Mobile object group control system and method, and communication device

Abstract

To reduce user's burden by enabling flexible control over a communication line corresponding to a service requirement in achieving satellite formation flight.SOLUTION: A movable body group control system forms a movable body group in order to control the movable body group that performs formation flight, includes follower movable bodies, respective movable bodies classified to leader movable bodies for collecting information of the follower movable bodies and controlling the information to mutually perform radio communication on the basis of beam forming or MIMO, and ground stations for performing radio communication with the respective movable bodies. The movable bodies perform control over the follower movable bodies by the leader movable bodies on the basis of an on-board processor to be mounted and control over own locations or postures for performing formation flight, and the ground stations perform line control over radio communication with the movable bodies or line control over radio communication between the movable bodies, and control over the selection of any ground station to perform radio communication with the movable bodies.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a mobile object group control system and method, and a communication device for controlling a group of mobile objects flying in formation, and in particular to a mobile object group control system and method, and a communication device that are suitable for flexibly controlling communication lines in accordance with service requirements. [Background technology]

[0002] In the satellite communications field, large satellites have traditionally been launched into geostationary orbits for operation. However, in recent years, the trend in the satellite communications field has been to shift to small satellites, which can be developed at low cost, due to factors such as manufacturing and launch costs.

[0003] However, the performance of each small satellite is limited compared to that of a large satellite, so this performance is compensated for by linking multiple satellites together to create a communications network.

[0004] Satellite systems that link multiple satellites include satellite constellations and satellite formation flights.

[0005] A satellite constellation is a system in which multiple satellites are placed in the same orbit at long distances from each other and operated without controlling their relative positions. When a satellite constellation is used as a communications system, it can provide global coverage of the Earth with multiple satellites, making it possible to provide a constant communications network to areas on Earth where terrestrial networks are not yet in place.

[0006] On the other hand, satellite formation flight is a system in which satellites are placed closer together than in a satellite constellation and their relative positions are controlled. With this satellite formation flight, by launching new satellites and adding them to the satellite constellation system, it is possible to gradually expand the performance and range of services, enabling more flexible operation. Furthermore, the more satellites there are in the constellation, the better the performance of the constellation becomes, and the weight and power consumption per satellite can be reduced.

[0007] In order to realize satellite formation flight, a technology that applies beamforming has been proposed in the past (see, for example, Patent Document 1).

[0008] Furthermore, in order to realize formation flight of microsatellites, a control method has been proposed in which the relative positions and attitudes are controlled by magnetic force (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 6506365 [Patent Document 2] Japanese Patent Publication No. 2020-32874 Summary of the Invention [Problem to be solved by the invention]

[0010] Current satellite communication systems are designed for each individual service. For example, a system specialized for communications is designed for communications, and a system specialized for observation is designed for observation. Therefore, from the user's perspective, in order to use multiple services, it is necessary to make adjustments with each service provider each time.

[0011] 3GPP is also considering collaboration between satellite communications and terrestrial systems such as 5G / Beyond 5G. (registered trademark)In the future, it is expected that the use cases and scenarios for satellite communications will expand, and services will become more diverse than just conventional broadband communications. It is also expected that the number of users requiring services via satellite communications will increase.

[0012] Therefore, the current policy of building systems specialized for individual services will likely increase the burden on users in coordinating with service providers and will likely be unable to respond to future trends. Furthermore, with conventional satellite formation flight technology, the control configuration of the leader and follower satellites in a constellation is predetermined. For this reason, if, for example, the leader satellite fails, it is not possible to respond flexibly, and the system may cease to function.

[0013] In other words, in order to realize satellite formation flights, there has long been a need for technology that reduces the burden on users by enabling flexible control of communication lines according to service requirements, rather than having to design specialized systems for each individual service.

[0014] Therefore, the present invention has been devised in consideration of the above-mentioned problems, and its purpose is to provide a mobile object group control system, method, and communication device that can reduce the burden on users by enabling flexible control of communication lines in accordance with service requirements when realizing satellite formation flights. [Means for solving the problem]

[0015] A mobile object group control system according to a first aspect of the present invention is a mobile object group control system for controlling a mobile object group flying in formation, the system comprising: mobile objects that constitute the mobile object group and are classified into follower mobile objects and leader mobile objects that collect information about the follower mobile objects and control them; each mobile object wirelessly communicating with each other based on beamforming or MIMO; and a ground station that wirelessly communicates with each of the mobile objects; the mobile objects control the follower mobile objects by the leader mobile object and control their own positions or attitudes for formation flight based on an onboard processor installed in the mobile objects; and the ground station controls the lines of wireless communication with the mobile objects or the lines of wireless communication between the mobile objects, and controls the selection of one of the ground stations that wirelessly communicates with the mobile objects. and further, determining and controlling the services to be provided to the mobile units, and controlling the change of platforms for connections from each mobile unit to a ground station, connections from a group of mobile units constituting each mobile unit to other groups of mobile units, or connections from a group of mobile units constituting each mobile unit to other mobile units. It is characterized by:

[0016] The mobile object group control system according to the second invention is characterized in that, in the first invention, the mobile object performs time synchronization control and mobile object group formation control for forming a mobile object group among other mobile objects based on an onboard processor installed therein.

[0017] A mobile object group control system according to a third aspect of the present invention is the mobile object group control system according to the first aspect of the present invention, If the group of mobile objects is unable to receive the service requirements required for one or more of meteorological observation, environmental observation, soil survey, land use survey, and forest survey, the processing operation is terminated, and if the service requirements are received, the ground station performs decision control of the service having those service requirements.

[0018] The mobile object group control system of the fourth invention is characterized in that, in the first invention, the mobile object performs time synchronization control and mobile object group formation control for forming a mobile object group among other mobile objects based on an onboard processor installed therein, and the ground station performs control to determine the services to be provided to the mobile object, and platform change control for connection from each mobile object to the ground station, connection from the mobile object group constituting each mobile object to other mobile object groups, or connection from the mobile object group constituting each mobile object to other mobile objects.

[0019] A mobile object group control system according to a fifth aspect of the present invention is the system of any one of the first to fourth aspects of the present invention, characterized in that the mobile objects are artificial satellites.

