Method for controlling flying object, and flying object

Abstract

To provide a method for controlling an electric flying body that can improve reliability of flight, and to provide an electric flying body.SOLUTION: A flying body 1 includes: a flying body propulsion device 16; and power storage devices 7, 8 including multiple power storage elements 6 to supply power to the flying body propulsion device. When a controlling unit 91 determines that isolation of a bank 8 is necessary if internal short circuit or the like occurs in the bank 8 during flight, the control unit isolates the bank 8.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for controlling an aircraft and the aircraft. [Background technology]

[0002] In recent years, various electric flying objects have been developed. Unmanned aircraft such as drones are equipped with a secondary battery and a battery control circuit, and the motor is rotated by discharging the secondary battery, which rotates the rotor blades. In order to ensure a predetermined flight distance while suppressing weight increase, the secondary battery is required to have a higher energy density than ever before.

[0003] High-altitude platform stations (HAPS) have also been developed that are equipped with radio relay stations and fly or glide in the stratosphere at altitudes of 11 to 50 km (see, for example, Patent Document 1). Various HAPS have been developed, such as solar planes, airships, and stratospheric jets. HAPS stays in the stratosphere at an altitude of, for example, 20 km during its operation (while functioning as a communications infrastructure). HAPS can simultaneously connect to many terminal devices over a wide area, and a high-speed communications infrastructure can be constructed by coordinating between HAPS, artificial satellites, and ground stations. A stable communications environment can be maintained even during disasters.

[0004] The HAPS may include a solar panel having solar cells, and a power storage device having a power storage element such as a lithium-ion secondary battery. The HAPS may fly in the stratosphere using power generated by the solar panel during the day and using power discharged from the power storage device at night. The power storage element included in the HAPS is required to have a high discharge capacity (full charge capacity) in order to keep a large flying object flying at night. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-54490 A Summary of the Invention [Problem to be solved by the invention]

[0006] The inventors have studied measures to allow HAPS to continue flying in the event of events such as a decrease in SOH (State Of Health), an internal short circuit, etc. It is expected that similar needs will increase in the future for aircraft other than HAPS. An object of the present invention is to provide a control method for an aircraft and an aircraft that contribute to improving flight reliability. [Means for solving the problem]

[0007] A method for controlling an aircraft according to one embodiment of the present invention separates one or more storage elements of an aircraft that includes an aircraft propulsion device and a storage device having multiple storage elements and supplying power to the aircraft propulsion device.

[0008] An aircraft according to one embodiment of the present invention comprises a power generation device having a solar cell and supplying power to an aircraft propulsion device, a power storage device having a plurality of storage elements and supplying power to the aircraft propulsion device, and a transport device for transporting one or more storage elements separated from the power storage device. Effect of the Invention

[0009] According to the above aspect, flight reliability can be improved. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of the appearance of a HAPS according to a first embodiment. [Diagram 2] FIG. 1 is a block diagram showing the configuration of a HAPS. [Diagram 3] FIG. [Figure 4] 5 is a flowchart showing a processing procedure of disconnection control by a control unit according to the first embodiment. [Diagram 5] 10 is a flowchart showing a processing procedure of disconnection control by a control unit according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Outline of the embodiment) A method for controlling an aircraft according to an embodiment separates one or more power storage elements of an aircraft including an aircraft propulsion device and a power storage device having a plurality of power storage elements and supplying power to the aircraft propulsion device.

[0012] The aircraft propulsion device may be, for example, a motor that rotates a propeller, etc. Alternatively, the aircraft propulsion device may be a hybrid propulsion device having an internal combustion engine and a motor for propulsion assistance. The energy storage device may be, for example, a battery cell (energy storage element) such as a lithium ion secondary battery, a battery module in which multiple such battery cells are connected in series and / or parallel, a multiple battery modules connected in series (a bank, also called a string), or a bank connected in parallel. The air vehicle may be, for example, a HAPS or an eVTOL (electric vertical takeoff and landing aircraft), but is not limited to these.

[0013] According to the above configuration, the weight of the aircraft can be reduced by detaching the storage element, allowing the aircraft to continue flying and extend its range. This improves the reliability and robustness of the flight, and improves the reliability of the aircraft's operation.

[0014] In the above-mentioned control method for an aircraft, one or more storage elements may be disconnected if an internal short circuit occurs, or if the temperature of the storage element is above a first threshold, or if the SOH is below a second threshold, or if the SOC (State Of Charge) is below a third threshold.

