Control system

Abstract

[Problem] To reduce the communication load with regard to control of a plurality of mobile bodies constituting a formation. [Solution] Provided is a control system comprising: a first mobile body; and at least one second mobile body that performs unidirectional communication with the first mobile body in accordance with a prescribed communication standard. The first mobile body comprises: a first self-position estimation unit that estimates the self-position of the first mobile body on the basis of a satellite signal; and at least one first wireless communication unit that transmits a broadcast signal including, as position information for the first mobile body, information on the self-position estimated by the first self-position estimation unit. The second mobile body comprises: at least one second wireless communication unit that receives the broadcast signal; and a second self-position estimation unit that estimates, as the self-position of the second mobile body and on the basis of the position information of the first mobile body, the relative position with respect to the first mobile body.

Description

Control System

[0001] The present invention relates to a control system.

[0002] In recent years, technologies for controlling multiple moving objects in a formation have been developed. For example, Patent Literature 1 discloses an autonomous flight control system for controlling multiple autonomous flying objects in a formation.

[0003] JP 2017-56899 A

[0004] In the autonomous flight control system disclosed in Patent Literature 1, the autonomous air vehicles to be controlled include a master drone and a slave drone. The master drone and the slave drone communicate with each other bidirectionally. In this case, the communication load increases as the number of autonomous air vehicles to be controlled increases.

[0005] Therefore, the present invention has been made in consideration of the above problems, and an object of the present invention is to reduce the communication load in relation to the control of multiple moving bodies that make up a formation.

[0006] In order to solve the above problem, according to one aspect of the present invention, a control system is provided, comprising: a first mobile body; and at least one second mobile body that performs one-way communication between the first mobile body in accordance with a specified communication standard, wherein the first mobile body comprises a first self-position estimation unit that estimates its own position based on satellite signals; and at least one first wireless communication unit that transmits a broadcast signal that includes information on the self-position estimated by the first self-position estimation unit as position information of the first mobile body, and the second mobile body comprises at least one second wireless communication unit that receives the broadcast signal; and a second self-position estimation unit that estimates its relative position with respect to the first mobile body as its own position based on the position information of the first mobile body.

[0007] As described above, according to the present invention, it is possible to reduce the communication load in controlling a plurality of moving bodies that constitute a formation.

[0008] FIG. 1 is a diagram for explaining an overview of a control system 1 according to a first embodiment of the present invention. FIG. 2 is a block diagram showing an example of the configuration of a drone 10 according to an embodiment of the present invention. FIG. 3 is a sequence diagram showing an example of the operation flow of a control system 1 according to a first embodiment of the present invention. FIG. 4 is a diagram for explaining an overview of a control system 1 according to a second embodiment of the present invention. FIG. 5 is a sequence diagram showing an example of the operation flow of a control system 1 according to a second embodiment of the present invention. FIG. 6 is a sequence diagram showing another example of the operation flow of a control system 1 according to the second embodiment of the present invention.

[0009] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant explanations will be omitted.

[0010] In addition, in this specification and drawings, when multiple identical components are to be described separately, letters or the like may be added to the end of the reference numerals. On the other hand, when it is not necessary to distinguish between multiple identical components, the letters or the like may be omitted and a description common to all of the multiple identical components may be given.

[0011] <1. First Embodiment> <<1.1. System Overview>> As described above, in recent years, techniques for controlling a plurality of moving bodies that form a formation have been developed.

[0012] Examples of the mobile object include various unmanned aerial vehicles, including drones.

[0013] Furthermore, for example, Patent Document 1 discloses an autonomous flight control system that controls the flight of a formation (drone formation) made up of multiple drones.

[0014] In the autonomous flight control system disclosed in Patent Document 1, the drones that make up the drone formation include one master drone and multiple slave drones controlled by the master drone.

[0015] In addition, to control the flight of the drone formation, the master drone and each of the slave drones communicate with each other bidirectionally.

[0016] However, when one master drone performs two-way communication with each of multiple slave drones, the number of communications increases as the number of slave drones increases, and ultimately the communication load increases.

[0017] In particular, relatively small unmanned aerial vehicles such as drones have limited battery capacity that can be carried, so an increase in communication load can also lead to a shortened flight duration.

[0018] The technical concept of the first embodiment of the present invention was conceived with the above points in mind, and aims to reduce the communication load in controlling multiple moving bodies that make up a formation.

[0019] For this purpose, the control system 1 (see Figure 1) according to the first embodiment of the present invention includes a first mobile body and at least one second mobile body that performs one-way communication between the first mobile body and the first mobile body in accordance with a specified communication standard.

