JP3473831B2 - Module connection type space structure and attitude control method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a module connection type suitable for construction of a large space structure used for attaching solar cells when large-scale solar power generation using solar cells is performed. The present invention relates to a space structure and its attitude control method.

[0002]

2. Description of the Related Art In the field of space development that requires a large-scale space structure, photovoltaic space power generation is the most representative field of space environment utilization, and in recent years, the ultimate energy production that is optimal for the conservation of the global environment. Has been attracting attention as a means of.

However, in order to perform 1 GW class photovoltaic power generation, a photovoltaic element is attached to a flat surface of several kilometers square, and a large scale is provided to support this flat surface so that sunlight can efficiently enter the flat surface. It is necessary to construct a space structure and control its attitude. In order for solar power generation to be economically viable, it is essential to reduce the space transportation cost of materials and the construction / maintenance cost of space structures. Therefore, it is necessary to study a configuration that simplifies construction work in outer space, such as assembling a space structure by connecting structural modules of appropriate size, and to study a form that enables weight reduction of the structural module. There is.

The solar space power generation system has been studied in the United States and Japan for more than a dozen years, and many proposals for a power generation method and a power transmission / reception method of generated power have been made. There are many technical and economic issues in the construction of large-scale space structures, and many researchers question their realization. The energy produced by photovoltaic power generation is obviously inexhaustible and clean energy for the global environment, so the result of this research is one solution to the current civilization problem and brings light to the future of humanity. Despite this, the issue of how to construct a huge space structure that far exceeds the international space station currently under development under international cooperation and how to transport enormous materials at low cost This is because there is no technical prospect for And the research up to now includes analysis of life cycle cost based on rough design parameters,
We have not exceeded the level of system-based trade-off studies.

[0005]

The construction of large-scale structures not only in the solar space power generation system but also in outer space is a technical field of extremely useful and high interest in the field of space environment utilization, and transportation materials. The research on space structures that enable lighter weight and easier assembly will affect the future of space development along with the task of space transportation cost reduction.

The present invention is capable of simplifying the construction and maintenance of a space structure having a three-dimensional shape such as a flat plate or a hollow cone, a parabola, etc., which is effective for large-scale solar power generation, and reducing the weight thereof. It is an object of the present invention to provide a module-connected space structure and at the same time realize an attitude control method capable of effectively controlling the attitude of a module-connected space structure having a flexible structure.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 comprises four storable extension masts and a mast drive support mechanism for expanding and supporting the extension masts in a cross shape. rectangle in a cross mast unit, a film-like material that is placed in the envelope space of the rectangle formed by connecting the tip of the cross-shaped mast unit developed with Rights
A structural module of a plate is configured, and a plurality of the structural modules are separably connected using a mast connecting unit to combine them to form a large space structure to form a module-connected space structure. .

In the module-coupled space structure constructed as described above, a rectangular flat plate- shaped structural module composed of a cross-shaped mast unit and a film material, and a module-coupled space structure using the mast-coupled unit as constituent elements. Lightweight because it is configured to assemble and disassemble
It is possible to easily construct and repair large-scale space structures that can be realized.

According to a second aspect of the present invention, in the module-connecting space structure according to the first aspect, the mast connecting unit connects the ends of the cross-shaped mast units of three or more structural modules in a separable manner. It is characterized in that it is configured to.

In the mast connecting unit thus constructed, by connecting the ends of three or more structural modules, the three or more structural modules can be fixed without a gap, so that the structure in space is high. It is possible to create strength. Therefore, it is possible to assemble a module-connected space structure having various properties in terms of structural strength depending on how to combine the structural modules.

According to a third aspect of the present invention, in the module-connected space structure according to the first or second aspect, the mast drive support mechanism of the cross-shaped mast unit extends in all directions when the cross-shaped mast unit is deployed. The structure module is constructed so that the lengths of the four masts can be adjusted, and a plurality of mast connecting units are separably connected through the mast connecting unit. It is characterized by being configured into a flat plate structure having an arbitrary shape.