[0015] Examples of the SOH include a capacity retention rate, a resistance value, a shape change, etc. Examples of the shape change include a displacement amount such as swelling of an element of the energy storage element, a displacement amount of a case that houses the element, a change in a force (reaction force) spreading outward, a change in pressure applied to at least one surface of the energy storage element, or a combination of these.

[0016] The first threshold value is, for example, the upper limit of the temperature at which charging and discharging can be continued. The second threshold value may be, for example, a lower limit of the SOH at which charging and discharging can be continued, or a lower limit of the discharge capacity (full charge capacity) required to perform flight operations. The third threshold value may be, for example, an SOC corresponding to the lower limit voltage of the voltage range in which reversible charging and discharging can be repeated. If a transport device (e.g., another aircraft) that detaches the storage element and transports it to the target landing point requires power, the SOH and SOC required for the transport device to land are simulated in advance, and the second and third thresholds are set taking these into consideration.

[0017] By disconnecting the storage element whose SOC is equal to or lower than the third threshold, the flight of the aircraft can be continued, the flight range can be extended, and the reliability of the flight can be improved. If the temperature of the storage element is equal to or higher than the first threshold, or the SOH of the storage element is equal to or lower than the second threshold, and the degree of deterioration is large, or an internal short circuit has occurred, the storage element is disconnected and charging and discharging can be continued using other storage elements, so that the flight can be continued, the flight range can be extended, and the reliability of the flight can be improved.

[0018] The aircraft of the embodiment includes a power generation device having a solar cell and supplying power to the aircraft propulsion device, a power storage device having a plurality of storage elements and supplying power to the aircraft propulsion device, and a transport device that transports one or more storage elements separated from the power storage device.

[0019] According to the above configuration, the weight of the flying object can be reduced by detaching the storage element, and the flying object can continue to fly and the flying distance can be extended. By detaching a storage element that has deteriorated or has an internal short circuit, the flying object can continue to be charged and discharged by another storage element, and the flying object can continue to fly and the flying distance can be extended, improving the reliability of the flight. The transported storage element may be reused or recycled.

[0020] As the power generating device, for example, a solar panel in which a plurality of modules, each having an array of solar cells, are arranged and connected may be used. The delivery device may be, for example, a glider, a parachute, or a drone. Gliders and parachutes do not require a drive mechanism and are lightweight. Drones are also lightweight and can be mounted or connected to an air vehicle. Drones have a drive mechanism and a control device, so they can transport the storage element to the target landing point with greater precision. The storage element may be housed in the glider or may be coupled to a parachute or drone, in which case the storage element can be released by releasing the glider, parachute or drone from the air vehicle.

[0021] The above-mentioned aircraft may be provided with a wireless relay station for wireless communication with the terminal device.

[0022] The terminal device may be a mobile phone such as a smartphone, a portable terminal device such as a notebook personal computer or a tablet, or a communication terminal device equipped on a drone, etc. The radio relay station performs wireless communication with a terminal device used by a user in an airplane located in an airspace below the airspace in which the radio relay station is located, or with the communication terminal device, and also performs wireless communication with relay stations on the ground or at sea, and is connected to the core network of the mobile communication network.

[0023] When the aircraft is a HAPS equipped with a radio relay station, it is necessary to perform flight operations in a specified airspace in the stratosphere, but by detaching the storage element, the aircraft can be made lighter, flight can be continued, and the flight range can be extended. If a storage element becomes degraded or has an internal short circuit during the operation of the aircraft, the storage element can be detached and charging and discharging can be continued using other storage elements, and flight and operation can be continued. This improves the reliability of the communications infrastructure. If the aircraft is a HAPS, it flies within a specified range of airspace, making it possible to estimate the recovery point for the detached storage element.

[0024] In the above-mentioned flying object, the power storage device may be configured by connecting in parallel a plurality of series-connected circuits, each of which has a plurality of power storage elements connected in series, and the series-connected circuits may be separated from the power storage device.

[0025] The series connection circuit may be a unit in which a plurality of power storage elements are managed by a Battery Management Unit (BMU), etc. The series connection circuits may be connected in parallel in a detachable manner.

