Lock control device

Abstract

This lock control device is applied to an electric vertical take-off and landing (eVTOL) aircraft that flies with a propeller rotated by an electric motor (61) and that has an occupant compartment or a luggage compartment in the fuselage thereof. The lock control device comprises an inverter device (80) (control device), and the inverter device (80) has a lock control unit. A plurality of inverter devices (80) are provided to one motor (61), and the motor (61) can be controlled by any one of the plurality of inverter devices. The lock control unit is provided to each of the plurality of inverter devices (80) and controls a lock device that locks the propeller in a non-rotatable state. One of the plurality of control devices executes lock control by means of the lock control unit in response to a lock request from the outside.

Description

Lock control device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-7420 filed in Japan on January 22, 2024, the contents of which are incorporated by reference in their entirety.

[0002] The disclosure herein relates to a lock control system for an electric aircraft.

[0003] Patent Document 1 describes an electric aircraft that flies by rotating a propeller with an electric motor. In this type of aircraft, there are situations where it is desired to lock the non-rotating propeller at a specific angle range. To address this, Patent Document 1 provides the aircraft with a lock control unit that locks the rotation of the propeller by applying an electric braking force to the motor.

[0004] JP 2021-79869 A

[0005] However, with the above-described structure, if the lock control unit fails, the propeller cannot be locked, and the lock control lacks redundancy. Even if multiple lock control units were provided to ensure redundancy, there would be concerns about control interference, where the controls of those lock control units interfere with each other.

[0006] One disclosed object is to provide a lock control device that ensures redundancy in lock control while eliminating concerns about control interference.

[0007] In order to achieve the above object, a lock control device according to one aspect of the present disclosure is a lock control device applied to an electric aircraft (10) that flies with a propeller (20) rotated by an electric motor (61) and has a crew compartment or a luggage compartment in the airframe, and is provided with a plurality of control devices (80, 80A, 80B) provided for each motor and that can control the motor by any of them, each of the plurality of control devices has a lock control unit (S10, S16, S16e, S10a, S10b) that controls a lock device (100) that locks the propeller in a state where it cannot rotate, and any one of the plurality of control devices executes lock control by the lock control unit in response to a lock request from outside.

[0008] According to the lock control device disclosed herein, since one lock device has multiple lock control units, it is possible to achieve redundancy of the lock control units so that the lock device does not fall into an uncontrollable state. At the same time, since lock control is executed by a single control unit, it is possible to avoid control interference, such as control content by multiple control units interfering with each other. In other words, it is not necessary to develop control logic to prevent control interference between multiple control units, and locking can be achieved with simple control.

[0009] The reference numbers in parentheses above merely indicate an example of the correspondence with specific configurations in the embodiments described below, and do not in any way limit the technical scope.

[0010] 1 is a diagram showing the configuration of an eVTOL in a first embodiment. FIG. 1 is a block diagram showing the electrical configuration of an EPU. FIG. 2 is a schematic diagram showing the configuration of a locking device in a locked state. FIG. 3 is a schematic diagram showing the configuration of a locking device in an unlocked state. FIG. 4 is a flowchart showing the procedure for locking control in the first embodiment. FIG. 5 is a flowchart showing the procedure for locking control in the second embodiment. FIG. 6 is a flowchart showing the procedure for locking control in the third embodiment. FIG. 7 is a flowchart showing the procedure for locking control in the fourth embodiment. FIG. 8 is a flowchart showing the procedure for locking control in the fifth embodiment. FIG. 9 is a flowchart showing the procedure for locking control in the sixth embodiment. FIG. 10 is a schematic diagram showing an anti-freeze heater in the eighth embodiment. FIG. 11 is a flowchart showing the procedure for anti-freeze control in the eleventh embodiment. FIG. 12 is a flowchart showing the procedure for ice-breaking control in the twelfth embodiment. FIG. 13 is a time chart illustrating the control content when unlocking without executing ice-breaking control in the twelfth embodiment. FIG. 14 is a time chart illustrating the control content when ice-breaking control is executed in the twelfth embodiment. 23 is a flowchart showing a procedure for executing a function test for various controls including anti-freeze control and ice-breaking control in the thirteenth embodiment.

[0011] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment will be assigned the same reference numerals, and duplicate descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other previously described embodiments may be applied to the other parts of the configuration. In addition to combinations of parts that are specifically specified as being combinable in each embodiment, it is also possible to partially combine embodiments even if not specified, as long as there is no particular problem with the combination.

[0012] (First embodiment) A flight system 30 shown in Fig. 1 is mounted on an eVTOL 10, which is an electric aircraft. The eVTOL 10 is an electric vertical take-off and landing aircraft, and is capable of taking off and landing vertically. eVTOL is an abbreviation for electric Vertical Take-Off and Landing aircraft. The eVTOL 10 is a manned aircraft on board. The flight system 30 is a system that drives the eVTOL 10 to fly, and includes a battery 31, a distributor 32, a flight control device 40, and an EPU 50.

[0013] The eVTOL 10 has an airframe 11 and a propeller 20. The airframe 11 has an airframe main body 12 and wings 13. The airframe main body 12 is the fuselage of the airframe 11 and has a shape that extends, for example, from front to back. The airframe main body 12 has a crew cabin for passengers. The wings 13 extend from the airframe main body 12 and multiple wings 13 are provided on the airframe main body 12. The wings 13 are fixed wings. The multiple wings 13 include main wings, a tail, and the like.

[0014] A plurality of propellers 20 are provided on the airframe 11. The eVTOL 10 is a multicopter having at least three propellers 20. For example, at least four propellers 20 are provided on the airframe 11. The propellers 20 are provided on each of the airframe body 12 and the wings 13. The propellers 20 rotate around a propeller axis. The propeller axis is, for example, the center line of the propeller 20. The propellers 20 can generate thrust and lift for the eVTOL 10. The propellers 20 correspond to rotating wings. The propellers 20 are sometimes referred to as rotors.

[0015] The propeller 20 has blades 21, a boss 22, and a propeller shaft 23. A plurality of blades 21 are arranged in the circumferential direction of the propeller axis. The boss 22 connects the plurality of blades 21. The blades 21 extend from the boss 22 in the radial direction of the propeller axis. The propeller shaft 23 is the rotation axis of the propeller 20 and extends from the boss 22 along the propeller axis.

[0016] The eVTOL 10 is a tilt rotor aircraft. In the eVTOL 10, the propeller 20 can be tilted. That is, the tilt angle of the propeller 20 is adjustable. For example, when the eVTOL 10 ascends, the orientation of the propeller 20 is set so that the propeller axis extends in the vertical direction. In this case, the propeller 20 functions as a lift propeller that generates lift for the eVTOL 10. When the eVTOL 10 moves forward, the orientation of the propeller 20 is set so that the propeller axis extends in the longitudinal direction. In this case, the propeller 20 functions as a cruise propeller that generates thrust for the eVTOL 10.

[0017] The battery 31 is electrically connected to the plurality of EPUs 50. The battery 31 is a power supply unit that supplies power to the EPUs 50 and corresponds to a power supply unit. The battery 31 is a DC voltage source that applies a DC voltage to the EPUs 50. The battery 31 has a rechargeable secondary battery. Examples of such secondary batteries include a lithium ion battery and a nickel-metal hydride battery. Note that a fuel cell, a generator, or the like may be used as the power supply unit in addition to or instead of the battery 31.

[0018] The distributor 32 is electrically connected to the battery 31 and the plurality of EPUs 50. The distributor 32 distributes the power from the battery 31 to the plurality of EPUs 50. The power distributed by the distributor 32 to the EPUs 50 is drive power for driving the EPUs 50.

