Edge computing systems and main satellites

Abstract

To provide an edge computing system based on LEO constellation, which enables each satellite and a ground facility to quickly communicate with an edge server included in a main satellite.SOLUTION: An edge computing system 11 comprises: a plurality of satellites 30 flying on a target track. Each satellite 30 includes a first communication device that communicates with the satellites 30 located front and rear in an advancing direction and a second communication device that communicates with a ground facility 90. The satellites 30 form an annular communication network. One of the satellites 30 is a main satellite 40 provided with a computer 41 and an edge server 42 that stores track information of each satellite 30. The computer 41 generates achievement information, and derives time TmO of passage, above the ground facility 90, of a satellite m passing above the ground facility 90. The main satellite 40 transmits the achievement information through the annular communication network to the satellite m. The satellite m transmits the achievement information to the ground facility 90.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present disclosure relates to an edge computing system and a main satellite.

Background Art

[0002] In communication using GEO (Geostationary Earth Orbit) satellites, latency associated with long-distance communication has been an issue. Therefore, in recent years, the development of communication satellite systems using mega constellations consisting of LEO (Low Earth Orbit) satellite groups has been progressing. However, in the current communication satellite system, although individual satellites communicate by the bent pipe method, inter-satellite communication is not implemented. Therefore, adding an inter-satellite communication function to the communication satellite system has been eagerly awaited.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 discloses a communication satellite system using an LEO constellation consisting of LEO satellites that perform optical inter-satellite communication with satellites located in the front, rear, left, and right. However, according to the communication satellite system, since the left-right replacement of the orbit occurs at the southern and northern ends of the orbital plane, there is a problem that communication interruption occurs twice per week in communication with satellites located on the left and right that are flying in adjacent orbits. Further, along with this problem, there is a problem that it is necessary to establish a high-precision optical axis alignment technology in order to establish a line by optical wireless communication twice per week, and there is also a problem that the loss time is large.

[0005] This disclosure aims to enable each satellite and ground equipment to rapidly communicate with the edge server provided by the main satellite in an edge computing system using an LEO constellation. [Means for solving the problem]

[0006] The edge computing system related to this disclosure is An edge computing system consisting of multiple satellites orbiting in a target orbital plane, Each of the aforementioned plurality of satellites is designated as a target satellite, and the target satellite is a satellite flying in the target orbital plane and is equipped with a first communication device that communicates with satellites located in front of and behind the target satellite in its direction of travel, and a second communication device that communicates with ground equipment installed on the ground. The aforementioned multiple satellites form a circular communication network. Any of the satellites comprising the aforementioned plurality of satellites is a main satellite equipped with a computer and an edge server that stores orbital information for each of the plurality of satellites. The aforementioned computer is By performing the analysis process, result information is generated. Based on the orbital information stored in the edge server, a satellite that passes over the ground facility is selected from among the multiple satellites as satellite m, and the time Tm0 at which satellite m passes over the ground facility is derived. The main satellite transmits the results information to the satellite m via the circular communication network. The satellite m transmits the results information to the ground equipment at the time Tm0. [Effects of the Invention]

[0007] The edge computing system relating to this disclosure may be based on an LEO constellation. In this disclosure, the edge computing system consists of multiple satellites orbiting in the target orbital plane. The multiple satellites form a ring-shaped communication network. One of the satellites constituting the multiple satellites is a main satellite equipped with a computer and an edge server that stores the orbital information of each of the multiple satellites. The computer generates result information by performing analysis processing, and based on the orbital information stored by the edge server, selects a satellite that will pass over the ground equipment from among the multiple satellites as satellite m, and derives the time Tm0 when satellite m will pass over the ground equipment. The main satellite transmits the result information to satellite m via the ring-shaped communication network. Satellite m transmits the result information to the ground equipment at time Tm0. Accordingly, according to this disclosure, in an edge computing system using an LEO constellation, each satellite and ground equipment can quickly communicate with the edge server provided by the main satellite. [Brief explanation of the drawing]

[0008] [Figure 1] A diagram showing an outline of the communications satellite system 10 according to Embodiment 1. [Figure 2] A diagram illustrating the circular communication network according to Embodiment 1. [Figure 3] A diagram showing an example of the hardware configuration of satellite 30 according to Embodiment 1. [Figure 4] A diagram showing an example of the hardware configuration of the ground equipment 90 according to Embodiment 1. [Figure 5] A diagram illustrating an example of the operation of the communications satellite system 10 according to Embodiment 1. [Figure 6] A diagram showing the formation of a circular communication network. [Figure 7] A diagram showing how communication is performed with satellites located in front, behind, to the left, and to the right. [Figure 8] A diagram illustrating the left-right reversal of satellite orientation. [Figure 9] A diagram illustrating inter-railway communication according to Embodiment 1. [Figure 10]A diagram for explaining inter-orbit communication according to Embodiment 1. [Figure 11] It is a diagram showing a state where the rotation of the earth and the rotation of the orbital plane of the inclined orbit satellite are not synchronized. (a) is a specific example of the state at 06:00, and (b) is a specific example of the state at 12:00. [Figure 12] A diagram showing an example of the hardware configuration of the ground facility 90 according to a modification of Embodiment 1. [Figure 13] A diagram showing a configuration example of the edge computing system 11 according to Embodiment 2. [Figure 14] A diagram for explaining an operation example of the edge computing system 11 according to Embodiment 2.

