Propulsion control device, propulsion control program, and propulsion control method

Abstract

An eVTOL (10) is equipped with a plurality of EPUs (50). The plurality of EPUs (50) include a landing device (51) and a flight device (52). The landing device (51) drives and rotates a lift propeller (21). The flight device (52) drives and rotates a cruise propeller (22). When the eVTOL 10 cruises, the cruise EPU (52) is driven while the driving of the lift EPU (51) is stopped. When the eVTOL 10 lands, the lift EPU (51) is driven. When the eVTOL 10 is cruising, the flight control device initiates preliminary driving of the lift EPU (51) before the eVTOL 10 begins landing.

Description

Propulsion control device, propulsion control program, and propulsion control method Cross-reference to Related Applications

[0001] This application is based on Japanese Patent Application No. 2025-056667 filed on March 28, 2025, and the entire content of the base application is incorporated herein by reference.

[0002] The disclosure in the present specification relates to a propulsion control device, a propulsion control program, and a propulsion control method.

[0003] Patent Document 1 describes an electric flying vehicle. The flying vehicle is equipped with a plurality of EPUs for propelling the flying vehicle. The EPU is configured to include a motor, and rotates the propeller of the flying vehicle by driving the motor. Electric power is supplied to the EPU from a battery.

[0004] Japanese Patent Application Laid-Open No. 2023-80614

[0005] After the flying vehicle takes off, some of the plurality of EPUs may be stopped along with the start of horizontal flight. It is considered that the temperature of the stopped EPUs decreases during horizontal flight. If a stopped EPU is re-driven when the flying vehicle starts landing after horizontal flight, it is conceivable that the output of the EPU will be insufficient due to the low temperature of the EPU. In this case, there is a concern that the safety of the flying vehicle may decrease.

[0006] An object of the present disclosure is to provide a propulsion control device, a propulsion control program, and a propulsion control method capable of improving safety when a flying vehicle lands.

[0007] The plurality of aspects disclosed in the present specification employ different technical means from each other to achieve the respective objects. Further, reference signs in parentheses described in the claims and this section are an example showing the correspondence with specific means described in the embodiments described later as one aspect, and do not limit the technical scope.

[0008] To achieve the above objective, the disclosed embodiment is a propulsion control device that drives and controls a plurality of electric propulsion devices provided on an aircraft, comprising: a horizontal flight unit that drives a flight device and stops the drive of a landing device among the plurality of propulsion devices when the aircraft is in horizontal flight; a landing unit that drives the landing device when the aircraft is landing; and a pre-drive unit that drives the landing device before the landing unit drives the landing device when the aircraft is in horizontal flight.

[0009] According to the above propulsion control system, when the aircraft is in level flight, the pre-launch unit drives the landing gear before the landing unit drives the landing gear. In this configuration, the landing gear is driven before the aircraft begins to land. Therefore, it is possible to raise the temperature of the landing gear before the aircraft begins to land. Consequently, it is possible to suppress the problem of insufficient output from the landing gear due to a low temperature during landing. This enhances safety during aircraft landing.

[0010] The disclosed embodiment is a propulsion control program used in an electric propulsion system that is driven to propel an aircraft and is provided on the aircraft, the propulsion control program causing at least one processing unit to execute: a horizontal flight unit that drives a flight unit and stops driving a landing unit among the multiple propulsion systems when the aircraft is in horizontal flight; a landing unit that drives the landing unit when the aircraft is landing; and a pre-operation unit that drives the landing unit before the landing unit drives the landing unit when the aircraft is in horizontal flight.

[0011] According to the above propulsion control program, safety during the landing of an aircraft can be enhanced, similar to the above propulsion control device.

[0012] The disclosed embodiment is a propulsion control method used for multiple electrically operated propulsion devices provided on an aircraft, which are driven to propel an aircraft, and the method includes a process in which at least one processing unit performs the following steps: when the aircraft is flying horizontally, it drives the flight device and stops the drive of the landing device among the multiple propulsion devices; when the aircraft is landing, it drives the landing device; and when the aircraft is flying horizontally, it drives the landing device before the landing unit drives the landing device.

[0013] According to the above propulsion control method, safety during the landing of an aircraft can be enhanced, similar to the above propulsion control device.

[0014] A diagram showing the configuration of the eVTOL in the first embodiment. A block diagram showing the electrical configuration of the propulsion system. A diagram showing the circuit configuration of the inverter device. A flowchart showing the procedure for flight control processing. A flowchart showing the procedure for landing-related processing. A flowchart showing the procedure for setting the pre-drive time. A flowchart showing the procedure for setting the pre-drive current. A diagram for explaining the temperature change of the EPU. A flowchart showing the procedure for landing-related processing in the second embodiment. A flowchart showing the procedure for setting the pre-drive time. A flowchart showing the procedure for setting the pre-drive current.

[0015] Several embodiments for implementing this disclosure are described below with reference to the drawings. In each embodiment, parts corresponding to matters described in a preceding embodiment are denoted by the same reference numerals, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, other parts of the configuration can be applied to other embodiments described in advance. Not only are combinations of parts that are explicitly shown to be combinable in each embodiment possible, but embodiments can also be partially combined even if not explicitly shown, as long as there are no particular problems with the combination.

[0016] <First Embodiment> The propulsion system 30 shown in Figure 1 is mounted on the eVTOL 10. The eVTOL 10 is an electric vertical take-off and landing aircraft. An electric vertical take-off and landing aircraft is an electric vertical take-off and landing aircraft that is capable of vertical take-off and landing. eVTOL is an abbreviation for electric Vertical Take-Off and Landing aircraft. The eVTOL 10 is an electric flying vehicle that flies in the atmosphere and is sometimes referred to as an electric flying vehicle. The eVTOL 10 is also an electric aircraft and is sometimes referred to as an electric aircraft. The eVTOL 10 is a manned flying vehicle that carries a crew. The crew of the eVTOL 10 includes a pilot as the operator or driver. The propulsion system 30 is a system that drives the eVTOL 10 to propel it. The propulsion system 30 is sometimes referred to as a flight system.

[0017] The eVTOL 10 has an airframe 11 and a propeller 20. The airframe 11 has a fuselage body 12 and wings 13. The fuselage body 12 is the body of the airframe 11 and has a shape that extends, for example, forward and backward. The fuselage body 12 has a crew compartment 14 for the crew. The wings 13 extend from the fuselage body 12 and are provided in multiples on the fuselage body 12. The wings 13 are fixed wings. The multiple wings 13 include main wings, tail wings, etc.

[0018] The eVTOL 10 has an aircraft cabin. The aircraft cabin is located inside the eVTOL 10. For example, the aircraft cabin is the internal space of the aircraft body 12 and is formed by the aircraft body 12. The aircraft cabin may include a crew compartment 14 or a cargo compartment. The crew compartment 14 may include a passenger cabin or a pilot's cabin. The crew compartment 14 is equipped with seats for the crew to sit in. The crew compartment 14 does not have to be occupied by crew, and may contain cargo.

[0019] Multiple propellers 20 are provided on the airframe 11. The eVTOL 10 is a multicopter having at least three propellers 20. For example, at least six propellers 20 are provided on the airframe 11. The propellers 20 are provided on the airframe body 12 and the wings 13, respectively. The propellers 20 rotate around their propeller axis. The propeller axis is, for example, the center line of the propeller 20. The propellers 20 can generate thrust and lift in the eVTOL 10. The propellers 20 are sometimes referred to as rotors or rotor blades.

[0020] The eVTOL10 has multiple propellers 20, which makes it easier to maintain aircraft balance. In the eVTOL10, even if the propeller output of one propeller 20 unintentionally decreases, the remaining propellers 20 can continue flight. Propeller output includes the rotational speed and torque of the propellers 20.

[0021] The propeller 20 has blades, a boss, and a propeller shaft. Multiple blades are arranged in the circumferential direction of the propeller axis. The boss connects the multiple blades. The propeller shaft is the axis of rotation of the propeller 20 and extends from the boss along the propeller axis.

[0022] The flight modes of the eVTOL10 include vertical takeoff, vertical landing, cruise, and hovering. Flight modes are sometimes referred to as flight patterns. In vertical takeoff, the eVTOL10 can take off without taxiing. In vertical takeoff, the eVTOL10 may ascend vertically or diagonally upwards. In vertical landing, the eVTOL10 can land without taxiing. In vertical landing, the eVTOL10 may descend vertically or diagonally downwards.

[0023] Cruise is sometimes referred to as horizontal flight. In cruise, the eVTOL 10 may fly horizontally without moving vertically, or it may fly horizontally while moving vertically. Hovering is sometimes referred to as stationary flight. In hovering, the eVTOL 10 may fly as if it were stationary in a predetermined position in the air, or the eVTOL 10 may deviate vertically or horizontally from its predetermined position.

[0024] Furthermore, the eVTOL10's flight modes include lift. In lift mode, the eVTOL10 moves vertically. As a lift, the eVTOL10 may ascend diagonally upwards or descend diagonally downwards. The eVTOL10 takes off vertically by lifting upwards. The eVTOL10 lands vertically by lifting downwards.

[0025] The multiple propellers 20 include lift propellers 21 and cruise propellers 22. The lift propellers 21 are propellers 20 for lifting the eVTOL 10. The lift propellers 21 enable the eVTOL 10 to take off vertically, land vertically, and hover. The lift propellers 21 are sometimes referred to as hover propellers. The cruise propellers 22 are propellers 20 for cruising the eVTOL 10.

[0026] The eVTOL 10 may also be a tiltrotor aircraft. In a tiltrotor aircraft, the tilt angle of the propeller 20 is adjustable. In a tiltrotor aircraft, one propeller 20 can function as both a lift propeller and a cruise propeller.

[0027] The eVTOL 10 includes a battery 31, a flight control device 40, and an EPU 50. The battery 31, the flight control device 40, and the EPU 50 are included in the propulsion system 30. The propulsion system 30 only needs to include at least the flight control device 40 and the EPU 50. The flight control device 40 is sometimes referred to as a flight controller.

[0028] The EPU 50 is a device that drives the propeller 20 to rotate, and is equivalent to a drive unit. EPU is an abbreviation for Electric Propulsion Unit. The EPU 50 is sometimes referred to as an electric drive unit or electric drive system. An EPU 50 is provided individually for each of the multiple propellers 20. The EPU 50s are arranged along the propeller axis on the propeller 20. All of the multiple EPU 50s are fixed to the aircraft body 11. The EPU 50 rotatably supports the propeller 20. The EPU 50 is connected to the propeller 20. The propeller 20 is fixed to the aircraft body 11 via the EPU 50.

[0029] Multiple EPUs 50 include lift EPUs 51 and cruise EPUs 52. For example, multiple lift EPUs 51 and multiple cruise EPUs 52 are installed in the eVTOL 10. The lift EPU 51 is an EPU 50 for driving and rotating the lift propeller 21. The lift EPU 51 is provided in relation to the lift propeller 21. The lift EPU 51 corresponds to the landing gear. The lift EPU 51 is sometimes referred to as the hover EPU. The cruise EPU 52 is an EPU 50 for driving and rotating the cruise propeller 22. The cruise EPU 52 is provided in relation to the cruise propeller 22. The cruise EPU 52 corresponds to the flight gear.