[0019] The EPU 50 is a device that propels the eVTOL 10 by driving and rotating the propellers 20, and corresponds to an electric propulsion device. EPU is an abbreviation for Electric Propulsion Unit. An EPU 50 is provided for each of the multiple propellers 20. The EPUs 50 are arranged on the propellers 20 along the propeller axes. All of the multiple EPUs 50 are fixed to the airframe 11. The EPUs 50 support the propellers 20 so that they can rotate. The EPUs 50 are connected to the propellers 20. The propellers 20 are fixed to the airframe 11 via the EPUs 50.

[0020] The EPU 50 has a motor device 60 and an inverter device 80. In the EPU 50, the motor device 60 and the inverter device 80 are arranged side by side along the motor axis Cm. The motor device 60 has a motor 61 and a motor housing. The motor housing accommodates the motor 61. The motor 61 is a rotating electric machine, and is a multi-phase AC motor. The motor 61 is, for example, a three-phase motor.

[0021] As shown in Fig. 2, the motor 61 has a stator 63, a rotor 64, and a motor shaft 65. The stator 63 is a stator, and the rotor 64 is a rotor. The motor shaft 65 is fixed to the rotor 64 and rotates together with the rotor 64. The motor 61 is an axial gap type rotating electric machine. In the motor 61, the stator 63 and the rotor 64 are aligned along the motor axis Cm.

[0022] The motor axis Cm is the rotation axis of the rotor 64. The rotor 64 rotates around the motor axis Cm. The motor axis Cm is, for example, the center line of the rotor 64. The motor axis Cm is also the center line of the motor 61 and the motor shaft 65. If the rotation of the rotor 64 is referred to as the rotation of the motor 61, then the motor 61 rotates around the motor axis Cm.

[0023] The stator 63 has a motor coil that forms an armature. The motor coil is a multi-phase coil. The motor coil has a plurality of individual coils. The individual coil is a multi-phase coil. The individual coil is an n-phase coil. n is a natural number. The motor coil has m individual coils. m is a natural number. The motor coil has m individual n-phase coils, and is an m×n-phase coil. When power is supplied to the m individual coils, the motor 61 operates as an m×n-phase motor. The motor 61 can be operated by supplying power to at least one individual coil. For example, when power is supplied to one individual coil, the motor 61 operates as a 1×n-phase motor.

[0024] In this embodiment, the motor coil has two individual coils. Each of the two individual coils is a three-phase coil. Therefore, the motor coil is a six-phase coil, and the motor 61 is a six-phase motor. When power is supplied to only one coil, the motor coil becomes a three-phase coil, and the motor 61 becomes a three-phase motor.

[0025] The motor coil has two individual coils, a first coil 63a and a second coil 63b. The first coil 63a and the second coil 63b are each a three-phase coil. In the motor coil, the first coil 63a and the second coil 63b are arranged in the circumferential direction of rotation of the motor 61. For example, the multiple coil portions forming the first coil 63a and the multiple coil portions forming the second coil 63b are arranged alternately in the circumferential direction.

[0026] The inverter device 80 is a control device that drives the motor device 60. The inverter device 80 has an inverter 81, an inverter control unit 82, and an inverter housing. The inverter housing is a housing that houses the inverter 81 and the inverter control unit 82. The inverter 81 drives the motor 61 by converting the power supplied to the motor 61. The inverter 81 corresponds to a power conversion unit.

[0027] The inverter 81 is configured to include a plurality of electronic components such as switching elements and capacitor elements. In the inverter 81, these electronic components are mounted on a circuit board or the like. The inverter control unit 82 controls the motor 61 by controlling the inverter 81. The inverter control unit 82 is configured to include a plurality of electronic components such as a microcomputer, a processor 83 (described later), and a memory 84. In the inverter control unit 82, these electronic components are mounted on a circuit board or the like. The inverter device 80 controls the power supplied to the motor coil. In the inverter device 80, one inverter 81 and one inverter control unit 82 form one inverter module. Note that the inverter 81 and the inverter control unit 82 may be configured to include a common circuit board.

[0028] The EPU 50 has a first inverter device 80A and a second inverter device 80B as inverter devices 80. The first inverter device 80A has a first inverter 81A as the inverter 81 and a first inverter control unit 82A as the inverter control unit 82. The second inverter device 80B has a second inverter 81B as the inverter 81 and a second inverter control unit 82B as the inverter control unit 82. The first inverter control unit 82A controls the power supplied to the first coil 63a as motor control. The second inverter control unit 82B controls the power supplied to the second coil 63b as motor control.

[0029] In the EPU 50, when both the first inverter control unit 82A and the second inverter control unit 82B perform motor control, the motor 61 is driven in six phases. In six phase drive, the motor 61 is driven as a six-phase motor. In addition, in the EPU 50, when only one of the first inverter control unit 82A and the second inverter control unit 82B performs motor control, the motor 61 is driven in three phases. In three phase drive, the motor 61 is driven as a three-phase motor. The flight control device 40 can switch between six phase drive and three phase drive of the motor 61 by controlling the inverter control units 82A and 82B. In short, each of the two inverter control units can independently control the motor 61.

[0030] In FIG. 2 , the flight control device 40 is illustrated as ECU, the processor 41 as PRO, the memory 42 as MEM, and the program 43 as PG. The motor device 60 is illustrated as eMOT, the first coil 63a as CL1, the second coil 63b as CL2, the first rotor 64a as Rot1, and the second rotor 64b as Rot2. The first inverter device 80A is illustrated as MCU1, the first inverter 81A as INV1, and the first inverter control unit 82A as ICD1. The second inverter device 80B is illustrated as MCU2, the second inverter 81B as INV2, and the second inverter control unit 82B as ICD2. In the inverter control units 82A and 82B, the processor 83 is illustrated as PRO, the memory 84 as MEM, and the program 85 as PG. MCU is an abbreviation for Motor Control Unit.

[0031] The EPU 50 has an EPU shaft 51 and a gear 53. The EPU shaft 51 is formed into a columnar shape from a metal material or the like. The EPU shaft 51 connects the motor 61 and the propeller 20. For example, the EPU shaft 51 connects the motor shaft 65 and the propeller shaft 23 via the gear 53. The EPU shaft 51 rotates around the motor axis Cm.

[0032] The EPU shaft 51 and the propeller 20 are aligned in the axial direction along the motor axis Cm. For example, the EPU shaft 51 is aligned in the axial direction with the boss 22 and the propeller shaft 23. The motor axis Cm coincides with the propeller axis.

[0033] The gear 53 mechanically connects the motor shaft 65 and the EPU shaft 51. The gear 53 transmits the rotation of the motor shaft 65 to the EPU shaft 51. The gear 53 is provided, for example, between the propeller 20 and the motor device 60 in the axial direction AD. The gear 53 has a reducer. The gear 53 is sometimes referred to as a gear box.

[0034] The EPU 50 has a rotation sensor 52. The rotation sensor 52 is provided for the EPU shaft 51. The rotation sensor 52 detects the rotation speed of the EPU shaft 51. For example, the rotation sensor 52 is provided on the gear 53. The rotation sensor 52 detects the rotation speed of the EPU shaft 51 as the rotation speed of the propeller 20. The rotation sensor 52 outputs a detection signal corresponding to the rotation speed of the EPU shaft 51 to the inverter control unit 82. The rotation sensor 52 is configured to include, for example, an encoder, a resolver, etc.

[0035] The flight control device 40 controls the inverter control unit 82. The flight control device 40 is, for example, an ECU, and performs flight control for flying the eVTOL 10. The flight control device 40 is a control device that controls the flight system 30. ECU is an abbreviation for Electronic Control Unit. The flight control device 40 is mainly composed of a computer. This computer has a processor 41, memory 42, an input / output interface, a bus connecting these, etc. The flight control device 40 executes various processes, such as flight control processing for flight control, by using the processor 41 to execute a control program 43 stored in the memory 42.