[0026] (Embodiment 1) The first embodiment will be described using HAPS as an example. Fig. 1 is a perspective view of the exterior of HAPS 1, and Fig. 2 is a block diagram showing the configuration of HAPS 1. In Fig. 2, the connections between the control device 9 and each part are omitted. The HAPS1 includes a wing section 2, a plurality of propellers 3, a plurality of legs 4, a plurality of solar panels 5, a plurality of banks 8, a control device 9, a wireless relay station 10, a first converter circuit 11, a second converter circuit 12, a switching unit 13, an inverter circuit 14, wheels 15, a switching unit 17, and a transport device 20. The propeller 3 is connected to a motor (electric motor) 16. The configuration of the HAPS1 is not limited to this example. The bank 8, the control device 9, the wireless relay station 10, the first converter circuit 11, the second converter circuit 12, the switching unit 13, and the inverter circuit 14 are housed in the legs 4. Alternatively, they may be provided in the wing section 2.

[0027] The solar panel 5 is formed by arranging and connecting a plurality of modules, each module being an array of a plurality of silicon-based solar cells. The bank 8 is formed by connecting a plurality of battery modules 7 in series, each of which has a plurality of battery cells 6, such as lithium ion secondary batteries, etc. A plurality of banks 8 are connected in parallel. In FIG. 2, the bank 8 has three battery modules 7 connected thereto, but this is not limited to this case. The vehicle 20 may be, for example, a glider, or alternatively, a parachute or a drone.

[0028] The control device 9 includes a control unit 91 , a storage unit 92 , an input unit 93 , a communication unit 94 , a motor drive unit 95 , a first disconnection unit 96 , and a second disconnection unit 97 . The control unit 91 is composed of, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and controls the operation of each part of the HAPS 1. The control unit 91 executes disconnection control processing by reading and executing a disconnection control program 921, which will be described later. The disconnection control processing refers to processing to disconnect the bank 8 and move it to the transporter 20, and to disconnect the transporter 20 from the HAPS 1 and land it, when an internal short circuit has occurred in the battery cells 6 of the bank 8, when the temperature of the battery cells 6 is equal to or higher than a first threshold, when the SOH of the bank 8 is equal to or lower than a second threshold, or when the SOC is equal to or lower than a third threshold.

[0029] The storage unit 92 stores various programs including a disconnection control program 921, and a history DB (database) 922. The disconnection control program 921 is provided in a state stored in a computer-readable recording medium 90, such as a CD-ROM, a DVD-ROM, or a USB memory, and is stored in the storage unit 92 by installing it in the control device 9. Alternatively, the disconnection control program 921 may be obtained from an external computer (not shown) connected to the communication network, and stored in the storage unit 92.

[0030] History DB 922 may store history data of power generation and discharge of solar panel 5, history data of charging and discharging of bank 8, history data of the temperature of bank 8, history data of weather information, history data of flight control of HAPS1, history data of disconnection of bank 8, etc. The history of power generation and discharge of solar panel 5 is the operation history of solar panel 5 and may include history of information indicating the period of use, information related to power generation (power, etc.), or information related to discharging (voltage, rate, etc.). The history of charging and discharging of bank 8 is the operation history of bank 8 and may include history of information indicating the period of use, and information related to charging or discharging (voltage, rate, etc.).

[0031] The history of meteorological information may be a history of the wind speed, wind direction, amount of sunlight, etc. at the position of the HAPS 1 at the time of acquisition, which is acquired from the meteorological server 40. The flight control history may be the history of flight control of HAPS1, including the rotational drive of the motor 16, such as the rotation speed and rotation time. The history data of the disconnection of the bank 8 may be a history of the ID number of the bank 8 that was disconnected by the control unit 91 and the date and time of the disconnection.

[0032] The input unit 93 receives inputs of detection results of the current and voltage of the solar panel 5 and the bank 8. An ammeter and a voltmeter are omitted in FIG. The communication unit 94 has a function of communicating with other devices such as the wireless relay station 10, and transmits and receives required information. The motor driving unit 95 controls the rotational driving of each motor 16 of each propeller 3. The first disconnection unit 96 disconnects the target bank 8 by the switching unit 17, which will be described later. The second disconnection unit 97 disconnects the transport device 20 from the HAPS 1 and transports the bank 8 to the ground.

[0033] The first converter circuit 11 is a DC / DC converter that is connected to the solar panel 5 and boosts the output voltage of the solar panel 5 and outputs the boosted voltage.

