JPH05139394A - Thruster jetting system for artificial satellite - Google Patents

Abstract

PURPOSE:To provide a thruster jetting system for an artificial satellite whose jet-timing is time-shared so that effective control torque may be generated through fixed number of thrusters. CONSTITUTION:The jet-cycles of thrusters 5-8 are time-shared to set up two times of jet-timings, and a jetting form is changed at the first and the second timing. For instance, jet is executed through the thrusters 5-8 at the second timing for the purpose of generating torques round X and Z axes. In this case, unnecessary torque is always generated round a Y axis by the first jetting, but it is allowed at this point of time. The jet is then executed through the thrusters 5-8 at the second jet-timing so that the generation of necessary torque round the Y axis and the compensation of unnecessary torque generated round the Y axis by the first jetting may be performed together. The effective torque can thereby be generated round each axis through the four thrusters 5-8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thruster jet system for a three-axis control type artificial satellite, and more particularly to a thruster jet system for controlling its attitude.

[0002]

2. Description of the Related Art Conventionally, in a three-axis control type artificial satellite, a large number of thrusters are used to reliably generate a torque around each control axis. First and second conventional thruster arrangements
Examples of the above are shown in FIGS. 2 and 3, respectively. In FIGS. 2 and 3, 9 to 12 are thrusters for control. In FIG. 2, it is necessary to combine thrusters 11 and 12 in order to generate torque in the positive direction around the Y axis. By combining the two thrusters 11 and 12 in this manner, a torque can be generated around a required axis. In this case, at least eight thrusters are required to control the three axes. In FIG. 3, only thrusters 20 need to be ejected to generate a positive torque about the Y axis, so the number of thrusters can be reduced. On the other hand, each thruster needs to be placed on a plane formed by any two control axes, which places a large constraint on the placement.

[0003]

The problem to be solved is that a large number of thrusters are required to control the attitude of the artificial satellite around the three axes, and the layout is also restricted by the relationship with the position of the center of gravity. It is a point.

[0004]

According to the present invention, thruster injection is time-divided to change the injection form between the first half and the second half, and in the first cycle, the torque around the first axis and the around the second axis are changed. And the torque is generated in the second cycle.
Is characterized in that the thruster is driven so as to generate a torque around the axis of and a torque in a direction to correct the disturbance around the third axis generated in the first cycle.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing an embodiment of a thruster injection system for an artificial satellite according to the present invention. In FIG. 1, 1 is the position of the center of gravity, 2-4 are control axes in the X-axis, Y-axis, and Z-axis directions, and 5-8 are thrusters for control. The artificial satellite performs attitude control around the control axes 2 to 4. Attitude control is performed using four thrusters 5-8.

The control torques generated by injecting the thrusters 5 to 8 are summarized as shown in Table 1 below. Therefore, the torque about the X axis and the torque about the Z axis cannot be independently generated by any combination of thrusters.

The present invention is intended to solve this problem by performing thruster injection in a time division manner. That is,
In general, this type of attitude control receives an attitude angle as an input at a certain fixed cycle, performs a necessary process, and then applies a control torque necessary as an output to a satellite to be controlled. At the stage of generating the required torque, the control cycle is temporally divided into two. In the first cycle, the thruster is jetted so as to generate the required torque around the X axis and the Z axis. In the second cycle, the disturbance torque around the Y axis generated in the injection in the first cycle is corrected and the necessary control torque is generated.

Therefore, in terms of the attitude control cycle,
A control in which a required torque is applied around the three control axes is realized. FIG. 2 is an explanatory diagram showing the timing relationship of attitude control. Thruster injection timing-1
During the period, the thruster injection command is issued after the injection calculation of the torque generated around the X axis and the Z axis is performed. In the period of thruster injection timing -2, the thruster injection command is issued after calculating the injection of the torque generated around the Y axis. Hereinafter, the same process is repeated.

[0009]

As described above, according to the present invention, the thruster injection is time-divided, the disturbance is ignored at the first timing, and the necessary torques about the first and second axes are generated, and the second torque is generated. The advantage of enabling control around three axes with a limited number of thrusters by correcting the disturbance torque generated at the first time and injecting the thruster so as to generate torque around the third axis at the timing There is.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an embodiment of a thruster injection system of an artificial satellite according to the present invention.

FIG. 2 is an explanatory diagram showing a timing of attitude control.

FIG. 3 is a perspective view showing a first example of thruster arrangement according to the prior art.

FIG. 4 is a perspective view showing a second example of thruster arrangement according to the prior art.

[Explanation of symbols]

 1 Center of gravity position 2-4 Control axis 5-22 Thruster

Claims (3)

[Claims] 1. A plurality of thrusters for controlling the attitude of a satellite in three axial directions are provided, and the thrusters are time-divided into two thrusters.
A thruster injection method which is performed by repeating the timing of one time, and includes first and second thrusters for generating necessary torques about the first and second axes by ignoring the disturbance at the first timing. A third thruster for generating a torque around a third axis at the second timing, and a third thruster for generating a torque for correcting the disturbance torque generated at the first timing at the second timing. A thruster injection method for an artificial satellite configured with 4 thrusters. 2. The torque around the first axis is torque in the X-axis direction, the torque around the second axis is torque in the Z-axis direction, and the torque around the third axis is Y-axis. The thruster injection method for an artificial satellite according to claim 1, wherein the thrust torque is directional torque, and the torque for correcting the disturbance torque is torque in the Y-axis direction. 3. The thruster injection method for an artificial satellite according to claim 1, wherein the thruster is injected by repeating the first timing and the second timing to control the attitude of the artificial satellite.