JP3891972B2 - Deployment antenna - Google Patents

Description

  The present invention relates to a deployment antenna that can be mounted on an artificial satellite or the like in a folded state and deployed in space.

  When a deployment antenna mounted on an artificial satellite or the like is transported to outer space, a rocket such as Ariane or H-IIA is used as a transport means. However, since the rocket's cargo storage space is limited, when transporting a large deployment antenna, it is housed in the rocket in a small folded state, and this deployment after the rocket has reached space. A system is used in which the antenna is released into space.

  Some such deployable antennas are configured by combining a plurality of basic structures. In the case of such a deployable antenna, a large deployable antenna can be configured depending on the number of basic structures to be combined.

  FIG. 7 is a perspective view showing the configuration of the basic structure of a conventional deployable antenna, and FIG. 8 is an exploded perspective view showing the basic structure of the conventional deployable antenna.

  As shown in FIGS. 7 and 8, the basic structure of the deployable antenna has a cable network 100 that functions as an antenna reflecting surface. The cable network 100 includes a surface cable 101, a metal mesh 102, a back cable 103, and a tie cable 104, and is supported by a deployment truss 106 as a frame structure by a plurality of standoffs 105.

  The deployment truss 106 is composed of eight planar link mechanisms 107 formed in a trapezoidal shape. The flat link mechanisms 107 share the central shaft member 108 and are equally distributed radially around the central link member 107. By sliding the slide hinge 109 along the axial direction of the central shaft member 108, the planar link mechanism 107 is shared. The deployment truss 106 can be stored and deployed (see, for example, Non-Patent Document 1).

  A configuration in which six flat link mechanisms that can expand and contract in the longitudinal direction are radially arranged as a deployment truss is also known. In this configuration, the deployment truss is stored and deployed by driving the plurality of planar link mechanisms to extend and contract.

An annular cable disposed around the deploying truss is used for expansion and contraction driving of the planar link mechanism. This cable is movably connected to the front end of each planar link mechanism, and the planar link mechanism is expanded and contracted in synchronization by adjusting the winding amount of the cable by the rotation of the motor.
Atsushi Meguro, Hitoshi Mitsuji, Kazuhide Ando: Construction of a large-sized satellite communication antenna with a modular cable mesh deployment structure, B-II volume of the IEICE B-II special issue, IEICE Transactions, B- II, Vol. j76-B-II, No. 5,1993.5, pp. 476-484.

  By the way, the above-mentioned cable network 100 is comprised by the flexible cable which has flexibility, and cannot maintain the shape as an antenna reflective surface with own force.

Therefore, the upper surface of the deployable truss 106, previously formed to approximate a spherical shape which is the minimum error approximates the parabolic surface, by pasting the cable network 100 via standoffs 105 thereon, parabolic surface cable network 100 The shape is maintained.

  However, when this method is used, since the shape of the cable network 100 greatly depends on the shape of the deployment truss 106, it is necessary to design the shape of the deployment truss 106 with high accuracy.

  Further, a large force acts on the deployment truss 106 due to the tension of the cable network 100. Therefore, when designing the deployment truss 106, it is necessary to give the deployment truss 106 great rigidity that does not lose the tension of the cable network 100.

  However, in order to give the deployment truss 106 great rigidity, it is necessary to increase the thickness of the members constituting the deployment truss 106, which increases the overall weight.

  Furthermore, since the upper surface of the deployment truss 106 has a spherical shape, there is a problem that the deployment truss 106 has a complicated structure that is deployed in a three-dimensional direction.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a low-weight and large-sized deployment antenna with a simpler configuration than a conventional deployment antenna.

  In order to solve the above problems and achieve the object, the deployable antenna of the present invention is configured as follows.

