JPH07228299A - Solar battery paddle drive control device for three-axis stable satellite - Google Patents

Abstract

PURPOSE:To prevent the occurrence of the solar steering error of a paddle owing to light, deflected by a globe, of solar light right after transfer from sun shadow to sunshine and right before transfer to sun shadow from sunshine through control of drive of the solar battery paddle of a three-axis stable satellite. CONSTITUTION:A timing processing part 7 is provided to make a signal, by means of which a signal for the paddle drive rotation angular velocity error of a rotation angle generating part 5 is used or not used by a drive pulse generating electronic circuit 10, according to specific delay times t1 and t2 based on an output signal from a solar presence generating part 4. A signal from a solar sensor for tracing is not used in a position on an orbit influenced by light, deflected by a globe, of solar light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell paddle drive control device for a triaxial stable satellite.

[0002]

2. Description of the Related Art FIG. 3 is a functional block diagram showing a conventional solar cell paddle drive controller for a triaxial stable satellite. In the figure, reference numeral 1 is a voltage signal proportional to the sun angle set on the solar cell paddle. Tracking solar cells A, 2 are tracking solar cells B 1, which output a voltage signal proportional to the sun angle set on the solar array paddle at an angle different from that of the tracking solar cells A 1, and 3 are tracking solar cells A 1, A tracking sun sensor composed of a tracking solar cell B2, 4 is a solar presence generator that generates a signal indicating that the tracking solar cell A1 and the tracking solar cell B2 are measuring the sun angle, and 5 is a tracking sun. A rotational angular velocity generator that generates a solar cell paddle rotational angular velocity error signal based on the sun angle calculated from the cell A1 and the tracking solar cell B2, and 6 rotates at an orbital angular velocity when the solar cell paddle is in the shade. An orbital angular velocity generating unit for generating a signal for generating a signal, an adder 8 for adding an output signal of the rotational angular velocity generating unit 5 and an output signal of the orbital angular velocity generating unit 6, and 9 for a sun presence generating unit 4, a rotational angular velocity generating unit 5, A paddle drive control circuit including an orbital angular velocity generator 6 and an adder 8 is a drive pulse generation electronic circuit for generating a pulse for driving a motor of a paddle drive mechanism based on a drive signal output from the paddle drive control circuit 9, 11 Is a paddle drive circuit for driving the solar cell paddle.

Next, a solar cell paddle drive control system using a tracking sun sensor will be described. As shown in FIG. 3, the output of the tracking sun sensor has a mountain shape with the difference between the sun direction angle and the paddle rotation angle as a variable, and the tracking solar cell A
1 and the tracking solar cell B2 have different output phases. The respective outputs are v ₁ and v _2, and v ₁ + v ₂ is input to the sun presence generator 4, and v ₂ −v ₁ is input to the rotational angular velocity generator 5. The sun presence generator 4 sets the presence signal from 0 to 1 when v ₁ + v ₂ is a certain value or more. The rotational angular velocity generator 5 outputs the paddle rotational angular velocity error Δω in a manner substantially proportional to v ₂ −v ₁ as shown in FIG. The paddle rotation angular velocity passed to the drive pulse generating electronic circuit 10 is the sum ω ₀ + Δω of the orbital angular velocities ω ₀ and Δω of the orbital angular velocity generator 6. It should be noted that when the sun presence signal is 0, that is, in the shade, zero is substituted for Δω. The drive pulse generation electronic circuit 10 generates current pulses for driving the step motor of the paddle drive mechanism 11 at pulse intervals inversely proportional to the input rotation angular velocity. The paddle drive mechanism 11 rotates the solar cell paddle at a constant angle increment each time the current pulse is input. Therefore, the paddle rotation angle θ _p is an amount obtained by integrating the rotation angular velocity signal ω ₀ + Δω with time. When the feedback loop of the solar cell paddle drive control is configured with the signal flow shown in FIG. 3, the entire closed-loop transfer function becomes the form of a first-order lag filter, and the control system outputs Δω for the v ₂ -v ₁ input of the rotational angular velocity generator 5. It is stable regardless of the size of the proportional coefficient of.