[0020] The communication device of the sixth invention is a communication device that is applicable to any one of the mobile body group control systems of the first to fifth inventions, and is characterized in that it is mounted on the mobile body and has an onboard processor that controls the follower mobile body by the leader mobile body and controls its own position or attitude to perform formation flight.

[0021] The communication device according to the seventh invention is a communication device applicable to any one of the mobile object group control systems of the first to fifth inventions, characterized in that it is mounted on the ground station and comprises control means for controlling the line of wireless communication with the mobile object or the line of wireless communication between the mobile objects, and for controlling the selection of one of the ground stations for wireless communication with the mobile object.

[0022] A mobile object group control method according to an eighth aspect of the present invention is a mobile object group control method for controlling a mobile object group flying in formation, in which the mobile object group is composed of follower mobile objects and leader mobile objects that collect information about the follower mobile objects and then control them, and the mobile objects communicate wirelessly with each other based on beamforming or MIMO, and based on an onboard processor mounted on each mobile object, the leader mobile object controls the follower mobile objects and controls its own position or attitude for performing formation flight, and a ground station that communicates wirelessly with each mobile object controls a line for wireless communication with the mobile object or a line for wireless communication between the mobile objects, and controls the selection of one of the ground stations that communicate wirelessly with the mobile object. and further, determining and controlling the services to be provided to the mobile units, and controlling the change of platforms for connections from each mobile unit to a ground station, connections from a group of mobile units constituting each mobile unit to other groups of mobile units, or connections from a group of mobile units constituting each mobile unit to other mobile units. It is characterized by: [Effects of the Invention]

[0023] According to the present invention having the above-described configuration, it is possible to flexibly control communication lines according to service requirements when realizing formation flights by a group of mobile objects. This makes it possible to flexibly control communication lines according to service requirements, rather than having to design a system specialized for each individual service, thereby reducing the burden on users. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a diagram showing the overall configuration of a mobile object group control system to which the present invention is applied; [Figure 2] FIG. 1 is a diagram showing a form in which data is relayed between a user on the ground and a ground station also installed on the ground via each of the mobile objects constituting a group of mobile objects. [Figure 3] FIG. 10 is a diagram illustrating an example in which data transmitted and received between a user and a ground station is relayed via individual mobile objects in a group of multiple mobile objects. [Figure 4] FIG. 1 is a diagram showing an example in which data transmitted from an Earth observation remote sensing system to a ground station is relayed via individual mobile bodies that make up a group of mobile bodies. [Figure 5] FIG. 1 is a diagram illustrating an example in which data transmitted from an Earth observation remote sensing system to a ground station is relayed via individual mobile bodies of a group of multiple mobile bodies. [Figure 6] FIG. 10 is a diagram showing an example in which data transmitted and received between a deep space observation gravitational wave measurement system and a ground station is relayed via individual moving bodies that make up a group of moving bodies. [Figure 7] FIG. 1 is a diagram showing a form in which data is relayed between a lander, rover, or space plane and a ground station installed on the ground via each of the moving bodies that make up the moving body group. [Figure 8] FIG. 1 is a diagram showing an example of radio wave monitoring of terrestrial stations and users on the ground via a mobile object. [Figure 9] FIG. 1 is a diagram illustrating an example of monitoring space debris. [Figure 10] FIG. 10 is a diagram illustrating an example of a common configuration that is also implemented in a mobile body. [Figure 11] FIG. 9 is a diagram showing a detailed block configuration of a communication unit used in the embodiments of FIGS. [Figure 12] FIG. 10 is a diagram showing a detailed block configuration of a communication unit used in the embodiments of FIGS. [Figure 13] 6 is a diagram showing a detailed block configuration of a communication unit used in the embodiment of FIG. 5. FIG. [Figure 14] FIG. 2 is a diagram showing a detailed block configuration of a control unit mounted on a moving body. [Figure 15] FIG. 1 is a diagram illustrating an example of a block configuration of a control system implemented in a ground station. [Figure 16] FIG. 1 is a diagram showing an example of dividing into an arbitrary number N of mobile object groups (clusters) according to services and users. [Figure 17] FIG. 1 is a diagram illustrating an example of beamforming and MIMO. [Figure 18] 10 is a flowchart showing a control flow in a group of moving objects. [Figure 19] FIG. 1 is a diagram showing an example in which there is a ground station that receives a service request from a user and a ground station to which the gateway station to be used belongs. [Figure 20] 1 is a flowchart for implementing communication at a ground station. [Figure 21] 10 is a flowchart illustrating a case where communication is performed at a ground station other than the ground station that has received a service request from a user. DETAILED DESCRIPTION OF THE INVENTION

[0025] A mobile object group control system to which the present invention is applied will be described in detail below with reference to the drawings.

[0026] 1 shows the overall configuration of a mobile object group control system 1 to which the present invention is applied. The mobile object group control system 1 includes a mobile object group 2 including a plurality of mobile objects 20, a ground station 3 capable of wireless communication with each of the mobile objects 20 constituting the mobile object group 2, an Earth observation remote sensing system 4, a user 5, a deep space observation gravitational wave measurement system 6, a lander 7a and a rover 7b for exploring the moon and planets, a space plane 8, space debris 9, etc. Furthermore, each of the mobile objects 20 constituting the mobile object group 2 can communicate wirelessly with other mobile objects 20 included in the other mobile object groups 2, and can also communicate wirelessly with a single mobile object 20 not included in the mobile object group 2.

[0027] The mobile body 20 is an artificial satellite. The artificial satellite applied to this mobile body 20 may be of any size, and may be a large satellite, a small satellite, or even a microsatellite such as a cubesat. The artificial satellite applied to the mobile body 20 may be in any orbit, such as a low earth orbit (LEO), a medium earth orbit (MEO), a geostationary orbit (GEO), a transfer orbit, a lunar vicinity, or deep space. It is not necessary for all the artificial satellites to be launched at the same time, and the system may expand or contract midway. Each mobile body 20 flies in formation with other mobile bodies 20 that make up the same mobile body group 2, a so-called formation flight.

[0028] In order to realize formation flight, it is not necessary for all of the moving bodies 20 that make up the moving body group 2 to be composed of artificial satellites; one or more or all of them may be composed of flying objects (aircraft, drones, HAPS (High-Altitude Platform Station), UAV (Unmanned Aerial Vehicle), etc.), or ships that move on the sea, underwater, on water, or underwater, such as UAVs and USVs, or vehicles such as automobiles and trains that run on land, or even communication equipment installed on these moving bodies 20.