With this structure, the shape of the rectangular flat plate of the structural module can be freely changed only by changing the lengths of the four masts of the cross type mast unit. By connecting them, it becomes possible to form a planar structure having an arbitrary shape. The simplest shape of the structural module is a rhombus that connects two identical equilateral triangles (hereinafter referred to as a standard rhombus).
It is possible to construct flat plate structures having various skeletons by connecting the standard diamonds.

According to a fourth aspect of the invention, in the module-coupled space structure according to the first or second aspect, the mast drive support mechanism of the cross-shaped mast unit extends in all directions when the cross-shaped mast unit is deployed. The structure module is constructed so that the length of the four masts can be adjusted, and a plurality of structural modules that are separably connected and combined through the mast connecting unit set all four sides of each structural module to the same length. In addition, by adjusting the length of the diagonal line, that is, the length of both ends of the mast extended in both directions, a hollow three-dimensional structure approximating the shape of a cone or parabola whose skeleton is the deployed cross-shaped mast unit and the mast connecting unit. It is characterized by being configured in.

When all of the structural modules are formed of standard diamonds as described above, the module connection type structure in which they are connected forms a flat plate structure, but the lengths of the four sides of the diamond-shaped structure module are not changed. By adjusting the length of the mast, the module connection type structure can be made into a three-dimensional shape such as a cone. Therefore, by controlling the mast drive support mechanism by the arithmetic processing unit for simultaneously adjusting the mast length of each structural module, it becomes possible to continuously and in real time change the shape of the module-connected space structure. .

According to a fifth aspect of the present invention, in the module connected space structure which is the hollow three-dimensional structure according to the fourth embodiment, the hollow structure module constituting the module connected space structure is stretched on the surface thereof. Characterized by controlling the attitude of the modular space structure by orienting the attitude of the module-connected space structure in the direction of the sun or the direction of travel by using the pressure of the solar wind or gas flow received by the film-shaped material Is.

In a three-dimensional module connection type structure having a conical shape or the like, when its central axis deviates from the direction in which pressure such as the solar wind is applied, a torque is generated which attempts to match the direction of the central axis with the direction of pressure. This torque can be used as the torque to control the attitude of the module-connected space structure used in the solar power generation system, etc., so the mast drive support of each structural module that constitutes the module-connected space structure by the arithmetic processing unit. By controlling the shape of the space structure via the mechanism, it becomes possible to easily control the attitude of the module-connected space structure.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments will be described. FIG. 1 is a diagram showing a functional configuration of a structural module and a mast connecting unit which constitute a first embodiment of a module connecting type space structure according to the present invention, and a method of connecting the structural modules by the mast connecting unit. is there. Structural module 1 is a mast 2-1 that expands and contracts in all directions.
A cross-shaped mast unit 2 composed of 2-2, 2-3, and 2-4, and a mast drive supporting portion 3 that drives the telescopic mast unit 2 to extend and retract.
And a film-shaped deployable material 4 such as a solar cell film installed in an envelope space formed by connecting the ends of the cross-shaped mast unit 2 into a rectangular flat plate . 5 is a mast connecting unit, and the mast connecting unit 5 is a mast 2-1, 2-2, 2-3, 2 of the cross-shaped mast unit 2.
-4 is grasped to connect the plurality of structural modules 1 in a separable manner to form a module-connected space structure. The mast connection unit 5 has a connection drive part for connecting the structural modules 1 in a separable manner, but the feature of the present invention is that the module connection type space structure of various shapes is constructed stepwise. And its attitude control, the mechanical structure is not particularly specified together with other mast drive supporting parts. It should be noted that the masts that expand in all directions that make up the cross-shaped mast unit 2 are those that are shortened at the time of transportation so as to be expanded and stored and deployed in space, but the masts that make up the cross-shaped mast unit are transported. At times, it may be folded and stored, and it may be configured to be deployed in space. Further, in order to simplify the explanation, in the following description, in the case where the shape connecting the tips of the masts extending in all directions, that is, the shape of the structural module forms a rhombus (at this time, the diagonal lines of the rhombus are in a state of being orthogonal to each other). The principle and method of constructing and controlling a module-coupled space structure will be described.

