JP7280910B2 - Communication system, control server, communication method, and program - Google Patents

Description

The present invention relates to a communication system, control server, communication method, and program.

Techniques related to communication by mobile bodies such as UAVs (Unmanned Aerial Vehicles) are known. In Patent Document 1, MEC (Mobile Edge Computing) technology is applied, and a mobile body that communicates with a first node that performs processing on behalf of the mobile body changes the communication destination for processing proxy from the first node to the first node. Techniques for switching to two nodes are disclosed.

WO2019/102993

Since a mobile body moves with the passage of time and performs various types of communication, there is a need for techniques that are more suitable for communication with the mobile body as the mobile body moves.

It is an object of the present invention to provide a technique for communication with mobile bodies, which is more suitable for moving mobile bodies.

A communication system according to an aspect of the present invention includes: a plurality of correction servers including a correction server set as a correction execution server that generates post-correction positioning information based on positioning information received from a mobile body; and the plurality of correction servers. and a control execution server that transmits a notification for switching the correction execution server from the first correction server to the second correction server to at least one of the first correction server and the second correction server.

A control server according to an aspect of the present invention is a control server that can communicate with a plurality of correction servers including a correction server set as a correction execution server that generates post-correction positioning information based on positioning information received from a mobile object. and transmitting a notification for switching the correction execution server from a first correction server to a second correction server among the plurality of correction servers to at least one of the first correction server and the second correction server. A communication unit is provided.

A communication method according to an aspect of the present invention includes a plurality of correction servers including a correction server set as a correction execution server that generates post-correction positioning information based on positioning information received from a mobile object, and a control execution server. wherein the control execution server notifies the first correction server and the second correction server of the plurality of correction servers to switch the correction execution server from transmitting to at least one of the second correction servers.

A program according to an aspect of the present invention is a computer control system capable of communicating with a plurality of correction servers including a correction server set as a correction execution server that generates post-correction positioning information based on positioning information received from a mobile object. A server that notifies at least one of the first correction server and the second correction server of the plurality of correction servers to switch the correction execution server from a first correction server to a second correction server. It functions as a control server having a communication unit for transmission.

ADVANTAGE OF THE INVENTION According to this invention, the technique by which a mobile body moves can be provided regarding communication with a mobile body.

It is a figure which shows the system configuration|structure of the communication system which concerns on one Embodiment. 1 is a block diagram showing an outline of a hardware configuration of a mobile terminal according to one embodiment; FIG. It is a block diagram showing an outline of hardware constitutions of a computer concerning one embodiment. FIG. 4 is a sequence diagram showing an example of control of correction processing of the positioning position of a mobile terminal by the communication system according to one embodiment; It is a flow chart which shows an example of processing control by a control server concerning one embodiment. FIG. 7 is a sequence diagram showing an example of control of switching processing between a correction execution server and a control execution server by a communication system according to an embodiment;

A communication system according to one embodiment will be described below. In addition, the following embodiments are examples for explaining the present invention, and are not intended to limit the present invention only to the embodiments. Also, the present invention can be modified in various ways without departing from the gist thereof. Furthermore, those skilled in the art can adopt embodiments in which each element described below is replaced with equivalents, and such embodiments are also included in the scope of the present invention.

A configuration example of a communication system according to an embodiment will be described with reference to FIG. The communication system 1 includes GNSS satellites 10a, 10b, 10c, 10d, reference stations 20a, 20b, 20c, mobile terminals 30a, 30b, 30c, a data center 40, correction servers 50a, 50b, 50c, and control servers 60a, 60b. Prepare.

Since the GNSS satellites 10a, 10b, 10c, and 10d have the same configuration, they may be collectively referred to as the GNSS satellite 10 without distinguishing between the GNSS satellites 10a, 10b, 10c, and 10d in the following description. Since the reference stations 20a, 20b, and 20c have the same configuration, they may be collectively referred to as the reference station 20 in the following description without distinguishing between the reference stations 20a, 20b, and 20c. Since the mobile terminals 30a, 30b, and 30c have the same configuration, in the following description, the mobile terminals 30a, 30b, and 30c may be collectively referred to as the mobile terminal 30 without distinction. Since the correction servers 50a, 50b, and 50c have the same configuration, they may be collectively referred to as the correction server 50 without distinguishing between the correction servers 50a, 50b, and 50c in the following description. Since the control servers 60a and 60b have the same configuration, they may be collectively referred to as the control server 60 without distinguishing between the control servers 60a and 60b in the following description. Also, the communication system 1 shown in FIG. 1 includes four GNSS satellites 10, three reference stations 20, three mobile terminals 30, one data center 40, three correction servers 50, and three control servers 60. Although configured, the number of devices included in communication system 1 is not limited to this and each may include any number of devices.

The mobile terminal 30, the correction server 50, and the control server 60 are configured to communicate with each other. Also, the mobile terminal 30 is configured to be able to communicate with a base station (not shown) in a mobile communication network. The mobile communication system adopts any communication technology such as fifth generation (5G) or fourth generation (4G). The reference station 20 is communicably connected to the data center 40 via a dedicated line. The correction server 50 is communicably connected to the data center 40 via a dedicated line.

The GNSS satellite 10 is an artificial satellite in GNSS (Global Navigation Satellite System) (for example, GPS (Global Positioning System)). GNSS satellites 10 emit GNSS signals that are used in the positioning process.

