs the W direction rotation direction signal, the control unit 20 causes the second motor M2 to rotate the second axis P2 forward, and when the determination circuit 5 outputs the E direction rotation direction signal. Is configured to cause the second motor M2 to reversely rotate the second shaft P2.

  Therefore, for example, when the determination circuit 5 outputs the NE direction rotation direction signal corresponding to the ninth light receiving state of the determination reference table of FIG. 5, the control unit 20 sets the first axis P1 to the first motor M1. And the second motor M2 is configured to reverse the second shaft P2.

  The incident state of sunlight into the cylinder 1 is changed by the rotation control of the cylinder 1 in a predetermined direction, and the output values from all the light receiving elements become equal, so that the direction of the cylinder becomes appropriate ( The light receiving state 1 is detected), and the rotation control of the cylindrical rotation mechanism 10 is stopped. Further, when the incident direction changes due to the movement of the sun, the control unit 20 controls and drives the cylindrical rotation mechanism 10 in accordance with the output from the determination circuit 5 of the sunlight incident direction sensor A. Is done.

The incident states as shown in the light receiving state numbers 11 and 12 in FIG. 5 are not considered to actually occur except in special cases such as the case where reflected light from an external reflector is incident. In such a case, it can be determined that an error has occurred and the rotation control is not performed. Further, when the outputs of all the light receiving elements indicated by the light receiving state number 10 in FIG. 5 are 0, it is considered cloudy at night or during the day. It can be configured not to perform dynamic control.
At dawn and when the axis of the incident direction sensor coincides with the incident direction of sunlight, all four light receiving elements are in the same light receiving state depending on the direction of the cylinder, but an appropriate threshold is set for the output value of the light receiving element. By doing so, it is possible to determine which one of them. By incorporating a clock in the sensor and using the time signal of the built-in clock as a discrimination criterion, it is also possible to determine whether the incident time sensor coincides with the incident direction of sunlight or not.

  The cylindrical rotation mechanism 10A of the solar light tracking device shown in FIGS. 7 and 8 is configured as follows. That is, the bottom of the cylinder 1 is formed into a bowl shape having an arc surface with an arc angle of 180 degrees protruding downward, and a shallow groove extending along the arc surface is formed at the center in the longitudinal direction of the outer peripheral surface. Is provided with a first gear (sector gear) g1 extending along the arc surface. The bottom portion of the cylinder is fitted to the concave surface of the bowl-shaped holder 11 having a concave surface that matches the convex surface of the cylindrical bottom portion, and is held rotatably around the center of the arc of the holder 11 and the cylindrical bottom portion. Further, a lateral hole penetrating the holder in the vertical direction is formed at the center in the longitudinal direction of the holder 11. The upper part of the second gear (gear) g2 fixed to the rotating shaft of the first motor M1 attached to the side surface of the holder 11 via the mounting plate 12 protrudes upward from the lateral hole of the holder 11, and It enters the shallow groove of the cylinder 1 and meshes with the first gear g1. Therefore, when the first motor M1 is rotated in a predetermined direction or in the reverse direction by the control signal from the control unit 20, the cylinder 1 can be rotated around the center of the arc of the holder 11, that is, the first axis P1.

Shaft 13 extending in a direction perpendicular to the first axis P1 between the upper part of both Chi ascending piece 14a of the base 14 of the top opening U-shape is rotatably supported. That is, the shaft 13 corresponds to the second axis P2. A third gear (gear) g3 is fixed to the shaft 13, and a fourth gear (gear) g4 fixed to the rotation shaft of the second motor M2 attached to the upper surface of the base 14 is attached to the third gear g3. It is engaged.
Accordingly, when the second motor M <b> 2 is rotated in a predetermined direction or in the reverse direction by a control signal from the control unit 20, the cylinder 1 can rotate around the second shaft 13.

  The solar light tracking device B shown in FIGS. 9 and 10 includes a housing 30 provided on the lower side of the sunlight incident direction sensor A. The control unit 20 is accommodated between the bottom 31 of the housing 30 and the intermediate partition wall 32, and the fourth gear g4 fixed to the rotating shaft of the second motor M2 attached to the upper surface of the intermediate partition wall 32 is provided in the housing. Is engaged with a third gear g3 that is fixed to a second shaft P2 that is rotatably supported via a bearing portion.