(1) In a deployable antenna mounted on an artificial satellite, a first network configured in a lattice shape by combining a plurality of first cable bodies, and radio wave reflection provided on the first network A membrane, a second network that is provided in the first network, and is configured by a plurality of second cords having a larger elasticity than the first cord, and an outer peripheral portion of the second network as a plurality of struts collapsible provided at predetermined intervals in the circumferential direction, provided on the inside of the plurality of struts, the struts by pushing radially on the outer circumference direction of the second network, application of a tension through the second network to the first network, characterized by comprising a developing means for developing the first network.

(2) The deployable antenna described in (1), wherein the first network is configured to have a substantially parabolic surface when deployed, depending on the length of each of the first cords. It is characterized by.

(3) The deployable antenna according to (1), further comprising a connecting means for connecting the deploying means and the artificial satellite.

  According to the present invention, it is possible to provide a low-weight and large deployable antenna with a simple configuration.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a perspective view showing the configuration of the deployed state of the deployment antenna according to the first embodiment of the present invention, FIG. 2 is a perspective view showing the configuration of the deployed state of the cable network according to the embodiment, and FIG. It is a perspective view which abbreviate | omits a wave reflection film and an expansion tube, and shows the structure of the expansion | deployment state of the expansion | deployment antenna which concerns on the same embodiment.

  As shown in FIG. 1, the deployable antenna has a cable network 1. As shown in FIG. 2, the cable network 1 is composed of a first network 11 (portion indicated by a thick line) and a second network 12 (portion indicated by a thin line). It has a polygonal shape like the shape.

  The first network 11 is configured in a triangular lattice shape by connecting a plurality of first cables 13 (first strips) having low stretchability by nodes 14, and one surface of the first network 11 is reflected by radio waves. It is a mounting surface 11a for mounting a film 2 (described later). The mounting surface 11 a is formed in a substantially parabolic shape depending on the length of each first cable 13.

  In the present embodiment, the node 14 is used to connect the first cables 13, but the present invention is not limited to this, and the ends of the first cables 13 may be simply bound together. Absent.

  On the other hand, the second network 12 includes a surrounding net 12 a provided on the outer periphery of the first network 11 and a counter net 12 b provided at a position facing the first network 11.

  The surrounding net 12 a and the opposing net 12 b are configured in a triangular lattice shape by connecting a plurality of second cables 15 having a larger elasticity than the first cable 13 by nodes 16.

  In the present embodiment, the node 16 is used to connect the second cables 15, but the present invention is not limited to this, and the ends of the second cables 15 may be simply bound together. Absent.

  The surrounding net 12a is coupled to a plurality of nodes 14 provided on the outer periphery of the first network 11, and pulls the first network 11 along the mounting surface 11a via these nodes 14.

  The opposing net 12b is coupled to a plurality of nodes 14 and 16 provided in the first and second networks 11 and 12, and the first network 11 is mounted via these nodes 14 and 16. It is pulled in the direction intersecting the surface 11a.

  As shown in FIG. 1, the radio wave reflection film 2 described above is attached to the mounting surface 11 a of the first network 11. The radio wave reflection film 2 is made of a radio wave reflection material such as a metal mesh, and is attached to a mounting surface 11a formed in a parabolic shape so as to function as an antenna reflection surface.

  On the outer periphery of the second network 12, a plurality of, for example, six struts 3 are provided at equal intervals in the circumferential direction. These struts 3 are constituted by foldable rod-like members, and connect the surrounding net 12a and the opposed net 12b at, for example, six apex portions of the second network 12 (see FIG. 3).

  Between the surrounding net 12a and the opposed net 12b, an inflatable tube 4 (expanding means) that can be inflated and contracted is provided so as to be surrounded by the column 3. The expansion tube 4 is formed in a donut shape, that is, tubular and annular, by a thin film-like material, and a gas supply device 18 that supplies compressed gas is connected to a predetermined position of the expansion tube 4.

  In this embodiment, compressed gas is used to expand the expansion tube 4, but the present invention is not limited to this as long as the property of vaporizing the substance is used.

