JPS6194900A - Digital solar sensor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital sun sensor that detects the incident angle of sunlight as a digital signal.

As is well known, information regarding the relative angle between the senna optical axis direction and the sun direction is necessary for determining the attitude of, for example, a three-axis controlled artificial satellite flying in space.

[Conventional technology]

First, a conventional solar sensor will be briefly explained.

FIGS. 3(a) and 3(b) are conceptual diagrams showing the appearance of one configuration example of a digital solar sensor.

In this figure, (1) is a slit, and (21 is a light shielding film).

(3) is a prism, (4) is a light-receiving surface with a gray code pattern formed by the light-shielding film (2), (5) is a photodetection element,
(6) is a fixed frame.

In such a configuration, the sunlight sl passing through the slit tl irradiates the light receiving surface (4) corresponding to the incident angle θ as shown in FIG. 3 (bl). As shown in the figure, a plurality of photodetecting elements (5) are arranged, and a gray code pattern is formed by a light-shielding film (2) on the light-receiving surface side. The photodetector element (5) hit by the light generates an electrical signal.

Then, this signal is set to "1" in the 0N10FF circuit (7), and the output signal of the photodetecting element that is not hit by light is set to "0" and sent to the register (8).

A combined signal of 1" and 0" in the figure can be obtained. Therefore, if the combination of 1" and 0" is made different depending on the irradiation position of the light, the solar incident angle θ can be determined from the output signal. be able to.

[Problem that the invention seeks to solve]

By the way, in the above-mentioned conventional sensor, the gray code pattern is directly formed on the photodetecting element due to the difference in dimensions between the light receiving surface and the light shielding surface.

Since the angle of incidence θ is detected by changing the combination of "0" signals, in principle a plurality of photodetecting elements are required, and in order to increase the detection accuracy.

There were problems such as the need to increase the number of photodetecting elements.

This invention was made to solve this problem, and is a digital sensor that can detect the solar incident angle θ with a single photodetector, without using a detection element with a gray code pattern formed directly on the photodetector. The purpose is to obtain a solar sensor.

[Failure to solve the problem]

The digital sun sensor according to the present invention has a light-receiving surface formed by a plurality of optical fibers, a repeater provided in the middle of each optical fiber, and an optical fiber bundle in which each optical fiber pulled out from the repeater is made into one bundle. A transmittance control device controls the light transmittance of the intermediary medium filled in the repeater, and output signals from the photodetector and transmittance control device are used to detect sunlight. It is equipped with a signal processing device that detects the angle of incidence.

[Effect]

In this invention, the transmittance control device changes the light transmittance of the intermediary medium filled in each repeater to block or conduct the sunlight signal transmitted in the optical fiber, and corresponds to the solar incident angle. When the solar light signal from the optical fiber is cut off, the output of the photodetecting element changes from 1 to 0, for example, so the solar incident angle can be detected from the optical fiber number at this time.
[Embodiment] Figure 5g1 is a schematic diagram showing the configuration of an embodiment of Jin's invention. In the figure, (11, (5), <6), +81
is exactly the same as or equivalent to the above-mentioned conventional device.

Moreover, FIG. 2 is a diagram showing the structural concept of the transmittance control device (9) and the repeater (C), which are the components of FIG. 1.

ff) is an optical fiber arranged in a row by a fixed frame (6) to form a light-receiving surface, and (C) is a repeater installed in the middle of the optical fiber (f), as shown in Fig. 2 in more detail. As such, the interior is filled with intermediary medium α4.

Furthermore, an electrode (US) is incorporated. Also, an optical fiber (f
) is cut off and fixed to the repeater (C)K.

(9) is a transmittance control device, as shown in FIG.

Switch control circuit value υ, switch section 13 and power supply circuit (+
It consists of 31. αQ is a signal processing device that receives signals from the photodetector (5) and the transmittance control device (9) and outputs an output signal to the register (8).

In the digital solar sensor configured as above-
[, sunlight S/ passing through the slit (1) irradiates the optical fiber (f3) corresponding to the incident angle θ. Sunlight S/ is transmitted through the optical fiber (f3) and illuminates the photodetector element (5) via the repeater (C3).

Switch control circuit αυ constituting the transmittance control device (9)
First, when the switch S of the switch part a''jJ corresponding to the repeater (cl) is closed, an electric signal is applied from the power supply circuit 13 to the electrode (I!9) and the intermediary medium (14
If a liquid crystal or the like is used as the material, it becomes cloudy and the transmittance of light decreases, making it possible to block the conduction of sunlight at. When the switch 8 is opened by the switch control circuit (Iυ), the electric signal is cut off and the intermediary medium I regains high transmittance and the sunlight S/ is conducted.However, in this embodiment, the sunlight
is conducting through the optical fiber (f5), so the output of the photodetecting element (5) remains unchanged in response to the above operation, and the signal processing equipment member selects the register ( 8) is set to "1". Below, the repeater (
C2), (C5), . . . block photoconduction.

In this process, if the signal of the register (8) corresponding to the number of the repeater (c) when the output of the photodetector (5) drops below a certain level is 0'', then the 101 signal of ``B'' in the figure A combination is obtained. Depending on the irradiation position of the light, this “1°”
, "0" are different, so the sunlight incident angle is detected.

[Effects of the invention] Show.

As explained above, this invention forms a light-receiving surface with a plurality of optical fibers, and a repeater is provided between each optical fiber to sequentially interrupt the transmission of light.
by several photodetecting elements.

It has the effect of being able to digitally detect the angle of incidence of the sun.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. Fig. 2 is a diagram showing the configuration concept of the transmittance control device and repeater that are the constituent elements of this invention, Fig. 3 is a schematic diagram of the configuration of a conventional digital sun sensor, and Fig. 4 is a conventional photodetector play configuration. FIG. 2 is a diagram showing the concept of digital signal generation. In the figure, (1) is Surin), (51 is a photodetector element, (fl is an optical fiber, (C) is a repeater, (6) is a fixed frame, (8) is a register, and (9) is a transmittance control equipment, Ql
is a signal processing device, aD is a switch control circuit, (I2 is a switch section, (11 is a power supply circuit, (14 is an intermediary medium, α
9 is an electrode.

Claims (1)

[Claims] An optical fiber cord configured by arranging a plurality of optical fibers, a repeater provided between each of the optical fibers, an intermediate medium filled in the repeater, and control of light transmittance of the intermediate medium. a transmittance control device, a photodetection element placed at one end of a bundle of optical fibers pulled out from the repeater, and an output signal from the transmittance control device and the photodetection element. A digital solar sensor comprising: a signal processing unit that measures a solar angle by inputting the signal.