Beam antenna device

Abstract

The purpose of the present invention is to provide a beam antenna device that tracks an aerial platform. The beam antenna device comprises: a flat plate part; a first rotating body that rotates about a first axis perpendicular to the flat plate part, the first axis serving as a rotation axis; a second rotating body that rotates about a second axis perpendicular to the first axis, the second axis serving as a rotation axis; a flat-plate-shaped phased array antenna having the second axis as a normal line; a position acquisition unit that acquires the position of an aerial platform; a rotating body control unit that controls the first rotating body and the second rotating body on the basis of the position of the aerial platform such that the plane of the phased array antenna faces the direction of the aerial platform; and a beam control unit that controls the direction of beam tracking by the phased array antenna in accordance with the rotation angles of the first rotating body and the second rotating body.

Description

Beam antenna device

[0001] This invention relates to a beam antenna device that forms antenna directivity for communication.

[0002] Conventionally, there is a technology that uses beamforming to create antenna directivity in order to suppress interference from communications with other parties during communication with a communication partner. In addition, a technology has been developed that uses base stations in the air, where the possibility of reflected waves and diffraction is low, to enable communication with smartphones and other devices. Patent Document 1 discloses a technology that equips an aircraft with base station functionality and performs beamforming control on terminals.

[0003] Japanese Patent Publication No. 2024-126594

[0004] In one aspect of the present invention, a beam antenna device comprises a flat plate portion, a first rotating body that rotates about a first axis perpendicular to the flat plate portion as its axis of rotation, a second rotating body that rotates about a second axis perpendicular to the first axis as its axis of rotation, a flat plate-shaped phased array antenna with the second axis perpendicular, a position acquisition unit that acquires the position of an aerial platform, a rotation body control unit that controls the first rotating body and the second rotating body based on the position of the aerial platform so that the plane of the phased array antenna faces the direction of the aerial platform, and a beam control unit that controls the direction of beam tracking by the phased array antenna according to the rotation angle between the first rotating body and the second rotating body.

[0005] Furthermore, the beam antenna device may include a first acquisition unit that acquires a first rotation angle from a reference position of the first axis, and a second acquisition unit that acquires a second rotation angle from a reference position of the second axis, and the rotating body control unit may control the first rotating body and the second rotating body based on the first rotation angle, the second rotation angle, and the position acquired by the position acquisition unit.

[0006] Furthermore, the beam antenna device may also include a first angle sensor for measuring the rotation angle of the first axis and a second angle sensor for measuring the rotation angle of the second axis, wherein the first acquisition unit acquires the rotation angle measured by the first angle sensor as the first rotation angle, and the second acquisition unit acquires the rotation angle measured by the second angle sensor as the second rotation angle, and the beam control unit controls the direction of beam tracking based on the first rotation angle acquired by the first angle sensor and the second rotation angle acquired by the second angle sensor until the angle between the first and second rotating bodies reaches the target angle.

[0007] Furthermore, the beam antenna device may also include a first motor for rotating a first rotating body and a second motor for rotating a second rotating body. The first acquisition unit calculates a first rotation angle based on the rotation angle per unit time of the first motor and the elapsed time from the start time of rotation control by the rotating body control unit. The second acquisition unit calculates a second rotation angle based on the rotation angle per unit time of the second motor and the elapsed time from the start time of rotation control by the rotating body control unit. The beam control unit controls the direction of beam tracking based on the first rotation angle calculated by the first acquisition unit and the second rotation angle acquired by the second acquisition unit until the angle between the first and second rotating bodies reaches a target angle.

[0008] Furthermore, a control method for a beam antenna device according to one aspect of the present invention includes a flat plate portion, a first rotating body that rotates about a first axis perpendicular to the flat plate portion as its axis of rotation, a second rotating body that rotates about a second axis perpendicular to the first axis as its axis of rotation, and a flat plate-shaped phased array antenna with the second axis perpendicular to it. The computer controlling the beam antenna device performs the following steps: a position acquisition step to acquire the position of an aerial platform; a rotation body control step to control the first rotating body and the second rotating body so that the plane of the phased array antenna faces the direction of the aerial platform based on the position of the aerial platform; and a beam control step to control the direction of beam tracking by the phased array antenna according to the rotation angle between the first rotating body and the second rotating body.