[0036] The processor 41 is hardware for arithmetic processing coupled to the memory 42. The processor 41 executes various processes such as flight control processing by accessing the memory 42. The memory 42 is a storage medium that stores a control program 43 and the like. For example, the memory 42 is a non-transitory tangible storage medium that non-temporarily stores computer-readable programs and data. The non-transitory tangible storage medium serving as the memory 42 is a non-transitory tangible storage medium, and is realized by a semiconductor memory, a magnetic disk, or the like.

[0037] The inverter control unit 82 controls the rotation of the propeller 20 by controlling the motor 61. The inverter control unit 82 performs propulsion control to propel the eVTOL 10. The inverter control unit 82 performs propulsion control using the detection results of various sensors such as the rotation sensor 52, command signals from the flight control device 40, and the like. The inverter control unit 82 corresponds to a propulsion control device. The inverter control unit 82 is mainly configured with a computer. This computer has a processor 83, a memory 84, an input / output interface, a bus connecting these, and the like. The inverter control unit 82 executes various processes, such as propulsion control processing for performing propulsion control, by having the processor 83 execute a control program 85 stored in the memory 84.

[0038] The processor 83 is hardware for arithmetic processing coupled to the memory 84. The processor 83 executes various processes such as flight control processing by accessing the memory 84. The memory 84 is a storage medium that stores a control program 85 and the like. For example, the memory 84 is a non-transitory tangible storage medium that non-temporarily stores computer-readable programs and data. The non-transitory tangible storage medium serving as the memory 84 is a non-transitory tangible storage medium, and is realized by a semiconductor memory, a magnetic disk, or the like.

[0039] The EPU 50 has a locking device 100. The locking device 100 is capable of locking the propeller 20. The locking device 100 is capable of transitioning between a locked state and an unlocked state. When in the locked state, the locking device 100 restricts the rotation of the propeller 20, thereby locking the propeller 20 in a non-rotatable state. When in the locked state, the locking device 100 holds the propeller 20 at a predetermined lock angle. Note that the lock angle may have a predetermined angle range.

[0040] When the locking device 100 is in the unlocked state, it does not lock the propeller 20. When the locking device 100 is in the unlocked state, it does not restrict the rotation of the propeller 20 and allows the rotation of the propeller 20. The unlocked state is a state in which the propeller 20 is unlocked.

[0041] The inverter control unit 82 controls the locking device 100. The inverter control unit 82 can transition the locking device 100 between a locked state and an unlocked state. The flight control unit 40 controls the locking device 100 via the inverter control unit 82 by outputting a command signal to the inverter control unit 82. The flight control unit 40 individually controls the locking device 100 for each of the multiple EPUs 50.

[0042] Flight control device 40 controls locking device 100 according to the flight state of eVTOL 10. For example, when eVTOL 10 lifts for vertical takeoff or the like, flight control device 40 drives and rotates propeller 20 that functions as a lift propeller with motor 61. In this case, flight control device 40 locks propeller 20 that does not function as a lift propeller with locking device 100.

[0043] For example, flight control device 40 locks propellers 20 that do not function as lift propellers in a state in which they extend along the pitch axis (the vertical direction on the page in FIG. 1 ) of airframe main body 12. For these propellers 20, the rotation angle in a state in which they extend along the pitch axis is the locked angle. Locking propellers 20 in this manner can avoid problems such as airflow turbulence caused by propellers 20 that do not function as lift propellers when eVTOL 10 lifts.

[0044] When the eVTOL 10 is cruising, the flight control device 40 drives and rotates the propeller 20 that functions as a cruise propeller using the motor 61. In this case, the flight control device 40 locks the propeller 20 that does not function as a cruise propeller using the locking device 100.

[0045] For example, flight control device 40 locks propeller 20 that does not function as a cruise propeller in a state in which it extends along the roll axis (the left-right direction on the page in FIG. 1 ) of airframe main body 12. For this propeller 20, the rotation angle in the state in which it extends along the roll axis is the locked angle. Locking propeller 20 in this manner can prevent problems such as airflow turbulence caused by propeller 20 that does not function as a cruise propeller when eVTOL 10 is cruising.

[0046] As shown in FIG. 3 , the locking device 100 includes a lock pin 101, a solenoid 110, a pressing force transmission unit 115, and a pressing unit 120. The lock pin 101 restricts rotation of the propeller 20 by engaging with the EPU shaft 51. That is, the lock pin 101 is a locking member capable of locking the propeller 20. The lock pin 101 corresponds to the restricting member. The circumferential direction CD shown in FIG. 3 is the rotation direction of the EPU shaft 51 and the propeller 20, and corresponds to the rotation direction of the propeller 20. The radial direction RD shown in FIG. 3 indicates the radial direction of the EPU shaft 51 and the propeller 20. The axial direction AD shown in FIG. 3 indicates the axial direction of the EPU shaft 51. The EPU axis and the motor axis Cm may be aligned or may be offset in the radial direction RD.

[0047] The lock pin 101 is movable between a locked position P11 and an unlocked position P12. When the lock pin 101 is in the locked position P11, it locks the propeller 20. When the lock pin 101 is in the locked position P11, it restricts the rotation of the propeller 20 by getting caught in the shaft groove 55 of the EPU shaft 51. When the lock pin 101 is in the unlocked position P12, it does not lock the propeller 20. When the lock pin 101 is in the unlocked position P12, it does not get caught in the shaft groove 55 and allows the rotation of the propeller 20. The locked position P11 corresponds to the restricting position, and the unlocked position P12 corresponds to the allowing position.

[0048] The shaft groove 55 is provided in the EPU shaft 51. The shaft groove 55 is a groove-shaped recess provided in the shaft outer peripheral surface 51a. The shaft outer peripheral surface 51a is the outer peripheral surface of the EPU shaft 51. The shaft groove 55 is open radially outward. The shaft groove 55 extends, for example, in the axial direction AD along the shaft outer peripheral surface 51a. The shaft groove 55 is configured to engage with a portion of the lock pin 101. For example, the pin portion 103 of the lock pin 101 engages in the shaft groove 55. The shaft groove 55 receives the engagement of the lock pin 101. The shaft groove 55 corresponds to a receiving portion. The pin portion 103 fits into the shaft groove 55, thereby holding the propeller 20 at a lock angle. Note that if a gap exists between the inner wall surface of the shaft groove 55 and the pin portion 103, the lock angle will be within a predetermined angle range.

[0049] The lock pin 101 is made of a metal material or the like. The lock pin 101 has a pin base 102 and a pin portion 103. The pin base 102 is formed in a plate shape and extends, for example, along the shaft outer circumferential surface 51a. The pin portion 103 is a protrusion provided on the plate surface of the pin base 102. The pin portion 103 protrudes radially inward from the pin base 102.

[0050] The lock pin 101 is movable in the radial direction RD relative to the EPU shaft 51. The lock pin 101 can move between a locked position P11 and an unlocked position P12 by moving in the radial direction RD. The lock pin 101 moves from the unlocked position P12 to the locked position P11 by approaching the EPU shaft 51. The locked position P11 is the position where the pin portion 103 of the lock pin 101 is caught in the shaft groove 55, locking the rotation of the propeller 20. The unlocked position P12 is the position where the pin portion 103 is not caught in the shaft groove 55, locking the rotation of the propeller 20.

[0051] The pressing unit 120 is capable of locking the propeller 20 by mechanical energy. The pressing unit 120 is capable of moving the lock pin 101 from the unlocked position P12 to the locked position P11 by mechanical energy. The pressing unit 120 uses the restoring force of an elastic member as the mechanical energy.

