JP6389580B1 - Wireless communication method and wireless communication system - Google Patents

Abstract

An antenna for wireless communication can be installed relatively easily and stably, and can be used within a reasonable cost range for applications such as temporary, emergency, and remote areas. An unmanned aerial vehicle 10 is moored at a mooring point 11 with a conductive cable 101, and a wireless communication device 102 is provided on the mooring point 11 side and connected to the cable 101 via a connecting portion 103. The wireless communication is performed using the cable 101 as an antenna in a state where the aircraft is flying and stagnating. A power supply device may be provided on the mooring point 11 side to supply power to the unmanned aerial vehicle 10 through the cable 101, and a wireless communication signal may be superimposed on the cable 101. [Selection] Figure 1

Description

  The present invention relates to a wireless communication method and a wireless communication system, and more particularly to a wireless communication method and a wireless communication system to which an unmanned aerial vehicle is applied.

  Short wave (HF) band communication is used for ship / aircraft communication and amateur radio, and very high frequency (VHF) band communication is used for disaster prevention, fire fighting, police, air traffic control and the like. These frequency bands are inferior in terms of information transmission capacity as compared to higher frequency bands, but they can propagate in such a way as to bypass obstacles because they are not straight ahead. Because of these characteristics, it is possible to communicate relatively long distances using mainly vertically polarized waves in a propagation environment with poor visibility in urban areas with many high-rise buildings, and mainly in propagation environments with few obstacles such as offshore. It has features such as being able to perform long-distance communication exceeding the line-of-sight range of radio waves using horizontally polarized waves.

  The communication using the HF band or the VHF band is suitable for emergency wireless communication at an urban disaster site or temporary wireless communication at a large-scale event venue due to the above-described characteristics. It is also suitable for communication between ships on the ocean or between ships and the ground, and for radio communications over a wide geographical area such as deserts and plains.

  There are various types of antennas used in the HF band and VHF band, but in particular, a line (conducting cable, etc.) with a length of several meters to several tens of meters suitable for the wavelength is provided in a place where visibility is as good as possible. Is often used. A target wireless communication can be performed by connecting a wireless communication device (provided with a transmitter and / or a receiver) to the antenna provided as described above.

  So, for example, a structure (steel tower, etc.) that is several tens of meters above the ground is built and a line is attached in the height direction. If horizontal polarization is required, the line is passed between two towers, The mast is used to attach and mine tracks. However, these methods are not suitable for the emergency and temporary purposes described above.

  In addition, it may be difficult to install in remote areas such as deserts and plains where people do not normally enter, considering the cost of construction and maintenance. The method of using the ship's mast at sea is considered to be more difficult to apply as the ship becomes smaller. Although it is possible to form the antenna in a spiral shape and make the outer shape compact while maintaining the line length, in that case, the antenna performance (gain) must be sacrificed.

  2. Description of the Related Art A technique that aims to install an antenna for an HF band communication device relatively easily is known (see, for example, Patent Document 1). Patent Document 1 discloses a wing-shaped airtight sheet-like floating body in which floating gas is injected, suspension means connected to both ends of the floating body, an upper end connected to the suspension means, and a lower end fixed to the ground. A communication antenna provided with an antenna line is described.

JP-A-8-335817

  According to the technique described in Patent Document 1, the installation of the communication antenna can be facilitated, but it is inevitable that the installation direction and stability of the antenna are affected by wind conditions. In this respect, Patent Document 1 describes that the lift generated by the wing shape of the floating body is combined with the buoyancy of the floating gas to keep the antenna wire vertical, but for conditions such as the upper limit of the wind speed that makes it possible, I do not know because there is no description. Moreover, it is difficult to apply the technique described in Patent Document 1 to a horizontally polarized antenna.

  The problem to be solved by the present invention is that the antenna for wireless communication can be installed relatively easily and stably, and within a reasonable cost range for applications such as temporary, emergency and remote areas. And making it applicable to both vertical and horizontal polarization.

