JP5433288B2 - Aircraft landing gear - Google Patents

Description

  The present invention relates to an apparatus for landing a flying object such as an airplane, and more particularly to a landing apparatus for landing a large number of flying objects safely and efficiently.

  Along with the rapid progress in the development and operation of robot technology and flight control technology in recent years, recently, many countries actively called for UAV (Unmanned Air Vehicle) research, development and practical application of unmanned aircraft Activities are ongoing. Research and development of DARPA (Defense Advanced Research Project Agency), development of ultra-small reconnaissance aircraft by the Japanese Ministry of Defense, research and development of UAV by multiple companies, and business applications, etc. You can see articles that introduce the technology, research and development related to this field.

  For example, a technology has been developed in which a relatively small UAV is thrown around the facility and the surroundings are monitored with a mounted camera. It would be possible to let UAV handle logistics. Since it is not necessary for humans to appear in UAV, there is a high possibility that UAV will become popular in the future because it does not cost much.

  However, the bottleneck for the spread of UAV is ground facilities. There has not been much research on the airports and facilities responsible for UAV takeoff and landing. The long-term prospects for the capacity of airports responsible for civil aviation transportation systems, including existing international airports and regional airports, have not yet been opened. If UAV usage increases in the future, it will not be possible to rely on existing airports. When demand for logistics, monitoring and monitoring using a large amount of UAV, aerial photography for disaster prevention, etc. arises in the future, it is unclear whether UAV can be used effectively in the suburbs of cities or in disaster areas. In particular, it is desirable to take advantage of the UAV so that the UAV can take off and land in a manner that requires minimal human hands.

JP 47-17198

  For UAV launch or takeoff, the “hand throw” method is currently mainstream. The hand throwing method is convenient because it does not require a large land such as an airfield, but it cannot be used when many UAVs are automatically operated. As a landing method, a method of slowly dropping using a balloon, or forcibly dropping a thrust while flying at low speed in a low sky is performed. However, all of these methods are unsuitable for automatically landing a large amount of UAVs.

  In order to deal with these problems, it is possible to prepare a large land and take off and land using the runway in the same way as a normal commercial airplane. However, it is impossible to establish airport facilities that can take off and land a large number of UAVs continuously, from the viewpoint of cost and the amount of maintenance work. Close to. Accordingly, it is considered that a system (including automatic guidance, guide, congestion avoidance, collision avoidance, etc.) capable of launching and landing a large amount of UAV is required as a business.

  As one measure for solving these problems, Patent Document 1 discloses an aircraft takeoff and landing facility in which a deck is provided at the tip of a rotating wing and an aircraft is landed on the deck. In the aircraft takeoff and landing facility disclosed in Patent Document 1, the aircraft is landed on the deck while the wing is rotated, and refueling is performed while continuing to rotate, and the aircraft is taken off from the deck again. Since the wing keeps rotating, it has a feature that it can take off easily. With such a configuration, it is possible to land and take off a large number of aircrafts continuously without using a large land.

  However, in Patent Document 1, an aircraft is to be piloted by a pilot in accordance with instructions from a control tower. Such a precondition is not satisfied in an unmanned flying vehicle such as UAV. When trying to guide the takeoff or landing of a large number of UAVs using radio, there is a problem in that guidance cannot be performed safely because the channel is limited. In particular, unlike takeoff, at the time of landing, the flying object must be guided to the deck while moving the flying object and the deck together, and the above-described problem appears remarkably.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a flying object landing device that allows a large number of flying objects to land safely within a limited area.

  A landing apparatus according to a first aspect of the present invention is a landing apparatus for landing a flying object, and includes a flying object landing deck provided with an attaching / detaching device that allows the flying object to be attached and detached, and a fixed orbit. And a driving means for moving the deck in a predetermined direction, and a passive guidance device for guiding the flying object by reflecting light from the flying object is provided at a predetermined position of the deck. .

  The drive means moves the deck in a predetermined direction on a fixed orbit. The flying object that is about to land on the deck emits light toward the deck. The passive induction device that has received the light reflects this light. This reflected light guides the flying object to land on the deck.

  Since light is used for guidance, unlike radio waves, there is little possibility of confusion when multiple flying objects try to land on the deck. A flying object can be automatically landed on the deck even when the deck moves. In order to land the flying object on the moving deck, it is not necessary to greatly reduce the speed of the flying object. Long runways like existing airports are therefore unnecessary.