[0030] The EPU 50 is a propulsion system for propelling the eVTOL 10. The EPU 50 propels the eVTOL 10 by rotating the propeller 20. The eVTOL 10 flies by being propelled by the EPU 50. The eVTOL 10 is also a mobile object that moves using the EPU 50. The propulsion system may include the propeller 20.

[0031] As shown in Figure 2, the EPU 50 has a motor unit 60 and an inverter unit 80. The motor unit 60 has a motor 61 and a motor housing 70. The motor housing 70 is a casing that houses the motor 61. The motor 61 is a multi-phase AC motor. The motor 61 is a multi-phase AC rotating electric machine. The motor 61 is the flight drive source for the eVTOL 10 and functions as an electric motor. The motor 61 is a motor generator. The motor 61 functions as a generator during regeneration. For example, a brushless motor is used as the motor 61.

[0032] Motor 61 enables the eVTOL 10 to fly by driving and rotating the propeller 20. Motor 61 is a flight motor for flying the eVTOL 10. Motor 61 drives and rotates the propeller 20 by being powered by battery power. Battery power is the power supplied to motor 61 from battery 31. In this embodiment, the powering of motor 61 is sometimes simply referred to as driving motor 61. Motor 61 generates regenerative power when the propeller 20 rotates due to external forces such as wind during flight. Regenerative power is the power generated by the regeneration of motor 61.

[0033] The motor 61 has a stator 62 and a rotor 63. The motor 61 has a stator 62. The stator 62 is a stator and is fixed to the motor housing 70. The rotor 63 rotates relative to the stator 62. The rotation of the rotor 63 is sometimes referred to as the rotation of the motor 61. The motor 61 is, for example, a radial gap type motor. In the motor 61, the stator 62 and the rotor 63 are arranged radially in the motor 61. The motor 61 has a motor shaft that rotates together with the rotor 63. The motor shaft is rotatably supported by the motor housing 70 or the like.

[0034] The motor 61 is driven by power supplied to the stator 62. The stator 62 has coils 62a (see Figure 3). Coils 62a are provided for each of the multiple phases. The coils 62a form the armature. When power is supplied to the stator 62, current flows through the coils 62a, causing the rotor 63 to rotate. The rotor 63 is formed by including multiple magnets, such as permanent magnets. The magnets form the magnetic field.

[0035] The inverter device 80 drives the motor device 60 by supplying power to it. The inverter device 80 is a drive unit for driving the motor 61 and corresponds to the motor drive unit. The inverter device 80 has an inverter circuit 85 and an inverter housing 90. The inverter circuit 85 converts the power supplied from the battery 31 to the motor 61. DC power is supplied to the inverter circuit 85 from the battery 31. The inverter circuit 85 converts the DC power to AC power and supplies the AC power to the motor 61. The inverter circuit 85 is sometimes referred to as an inverter or power conversion unit. The inverter circuit 85 performs power conversion for each of the multiple phases. The motor 61 is driven according to the voltage and current supplied from the inverter circuit 85. The inverter housing 90 is an enclosure that houses the inverter circuit 85 and the inverter control unit 81, which will be described later.

[0036] The battery 31 supplies power to the EPU 50. For example, the battery 31 supplies power to the motor unit 60 via the inverter device 80. The battery 31 is connected to the motor 61 via the inverter circuit 85 so that it can be energized. The battery 31 has a rechargeable secondary battery. This secondary battery may be a lithium-ion battery or a nickel-metal hydride battery. The battery 31 is an energy storage device capable of storing electricity. The battery 31 is sometimes referred to as a power supply unit. In addition to or instead of the battery 31, a fuel cell or a generator may be used as the power supply unit.

[0037] The inverter device 80 has an inverter control unit 81. The inverter control unit 81 performs motor control via an inverter circuit 85. Motor control is the control for driving the motor 61. The inverter control unit 81 also performs propulsion control. Propulsion control is the control for driving the EPU 50. Propulsion control includes motor control. Propulsion control is also the control for controlling the EPU 50 and is sometimes referred to as EPU control.

[0038] The inverter control unit 81 has, for example, an ECU. ECU is an abbreviation for Electronic Control Unit. The inverter control unit 81 has a processor 82, a memory 83, and a program 84. The inverter control unit 81 is mainly composed of a computer. This computer has a processor 82, a memory 83, an input / output interface, a bus connecting these, etc. The memory 83 stores the program 84. The program 84 is a program for performing propulsion control. Program 84 corresponds to the propulsion control program.

[0039] The processor 82 is hardware for arithmetic processing coupled to the memory 83. The processor 82 performs various processes by accessing the memory 83. The memory 83 is a storage medium that stores control programs and the like. For example, the memory 83 is a non-transitory tangible storage medium that non-temporarily stores computer-readable programs and data. A non-transitory tangible storage medium is a semiconductor memory or magnetic disk, etc. The program 84 contains computer-readable instructions that cause the processor 82 to perform various functions. The processor 82 is a processing unit that performs predetermined processes by executing the instructions contained in the program 84.

[0040] The inverter control unit 81 controls the motor according to the requested output. The requested output is the motor output required by the inverter control unit 81. Examples of requested output include the required torque relative to the output torque. The requested output is included in the command signal etc. that the flight control device 40 outputs to the inverter control unit 81. The inverter control unit 81 adjusts the motor output according to the requested output. The requested output and required torque are sometimes referred to as the target output and target torque. Note that the motor output may also be torque, current, voltage, motor speed, etc.

[0041] The inverter control unit 81 controls the motors using command signals from the flight control device 40 and detection signals from various sensors. The various sensors are connected to the inverter control unit 81 for communication. The various sensors output detection signals to the inverter control unit 81. The various sensors include motor sensors, inverter sensors, and battery sensors. The motor sensor detects information from the motor device 60. The inverter sensor detects information from the inverter device 80. The battery sensor detects information from the battery 31.

[0042] Motor sensors include motor temperature sensors such as the motor temperature sensor 67. The motor temperature sensor 67 detects the temperature of the motor 61. For example, the motor temperature sensor 67 detects the temperature of the coil 62a. The motor temperature sensor 67 detects the temperature of the coil 62a. The motor temperature sensor 67 outputs a detection signal corresponding to the temperature of the coil 62a. The motor temperature sensor 67 is provided for the motor 61 by being attached to the coil 62a or the motor housing 70. The motor temperature sensor 67 corresponds to the temperature detection unit. The motor temperature sensor 67 may also detect the temperature of the stator 62 or the temperature of the rotor 63.

[0043] Examples of inverter sensors include a current sensor 88 and a voltage sensor 89. The current sensor 88 and the voltage sensor 89 are provided in the inverter device 80. The current sensor 88 detects a motor current flowing through the motor 61. The motor current is a current flowing through the coil 62a. The current sensor 88 outputs a detection signal corresponding to the motor current. The voltage sensor 89 detects a motor voltage generated in the motor 61. The motor voltage is a voltage of the coil 62a. The voltage sensor 89 outputs a detection signal corresponding to the motor voltage. The voltage sensor 89 detects inter-phase voltages of a plurality of phases in the motor 61.

[0044] A battery sensor 31a included in the various sensors is provided on the battery 31. The battery sensor 31a has a plurality of sensors. The plurality of sensors may be integrated with each other, or may be provided independently of each other. For example, the battery sensor 31a includes a battery temperature sensor, a battery voltage sensor, a battery current sensor, and the like.

[0045] The battery temperature sensor detects the temperature of the battery 31. The battery temperature sensor outputs a detection signal corresponding to the temperature of the battery 31. The battery voltage sensor detects a battery voltage. The battery voltage is an output voltage of the battery 31. The battery voltage sensor outputs a detection signal corresponding to the battery voltage. The battery current sensor detects a battery current. The battery current is an output current of the battery 31. The battery current sensor outputs a detection signal corresponding to the battery current.

[0046] The various sensors include an outside air temperature sensor 35. The outside air temperature sensor 35 detects an outside air temperature. The outside air temperature sensor 35 outputs a detection signal corresponding to the outside air temperature. The outside air temperature sensor 35 is provided on the airframe 11. The outside air temperature sensor 35 is provided at a position sufficiently distant from the EPU 50 and the battery 31.

[0047] The flight control device 40 is communicably connected to the inverter control unit 81. The flight control device 40 and the inverter control unit 81 may be capable of wireless communication. The flight control device 40 performs overall control for overall managing the driving of a plurality of EPUs 50. In the overall control, propulsion control performed by each of the plurality of inverter control units 81 is managed. The flight control device 40 performs flight control. The flight control is control for causing the eVTOL 10 to fly. The flight control device 40 controls the propulsion system 30 and the EPUs 50 as the flight control. The flight control is also control for propelling the eVTOL 10, and is sometimes referred to as propulsion control. The flight control device 40 corresponds to a propulsion control device.

[0048] The flight control device 40 includes, for example, an ECU. The flight control device 40 includes a processor 42, a memory 43, and a program 44. The flight control device 40 is configured mainly with a computer. This computer includes the processor 42, the memory 43, an input / output interface, a bus connecting these components, and the like. The program 44 is stored in the memory 43. The program 44 is a program for performing flight control.

[0049] The processor 42 is hardware for arithmetic processing coupled to the memory 43. The processor 42 executes various processes by accessing the memory 43. The memory 43 is a storage medium that stores control programs and the like. For example, the memory 43 is a non-transitional tangible storage medium that non-temporarily stores computer-readable programs and data. The program 44 includes computer-readable instructions that cause the processor 42 to execute various functions. The processor 42 is a processing unit that executes predetermined processing by executing the instructions included in the program 44.

[0050] The flight control device 40 outputs information necessary for propulsion control to the inverter control unit 81. The flight control device 40 is a higher-level ECU for the inverter control unit 81. The flight control device 40 individually controls multiple EPUs 50 according to the flight mode of the eVTOL 10. The flight control device 40 can individually adjust the output of each EPU 50. For example, the flight control device 40 outputs a request output to each of the multiple EPUs 50. The request output is the output requested from the EPU 50. Examples of request outputs include the requested torque for the motor 61. Note that torque, current, voltage, motor speed, etc., may also be used as the request output.

[0051] The flight control device 40 performs flight control according to the flight status of the eVTOL 10 and detection signals from various sensors. The flight status of the eVTOL 10 includes the flight mode and the flight attitude of the eVTOL 10. Various sensors are connected to the flight control device 40 in a communication manner.

[0052] In Figure 2, the motor unit 60 is denoted as MOT, the stator 62 as STA, and the rotor 63 as ROT. The inverter unit 80 is denoted as MCU, the inverter circuit 85 as INV, and the inverter control unit 81 as ICD. The processor 82 is denoted as PRO, the memory 83 as MEM, and the program 84 as PG. The flight control device 40 is denoted as FCD, the processor 42 as PRO, the memory 43 as MEM, and the program 44 as PG. The battery 31 is denoted as BAT.

