JP6680740B2 - Water targets and corner reflectors - Google Patents

Description

  The present invention relates to a corner reflector that reflects radio waves and a water-based target equipped with the corner reflector.

  A water target equipped with a corner reflector is used as a target for performance test of a flying object, launch training, or bombing training. The corner reflector is formed of three radio wave reflecting surfaces that are orthogonal to each other. The radio wave reflection surface is formed from an isosceles right triangle. Therefore, the corner reflector has a triangular pyramid shape with an open bottom. The incident radio wave is sequentially reflected by the three radio wave reflection surfaces and emitted in the direction opposite to the incident direction.

  Generally, a water target is provided with a reflector that can be detected from a ship, an aircraft, a flying object, etc. by using a light wave such as a radio wave or an infrared ray on a boat or a remotely controllable boat. The test or training water area is limited to a place away from land, and there is a problem that it takes time to tow a water target to the target installation site by a towing ship.

  Therefore, a water target formed by an inflatable tube or balloon has been proposed. The water target stored in the storage body is moved by an aircraft or a helicopter and dropped at the installation location. When dropped, the tubes and balloons expand to form the frame of the water target. Further, the folded corner reflector is expanded in the frame, and the radio wave reflection surface is formed at a predetermined position (for example, Patent Document 1).

  On the other hand, there is a problem that a corner reflector provided on a water target formed by an inflatable tube or a balloon has low rigidity and is deformed by a strong wind or the like to deteriorate radio wave reflection characteristics.

  On the other hand, in Patent Document 2, three corners of the open surface of the corner reflector are supported by a frame formed of an icosahedron, and the apex of the corner reflector is supported by a sphere installed in the icosahedron, so that the corner reflector is supported. Suppresses the deformation of.

JP-A-7-0146099 Japanese Utility Model Publication No. 61-195610

  However, the water target formed by an inflatable tube or a balloon has room for improvement in stability when floating, and as a result, there is a problem that radio wave reflection characteristics deteriorate.

  Further, in the technique of Patent Document 2, although the rigidity of the corner reflector is improved, when the frame itself is deformed by a strong wind or the like, the corner reflector is also deformed accordingly, and the radio wave reflection characteristic is deteriorated.

  The present invention is to solve the above problems, while improving the stability during floating, by suppressing the deformation of the corner reflector, an object of the present invention is to provide a corner reflector and a water target that can maintain radio wave reflection characteristics. To do.

  The present invention which solves the above-mentioned subject is a water target. Water targets are polyhedral structures composed of multiple triangles and polygons other than one or more triangles. Each side of the polyhedral structure is formed by an air column. A corner reflector is installed on a part or all of the surface formed by the triangle. The corner reflector is composed of three surfaces that are orthogonal to each other.

  Since the bottom surface is a polygon other than a triangle (for example, a quadrangle, a pentagon, a hexagon), the stability during floating is improved.

  Preferably, the above-mentioned water target is provided with an expansion means for expanding the air column, and a container for housing the air column, the corner reflector, and the expansion means.

  This allows the aircraft or helicopter to drop.

  More preferably, the container is connected to an air column forming a polygon other than the triangle.

  This ensures that when a polyhedron structure is formed, polygons other than triangles (for example, pentagons) become the bottom surface.

  Preferably, each surface of the corner reflector is formed of a mesh material made of metal fiber.

  Thereby, the deformation of the corner reflector is suppressed.

  More preferably, each surface of the corner reflector is formed by a knitted fabric.

  Thereby, the deformation of the corner reflector is suppressed.

  More preferably, each side of the corner reflector is formed of a non-stretchable rope, and each point of the corner reflector is supported by the air column via a stretchable member.

  Thereby, the deformation of the corner reflector is suppressed.

  More preferably, a curtain covering the corner reflector opening is provided corresponding to the surface formed by the triangle on which the corner reflector is installed.

  Thereby, the deformation of the corner reflector is suppressed. It also functions as a laser reflector that reflects light waves such as infrared rays.

  Preferably, the water target comprises a self-precipitating system.

