Mobile body and method for controlling movement

Abstract

To enhance the precision in alignment.SOLUTION: A mobile body according an embodiment of the present disclosure includes: a communication unit that wirelessly communicates with an external apparatus; an acquisition unit that acquires, through communication with the external apparatus, a communication connection relationship with a communication network, which includes the external apparatus and other communication apparatuses; and a movement control unit that, on the basis of the communication connection relationship, determines a first direction, in which the moving body will move, and that causes the mobile body to move in the first direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a moving object and a movement control method. [Background Art]

[0002] Conventionally, there exists a technique for supplying power to a moving object underwater such as in the sea (for example, Patent Document 1). Patent Document 1 discloses that a moving object is supplied with power at a power feeding station (charging device) located underwater.

[0003] There is also a technique in which a moving object moves to a power feeding station for power supply (for example, Patent Document 2). Patent Document 2 discloses that a moving object lands on a charging station by using an image acquired by a camera. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2018-191474 [Patent Document 2] Japanese Unexamined Patent Publication No. 2021-172318 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] However, when a camera is used to move to a destination such as a power feeding station, positioning becomes difficult in the case of poor visibility. For example, in the sea, depending on the depth, the water may be dark even during the daytime, may be turbid, or may be blocked by seaweed or the like; in the air, the amount of external light varies depending on the time of day; and a mark may become difficult to see due to aging degradation. Thus, the technique is susceptible to environmental factors, and there is a problem in positioning accuracy such as landing accuracy.

[0006] Non-limiting embodiments of the present disclosure contribute to providing a moving object and a movement control method capable of improving positioning accuracy. [Means for solving the problem]

[0007] A mobile body according to one embodiment of the present disclosure comprises a communication unit that performs wireless communication with an external device, an acquisition unit that acquires a communication connection relationship of a communication network including the external device and other communication devices through communication with the external device, and a movement control unit that determines a first direction in which the mobile body moves based on the communication connection relationship and moves the mobile body in the first direction.

[0008] A motion control method according to one embodiment of the present disclosure involves a mobile body communicating wirelessly with an external device, acquiring a communication connection relationship of a communication network including the external device and other communication devices through communication with the external device, determining the direction in which the mobile body will move based on the communication connection relationship, and moving the mobile body in that direction.

[0009] These comprehensive or specific embodiments may be implemented as systems, devices, methods, integrated circuits, computer programs, or recording media, or as any combination of systems, devices, methods, integrated circuits, computer programs, and recording media. [Effects of the Invention]

[0010] According to one embodiment of the present disclosure, the direction in which the moving object moves is determined based on the communication connection relationships of a communication network including external devices and other communication devices, and the moving object is controlled to move in the determined direction, thereby improving the accuracy of alignment.

[0011] Further advantages and effects of one embodiment of this disclosure will be made apparent from the specification and drawings. Such advantages and / or effects are provided by several embodiments and features described in the specification and drawings, but not all of them are necessarily provided in order to obtain one or more identical features. [Brief explanation of the drawing]

[0012] [Figure 1]Diagram showing a configuration example of a wireless power and data transmission system according to the first embodiment of the present disclosure [Figure 2] Diagram showing a hardware configuration example of an underwater drone according to the first embodiment of the present disclosure [Figure 3] Diagram showing a functional configuration example of a CPU of an underwater drone according to the first embodiment of the present disclosure [Figure 4] Flowchart showing an example of alignment according to the first embodiment of the present disclosure [Figure 5] Sequence diagram showing an example of tone map determination according to the first embodiment of the present disclosure [Figure 6] Diagram showing the correspondence between the distance between communication devices (distance between transmission and reception) and PHY rate (PHY rate profile) according to the first embodiment of the present disclosure [Figure 7] Diagram showing step S402 of FIG. 4 [Figure 8] Flowchart showing an example of alignment according to the first embodiment of the present disclosure [Figure 9] Diagram showing a situation where a parking apron for landing is determined based on topology information according to the first embodiment of the present disclosure [Figure 10] Diagram showing an example of a multi-hop network according to the first embodiment of the present disclosure [Figure 11] Flowchart showing an example of alignment according to the first embodiment of the present disclosure [Figure 12] Diagram showing that an underwater drone moves to connect directly under a terminal parking apron according to the first embodiment of the present disclosure [Figure 13A] Diagram showing an example of a multi-hop network according to the first embodiment of the present disclosure [Figure 13B] Diagram showing an example of a multi-hop network according to the first embodiment of the present disclosure [Figure 13C] Diagram showing an example of a multi-hop network according to the first embodiment of the present disclosure [Figure 14] Flowchart showing an operation example of an underwater drone according to the first embodiment of the present disclosure [Figure 15] Flowchart showing an operation example of an underwater drone according to the first embodiment of the present disclosure [Figure 16] Flowchart showing an example of operation of an underwater drone according to Embodiment 1 of the present disclosure [Figure 17A] Flowchart showing an example of operation of an underwater drone according to Embodiment 1 of the present disclosure [Figure 17B] Flowchart showing an example of operation of an underwater drone according to Embodiment 1 of the present disclosure [Figure 18] Diagram showing an example of the functional configuration of a CPU of an underwater drone according to Embodiment 2 of the present disclosure [Figure 19] Diagram showing PHY rate profiles for different communication media according to Embodiment 2 of the present disclosure [Figure 20] Flowchart showing an example of mode determination according to Embodiment 2 of the present disclosure [Figure 21] Flowchart showing an example of mode determination according to Embodiment 2 of the present disclosure [Figure 22] Flowchart showing an example of mode determination according to Embodiment 2 of the present disclosure [Figure 23] Flowchart showing an example of operation of a drone according to Embodiment 2 of the present disclosure Description of Embodiments

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with appropriate reference to the drawings. However, excessive detailed description may be omitted in some cases. For example, detailed description of already well-known matters and repeated description of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and facilitate understanding for those skilled in the art.

[0014] The accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims thereby.

[0015] (Embodiment 1) <Configuration of Wireless Power and Data Transmission System> Figure 1 shows an example configuration of a wireless power and data transmission system (or wireless power and data transmission network) 1 according to Embodiment 1 of this disclosure.

[0016] As shown in Figure 1, the wireless power and data transmission system 1 is deployed on the water (e.g., at sea) and underwater (e.g., in the sea). The wireless power and data transmission system 1 includes power supply and communication equipment 10, a parking area (which may also be called a charging (power supply) device, charging (power supply) station or station) 20, and an underwater drone 30.

[0017] The power supply and communication equipment 10 is installed, for example, inside a ship anchored at sea (one example being on the water). The power supply and communication equipment 10 is wired to the parking area 20 using communication lines (including power lines), etc. The power supply and communication equipment 10 communicates data with the parking area 20 and also supplies power to the parking area 20. The power supply and communication equipment 10 may also be referred to as the master unit, master (communication) device, etc., of the wireless power and data transmission system 1.

[0018] The parking area 20 has wireless power transmission and wireless communication functions. The parking area 20 communicates data with the power supply and communication equipment 10, and receives and supplies power transmitted from the power supply and communication equipment 10. In addition, the parking area 20 communicates data wirelessly with the underwater drone 30 and wirelessly transmits power to the underwater drone 30. There may be multiple parking areas 20, and the parking areas 20 may be connected to each other by wire or wireless. In this case, the power transmission and data communication between the parking areas 20 may be the same as the power transmission and data communication between the power supply and communication equipment 10 and the parking area 20, or between the parking area 20 and the underwater drone 30.

[0019] The underwater drone 30 acquires various data related to operations such as ocean exploration. The underwater drone 30 communicates data with the parking area 20 and receives and supplies power from the parking area 20. For example, the underwater drone 30 receives instructions from the power supply and communication equipment 10 via the parking area 20 and transmits data (images, etc.) acquired during operations, the charging status of the underwater drone 30, etc. to the power supply and communication equipment 10 via the parking area 20. The underwater drone 30 may also be called, for example, an autonomous underwater vehicle (AUV), a remotely operated vehicle (ROV), or an unmanned underwater vehicle (UUV). The underwater drone 30 may move on the water surface or move through the air. There may be multiple underwater drones 30. The underwater drone 30 is an example of a "mobile body" related to this disclosure.

[0020] The parking area 20 may also be realized by an underwater drone 30. In other words, the underwater drone 30 may function as the parking area 20.

[0021] [Underwater drone configuration] Figure 2 shows an example of the hardware configuration of the underwater drone 30 according to this embodiment.

[0022] As shown in Figure 2, the underwater drone 30 includes a central processing unit (CPU) 201, memory 202, user interface (UI) 203, drive system 204, GPS (Global Positioning System) receiver 205, camera 206, sensor 207, long-range antenna 208, long-range wireless communication circuit 209, short-range antenna 210, short-range wireless communication circuit 211, power receiving antenna 212, power receiving circuit 213, battery 214, and power supply circuit 215.

[0023] CPU201 controls the processing of each component and executes processes as described with reference to Figures 3 and 18, etc.

[0024] Memory 202 stores (saves, holds, stores) programs and data necessary for the operation of the underwater drone 30, data generated by the components of the underwater drone 30, data received by the underwater drone 30 from external devices, etc.

[0025] UI203 includes an input device that accepts commands for the underwater drone 30 and an output device that provides output such as sound.

[0026] The drive system 204 is a drive system for propelling the underwater drone 30. The drive system includes, for example, a propeller, a motor for rotating the propeller, and a battery that powers the motor. If the underwater drone 30 is also capable of moving through the air, the drive system may also include a propeller, a motor for rotating the propeller, and a battery that powers the motor.

[0027] The GPS receiver 205 receives radio waves from GPS satellites and uses the received radio waves to measure the position (e.g., latitude and longitude) of the underwater drone 30.

[0028] Camera 206 is, for example, a 360-degree camera capable of capturing images in the front, back, left, right, up, and down directions of the underwater drone 30.

