Public address system using unmanned aerial vehicles, air vehicle system with multiple unmanned aerial vehicles, and public address method

Abstract

To maintain the continuity of voice amplified by an unmanned flight body.SOLUTION: A management device 10 includes: a communication unit for communicating with an unmanned flight body 501 and an unmanned flight body 502 each having a voice amplification device; and a control unit for causing the unmanned flight body 501 and the unmanned flight body 502 to preform a voice amplification operation of amplifying a voice content to a target area and a flying operation. The control unit acquires charge information showing the remaining battery life of the unmanned flight body 501 when flying, acquires voice amplification information of the voice amplification device of the unmanned flight body 501, starts a flying operation of the unmanned flight body 502 according to the charge information, and starts the voice amplification operation of the unmanned flight body 502 on the voice amplification information in the target area instead of the voice amplification operation of the unmanned flight body 501 when flying.SELECTED DRAWING: Figure 5A

Description

[Technical field]

[0001] The present disclosure relates to a public address system that uses an unmanned aerial vehicle, an aerial vehicle system including a plurality of unmanned aerial vehicles, and a public address method. [Background technology]

[0002] Unmanned aerial vehicles such as drones fly using battery power, and methods for dealing with a lack of remaining battery power are known. Patent Document 1 discloses an unmanned aerial vehicle used as an aerial sprayer. The unmanned aerial vehicle is equipped with a charge amount detection device that detects the charge amount of the battery. The charge amount detection device calculates the return distance to a specified charging position and the possible flight distance based on the charge amount. The unmanned aerial vehicle is controlled so that it suspends spraying operations and returns to the charging position when the return distance is within the possible flight distance (see, for example, Patent Document 1 (paragraphs 0010, 0034-0035)). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-127076 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is known to use unmanned aerial vehicles equipped with speakers to amplify audio content. Using unmanned aerial vehicles has the advantage that it is possible to broadcast to areas where speakers cannot be installed or where audio is difficult to hear. However, when the unmanned aerial vehicle runs out of battery, it is forced to return to a waiting location to recharge. In that case, the broadcast is interrupted, and the audio content is cut off midway. Interruptions in broadcasting are an issue that should be avoided, especially when the audio content is important, such as evacuation information.

[0005] In view of the above, the object of the present disclosure is to provide an audio amplification system using an unmanned aerial vehicle, an air vehicle system having multiple unmanned aerial vehicles, and an audio amplification method that are effective in maintaining continuity of the sound amplified by the unmanned aerial vehicle. [Means for solving the problem]

[0006] In order to solve the above problems, according to one aspect of the present disclosure, a loudspeaker system includes a communication unit that communicates with a first unmanned aerial vehicle and a second unmanned aerial vehicle each having a loudspeaker device, and a control unit that causes the first unmanned aerial vehicle and the second unmanned aerial vehicle to execute a loudspeaker operation and a flight operation for loudspeaking audio content in a target area. The control unit acquires charging information indicating a remaining battery level of the first unmanned aerial vehicle during flight, acquires loudspeaker information of the loudspeaker device of the first unmanned aerial vehicle, starts the flight operation of the second unmanned aerial vehicle according to the charging information, and starts the loudspeaker operation of the second unmanned aerial vehicle during flight in the target area based on the loudspeaker information instead of the loudspeaker operation of the first unmanned aerial vehicle during flight.

[0007] According to another aspect of the present disclosure, an air vehicle system includes a first unmanned air vehicle and a second unmanned air vehicle. Each of the first unmanned air vehicle and the second unmanned air vehicle includes a battery, a loudspeaker device that performs a loudspeaker operation to loudspeak audio content, a communication device capable of communicating with the other unmanned air vehicle, and a control device that controls the flight operation and the loudspeaker operation. The second unmanned air vehicle starts a flight operation in a target area according to charging information indicating a remaining battery level of the first unmanned air vehicle during flight, and receives loudspeaker information of the loudspeaker device of the first unmanned air vehicle. The second unmanned air vehicle starts a loudspeaker operation in the target area based on the loudspeaker information, instead of the loudspeaker operation of the first unmanned air vehicle during flight.

[0008] According to yet another aspect of the present disclosure, a method for amplifying audio content in a target area by controlling a first unmanned aerial vehicle and a second unmanned aerial vehicle, each having a public address system, includes acquiring charging information indicating a remaining battery level of the first unmanned aerial vehicle during flight, acquiring public address information of the public address system of the first unmanned aerial vehicle, starting a flight operation of the second unmanned aerial vehicle according to the charging information, and starting the public address operation of the second unmanned aerial vehicle in the target area based on the public address information instead of the public address operation of the first unmanned aerial vehicle during flight. Effect of the Invention

[0009] The public address system using an unmanned aerial vehicle, the air vehicle system including multiple unmanned aerial vehicles, and the public address method of the present disclosure are effective in maintaining continuity of the sound amplified by the unmanned aerial vehicles. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 shows an example of the overall configuration of a system including an unmanned aerial vehicle according to the present disclosure. [Diagram 2] FIG. 2 illustrates an example of the configuration of a management device according to the present disclosure. [Diagram 3] FIG. 3 shows an example of the appearance of an unmanned aerial vehicle according to the present disclosure. [Figure 4] FIG. 4 shows an example configuration of an unmanned aerial vehicle according to the present disclosure. [Figure 5A] FIG. 5A is a flowchart showing the operation of the loudspeaker system realized by the management device according to the first embodiment. [Figure 5B] FIG. 5B is a flow chart showing a part of the operation of FIG. 5A. [Figure 6] FIG. 6 is a diagram for explaining the flight operation of the unmanned aerial vehicle according to the operation shown in FIG. 5A. [Figure 7A] FIG. 7A illustrates an example of audio content according to the present disclosure. [Figure 7B] FIG. 7B illustrates an example of broadcasting audio content by an unmanned aerial vehicle in accordance with the present disclosure. [Figure 7C]FIG. 7C shows another example of broadcasting audio content by an unmanned aerial vehicle in accordance with the present disclosure. [Figure 8A] FIG. 8A is a diagram showing the operation of the aircraft system according to the second embodiment. [Figure 8B] FIG. 8B is a flow chart showing a part of the operation of FIG. 8A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. Note that the attached drawings and the following explanation are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0012] In the following description, the Z-axis direction indicates the up-down direction or flight height direction of the unmanned aerial vehicle. The plane (XY plane) formed by the X-axis perpendicular to the Z-axis and the Y-axis perpendicular to the Z-axis and X-axis is a plane parallel to the ground. The "target area" is the area to which the audio content will be amplified by the unmanned aerial vehicle.

