JP2007155625A - Sunlight spectrum tracking apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sunlight spectrum tracking apparatus used for a sunlight spectrum apparatus for measuring sunlight spectrums in a predetermined area and researching an air pollution in the area, reducing a noise due to a scattered light, and enabling a continuous measurement for a fixed time. <P>SOLUTION: The sunlight spectrum tracking apparatus is provided with a cylindrical telescope installed in the rotational center, three or more slits having minute holes on the central axis in the longitudinal direction of the telescope, and a photodiode disposed in a bottommost section. The telescope is disposed on a latitude controller whose angle is adjusted in the latitude direction on a circular quarter seat. The circular quarter seat is disposed on a longitude controller whose angle is adjusted in the longitude direction over 360°. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solar spectrum tracking device.

  It is possible to observe the state of the earth's atmosphere with the sun as a reference, and if the spectrum of sunlight is observed from the ground, the state of air pollution can be known. It may be possible to observe changes in the degree of air pollution between metropolitan areas such as Tokyo and rural mountainous areas, and changes in the destruction of the ozone layer as differences in spectral intensity. To that end, it is important to develop a spectroscopic system that observes sunlight. However, before that, first of all, it becomes a problem to manufacture a telephoto device that can accurately measure the solar spectrum and a cheap, simple and highly accurate solar tracking device. The present invention relates to a solar spectrum tracking device.

  As a prior patent document, there is a “solar automatic tracking device” (Patent Document 1). However, in the device of this publication, A / D conversion is performed on the output of four or more sensors in which filters are arranged on the light receiving element washing surface. The apparatus is complicated and expensive.

JP-A-8-63232

  The present invention is for a solar spectrum observation apparatus for investigating atmospheric pollution in a given area by measuring the spectrum of sunlight in a given area. An object of the present invention is to provide a solar spectrum tracking device that can be measured.

  In the present invention, a cylindrical telescope installed at the center of rotation, three or more slits having micro holes on the central axis in the length direction of the telescope, and a photodiode at the bottom And the telescope tube is disposed on a latitude control device whose angle is adjusted in the latitude direction on a substantially circular ¼ pedestal, and further, the substantially circular 1 / The pedestal 4 is a solar spectrum tracking device characterized by a structure arranged on a longitude control device whose angle is adjusted in a substantially circular longitude direction.

  FIG. 1 shows an overall view of the apparatus. The upper round part is a plan view of the device. Based on the center of the circle, there is a base that is 1/4 the size of the circle and rotates in the longitude direction. On the pedestal is installed a telescope that allows sunlight to enter the center of the circle via the motor 1 and the worm gear. Figure 2 shows a schematic view of the desired cylinder. In order to prevent the scattered light from entering the photodiode so that the scattered light from the sunlight does not affect the spectrum measurement, the telescopic tube is set with a three-stage slit. The telescope tube rotates in the latitude and longitude directions of the sun. The lower side view is a view of the device from the side. In this figure, the telephoto tube is located at the center upper part and faces directly upward. Here, for example, if the telescope is to be adjusted to the height of the sun, the motor 2 is rotated to move the upper pedestal so that it is aligned with the longitude direction of the sun. Next, rotate the motor 1 and move the telescope to adjust the height to the latitude of the sun. The sun can be tracked just by aligning these two axes.

  Next, the desired cylindrical portion that receives sunlight will be described in detail. A schematic view of the desired cylinder is shown in FIG. The total length is 161 mm, and the inner diameter is φ26 mm and φ14 mm, and each length is about 60 mm. Between them, three slits with a hole of φ1 mm are incorporated. Sunlight enters through slit 1, passes through slit 2, and passes through slit 3. The light then enters a photodiode (Hamamatsu Photonics: S2386-18L type). The cylinder that houses the photodiode has an inner diameter of 14 mm and a length of 37.5 mm. A 100Ω resistor is connected to the output terminal of the photodiode, and the output current of the photodiode flows through the resistor. An output voltage is generated across the resistor. The output voltage is measured with a digital multimeter (Advantest: R6552). The highest output voltage measured so far was 6V. The output power is 360 mW, and has not yet reached the saturation power of the photodiode. In addition, when sunlight does not enter the observation cylinder, there is no influence of scattered light, so the output voltage of the photodiode becomes a value near 0 mV.

