JPS6218399A - Controller for attitude of artificial satellite - 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 an attitude control device for an artificial satellite during steady operation.

[Conventional technology]

As a conventional three-axis attitude control device for a satellite.

“6 Systems and Control” published by Japan Automatic Control Association, v.

127, no. 6 As shown in "Three-axis attitude control of artificial satellites", there are the zero momentum method (Figure 3) and the bias momentum method (Figure 4).

(1) is the roll/yaw detection device (earth sensor 1. (21)
(3) is the roll/yaw detection device electronic circuit, and (3) is the yaw sensor.

(4) is a yaw sensor electronic circuit, (5) is an attitude control device,
0°+91. (71 are roll, pitch, and yaw wheels respectively.

(II, 181. (61 are roll, pitch, and yaw wheel drive circuits, respectively.

In the zero-momentum method shown in Fig. 3, attitude control is performed independently on three axes. That is, the roll angle is detected by the earth sensor (1), and the roll angle is controlled by changing the rotational speed of the roll wheel (111).Similarly, the pitch angle is detected by the earth sensor (1), and the roll angle is controlled by changing the rotation speed of the roll wheel (111). The pitch angle is controlled by changing the rotational speed of the yaw wheel (9).The yaw angle is detected by the yaw sensor (3), and the yaw angle is controlled by changing the rotational speed of the yaw wheel (7).

In the bias momentum method shown in FIG. 4, the roll/yaw axis has a strong continuous punch effect because it uses gyro rigidity. Even with the same bias momentum system, the control device differs depending on the wheel configuration, but here we will consider the bias momentum system with one momentum wheel, one reaction wheel, and a configuration control.Roll angle is the earth sensor (1
1, and the roll angle is controlled by changing the rotational speed of the yaw wheel (7). The yaw angle is passively controlled by controlling the roll angle using gyro stiffness due to pitch wheel bias momentum and roll/yaw conversion due to orbital motion coupling.

The pitch axis can be considered independently of the other two axes.

The pitch angle is detected by the earth sensor (1), and the pitch angle is controlled by changing the rotation speed of the pitch wheel (9).

[Problem that the invention seeks to solve]

Since the zero-momentum device controls each of the three axes independently, the attitude control logic is simple, and a control system with high attitude control accuracy can be realized. It is assumed that the yaw sensor will be used continuously, and considering the current situation where a highly reliable yaw sensor has not been developed2, it must be said that the integrity of the system is low. In the bias momentum system, passive stability is achieved by the gyroscopic rigidity of the pitch bias momentum, and the attitude can be maintained to some extent even if the control system does not work. However.

Due to the strong b-coupling effect of the roll/yaw axis.

It is difficult to achieve high posture accuracy because the posture disturbances influence each other. Also, 1 momentum wheel to achieve high posture accuracy.

When adopting the chondral bias momentum method for the two-reaction wheel configuration, the attitude control logic design is a two-man, two-output, multivariable control system design, which cannot be handled using the conventional design method for one man, one output. A fair argument.

[Failure to solve the problem]

This invention is intended to improve this problem.

That is, when using a solar sensor, the pitch bias momentum is canceled by the yaw rate foot knock signal, and the influence of roll from yaw is cut off and non-interfered, thereby achieving characteristics equivalent to the zero momentum method. In addition, when the sun sensor is in use, the yaw signal disappears, so the control automatically shifts to the pitch bias momentum control system. This device realizes a satellite attitude control device that combines the advantages of the zero momentum method and the bias momentum method.

[Effect]

The roll output in this invention is not affected by the yaw angle when the sun sensor is in use, so it can be controlled with high precision.

〔Example〕

FIG. 1 is an overall configuration diagram showing an embodiment of an attitude control device for an artificial satellite according to the present invention. As is clear from FIG. 1, in this embodiment, a roll/pitch detection device 10-
For example, earth sensors.

and its electronic circuit (2), and a yaw detection device (3) that detects the yaw angle - for example, a solar sensor and its electronic circuit (4). The rate of change of angle is the target attitude angle.

and the rate of change of attitude angle, roll wheel (7), pitch wheel (9), yaw wheel (11)
In order to change the rotational speed of each wheel, the drive circuit +61.181. and attitude control accuracy for outputting QIIC control signals.

FIG. 2 is a block diagram showing the roll/yaw system of one device. The roll angle and yaw angle are detected by an earth sensor and a sun sensor, respectively, and are fed back to the system to generate an error signal. The roll angle and yaw angle error signals are compensated by the PD gain of α~aS, and after passing through the coupling factor of aO~Nishiki, become a command signal for the wheel, which is an actuator. Here, αδ is roll rate gain, α row roll position gain, a41
Hayaw rate gain and αS are yaw position gain.

αe is the coupling factor from the roll rate signal to yaw, +lη is the coupling factor from the roll signal to yaw, and (II is the coupling factor from the yaw rate signal to roll.The wheel is driven by the wheel command signal. This is transmitted to the dynamics of αl~@, and the attitude angle roll and yaw change.At the same time,
A disturbance Hz, Hz is added to the system. Here, 0 is roll inertia dynamics, (a) is yaw inertia dynamics, and Qυ is roll/yaw coupling due to pitch bias momentum.