The reference station 20 is a reference station (also referred to as a reference station) required for positioning processing of the mobile terminal 30 by RTK (Real Time Kinematic). The reference station 20 is installed at a position whose coordinate values (for example, latitude, longitude, and altitude) are known as position information. Each reference station 20 performs positioning processing based on the GNSS signals received from a plurality of GNSS satellites 10, and calculates the distance from each GNSS satellite 10 to the reference station 20 (hereinafter referred to as "pseudorange"). Each reference station 20 transmits the pseudorange information calculated by the positioning process to the data center 40 .

The mobile terminal 30 is configured by a moving object such as a UAV, a vehicle, or a mobile terminal (including embedded communication modules, smart phones, tablets, and personal computers). The mobile terminal 30 performs positioning processing (hereinafter also referred to as “single positioning processing”) using GNSS signals received from a plurality of GNSS satellites 10 . The mobile terminal 30 transmits the positioning information of the mobile terminal 30 obtained by the single positioning process to the correction server 50 .

The data center 40 stores and manages known position information of all reference stations 20 in the communication system 1 and correction information of "pseudoranges received from the reference stations 20" (hereinafter referred to as "pseudorange correction information"). do. The pseudorange correction information is information for correcting the pseudorange from the reference station 20 to the GNSS satellite 10 to the actual range, and is calculated by comparing the actual range and the pseudorange. The data center 40 transmits to the correction server 50 known position information of the reference station 20 and pseudorange correction information necessary for processing by the correction server 50 to be described later.

The correction server 50 is configured by a computer such as a server device. The correction server 50 corrects the positioning information of the mobile terminal 30 obtained by the independent positioning processing of the mobile terminal 30 . Specifically, the correction server 50 corrects the positioning information obtained by the independent positioning processing by the mobile terminal 30 based on the pseudorange correction information received from the data center 40 and the known position information of the reference station 20. and outputs more accurate positioning information (hereinafter referred to as "corrected positioning information"). The correction is performed by any method, and for example, a method in FKP (Flachen Korrek-tur Parameter) is adopted.

Each of the plurality of correction servers 50 may be distributed and configured by applying edge computing technology such as MEC. In a configuration to which edge computing technology is applied, each correction server 50 is implemented by an edge server (for example, an MEC server). Correction of the positioning information of each mobile terminal 30 is performed by the correction server 50 installed near the mobile terminal 30 whose positioning information is to be corrected. In this way, by configuring the correction server 50 installed near the mobile terminal 30 to correct the positioning information of the mobile terminal 30, the communication load for correcting the positioning position can be reduced. Correction processing can be performed at a higher speed. The correction server 50 may be installed near each base station that communicates with the mobile terminal 30, for example. The correction server 50 may be configured to correct the positioning information of mobile terminals 30 communicating with nearby base stations. As another example, each correction server 50 may be distributed and installed near some base stations among a plurality of base stations instead of being installed near all base stations.

The control server 60 is configured by a computer such as a server device. The control server 60 controls movement of the mobile terminal 30 . More specifically, the control server 60 stores weather data, radio wave area information, obstacle information, movement plan information of other mobile terminals, the destination and departure point of the mobile terminal (or the destination and departure point of the mobile terminal). route information), waypoints, fuel (or on-board battery) information, and aircraft information of the mobile terminal, and support the movement (for example, flight) of the mobile terminal 30. All of the above weather data, radio wave area information, obstacle information, movement plan information of other mobile terminals, destination and departure points of mobile terminals, transit points, fuel (or on-board battery) information, and aircraft information of mobile terminals , or part of the information is referred to as mobile flight support information. Meteorological data includes, for example, weather, wind direction, wind speed, atmospheric pressure, and the like. The radio wave area information includes, for example, information indicating whether or not the mobile terminal 30 is within the radio wave area. Obstacle information includes, for example, position information of buildings, steel towers, airports, and the like. Further, the control server 60 transmits data based on the mobile flight support information to the mobile terminal 30 , for example, for controlling (supporting) the movement of the mobile terminal 30 .

The control server 60 transmits network assist data to the mobile terminal 30 . The network assist data may be information specifying the GNSS satellites required for positioning. Specifically, for example, the network assistance data may be information specifying the minimum number of visible GNSS satellites required for positioning. Network assistance data may be generated based on the location where the mobile terminal 30 is located. Since the mobile terminal 30 can specify the GNSS satellite to be used by the network assist data, the positioning time can be shortened.

Each of the plurality of control servers 60 may be distributed and configured by applying edge computing technology such as MEC. In a configuration to which edge computing technology is applied, each control server 60 is implemented by an edge server. Control of each mobile terminal 30 is performed by a control server 60 installed near the mobile terminal 30 . In this way, by adopting a configuration in which control of the mobile terminal 30 is performed by the control server 60 installed near the mobile terminal 30, communication between the control server 60 and the mobile terminal 30 can be performed at a higher speed. Delay can be reduced. The control server 60 may be installed near each base station communicating with the mobile terminal 30, for example. The control server 60 may be configured to control mobile terminals 30 communicating with nearby base stations. As another example, each control server 60 may be installed in a distributed manner near some base stations among a plurality of base stations instead of being arranged near all base stations. Also, the correction server 50 and the control server 60 may be implemented by the same edge server. This makes it possible to speed up the communication between the correction server 50 and the control server 60 and reduce the communication delay.

An example of the main hardware configuration of the mobile terminal 30 when the mobile terminal 30 is a UAV will be described with reference to FIG. As shown in FIG. 2, the mobile terminal 30 includes a control unit 31, a communication unit 32, a storage unit 33, an imaging unit 34, a propulsion unit 35, a signal receiver 36, a sensor 37, and a battery 38 as a hardware configuration. . If the mobile terminal 30 is a moving object other than a UAV, it may have a configuration similar to at least part of the above configuration, or may have a configuration different from the above configuration.

