JPH11165700A - Controller for solar battery paddle mounted on artificial satellite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce mechanical reaction at the time of correcting the angle of displacement between cell surface direction and sun direction in a solar battery paddle mounted on an artificial earth satellite. SOLUTION: This controller, which controls the rotational rate (angular velocity) of a solar battery paddle 11 in answer to an artificial satellite orbital rate, in order to make the panel surface 11a of the solar battery paddle 11 mounted on the artificial satellite 1 which goes around the earth four times direct a sun direction θ, is constituted so as to detect the magnitude of displacement between the rotational rate and the orbital rate by a sun sensor, and change the rotational rate of the solar battery paddle 11 according to the detected amount. The error between the orbital rate of the satellite 1 and the rotational rate of the solar battery paddle 11 is corrected by adjusting and controlling the rotational rate value, thus it is possible to minimize correction amount and reduce reaction against a satellite body 12 at the time of array trim.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation control device for a solar battery paddle mounted on an artificial satellite.

[0002]

2. Description of the Related Art In an artificial satellite orbiting the earth while pointing in the direction of the earth by three-axis attitude control or the like, the cell surface 11a of a solar battery paddle 11 mounted on the artificial satellite 1 has, as shown in FIG. During the orbit, the rotation is controlled so as to always face the sun 2 direction θ.

Accordingly, when the artificial satellite 1 orbits along the orbit 3 in the direction of the arrow X, the satellite body 12 moves in the direction of the arrow 12a.
Solar array paddle 1
1 rotates around the pitch axis Y in the direction of arrow 11b.
However, while the artificial satellite 1 makes one orbit in orbit 3,
The artificial satellite 1 turns in the shadow of the earth 4 and the cell surface 11a of the solar battery paddle 11 may not receive the sunlight in some cases. During that time, the rotation of the cell surface 11a is controlled so as to face the sun 2 direction θ.

In the inertial space in which the artificial satellite 1 orbits the earth 4, the sun 2 can be regarded as being fixed, so that the cell surface 11a always points in the sun 2 direction θ. It is necessary that the rotation cycle of the solar battery paddle 11 about the pitch axis Y be synchronized with the orbital cycle of the artificial satellite body 12, and the solar battery paddle 11 rotates the artificial satellite body 12 (in the direction of arrow 12a). The rotation is controlled in the direction of the arrow 11b to cancel (cancel).

That is, the solar battery paddle 11 is controlled so that its rotation rate (angular velocity) matches the orbiting rate (angular velocity) of the artificial satellite main body 12, and the cell surface 11a always points in the two directions of the sun θ. Is always obtained.

[0006] The orbital rate of the artificial satellite 1 is obtained by measuring the distance from the ground station side to the artificial satellite 1 called ranging, or by calculation based on modeling of the orbit 3. However, satellite 1
The circulating rate fluctuates due to various factors, and it is not easy to grasp an accurate circulating rate.

That is, although the earth 4 revolves around the sun 2, its orbit is not a simple circle but a complex ellipse, and has seasonal fluctuations. It is considered difficult to accurately obtain the actual orbital rate of the artificial satellite 1 by calculation, because disturbance due to the solar wind or air resistance occurs when orbiting the orbit 3 relatively close to the earth 4.

As described above, since the orbiting rate of the artificial satellite body 12 fluctuates due to various factors, the solar cell paddle 1
A difference is generated between the rotation rate and the rotation rate set to 1, which is a deviation (error angle θs) between the direction of the cell surface 11a and the sun direction θ. Battery output power was reduced.

Therefore, as shown in FIG. 4, the solar battery paddle 11 and the sun sensor 11
d is provided, and a correction operation for correcting the rotation rate of the paddle drive mechanism 11c based on the detection signal of the sun 2 direction θ by the sun sensor 11d, ie, an array trim
trim) in accordance with the orbital cycle, and the error angle θ
By correcting s, the panel surface 11a is configured to track and direct in the two directions of the sun θ.

That is, the conventional solar cell paddle control device shown in FIG.
3, a clock rate signal corresponding to a preset rotation rate (angular velocity ωc) of the solar cell paddle 11 is transmitted from the clock rate generation circuit 13a to the switch 13b.
By being supplied to the paddle driving mechanism 11c via the paddle driving circuit 13c, the solar cell paddle 11 rotates in synchronization with the orbital rate of the artificial satellite body 12.