In order to solve the above-described problems, a wireless communication method according to the present invention includes an unmanned aerial vehicle that can be operated by remote control or autonomously moored at a mooring point with a conductive cable, and is provided on the mooring point side. The power supply device is connected so that power can be supplied to the unmanned aircraft through the cable, and a wireless communication device provided on the mooring point side exchanges wireless communication signals with the cable. Connecting the wireless communication device and the cable via electromagnetic coupling, allowing the unmanned aircraft to fly, extending the cable between the mooring point and the unmanned aircraft, and unmanned supplies power from the power supply device relative to the aircraft, the said cable as an antenna while avoiding the influence of the power supply bias to the wireless communication device And performs radio communication by a line communication device.

In order to solve the above-described problems, a wireless communication system according to the present invention includes a wireless communication device, a conductive cable capable of mooring an unmanned aerial vehicle capable of flying by remote control or autonomously at a mooring point, The cable is connected to a power supply device provided on the mooring point side, and wireless communication signals are exchanged between the wireless communication device and the cable while avoiding the influence of a power supply bias on the wireless communication device. In order to make it possible, the wireless communication device and the cable can be connected via an electromagnetic coupling .

  According to the present invention, an antenna for wireless communication can be installed relatively easily and stably, and can be used for temporary, emergency, remote areas, etc. within a reasonable cost. And can be applied to both vertically and horizontally polarized waves.

FIG. 1 is a diagram showing a concept and main configuration according to an embodiment of the present invention. FIG. 2 is a diagram showing the concept and main configuration of the first embodiment of the present invention. FIG. 3 is a diagram illustrating the configuration and connection of the connection unit according to the first embodiment. FIG. 4 is a diagram showing the concept and main configuration of the second embodiment of the present invention. FIG. 5 is a diagram illustrating the configuration and connection of the connection unit according to the second embodiment. FIG. 6 is a diagram illustrating the configuration of the impedance matching circuit according to the second embodiment. FIG. 7 is a diagram illustrating the configuration and connection of the connection unit according to the third embodiment of the present invention. FIG. 8 is a flowchart for explaining a wireless communication method according to the third embodiment. FIG. 9 is a diagram showing the concept and main configuration of the fourth embodiment of the present invention. FIG. 10 is a diagram illustrating the configuration and connection of the connection unit according to the fourth embodiment. FIG. 11 is a diagram for explaining an application example of the fourth embodiment.

  Hereinafter, a plurality of examples according to embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a concept and a main configuration (including a wireless communication system 100) according to an embodiment of the present invention. An example of an unmanned aerial vehicle used in an embodiment of the present invention is a so-called drone (autonomous flight based on remote control, programming or artificial intelligence, etc., which is indicated by reference numeral 10 in FIG. Unmanned aerial vehicles that can The unmanned aerial vehicle 10 can fly by remote control or autonomously while being moored via a conductive cable 101 at a mooring point 11 provided on the ground (indicated by a dashed ellipse in FIG. 1), for example. it can.

  A mooring point 11 is provided with a wireless communication device 102. For example, the wireless communication device 102 can transmit or receive radio waves in the HF band or the VHF band, or perform both transmission and reception (the radio wave band is not limited to the HF band or the VHF band). The wireless communication apparatus 102 may be connected to a voice communication terminal, a data communication terminal, or a network (not shown) depending on the form of use.

  A connecting portion 103 is provided at the mooring point 11. The connection unit 103 can connect the cable 101 to the wireless communication apparatus 102 on the mooring point 11 side. This connection is performed so that the wireless communication apparatus 102 can exchange wireless communication signals with the cable 101 (for this reason, the wireless communication apparatus 102 and the connection unit 103 are connected as shown in FIG. 1). ). The specific method will be described in the following examples.

  The main components of the wireless communication system 100 are the cable 101, the wireless communication apparatus 102, and the connection unit 103 described above. In addition, the mooring point 11 may be provided not only on the ground but also in a space of a building or a structure such as a building or a steel tower, or on a ship. The cable 101 may be a single line (in that case, the unmanned aircraft 10 flies without receiving external power supply), but may be paired for use as an external power supply line for the unmanned aircraft 10 as will be described later. .