[0029] Sensor 207 includes sensors for measuring the state of the underwater drone 30 (acceleration, velocity, etc.), sensors for measuring the state of the surrounding environment of the underwater drone 30, and sensors for measuring the state of the drive system 204 (sensors for measuring the state of the motor, sensors for measuring the state of the battery (including remaining charge), etc.). Sensors for measuring the state of the surrounding environment include moisture sensors, salinity sensors (salinity meter), pressure sensors, temperature sensors, humidity sensors, and illuminance sensors.

[0030] The long-range antenna 208 is an antenna for communication via mobile communication networks that support LTE (Long Term Evolution), NR (New Radio), etc.

[0031] The long-range wireless communication circuit 209 is a communication circuit that performs transmission and reception processing in order to send and receive signals via a mobile communication network compatible with LTE, NR, etc., and a long-range antenna 208.

[0032] The short-range antenna 210 is an antenna used to communicate with external devices such as the aforementioned master unit 10, parking area 20, and other underwater drones 30, which are located at a short distance, for example, with a transmission distance of 10m or less, using a frequency band such as 2MHz to 100MHz.

[0033] The short-range wireless communication circuit 211 is a communication circuit that performs transmission and reception processing in order to send and receive signals via the short-range antenna 210.

[0034] The power receiving antenna 212 is an antenna for receiving power from an external device located at a short distance.

[0035] The power receiving circuit 213 is a circuit that receives power via the power receiving antenna 212.

[0036] The battery 214 supplies power to each component of the underwater drone 30.

[0037] The power supply circuit 215 converts the power from the battery 214 into the output power required for each component of the underwater drone 30.

[0038] In this embodiment and other embodiments, the power supply coil and communication coil of the underwater drone 30 are located in close proximity to each other.

[0039] The underwater drone 30 communicates with an external device via a short-range antenna 210 and a short-range wireless communication circuit 211 (referred to as the short-range wireless unit). The external device may be a fixed device such as a parking area 20 or a fixed wireless communication device, or it may be a mobile device such as an aerial drone, another underwater drone, or a ship at sea. The short-range antenna 210 and the short-range wireless communication circuit 211 are examples of the "communication unit" as described herein.

[0040] The underwater drone 30 aligns, for example, with the parking area 20 and a vessel at sea for wireless power transfer and / or data communication. The underwater drone 30 aligns, for example, with a fixed wireless communication device for data communication. The underwater drone 30 aligns, for example, with an aerial drone and other underwater drones for multi-hop formation (topology formation).

[0041] Furthermore, the power supply and communication equipment 10 and the parking area 20 may have the same configuration as the underwater drone 30.

[0042] Figure 3 shows an example of the functional configuration of CPU201.

[0043] The CPU 201 includes a packet analysis unit 301, an authentication processing unit 302, a link cost calculation unit 303, a topology management unit 304, a packet generation unit 305, a measurement unit 306, a distance estimation unit 307, a transmission power determination unit 308, an AGC (Automatic Gain Control) value confirmation unit 309, and a movement control unit 310. The power supply and communication equipment 10 and the parking area 20 have the same functional configuration as the underwater drone 30. In the following, the power supply and communication equipment 10, the parking area 20, and the underwater drone 30 will be collectively referred to as the communication device.

[0044] CPU 201 receives H packets, authentication packets, and normal packets (for example, data acquired by the underwater drone 30). H packets are packets that are simultaneously transmitted from one communication device to all connected communication devices prior to the authentication process performed in the wireless power and data transmission network 1. Authentication packets are packets that are sent and received during the authentication process.

[0045] The packet analysis unit 301 analyzes the data structure of various incoming packets (H packets, authentication packets, and normal packets) to determine the type of packet and distributes the packet to its destination based on the determination result. For example, if the packet analysis unit 301 determines that the incoming packet is an H packet, it outputs the H packet to the link cost calculation unit 303. For example, if the packet analysis unit 301 determines that the incoming packet is an authentication packet, it outputs the authentication packet to the authentication processing unit 302. For example, if the packet analysis unit 301 determines that the incoming packet is a normal packet, it outputs the normal packet to the topology management unit 304.

[0046] The authentication processing unit 302 uses the authentication packet input from the packet analysis unit 301 to perform authentication processing with the communication device that sent the authentication packet. The authentication processing unit 302 outputs the authentication packet generated during the authentication processing, or the response to the authentication packet sent from another communication device, to the topology management unit 304.

[0047] The link cost calculation unit 303 uses the H packets input from the packet analysis unit 301 to calculate the link cost, which indicates the reception quality of the H packets received by the underwater drone 30 from the source communication device. The link cost calculation unit 303 writes (stores) the result of the link cost calculation into the data structure of the H packet. The H packet also stores the link cost values ​​for each case when the H packet is transmitted from the master unit 10. The link cost calculation unit 303 outputs the H packet containing the link cost calculation result to the topology management unit 304.

[0048] The topology management unit 304 manages (acquires) topology information indicating the topology generated by the master unit 10 (i.e., the communication devices constituting the wireless power and data transmission network 1 and their connection configurations), and distributes and outputs various packets to their respective output destinations (e.g., the packet generation unit 305) based on the topology information. The topology information is stored in the topology management unit 304 or memory 202 of each communication device. The topology management unit 304 of the master unit 10 generates (forms) a topology based on the link cost calculated by the link cost calculation unit 303 of the master unit 10 in response to H packets transmitted from each of the one or more communication devices subject to authentication processing, and provides the topology information indicating the topology to other communication devices. The topology management unit 304 is an example of an "acquisition unit" as described herein.

[0049] The packet generation unit 305 generates and outputs data communication packets to other communication devices that will be the destination, or H packets for authentication processing, based on the authentication packets or normal packets input from the topology management unit 304.

[0050] The measurement unit 306 uses transmission path estimation technology to perform transmission path estimation with the communication partner (acquiring (calculating) an index value or transmission path characteristics that indicate the transmission path characteristics) and measures (calculates and acquires) the physical layer communication speed (also called PHY speed) with the communication partner. The measurement unit 306 is an example of an "index acquisition unit" or "index calculation unit" related to this disclosure.

[0051] The distance estimation unit 307 estimates the distance to the communication partner based on the correspondence between the distance between communication devices (distance between transmission and reception) and the PHY speed (transmission path characteristics) (referred to as the PHY speed profile or simply the profile), and the PHY speed of the communication partner.

[0052] The transmission power determination unit 308 determines and sets the transmission power to send signals (packets) to the communication partner.

[0053] The AGC value confirmation unit 309 confirms the AGC value adjusted by the AGC circuit (not shown). The AGC circuit sets an appropriate amplification level according to the power of the received signal, for example.

[0054] The movement control unit 310 controls the drive system 204 to move the underwater drone 30 to a certain position or in a certain direction, or to stop the underwater drone 30 at a certain position, thereby moving the underwater drone 30 to a certain position or in a certain direction. For example, the movement control unit 310 controls the drive system 204 as described above to move or stop the underwater drone 30 based on topology information acquired by the topology management unit 304, the PHY speed acquired by the measurement unit 306, etc.

[0055] <Operation of Wireless Power and Data Transmission Systems> Next, we will describe the common operation of the power supply and communication equipment 10, the parking area 20, and the underwater drone 30. The following explanation will use the underwater drone 30 as an example, but the power supply and communication equipment 10 and the parking area 20 can also perform similar operations.

[0056] [Authentication process] This section describes an example of the authentication process performed between communication devices (authentication between the master unit 10 and the parking area 20 or underwater drone 30). This authentication process is mainly performed by the respective authentication processing units 302. As a prerequisite, the master unit 10 sends an H packet to the parking area 20 or underwater drone 30, and the parking area 20 or underwater drone 30 receives the H packet sent from the master unit 10. In the following explanation, the underwater drone 30 will be used as an example, but the parking area 20 can perform the same operation.

[0057] The underwater drone 30 issues an authentication packet containing a participation request frame to the master unit (master unit 10) of the network it wishes to join (for example, wireless power and data transmission network 1) and transmits it to the master unit 10. When the master unit 10 receives the authentication packet transmitted from the underwater drone 30, it sets a predetermined text string to generate an authentication packet and transmits it to the requesting underwater drone 30 (the underwater drone 30 that issued the authentication packet).

[0058] The underwater drone 30 encodes a predetermined text sequence contained in the authentication packet transmitted from the master unit 10 using a unique key that the underwater drone 30 has previously stored in memory 202 or the like, generates an authentication packet containing the encoded text sequence, and transmits it to the master unit 10.

[0059] When the master unit 10 receives an authentication packet transmitted from the underwater drone 30, it decodes the encoded text sequence contained in the authentication packet using a unique key that has been pre-configured and stored in memory 202 or elsewhere. The master unit 10 also determines whether the decoded text sequence matches a predetermined text sequence configured as described above. If the master unit 10 determines that the decoded text sequence matches a predetermined text sequence (i.e., it determines that participation in the wireless power and data transmission network 1 should be permitted), it encodes the network key specific to the wireless power and data transmission network 1 using the unique key and transmits it to the underwater drone 30.

[0060] The underwater drone 30 decodes the encoded network key transmitted from the master unit 10 using its unique key to obtain the network key. By obtaining this network key, the underwater drone 30 is officially authenticated as a data communication destination for the master unit 10. When communicating data within the network (wireless power / data transmission network 1), the underwater drone 30 performs data communication by encoding or decoding using the network key.

[0061] The authentication process is based on a 4-way handshake as defined in the HD-PLC (High Definition Power Line Communication) standard, for example. However, the authentication process may be based on other methods besides the aforementioned standard. For example, the authentication process may be based on methods such as G.hn (Gigabit Home Networking), a unified standard for wired high-speed network communication technology, or Home Plug (Home Plug Power Line Alliance), an industry association for power line communication.

[0062] [Topology generation (multi-hop formation) processing and multi-hop transmission] Next, topology generation and multi-hop transmission between the master unit 10, the parking area 20, and the underwater drone 30 will be described.

[0063] The master unit 10 simultaneously transmits an H packet to all communication devices. Let's assume that only the parking area 20 receives the H packet from this broadcast. Then, the authentication process described above is performed between the master unit 10 and the parking area 20. This enables power transmission and data communication between the master unit 10 and the parking area 20.