  More preferably, the self-sinking system has a first valve that operates based on a control command, and a second valve that operates when the pressure falls below a predetermined pressure.

  When the first bubble operates, the second valve automatically operates. This ensures that it will sink.

  Further, by reducing the number of first valves, the configuration is simplified, failures are reduced, and cost is reduced.

  More preferably, the air column forming the polyhedral structure is continuous inside the air column.

  As a result, the self-sink more reliably.

  The present invention which solves the above-mentioned subject is a corner reflector which is constituted by three sides which intersect at right angles, and each side is formed by mesh cloth formed by metal fiber.

  The present invention for solving the above-mentioned problems is a method for forming a target on water. The storage body is dropped, the expansion means opens the cover of the storage body, the storage body sinks below the water surface, the expansion means expands the air column, the air column rises, and the polygon except the triangle A polyhedron structure is formed with the bottom surface as the bottom surface to form a target on the water.

  The water target according to the present invention has improved stability during suspension. Further, the deformation of the corner reflector is suppressed. As a result, the radio wave reflection characteristic is maintained.

Water Target Appearance Diagram Water Target Appearance Diagram Main target configuration diagram on water Corner reflector conceptual diagram Corner reflector detail drawing Internal structure of target on water External view of the container Internal structure of storage Water target formation diagram Self-precipitation system configuration diagram Self-precipitation system operation explanatory diagram Low pressure operation valve operation explanatory diagram Modification of polyhedral structure

~ Overall structure of water target ~
1 and 2 are external configuration diagrams of a water target. 1 is a perspective view seen from substantially above, and FIG. 2 is a perspective view seen from below. FIG. 3 is a main block diagram of a water target.

  The water target of this embodiment is a polyhedral structure composed of 15 regular triangles and 1 regular pentagon. In the polyhedral structure of this embodiment, five regular triangles of a regular icosahedron composed of regular triangles are replaced with one regular pentagon.

  Each side of the polyhedral structure is formed by the air column 1. The air column is formed by expanding a tube made of rubber or the like and maintains a predetermined rigidity. Each air column 1 is continuous inside.

  The corner reflector 2 is embedded corresponding to the surface formed by each equilateral triangle. In this embodiment, 10 corner reflectors are embedded in 10 surfaces excluding the upper 5 surfaces.

  The corner reflector 2 has a triangular pyramid shape with an open bottom (details will be described later in the description corresponding to FIGS. 4 and 5). The equilateral triangular surface formed by the air column 1 and the triangular pyramid-shaped open surface formed by the corner reflector 2 correspond to each other.

  A laser reflection screen 3 (described in detail later) is provided so as to face an equilateral triangular surface formed by the air column 1 and a triangular pyramid-shaped open surface formed by the corner reflector 2.

  The wave curtain 4 is provided on the regular pentagonal surface formed by the air column 1. The wave screen 4 prevents waves from entering from below.

~ Floating stability ~
In the polyhedral structure, the surface formed by the regular pentagon is the bottom surface. This improves the stability when floating. A storage case 5 (details will be described later in the description corresponding to FIGS. 7 and 8) is connected downward from the center of the regular pentagon through a rope. The storage case 5 has a predetermined weight and acts as a weight so as to counter the buoyancy of the target on the water.

  The anchor 6 is connected from one end of the regular pentagon.

  Furthermore, the air column 1 forming a regular pentagonal surface is provided with a water bladder 7. The water bladder 7 is attached to the tube, and water is inserted inside. The water bladder 7 into which the water is inserted acts to counter the buoyancy of the target on the water.

~ Corner reflector ~
FIG. 4 is a conceptual diagram of a corner reflector. The corner reflector 2 is formed of three radio wave reflecting surfaces that are orthogonal to each other. The radio wave reflection surface is formed from an isosceles right triangle. Therefore, the corner reflector 2 has a triangular pyramid shape with an open bottom.

  The radio wave that has entered the corner reflector 2 is sequentially reflected by the three radio wave reflection surfaces and emitted in the direction opposite to the incident direction. In this way, the radio wave reflection characteristics are maintained by maintaining the orthogonal positions of the three radio wave reflection surfaces.