[0004]

In the conventional solar cell paddle drive control device, when the satellite is in the shade, the solar cell paddle is driven at a constant rotational speed of the orbital angular velocity, and when the satellite is in the sunshine, the tracking sun sensor outputs. The solar array paddle is driven by closed loop control so that the sun angle is zero. However, immediately after the satellite shifts from the shade to the sunshine and immediately before the shift from the sunshine to the shade, sunlight reflected on the earth, that is, light in which albedo and original sunlight are combined, enters the tracking sun sensor. Since this synthetic light is different from the original direction of the sun, the solar cell paddle is controlled so as to point in the direction of the synthetic light by closed loop control during sunshine. Therefore, an error occurs in the pointing direction of the solar cell paddle.

The present invention has been made to solve the above problems, and an error occurs in the solar direction of the solar array paddle immediately after the satellite moves from the shade to the sunshine and immediately before the satellite moves from the sunshine to the shade. The purpose is not to.

[0006]

According to the solar cell paddle drive control method of the present invention, the timing of outputting the availability signal of the output signal of the rotational angular velocity generator according to a predetermined delay time based on the output signal of the solar presence generator. A processing unit is provided, and whether or not to use the rotational angular velocity error signal based on the tracking sun sensor in the paddle drive control circuit is determined according to the output signal.

[0007]

The timing processing unit in the present invention has predetermined delay times t ₁ , t ₂ (t) starting from the time when the sun presence signal of the sun presence generating unit changes from 0 to 1, that is, the time when the satellite moves from shade to sunshine. by ₁ ≦ t _2), so as to use the output signal of the rotational angular velocity generating unit from ₁ hour after t. Furthermore, the output signal of the rotational angular velocity generator is not used after t ₂ time has elapsed. That is, the tracking control using the tracking sun sensor is performed only from time t ₁ to time t ₂ . Between the time t _{1 and the} time t ₂ , t ₁ and t ₂ are set so that there is no influence of the albedo.

[0008]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram showing a solar array paddle drive controller for a triaxial stable satellite according to the present invention.
1 to 6, 8, 10, and 11 are exactly the same as the solar cell paddle drive control device of the conventional triaxial stable satellite shown in FIG. Reference numeral 7 denotes a timing processing unit that outputs a usability signal of the output signal of the rotational angular velocity generation unit according to a predetermined delay time based on the output signal of the sun presence generation unit 4. 12
Is a command processing unit that decodes a command signal from the ground and sets the delay time of the timing processing unit 7. 9
Is a paddle drive control circuit including a sun presence generator 4, a rotational angular velocity generator 5, an orbital angular velocity generator 6, a timing processor 7, and an adder 8.

FIG. 2 is a diagram showing the relationship between the sunlight and the satellite when the satellite is in orbit. In the figure, 13 is the satellite orbit and 1
4 is the earth, 15 is the shade, 16 is the sun, 17 is the sun 1
Reference numeral 6 is a combined light of sunlight and reflected light (albedo) from the earth, and reference numeral 18 is a combined light of sunlight 16 and reflected light (albedo) of the sun from the earth. In addition, 17 is a synthetic light immediately after moving from the shade to the sunshine, and 18 is a synthetic light immediately before moving from the sunshine to the shade. 19 is a position on the orbit that moves from the shade to sunshine, 20 is a position on the orbit where the tracking sun sensor measures the combined light 17, 21 is a position on the orbit where the influence of the combined light 17 is almost zero, and 22 is a combined light 18 Is a position on the orbit where the influence of the above is almost eliminated, 23 is a position on the orbit measured by the tracking sun sensor, and 24 is a position on the orbit where the sun moves from the sunshine to the shade.

Tracking solar cell A1 and tracking solar cell B2
Difference v ₂ −v ₁ between the outputs v ₁ and v ₂ of each is proportional to the difference Δθ between the sun direction angle and the paddle rotation angle Q _p , and when the sun direction is ahead of the paddle rotation angle, v ₂ −v ₁ > 0, the paddle rotation angular velocity becomes larger than the orbital angular velocity, and | Δθ | is reduced. Conversely, when the paddle rotation angle is ahead of the sun, v ₂ −v ₁ <0, the paddle rotation angular velocity becomes smaller than the orbital angular velocity, and | Δθ | becomes small. When the satellite enters the shade, the sun presence signal becomes zero and the angular velocity of the paddle rotates at a constant speed.

As can be seen from FIG. 2, satellites from 19 to 2
The rays measured by the tracking sun sensor when between 1 or between 22 and 24 are synthetic rays 17 and 18, which are different in direction from the original sunlight 16. Therefore, when the closed loop tracking control is performed using the signal of the tracking sun sensor 3 when the satellite is between 19 and 21 or between 22 and 24, the solar array paddle points in the direction of the combined light 17 or 18. It does not face the original direction of sunlight 16. On the contrary, it can be seen that when the satellite is between 21 and 22, it is not affected by the combined lights 17 and 18.