  FIG. 2 is a diagram showing the concept and main configuration of the first example (Example 1) according to the embodiment of the present invention. In FIG. 2, the configurations denoted by reference numerals 10, 11, 100 to 103 are the same as the configurations denoted by the same reference numerals in FIG. In FIG. 2, the cable 101 is clearly shown as a pair.

  The mooring point 11 is provided with a power supply device 12. The power supply device 12 is connected to the cable 101 via the connection unit 103 and can supply direct current or alternating current power to the unmanned aircraft 10. Thus, by supplying power from the mooring location 11 side, the continuous flight time of the unmanned aerial vehicle 10 can be extended as compared with the case where power is not supplied.

  FIG. 3 is a diagram illustrating the configuration of the connection unit 103 and the connection between the power supply device 12, the cable 101, and the wireless communication device 102. The connection unit 103 includes a transformer 106. Both ends of the primary side (right side in the figure) of the transformer 106 are connected to the connection terminals 102b and 102c of the wireless communication apparatus 102 through the feeder line 102a, respectively.

  The secondary winding of the transformer 106 is a pair of wires connected to the pair of cables 101, and one of the pairs is connected to one output terminal (represented by the symbol “+”) of the power supply device 12. Then, the other of the paired wires is connected to the other output terminal (represented by a symbol “−”) of the power supply device 12.

  With the configuration and connection described above, power can be supplied from the power supply device 12 to the unmanned aerial vehicle 10 via the cable 101. If the wireless communication device 102 has a wireless transmission function, the transmission signal obtained between the connection terminals 102b and 102c excites the secondary winding through the primary winding of the transformer 106, and Power is supplied to the cable 101 connected to the secondary winding. Since the transmission signal is fed to the cable 101 by electromagnetic coupling via the transformer 106, the wireless communication apparatus 102 can avoid the influence of the bias voltage by the power supply apparatus 12.

  The secondary winding and the pair of wires constituting the cable 101 are equivalent to a single wire for frequencies sufficiently higher than the frequency of the power supply (for example, higher than the HF band). Therefore, the cable 101 when the unmanned aerial vehicle 10 is lifted and extended in the vertical direction from the mooring point 11 acts as an antenna, and the transmission signal can be radiated into the air. For example, if the unmanned aircraft 10 is transmitted at a frequency of 3 MHz while keeping the position and altitude above 25 m of the mooring point 11, the cable 101 having a length of 25 m can be used as a quarter-wave monopole antenna.

  The relationship between the cable length and the frequency described above is merely an example, and is not limited to the configuration of a quarter-wave monopole antenna. If the wireless communication apparatus 102 has a wireless reception function, it is possible to receive radio waves coming from the outside through an antenna configured by extending the cable 101. If the wireless communication apparatus 102 has a wireless transmission / reception function and a transmission / reception switching function, transmission / reception can be performed through an antenna configured by extending the cable 101. The unmanned aerial vehicle 10 is more stable in flight and airspace than in the case of using a floating body as in Patent Document 1, and is easy to prepare. For example, the unmanned aircraft 10 can be used for quickly deploying wireless communication facilities at a disaster site. Very suitable.

As described above, when the unmanned aircraft 10 is lifted from the mooring point 11 in the vertical direction, the extended cable 101 can be used as an antenna for vertically polarized waves. When the mooring point 11 is provided at a higher altitude than the ground or on a ship, the unmanned aircraft 10 is allowed to fly horizontally from the mooring point 11 and the extended cable 101 is used as an antenna for horizontally polarized waves. be able to.
According to Example 1 of the embodiment of the present invention, the wireless communication signal is superimposed on the cable that supplies power to the unmanned aircraft in flight from the mooring point side without being affected by the power supply bias. Thus, an antenna for vertical polarization or horizontal polarization can be configured.

  FIG. 4 is a diagram illustrating the concept and main configuration of a second example (Example 2) according to the embodiment of the present invention. In the second embodiment, the unmanned aerial vehicle 10 is used as in the first embodiment. The main components of a wireless communication system 200 according to the second embodiment are a cable 101, a wireless communication device 102, and a connection unit 203. Among these, the cable 101 and the wireless communication apparatus 102 have the same configurations as those indicated by the same reference numerals in the first embodiment.