[0029] In the overall configuration of the mobile object group control system 1 shown in Figure 1, wireless communication is centered around the individual mobile objects 20 that make up the mobile object group 2, but this can be further classified into the following forms depending on each purpose and use.

[0030] 2 and 3 show a configuration in which data is relayed between a user 5 on the ground and a ground station 3 also installed on the ground via individual mobile objects 20 constituting a mobile object group 2. Here, the term "user 5" collectively refers to any communication device, such as a communication device mounted on an airplane, ship, vehicle, or building on the ground, or an individual mobile terminal, smartphone, tablet terminal, or wearable terminal. The configuration in FIG. 2 is an example in which data transmitted and received between the user 5 and the ground station 3 is relayed via individual mobile objects 20 constituting one mobile object group 2. The configuration in FIG. 3 is an example in which data transmitted and received between the user 5 and the ground station 3 is relayed via individual mobile objects 20 in multiple mobile object groups 2 consisting of mobile object group 2a and mobile object group 2b. In this case, relaying may be performed via a single mobile object 20 that does not belong to either mobile object group 2, instead of mobile object group 2b.

[0031] 4 and 5 show data relaying between an Earth observation remote sensing system 4 and a ground station 3 installed on the ground via individual mobile objects 20 constituting a mobile object group 2. The Earth observation remote sensing system 4 here is a sensing system for observing various phenomena on Earth, such as meteorological information, resource exploration, geological exploration, land use surveys, various marine and environmental observations, forest conditions, and crop growth conditions. The configuration in FIG. 4 is an example in which data transmitted from the Earth observation remote sensing system 4 to the ground station 3 is relayed via individual mobile objects 20 constituting one mobile object group 2. The configuration in FIG. 5 is an example in which data transmitted from the Earth observation remote sensing system 4 to the ground station 3 is relayed via individual mobile objects 20 of multiple mobile object groups 2 consisting of mobile object group 2a and mobile object group 2b. In this case, relaying may be performed via a single mobile object 20 that does not belong to either mobile object group 2, as an alternative to mobile object group 2b.

[0032] 6 shows a form in which data is relayed between a deep space observation gravitational wave measurement system 6 and a ground station 3 installed on the ground via individual mobile bodies 20 that make up a mobile body group 2. The deep space observation gravitational wave measurement system 6 here is a system that conducts space observations using gravitational waves. The form in FIG. 6 is an example in which data transmitted and received between the deep space observation gravitational wave measurement system 6 and the ground station 3 is relayed via individual mobile bodies 20 that make up one mobile body group 2. In this case, as an alternative to the mobile body group 2, relaying may be performed via a single mobile body 20 that does not belong to any of the mobile body groups 2.

[0033] FIG. 7 shows a data relay configuration between a lander 7a, a rover 7b, a space plane 8, and a ground station 3 installed on the ground via individual mobile bodies 20 constituting a mobile body group 2. The lander 7a includes any lander capable of landing on the surface of a celestial body. The rover 7b is a vehicle for traveling and observing the surface of a celestial body, but is not limited to this and includes any type of mobile means capable of traveling on the surface of a celestial body. Furthermore, as an alternative to the lander 7a and the rover 7b, data may be relayed via the mobile bodies 20 between an immobile, fixed base station set on the surface of a celestial body. Data transmitted and received between the lander 7a, the rover 7b, the space plane 8, and the ground station 3 is relayed via individual mobile bodies 20 constituting one mobile body group 2b. In this case, relay may be performed from the mobile body group 2b via another mobile body group 2a, or via a single mobile body 20 that does not belong to any mobile body group 2.

[0034] 8 shows an example in which radio wave monitoring of a terrestrial ground station 3 and a user 5 is performed via a mobile object 20. A terrestrial ground station 3 or a user 5 normally communicates with another terrestrial station 3 via a mobile object 20 included in a group of mobile objects 2 as shown in FIGS. 2 and 3. At this time, it is assumed that the mobile object 20 detects illegal radio waves from the terrestrial ground station 3 or the user 5. At this time, the mobile object 20 that detected the illegal radio waves transmits a message to the other terrestrial station 3 via another mobile object 20 included in the group of mobile objects 2, or directly.

[0035] 9 shows an example of space debris monitoring. When space debris 9 is detected through a moving body 20, it is transmitted to the ground station 3 via an individual moving body 20 of the moving body group 2. At this time, it may be relayed via another moving body group 2 or a single moving body 20 that does not belong to the moving body group 2.

[0036] Next, we will explain the configuration of the moving body 20 applied to each embodiment of the moving body group control system 1. In the following, we will explain the case where the moving body 20 is an artificial satellite as an example, but if the moving body 20 is applied to a moving body other than an artificial satellite, it goes without saying that various configurations will be further implemented according to the application target.

[0037] 10 shows an example of a common configuration that can be implemented in any moving body 20. The moving body 20 includes a power supply unit 21, and a recording unit 22, a data acquisition processing unit 23, a communication unit 24, a control unit 25, and a time generation unit 26, each of which is connected to the power supply unit 21. The recording unit 22 is connected to the data acquisition processing unit 23 and the communication unit 24, the communication unit 24 is connected to the control unit 25, and the control unit 25 is connected to the time generation unit 26. Note that not all of the components shown in this moving body 20 are essential, and each component may be omitted as necessary.

[0038] The power supply unit 21 stores the power required for the operation of the moving body 20 itself, and is composed of, for example, a power supply module and batteries specialized for satellites. This power supply unit 21 may incorporate a solar power generation system as needed. The power supply unit 21 supplies the stored power to the recording unit 22, data acquisition processing unit 23, communication unit 24, control unit 25, and time generation unit 26 that are connected to it.

[0039] The recording unit 22 is composed of a server and a storage device for storing various types of information. This recording unit 22 not only stores various types of information required for wireless communication, but also pre-records data according to the various services to be provided and applications. This recording unit 22 also records various types of data acquired and processed by the data acquisition processing unit 23.

[0040] The data acquisition processing unit 23 acquires new data obtained during the flight of the moving body 20, performs various processes on the data, and sends the data to the recording unit 22.