[0034] The second converter circuit 12 is connected to the banks 8, and is a bidirectional DC / DC converter that charges and discharges the banks 8. The connection between each bank 8 and the second converter circuit 12 is turned on or off by a switching unit 17. The switching unit 17 has a switch 171, and turns on or off the power supply to the bank 8 by opening or closing the switch 171. The bank 8 with the switch 171 turned on is connected to the second converter circuit 12. When performing a disconnection, which will be described later, the switching unit 17 is configured to separate the bank 8.

[0035] The inverter circuit 14 converts DC to AC, that is, converts the direct current power input from the switching unit 13 into alternating current power and outputs it.

[0036] The switching unit 13 includes, for example, two switches, a switch 131 and a switch 132, connected in series. A control circuit for controlling charging and discharging is omitted in Fig. 2. The switches 131 and 132 are formed of switching elements such as relays and power MOSFETs. The connection point between the switches 131 and 132 is connected to the inverter circuit 14. The other end of the switch 131 and the other end of the switch 132 are connected to the first converter circuit 11 and the second converter circuit 12, respectively.

[0037] The inverter circuit 14 is connected to the wireless relay station 10 and a load such as a motor 16 . When discharging from the solar panel 5 to a load, the switch 131 is turned on to connect the solar panel 5 to the load. When discharging from bank 8 to a load, switch 132 is turned on to connect bank 8 to the load. Fig. 2 shows a state in which switch 132 is on and power is being supplied from bank 8 to the load. When discharging from the solar panel 5 and the bank 8 to a load, both the switch 131 and the switch 132 are turned on to connect the solar panel 5 and the bank 8 to the load.

[0038] The wireless relay station 10 includes a first communication unit 101, a second communication unit 102, and a third communication unit 103. The first communication unit 101 has an antenna, a duplexer, an amplifier, etc., and transmits and receives radio signals with a terminal device 30 used by a user in an airplane, or a communication terminal device 30 of a drone. The second communication unit 102 has an antenna, a duplexer, an amplifier, etc., and transmits and receives radio signals with a relay station on the ground or at sea. The wireless relay station 10 is connected to a network NW of a mobile communication network via the relay station. The terminal device 30 is connected to the network NW, and a weather server 40 is also connected. In FIG. 2, the terrestrial or marine relay station is omitted. The third communication unit 103 transmits and receives with an artificial satellite and another HAPS by laser light or the like. The configuration of the wireless relay station 10 is not limited to this example.

[0039] The motor 16 rotates and drives the propeller 3. Alternatively, the motor 16 may drive an air vehicle propulsion device or an air vehicle lift device of a configuration other than that shown in FIG.

[0040] FIG. 3 is a perspective view showing an example of the battery module 7. As shown in FIG. The battery module 7 includes a rectangular parallelepiped case 71 and a plurality of battery cells 6 housed in the case 71 .

[0041] The battery cell 6 comprises a rectangular parallelepiped (prismatic) case body 61, a cover plate 62, a positive terminal 63 and a negative terminal 66 provided on the cover plate 62, a burst valve 64, and an electrode body 65. Instead of a prismatic cell, the battery cell may be a so-called pouch cell having a laminated case. The electrode body 65 is made by laminating a positive electrode plate, a separator, and a negative electrode plate, and is housed in the case body 61. The electrode body 65 may be obtained by winding a positive electrode plate and a negative electrode plate in a flat shape with a separator between them, or may be obtained by stacking multiple positive electrode plates and negative electrode plates with separators between them.

[0042] The positive electrode plate is a positive electrode substrate foil, which is a plate-shaped (sheet-shaped) or long strip-shaped metal foil made of metals such as aluminum, titanium, tantalum, stainless steel, etc., or alloys thereof, and has an active material layer formed thereon. The negative electrode plate is a negative electrode substrate foil, which is a plate-shaped (sheet-shaped) or long strip-shaped metal foil made of metals such as copper, nickel, stainless steel, nickel-plated steel, etc., or alloys thereof, and has an active material layer formed thereon. The separator is a microporous sheet made of synthetic resin.

[0043] When the lower limit voltage is reached, the battery cell 6 is preferably capable of demonstrating a predetermined discharge capacity in a voltage range lower than the lower limit voltage, thereby enabling the battery cell 6 to generate energy for decreasing the voltage of HAPS1. The battery cell 6 is preferably capable of dissolving lithium ions in the electrolyte (non-aqueous electrolyte) from the negative electrode and transferring them to the positive electrode in a voltage range lower than the lower limit voltage. Lithium ions can be transferred from the negative electrode to the positive electrode in a voltage range lower than the lower limit voltage, and a required discharge capacity can be achieved.