  The unmanned aerial vehicle 10 can fly while being moored at the mooring point 11 via the cable 101 as in the first embodiment. The wireless communication system 200 is provided on the mooring point 11 side as in the case of the first embodiment. The mooring point 11 is provided with a power supply device 12 as in the first embodiment.

  FIG. 5 is a diagram illustrating the configuration of the connection unit 203 and the connection between the power supply device 12, the cable 101, and the wireless communication device 102. The connection unit 203 includes a winding shaft 206, a coil 207, and an impedance matching circuit 208. The take-up shaft 206 is formed in a hollow drum shape, and can be wound around a rotating shaft that is oriented in the left-right direction in the drawing as the cable 101 is wound or fed. The left end of the pair of cables 101 in the drawing is connected to one output end (represented by the symbol “+”) and the other output end (represented by the symbol “−”) of the power supply device 12, respectively.

  The coil 207 has a conductive wire formed in a spiral shape, and can be inserted into the hollow interior of the winding shaft 206 in the direction of the block arrow in the figure. The impedance matching circuit 208 is provided between the wireless communication device 102 and the coil 207, and the terminal on the wireless communication device 102 side of the impedance matching circuit 208 is connected to the connection terminals 102b and 102c of the wireless communication device 102 through the feeder line 102a, respectively. The A terminal on the coil 207 side of the impedance matching circuit 208 is connected to both ends of a conducting wire constituting the coil 207.

  FIG. 6 is a diagram illustrating the configuration of the impedance matching circuit 208. The impedance matching circuit 208 is configured so that a plurality of circuits composed of reactance elements can be switched and connected to the coil 207 in series. In the example of FIG. 6, the inductance element 208a, the capacitance element and inductance element series circuit 208b, the capacitance element and inductance element parallel circuit 208c, and the capacitance element 208d can be switched.

  The operation of the wireless communication system 200 according to the second embodiment will be described with reference to FIGS. 4 to 6. Power can be supplied from the power supply device 12 to the unmanned aircraft 10 via the cable 101. If the wireless communication apparatus 102 has a wireless transmission function, a transmission signal obtained between the connection terminals 102b and 102c excites the coil 207 via the impedance matching circuit 208. The transmission signal is fed to the cable 101 through electromagnetic coupling between the coil 207 arranged coaxially and the cable 101 wound around the winding shaft 206.

  Since the transmission signal is fed to the cable 101 by electromagnetic coupling between the coil 207 having the coaxial positional relationship and the winding portion of the cable 101, the wireless communication apparatus 102 avoids the influence of the bias voltage by the power supply apparatus 12. be able to. Similar to the first embodiment, the cable 101 when the unmanned aerial vehicle 10 is lifted and extended in the vertical direction from the mooring point 11 acts as an antenna for vertical polarization, and the transmission signal can be radiated into the air. . Similar to the first embodiment, the same antenna can be used for reception or the unmanned aerial vehicle 10 can be used as a horizontally polarized antenna by flying horizontally.

  A wireless communication method using the wireless communication system 200 according to the second embodiment will be described below. First, a radio communication frequency is selected, and the radio communication apparatus 102 sets the frequency. In the case of vertical polarization, when the unmanned aerial vehicle 10 is raised to an altitude at which an antenna length suitable for the selected frequency can be obtained, the winding shaft 206 rotates and the cable 101 is drawn upward by a required length. Since the antenna impedance varies depending on the frequency and the antenna length, the most suitable circuit among the plurality of circuits 208a to 208d of the impedance matching circuit 208 is selected so as to be close to the impedance matching condition.

  The closer the selected frequency is to the longer wavelength side, the longer the antenna length, that is, the extension length of the cable 101, and the inductance component becomes dominant. Therefore, the impedance matching circuit 208 approaches the impedance matching condition, so the inductance element 208a is selected. Conversely, as the selected frequency is closer to the short wavelength side, the capacitance element 208d is selected to cancel the inductance component by the capacitance component.