The control unit 31 mainly includes a CPU (Central Processing Unit) 31a and a memory 31b. The control unit 31 controls operations of the components of the mobile terminal 30 . For example, in the control unit 31, the CPU 31a controls the configuration of the mobile terminal 30 by deploying and executing a computer program including various instructions stored in the storage unit 33 or the like in the memory 31b. Realize the functions that you have. Details of the processing executed in the control unit 31 will be described later.

The communication unit 32 is a communication interface for communicating with an external device. For example, the communication unit 32 receives data used in processing by the control unit 31 from an external device, and transmits data resulting from processing by the control unit 31 to the external device. The communication unit 32 is configured by, for example, a network module.

The storage unit 33 is configured by a storage device such as a semiconductor storage device. The storage unit 33 stores various programs and data necessary for execution of processing in the control unit 31 and various data obtained as a result of processing by the control unit 31 .

The imaging unit 34 is composed of one or more cameras. The imaging unit 34 photographs a subject and acquires image information (image data) of a still image or a moving image according to control by the control unit 31 or the like.

The propulsion unit 35 is a mechanism for propelling the mobile terminal 30 . The propulsion unit 35 has rotary blades and a drive motor. The drive motor rotates the rotor blades to generate thrust for flight of the mobile terminal 30 .

The signal receiver 36 receives signals used for GNSS positioning processes or other positioning processes (eg, RTK positioning processes). Signal receiver 36 receives, for example, GNSS signals emitted from a plurality of GNSS satellites 10 . Signal receiver 36 identifies the position (eg, latitude, longitude, and altitude) of mobile terminal 30 through positioning processing based on the received GNSS signals. The process of specifying the position of the mobile terminal 30 may be performed by the control unit 31 .

Sensors 37 include sensors such as a compass, barometric altitude sensor, temperature sensor, acceleration sensor, obstacle sensor, and angular rate sensor. Information sensed by the sensor 37 is used by the control unit 31 to control the movement and attitude of the mobile terminal 30, for example. The battery 38 supplies power necessary for the operation of the components of the mobile terminal 30 such as the propulsion unit 35 . The battery 38 is composed of, for example, a lithium ion battery.

An example of the main hardware configuration of the computer 100 for implementing one or both of the correction server 50 and the control server 60 will be described with reference to FIG. As shown in FIG. 3 , the computer 100 includes a control section 51 , a communication section 54 and a storage section 55 . The control unit 51 mainly includes a CPU 52 and a memory 53 . In the control unit 51, the CPU 52 expands the program stored in the storage unit 55 or the like in the memory 53 and executes it, thereby controlling the operation of the configuration of the computer 100 and realizing various functions. The communication unit 54 is a communication interface for communicating with an external device, and is configured by, for example, a network card. The storage unit 55 is configured by a storage device capable of high-speed response, such as a memory module. The storage unit 55 stores various programs (including application programs) necessary for executing processing in the control unit 51 , various data (information), and various data obtained as a result of processing by the control unit 51 . The computer 100 may be composed of a single information processing device, or may be composed of a plurality of information processing devices distributed over a network. In addition, in order to implement the control server 60, the computer 100 may further include a user interface device (device having a display function and an input function) for operation by the user, or may be configured to be connected to the user interface device. It may be configured to be possible.

Since the reference station 20 includes the same hardware as the control unit 31, the communication unit 32, the storage unit 33, and the signal receiver 36 of the mobile terminal 30 described with reference to FIG. is omitted here. Since the data center 40 includes hardware similar to that of the computer 100 described with reference to FIG. 3, a brief description of the hardware configuration of the data center 40 is omitted here.

<Correction processing of positioning information of mobile terminal>
Next, an example of control of correction processing of the positioning information of the mobile terminal 30 by the communication system 1 will be described with reference to FIG. In this processing, it is assumed that the mobile terminal 30 is a UAV and that the flight of the mobile terminal 30 is automatically controlled by the control server 60 based on the mobile flight support information including preset movement route information. there is The movement route information includes flight route information for the mobile terminal 30 and information for controlling the flight altitude of the mobile terminal 30 . Further, the movement route information may include information on points connecting the departure point, transit point, and destination of the mobile terminal 30 .

In general, RTK positioning processing can measure a position with high accuracy, but consumes a large amount of power. Therefore, when the small mobile terminal 30 is required to move with limited power, it is not appropriate to perform the RTK positioning process for a long time. On the other hand, in general, positioning processing by GNSS consumes less power than RTK, but positioning accuracy is lower than that of RTK. Therefore, in a situation where the mobile terminal 30 is required to move with limited power, by controlling the positioning process so as to minimize the usage period of the RTK, it is possible to perform the positioning process with high precision and to move. It is possible to achieve both of not decreasing the available time. Since the correction processing of the positioning position of the mobile terminal 30 requires highly accurate positioning processing, it is preferable that the positioning processing of the mobile terminal 30 is performed by RTK in the processing shown in FIG.