[0020] Below, an overview of the control system 1 will be described using the example in which the moving object is a drone.

[0021] FIG. 1 is a diagram illustrating an overview of a control system 1 according to a first embodiment of the present invention.

[0022] As shown in FIG. 1 , a control system 1 according to a first embodiment of the present invention includes a plurality of drones 10 .

[0023] In addition, the drone 10 according to the first embodiment includes a drone 10M (sometimes simply referred to as the master) that operates as a master aircraft, and a drone 10P (sometimes simply referred to as the passive aircraft) that operates as a passive aircraft.

[0024] The drone 10M of this embodiment directly or indirectly controls the flight of at least one drone 10P by transmitting wireless signals that comply with a specified communication standard to at least one drone 10P.

[0025] The control system 1 according to this embodiment includes one drone 10M.

[0026] The drone 10M in this embodiment is an example of a first moving body.

[0027] On the other hand, the drone 10P according to this embodiment flies based on the radio signal received from the drone 10M.

[0028] Furthermore, one of the features of the drone 10P according to this embodiment is that it does not transmit any wireless signals to the drone 10M.

[0029] That is, drone 10M and drone 10P perform one-way communication from drone 10M to drone 10P.

[0030] The control system 1 according to this embodiment includes at least one drone 10P.

[0031] The drone 10P according to this embodiment is an example of a second moving body.

[0032] According to the configuration described above, it is possible to reduce the communication load compared to when two-way communication is performed between mobile bodies that make up the formation.

[0033] The effect of reducing the communication load becomes more pronounced as the number of mobile objects increases.

[0034] In addition, one-way communication between the drones 10M and 10P in this embodiment is realized by one or more wireless communication units 120 installed in each of the drones 10.

[0035] In the example shown in Figure 1, the drone 10M is equipped with four wireless communication units 120M, and the drone 10P is equipped with four wireless communication units 120P.

[0036] In this way, when multiple wireless communication units 120 are installed on the drone 10, the communication load increases as the number of wireless communication units 120 installed increases.

[0037] However, even in this case, the one-way communication according to this embodiment makes it possible to reduce the communication load compared to when two-way communication is performed.

[0038] <<1.2. Configuration Example of Drone 10>> Next, a configuration example of the drone 10 according to one embodiment of the present invention will be described.

[0039] In the following, a description will be given of the configuration common to the drone 10M, the drone 10P, and the drone 10S (see Figure 4) described later in the second embodiment.

[0040] On the other hand, when it is necessary to distinguish between the configuration of drone 10M, the configuration of drone 10P, and the configuration of drone 10S, the three are distinguished by adding "M," "P," or "S" to the end of the symbol.

[0041] FIG. 2 is a block diagram showing an example of the configuration of the drone 10 according to one embodiment of the present invention.

[0042] As shown in FIG. 2 , the drone 10 according to one embodiment of the present invention includes a control unit 110 , a wireless communication unit 120 , a self-position estimation unit 130 , a drive unit 140 , and a memory unit 150 .

[0043] That is, a drone 10M according to one embodiment of the present invention includes a control unit 110M, a wireless communication unit 120M, a self-position estimation unit 130M, a drive unit 140M, and a memory unit 150M.

[0044] A drone 10P according to one embodiment of the present invention includes a control unit 110P, a wireless communication unit 120P, a self-position estimation unit 130P, a drive unit 140P, and a memory unit 150P.

[0045] Furthermore, the drone 10S according to one embodiment of the present invention includes a control unit 110S, a wireless communication unit 120S, a self-position estimation unit 130S, a drive unit 140S, and a memory unit 150S.

[0046] (Drone 10) The drone 10 according to one embodiment of the present invention is an example of a moving body.

[0047] The drone 10 according to one embodiment of the present invention may be an autonomous mobile drone.

[0048] On the other hand, the movement of the drone 10M according to one embodiment of the present invention may be controlled by operation by a pilot.

[0049] (Control Unit 110) The control unit 110 according to one embodiment of the present invention controls the operation of each component included in the drone 10.

[0050] The control unit 110 in one embodiment of the present invention controls, for example, wireless communication by the wireless communication unit 120 in accordance with a specified communication standard, self-position estimation by the self-position estimation unit 130, operation of the drive unit 140, storage of information by the memory unit 150, etc.

[0051] The functions of the control unit 110 according to one embodiment of the present invention are realized by cooperation between various processors, such as a central processing unit (CPU) and a graphics processing unit (GPU), and memories.