[0064] Next, the parking area 20 broadcasts H packets to other communication devices simultaneously. If any communication device receives an H packet in response to this broadcast, the authentication process described above is performed between that communication device and the master unit 10 via the parking area 20. As a result, data communication between that communication device and the master unit 10 via the parking area 20 becomes possible, and power transmission between the parking area 20 and that communication device becomes possible. The same process is performed for that communication device.

[0065] Now, let's assume that the underwater drone 30 approaches the communication device. The communication device then transmits an H packet to the underwater drone 30. Let's assume that the underwater drone 30 receives the H packet. Then, the authentication process described above is performed between the underwater drone 30 and the parking area 20 via the communication device and the parking area 20. As a result, data communication between the underwater drone 30 and the master unit 10 via the communication device and the parking area 20 becomes possible, and power transmission between the communication device and the master unit becomes possible.

[0066] [First alignment example] As described above, the underwater drone 30 uses functions such as the GPS receiver 205 and sensors 207 to determine the direction and distance from the starting point and move toward the destination. The underwater drone 30 is also equipped with a mobile communication module (long-range antenna 208, long-range wireless communication circuit 209), and when it comes out of the water, it can communicate two-way with control signals, communicate using lateral waves that travel directly across the water surface, or determine its position via the GPS receiver 205. The underwater drone 30 can use the camera 206 to determine the landing site, and after landing at the landing site, it can be wirelessly charged at the parking area and send and receive data via two-way communication. In this specification, reaching the underwater destination is referred to as landing, and leaving the underwater destination is referred to as takeoff.

[0067] However, when attempting to land at a destination using GPS, sensors, cameras, etc., as mentioned earlier, there is a risk that the drone may not be able to land in the optimal location due to accuracy issues. In such cases, for example, when landing for charging, the charging efficiency via wireless power transmission will decrease. For example, if the underwater drone 30 is to land on a roughly circular parking area, it is desirable for the underwater drone 30 to land near the center of the parking area because the communication speed is faster and the charging efficiency is higher the closer it is to the center (because the power supply coil and communication coil are located close together).

[0068] Generally, when two communication devices communicate wirelessly over short distances, the attenuation of the transmission path increases as the distance between the devices (transmitter-receiver distance) increases, resulting in a slower communication speed. Underwater, attenuation with respect to distance is greater than in air, and in the ocean, attenuation with respect to distance tends to be even greater. In such cases, wireless communication using the air at the landing site is difficult. Therefore, the underwater drone 30 approaches the landing site to some extent using, for example, a GPS receiver 205 and sensors 207, and then uses a camera 206 to confirm the landing site. Subsequently, in the first alignment example, transmission path estimation technology and physical layer communication speed (PHY speed) are used to improve accuracy.

[0069] Figure 4 is a flowchart showing an example of alignment according to this embodiment. This alignment may be performed, for example, for wireless power transfer and / or data communication.

[0070] When the underwater drone 30 approaches the landing site (parking area 20), in step S401, the authentication processing unit 302 of the underwater drone 30 performs the authentication process described above with the master unit 10 (via the parking area 20).

[0071] If authentication is successful, in step S402, the underwater drone 30 moves horizontally under the control of the movement control unit 310, and the measurement unit 306 of the underwater drone 30 performs transmission path estimation at multiple points and measures the PHY speed. For example, the multiple points may be five points consisting of the point where the authentication process was performed and the vertices of an arbitrary square with a predetermined side length, with the said point as the centroid. However, it is not limited to this. Transmission path estimation and PHY speed measurement will be described later.

[0072] In step S403, the underwater drone 30, under the control of the movement control unit 310, moves to the point among several points where the PHY speed is fastest (referred to as the maximum PHY speed point), and then descends a predetermined distance (e.g., 10 cm) from there.

[0073] The underwater drone 30 will then land at the parking area 20 by repeatedly performing steps S402 and S403. The number of repetitions may be predetermined, or the repetitions may continue until the distance to the parking area 20 is less than or equal to a predetermined value. Alternatively, the underwater drone 30 may stop the repetitions if the PHY speed at the current location exceeds a threshold. Multiple locations may also be set so that the length of the sides of the square decreases with each repetition. After that, the underwater drone 30 may remain at the position after the repetition, or it may descend from that position to the parking area 20.

[0074] [[Transmission path estimation technology]] A (transmission) tone map created by transmission path estimation is shared between communication devices. Here, the tone map sets the optimal modulation level for each OFDM (Orthogonal Frequency Division Multiplexing) subcarrier (for example, modulation level 5: 32PAM (Pulse Amplitude Modulation), modulation level 4: 16PAM, modulation level 3: 8PAM, modulation level 2: 4PAM, modulation level 1: 2PAM, modulation level 0: none; the noise level becomes relatively larger relative to the signal level as the modulation level decreases), and communication is performed by optimizing the amount of information for each carrier according to the signal-to-noise ratio (SNR). For example, the tone map may be a table that associates OFDM subcarriers with modulation levels. If we assume that the modulation level is set in 5 stages, for example, for each of the 360 ​​transmitting and receiving carriers, then a huge number (5 to the power of 360) key patterns can be constructed, and a tone map is selected from among them. In this way, the tone map depends on the state of the transmission path and is almost always different for each transmission path, making eavesdropping within the network difficult.

[0075] Figure 5 is a sequence diagram showing an example of tone map determination according to this embodiment.

[0076] In step S501, the transmitting terminal (one communication device) sends a training packet to the receiving terminal (the other communication device).

[0077] In step S502, the receiving terminal uses the received training packets to obtain the signal-to-noise ratio characteristics and perform transmission path characteristics evaluation.

[0078] In step S503, the receiving terminal determines (creates) the tone map.

[0079] In step S504, the receiving terminal notifies (sends) the determined tone map to the transmitting terminal.

[0080] Subsequently, the transmitting terminal sends data to the receiving terminal based on the tone map (step S505). This transmission allows for high-speed transmission suited to the transmission path. The receiving terminal then returns a response (step S506). This transmission and reception process may be repeated further.

[0081] In the example above, training packets were used to create a tone map, but regular data packets used in normal communication can be used instead of training packets.

[0082] The transmitting terminal and the receiving terminal may be either an external device including the parking area 20 or the underwater drone 30. For example, in the flow shown in Figure 4, if the transmitting terminal is an external device, the receiving terminal is the underwater drone 30, and if the transmitting terminal is the underwater drone 30, the receiving terminal is an external device. Therefore, in this embodiment and other embodiments, the mobile body such as the underwater drone 30 may measure the PHY speed based on the transmission path estimation result, as described below, by receiving (acquiring) the transmission path estimation result (transmission path characteristics such as a tone map) transmitted to the mobile body such as the underwater drone 30 by the external device performing transmission path estimation.

[0083] The signal-to-noise ratio, tone map, and PHY speed of each subcarrier are examples of "indicator values ​​showing transmission path characteristics" or "transmission path characteristics" related to this disclosure, which are calculated or obtained from the transmission and reception of signals with external devices.

[0084] In this embodiment and other embodiments, the trigger for transmission path estimation may be when a mobile body such as the underwater drone 30 determines, based on GPS location information, that it is located near the destination (external device) (e.g., above or directly below it), or when it determines, based on camera images, that it is located near the destination (external device) (e.g., above or directly below it). Additionally or alternatively, the trigger for transmission path estimation may be when a mobile body such as the underwater drone 30 receives or transmits a predetermined signal. The predetermined signal may be, for example, a signal notifying the completion of the authentication process described above. Furthermore, the predetermined signal may be received or transmitted periodically (e.g., once every few seconds), or it may be started after determining, based on GPS location information, camera images, etc., that the mobile body is located near the destination (external device) (e.g., above or directly below it).

[0085] [[Relationship between transmission / reception distance and PHY speed]] The modulation levels included in the tone map described above are associated with the PHY speed. This association between modulation levels and PHY speed is pre-stored in the memory 202 of the underwater drone 30. Therefore, the measurement unit 306 of the underwater drone 30 can measure the PHY speed based on the acquired tone map and the association.

[0086] Figure 6 shows the correspondence between the distance between communication devices (transmitter-to-receiver distance) and the PHY speed. Such correspondences are also pre-stored in the memory 202 of the underwater drone 30. As described above and as shown in the figure, as the transmitter-to-receiver distance increases, the attenuation of the transmission path increases, and the communication speed slows down. The distance estimation unit 307 of the underwater drone 30 can estimate the transmitter-to-receiver distance based on the measured PHY speed and the correspondence.

[0087] As a result, the underwater drone 30 can land at the parking area 20 by estimating the distance between the transmitter and receiver (distance to the parking area 20) from the PHY speed.

[0088] Figure 7 shows step S402 in Figure 4.

[0089] When the underwater drone 30 approaches the parking area 20, it first performs an authentication process with the master unit 10 at point T1.

[0090] Upon successful authentication, the underwater drone 30 performs transmission path estimation at points T1 to T5 and measures the PHY speed. If the PHY speeds are arranged in descending order, for example, point T3, point T1, point T4, point T2, and point T5.

[0091] The underwater drone 30 moves to point T3, where it has the maximum PHY velocity, and then descends a predetermined distance from there.

[0092] As described above, authentication processing begins as the drone approaches the landing site, and landing guidance is provided. Therefore, in this example, the underwater drone 30 will move to the point of maximum PHY speed close to the center of the parking area 20, enabling highly accurate landing. Furthermore, because it lands near the center, it is possible to charge it with high efficiency.

[0093] [Second alignment example] As shown on the left side (flat area F) of Figure 6, if the underwater drone 30 and the parking area 20 are too close together, in step S402 of Figure 4, the PHY speed measured at multiple points may saturate and show values ​​close to the upper limit, which may not lead to improved accuracy. Therefore, in order to prevent saturation of the PHY speed obtained from transmission path estimation at multiple points, the underwater drone 30 may perform power control if it is determined that the transmission power is large while checking the AGC value, etc.

[0094] By checking the AGC value, it is possible to understand the degree of attenuation occurring in the transmission path. A large AGC value means that the amplification is large due to high transmission path attenuation. In such an environment, the power of the received signal is small enough that it needs to be amplified significantly, meaning that the distance between the sender and receiver becomes longer. For example, the greater the transmission path attenuation, the larger the AGC value needs to be to increase the amplification and amplify the signal. On the other hand, a small AGC value (i.e., there is no need for significant amplification) suggests that the power of the received signal is large.