[0044] The positive electrode active material can be appropriately selected from, for example, known positive electrode active materials. A material capable of absorbing and releasing lithium ions is usually used as the positive electrode active material for a lithium ion secondary battery. Examples of the positive electrode active material include lithium transition metal composite oxides having an α-NaFeO2 type crystal structure and lithium transition metal oxides having a spinel type crystal structure. Examples of the lithium transition metal composite oxides having an α-NaFeO2 type crystal structure include Li[Li x Ni 1-x ]O2(0≦x<0.5), Li[Li x Ni γ Co (1-x-γ) ]O2(0≦x<0.5, 0<γ<1), Li[Li x Co (1-x) ]O2(0≦x<0.5), Li[Li x Ni γ Mn (1-x-γ) ]O2(0≦x<0.5, 0<γ<1), Li[Li x Ni γ Mn β Co(1-x-γ-β) ]O2(0≦x<0.5, 0<γ, 0<β, 0.5<γ+β≦1), Li[Li x Ni γ Co β Al (1-x-γ-β) ]O2 (0≦x<0.5, 0<γ, 0<β, 0.5<γ+β<1), etc. Lithium transition metal oxides with spinel crystal structure include Li x Mn2O4, Li x Ni γ Mn (2-γ) O4, etc. The surfaces of these materials may be coated with other materials. In the positive electrode active material layer, one of these materials may be used alone, or two or more of them may be mixed. In the positive electrode active material layer, one of these compounds may be used alone, or two or more of them may be mixed. The content of the positive electrode active material in the positive electrode active material layer is not particularly limited, but the lower limit is preferably 50 mass%, more preferably 80 mass%, and further preferably 90 mass%. The upper limit of the content is preferably 99 mass%, and more preferably 98 mass%.

[0045] The positive electrode mixture forming the active material layer of the positive electrode contains optional components such as a conductive agent, a binder, a thickener, and a filler as necessary. Examples of the conductive agent include carbonaceous materials such as carbon black, metals, and conductive ceramics. Examples of the binder include thermoplastic resins such as fluororesins (polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), etc.), polyethylene, polypropylene, and polyimide. Examples of the thickener include polysaccharide polymers such as carboxymethylcellulose (CMC), methylcellulose, etc. Examples of the filler include polyolefins such as polypropylene and polyethylene.

[0046] As the negative electrode active material used in the negative electrode active material layer, it is preferable to contain lithium metal. Since the negative electrode active material contains lithium metal, it has surplus lithium ions and can transfer lithium ions from the negative electrode to the positive electrode to exhibit the required discharge capacity. Lithium metal includes not only lithium alone but also lithium alloys. Examples of the lithium alloy include a lithium aluminum alloy. The negative electrode containing lithium metal can be manufactured by cutting the lithium metal into a predetermined shape or forming it into a predetermined shape.

[0047] Furthermore, the negative electrode active material layer may contain elements such as Na, K, Ca, Fe, Mg, Si, N, etc. As the lower limit of the content of lithium metal in the above negative electrode active material, 80% by mass is preferable, 90% by mass is more preferable, and 95% by mass is even more preferable. The upper limit of the content may be 100% by mass.

[0048] The electrolytic solution is injected into the case body 61. The electrolytic solution includes a non-aqueous solvent, and a sulfur-based cyclic compound, a fluorinated cyclic carbonate, a chain carbonate, and an electrolyte salt dissolved in the non-aqueous solvent. Examples of the sulfur-based cyclic compound include a compound having a sultone structure or a cyclic sulfate structure. Examples of the fluorinated cyclic carbonate include fluoroethylene carbonate. Examples of the chain carbonate include ethyl methyl carbonate.

[0049] The negative electrode active material of the battery cell 6 may contain lithium metal, and the positive electrode active material may be a lithium-excess type. According to such a battery cell 6, a high discharge capacity can be exhibited.

[0050] As the positive electrode active material, Li x (Ni a Co b Mn c )O2 (a + b + c = 1, 0 < x < 1.1) represented by NCM (a mixed positive electrode active material of the Ni + Co + Mn system) etc. may be used. In order to realize a high energy density of the battery cell 6, the content of Ni may be increased.