  As a result, it is possible to provide a flying object landing device that allows a large number of aircrafts to land safely within a limited area.

  Preferably, the passive guidance device includes a plurality of right angle reflectors arranged so as to have a predetermined relationship with respect to a reference plane determined by the attitude of the deck, and a substrate to which the plurality of right angle reflectors are attached, Each of the plurality of right angle reflectors has two reflective surfaces that are combined to form a ridgeline and to form a right angle between each other, the plurality of right angle reflectors having a respective ridgeline They are attached to the substrate so that the angles formed with the reference plane are different from each other.

  The right-angle reflectors are attached to the substrate so that the angles formed by the respective ridge lines and the reference plane are different from each other. When the flying object approaches the deck, the reflected light from the different right-angle reflectors returns to the flying object according to the change in the descent angle. It can be known that the reflected light has changed the approach angle of the flying object with respect to the reference plane.

  More preferably, the plurality of right angle reflectors includes first, second and third right angle reflectors.

  More preferably, the difference between the angle formed by the ridge line of the first right-angle reflector with the reference plane and the angle formed by the second right-angle reflector with the reference plane, the angle formed by the ridge line of the second right-angle reflector with the reference plane, The difference between the angle formed by the third right-angle reflector and the reference plane is equal to each other.

  At least a part of the first, second, and third right-angle reflectors may be provided with filters that have different colors of reflected light from the first, second, and third right-angle reflectors.

  The colors of reflected light from different right-angle reflectors are different from each other. By determining the color of the reflected light in the flying object, it is possible to know the descending angle of the flying object with respect to the reference plane. Therefore, the flying object can approach the deck safely.

  The passive guidance device further includes a retroreflective device disposed adjacent to the plurality of right angle reflectors.

  The retroreflective device reflects incident light from a wide range in a direction parallel to the incident light direction. By detecting the reflected light from the retroreflective device when the flying object irradiates light, it is possible to know the rough direction of the deck and to control the course of the flying object on the correct approach path . Furthermore, the distance from the flying object to the deck can be known by measuring the time taken for the light irradiated from the flying object to be reflected by the retroreflective device and return to the flying object. As a result, the flying object can be safely guided to the deck.

  Preferably, the plurality of right-angle reflectors are arranged on a straight line parallel to the reference plane.

  More preferably, the passive guidance device further includes first and second retroreflecting plates respectively provided outside both ends of the plurality of right-angle reflectors arranged in a straight line, and the first and second retroreflectors, respectively. And a first polarizing plate and a second polarizing plate provided on the retroreflecting surface of the retroreflecting plate and having polarizing surfaces that form different angles with respect to the reference surface, respectively.

  By providing such a polarizing plate and a retroreflecting plate, it is possible to know the angle between the flying object and the polarization plane, and thus the relative rolling angle between the flying object and the reference surface. Furthermore, since the first and second retroreflecting plates and the polarizing plate are disposed outside both ends of the plurality of right-angle reflectors, the above-described angle can be accurately measured.

It is a perspective view which shows the outline of the single layer type rotary airport which concerns on one embodiment of this invention. It is a top view of the wing 52 of the rotary airport shown in FIG. 1, and the deck 54 provided in the front-end | tip. FIG. 3 is a perspective view of a deck 54 shown in FIG. 2. 7 is a perspective view of a passive guidance / guide device 86 provided on the rear end surface of the deck 54. FIG. It is a figure for demonstrating the inclination of three types of right angle reflectors 130, 132, and 134 which the passive guidance and guide apparatus 86 has. It is a figure for demonstrating the guidance system of UAV230 which approachs the deck 54 using the passive guidance and guide apparatus 86. FIG. It is a perspective view which shows the outline of the multilayer type | mold rotary airport which concerns on embodiment of this invention.

  In the following drawings and description, the same reference numerals are assigned to the same components. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  Referring to FIG. 1, a rotary airport 40 according to an embodiment of a flying object landing apparatus of the present invention is a single-layer rotary airport, and includes a central deck 50 installed on the ground, and a central deck 50. Two wings 52A and 52B of an airfoil cross section, which are coupled to the central deck 50 so as to be rotatable around a central axis thereof (such wings are simply referred to as wings 52), wings 52A and Decks 54A and 54B (collectively referred to as decks 54) provided on the front ends of the wings 52B and equipped with mechanisms for releasing and holding the UAV 58 at takeoff and landing. Including. The wing 52 is attached to a ring (not shown) mounted on the central deck 50 and rotatable around the central deck 50 by pin connection. However, this connection is not a pin connection and may be fixed.