[0009] Furthermore, a control program for a beam antenna device according to one aspect of the present invention provides a computer that controls a beam antenna device comprising a flat plate portion, a first rotating body that rotates about a first axis perpendicular to the flat plate portion as its axis of rotation, a second rotating body that rotates about a second axis perpendicular to the first axis as its axis of rotation, and a flat plate-shaped phased array antenna with the second axis perpendicular to it, with the following functions: a position acquisition function for acquiring the position of an aerial platform, a rotation body control function for controlling the first rotating body and the second rotating body so that the plane of the phased array antenna faces the direction of the aerial platform based on the position of the aerial platform, and a beam control function for controlling the direction of beam tracking by the phased array antenna according to the rotation angle between the first rotating body and the second rotating body.

[0010] This is a perspective view showing the external appearance of a beam antenna device. This is a schematic diagram showing an example of a communication system configuration. This is a block diagram showing a first configuration example of a beam antenna device. This is a diagram showing various angles in a beam antenna device. This is a diagram schematically showing various angles in a beam antenna device. This is a flowchart showing an example of the operation of a beam antenna device. This is a block diagram showing a second configuration example of a beam antenna device. This is a flowchart showing an example of the operation of a beam antenna device.

[0011] In recent years, by deploying wireless communication base stations at high altitudes, the communication area of ​​the base stations can be expanded. As a result, communication systems using HAPS (High Altitude Platform Station), known as a high-altitude platform that mounts radio stations on aircraft that remain airborne at high altitudes, have been developed.

[0012] This HAPS communicates with ground stations and works in conjunction with ground-based communication systems to provide communication services to users' wireless terminals. Therefore, ground stations need to communicate with HAPS at all times. To ensure good communication with HAPS, ground stations form antenna directivity towards the HAPS in the air and communicate. Forming antenna directivity allows for good communication within the range of the formed antenna directivity, but it narrows the communication range. Therefore, in order to communicate with HAPS orbiting in the air, ground stations need to constantly form antenna directivity towards HAPS and keep tracking it.

[0013] Therefore, we consider a beam antenna device 1 that forms antenna directivity relative to HAPS in order to continue tracking (hereinafter, antenna directivity will be referred to as a beam, and the process of forming antenna directivity may be called beam tracking).

[0014] As shown in Figure 1, the beam antenna device 1 may consist of a flat plate portion 10, a first shaft portion 11, a first rotating body 12, a second shaft portion 13, a second rotating body 14, an antenna mounting portion 15, and a planar antenna 16. The flat plate portion 10 is a flat plate, and the first shaft portion 11 is an axis perpendicular to the plane formed by the flat plate portion 10. The first rotating body 12 rotates around the first shaft portion 11, that is, around the first axis 21. The second shaft portion 13 is provided on the first rotating body 12 and is an axis perpendicular to the first shaft portion 11. The second rotating body 14 rotates around the second shaft portion 13, that is, around the second axis 23. The antenna mounting portion 15 is a base portion for mounting the antenna fixed to the second rotating body 14, and the planar antenna 16 is provided on it. The planar antenna 16 may be a planar antenna for general satellite communication, and basically forms antenna directivity in a direction perpendicular to the plane formed by this planar antenna.

[0015] When this beam antenna device 1 is to communicate with HAPS by forming an antenna directivity as shown in Figure 2, the first rotating body 12 is rotated around the first shaft portion 11, while the second rotating body 14 is rotated around the second shaft portion 13, so that the beam 30 formed by the planar antenna 16 mounted on the antenna mounting portion 15 is directed towards HAPS 100. Incidentally, HAPS 100 continues to rotate in basically the same direction while drawing a swirling trajectory 101. In order to continue to follow the continuously rotating HAPS 100, it is desirable that the beam antenna device 1 be configured so that the first rotating body 12 rotates infinitely around the first shaft portion 11. Infinite rotation means rotating in the same direction. In other words, in the state shown in Figure 2, the beam antenna device 1 continues to rotate in one direction, the pan direction (also called the yaw direction). However, depending on the beam antenna device 1, infinite rotation may not be possible. Also, even if infinite rotation is possible, the rotation of the beam antenna device 1 may not be able to keep up. Therefore, depending on the position of the HAPS 100, it may be difficult for the beam antenna device 1 to follow it. In particular, if the beam antenna device 1 has reached the end of its rotation, it may be necessary to rotate it back to the opposite side, and in that case, it may be difficult to follow it at the timing of that rotation reversal. As a result, there is a problem that the wireless communication between the HAPS 100 and the entire communication service of the wireless terminals 300a and 300b, which are providing the communication service, will be interrupted.