[0051] The positive electrode terminals 63 and the negative electrode terminals 66 of adjacent battery cells 6 in the battery module 7 are electrically connected by a bus bar 72, so that the multiple battery cells 6 are connected in series. A positive electrode lead 74 and a negative electrode lead 73 are provided on the positive electrode terminal 63 and the negative electrode terminal 66 of the battery cells 6 on both ends of the battery module 7 for extracting electric power.

[0052] After leaving the ground diagonally upward, HAPS1 uses lift to fly up while circling within a specified horizontal area, and rises to airspace A. Airspace A can be, for example, an airspace in the stratosphere at an altitude of 11 km to 50 km. Of these, an airspace at an altitude of 20 km is preferable. After rising to airspace A, HAPS1 moves horizontally to position B and remains at position B. At night, it glides within airspace A while circling at a downward angle.

[0053] In this embodiment, when the control unit 91 determines that separation of the bank 8 is necessary during flight of the HAPS1, the control unit 91 separates the bank 8. The control process for disconnecting the bank 8 by the control unit 91 will be described below.

[0054] FIG. 4 is a flowchart showing a procedure for the disconnection control performed by the control unit 91. The control unit 91 determines (S1) whether or not an internal short circuit has occurred in the bank 8. If an internal short circuit has occurred (S1: YES), the control unit 91 advances the process to S5. If no internal short circuit has occurred (S1: NO), the control unit 91 determines whether or not the temperature of at least one battery cell 6 is equal to or higher than the first threshold value a (S2). The first threshold value a is set as described above. If the temperature of the battery cell 6 is equal to or higher than the first threshold value a (S2: YES), the control unit 91 advances the process to S5.

[0055] If the temperatures of all the battery cells 6 are not equal to or higher than the first threshold value a (S2: NO), the control unit 91 determines whether or not the overall SOH of the bank 8 is equal to or lower than the second threshold value b (S3). The second threshold value b is set as described above. If the SOH is equal to or lower than the second threshold value b (S3: YES), the control unit 91 proceeds to S5.

[0056] If the SOH is not equal to or less than the second threshold b (S3: NO), the control unit 91 determines whether or not the overall SOC of the bank 8 is equal to or less than the third threshold c (S4). The third threshold c is set as described above. If the SOC is equal to or less than the third threshold c (S4: YES), the control unit 91 advances the process to S5. If the SOC is not equal to or less than the third threshold c (S4: NO), the control unit 91 ends the process. The control unit 91 performs the processes of S1 to S4 for each bank 8.

[0057] In S5, the control unit 91 turns off the switch 171 of the switching unit 17 of the corresponding bank 8 to isolate the bank 8. The control unit 91 transports the detached bank 8 to the transport device 20 using a robot arm or the like, and detaches the transport device 20 carrying the bank 8 from the HAPS 1 (S6), ending the process. If the transport device 20 is a glider, it glides down and transports the bank 8 to the target landing point. If the transport device 20 is a drone, the detached and mounted bank 8 discharges electricity to drive the drive unit, and the drone lands at the target point.

[0058] When the battery cells 6 are configured as described above, the bank 8 can discharge even at or below the lower limit voltage. In this embodiment, when the SOC is equal to or lower than the third threshold c and the bank 8 cannot be used, the bank 8 is disconnected to continue the flight of the HAPS1 or extend the flight range, thereby improving the reliability of the flight. When the temperature of the battery cells 6 is equal to or higher than the first threshold a, or the SOH is equal to or lower than the second threshold b, and the degree of deterioration of the bank 8 is large, or when an internal short circuit occurs, the bank 8 is disconnected and charging and discharging is continued by the other bank 8, thereby continuing the flight or extending the flight range, thereby improving the reliability of the flight. In this way, the reliability of the flight operation can be improved. During normal operation, the HAPS1 glides in the airspace A at position B, and the landing position can be assumed by descending the carrier 20 from position B. Note that this is not limited to separating the bank 8. The battery modules 7 or the battery cells 6 may be separated. In addition, the bank 8 may be mounted inside the transport device 20, and when the degree of deterioration of the bank 8 is large, the bank 8 may be separated together with the transport device 20.