[0095] Therefore, in this example, when the AGC value decreases (in other words, when the power of the received signal is high), the transmission power is controlled to decrease, and the transmission path attenuation is increased relatively. This changes the scale of the horizontal axis shown in Figure 6, allowing the evaluation to be changed from using the left side of Figure 6 (flat portion F) to using the right side of Figure 6 (sloping portion S). This makes it possible to perform highly accurate measurements even when the distance between transmission and reception is shortened.

[0096] Figure 8 is a flowchart showing an example of alignment according to this embodiment. This alignment may be performed, for example, for wireless power supply and / or data communication.

[0097] Step S801 is the same as step S401 in Figure 4.

[0098] If authentication is successful, in step S802, the AGC value verification unit 309 of the underwater drone 30 determines whether or not the AGC value is below a threshold.

[0099] If the AGC value is not below the threshold (NO in step S802), the flow proceeds to step S804.

[0100] If the AGC value is below a threshold (YES in step S803), in step S803, the transmission power determination unit 308 of the underwater drone 30 determines and sets the transmission power to reduce the set transmission power. For example, the transmission power determination unit 308 determines and sets the transmission power to a value such as half or a quarter of the original transmission power.

[0101] Steps S804 and S805 are the same as steps S402 and S403 in Figure 4, respectively.

[0102] The underwater drone 30 will then land at the parking area 20 by repeatedly performing steps S802 to S805. The number of repetitions may be predetermined, or the repetitions may continue until the distance to the parking area 20 is less than or equal to a predetermined value. Alternatively, the underwater drone 30 may stop the repetitions if the PHY speed at the current location exceeds a threshold. Multiple locations may also be set so that the length of the sides of the square decreases with each repetition. After that, the underwater drone 30 may remain at the position after the repetition, or it may descend from that position to the parking area 20.

[0103] Thus, before performing transmission path estimation at multiple locations, the underwater drone 30 may check the AGC value and determine the transmission power (for example, if the AGC value is below a threshold, it may decide to reduce the transmission power to half or a quarter of the original value, and otherwise, it may decide to keep the transmission power at the original value), and then perform transmission path estimation at multiple locations using the determined transmission power.

[0104] In this way, by checking the AGC value, the saturation of the PHY velocity is suppressed. Therefore, according to this example, the underwater drone 30 can perform a more precise landing.

[0105] Furthermore, if it is confirmed that the PHY speed of the underwater drone 30 is saturated, it may reduce the transmission power and retransmit the signal, as described above, to calculate or obtain an index value indicating the transmission path characteristics. In this case, the position where the signal was first transmitted (the position where it was confirmed that the PHY speed was saturated) and the position where the signal was retransmitted may be the same or different.

[0106] [Third alignment example] Parking area 20 can also support wired communication by connecting wired lines (control lines, etc.) to another parking area 20 in addition to the antenna. Furthermore, it is possible to realize such a hybrid terminal that utilizes both wired and wireless communication using a single communication method (for example, LSI (Large Scale Integration)).

[0107] In a wireless power and data transmission network 1 where such parking areas 20 exist, the underwater drone 30 can determine a parking area to land on based on the topology information of the network and move toward that parking area. Therefore, this alignment may be performed for the purpose of forming a multi-hop.

[0108] Figure 9 shows the situation in which a parking area for landing is determined based on topology information according to this embodiment.

[0109] The wireless power and data transmission network 1 includes a master unit 10, parking areas 20A to 20C, and underwater drones 30A to 30C. The master unit 10 and parking areas 20A to 20C are connected by wire, parking area 20A and underwater drone 30A are connected wirelessly, and parking area 20C and underwater drone 30C are connected wirelessly.

[0110] In this situation, the underwater drone 30B moves near the underwater drone 30A, performs authentication processing with the master unit 10 via the underwater drone 30A, and is deemed to have joined the wireless power and data transmission network 1.

[0111] After joining the network via the short-range wireless unit (after successful authentication), the underwater drone 30B can request topology information (an example of a communication connection relationship related to this disclosure) from the master unit 10 (by transmitting a signal requesting topology information (also called a topology information request)), and receive (acquire) the topology information transmitted from the master unit 10 as a response. Alternatively, if the parking area 20A or the underwater drone 30A holds topology information, the parking area 20A or the underwater drone 30A may transmit the topology information to the underwater drone 30B.

[0112] The topology information may include, for example, the master unit 10 (its identification information (ID)), the parking area 20 (its ID), the connection relationship between the master unit 10 and the parking area 20, the connection relationship between the parking areas 20, and the connection position of the underwater drone 30 (for example, the parking area 20 (its ID)). Alternatively, the topology information may be, for example, the above excluding the connection position of the underwater drone 30.

[0113] In this embodiment and other embodiments, the trigger for acquiring topology information may be when a mobile body such as the underwater drone 30 determines, based on GPS location information, that it is located near the destination (external device) (e.g., above or directly below it), or when it determines, based on camera images, that it is located near the destination (external device) (e.g., above or directly below it). Additionally or alternatively, the trigger for acquiring topology information may be when a mobile body such as the underwater drone 30 receives or transmits a predetermined signal. The predetermined signal may be, for example, a signal notifying the completion of the authentication process described above or a signal requesting topology information. Furthermore, the predetermined signal may be received or transmitted periodically (e.g., once every few seconds), or it may be started after determining, based on GPS location information, camera images, etc., that the mobile body is located near the destination (external device) (e.g., above or directly below it).

[0114] In this way, by acquiring topology information, the underwater drone 30B can confirm that no other underwater drones (communication devices) are connected to parking area 20B. Therefore, it can decide on parking area 20B as the parking area to land on and move towards parking area 20B based on camera images, etc.

[0115] In this embodiment and other embodiments, authentication processing is not required for the underwater drone 30B to acquire topology information. For example, the master unit 10, parking areas 20A to 20C, and other parking areas 30A and 30C may periodically transmit topology information like beacons, and the underwater drone 30B may receive that topology information.

[0116] The above-described example of underwater positioning may also be applied to aerial drones (aerial drones) and parking areas located on land. In this case, once a desired parking area is found, the aerial drone can move towards the parking area based on GPS location information, camera images, etc. Alternatively, the above-described example of underwater positioning may also be applied to aerial drones and stations that only have wireless data transmission capabilities. Examples of such stations include those used for loading and unloading cargo.

[0117] [Fourth alignment example] Underwater drones are expected to perform tasks (such as ocean exploration) in work areas underwater (e.g., on the seabed). In such cases, it is useful to connect a master unit and a parking area or the underwater drone (which may also be called a slave unit) via a multi-hop network to comprehensively cover the work area where the underwater drone operates, so that the drone can transmit data or be charged as needed. When constructing such a network (forming a multi-hop network), it is desirable that the parking area or the underwater drone be properly aligned with other communication devices to cover a wide area of ​​the work area.

[0118] Figure 10 shows an example of a multi-hop network 100 according to this embodiment.

[0119] The multi-hop network 100 has a multi-hop topology with 5 hops. In the multi-hop network 100, there is a parking area 20 (realized by, for example, an underwater drone 30_0) below the master unit 10, an underwater drone 30_1 is located below (for example, directly below) the underwater drone 30_0, an underwater drone 30_2 is located below (for example, directly below) the underwater drone 30_1, an underwater drone 30_3 is located below (for example, directly below) the underwater drone 30_2, and underwater drones 30_4 and 30_5 are deployed laterally from underwater drone 30_3 along the work area WA. With respect to the work area WA, the underwater drones may be deployed and arranged in a planar manner in the lateral direction.

[0120] In the fourth alignment example, the operation is the reverse of landing at the parking area. The underwater drone first moves downwards as if taking off from the parking area, performing transmission path estimation and measuring the PHY speed. Alternatively, the underwater drone may move horizontally while performing transmission path estimation and measuring the PHY speed at multiple points to determine whether it is moving directly downwards. Multiple underwater drones repeat the same operation, treating a fixed underwater drone as a parking area, thereby determining their placement (a network is established). Note that movement to predetermined approximate locations may be performed using cameras.

[0121] Figure 11 is a flowchart illustrating an example of alignment according to this embodiment. This alignment may be performed, for example, to form a multi-hop network. In this example, a topology is formed in which drones are connected in a column, and the next underwater drone (referred to as the target drone) is connected to the last underwater drone (referred to as the target drone). It is assumed that multiple underwater drones are already connected in a column and that a topology has been formed.

[0122] In step S1101, the authentication processing unit 302 of the target drone performs authentication processing with the master unit 10 and joins the network (for example, the wireless power and data transmission network 1).

[0123] In step S1102, the target drone, while confirming the topology indicated by the topology information obtained by transmitting topology information requests as appropriate via the short-range wireless unit (or by periodically receiving topology information) (by the topology management unit 304), descends directly below under the control of the movement control unit 310 and connects to the target drone.

[0124] In step S1103, the target drone moves further downward under the control of the movement control unit 310.

[0125] In step S1104, the target drone performs transmission path estimation using the measurement unit 306, measures the PHY speed, and confirms that the PHY speed is below a threshold α (e.g., 40 Mbps), and then stops under the control of the movement control unit 310.

[0126] In step S1105, the target drone moves horizontally by a predetermined distance at a time, starting from the point where it stopped in step S1104, under the control of the movement control unit 310. At a predetermined number of points, the measurement unit 306 performs transmission path estimation and measures the PHY speed. For example, the points may be four points that are the four vertices of an arbitrary square with the point where it stopped in step S1104 as its center of gravity and diagonals that are twice the length of a predetermined distance.

[0127] In step S1106, the target drone moves to the point with the fastest PHY speed among several points (the point with the highest PHY speed) under the control of the movement control unit 310.

[0128] In step S1107, the target drone moves horizontally by a predetermined distance at a time, starting from the point where it moved (stopped) in step S1106, under the control of the movement control unit 310. At one or more points, the measurement unit 306 performs transmission path estimation and measures the PHY speed, until the relative difference (absolute value of the difference) between the maximum PHY speed and the maximum PHY speed measured in step S1105 is less than or equal to a threshold β (for example, 20 Mbps).