[0052] The pressing unit 120 has a pressing member 121 and a pressing support portion 122. The pressing member 121 is configured to include an elastic member such as a spring. The pressing member 121 is elastically deformable as a whole. The pressing member 121 is in an elastically deformed state when the lock pin 101 is in the unlock position P12. The pressing member 121 urges the lock pin 101 from the unlock position P12 toward the locked position P11 by a mechanical pressing force F12 generated by the elastic deformation of the pressing member 121. The mechanical pressing force F12 is a restoring force of the pressing member 121. The mechanical pressing force F12 is a force due to mechanical energy generated in the pressing member 121. The pressing member 121 presses the lock pin 101 toward the EPU shaft 51 by the mechanical pressing force F12.

[0053] The pressing support portion 122 supports the pressing member 121 in a state in which the pressing member 121 is elastically deformable. The pressing support portion 122 is fixed to a motor housing of the EPU 50. Note that the pressing support portion 122 may be part of the motor housing.

[0054] The solenoid 110 is capable of unlocking the propeller 20 using electrical energy. The solenoid 110 is capable of moving the lock pin 101 from a locked position P11 to an unlocked position P12 using electrical energy. The solenoid 110 uses, as its electrical energy, power supplied to the solenoid 110 from the battery 31. For example, the power of the battery 31 is supplied to the solenoid 110 via the inverter control unit 82.

[0055] The solenoid 110 has a solenoid coil 111 and a plunger 112. In the solenoid 110, the plunger 112 is displaced when the solenoid coil 111 is energized. For example, the plunger 112 is movable along the center line of the solenoid coil 111. The plunger 112 biases the lock pin 101 from the locked position P11 toward the unlocked position P12 by an electric pressing force F11 generated when the solenoid coil 111 is energized. The electric pressing force F11 is a force generated by the electromagnetic attractive force of the solenoid 110. This electromagnetic attractive force is a force generated when the solenoid 110 is excited. The excitation of the solenoid 110 is generated by energizing the solenoid coil 111. The electric pressing force F11 is a force due to electrical energy generated when the solenoid coil 111 is energized. The electrical pressing force F11 is greater than the mechanical pressing force F12.

[0056] A plurality of energizable current paths are connected to the solenoid 110. The plurality of energizable current paths include a first parallel path 130a and a second parallel path 130b. The parallel paths 130a and 130b electrically connect the inverter control unit 82 and the solenoid coil 111. The parallel paths 130a and 130b are formed by including electrical wiring such as communication lines. The first parallel path 130a and the second parallel path 130b are connected in parallel with each other. The inverter control unit 82 controls the energization of the solenoid coil 111 so that a signal current Is flows through one of the first parallel path 130a and the second parallel path 130b. The solenoid 110 generates an electric pressing force F11 when the signal current Is flows through the solenoid coil 111.

[0057] Note that, as long as a current such as the signal current Is flows through the solenoid coil 111, the solenoid coil 111 may be connected to the battery 31 so as to be electrically connected thereto without passing through the inverter control unit 82. For example, in a configuration in which the electrical connection between the battery 31 and the solenoid coil 111 is interrupted by a predetermined switch, the opening and closing of this switch may be controlled by the inverter control unit 82.

[0058] The solenoid 110 drives the lock pin 101 to move from the locked position P11 to the unlocked position P12 when current is applied to the solenoid coil 111. The solenoid coil 111 corresponds to a current-carrying portion, and the solenoid 110 corresponds to a current-carrying driving portion.

[0059] The pressing force transmission unit 115 transmits pressing forces F11 and F12 to the lock pin 101. For example, the mechanical pressing force F12 generated by the pressing unit 120 is applied to the lock pin 101 via the pressing force transmission unit 115. The mechanical pressing force F12 is also applied to the solenoid 110 via the pressing force transmission unit 115. In addition, the electrical pressing force F11 generated by the solenoid 110 is applied to the lock pin 101 via the pressing force transmission unit 115. The electrical pressing force F11 is also applied to the pressing unit 120 via the pressing force transmission unit 115.

[0060] The pressing force transmission unit 115 has a transmission plate unit 116 and a transmission shaft unit 117. The transmission plate unit 116 is rotatable around the transmission shaft unit 117 as a rotation axis. The transmission plate unit 116 rotates when pressing forces F11, F12 are applied to it. For example, the transmission plate unit 116 rotates to one side in the circumferential direction of the transmission shaft unit 117 to transmit the mechanical pressing force F12 to the lock pin 101 and the solenoid 110. The transmission plate unit 116 rotates to the other side in the circumferential direction to apply the electrical pressing force F11 to the lock pin 101 and the pressing unit 120.

[0061] Next, the operation of the locking device 100 will be described.

[0062] As shown in FIG. 3 , the locking device 100 is in a locked state when the solenoid coil 111 is not energized. When the solenoid coil 111 is not energized, the solenoid 110 does not generate an electrical pressing force F11. That is, the plunger 112 does not bias the lock pin 101 toward the unlocked position P12. In this case, the pressing unit 120 holds the lock pin 101 at the locked position P11 by a mechanical pressing force F12. The mechanical pressing force F12 is a force capable of holding the lock pin 101 at the locked position P11. The mechanical pressing force F12 corresponds to a mechanical restricting force, and the pressing unit 120 corresponds to a mechanical restricting portion.

[0063] As shown in FIG. 4 , the locking device 100 transitions to an unlocked state when the solenoid coil 111 is energized. When the solenoid coil 111 is energized, the solenoid 110 generates an electrical pressing force F11. In this case, the plunger 112 moves the lock pin 101 from the locked position P11 to the unlocked position P12 against a mechanical pressing force F12 generated by the pressing unit 120. The plunger 112 holds the lock pin 101 at the unlocked position P12 while the solenoid coil 111 remains energized. The plunger 112 corresponds to an energization permission unit.

[0064] <Propulsion Control> Next, the propulsion control of the EPU 50 by the inverter control unit 82 will be described. First, the inverter control unit 82 acquires motor information related to the state of the motor 61. The motor information includes the propeller rotation speed, for example. The propeller rotation speed is the number of rotations of the propeller 20 per unit time. The inverter control unit 82 acquires the motor information using detection signals from various sensors such as the rotation sensor 52.

[0065] Next, the inverter control unit 82 determines whether to lock the propeller 20 based on the motor information. The inverter control unit 82 determines whether to lock the propeller 20 depending on the flight status and flight schedule of the eVTOL 10. For example, if the propeller 20 does not function as a lift propeller when the eVTOL 10 lifts, the inverter control unit 82 locks the propeller 20. If the propeller 20 functions as a lift propeller when the eVTOL 10 lifts, the inverter control unit 82 does not lock the propeller 20.

[0066] Furthermore, if it is determined that the propeller 20 should not be locked, the inverter control unit 82 determines whether or not to unlock the propeller 20. In unlocking, the locking device 100 transitions from a locked state to an unlocked state. The inverter control unit 82 determines whether or not to unlock the propeller 20 depending on the flight state and flight schedule of the eVTOL 10. For example, when the eVTOL 10 cruises after lift, if the propeller 20 that was locked and not functioning as a lift propeller is to be used as a cruise propeller, the inverter control unit 82 unlocks the propeller 20.

[0067] When it is determined that the propeller 20 should be locked, the inverter control unit 82 performs lock control to transition the locking device 100 from the unlocked state to the locked state. This lock control will be described in detail later. When unlocking the propeller 20, the inverter control unit 82 performs unlock control to transition the locking device 100 from the locked state to the unlocked state.