Modes for Carrying Out the Invention

[0009] In the description of the embodiments and the drawings, the same elements and corresponding elements are denoted by the same reference numerals. The description of the elements denoted by the same reference numerals will be omitted or simplified as appropriate. The arrows in the figures mainly indicate the flow of data or the flow of processing. Also, "section" may be appropriately read as "circuit", "step", "procedure", "process" or "circuitry". In this specification, an artificial satellite may also be simply referred to as a satellite. Also, in the description of the embodiments, directions or positions such as "up", "down", "left", "right", "front", "rear", "front", and "back" may be indicated. Those notations are only for convenience of explanation and do not limit the arrangement and orientation of the configuration such as devices, instruments, or components.

[0010] Embodiment 1. Hereinafter, this embodiment will be described in detail with reference to the drawings.

[0011] ***Description of the Configuration*** FIG. 1 shows an overview of the communication satellite system 10 according to this embodiment. As shown in this figure, the communication satellite system 10 includes a satellite constellation 20 and a ground facility 90.

[0012] The satellite constellation 20 consists of multiple orbital planes and is typically an inclined orbit satellite constellation in which each satellite 30 is in an inclined orbit. That is, the communications satellite system 10 consists of multiple orbital planes. The satellite constellation 20 may also be a Low Earth Orbit (LEO) constellation. Furthermore, the azimuth component of the normal vector to each of the multiple orbital planes is dispersed in the longitude direction. When each of the multiple orbital planes is considered a target orbital plane, the target orbital plane is an orbital plane corresponding to an inclined orbit, and multiple satellites 30 are flying in the target orbital plane. Furthermore, when each satellite 30 flying in the target orbital plane is considered a target satellite, the target satellite is equipped with a first communications device, a second communications device, and a third communications device. The first communications device communicates with satellites 30 flying in the orbital plane in which the target satellite is flying, and which are located in front of and behind the target satellite in the direction of travel. The second communications device communicates with ground equipment 90 installed on the ground. The third communication device communicates with satellite 30 flying in a different orbital plane in the vicinity of the intersection point formed in a plan view between the orbital plane in which the target satellite is flying and a different orbital plane. At least two of the first, second, and third communication devices may be configured as an integral unit. The vicinity of the intersection point is the area surrounding the intersection point, including the intersection point itself. The range of the vicinity of the intersection point may be defined as appropriate. Furthermore, in the target orbital plane, multiple satellites 30 flying in the target orbital plane form a circular communication network. Figure 2 is a diagram illustrating the circular communication network formed by multiple satellites 30. As shown in Figure 2, by communicating between adjacent satellites 30 on the same orbit, a circular communication network is formed in each of the multiple orbital planes. Specific examples of the satellite constellation 20 are disclosed in [Reference 1] and [Reference 2]. The communications satellite system 10 appropriately incorporates the functions disclosed in these references. The satellite constellation 20 may also be a megaconstellation.

[0013] [Reference 1] Japanese Patent Publication No. 2021-054167 [Reference 2] Japanese Patent Publication No. 2021-070342

[0014] The ground equipment 90 includes a ground-side communication device 810 and a satellite control device 91, and controls the satellite constellation 20 by communicating with each satellite 30. The satellite control device 91 is a computer that generates various commands for controlling each satellite 30, and includes hardware such as processing circuits and input / output interfaces. The processing circuits generate various commands. Input devices and output devices are connected to the input / output interfaces. The satellite control device 91 is connected to the ground-side communication device 810 via the input / output interfaces. The ground-side communication device 810 communicates with each satellite 30. Specifically, the ground-side communication device 810 transmits various commands to each satellite 30.

[0015] Figure 3 shows an example of the hardware configuration of satellite 30. The hardware configuration of satellite 30 will be explained with reference to Figure 3. Satellite 30 comprises a satellite control device 31, a communication device 32, a propulsion device 33, an attitude control device 34, and a power supply device 35. Satellite 30 may also have components that realize various other functions, but Figure 3 describes the satellite control device 31, the communication device 32, the propulsion device 33, the attitude control device 34, and the power supply device 35.

[0016] The satellite control device 31 is a computer that controls the propulsion system 33 and the attitude control device 34, and is equipped with processing circuits. Specifically, the satellite control device 31 controls the propulsion system 33 and the attitude control device 34 according to various commands transmitted from ground equipment 90 and the like. The communication device 32 is a device that performs communication with the outside of the satellite 30. The communication device 32 is also a collective term for the first communication device, the second communication device, and the third communication device. The propulsion device 33 is a device that provides thrust to the satellite 30 and changes the speed of the satellite 30. The attitude control device 34 is a device for controlling attitude elements such as the attitude of the satellite 30, its angular velocity, and its line of sight. The attitude control device 34 changes each attitude element in a desired direction, or maintains each attitude element in a desired direction. The attitude control device 34 comprises attitude sensors, actuators, and a controller. The attitude sensors include devices such as a gyroscope, Earth sensor, solar sensor, star tracker, thruster, and magnetic sensor. The actuators include devices such as attitude control thrusters, momentum wheels, reaction wheels, and control moment gyros. The controller controls the actuators according to measurement data from the attitude sensors or various commands from ground equipment 90, etc. The power supply unit 35 is equipped with devices such as solar cells, batteries, and a power control device, and supplies power to each device mounted on the satellite 30.