  The rotary airport 40 further includes propulsion devices 56A and 56B made of ducted fans fixed to the lower surfaces of the wings 52A and 52B, respectively (such propulsion devices are collectively referred to as propulsion devices 56). Since it is not necessary to rotate the wing 52 at a high speed, it is preferable to use a propulsion device 56 that is as economical as possible even at a low speed. In the present embodiment, an electric ducted fan is used as the propulsion device 56.

  Referring to FIG. 2, the wing 52 is fixed to the central deck 50 via a ring or the like (not shown). A flap 60 for adjusting the lift of the wing 52 is provided at the rear edge near the tip of the wing 52. By making the cross section of the wing 52 into an airfoil, lift is generated when the wing 52 rotates around the central deck 50 in the direction indicated by the arrow 62 by the propulsive force of the propulsion device 56. By adjusting this lift with the flap 60, the inclination of the tip of the wing 52 can be adjusted. When the propulsive force is reduced, the tip of the wing 52 is lowered. If the height at which the wings 52 are provided in advance is set to an appropriate height, the deck 54 can be safely lowered to the ground.

  The deck 54 includes a platform 80 having a flat rectangular parallelepiped shape, a clamp mechanism 82 provided on the upper surface of the platform 80 and having a function of holding and releasing the UAV, and a wing width direction of the wing 52 on the upper surface of the platform 80. By moving the clamp mechanism 82 in a direction (perpendicular to the rotation direction of the wings 52), the positional deviation between the flight course and the deck 54 at the time of landing of the UAV is corrected, and the UAV can be easily held by the clamp mechanism 82. And a passive guidance / guide device 86 that is provided on the rear end surface of the platform 80 and guides the UAV when the UAV is about to land on the deck 54.

  Referring to FIG. 4, the passive guide / guide device 86 is fixed on the block 110 as a substrate having an L-shaped cross section and the block 110 so as to be aligned in substantially the same direction. Each reflector has two reflecting surfaces combined at right angles so as to form a ridgeline, and reflects only light incident parallel to a predetermined surface to the light source side (hereinafter, such a reflector is referred to as a “right angle reflector”). When the UAV measures the distance from the deck 54, which is provided between the right-angle reflectors 130, 132 and 134 and between the right-angle reflectors 130 and 132 and between the right-angle reflectors 132 and 134, respectively. Are installed outside the reflex reflectors 150 and 152 and the right angle reflectors 130 and 134, respectively. Is used to stably hold the recursive reflectors 120 and 122 with a polarizing plate, the right-angle reflectors 130, 132, and 134, and the reflexive reflectors 150 and 152 that are used in detecting the relative rolling angle with respect to the reference plane. And a support member 140 fixed to the head.

  Each of the retroreflectors with a polarizing plate 120 and 122 includes a retroreflective plate and a polarizing plate attached on the retroreflective plate so that the deflection angle forms a predetermined angle with reference to the long side of the retroreflective plate. A plurality of polarizing plates having different polarization angles are preferably provided in a predetermined order on the retroreflectors 120 and 122 with polarizing plates. By doing so, it is possible to scan these retroreflectors with a polarizing plate 120 and 122 using polarized light, and to estimate the relative pitch angle between the deck 54 and the UAV from the pattern of the reflected light.

  Each of the right-angle reflectors 130, 132, and 134 includes two mirror surfaces combined to form a right angle so as to form a ridgeline. In such a right-angle reflector, light incident from a direction parallel to a plane perpendicular to both of these mirror surfaces is reflected in that direction. Light incident from other directions is reflected in another direction and is not reflected on the light source side. The back surface of the mirror surface is painted to prevent light from passing therethrough.

  The right angle reflectors 130, 132, and 134 form 5 degrees, 10 degrees, and 15 degrees with respect to the upper surface of the block 110, respectively, as shown in FIGS. It is fixed on the top surface. Therefore, when light is irradiated from the UAV that enters the block 110 toward the passive guidance / guide device 86, only the reflected light from the right-angle reflector 130 is obtained when the approach angle is approximately 5 degrees, and the right-angle reflector when the approach angle is approximately 10 degrees. Only the reflected light from 132 and only the reflected light from the right-angle reflector 134 at around 15 degrees return to the UAV, respectively. By making the angle difference of these reflectors equal to each other in this way, there is an effect that the control during the approach becomes easy.