[0068] <Lock Control> Next, lock control by the inverter control unit 82 will be described. First, the inverter control unit 82 determines whether the rotation speed of the propeller 20 is sufficiently slow. For example, if the rotation speed detected by the rotation sensor 52 is slower than a preset threshold, the inverter control unit 82 determines that the rotation speed of the propeller 20 is sufficiently slow. If the rotation speed is not sufficiently slow, the inverter control unit 82 performs a process (rotation deceleration process) to decelerate the rotation of the motor 61 so as to slow down the rotation of the propeller 20. In the rotation deceleration process, current is applied to the motor coils in a current application pattern different from that used when the motor is driven, so that a magnetic field is generated in the stator 63 that applies a braking force to the rotor 64. This current application applies a braking force to the rotor 64, thereby decelerating the rotation of the rotor 64.

[0069] When the rotation of the propeller 20 is sufficiently slow, the inverter control unit 82 moves the lock pin 101 from the unlock position P12 to the lock position P11. Specifically, the inverter control unit 82 performs processing to cut off the power supply to the solenoid coil 111 so that the signal current Is does not flow to the solenoid coil 111. As a result, the pressing unit 120 biases the lock pin 101 toward the lock position P11.

[0070] When the power supply to the solenoid coil 111 is cut off, if the shaft groove 55 is in a position facing the pin portion 103, the pin portion 103 will enter the shaft groove 55 due to the mechanical pressing force F12. That is, the lock pin 101 will be caught in the shaft groove 55. On the other hand, if the shaft groove 55 is not in a position facing the pin portion 103, the lock pin 101 will be pressed against the shaft outer circumferential surface 51 a by the mechanical pressing force F12. Then, when the shaft groove 55, which is moving in the circumferential direction CD, reaches a position facing the pin portion 103, the pin portion 103 will enter the shaft groove 55 due to the mechanical pressing force F12. That is, the lock pin 101 moves to the lock position P11.

[0071] If the rotation of the propeller 20 is not slow enough, even if the shaft groove 55 reaches a position opposite the pin portion 103, the pin portion 103 cannot enter the shaft groove 55 and the shaft groove 55 passes through the pin portion 103. In contrast, if the rotation of the propeller 20 is slow enough, it is unlikely that the pin portion 103 will not enter the shaft groove 55 and the shaft groove 55 will pass through the pin portion 103. In other words, the mechanical pressing force F12 will easily move the lock pin 101 to the lock position P11.

[0072] <Determination of Locking Completion> After executing the locking control, the inverter control unit 82 executes a determination of locking completion, such as determining whether or not the rotation of the propeller 20 has stopped. For example, the inverter control unit 82 determines whether or not the propeller rotation speed is zero using the detection signal of the rotation sensor 52. If the propeller rotation speed is zero, the inverter control unit 82 determines that the rotation of the propeller 20 has stopped. If the propeller rotation speed is not zero, the inverter control unit 82 determines that the rotation of the propeller 20 has not stopped.

[0073] Even if the locking completion is confirmed in the locking completion determination, the inverter control unit 82 may perform the following locking confirmation process. The locking confirmation process is a process for confirming that the propeller 20 does not rotate. In the locking confirmation process, assuming that the lock pin 101 has moved to the locking position P11, the motor 61 is energized so that a rotational force is generated in the propeller 20 that is not enough to release the lock pin 101 from the shaft groove 55. In addition, in the locking confirmation process, assuming that the lock pin 101 has not moved to the locking position P11 and the propeller 20 has stopped rotating, the motor 61 is energized so that a rotational force greater than the frictional force between the pin portion 103 and the shaft outer circumferential surface 51 a is generated in the propeller 20. When the locking confirmation process is performed, the locking completion determination is performed again. When it is determined in this locking completion determination that the rotation of the propeller 20 has stopped, the locking completion is confirmed.

[0074] In the unlock control, the inverter control unit 82 controls the signal current Is to flow through the solenoid coil 111. As a result, an electric pressing force F11 acts on the lock pin 101, and the lock pin 101 moves from the locked position P11 to the unlocked position P12. In other words, the lock device 100 transitions from the locked state to the unlocked state.

[0075] <Allocation of Control Roles> The above-described locking control, locking completion determination, and unlocking control can be performed by either the first inverter control unit 82A or the second inverter control unit 82B. The flight control device 40 determines whether these controls should be performed by the inverter device. The flight control device 40 then commands the determined inverter device to perform the control. The first inverter control unit 82A and the second inverter control unit 82B do not cooperate to perform any of the above-described various controls; each inverter device performs the control independently. In other words, the flight control device 40 determines the allocation of control roles for each of the first inverter control unit 82A and the second inverter control unit 82B.

[0076] For example, the lock control is executed by either the first inverter control unit 82A or the second inverter control unit 82B, and is not executed by both inverter control units in cooperation with each other. Similarly, the lock completion determination is executed by either one of the inverter control units. Similarly, the lock release control is executed by either one of the inverter control units. Similarly, the lock maintenance control described below is executed by either one of the inverter control units.

[0077] A specific example of the division of control roles will be described in detail below with reference to Figure 5. The process shown in Figure 5 is a process in which both inverter control units perform their respective roles. When the conditions for executing lock control are met, the flight control device 40 issues a command to both inverter control units, causing both inverter control units to start executing the process shown in Figure 5. Note that the symbol A: in the figure indicates that the first inverter control unit 82A is the entity that executes the process, and the symbol B: in the figure indicates that the second inverter control unit 82B is the entity that executes the process.

[0078] First, in step S10 of FIG. 5, one of the two inverter control units executes locking control. In this embodiment, the first inverter control unit 82A is responsible for locking control. In the following step S11, the first inverter control unit 82A detects the behavior of the propeller 20. Specifically, the rotation speed of the propeller 20 is calculated based on the detection signal of the rotation sensor 52. In the following step S12, the first inverter control unit 82A executes a locking completion determination.

[0079] If it is determined in step S12 that locking is complete, the process proceeds to step S13, where the fact that locking is complete is stored. This storage location may be memory 84 of inverter device 80 or memory 42 of flight control device 40. In this embodiment, the fact that locking is complete is stored in memory 42 of flight control device 40, but it may also be stored in multiple memories.

[0080] In the next step S14, the first inverter control unit 82A executes lock maintenance control. In the lock maintenance control, the inverter control unit 82 controls the operation of the lock device 100 so as to maintain the locked state. Specifically, in the lock maintenance control, the solenoid coil 111 is continuously de-energized so that the signal current Is does not flow through the solenoid coil 111.

[0081] In short, of the two inverter control units, the same inverter control unit that executed the lock control in step S10 performs the roles of propeller behavior detection, lock completion determination, and lock maintenance control.

[0082] On the other hand, if it is determined in step S12 that locking has not been completed, then in the following step S15, a message indicating that locking has failed is stored. This message may be stored in the memory 84 of the inverter device 80 or in the memory 42 of the flight control device 40. In this embodiment, the message indicating that locking has failed is stored in the memory 84 of the inverter device 80. In other words, the message indicating that locking has failed is stored in the memory 84 of the inverter device that executed the locking completion determination, out of the two inverter control units.

[0083] In the following step S16, the inverter control unit that did not execute locking control in step S10 executes locking control. That is, in this embodiment, the second inverter control unit 82B executes locking control in step S16. Note that a request to change the inverter control unit 82 executing locking control is output from the flight control device 40 to the inverter control unit 82. In the following step S17, the second inverter control unit 82B detects the behavior of the propeller 20. In the following step S18, the second inverter control unit 82B executes locking completion determination.

[0084] If it is determined in step S18 that locking is complete, the process proceeds to step S19, where the locking completion information is stored. This information may be stored anywhere, but in this embodiment, the locking completion information is stored in the memory 42 of the flight control device 40, as in step S13. In step S20, the second inverter control unit 82B executes lock maintenance control. In the lock maintenance control, the inverter control unit 82 controls the operation of the locking device 100 to maintain the locked state.

[0085] In short, of the two inverter control units, the same inverter control unit that executed the lock control in step S16 performs the roles of propeller behavior detection, lock completion determination, and lock maintenance control.