[0041] The communication unit 24 is configured with an antenna for wireless communication with the ground station 3, the Earth observation remote sensing system 4, the user 5, the deep space observation gravitational wave measurement system 6, the lander 7a and rover 7b for exploring the moon and planets, the space plane 8, etc., under the control of the control unit 25, and a circuit unit for performing amplification, frequency conversion, modulation, etc. required for communication. The details of this communication unit 24 will be described later.

[0042] The control unit 25 serves as a central control unit for controlling the entire moving body 20 .

[0043] The time generating unit 26 is a unit for generating accurate time within the moving object 20 .

[0044] 2, 3, 7, and 8. The communication unit 24 includes an RF receiving unit 241, an amplifier 242 connected to the RF receiving unit 241, a frequency conversion unit 243 connected to the amplifier 242, an AD conversion unit 244 and an amplifier 251 connected to the frequency conversion unit 243, a demodulation unit 245 connected to the AD conversion unit 244, a digital processing unit 246 connected to the demodulation unit 245, a modulation unit 248 connected to the digital processing unit 246, a DA conversion unit 249 connected to the modulation unit 248, a frequency conversion unit 250 connected to the DA conversion unit 249 and the amplifier 251, and an RF transmission unit 252 connected to the amplifier 251.

[0045] 2, 3, 7, and 8, the communication unit 24 receives data from the user 5, other mobile bodies 20, the ground station 3, etc., and relays the data to the other users 5, other mobile bodies 20, and the ground station 3. For this reason, the RF receiver 241 transmits the data received to the RF transmitter 252, which is called relay processing. If digital processing is not performed on the mobile body 20 side, the AD converter 244, demodulator 245, digital processor 246, modulator 248, and DA converter 249 may be omitted.

[0046] The RF receiving unit 241 is composed of an antenna or the like that receives a data signal received from an external source. The amplifier unit 242 is composed of an amplifier circuit that amplifies the data signal received by the RF receiving unit 241. The frequency converting unit 243 performs frequency conversion by superimposing the data signal amplified by the amplifier unit 242 on a signal of a desired intermediate frequency. If digital processing is not performed on the mobile object 20 side, the amplifier unit 251 performs amplification processing. However, if digital processing is performed on the mobile object 20 side, the AD converting unit 244 performs AD conversion. The demodulating unit 245 performs demodulation processing on the AD converted data signal. The digital processing unit 246 performs necessary digital processing on the demodulated data signal. At this time, outside the communication unit 24, under the control of the control unit 25, data may be acquired in the data acquisition processing unit 23, and necessary processing may be performed, and necessary information may further be superimposed. The modulator unit 248 modulates the digitally processed data signal. The DA conversion unit performs DA conversion on the modulated data signal and sends it to the frequency conversion unit 250. The frequency conversion unit 250 converts the data signal converted to an intermediate frequency back to the original band. The amplification unit 251 amplifies the input data signal. The RF transmission unit 241 is composed of an antenna and the like that transmits the data signal amplified in the amplification unit 251 to the outside.

[0047] 12 shows a detailed block configuration of the communication unit 24 used in the embodiments of FIGS. 4, 6, and 9. In the embodiments of FIGS. 4, 6, and 9, data observed and measured by the Earth observation remote sensing system 4 and the deep space observation gravitational wave measurement system 6, as well as data from space debris 9, are acquired by the data acquisition processing unit 23, and after performing desired processing on the data, the data is transmitted to the ground station 3 or the like via the communication unit 24. The communication unit 24 used in such a case includes a DA conversion unit 249 connected to the data acquisition processing unit 23, a frequency conversion unit 250 connected to the DA conversion unit 249 and an amplifier unit 251, and an RF transmission unit 252 connected to the amplifier unit 251. The same components and members as those in the above-described configuration are designated by the same reference numerals, and description thereof will be omitted below.

[0048] The DA conversion unit 249 performs DA conversion processing on the data signal acquired by the data acquisition processing unit 23 and outputs the result to the frequency conversion unit 250 .

[0049] Fig. 13 shows a detailed block configuration of the communication unit 24 used in the embodiment of Fig. 5. In the embodiment of Fig. 5, in addition to the case where data observed and measured by the Earth observation remote sensing system 4 is acquired by the data acquisition processing unit 23, there is also a case where data acquired from the Earth observation remote sensing system 4 by another mobile body group 2a is relayed. The communication unit 24 used in such a case includes a DA conversion unit 249 connected to the data acquisition processing unit 23, a frequency conversion unit 250 connected to the DA conversion unit 249 and an amplifier unit 251, an RF transmission unit 252 connected to the amplifier unit 251, an RF receiving unit 241, and an amplifier unit 242 connected to the RF receiving unit 241 and the frequency conversion unit 250. The same components and members as those in the above-mentioned configuration are denoted by the same reference numerals, and description thereof will be omitted below.

[0050] The RF receiving unit 241 receives data signals acquired by other moving object groups 2a from the Earth observation remote sensing system 4. The amplifier 242 amplifies the data signals received by the RF receiving unit 241 and outputs them to the frequency conversion unit 250.

[0051] 14 shows a detailed block configuration of the control unit 25 mounted on the moving object 20. The control unit 25 includes an attitude control unit 261, a formation control unit 262, a time synchronization control unit 263, and an orbit database 265, each connected to a parameter calculation unit 264, and the parameter calculation unit 264 includes a formation parameter calculation unit 264a and a communication parameter control unit 264b. The control unit 25 is mounted on the moving object 20 as an on-board processor in which all of these components are implemented.

[0052] The communication unit 24 connected to the control unit 25 includes a transmitting / receiving unit 271 and a telemetry command transmitting / receiving unit 72 .

[0053] The attitude control unit 261 controls the attitude of the moving body 20 when it flies. The formation control unit 262 performs various controls to coordinate with other moving bodies 20 and fly in formation, i.e., perform so-called formation flight. The attitude control unit 261 and the formation control unit 262 actually generate and transmit control instruction signals, i.e., perform control execution. Parameters required for these controls by the attitude control unit 261 and the formation control unit 262 are sent from the parameter calculation unit 264.

[0054] The time synchronization control unit 263 controls time synchronization and time compensation required for the formation control unit 262 to perform formation flight. The time synchronization control unit 263 works in conjunction with the time generation unit 26, and transmits and receives time information to and from the time generation unit 26 as necessary.