[0016] Therefore, in this embodiment, the objective is to provide a beam antenna device 1 that can perform beam tracking to follow the HAPS 100 and provide wireless communication services, even if the beam antenna device 1, as shown in Figure 1, has a first rotating body 12 that cannot rotate infinitely relative to the first shaft portion 11, that is, a beam antenna device 1 that cannot rotate infinitely in the pan direction.

[0017] In this beam antenna device 1, by rotating the device and using a planar antenna whose direction of directivity can be controlled, the direction of beam tracking can be sequentially controlled, thereby enabling the first rotating body 12 to continue following the HAPS 100 and perform beam tracking even if it cannot rotate infinitely relative to the first shaft portion 11.

[0018] The beam antenna device 1 will be described in detail below with reference to the drawings.

[0019] <Embodiment 1> <Configuration> Figure 1 is a perspective view showing the external shape of the beam antenna device 1. The beam antenna device 1 may be a device that follows the HAPS 100 as an aerial platform, that is, a device that forms antenna directivity relative to the HAPS 100, but the object of tracking is not limited to the HAPS 100, but can be any flying object.

[0020] As shown in Figure 1, the beam antenna device 1 may consist of a flat plate portion 10, a first shaft portion 11, a first rotating body 12, a second shaft portion 13, a second rotating body 14, an antenna mounting portion 15, and a planar antenna 16.

[0021] The flat plate section 10 is a flat plate. The flat plate section 10 is basically installed horizontally.

[0022] The first shaft portion 11 is connected to the flat plate portion 10.

[0023] Furthermore, the first rotating body 12 is connected to the first shaft portion 11.

[0024] The first rotating body 12 rotates around the first axis 21 of the first shaft portion 11. In this embodiment, the first rotating body 12 does not rotate infinitely relative to the first axis 21. The first rotating body 12 may be configured to be rotatable relative to the first shaft portion 11, or it may be fixed to the first shaft portion 11 so that the first shaft portion 11 is rotatable relative to the flat plate portion 10. The first rotating body 12 may be rotated by a first motor (not shown in Figure 1). The first rotating body 12 (first axis 21) is an axis perpendicular to the plane formed by the flat plate portion 10.

[0025] The first rotating body 12 is provided with a second shaft portion 13. The second rotating body 14 is connected to the second shaft portion 13. The second rotating body 14 rotates around the second axis 23 of the second shaft portion 13. The second rotating body 14 may be configured to be rotatable relative to the second shaft portion 13, or it may be fixed to the second shaft portion 13 so that the second shaft portion 13 is rotatable relative to the first rotating body 12. The second shaft portion 13 (second axis 23) is an axis perpendicular to the first axis 21. The second rotating body 14 may be rotated by a second motor (not shown in Figure 1).

[0026] An antenna mounting section 15 is connected to the second rotating body 14. The antenna mounting section 15 is a base on which a planar antenna 16 is placed, and the planar antenna 16 forms an antenna directivity to communicate with HAPS 100. The planar antenna 16 can form an antenna directivity by tilting it at a certain angle from a direction perpendicular to the plane formed by the planar antenna 16. However, the gain of the antenna is maximized when the antenna directivity is directed perpendicular to the plane of the planar antenna 16, and decreases as the angle in the directivity direction increases from there. For this reason, in the beam antenna device 1, it is preferable to form the antenna directivity as perpendicular as possible to the plane formed by the planar antenna 16, but priority is given to enabling communication with HAPS 100. The planar antenna 16 may be a so-called PAAM (Phaseed Array Antenna Module).

[0027] As shown in Figure 2, the beam antenna device 1 is installed on the ground within the range vertically below the rotating trajectory 101 traced by the HAPS 100, i.e., within the range of the circle 102. The beam antenna device 1 is connected to a ground station (ground gateway station) or installed at a ground station and communicates with the HAPS 100. Note that the beam antenna device 1 is not limited to the shape shown, as long as it has the configuration described above.

[0028] <Example of Functional Configuration> Figure 3 is a functional block diagram showing an example of the configuration of an information processing device that controls the beam antenna device 1.

[0029] As shown in Figure 3, the beam antenna device 1 includes a communication unit 110, an input unit 120, a first angle sensor 121, a second angle sensor 122, a control unit 130, a storage unit 140, and a drive unit 150.

[0030] The communication unit 110 has the function of communicating with the connected ground station. The communication unit 110 also has the function of communicating with HAPS 100 via the planar antenna 16. The communication unit 110 forms an antenna directivity (beam 30) toward HAPS 100 and communicates with HAPS 100. The communication unit 110 also receives information indicating the position of HAPS 100 from the ground station and transmits it to the control unit 130.

