JPH07281592A - Planetarium - Google Patents

Abstract

PURPOSE:To enable spectators to sufficiently understand precession by executing performance of the precession having high reality. CONSTITUTION:The virtual unit time DELTAtau is set in accordance with the ratio Vt of the virtual unit time in performance to the real unit time inputted from a console (S3). Next, rotating amts. DELTAtheta1 to DELTAtheta5 corresponding to the virtual unit time DELTAtau are calculated (S4). Respective motors are thereafter rotated by DELTAtheta1 to DELTAtheta5 determined in the step S4 when the lapse of the actual unit time deltat (1 second) is judged. The precession is continuously reproduced along the flow of the time by repeating such processing.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a planetarium.

[0002]

2. Description of the Related Art The direction of the earth's axis of rotation on a celestial sphere is not constant, but changes due to precession and nutation. There are two types of precession: day-month precession and planetary precession. In the following description, precession and nutation are collectively referred to as “precession and the like”.

The sun-moon precession is a precession due to the attractive force between the sun and the moon, which causes the celestial north pole of the earth to have a polar distance of about 23 ° from the north pole of the ecliptic. It moves on the circle of 5 with a cycle of about 25,800 years.

Planetary precession is a precession due to the attractive force of the planet, and the ecliptic inclination angle is 21 °. 9 to 24 °. Change to 3 in 40,000 year cycle. As a result, about 10,000 years ago, 24
°. The angular distance between the ecliptic pole, which was 2, and the celestial north pole, is now about 23 °. 5 and 22 °. After about 10,000 years. Becomes 6. Although this planetary precession is less affected than the Japan-Months precession, it is not a negligible amount.

The nutation is caused by a change in the positional relationship between the white and ecliptic planes, and the maximum amplitude of the rotation axis is about 9 ".2.
It vibrates at a cycle of about 18.6 years.

As described above, in the case of reproducing the change of the earth's rotation axis with respect to the celestial sphere with the planetarium, the conventional planetarium is reproduced by the three-axis synthetic motion of the diurnal axis, the latitude change axis and the horizontal rotation axis. , 23 ° to the diurnal axis. A method is adopted in which a precession axis with five inclinations is provided and a star sphere is rotated about the axis to reproduce the day-month precession.

[0007]

However, the conventional reproduction of the precession and the like has been performed independently of the other effects in any of the above methods. In other words, it ignored the actual flow of time (that is, the movement of the celestial body) and simply changed the position of the celestial north pole on the celestial sphere. For example, the effect is to instantly move the heavenly North Pole from the position of AD 1993 to the position of BC 3000. Thus, conventionally,
Because the production was performed ignoring the flow of time during production,
It was an obstacle for the audience to understand the precession.

Further, only a star projector can automatically reproduce the precession and the like, and the operator's manual work is left to reproduce the position of the planet at that time, so that the operator's burden is heavy.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a planetarium in which the audience can easily understand the precession and the like and the operator's burden is small.

[0010]

In order to achieve the above object, the invention according to claim 1 sets a virtual time flow at the time of performance, and a time flow based on the time flow in the setting means. And a directing means for directing a difference or the like.

According to a second aspect of the present invention, a projector for projecting an celestial body on a dome, which is supported so as to be rotatable about a plurality of axes, and setting means for setting a virtual unit time for performance. And a daily driving calculation means for calculating the rotation angle of each axis required to produce a daily movement corresponding to the virtual unit time, and a precession corresponding to the virtual unit time. A precession drive calculation means for calculating the rotation angle of each of the axes necessary for producing the
Drive means for rotationally driving each of the axes at every actual unit time based on the calculation results of the daily drive calculation means and the precession drive calculation means.

The invention of claim 3 is characterized in that the projector includes a star projector and a planet projector. In particular, the invention according to claim 4 is characterized in that the planetary projector projects only planets beyond Jupiter during the operation of the drive means in order to make the production more understandable to the audience.

In order to make the operation of the operator simpler, the invention according to claim 5 is characterized in that the setting means includes input means for inputting a ratio of the virtual unit time to the actual unit time. And

[0014]

According to the first aspect of the invention, the precession and the like are reproduced along the virtual flow of time set by the setting means. For example, as described in claim 2, first, the rotation angle of each axis of the projector necessary to produce the diurnal motion and precession corresponding to the virtual unit time is calculated every time the actual unit time elapses. To do. Then, based on the calculation result, each axis may be driven every time the actual unit time elapses.

For the production of precession and the like, both a star projector and a planet projector can be used as described in claim 3. At this time, as described in claim 4, it is desirable that the planetary projector projects only planets beyond Jupiter.