[0013] Each embodiment of the present invention will be described below.

[0014] 1. First embodiment The public address system including the management device according to the present embodiment is a system for controlling the flight and public address operations of a plurality of unmanned aerial vehicles. In the public address system, before the battery of a first unmanned aerial vehicle flying and amplifying audio content runs out, a second unmanned aerial vehicle seamlessly takes over the flight and public address operations of the first unmanned aerial vehicle.

[0015] 1-1.Configuration 1-1-1. Overall system configuration FIG. 1 shows a schematic diagram of the overall system configuration. A management device 10 (an example of a public address system) communicates with multiple unmanned aerial vehicles 50 via a network N. The network N includes a wired LAN (Local Area Network), a wireless LAN, a WAN (Wide Area Network), and / or the Internet. The network N also includes a wireless base station set up for each predetermined area. The management device 10 and the multiple unmanned aerial vehicles 50 have synchronized time information.

[0016] 1-1-2. Management device configuration The management device 10 shown in FIG. 2 is a computer device that functions as a server or the like, and includes a control unit 11, a storage unit 12, and a communication unit 19. The control unit 11 is an electronic circuit such as a CPU (Central Processing Unit). The control unit 11 (an example of a control unit) operates as an arithmetic processing device and a control device, and controls the management device 10 according to various programs to execute functions described below. The storage unit 12 (an example of a storage unit) is a ROM (Read Only Memory), a RAM (Random Access Memory), a HDD (Hard Disk Drive), an SSD (Solid State Drive), a FeRAM (Ferroelectric Random Access Memory), or the like. The ROM, HDD, SSD, FeRAM, or the like stores programs, calculation parameters, calculation results, and the like used by the control unit 11. The RAM temporarily stores programs used in the execution of the functions of the control unit 11, parameters that change appropriately in the execution, and the like. The communication unit 19 (an example of a communication unit) is, for example, a network interface card for connecting to a wired LAN or the Internet. The communication unit 19 may be a wireless communication interface for connecting to a wireless base station or a communication interface compatible with a wireless LAN.

[0017] The control unit 11 executes a predetermined program read from the memory unit 12, thereby executing the functions of a battery remaining amount determination unit 111, a flight information acquisition unit 112, amplified sound information acquisition unit 113, a flight instruction unit 114, and amplified sound instruction unit 115. Each function will be explained below using as examples an unmanned aerial vehicle 501 in flight and an unmanned aerial vehicle 502 that takes over the amplified sound operation of the unmanned aerial vehicle 501.

[0018] The battery remaining amount determination unit 111 acquires information indicating the remaining battery amount (%) transmitted at a predetermined interval from the unmanned aerial vehicle 501 in flight, and determines whether the remaining battery amount is less than a predetermined value. The predetermined value is a remaining amount sufficient for the unmanned aerial vehicle 501 to return to a waiting location equipped with a charging port or the like, and is set in advance. Battery consumption increases due to factors such as flying in a headwind, low temperature, low pressure, and frequency of ascent. Therefore, the predetermined value serving as the determination criterion is preferably a remaining battery amount sufficient for returning to the waiting location even if these factors occur, for example, about 30%.

[0019] The flight information acquisition unit 112 acquires flight information of the unmanned aerial vehicle 501 and the unmanned aerial vehicle 502. The flight information acquisition unit 112 stores the flight information in the flight information memory unit 121 of the memory unit 12.

[0020] The flight information includes flight information transmitted at predetermined intervals from the unmanned aerial vehicle 501, such as current position information on the flight route of the unmanned aerial vehicle 501, flight altitude, flight angle, and / or flight speed. The flight information also includes the flight route of the unmanned aerial vehicle 501 (including flight altitude and flight altitude on the flight route. Hereinafter, referred to as the amplified flight route). The amplified flight route is set in advance and stored in the flight information storage unit 121. The flight information also includes information indicating a handover position. The handover position is a position where the unmanned aerial vehicle 502 is approximately parallel to the unmanned aerial vehicle 501 during flight, and is calculated from the flight information of the unmanned aerial vehicle 501. For example, the handover position is a position selected from positions near the current position of the unmanned aerial vehicle 501 within a range where the unmanned aerial vehicles 501 and 502 do not collide with each other. For example, the handover position is a position shifted a predetermined amount in the lateral direction of the aircraft (X-axis direction or Y-axis direction shown in FIG. 3) based on the current position of the unmanned aerial vehicle 501. This predetermined amount is set, for example, based on the lateral size of each of the unmanned aerial vehicles 501, 502 in the lateral direction (X-axis direction or Y-axis direction shown in FIG. 3) so that the unmanned aerial vehicles 501, 502 do not collide in the lateral direction when running side by side. It is preferable that the position of the aircraft in the vertical direction (Z-axis direction shown in FIG. 3) at the handover position is approximately the same as the vertical direction of the aircraft at the current position of the unmanned aerial vehicle 501 so that the altitudes of the unmanned aerial vehicles 501, 502 are approximately the same when running side by side. The handover position is calculated so as not to overlap with the sound amplification direction of the speaker 62 of the unmanned aerial vehicle 501.

[0021] The loudspeaker information acquisition unit 113 acquires loudspeaker information from the speaker 62 (an example of a loudspeaker device) of the unmanned air vehicle 501 or the unmanned air vehicle 502. The loudspeaker information acquisition unit 113 stores the loudspeaker information in the loudspeaker information storage unit 122 of the storage unit 12.

[0022] The sound amplification information includes, for example, the angle of the speaker 62 (hereinafter referred to as the speaker angle), the volume level, and / or the setting value of the equalizer. The volume level of the speaker 62 is set based on characteristic information such as the output sound pressure level and frequency characteristics of the speaker 62. The characteristic information may be stored in advance in the storage unit 12 according to the type of speaker. The speaker angle indicates the speaker angle θ between the Z axis along the up-down direction of the unmanned aerial vehicle 50 and the traveling direction of the unmanned aerial vehicle 50, as shown in FIG. 3.

[0023] The loudspeaker information also includes audio content information indicating the audio content being loudspeaked by unmanned aerial vehicle 501. The audio content information is information that identifies the audio content being played and loudspeaked by unmanned aerial vehicle 501 when the broadcast is handed over from unmanned aerial vehicle 501 to unmanned aerial vehicle 502, and is identification information and metadata such as the file name of the audio file related to the audio content and a unique ID.