[0031] The input unit 120 is an input interface provided on the beam antenna device 1 that provides input to the beam antenna device 1. The input unit 120 may be implemented by, for example, a keyboard or a touch panel. The input unit 120 may, for example, receive input of information indicating the position of the HAPS 100 and transmit it to the control unit 130.

[0032] The first angle sensor 121 is provided on the first shaft portion 11 (or the first rotating body 12) and measures a first angle, which is how much the first rotating body 12 has rotated relative to the first shaft portion 11 from a reference position, and transmits this to the control unit 130. The first angle sensor 121 measures the first angle sequentially (for example, every second, but is not limited to this, and may be at time intervals that are easy for the HAPS 100 to track) and transmits this to the control unit 130.

[0033] The second angle sensor 122 is provided on the second shaft portion 13 (or the second rotating body 14) and measures the second angle, which is how much the second rotating body 14 has rotated relative to the second shaft portion 13 from a reference position, and transmits this to the control unit 130. The second angle sensor 122 measures the second angle sequentially (for example, every second, but is not limited to this, and may be at time intervals that are easy for the HAPS 100 to track) and transmits this to the control unit 130.

[0034] The control unit 130 is a processor that controls each unit of the beam antenna apparatus 1. The control unit 130 refers to various data stored in the storage unit 140, executes various programs, and implements functions to be fulfilled as the beam antenna apparatus 1. That is, the control unit 130 calculates the rotation angles of the first rotating body 12 and the second rotating body 14 and the direction in which the antenna directivity of the planar antenna 16 is directed, based on the sequentially transmitted first angle, second angle, and information indicating the position of HAPS 100, and controls the first rotating body 12, the second rotating body 14, and the planar antenna 16.

[0035] The control unit 130 includes, as functions to be fulfilled as the beam antenna apparatus 1, a first acquisition unit 131, a second acquisition unit 132, a position acquisition unit 133, a rotating body control unit 134, and a beam control unit 135.

[0036] The first acquisition unit 131 acquires the first angle indicating the rotation angle from the reference position of the first axis that is sequentially transmitted from the first angle sensor 121, and transmits the first angle to the beam control unit 135. The first acquisition unit 131 may also transmit the first angle to the rotating body control unit 134.

[0037] The second acquisition unit 132 acquires the second angle indicating the rotation angle from the reference position of the second axis that is sequentially transmitted from the second angle sensor 122, and transmits the second angle to the beam control unit 135. The second acquisition unit 132 may also transmit the second angle to the rotating body control unit 134.

[0038] The position acquisition unit 133 acquires information indicating the position of HAPS 100. For example, the position acquisition unit 133 may acquire information indicating the position of HAPS 100 via the communication unit 110 from a management apparatus that manages the position of HAPS 100 or a ground gateway station of a communication system. The information indicating the position of HAPS 100 may be, for example, information on longitude, latitude, and altitude, and may include information indicating where HAPS 100 is located at any time. The position acquisition unit 133 transmits the acquired information indicating the position of HAPS 100 to the rotating body control unit 134.

[0039] The rotating body control unit 134 calculates rotation angles for rotating the first rotating body 12 and the second rotating body 14 based on the transmitted information indicating the first angle, the second angle, and the position of HAPS 100. The rotating body control unit 134 transmits the calculated angle to the driving unit 150.

[0040] The beam control unit 135 calculates the direction of antenna directivity formed by the planar antenna 16, and controls the planar antenna 16 so as to form the antenna directivity in the calculated direction. Note that the beam control unit 135 may also be referred to as a PAAM control unit.

[0041] The driving unit 150 controls the first motor 151 such that the rotation angle of the first rotating body 12 from the reference position matches the angle transmitted from the rotating body control unit 134. The driving unit 150 also controls the second motor 152 such that the rotation angle of the second rotating body 14 from the reference position matches the angle transmitted from the rotating body control unit 134. Note that, due to the torque relationship between the first motor 151 and the second motor 152, a certain amount of time is required to reach a desired angle. Therefore, in addition to rotation control, beam tracking direction control is also performed by the beam control unit 135.

[0042] Here, a method for calculating the rotation angle and beam direction of each rotating body of the beam antenna device 1 will be described with reference to FIGS. 4 and 5.