[0086] On the other hand, if it is determined in step S18 that locking has not been completed, the following step S21 stores information indicating that a lock abnormality has occurred and that the aircraft is in an unlocked state. This information may be stored anywhere, but it is stored in the memory 42 of the flight control device 40 in the same manner as in step S13.

[0087] As described above, in the process of FIG. 5 , one of the inverter control units executes lock control. If the locking attempt fails, the other inverter control unit executes lock control. In other words, the two inverter control units do not cooperate to execute lock control. While one control unit is executing lock control, the other control unit is prohibited from executing lock control. For example, contrary to the present embodiment, consider a case in which both inverter control units simultaneously flow a signal current Is to the solenoid coil 111, causing the two inverter control units to cooperate to execute unlock control. In this case, to execute lock control, both inverter control units must interrupt the signal current Is, resulting in the cooperative execution of lock control. In this embodiment, by prohibiting such cooperative unlock control, the cooperative execution of lock control is also prohibited.

[0088] The lock maintenance control is also performed by one of the inverter control units in the same manner as the lock control. In other words, while one control unit is performing the lock maintenance control, the other control unit is prohibited from performing the lock maintenance control. The first inverter device 80A and the second inverter device 80B that perform such lock control correspond to lock control devices.

[0089] <Operation and Effect of First Embodiment> In this embodiment, the first inverter control unit 82A when executing the process of step S10 in Figure 5 and the second inverter control unit 82B when executing the process of step S16 correspond to lock control units. In other words, each of the multiple inverter control units 82 has a lock control unit. In response to a lock request from the flight control device 40 external to the EPU 50, one of the multiple inverter control units 82 executes lock control using the lock control unit.

[0090] This allows for multiple lock control units to be provided for one lock device 100, making it possible to provide redundancy for the lock control units so that the lock device 100 does not fall into an uncontrollable state. Furthermore, since lock control is performed by a single inverter control unit, it is possible to avoid control interference, such as control content interference between multiple inverter control units 82. In other words, it is not necessary to create a control logic to prevent control interference between multiple inverter control units 82, and locking can be achieved with simple control.

[0091] Furthermore, in this embodiment, if the first inverter device 80A among the multiple inverter devices 80 (control devices) executes locking control and the locking is not completed normally, the second inverter device 80B executes locking control. As a result, if locking fails due to an abnormality in the first inverter device 80A even though the locking device 100 is normal, there is a possibility that locking can be completed normally through locking control by the second inverter device 80B. This reduces the possibility of encountering a situation where locking cannot be completed.

[0092] Furthermore, in this embodiment, the first inverter control unit 82A when executing the process of step S14 in Fig. 5 and the second inverter control unit 82B when executing the process of step S20 correspond to lock maintenance control units. In other words, each of the multiple inverter control units 82 has a lock maintenance control unit, and when locking by lock control is successfully completed, the lock maintenance control is executed by the lock maintenance control unit. In this way, since one lock device 100 has multiple lock maintenance control units, it is possible to achieve redundancy of the lock maintenance control so as to prevent the lock from becoming unable to be maintained.

[0093] Furthermore, in this embodiment, the lock maintenance control is executed by the lock maintenance control unit of one of the plurality of inverter control units 82. In this way, when the lock maintenance control is executed, the lock maintenance control is executed by one inverter device 80 (control device), which eliminates the need to configure a control logic to prevent control interference, and enables lock maintenance with simple control.

[0094] Furthermore, in this embodiment, the lock pin 101 moves from the locked position P11 to the unlocked position P12 by energizing the solenoid coil 111. On the other hand, the lock pin 101 moves from the unlocked position P12 to the locked position P11 using the elastic deformation force of the pressing member 121, without requiring energization. This reduces power consumption during locking.

[0095] Second Embodiment In the first embodiment, the first inverter control unit 82A and the second inverter control unit 82B, which are the same inverter control unit that executed the locking control in step S10, perform the functions of detecting the propeller behavior and determining whether locking is complete. In contrast, in the present embodiment, a control unit different from the inverter control unit that executed the locking control in step S10 performs the functions of detecting the propeller behavior and determining whether locking is complete. Specifically, steps S11, S12, S17, and S18 in FIG. 5 according to the first embodiment are changed to steps S11x, S12x, S17x, and S18x in FIG. 6 in the present embodiment. Note that the same explanation may be used for processes in the figures that share the same reference numerals as those in other figures.

[0096] 6 , first, in step S10, first inverter control unit 82A executes locking control. In the following step S11x, second inverter control unit 82B, which is a control unit separate from the control unit that executed the locking control, detects the behavior of propeller 20. In the following step S12x, second inverter control unit 82B, which is a control unit separate from the control unit that executed the locking control, executes locking completion determination.

[0097] Furthermore, if it is determined in step S12x that locking has failed, then in step S16, second inverter control unit 82B executes locking control. In this case, in the following step S17x, first inverter control unit 82A, which is a control unit different from the control unit that executed the locking control in step S16, detects the behavior of propeller 20. In the following step S18x, first inverter control unit 82A, which is a control unit different from the control unit that executed the locking control, executes locking completion determination.

[0098] In this embodiment, the first inverter device 80A among the multiple inverter devices 80 (control devices) executes the locking control, and the second inverter device 80B, which is separate from the first inverter device 80A, determines whether locking by the locking control has been successfully completed. Contrary to this embodiment, if the same control device that executed the locking control were to execute the locking completion determination, there is a risk that if an abnormality occurs in that control device, the locking completion may be erroneously determined to be complete even when it is not. Therefore, this embodiment reduces this risk, enabling a more objective and accurate determination of locking completion.

[0099] Furthermore, in this embodiment, of the multiple inverter devices 80 (control devices), a first inverter device 80A executes locking control, and a second inverter device 80B separate from the first inverter device executes propeller behavior detection. This allows for more objective and accurate propeller behavior detection compared to when the same control device that executed the locking control executes propeller behavior detection.

[0100] (Third embodiment) In this embodiment, the presence or absence of an abnormality is determined for each of the multiple inverter devices 80 (control devices). Depending on the determination result, which control device is to execute various processes such as lock control is changed. Specifically, as shown in FIG. 7, first, in step S5, it is determined whether both the first inverter control unit 82A and the second inverter control unit 82B are normal. Note that in the figure, MCU_A refers to the first inverter device 80A, and MCU_B refers to the second inverter device 80B.

[0101] If it is determined that both the first inverter control unit 82A and the second inverter control unit 82B are normal, the same processing from step S10 onwards as in Fig. 6 is executed. If it is determined that neither is normal, it is determined in the following step S5a whether the first inverter control unit 82A is normal and the second inverter control unit 82B is abnormal. If the determination in step S5a is negative, it is determined in the following step S5b whether the first inverter control unit 82A is abnormal and the second inverter control unit 82B is normal.

[0102] If the determination in step S5a is affirmative, then in step S10a, the first inverter control unit 82A, which is the normal control unit, executes locking control. Also in step S11a, the first inverter control unit 82A, which is the normal control unit, executes propeller behavior detection. Also in step S12a, the first inverter control unit 82A, which is the normal control unit, executes locking completion determination.

[0103] If it is determined in step S12a that locking is complete, the following step S13a causes the flight control device 40 to store information indicating that locking is complete. In the following step S14a, the first inverter control device 82A, which is the normal control device, executes lock maintenance control. On the other hand, if it is determined in step S12a that locking is not complete, the following step S21a causes the flight control device 40 to store information indicating that a lock abnormality has occurred and that the device is in an unlocked state.

[0104] If the determination in step S5a is negative and the determination in the subsequent step S5b is affirmative, then in step S10b, the second inverter control unit 82B, which is the normal control unit, executes locking control. Also in step S11b, the second inverter control unit 82B, which is the normal control unit, executes propeller behavior detection. Also in step S12b, the second inverter control unit 82B, which is the normal control unit, executes locking completion determination.