[0052] (Wireless communication unit 120) The wireless communication unit 120 according to one embodiment of the present invention performs wireless communication in accordance with a prescribed communication standard with other wireless communication units 120 mounted on different drones 10.

[0053] An example of the above-defined communication standard is Ultra-Wide Band (UWB) wireless communication.

[0054] However, the prescribed communication standard is not limited to this example. For example, Bluetooth (registered trademark) Low Energy (BLE), Wi-Fi (registered trademark), etc. may be adopted as the prescribed communication standard.

[0055] The wireless communication unit 120M provided in the drone 10M and the wireless communication unit 120P provided in the drone 10P perform one-way communication in accordance with the above-specified communication standard.

[0056] More specifically, the wireless communication unit 120M included in the drone 10M transmits a wireless signal that complies with the above-mentioned prescribed communication standard, and the wireless communication unit 120P included in the drone 10P receives the above-mentioned wireless signal transmitted by the wireless communication unit 120M included in the drone 10M.

[0057] The wireless communication unit 120M according to an embodiment of the present invention is an example of a first wireless communication unit, and the wireless communication unit 120P according to an embodiment of the present invention is an example of a second wireless communication unit.

[0058] Each drone 10 according to one embodiment of the present invention includes at least one wireless communication unit 120 .

[0059] In the example shown in Figure 2, each drone 10 has four wireless communication units 120.

[0060] (Self-position estimation unit 130) The self-position estimation unit 130 according to one embodiment of the present invention estimates the position (self-position) of the drone 10 on which it is mounted.

[0061] The method of self-position estimation differs significantly between the self-position estimation unit 130M provided in the drone 10M and the self-position estimation unit 130P provided in the drone 10P.

[0062] One of the features of the self-position estimation unit 130M provided in the drone 10M is that it estimates its own position (the position of the drone 10M) based on satellite signals.

[0063] The self-position estimation unit 130M may estimate its own position (the position of the drone 10M) using the Global Navigation Satellite System (GNSS).

[0064] For example, the self-position estimation unit 130M may estimate its own position based on satellite signals received from a plurality of satellites provided by the GNSS.

[0065] For this purpose, the self-position estimation unit 130M may include a receiver for receiving satellite signals.

[0066] On the other hand, the self-position estimation unit 130M may estimate its own position based on satellite signals received by another device, such as a controller used to operate the drone 10M. As an example, the self-position estimation unit 130M may estimate its own position (the position of the device, such as the controller) relative to the device, such as the controller, as its own position (the position of the drone 10M), based on its own position (the position of the device, such as the controller) estimated by the device, such as the controller, using GNSS.

[0067] The self-location estimating unit 130M according to one embodiment of the present invention is an example of a first self-location estimating unit.

[0068] On the other hand, one of the features of the self-position estimation unit 130P provided in the drone 10P is that it estimates its relative position with respect to the drone 10M as its own position (the position of the drone 10P) based on the position information of the drone 10M estimated by the self-position estimation unit 130M provided in the drone 10M.

[0069] The self-location estimator 130P according to one embodiment of the present invention is an example of a second self-location estimator.

[0070] For this purpose, the wireless communication unit 120M of the drone 10M transmits a broadcast signal including information on the self-position estimated by the self-position estimation unit 130M as the position information of the drone 10M.

[0071] In addition, the wireless communication unit 120P of the drone 10P receives the above-mentioned broadcast signal.

[0072] For example, the self-position estimation unit 130P of the drone 10P may estimate its relative position with respect to the drone 10M as its self-position (the position of the drone 10P) based on the distance to the drone 10M estimated by the wireless communication unit 120P based on the above-mentioned broadcast signal and the position information of the drone 10M.

[0073] In this case, the wireless communication unit 120M of the drone 10M may transmit a broadcast signal that further includes the transmission time of the broadcast signal.

[0074] The wireless communication unit 120P of the drone 10P estimates the distance to the drone 10M (more precisely, the wireless communication unit 120M that transmitted the broadcast signal) based on the transmission time and reception time of the broadcast signal.

[0075] For example, if drone 10M has two wireless communication units 120M and drone 10P has two wireless communication units 120P, the self-position estimation unit 130P of drone 10P can estimate its two-dimensional relative position with respect to drone 10M based on the distance to drone 10M estimated by each of the wireless communication units 120P.