  The radio wave reflection surface is formed of a mesh material made of metal fibers.

  The larger the aperture ratio, the lighter the weight and the better the air permeability. As a result, bending due to its own weight is reduced, wind resistance and wave resistance are reduced, deformation of the radio wave reflection surface is suppressed, and orthogonality of the radio wave reflection surface can be maintained.

  In the prototype, the electromagnetic wave shield fabric DALI from Ecologa Europe GmbH was used, but sufficient electromagnetic wave reflection characteristics could be confirmed. The mesh opening was 0.5 x 0.5 mm.

  In order to obtain reliable lightness and air permeability, it is preferable that the mesh material has an opening ratio of 30% or more, preferably 50% or more. However, the aperture size is preferably half or less of the wavelength of the transmitted radio wave. Thereby, the mesh material functions as a radio wave reflection surface.

  In addition, since it is a mesh, the tide due to waves is unlikely to adhere, and the radio wave reflection characteristics are less likely to deteriorate.

  As the metal fiber, resin fiber coated with metal is used. Specifically, nylon is coated with silver or nickel. The metal may be stretched to form a thin wire.

  The fabric may be woven, but it is still better if it is knitted. The knitted fabric has elasticity. When used as a radio wave reflection surface, the fabric is less likely to bend due to its own weight. Thereby, the orthogonality of the radio wave reflection surface can be maintained.

  In the prototype, when the fabric was stretched horizontally, the amount of deflection due to its own weight with respect to the length of one side of the equilateral triangle was 2% or less. In addition, it was confirmed that such a degree of bending does not affect the radio wave reflection characteristics.

  When the cloth is a woven material, a plain cloth or the like may be used, but a honeycomb cloth is more preferable. Honeycomb has elasticity. When used as a radio wave reflection surface, the fabric is less likely to bend due to its own weight. Thereby, the orthogonality of the radio wave reflection surface can be maintained.

  5 and 6 are detailed views of the corner reflector. FIG. 5 shows the support state of the corner reflectors, and FIG. 6 shows the relationship between the corner reflectors.

  The corner reflector 2 has a triangular pyramid structure (a tetrahedron formed from three right-angled isosceles triangles and one equilateral triangle, where the equilateral triangle is an open surface). A non-stretchable rope 11 is arranged along each side of the tetrahedron. As the non-stretchable rope 11, for example, Dyneema (registered trademark) rope or Kevlar (registered trademark) rope is used.

  Elastic members 12 are continuously provided at the three vertices on the open side of the corner reflector 2. Specifically, the three non-stretchable ropes 11 and the stretchable members 12 are continuous at each vertex. The other end of the elastic member 12 is supported by the air column 1. The elastic member 12 is, for example, a rubber cord.

  An elastic member 12 is continuously provided at the apex of the corner reflector 2. Specifically, the three non-stretchable ropes 11 and the stretchable members 12 are continuous at each vertex. The other end of the elastic member 12 is connected to the round link 13.

  The round link 13 is arranged substantially at the center of the polyhedral structure. The round link 13 is provided with the other end of the elastic member 12 at the apex on the back side of each corner reflector 2. Thereby, in the round link 13, the tensions of the elastic members 12 are balanced.

  That is, the stretchable members 12 are connected to both ends of each non-stretchable rope 11. By giving an appropriate tension to the stretchable member 12, an appropriate tension is also generated in the non-stretchable rope 11. The elastic member 12 expands and contracts in response to the deformation of the air column 1 and the deformation of the corner reflector 2 itself. Thereby, each non-stretchable rope 11 does not bend and always maintains the same length.

  As a result, the tetrahedral structure formed by the six non-stretchable ropes 11 is always maintained. In other words, the deformation of the corner reflector 2 is suppressed.

~ Laser reflector ~
A laser reflection screen 3 is provided so as to face the open surface of the corner reflector 2. The laser reflection screen 3 is supported at each vertex of an equilateral triangle formed by the air column 1.