[0043] First, let the installation angle of the beam antenna device 1 be (θ pitch ,ψ yaw ). ψ yaw is the angle from true north of the reference direction set for the flat plate portion 10. In addition, θ pitch is the angle between the flat plate portion 10 and the horizontal plane. That is, when the reference direction of the flat plate portion 10 is set to true north, ψ yaw is 0 degrees, and when the flat plate portion 10 is parallel to the horizontal plane, θ pitch is 0 degrees.

[0044] Further, as shown in FIG. 4, let the rotation angle of the first rotating body 12 from the reference position be ψ pan , and let the rotation angle of the second rotating body 14 from the reference position be θ tilt. Therefore, when the reference direction of the flat plate portion 10 is set to true north, ψ pan is the rotation angle from true north. Further, in FIG. 4, the z1 direction (zenith direction) is the reference direction of the second rotating body 14.

[0045] Let the relative position of HAPS 100 at time t, when the position of the beam antenna device 1 is taken as the origin and true north is taken as the x-axis, be (x(t), y(t), z(t)), and let the relative position of HAPS 100 at time t, when the reference direction of the flat plate portion 10 is taken as the x-axis, be (X(t), Y(t), Z(t)).

[0046]

[0047] holds. In the above formula (1), Ry and Rz are rotation matrices that satisfy the following.

[0048]

[0049] At this time, from the above formula (1),

[0050]

[0051]

[0052] can be calculated, and these become the target angles for the first angle and the second angle. That is, the rotating body control unit 134 instructs the drive unit 150 to adjust the first axis to the angle represented by formula (2) and the second axis to the angle represented by formula (3). The drive unit 150 controls the first motor 151 and the second motor 152 to achieve the instructed angles. Note that the first axis and the second axis cannot always reach the target angles instantaneously, and time may be required depending on the respective known speeds of the first motor 151 and the second motor 152 and the angle difference to the target angle.

[0053] Therefore, in the process in which the drive unit 150 rotates the first rotating body 12 and the second rotating body 14 to reach the target angle calculated by the rotating body control unit 134, the beam control unit 135 sequentially controls the beam direction such that the beam tracking direction corresponding to the current position faces the direction of HAPS 100.

[0054] As shown in Figures 4 and 5, the plane formed by the planar antenna 16 is defined as the x2y2 plane, and the direction perpendicular to it is defined as the z2 direction (the direction in which the antenna gain is greatest). Then, as shown in Figure 5, the direction of beam tracking is defined as arrow BF. Here, x2 and y2 are reference directions set in advance for the planar antenna 16, y2 is orthogonal to x2, and z2 is orthogonal to both x2 and y2. The angle between arrow BF and the z2 direction is θ. ＢＦ Let φ be the angle from the reference direction (x2 direction) in the x2y2 plane when arrow BF is dropped onto the x2y2 plane. ＢＦ Let's assume that.

[0055] Then, the first angle acquired by the first acquisition unit 131, that is, the first angle sequentially sensed by the first angle sensor 121, is ψ' pan Furthermore, the second angle acquired by the second acquisition unit 142, that is, the second angle sequentially sensed by the second angle sensor 122, is defined as θ'. tilt Let's assume that at this time,

[0056]

[0057] The following equation holds true. Based on equation (4), the beam control unit 135,

[0058]

[0059]

[0060] This allows us to calculate the direction in which the directivity of the antenna formed from the planar antenna 16 is directed (the direction of beam tracking).

[0061] The storage unit 140 has the function of storing various programs and data required for the operation of the beam antenna device 1. The storage unit 140 can be implemented using, for example, an HDD (Hard Disc Drive), an SSD (Solid State Drive), or flash memory, but is not limited to these. The storage unit 140 may also be cloud storage accessible by the beam antenna device 1. The storage unit 140 may store various programs and data necessary to realize the functions that the beam antenna device 1 should perform. The storage unit 140 may store programs that calculate the rotation angle of the first motor 151 that controls the rotation of the first rotating body 12 and the rotation angle of the second motor 152 that controls the rotation of the second rotating body 14 based on the relative positional relationship between the beam antenna device 1 and the HAPS 100, and programs that control the rotation of the first rotating body 12 and the second rotating body 14 based on the calculated rotation angles. The storage unit 140 may also store a program that calculates the direction of beam tracking based on the first angle and the second angle.

[0062] The above is an example of the configuration of the beam antenna device 1.

[0063] <Operation> Figure 6 is a flowchart showing an example of the operation of the beam antenna device 1. As shown in Figure 6, the position acquisition unit 133 acquires information indicating the position of HAPS 100 via the communication unit 110 (step S601). The position acquisition unit 133 transmits the acquired information indicating the position of HAPS 100 to the rotating body control unit 134.