Now, assuming that the length of the shorter diagonal line of the diamond-shaped structural module 1 is 2A and the length of the longer diagonal line is 2B, the side length C of the diamond is given by the following equation (1). To be done. C = (A ² + B ² ) ^1/2 ····· (1) When the side length C of the rhombus is equal to 2A, the rhombus structure module synthesizes two equilateral triangles. Since it is a standard rhomboid, that is, the standard rhombus described above, it is possible to form a flat plate structure by connecting standard rhomboid structural modules whose lengths are all C by a mast connecting unit. FIG. 1 shows a mode in which six standard diamond-shaped structure modules 1 are connected via six mast connection units 5.

FIG. 2 is a diagram showing the structure of a module-connected space structure according to the first embodiment in which a flat plate structure is formed by connecting standard diamond-shaped structure modules 1. The first embodiment is a module-connected space structure constructed by using 6 structural modules and 13 mast connecting units. The mast connecting unit 5 that connects the structural modules 1 has at least three structural modules 1
The cross-shaped mast unit 2 is configured so that its tip can be detachably connected. In the first embodiment shown in FIGS. 1 and 2, the mast connecting unit arranged at the center is configured so that the tips of the six cross-shaped mast units can be connected, and the six structural modules are provided. 1 are connected without a gap to form a regular hexagonal structure portion 6 to form a flat plate structure module connection type space structure 7 having improved mechanical strength.

FIG. 3 is a view showing a modified example of the first embodiment shown in FIG. 2, and this modified example further has a structural module 1 on the outer peripheral portion of the module connection type space structure 7 shown in FIG.
The module-connected space structure 8 is constructed by using 18 structural modules and 31 mast connecting units. FIG. 4 is a diagram showing still another modification of the first embodiment. In this modification, the structural module 1 is additionally connected to the outer peripheral portion of the module-connected space structure 8 shown in FIG. The structure is expanded to form a module connection type space structure 9 using 36 structural modules and 55 mast connection units. Since these modified examples also use the standard rhomboid structure module 1, the overall structure has a flat plate structure.

In the first embodiment and the modified examples described above, as each structural module 1 constituting the module-coupled space structures 7, 8 and 9, a film-shaped deployable material such as a solar cell film is previously prepared. As shown in the figure, each structural module is composed of a cross-shaped mast unit and a mast drive supporting portion, and a plurality of structural modules are connected by a mast connecting unit to form a composite structure, and then the composite structure is formed. It is also possible to dispose a film-shaped deployable material over the entire structure to form a module-connected space structure.

Next, a second embodiment will be described. In the first embodiment and its modification shown in FIGS. 1 to 4, the rhombus structure module 11 in which the lengths of the shorter diagonals of all rhombus structure modules are changed from 2A to 2A cos θ is coupled by the coupling unit 5. Then, when the module-coupled space structure 12 is configured, as shown in the cross-sectional view of FIG. 5, the envelope surface of the module-coupled space structure 12 becomes a cone with the center of the structure as the apex. As shown in, the receding angle of the cone (the angle of inclination with respect to the flat plate) is θ.