[0105] If the determination is negative in both step S5a and step S5b, the flight control device 40 stores information indicating that locking is not possible in the subsequent step S22. Note that the information indicating that both the first inverter control unit 82A and the second inverter control unit 82B are in an abnormal state may also be stored together with the information indicating that locking is not possible.

[0106] As described above, in this embodiment, if an abnormal control unit is present, the locking control, propeller behavior detection, locking completion determination, and locking maintenance control are executed using a normal control unit instead of the abnormal control unit, thereby improving the reliability of executing these controls normally.

[0107] Fourth Embodiment In each of the above embodiments, one locking device 100 is provided for one EPU 50. In contrast, in this embodiment, multiple locking devices are provided for one EPU 50. The locking device 100 described above corresponds to the first locking device, and in this embodiment, a second locking device is also provided. The first locking device can be said to be a device that mechanically locks the propeller 20 by using a lock pin 101 as a locking member to inhibit rotation of the propeller 20. In contrast, the second locking device is a device that locks the propeller 20 by the electrical braking force of the motor 61.

[0108] The second locking device is provided by the inverter device 80 that controls the motor 61 as follows. That is, the inverter device 80 energizes the motor coils in a different energization pattern from when the motor is driven, so as to generate a magnetic field in the stator 63 that applies a braking force to the rotor 64. This energization applies a braking force to the rotor 64, causing the rotation of the rotor 64 to slow down and stop. The inverter device 80 performing this type of stop control corresponds to the second locking device.

[0109] Furthermore, the inverter device 80 can also perform stop maintenance control, which energizes the motor coil so as to apply a braking force to the rotor 64, which is stopped from rotating. This stop maintenance control makes it possible to maintain the propeller 20 at a predetermined lock angle. Note that in the stop maintenance control, feedback control may be continued with the locked position set as a target position.

[0110] The "lock control" and "lock maintenance control" described in each of the above embodiments are described as "mechanical lock control" and "mechanical lock maintenance control" by the first locking device in this embodiment. Furthermore, in this embodiment, the stop control by the second locking device is described as "electrical lock control," and the stop maintenance control by the second locking device is described as "electrical lock maintenance control." In this embodiment, both the first inverter 81A and the second inverter 81B can execute the stop control and the stop maintenance control.

[0111] A specific example of the division of control roles according to this embodiment will be described in detail below with reference to Fig. 8. The process shown in Fig. 8 is a process in which both inverter control units execute their respective roles. Note that for processes in the figure where the reference numerals are the same as those in other figures, the explanations for those processes may be cited.

[0112] First, in step S10 of FIG. 8 , one of the two inverter control units executes mechanical lock control. In this embodiment, the first inverter control unit 82A is responsible for the mechanical lock control. In the following step S11x, the second inverter control unit 82B, which is a control unit different from the control unit that executed the mechanical lock control, detects the behavior of the propeller 20. In the following step S12x, the second inverter control unit 82B also executes a determination as to whether the mechanical lock has been completed.

[0113] If it is determined in step S12x that the mechanical locking is complete, the completion of the mechanical locking is stored in the flight control device 40 in the following step S13. In the following step S14, the first inverter control unit 82A executes mechanical lock maintenance control.

[0114] On the other hand, if it is determined in step S12x that the mechanical locking has not been completed, then in the following step S15, a message indicating that the mechanical locking has failed is stored. In the following step S16ex, the first inverter control unit 82A, which is the same control unit that executed the mechanical locking control, executes the electrical locking control. In the following step S17ex, the second inverter control unit 82B, which is a control unit different from the control unit that executed the electrical locking control, detects the behavior of the propeller 20. In the following step S18x, the second inverter control unit 82B, which is a control unit different from the control unit that executed the electrical locking control, determines whether the electrical locking has been completed.

[0115] Furthermore, if it is determined in step S12x that locking has failed, then in step S16, second inverter control unit 82B executes locking control. In this case, in the following step S17x, first inverter control unit 82A, which is a control unit different from the control unit that executed the locking control in step S16, detects the behavior of propeller 20. In the following step S18x, first inverter control unit 82A, which is a control unit different from the control unit that executed the locking control, executes locking completion determination.

[0116] If it is determined in step S18x that the electrical locking is complete, the completion of the electrical locking is stored in the following step S19e. In the following step S20ex, the first inverter control unit 82A, which is the same control unit that executed the electrical locking control, executes the electrical locking maintenance control. In other words, of the two inverter control units, the same inverter control unit that executed the electrical locking control in step S16ex plays the role of the electrical locking maintenance control.

[0117] In short, the first inverter control unit 82A performs the functions of mechanical lock control, electrical lock control, mechanical lock maintenance control, and electrical lock maintenance control. The second inverter control unit 82B performs the functions of propeller behavior detection and lock completion determination. However, if both the mechanical lock control and the electrical lock control by the first inverter control unit 82A fail, the second inverter control unit 82B may then perform mechanical lock control. If that also fails, the second inverter control unit 82B may then perform electrical lock control.

[0118] In this embodiment, multiple locking devices are provided for one propeller 20. At least one lock control unit can execute locking control for the multiple locking devices. If locking is not completed successfully as a result of executing locking control for a first locking device among the multiple locking devices, locking control is executed for a second locking device. This allows for redundant locking devices, enabling reliable locking control.

[0119] Furthermore, in this embodiment, the first locking device is a device that mechanically locks the propeller 20 by using a lock pin 101 (locking member) to inhibit rotation of the propeller 20. The second locking device is a device that locks the propeller 20 by using the electrical braking force of the motor 61. Because a mechanical locking device requires less energy to lock than an electrical locking device, this embodiment, in which the mechanical locking device is activated with priority over the electrical locking device, allows locking to be performed with less energy.

[0120] Furthermore, in this embodiment, when the first inverter control unit 82A executes lock control for the first locking device, the first inverter control unit 82A also executes lock control for the second locking device thereafter, thereby ensuring redundancy of locking control with a single inverter control unit.

[0121] Fifth Embodiment In the fourth embodiment, when the mechanical lock control is executed and then the electrical lock control is executed, the same control unit executes both lock controls. In contrast, in this embodiment, the control unit that executes the mechanical lock control and the control unit that executes the subsequent electrical lock control are different. Specifically, steps S16ex and S20ex in FIG. 8 according to the fourth embodiment are changed to steps S16e and S20e in FIG. 9 in this embodiment. Note that the same explanation may be used for processes in the figures that share the same reference numerals as those in other figures.

[0122] 8 according to the fourth embodiment, the first inverter control unit 82A, which is the same control unit that executed the mechanical lock control in step S10, executes the electrical lock control and the electrical lock maintenance control. In contrast, in this embodiment, the second inverter control unit 82B, which is different from the control unit that executed the mechanical lock control in step S10, executes the electrical lock control and the electrical lock maintenance control in steps S16e and S20e shown in FIG.

[0123] In other words, in this embodiment, if a first control device among the multiple control devices executes lock control for a first locking device and the locking is not completed successfully, a second control device executes lock control for a second locking device. In other words, if the first locking control fails, both the control device and the locking device are switched and a second locking control attempt is attempted. Therefore, regardless of whether the cause of the first locking control failure is the control device or the locking device, the possibility of success in subsequent locking controls is increased.

[0124] Furthermore, in this embodiment, the first locking control is a mechanical locking control and the second locking control is an electrical locking control. In this way, according to this embodiment, which operates the mechanical locking device with priority over the electrical locking device, locking can be performed with less energy.