[0129] In step S1108, the target drone, under the control of the movement control unit 310, descends from the point of maximum PHY speed where the relative difference is below a threshold to a point where the PHY speed is below a threshold α, while measuring the PHY speed using the measurement unit 306.

[0130] Furthermore, the predetermined distance in steps S1105 and S1107 may be set to decrease in stages according to the maximum PHY speed. For example, the predetermined distance may initially be set to a first value such as 1m, and when the maximum PHY speed exceeds a threshold γ (e.g., 80Mbps), the predetermined distance may be set to a second value smaller than the first value, such as 0.5m.

[0131] In this way, the target drone can move almost directly beneath the target drone, expanding the area covered by the network.

[0132] In this example, the network is expanded vertically, but it is also possible to expand the network horizontally in a similar manner.

[0133] Figure 12 shows that the target drone, the underwater drone 30, moves to connect directly below the terminal target drone, the parking area 20B, in order to expand the network.

[0134] Figures 12(A) and (B) correspond to steps S1102 and S1103 in Figure 11, showing that the underwater drone 30 descends while confirming the topology and changes from connecting to parking area 20A to connecting to parking area 20B.

[0135] Figure 12(B) corresponds to step S1104 in Figure 11, and shows that the underwater drone 30 stopped after confirming that the PHY speed between it and the parking area 20B was α or less.

[0136] Figure 12(C) corresponds to steps S1105 to S1108 in Figure 11, showing that the underwater drone 30 is located directly below the parking area 20B.

[0137] Figure 12(D) corresponds to step S1108 in Figure 11 and shows that there is a certain distance between the underwater drone 30 and the parking area 20B.

[0138] The following describes some examples of multi-hop networks.

[0139] Figure 13A shows an example of a multi-hop network 130A having a multi-hop topology with 3 hops.

[0140] In the multi-hop network 130A, a parking area 20 (for example, implemented by an underwater drone 30_0) exists below the master unit 10, and an underwater drone 30_3 is wired to the underwater drone 30_0 (for example, directly below it). The wired connection extends to the vicinity of the work area WA. Underwater drones 30_4 and 30_5 are deployed laterally from underwater drone 30_3 along the work area WA and are wirelessly connected to underwater drone 30_3. Note that underwater drones 30_3, 30_4, and 30_5 may also be wired to each other (all communication devices may be wired to each other). Furthermore, in order to cover a wide area of ​​the work area with a small number of hops, the parking area 20 is preferably located near the center of the work area WA.

[0141] Figure 13B shows an example of a multi-hop network 130B having a multi-hop topology with 2 hops.

[0142] In the multi-hop network 130B, a parking area 20A (implemented, for example, by an underwater drone 30_0) exists below the master unit 10, and a parking area 20B is connected by wire to the underwater drone 30_0 (for example, directly below it). In addition, parking areas 20C and 20D are deployed laterally from parking area 20B along the work area WA and are connected to parking area 20B by wire.

[0143] Thus, in the multi-hop network 130B, the number of parking spaces is increased, and each parking space is equipped with a unique underwater drone. For example, underwater drone 30_3 lands at parking space 20B, underwater drone 30_4 lands at parking space 20C, and underwater drone 30_4 lands at parking space 20D. The connections between parking spaces may be wireless connections using multi-hop technology.

[0144] Figure 13C shows an example of a multi-hop network 130C having a multi-hop topology with 2 hops.

[0145] The multi-hop network 130C is similar to the multi-hop network 120B, but differs in that one or more predetermined underwater drones land at each parking area. For example, underwater drone 30_3 or underwater drone 30_6 land at parking area 20B, underwater drone 30_4 or underwater drone 30_7 land at parking area 20C, and underwater drone 30_4 or underwater drone 30_8 land at parking area 20D. The number of underwater drones that can land at each parking area may be the same or different.

[0146] [Example of operation] Figure 14 is a flowchart showing an example of the operation of the underwater drone 30 according to this embodiment.

[0147] In step S1401, the underwater drone 30 initiates short-range communication with other nearby communication devices participating in the wireless power and data transmission network 1 via its short-range radio unit.

[0148] In step S1402, the authentication processing unit 302 of the underwater drone 30 performs an authentication process with the master unit 10 to determine whether or not the authentication was successful.

[0149] If authentication fails (NO in step S1402), the flow terminates.

[0150] On the other hand, if authentication is successful (YES in step S1402), in step S1403, the topology management unit 304 or measurement unit 306 (referred to as the index acquisition unit or index calculation unit) of the underwater drone 30 acquires (calculates) index information. The index information may be, for example, the transmission path characteristics (indicating index values) between the drone and other communication devices (SNR, tone map, PHY speed, etc.), or the communication connection relationship of the wireless power and data transmission network 1 (topology information, etc.).

[0151] In step S1404, the movement control unit 310 of the underwater drone 30 determines whether the current location is appropriate based on the indicator information acquired in step S1403.

[0152] If the current location is appropriate (YES in step S1404), in step S1408, the underwater drone 30 stops moving under the control of the movement control unit 310.

[0153] In step S1409, the underwater drone 30 starts processing such as performing tasks, sending and receiving data, and supplying or receiving power. Then the flow ends.

[0154] On the other hand, if the current location is not appropriate (NO in step S1404), in step S1405, the movement control unit 310 of the underwater drone 30 determines the direction of movement.

[0155] In step S1406, the underwater drone 30 moves in the direction of movement determined in step S1405 under the control of the movement control unit 310.

[0156] In step S1407, the indicator acquisition unit of the underwater drone 30 reacquires the indicator information. Thereafter, the process returns to step S1404 and the above-described process is repeated.

[0157] Figure 15 is a flowchart showing an example of the operation of the underwater drone 30 according to this embodiment.

[0158] In step S1501, the underwater drone 30 initiates short-range communication with other nearby communication devices participating in the wireless power and data transmission network 1 via its short-range radio unit.

[0159] In step S1502, the authentication processing unit 302 of the underwater drone 30 performs an authentication process with the master unit 10 to determine whether or not the authentication was successful.

[0160] If authentication fails (NO in step S1502), the flow terminates.

[0161] On the other hand, if authentication is successful (YES in step S1502), in step S1503, the measurement unit 306 of the underwater drone 30 acquires transmission path characteristics at one or more locations. The transmission path characteristics may be, for example, the signal-to-noise ratio, tone map, PHY speed, etc. If the underwater drone 30 moves horizontally to acquire transmission path characteristics at multiple locations, the underwater drone 30 moves (for example, slowly) in a predetermined direction, a randomly determined direction, or another location determined from the camera image, under the control of the movement control unit 310, regardless of the calculated transmission path characteristics.

[0162] In step S1504, the movement control unit 310 of the underwater drone 30 determines whether the current location is appropriate based on the transmission path characteristics acquired in step S1503.

[0163] If the current location is appropriate (YES in step S1504), in step S1508, the underwater drone 30 stops moving under the control of the movement control unit 310.

[0164] For example, when the underwater drone 30 is performing positioning for charging and / or data communication, if the transmission path characteristics (PHY speed) at the current location are above a threshold, the movement control unit 310 determines that the current location is appropriate and stops the underwater drone 30 at the current location.

[0165] Furthermore, for example, when the underwater drone 30 is performing positioning for multi-hop formation, if the transmission path characteristics (PHY speed) at the current location are below a threshold, the movement control unit 310 determines that the current location is appropriate and stops the underwater drone 30 at the current location.

[0166] In step S1509, the underwater drone 30 starts processing such as performing tasks, sending and receiving data, and charging. Then the flow ends.

[0167] On the other hand, if the current location is not appropriate (NO in step S1504), in step S1505, the movement control unit 310 of the underwater drone 30 determines the direction of movement.

[0168] For example, when the underwater drone 30 is performing positioning for charging and / or data communication, if the current location is not the location where the maximum transmission path characteristics (PHY speed) among the transmission path characteristics measured at multiple locations were measured, the movement control unit 310 determines that the current location is not appropriate and sets the direction of movement to a horizontal direction and towards the location where the maximum transmission path characteristics were measured (the direction in which the transmission path characteristics are higher).

[0169] Furthermore, for example, when the underwater drone 30 performs positioning for charging and / or data communication, if the transmission path characteristics (PHY speed) at the current location are below a threshold, the movement control unit 310 determines that the current location is not suitable and sets the direction of movement to a horizontal direction, a predetermined direction, a randomly determined direction, a direction determined from the camera image, etc.

[0170] Furthermore, for example, when the underwater drone 30 performs positioning for multi-hop formation, if the transmission path characteristics (PHY speed) at the current location are greater than a threshold, the movement control unit 310 determines that the current location is not appropriate and sets the direction of movement to directly downwards (the direction in which the transmission path characteristics become lower), which is the direction away from the external device from which the transmission path characteristics were acquired.

[0171] In step S1506, the underwater drone 30 moves in the direction of movement determined in step S1505 under the control of the movement control unit 310.

[0172] In step S1507, the measurement unit 306 of the underwater drone 30 reacquires the transmission path characteristics. Thereafter, the process returns to step S1504 and the above-described process is repeated.

[0173] Figure 16 is a flowchart showing an example of the operation of the underwater drone 30 according to this embodiment.

[0174] In step S1601, the underwater drone 30 initiates communication with other nearby communication devices participating in the wireless power and data transmission network 1 via its short-range radio unit.

[0175] In step S1602, the authentication processing unit 302 of the underwater drone 30 performs an authentication process with the master unit 10 and determines whether or not the authentication was successful.

[0176] If authentication fails (NO in step S1602), the flow terminates.

[0177] On the other hand, if authentication is successful (YES in step S1602), in step S1603, the topology management unit 304 of the underwater drone 30 acquires the communication connection relationship of the wireless power and data transmission network 1. The communication connection relationship may be, for example, topology information of the wireless power and data transmission network 1.

[0178] In step S1604, the movement control unit 310 of the underwater drone 30 determines whether the current location is appropriate based on the communication connection relationship acquired in step S1603.