[0064] The rotating body control unit 134 calculates the angles of the first rotating body 12 and the second rotating body 14, i.e., the target angle, based on the acquired information indicating the position of the HAPS 100 (step S602). Then, the rotating body control unit 134 transmits the calculated target angle to the drive unit 150.

[0065] The drive unit 150 starts driving the first motor 151 and the second motor 152 so that the first rotating body 12 and the second rotating body 14 reach the target angle to which the signal has been transmitted (step S603).

[0066] The first acquisition unit 131 acquires a first angle, which indicates the rotation angle of the first axis from the reference position sensed by the first angle sensor 121, and transmits it to the beam control unit 135 (step S604).

[0067] The second acquisition unit 132 acquires the second angle, which indicates the rotation angle of the second axis from the reference position sensed by the second angle sensor 122, and transmits it to the beam control unit 135 (step S605).

[0068] The beam control unit 135 calculates the direction of beam tracking based on the transmitted first and second angles (step S606), and controls the planar antenna 16 to form the antenna's directivity in the calculated direction (step S607).

[0069] The position acquisition unit 133 acquires information indicating the new position of HAPS 100 (step S608). Then, the position acquisition unit 133 determines whether or not the position has been updated (step S609). If it has been updated (YES in step S609), the process returns to step S602.

[0070] If the data has not been updated (NO in step S609), the control unit 130 determines whether the angle between the first rotating body 12 and the second rotating body 14 has reached the calculated target angle (step S610). If the target angle has not been reached (NO in step S610), the process returns to step S604. If the target angle has been reached (YES in step S610), the process ends. In the process shown in Figure 6, if the target angle has been reached, beam tracking control may be performed one last time at that point. The direction of beam tracking when the target angle has been reached should basically be perpendicular to the plane formed by the planar antenna 16.

[0071] <Summary> In this way, the beam antenna device 1 can maintain communication even if the planar antenna 16 is not perfectly facing the direction of HAPS 100 by sequentially controlling the direction of beam tracking in the process of controlling the rotation of the first rotating body 12 and the second rotating body 14 so that the planar antenna 16 faces the direction of HAPS 100.

[0072] <Embodiment 2> <Configuration> Figure 7 is a block diagram showing an example configuration of the beam antenna device 1 according to Embodiment 2. The beam antenna device 1 according to Embodiment 2 differs only in that it does not have a first angle sensor 121 and a second angle sensor 122, and that the control unit 130 obtains both angles (first angle and second angle) by calculation. The other configurations are the same as those shown in Embodiment 1. The differences will be explained here.

[0073] As shown in Figure 7, the beam antenna device 1 according to Embodiment 2 includes a communication unit 110, an input unit 120, a control unit 130, a storage unit 140, and a drive unit 150. The control unit 130 also includes a first acquisition unit 131, a second acquisition unit 132, a position acquisition unit 133, a rotating body control unit 134, and a beam control unit 135.

[0074] Unlike Embodiment 1, the first acquisition unit 131 acquires the current first angle by calculation. Since the first rotating body 12 rotates at a known speed by the first motor 151, the first acquisition unit 131 can calculate the current first angle from the elapsed time since the start of the first motor 151's drive and the angle of the first rotating body 12 at the start of its control (the cumulative value of the rotation control up to that point). The first acquisition unit 131 transmits the calculated first angle to the beam control unit 135.

[0075] Unlike Embodiment 1, the second acquisition unit 132 acquires the current second angle by calculation. Since the second rotating body 14 rotates at a known speed by the second motor 152, the second acquisition unit 132 can calculate the current second angle from the elapsed time since the start of the second motor 152's drive and the angle of the second rotating body 14 at the start of its control (the cumulative value of the rotation control up to that point). The second acquisition unit 132 transmits the calculated second angle to the beam control unit 135.

[0076] The memory unit 140 stores the rotation angle (rotation speed) of the first motor 151 and the second motor 152 over a predetermined period of time. The memory unit 140 may also store a program for calculating a first angle and a program for calculating a second angle based on the rotation speed.

[0077] The other configurations are the same as in Embodiment 1.

[0078] <Operation> Figure 8 is a flowchart showing an example of operation of the beam antenna device 1 according to Embodiment 2. As is clear from comparing Figure 8 and Figure 6, the only difference is that the processes of steps S604 and S605 in the flowchart shown in Figure 6 have been changed to the processes of steps S804 and S805 in Figure 8. Therefore, the processes of steps S804 and S805 will be explained here, and the other processes will be omitted as they are the same as in Embodiment 1.