[0024] The amplification information also includes the end position of the amplification of the audio content by the unmanned aerial vehicle 501. The amplification end position is temporal position information related to the audio content at which the unmanned aerial vehicle 501 ends the amplification in order to hand over the amplification broadcast to the unmanned aerial vehicle 502. FIG. 7A shows an example of audio content C to be amplified. The audio content C has a predetermined length. The audio content C is divided into content blocks CB, and has delimiter positions P1, P2, ... between each content block CB. The delimiter position is, for example, the position of a period that exists in a sentence corresponding to the audio related to the audio content. An example of the amplification end position is time information indicating any one of one or more delimiter positions that exist in the audio content. The time information indicating the delimiter position is time information indicating the elapsed time from the start (0 minutes 00 seconds) of the audio content to the delimiter position. Another example of the amplification end position is time information indicating the end position of the audio content (for example, information indicating 5 minutes 00 seconds in audio content having a length of 5 minutes 00 seconds). The amplification time of each content block CB is stored in advance in the storage unit 12. The amplification blank time at the division position is set to a sufficient time (for example, several seconds) to allow for takeover of the amplification operation described below.

[0025] The storage unit 12 has an audio content storage unit 123 that stores audio content. At least one piece of audio content to be amplified by the unmanned aerial vehicle 501 is stored in the audio content storage unit 123 in advance.

[0026] The flight instruction unit 114 issues flight instructions to the unmanned aerial vehicle 501 and the unmanned aerial vehicle 502. In particular, the flight instruction unit 114 issues flight instructions to the unmanned aerial vehicle 501 and the unmanned aerial vehicle 502 based on the above-mentioned flight information, as described below.

[0027] The loudspeaker instruction unit 115 issues loudspeaker instructions to the unmanned aerial vehicle 501 and the unmanned aerial vehicle 502. In particular, the loudspeaker instruction unit 115 issues loudspeaker instructions to the unmanned aerial vehicle 501 and the unmanned aerial vehicle 502 based on the loudspeaker information, as described below.

[0028] 1-1-3. Configuration of unmanned aerial vehicles FIG. 3 shows a part of the appearance of the unmanned aerial vehicle 50 (501, 502), and FIG. 4 shows an example of the overall configuration of the unmanned aerial vehicle 50. The unmanned aerial vehicle 50 (an example of an unmanned aerial vehicle) is an unmanned aircraft that can be remotely controlled or automatically piloted, and performs flight operations such as ascending, moving forward, rotating, descending, and hovering in response to flight instructions from an operation terminal (not shown). The unmanned aerial vehicle 50 includes a main body 50a, a plurality of arms 50b extending horizontally radially from the main body 50a, a plurality of legs 50c extending downward, and rotors 55 attached to the upper ends of each leg 50c. The unmanned aerial vehicle 50 flies using lift generated by rotating the rotors 55 by the rotation of the motor 56, and generates a reaction by changing the rotation direction of some of the rotors 55 to prevent the main body 50a itself from rotating. A speaker 62 is mounted on the main body 50a of the unmanned aerial vehicle 50. The speaker 62 has a sound output direction facing downward, and the speaker angle θ can be changed as shown by the arrow by the speaker direction control mechanism 61. This makes it possible to change the sound output direction of the speaker 62.

[0029] As shown in FIG. 4, the unmanned aerial vehicle 50 includes a control device 51, a storage device 52, a group of sensors 53, a GPS receiver 54, a battery 58, and a wireless communication device 59 as components for performing flight operations. The control device 51 (an example of a control device) is an electronic circuit such as a CPU, functions as an arithmetic processing device and a control device, and controls the unmanned aerial vehicle 50 according to various programs to perform functions described below. The storage device 52 (an example of a storage device) is a memory such as a ROM, a RAM, or a flash memory. The ROM and the flash memory store programs, calculation parameters, calculation results, etc. used by the control device 51. The RAM temporarily stores programs used in executing the functions of the control device 51 and parameters that change as appropriate during the execution of the functions.

[0030] The sensor group 53 includes an acceleration sensor and an angular velocity sensor for detecting acceleration and angular velocity for controlling the attitude of the unmanned aerial vehicle 50, an air pressure sensor for detecting the flight altitude of the unmanned aerial vehicle 50, an ultrasonic sensor for maintaining altitude, a geomagnetic sensor for detecting the orientation of the unmanned aerial vehicle 50, etc. The GPS receiver 54 includes an antenna and a signal processing unit, and receives signals from GPS satellites to detect the position information of the unmanned aerial vehicle 50.

[0031] The battery 58 stores and supplies the power required for the operation of the unmanned aerial vehicle 50. The battery 58 is, for example, a lithium ion polymer secondary battery. When the unmanned aerial vehicle 50 returns to the waiting location, the battery 58 is connected to a charging port that connects to an external power source, and is charged under the control of a charging control IC.

[0032] The wireless communication device 59 includes a wireless communication interface for wireless communication with the management device 10 and other unmanned aerial vehicles. For example, the wireless communication device 59 includes a communication module for cellular communication such as 3G (3rd Generation), LTE (Long Term Evolution), 4G (4th Generation), and 5G (5th Generation) for communicating with the management device 10 and other unmanned aerial vehicles from a long distance. For example, the wireless communication device 59 includes a communication module conforming to a short-range wireless communication standard such as wireless LAN, Bluetooth, and Zigbee for wireless communication with other unmanned aerial vehicles in a short distance. The position information of the unmanned aerial vehicle 50 is transmitted to the management device 10 via the wireless communication device 59 at a predetermined interval.

[0033] The unmanned aerial vehicle 50 further includes a microphone direction control mechanism 63, a microphone 64, a camera direction control mechanism 65, and a camera 66. The microphone 64 can change its sound collection direction by changing its angle in the vertical direction, similar to the speaker 62, using the microphone direction control mechanism 63. The camera 66 can change its shooting direction by changing its angle in the vertical direction, similar to the speaker 62, using the camera direction control mechanism 65.

[0034] The control device 51 executes the functions of a flight control unit 511, a sound amplification control unit 512, a sound collection control unit 513, an image control unit 514, and a battery remaining capacity measurement unit 515 by executing a program read from the storage device 52.

[0035] The flight control unit 511 controls the number of rotations and the rotation speed of the motor 56 according to flight instructions received from the management device 10 via the wireless communication device 59 to perform flight operations of the unmanned aerial vehicle 50. The flight control unit 511 acquires position information including the inclination and rotation of the main body 50a shown in FIG. 3, latitude and longitude during flight, altitude, and azimuth of the main body 50a based on the output data of the sensor group 53 and the GPS receiver 54. The storage device 52 stores a program in which an algorithm is implemented to control the attitude and basic flight operations of the unmanned aerial vehicle 50 during flight. The program flies the unmanned aerial vehicle 50 while correcting the attitude and position of the main body 50a according to flight instructions received by the wireless communication device 59. The flight control unit 511 also transmits the flight information (current position information on the loudspeaker flight route, flight altitude, flight angle, and / or flight speed, etc.) to the management device 10 at predetermined intervals.