  On the other hand, in this embodiment, one of the mirror surfaces of the right-angle reflector 130 is provided with a green filter, and one of the mirror surfaces of the right-angle reflector 134 is provided with a red filter. No filter is provided on the surface of the right-angle reflector 132. Therefore, when irradiating light from the UAV that enters the block 110 toward the passive guidance / guide device 86, green reflected light is emitted when the approach angle is around 5 degrees, and white reflected light when the approach angle is around 10 degrees, At around 15 degrees, only red reflected light is observed from the UAV. By looking at the color of the light, it is possible to know the approach angle at which the UAV approaches the deck 54 relatively.

  5A is a side view of the right-angle reflector 130, FIG. 5B is a side view of the right-angle reflector 132, and FIG. 5C is a side view of the right-angle reflector 134. In these figures, the right-angle reflectors, the retroreflectors 150 and 152, the support members 140 and the like existing behind are not shown for the sake of clarity.

  Referring to FIG. 5B, the right-angle reflector 132 has a ridge line (corresponding to the back of the intersection of two mirror surfaces constituting the right-angle reflector 132) rearward by 10 degrees from the perpendicular to the upper surface of the block 110. It is fixed to the upper surface of the block 110 so as to be inclined. Therefore, the right-angle reflector 132 faces 10 degrees above the direction 170 parallel to the upper surface of the block 110 as shown in FIG. That is, the right-angle reflector 132 reflects light incident in a plane facing upward by 10 degrees from a direction parallel to the upper surface of the block 110, but reflects light incident from other directions to the light source side. do not do.

  Similarly, with reference to FIG. 5A, the right-angle reflector 130 is fixed to the upper surface of the block 110 so that the ridgeline is inclined backward by 10 degrees from a position perpendicular to the upper surface of the block 110. As a result, the right-angle reflector 130 reflects light incident in a plane having an elevation angle of 10 degrees in that direction. Light incident from other directions is reflected in another direction and is not reflected on the light source side.

  Referring to FIG. 5C, the right-angle reflector 134 is fixed to the upper surface of the block 110 such that the ridge line is inclined backward by 15 degrees from a position perpendicular to the upper surface of the block 110. As a result, the right-angle reflector 134 reflects light incident in a plane with an elevation angle of 15 degrees in that direction, and does not reflect light incident from other directions.

  For example, it is assumed that incident light 180 to the right-angle reflector 132 shown in FIG. 5B is incident in a plane having an elevation angle of 10 degrees. Then, this light is reflected by the two reflecting surfaces of the right-angle reflector 132 and reflected to the light source side. On the other hand, in the case of incident light 182 incident from a surface with an elevation angle other than 10 degrees, as shown in FIG. 5B, it is reflected in a direction different from the light source and does not return to the light source. The same applies to the right angle reflectors 130 and 134.

  The configuration of the passive guidance / guide device 100 described above is summarized as follows. Referring to FIG. 4, for example, the right-angle reflector 132 has a ridge line obtained by combining two reflecting surfaces at right angles to each other. The right-angle reflector 132 has two mirror surfaces that are centered on the orthogonal plane (the central plane of the right-angle reflector 132) so that the ridge line is in a plane orthogonal to the upper surface of the block 110 and as is apparent from FIG. It is being fixed to the upper surface of the block 110 so that it may become symmetrical.

  According to the passive guidance / guide device 100 configured as described above, the UAV can be landed on the deck 54 as follows. When the thrust of an appropriate magnitude is generated by the propulsion device 56, the wing 52 rotates. Along with this rotation, since the cross section of the wing 52 is an airfoil, lift is generated in the wing 52 and the deck 54 can be maintained at an appropriate height. When the deck 54 is rotating at a constant speed, the UAV approaches the deck 54, and when the relative speed between the two becomes almost zero, the UAV speed is positioned on the deck 54. The clamp mechanism 82 holds the UAV.

  At this time, the UAV approaches the deck 54 as follows. When the UAV approaches the deck 54, it illuminates with white light. The reflected light from the passive guidance / guide device 100 will appear to the UAV as follows.

  Referring to FIG. 6, all of the retroreflectors with polarizing plates 120 and 122 and the retroreflectors 150 and 152 shown in FIG. 4 have retroreflectivity. Therefore, as long as the UAV 230 is generally directed toward the deck 54, if the white light is irradiated toward the deck 54 anywhere in a wide area such as between the half lines 200 and 202 in FIG. Come back to. This reflected light can be used to measure the relative rolling angle and distance of the UAV 230 relative to the deck 54 to approach the deck 54.