[0079] After the first motor 151 and the second motor 152 start to operate (step S603), the first acquisition unit 131 calculates the current first angle based on the elapsed time since the start of control and the rotation speed of the first motor 151 (step S804). The first acquisition unit 131 transmits the calculated first angle to the beam control unit 135.

[0080] Furthermore, the second acquisition unit 132 calculates the current second angle based on the elapsed time since the start of control of the second motor 152 and the rotational speed of the second motor 152 (step S805). The second acquisition unit 132 transmits the calculated second angle to the beam control unit 135.

[0081] As a result, the beam control unit 135 performs beam tracking based on the current first angle and second angle obtained by calculation.

[0082] <Summary> In the beam antenna device 1 according to Embodiment 2, in the process of controlling the rotation of the first rotating body 12 and the second rotating body 14 so that the planar antenna 16 faces the direction of HAPS 100, the first angle and the second angle can be obtained by sequential calculation without mounting angle sensors, so the direction of beam tracking can be controlled sequentially. In this case, it is not necessary to mount two angle sensors on the beam antenna device 1, so a lighter and less expensive beam antenna device can be provided than the beam antenna device 1 shown in Embodiment 1.

[0083] <Modifications> It goes without saying that the beam antenna device 1 according to the above embodiment is not limited to embodiments 1 and 2, and may be realized by other methods. Various modifications will be described below.

[0084] (1) In the above embodiment, an example was described in which the beam antenna device 1 performs beam tracking on a HAPS orbiting in the air to perform communication. However, the target of beam tracking by the beam antenna device 1 is not limited to a HAPS. Any flying object that orbits in the air and has a communication function may be other than a HAPS, such as an aircraft, drone, helicopter, or airship.

[0085] (2) In the above embodiment, the beam antenna device 1 is configured to have a control mechanism for controlling itself. However, the mechanism for controlling the angles of each rotating body of the beam antenna device 1 and the angle of the beam formed by the planar antenna 16 may exist as an external information processing device to the beam antenna device 1. In that case, the beam antenna device 1 may be instructed to set the angles of each rotating body and the beam by communication from the outside. In this case, the beam antenna device 1 may receive information on the angles of the rotating bodies and the beam from the information processing device and control the rotating bodies and the beam to set them to the received angles.

[0086] (3) In the above embodiment, the flat plate portion 10 of the beam antenna device 1 may be installed at a predetermined angle with respect to the horizontal plane. In this case, the beam antenna device 1 can be configured to rotate infinitely in a pseudo-continuous manner, making it easier for the HAPS 100 to follow.

[0087] (4) The program for the beam antenna device 1 of this disclosure to calculate the rotation angles of the first rotating body 12 and the second rotating body 14 and the beam angle of the planar antenna 16 based on the position of the aircraft (HAPS), and to control the angles of each rotating body and the beam angle of the beam antenna device 1, may be provided stored in a computer-readable storage medium. The storage medium is a “non-temporary tangible medium” capable of storing the program. The storage medium may include any suitable storage medium such as an HDD or SSD, or two or more suitable combinations thereof. The storage medium may be volatile, non-volatile, or a combination of volatile and non-volatile. However, the storage medium is not limited to these examples, and may be any device or medium capable of storing the program.

[0088] The beam antenna device 1 can realize the functions of the multiple functional units shown in each embodiment by, for example, reading a program stored on a storage medium and executing the read program. Furthermore, the program may be provided to the beam antenna device 1 via any transmission medium (such as a communication network or broadcast waves). The beam antenna device 1 realizes the functions of the multiple functional units shown in each embodiment by, for example, executing a program downloaded via the Internet or the like. This program may be executed by the beam antenna device 1 or the like.

[0089] The program can be implemented using, but is not limited to, scripting languages ​​such as ActionScript and JavaScript®, object-oriented programming languages ​​such as Objective-C, Java®, and Python®, and markup languages ​​such as HTML5.

[0090] At least a portion of the processing in the beam antenna device 1 may be implemented by cloud computing, which is comprised of one or more computers. Furthermore, each functional unit of the beam antenna device 1 may be implemented by one or more circuits that implement the functions shown in the above embodiment, or one circuit may implement the functions of multiple functional units.

[0091] (5) The configuration and processing of the beam antenna device 1 shown in the above embodiment may be combined or modified as appropriate to achieve the objective. For example, the processing in steps S604 and S605 may be executed in parallel, or in the order of S605 and S604.