If the rotation rate of the satellite main body 12 is delayed or advanced with respect to the rotation rate of the paddle drive mechanism 11c, the deviation angle between the direction of the cell surface 11a and the two directions of the sun θ is increased. Therefore, an angle detection signal corresponding to the shift angle is obtained by the sun sensor 11d and supplied to the sensor input signal processing circuit 13d. The sensor input signal processing circuit 13d includes a solar cell panel 11a
Difference between the direction of the sun and the sun direction θ, that is, the error angle θ
s (deg (degree)) is calculated and supplied to the control circuit 13e.

The tracking control unit 13 is provided with an array trim rate generator 13f for generating a clock signal for an array trim rate (angular velocity ωp) having a cycle faster than the clock rate in order to correct a delay of the rotation rate in advance. As shown in FIG. 5A, the switching clock signal for the correction is changed by the time W corresponding to the delay of the rotation rate, as shown in FIG.
3b, paddle drive mechanism 1 via paddle drive circuit 13c
1c, the delay of the rotation rate is corrected.

Accordingly, the control circuit 13e receives the signal from the sensor input signal processing circuit 13d, calculates the required array trim correction time W according to the error angle θs due to the delay or advance of the rotation rate, and And control was performed. FIG. 5A shows a case where the delay of the error angle θs is corrected, but if the advance is corrected, the switching circuit 13 outputs the calculated time width W from the clock rate generator 13a. By stopping the supply of the clock rate signal, the correction for the advance is performed.

As described above, in the conventional apparatus, the rotation rate of the solar cell paddle 11 is corrected by the pulse-shaped correction control signal having the time W width according to the degree of delay or advance of the rotation rate.

Therefore, in the conventional rotation rate correction operation as described above, the pitch angular velocity of the solar cell paddle 11 is
As shown in FIG. 5B, the pitch attitude angle changed suddenly, and the pitch attitude angle of the satellite body 12 which received the reaction changed instantaneously as shown in FIG. 5C.

[0016]

As described above, in the conventional solar cell paddle control device, the magnitude of the delay or advance of the rotation rate of the solar cell paddle is controlled in accordance with the orbital cycle of the artificial satellite body. Since the array trimming was performed by the switching control with the time width corresponding to the above, the main body of the artificial satellite received a large reaction centering on the pitch axis, and the main body of the artificial satellite was disturbed in angular momentum in a step-like manner.

In recent satellites, solar battery paddles have been increased in size and weight with the increase in power demand. Therefore, the mechanical operation of the solar battery paddle has a greater effect on the satellite body, and the reaction of the array trim around the pitch axis has affected the attitude control of the satellite body as described above.

As described above, the attitude disturbance applied to the artificial satellite body degrades the attitude stability and, for example, does not achieve the observation accuracy required by the mounted observation sensor. Therefore, improvement has been demanded.

[0019]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a panel surface of a solar battery paddle mounted on an artificial satellite orbiting around the earth while pointing in the earth direction is directed in the sun direction. In order to control the rotation of the solar battery paddle in accordance with the orbital rate of the satellite, in a control device of a solar cell mounted paddle, the rotation rate of the solar cell paddle corresponds to the orbital rate of the satellite. And a control means for performing control in accordance with the magnitude of the deviation.

As described above, according to the present invention, the magnitude of the difference between the rotation rate of the solar battery paddle and the orbital rate of the satellite is detected by, for example, a sun sensor, and based on the detected sun tracking error. The correction is performed by changing the clock rate level of the solar battery paddle.

As described above, the device of the present invention corrects the difference between the rotation rate of the solar battery paddle and the orbital rate of the artificial satellite by adjusting the clock rate of the solar battery paddle. The size can be reduced, the angular momentum disturbance applied to the satellite body is reduced, and the performance of the artificial satellite can be greatly improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a control device for a solar battery paddle mounted on a satellite according to the present invention will be described below in detail with reference to FIGS. The same components as those of the conventional configuration shown in FIGS. 3 to 5 are denoted by the same reference numerals, and detailed description is omitted.

FIG. 1 is a block diagram showing one embodiment of a control device for a solar battery paddle mounted on a satellite according to the present invention.