[0059] (Embodiment 2) FIG. 5 is a flowchart showing a procedure of the disconnection control performed by the control unit 91 according to the second embodiment. The control unit 91 determines whether a particular bank 8 is unnecessary (S11). The control unit 91 determines whether some banks 8 have become unnecessary due to takeoff, or whether a predetermined period of time has passed, or the like. Banks 8 that will become unnecessary after takeoff, including the number of battery modules 7 that constitute them, may be determined in advance based on the power required for takeoff of the HAPS1, the power required for operation of the HAPS1 during the day and night, and the amount of power generated by the solar panels 5, etc. If the HAPS1 has multiple banks 8 with different usage periods, a bank 8 that has been in use for a predetermined period of time may be determined to be unnecessary. If it is not unnecessary (S11: NO), the control unit 91 ends the process.

[0060] If not required (S11: YES), the control unit 91 turns off the switch 171 of the switching unit 17 of the corresponding bank 8 to isolate the bank 8 (S12). The control unit 91 transports the detached bank 8 to the transport device 20 by a robot arm or the like, and detaches the transport device 20 from the HAPS 1 (S13), ending the process. The transport device 20 glides down and transports the bank 8.

[0061] In this embodiment, by separating the bank 8, weight can be reduced, flight can be continued, and the flight range can be extended, thereby improving the flight reliability of HAPS1.

[0062] The above-described embodiments are not limiting, and the scope of the present invention is intended to include all modifications within the meaning and scope of the claims. The power generating device is not limited to one having a solar cell. It is preferable that the power generating device emits less carbon dioxide when generating electricity than when an internal combustion engine is driven. The present invention is not limited to providing the control device 9 in the HAPS 1. A computer or a server wirelessly connected to the HAPS 1 may control the disconnection of the bank 8.

[0063] HAPS1 is not limited to a solar plane. HAPS1 may be an airship, a stratospheric jet, etc. The flying object is not limited to HAPS. The present invention can also be applied to other electric flying objects such as eVTOLs and hybrid flying objects equipped with a power generation device and an internal combustion engine. The present invention can also be applied to an aircraft equipped with a power storage device but not a power generation device. For example, when the SOH of the power storage device falls below the second threshold and the degree of deterioration is large, or when an internal short circuit occurs, the disconnection control of the present invention is performed.

[0064] The power storage element is not limited to a lithium ion secondary battery, and may be another type of secondary battery or a capacitor. [Explanation of symbols]

[0065] 1 HAPS 2 Wings 3 Propeller 4 legs 5. Solar panels (power generation equipment) 6 Battery cell (energy storage element) 7 Battery module (energy storage device) 8 Bank (Electricity Storage Device) 9 Control device 90 Recording media 91 Control Unit 92 Memory section 921 Disconnection Control Program 922 History DB 93 Input section 94 Communications Department 95 Motor drive unit 96 1st separation part 97 Second separation part 10 Radio repeater station 11 First converter circuit 12 Second converter circuit 13 Switching section 14 Inverter circuit 15 wheels 16 Motor 17 Switching section 20 Transport Equipment 30 Terminal Equipment

Claims

1. A method for controlling an aircraft including an aircraft propulsion device and a power storage device having a plurality of power storage elements and supplying power to the aircraft propulsion device, comprising: During the flight of the aircraft, some of the plurality of storage elements are detached from the aircraft, other storage elements are not detached, and no new storage elements are added. A method for controlling an aircraft.

2. The control method for an aircraft as described in claim 1, wherein one or more storage elements are disconnected when an internal short circuit occurs, or when the temperature of the storage element is equal to or higher than a first threshold, or when the SOH is equal to or lower than a second threshold, or when the SOC is equal to or lower than a third threshold.

3. A power generation device having a solar cell and supplying power to the aircraft propulsion device; a power storage device having a plurality of power storage elements and supplying power to the aircraft propulsion device; a transport device that carries one or more power storage elements separated from the power storage device, is separated from the aircraft, and transports the one or more power storage elements; During flight, some of the plurality of storage elements are detached from the storage device, other storage elements are not detached, and new storage elements are not added. Flying vehicle.

4. The flying object according to claim 3 , further comprising a wireless relay station for wirelessly communicating with a terminal device.

5. 5. The aircraft according to claim 3, wherein the power storage device is configured by connecting in parallel a plurality of series-connected circuits, each of which has a plurality of power storage elements connected in series, and the series-connected circuits are disconnected from the power storage device.

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