In the case of an intermediate frequency, a capacitance element and inductance element series circuit 208b or a capacitance element and inductance element parallel circuit 208c can be selected.
According to Example 2 according to the embodiment of the present invention, the antenna length, that is, the length of the cable that anchors the unmanned aircraft 10 is changed to cope with the selective switching of the frequency, and the impedance matching condition can be approximated each time. The additional effect that it can be obtained.

  The third embodiment is a modification example in which the wireless communication method according to the second embodiment is automated. The system configuration used in the third embodiment is obtained by replacing the connection unit 203 in FIG. 4 with a connection unit 303 (other configurations are the same as those in FIG. 4). FIG. 7 is a diagram illustrating an internal configuration of the connection unit 303 and a connection with another configuration. The connection unit 303 is obtained by adding a control unit 309 to the same configuration as the control unit 203 according to the second embodiment. As the control unit 309, for example, a microprocessor, a digital signal processor, a personal computer, or the like can be used.

  FIG. 7 includes flight instruction means 13 for instructing the unmanned aircraft 10 to fly. The flight instruction unit 13 is used for a flight instruction to the unmanned aircraft 10 by manual operation, and is connected to the control unit 309 through, for example, a commercial short-range wireless communication unit (indicated by a broken line with a double-pointed arrow in the figure). .), And can instruct flight to the unmanned aircraft 10 automatically upon receiving an instruction from the control unit 309. The control unit 309 is also connected to the wireless communication device 102 and the impedance matching circuit 208 by wire or wirelessly (also represented by a broken line with a double-pointed arrow).

  FIG. 8 is a flowchart for explaining a wireless communication method according to the third embodiment. Subsequent to the start of processing (START), a use frequency is set for the wireless communication apparatus 102 (step S81). The wireless communication apparatus 102 notifies the control unit 309 of the set value of the used frequency. The control unit 309 selects an antenna length suitable for the set use frequency (step S82). The control unit 309 sends an instruction to the flight instruction unit 13 so that the unmanned aircraft 10 flies to the altitude or position that realizes the selected antenna length, and stays at that position (step S83).

The control unit 309 instructs the impedance matching circuit 208 to select an impedance suitable for the set use frequency (step S84). This processing is ended (END), and then wireless communication using the set frequency can be performed.
According to Example 3 according to the embodiment of the present invention, there is an additional effect that it is possible to automatically perform from the setting of the use frequency to the selection of the antenna length and the impedance.

  FIG. 9 is a diagram illustrating a concept and a main configuration (including wireless communication system 400) of a fourth example (Example 4) according to the embodiment of the present invention. In the fourth embodiment, the same unmanned aircraft as the unmanned aircraft 10 of the first embodiment is used (represented by reference numerals 20 and 30, respectively).

  The unmanned aerial vehicle 20 can fly by remote control or autonomously while being moored via a conductive cable 420 at a mooring point 11 provided on the ground (same as in the first embodiment). The unmanned aerial vehicle 30 can fly by remote control or autonomously while being moored via a conductive cable 430 at a mooring point 11 provided on the ground (same as in the first embodiment). The cable 420 and the cable 430 are the same as the cable 101 of the first embodiment. The cable 420 and the cable 430 are combined to form a cable 401.

  The mooring point 11 is provided with a power supply device 12 (same as in the first embodiment), a wireless communication device 102 (same as in the first embodiment), and a connection unit 403. The power supply device 12 is connected to the cable 420 and the cable 430 via the connection unit 403, and can supply direct current or alternating current power to the unmanned aircraft 20 and the unmanned aircraft 30. The connection unit 403 can connect the cable 420 and the cable 430 to the wireless communication device 102 on the mooring point 11 side. This connection is performed so that the wireless communication apparatus 102 can exchange wireless communication signals with the cable 420 and the cable 430 and excites the cable 420 and the cable 430 with opposite polarities (described later).

  The cable 420 and the cable 430 are bundled over a certain length (indicated by the symbol “L” in the drawing) from the mooring point 11 side (in FIG. 9, they are shown to form a stranded wire. However, it is branched at the branching point 450 and connected to the unmanned aircraft 20 and the unmanned aircraft 30 respectively.