[0053] As shown in Figure 3, the propulsion system 30 has a P line 91, an N line 92, and an output line 93. The P line 91 and the N line 92 are energetically connected to the battery 31 and the inverter circuit 85. The P line 91 and the N line 92 are formed by busbars, electrical wiring, etc. At least a portion of the P line 91 and at least a portion of the N line 92 are included in the EPU 50. Figure 3 shows a circuit in which one inverter device 80 is connected to a three-phase coil 62a.

[0054] The P line 91 is electrically connected to the positive electrode of the battery 31. The N line 92 is electrically connected to the negative electrode of the battery 31. In the battery 31, the positive electrode is the electrode on the high potential side, and the negative electrode is the electrode on the low potential side. The P line 91 and the N line 92 are power lines for supplying power from the battery 31 to the inverter circuit 85. The P line 91 is the power line on the high potential side and is sometimes referred to as the high potential line. The N line 92 is the power line on the low potential side and is sometimes referred to as the low potential line.

[0055] The output line 93 is a power line for supplying power from the inverter circuit 85 to the motor 61. The output line 93 connects the motor 61 and the inverter circuit 85 in a conduction manner. For example, the output line 93 is conductionally connected to the stator 62. The output line 93 is formed by busbars, electrical wiring, etc. At least a portion of the output line 93 is included in the EPU 50.

[0056] The inverter device 80 has a smoothing capacitor 94. The smoothing capacitor 94 is a capacitor that smooths the DC voltage supplied from the battery 31. The smoothing capacitor 94 is connected to the P line 91 and the N line 92 between the battery 31 and the inverter circuit 85. The smoothing capacitor 94 is connected in parallel to the inverter circuit 85.

[0057] The inverter circuit 85 is a power conversion circuit, for example, a DC-AC conversion circuit. The inverter circuit 85 has multiple phase upper and lower arm circuits 95. For example, the inverter circuit 85 has upper and lower arm circuits 95 for each of the U phase, V phase, and W phase. The upper and lower arm circuits 95 have an upper arm switch 96 and a lower arm switch 97. The arm switches 96 and 97 are connected in series with the battery 31. The upper arm switch 96 is connected to the P line 91 so as to be energized. The lower arm switch 97 is connected to the N line 92 so as to be energized.

[0058] The arm switches 96 and 97 are formed from semiconductor switches, etc. Semiconductor switches are switches that do not have mechanical contacts. The arm switches 96 and 97 are transistors such as MOSFETs and IGBTs. MOSFET is an abbreviation for Metal-Oxide-Semiconductor Field-Effect Transistor. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. The arm switches 96 and 97 are switching elements and can convert power by switching. Switching elements are semiconductor elements such as power elements. The arm switches 96 and 97 are conversion switches for converting power. The arm switches 96 and 97 can transition between an energized state where power can be supplied and an interrupted state where power is cut off.

[0059] The upper and lower arm circuit 95 has an upper arm diode 96a and a lower arm diode 97a. The arm diodes 96a and 97a are freewheeling diodes and are connected in reverse parallel to the arm switches 96 and 97. The arm diodes 96a and 97a may be parasitic diodes of the arm switches 96 and 97, or they may be diodes provided separately from the parasitic diodes. The upper arm diode 96a is connected in reverse parallel to the upper arm switch 96. The lower arm diode 97a is connected in reverse parallel to the lower arm switch 97.

[0060] The output line 93 is connected to the upper and lower arm circuit 95 so that power can be supplied to each of the multiple phases. The output line 93 is connected between the upper arm switch 96 and the lower arm switch 97. Multiple output lines 93 are connected to the motor 61.

[0061] The inverter control unit 81 is formed by a control circuit and the like. The control circuit is provided on a control board. The control board is sometimes referred to as a control board. The inverter device 80 has a drive circuit (not shown). The drive circuit drives the arm switches 96 and 97 in response to command signals from the inverter control unit 81. For example, the drive circuit can apply a drive voltage to the gate terminals of the arm switches 96 and 97. The drive circuit is sometimes referred to as a gate drive circuit. The drive circuit is provided on a drive board. The drive board is sometimes referred to as a drive board or gate drive board.

[0062] The propulsion system 30 has a power switch 86. The power switch 86 is a switch such as an SMR. SMR is an abbreviation for System Main Relay. The power switch 86 is formed by including a mechanical switch or mechanical relay having mechanical contacts. The power switch 86 can switch between an energized state and an disconnected state. The energized state of the power switch 86 is sometimes referred to as the closed state, and the disconnected state is sometimes referred to as the open state. The power switch 86 is provided between the battery 31 and the inverter circuit 85 in both the P line 91 and the N line 92.

[0063] The flight control device 40 performs flight control processing. The flight control processing will be explained with reference to the flowchart in Figure 4. The flight control device 40 repeatedly executes the flight control processing at a predetermined control cycle. The flight control device 40 has the function of executing the processing at each step of the flight control processing. The control method executed by the flight control processing corresponds to the propulsion control method.

[0064] In step S101 shown in Figure 4, the flight control device 40 determines whether or not to allow the eVTOL 10 to take off. It determines whether or not a takeoff start request has been received to initiate the takeoff mode of the eVTOL 10. A takeoff start request is input to the flight control device 40 when an operation to initiate the takeoff of the eVTOL 10 is performed by a pilot or the like. If the eVTOL 10 is to take off, the flight control device 40 proceeds to step S102.

[0065] In step S102, the flight control device 40 sets the flight mode of the eVTOL 10 to takeoff mode. Takeoff mode is a flight mode for taking off the eVTOL 10. In takeoff mode, the flight control device 40 drives the lift EPU 51 to lift the eVTOL 10 upward. In takeoff mode, the lift EPU 51 is driven in a manner that allows the eVTOL 10 to take off. For example, in takeoff mode, the lift EPU 51 is controlled by the flight control device 40 and the inverter control unit 81 so that the motor voltage and motor current are values ​​necessary for the eVTOL 10 to take off. In takeoff mode, the cruise EPU 52 may be driven, or the cruise EPU 52 may be deactivated.

[0066] In step S103, the flight control device 40 determines whether or not to allow the eVTOL 10 to cruise. It determines whether or not a cruise start request has been received to initiate cruise mode for the eVTOL 10. A cruise start request is input to the flight control device 40 when an operation to initiate cruise mode for the eVTOL 10 is performed by a pilot or the like. If the eVTOL 10 is to cruise, the flight control device 40 proceeds to step S104.

[0067] In step S104, the flight control device 40 sets the flight mode of the eVTOL 10 to cruise mode. Cruise mode is a flight mode for cruising the eVTOL 10. In cruise mode, the flight control device 40 drives the cruise EPU 52 and stops driving the lift EPU 51 to cruise the eVTOL 10. In cruise mode, the cruise EPU 52 is driven in a manner that allows the eVTOL 10 to cruise. For example, in cruise mode, the cruise EPU 52 is controlled by the flight control device 40 and the inverter control unit 81 so that the motor voltage and motor current become values ​​necessary for cruising the eVTOL 10. The function in the flight control device 40 that executes the process in step S104 corresponds to the horizontal flight unit. In cruise mode, some of the lift EPUs 51 may be driven.

[0068] The flight control device 40 also sets the drive mode of the EPU 50 to cruise mode. In cruise mode, the EPU 50 is driven so that the eVTOL 10 can cruise. For example, in the drive mode of the EPU 50, the EPU 50 is controlled by the inverter control unit 81 and the flight control device 40 so that the motor voltage and motor current are values ​​required for the eVTOL 10 to cruise.

[0069] In step S105, the flight control device 40 sets the destination for the eVTOL 10. The destination is the planned landing location for the eVTOL 10. If a destination has already been set, the flight control device 40 acquires the destination using eVTOL information, etc. eVTOL information is information indicating the status of the eVTOL 10. eVTOL information includes information indicating the flight status of the eVTOL 10, information indicating the position of the eVTOL 10, and information indicating the status of the EPU 50.

[0070] In step S106, the flight control device 40 acquires the current position of the eVTOL 10 using eVTOL information, etc. In step S107, the flight control device 40 acquires the battery status. For example, the flight control device 40 detects the battery status using the detection signal from the battery sensor 31a.

[0071] Battery status includes battery charge Eb, battery temperature Tb, and battery voltage Vb. Battery charge Eb is a value indicating the remaining power in battery 31. Battery charge Eb is sometimes referred to as the amount of charge stored in battery 31. The flight control device 40 detects battery charge Eb using detection signals from a battery voltage sensor or battery current sensor. Battery temperature Tb is the temperature of battery 31. The flight control device 40 detects battery temperature Tb using detection signals from a battery temperature sensor or the like. Battery voltage Vb is the voltage that battery 31 outputs to the EPU 50. The flight control device 40 detects battery voltage Vb using detection signals from a battery voltage sensor or the like.

[0072] In step S108, the flight control device 40 acquires the motor temperature Tm. For example, the flight control device 40 detects the motor temperature Tm using the detection signal from the motor temperature sensor 67. The motor temperature Tm is a value that indicates the temperature of the motor device 60 or the motor 61. For example, the motor temperature Tm is a value that indicates the temperature of the coil 62a. The motor temperature Tm is also a value that indicates the temperature of the EPU 50. Note that the inverter temperature may be used as the temperature of the EPU 50. The inverter temperature is a value that indicates the temperature of the inverter device 80 or the inverter circuit 85.

[0073] The flight control device 40 may acquire motor status. Motor status includes motor temperature Tm, motor current, and motor voltage. The flight control device 40 detects motor current using the detection signal from the current sensor 88. The flight control device 40 detects motor voltage using the detection signal from the voltage sensor 89.

[0074] In step S109, the flight control device 40 acquires the outside air temperature Tout. For example, the flight control device 40 detects the outside air temperature sensor 35 using the detection signal from the outside air temperature sensor 35. The flight control device 40 may also acquire the outside air temperature Tout using eVTOL information.

[0075] In step S110, the flight control device 40 sets the pre-drive start time BP for the lift EPU 51. Pre-drive is the operation of the lift EPU 51 while the eVTOL 10 is cruising, at a time earlier than the scheduled start time for the eVTOL 10's landing. Pre-drive is sometimes referred to as pre-drive or warm-up. The scheduled start time for landing is the scheduled time when the eVTOL 10 is expected to reach the airspace above the destination. For example, the scheduled start time for landing is the timing when the eVTOL 10 begins its landing. The pre-drive start time BP is the timing when the pre-drive is started. The flight control device 40 sets the pre-drive start time BP using information about the destination, current position, and eVTOL information. For example, the flight control device 40 sets the pre-drive start time BP to a time a few minutes or a few tens of minutes before the scheduled time when the eVTOL 10 is expected to arrive above the destination.