  Referring to FIG. 6, the relative approach (drop) angle when UAV 230 approaches deck 54 can be adjusted as follows. The angle regions 210, 212, and 214 shown in FIG. 6 indicate regions where the relative approach angles with respect to the deck 54 are in the vicinity of 5 degrees, 10 degrees, and 15 degrees, respectively.

  When the UAV is located in the region 210, the light from the UAV is reflected only by the right angle reflector 134 and returns in the direction of the UAV. The reflected light from the right angle reflector 132 and the right angle reflector 130 does not return to the UAV. As a result, only one reflected light can be seen from the UAV. The light returning to the UAV is red because it is from the right angle reflector 134.

  When the UAV is located in the region 212, light from the UAV is reflected only by the right-angle reflector 132 and returns in the direction of the UAV. Reflected light from the right angle reflector 134 and the right angle reflector 130 does not return to the UAV. As a result, only one reflected light can be seen from the UAV. Since this is due to the right-angle reflector 132, it is the same as the color of the incident light.

  When the UAV is located in the region 214, light from the UAV is reflected only by the right-angle reflector 130 and returns in the direction of the UAV. The reflected light from the right angle reflector 134 and the right angle reflector 132 does not return to the UAV. As a result, only one reflected light can be seen from the UAV. Since this is due to the right angle reflector 130, it is green.

  When the UAV is above the upper limit of the angle region 210, the light from the UAV enters the passive guidance / guide device 100 at an angle different from any of 5 degrees, 10 degrees, and 15 degrees. The direction of the reflected light from the right-angle reflectors 132, 134, and 130 is different from the UAV. As a result, no light is reflected from the passive guidance / guide device 100 to the UAV.

  From the above, it can be seen that when entering the runway 60 at an angle such that white reflected light can always be seen from the passive guidance / guide device 100 as viewed from the UAV, the entry angle is safe. If you can see the red reflected light, you know that the altitude is too high. If you can see the green reflected light, you can see that the altitude is too low. In UAV, it is possible to perform automatic landing safely and efficiently by capturing this reflected light with a camera and converting it into an electrical signal.

  By using the rotary airport as in this embodiment, a large number of UAVs can be landed and taken off efficiently. Less space is required to set up a rotary airport. Since radio waves are not used, there is little risk of confusion in UAV guidance.

  In the present embodiment, the light beam irradiated at the time of landing in the UAV is white light, and although the irradiation range is narrowed, it has a certain spread, so that the light from the UAV is reflected by the right-angle reflectors 130 and 132 and Regardless of whether the light is reflected by any of 134, if the approach angle is around 5 degrees, 10 degrees, and 15 degrees, the reflected light reliably reaches the UAV.

  In the above-described embodiment, an electric ducted fan is used as the propulsion device 56, but is not limited thereto. You may use what works with an engine. A motor may be provided in the central deck 50, and the wings 52 may be rotated by the motor. A motor provided in the central deck 50 and a propulsion device provided in the wing 52 may be used in combination.

  In the above embodiment, there are only two wings 52. Of course, this number may be increased. In order to prevent resonance, the wings 52 may be an odd number.

  Further, in the above embodiment, the recursive reflectors 150 and 152 are used only for measuring the distance from the UAV to the deck 54. However, the present invention is not limited to such an embodiment. Recursive reflectors 150 and 152 can also be used for optical communication. In optical communication, information for identifying the deck 54 can be transmitted to all UAVs, or can be communicated with each of a plurality of UAVs in a time division manner.

  In the above embodiment, only the case where the rotary airport is used for UAV takeoff and landing has been described. However, the present invention is not limited to such an embodiment, and can be used for takeoff and landing of manned aircraft.

  In the above embodiment, the wing 52 is rotated in the horizontal plane. However, the present invention is not limited to such an embodiment. It is also possible to rotate the wing 52 with a slight angle. The mechanism for moving the deck is not limited to the rotating wing, and may be a belt conveyor, for example. When the target flying object is limited to UAV, land the flying object while the deck is moving on the upper surface of the belt conveyor, and remove the flying object from the deck when there is a deck on the lower surface of the belt conveyor. Such a mechanism may be used. In any case, the UAV can be automatically landed by providing a device such as the passive guidance / guide device 86 at the rear end of the deck.