  The main configuration of the wireless communication system 400 is the cable 401, the wireless communication apparatus 102, and the connection unit 403 described above. FIG. 10 is a diagram illustrating the configuration of the connection unit 403 and the connection between the power supply device 12, the cable 401, and the wireless communication device 102. The connection unit 403 includes a transformer 106a and a transformer 106b (both are the same as the transformer 106 of the first embodiment). The connection unit 403 includes a distribution synthesizer 405. The distribution synthesizer 405 distributes the power of the transmission signal output by the wireless communication apparatus 102 between the connection terminals 102b and 102c evenly, and the primary winding of the transformer 106a and the primary winding of the transformer 106b. Supply to the wire.

  The secondary winding of the transformer 106a is a pair of wires connected to the pair of cables 420, and one of the pairs is connected to one “+” side output end of the power supply device 12, and the pair The other end of the line is connected to the output terminal on the “−” side of the power supply device 12. The winding on the secondary side of the transformer 106b is composed of a pair of wires connected to the pair of cables 430, and one of the pair of wires is connected to the output terminal on the “+” side of the power supply device 12, and The other is connected to the output terminal on the “−” side of the power supply device 12. With the above configuration and connection, power can be supplied from the power supply device 12 to the unmanned aircraft 20 via the cable 420. Further, power can be supplied from the power supply device 12 to the unmanned aircraft 30 via the cable 430.

  One of the transmission signals output from the wireless communication apparatus 102 and distributed by the distribution synthesizer 405 has an electromagnetic coupling between the primary side winding and the secondary side winding of the transformer 106a, as in the first embodiment. Then, power is supplied to the cable 420. Similarly, the other of the transmission signals output from the wireless communication apparatus 102 and distributed by the distribution synthesizer 405 is fed to the cable 430 through the electromagnetic coupling between the primary winding and the secondary winding of the transformer 106b. Is done.

  However, cable 420 is connected to the upper terminal in FIG. 10 of the secondary winding of transformer 106a, whereas cable 430 is the lower terminal in FIG. 10 of the secondary winding of transformer 106b. It is connected to the. That is, the transmission signal supplied to the cable 420 and the transmission signal supplied to the cable 430 have opposite polarities.

  A wireless communication method according to the fourth embodiment will be described. The unmanned aircraft 20 and the unmanned aircraft 30 are caused to fly, and the branch point 450 rises vertically from the mooring point 11 to extend the portion below the branch point 450 of the cable 401 and the unmanned aircraft 20 from the branch point 450 of the cable 420. And the portion from the branching point 450 of the cable 430 to the unmanned aircraft 30 form a horizontal straight line (as shown in FIG. 9).

  The transmission signal output from the wireless communication apparatus 102 is evenly distributed as described above, and excites the cable 420 and the cable 430 with opposite polarities (the relationship represented by the curved block arrows in FIG. 9). become.). Then, in the portion below the branching point 450 of the cable 401, the excitation signal of the cable 420 and the excitation signal of the cable 430 cancel each other, so that radiation of electromagnetic waves (vertically polarized waves) is suppressed. On the other hand, the portion from the branching point 450 to the unmanned aerial vehicle 20 of the cable 420 extended in a horizontal straight line and the portion from the branching point 450 to the unmanned aircraft 30 of the cable 430 are excited in the same direction. The electromagnetic wave (horizontal polarization) is radiated in a state equivalent to the antenna.

  For example, if the part from the branching point 450 of the cable 420 to the unmanned aerial vehicle 20 and the part from the branching point 450 to the unmanned aircraft 30 of the cable 430 are both equal in length to 25 m and the transmission frequency is 3 MHz, the horizontal straight line shape is obtained. The part from the branching point 450 of the extended cable 420 to the unmanned aerial vehicle 20 and the part from the branching point 450 of the cable 430 to the unmanned aircraft 30 constitute a half-wave dipole antenna as a whole.