[0076] Also, for example, if drone 10M has three wireless communication units 120M and drone 10P has three wireless communication units 120P, the self-position estimation unit 130P of drone 10P can estimate its three-dimensional relative position with respect to drone 10M based on the distance to drone 10M estimated by each of the wireless communication units 120P.

[0077] Furthermore, for example, if drone 10M has four or more wireless communication units 120M and drone 10P has four wireless communication units 120P, the self-position estimation unit 130P of drone 10P can more accurately estimate its three-dimensional relative position with respect to drone 10M based on the distance to drone 10M estimated by each of the wireless communication units 120P.

[0078] In addition, the self-position estimation unit 130P of drone 10P can also estimate the three-dimensional relative position with respect to drone 10M by using various sensor information such as images in combination, regardless of the number of wireless communication units 120 equipped in drone 10M or the number of wireless communication units 120 equipped in drone 10M.

[0079] For example, it is assumed that the drone 10M includes one wireless communication unit 120M, and the drone 10P includes one wireless communication unit 120P. It is also assumed that the drone 10P is equipped with a camera.

[0080] In this case, the self-position estimation unit 130P of the drone 10P can estimate the three-dimensional relative position with respect to the drone 10M based on the position information of the drone 10M included in the broadcast signal and the analysis results of the image captured by the camera that includes the drone 10M as a subject. In addition, at this time, the self-position estimation unit 130P may estimate the three-dimensional relative position with respect to the drone 10M further based on the distance to the drone 10M estimated by the wireless communication unit 120P.

[0081] Furthermore, when the self-position estimation unit 130P of the drone 10P estimates the three-dimensional relative position of the drone 10M based on the analysis result of an image that includes the drone 10M as a subject, the transmission time of the broadcast signal can also be estimated from the reception time of the broadcast signal and the capture time of the image. Therefore, the broadcast signal does not necessarily have to include the transmission time.

[0082] In this way, the self-position estimation unit 130P of the drone 10P may estimate its three-dimensional relative position with respect to the drone 10M based on information other than the radio signal received from the drone 10M.

[0083] Furthermore, when the drone 10M is equipped with multiple wireless communication units 120M and the drone 10P is equipped with multiple wireless communication units 120P, the self-position estimation unit 130P of the drone 10P may estimate the three-dimensional relative position with respect to the drone 10M based on information regarding the positional relationships of the wireless communication units 120M mounted on the drone 10M, information regarding the positional relationships of the wireless communication units 120M mounted on the drone 10P, etc. This information may be stored in the storage unit 150.

[0084] Furthermore, if drone 10M is equipped with multiple wireless communication units 120M and drone 10P is equipped with multiple wireless communication units 120P, the self-position estimation unit 130P of drone 10P may estimate the angle of arrival (Angle of Arrival, AoA) and further estimate the three-dimensional relative position with respect to drone 10M based on the estimated angle of arrival.

[0085] (Drive Unit 140) The drive unit 140 according to one embodiment of the present invention includes a propeller, a rotor, a motor, and the like for enabling the drone 10 to fly.

[0086] The control unit 110M of the drone 10M controls the flight of the drone 10M by controlling the drive unit 140M based on the self-position estimated by the self-position estimation unit 130M.

[0087] In addition, the control unit 110P of the drone 10P controls the flight of the drone 10P by controlling the drive unit 140P based on the self-position estimated by the self-position estimation unit 130P.

[0088] (Storage unit 150) The storage unit 150 according to one embodiment of the present invention stores various types of information used by the drone 10.

[0089] The above describes an example of the configuration of the drone 10 according to one embodiment of the present invention. Note that the configuration described above with reference to Fig. 2 is merely an example, and the configuration of the drone 10 according to one embodiment of the present invention is not limited to this example.

[0090] For example, the drone 10 according to one embodiment of the present invention may further include a camera, other sensors, a display unit, an operation unit, etc.

[0091] Furthermore, although the above describes a case where drone 10M, drone 10P, and drone 10S have a common configuration, drone 10M, drone 10P, and drone 10S may each be manufactured as a different dedicated machine.

[0092] The configuration of the drone 10 according to one embodiment of the present invention can be flexibly modified depending on the specifications, operation, etc.

[0093] <<1.3. Operational Flow>> Next, an example of the operational flow of the control system 1 according to this embodiment will be described.

[0094] FIG. 3 is a sequence diagram showing an example of the flow of operations of the control system 1 according to this embodiment.

[0095] In the example shown in Figure 3, first, the self-position estimation unit 130M of the drone 10M receives multiple satellite signals (S101).