[0036] The loudspeaker control unit 512 executes a loudspeaker operation to loudspeak the audio content in accordance with a loudspeaker instruction from the management device 10 received via the wireless communication device 59. As an example, the audio content may be stored in advance in the storage device 52. In this case, the storage device 52 of the unmanned aerial vehicle 501 and the storage device 52 of the unmanned aerial vehicle 502 may store the same audio content to be broadcast, or each storage device 52 may store multiple audio contents to be broadcast and a selected audio content may be played. As another example, the loudspeaker control unit 512 may acquire any one of the one or more audio contents stored in the audio content storage unit 123 of the management device 10, store it in the storage device 52, and play the audio content stored in the storage device 52.

[0037] In the case of the unmanned aerial vehicle 501 returning from the unmanned aerial vehicle 50, the loudspeaker control unit 512 acquires a loudspeaker end instruction received from the management device 10, and in response thereto, identifies a loudspeaker end position where loudspeaker should end, and transmits a response signal including the identified loudspeaker end position to the management device 10. The loudspeaker control unit 512 ends the audio content being loudspeaked at the loudspeaker end position. As an example, the loudspeaker control unit 512 identifies an arbitrary delimiter position that exists after the playback position of the audio content being played at the time when the loudspeaker end instruction is acquired as the loudspeaker end position. For example, in the case of the audio content C shown in FIG. 7A, if the audio content was being played at a position within the first content block CB when the loudspeaker end instruction was acquired, one of the delimiter positions P1 and P2 that exist after the delimiter position is identified as the loudspeaker end position. For example, it is preferable to identify the delimiter position P1 that is closest in time as the loudspeaker end position. Also, for example, in consideration of the time allowance until the handover starts, the closest division position existing a predetermined time (e.g., 10 seconds) or more after the playback position may be specified as the amplification end position. As another example, the amplification control unit 512 specifies the end point of the audio content being played back at the time when the amplification end instruction is acquired as the amplification end position. In this case, amplification is taken over after the audio content is played back to the end.

[0038] When the unmanned aerial vehicle 50 is the unmanned aerial vehicle 502 that takes over the loudspeaker operation, the loudspeaker control unit 512 executes the loudspeaker operation in accordance with the loudspeaker start instruction received from the management device 10. The loudspeaker start instruction includes the speaker angle θ, the volume level, and / or the equalizer setting value based on the loudspeaker information from the unmanned aerial vehicle 501, and sets the speaker 62 to these parameters. The loudspeaker control unit 512 also refers to the audio content information included in the loudspeaker start instruction to identify the audio content to be taken over for broadcast, reads it out from the storage device 52, and plays it. At this time, the audio content is played back from a predetermined time position based on the loudspeaker end position included in the loudspeaker start instruction. The sound collection control unit 513 transmits the sound collected by the microphone 64 to an external device such as the management device 10 or the operation terminal of the unmanned aerial vehicle 50. The image control unit 514 temporarily stores the video and images captured by the camera 66 in the storage device 52 and transmits them to an external device.

[0039] The battery remaining capacity measuring unit 515 is, for example, a battery remaining capacity IC, and measures the remaining battery capacity (%) based on the voltage and current of the battery cell. The battery remaining capacity measuring unit 515 transmits the measured remaining battery capacity to the management device 10 at predetermined intervals.

[0040] 1-2.Operation 5A and 5B, the operation of the management device 10 shown in Fig. 2 will be described. The management device 10 controls the flight operations and sound amplification operations of the multiple unmanned aerial vehicles 501 and 502 (Fig. 1).

[0041] Assume that the unmanned aerial vehicle 501 is flying in the target area 100 as shown in FIG. 6(a) and is amplifying audio content C (FIG. 7A) from the speaker 62 (FIG. 4) (S101). Meanwhile, the unmanned aerial vehicle 502 is waiting in a waiting area and its battery is fully charged. The unmanned aerial vehicle 501 flies in the target area 100 according to a predetermined flight route and plays and broadcasts the audio content stored in the storage device 52.

[0042] The management device 10 receives flight information and charging information from the unmanned aerial vehicle 501 at predetermined intervals (S102, S103). The battery remaining amount determination unit 111 of the management device 10 determines whether the battery remaining amount is less than a predetermined value based on the charging information (S104). If the battery remaining amount is less than the predetermined value, the loudspeaker information acquisition unit 113 requests loudspeaker information from the unmanned aerial vehicle 501, and the flight instruction unit 114 instructs the unmanned aerial vehicle 501 to hover (S105). The unmanned aerial vehicle 501 hovers (S106). This suppresses battery consumption of the unmanned aerial vehicle 501 and allows for a smoother handover to the unmanned aerial vehicle 502 that is about to begin flying.

[0043] The flight instruction unit 114 of the management device 10 transmits flight instructions to the unmanned aerial vehicle 502 (S107). The flight instructions include flight information. The flight information includes current position information of the unmanned aerial vehicle 501 on its flight route, flight altitude, flight angle and / or flight speed, amplified flight route, handover position, etc. Additionally, the loudspeaker information acquisition unit 113 of the management device 10 receives loudspeaker information from the unmanned aerial vehicle 501 and transmits it to the unmanned aerial vehicle 502 (S108). The loudspeaker information includes the speaker angle θ of the speaker 62, the volume level, and / or the equalizer setting value. Additionally, the loudspeaker information includes audio content information indicating the audio content being broadcast by the unmanned aerial vehicle 501.

[0044] Upon receiving the flight instruction, the unmanned aerial vehicle 502 starts flight operations in accordance with the flight instruction (S109), and transmits flight information including its own position information to the management device 10 at predetermined intervals (S110). In addition, the loudspeaker control unit 512 of the unmanned aerial vehicle 502 that has received the loudspeaker information sets the angle of the speaker 62 of the vehicle, the sound level, the setting values ​​of the equalizer, etc., according to the loudspeaker information (S109). The loudspeaker control unit 512 of the unmanned aerial vehicle 502 determines whether the sound content indicated by the sound content information is stored in the storage device 52, and if not stored, communicates with the management device 10 to acquire (download) the sound content indicated by the sound content information from the sound content storage unit 123 and store it in the storage device 52. More specifically, as shown in FIG. 5B, the unmanned aerial vehicle 502 transmits a sound content request including the sound content information to the management device 10 (S109a). In response to the sound content request, the management device 10 identifies the sound content indicated by the sound content information, reads out the identified sound content from the sound content storage unit 123, and transmits it to the unmanned aerial vehicle 502 (S109b, S109c). Unmanned aerial vehicle 502 stores the received audio content in storage device 52 (S109d).