As seen in the modified example of the first embodiment shown in FIG. 4, in the case of the expanded structure, the frame of the structure is a regular hexagonal structure shown by dotted lines at equal intervals from the center of the structure. Since the structure is such that the rings of the parts 6 are joined, by appropriately adjusting the length of the diagonal line of the diamond-shaped structure module forming the regular hexagonal structure part 6 for each size of the regular hexagonal structure part 6. , Three-dimensional structures of various shapes can be formed. For example, when it is desired to form a spherical surface having a radius of curvature R, Ψ _i = 2 × sin ⁻¹ (i × C / 2R) (2) Ψ _i defined by the above equation (2) By using, the length 2A _i of the shorter diagonal line of the diamond-shaped structure module forming the i-th regular hexagonal structure portion 6 from the inside may be set to the following expression (3). 2A _i = C × cos Ψ _i (3) Further, the length 2B _i of the longer diagonal line has the length C of the side of the diamond, so It is expressed by the following equation (4) from the equation (1). 2B _i = C (4- cos Ψ _i ) ^1/2 ... (4)

Next, the attitude control method of the module-connected space structure will be described. In the conical module-connected space structure 12 shown in FIG. 5, the direction M of the central axis of the conical space structure 12 is the solar wind direction S as shown in FIG.
When the solar wind is received on the surface of the conical space structure 12 when the conical space structure 12 is deviated by an angle φ from, a torque T that rotates the conical space structure 12 in a direction of reducing the displacement angle φ is generated. The magnitude of the torque T is approximately obtained by the following equation (5) when the deviation angle φ is a minute angle. T = {(πPL ³ sin 2θ) / 6} · φ (5) where P is the pressure of sunlight per unit area (kgm / se
c ² / m ² ), θ is the receding angle (degree) of the conical space structure 12,
L is a radius (m) along the slope of the conical space structure 12.

If the surface density (kg / m ² ) of the conical space structure is ρ in the above equation (5), the equation of motion given by the following equation (6) can be approximately obtained with respect to the deviation angle φ. To be d ² φ / dt ² + (2P sin2θ / 3ρL) φ = 0 (6) where d ² φ / dt ² is the angular acceleration obtained by second-order differentiating the deviation angle φ. Therefore, when the conical space structure 12 orbits the sun, the direction S of the sun and the conical space structure 12
The deviation angle φ from the central axis direction M can be attenuated by adding a damping torque necessary for damping to the torque of the formula (5) for this rotation.

For reference, when the natural frequency ω of the rotary motion given by the above equation (6) is obtained, P = 4.5 × 10 ⁻⁸ k
gm / sec ² / m ² , L = 5000m, θ = 30 degrees, ρ = 5kg / m
^{On the} other hand, ω = 1.0 × 10 ^-6 rad / sec, that is, the period of angular vibration is 71 days. Further, if the attitude control is performed in a long period, the damping torque described above can be generated by partially deforming the structure shape or the expanded shape of the film-like expanded material. Thus, the control of a huge space structure, the shape of the space structure, by calculating the receding angle and the like in the arithmetic processing unit (not shown) and appropriately adjust through the mast drive support of each structural module, It can be performed by utilizing the natural pressure of the solar wind or the like applied to the surface of the space structure without using a propulsion device such as an ion engine or a gas jet.

[0027]

As described above on the basis of the embodiments, according to the invention according to claim 1, a large-scale module connection type space structure is a simple rectangular plate structure module and a mast connection unit. By combining the components, it becomes possible to easily construct in space,
In addition, since the weight of the space structure can be reduced and the maintainability thereof can be improved, the possibility of commercial operation of the solar space power generation system can be brought about. Further, according to the invention of claim 2, since the mast connecting unit is configured such that three or more structural modules can be connected / separated, the plurality of structural modules are connected and fixed without a gap between the respective structural modules. It is possible to form a mechanically strong space structure. Further, according to the invention of claim 3, since the mast drive support mechanism of the cross type mast unit is configured so that the lengths of the four masts can be adjusted, the flat plate structures having various shapes can be easily formed. A module-connected space structure can be formed. Further, according to the invention of claim 4, the length of the four masts is adjusted by the mast drive support mechanism of the cross-shaped mast unit to easily form a three-dimensional structure of various forms, which is higher. It is possible to realize a module-connected space structure having mechanical strength. According to the invention of claim 5, the shape of the module-coupled space structure is controlled by the mast drive support mechanism of the structural module, so that a propulsion device such as a gas jet or an ion engine can be easily used. The attitude can be controlled, and therefore, the reliability and the weight can be reduced by simplifying the space structure.