[0076] In step S111, the flight control device 40 performs landing-related processing. The landing-related processing will be explained with reference to the flowchart shown in Figure 5. In step S201 of the landing-related processing, the flight control device 40 determines whether it is currently the pre-drive start time BP. If it is currently the pre-drive start time BP, the flight control device 40 proceeds to step S202.

[0077] In step S202, the flight control device 40 determines whether the motor temperature Tm is lower than the first temperature threshold JTm1. The first temperature threshold JTm1 is a value predetermined by testing or the like and stored in memory 43 or the like. The first temperature threshold JTm1 is a value that indicates that the output of the lift EPU 51 is sufficient for the landing of the eVTOL 10, assuming that the lift EPU 51 is driven for the landing of the eVTOL 10. For example, the first temperature threshold JTm1 is set to the lower limit of the allowable range for the motor temperature Tm. The first temperature threshold JTm1 corresponds to a pre-set threshold. The output of the lift EPU 51 is the motor output.

[0078] The first temperature threshold JTm1 is a value that indicates that, at the pre-drive start time BP, prior to the start of driving the lift EPU 51 for the landing of the eVTOL 10, the output of the lift EPU 51 at the scheduled start of landing will be insufficient to land the eVTOL 10. For example, the lower the motor temperature Tm at the pre-drive start time BP, the lower the motor temperature Tm at the scheduled start of landing is expected to be. Therefore, if the motor temperature Tm is lower than the first temperature threshold JTm1, it is highly likely that the motor temperature Tm at the scheduled start of landing will be so low that the output of the lift EPU 51 will be insufficient for the landing of the eVTOL 10. Accordingly, if the motor temperature Tm is lower than the first temperature threshold JTm1, it is preferable to perform pre-drive to raise the motor temperature Tm so that the output of the lift EPU 51 is not insufficient for the landing of the eVTOL 10.

[0079] If the motor temperature Tm is lower than the first temperature threshold JTm1, the flight control device 40 proceeds to step S203. In step S203, the flight control device 40 determines whether or not to perform pre-drive of the lift EPU 51. If performing pre-drive would likely reduce the safety of the eVTOL 10 during cruising and landing, the flight control device 40 decides not to perform pre-drive.

[0080] For example, the flight control device 40 determines whether or not there is a malfunction in the lift EPU 51, and whether or not there is a possibility of insufficient battery charge Eb. If a malfunction occurs in the lift EPU 51, or if there is a possibility of insufficient battery charge Eb, the flight control device 40 decides not to perform pre-drive. Situations where there is a possibility of insufficient battery charge Eb include cases where the battery charge Eb is very low and there is no room to consume battery charge Eb by performing pre-drive. For example, if pre-drive is performed, there is a possibility that the battery charge Eb will become zero before the eVTOL 10 reaches its destination.

[0081] The flight control system 40 may notify the pilot or an external control center of the result of its determination on whether or not to perform pre-drive. For example, if the flight control system 40 does not perform pre-drive despite the pre-drive condition being met (motor temperature Tm being lower than the first temperature threshold JTm1), it may notify the pilot or a control center of the failure to perform pre-drive. The flight control system 40 may also determine whether or not the pilot or other personnel have performed an operation to prohibit pre-drive. If pre-drive is prohibited, the flight control system 40 will determine not to perform pre-drive.

[0082] If the motor temperature Tm is lower than the first temperature threshold JTm1 and the lift EPU 51 is pre-driven, the flight control device 40 proceeds to step S204. In step S204, the flight control device 40 performs pre-drive time setting processing. In the pre-drive time setting processing, the pre-drive time TS is set. The pre-drive time TS is the duration for which pre-drive is continued. When pre-drive is performed, the longer the pre-drive time TS, the more likely the motor temperature Tm is to rise. The pre-drive time setting processing will be explained with reference to the flowchart in Figure 6.

[0083] In step S301 of the pre-drive time setting process, the flight control device 40 calculates the pre-drive time TS using the motor temperature Tm. For example, the flight control device 40 calculates the pre-drive time TS from the motor temperature Tm using correlation information that shows the relationship between the motor temperature Tm and the pre-drive time TS. Correlation information related to the pre-drive time TS can include maps, functions, or calculation formulas. Correlation information related to the pre-drive time TS is information obtained through tests, etc., and is stored in memory 43, etc. The flight control device 40 sets the pre-drive time TS such that the pre-drive time TS becomes longer as the motor temperature Tm decreases. For example, the flight control device 40 sets the pre-drive time TS such that the pre-drive time TS when the motor temperature Tm is lower than the reference temperature is longer than the pre-drive time TS when the motor temperature Tm is not lower than the reference temperature. The function that executes the process in step S301 in the flight control device 40 corresponds to the time adjustment unit.

[0084] In step S302, the flight control device 40 adjusts the pre-drive time TS using the ambient temperature Tout. The flight control device 40 adjusts the pre-drive time TS so that the lower the ambient temperature Tout, the longer the pre-drive time TS becomes. For example, the flight control device 40 adjusts the pre-drive time TS so that when the ambient temperature Tout is lower than the reference temperature, the pre-drive time TS is longer than when the ambient temperature Tout is not lower than the reference temperature. The adjustment of the pre-drive time TS is sometimes referred to as correction of the pre-drive time TS. The function in the flight control device 40 that performs the processing in step S302 corresponds to the time adjustment unit.

[0085] The power supply capacity of the battery 31, which is the ability of the battery 31 to supply power to the EPU 50, is prone to change depending on the battery state. For example, the power supply capacity of the battery 31 is prone to change depending on the battery level Eb, battery temperature Tb, and battery voltage Vb. The lower the battery level Eb, the lower the voltage and current supplied from the battery 31 to the EPU 50, and the more likely the power supply capacity of the battery 31 is to decrease. For example, when the battery level Eb is lower than a predetermined standard value, the power supply capacity of the battery 31 is more likely to decrease than when the battery level Eb is not lower than that standard value. Power supply capacity is sometimes referred to as discharge capacity.

[0086] The lower the battery temperature Tb, the more likely the battery 31 is to decrease in power supply capacity, for example, due to an increase in the internal resistance of the battery 31. For example, when the battery temperature Tb is lower than a predetermined reference value, the power supply capacity of the battery 31 decreases compared to when the battery voltage Vb is not lower than that reference value.

[0087] The lower the battery voltage Vb, the more likely the power supply capacity of the battery 31 is to decrease, such as the voltage that the battery 31 applies to the EPU 50 decreasing. For example, when the battery voltage Vb is lower than a predetermined reference value, the power supply performance of the battery 31 is more likely to decrease compared to when the battery voltage Vb is not lower than that reference value.

[0088] In steps S303 to S305, the flight control device 40 adjusts the pre-operation time TS according to the battery status, such as the power supply capacity of the battery 31. The flight control device 40 adjusts the pre-operation time TS so that the lower the power supply capacity of the battery 31, the longer the pre-operation time TS becomes. For example, the flight control device 40 adjusts the pre-operation time TS so that when the power supply capacity of the battery 31 is below a standard, the pre-operation time TS is longer than when the power supply capacity of the battery 31 is not below a standard. The functions that execute the processing in steps S303 to S305 in the flight control device 40 correspond to the power supply adjustment unit and the time adjustment unit.

[0089] In step S303, the flight control device 40 adjusts the reserve operating time TS according to the remaining battery charge Eb. The flight control device 40 adjusts the reserve operating time TS so that the lower the remaining battery charge Eb, the longer the reserve operating time TS becomes. For example, the flight control device 40 adjusts the reserve operating time TS so that when the remaining battery charge Eb is less than the reference charge, the reserve operating time TS is longer than when the remaining battery charge Eb is not less than the reference charge.

[0090] In step S304, the flight control device 40 adjusts the pre-operation time TS according to the battery temperature Tb. The flight control device 40 adjusts the pre-operation time TS so that the lower the battery temperature Tb, the longer the pre-operation time TS becomes. For example, the flight control device 40 adjusts the pre-operation time TS so that when the battery temperature Tb is lower than the reference temperature, the pre-operation time TS is longer than when the battery temperature Tb is not lower than the reference temperature.

[0091] In step S305, the flight control device 40 adjusts the pre-operation time TS according to the battery voltage Vb. The flight control device 40 adjusts the pre-operation time TS so that the lower the battery voltage Vb, the longer the pre-operation time TS becomes. For example, the flight control device 40 adjusts the pre-operation time TS so that when the battery voltage Vb is lower than the reference voltage, the pre-operation time TS is longer than when the battery voltage Vb is not lower than the reference voltage.

[0092] Returning to Figure 5, the flight control device 40 performs a pre-drive current setting process in step S205, after step S204. In the pre-drive current setting process, the pre-drive current IS is set. The pre-drive current IS is the current that flows to the lift EPU 51 in order to pre-drive the lift EPU 51. In other words, the pre-drive current IS is the motor current that flows to the lift EPU 51 during pre-drive. For example, the pre-drive current IS is smaller than the motor current that flows to the lift EPU 51 when the eVTOL 10 lands. When pre-drive is performed, the larger the pre-drive current IS, the more likely the motor temperature Tm is to rise. The pre-drive current setting process will be explained with reference to the flowchart in Figure 7.

[0093] In step S401 of the pre-drive current setting process, the flight control device 40 calculates the pre-drive current IS using the motor temperature Tm. For example, the flight control device 40 calculates the pre-drive current IS from the motor temperature Tm using correlation information that shows the relationship between the motor temperature Tm and the pre-drive current IS. Correlation information related to the pre-drive current IS includes maps, functions, and calculation formulas. Correlation information related to the pre-drive current IS is information obtained through tests, etc., and is stored in memory 43, etc. The flight control device 40 sets the pre-drive current IS such that the pre-drive current IS increases as the motor temperature Tm decreases. For example, the flight control device 40 sets the pre-drive current IS such that the pre-drive current IS when the motor temperature Tm is lower than the reference temperature is larger than the pre-drive current IS when the motor temperature Tm is not lower than the reference temperature. The function that executes the process in step S401 in the flight control device 40 corresponds to the current adjustment unit.

[0094] In step S402, the flight control device 40 adjusts the pre-drive current IS using the ambient temperature Tout. The flight control device 40 adjusts the pre-drive current IS so that the lower the ambient temperature Tout, the larger the pre-drive current IS becomes. For example, the flight control device 40 adjusts the pre-drive current IS so that when the ambient temperature Tout is lower than the reference temperature, the pre-drive current IS is larger than when the ambient temperature Tout is not lower than the reference temperature. The adjustment of the pre-drive current IS is sometimes referred to as correction of the pre-drive current IS. The function in the flight control device 40 that performs the processing in step S402 corresponds to the current adjustment unit.

[0095] In steps S403 to S405, the flight control device 40 adjusts the pre-drive current IS according to the battery status, such as the power supply capacity of the battery 31. The flight control device 40 adjusts the pre-drive current IS so that the lower the power supply capacity of the battery 31, the larger the pre-drive current IS becomes. For example, the flight control device 40 adjusts the pre-drive current IS so that when the power supply capacity of the battery 31 is below a standard, the pre-drive current IS is larger than when the power supply capacity of the battery 31 is not below a standard. The functions that perform the processing in steps S403 to S405 in the flight control device 40 correspond to the power supply adjustment unit and the current adjustment unit.