[0017] The processing circuit provided in the satellite control device 31 will now be described. The processing circuit may be dedicated hardware or a processor that executes a program stored in memory. In the processing circuit, some functions may be implemented by dedicated hardware, and the remaining functions may be implemented by software or firmware. In other words, the processing circuit can be implemented by hardware, software, firmware, or a combination thereof. Dedicated hardware specifically includes single circuits, composite circuits, programmed processors, parallel programmed processors, ASICs, FPGAs, or a combination thereof. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field Programmable Gate Array.

[0018] Figure 4 shows an example of the hardware configuration of the ground equipment 90. The ground equipment 90 communicates with the satellite 30. The ground equipment 90 is connected to the ground-side communication device 810, and the ground equipment 90 communicates with the satellite 30 via the ground-side communication device 810. The ground equipment 90 may also be a mobile terminal.

[0019] The ground equipment 90 includes a processor 710, as well as other hardware such as a main memory 720, an auxiliary memory 730, an input interface 740, an output interface 750, and a communication interface 760. In Figure 4, interfaces are denoted as IF. The processor 710 is connected to the other hardware via signal lines 770 and controls this other hardware.

[0020] The ground equipment 90 includes a control unit 711 as a functional element. The functions of the control unit 711 are realized by hardware or software. The control unit 711 performs processing according to the instructions of the communications satellite program.

[0021] ***Explanation of operation*** The operating procedures of the communications satellite system 10 correspond to communications satellite methods. Furthermore, the program that implements the operation of the communications satellite system 10 corresponds to a communications satellite program. The communications satellite program is also a general term for the programs that operate in each device of the communications satellite system 10. The communications satellite program may be recorded on a computer-readable non-volatile recording medium. Specific examples of non-volatile recording media include optical discs or flash memory. The communications satellite program may also be provided as a program product.

[0022] <Example of operation according to Embodiment 1> Figure 5 illustrates this example of operation. This example of operation will be explained with reference to Figure 5.

[0023] (1) Communication with ground equipment The first receiving satellite, which is satellite 30 orbiting in the first orbital plane, receives communication data, which is data transmitted by the first ground facility 90, above the first ground facility 90. The first orbital plane is the orbital plane that passes above the first ground facility 90, and is one of several orbital planes. The area above the ground facility 90 is the region in which satellite 30 can communicate with the ground facility 90.

[0024] (2) Communication on the same orbit The first receiving satellite shares communication data with other satellites 30 flying in the first orbital plane through a circular communication network formed in the first orbital plane.

[0025] (3) Inter-orbit communication Any of the multiple satellites 30 flying in the first orbital plane transmits communication data to the second receiving satellite, which is a satellite 30 flying in the second orbital plane, near the intersection point formed in a plan view between the first orbital plane and the second orbital plane. The second orbital plane is the orbital plane that passes over the second ground facility 90 and is any of the multiple orbital planes other than the first orbital plane.

[0026] (4) Communication on the same orbit The second receiving satellite shares communication data with other satellites 30 orbiting in the second orbital plane through a circular communication network formed in the second orbital plane.

[0027] (5) Communication with ground facilities One of the multiple satellites 30 orbiting in the second orbital plane transmits communication data to the second ground facility 90 while orbiting above it.

[0028] In recent years, there has been an increase in plans to construct communication satellite networks using large-scale satellite constellations called megaconstellations. In a megaconstellation, for example, each satellite in each orbital plane communicates with the satellites in front of and behind it to form a ring-shaped communication network. Furthermore, each satellite in each orbital plane communicates with satellites in adjacent orbital planes that are located to the left and right of each satellite in that orbital plane. As a result, a mesh communication network is constructed in which each satellite communicates with a total of four satellites located in front, behind, to the left and to the right. Figure 6 shows how the ring-shaped communication network is formed. Figure 7 shows how a satellite communicates with a total of four satellites located in front, behind, to the left and to the right. However, directing control of the communication device is necessary to maintain communication status when communicating with adjacent orbits. Furthermore, because the orbits are swapped left and right at the northernmost and southernmost points of the orbital plane, it is difficult to maintain a single communication. Figure 8 shows how the left-right swap occurs at the northernmost point of the orbital plane. In Figure 8, until the northernmost point is reached, the satellite flying in orbit 2 is positioned to the right of the direction of travel of the satellite flying in orbit 1. On the other hand, after reaching the northernmost point, the satellite flying in orbit 2 is positioned to the left of the direction of travel of the satellite flying in orbit 1.

[0029] In an inclined orbit satellite constellation, there are two intersection points between two orbital planes with different normal vectors. Therefore, if satellite 30 flying in one orbital plane and satellite 30 flying in another orbital plane having a normal vector different from that of the first orbital plane communicate satellite information via inter-orbital communication at the point when both satellites pass near one of the intersection points formed by the first orbital plane and the other orbital plane in a plan view, satellite information for both orbital planes can be shared between the two satellites 30. Similarly, each satellite 30 can share satellite information for all orbital planes. Figure 9 is a diagram illustrating inter-orbital communication, showing a specific example of a satellite 30 orbiting in one orbital plane communicating with satellites 30 orbiting in all other orbital planes. Figure 10 is a diagram illustrating inter-orbital communication, showing a specific example of a satellite 30 flying in one orbital plane communicating with two other satellites 30 flying in the other two orbital planes.