First, in step S<b>9 , the control server 60 transmits the aforementioned network assist data to the mobile terminal 30 . In step S<b>10 , the control server 60 transmits the aforementioned mobile flight support information to the mobile terminal 30 . The mobile flight support information includes departure point information (current location information) based on the mobile flight plan information, route information, and the like. The mobile flight plan information may include, for example, information about the departure point (departure point information), information about the destination (destination information), and information about the waypoint (waypoint information). The origin, destination, and waypoints may each be indicated by coordinates. That is, the mobile flight plan information may include coordinate information. The mobile terminal 30 acquires its own position information (information on the current location, which is the starting point) by receiving the mobile flight support information before the positioning process. The processing by the control server in step 10 may be started, for example, based on a signal received from the mobile terminal 30 (in response to an instruction from the operator) or by a timer. As a modification, the correction server 50 receives and stores the mobile flight support information from the control server 60 in advance, and the correction server 50 transmits the stored mobile flight support information to the mobile terminal 30. may

In this way, the mobile terminal 30 utilizes the position information (mobile flight support information) received from the control server 60 before the positioning process, so that there is no need to wait until the GNSS positioning function stabilizes. . Therefore, the mobile terminal 30 can start flying earlier. In other words, wasteful warm-up time is eliminated, and power can be used for flight for a longer period (the mobile terminal 30 can fly for a longer period).

In step S<b>11 , the control server 60 transmits to the correction server 50 information about the area through which the mobile terminal 30 passes or stays. The correction server 50 receives information about the area from the control server 60 via the communication unit 54 . The information (area information) about the area through which the mobile terminal 30 passes or stays is information for reducing the amount of calculation of the correction server and shortening the processing time by narrowing down the area. Information about the area is transmitted from the control server to a correction server 50 (for example, one of the correction servers 50a, 50b, and 50c) installed near the area, among the plurality of correction servers 50 .

In step S12, the correction server 50 transmits to the data center 40 the information about the area received in step S11.

In step S13, the data center 40 stores and manages known position information of all reference stations 20 and information including pseudorange correction information (hereinafter also referred to as "wide-area positioning information"). , information corresponding to the information about the area received from the correction server 50 is transmitted to the correction server 50 as narrow-area positioning information (hereinafter also referred to as "specific area positioning information"). The known location information of reference station 20 may include coordinate information. Among the wide area positioning information stored and managed by the data center 40, the narrow area positioning information corresponding to the information related to the area received from the correction server 50 is used for the later-described correction of the positioning information by the mobile terminal 30 located in the area. Contains information used for The information used for correcting the positioning information by the mobile terminal 30 located in the area is, for example, the information of each reference station 20 installed in the area from 2 km to 800 m from the position of the mobile terminal 30 whose positioning information is to be corrected. Known position information and pseudorange correction information may be used. In this way, the correction server 50 stores not all known position information and pseudorange correction information of the reference station 20 stored and managed by the data center 40, but narrow-area positioning information that is necessary for correction for the mobile terminal 30. receive information; Therefore, compared to the case where the correction server 50 receives all known position information and pseudorange correction information of the reference station 20, it is possible to reduce the communication load and improve the transmission speed.

In step S<b>14 , the mobile terminal 30 transmits to the correction server 50 the positioning information obtained by the single positioning process by GNSS using the network assist data. The positioning information is transmitted to the correction server 50 installed near the positioning position of the mobile terminal 30 (or the position closest to the positioning position) among the plurality of correction servers 50 .

In step S15, the correction server 50 corrects the positioning information based on the narrow-area positioning information received from the data center 40 in step S13 and the positioning information received from the mobile terminal 30 in step S14 to obtain more accurate positioning information. Positioning information (that is, post-correction positioning information) is calculated. The correction is performed by any method, and for example, the FKP method may be adopted. Further, as described in step S13, according to the present embodiment, the correction server 50 stores not the entire wide-area positioning information stored and managed by the data center 40, but the narrow-area positioning information necessary for calculating the post-correction positioning information. and calculate corrected positioning information. Therefore, the calculation speed of the corrected positioning information can be increased, and the positioning time can be shortened.

In step S<b>16 , the correction server 50 transmits the post-correction positioning information calculated in step S<b>15 to the control server 60 . The control server 60 may generate flight control information for controlling the flight of the mobile terminal 30 based on the corrected positioning information and the mobile flight plan information. For example, the control server 60 may compare and analyze the corrected positioning information and the mobile flight plan information, and calculate the error between the coordinates indicated by the corrected positioning information and the coordinates indicated by the mobile flight plan information. The control server may generate information for the mobile terminal 30 to correct the error and fly as flight control information. That is, the flight control information may include flight change information indicating changes in the flight plan of the mobile terminal 30 .

In step S<b>17 , the control server 60 transmits flight control information to the mobile terminal 30 to control the flight of the mobile terminal 30 and control the flight of the mobile terminal 30 . When the mobile terminal 30 receives flight control information including flight change information, the mobile terminal 30 may fly according to the flight change information. Further, for example, when the flight path of the mobile terminal 30 overlaps with that of another mobile terminal 30, the mobile terminal 30 may hover and wait until the other mobile terminal 30 passes through a cross point, or may change the movement speed. .

As described above, according to this embodiment, the correction server 50 communicates with the mobile terminal 30 and the data center 40 in the communication system 1 . The correction server 50 transmits to the data center 40 via the communication unit 54 information about the area corresponding to the route of movement of the mobile terminal 30 . The correction server 50 receives the specific area positioning information including information for correcting the positioning information of the mobile terminal 30 in the area and the positioning information of the mobile terminal 30 from the mobile terminal 30 via the communication unit 54 . Based on the specific area positioning information and the positioning information of the mobile terminal 30 received from the mobile terminal 30 , the correction server 50 calculates post-correction positioning information by correcting the positioning information. That is, the correction server 50 acquires the specific area positioning information necessary for calculating the correction information instead of the entire wide area positioning information stored and managed by the data center 40, and calculates the post-correction positioning information. Therefore, it is possible to improve the calculation speed of the post-correction positioning information.

According to this embodiment, the plurality of correction servers 50 are arranged in a distributed manner. In such a configuration, the positioning information of each mobile terminal 30 is corrected by the correction server 50 installed near the mobile terminal 30 whose positioning information is to be corrected. Therefore, the correction processing of the positioning information of each mobile terminal 30 can be performed at a higher speed.