[0012] The time to move from the satellite from above 19 to 21 and t _1, the time to move from the satellite 19 to 21 as t _2, to set the delay time t _1, t ₂ of the timing processor 7. Since the relationship between the orbit and the sun is obtained by analysis before launch, t ₁ and t ₂ can be determined in advance. Therefore, the delay time t ₁ of the timing processing unit 7,
Since t ₂ is set in this way, even if the satellite moves from the shade to the sunshine, the paddle is driven at a constant rotation of the orbital angular velocity until it reaches the on-orbit position 21. The closed loop tracking control using the tracking sun sensor 3 is performed from the positions 21 to 22 on the orbit, and the pointing error due to the influence of the reflected light of the sun on the earth does not occur. Further, the paddle is driven at a constant rotation of the orbital angular velocity from the on-orbit position 22 to the shade.

In FIG. 1, the sun presence generator 4, the rotational angular velocity generator 5, the orbital angular velocity generator 6, the timing processor 7, and the paddle drive control circuit 9 can be realized by a program using a digital computer. There is no end.

Further, a command processing unit 12 is provided in FIG.
It is also possible to change the delay times t ₁ and t ₂ of the timing processing section 7 by a ground command. This change in time makes it possible to correct the unpredictable effects of sunlight reflected by the earth even after the satellite is launched.

[0015]

As described above, according to the present invention, the timing processor 7 restricts the on-orbit position for performing closed-loop tracking control using the tracking sun sensor 3, so that sunlight reflected by the earth ( This has the effect of suppressing the influence of the albedo) and suppressing the sun pointing error of the solar cell paddle.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a triaxial stable satellite and sunlight in orbit.

FIG. 3 is a functional block diagram showing a conventional solar cell paddle drive control device for a triaxial stable satellite.

[Explanation of symbols]

1 solar cell for tracking A 2 solar cell for tracking B 3 solar sensor for tracking 4 solar presence generation section 5 rotational angular velocity generation section 6 orbital angular velocity generation section 7 timing processing section 8 adder 9 paddle drive control circuit 10 drive pulse generation electronic circuit 11 Paddle drive mechanism 12 Command processing unit 13 Satellite orbit 14 Earth 15 Shade 16 Sunlight 17 Synthetic light of sunlight and reflected light from the earth 18 Synthetic light of sunlight and reflected light from the earth 19 Position on the orbit that moves from shade to sunshine 20 Position on the orbit where the tracking sun sensor measures the synthetic light 21 Position on the orbit where the influence of the synthetic light is almost eliminated 22 Position on the orbit where the influence of the synthetic light is almost eliminated 23 Position on the orbit measured by the tracking sun sensor for synthetic light 24 Position on the orbit that moves from sunshine to shade

Claims (2)

[Claims] 1. A tracking sun sensor installed on a solar array paddle of a triaxial stability satellite and a tracking sun sensor, and a sun generating a signal indicating that the tracking sun sensor is measuring the solar angle. Presence generation unit, generates a solar cell paddle rotation angular velocity error signal based on the sun angle calculated from the tracking sun sensor, a rotation angular velocity generation unit, generates a signal for the solar cell paddle to rotate at an orbital angular velocity when in shade Orbital angular velocity generator, a timing processing unit that outputs the availability signal of the output signal of the rotational angular velocity generator in accordance with a predetermined delay time based on the output signal of the sun presence generator, the output signal of the rotational angular velocity generator and the orbital angular velocity A solar cell including an adder for adding output signals of the generator, and using the tracking sun sensor after a predetermined delay time when the satellite shifts from the shade to the sunshine A paddle drive control circuit that controls the paddle tracking and a constant rotation speed control only by the signal of the orbital angular velocity generator when the satellite shifts from sunshine to shade in the predetermined time, and an adder of the paddle drive control circuit A solar cell paddle drive control device for a three-axis stable satellite, which includes a drive pulse generating electronic circuit that generates a pulse that drives a motor of a paddle drive mechanism based on the output signal of 1. 2. The delay time of the timing processing unit for outputting the availability signal of the output signal of the rotational angular velocity generation unit according to a predetermined delay time based on the output signal of the sun presence generation unit is changed by a ground command. The solar cell paddle drive control device of the triaxial stable satellite according to claim 1.