[0045] The flight instruction unit 114 of the management device 10 determines that the unmanned aerial vehicle 502 has reached the handover position based on the position information transmitted from the unmanned aerial vehicle 502 (S111). In response to this determination, the flight instruction unit 114 instructs the unmanned aerial vehicle 502 to hover (S112). In response to the hovering instruction, the unmanned aerial vehicle 502 performs hovering (S113). As a result, as shown in FIG. 6(b), the unmanned aerial vehicle 501 and the unmanned aerial vehicle 502 are traveling approximately side by side in the target area.

[0046] When the unmanned aerial vehicle 501 and the unmanned aerial vehicle 502 are traveling substantially parallel to each other, preparations for handover of broadcasting are completed. The loudspeaker instruction unit 115 of the management device 10 transmits a loudspeaker end instruction to the unmanned aerial vehicle 501 (S114). Upon receiving the loudspeaker end instruction, the loudspeaker control unit 512 of the unmanned aerial vehicle 501 identifies the loudspeaker end position (e.g., division positions P1, P2 or end position) of the currently played audio content, plays and broadcasts the audio content up to this loudspeaker end position, and ends the broadcast there (S115). The loudspeaker control unit 512 of the unmanned aerial vehicle 501 transmits the identified loudspeaker end position to the management device 10 (S116). Upon receiving the loudspeaker end position, the loudspeaker instruction unit 115 of the management device 10 transmits a loudspeaker start instruction including the loudspeaker end position to the unmanned aerial vehicle 502 (S117). Upon receiving the loudspeaker start instruction, the loudspeaker control unit 512 of the unmanned aerial vehicle 502 reads out the audio content from the storage device 52 and starts loudspeaking the audio content based on the loudspeaker end position included in the loudspeaker start instruction (S118). In step S118, if a plurality of audio contents are stored in the storage device 52, the loudspeaker control unit 512 refers to the audio content information, identifies the audio content indicated by the audio content information, and reads it out from the storage device 52. Also, in step S118, the loudspeaker control unit 512 may start playing the audio content from a time position adjacent to the time position indicated by the loudspeaker end position. That is, as an example, if the loudspeaker end position is time information indicating 2 minutes 30 seconds, the playback may start from 2 minutes 31 seconds of the audio content. As another example, if the loudspeaker end position is time information indicating the end point (5 minutes 00 seconds) of the 5-minute long audio content, the playback may return to the beginning of the audio content and start playing from 0 minutes 00 seconds of the audio content. The unmanned aerial vehicle 502 starts amplifying the voice and starts normal flight along the amplifying flight route (S119). As a result, for example, when the amplifying end position is the division position P1 shown in Fig. 7A, the unmanned aerial vehicle 501 amplifies "Announcement from XX", as shown in Fig. 7B, and then the unmanned aerial vehicle 502 takes over the amplifying voice with "Today is the voting day for the XX city mayoral election. Voting hours are until 8 p.m....". When the amplifying end position is P2, the unmanned aerial vehicle 501 amplifies "Announcement from XX. Today is the voting day for the XX city mayoral election", as shown in Fig. 7C, and then the unmanned aerial vehicle 502 takes over the amplifying voice with "Voting hours are until 8 p.m....".

[0047] The flight instruction unit 114 of the management device 10 transmits a return instruction to the unmanned aerial vehicle 501 (S120). In response to this, the unmanned aerial vehicle 501 flies along a predetermined return route to a waiting location (S121). As a result, as shown in FIG. 6(c), the unmanned aerial vehicle 502 performs flying and amplifying operations in the target area in place of the unmanned aerial vehicle 501. The return route may be instructed in advance by the management device 10 to the unmanned aerial vehicle 501, or may be a route calculated by the unmanned aerial vehicle 501 according to a flight route previously stored in memory.

[0048] As in steps S102 to S103, the management device 10 receives flight information and charging information at predetermined intervals from the unmanned aerial vehicle 502 during flight and loudspeaker operation (S122, S123). When the remaining battery charge of the unmanned aerial vehicle 502 falls below a predetermined value, the management device 10 executes a handover operation to another unmanned aerial vehicle (including the unmanned aerial vehicle 501 that has finished charging).

[0049] Features The management device 10 or the sound amplification method according to the above embodiment acquires charging information indicating the remaining battery power of the unmanned aerial vehicle 501 flying in the target area, and starts the flight operation of the waiting unmanned aerial vehicle 502 according to the remaining battery power. The management device 10 further acquires sound amplification information of the speaker 62 of the unmanned aerial vehicle 501, and starts the sound amplification operation of the unmanned aerial vehicle 502 based on the sound amplification information in place of the sound amplification operation of the unmanned aerial vehicle 501 flying in the target area. This makes it possible to avoid interrupting not only the flight operation but also the sound amplification operation due to the battery running out of the unmanned aerial vehicle 501. This makes it possible to maintain the continuity of the sound amplified by the unmanned aerial vehicle in the target area.

[0050] In addition, unmanned aerial vehicle 502 inherits the flight information (including flight altitude and flight route) of unmanned aerial vehicle 501, as well as the amplification information of speaker 62 (volume level, speaker angle, characteristic information, and amplification end position of the audio content), so that flight operations and amplification operations can be performed seamlessly between unmanned aerial vehicle 501 and unmanned aerial vehicle 502.

[0051] Furthermore, since unmanned aerial vehicles 501 and 502 take over the amplification operation while their positions, including flight altitude, are aligned, unnatural interruptions or overlaps in the amplification of audio content in the target area can be prevented.

[0052] 1-4.Modifications The management device 10 may constitute a system (an example of a public address system) that can be connected to an operation terminal (not shown) of each unmanned aerial vehicle. The operation terminal is a computer terminal that can communicate with the management device 10 via a network N. Each operation terminal mediates communication between the management device 10 and the unmanned aerial vehicle 50. A user can also directly perform operations for the flight operations and public address operations of the unmanned aerial vehicle 50 using input means such as buttons, joysticks, and touch panels provided on the operation terminal.

[0053] 2. Second embodiment This embodiment relates to an aircraft system having multiple unmanned aircraft, and differs from embodiment 1 in that it is an autonomous system in which the first and second unmanned aircraft communicate with each other and take over flight operations and loudspeaker operations between the unmanned aircraft.