[0030] The inter-satellite communication conducted when satellite 30 passes near an intersection of orbital planes is not long-distance communication like inter-orbital communication, but rather short-range communication. Therefore, as a concrete example, this inter-satellite communication can be realized using a simple communication device with an omnidirectional antenna or a fixed antenna. Furthermore, there are numerous combinations of intersections where communication is necessary to share satellite information across all orbital planes. Therefore, each satellite 30 does not need to perform proximity communication at all intersections of its inclined orbit; it only needs to perform proximity communication in the vicinity of each intersection belonging to a rationally selected combination of intersections. As a specific example, consider the case where the first ground facility 90 communicates with the second ground facility 90 via the communication satellite system 10. In this case, the rotation of the Earth and the rotation of the orbital plane of the inclined satellite are not synchronized. Therefore, the orbital plane to which the satellite 30 flying above the first ground facility 90 at time T0 belongs is limited. Figure 11 illustrates the situation where the rotation of the Earth and the rotation of the orbital plane of the inclined satellite are not synchronized. In Figure 11, (a) shows a specific example of the situation at 06:00, and (b) shows a specific example of the situation at 12:00. In Figure 11, the orbital plane to which the satellite 30 capable of communicating with the ground facility 90 flies is not necessarily the same at 06:00 and 12:00. Here, the orbital plane over the first ground facility 90 at time T0 is called the first orbital plane. The orbital plane over the second ground facility 90 at time T0 is called the second orbital plane. When the first and second orbital planes are the same, communication can be made between the first and second ground facility 90 via the annular communication network. On the other hand, when the first and second orbital planes are different, it is necessary to connect the first annular communication network formed by the first orbital plane and the second annular communication network formed by the second orbital plane. Therefore, the first annular communication network and the second annular communication network can be connected by communication between satellites 30 passing near one of the intersection points formed by the first and second orbital planes in a plan view. Furthermore, if the orbital altitude of the first orbital plane and the orbital altitude of the second orbital plane are the same, then an intersection point exists between the first and second orbital planes. Therefore, communication between satellite 30 belonging to the first orbital plane and satellite 30 belonging to the second orbital plane can be performed near one of the intersection points formed by the first and second orbital planes. On the other hand, in cases where the orbits of the first and second orbital planes are elliptical orbits with eccentricity, as a specific example, communication between satellite 30 belonging to the first orbital plane and satellite 30 belonging to the second orbital plane can be performed near the point of closest approach between the first and second orbital planes, rather than at the intersection point. In other words, the intersection point formed by the first and second orbital planes in a plan view may not be the point where the first and second orbital planes actually intersect, such as the point of closest approach between the first and second orbital planes.

[0031] Here, LEO satellites pass over any ground equipment in a short amount of time. Furthermore, LEO satellites have asynchronous orbits, meaning that the rotation of the LEO satellite's orbital plane is not synchronized with the Earth's rotation, so the orbital plane over which the LEO satellite passes changes moment by moment. Therefore, in order to communicate from one ground equipment to another using conventional technology, it is necessary to plan the operation in advance by searching for the orbital plane over each of the two ground equipment, searching for the communication path, selecting the satellites to pass through, and setting the times when each satellite along the communication path will send and receive information. Consequently, conventional technology has the problem of making the operation of the communication satellite system complicated. In addition, conventional technology has the problem that the ground equipment must generate communication commands to the satellite based on the operation plan and transmit the generated communication commands to the satellite in orbit. According to this example, since the longitude separation angle of the normal vectors of the first and second orbital planes is known, the position of the intersection point between the first and second orbital planes is also known. Therefore, according to this example, when the first ground equipment 90 communicates with the second ground equipment 90 via the communication satellite system 10, it is not necessary to go through multiple orbital planes by utilizing the known position of the intersection point between the first and second orbital planes. Thus, this example has the effect of enabling communication between adjacent orbits without complex communication route searching. Furthermore, this example has the effect of reducing the load on the ground equipment.

[0032] <Example of operation according to Embodiment 1> This example of operation is an extended version of Example 1 of Embodiment 1. In this example of operation, the total number of orbital planes constituting the multiple orbital planes is 12 or more, and the total number of satellites 30 flying in each of the multiple orbital planes is 15 or more.

[0033] With the advent of supersonic glide missiles, relying solely on geostationary satellites for launch detection is no longer sufficient to deal with projectiles. Therefore, a projectile tracking system using low Earth orbit satellite constellations is urgently needed. Monitoring directed towards the Earth's periphery is also called rim monitoring, and it allows for the monitoring of projectiles against a backdrop of space. Therefore, it has the effect of allowing the projectile itself, whose temperature rises after the end of its thrust, to be monitored by infrared monitoring equipment without being obscured by errors. Information about projectiles acquired by low-Earth orbit satellites needs to be transmitted quickly to the appropriate response assets. In this context, a communications satellite system capable of rapidly transmitting satellite information to ground facilities 90 located at 35 degrees North latitude and 140 degrees East longitude was highly desired.

[0034] This example demonstrates the ability to quickly transmit satellite information to ground equipment 90. Furthermore, it allows for the implementation of communication devices between orbital planes with different normal vectors at a relatively low cost.

[0035] ***Other configurations*** <Example 1> In this embodiment, the functions of the control unit 711 are implemented in software. As an alternative, the functions of the control unit 711 may be implemented in hardware. Figure 12 shows this alternative.