<Switching processing of correction server and control server>
The communication system 1 according to this embodiment may be configured to be switchable between the correction server 50 that corrects the positioning information of the mobile terminal 30 and the control server 60 that controls the mobile terminal 30 .

For example, in the present embodiment, target areas are set in advance for each of the plurality of correction servers 50 . The target area set for each correction server 50 defines the area in which each correction server 50 is in charge of correcting the positioning information of the mobile terminal 30. Each correction server 50 sets the target area for its own device. The positioning information of the mobile terminal 30 existing in the selected target area is corrected. Therefore, for example, when the mobile terminal 30a moves from one target area to another target area, the correction server 50 that corrects the positioning information of the mobile terminal 30a is switched along with the movement. The target area set for each correction server 50 is set for an area within a predetermined distance from the correction server 50, for example.

Further, for example, it is assumed that among the plurality of correction servers 50, the correction server 50a is set as a correction execution server that generates post-correction positioning information based on the positioning information received from the moving body 30a. It is also assumed that the moving body 30a is about to move from the target area set for the correction server 50a to the target area set for the correction server 50b. In this case, the control server 60a switches the correction execution server by transmitting a notification for switching the correction execution server from the correction server 50a to the correction server 50b to at least one of the correction server 50a and the correction server 50b. conduct. For example, the control server 60 controls the switching based on the information of each correction server 50 and the position information of the target area set for each correction server 50 . The information of each correction server 50 and the position information of the target area set for each correction server 50 may be stored in the control server 60 or may be received by the control server 60 from the correction server 50 . In this way, by enabling the correction execution server to be switched under the control of the control server 60a, the correction server 50 located closer to the moving object 30a can correct the positioning information. As a result, the speed of communication between the mobile unit 30a and the correction server 50 can be increased, and the communication delay can be reduced. That is, according to the present embodiment, it is possible to implement a technique that is more suitable for the movement of the moving body 30 .

Similarly, target areas are set in advance for each of the plurality of control servers 60 . The target area set for each control server 60 defines the area in which each control server 60 is in charge of controlling the mobile terminal 30. Each control server 60 controls the target area set for its own device. is in charge of control of the mobile terminal 30 existing in the The target area set for each control server 60 may be the same as the target area set for each correction server 50 . In this case, when the mobile terminal 30a moves from one target area to another target area, the correction server 50 for correcting the positioning information of the mobile terminal 30a is switched along with the movement, and furthermore, the mobile terminal 30a is controlled. The control server 60 to be used is switched. Also, the target area set for each control server 60 may be set for an area within a predetermined distance from the control server 60, for example.

Further, for example, among the plurality of control servers 60, it is assumed that the control server 60a is set as the control execution server that transmits the notification for switching the correction execution server (or controls the mobile terminal 30a). . In this case, the control server 60a transmits a request for switching the control execution server from the control server 60a to the control server 60b to the control server 60b, and switches the control execution server (of the mobile terminal 30a).

The switching process of the correction server 50 that corrects the positioning information of the mobile terminal 30 and the switching process of the control server 60 that controls the mobile terminal 30 will be described in more detail below with reference to FIGS. In the processing shown in FIGS. 5 and 6, it is assumed that the mobile terminal 30 is a UAV and that the flight of the mobile terminal 30 is automatically controlled by the control server 60 based on preset movement route information. . The movement route information includes flight route information for the mobile terminal 30 and information for controlling the flight altitude of the mobile terminal 30 .

An example of control of the switching process of the correction server 50 by the control server 60 will be described with reference to FIG. This process is realized by the control unit 51 reading and executing a computer program stored in the storage unit 55 in the control server 60 . Further, the processing shown in FIG. 5 is started while the mobile terminal 30a whose positioning information is corrected by the correction server 50a and which is controlled by the control server 60a is moving. Further, in the processing shown in FIG. 5, it is assumed that the moving body 30a is about to move from the target area set for the correction server 50a to the target area set for the correction server 50b. The target area set for the correction server 50a and the target area set for the correction server 50b partially overlap (or are adjacent to) each other. In the example of processing shown in FIG. 5, steps S501 to S506 are executed by the control server 60a, and steps S507 to S508 are executed by the control server 60b.

In step S501, in order to switch the correction server 50, the control server 60a determines whether or not a condition for switching the positioning method of the moving (in flight) mobile terminal 30a is satisfied. For example, when the mobile terminal 30a is approaching the boundary of the target area set for the correction server 50a while performing positioning processing by GNSS, the control server 60a controls the or the distance between the mobile terminal 30a and the boundary of the target area or the like (positioning method switching condition) is satisfied. The determination in step S501 is performed until the positioning method switching condition is satisfied (No in step S501), and when the positioning method switching condition is satisfied, the process proceeds to step S502 (Yes in step S501).

The time required for the mobile terminal 30a to reach the boundary of the target area is calculated based on, for example, the moving speed and moving direction of the mobile terminal 30a and the distance from the mobile terminal 30a to the boundary. The distance from the mobile terminal 30a to the boundary is calculated using, for example, the corrected positioning information of the mobile terminal 30a received by the control server 60a from the correction server 50a and the target area information stored in the control server 60a. If the condition is the time until the boundary is reached, the positioning method switching condition may be set to, for example, 10 seconds remaining. Further, the distance between the mobile terminal 30a and the boundary of the target area can be obtained by, for example, using the corrected positioning information of the mobile terminal 30a received by the control server 60a from the correction server 50a and the target area information stored in the control server 60a. calculated using If the condition is the distance to the boundary, the positioning method switching condition may be set to, for example, 110 m remaining.