  The substrate 33 is fixed to the second axis P2, and the frame 34 stands upward on the opposite side of the substrate from the second axis P2. The first axis P1 is orthogonal to the second axis P2 at the upper end of the frame 34. It is penetrated in the direction to turn and is supported rotatably through a bearing. The lower ends of a pair of support plates 35 that extend downward from the bottom surface of the cylinder 1 of the sunlight incident direction sensor A are fixed to both ends of the first axis P1. A first gear g1 is fixed to the tip of the first shaft P1 penetrating one support plate 35, and is fixed to the first gear g1 and the rotation shaft of the first motor M1 attached to the upper surface of the substrate 33. A toothed belt 36 is wound around the second gear g2.

  With the above configuration, a control signal corresponding to the rotation direction signal from the determination circuit 5 is given from the control unit 20 to the first motor M1 and / or the second motor M2, and the central axis of the cylinder 1 is the sunlight incident direction. Until it matches with the first axis P1 or the second axis P2.

  FIG. 11 is a plan view of the solar power generation device C. FIG. SP is a known solar panel, A is the sunlight incident direction sensor of FIG. 1 fixed to a part of the outer periphery of the solar panel, B is the above-described solar tracking device, and the solar tracking device B When using what is shown in FIGS. 7 and 8, the saddle bottom of the cylinder 1 shown in FIG. 7 is added to the bottom surface of the solar panel SP, and the saddle bottom fits in the holder 11 of FIGS. The rotating mechanism 10A is used.

  When the solar tracking device B shown in FIGS. 9 and 10 is used, a solar panel SP is connected to the upper end of the support plate 35 of FIGS.

  In addition, in order for the said solar power generation device to exhibit an electric power supply function as a desired solar power generation device, the electrical circuit which is illustrated in FIG. 12 is added.

The perspective view of the sunlight incident direction sensor which concerns on this invention. FIG. XX sectional drawing of FIG. The circuit diagram which shows mainly an example of a structure of the determination circuit mainly. Explanatory drawing explaining the relationship between the light reception state of a light receiving element, the reference table for incident direction determination, and an incident direction determination signal. The front view which shows notionally the structure of a sunlight tracking apparatus. The side view which shows an example of the specific structure of a sunlight tracking apparatus. Similarly side view. The front view which shows the other example of the specific structure of a sunlight tracking apparatus. Similarly side view. The top view of a solar power generation device. The circuit diagram which shows an example of the electrical constitution of a solar power generation device.

A Light incident direction sensor 1 Cylinder 21, 2 2, 2 3, 2 4 Light receiving element 3 Shading mark 5 Determination circuit 51, 52, 53, 54 Incident light quantity measurement circuit 55 Comparison circuit a Incident direction determination signal B Sun light tracking device 10, 10 A , 10B Rotating mechanism P1 First shaft P2 Second shaft M1 First motor M2 Second motor C Solar power generation device

Claims (2)

A light receiving element disposed at four intersections of a cylinder having a transparent top wall and a side wall, and two straight lines orthogonal to each other at the center of the cylinder and a circle centered on the center of the cylinder inside the bottom of the cylinder A light-shielding mark provided at the center of the top wall of the cylinder and having a size capable of shielding two adjacent light-receiving elements at maximum among the four light-receiving elements, and an output of each light-receiving element. Incident light quantity measuring means for measuring the incident light quantity at the four intersections, and incident direction judging means for judging the incident direction based on the output value of the incident light quantity measuring means, and at least the cylinder, the light receiving element, and the light incident direction sensor shading marks constituting the sensor main body of the one unit.   The incident light quantity measured by the incident light quantity measuring means is compared, and the incident direction is detected and an incident direction detection signal is output. Further, the central axis of the cylinder corresponds to the detected incident direction. The light incident direction sensor according to claim 1, further comprising a determination unit that outputs a rotation direction signal indicating a direction in which the direction of the cylinder should be changed so as to coincide with the direction.

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