That is, the sensor input signal processing circuit 13d of the tracking control unit 13 receives the angle detection signal of the sun direction θ from the sun sensor 11b and, as in the prior art, the pond cell surface 1d.
An angle difference between the direction of 1a and the sun direction θ, that is, an error angle θs (deg) is calculated and supplied to the control circuit 13e.
The detection of the error angle θs by the sun sensor 11d is performed at a timing at which sunlight can be received most and detected with good sensitivity in the orbit of the artificial satellite.

The control circuit 13e includes the sensor input processing circuit 1
A rate correction value Δω of the clock rate is calculated based on the error angle θs from 3d, and a correction value Δω obtained as a result of the calculation is obtained.
Is supplied to the variable clock rate generator 13g.

The variable clock rate generator 13a comprises a CPU together with the control circuit 13e.
The clock rate corrected based on the correction signal H from 3e is supplied to the paddle drive circuit 13c.

That is, the error angle θs (deg) of the sun tracking per orbit of the solar battery paddle 11 is calculated based on the angle detection signal of the sun direction by the sun sensor 11d and is expressed by the following equation (1). You.

Θs = ωp · T + ∫ωodt (1) where ωp: the driving rate of the solar cell paddle (deg /
sec) T: orbital cycle of artificial satellite (sec) ωo: average orbital rate of artificial satellite (360 / T) (de
g / sec) Further, since the error angle θs is the angle difference between the two sun directions θ detected by the sun sensor 11d and the direction of the panel surface 11a, the clock rate correction formula per orbital orbit by error correction is given by 2) It can be expressed by the following equation.

Ωp (n + 1) = ωp (n) − (Kp · θs + Kd · Δθs) (2) where Kp and Kd are the error angle θs and the error angle orbit change Δθs in the control system. Feedback gain Δθs: θs (n)-θs (n-1) n: Indicates the number of orbits of the artificial satellite.

In the above equation (2), the clock rate is corrected by the tracking control unit 13, and the correction amount of the clock rate per orbit of the artificial satellite body 12, that is, (ωp (n + 1) −
By setting ωp (n)) to a sufficiently small value, it means that the tracking error of the solar cell paddle 11 can be kept within the required accuracy.

That is, as shown in FIG. 2, the rotation rate (angular velocity) of the solar battery paddle 11 in the orbit of the satellite satellite body 12n is ωp (n) as shown in FIG. In order to correct the rate delay, the rotation rate in the next (n + 1) orbital orbit is set to ωp (n + 1), so that a small correction amount (ωp (n + 1) −ωp (n)) The required error angle θs can be corrected.

The accuracy required for the array trim is determined by the allowable fluctuation range of the power required from the artificial satellite main body 12 side. In general, the allowable accuracy of the sun tracking angle on the cell surface 11a of the solar cell in the artificial satellite. Is said to be about ± 2.5 degrees (deg).

Therefore, a description will be given in comparison with the conventional apparatus using specific numerical values.
Assuming 60 seconds (seconds), the orbit rate ω of the artificial satellite 1
o is 360 / T (deg / sec) = 1 (deg / sec)
c). Therefore, the rotation rate ω of the solar cell paddle 11
c is the same as the circulation rate ωo, ωc = 1 (deg / se
c) is set.

Now, in the conventional apparatus, for example, ±
Assuming that the angle error θs of 2.5 deg is corrected, the solar cell paddle 11 is rotated at a rotation rate ωc = 1 (deg / sec).
In c), it is necessary to control for a time W = 2.5 sec.

On the other hand, the correction amount of the clock rate in the apparatus according to the present embodiment is 1 as shown in FIG.
Since ± 2.5 deg is corrected in the time of the orbit (T = 360 sec), the correction rate amount (ωp (n + 1))
−ωp (n)) is the rotation rate ωc = 1 (deg / sec)
About ± 2.5 / T = ± 2.5 / 360 (de
g / sec), that is, ± 0.007 (deg / sec)
It can be corrected by the adjustment control of c).

As described above, the correction amount of the rotation rate of the solar cell paddle 11 is 1 (deg / sec) as compared with the conventional 1 (deg / sec).
According to this embodiment, ± 0.007 (deg / sec)
c), which can be suppressed to 1/100 or less as compared with the related art, so that the amount of disturbance caused by driving the solar cell paddle body 12 can be significantly reduced or eliminated.