[0096] In step S403, the flight control device 40 adjusts the pre-drive current IS according to the battery charge level Eb. The flight control device 40 adjusts the pre-drive current IS so that the lower the battery charge level Eb, the higher the pre-drive current IS becomes. For example, the flight control device 40 adjusts the pre-drive current IS so that when the battery charge level Eb is lower than the reference charge level, the pre-drive current IS is higher than when the battery charge level Eb is not lower than the reference charge level.

[0097] In step S404, the flight control device 40 adjusts the pre-drive current IS according to the battery temperature Tb. The flight control device 40 adjusts the pre-drive current IS so that the lower the battery temperature Tb, the larger the pre-drive current IS becomes. For example, the flight control device 40 adjusts the pre-drive current IS so that when the battery temperature Tb is lower than the reference voltage, the pre-drive current IS is larger than when the battery temperature Tb is not lower than the reference voltage.

[0098] In step S405, the flight control device 40 adjusts the pre-drive current IS according to the battery voltage Vb. The flight control device 40 adjusts the pre-drive current IS such that the lower the battery voltage Vb, the larger the pre-drive current IS becomes. For example, the flight control device 40 adjusts the pre-drive current IS such that when the battery voltage Vb is lower than the reference voltage, the pre-drive current IS is larger than when the battery voltage Vb is not lower than the reference voltage.

[0099] Returning to Figure 5, after step S205, in step S206, the flight control device 40 sets the flight mode of the eVTOL 10 to the pre-drive mode. The pre-drive mode is a flight mode for continuing the cruise of the eVTOL 10 and pre-driving the lift EPU 51. In the pre-drive mode, the flight control device 40 drives the lift EPU 51 so that the pre-drive time TS set in step S204 and the pre-drive current IS set in step S205 are achieved. The function in the flight control device 40 that executes the process in step S206 corresponds to the pre-processing step.

[0100] In the pre-drive mode, the flight control device 40 drives the lift EPU 51 such that the change in the flight attitude of the eVTOL 10 caused by the drive of the lift EPU 51 falls within an acceptable range. The flight attitude is the attitude of the aircraft 11 and is sometimes referred to as the aircraft attitude. For example, the flight control device 40 determines that the change in flight attitude falls within an acceptable range if, before and after the start of driving the lift EPU 51, the amount of change per unit time of the yaw angle, pitch angle, and roll angle of the aircraft 11 is smaller than the amount of change from a reference. The flight control device 40 also determines that the change in flight attitude falls within an acceptable range if, before and after the start of driving the lift EPU 51, the yaw angle, pitch angle, and roll angle are smaller than their respective reference angles.

[0101] The flight control device 40 limits the pre-drive current IS and the rotational speed of the lift propeller 21 so that the change in flight attitude falls within an acceptable range. For example, the flight control device 40 limits the pre-drive current IS so that the change in flight attitude falls within an acceptable range. For example, the flight control device 40 sets an upper limit for the pre-drive current IS in step S204. The upper limit for the pre-drive current IS is a value that does not cause the change in flight attitude to exceed an acceptable range. By limiting the pre-drive current IS, the flight control device 40 can limit the rotational speed of the lift propeller 21. The flight control device 40 sets the upper limit for the pre-drive current IS so that the rotational speed of the lift propeller 21 is limited to a rotational speed that does not generate thrust or lift that would affect the flight attitude of the eVTOL 10.

[0102] The flight control device 40 may limit the rotation speed of the lift propeller 21 so that the change in flight attitude falls within an acceptable range. For example, in a configuration in which a gear is provided between the lift EPU 51 and the lift propeller 21, the flight control device 40 may limit the rotation speed of the lift propeller 21 by the gear so that the change in flight attitude falls within an acceptable range.

[0103] Furthermore, in a configuration in which a clutch is provided for the lift EPU 51, the lift propeller 21 may be disengaged from the lift EPU 51 by the clutch, and the lift EPU 51 may be pre-driven, so as not to change the flight attitude. In this configuration, the lift propeller 21 does not rotate regardless of the magnitude of the pre-drive current IS, so it is possible to set the pre-drive current IS to a value that makes it easier to raise the motor temperature Tm, prioritizing the increase in motor temperature Tm.

[0104] In a configuration where a pitch controller is provided for the lift EPU 51 and the lift propeller 21, the lift EPU 51 may be pre-driven while the pitch of the lift propeller 21 is changed by the pitch controller so as not to change the flight attitude. In this configuration, the flight control device 40 may adjust the pitch of the lift propeller 21 by the pitch controller so that the thrust generated by the rotation of the lift propeller 21 becomes small enough that the change in flight attitude falls within an acceptable range.

[0105] Furthermore, the flight control device 40 pre-drives the lift EPU 51 such that the pre-drive current IS is greater than the no-load current. The no-load current is the motor current that flows through the lift EPU 51 during no-load operation, when the lift EPU 51 is operated without load. The no-load current may also be the motor current that flows through the lift EPU 51 during no-load idling. For example, the d-axis current included in the pre-drive current IS is greater than the d-axis current included in the no-load current.

[0106] Furthermore, the flight control device 40 drives the lift EPU 51 while controlling the current phase so that the power factor of the lift EPU 51 in the pre-drive mode is lower than the power factor of the lift EPU 51 in the landing mode. For example, the flight control device 40 controls the phase of the pre-drive current IS so that the power factor in the pre-drive mode is lower than the power factor in the landing mode. The power factor of the lift EPU 51 is the power factor of the motor 61 that the lift EPU 51 has. In the pre-drive mode, the losses caused by driving the lift EPU 51 are greater than the losses caused by driving the lift EPU 51 in the landing mode.

[0107] In step S207, the flight control device 40 determines whether or not to land the eVTOL 10. For example, the flight control device 40 determines whether or not a landing commencement request has been received to initiate the landing mode of the eVTOL 10. A landing commencement request is input to the flight control device 40 when an operation to initiate the landing of the eVTOL 10 is performed by a pilot or the like.

[0108] When landing the eVTOL 10, the flight control device 40 proceeds to step S208. In step S208, the flight control device 40 determines whether the motor temperature Tm is higher than the second temperature threshold JTm2. The second temperature threshold JTm2 is a value predetermined by testing, etc., and is stored in memory 43, etc. The second temperature threshold JTm2 is a value that indicates that the output of the lift EPU 51 is sufficient for the landing of the eVTOL 10, assuming that the lift EPU 51 is driven for the landing of the eVTOL 10. For example, the second temperature threshold JTm2 is set to the lower limit of the allowable range for the motor temperature Tm. For example, the second temperature threshold JTm2 is set to the same value as the first temperature threshold JTm1. Note that the second temperature threshold JTm2 may be set to a higher value than the first temperature threshold JTm1, or it may be set to a lower value. The second temperature threshold JTm2 corresponds to the landing threshold.

[0109] If the motor temperature Tm is higher than the second temperature threshold JTm2, the flight control device 40 proceeds to step S209. In step S209, the flight control device 40 sets the flight mode of the eVTOL 10 to landing mode. That is, the flight control device 40 transitions the flight mode from cruise mode to landing mode. Landing mode is a flight mode for landing the eVTOL 10. For example, landing mode is a flight mode for vertically landing the eVTOL 10 at a destination. In landing mode, the flight control device 40 drives the lift EPU 51 to lift the eVTOL 10 downwards. In landing mode, the cruise EPU 52 may be driven, or the cruise EPU 52 may be deactivated.

[0110] In landing mode, the lift EPU 51 is driven in a manner that allows the eVTOL 10 to land. For example, in landing mode, the lift EPU 51 is controlled by the flight control device 40 and the inverter control unit 81 so that the motor voltage and motor current become values ​​necessary for the landing of the eVTOL 10. For example, the flight control device 40 controls the lift EPU 51 so that the motor current flowing to the lift EPU 51 in landing mode is greater than the pre-drive current IS. The function that executes the processing in step S209 in the flight control device 40 corresponds to the landing unit.

[0111] If the motor temperature Tm is not higher than the second temperature threshold JTm2, the flight control device 40 proceeds to step S210. In step S210, the flight control device 40 restricts the landing mode of the eVTOL 10. The flight control device 40 restricts the transition of the flight mode from cruise mode to landing mode. The flight control device 40 does not allow the flight mode to transition from cruise mode to landing mode until the motor temperature Tm exceeds the second temperature threshold JTm2. For example, the flight control device 40 causes the eVTOL 10 to circle above the destination, thereby continuing to pre-drive the lift EPU 51, until the motor temperature Tm exceeds the second temperature threshold JTm2. The function in the flight control device 40 that performs the processing in step S210 corresponds to the landing restriction unit. Then, when the motor temperature Tm exceeds the second temperature threshold JTm2, the flight control device 40 proceeds to step S209 and starts the landing of the eVTOL 10.

[0112] Regarding step S202, if the motor temperature Tm is not lower than the first temperature threshold JTm1, the flight control device 40 decides not to perform pre-drive of the lift EPU 51 and proceeds to step S211. Regarding step S203, if the flight control device 40 decides not to perform pre-drive, it also proceeds to step S211.

[0113] In step S211, the flight control device 40 determines whether or not to initiate landing of the eVTOL 10, similar to step S207. If it determines to initiate landing of the eVTOL 10, the flight control device 40 proceeds to step S212 and sets the flight mode of the eVTOL 10 to landing mode, similar to step S209. In this way, if the lift EPU 51 is not pre-driven, the flight control device 40 initiates landing of the eVTOL 10 regardless of the motor temperature Tm. In this case, the flight control device 40 does not transition the flight mode of the eVTOL 10 to the landing restriction mode.

[0114] Next, the temperature change of the EPU 50 will be explained with reference to Figure 8. At timing t1, when the eVTOL 10 starts to take off in takeoff mode, the motor temperature Tm [°C] of both the lift EPU 51 and the cruise EPU 52 begins to rise. In takeoff mode, in addition to the lift EPU 51, at least one cruise EPU 52 is driven.

[0115] At timing t2, the eVTOL 10 begins cruising as the flight mode transitions from takeoff mode to cruise mode. In cruise mode, the lift EPU 51 is deactivated, and the output of the cruise EPU 52 is reduced. With the deactivation of the lift EPU 51, the motor temperature Tm begins to decrease. With the reduction in output of the cruise EPU 52, the motor temperature Tm decreases slightly. The output of the cruise EPU 52 is, for example, torque [Nm].

[0116] If pre-drive is required for the lift EPU 51, pre-drive is initiated at timing t3 when the flight mode transitions from cruise mode to pre-drive mode. Timing t3 is the pre-drive start time BP. In the lift EPU 51, the motor temperature Tm begins to rise as pre-drive begins. At timing t4, which is the pre-drive time TS elapsed from timing t3, the flight mode transitions from pre-drive mode to landing mode, and the landing of the eVTOL 10 begins.

