JPH10278898A - Spacecraft attitude control thruster - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To be able to cope with failure of a thruster without having two thruster groups, to be able to use the thruster rationally and to contribute to weight reduction of a spacecraft. An attitude control thruster for a spacecraft is provided. SOLUTION: A set of thrusters composed of a plurality of thrusters 10 is provided outside a spacecraft, and each thruster 10 is provided so as to be able to change an angle by a telescopic drive bar. This can be complemented by changing the angle of other thrusters except for.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a plurality of thrusters arranged at predetermined positions outside a spacecraft such as a satellite, and selectively controls each thruster during attitude control of the spacecraft. The present invention relates to an attitude control system thruster of an artificial satellite used.

[0002]

2. Description of the Related Art A spacecraft such as an artificial satellite which flies in another orbit such as an orbit around the earth or a planetary space has a thruster for ejecting a propellant to the outside for attitude control or the like.

[0003] The thruster of the attitude control system is capable of causing a spacecraft to have six degrees of freedom of displacement (rotation about three orthogonal axes and translation in three axes).
A plurality of spacecrafts are provided at respective portions on the outer surface thereof in a predetermined direction.

[0004] For example, as shown in FIG.
On the outer surface of the spacecraft 1, a total of twelve elements are provided, one for each of three orthogonal axes (X, Y, Z) in the forward and reverse directions.
In this configuration, by operating a pair of thrusters 10 in the respective axial directions, the thrusters 10 can be translated (translated) in that direction. By operating the thrusters 10 at point-symmetric positions with respect to the center of gravity position C. Can be rotated. This arrangement is ideal, and more thrusters are actually provided to avoid interference with equipment such as a solar cell panel and an antenna.

In such an attitude control system, if at least one of the thrusters constituting the attitude control system fails, the attitude control is hindered, and in the worst case, the operation of the spacecraft itself becomes impossible. For this reason, two identical thruster groups (A and B) are provided as shown in the system diagram of FIG. That is, two identical thrusters belonging to independent operation systems are provided at the same location. In the above-described configuration, one thruster group is composed of twelve thrusters. A total of 24 systems are provided.

[0006]

However, as described above, in a configuration in which two systems of the thruster group of the attitude control system are provided in preparation for a failure of the thruster, if one of the thrusters fails, the system is switched to the other system, so that a failure occurs. The remaining thrusters belonging to the system to which the thrusters belong become unnecessarily long ones that are not used in spite of being normal, and are extremely wasteful and irrational.

[0007] Further, there is a problem that the weight is increased due to the necessity of twice as many thrusters as required, and the weight of the mounted equipment is restricted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and can cope with a failure of a thruster without having two sets of thruster groups. An object of the present invention is to provide a spacecraft attitude control system thruster that can contribute to weight reduction of a spacecraft.

[0009]

A spacecraft attitude control system thruster according to the present invention that achieves the above object has a set of thrusters composed of a plurality of thrusters arranged outside a spacecraft, and Each of the thrusters is provided so that its angle can be changed by a driving means, and when the thruster fails, the thruster can be complemented by changing the angle of another thruster other than the thruster.

Further, the driving means is characterized in that the thruster, which is swingably supported at a fulcrum, is operated to swing by deformation of a shape memory alloy.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a spacecraft to which one configuration example of a spacecraft attitude control system thruster according to the present invention is applied, and FIG. 2 is an external view of the thruster.

On the outer surface of the illustrated spacecraft 1, a thruster 10 is provided.
(10Xa, 10Xb, 10xa, 10xb, 10Y
a, 10Yb, 10ya, 10yb, 10Za, 10Z
b, 10za, 10zb) are orthogonal to each other (X, Y,
Z) Each pair is disposed in the forward and reverse directions of each axis. In this configuration, the spacecraft 1 translates (translates) in the axial direction by the operation of the pair of thrusters 10 in the respective axial directions, and rotates by the operation of the thrusters 10 at the symmetric positions with respect to the center of gravity position C, and has six degrees of freedom. Can be displaced.

For example, the spacecraft 1 has a thruster (10Xa,
10Xb) or (10xa, 10xb) actuates to translate in the X-axis direction, and the thruster (10Ya, 10yb) or (10Yb, 10ya) actuates to rotate about the X-axis. As shown in FIG. 2, each thruster 10 includes a swing support arm 11 serving as a fulcrum, a swing restriction link bar 12, and a telescopic drive bar 13 serving as a swing drive unit. The spacecraft 1 is supported on the outer surface of the spacecraft 1, and swings by a predetermined angle when the telescopic drive bar 13 is driven.

The swing support arm 11 has its end supported by a spherical bearing on the outer surface of the spacecraft 1 so as to be able to swing freely, and has its tip supporting the base end of the thruster 10.

The swing regulation link bar 12 has a predetermined length, and its base end is swingably supported on the outer surface of the spacecraft 1 and its tip is fitted and fixed near the tip of the thruster 10. It is pivotally attached to the ring 10A.

The telescopic drive bar 13 has a base end pivotally supported on the outer surface of the spacecraft 1 and a distal end pivotally attached to the ring 10A, similarly to the swing regulation link bar 12, and has a predetermined length. The extension displacement drive can be performed from the short initial setting state to the extension state of a predetermined length. In this configuration example,
An electric heater 13B is wound around a shape memory core 13A formed of a shape memory alloy such as a Ti-Ni alloy. The shape memory core 13A stores an elongated state of a predetermined length. It is arranged after being compressed and deformed to the length (initial setting state). Thereby, when the electric heater 13B is energized, the shape memory core 13A is heated and extends from the initial setting state to the storage state of a predetermined length.