  However, when forming the polyhedral structure, an opening is provided so that a negative pressure is not generated, and the equilateral triangle formed by the air column 1 is not completely sealed. As a result, the laser reflection screen 3 has a shape (hexagon) in which the vertices of an equilateral triangle are missing.

  The laser reflecting screen 3 is, for example, a woven material made of nylon fiber.

  It is preferable that the laser reflection screen 3 does not pass wind or waves. Thereby, in the corner reflector 2, the deformation of the radio wave reflection surface is suppressed, and the orthogonality of the radio wave reflection surface can be maintained. In addition, in the corner reflector 2, the tide due to waves is unlikely to adhere, and the radio wave reflection characteristics are less likely to deteriorate.

  The laser reflector 3 transmits the radar radio wave and reflects the laser. As a result, the corner reflector 2 functions as a laser reflector without impairing the function of the corner reflector 2.

~ Storage case ~
FIG. 7 is an external configuration diagram of the storage case. The storage case 5 is, for example, a metal housing and has a predetermined weight so as to act as a weight. On the other hand, it is preferably compact because it is loaded on an aircraft or a helicopter.

  The storage case 5 is formed so that the two case halves face each other and cover. The storage case 5 is provided with an actuation cord 16 and a fork insertion port 17.

  FIG. 8 is an internal configuration diagram of the storage case 5.

  The storage case 5 stores a tube made of rubber or the like which becomes the air column 1, a corner reflector 2, a laser reflection screen 3, a wave screen 4, and a high-pressure gas container 18.

  Inside the storage case 5, the tube made of rubber or the like that becomes the air column 1, the corner reflector 2, the laser reflection screen 3, and the wave screen 4 are folded to form a floating body 19.

  The high-pressure gas container 18 and the floating body 19 (in particular, a tube made of rubber or the like) are continuous via a pressure resistant hose.

  When the actuation cord 16 is pulled, the hammer is activated and the high pressure gas container 18 is opened.

~ Water target formation ~
FIG. 9 is an explanatory diagram of the operation of forming a water target.

  The storage case 5 is loaded on an aircraft, a helicopter, or the like, moved to a target installation location, and dropped. It may be dropped from platforms such as decks of ships and quays of ports.

  When the storage case 5 suspended from a helicopter or the like is dropped, the actuation rope 16 is pulled, the hammer is activated, and the high-pressure gas container 18 is opened.

  A high-pressure gas (for example, carbon dioxide gas) is supplied to the floating body 19 (in particular, a tube made of rubber or the like). The lid of the storage case 5 is opened by the expansion pressure of the floating body 19.

  At this time, the storage case 5 once sinks below the water surface. The storage case 5 and the floating boat 19 are separated. Note that the storage case 5 and the floating body 19 are reliably separated by the wave curtain 4.

  The air column 1 expands, and the floating boat body 19 floats. At this time, the storage case 5 is connected via a rope downward from the center of the regular pentagon in the polyhedral structure, and acts so as to oppose buoyancy. As a result, the surface formed by the regular pentagon surely becomes the bottom surface.

  As the bottom surface is formed, an air column extending upward is formed to form a polyhedral structure.

  The corner reflector 2, the laser reflection curtain 3, and the wave curtain 4 are unfolded together with the exhibition operation of the polyhedron structure. This forms a water target.

~effect~
The effects of this embodiment will be briefly summarized.

  When the book operation of the polyhedral structure is performed, the surface formed by the regular pentagon is surely the bottom surface. The pentagonal shape of the bottom surface improves stability when floating. As a result, the deformation of the corner reflector 2 is suppressed.

  Since the radio wave reflection surface of the corner reflector 2 is made of mesh fabric, the weight is reduced and the air permeability is improved, so that the deformation of the radio wave reflection surface, that is, the deformation of the corner reflector 2 is suppressed.

  Each side of the corner reflector 2 is formed by the non-stretchable rope 11, and each point of the corner reflector 2 is supported by the air column 1 and the round ring 13 via the stretchable member 12. The elastic member 12 expands and contracts in response to the deformation of the air column 1 and the deformation of the corner reflector 2 itself. That is, the deformation of the corner reflector 2 is suppressed.