[0096] The self-position estimation unit 130M estimates its own position (the position of the drone 10M) based on the multiple satellite signals received in step S101 (S102).

[0097] The control unit 110M of the drone 10M controls the flight of the drone 10M by controlling the drive unit 140M based on the self-position estimated by the self-position estimation unit 130M in step S102 (S103).

[0098] In addition, each of the wireless communication units 120M provided in the drone 10M transmits a broadcast signal, and each of the wireless communication units 120P provided in the drone 10P receives the broadcast signal (S104).

[0099] The broadcast signal includes, for example, the location information of the drone 10M and the transmission time of the broadcast signal.

[0100] In addition, the broadcast signal may include an identifier of the drone 10M and an identifier of the wireless communication unit 120M that transmits the broadcast signal.

[0101] The self-position estimation unit 130P of the drone 10P estimates its relative position with respect to the drone 10M as its own position based at least on the broadcast signal received by the wireless communication unit 120P (each of the wireless communication units) in step S104 (S105).

[0102] The control unit 110P of the drone 10P controls the flight of the drone 10P by controlling the drive unit 140P based on the self-position estimated by the self-position estimation unit 130P in step S105 (S106).

[0103] <2. Second embodiment> <<2.1. System overview>> Next, a second embodiment of the present invention will be described. Note that the following mainly describes the differences from the first embodiment, and detailed descriptions of the configuration, functions, effects, etc. that are common to the first embodiment will be omitted.

[0104] FIG. 4 is a diagram illustrating an overview of a control system 1 according to a second embodiment of the present invention.

[0105] In the first embodiment, the control system 1 includes one drone 10M that operates as a master drone and at least one drone 10P that operates as a passive drone.

[0106] On the other hand, one of the features of the control system 1 according to the second embodiment of the present invention is that, in addition to the drone 10M and the drone 10P, it further comprises at least one drone 10S (sometimes simply referred to as a slave) that operates as a slave machine.

[0107] The drone 10S according to the second embodiment is an example of a third moving body.

[0108] The drone 10M of the second embodiment directly or indirectly controls the flight of each of the drones 10P and 10S by transmitting radio signals that comply with specified communication standards to at least one or more drones 10P and at least one or more drones 10S.

[0109] One of the features of the drone 10S according to the second embodiment is that it performs two-way communication with the drone 10M in accordance with a prescribed communication standard.

[0110] In addition, the drone 10S may estimate its own position based on the above-mentioned two-way communication.

[0111] The wireless communication unit 120S provided in the drone 10S can estimate the distance to the drone 10M (more precisely, the wireless communication unit 120M) by, for example, sending and receiving multiple ranging signals between the drone 10S and the wireless communication unit 120M provided in the drone 10M.

[0112] As an example, consider a case where the wireless communication unit 120S provided in the drone 10S transmits a first ranging signal, and the wireless communication unit 120M provided in the drone 10M transmits a second ranging signal in response to the first ranging signal.

[0113] In this case, the wireless communication unit 120S provided in the drone 10S can estimate the distance to the drone 10M based on, for example, the time ΔT1 from the time the first ranging signal is transmitted to the time the second ranging signal is received, and the time ΔT2 from the time the wireless communication unit 120M provided in the drone 10M receives the first ranging signal to the time the second ranging signal is transmitted.

[0114] More specifically, the wireless communication unit 120S included in the drone 10S calculates the time required for round-trip communication of the ranging signal by subtracting the time ΔT2 from the time ΔT1, and calculates the time required for one-way communication of the ranging signal by dividing this time by 2. The wireless communication unit 120S can further calculate a ranging value, which is an estimate of the distance to the drone 10M, by multiplying the value of (time ΔT1 - time ΔT2) / 2 by the speed of the ranging signal.

[0115] Therefore, for example, when the wireless communication unit 120M provided in the drone 10M transmits the value of time ΔT2 included in the second ranging signal, the wireless communication unit 120S provided in the drone 10S can calculate the ranging value from the value of time ΔT2 included in the received second ranging signal and the value of time ΔT1 calculated by the wireless communication unit 120S itself.

[0116] The wireless communication unit 120S according to the second embodiment is an example of a third wireless communication unit.

[0117] In addition, the self-position estimation unit 130S of the drone 10S may estimate its own position (the position of the drone 10S) based on the distance to the drone 10M estimated by the wireless communication unit 120S and the position information of the drone 10M received by the wireless communication unit 120S.

[0118] The self-position estimator 130S according to the second embodiment is an example of a third self-position estimator.