In step S502, the control server 60a controls switching of the positioning method of the mobile terminal 30a. For example, the control server 60a transmits a control signal to the mobile terminal 30a, which is performing positioning processing by GNSS, for performing positioning processing by a method such as RTK, which has higher positioning accuracy than GNSS. In order to safely perform the switching processing of the correction server 50, which will be described later, it is preferable that the positioning processing of the mobile terminal 30a is performed with higher accuracy. Therefore, in step S502, by switching the positioning method so that the positioning process is performed by a method such as RTK having higher positioning accuracy, the switching process of the correction server 50, which will be described later, can be performed more safely. Become.

Next, in step S503, the control server 60a determines whether or not the switching condition of the correction server 50 is satisfied. For example, when the mobile terminal 30a is approaching the boundary of the target area set for the correction server 50a, the control server 60a determines the time until the mobile terminal 30a reaches the boundary of the target area, or and a predetermined condition (server switching condition) set in advance with respect to the distance between the boundary of the target area and the like is satisfied. For example, the control server 60a may determine that the server switching condition is satisfied when the time to reach the boundary reaches 4 seconds, or when the distance to the boundary reaches 44 m. Further, the switching condition of the correction server 50 may be a condition preset with respect to the distance from the mobile terminal 30a to the obstacle or the time required for the mobile terminal 30a to reach the location of the obstacle. For example, if there is an obstacle (such as a building) near the boundary of the target area, a condition based on that obstacle may be used as the switching condition for the correction server 50 . When a switching condition based on the boundary of the target area is adopted, a situation may arise in which obstacles near the boundary of the target area are not avoided in time after the correction server 50 is switched. Therefore, according to one embodiment of the present invention, when there is an obstacle near the boundary of the target area, by adopting a switching condition based on the obstacle, the possibility of an accident due to a collision or a crash occurring is reduced. can be reduced.

The control server 60a allows the mobile terminal 30a to determine the boundary of the target area based on the position of the boundary of the target area set for the correction server 50a, the post-correction positioning information of the mobile terminal 30a, and the speed of the mobile terminal 30a. Determine the time to reach Further, the control server 60a specifies the distance between the mobile terminal 30a and the boundary of the target area based on the position of the target area preset for the correction server 50a and the post-correction positioning information of the mobile terminal 30a. do. That is, the control server 60a determines the time required to reach the boundary based on at least part of the position information of the target area, the corrected positioning information of the mobile terminal 30a received by the control server 60a, or the speed information of the mobile terminal 30a. Alternatively, when the distance to the boundary satisfies a predetermined condition, it is determined that the server switching condition has been satisfied.

The determination in step S503 is performed until the server switching condition is satisfied (No in step S503), and when the server switching condition is satisfied, the process proceeds to step S504 (Yes in step S503).

In step S504, the control server 60a controls switching of the correction server 50 (correction executing server) that corrects the positioning information of the mobile terminal 30a. For example, the control server 60a notifies the correction server 50b from the correction server 50a (the correction server 50 currently correcting the positioning information of the mobile terminal 30a) to the correction server 50b to switch the correction execution server. Send to The notification may be sent to one of the correction server 50a and the correction server 50b. By the notification, the correction execution server switching process is performed. The details of the correction execution server switching process will be described later.

As described above, according to this embodiment, in step S503, based on at least part of the position information of the target area, the corrected positioning information received by the control server 60a, or the speed information of the mobile terminal 30a, the server switching condition is satisfied, the control server 60a transmits the notification in step S504. That is, the control server 60a determines the time required to reach the boundary based on at least part of the position information of the target area, the corrected positioning information of the mobile terminal 30a received by the control server 60a, or the speed information of the mobile terminal 30a. Alternatively, at the timing when the distance to the boundary satisfies a predetermined condition, it is determined that the server switching condition has been satisfied, and the above notification is transmitted.

Next, in step S505, the control server 60a receives the post-correction positioning information of the mobile terminal 30a from the correction server 50b newly set as the correction execution server. Further, the control server 60a transmits to the mobile terminal 30a flight control information (see step S17 in FIG. 4) including the corrected positioning information of the mobile terminal 30a received from the correction server 50b.

Next, in step S506, the control server 60a performs control of the mobile terminal 30a as necessary (for example, transmits the notification of step S504 for switching the correction execution server). Control switching. For example, the control server 60a transmits to the control server 60b a request for switching the control execution server from the control server 60a (currently controlling the mobile terminal 30a) to the control server 60b. By transmitting the request, switching processing of the control execution server is performed. The details of the control execution server switching process will be described later.

Note that the size (boundary) of the target area set for the control server 60 and the size (boundary) of the target area set for the correction server 50 may be different. For example, the size of the target area set for the control server 60 may be larger than the size of the target area set for the correction server 50 . In such a case, the switching of the control server 50 in step S506 may not be executed. For example, when the mobile terminal 30a leaves the target area of the correction server 50 but does not leave the target area of the control server 60a, the control server 60a does not need to execute the control execution server switching process. That is, in such a case, the control server 60a does not need to execute step S506. Further, for example, although not shown, the control server 60a may determine whether the switching process of the control server 50 is necessary before step S506. For example, the control server 60a may determine whether or not the mobile terminal 30a will leave the target area set for the control server 60a due to flight, based on preset movement route information. For example, in such a case, when the mobile terminal 30a moves out of the target area set for the control server 60a, the control server 60a may execute step S506. Further, for example, when the mobile terminal 30a does not leave the target area set for the control server 60a, the control server 60a does not need to execute step S506. That is, the control server 60 a may control the control server 60 a not to switch to another control server 60 .