[0117] Furthermore, if the motor temperature Tm of the lift EPU 51 exceeds the second temperature threshold JTm2 before timing t4, the landing of the eVTOL 10 will start at timing t4 as described above. On the other hand, if the motor temperature Tm does not exceed the second temperature threshold JTm2 even at timing t4, the landing of the eVTOL 10 will not start. In this case, the pre-drive will continue for a longer period than the pre-drive time TS until the motor temperature Tm exceeds the second temperature threshold JTm2.

[0118] For example, unlike this embodiment, consider a comparative example in which no pre-drive is performed even if the motor temperature Tm of the lift EPU 51 is lower than the first temperature threshold JTm1 at timing t3. The motor temperature Tm of the lift EPU 51 in this comparative example is shown by a dashed line in Figure 8. In the comparative example of the lift EPU 51, the motor temperature Tm is even lower at timing t4 because no pre-drive is performed at timing t3. Therefore, there is a concern that the output of the lift EPU 51 will be insufficient to land the eVTOL 10 when landing of the eVTOL 10 is initiated at timing t4.

[0119] In motor 61, the lower the temperature of the magnet, the greater the magnetic force generated by the magnet. Therefore, in motor 61, the lower the motor temperature Tm, the greater the back electromotive force generated by the magnetic force. For example, if the motor temperature Tm of the lift EPU 51 is lower than the second temperature threshold JTm2, there is a concern that the output voltage of motor 61 will be reduced by the back electromotive force, resulting in insufficient output from the lift EPU 51.

[0120] In contrast, according to this embodiment, when the eVTOL 10 is cruising, the pre-drive of the lift EPU 51 is started at a timing t3 prior to the start of landing of the eVTOL 10. Therefore, it is possible to raise the motor temperature Tm of the lift EPU 51 before the start of landing of the eVTOL 10. Consequently, it is possible to suppress the issue of insufficient output from the lift EPU 51 due to a low motor temperature Tm during landing of the eVTOL 10. This enhances safety during the landing of the eVTOL 10.

[0121] For example, in the lift EPU 51, pre-drive is performed to raise the motor temperature Tm to the second temperature threshold JTm2. This prevents the back electromotive force in the motor 61 from becoming too large, which would reduce the output of the lift EPU 51.

[0122] If the eVTOL 10 continues flying in a low-temperature environment with the lift EPU 51 stopped, the temperature of the stopped lift EPU 51 will drop to near the ambient temperature. In a motor 61 using permanent magnets, the back electromotive force tends to be larger at low temperatures than at high temperatures, requiring a larger current to meet the required output. By pre-heating the motor temperature Tm of the lift EPU 51 through pre-drive, it is possible to avoid insufficient output from the lift EPU 51 due to the low temperature of the motor 61, enabling a safe landing operation.

[0123] According to this embodiment, the flight control device 40 performs pre-drive if it predicts that the lift EPU 51 will have insufficient power to land the eVTOL 10 before the start of the eVTOL 10's landing. This configuration prevents the eVTOL 10's landing from starting while the lift EPU 51 is still underpowered, even though insufficient power is predicted for the lift EPU 51. Furthermore, this configuration allows pre-drive to be performed only when insufficient power for the lift EPU 51 is predicted. In other words, pre-drive can be omitted when insufficient power for the lift EPU 51 is not predicted. Therefore, energy saving for the lift EPU 51 can be achieved while enhancing the safety of the eVTOL 10.

[0124] According to this embodiment, the flight control device 40 pre-drives the lift EPU 51 when the motor temperature Tm of the lift EPU 51 is lower than the first temperature threshold JTm1 while the eVTOL 10 is cruising. In this way, if the motor temperature Tm is too low, the pre-drive can prevent insufficient output from the lift EPU 51 during landing. On the other hand, the flight control device 40 does not pre-drive the lift EPU 51 when the motor temperature Tm of the lift EPU 51 is not lower than the first temperature threshold JTm1 while the eVTOL 10 is cruising. In this way, energy saving of the lift EPU 51 can be achieved by not performing pre-drive when the motor temperature Tm is not too low.

[0125] According to this embodiment, even if pre-drive is being performed, the flight control device 40 restricts the landing of the eVTOL 10 if the motor temperature Tm of the lift EPU 51 is not higher than the second temperature threshold JTm2. This configuration prevents the eVTOL 10 from starting its landing while the output of the lift EPU 51 is insufficient for the eVTOL 10 to land.

[0126] According to this embodiment, the flight control device 40 adjusts the pre-drive time TS such that the lower the motor temperature Tm of the lift EPU 51 is while the eVTOL 10 is cruising, the longer the pre-drive time TS becomes. Therefore, the possibility that the motor temperature Tm of the lift EPU 51 has not yet reached the second temperature threshold JTm2 at the start of landing of the eVTOL 10 can be reduced by the pre-drive time TS.

[0127] According to this embodiment, the flight control device 40 adjusts the pre-drive current IS such that the lower the motor temperature Tm of the lift EPU 51 is while the eVTOL 10 is cruising, the larger the pre-drive current IS becomes. Therefore, the possibility that the motor temperature Tm of the lift EPU 51 has not yet reached the second temperature threshold JTm2 when the eVTOL 10 starts landing can be reduced by the pre-drive current IS.

[0128] In the lift EPU 51, when the motor temperature Tm is susceptible to the ambient temperature Tout, the motor temperature Tm tends to be lower as the ambient temperature Tout decreases. Therefore, according to this embodiment, the flight control device 40 adjusts the pre-drive time TS so that the pre-drive time TS becomes longer as the ambient temperature Tout decreases while the eVTOL 10 is cruising. As a result, even if the motor temperature Tm is low due to the influence of the ambient temperature Tout, the motor temperature Tm tends to rise as the pre-drive time TS is longer. Consequently, the possibility that the motor temperature Tm of the lift EPU 51 has not yet reached the second temperature threshold JTm2 at the start of landing of the eVTOL 10 can be reduced by the ambient temperature Tout and the pre-drive time TS.

[0129] According to this embodiment, the flight control device 40 adjusts the pre-drive current IS such that the lower the ambient temperature Tout is while the eVTOL 10 is cruising, the larger the pre-drive current IS becomes. Therefore, even if the motor temperature Tm is low due to the influence of the ambient temperature Tout, the motor temperature Tm is more likely to rise if the pre-drive current IS is large. Consequently, the possibility that the motor temperature Tm of the lift EPU 51 has not yet reached the second temperature threshold JTm2 at the start of landing of the eVTOL 10 can be reduced by the ambient temperature Tout and the pre-drive current IS.

[0130] The power supply capacity of the battery 31 may change depending on the battery state. For example, the power supply capacity of the battery 31 may decrease depending on the values ​​of the battery charge Eb, battery temperature Tb, and battery voltage Vb. In contrast, according to this embodiment, the flight control device 40 adjusts the pre-drive time TS and pre-drive current IS according to the battery state. In this configuration, by adjusting the pre-drive time TS and pre-drive current IS, it is possible to suppress the decrease in the power supply capacity of the battery 31 and the resulting decrease in the heating effect of the lift EPU 51 due to pre-drive.

[0131] In battery 31, the discharge capacity may decrease due to low battery charge Eb, low battery temperature Tb, or low battery voltage Vb. When the discharge capacity of battery 31 is reduced, raising the motor temperature Tm to suppress the back electromotive force of motor 61 makes it easier for the lift EPU 51 to produce the output necessary for landing. In addition, by adjusting the pre-drive time TS and pre-drive current IS according to the battery state, the motor temperature Tm can be appropriately raised to a level where the lift EPU 51 can produce the output necessary for landing without excessively consuming the power of battery 31.

[0132] When the power supply capacity of the battery 31 is reduced, there is a concern that the motor temperature Tm may not rise easily even if the lift EPU 51 is pre-driven. In contrast, according to this embodiment, the flight control device 40 increases the pre-drive time TS or the pre-drive current IS as the power supply capacity of the battery 31 decreases. Therefore, even if the rate of temperature rise due to pre-drive decreases as the power supply capacity of the battery 31 decreases, the decrease in the rate of temperature rise can be compensated for by extending the pre-drive time TS or increasing the pre-drive current IS.

[0133] According to this embodiment, the flight control device 40 drives the lift EPU 51 so that the change in flight attitude due to pre-drive falls within an acceptable range while the eVTOL 10 is cruising. In this configuration, it is possible to suppress the change in the flight attitude of the eVTOL 10 that exceeds the acceptable range due to pre-drive. Therefore, it is possible to suppress the decrease in the safety of the eVTOL 10 due to pre-drive.

[0134] According to this embodiment, in the lift EPU 51, pre-drive is performed such that the pre-drive current IS is greater than the no-load current. Therefore, in the lift EPU 51, the rate of increase in motor temperature Tm due to pre-drive can be maximized by the pre-drive current IS.

[0135] According to this embodiment, in the lift EPU 51, the current phase of the motor 61 is controlled so that the power factor due to the pre-drive is smaller than the power factor due to the drive for landing the eVTOL 10. In this configuration, as the power factor decreases, losses increase, which increases the amount of heat generated by the losses and makes it easier for the motor temperature Tm of the lift EPU 51 to rise.

[0136] In the pre-drive of the lift EPU 51, a larger pre-drive current IS is better for raising the temperature of the motor 61, but if the thrust becomes too large, it will affect the aircraft's attitude. Therefore, it is necessary to set the pre-drive current IS to an appropriate value for raising the temperature of the motor 61 within a range that does not affect the aircraft's attitude. Also, during normal flight control, the current phase is controlled so that the greatest possible thrust is generated with the power consumption. That is, during cruising and landing of the eVTOL 10, the switching control of the inverter circuit 85 is performed so that the power factor of the lift EPU 51 is optimized. However, since the purpose of pre-drive is to raise the temperature of the motor 61, the current phase is controlled to deliberately lower the power factor. In other words, in pre-drive, the current phase is controlled so that even if a large pre-drive current IS is applied, it is difficult for thrust to be generated in the lift propeller 21. This makes it easier to raise the temperature of the motor 61.

[0137] <Second Embodiment> In the first embodiment described above, the necessity of pre-drive is determined using the motor temperature Tm of the lift EPU 51. In contrast, in the second embodiment, the necessity of pre-drive may be determined using the ambient temperature Tout. Configurations, operations, and effects not specifically described in the second embodiment are the same as in the first embodiment described above. The second embodiment will be described focusing on the differences from the first embodiment described above.