  The laser reflection screen 3 does not pass wind or waves. As a result, the deformation of the corner reflector 2 is suppressed.

  As a result of suppressing the deformation of the corner reflector 2 as described above, the orthogonality of the radio wave reflection surface can be maintained and the radio wave reflection characteristic can be maintained. That is. The position of the target on the water can be confirmed accurately by the radar.

~ Self-sinking system configuration ~
The water target is destroyed by the collision of the flying object. However, there is a possibility that the destruction may fail or that the performance test of the flying object, the launch training, the bombing training, etc. may be stopped. In that case, the water target is collected, but if the water target cannot be collected due to deterioration of weather and sea conditions, it is not preferable that the water target continues to be unnecessarily suspended. As such, the water target may be equipped with a self-precipitation system.

  FIG. 10 is a block diagram of the self-precipitation system. The self-precipitation system includes a control device 21, a control valve 22 (first valve), and a low pressure operation valve 23 (second valve).

  At least one of the control device 21 and the control valve 22 is provided in the middle air column of the polyhedral structure. When the control device 21 receives the command signal or determines that a predetermined time has elapsed, the control device 21 transmits an operation signal to the control valve 22. Based on the actuation signal, the control valve 22 is opened and the gas in the air column 1 is released.

  The low-pressure actuated valves 23 are provided in the air columns 1 substantially uniformly. When the pressure becomes equal to or lower than the predetermined pressure, the low-pressure operation valve 23 is automatically opened, and the gas in the air column 1 is released (details will be described later in the description corresponding to FIG. 12).

  FIG. 11 is an explanatory diagram of the operation of the self-sinking system. The air column 1 is filled with high-pressure gas and maintains a predetermined pressure (see FIG. 9).

  First, based on a command from the control device 21, the control valve 22 is opened and the gas in the air column 1 is released. As a result, the pressure in the air column 1 gradually decreases (see the upper part of FIG. 11).

  When the pressure becomes equal to or lower than a predetermined pressure, the low pressure operation valve 23 is opened and the gas in the air column 1 is released. Since the plurality of low-pressure actuating valves 23 are evenly arranged, the pressure in the air column 1 drops sharply (see the middle part of FIG. 11).

  By the way, each air column 1 is continuous inside. That is, there is no partition wall or the like that obstructs the flow of gas. As a result, gas is evenly released from each low pressure operation valve 23. There is little risk of gas accumulation. Further, even if a part of the low-pressure operation valve 23 does not operate, the pressure can be reliably reduced.

  When most of the gas in the air column 1 is released, the water target loses buoyancy and sinks below the water surface due to the weight of the storage case 5 (see the lower part of FIG. 11).

  In this way, the self-sinking system is able to reliably sink the water target in a short time.

  Here, at least one control valve 22 is enough, and the wiring from the control device 21 can be the shortest. Further, by reducing the number of control valves 22 as much as possible, the risk of failure is low. Furthermore, by reducing the number of control valves 22 as much as possible, the cost can be reduced.

  FIG. 12 is an operation explanatory view of the low pressure operation valve 23. The low-pressure operation valve 23 is composed of a valve 23A and a valve 23B that are connected in series.

  The valve 23A is open below the first threshold value, and is closed above the first threshold value.

  The valve 23B is closed below the second threshold value (higher than the first threshold value), and is opened above the second threshold value. The valve 23B has a permanent magnet, and once opened, the open state is maintained by the permanent magnet.

  In the storage case, almost no pressure acts on the low pressure operation valve 23 (see FIG. 7). That is, when it is less than the first threshold value, the valve 23A is open and the valve 23B is closed. That is, the low pressure operation valve 23 is closed (gas is not released).

  When the high pressure gas is supplied to the air column 1 and becomes equal to or higher than the first threshold value (less than the second threshold value), the valve 23A is closed. On the other hand, the valve 23B remains closed. That is, the low pressure operation valve 23 is closed.

  Further, when the high pressure gas is supplied to the air column 1 and becomes equal to or higher than the second threshold value, the valve 23A remains closed and the valve 23B opens. That is, the low pressure operation valve 23 is closed. Further, high-pressure gas is supplied to the air column 1 to form a polyhedral structure (see FIG. 9).