[0055] The formation parameter calculation unit 264a in the parameter calculation unit 264 receives service requirements from the telemetry command transmission / reception unit 272. The formation parameter calculation unit 264a calculates formation parameters such as the configuration of the moving object group 2 (cluster) and the leader-follower relationship according to the received service requirements and the orbital data of the moving object group 2 to which the moving object 20 belongs. Incidentally, if the moving object 20a is the leader moving object, the formation parameter calculation unit 264a generates commands for the follower moving objects 20b and telemetry commands for the ground station 3 and sends these to the telemetry command 272. The formation parameter calculation unit 264a calculates communication parameters required for communication using beamforming, MIMO, etc., based on the information received from the telemetry command transmission / reception unit 272. The formation parameter calculation unit 264a communicates with the formation control unit 262, attitude control unit 261, and time synchronization control unit 263 according to the calculation results, thereby performing time synchronization and formation configuration.

[0056] The communication parameter calculation unit 264b in the parameter calculation unit 264 calculates optimal parameters for amplitude and phase required to perform beamforming, MIMO, etc. based on the line parameters received from the communication unit 24, and transmits them to the communication unit 24.

[0057] The trajectory database 265 stores trajectory data required for the formation parameter calculation unit 264a to calculate various parameters.

[0058] According to the present invention, the communication unit 24 and the control unit 25 shown in FIG. 14 may be realized as an independent communication device.

[0059] 15 shows an example of a block configuration of a control system implemented in the ground station 3. The ground station 3 includes a line monitoring database 31, an orbit database 32, a service providing function unit 33, a telemetry command transmitting / receiving unit 36, and a gateway station transmitting / receiving unit 35, which are each connected to a parameter calculation unit 34, and a communication data processing unit 37 is connected to the gateway station transmitting / receiving unit 35. The parameter calculation unit 34 includes a line parameter calculation unit 341, a gateway station selection calculation unit 342, and a connection destination platform change calculation unit 343.

[0060] The line monitoring database 31 is a database for storing line monitoring information obtained by the gateway station transceiver 35 and the telemetry command transceiver 36. The line monitoring information includes received power, received C / NO (carrier power to noise power density ratio), center frequency, bandwidth, throughput, bit error rate (BER), packet loss rate, rain attenuation, etc.

[0061] The trajectory database 32 stores trajectory data required for the parameter calculation unit 34 to calculate various parameters.

[0062] The line monitoring database 31 and orbit database 32 are connected to a cloud server, shared with all ground stations, and used for parameter optimization.

[0063] The service providing function unit 33 identifies functions required by the moving object group control system 1 in accordance with service requirements from the user.

[0064] The line parameter calculation unit 341 calculates line parameters such as the optimum amplitude and phase parameters required to implement beamforming, MIMO, etc., as well as carrier frequency, bandwidth, output power, modulation method, type of error correction code and its coding rate, multiplexing method, and number of carriers.

[0065] The gateway station selection calculation unit 342 determines the gateway station with which each mobile object 20 in the mobile object group 2 will communicate.

[0066] The destination platform change calculation unit 343 determines the destination platform with which each moving object 20 in the moving object group 2 will communicate.

[0067] The information obtained by each component of the parameter calculation unit 34 is transmitted to each moving object group 2 by command via the telemetry command transmission / reception unit 36 ​​.

[0068] The gateway station transceiver unit 35 has a function of compensating for the amount of Doppler shift with the group of moving objects 2. Radio wave or optical signal communication data to be transmitted from various locations on the ground via the group of moving objects 2 is transmitted to the group of moving objects 2 via the communication data processing unit 37 and the gateway station transceiver unit 35. Furthermore, communication data received from the group of moving objects 2 is transmitted to various locations on the ground via the gateway station transceiver unit 35 and the communication data processing unit 37.

[0069] The present invention may be embodied as an independent communication device including the elements that make up the ground station 3 shown in FIG.

[0070] As shown in FIG. 16, a mobile object group control system 1 to which the present invention is applied may be divided into N mobile object groups (clusters) 2, consisting of an arbitrary number (one or more) of mobile object groups depending on the service and users. In each mobile object group 2, at least one mobile object 20 is assigned as a leader mobile object 20a, and the other mobile objects 20 are designated as follower mobile objects 20b. The leader mobile object 20a collects information about the follower mobile objects 20b, determines parameters such as formation and beamforming, and transmits commands to each follower mobile object 20b. This allows the leader mobile object 20a to control the follower mobile objects 20b. In other words, the leader mobile object 20a may collect the status of each follower mobile object 20b, such as the relative position, attitude, and time, and send commands to the follower mobile objects 20b to control the relative position and attitude of each follower mobile object 20b. Different communication frequencies may be used among the mobile object groups 2. Also, beamforming or MIMO may be used for each moving object group 2.

[0071] The leader mobile unit 20a can be changed depending on the situation. If the performance of the mobile units 20 is uniform, any mobile unit 20 may be assigned as the leader mobile unit 20a. If the performance of the mobile units 20 is not uniform, the mobile unit 20 with the highest performance may be designated as the leader mobile unit 20a. The leader mobile unit 20a may be any mobile unit 20 located at any position in the formation flight.

[0072] FIG. 17 shows examples of beamforming and MIMO. In beamforming, as shown in FIG. 17(a), in a mobile object group 2 consisting of N mobile objects 20 and a mobile object group 2 consisting of M mobile objects 20, beamforming is performed by controlling the phase of radio waves at each satellite, thereby maximizing the overall communication channel capacity. In this case, at least one mobile object 20 constituting the mobile object group 2 may have a beamforming function. In MIMO, as shown in FIG. 17(b), the overall communication channel capacity is maximized in a matrix channel consisting of N×M transmission paths between a mobile object group 2 consisting of N mobile objects 20 and a mobile object group 2 consisting of M mobile objects 20.

[0073] The formation flight of the group of mobile units 2 consisting of such leader mobile unit 20a and follower mobile units 20b may take any form. The formation is changed depending on the users 5 and services being used, and beamforming is used to form a large number of sharp beams, a small number of broad beams, etc. The number of beams can be any number and can be changed depending on the users 5 and services being used.