The simplified attitude equation of the roll/yaw system is of first order.

Work Xφ + hBψ = Hx - hx Work 2ψ - hBφ = Hz - hz However, IXH roll axis inertia moment 2 is the yaw axis moment of inertia, φ is the roll angle, and ψ is the yaw angle.

hB is pitch bias momentum, Hxi[fi
Hz is the yaw disturbance moment applied to the satellite, hx is the roll wheel control momentum, hZit is the yaw wheel control momentum.

In the attitude control device configured as described above.

The wheel control law is as follows.

a) When the yaw sensor is ON hx = (Kdx+”-) (φC-φ) 1γKdz (ψC
-ψ) (ψC-ψ) bl Yaw sensor 0IFF' -hx = (Kd+c-1-'E”-) (φ.-6, -h
z=-(aKdz-4-ξ3)(φC-φ) However, Kd
X is roll rate gain, Kdz is yaw rate gain,
Kpx is roll position cane.

Kpztti yaw position gain, φC is the roll angle command, ψC is the yaw angle command, α is the coupling factor from the roll rate signal to yaw, and β is the coupling factor from the roll signal to yaw.

γ is the coupling factor from the yaw rate signal to the roll.

Here, by adjusting the coupling factors α, β, and r, the pitch bias momentum can be canceled by the yaw rate foot check signal when the yaw sensor is used.

At this time, the closed loop equation for the roll/yaw system is:

It is as follows.

a) When the yaw sensor is ON b) When the yaw sensor is ON b) When the yaw sensor is ON As a result of cutting off the influence of yaw and roll when the yaw sensor is ON and making it non-interfering, the yaw transient wide response from the time the yaw sensor is ON to 077, and from 077 to QN will affect the roll. I don't.

The attitude notification control system of this device has the characteristics of a zero momentum system when using a yaw sensor, and a bias momentum system when using a yaw sensor, and in either case, a system with guaranteed stability can be used.

In the attitude control system of this device, the roll system can be designed independently. Also, the yaw system is designed taking into account the designed roll. The remaining off-diagonal term is yaw sensor 07
Determined by the characteristics of 7 o'clock.

FIG. 5 is an example of a numerical simulation for confirming the performance of one device. Yaw sensor ON.

OF'? , ○N were switched every 10 minutes to show the attitude angle and wheel drive command when a constant disturbance f)JD was applied to the satellite. This figure confirms the following.

The roll angle is always controlled to the target value. On the other hand, while the yaw angle is controlled to the target value when the yaw sensor is ON, an error occurs when the yaw sensor is 077.

Therefore, a transient response occurs in the yaw angle at 077 hours from when the yaw sensor is turned on, but the roll angle is not affected due to non-interference.

〔Effect of the invention〕

As explained above, this invention uses a simple structure in the attitude control system of 9 artificial satellites, in which the pitch bias momentum is canceled by the yaw rate feedback signal when the yaw sensor is in use. This has the effect that a stable attitude control system can be constructed.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an embodiment of the present invention, Fig. 2 is a roll/yaw system block diagram showing an embodiment of the invention, and Fig. 3 is one of the conventional attitude control devices for an artificial satellite. FIG. 4 is a configuration diagram showing a certain zero momentum method, FIG. 4 is a configuration diagram showing a bias momentum method which is one of the conventional attitude control devices for artificial satellites, and FIG. 5 is a diagram for confirming the performance of an embodiment of the present invention. This is a simulation example. In the figure, (1) is a roll/pitch detection device, (2)
is the roll/pitch electronic circuit, and (3) is the yaw detection device. (4) is a yaw electronic circuit, (51 is an attitude control device, (6)
is the yaw wheel drive circuit, (7) is the yaw wheel, (8
) is the pitch wheel drive circuit, (9) is the pitch wheel, α value is the roll wheel ffi driving circuit, and all is the roll wheel. as halo roll rate cane, α3 is the roll position gain, I is the yaw rate gain, α is the yaw position gain, αe is the coupling factor from the low ray 88-bh to the yaw, (lη is the color pulling twister from the roll signal to the yaw) , α seconds is the yaw rate (coupling factor from No. 8 to roll, α value is roll inertia dynamics, m, eυ is roll/yaw coupling due to pitch bias momentum, (2) is yaw inertia dynamics @ Figure 2 Inside, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] Earth sensors and solar sensors that detect the attitude angle of artificial satellites,
In order to make the attitude angle and attitude angle change rate of the artificial satellite reach the target attitude angle and attitude angle change rate by inputting the output signals of the respective electronic circuits and the respective electronic circuits of the earth sensor and the sun sensor. driven roll wheel,
PD control using pitch wheel, yaw wheel, drive circuit that controls the rotational speed of these three wheels, and roll angle, roll rate, pitch angle, pitch rate, yaw angle, and yaw rate signals from each sensor electronic circuit. and an attitude control device that outputs a control signal to the wheel drive circuit.The attitude control device is used only when the sun sensor is used, and the bias momentum of the pitch wheel is canceled by the yaw rate signal, and when the sun sensor is not used, An artificial satellite attitude control device characterized by automatically shifting to a control bias momentum method.