  Next, the operation when the deployable antenna having the above-described configuration is constructed in outer space will be described.

  When launching the deployment antenna having the above configuration with a rocket, the cable network 1, the radio wave reflection film 2, the support column 3, and the expansion tube 4 are folded into a small size and stored in the rocket fairing.

  When the rocket is launched and the satellite is separated from the rocket and reaches a predetermined orbit, compressed gas is supplied from the gas supply device 18 into the expansion tube 4 in order to deploy the deployment antenna. When compressed gas is supplied to the expansion tube 4, the expansion tube 4 expands in a donut shape, and, for example, six struts 3 are radially expanded. As a result, the strut 3 that has been folded extends, and tension is applied to the first network 11 via the second network 12.

  As a result, the mounting surface 11a of the first network 11 has a parabolic shape, and the radio wave reflecting film 2 attached thereon has a function as an antenna reflecting surface. This completes the construction of the deployable antenna. Even after the construction of the deployable antenna is completed, it is necessary to keep applying a predetermined gas pressure in the expansion tube 4 and maintain the mounting surface 11a of the first network 11 in a parabolic shape.

  According to the deployable antenna having the above-described configuration, the first network 11 is configured in a triangular lattice shape by coupling the plurality of first cables 13, and the first cable 13 has a first length depending on the length of each first cable 13. The mounting surface 11a of the network 11 is formed in a substantially parabolic shape. Therefore, it is possible to make the shape of the parabolic surface simply by stretching the first network 11, so that the configuration of the expanding means for expanding the first network 11 can be simplified. As a result, since a conventional and heavy deployment truss is not required, a simple and light configuration such as the expansion tube 4 can be used.

  Further, the first network 11 is supported by the expansion tube 4 via the second network 12 having a large stretchability. Therefore, even if the expansion tube 4 is greatly deformed, the elasticity of the second network 12 absorbs the deformation, so that the first network 11 is not affected by the deformation, and the antenna reflecting surface is not affected. Shape accuracy can be maintained.

  Further, the first cable 13 is formed of a material having small stretchability. Therefore, even if tension is applied to the first network 11, each first cable 13 hardly stretches, so even if the applied tension is unbalanced, the parabolic surface shape is distorted. There is no.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  FIG. 4 is a perspective view showing the configuration of the deployed state of the deployed antenna according to the second embodiment of the present invention.

  As shown in FIG. 4, the deployable antenna according to the present embodiment is obtained by providing a high-precision antenna 21 on the radio wave reflecting film 2 according to the first embodiment. The high-precision antenna 21 is supported by a plurality of nodes 14 and 16 provided in the cable network 1, and the reflection surface 21a is formed in a parabolic surface shape with higher accuracy than the mounting surface 11a of the first network. ing.

  As described above, the deployable antenna according to the present embodiment includes two reflecting surfaces, that is, the antenna reflecting surface formed by the first network 11 and the highly accurate reflecting surface 21a. Therefore, both a low frequency and a high frequency can be reflected by one antenna reflector.

  Next, a third embodiment of the present invention will be described with reference to FIG.

  FIG. 5 is a perspective view showing the configuration of the deployed state of the deployed antenna according to the third embodiment of the present invention.

  As shown in FIG. 5, the deployable antenna according to the present embodiment is obtained by connecting a connecting member 31 (connecting means) to a predetermined position of the expansion tube 4 according to the first embodiment. The connecting member 31 is formed in a tubular shape from the same material as the expansion tube 4, that is, a thin film-like material, and plays a role of connecting the expansion tube 4 and an artificial satellite (not shown).

  The connection member 31 and the expansion tube 4 communicate with each other, and the connection member 31 and the expansion tube 4 can be expanded by supplying compressed gas from the gas supply device 18 provided in the connection member 31.