[0119] In addition, the wireless communication unit 120M provided in the drone 10M may include the position information of the drone 10M in the second ranging signal and transmit it.

[0120] This makes it possible to reduce the number of communications between the wireless communication unit 120M and the wireless communication unit 120S.

[0121] The drone 10S can estimate its own position with higher accuracy compared to the drone 10P through the above-described two-way communication.

[0122] Furthermore, one of the features of the drone 10S according to the second embodiment is that it performs one-way communication with the drone 10P in accordance with a prescribed communication standard.

[0123] One of the features of the drone 10P according to the second embodiment is that it receives radio signals transmitted by the drone 10S, but does not transmit any radio signals to the drone 10S.

[0124] Furthermore, one of the features of the drone 10P according to the second embodiment is that it estimates its own position further based on a radio signal received from the drone 10S.

[0125] Specifically, the wireless communication unit 120P of the drone 10P receives a wireless signal including the position information of the drone 10S transmitted by the wireless communication unit 120S of the drone 10S.

[0126] In addition, the self-position estimation unit 130P of the drone 10P estimates its own position based on the position information of the drone 10M and the position information of the drone 10S.

[0127] For example, the self-position estimation unit 130P of drone 10P may estimate its relative position with respect to drone 10S based on the distance to drone 10S estimated by the wireless communication unit 120P and the position information of drone 10S, and estimate its own position based on the relative position with respect to drone 10S and the relative position with respect to drone 10M.

[0128] By performing the above-described processing, the drone 10P according to the second embodiment is able to estimate its own position with higher accuracy than the drone 10P according to the first embodiment.

[0129] <<2.2. Operational Flow>> Next, the operational flow of the control system 1 according to the second embodiment of the present invention will be described.

[0130] FIG. 5 is a sequence diagram showing an example of the flow of operations of the control system 1 according to the second embodiment of the present invention.

[0131] In the example shown in Figure 5, first, the self-position estimation unit 130M of the drone 10M receives multiple satellite signals (S201).

[0132] The self-position estimation unit 130M estimates its own position (the position of the drone 10M) based on the multiple satellite signals received in step S201 (S202).

[0133] The control unit 110M of the drone 10M controls the flight of the drone 10M by controlling the drive unit 140M based on the self-position estimated by the self-position estimation unit 130M in step S202 (S203).

[0134] Also, after completion of step S202, distance measurement signals are transmitted and received between the wireless communication unit 120M provided in the drone 10M and the wireless communication unit 120S provided in the drone 10S (S204).

[0135] In step S204, the first ranging signal and the second ranging signal described above may be transmitted and received. As described above, the second ranging signal may include the value of the time ΔT2 and the position information of the drone 10M.

[0136] However, the above is merely an example, and the sequence for two-way communication between the drone 10M and the drone 10S is not limited to this example.

[0137] The two-way communication between drone 10M and drone 10S may include at least the transmission and reception of signals that allow drone 10S to estimate the distance to drone 10M, and the transmission and reception of position information of drone 10M.

[0138] After step S204, the self-position estimation unit 130S of the drone 10S estimates its own position (the position of the drone 10S) using the method described above (S205).

[0139] The control unit 110S of the drone 10S controls the flight of the drone 10S by controlling the drive unit 140S based on the self-position estimated by the self-position estimation unit 130S in step S205 (S206).

[0140] Also, after step S202, the wireless communication unit 120M of the drone 10M transmits a broadcast signal including at least the position information of the drone 10M estimated in step S202 (S207).

[0141] Similarly, after step S205, the wireless communication unit 120S of the drone 10S transmits a broadcast signal including at least the position information of the drone 10S estimated in step S205 (S208).

[0142] The self-position estimation unit 130P of drone 10P estimates its own position (the position of drone 10P) based on the position information of drone 10M contained in the broadcast signal received in step S207 and the position information of drone 10S contained in the broadcast signal received in step S208 (S209).

[0143] The control unit 110P of the drone 10P controls the flight of the drone 10P by controlling the drive unit 140P based on the self-position estimated by the self-position estimation unit 130P in step S209 (S210).

[0144] An example of the flow of operations of the control system 1 according to the second embodiment of the present invention has been described above.

[0145] In the example shown in Figure 5, we have described a case where drone 10M and drone 10S each transmit a broadcast signal containing information about their own location, but the operational flow of control system 1 related to the second embodiment of the present invention is not limited to such an example.

[0146] FIG. 6 is a sequence diagram showing another example of the flow of operations of the control system 1 according to the second embodiment of the present invention.