[0036] The ground equipment 90 is equipped with an electronic circuit 780 instead of a processor 710. The electronic circuit 780 is a dedicated electronic circuit that implements the functions of the control unit 711. Specifically, the 780 electronic circuits include single circuits, complex circuits, programmed processors, parallel programmed processors, logic ICs (Integrated Circuits), GAs (Gate Arrays), ASICs, or FPGAs. The functions of the control unit 711 may be implemented by a single electronic circuit, or they may be implemented by distributing them across multiple electronic circuits. As another variation, some functions of the control unit 711 may be implemented by the electronic circuit 780, and the remaining functions may be implemented in software.

[0037] The processor 710, electronic circuit 780, main memory 720, and auxiliary memory 730 are collectively referred to as the processing circuit. In other words, in the ground equipment 90, the functions of the control unit 711 are realized by the processing circuit. The ground equipment 90 according to other embodiments may also have the same configuration as this modified example.

[0038] Embodiment 2. The following will explain the differences from the previously described embodiment, primarily with reference to the drawings.

[0039] ***Explanation of the structure*** Figure 13 shows an example configuration of the edge computing system 11 according to this embodiment. The edge computing system 11 consists of a plurality of satellites 30 orbiting in the target orbital plane, and also includes a main satellite 40. The number of main satellites 40 in the edge computing system 11 may be any number. A circular communication network is formed in the target orbital plane by the satellites 30 and the main satellite 40.

[0040] The satellite 30 according to this embodiment does not need to be equipped with a third communication device.

[0041] The configuration of the main satellite 40 is the same as that of satellite 30, except that it includes a computer 41 and an edge server 42. The main satellite 40 may implement the functions of satellite 30. Each of the computer 41 and the edge server 42 is a computer. These computers may be the same as the computers provided in the ground equipment 90. The computer 41 and the edge server 42 may be configured as an integrated unit as appropriate. Computer 41 performs analysis processing based on instructions from ground equipment 90. During this process, computer 41 receives data from ground equipment 90 as needed. Computer 41 also generates a transmission command, which is a command for satellite m, to communicate the results information to ground equipment 90. The edge server 42 stores orbital information for satellite 30 and the main satellite 40.

[0042] Ground equipment 90 refers to ground equipment that constitutes the data center, or ground equipment owned by a user. A user, specifically, is a customer who has a contract with the data center operator.

[0043] ***Explanation of operation*** <Example of operation according to Embodiment 2> The following describes an example of the operation of the edge computing system 11. First, the computer 41 generates result information by performing analysis processing. Next, the computer 41 selects a satellite that passes over the ground facility 90 from among several satellites based on the orbital information stored by the edge server 42, and derives the time Tm0 when satellite m passes over the ground facility 90. Here, the collective term for satellite 30 and the main satellite 40 is sometimes referred to as "satellite". Next, the main satellite 40 transmits the results information to satellite m via the circular communication network. Next, at time Tm0, satellite m transmits the results information to ground equipment 90.

[0044] In this example, the main satellite 40, which is equipped with an edge server 42 and performs edge computing, generates a communication command to the ground equipment 90 for satellites flying in the target orbital plane when transmitting the generated result information to the ground equipment 90. Subsequently, the main satellite 40 transmits the generated communication command to the satellites flying in the target orbital plane via the circular communication network. Furthermore, even if the ground equipment 90 is located directly below the target orbital plane, the time at which a satellite flying in the target orbital plane passes over individual ground equipment 90 depends on its flight position within the orbital plane. Therefore, the main satellite 40 derives the time Tm0 at which satellite m passes over individual ground equipment 90 based on the satellite orbital information stored in the edge server 42, and also generates a communication command.

[0045] According to this example of operation, the main satellite 40 generates communication commands in orbit, which has the effect of reducing the load on the ground equipment 90 that was previously generated on the ground, specifically the load related to command generation, command transmission, creation of communication operation plans, and control. Furthermore, according to this example, the main satellite 40 is considered to be an IoT (Internet of Things) device, and the main satellite 40 is equipped with a computer 41 and an edge server 42. In addition, each satellite 30 can communicate satellite information with the ground equipment 90 that constitute the data center via a circular communication network. Therefore, according to this example, each satellite 30 and the ground equipment 90 have the effect of being able to communicate quickly with the edge server 42 equipped on the main satellite 40. Furthermore, according to this example of operation, the results of calculations performed in orbit can be directly transmitted to the user's ground facilities 90. This has the effect of reducing the burden on the ground facilities 90, which are equipped with a data center.

[0046] Embodiment 3. The following will explain the differences from the previously described embodiment, primarily with reference to the drawings.

[0047] ***Explanation of the structure*** The configuration of the edge computing system 11 according to this embodiment is a combination of the communication satellite system 10 according to Embodiment 1 and the edge computing system 11 according to Embodiment 2. That is, the edge computing system 11 consists of multiple orbital planes. Among the satellites that make up the edge computing system 11 is the main satellite 40. The main satellite 40 may be flying in each of two or more orbital planes. The edge server 42 stores orbital information for each of the satellites 30 that make up the edge computing system 11 and the main satellite 40.