  Thus, in the present embodiment, the connecting member 31 that connects the deployment antenna and the artificial satellite is formed of the same thin film-like material as the expansion tube 4. Therefore, the overall configuration of the deployable antenna can be simplified and the total weight can be reduced.

  Next, a fourth embodiment of the present invention will be described with reference to FIG.

  FIG. 6 is a perspective view showing the configuration of the deployed state of the deployed antenna according to the fourth embodiment of the present invention.

  As shown in FIG. 6, the deployable antenna according to the present embodiment is provided with a support mechanism 41 (support means) at a predetermined position of the expansion tube 4 according to the second embodiment. The support mechanism 41 has a plurality of booms 43 and 44 which are connected to be bent by a first joint 42, and in the present embodiment, two booms 43 and 44. Is supported. The booms 43 and 44 are formed of a material having high rigidity that hardly deforms in an environment where the deployable antenna of the present invention is used.

  A second joint 45 and a third joint 46 (adjustment means) having the same configuration as that of the first joint 42 are provided at the distal end and the base end of the support mechanism 41, respectively. Connected to the artificial satellite, the third joint 46 is connected to the expansion tube 4 via a connecting portion 47. That is, the support mechanism 41 also plays a role of connecting the deployable antenna and the artificial satellite.

  The connecting portion 47 has a configuration in which the connecting member 31 according to the third embodiment is shortened in the axial direction, and the compressed gas is supplied from the gas supply device 18 so that the connecting portion 47 and the expansion portion are expanded. The tube 4 can be expanded.

  Thus, in this embodiment, since the high-precision antenna 21 is supported by the support mechanism 41 having rigidity connected to the expansion tube 4, compared to the case where it is directly mounted on the flexible first network 11. The high-precision antenna 21 can be accurately positioned.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

The perspective view which shows the structure of the expansion | deployment state of the expansion | deployment antenna which concerns on the 1st Embodiment of this invention. The perspective view which shows the structure of the expansion | deployment state of the cable network which concerns on the embodiment. The perspective view which abbreviate | omits a wave reflection film and an expansion tube, and shows the structure of the expansion | deployment state of the expansion | deployment antenna which concerns on the embodiment. The perspective view which shows the structure of the expansion | deployment state of the expansion | deployment antenna which concerns on the 2nd Embodiment of this invention. The perspective view which shows the structure of the expansion | deployment state of the expansion | deployment antenna which concerns on the 2nd Embodiment of this invention. The perspective view which shows the structure of the expansion | deployment state of the expansion | deployment antenna which concerns on the 2nd Embodiment of this invention. The perspective view which shows the structure of the basic structure of the conventional expansion | deployment antenna. The perspective view which decomposes | disassembles and shows the basic structure of the conventional expansion | deployment antenna.

Explanation of symbols

  2 ... Radio wave reflecting film, 3 ... support, 4 ... expansion tube (deployment means), 11 ... first network, 12 ... second network, 13 ... first cable (first cable), 15 ... 2nd cable (2nd cable body), 21 ... High-precision antenna, 31 ... Connection member (connection means), 41 ... Support mechanism (support means).

Claims (3)

In deployable antennas mounted on artificial satellites,
A first network configured in a lattice shape by combining a plurality of first striate bodies;
A radio wave reflection film provided on the first network;
A second network that is provided in the first network and is configured by a plurality of second cords having a larger elasticity than the first cords;
A plurality of collapsible support columns provided at predetermined intervals in the circumferential direction on the outer periphery of the second network;
Provided inside of the plurality of struts, the struts by pushing radially on the outer circumference direction of the second network, an application of a tension through the second network to the first network, the first Deployment means for deploying one network;
A deployable antenna comprising:   The deployment antenna according to claim 1, wherein the first network is configured to have a substantially parabolic surface when deployed according to the length of each of the first striated bodies. Deployable antenna according to claim 1, characterized by further comprising a connecting means for connecting the said expansion means and said satellites.

Images