[0054] 2-1.Configuration The appearance and configuration of each unmanned aerial vehicle in this embodiment are similar to the unmanned aerial vehicle 50 shown in Figures 3 and 4, so descriptions will be omitted and similar reference symbols will be used. 2-2.Operation The operation of the aircraft system 500 according to this embodiment will be described with reference to Figs. 8A and 8B. The aircraft system 500 includes an unmanned aircraft 501 and an unmanned aircraft 502 shown in Fig. 4. The unmanned aircraft 501 is flying in the target area 100 as shown in Fig. 6(a) and is amplifying audio content C from the speaker 62 (S201). The unmanned aircraft 502 is waiting in a waiting area and its battery is fully charged. The management device 10 is also assumed to have acquired position information of the unmanned aircraft in flight. The unmanned aircraft 501 flies in the target area 100 according to a predetermined flight route and plays and broadcasts audio content stored in the storage device 52.

[0055] The battery remaining charge measurement unit 515 of the control device 51 of the unmanned aerial vehicle 501 determines whether the remaining battery charge is less than a predetermined value (S202), and if it is less than the predetermined value, notifies the management device 10 (S203). In response to the notification (S203), the management device 10 transmits a flight instruction to the waiting unmanned aerial vehicle 502 (S204). The flight instruction includes a handover position based on the current position information of the unmanned aerial vehicle 501.

[0056] The unmanned aerial vehicle 501, whose remaining battery power falls below a predetermined level, hovers (S205). Meanwhile, the unmanned aerial vehicle 502, which has received a flight instruction, starts flying in accordance with the flight instruction (S206). When the unmanned aerial vehicle 502 arrives at the handover position or in its vicinity (S207), it hovers (S208) and starts communication with the unmanned aerial vehicle 501 (S209). Specifically, when the unmanned aerial vehicle 501 starts hovering in step S205, it enters a state of waiting for communication with other unmanned aerial vehicles by short-range wireless communication using the wireless communication device 59, and when the unmanned aerial vehicle 502 starts hovering in step S208, it enters a state of searching for other unmanned aerial vehicles using the wireless communication device 59. As a result, in step S209, the unmanned aerial vehicle 502 discovers the unmanned aerial vehicle 501 by short-range wireless communication, and the unmanned aerial vehicle 501 and the unmanned aerial vehicle 502 are interconnected and can communicate with each other. For example, after starting hovering (S205), the unmanned aerial vehicle 501 transmits a periodic signal defined by a short-range wireless communication standard, and after starting hovering (S208), the unmanned aerial vehicle 502 starts scanning for the periodically transmitted signal, and the unmanned aerial vehicle 502 receives the signal transmitted from the unmanned aerial vehicle 501 to establish a connection (S209). The periodically transmitted signal may be, for example, in accordance with a wireless LAN standard, and the unmanned aerial vehicle 501 may periodically transmit a beacon signal as an access point, and the unmanned aerial vehicle 502 may scan for the beacon signal. For example, in accordance with the Bluetooth standard, the unmanned aerial vehicle 501 may periodically transmit an advertising signal, and the unmanned aerial vehicle 502 may scan for the advertising signal.

[0057] When wireless communication with the unmanned aerial vehicle 502 is established (S209), the unmanned aerial vehicle 501 transmits its own flight information and loudspeaker information to the unmanned aerial vehicle 502 (S210). The flight information includes the current flight altitude, flight speed, flight angle, and loudspeaker flight route (including flight speed and flight altitude on the loudspeaker flight route) of the unmanned aerial vehicle 501. The loudspeaker information includes audio content information indicating the audio content being broadcast by the unmanned aerial vehicle 501, speaker angle, volume level, and / or equalizer setting value. The unmanned aerial vehicle 502 performs a preparation operation to take over loudspeaker broadcasting from the unmanned aerial vehicle 501 according to the received flight information and loudspeaker information (S211). In step S211, the flight control unit 511 of the unmanned aerial vehicle 502 adjusts its own flight altitude and flight angle to the flight altitude and flight angle of the unmanned aerial vehicle 501 according to the flight information. In step S211, the loudspeaker control unit 512 of the unmanned aerial vehicle 502 adjusts the angle, volume level, equalizer settings, etc. of its own speaker 62 according to the loudspeaker information. Also, in step S211, the loudspeaker control unit 512 of the unmanned aerial vehicle 502 determines whether the audio content indicated by the audio content information is stored in the storage device 52, and if not stored, acquires the audio content from the management device 10 or the unmanned aerial vehicle 501. More specifically, when acquiring audio content from the management device 10, as shown in FIG. 5B, the unmanned aerial vehicle 502 communicates with the management device 10 to acquire (download) the audio content and store it in the storage device 52 (S109a to S109d). When acquiring audio content from the unmanned aerial vehicle 501, as shown in FIG. 8B, the unmanned aerial vehicle 502 transmits an audio content request including audio content information to the unmanned aerial vehicle 501 by short-range wireless communication (S211a). In response to the audio content request, the unmanned aerial vehicle 501 identifies the audio content indicated by the audio content information, reads the identified audio content from its own audio content storage unit 123, and transmits it to the unmanned aerial vehicle 502 by short-range wireless communication (S211b, S211c). The unmanned aerial vehicle 502 stores the received audio content in its own storage device 52 (S211d). When the unmanned aerial vehicle 502 completes preparations for amplification based on flight information and amplification information (S211), it transmits such information to the unmanned aerial vehicle 501 via short-range wireless communication (S212).

[0058] When the unmanned aerial vehicle 502 notifies the unmanned aerial vehicle 501 that it is ready to amplify, the amplifying control unit 512 of the unmanned aerial vehicle 501 identifies the amplifying end position (e.g., division positions P1, P2 or end position) of the currently playing audio content, plays and broadcasts the audio content up to this amplifying end position, and ends the broadcast (S213). The amplifying control unit 512 of the unmanned aerial vehicle 501 transmits an amplifying start instruction including the identified amplifying end position to the unmanned aerial vehicle 502 by short-range wireless communication (S214). Upon receiving the amplifying start instruction, the amplifying control unit 512 of the unmanned aerial vehicle 502 reads out the audio content from the storage device 52 and starts amplifying the audio content based on the amplifying end position included in the amplifying start instruction (S215). In step S215, if multiple audio contents are stored in the storage device 52, the amplifying control unit 512 of the unmanned aerial vehicle 502 refers to the audio content information, identifies the audio content indicated by the audio content information, and reads it out from the storage device 52. Also, in step S215, the loudspeaker control unit 512 of the unmanned aerial vehicle 502 may start playing the audio content from a time position adjacent to the time position indicated by the loudspeaker end position. That is, as an example, if the loudspeaker end position is time information indicating 2 minutes 30 seconds, the playback may start from 2 minutes 31 seconds into the audio content. As another example, if the loudspeaker end position is time information indicating the end point (5 minutes 00 seconds) of the 5-minute long audio content, the playback may start from 0 minutes 00 seconds into the audio content by returning to the beginning of the audio content. The unmanned aerial vehicle 502 starts loudspeaker and starts normal flight along the loudspeaker flight route (S216). As a result, for example, if the loudspeaker end position is P1 shown in FIG. 7A, the unmanned aerial vehicle 501 loudspeaks "Announcement from XX," as shown in FIG. 7B, and then the unmanned aerial vehicle 502 takes over the loudspeaker by saying, "Today is the voting day for the XX City mayoral election. Voting is open until 8 p.m...."