[0048] The computer 41 installed on the main satellite 40 generates command instructions for at least one of transmission and reception. The computer 41 may also use an inference model that has learned the relationship between the satellite arrangement in the edge computing system 11 and the communication routes in communication between the satellites constituting the edge computing system 11, and information indicating the arrangement of multiple satellites constituting the edge computing system 11, to search for a communication route in communication between the main satellite 40 and each satellite equipped with an information gathering device. The computer 41 may also use an inference model that has learned the relationship between information about a moving object collected by the information gathering device and the movement path of a moving object corresponding to the information collected by the information gathering device, and target moving object information, to predict the movement path of a target moving object. Here, the information gathering device is a device that collects information from outside the satellite. The target moving object information is information collected by the information gathering device and is information about a target moving object. The target moving object is a moving object. The main satellite 40 transmits command signals to satellites flying in the same orbital plane as the main satellite 40, and which pass near the intersection of that orbital plane with other orbital planes, via a circular communication network formed in the orbital plane in which the main satellite 40 is flying.

[0049] ***Explanation of operation*** <Example of operation according to Embodiment 3> Figure 14 is a diagram illustrating this example of operation. This example of operation will be explained with reference to Figure 14. First, the computer 41 generates result information by performing analysis processing. Next, the computer 41, based on the orbital information stored in the edge server 42, selects an orbital plane other than the main satellite orbital plane among several orbital planes that passes over the ground equipment 90 as the overhead transit orbital plane. Here, the main satellite orbital plane is the orbital plane in which the main satellite 40, which is equipped with the computer 41, is flying. Subsequently, the computer 41 derives the overhead transit time, which is the time when the overhead transit orbital plane passes over the ground equipment 90. Note that the overhead transit time may be any time period. Next, the computer 41 derives the position of the target intersection point, which is the intersection point formed in a plan view between the main satellite orbit plane and the transit orbit plane, based on the orbital information stored in the edge server 42. Next, the main satellite 40 shares results information with other satellites flying in the main satellite orbital plane through a circular communication network formed in the main satellite orbital plane. Next, the first communications satellite transmits the results information to the second communications satellite in the vicinity of the target intersection. Here, the first communications satellite is one of several satellites flying in the main satellite orbit plane. The second communications satellite is one of several satellites flying in the upper orbit plane. Next, the second communications satellite transmits the results information to the third communications satellite through a ring-shaped communication network formed in the orbital plane above the sky. Here, the third communications satellite is a satellite flying in the orbital plane that passes over ground facilities at the time of the sky transit. The second and third communications satellites may be the same satellite, in which case the second communications satellite does not transmit results information to the third communications satellite. Next, the third communications satellite transmits the results information to the ground equipment 90 at the time of its overhead passage.

[0050] In this example, the rotation of the orbital plane around the Earth is not synchronized with the Earth's rotation. Therefore, the time that a satellite in a particular orbital plane passes over a particular ground facility 90 is limited. By providing multiple orbital planes with dispersed longitude components of the normal vector, the number of orbital planes that pass over any given ground facility 90 is increased, thereby increasing the time that any given ground facility 90 can communicate with any of the satellites. If the edge computing system 11 is equipped with a sufficient number of orbital planes and satellites, a constant communication environment can be established so that any ground equipment 90 can communicate with any satellite in any orbital plane at any time. In this case, in order to transmit result information generated by a main satellite 40 in a specific orbital plane to any ground equipment 90, the result information can be transmitted to a satellite in an orbital plane that passes over the ground equipment 90 at a specific time, and the satellite passing over the ground equipment 90 can then transmit the result information to the ground equipment 90.

[0051] <Example of operation according to Embodiment 3> This example of operation is an extended version of Example 1 according to Embodiment 3. In this example, the first communication satellite transmits results information to the second communication satellite in the vicinity of the target intersection if its direction of travel at the target intersection is closer to the target direction than the direction of travel of the second communication satellite at the target intersection. The target direction is, in specific examples, north.

[0052] In an edge computing system 11 having a main satellite 40 for each orbital plane, it is necessary to determine the timing of sending and receiving results information, and which satellites will send and receive it, by prioritizing the orbital planes or prioritizing based on the relative orbital position. Near the intersection of two points formed at orbital altitudes on the line of intersection of two orbital planes with orbital inclinations, satellites traveling north from the Southern Hemisphere to the Northern Hemisphere and satellites traveling south from the Northern Hemisphere to the Southern Hemisphere will pass through. For example, if the satellite traveling north from the Southern Hemisphere to the Northern Hemisphere becomes the transmitter and the satellite traveling south from the Northern Hemisphere to the Southern Hemisphere becomes the receiver, a system can be constructed in which the northbound satellite 30 takes priority. In this case, the direction of travel of the northbound satellite is more north than the direction of travel of the southbound satellite. Note that the transmitter and receiver may be reversed. Also, if satellites flying on both orbital planes near the intersection are either traveling north or south, it is necessary to note that the orbital inclinations of the two orbital planes are different.

[0053] <Example of operation according to Embodiment 3> This example of operation is an extended version of one of the aforementioned examples of operation according to Embodiment 3. In this example, each of the multiple orbital planes has a priority assigned to it regarding the transmission order.