[0092] (6) According to each aspect of the present disclosure described above, a beam antenna device can be provided that performs uninterrupted beam tracking with a base station (HAPS) orbiting in the air to provide communication services, thereby contributing to the achievement of Sustainable Development Goal 9, "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation."

[0093] 1 Beam antenna device 10 Flat plate section 11 First shaft section 12 First rotating body 13 Second shaft section 14 Second rotating body 15 Antenna mounting section 16 Planar antenna 100 HAPS 110 Communication section 120 Input section 121 First angle sensor 122 Second angle sensor 130 Control unit 131 First acquisition section 132 Second acquisition section 133 Position acquisition section 134 Rotating body control unit 135 Beam control unit 140 Storage section 150 Drive unit 151 First motor 152 Second motor 300 (300a, 300b) Terminal

Claims

1. A beam antenna device comprising: a flat plate portion; a first rotating body that rotates about a first axis perpendicular to the flat plate portion as its axis of rotation; a second rotating body that rotates about a second axis perpendicular to the first axis as its axis of rotation; a flat, plate-shaped phased array antenna with the second axis perpendicular to it; a position acquisition unit that acquires the position of an aerial platform; a rotation body control unit that controls the first rotating body and the second rotating body based on the position of the aerial platform so that the plane of the phased array antenna faces the direction of the aerial platform; and a beam control unit that controls the direction of beam tracking by the phased array antenna according to the rotation angle between the first rotating body and the second rotating body.

2. The beam antenna device according to claim 1, further comprising: a first acquisition unit for acquiring a first rotation angle from a reference position of the first axis; and a second acquisition unit for acquiring a second rotation angle from a reference position of the second axis, wherein the rotating body control unit controls the first rotating body and the second rotating body based on the first rotation angle, the second rotation angle, and the position acquired by the position acquisition unit.

3. The beam antenna device according to claim 2, further comprising: a first angle sensor for measuring the rotation angle of the first axis; and a second angle sensor for measuring the rotation angle of the second axis, wherein the first acquisition unit acquires the rotation angle measured by the first angle sensor as the first rotation angle; the second acquisition unit acquires the rotation angle measured by the second angle sensor as the second rotation angle; and the beam control unit controls the direction of the beam tracking based on the first rotation angle acquired by the first angle sensor and the second rotation angle acquired by the second angle sensor until the angle between the first and second rotating bodies reaches a target angle, as determined by the rotating body control unit.

4. The beam antenna device according to claim 2, comprising a first motor for rotating the first rotating body and a second motor for rotating the second rotating body, wherein the first acquisition unit calculates the first rotation angle based on the rotation angle per unit time of the first motor and the elapsed time from the start time of rotation control by the rotating body control unit, the second acquisition unit calculates the second rotation angle based on the rotation angle per unit time of the second motor and the elapsed time from the start time of rotation control by the rotating body control unit, and the beam control unit controls the direction of beam tracking based on the first rotation angle calculated by the first acquisition unit and the second rotation angle acquired by the second acquisition unit until the angle between the first rotating body and the second rotating body reaches a target angle by the rotating body control unit.

5. A control method for a beam antenna device comprising a flat plate portion, a first rotating body that rotates about a first axis perpendicular to the flat plate portion as its axis of rotation, a second rotating body that rotates about a second axis perpendicular to the first axis as its axis of rotation, and a flat plate-shaped phased array antenna with the second axis perpendicular to it, wherein the computer controlling the device performs: a position acquisition step to acquire the position of an aerial platform; a rotation body control step to control the first rotating body and the second rotating body based on the position of the aerial platform so that the plane of the phased array antenna faces the direction of the aerial platform; and a beam control step to control the direction of beam tracking by the phased array antenna according to the rotation angle between the first rotating body and the second rotating body.

6. A control program for a computer that controls a beam antenna device comprising a flat plate portion, a first rotating body that rotates about a first axis perpendicular to the flat plate portion as its axis of rotation, a second rotating body that rotates about a second axis perpendicular to the first axis as its axis of rotation, and a flat plate-shaped phased array antenna with the second axis perpendicular to it, the program implements: a position acquisition function for acquiring the position of an aerial platform; a rotation body control function that controls the first rotating body and the second rotating body based on the position of the aerial platform so that the plane of the phased array antenna faces the direction of the aerial platform; and a beam control function that controls the direction of beam tracking by the phased array antenna according to the rotation angle between the first rotating body and the second rotating body.

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