[0179] If the current location is appropriate (YES in step S1604), in step S1608, the underwater drone 30 stops moving under the control of the movement control unit 310.

[0180] For example, when the underwater drone 30 is aligning itself to form a desired topology, the movement control unit 310 determines that the current location is appropriate based on the topology information, and stops the underwater drone 30 at the current location if the current location is a desired connection location (e.g., an available parking spot).

[0181] In step S1609, the underwater drone 30 starts processing such as performing tasks, sending and receiving data, and charging. Then the flow ends.

[0182] On the other hand, if the current location is not appropriate (NO in step S1604), in step S1605, the movement control unit 310 of the underwater drone 30 determines the direction of movement.

[0183] For example, when the underwater drone 30 is aligning itself to form a desired topology, the movement control unit 310 determines, based on topology information, that the current location is not suitable if it is not a desired connection location (e.g., an available parking spot), and determines the direction of movement to be towards another parking spot or a destination for the underwater drone.

[0184] In step S1606, the underwater drone 30 moves in the direction of movement determined in step S1605 under the control of the movement control unit 310.

[0185] For example, the underwater drone 30 moves in the direction of the destination under the control of the movement control unit 310 based on camera images, etc. In the case of an aerial drone, the aerial drone may also move in the direction of the destination under the control of the movement control unit 310 based on position information using GPS, etc.

[0186] In step S1607, the topology management unit 304 of the underwater drone 30 reacquires the communication connection relationship. Thereafter, the process returns to step S1604 and the above-described process is repeated.

[0187] Figures 17A and 17B are flowcharts showing examples of the operation of the underwater drone 30 according to this embodiment.

[0188] In step S1701, the underwater drone 30 initiates communication with other nearby communication devices participating in the wireless power and data transmission network 1 via its short-range radio unit.

[0189] In step S1702, the authentication processing unit 302 of the underwater drone 30 performs an authentication process with the master unit 10 and determines whether or not the authentication was successful.

[0190] If authentication fails (NO in step S1702), the flow terminates.

[0191] On the other hand, if authentication is successful (YES in step S1702), in step S1703, the topology management unit 304 of the underwater drone 30 acquires the communication connection relationship of the wireless power and data transmission network 1. The communication connection relationship may be, for example, topology information of the wireless power and data transmission network 1.

[0192] In step S1704, the movement control unit 310 of the underwater drone 30 determines whether the current location is appropriate based on the communication connection relationship acquired in step S1703.

[0193] If the current location is appropriate (YES in step S1704), the flow proceeds to step S1708.

[0194] For example, when the underwater drone 30 performs alignment to form a desired topology, the movement control unit 310 determines that the current location is appropriate based on the topology information, if the current location is a desired connection point (e.g., the end of the topology).

[0195] If the current location is not appropriate (NO in step S1704), in step S1705, the movement control unit 310 of the underwater drone 30 determines the direction of movement.

[0196] For example, when the underwater drone 30 is aligning itself to form a desired topology, if the current location is not a desired connection location (e.g., the end of the topology) based on the topology information, the movement control unit 310 determines that the current location is inappropriate and determines the direction of movement to be in the direction along the movement route (e.g., in the direction of the communication device located at the end (e.g., directly below)).

[0197] In step S1706, the underwater drone 30 moves in the direction of movement determined in step S1705 under the control of the movement control unit 310.

[0198] In step S1707, the topology management unit 304 of the underwater drone 30 reacquires the communication connection relationship. Thereafter, the process returns to step S1704 and the above-described process is repeated.

[0199] In step S1708, the measurement unit 306 of the underwater drone 30 acquires transmission path characteristics at one or more locations. The transmission path characteristics may be, for example, the signal-to-noise ratio, tone map, PHY speed, etc. If the underwater drone 30 moves horizontally to acquire transmission path characteristics at multiple locations, the underwater drone 30 moves (for example, slowly) in a predetermined direction, a randomly determined direction, or another location determined from the camera image, under the control of the movement control unit 310, regardless of the calculated transmission path characteristics.

[0200] In step S1709, the movement control unit 310 of the underwater drone 30 determines whether the current location is appropriate based on the transmission path characteristics acquired in step S1708.

[0201] If the current location is appropriate (YES in step S1709), in step S1713, the underwater drone 30 stops moving under the control of the movement control unit 310.

[0202] For example, when the underwater drone 30 is aligning itself to form a desired topology, if the transmission path characteristics (PHY speed) at the current location are below a threshold, the movement control unit 310 determines that the current location is appropriate and stops the underwater drone 30 at that location.

[0203] In step S1714, the underwater drone 30 starts processing such as performing tasks, sending and receiving data, and charging. Then the flow ends.

[0204] On the other hand, if the current location is not appropriate (NO in step S1709), in step S1710, the movement control unit 310 of the underwater drone 30 determines the direction of movement.

[0205] For example, when the underwater drone 30 is aligning itself to form a desired topology, if the transmission path characteristics (PHY speed) at the current location are greater than a threshold, the movement control unit 310 determines that the current location is not suitable and sets the direction of movement to directly downwards (the direction in which the transmission path characteristics become lower), which is the direction away from the external device from which the transmission path characteristics were acquired.

[0206] In step S1711, the underwater drone 30 moves in the direction of movement determined in step S1710 under the control of the movement control unit 310.

[0207] In step S1712, the measurement unit 306 of the underwater drone 30 reacquires the transmission path characteristics. Thereafter, the process returns to step S1709 and the above-described process is repeated.

[0208] The functional units of the CPU 201 described in this embodiment may be integrated with other functional units as appropriate, or they may be divided into two or more sub-functional units. Furthermore, the order of the steps shown in the flowchart and the like described in this embodiment is not limited to the order shown.

[0209] <Effects in Embodiment 1> The underwater drone 30 according to this embodiment communicates wirelessly with external devices such as the master unit 10, the parking area 20, and other underwater drones 30 via a short-range antenna 210 and a short-range wireless communication circuit 211. The CPU 201 (measurement unit 306) of the underwater drone 30 obtains index values ​​(S / N ratio, tone map, PHY speed, etc.) indicating the transmission path characteristics between the underwater drone and the external device by sending and receiving signals with the external device. The CPU 201 (movement control unit 310) of the underwater drone 30 determines the position or direction in which the underwater drone 30 will move based on these index values ​​and moves the underwater drone 30 to the determined position or direction. As a result, the position or direction in which the underwater drone 30 will move is determined based on index values ​​indicating the transmission path characteristics between the underwater drone and the external device, which are less affected by environmental factors around the underwater drone 30, and the underwater drone 30 is controlled to move to the determined position or direction, thereby improving the accuracy of alignment.

[0210] Furthermore, the underwater drone 30 according to this embodiment communicates wirelessly with external devices such as the master unit 10, the parking area 20, and other underwater drones 30 via a short-range antenna 210 and a short-range wireless communication circuit 211. The CPU 201 (topology management unit 304) of the underwater drone 30 acquires topology information of the communication network (e.g., wireless power and data transmission network 1) from the master unit 10, etc., either by transmitting a topology information request or periodically without transmitting a topology information request. The CPU 201 (movement control unit 310) of the underwater drone 30 determines the position or direction in which the underwater drone 30 will move based on the topology information, and moves the underwater drone 30 to the determined position or direction. As a result, the position or direction in which the underwater drone 30 moves is determined based on the topology information of the communication network, which is less affected by environmental factors around the underwater drone 30, and the underwater drone 30 is controlled to move to the determined position or direction, thereby improving the accuracy of alignment.

[0211] <Summary of Embodiment 1> A mobile body according to one embodiment of the present disclosure comprises: a communication unit that performs wireless communication with an external device; an index acquisition unit that acquires a first index value indicating the transmission path characteristics between the external device and the communication unit; and a movement control unit that determines a first position or a first direction in which the mobile body moves based on the first index value and moves the mobile body in the first position or first direction.

[0212] In this mobile device, the index acquisition unit acquires a plurality of first index values ​​corresponding to a plurality of locations, and the movement control unit determines the first position to be the location from which the maximum value of the plurality of first index values ​​was acquired.

[0213] In this mobile body, the index acquisition unit acquires a first index value based on a first signal transmitted by the communication unit to the external device with a first transmission power, and after the mobile body moves to the first position, the index acquisition unit acquires a second index value indicating the transmission line characteristics based on a second signal transmitted by the communication unit to the external device with a second transmission power lower than the first transmission power, and the movement control unit determines a second position or second direction in which the mobile body will move based on the second index value, and moves the mobile body to the second position or second direction.

[0214] In this mobile body, the movement control unit determines the first direction to be away from the external device if the first index value is higher than the first threshold.

[0215] In this mobile body, if the first index value is less than or equal to the first threshold, the mobile body is stopped at the point where the first index value was obtained.

[0216] A movement control method according to one embodiment of the present disclosure involves a mobile body communicating wirelessly with an external device, acquiring an index value indicating the transmission path characteristics between the mobile body and the external device, determining the position or direction of movement of the mobile body based on the index value, and moving the mobile body to the position or direction.

[0217] A mobile body according to one embodiment of the present disclosure comprises a communication unit that performs wireless communication with an external device, an acquisition unit that acquires a communication connection relationship of a communication network including the external device and other communication devices through communication with the external device, and a movement control unit that determines a first direction in which the mobile body moves based on the communication connection relationship and moves the mobile body in the first direction.

[0218] In this mobile unit, if the communication connection relationship indicates that the other communication device is located at the end of the communication network, the mobile control unit determines the first direction to be the direction of the other communication device.

[0219] The mobile unit further includes an index acquisition unit that acquires an index value indicating the transmission path characteristics with the other communication device, and the mobile control unit determines a second direction in which the mobile unit moves based on the index value and moves the mobile unit in the second direction.

[0220] In this mobile unit, if the index value is higher than a threshold, the movement control unit determines the second direction to be a direction away from the other communication device.

[0221] If the communication connection relationship indicates that there are no other communication devices wirelessly connected to the other communication devices in this mobile unit, the mobile control unit determines the first direction to be the direction of the other communication devices.