[0074] The mobile object group control system 1 may also transmit the time generated by each mobile object 20 when transmitting data. This time is generated by the time generating unit 26 described above. The time generating unit 26 may be equipped with an atomic clock, an optical lattice clock, or the like to generate highly accurate time. This enables efficient retransmission based on the transmitted time information when the communication network or data transmission is interrupted and data needs to be retransmitted.

[0075] In the mobile object group control system 1 to which the present invention is applied, the position and speed of the mobile object group 2 may be estimated from the delay and Doppler that can be detected between the mobile object group 2 and the ground station 3 or between the mobile object groups 2 and each other, and the position and beamforming errors of the mobile object 20 may be corrected from the estimated values. Also, the position error of the mobile object group 2 may be detected from the distortion of the receiving beam pattern of the ground station 3, and the position and beamforming parameters (amplitude and phase) of the mobile object 20 may be corrected.

[0076] Furthermore, radio waves may be used between the group of mobile bodies 2 and the ground station 3, between the group of mobile bodies 2 and other groups of mobile bodies 2, between the group of mobile bodies 2 and the deep space observation gravitational wave measurement system 6, and between the group of mobile bodies 2 and a single mobile body 20, and radio waves or light may be used for communication between the mobile bodies 20 within the group of mobile bodies 2. A standardized interface may be implemented in each mobile body 20.

[0077] Next, the operation of the moving object group control system 1 to which the present invention is applied will be described.

[0078] FIG. 18 shows a control flow in the group of moving objects 2. In step S11, it is determined whether or not service requirements have been received. The service requirements here are, for example, requirements required for services provided by the group of moving objects 2 (for example, weather observation, environmental observation, soil survey, land use survey, forest survey, etc.). If these service requirements have been received, the process proceeds to step S12. On the other hand, if the service requirements have not been received, this processing operation is temporarily terminated.

[0079] In step S12, a cluster configuration calculation process is performed. If the cluster is the above-mentioned moving object group 2, the number of moving object groups 2 is detected. Here, it is assumed that the number of moving object groups 2 as a cluster is N.

[0080] Next, the process proceeds to step S13, where cluster formation is started. In this cluster formation, i=1 is set and the process is repeated until i becomes N. As a result, i=1 to N are assigned to the moving object group 2 as each cluster.

[0081] Next, when the process proceeds to step S14, a leader mobile object 20a and a follower mobile object 20b are assigned to the i-th cluster (mobile object group 2).

[0082] Next, the process proceeds to step S15, where a frequency to be used is determined for each of the i-th clusters (groups of moving objects 2). The operations of steps S14 to S15 are repeated for each cluster (group of moving objects 2) until i reaches N. Then, for all of the groups of moving objects 2, a leader moving object 20a and a follower moving object 20b have been assigned and frequencies to be used have been determined, and the process proceeds to step S16.

[0083] Step S16 and subsequent steps are operations that are executed for each moving body group 2. In step S16, a position calculation process is performed for each moving body 20. In this case, time information is transmitted and received between the leader moving body 20a and the follower moving bodies 20b. At this time, the leader moving body 20a calculates the position information of each follower moving body 20b by collecting time information from each follower moving body 20b.

[0084] Next, the process proceeds to step S17, where position and attitude control of the moving bodies 20 is performed. In this case, each moving body 20 controls its own position and attitude using the attitude control unit 261 and formation control unit 262 on the onboard processor installed therein. At this time, each follower moving body 20b may receive information necessary for control from the leader moving body 20a and perform its own position and attitude control based on this information. This allows for formation flight with the leader moving body 20a at the center and the follower moving bodies 20b following it.

[0085] Next, the process proceeds to step S18, where a process for calculating an error from the target position is performed. In this step S18, an error between the actual distance and position information between the moving bodies 20 and the actual target position calculated from the time information is calculated in order to perform the desired formation flight.

[0086] Next, the process proceeds to step S19, where it is determined whether the error calculated in step S18 is within the allowable range. If the result of the determination is that it is within the allowable range, the process proceeds to step S20. If the result of the determination is that it is outside the allowable range, the process returns to step S17, where position control and attitude control of the moving body 20 are performed. In such a case, position control and attitude control of the moving body 20 are performed so as to reduce the error calculated in step S18.

[0087] When the process proceeds to step S20, the location information of each moving object 20 is stored. The location information is stored in the recording unit 22, for example.

[0088] Next, the process proceeds to step S21, where it is determined whether the communication format is beamforming or MIMO. If it is beamforming, the process proceeds to step S22, and if it is MIMO, the process proceeds to step S28.

[0089] When the process proceeds to step S22, a beamforming parameter calculation process is performed. In this case, the communication parameter calculation unit 264a in the parameter calculation unit 264 calculates optimal parameters of amplitude and phase required to perform beamforming.

[0090] Next, the process proceeds to step S23, where provision of the service having the service requirements received in step S11 is started. In this case, the actual service is provided by performing communication using beamforming based on the parameters calculated in step S22.

[0091] Next, the process proceeds to step S24, where the beamforming parameters are updated. Since various communication conditions and line conditions may change while the service of step S23 is actually being provided, the beamforming parameters are updated by recalculating the optimal parameters of amplitude and phase required to perform beamforming.

[0092] Next, the process proceeds to step S25, where the line information is monitored. Next, in step S26, it is determined whether the monitored line information is within an allowable range. If it is within the allowable range, the process proceeds to step S27. On the other hand, if it is outside the allowable range, the process returns to step S24, where the beamforming parameter update process is performed again.

[0093] When the process proceeds to step S27, it is determined whether the service to be provided has been completed. If the service to be provided has been completed, the process ends. On the other hand, if the service to be provided has not been completed, the process from step S23 onwards is repeated.

[0094] When the process proceeds to step S28, a calculation process of MIMO parameters is performed. In this case, communication parameter calculation unit 264a in parameter calculation unit 264 calculates optimal parameters of amplitude and phase required to implement MIMO.

[0095] Next, the process proceeds to step S29, where provision of the service having the service requirements received in step S11 is started. In this case, the actual service is provided by performing MIMO communication based on the parameters calculated in step S28.

[0096] Next, the process proceeds to step S30, where MIMO parameter updating processing is performed. Since various communication conditions and line conditions may change while the service of step S29 is actually being provided, the MIMO parameter updating processing is performed by recalculating the optimal parameters required to implement MIMO.