[0138] In this embodiment, the landing-related processing will be explained with reference to the flowchart in Figure 9. In step S201 shown in Figure 9, if the current time is the pre-drive start time BP, the flight control device 40 proceeds to step S501. In step S501, the flight control device 40 determines whether the ambient temperature Tout is lower than the ambient temperature threshold JTout. The ambient temperature threshold JTout is a value predetermined by testing, etc., and is stored in memory 43, etc. The ambient temperature threshold JTout is a value that indicates that even if the motor temperature Tm becomes close to the ambient temperature Tout, the output of the lift EPU 51 will not be insufficient for the landing of the eVTOL 10, assuming that the lift EPU 51 is driven for the landing of the eVTOL 10. For example, the ambient temperature threshold JTout is set as the lower limit of the allowable range for the motor temperature Tm, assuming that the motor temperature Tm will be close to the ambient temperature Tout. The ambient temperature threshold JTout corresponds to the ambient temperature threshold.

[0139] If the ambient temperature Tout is lower than the ambient temperature threshold JTout, the flight control device 40 proceeds to step S203. In steps S203 to S212, the flight control device 40 performs the same processing as in the first embodiment. However, in this embodiment, the processing in steps S208 and S210 is not performed. For example, in step S207, when the eVTOL 10 is to land, the flight control device 40 proceeds to step S209 regardless of the motor temperature Tm and sets the flight mode to landing mode.

[0140] If the outside air temperature Tout is lower than the outside air temperature threshold JTout and the lift EPU 51 is to be pre-driven, the flight control device 40 performs a pre-drive time setting process in step S204 and a pre-drive current setting process in step S205.

[0141] The pre-drive time setting process will be explained with reference to the flowchart in Figure 10. In step S601 of the pre-drive time setting process, the flight control device 40 calculates the pre-drive time TS using the ambient temperature Tout. For example, the flight control device 40 calculates the pre-drive time TS from the ambient temperature Tout using correlation information that shows the relationship between the ambient temperature Tout and the pre-drive time TS. The flight control device 40 sets the pre-drive time TS such that the lower the ambient temperature Tout, the longer the pre-drive time TS becomes. For example, the flight control device 40 sets the pre-drive time TS such that the pre-drive time TS when the ambient temperature Tout is lower than the reference temperature is longer than the pre-drive time TS when the ambient temperature Tout is not higher than the reference temperature. The function that executes the process in step S601 in the flight control device 40 corresponds to the time adjustment unit.

[0142] After step S601, the flight control device 40 performs the processing in steps S303 to S305, similar to the first embodiment. However, in this embodiment, unlike the first embodiment, the processing in step S302 is not performed.

[0143] Next, the pre-drive current setting process will be explained with reference to the flowchart in Figure 11. In step S701 of the pre-drive current setting process, the flight control device 40 calculates the pre-drive current IS using the ambient temperature Tout. For example, the flight control device 40 calculates the pre-drive current IS from the ambient temperature Tout using correlation information that shows the relationship between the ambient temperature Tout and the pre-drive current IS. The flight control device 40 sets the pre-drive current IS such that the lower the ambient temperature Tout, the larger the pre-drive current IS becomes. For example, the flight control device 40 sets the pre-drive current IS such that when the ambient temperature Tout is lower than the reference temperature, the pre-drive current IS is larger than when the ambient temperature Tout is not higher than the reference temperature. The function that executes the process in step S701 in the flight control device 40 corresponds to the current adjustment unit.

[0144] After step S701, the flight control device 40 performs the processing of steps S403 to S405 in the same manner as in the first embodiment. However, in this embodiment, unlike the first embodiment, the processing of step S402 is not performed.

[0145] When the eVTOL 10 is cruising, the non-driven lift EPU 51 is exposed to the low temperatures of the upper atmosphere. Therefore, the longer the flight time of the eVTOL 10, the more likely the motor temperature Tm of the lift EPU 51 is to drop to a temperature close to the ambient temperature Tout. In other words, the motor temperature Tm of the lift EPU 51 is easily affected by the ambient temperature Tout.

[0146] In contrast, according to this embodiment, the flight control device 40 pre-drives the lift EPU 51 when the outside air temperature Tout is lower than the outside air temperature threshold JTout while the eVTOL 10 is cruising. Therefore, even if the outside air temperature Tout is low enough that there is a high possibility of insufficient output from the lift EPU 51, the pre-drive raises the motor temperature Tm, thereby suppressing insufficient output from the lift EPU 51 during landing. On the other hand, the flight control device 40 does not pre-drive the lift EPU 51 when the outside air temperature Tout is not lower than the outside air temperature threshold JTout while the eVTOL 10 is cruising. In this case, energy saving of the lift EPU 51 can be achieved by not performing the pre-drive.

[0147] For the eVTOL 10, the ambient temperature Tout does not change even when the lift EPU 51 is pre-driven. Therefore, by setting a longer pre-drive time TS for the lift EPU 51 or a larger pre-drive current IS for lower ambient temperatures Tout, the possibility that the motor temperature Tm is still low when the eVTOL 10 starts its landing operation can be reduced.

[0148] <Other Embodiments> The disclosures in this specification are not limited to the exemplary embodiments. The disclosures encompass the exemplary embodiments and variations thereof by those skilled in the art. For example, the disclosures are not limited to the combinations of parts and elements shown in the embodiments, but can be implemented in various variations. The disclosures can be implemented in a variety of combinations. The disclosures may have additional parts that can be added to the embodiments. The disclosures encompass embodiments in which parts and elements have been omitted. The disclosures encompass substitutions or combinations of parts and elements between one embodiment and another. The scope of the disclosed technical field is not limited to the descriptions of the embodiments. The scope of the disclosed technical field is indicated by the claims and should be understood to include all modifications within the meaning and scope equivalent to the claims.

[0149] In each of the above embodiments, the pre-drive current IS for the pre-drive of the lift EPU 51 does not necessarily have to be smaller than the motor current that flows to the lift EPU 51 when the eVTOL 10 lands.

[0150] In each of the above embodiments, the flight control device 40 may variably set the pre-drive start time BP according to the motor temperature Tm of the lift EPU 51, the ambient temperature Tout, etc. For example, the flight control device 40 may be set to advance the pre-drive start time BP the lower the motor temperature Tm of the lift EPU 51. Alternatively, the flight control device 40 may be set to advance the pre-drive start time BP the lower the ambient temperature Tout. By advancing the pre-drive start time BP, a longer pre-drive time TS can be secured, thereby suppressing the restriction of the landing mode after the pre-drive mode.

[0151] In each of the above embodiments, the flight control device 40 may stop the drive of the lift EPU 51 during the period between the timing when the pre-drive is completed and the timing when the drive is started to land the eVTOL 10. Preferably, this stop time is long enough so that the motor temperature Tm of the lift EPU 51 does not fall below the second temperature threshold JTm2.

[0152] In each of the above embodiments, the flight control device 40 may determine whether or not to perform a pre-drive mode using at least one of the motor temperature Tm and the ambient temperature Tout. For example, by combining the first embodiment and the second embodiment, the flight control device 40 may perform both a determination of whether the motor temperature Tm is lower than a first temperature threshold JTm1 and a determination of whether or not the ambient temperature Tout is lower than the ambient temperature threshold JTout. The flight control device 40 can pre-drive the lift EPU 51 when the motor temperature Tm is lower than the first temperature threshold JTm1 and the ambient temperature Tout is lower than the ambient temperature threshold JTout.

[0153] In each of the above embodiments, the flight control device 40 only needs to perform at least one of the pre-drive time setting process in step S204 and the pre-drive current setting process in step S205 during the landing-related processing. In other words, the flight control device 40 only needs to have at least one of the time adjustment unit and the current adjustment unit.

[0154] In each of the above embodiments, the flight control device 40 may use at least one of the following to calculate the pre-drive time TS and pre-drive current IS: motor temperature Tm, ambient temperature Tout, battery charge Eb, battery temperature Tb, and battery voltage Vb.

[0155] In each of the above embodiments, the flight control device 40 may always pre-drive the lift EPU 51 regardless of the motor temperature Tm or ambient temperature Tout when the eVTOL 10 is cruising. By always performing this pre-drive, it is possible to confirm that the lift EPU 51 is operating normally before the eVTOL 10 begins landing. The flight control device 40 may also have a function to perform pre-drive for motor warm-up and a function to perform pre-drive for operation confirmation.

[0156] In each of the above embodiments, at least a portion of the programs stored in the memories 43 and 83 may be rewritten via wireless communication such as OTA. OTA is an abbreviation for Over the Air.

[0157] In each of the above embodiments, at least one of the inverter control unit 81 and the flight control device 40 may perform flight control processing. In this configuration, at least one of the inverter control unit 81 and the flight control device 40 corresponds to a propulsion control device.

[0158] Furthermore, the propulsion control program may be included in at least one of programs 44 and 84. In addition, at least one processing unit that executes the propulsion control program may include at least one of processors 42 and 82.

[0159] In each of the above embodiments, the vertical take-off and landing aircraft equipped with the flight control device 40 may be an electrically powered vertical take-off and landing aircraft in which at least one propeller 20 is driven by at least one EPU 50. For example, one propeller 20 may be driven by multiple EPUs 50, or multiple propellers 20 may be driven by one EPU 50.

[0160] In each of the above embodiments, the aircraft on which the EPU 50 is mounted does not have to be a vertical take-off and landing aircraft, as long as it is electrically powered. For example, the aircraft may be an electric aircraft capable of taking off and landing with a runway. Furthermore, the aircraft may be a rotary-wing aircraft or a fixed-wing aircraft. The aircraft may be an unmanned aircraft without a person on board. The unmanned aircraft may have a crew compartment 14 or may not have a crew compartment 14. Also, the pilot may remotely control the aircraft. The eVTOL 10 may be referred to as a manned aircraft even if there is no person on board, as long as it is capable of carrying a person.

[0161] In each of the above embodiments, the mobile body on which the EPU 50 is mounted does not have to be an aircraft, as long as it is movable by the rotation of a rotating body. For example, the mobile body may be a vehicle, a ship, construction machinery, or agricultural machinery. For example, if the mobile body is a vehicle or construction machinery, the rotating body may be a wheel for movement, and the output shaft may be an axle. If the mobile body is a ship, the rotating body may be a screw propeller for propulsion, and the output shaft may be a propeller shaft.

[0162] In each of the above embodiments, the flight control device 40 and the inverter control unit 81 are provided by a control system including at least one computer. The control system includes at least one hardware processor. If this processor is referred to as a hardware processor, the hardware processor can be provided by (i), (ii), or (iii) below.

[0163] (i) A hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit that includes a number of programmed logic units (gate circuits). The digital circuit may include memory that stores at least one of the program and / or data. The computer may be provided by an analog circuit. The computer may be provided by a combination of a digital circuit and an analog circuit.

[0164] (ii) A hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, the computer is provided by at least one memory and at least one processor core. The processor core is, for example, referred to as a CPU. Memory is also referred to as a storage medium. Memory is a non-transitional and substantial storage medium that non-temporarily stores “at least one of a program and data” that is readable by the processor.

[0165] (iii) The hardware processor may be a combination of (i) and (ii) above. (i) and (ii) may be located on different chips or on a common chip.

[0166] In other words, at least one of the means and functions provided by the flight control device 40 and the inverter control unit 81 can be provided by hardware alone, software alone, or a combination thereof.