[Brief description of drawings]

FIG. 1 is a diagram showing a mode in which structural modules in a first embodiment of a module-connected space structure according to the present invention are connected to each other via a mast connection unit.

FIG. 2 is a diagram showing a basic configuration in which six structural modules are connected by a mast connecting unit to form a regular hexagonal structure portion in the first embodiment.

FIG. 3 is a diagram showing a modification of the first embodiment in which one layer of structural module is added to the outside of the regular hexagonal structure portion shown in FIG. 2 to expand it.

FIG. 4 is a diagram showing another modification of the first embodiment in which one more structural module is added to the outside of the regular hexagonal structure portion of the modification shown in FIG. 3 to expand it.

FIG. 5 is a view showing a cross section of a module-coupled space structure having a conical structure with a receding angle θ according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a mode in the case where a pointing direction error occurs in the module-connected space structure having the conical structure having the receding angle θ shown in FIG. 5;

[Explanation of symbols]

1 Structural module 2 cross type mast unit 2-1, 2-2, 2-3, 2-4 mast 3 Mast drive support 4 Membrane development material 5 mast connection unit 6 Regular hexagon structure 7,8,9 Module connected space structure 11 Structural module 12 Conical space structure

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hideo Ohba 2-4-1, Hamamatsucho, Minato-ku, Tokyo Space Development Agency (72) Inventor Masahiro Mori 2-4-1-1, Hamamatsucho, Minato-ku, Tokyo Within the Space Development Agency (56) Reference Japanese Patent Laid-Open No. 1-122800 (JP, A) Actual Development 1-63600 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B64G 1 /twenty two

Claims (5)

(57) [Claims] 1. A cross-shaped mast unit having four storable extension masts and a mast drive support mechanism for deploying and supporting the extension masts in a cross shape, and by connecting the tip of the deployed cross-shaped mast unit. A rectangular flat plate structural module is configured with the film-shaped material installed in the formed rectangular envelope space, and a plurality of the structural modules are separably connected and combined using a mast connecting unit,
A module-connected space structure characterized by comprising a large space structure. 2. The module-connection-type space according to claim 1, wherein the mast connection unit is configured to connect the ends of the cross-shaped mast units of three or more structural modules in a separable manner. Structure. 3. The mast drive support mechanism of the cross-shaped mast unit is configured to be able to adjust the lengths of four masts that extend in all directions when the cross-shaped mast unit is deployed, and the mast connecting unit is used. The plurality of structural modules that are separably connected to each other are combined into a flat plate structure having an arbitrary shape having a developed cruciform mast unit and a mast connection unit as a skeleton. Such a module-connected space structure. 4. The mast drive support mechanism of the cross-shaped mast unit is configured to be able to adjust the lengths of four masts that are extended in all directions when the cross-shaped mast unit is deployed, and the mast connecting unit is used. In the structural module that is connected in a separable manner, all four sides of each structural module are set to the same length and the length of the diagonal line, that is, the length of both ends of the mast extended in both directions is adjusted. The module-connected space structure according to claim 1 or 2, which is configured as a hollow three-dimensional structure that approximates the shape of a cone or a parabola having the expanded cruciform mast unit and the mast connection unit as a skeleton. . 5. The module-coupled space structure as the hollow three-dimensional structure according to claim 4, wherein the film-shaped material stretched on the surface of the diamond-shaped structure module constituting the module-coupled space structure receives the solar wind. A method for controlling the attitude of a module-connected space structure, wherein the attitude of the module-connected space structure is oriented in the direction of the sun or the traveling direction by using the pressure of the gas flow.