The thruster 10 having the above-described configuration is swingably supported by the swing support arm 11 and its swing direction is regulated by the swing restricting link bar 12. The swing angle is determined by this. The telescopic drive bar 13 is the shape memory core 1
Since the extension of the thruster 10 from the initial setting state to the storage state causes the thruster 10 to swing, the thruster 10 is changed from the initial state shown in FIG. 3A, which is a conceptual diagram, to the state shown in FIG. As described above.

By providing the thruster 10 capable of oscillating drive as described above, the spacecraft 1 can operate the other normal thruster 10 when a specific thruster 10 fails.
Can be configured to complement the failed thruster 10 by changing the angle of the thruster.

For example, out of the twelve thrusters 10 of the spacecraft shown in FIG. 1, eight thrusters 10 (10Ya, 10Yb, 10ya, 10yb, 1) located on planes of symmetry with each other.
0Za, 10Zb, 10za, and 10zb) at predetermined angles so as to be substantially radial as shown in FIG. 4 and FIG.
By operating four of the thrusters 10 at the same time, it becomes possible to cause the spacecraft 1 to have a displacement of six degrees of freedom.

That is, the spacecraft 1 is, for example, a thruster (10ya, 10yb, 10Zb, 10zb) or (1
0Ya, 10Yb, 10Za, and 10za) are simultaneously actuated to move (translate) in the X-axis direction and to be located symmetrically with respect to the center of gravity C.
10Zb, 10yb, 10za) or (10ya, 10
Za, 10Yb, 10zb) are simultaneously operated to rotate around the X axis. Note that, in this example, the absolute positions of the X axis and the Y axis with respect to the
Four thrusters 10 around the Z-axis compared to the case where thrusters 10 are used.
Although it rotates five degrees, there is no problem in attitude control by considering it in advance.

In this configuration example, since there are three combinations to select eight out of the thirteen thrusters 10, when a failure occurs in the thruster 10, a combination that does not use the thruster 10 is selected. It is good to do.

Here, as described above, the eight thrusters 10
In the case of performing the attitude control operation, the four thrusters 10 must be operated at one time, so that the consumption of the propellant increases and the life of the entire attitude control system may be shortened. However, since the failure of the thruster 10 is extremely rare and the weight of one system can be reduced because there is no need to provide two systems of thrusters, such a problem is solved by increasing the loading amount of the propellant or the like. Gained greater benefits.

The above configuration example is an example in which when a failure occurs in the thruster 10 of the spacecraft 1 having twelve thrusters 10, eight of the other normal thrusters 10 are changed in angle and complemented. However, the number of thrusters 10 is not limited to twelve, and the number of thrusters 10 to be used is not limited to eight but can be set as appropriate.

Further, the thruster 1 to be used after changing the angle once
When a failure occurs in the thruster 10, the angle of the remaining thruster 10 may be changed again to make it possible to complement the thruster 10, as shown in the conceptual views of FIGS. 6A and 6B.
Is supported by two sets of driving means (telescopic drive bars 13 and 14), or the drive means (telescopic drive bars 13 and 14) are arranged in series to support the thruster 10. .

Although the shape memory alloy is used as the driving means for swinging the thruster 10, the driving means is not limited to this, but can be changed as appropriate, such as using a motor or a cylinder operated by hydraulic or gas pressure. .

[0026]

As described above, according to the attitude control system thruster for a spacecraft according to the present invention, a set of thrusters composed of a plurality of thrusters is arranged outside the spacecraft, and each thruster is arranged. Each is provided so that the angle can be changed by the driving means, and when a thruster fails, it is configured to be able to complement this by changing the angle of other thrusters other than that thruster, so that it does not have two thruster groups Can respond to thruster failure,
The thruster can be used rationally and can contribute to the weight reduction of the spacecraft.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a spacecraft to which a configuration example of a spacecraft attitude control system thruster according to the present invention is applied.

FIG. 2 is an external view of a thruster.

FIGS. 3A and 3B are conceptual diagrams showing the swing of the thruster, where FIG. 3A is an initial state and FIG. 3B is a swing state.

FIG. 4 is a schematic diagram of a spacecraft in a complementary state with eight thrusters.

FIG. 5 is a conceptual diagram of a spacecraft in a complementary state with eight thrusters.

FIGS. 6A and 6B are conceptual diagrams of a configuration example in which the angle of the thruster can be changed in two stages.

FIG. 7 is a conceptual diagram of a conventional spacecraft including an attitude control system thruster.

FIG. 8 is a block diagram of a posture control system as a conventional example.

[Explanation of symbols]

 Reference Signs List 1 spacecraft 10 thruster 11 swing support arm (fulcrum) 13, 14 telescopic drive bar (drive means) 13A shape memory core material (shape memory alloy)

Claims (2)

[Claims] 1. A set of thrusters comprising a plurality of thrusters is provided outside a spacecraft, and each of the thrusters is provided so as to be capable of changing its angle by a driving means.
An attitude control system thruster for a spacecraft, characterized in that when a thruster fails, the thruster other than the thruster can be supplemented by changing the angle of the thruster. 2. The space according to claim 1, wherein said driving means is configured to swing the thruster swingably supported by a fulcrum by deformation of a shape memory alloy. Machine attitude control thruster.