According to the fifth aspect of the present invention, the virtual flow of time can be set only by inputting the ratio using the input means.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross section of the slanted dome D taken along the meridian plane. The horizontal line is indicated by a point 4, and the direction of the heavenly North Pole is indicated by an arrow with a figure number 5. In addition, in the figure, the pole of the ecliptic is south-south, and the arrow with the reference number 6 indicates the pole of the ecliptic. The celestial north pole 5 moves on a small circle passing through the celestial north pole 5 around the ecliptic pole 6. Arrow 5'represents the position of the heavenly North Pole to be moved by the lunar precession.

A star projector 2 and a planet projector 3 are installed at the center of the inclined surface of the dome D. Planetary projectors 3 are installed as many as the Sun, Mercury, Venus, Earth, Moon, Mars, Jupiter, Saturn, Uranus and major planets. This may be increased or decreased as needed. A console 1 for operating and controlling the star projector 2 and the planet projector 3 is installed behind the dome D.

FIG. 2 shows a star projector 2 for projecting a star image. The star projector 2 generally supports a star sphere 10 rotatably about axes I to III. A plurality of star projectors 7 and constellation projectors 8 are provided around the star sphere 10. Further, the main body of the star sphere 10 is supported by a diurnal rotation ring 9 provided around it so as to be rotatable about a diurnal axis I. The daily rotation ring 9
Two latitude change axes II and II 'are extended. Latitude change axis I
I and II 'are bearings 1 installed on the azimuth rotary ring 12.
It is rotatably supported by 1, 11 '. The azimuth rotary ring 12 is supported by a main body stand 13 so as to be rotatable about a horizontal rotary shaft III. This horizontal axis of rotation II
I coincides with arrow 6 indicating the zenith. Also, θ1, θ
2 and θ3 respectively indicate the rotation angles of the diurnal axis I, the latitude change axes II and II ′, and the horizontal rotation axis III.

FIG. 3 shows one of the planetary projectors 3. The projection unit 40 of the planet projector 3 has two orthogonal axes.
It is supported so as to be rotatable around IV and V, and the planet can be projected at any position on the dome D. Further, θ4 and θ5 represent the rotation angles of the axes IV and V.

FIG. 4 is a block diagram showing the control circuit of the star projector 2 and the planet projector 3. The CPU 50 housed in the console 1 includes a latitude setting volume, a longitude setting volume, an azimuth angle setting volume, an operation end switch (not shown), a general command input keyboard 52, and a time setting volume 51. It is connected. The volume and keyboard 52 are operated by the commentator on the console 1. The time setting volume 51 is a means for inputting a ratio Vt of a unit time (virtual unit time) of virtual time in the effect to a unit time (actual unit time) of real time. Further, the CPU 50 stores in advance various parameters relating to the operation of the celestial body, particularly parameters relating to precession (amplitude, cycle, etc.).

The value set on these consoles 1 is C
It is input to the PU 50. The CPU 50 instructs each motor drive circuit for rotationally driving the axes of the star projector 2 and each planet projector 3 to control the rotation speed and the rotation angle.
Each motor drive circuit controls the motor in charge according to a control signal input from the CPU 50.

If the values of these volumes are set to be constant, the time and angle of the controlled object are increased at a constant rate. For example, if the value of the time setting volume 51 is always set to 100, 1 of the real time t
The virtual time τ advances in the dome D at a speed of 00 times. Then, the respective axes of the star projector 2 and the planet projector 3 are rotationally driven with the virtual time τ as a reference.

Next, the operation of this embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing the control procedure of the CPU 50.

First, as an initial setting, the input of the starting date and time is accepted from the keyboard 52 (step S
1). For example, when observing a change from January 1, BC 3000, such an input is made. If you want to observe the change from the current time, enter the current date and time. Similarly, the longitude and latitude of the observer are input from the keyboard 52. As a result, the star projector 2 and the planet projector 3 reproduce the celestial sphere at the designated time and at the designated time on the dome D. Then, the values of θ1 to θ5 at that time are set as initial setting values θ10 to θ50. At the same time, the value of the time setting volume 51 is checked to initialize the ratio Vt of the virtual unit time to the actual unit time.

Next, when there is an effect start instruction from the keyboard 52 (step S2: y), the process proceeds to step S3. In step S3, the value Vt of the time setting volume at that time is determined, and the virtual unit time Δτ (= k · Vt) in the production in the dome D proportional to Vt is set. Here, k is a proportional constant and is stored in the CPU 50 in advance.

Next, Δθ1 to Δθ5 when the virtual unit time Δτ is advanced are calculated (step S4). here,
[Delta] [theta] 1 to [Delta] [theta] 3 are calculated by the sum of the changes due to the diurnal motion and the changes due to the day / month precession.
That is, this step S4 corresponds to the daily driving calculation means and the precession driving calculation means. After that, when it is determined that the virtual unit time Δτ, that is, the real unit time Δt (1 second) has elapsed (step S5: y), each motor drive circuit is caused to rotate each motor by Δθ1 to Δθ5. A command is issued (step S6). Then, if there is a continuation of the effect (step S7: n), the process returns to step S3 and the above procedure is repeated. On the other hand, when it is determined that the effect is finished by operating the keyboard 52 (step S7: n), a series of controls is finished. As described above, the sun and moon precession of stars and planets are reproduced on the dome D.