[0059] After completing the broadcasting, the unmanned aerial vehicle 501 returns to the waiting location along a predetermined return route (S217). When the battery of the unmanned aerial vehicle 502 during flying and sound amplification operations falls below a predetermined value, a flight instruction is sent from the management device 10 to other unmanned aerial vehicles (including the unmanned aerial vehicle 501 that has finished charging), and a similar handover operation is performed.

[0060] Features The flying object system 500 or the sound amplification method according to this embodiment includes an unmanned flying object 501 and an unmanned flying object 502 that can communicate with each other. The unmanned flying object 502 starts flying in the target area according to charging information indicating the remaining battery level of the flying unmanned flying object 501, receives sound amplification information from the speaker 62 of the unmanned flying object 501, and starts sound amplification in the target area based on the sound amplification information instead of the sound amplification operation of the flying unmanned flying object 501. Therefore, the flying object system 500 can maintain the continuity of the sound amplified by the unmanned flying object in the target area, as in the first embodiment. The flying object system 500 can further be realized by the unmanned flying object 501 and the unmanned flying object 502 that fly autonomously without the intervention of the management device 10.

[0061] 3. Other embodiments As described above, each embodiment has been described as an example of the technology disclosed in this application. However, the technology in this disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are appropriately performed. In addition, it is also possible to combine the components described in the above embodiments to create a new embodiment. For example, the following embodiments are possible.

[0062] (1) In the above embodiment, the takeover of flight operations and loudspeaker operations may be performed by three or more unmanned aerial vehicles.

[0063] (2) In the above embodiment, the charging information is the remaining battery power, but is not limited thereto. The charging information may be replaced by the flight time of the unmanned aerial vehicle 50, which is correlated with the remaining battery power. In this case, a flight time (hereinafter referred to as flight time limit) for safe flight is set in advance based on past flight performance data of the unmanned aerial vehicle 50. In the first embodiment, instead of steps S103 to S104 in FIG. 5A, the management device 10 that manages the flight of the unmanned aerial vehicle 501 monitors the flight time of the unmanned aerial vehicle 501, and when the flight time limit is reached, transmits a request for loudspeaker information or a hovering instruction to the unmanned aerial vehicle 501 (S105). In the second embodiment, instead of steps S202 to S203 in FIG. 8A, the unmanned aerial vehicle 501 monitors its own flight time, and when the flight time limit is reached, notifies the management device 10, and the management device 10 transmits a flight instruction to the unmanned aerial vehicle 502 (S204).

[0064] The predetermined value of the remaining battery charge or the flight time limit, which is the criterion for determining whether the unmanned aerial vehicle 501 should return, may be changed according to the return distance to the waiting location. In this case, the management device 10 in the first embodiment and the unmanned aerial vehicle 501 in the second embodiment calculate the predetermined value of the remaining battery charge or the flight time limit based on the current position information, and update and store them at a predetermined time interval.

[0065] (3) In the above embodiment, the unmanned aerial vehicle 501 and the unmanned aerial vehicle 502 hover when taking over the loudspeaker operation, but this is not limited to the above. The unmanned aerial vehicle 501 and the unmanned aerial vehicle 502 may take over the loudspeaker operation while flying side by side at the same low flight speed (e.g., 5 km / h). (4) In the above embodiment, the audio content to be amplified may be Japanese audio content or audio content in a language other than Japanese. The audio content may include Japanese audio content and audio content in a language other than Japanese. In this case, the audio content in the other language may be amplified together with the Japanese audio content.

[0066] (5) In the above-described embodiments, each device or system may have a cloud computing configuration in which one function is shared and processed jointly by multiple devices via a network.

[0067] In the above embodiments, the term "device" or "system" includes cases where it means a collection of multiple components (devices, modules (parts), etc.), regardless of whether all the components are in the same housing. In addition, multiple devices housed in separate housings and connected via a network, and a single device in which multiple modules are housed in a single housing, may both be called a system.

[0068] Each step described in the above flow chart can be executed by one device or can be shared among multiple devices. Furthermore, when one step includes multiple processes, the multiple processes included in the step can be executed by one device or can be shared among multiple devices.

[0069] The order of execution of operations by the management device 10, the aircraft system 500, or the amplification method shown in Figures 5A and B or Figures 8A and B is not necessarily limited to that described in the above embodiments, and the order of execution can be changed or multiple operations can be executed simultaneously without departing from the gist of the invention.

[0070] (6) In the above embodiments, the control unit or control device of each device or equipment may include a processor configured with a dedicated electronic circuit designed to realize a predetermined function according to the function required for each device or equipment. The control unit or control device may be realized by various processors such as MPU, GPU, DSP, FPGA, ASIC, etc. The control unit or control device may be configured with one or more processors.

[0071] Part or all of the memory unit or storage device of each device or equipment may be composed of any computer-readable recording medium, such as an optical disk, magnetic disk, magneto-optical disk, magnetic tape, HDD, SD card, SSD, etc., depending on the functions required for each device or equipment.

[0072] The communication unit or communication device of each device or equipment may be any communication interface, such as a wireless LAN, wired LAN, 3G, LTE, 4G, 5G, or millimeter wave wireless communication interface, depending on the functions required for each device or equipment. Preferably, the unmanned aerial vehicle 50 and the management device 10 communicate with each other using cellular communication such as 3G, LTE, 4G, or 5G, which allows long-distance communication, and the unmanned aerial vehicles 50 communicate with each other using a short-range wireless communication standard such as wireless LAN, Bluetooth, or Zigbee, since short-range communication is sufficient.