[0147] In the example shown in Figure 6, first, the self-position estimation unit 130M of the drone 10M receives multiple satellite signals (S301).

[0148] The self-position estimation unit 130M estimates its own position (the position of the drone 10M) based on the multiple satellite signals received in step S301 (S302).

[0149] The control unit 110M of the drone 10M controls the flight of the drone 10M by controlling the drive unit 140M based on the self-position estimated by the self-position estimation unit 130M in step S302 (S303).

[0150] Also, after completion of step S302, ranging signals are transmitted and received between the wireless communication unit 120M provided in the drone 10M and the wireless communication unit 120S provided in the drone 10S (S304-1).

[0151] After step S304-1, the self-position estimation unit 130S of the drone 10S estimates its own position (the position of the drone 10S) using the method described above (S305).

[0152] After step S305, the wireless communication unit 120S of the drone 10S transmits a wireless signal including the position information of the drone 10S estimated by the self-position estimation unit 130S in step S305 to the drone 10M (S306-1).

[0153] In addition, the control unit 110S of the drone 10S controls the flight of the drone 10S by controlling the drive unit 140S based on the self-position estimated by the self-position estimation unit 130S in step S305 (S307).

[0154] Meanwhile, in step S304-1, the wireless communication unit 120P of the drone 10P receives the ranging signal transmitted and received between the drone 10M and the drone 10S (S304-2).

[0155] In step S304-2, the wireless communication unit 120P of the drone 10P receives at least a ranging signal including the position information of the drone 10M.

[0156] In addition, in step S306-1, the wireless communication unit 120P of the drone 10P receives a wireless signal including the position information of the drone 10S that is transmitted from the drone 10S to the drone 10M (S306-2).

[0157] The self-position estimation unit 130P of the drone 10P estimates its own position (the position of the drone 10P) based on the position information of the drone 10M contained in the ranging signal received in step S304-2 and the position information of the drone 10S contained in the radio signal received in step S306-2 (S308).

[0158] The control unit 110P of the drone 10P controls the flight of the drone 10P by controlling the drive unit 140P based on the self-position estimated by the self-position estimation unit 130P in step S308 (S309).

[0159] Another example of the flow of operations of the control system 1 according to the second embodiment of the present invention has been described above with reference to FIG.

[0160] According to another example shown in Figure 6, unlike the example shown in Figure 5, there is no need for each of drone 10M and drone 10S to transmit a broadcast signal containing information about their own location, thereby further reducing the communication load.

[0161] However, in the example shown in Figure 6, the drone 10S is required to transmit a wireless signal including the position information of the drone 10S to the drone 10M.

[0162] However, in this case, drone 10M will be able to estimate its own relative position with respect to drone 10S based on the position information of drone 10S, which is expected to improve the accuracy of self-position estimation.

[0163] 3. Modifications Next, modifications of the present invention will be described.

[0164] In the above embodiment, a case has been described in which drone 10P, which is a passive device, receives a radio signal including position information of drone 10M from drone 10M, which is a master device, and performs self-position estimation based on the position information of drone 10M.

[0165] However, the drone 10P, which is a passive drone, does not necessarily need to receive a wireless signal from the master drone 10M. The drone 10P can also receive a wireless signal containing position information of the drone 10S, which is a slave drone, from the drone 10S and estimate its own position based on the position information of the drone 10S. In this case, the drone 10S, which is a slave drone, can be considered an example of a first moving body.

[0166] In addition, in the second embodiment described above, the drone 10P, which is a passive device, estimates its own position based on the position information of the drone 10M, which is a master device, and the position information of the drone 10S, which is a slave device.

[0167] In this case, the drone 10P, which is a passive aircraft, may receive position information from each of the multiple drones 10S and estimate its own position. On the other hand, the drone 10P may receive position information from a predetermined one of the multiple drones 10S that make up the formation and estimate its own position. In the latter example, it is possible to form a platoon in which multiple passive aircraft are associated with one slave aircraft, such as multiple slave aircraft associated with a master aircraft and multiple passive aircraft associated with each of the multiple slave aircraft.

[0168] Furthermore, in the above embodiment, a drone is given as an example of a moving body, but moving bodies to which the technical concept of the present invention can be applied are not limited to such examples.

[0169] The technical concept of the present invention can be widely applied to the control of a formation of moving objects such as two-wheeled vehicles, four-wheeled vehicles, ships, and robots.

[0170] The formation may also include multiple types of moving objects.