[0097] Next, the process proceeds to step S31, where line information is monitored. Next, in step S32, it is determined whether the monitored line information is within an allowable range. If the line information is within the allowable range, the process proceeds to step S33. On the other hand, if the line information is outside the allowable range, the process returns to step S30, where the beamforming parameter update process is performed again.

[0098] When the process proceeds to step S33, it is determined whether the service to be provided has been completed. If the service to be provided has been completed, the process ends. On the other hand, if the service to be provided has not been completed, the process from step S29 onwards is repeated.

[0099] Next, we will explain the operation of ground station 3 that receives a service request from a user on the ground. As shown in Figure 19, when there is ground station 3a that receives a service request from a user and ground station 3b to which the gateway station to be used belongs, the flowchart in Figure 20 described below is an example in which communication is carried out at ground station 3a. In ground station 3a, control function 3-1 receives a service request from a user, and communication function 3-2 is responsible for sending and receiving data to and from the user. In ground station 3b, communication function 3-4 is responsible for sending and receiving data to and from the user under the control of control function 3-3.

[0100] As shown in Fig. 20, first, in step S41, it is determined whether or not the service requirements have been received. If the service requirements have been received, the process proceeds to step S42. On the other hand, if the service requirements have not been received, the process ends for the time being.

[0101] When the process proceeds to step S42, control is performed to determine the service to be actually provided.

[0102] Next, the process proceeds to step S43, where the parameter calculation unit 34 reads out from the trajectory database 32 the trajectory data required for calculating various parameters.

[0103] Next, proceed to step S44, where the platform to be actually used when connecting from each mobile body 20 to the ground station 3, connecting from the mobile body group 2 that makes up each mobile body 20 to other mobile body groups 2, or connecting from the mobile body group 2 that makes up each mobile body 20 to other mobile bodies 20 is determined.

[0104] Next, the process proceeds to step S45, where a process is performed to determine which gateway station to use from among ground station 3a, ground station 3b, etc. Next, the process proceeds to step S46, where it is determined whether or not ground station 3a will initiate communication. If ground station 3a will initiate communication, the process proceeds to step S48. On the other hand, if ground station 3a will not initiate communication, the process proceeds to step S47, where the ground station 3 to use for communication is specified. The processing operations after proceeding to step S47 will be described in detail later in FIG. 21.

[0105] Next, the process proceeds to step S48, where it is determined whether various parameters can be calculated on the on-board processor of the mobile unit 20 when wirelessly communicating with the mobile unit 20. If it is determined that the various parameters can be calculated on the on-board processor of the mobile unit 20, the process proceeds to step S50. On the other hand, if it is determined that the various parameters cannot be calculated on the on-board processor of the mobile unit 20, the process proceeds to step S49.

[0106] When proceeding to step S49, the ground station 3 calculates parameters necessary for performing communications using beamforming or MIMO via the parameter calculation unit 34, and transmits the calculated parameters to the mobile object 20. In this case, the line parameter calculation unit 341 refers to the line monitoring database 31 and calculates line parameters such as optimal parameters for amplitude and phase necessary for performing beamforming, MIMO, etc., as well as carrier frequency, bandwidth, output power, etc.

[0107] When the process proceeds to step S50, the ground station 3 transmits various commands required to start the service to the mobile object 20. These commands include information required for channel control based on the channel parameters calculated in step S49 described above. By receiving the command including the information required for this channel control from the ground station 3, each mobile object 20 in the mobile object group 2 can take the initiative in controlling the channel for wireless communication between the ground station 3 and the mobile object 20, in addition to controlling the channel for wireless communication between the mobile objects 20 themselves.

[0108] Next, the process proceeds to step S51, where the service is started. In this case, the ground station 3 monitors the line information (step S52), and stores the monitored line information in the line monitoring database 31 (step S53).

[0109] Next, the process proceeds to step S54, where the ground station 3a transmits and receives data to and from the ground station 3b, which is the gateway station, and then proceeds to step S55, where the ground station 3b transmits communication data to the user.

[0110] Next, the process proceeds to step S56, where it is determined whether the service has ended. If the service has ended, the process proceeds to step S57. On the other hand, if the service has not ended, the process from step S52 onwards is repeated.

[0111] When the process proceeds to step S57, the parameter calculation unit 34 stores trajectory data necessary for calculating various parameters in the trajectory database 32. When the process of step S57 ends, this flow itself ends.

[0112] FIG. 21 is a flowchart showing a case where communication is carried out at a ground station 3b other than the ground station 3a that has received a service request from a user.

[0113] First, in step S58, the ground station 3b determines whether or not it has received an instruction from another ground station 3a. In such a case, in step S47 in Fig. 20, it determines whether or not an instruction has been sent to itself (ground station 3b) as the ground station 3 to be used for communication.

[0114] As a result, if the instruction is given to the ground station 3 itself (ground station 3b) as the ground station 3 to be used for communication, the process proceeds to step S48. On the other hand, if the instruction is not given to the ground station 3 itself (ground station 3b) as the ground station 3 to be used for communication, the process ends.

[0115] The processing operations after proceeding to step S48 are the same as those in Fig. 20, and therefore the same reference numerals and steps are used and the description thereof will be omitted. However, when proceeding to step S54, if the earth station 3b itself is a gateway station, this step may be omitted.

[0116] As described above, the mobile object group control system 1 to which the present invention is applied classifies mobile objects into follower mobile objects 20b and leader mobile objects 20a that collect information about the follower mobile objects 20b and control them. Based on an onboard processor installed on the mobile object 20, the leader mobile object 20a controls the follower mobile objects 20b and controls its own position or attitude for formation flight. The ground station 3 takes the lead in controlling the wireless communication link between the ground station 3 and the mobile objects 20, or the wireless communication link between the mobile objects 20, and also takes the lead in controlling the selection of one of the ground stations 3a, 3b, ... that will communicate wirelessly with the mobile object 20.

[0117] Of these various types of control, the control of the follower mobile body 20b by the leader mobile body 20a and the control of its own position or attitude for formation flight based on an onboard processor mounted on the mobile body 20 side are relatively affected by delays, the amount of calculation is relatively small, and the control can be completed using only local information in the mobile body group 2. Only such control is left to the mobile body 20 side.