  If the water target cannot be recovered due to bad weather or sea conditions, the self-sinking system operates (see FIG. 11). The control valve 22 is opened, and the pressure in the air column 1 gradually decreases. However, even if it is less than the second threshold value, the valve 23B is kept open by the permanent magnet. On the other hand, when the pressure further decreases and falls below the first threshold value, the valve 23A opens again. That is, the low pressure operation valve 23 opens.

  As described above, during the operation of the self-sinking system, the low-pressure operation valve 23 automatically operates when the pressure becomes less than the first threshold.

~ Modification ~
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the technical idea thereof.

  In this embodiment, the polyhedral structure is composed of 15 regular triangles and 1 regular pentagon. By the way, in the case of long-distance incidence, radio waves are incident from an angle that is almost horizontal. Of the 15 equilateral triangles, the corner reflectors 2 on the upper 5 planes are unlikely to be used.

  Therefore, the corner reflectors 2 do not have to be installed on the upper five surfaces. As a result, among the 15 equilateral triangles, 10 corner reflectors 2 are embedded on the side surface.

  FIG. 13 is a modification of the polyhedral structure or a modification of the number of corner reflectors.

  In FIG. 13A, 15 corner reflectors 2 are embedded corresponding to 15 equilateral triangles.

  The polyhedral structure of FIG. 13B is composed of 10 regular triangles and 2 regular pentagons. 10 corner reflectors 2 are embedded corresponding to 10 equilateral triangles.

  The polyhedral structure of FIG. 13C is composed of 12 regular triangles and 1 regular square. Twelve corner reflectors 2 are embedded corresponding to twelve equilateral triangles.

  The polyhedral structure of FIG. 13D is composed of 12 regular triangles and 1 regular square. Eight corner reflectors 2 are embedded in the side surface of the twelve regular triangles.

  The polyhedral structure of FIG. 13E is composed of 8 equilateral triangles and 2 equilateral quadrilaterals. Corresponding to eight regular triangles, eight corner reflectors 2 are embedded.

  The polyhedral structure of FIG. 13F is composed of four regular triangles and one regular quadrangle. Corresponding to the four equilateral triangles, four corner reflectors 2 are embedded.

  The polyhedral structure of FIG. 13G is composed of 12 regular triangles and 2 regular hexagons. Twelve corner reflectors 2 are embedded corresponding to twelve equilateral triangles.

  In any of the modified examples, stability during floating is improved. It can also reflect radio waves from all directions.

  Although the present embodiment has been described as a water target for performance test of a flying object, launch training or bombing training, it may be used as a rescue buoy or decoy.

1 Air column 2 Corner reflector 3 Laser reflector 4 Wave unveiling 5 Storage case 6 Anchor 7 Water bag 11 Non-stretchable rope 12 Stretchable member 13 Round link 16 Actuation line 17 Fork insertion hole 18 High pressure gas container 19 Floating body 21 Control Device 22 Control valve (first valve)
23 Low pressure actuated valve (second valve)

Claims (5)

A polyhedral structure composed of a plurality of triangles and one or more pentagons or more polygons,
Each side of the polyhedral structure is formed by an air column,
A corner reflector is installed on a part or all of the surface formed by the triangle,
The above-mentioned corner reflector is composed of three surfaces orthogonal to each other. Expansion means for expanding the air column,
The water target according to claim 1, further comprising: a storage body that stores the air column, the corner reflector, and the expansion means. The water target according to claim 2, wherein the container is connected to an air column forming a polygon other than the triangle. The water target according to any one of claims 1 to 3, wherein each of the surfaces of the corner reflector comprises a mesh material formed of metal fibers. The container is dropped,
The expansion means opens the lid of the container,
The storage body sinks below the surface of the water,
The expansion means expands the air column,
As the polyhedral structure is formed by the expansion of each air column, it floats,
A polyhedral structure is formed with the pentagon or more polygon as the bottom surface,
A method for forming a target on water, comprising forming the target on water according to claim 3.