As described above, according to the present embodiment, after the correction execution server is switched from the correction server 50a to the correction server 50b in step S504, the control server 60a transmits a request for switching the control execution server in step S506. . From the viewpoint of safety, it is desirable that the switching of the control execution server that controls the mobile terminal 30 is performed when the positioning of the mobile terminal 30 is being performed with high accuracy. In this embodiment, after switching the correction execution server that corrects the positioning information of the mobile terminal 30 that is approaching the boundary of the target area, the control execution server is switched. is performed when the positioning of the mobile terminal 30 is being performed, and higher security can be ensured.

As described above, according to the present embodiment, the correction execution server is switched from the correction server 50a to the correction server 50b in step S504, and in step S505, the control server 60a receives corrected positioning information of the mobile terminal 30a from the correction server 50b. , in step S506, the control server 60a transmits a request to switch the control execution server in step S506. That is, after the control server 60a receives the post-correction positioning information of the mobile terminal 30a from the post-switching correction execution server after switching the correction execution server that corrects the positioning information of the mobile terminal 30 that is approaching the boundary of the target area. , a request to switch the control execution server is sent. Therefore, switching of the control execution server is performed when positioning of the mobile terminal 30 is being performed with high accuracy, and higher safety can be ensured.

Next, in step S507, the control server 60b determines whether or not the mobile terminal 30a has passed through the boundary of the target area set for the correction server 50a. Whether or not the boundary has been passed is determined based on, for example, the position of the boundary of the target area set for the correction server 50a and the corrected positioning information of the mobile terminal 30a transmitted from the correction server 50b. be.
The determination in step S507 is performed until it is determined that the boundary of the target area has been passed (No in step S507), and when it is determined that the boundary has been passed, the process proceeds to step S508 (Yes in step S507).

In step S508, the control server 60a controls switching of the positioning method of the mobile terminal 30a. For example, the control server 60a sends a control signal to the mobile terminal 30a, which is performing positioning processing using RTK, to perform positioning processing using a method such as GNSS, which has lower positioning accuracy than RTK but consumes less power. Send. As described above, according to the present embodiment, after switching the correction execution server or after switching the control execution server, the positioning method of the mobile terminal 30a is controlled to be switched to a method that consumes less power. As a result, the mobile terminal 30a can fly for a longer time.

Details of the processing corresponding to steps S504 to S506 in FIG. 5 among the processing executed in the communication system 1 will be described with reference to FIG. The processing shown in FIG. 6 is realized by reading and executing a computer program stored in a storage unit by the control unit of the main processing device for each processing.

In step S21, in order to switch the correction execution server from the correction server 50a to the correction server 50b, the control server 60a notifies the correction server 50b of a correction execution server switching request. In step S23, the correction server 50b transmits an acknowledgment to the control server 60a in response to the request for switching the correction execution server.

Next, the control server 60a transmits information (area information) about the area through which the mobile terminal 30a passes or stays to the correction server 50b newly set as the correction execution server (step S25), and the correction server 50b The area information is transmitted to the data center 40 (step S27). The data center 40 transmits information corresponding to the area information received from the correction server 50b in step S27 among the wide-area positioning information to the correction server 50b as narrow-area positioning information (step S29). Next, the mobile terminal 30a transmits the positioning information obtained by the RTK positioning process to the correction server 50b (step S31). The correction server 50b corrects the positioning information based on the narrow-area positioning information received from the data center 40 in step S29 and the positioning information received from the mobile terminal 30a in step S31 to obtain more accurate positioning information (i.e. , corrected positioning information) is calculated (step S33). Next, the correction server 50b transmits the corrected positioning information calculated in step S33 to the control server 60 (step S35). The control server 60 may generate flight control information based on the corrected positioning information and the mobile flight plan information. For example, the control server 60 may compare and analyze the corrected positioning information and the mobile flight plan information, and calculate the error between the coordinates indicated by the corrected positioning information and the coordinates indicated by the mobile flight plan information. The control server may generate information for the mobile terminal 30 to correct the error and fly as flight control information. The control server 60a transmits the flight control information to the mobile terminal 30a (step S37), and controls the flight of the mobile terminal 30a.

Since steps S25 to S37 are the same as the processing shown in steps S11 to S17 in FIG. 4, detailed description thereof is omitted here.

Thereafter, in step S39, the control server 60a transmits a communication connection disconnection request to the correction server 50a. When the correction server 50a receives the request, the communication connection for transmitting the corrected positioning information between the control server 60a and the correction server 50a is disconnected. In subsequent processing, the correction server 50b functions as a correction execution server.

Next, in step S41, in order to switch the control execution server from the control server 60a to the control server 60b, the control server 60a transmits a control right transfer request to the control server 60b. In step S43, the control server 60b transmits an acknowledgment to the control right transfer request to the control server 60a.

In response to receiving the confirmation response from the correction server 50b in step S43, the control server 60a transmits the accumulated positioning data of the mobile terminal 30a and the control information necessary for controlling the mobile terminal 30a to the control server 60b ( Steps S45, S47). The accumulated positioning data of the mobile terminal 30a includes the accumulated past corrected positioning information of the mobile terminal 30a. That is, the accumulated positioning data includes post-correction positioning information of the mobile terminal 30a held by the control server 60a. The accumulated positioning data is transmitted from the control server 60a to the control server 60b in step S45. The control information necessary for controlling the mobile terminal 30a includes the destination and departure point of the mobile terminal 30a (or route information connecting the destination and departure point of the mobile terminal 30a), waypoints, fuel (or on-board battery). information, and at least part of the machine information of the mobile terminal 30a. In step S49, the control server 60b transmits an acknowledgment to the control server 60a in response to receiving the accumulated positioning data and the control information in steps S45 and S47. The control information transmitted in step S47 is information including, for example, the latest mobile flight support information (see, for example, step S10 in FIG. 4) and flight control information (see, for example, step S17 in FIG. 4). be.