  In the above embodiment, the passive guidance / guide device 86 is irradiated with light from the flying object, and the reflected light is used for guiding the flying object. If the flying object has a mechanism for detecting reflected light, the light emitted from the flying object is not limited to visible light. For example, far infrared rays, infrared rays, or ultraviolet rays may be used. In this way, by using light for guidance, unlike the case of using radio waves, guidance with high security against interference can be performed.

  Further, in the above embodiment, the wing 52 is used in a single layer. However, the present invention is not limited to such an embodiment. If the wings 52 are provided in a plurality of stages and are multi-layered, the mechanism becomes complicated, but the capacity of takeoff and landing such as UAV can be increased. FIG. 7 shows an outline of a multilayer rotary airport 240.

  Referring to FIG. 7, the rotary airport 240 has a central deck 250 in which the tip portion of the central deck 50 according to the first embodiment is extended upward, and the periphery of the central deck 250 is rotatable. The first layer wings 52A and 52B attached to the central deck 250 and the upper part of the first layer wings 52A and 52B can rotate around the central deck 250 in the same manner as the first layer wings 52A and 52B. And wings 252A and 252B of the second layer provided in the first layer.

  The configuration of the wings 252A and 252B of the second layer is the same as that of the wing 52. Specifically, a deck 254A having the same structure as the deck 54 is provided at the tip of the second layer wing 252A. A propulsion device 256A similar to the propulsion device 56 is provided at the lower end of the tip of the second wing 252A. Similarly, the deck 254B and the propulsion device 256B are provided in the second wing 252B.

  The wing 52 may have three or more layers. In this way, by using a multi-layer wing, it is possible to remarkably improve the take-off and landing processing capacity of the rotary airport as compared with the case of a single-layer system.

  The embodiment disclosed herein is merely an example, and the present invention is not limited to the above-described embodiment. The scope of the present invention is indicated by each claim of the claims after taking into account the description of the detailed description of the invention, and all modifications within the meaning and scope equivalent to the wording described therein are included. Including.

40,240 Rotary airport 50,250 Central deck 52,52A, 52B, 252,252A, 252B Wing 54,54A, 54B, 254,254A, 254B Deck 56,56A, 56B, 256,256A, 256B Propeller 60 Flap 80 Platform 82 Clamping mechanism 84 Moving mechanism 86 Passive guidance / guide device 120, 122 Retroreflector 130, 132, 134 with polarizing plate Right angle reflector 150, 152 Retroreflector

Claims (7)

A landing device for landing a flying object,
A flying object landing deck equipped with a detachable device that can detach the flying object,
Drive means for moving the deck in a predetermined direction on a fixed orbit,
A passive guidance device that guides the flying object by reflecting light from the flying object is provided at a predetermined position of the deck ,
The passive guidance device is:
A plurality of right angle reflectors arranged so as to have a predetermined relationship with respect to a reference plane determined by the attitude of the deck;
A substrate to which the plurality of right angle reflectors are attached;
Each of the plurality of right angle reflectors has two reflective surfaces combined to form a ridgeline and to form a right angle between each other;
The landing apparatus , wherein the plurality of right-angle reflectors are attached to the substrate such that angles formed between the respective ridge lines and the reference plane are different from each other . The plurality of right angle reflector includes a first, second and third quadrature reflector, landing gear according to claim 1. A difference between an angle formed by a ridge line of the first right-angle reflector with the reference plane and an angle formed by the second right-angle reflector with the reference plane;
The landing apparatus according to claim 2 , wherein a difference between an angle formed by a ridge line of the second right-angle reflector with the reference plane and an angle formed by the third right-angle reflector with the reference plane are equal to each other. At least a part of the first, second, and third right-angle reflectors is provided with a filter that has different colors of reflected light from the first, second, and third right-angle reflectors. Item 4. The landing apparatus according to item 3 . The passive induction device further comprises a retroreflective device provided adjacent to the plurality of right angle reflector, landing gear according to any one of claims 1 to 4. The plurality of right angle reflector is arranged on the reference plane and a straight line parallel, landing gear according to any one of claims 1 to 4. The passive guidance device further includes first and second retroreflecting plates respectively provided outside both ends of the plurality of right-angle reflectors arranged on the straight line;
A first polarizing plate and a second polarizing plate provided on the retroreflective surfaces of the first and second retroreflective plates, respectively, and having polarizing surfaces that form different angles with respect to the reference surface, respectively. Item 7. The landing gear according to item 6 .

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