[0054] The assumptions for this example operation are explained below. The main satellite 40 is flying in orbital plane α and orbital plane β, which are orbital planes that make up multiple orbital planes. The computer 41 installed in the main satellite 40 flying in orbital plane α generates result information αR as result information. The computer 41 installed in the main satellite 40 flying in orbital plane β generates result information βR as result information. One of the satellites flying in orbital plane α transmits result information αR to one of the satellites flying in orbital plane β. One of the satellites flying in orbital plane β transmits result information βR to one of the satellites flying in orbital plane α. First, we will explain the operation when the priority set for orbital plane α is higher than the priority set for orbital plane β. In this case, before any of the multiple satellites flying in orbital plane β transmits result information βR to any of the multiple satellites flying in orbital plane α, any of the multiple satellites flying in orbital plane α transmits result information αR to any of the multiple satellites flying in orbital plane β. Next, we will explain the operation when the priority set for orbital plane α is lower than the priority set for orbital plane β. In this case, one of the multiple satellites flying in orbital plane β transmits result information βR to one of the multiple satellites flying in orbital plane α, and then one of the multiple satellites flying in orbital plane α transmits result information αR to one of the multiple satellites flying in orbital plane β.

[0055] By pre-determining the priority of orbital planes, a default priority for communication is established when satellites pass near the intersection of orbital planes. However, it is also possible to transmit data generated by the main satellite 40, which is flying in an orbital plane with a relatively lower priority, via an orbital plane with a relatively higher priority. Therefore, when transmitting data from a satellite flying in an orbital plane with a relatively higher priority to a satellite flying in an orbital plane with a relatively lower priority, it is reasonable for both satellites to share the communication procedure between their respective orbital planes.

[0056] <Example of operation according to Embodiment 3> This example of operation is an extended version of one of the aforementioned examples of operation according to Embodiment 3. In this example of operation, when multiple main satellites 40 are orbiting in the orbital plane that constitutes the edge computing system 11, a priority order for transmission is set for each of the multiple main satellites 40.

[0057] In an edge computing system 11 where multiple main satellites 40, each equipped with at least one of an edge server 42 and a computer 41 with AI (Artificial Intelligence), exist in the same orbital plane, there is a risk of network disruption if each main satellite 40 communicates with satellites orbiting in other orbital planes without coordinating. Therefore, priorities among the main satellites 40 are predetermined for each orbital plane, and when inter-orbital communication with a particular orbital plane overlaps among multiple main satellites 40, the main satellite 40 with a relatively higher priority among those multiple main satellites 40 can manage the transmission of result information from other main satellites 40 in the same orbital plane. The primary satellite 40, which has a relatively high priority, performs the aforementioned processing, which has the effect of preventing disruptions to the communication network.

[0058] <Example of operation according to Embodiment 3> This example of operation is an extended version of one of the aforementioned examples of operation according to Embodiment 3. In this example of operation, one of the satellites constituting the edge computing system 11 is equipped with an information gathering device. Here, the information gathering device equipped on the satellite may be an image information gathering device, a radio wave information gathering device, or a space environment monitoring information gathering device. The image information gathering device may be an optical monitoring device that acquires visible images, a synthetic aperture radar that acquires radio wave images, or an infrared monitoring device that visualizes temperature information.

[0059] <Example of operation according to Embodiment 3> This example of operation is an extended version of the example of operation 5 according to Embodiment 3. In this example of operation, each of the two or more satellites constituting the edge computing system 11 is equipped with an information gathering device. Edge server 42 stores the flight path model. The flight path model is used to estimate the flight path of a moving object. The flight path of the object corresponds to the movement path of the moving object. The information gathering device is an infrared surveillance device and also generates projectile detection information. The projectile detection information shows the results of detecting projectiles. Each satellite equipped with an information gathering device shares projectile detection information with the main satellite 40 and other satellites equipped with information gathering devices through communication via a ring-shaped communication network formed in each of the multiple orbital planes, and through communication near the intersections formed in a plan view by two different orbital planes. Computer 41 predicts the flight path of the projectile using the projectile detection information and the flight path model stored in the edge server 42, and generates an information acquisition command. The information acquisition command is a command to a satellite equipped with an information gathering device, and it is a command that instructs the satellite to acquire information about the projectile. The main satellite 40 transmits information acquisition commands to each satellite equipped with an information gathering device via communication through a ring-shaped communication network formed on each of the multiple orbital planes, and via communication near the intersection points formed in a plan view by two different orbital planes.