  The relationship between the cable length and the frequency described above is merely an example, and is not limited to the configuration of a half-wave dipole antenna. Further, the part from the branching point 450 of the cable 420 to the unmanned aerial vehicle 20 and the part from the branching point 450 of the cable 430 to the unmanned aircraft 30 do not have to be equal in length. The fact that the horizontally polarized antenna configured as described above can be used for reception is the same as in the first embodiment. As a method of electromagnetic coupling to the cable 420 and the cable 430, the coaxial coupling method of the second embodiment may be used.

  FIG. 11 is a diagram illustrating an application example of the fourth embodiment. FIG. 11 shows the configuration shown in FIG. 9 with the portion from the branching point 450 to the unmanned aerial vehicle 20 of the cable 420 stretched in a straight line and the portion from the branching point 450 to the unmanned aircraft 30 of the cable 430 upward. It is seen from Since the above horizontal linearly stretched portion constitutes a horizontally polarized antenna, it has directivity in a horizontal plane (in the figure, a directivity pattern is formed by a pair of rice ball-like broken lines sandwiching the branching point 450. Represents.)

  By moving either one or both of the unmanned aircraft 20 and the unmanned aircraft 30 in the horizontal plane and rotating the whole in the horizontal plane, as indicated by a broken line with a clockwise or counterclockwise arrow at the top of FIG. Directivity can be changed. This is effective when the direction of the communication partner is limited or when it is desired to discriminate between the desired group and the jamming wave.

In the case of the first embodiment as well, a horizontally polarized antenna can be configured by flying an unmanned aircraft horizontally from a mooring point. However, for example, in the case of the ground, it is desirable that the mooring point itself has a certain level of ground height in order to ensure the safety of unmanned aircraft flight and the visibility of the antenna. On the other hand, the method of Example 4 is applicable also when the ground height of a mooring location is low.
According to Example 4 according to the embodiment of the present invention, the horizontally polarized antenna is configured safely and surely even when the mooring point itself is at a low altitude position, and the directivity in the horizontal plane is achieved by moving the unmanned aircraft. An additional effect that it can be changed is obtained.

10, 20, 30 Unmanned aerial vehicle 11 Moored place 12 Power supply device 13 Flight instruction means 100, 200, 400 Wireless communication system 101, 401, 420, 430 Cable 102 Wireless communication device 102a Feeder wire 102b, 102c Connection terminal 103, 203, 303 , 403 Connection 106, 106a, 106b Transformer 206 Winding shaft 207 Coil 208 Impedance matching circuit 208a Inductance element 208b Capacitance element and series circuit of inductance element 208c Capacitance element and parallel circuit of inductance element 208d Capacitance element 309 Control unit 405 Distribution Synthesizer 450 Branch point

Claims (13)