An example of an effect according to this flowchart will be described below. For example, it is assumed that the operator sets Vt so that 1 second of the real time corresponds to a virtual time of 1 year in the effect in the dome. At this time, in terms of performance, 31
Time flows at a speed of 536,000 times. Therefore, when the actual unit time Δt is 1 second, the axes I to V are intermittently driven and controlled every 1 second, but each time the axes I to V are driven, the effect on the dome D is 1 in terms of performance. The year (= Δτ) will pass. That is, the precession can be changed by one year every second of the real time. When the total time required for the presentation is 30 minutes (1800 seconds) in real time, a precession of 1800 years can be produced during that time. In the case of continuous precession like this, the movement of Mars, Venus, and Mercury is too fast, which is annoying. Therefore, it is desirable to limit the planets projected at the time of precession to planets beyond Jupiter. In order to reproduce the precession and the like for one cycle, it is desirable to set Δτ to about 20 to 30 years.

In the present embodiment, the precession can be reproduced only by calculating the change in the positions of θ1 to θ5 by the calculation of the CPU 50, so that not only the day-month precession but also the planet precession and nutation are reproduced. It's also easy.

Further, since the flow of virtual time can be set only by inputting the ratio of the virtual unit time to the actual unit time, the operation is easy. In particular, even during production, the ratio Vt of the virtual unit time Δτ to the actual unit time Δt, that is, the flow of virtual time can be changed by operating the time setting volume 51, so that the degree of freedom of production is increased. It is expensive and can easily perform various effects.

In the above embodiment, the example in which the present invention is applied to reproduce the precession motion by the three-axis combined motion of the diurnal axis, the latitude change axis, and the horizontal rotation axis has been described.
It can also be applied to one that reproduces precession by using four axes in which a precession axis is added to the axis.

[0032]

According to the first aspect of the invention, the precession and the like are reproduced along the virtual flow of time set by the setting means. For example, as described in claim 2, first, the rotation angle of each axis of the projector necessary for producing the diurnal motion and the precession corresponding to the virtual unit time is calculated every time the actual unit time elapses. Based on the result, each axis is driven every time a real unit time elapses. Therefore, the precession and the like can be produced along the actual flow of time, and the precession and the like can be explained to the audience in an easy-to-understand manner.

Further, as described in claim 3, both the star projector and the planet projector can be used for the production of precession and the like, and all the projectors are automatically operated only by setting a virtual time flow. Since it is driven by, the operation by the operator is easy. At this time, the movements of Mars, Venus, and Mercury are too fast, which is rather annoying to the audience. Therefore, as described in claim 4, it is desirable that the planetary projector projects only planets beyond Jupiter.

According to the fifth aspect of the present invention, the virtual flow of time can be set only by inputting the ratio using the input means, so that the operation by the operator is further facilitated.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an inclined dome D.

FIG. 2 is a perspective view showing a star projector 2. FIG.

FIG. 3 is a perspective view showing a planetary projector 3.

FIG. 4 is a block diagram showing a control circuit according to the present invention.

FIG. 5 is a flowchart showing control of a CPU 50.

[Explanation of symbols]

 D ... Dome 2 ... Stellar projector 3 ... Planetary projector 50 ... CPU 51 ... Time setting volume 52 ... Keyboard θ1 ... Rotation angle of diurnal axis I θ2 ... Rotation angle of latitude change axis II θ3 ... Rotation of horizontal rotation axis III Angle θ4 ... Rotation angle of axis IV θ5 ... Rotation angle of axis V

Claims (5)

[Claims] 1. A planetarium, comprising: setting means for setting a virtual flow of time during production, and production means for producing a precession or the like based on the flow of time in the setting means. . 2. A projector for projecting an celestial body on a dome, which is supported so as to be rotatable about a plurality of axes, a setting unit for setting a virtual unit time for presentation, and a unit corresponding to the virtual unit time. The daily drive calculation means for calculating the rotation angle of each axis required for producing the diurnal movement every time the actual unit time elapses, and necessary for producing the precession or the like corresponding to the virtual unit time. Based on the calculation results of the precession drive calculation means for calculating the rotation angle of each axis at each actual unit time, and the daily drive calculation means and the precession drive calculation means, each axis is calculated at each actual unit time. A planetarium comprising: a driving unit that is rotationally driven. 3. The planetarium according to claim 2, wherein the projector includes a stellar projector and a planetary projector. 4. The planetarium according to claim 3, wherein the planet projector projects only planets beyond Jupiter during operation of the drive means. 5. The planetarium according to claim 2, wherein the setting unit includes an input unit that inputs a ratio of the virtual unit time to the actual unit time.