[0171] <4. Supplementary Information> Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modified or altered examples within the scope of the technical idea described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

[0172] Furthermore, the steps of the processes described in this specification do not necessarily have to be processed in chronological order according to the order shown in the sequence diagrams. For example, the steps of the processes of each device may be processed in an order different from the order shown, or may be processed in parallel.

[0173] Furthermore, the series of processes performed by each device described in this specification may be realized by a program stored in a non-transitory computer-readable storage medium. Each program is, for example, loaded into RAM when executed by a computer and executed by a processor such as a CPU. The storage medium may be, for example, a magnetic disk, an optical disk, a magneto-optical disk, or a flash memory. The program may also be distributed, for example, via a network, without using a storage medium.

[0174] Furthermore, the effects described in this specification are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present invention may achieve other effects that will be apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0175] 1: Control system, 10, 10M, 10P, 10S: Drone, 110, 110M, 110P, 110S: Control unit, 120, 120M, 120P, 120S: Wireless communication unit, 130, 130M, 130P, 130S: Self-position estimation unit, 140, 140M, 140P, 140S: Driving unit, 150, 150M, 150P, 150S: Memory unit

Claims

1. A control system comprising: a first mobile body; and at least one second mobile body that performs one-way communication with the first mobile body in accordance with a specified communication standard; wherein the first mobile body comprises: a first self-position estimation unit that estimates its own position based on satellite signals; and at least one first wireless communication unit that transmits a broadcast signal that includes information on the self-position estimated by the first self-position estimation unit as position information of the first mobile body; and wherein the second mobile body comprises: at least one second wireless communication unit that receives the broadcast signal; and a second self-position estimation unit that estimates its position relative to the first mobile body as its own position based on the position information of the first mobile body.

2. The control system described in claim 1, wherein the first wireless communication unit transmits the broadcast signal further including the transmission time of the broadcast signal, the second wireless communication unit estimates the distance to the first moving body based on the transmission time and reception time of the broadcast signal, and the second self-position estimation unit estimates its relative position with respect to the first moving body as its self-position based further on the distance to the first moving body estimated by the second wireless communication unit.

3. The control system described in claim 1, wherein the first moving body is equipped with a plurality of the first wireless communication units, the second moving body is equipped with a plurality of the second wireless communication units, and the second self-position estimation unit estimates its own position relative to the first moving body based on the distance to the first moving body estimated by each of the plurality of second wireless communication units.

4. The control system described in claim 1, wherein the first moving body further comprises a control unit that controls the movement of the first moving body based on the self-position estimated by the first self-position estimation unit, and the second moving body further comprises a control unit that controls the movement of the second moving body based on the self-position estimated by the second self-position estimation unit.

5. The control system of claim 1, further comprising at least one third mobile body that performs two-way communication with the first mobile body in accordance with the specified communication standard, wherein the third mobile body comprises at least one third wireless communication unit that transmits and receives wireless signals with the first wireless communication unit, and a third self-position estimation unit that estimates its own position based on the wireless signals that the third wireless communication unit transmits and receives with the first wireless communication unit, wherein the third wireless communication unit receives at least a wireless signal including position information of the first mobile body from the first wireless communication unit, and the third self-position estimation unit estimates its own position based on the position information of the first mobile body.

6. The control system described in claim 5, wherein the third mobile body performs one-way communication with the second mobile body in accordance with the specified communication standard, the second wireless communication unit receives a wireless signal transmitted by the third wireless communication unit, the wireless signal including information on the self-position estimated by the third self-position estimation unit as position information of the third mobile body, and the second self-position estimation unit estimates its self-position based on the position information of the first mobile body and the position information of the third mobile body.

7. The control system described in claim 5, wherein the second wireless communication unit receives a wireless signal transmitted by the first wireless communication unit and a wireless signal transmitted by the third wireless communication unit in two-way communication between the first moving body and the third moving body; the second self-position estimation unit estimates a relative position with respect to the first moving body based on the wireless signal transmitted by the first wireless communication unit in two-way communication between the first moving body and the third moving body, estimates a relative position with respect to the third moving body based on the wireless signal transmitted by the third wireless communication unit in two-way communication between the first moving body and the third moving body, and estimates a self-position based on the relative position with respect to the first moving body and the relative position with respect to the third moving body.

8. The control system according to claim 1, wherein the specified communication standard includes ultra-wideband wireless communication.

9. The control system according to any one of claims 1 to 8, wherein the first moving body and the second moving body include unmanned aerial vehicles.

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