  The motor that moves the telescope and pedestal uses a 5-phase stepping motor (Oriental Motor Company: RK564BA). The rotation of the motor is converted by a worm gear, and the rotation speed of each shaft that moves the telescope and the pedestal is changed. The worm used is W1S R1 + B-8, and the foil is G1C 60 + R1. Here, the number of pulses put into the stepping motor to rotate the telescope 180 ° is 7500 pulses. There are 41.66 pulses per degree. The number of pulses actually used for control is 2 pulses per step. In other words, it takes 2.88 minutes per step.

  Next, a program for tracking the sun for a certain period of time, in which the spectrum of the sunlight can be measured as a result of actually tracking the sun, will be described. FIG. 3 shows a flowchart thereof. Start the program and read the photodiode voltage first. Here, five samples of voltage values are taken, and the average of the five values is calculated as a voltage value. Then, it is determined whether the voltage value has increased or decreased by comparing this voltage value with the newly acquired new voltage value. Also, voltage values are plotted on a graph. Here, the desired cylinder is set to the sun so that the voltage value is about 3V to 5V in advance. Then, tracking is started. The development program software used is LabVIEW 7.1. The program consists of four condition cases. The first is when the voltage value is decreasing when the voltage value: X is 5.5V or less and 1V or more. At this time, the sunlight moves away more and more, so the step interval time moves fast to catch up with the sun. The second case is when the voltage is rising when X is 5.5V or less and 1V or more. In this case, since the angle of the telescope is ahead of the movement of the sun, the movement of the telescope is slowly moved to wait for the sun to follow. At this time, the step interval time is delayed. The third is when X reaches 5.5V or higher and reaches its peak value. At this time, the movement of the desired cylinder is stopped. Then, the sun moves (exactly the earth moves), so X descends. And when X becomes 5.5V or less, the telephoto tube starts to move.

  The principle of solar light tracking has been described above with reference to the flowchart. FIG. 4 shows a voltage value graph in a situation where tracking is actually performed. In this graph, time passes from the left side to the right side. The beginning gradually moves to the right side on the left side. The vertical axis is the voltage value. In the graph, tracking reached its peak value (6V) at first. Here, tracking stops. When the voltage drops below 5.5V, tracking starts again. At first, the observation cylinder (latitude direction) is rotated and the peak is reached. Next, the pedestal (longitude direction) is rotated and tracking is performed until the peak is reached. Here, the voltage drops to the lower right when stopped, because the sun moves, so the voltage drops because of the slur from the peak position. It becomes jagged during tracking when moving the cylinder in one step to measure the voltage and then measuring the voltage after 3 seconds, the cylinder is stopped. And since the sun passes in the meantime, the voltage drops and becomes jagged. This tracking mode is a tracking mode in which X is in a descending state. Here, the number of desired cylinder rotation (latitude) pulses is 174, the number of pedestal rotation (longitude) pulses is 642, and the movement in the longitude direction is about 3.7 times the movement in the latitude direction. From this, it can be seen that tracking is performed while maintaining the peak value with a period of about 100 seconds with a vibration width of 10% of the peak voltage.

  Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and additions within the scope of the present invention are included in the present invention. It is.

FIG. FIG. The flowchart of sunlight tracking. Voltage value graph in the sunlight tracking state.

Claims (2)

  Solar spectrum tracking, characterized in that a cylindrical telescope installed at the center of rotation, a slit having a minute hole on the central axis in the length direction of the telescope, and a photodiode at the bottom apparatus.   The telescope tube is disposed on a latitude control device whose angle is adjusted in the latitude direction on a substantially circular ¼ pedestal, and the substantially circular ¼ pedestal is angled in a substantially circular longitude direction. The solar spectrum tracking device according to claim 1, wherein the solar spectrum tracking device is arranged on an adjusted longitude control device.