Next, in step S51, the control server 60b transmits to the data center 40 a connection switching request for switching the control execution server from the control server 60a to the control server 60b. In step S53, the data center 40 transmits an acknowledgment to the control server 60b in response to receiving the connection switching request from the control server 60b.

Next, in step S55, the control server 60b transmits a connection switching request for switching the control execution server from the control server 60a to the control server 60b to the mobile terminal 30a. In step S57, the mobile terminal 30a transmits an acknowledgment to the control server 60b in response to receiving the connection switching request from the control server 60b.

Next, in step S59, the control server 60b transmits a connection switching request for switching the control execution server from the control server 60a to the control server 60b to the correction server 50b. In step S61, the correction server 50b transmits an acknowledgment to the control server 60b in response to receiving the connection switching request from the control server 60b. As a result, a pair (relationship between the controlled side and the controlling side) is established between the correction server 50b and the control server 60b.

Next, in step S63, the mobile terminal 30a transmits the positioning information of the mobile terminal 30a to the correction server 50b. In step S65, the correction server 50b calculates post-correction positioning information based on the received positioning information of the mobile terminal 30a.

In step S67, the correction server 50b transmits the calculated post-correction positioning information of the mobile terminal 30a to the control server 60b. In step S69, the control server 60b transmits flight control information including the received corrected positioning information of the mobile terminal 30a to the mobile terminal 30a. In subsequent processing, the control server 60b functions as a control execution server.

The embodiments described above are for facilitating understanding of the present invention, and are not intended to limit and interpret the present invention. Elements, conditions, and the like included in the embodiments are not limited to those illustrated, and can be changed as appropriate. Also, it is possible to partially replace or combine the configurations shown in different embodiments.

1 communication system 10 GNSS satellite 20 reference station 30 mobile terminal 31, 51 control unit 31a, 52 CPU
31b, 53 memories 32, 54 communication units 33, 55 storage unit 34 imaging unit 35 promotion unit 36 signal receiver 37 sensor 40 data center 50 correction server 60 control server 100 computer

Claims (11)

a plurality of correction servers including a first correction server set as a correction execution server that generates post-correction positioning information based on positioning information received from a mobile;
a control execution server that transmits a notification for switching the correction execution server from the first correction server to the second correction server to at least one of the first correction server and the second correction server ;
The receiving unit communication system, wherein the control execution server includes a receiving unit that receives the corrected positioning information generated for the moving object from the first correction server. The control execution server,
The communication system according to claim 1, further comprising a transmitting unit configured to transmit the notification at a timing based on the position of the target area preset for the first correction server and the received corrected positioning information. . The control execution server includes a control unit that specifies a time for the moving body to reach a boundary of the target area based on the position of the target area, the corrected positioning information, and the speed of the moving body. ,
The transmission unit transmits the notification at a timing based on the specified time.
3. The communication system of claim 2, comprising: The communication system includes a plurality of control servers including a first control server set as the control execution server that transmits a notification for switching the correction execution server,
The first control server includes a communication unit that transmits a request for switching the control execution server from the first control server to the second control server to the second control server.
A communication system according to any one of claims 1 to 3. 5. The communication system according to claim 4, wherein said communication unit transmits said request after said correction execution server is switched from said first correction server to said second correction server. 6. The communication unit transmits the request after the correction execution server is switched from the first correction server to the second correction server and the corrected positioning information is received from the second correction server. a communication system as described in . 7. The correction server and the control server are configured by edge computing, and one edge server is configured to function as the correction execution server and the control execution server. a communication system as described in paragraph 1. A control server capable of communicating with a plurality of correction servers including a correction server set as a correction execution server that generates post-correction positioning information based on positioning information received from a mobile body,
a receiving unit that receives the post-correction positioning information generated for the mobile object from the correction server;
a communication unit that transmits a notification for switching the correction execution server from a first correction server to a second correction server among the plurality of correction servers to at least one of the first correction server and the second correction server; , a control server. A communication method in a communication system comprising a plurality of correction servers including a correction server set as a correction execution server for generating corrected positioning information based on positioning information received from a mobile body, and a control execution server,
receiving the corrected positioning information generated for the mobile object from the correction server;
The control execution server notifies at least one of the first correction server and the second correction server of the plurality of correction servers to switch the correction execution server from a first correction server to a second correction server. A method of communication , including sending to. A communication method for a control server capable of communicating with a plurality of correction servers including a correction server set as a correction execution server that generates post-correction positioning information based on positioning information received from a mobile object,
The receiving unit of the control server receives the post-correction positioning information generated for the moving object from the correction server;
The communication unit of the control server, among the first correction server and the second correction server, sends a notification for switching the correction execution server from a first correction server to a second correction server among the plurality of correction servers. and transmitting to at least one. the computer,
A control server capable of communicating with a plurality of correction servers including a correction server set as a correction execution server that generates post-correction positioning information based on positioning information received from a mobile body,
a receiving unit that receives the post-correction positioning information generated for the mobile object from the correction server;
a communication unit that transmits a notification for switching the correction execution server from a first correction server to a second correction server among the plurality of correction servers to at least one of the first correction server and the second correction server; , A program for functioning as a control server.

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