[0222] A motion control method according to one embodiment of the present disclosure involves a mobile body communicating wirelessly with an external device, acquiring a communication connection relationship of a communication network including the external device and other communication devices through communication with the external device, determining the direction in which the mobile body will move based on the communication connection relationship, and moving the mobile body in that direction.

[0223] (Embodiment 2) <Configuration of Wireless Power and Data Transmission System> Embodiment 1 primarily described a wireless power and data transmission system deployed on water (e.g., at sea) and underwater (e.g., in the ocean). However, in Embodiment 2, the wireless power and data transmission system may be deployed on and in the ocean, on land and in the air, on and in freshwater, or in a combination of these. While the wireless power and data transmission system 1 according to Embodiment 1 included an underwater drone 30, in the wireless power and data transmission system according to Embodiment 2, the underwater drone 30 is replaced with a drone 30' that includes an underwater drone and an aerial drone (or a drone capable of moving underwater, in the air, and on land (hereinafter referred to as an amphibious drone)). The drone 30' is an example of a "mobile body" according to this disclosure.

[0224] <Configuration of Wireless Power and Data Transmission System> [Drone configuration] Figure 18 shows an example of the functional configuration of the CPU 201 of drone 30'. Note that explanations of elements identical to those in drone 30 are omitted.

[0225] As shown in Figure 18, in addition to the elements shown in Figure 3, the drone 30' includes a user input information acquisition unit 311, a sensor information acquisition unit 312, a mode determination unit 313, and a profile selection unit 314.

[0226] The user input information acquisition unit 311 acquires information (user input information) entered by the user via the UI 203 or via a mobile communication network and a browser, etc. The user input information may, for example, specify a mode related to the operating environment of the drone 30' (the mode in which the drone 30' operates). Such a mode may include an aerial mode, a saltwater mode and a freshwater mode, or it may include an aerial mode and an underwater mode.

[0227] The sensor information acquisition unit 312 acquires sensor information measured or sensed by the sensor 207 from the sensor 207. The sensor information includes, for example, information indicating whether or not moisture is detected (present), salinity, atmospheric pressure, etc. The sensor information may also include location information using GPS. In other words, the GPS receiver 205 may be considered as part of the sensor 207.

[0228] The mode determination unit 313 determines the mode related to the operating environment of the drone 30' (such as the medium on which the drone 30' moves, or the medium in which the drone 30' exists) based on user input information, sensor information, etc.

[0229] The profile selection unit 314 selects a PHY speed profile that corresponds to the mode determined by the mode determination unit 313. The profile selection unit 314 is an example of a "selection unit" as described herein.

[0230] Figure 19 shows the PHY speed profiles for different communication media for the same constant transmit power.

[0231] Figure 19(A) shows the PHY speed profile when the communication medium is air, Figure 19(B) shows the PHY speed profile when the communication medium is freshwater, and Figure 19(C) shows the PHY speed profile when the communication medium is seawater. If the drone 30' is an amphibious drone, the drone 30' may store in memory 202 the aerial profile shown in Figure 19(A), the freshwater profile shown in Figure 19(B), and the seawater profile shown in Figure 19(C). If the drone 30' is an underwater drone, the drone 30' may store in memory 202 the freshwater profile shown in Figure 19(B) and the seawater profile shown in Figure 19(C).

[0232] As shown in Figure 19, the transmission-to-transmitter distance (communication distance) is longest when the communication medium is air, shorter when the communication medium is freshwater than when the communication medium is air, and even shorter when the communication medium is seawater.

[0233] Thus, even with the same PHY speed, the distance between transmission and reception differs depending on the communication medium. Therefore, unless the appropriate profile is selected according to the environment in which the drone is moving (i.e., the communication medium), it is not possible to accurately estimate the distance.

[0234] In light of the above, we will explain a solution for appropriately estimating the distance to the communication partner even when the drone 30' moves using a different communication medium.

[0235] <Operation of Wireless Power and Data Transmission Systems> [Example of determining the first mode] Figure 20 is a flowchart showing an example of mode determination according to this embodiment.

[0236] In step S2001, the mode determination unit 313 determines whether or not a mode has been specified by the user based on the user input information acquired by the user input information acquisition unit 311.

[0237] If a mode is specified by the user (YES in step S2001), in step S2002, the mode determination unit 313 determines the mode for the operating environment of the drone 30' to the mode specified by the user. Then the flow ends.

[0238] On the other hand, if the user has not specified a mode (NO in step S2001), in step S2003, the mode determination unit 313 uses the position information (e.g., latitude and longitude) measured by the GPS receiver 205 and the map information stored in the memory 202 to determine whether or not the drone 30' is on the water. Here, "on the water" does not mean that the drone 30' is in contact with the water, but rather that the measured latitude and longitude coincide with the sea, lake, etc.

[0239] If the drone 30' is not on the water (NO in step S2003), in step S2007, the mode determination unit 313 determines the mode of the drone 30's operating environment to the aerial mode. The flow then ends.

[0240] On the other hand, if the drone 30' is on the water (YES in step S2003), in step S2004, the mode determination unit 313 determines whether or not it has detected water based on the sensor information acquired by the sensor information acquisition unit 312.

[0241] If no moisture is detected (NO in step S2004), in step S2007, the mode determination unit 313 determines the operating environment mode of the drone 30' to aerial mode. The flow then ends.

[0242] On the other hand, if moisture is detected (YES in step S2004), in step S2005, the mode determination unit 313 determines whether the atmospheric pressure is above a threshold based on the sensor information acquired by the sensor information acquisition unit 312.

[0243] If the atmospheric pressure is not above the threshold (NO in step S2005), in step S2007, the mode determination unit 313 determines the mode for the operating environment of the drone 30' to the aerial mode. Then the flow ends.

[0244] On the other hand, if the atmospheric pressure is above a threshold (YES in step S2005), in step S2006, the mode determination unit 313 determines whether the salinity is above a threshold based on the sensor information acquired by the sensor information acquisition unit 312.

[0245] If the salinity is above the threshold (YES in step S2006), in step S2008, the mode determination unit 313 determines the mode for the operating environment of the drone 30' to seawater mode. The flow then ends.

[0246] On the other hand, if the salinity is not above the threshold (NO in step S2006), in step S2009, the mode determination unit 313 determines the mode for the operating environment of the drone 30' to freshwater mode. Then the flow ends.

[0247] In the first mode determination example, if drone 30' is not an amphibious drone, step S2003 may be skipped.

[0248] [Example of determining the second mode] Figure 21 is a flowchart showing an example of mode determination according to this embodiment. In this example, the drone 30' does not use or does not have GPS functionality.

[0249] In step S2101, the mode determination unit 313 determines whether or not a mode has been specified by the user based on the user input information acquired by the user input information acquisition unit 311.

[0250] If a mode is specified by the user (YES in step S2101), in step S2102, the mode determination unit 313 determines the mode for the operating environment of the drone 30' to the mode specified by the user. Then the flow ends.

[0251] On the other hand, if the user has not specified a mode (NO in step S2101), in step S2103, the mode determination unit 313 determines whether or not moisture has been detected based on the sensor information acquired by the sensor information acquisition unit 312.

[0252] If no moisture is detected (NO in step S2103), in step S2104, the mode determination unit 313 determines whether the atmospheric pressure is above a threshold based on the sensor information acquired by the sensor information acquisition unit 312.

[0253] On the other hand, if moisture is detected (YES in step S2103), the flow proceeds to step S2105.

[0254] If the atmospheric pressure is not above the threshold (NO in step S2104), in step S2106, the mode determination unit 313 determines the mode for the operating environment of the drone 30' to the aerial mode. The flow then ends.

[0255] On the other hand, if the atmospheric pressure is above the threshold (YES in step S2104), the flow proceeds to step S2105.

[0256] In step S2105, the mode determination unit 313 determines whether the salt concentration is above a threshold value based on the sensor information acquired by the sensor information acquisition unit 312.

[0257] If the salinity is above the threshold (YES in step S2105), in step S2107, the mode determination unit 313 determines the mode for the operating environment of the drone 30' to seawater mode. The flow then ends.

[0258] On the other hand, if the salinity is not above the threshold (NO in step S2105), in step S2108, the mode determination unit 313 determines the mode for the operating environment of the drone 30' to freshwater mode. Then the flow ends.

[0259] In the second mode determination example, if the drone 30' is not an amphibious drone, steps S2103 and S2104 may be skipped.

[0260] [Example of determining the third mode] Figure 22 is a flowchart showing an example of mode determination according to this embodiment. In this example, the user specifies whether the drone 30' operates in aerial mode or underwater mode, and if the drone 30' operates in underwater mode, it is automatically determined whether the drone 30' operates in freshwater mode or saltwater mode.

[0261] In step S2201, the mode determination unit 313 determines whether or not the underwater mode has been specified by the user based on the user input information acquired by the user input information acquisition unit 311.

[0262] If the user has not specified an underwater mode (NO in step S2201), in step S2203, the mode determination unit 313 determines the operating environment mode of the drone 30' to aerial mode. The flow then ends.

[0263] On the other hand, if the underwater mode is specified by the user (YES in step S2201), in step S2202, the mode determining unit 313 determines whether or not the salt concentration is equal to or higher than a threshold based on the sensor information acquired by the sensor information acquiring unit 312.

[0264] If the salt concentration is equal to or higher than the threshold (YES in step S2202), in step S2204, the mode determining unit 313 determines the mode related to the operating environment of the drone 30' as the seawater mode. Then, the flow ends.

[0265] On the other hand, if the salt concentration is not equal to or higher than the threshold (NO in step S2202), in step S2205, the mode determining unit 313 determines the mode related to the operating environment of the drone 30' as the freshwater mode. Then, the flow ends.

[0266] In the first to third mode determination examples described above, the air mode may be employed even when the drone 30' is movable on land.

[0267] [Operation Example] Next, an operation example of the drone 30' will be described with reference to FIG. 23. The process shown in FIG. 23 may be started, for example, when the drone 30' is activated.

[0268] In step S2301, the user input information acquiring unit 311 acquires user input information from the user.