[0073] (7) The computer program is not limited to being recorded on a recording medium, but may be acquired via the communication unit or communication device.

[0074] Each process in the above-described embodiment may be realized by hardware or software (including the case where it is realized together with an OS (operating system), middleware, or a predetermined library). Furthermore, each process may be realized by a combination of software and hardware. [Industrial Applicability]

[0075] The present disclosure is applicable to a public address system using an unmanned aerial vehicle, an air vehicle system including multiple unmanned aerial vehicles, or a public address method using an unmanned aerial vehicle. [Explanation of symbols]

[0076] 10: Management device 11: Control section 12: Storage section 19: Communications Department 50,501,502: Unmanned aerial vehicle 50a: Main unit 50b: Arm 50c: Legs 51: Control device 52: Storage device 53: Sensor group 54: GPS receiver 55: Rotor 56: Motor 58: Battery 59: Wireless communication equipment 61: Speaker direction control mechanism 62: Speaker 63: Microphone directional control mechanism 64: Mike 65: Camera direction control mechanism 66: Camera 100: Target area 111: Battery remaining capacity determination unit 112:Flight information acquisition section 113: Amplification information acquisition unit 114:Flight instruction department 115: Public address system 121:Flight information storage unit 122: Amplification information storage unit 500: Aircraft Systems 511: Flight control unit 512: Amplification control unit 513: Sound collection control unit 514: Image control unit 515: Battery level measurement unit C: Audio content CB : Content Block N: Network

Claims

1. A communication unit that communicates with a first unmanned aerial vehicle and a second unmanned aerial vehicle, each of which has a loudspeaker; A control unit that causes the first unmanned aerial vehicle and the second unmanned aerial vehicle to perform a voice amplification operation and a flight operation for amplifying audio content in a target area; A loudspeaker system comprising: The control unit is Acquire charging information indicating a remaining battery charge of the first unmanned aerial vehicle during flight; Acquire loudspeaker information of the loudspeaker device of the first unmanned aerial vehicle; In response to the charging information, the second unmanned aerial vehicle is caused to start a flight operation to fly to a handover position to take over the loudspeaker operation of the first unmanned aerial vehicle; In the target area, instead of the loudspeaker operation of the first unmanned aerial vehicle during flight, control is performed to start the loudspeaker operation of the second unmanned aerial vehicle based on the loudspeaker information; the control unit, while the first unmanned aerial vehicle is amplifying the audio content, causes the second unmanned aerial vehicle to fly to the handover position and become substantially parallel to the first unmanned aerial vehicle, to end the amplifying operation of the audio content in the first unmanned aerial vehicle, and causes the second unmanned aerial vehicle to start the amplifying operation of the audio content from a playback position adjacent to the position where the first unmanned aerial vehicle ended the amplifying operation of the audio content; Public address system.

2. The audio content is divided into two or more blocks based on a time division position, The control unit causes the first unmanned aerial vehicle to end the amplified operation at the division position that exists after the block of the audio content being amplified when the second unmanned aerial vehicle is in a state of running approximately parallel to the first unmanned aerial vehicle, and causes the second unmanned aerial vehicle to start the amplified operation of the audio content from the block following the division position.

2. The public address system of claim 1.

3. The control unit causes the first unmanned aerial vehicle to end the amplification operation at the end point of the audio content being amplified, and causes the second unmanned aerial vehicle to return to the beginning of the audio content and start the amplification operation of the audio content.

2. The public address system of claim 1.

4. The control unit controls the first unmanned aerial vehicle to hover when the flight operation is initiated, and controls the second unmanned aerial vehicle to hover when the second unmanned aerial vehicle flies to the handover position, so that the first unmanned aerial vehicle and the second unmanned aerial vehicle both hover and fly approximately side by side.

2. The public address system of claim 1.

5. The loudspeaker information includes information regarding the playback position. A sound reinforcement system according to any one of claims 1 to 4.

6. The control unit returns the first unmanned aerial vehicle from the target area to a waiting location after the second unmanned aerial vehicle starts a loudspeaking operation. A sound reinforcement system according to any one of claims 1 to 5.

7. The charging information is the remaining battery charge or a flight time limit of the first unmanned aerial vehicle correlated with the remaining battery charge. A sound reinforcement system according to any one of claims 1 to 6.

8. An air vehicle system including a first unmanned air vehicle and a second unmanned air vehicle, The first unmanned aerial vehicle and the second unmanned aerial vehicle each include: A battery; a loudspeaker that performs a loudspeaking operation to louden audio content; A communication device capable of communicating with another unmanned aerial vehicle; A control device for controlling the flight operation and the loudspeaker operation; Equipped with The second unmanned aerial vehicle is In a target area, in response to charging information indicating a remaining charge of the battery of the first unmanned aerial vehicle during flight, a flight operation is started to fly to a handover position for taking over the loudspeaker operation of the first unmanned aerial vehicle; receiving loudspeaker information from a loudspeaker device of the first unmanned aerial vehicle; In the target area, instead of the loudspeaker operation of the first unmanned aerial vehicle during flight, a loudspeaker operation is started based on the loudspeaker information; the second unmanned aerial vehicle flies to the handover position while the first unmanned aerial vehicle is amplifying the audio content and becomes in a state of running substantially parallel to the first unmanned aerial vehicle, and then, after the first unmanned aerial vehicle has finished amplifying the audio content, the second unmanned aerial vehicle starts amplifying the audio content from a playback position adjacent to the position where the first unmanned aerial vehicle finished amplifying the audio content; Aircraft system.

9. A method for amplifying audio content in a target area by controlling a first unmanned aerial vehicle and a second unmanned aerial vehicle each having a public address device, the method comprising: Obtaining charging information indicating a remaining battery charge of the first unmanned aerial vehicle during flight; Acquire loudspeaker information of the loudspeaker device of the first unmanned aerial vehicle; In response to the charging information, the second unmanned aerial vehicle is caused to start a flight operation to fly to a handover position to take over the loudspeaker operation of the first unmanned aerial vehicle; In the target area, starting a loudspeaker operation of the second unmanned aerial vehicle based on the loudspeaker information instead of the loudspeaker operation of the first unmanned aerial vehicle during flight, The method for amplifying the audio content includes having the second unmanned aerial vehicle start the amplification operation of the audio content after the second unmanned aerial vehicle flies to the handover position and becomes approximately parallel to the first unmanned aerial vehicle while the first unmanned aerial vehicle is amplifying the audio content, and having the first unmanned aerial vehicle start the amplification operation of the audio content from a playback position adjacent to the position where the first unmanned aerial vehicle ended the amplification operation of the audio content.

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