JPH04108098A - Sun following sensor - Google Patents

Abstract

PURPOSE:To detect a direction of the sun in a wide range by providing a plurality of photoelectric elements in a side surface, mounted to a space flying vehicle, and comparing a level of electric signals, output from these photoelectric elements, to judge the direction of the sun. CONSTITUTION:A bottom surface of a conical structural body 3 is connected to a side surface of a solar battery paddle 1 extended from an artificial satellite, and an axis of this conical structural body 3 is set to a vertical direction to a cell surface 2 of a solar battery cell. A plurality of photoelectric elements 4 of photodiode or the like for converting sunlight energy into an electric signal are arranged in a side surface of this conical structural body 3. A plurality of the photoelectric elements II are provided so as to constitute a plurality of element groups 5a, 5b... in which these photoelectric elements are group divided in a vertical direction from the point end toward the bottom surface along the side surface of the conical structural body 3. A suitable threshold level in accordance with performance of the photoelectric element 4 is set to an output electric signal of the photoelectric element 4, and a direction, to which the element group of outputting the electric signal of the threshold level or more is opposed, is judged the direction of the sun.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a sensor mounted on a spacecraft for detecting the direction of the sun, and particularly relates to a sensor mounted on a spacecraft for detecting the direction of the sun. This invention relates to a solar tracking sensor suitable for pointing purposes.

[Conventional technology]

Conventionally, in this type of sun tracking sensor, detection information on the direction of the sun is effective only when the sun is present within a certain limited range from the center of the sensor's field of view.

The direction of the center of the sensor's field of view is usually fixed in a direction substantially perpendicular to the solar cell surface, and the method has become such that the deviation between the center of the sensor's field of view and the direction of the sun is used as direction detection information.

(Problems to be Solved by the Invention) In the conventional solar tracking sensor described above, direction detection information is valid when the solar cell surface is approximately facing the desired direction of the sun. If an abnormal attitude of the satellite occurs and the sun is outside the field of view of the solar tracking sensor, the direction detection information will be invalid. The disadvantage was that it was not possible to obtain the desired results satisfactorily.

Means for Solving Jt] The solar tracking sensor of the present invention is mounted on a spacecraft and detects the direction of the sun, and includes a conical structure attached to the spacecraft and a It has a plurality of photoelectric elements disposed on the side surface, and a logic circuit that compares the magnitudes of electrical signals output from the plurality of photoelectric elements to determine the direction of the sun.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a conceptual diagram of a first embodiment of the present invention. In this embodiment, a solar array paddle 1 deployed from an artificial satellite is
A solar battery cell for supplying power to the satellite is installed on the surface of the conical structure 3, and the bottom surface of the conical structure 3 is connected to the side surface of the solar battery paddle 1. The axis of the conical structure 3 is perpendicular to the cell surface 2 of the solar cell.6 The side surface of the conical structure 3 is equipped with a photoelectric device such as a photodiode or a photoresistor that converts sunlight energy into an electrical signal. A plurality of elements 4 are arranged. The plurality of photoelectric elements 4 are divided into groups 2a, 2b, 2c, vertically along the side surface of the conical structure 3 from the tip to the bottom.
-, 2n (the n-th element group is not shown). Note that the number of photoelectric elements 4 in the element groups 2a to 2n may be one, but two or more are provided to provide redundancy in case of an abnormality.

In this configuration, the photoelectric element 4 of the element group that faces the sun most directly receives the largest amount of solar energy,
The electrical signal level outputted by the photoelectric element 4 becomes higher than the electrical signal level outputted by the photoelectric elements 4 of the other element groups. Utilizing this, the output electric signal of photoelectric element f4 is applied to photoelectric element 4.
Set an appropriate threshold level according to the performance. Then, the direction in which the element groups (which one of 5a to 5n) that output electrical signals equal to or higher than the threshold level are facing is determined to be the solar direction.

In this embodiment, by arranging a plurality of photoelectric elements 4 or element groups 5a to 5n on the side surface of the conical structure 3, it is possible to have a 360° field of view and detect the direction of the sun over a wide range. can.

FIG. 2 is a functional block diagram of a second embodiment of the present invention. In this embodiment, the solar tracking sensor of the present invention is used for solar tracking on the cell surface of a solar array paddle. Each of the plurality of element groups 2a, 2b, 2C, . . . , 2n has a plurality of charging elements 4. 2 made by thread/Soshold level judgment according to the performance of charging element 4
The value signal is inputted to the OR gate 6 for each element group, an OR gate is performed, and a directional light incident signal 11 is generated. These plurality of directional light incident signals 11 are sent to the drive logic circuit 7. Then, calculation is performed according to a predetermined logical operation formula, and based on the result, the element group (5a to
Drive signal 1 for directing in the direction of
Generates 2. The drive signal 12 is sent to a drive motor 8 that drives the solar battery paddle, and the torque generated by the drive motor 8 causes the solar battery paddle cell surface 2 to face directly toward the sun, which is the target direction.

〔Effect of the invention〕

As explained above, the present invention makes it possible to detect the direction of the sun over a wide range by arranging a plurality of photoelectric elements or element groups on the surface of a conical structure.
This has the effect of directing the cell surface of the solar array paddle towards the sun even in the event of an abnormal attitude of the satellite.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of a first embodiment of the invention, and FIG. 2 is a functional block diagram of a second embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Solar cell paddle, 2... Cell surface, 3... Conical structure, 4... Photoelectric element, 5a-5n... Element group, 6... OR gate, 7... Drive logic circuit,
8... Drive motor, 〕1... Direction incident light signal, 12...
・Solar battery paddle drive signal.

Claims (1)

[Claims] 1. A solar tracking sensor mounted on a spacecraft and detecting the direction of the sun, which includes a conical structure attached to the spacecraft, and a plurality of conical structures arranged on a side surface of the conical structure. A solar tracking sensor comprising: a photoelectric element; and a logic circuit that compares the magnitude of electrical signals output from the plurality of photoelectric elements to determine the solar direction. 2. The photoelectric element is divided into a plurality of element groups in the circumferential direction of the side surface of the conical structure, and an electric signal representing each element group is input to the logic circuit. The solar tracking sensor according to claim 1. 3. The solar tracking sensor according to claim 1 or 2, wherein the photoelectric element included in the element group is single or plural. 4. The logic circuit includes a binary signal conversion circuit that converts the electrical signal output from the photoelectric element in the element group into a binary signal, an OR circuit that takes an OR gate of the binary signal, and a plurality of the OR circuits. 4. The sun tracking sensor according to claim 1, further comprising a logic circuit that determines the direction of the sun from an OR gate output output from the sun tracking sensor. 5. In the solar battery paddle mounted on the spacecraft, the solar battery cell surface is adjusted using a drive signal created from the solar direction signal output from the solar tracking sensor according to claim 1, 2, 3, or 4. A solar cell paddle characterized in that the solar cell paddle is oriented in the direction of the sun.