[0118] On the other hand, the control of the radio communication line between the ground station 3 and the mobile body 20, or the radio communication line control between the mobile bodies 20, and further the selection of one of the ground stations 3 to communicate with the mobile body 20 by radio, which is relatively less affected by delay, requires a relatively large amount of calculation, and requires global information such as the ground network and use cases, is left to the ground station 3.

[0119] This enables flexible control of communication lines according to service requirements when realizing formation flight by the mobile object group 2. This makes it possible to flexibly control communication lines according to service requirements, rather than having to design a specialized system for each individual service, thereby reducing the burden on users.

[0120] In addition, according to the present invention, based on an onboard processor mounted on the moving body 20 side, the formation control of a moving body group 2 (cluster) with other moving bodies 20 and the control of time synchronization are performed, which are relatively affected by delay, have a relatively small amount of calculation, and can be completed using only local information in the moving body group 2. Furthermore, the ground station 3 performs control to determine services to be provided to the moving bodies 20, which are relatively calculated and require global information such as terrestrial networks and use cases, and platform change control for connections from each moving body 20 to the ground station 3, connections from the moving body group 2 constituting each moving body 20 to other moving body groups 2, and connections from the moving body group 2 constituting each moving body 20 to other moving bodies 20. This enables more flexible control of communication lines according to service requirements when realizing formation flights by the moving body group 2. [Explanation of symbols]

[0121] 1 Mobile fleet control system 2. Mobile Groups 3. Ground Station 4. Earth Observation Remote Sensing System 5 users 6. Deep Space Observation Gravitational Wave Measurement System 7a Lander 7b Rover 8 Space Plane 9 Space Debris 20 Mobile 21 Power supply section 22 Recording section 23 Data acquisition processing section 24 Communications Department 25 Control Unit 26 Time generator 31 Line Monitoring Database 32 Orbital Database 33 Service Provision Function Department 34 Parameter calculation unit 35 Gateway station transmitter / receiver 36 Telemetry command transmitter / receiver 37 Communication data processing section 72 Telemetry command transmitter / receiver 241 Receiving unit 241 Transmitter 242 Amplifier 243 Frequency conversion unit 244 Conversion Unit 245 Demodulation Section 246 Digital Processing Unit 248 Modulation section 249 Conversion Unit 250 Frequency conversion unit 251 Amplification Unit 252 Transmitter 261 Attitude Control Unit 262 Formation Control Unit 263 Time Synchronization Control Unit 264 Parameter Calculation Unit 265 Trajectory Database 271 Transmitter / Receiver 272 Telemetry Commands 272 Telemetry command transmitter / receiver 341 Line Parameter Calculation Unit 342 Gateway Station Selection Calculation Unit 343 Connection Platform Change Calculation Unit

Claims

1. A mobile object group control system for controlling a group of mobile objects flying in formation, Each mobile object constituting the group of mobile objects is classified into a follower mobile object and a leader mobile object that collects information about the follower mobile objects and controls the follower mobile objects, and the mobile objects communicate with each other wirelessly based on beamforming or MIMO; a ground station for wireless communication with each of the mobile units; The moving body controls the follower moving body by the leader moving body and controls its own position or attitude for formation flight based on an onboard processor installed therein; The ground station performs line control of wireless communication with the mobile unit or line control of wireless communication between the mobile units, and control of selection of any of the ground stations to wirelessly communicate with the mobile unit, and further performs control of determining services to be provided to the mobile units, and control of platform changes for connections from each mobile unit to the ground station, connections from a group of mobile units constituting each mobile unit to other groups of mobile units, or connections from a group of mobile units constituting each mobile unit to other mobile units. A mobile object group control system characterized by the above.

2. The mobile body performs time synchronization control and mobile body group formation control for forming a mobile body group among other mobile bodies based on an on-board processor mounted thereon.

2. The mobile object group control system according to claim 1, wherein:

3. A mobile object group control system as described in claim 1, characterized in that if the mobile object group is unable to receive service requirements required for one or more of meteorological observation, environmental observation, soil survey, land use survey, and forest survey, the processing operation is terminated, and if the service requirements are received, the ground station performs decision control of the service having those service requirements.

4. the mobile body performs time synchronization control and mobile body group formation control for forming a mobile body group among other mobile bodies based on an onboard processor installed therein; The ground station determines and controls the services to be provided to the mobile units, and controls the change of platforms for connections from each mobile unit to the ground station, connections from a group of mobile units constituting each mobile unit to other groups of mobile units, or connections from a group of mobile units constituting each mobile unit to other mobile units.

2. The mobile object group control system according to claim 1, wherein:

5. The above moving object is an artificial satellite.

5. The mobile object group control system according to claim 1, wherein:

6. A communication device applicable to the mobile object group control system according to any one of claims 1 to 5, An on-board processor is installed on the moving body and controls the follower moving body by the leader moving body and controls its own position or attitude for formation flight. A communication device comprising:

7. A communication device applicable to the mobile object group control system according to any one of claims 1 to 5, The ground station is equipped with a control means for controlling a line of wireless communication with the mobile unit or a line of wireless communication between the mobile units, and for selecting one of the ground stations for wireless communication with the mobile unit. A communication device comprising:

8. A method for controlling a group of moving objects flying in formation, comprising: The group of mobile bodies is composed of follower mobile bodies and leader mobile bodies that collect information on the follower mobile bodies and then control them, and the leader mobile body controls the follower mobile bodies and its own position or attitude for formation flight based on an onboard processor mounted on each mobile body that wirelessly communicates with each other based on beamforming or MIMO; At a ground station that wirelessly communicates with each of the mobile units, control of the line for wireless communication with the mobile unit or the line for wireless communication between the mobile units, and control of selection of any of the ground stations that wirelessly communicate with the mobile unit, and further control of determining services to be provided to the mobile units, and control of changing platforms for connections from each of the mobile units to the ground station, connections from a group of mobile units that constitute each of the mobile units to other groups of mobile units, or connections from a group of mobile units that constitute each of the mobile units to other mobile units. A mobile object group control method characterized by the above.

9. A method for controlling a group of mobile objects as described in claim 8, characterized in that if the group of mobile objects cannot receive service requirements required for one or more of meteorological observation, environmental observation, soil survey, land use survey, and forest survey, the processing operation is terminated, and if the service requirements are received, the ground station performs decision control to determine the service having those service requirements.

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