[0167] (Disclosure of Technical Ideas) This specification discloses several technical ideas as described in the following paragraphs. Some paragraphs may be written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs may be written in a multiple dependent form, where they refer to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical ideas.

[0168] (Technical Concept 1) A propulsion control device (40) that drives a flying body (10) to propel the flying body and controls a plurality of electric propulsion devices (50) provided on the flying body, comprising: a horizontal flight unit (S104) that drives a flight device (52) and stops the drive of a landing device (51) among the plurality of propulsion devices when the flying body is in horizontal flight; a landing unit (S209) that drives the landing device when the flying body is landing; and a pre-drive unit (S206) that drives the landing device before the landing unit drives the landing device when the flying body is in horizontal flight.

[0169] (Technical Concept 2) The propulsion control device according to Technical Concept 1, wherein the pre-operation unit drives the landing device when it is predicted that the landing device will not have enough power to land the aircraft, prior to the landing unit driving the landing device.

[0170] (Technical Concept 3) The propulsion control device according to Technical Concept 1 or 2, wherein the pre-unit drives the landing gear when the temperature (Tm) of the landing gear is lower than a pre-threshold (JTm1) while the aircraft is in horizontal flight, and does not drive the landing gear when the temperature is not lower than the pre-threshold while the aircraft is in horizontal flight.

[0171] (Technical Concept 4) A propulsion control device according to any one of Technical Concepts 1 to 3, comprising: a landing limiting unit (S210) that limits the landing of the aircraft when the aircraft is in horizontal flight and the front unit is driving the landing gear, but the temperature (Tm) of the landing gear is not higher than a landing threshold (JTm2).

[0172] (Technical Concept 5) A propulsion control device according to any one of Technical Concepts 1 to 4, comprising: a time adjustment unit (S301) that adjusts the duration such that the lower the temperature (Tm) of the landing gear when the aircraft is in horizontal flight, the longer the duration (TS) for which the pre-mount unit drives the landing gear.

[0173] (Technical Concept 6) A propulsion control device according to any one of Technical Concepts 1 to 5, comprising a current adjustment unit (S401) that adjusts the current such that the lower the temperature (Tm) of the landing gear when the aircraft is in horizontal flight, the greater the current (IS) that flows to the landing gear in order for the pre-unit to drive the landing gear.

[0174] (Technical Concept 7) The propulsion control device according to any one of Technical Concepts 1 to 6, wherein the preceding unit drives the landing gear when the outside air temperature (Tout) is lower than the outside air threshold (JTout) while the aircraft is in horizontal flight, and does not drive the landing gear when the outside air temperature is not lower than the outside air threshold while the aircraft is in horizontal flight.

[0175] (Technical Concept 8) A propulsion control device according to any one of Technical Concepts 1 to 7, comprising a time adjustment unit (S302, S601) that adjusts the duration such that the lower the outside air temperature (Tout) is when the aircraft is in horizontal flight, the longer the duration (TS) for which the front unit drives the landing device.

[0176] (Technical Concept 9) A propulsion control device according to any one of Technical Concepts 1 to 8, comprising a current adjustment unit (S402, S701) that adjusts the current such that the lower the outside air temperature (Tout) is when the aircraft is in horizontal flight, the greater the current (IS) that the front unit supplies to the landing gear in order to drive the landing gear.

[0177] (Technical Concept 10) A propulsion control device according to any one of Technical Concepts 1 to 9, comprising: a power supply adjustment unit (S303 to S305, S403 to S405) that adjusts at least one of the duration (TS) during which the pre-set unit drives the landing gear and the current (IS) that the pre-set unit supplies to the landing gear to drive the landing gear, depending on the state of the power supply unit (31) that supplies power to the propulsion device when the aircraft is in horizontal flight.

[0178] (Technical Concept 11) The propulsion control device according to Technical Concept 10, wherein the pre-flight unit comprises at least one of: a time adjustment unit (S303 to S305) that adjusts the duration such that the duration becomes longer the lower the power supply capacity of the power supply unit that supplies power to the landing device when the aircraft is in horizontal flight; and a current adjustment unit (S403 to S405) that adjusts the current such that the current becomes larger the lower the power supply capacity is when the aircraft is in horizontal flight.

[0179] (Technical Concept 12) The propulsion control device according to any one of Technical Concepts 1 to 11, wherein the preceding unit drives the landing gear such that the change in flight attitude due to the driving of the landing gear falls within an acceptable range when the aircraft is in horizontal flight.

[0180] (Technical Concept 13) The propulsion control device according to any one of Technical Concepts 1 to 12, wherein the preceding unit controls the current phase of the landing gear such that the current (IS) supplied to the landing gear is greater than the no-load current supplied to the landing gear to drive the landing gear under no load.

[0181] (Technical Concept 14) A propulsion control device according to any one of Technical Concepts 1 to 13, wherein the pre-mount unit drives the landing device such that the power factor of the landing device is smaller than the power factor when the landing unit drives the landing device.

[0182] (Technical Concept 15) A propulsion control program (44) used in an electric propulsion device (50) which is driven to propel an aircraft (10) and is provided on the aircraft, wherein the propulsion control program causes at least one processing unit (42) to execute: a horizontal flight unit (S104) which drives a flight device (52) and stops driving a landing device (51) among the plurality of propulsion devices when the aircraft is flying horizontally; a landing unit (S209) which drives the landing device when the aircraft is landing; and a pre-operation unit (S206) which drives the landing device before the landing unit drives the landing device when the aircraft is flying horizontally.

[0183] (Technical Concept 16) A propulsion control method used for an electric propulsion device (50) that is driven to propel an aircraft (10) and is provided on the aircraft, the method comprising the steps of: when the aircraft is flying horizontally, driving a flight device (52) and stopping the driving of a landing device (51) among the plurality of propulsion devices (S104); driving the landing device (S209) when the aircraft is landing; and driving the landing device before the landing device is driven by the landing device when the aircraft is flying horizontally (S206), which are performed by at least one processing unit (42).

Claims

1. A propulsion control device (40) that drives a flying body (10) to propel the flying body and controls a plurality of electric propulsion devices (50) provided on the flying body, comprising: a horizontal flight unit (S104) that drives a flight device (52) and stops driving a landing device (51) among the plurality of propulsion devices when the flying body is flying horizontally; a landing unit (S209) that drives the landing device when the flying body is landing; and a pre-drive unit (S206) that drives the landing device before the landing unit drives the landing device when the flying body is flying horizontally.

2. The propulsion control device according to claim 1, wherein the pre-operation unit drives the landing device when it is predicted that the landing device will not have enough power to land the aircraft, prior to the landing unit driving the landing device.

3. The propulsion control device according to claim 1 or 2, wherein the pre-unit drives the landing gear when the temperature (Tm) of the landing gear is lower than a pre-threshold (JTm1) while the aircraft is in horizontal flight, and does not drive the landing gear when the temperature is not lower than the pre-threshold while the aircraft is in horizontal flight.

4. The propulsion control device according to claim 1 or 2, further comprising: a landing limiting unit (S210) that limits the landing of the aircraft when the aircraft is in horizontal flight and the pre-mounting unit is driving the landing gear, but the temperature (Tm) of the landing gear is not higher than a landing threshold (JTm2); 5. The propulsion control device according to claim 1 or 2, further comprising: a time adjustment unit (S301) that adjusts the duration such that the lower the temperature (Tm) of the landing gear while the aircraft is in horizontal flight, the longer the duration (TS) for which the pre-mount unit drives the landing gear.

6. The propulsion control device according to claim 1 or 2, further comprising: a current adjustment unit (S401) that adjusts the current such that the lower the temperature (Tm) of the landing gear when the aircraft is in horizontal flight, the greater the current (IS) that flows to the landing gear in order for the pre-mount to drive the landing gear.

7. The propulsion control device according to claim 1 or 2, wherein the pre-mount unit drives the landing gear when the ambient temperature (Tout) is lower than the ambient temperature threshold (JTout) while the aircraft is in horizontal flight, and does not drive the landing gear when the ambient temperature is not lower than the ambient temperature threshold while the aircraft is in horizontal flight.

8. The propulsion control device according to claim 1 or 2, further comprising: a time adjustment unit (S302, S601) that adjusts the duration such that the lower the ambient temperature (Tout) is when the aircraft is in horizontal flight, the longer the duration (TS) for which the front unit drives the landing gear.

9. The propulsion control device according to claim 1 or 2, further comprising: a current adjustment unit (S402, S701) that adjusts the current such that the lower the ambient temperature (Tout) is when the aircraft is in level flight, the greater the current (IS) that the front unit supplies to the landing gear in order to drive the landing gear.

10. The propulsion control device according to claim 1 or 2, further comprising: a power supply adjustment unit (S303-S305, S403-S405) that adjusts at least one of the duration (TS) during which the pre-operation unit drives the landing gear and the current (IS) that the pre-operation unit supplies to the landing gear to drive the landing gear, depending on the state of the power supply unit (31) that supplies power to the propulsion device while the aircraft is in horizontal flight.

11. The propulsion control device according to claim 10, wherein the pre-flight unit comprises at least one of: a time adjustment unit (S303 to S305) that adjusts the duration such that the duration becomes longer the lower the power supply capacity of the power supply unit that supplies power to the landing device while the aircraft is in horizontal flight; and a current adjustment unit (S403 to S405) that adjusts the current such that the current becomes larger the lower the power supply capacity is while the aircraft is in horizontal flight.

12. The propulsion control device according to claim 1 or 2, wherein the pre-mount unit drives the landing gear such that the change in flight attitude due to the driving of the landing gear falls within an acceptable range when the aircraft is in horizontal flight.

13. The propulsion control device according to claim 1 or 2, wherein the pre-control unit controls the current phase of the landing gear such that the current (IS) supplied to the landing gear is greater than the no-load current supplied to the landing gear to drive the landing gear under no load.

14. The propulsion control device according to claim 1 or 2, wherein the pre-unit drives the landing device such that the power factor of the landing device is smaller than the power factor when the landing unit drives the landing device.

15. A propulsion control program (44) used in an electric propulsion device (50) that is driven to propel an aircraft (10) and is provided on the aircraft, wherein the propulsion control program causes at least one processing unit (42) to execute: a horizontal flight unit (S104) that drives a flight device (52) and stops driving a landing device (51) among the plurality of propulsion devices when the aircraft is flying horizontally; a landing unit (S209) that drives the landing device when the aircraft is landing; and a pre-operation unit (S206) that drives the landing device before the landing unit drives the landing device when the aircraft is flying horizontally.

16. A propulsion control method used for an electric propulsion device (50) that is driven to propel an aircraft (10) and is provided on the aircraft, the method comprising the steps of: when the aircraft is flying horizontally, driving a flight device (52) and stopping the driving of a landing device (51) among the plurality of propulsion devices (S104); driving the landing device (S209) when the aircraft is landing; and driving the landing device (S206) when the aircraft is flying horizontally, performed by at least one processing unit (42).

Images