JPS5957100A - Control system of directivity of spin 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 The present invention relates to a pointing control system for a satellite that performs attitude control using spin stabilization.

A conventional system of this type is shown in FIG.

In Fig. 1, (1) is an earth sensor that outputs an earth width signal A, which is a signal proportional to the earth width, when it detects the earth;
(2) is a despan mechanism that rotates in a direction opposite to the spin direction of the satellite and directs the equipment. This despan mechanism consists of a motor, a slip ring, a lubricating part, a tachometer, and a position detector. The speed signal C and the position detectors attached to the stator side and the rotor side of the motor generate a position pulse signal that is output once in one rotation of the motor.

(3) is a directional control circuit that generates a satellite rotational speed signal from the repetition rate of the earth width signal from the earth sensor and outputs a drive signal B to the motor so that there is no difference with the motor speed signal from the despan mechanism. It is. After this directional control circuit harvests the difference between the satellite rotation speed and motor speed above.

Pointing control is performed by controlling the position pulse and the earth width signal A so that the position pulse signal comes to the center of the earth width signal A.

The conventional system is configured as described above, and a signal serving as a reference for direction control is output from the earth sensor. When the moon or the sun enters the field of view of the earth sensor, that is, when so-called interference occurs, the earth width signal A fluctuates greatly.

As a result, an error occurs in pointing control. Normally, the earth sensor has a redundant configuration, and when there is interference with the earth sensor from September or the sun, it switches to a redundant earth sensor that does not interfere. Sometimes there is interference with each redundant sensor, and in this case, pointing control will be affected. In this way, it is impossible to avoid the effects of the moon and the sun when using the earth sensor as a reference signal generation source for pointing control. In addition, there is an example of using a solar sensor to generate a reference signal for directional control, but it is necessary to prepare a substitute sensor during a solar eclipse, and it is similarly affected by celestial bodies.

In order to solve these problems, the present invention provides a pointing control method that is not affected by the moon or the sun.

An embodiment of the present invention shown in FIG. 2 will be described below.

In FIG. 2, (4) is a rate gyro which is an inertial sensor that detects the angular velocity of the satellite, and is attached to the satellite body and outputs a rate signal F proportional to the angular velocity of the satellite.

(5) is mounted on the part to be controlled by the despan mechanism (2), and the direction signal Be of the part to be controlled is
It is an azimuth gyro that outputs. The satellite rate signal from the rate gyro and the azimuth signal E from the azimuth gyro are input to the pointing control circuit (31). (2) is a despan mechanism similar to that explained in FIG. The error between the satellite rate signal F from the gyro and the motor speed signal C from the despan mechanism is corrected, and after this operation is completed, the azimuth signal E from the azimuth gyro when the position pulse signal from the despan mechanism is generated. The steering control is performed by turning the vehicle onto its side so that the error in the position becomes zero.

FIG. 8 shows a layout diagram of two types of inertial sensors on the satellite. The rate gyro (4) is on the spin side of the satellite (9b)
It is attached to the satellite and directly detects the angular velocity of the satellite. On the other hand, the direction gyro (5) is the side whose direction is controlled by the despan mechanism,
That is, it is attached to the satellite Tespan side (9a). Furthermore, position detectors (6a) and (6b) that are attached to the spin side and despin side of the satellite and output position pulse signals indicating the relative positions of the spin side and 1 spin side, and the azimuth detection axis of the azimuth gyro. By matching them, pointing control will be performed to a single point on the satellite. Furthermore, as shown in Figure 4, a bias control circuit (7) is used which can arbitrarily add a bias angle from 0° to 860° to the azimuth signal E from the azimuth gyro within the directional control circuit using a command G from the ground. A biased azimuth signal H can be generated to bias the pointing direction.

After setting the bias angle to point in the earth direction when performing all earth pointing on geostationary orbit.

By changing the bias angle according to the orbital period of the satellite, the pointing direction can be directed toward the earth.

Also, during the initial orientation to the earth, use the earth width signal as the azimuth reference, and after aligning the detection axis of the azimuth gyro.

Earth pointing is possible by changing the bias angle in synchronization with the orbital period.

As described above, according to the present invention, a signal from an inertial sensor is used as a reference signal.

This solves the problem of interference from the moon and the sun on earth sensors that have been used in the past. Furthermore, by adding a bias to the azimuth signal from the azimuth gyro, it is also possible to set the pointing direction in any direction. Further, even when a solar sensor is used as a reference signal source for pointing direction, it is necessary to prepare an alternative sensor during a solar eclipse. For these reasons as well, the pointing control method of the invention has the advantage of being able to independently generate a reference signal for pointing control without being influenced by celestial body movements.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional pointing control system, Fig. 2 is a block diagram of a pointing control system according to the present invention, and Fig. 8 shows the arrangement of the satellite main body, the rate gyro that is an inertial sensor, the azimuth gyro, and the position detector. Figure 4 shows the arrangement of the earth sensor, (2) the despan mechanism, (3) the earth sensor, (2) the despan mechanism, and (3) the earth sensor.
1 is one circuit on the directional side, (4) is a rate gyro, (5)
is an azimuth gyro, (6ai), (6b) is a position detector, and (7) is a bias control circuit. Identical or equivalent parts in the figures are indicated by the same symbols. Agent Shin Kuzuno - Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] It has two types of inertial sensors that detect the rotational speed (rate) of the spin satellite and the orientation in a plane perpendicular to the rotational axis of this satellite, respectively, and the rate signal and orientation signal from the two inertial sensors are used as reference signals. A pointing control method for a spinning satellite, characterized in that input is input to a pointing control circuit to perform pointing control of equipment to be directed to a satellite rotating once.