[0269] In step S2302, the sensor information acquiring unit 312 acquires sensor information from the sensor 207.

[0270] In step S2303, the mode determining unit 313 determines the mode related to the operating environment of the drone 30'. The mode determining unit 313 may determine the mode, for example, as described with reference to FIGS. 20 to 22.

[0271] In step S2304, the profile selection unit 314 selects a profile from a plurality of profiles that corresponds to the mode determined in step S2303. For example, if the determined mode is the air mode, the profile shown in Figure 19(A) is selected; if the determined mode is the freshwater mode, the profile shown in Figure 19(B) is selected; and if the determined mode is the seawater mode, the profile shown in Figure 19(C) is selected.

[0272] In step S2305, the measurement unit 306 acquires the transmission path characteristics with the communication partner and measures the PHY speed. The acquisition of transmission path characteristics and the measurement of the PHY speed may be performed as described in Embodiment 1. For example, if the AGC value is below a threshold, control may be performed to reduce the transmission power.

[0273] In step S2306, the distance estimation unit 307 estimates the distance to the communication partner using the profile selected in step S2304.

[0274] In step S2307, the movement control unit 310 controls the drive system 204 (for example, a propeller in the aerial mode; a screw in the freshwater or saltwater mode) corresponding to the mode determined in step S2303 to move or stop the drone 30'. The conditions for the drone 30' to move, the determination of the direction in which the drone 30' moves, the conditions for the drone 30' to stop, etc., may be as described in Embodiment 1.

[0275] If, after step S2307, movement exceeding a predetermined value occurs (for example, if movement exceeding a predetermined value occurs based on location information using GPS, or if the motor rotation speed exceeds a threshold), the process shown in Figure 23 may be repeated from step S2301 or S2302.

[0276] Furthermore, whenever sensor information is acquired that shows a change of more than a threshold from the previous value, the process shown in Figure 23 may be repeated from step S2301, S2302, or S2303.

[0277] The above describes an example where mode determination is performed based on user input information and / or sensor information, but mode determination may also be performed based on other information, either alternatively or additionally. For example, mode determination may be performed based on user input information, sensor information, and / or communication information from an external device.

[0278] The above describes an example where the process shown in Figure 23 is performed when the drone 30' is started and the mode is determined. However, mode determination does not necessarily have to be performed when the drone 30' is started. For example, when the drone 30' is started, the mode that was in immediately before the drone 30' was last turned off may be used.

[0279] The above example described user input information as information about the mode itself, but user input information may also be information about the conditions that determine the mode.

[0280] The functional units of the CPU 201 described in this embodiment may be integrated with other functional units as appropriate, or they may be divided into two or more sub-functional units. Furthermore, the order of the steps shown in the flowchart and the like described in this embodiment is not limited to the order shown.

[0281] <Effects in Embodiment 2> The drone 30', capable of moving through multiple media such as air, seawater, and freshwater, communicates wirelessly with external devices such as the master unit 10, the parking area 20, and other drones 30' via a short-range antenna 210 and a short-range wireless communication circuit 211. The CPU 201 (measurement unit 306) of the drone 30' acquires transmission path characteristics (S / N ratio, tone map, PHY speed, etc.) between the drone and the external device by sending and receiving signals. The CPU 201 (profile selection unit 314) of the drone 30' selects a profile corresponding to the medium in which the drone 30' is located from among multiple profiles corresponding to multiple different media. The CPU 201 (distance estimation unit 307) of the drone 30' estimates the distance to the external device based on the acquired transmission path characteristics and the selected profile. As a result, the distance between the drone 30' and the external device is estimated based on the profile corresponding to the medium in which the drone 30' is located, so that the distance estimation error can be suppressed in any medium when the drone 30' moves through multiple different media.

[0282] <Summary of Embodiment 2> A mobile body according to one embodiment of the present disclosure is a mobile body capable of moving through a plurality of different media, and comprises: a communication unit that performs wireless communication with an external device; an index acquisition unit that acquires transmission path characteristics between the mobile body and the external device; a selection unit that selects a profile corresponding to the medium in which the mobile body is located; and a distance estimation unit that estimates the distance to the external device based on the transmission path characteristics and the profile.

[0283] The mobile body further comprises a sensor for measuring the state of the surrounding environment of the mobile body, and a determination unit for determining the medium in which the mobile body exists based on the state of the surrounding environment.

[0284] In this mobile device, the plurality of different media include air, seawater, and freshwater.

[0285] In this mobile body, the sensor includes a salinity sensor, and the determination unit determines that the medium in which the mobile body exists is seawater if the salinity measured by the salinity sensor is equal to or greater than a threshold.

[0286] In the present moving body, the profile associates the distance between communication devices with transmission path characteristics in a medium where the moving body is located.

[0287] A distance estimation method according to an embodiment of the present disclosure is performed by a moving body that is movable across a plurality of different media and performs wireless communication with an external device, the method comprising: acquiring transmission path characteristics with the external device; selecting a profile corresponding to a medium where the moving body is located; and estimating the distance to the external device based on the transmission path characteristics and the profile.

[0288] In the above-described embodiments, the notation "...unit" used for each component may be replaced with other notations such as "...circuitry", "...assembly", "...device", "...unit, or "...module.

[0289] Although the embodiments have been described above with reference to the drawings, the present disclosure is not limited to such examples. It is obvious to those skilled in the art that various changes and modifications can be conceived within the scope described in the claims. It is understood that such changes and modifications also fall within the technical scope of the present disclosure. In addition, each component in the embodiments may be arbitrarily combined without departing from the spirit of the present disclosure.

[0290] The present disclosure can be implemented by software, hardware, or software cooperating with hardware. Each functional block used in the description of the above embodiments is partially or entirely implemented as an LSI, which is an integrated circuit, and each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be configured from individual chips, or may be configured from a single chip so as to include some or all of the functional blocks. The LSI may include data input and output. Depending on the degree of integration, LSIs may also be called ICs, system LSIs, super LSIs, or ultra LSIs.

[0291] The method of integration is not limited to LSIs; it may also be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, FPGAs (Field Programmable Gate Arrays) that can be programmed after LSI manufacturing, or reconfigurable processors that allow for the reconfiguration of the connections and settings of circuit cells within the LSI, may also be used. This disclosure may be implemented as digital or analog processing.

[0292] Furthermore, if advancements in semiconductor technology or related technologies lead to the emergence of integrated circuit technologies that replace LSIs, then naturally, these technologies can be used to integrate functional blocks. The application of biotechnology, for example, is a possible possibility.

[0293] This disclosure is applicable to all types of devices, systems, and equipment having communication capabilities (collectively referred to as communication equipment). Communication equipment may include a radio transceiver and a processing / control circuit. A radio transceiver may include a receiver and a transmitter, or both as functions. A radio transceiver (transmitter, receiver) may include an RF (Radio Frequency) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or similar. Non-exclusive examples of communication devices include telephones (mobile phones, smartphones, etc.), tablets, personal computers (PCs) (laptops, desktops, notebooks, etc.), cameras (digital still / video cameras, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, digital book readers, telehealth / telemedicine devices, vehicles or mobile transport with communication capabilities (cars, airplanes, ships, etc.), and combinations of the above-mentioned devices.

[0294] Communication devices are not limited to portable or movable devices, but also include all kinds of non-portable or fixed devices, devices, and systems, such as smart home devices (appliances, lighting equipment, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0295] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0296] Furthermore, the communication device also includes devices such as controllers and sensors that are connected to or linked to a communication device that performs the communication functions described in this disclosure. For example, this includes controllers and sensors that generate control signals and data signals used by the communication device that performs the communication functions of the communication device.

[0297] Furthermore, communication equipment includes infrastructure facilities such as base stations, access points, and any other devices, devices, and systems that communicate with or control the aforementioned non-limited types of equipment. [Industrial applicability]

[0298] This disclosure is useful for positioning technology for moving objects. [Explanation of Symbols]

[0299] 1. Wireless Power and Data Transmission System 10 Power supply and communication equipment 20 Tarmac 30 Underwater Drones 201 CPU 202 memory 203 UI 204 Drivetrain 205 GPS receiver 206 Camera 207 Sensors 208 Long-range antenna 209 Long-range wireless communication circuit 210 Short-range antenna 211 Near field wireless communication circuit 212 Receiving Antenna 213 Power receiving circuit 214 batteries 215 Power supply circuit 301 Packet Analysis Unit 302 Authentication Processing Unit 303 Link Cost Calculation Unit 304 Topology Management Department 305 Packet Generation Unit 306 Measuring part 307 Distance Estimation Unit 308 Transmission power determination unit 309 AGC value confirmation section 310 Movement Control Unit 311 User Input Information Acquisition Unit 312 Sensor Information Acquisition Unit 313 Mode Determination Unit 314 Profile Selection Section

Claims

1. It is a mobile object, A communication unit that performs wireless communication with external devices, An acquisition unit that acquires the communication connection relationship of a communication network including the external device and other communication devices through communication with the external device, Based on the aforementioned communication connection relationship, a movement control unit determines a first direction in which the moving body moves and moves the moving body in the first direction, A mobile device equipped with [the following features].

2. If the aforementioned communication connection relationship indicates that the other communication device is located at the end of the communication network, the movement control unit determines the first direction to be the direction of the other communication device. The mobile body according to claim 1.

3. An index acquisition unit that acquires an index value indicating the transmission path characteristics between the aforementioned communication device and other communication devices. Furthermore, The movement control unit determines a second direction in which the moving body moves based on the index value, and moves the moving body in the second direction. The mobile body according to claim 2.

4. The movement control unit determines the second direction to be a direction away from the other communication device if the index value is higher than the threshold. The mobile body according to claim 3.

5. If the aforementioned communication connection relationship indicates that no communication device is wirelessly connected to the other communication device, the movement control unit determines the first direction to be the direction of the other communication device. The mobile body according to claim 1.

6. A mobile device that communicates wirelessly with an external device, By communicating with the external device, the communication connection relationship of the communication network including the external device and other communication devices is obtained. Based on the aforementioned communication connection relationship, the direction in which the moving object moves is determined. Move the moving body in the aforementioned direction. A method for controlling movement.

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