[0060] The edge computing system 11 may use machine learning to perform the processing described in the above example. Machine learning will be explained below. Machine learning can be divided into supervised learning, which is optimized by inputting training signals (correct answers), and unsupervised learning, which does not require training signals. As a concrete example, by generating an inference model by pre-training it with the types of projectiles, the types of propellants, and typical flight models as training models, inference using actual measurement data of projectiles whose launches are detected and whose trajectory information is acquired by the information gathering device becomes relatively easy and rapid. Here, the computer 41 uses the inference model to predict the flight path of the projectile and estimate its landing position. However, in order to predict the flight path of a projectile whose direction of flight is unknown at the stage of launch detection, it is necessary to track and monitor the projectile using subsequent surveillance satellites. Here, surveillance satellites are satellites equipped with information gathering devices. Therefore, in order to transmit launch detection information to subsequent surveillance satellites, the launch detection information must pass through a communication network formed by a constellation of communication satellites. In a communication network using a constellation of communication satellites, the flight position of the communication satellites changes moment by moment. Therefore, surveillance satellites need to search for the optimal communication route and determine the ID (Identification) of the communication satellite that will send and receive projectile information, as well as the time for sending and receiving the launch detection information. This is also true for the exchange of projectile information between surveillance satellites and communication satellites. Note that surveillance satellites may also have the functions of communication satellites. When the optimal communication route is searched using ground equipment 90, it is necessary to send commands to both the surveillance satellite and the communication satellite, indicating the time of exchange of projectile information and the satellite ID. However, the communication network for sending these commands becomes a challenge in this case. Therefore, it is reasonable for the main satellite 40 to be equipped with a machine learning analysis device that searches for the optimal communication route in orbit, generates communication commands, and transmits the generated communication commands to each satellite that makes up the searched optimal communication route. The analysis device is typically a computer 41. A method using an algorithm known as Dijkstra's algorithm is effective for searching for the optimal communication route. In static Dijkstra's algorithm, the weights of each route do not change. However, in a communication network formed by a communication satellite constellation, the weights of each communication route change with changes in the flight position of the communication satellites; that is, the weights of each communication route change with the change in time. Therefore, for each communication satellite that searches for the optimal communication route while updating its orbital information, the operation of a communication satellite that receives information about a flying object searching for the optimal communication route and transmitting the information about the flying object to the next communication satellite may be repeated. In other words, each satellite 30 may be equipped with a computer 41. Furthermore, the computer 41 may generate an inference model that infers the optimal communication route based on the optimal communication route searched in the past and the arrangement of satellites at the time the optimal communication route was searched, using as input information that indicates the starting and ending satellites of the communication and information that indicates the arrangement of satellites in the edge computing system 11.

[0061] Furthermore, in route searching, breadth-first search and depth-first search are known. For launch detection information, priority is given to rapidly transmitting projectile information to the communication network using breadth-first search, and subsequent satellites repeat the tracking. However, when the direction of the projectile's flight can be roughly estimated, it is reasonable to perform depth-first search.

[0062] In the projectile tracking system, the projectile is tracked and monitored by repeatedly performing the aforementioned machine learning-based flight path prediction and Dijkstra's algorithm to search for communication routes, and the final landing position of the projectile is inferred.

[0063] Furthermore, as a concrete example, computer 41 generates an inference model by repeatedly tracking and monitoring the flying object, then performing machine learning using past tracking and monitoring results, and by performing deep learning using examples of flying object behavior that do not match the multiple flying object models used as training models. Here, the tracking and monitoring results of the flying object consist of information collected by the information gathering device and information indicating the flight path of the flying object. This improves the accuracy of predictions and speeds up predictions regarding the flight path of the flying object.

[0064] Furthermore, there are discrepancies between the flight direction and distance of projectiles launched from mobile launchers (TELs) or similar devices, rather than fixed launch pads, and those predicted by typical flight models. Therefore, it is effective to correct the projectile's trajectory model by performing deep learning using actual measured projectile data.

[0065] This example demonstrates the effect of rapidly sharing satellite information between satellites. Furthermore, the edge computing system 11 in this example may be configured to transmit information obtained through infrared monitoring in orbit via edge computing to other satellites equipped with infrared monitoring devices, in order to track a projectile known as a supersonic glide missile.

[0066] <Example of operation according to Embodiment 3> This example of operation is an extended version of operation example 5 or operation example 6 according to Embodiment 3. In this example, the information gathering device is a synthetic aperture radar or optical surveillance device, and has the function of tracking and monitoring a moving object. A specific example of the moving object is a ship.

[0067] According to this example, when tracking a vessel navigating the ocean using synthetic aperture radar or optical surveillance equipment, sharing surveillance information between different trajectories allows for rapid tracking with a lower risk of losing sight of the vessel.

[0068] ***Other Embodiments*** The embodiments described above can be freely combined, any component of each embodiment can be modified, or any component can be omitted in each embodiment. Furthermore, the embodiments are not limited to those shown in Embodiments 1 to 3, and various modifications can be made as needed. The procedures described using diagrams and other visual aids may be modified as appropriate. [Explanation of Symbols]

[0069] 10 Communications satellite system, 11 Edge computing system, 20 Satellite constellation, 30 Satellite, 31 Satellite control device, 32 Communication device, 33 Propulsion device, 34 Attitude control device, 35 Power supply, 40 Main satellite, 41 Computer, 42 Edge server, 90 Ground equipment, 91 Satellite control device, 710 Processor, 711 Control unit, 720 Main memory, 730 Auxiliary memory, 740 Input interface, 750 Output interface, 760 Communication interface, 770 Signal line, 780 Electronic circuit, 810 Ground-side communication device.

Claims

1. An edge computing system consisting of multiple satellites orbiting in a target orbital plane, Each of the aforementioned plurality of satellites is designated as a target satellite, and the target satellite is a satellite flying in the target orbital plane and is equipped with a first communication device that communicates with satellites located in front of and behind the target satellite in its direction of travel, and a second communication device that communicates with ground equipment installed on the ground. The aforementioned multiple satellites form a circular communication network. Any of the satellites comprising the aforementioned plurality of satellites is a main satellite equipped with a computer and an edge server that stores orbital information for each of the plurality of satellites. The aforementioned computer is By performing the analysis process, result information is generated. Based on the orbital information stored in the edge server, a satellite that passes over the ground facility is selected from among the multiple satellites as satellite m, and the time Tm0 at which satellite m passes over the ground facility is derived. The main satellite transmits the results information to the satellite m via the circular communication network. The satellite m is an edge computing system that transmits the results information to the ground equipment at the time Tm0.

2. The main satellite according to claim 1.

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