Moored unmanned aerial vehicles that can be operated remotely or autonomously at mooring points with conductive cables;
Connecting the cable to the power supply so that power can be supplied to the unmanned aircraft through the cable from the power supply provided on the mooring point side;
Connecting the cable to the wireless communication device via electromagnetic coupling so that the wireless communication device provided on the mooring point side allows wireless communication signals to be exchanged with the cable ;
Flying the unmanned aerial vehicle and extending the cable between the mooring point and the unmanned aerial vehicle;
Power is supplied from the power supply device to the unmanned aircraft, and wireless communication is performed by the wireless communication device using the cable as an antenna while avoiding an influence of a power supply bias on the wireless communication device. the method of. The wireless communication method according to claim 1 , wherein the unmanned aircraft is allowed to fly in the vertical direction from the mooring point to perform wireless communication using vertically polarized waves. The wireless communication method according to claim 1 , wherein the unmanned aircraft is allowed to fly horizontally from the mooring point so that wireless communication using horizontally polarized waves can be performed. By connecting a feeder line connected to a connection terminal of a wireless communication signal of the wireless communication device to a primary side of a transformer, and connecting the cable to a secondary side of the transformer, the wireless communication device is The wireless communication method according to claim 1, wherein the wireless communication device and the cable are connected via electromagnetic coupling so as to enable exchange of wireless communication signals with the cable. The cable is wound around a hollow winding shaft, and is configured such that the winding shaft rotates as the cable is unwound or fed.
By inserting a coil connected to a connection terminal of a wireless communication signal of the wireless communication device through a feeder line into a hollow portion of the winding shaft, the wireless communication device exchanges a wireless communication signal with the cable. The method of wireless communication according to claim 1 , wherein the cable is connected to the wireless communication device via electromagnetic coupling so as to enable. In the case of providing an impedance matching circuit between the feeder line and the coil,
Select a use frequency of the wireless communication device,
Flying the unmanned aerial vehicle to a position where a cable feed length corresponding to an antenna length suitable for the selected operating frequency is obtained;
The wireless communication method according to claim 5 , wherein an impedance of the impedance matching circuit is adjusted so as to match the selected use frequency. The unmanned aerial vehicle includes a plurality of aircraft including a first unmanned aerial vehicle and a second unmanned aerial vehicle. The cable includes a first cable for mooring the first unmanned aerial vehicle at the mooring point and the second unmanned aerial vehicle. In the case of a plurality of cables including the second cable moored at the mooring point,
The first cable and the second cable are bundled over a certain length from the mooring point side and then branched at the branch point, and then the first unmanned aircraft and the second unmanned aircraft are separated. Connect each one
The first cable and the second cable extend vertically from the mooring point to the branch point, and the portion of the first cable from the branch point to the first unmanned aircraft and the second The first unmanned aircraft and the second unmanned aircraft are allowed to fly such that a portion from the branch point of the cable to the second unmanned aircraft forms a horizontal straight line,
The wireless communication signal exchanged between the wireless communication device and the first cable and the wireless communication signal exchanged between the wireless communication device and the second cable have opposite polarities. The wireless communication method according to claim 1. A wireless communication device;
A conductive cable capable of mooring an unmanned aerial vehicle that can be operated remotely or autonomously at a mooring point;
The cable is connected to a power supply device provided on the mooring location side, and wireless communication signals are exchanged between the wireless communication device and the cable while avoiding the influence of a power supply bias on the wireless communication device. A wireless communication system comprising: a connection unit capable of connecting the wireless communication device to the cable through electromagnetic coupling . The connection unit includes a transformer formed by connecting a feeder line connected to a connection terminal of a wireless communication signal of the wireless communication device to a primary side and connecting the cable to a secondary side. The wireless communication system according to claim 8 . The connecting portion is
A hollow winding shaft configured to wind the cable around and rotate as the cable is unwound or fed; and
A coil that is connected to a connection terminal of a wireless communication signal of the wireless communication device through a feeder line, and is inserted into a hollow portion of the winding shaft,
The wireless communication system according to claim 8 , further comprising: an impedance matching circuit provided between the feeder line and the coil. In the case where the unmanned aircraft can fly by receiving a flight instruction from a flight instruction means placed on the mooring point side,
When the wireless communication device, the impedance matching circuit, and the flight instruction means of the unmanned aircraft are connected by wire or wirelessly and the use frequency of the wireless communication device is selected, the flight instruction means Flying to a position where the cable feed length corresponding to the antenna length suitable for the selected use frequency is obtained, and adjusting the impedance of the impedance matching circuit so as to match the selected use frequency The wireless communication system according to claim 10 , further comprising a control unit that can perform the control. It said impedance matching circuit, any one of claims 10 and claim 11, characterized in that it is configured to be able to connect in series with the coil switching circuitry plural kinds consisting of reactive elements The wireless communication system according to item. In the case where the unmanned aerial vehicle includes a plurality of aircraft including a first unmanned aerial vehicle and a second unmanned aerial vehicle,
The cable comprises a plurality of cables including a first cable for mooring the first unmanned aircraft at the mooring location and a second cable for mooring the second unmanned aircraft at the mooring location;
The first cable and the second cable are bundled over a certain length from the mooring point side and then branched at a branch point, and then the first unmanned aircraft and the second unmanned aircraft Each connected to
The connection unit is configured such that a radio communication signal exchanged between the radio communication device and the first cable and a radio communication signal exchanged between the radio communication device and the second cable have opposite polarities. The wireless communication system according to claim 8 , further comprising:

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