As described above, according to the apparatus of the present invention, the level of the rotation rate of the solar battery paddle 11 is adjusted and controlled in accordance with the magnitude of the error between the orbit rate of the artificial satellite and the amount of correction. Is small, and the attitude stability of the satellite at the time of array trimming can be greatly improved as compared with the conventional art.

In this embodiment, the solar sensor 1
Although the error angle θs with respect to the sun direction θ detected in 1d has been described as being corrected in one round of the artificial satellite 1, it is needless to say that the error is corrected over a plurality of rounds so that the correction amount can be reduced. Can be adjusted. Furthermore, during the correction period, a smoother array trim may be performed by continuously changing the correction amount.

In the above embodiment, the sun sensor 11
d is attached to the solar cell paddle 11 that is driven to rotate, and the closed loop is configured to continuously control the rotation rate of the solar cell paddle 11 based on the detection signal of the sun direction θ by the sun sensor 11d. The rotation rate of the solar cell paddle 11 based on the detection signal in the sun direction θ can be intermittently corrected by an open loop.

In any case, according to the apparatus of the present invention, in the earth-oriented satellite, the difference between the rotational driving rate of the solar battery paddle and the orbital rate of the satellite body (error angle θ)
Since s) is corrected by changing the value of the rotation rate of the solar battery paddle, the error angle can be corrected with a small correction amount, and the mechanical reaction to the artificial satellite body can be greatly reduced.

Therefore, various observations and the like by the equipment mounted on the artificial satellite can be performed with high accuracy, and a great effect can be obtained in practical use.

[0042]

As described above, the apparatus of the present invention changes the level of the rotation rate of the solar cell panel according to the magnitude of the error between the rotation rate of the satellite and the orbital rate of the artificial satellite, so that the amount of change is small. Since the correction can be performed and the influence on the artificial satellite body can be reduced or eliminated, the function of the artificial satellite can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a control device for a solar battery paddle mounted on a satellite according to the present invention.

FIG. 2 is an explanatory diagram showing rotation rate control during trimming of a solar battery paddle array of the apparatus shown in FIG. 1;

FIG. 3 is an explanatory diagram for explaining rotation of an artificial satellite orbit and rotation of a solar battery paddle.

FIG. 4 is a configuration diagram showing a conventional control device for a solar battery paddle mounted on an artificial satellite.

FIG. 5 is an explanatory diagram showing rotation rate control during trimming of a solar battery paddle array of the device shown in FIG. 4;

[Explanation of symbols]

 Reference Signs List 1 artificial satellite 11 solar battery paddle 11a cell surface 11c panel driving mechanism 11d sun sensor 12 artificial satellite body 13 tracking control unit 13a clock rate generating circuit 13b switching circuit 13c paddle driving circuit 13d sensor input signal processing circuit 13e control circuit 13f array trim rate Generation circuit 13g Variable clock rate generation circuit 2 Sun 3 Orbit θ Sun direction Δθ Error angle 4 Earth

Claims (4)

[Claims] 1. A solar battery paddle corresponding to an orbiting rate of a satellite so that a panel surface of a solar battery paddle mounted on a satellite orbiting around the earth while pointing in the direction of the earth is directed in the direction of the sun. A control unit for controlling the rotation rate of the solar battery paddle in accordance with the magnitude of the deviation from the orbital rate of the artificial satellite. A control device for a solar array paddle mounted on a satellite, comprising: 2. The solar cell paddle according to claim 1, wherein a value of a difference between a rotation rate of said solar battery paddle and a orbital rate of said artificial satellite is detected by a solar sensor provided on said solar battery paddle. The control device of the solar cell paddle mounted on the artificial satellite described in the above. 3. A difference occurs between the rotation rate of the solar cell paddle and the orbital rate of the artificial satellite, and the rotation rate of the solar cell paddle changed according to the deviation is at least as large as the artificial satellite can change the earth. The control device for a solar cell paddle mounted on a satellite according to claim 1 or 2, wherein the control is continued during one orbit. 4. The solar cell paddle according to claim 1, wherein a rotation rate of said solar cell paddle is continuously changed.
The control device for a solar cell paddle mounted on a satellite according to any one of the above.