[0125] Sixth Embodiment In each of the above embodiments, one of the multiple inverter control units 82 executes lock control using a lock control unit. In contrast, in this embodiment, the multiple inverter control units 82 simultaneously cooperate to execute lock control. In addition, in the lock maintenance control according to this embodiment, first, one of the control units executes lock maintenance control independently. If this attempt to maintain lock fails, the other control unit independently attempts a second lock control.

[0126] A specific example of the control flow shown in Fig. 10 will be described below for the lock control and lock maintenance control according to this embodiment. Note that the explanations for processes in the figure that share the same reference numerals as those in other figures may be used.

[0127] First, in step S10w of Fig. 10, both the first inverter control unit 82A and the second inverter control unit 82B simultaneously cooperate to execute mechanical lock control. In the subsequent step S11w, both the first inverter control unit 82A and the second inverter control unit 82B independently detect the propeller behavior. That is, both control units acquire the detection signal output from the rotation sensor 52, and each control unit calculates the rotation speed of the propeller 20.

[0128] In the following step S12w, both the first inverter control unit 82A and the second inverter control unit 82B independently perform a provisional determination of locking completion. In step S12w, if both control units provisionally determine that locking is complete, a final determination is made that locking is actually complete. If at least one control unit provisionally determines that locking is not yet complete, a determination is made that locking has failed. This reduces the risk of erroneously determining that locking is complete when it is not. Note that, if it is desired to reduce the risk of erroneously determining that locking has failed when locking is complete, a final determination may be made that locking is actually complete when at least one control unit provisionally determines that locking is complete.

[0129] If it is determined in step S12w that locking has been completed, then in step S23, mechanical lock maintenance control and propeller behavior monitoring are performed. The mechanical lock maintenance control is performed solely by the first inverter control unit 82A. The propeller behavior monitoring is performed solely by the second inverter control unit 82B.

[0130] In the next step S24, it is determined whether the locked state is stable. This determination is made by the second inverter control unit 82B, which is the control unit that monitored the propeller behavior, based on the results of monitoring the propeller behavior. If it is determined that the locked state is not stable, in the next step S25, a message indicating that the mechanical locking has failed is stored.

[0131] In the subsequent step S26, a control unit different from the control unit that executed the mechanical lock control in step S23 executes the mechanical lock control and the mechanical lock maintenance control. That is, the second inverter control unit 82B executes the mechanical lock control and the mechanical lock maintenance control.

[0132] On the other hand, if it is determined in step S12w that locking has not been completed (locking has failed), the locking failure is stored in the next step S27. In the following step S10we, both the first inverter control unit 82A and the second inverter control unit 82B simultaneously cooperate to execute electrical locking control. In the following step S11we, both control units independently detect the propeller behavior.

[0133] In the next step S12we, similar to the above-described step S12w, both control units independently perform a provisional determination of the completion of locking. For example, if both control units provisionally determine that locking is complete, it is determined that locking is actually completed.

[0134] If it is determined in step S12we that locking has been completed, the next step S23e is to execute electrical lock maintenance control and monitor the propeller behavior. The electrical lock maintenance control is executed solely by the first inverter control unit 82A. The propeller behavior monitoring is executed solely by the second inverter control unit 82B.

[0135] In the next step S24e, the second inverter control unit 82B determines whether the locked state is stable based on the results of monitoring the propeller behavior. If it is determined that the locked state is not stable, in the next step S25e, a message indicating that the electrical locking has failed is stored.

[0136] In the next step S26e, a control unit different from the control unit that executed the electric lock control in step S23e executes the electric lock control and the electric lock maintenance control. That is, the second inverter control unit 82B executes the electric lock control and the electric lock maintenance control. If it is determined in step S12we that the locking has not been completed (locking has failed), the next step S21 stores information that a lock abnormality has occurred and the vehicle is in an unlocked state.

[0137] As described above, in this embodiment, the first inverter device 80A and the second inverter device 80B simultaneously cooperate to execute locking control, thereby improving the reliability of locking. Furthermore, since both inverter devices cooperate to determine whether locking is complete, the risk of erroneously determining that locking is complete when locking is not achieved can be reduced.

[0138] Furthermore, in this embodiment, if the first inverter device 80A among the multiple inverter devices 80 (control devices) executes lock maintenance control and fails to maintain lock, resulting in unlocking, the second inverter device 80B executes lock control, thereby improving the reliability of locking.

[0139] Seventh Embodiment However, if the propeller 20 is kept stopped from rotating by the lock maintenance control for a long period of time, there is a concern that the following problem of freezing may occur. That is, there is a concern that moisture adhering between the lock pin 101 and the shaft groove 55 may freeze, making it impossible to release the lock. In other words, there is a concern that the lock pin 101 and the shaft groove 55 may become stuck together by ice, and as a result, even if the solenoid coil 111 is energized to generate the electrical pressing force F11, the lock pin 101 may not be able to be removed from the shaft groove 55.

[0140] There is also a concern that moisture adhering to the bearings supporting the EPU shaft 51 and the motor shaft 65 will freeze, making it impossible to resume rotation of the propeller 20. In other words, there is a concern that mechanical operating parts such as the locking device 100 and bearings will freeze and cause malfunctions.

[0141] In addition to these mechanical operating points, there is also concern about freezing of the liquid refrigerant that cools the motor device 60 and the inverter device 80. When the propeller 20 stops rotating, the motor device 60 and the inverter device 80 are also stopped, so there is no need to circulate the liquid refrigerant with a pump. Therefore, when the propeller 20 stops rotating, there is concern about the liquid refrigerant freezing as described above.

[0142] The present embodiment and the following embodiments aim to solve the above-mentioned problem, i.e., the problem of freezing that occurs when lock maintenance is performed. In this embodiment, the inverter device 80 executes the process shown in FIG. 11 to solve the above problem. The process shown in FIG. 11 is executed by either the first inverter control unit 82A or the second inverter control unit 82B. The process shown in FIG. 11 is executed continuously while lock maintenance control is required.

[0143] In the process shown in Figure 11, first, in step S100, the outside air temperature is measured. Next, in step S101, the lock maintenance duration, which is the time during which the lock maintenance control is continued, is measured. Next, in step S102, it is determined whether or not anti-freeze control is necessary based on the outside air temperature and the lock maintenance duration obtained by the above-mentioned measurements. Anti-freeze control is control to prevent freezing in advance so that it does not occur.

[0144] For example, when the outside air temperature is 0°C or lower and the lock-maintained duration is equal to or longer than a predetermined time, it is determined that anti-freeze control is necessary. Note that in addition to the outside air temperature and the lock-maintained duration, humidity, weather (rain, etc.), etc. may also be used as the determination conditions in step S102. The length of the predetermined time used for the above determination may also be changed depending on the outside air temperature, humidity, weather (rain, etc.), etc. The lower the temperature and the higher the humidity, the more likely freezing occurs, so for example, the lower the temperature and the higher the humidity, the shorter the predetermined time may be set.

[0145] If it is determined in step S102 that anti-freeze control is not necessary, the lock maintaining control is continued in the next step S103. On the other hand, if it is determined that anti-freeze control is necessary, the anti-freeze control is executed in the following steps S104 and S105. The inverter control unit 82 when executing the processes of steps S104 and S105 corresponds to the "anti-freeze control unit."

[0146] In step S104 relating to the anti-freeze control, the lock release control is executed. That is, the signal current Is is controlled to flow through the solenoid coil 111, thereby disengaging the lock pin 101 from the shaft groove 55.

[0147] Here, when the flight state requires that the propeller 20 be locked within a specific angle range, the flight control device 40 issues a lock control command to the inverter device 80. Then, when the lock request is canceled, the flight control device 40 outputs an unlock command to the inverter device 80. Unlike this normal unlocking, the process executed in step S104 is anti-freeze unlocking control. Anti-freeze unlocking control is executed when a lock command is output from the flight control device 40 to the inverter device 80.

[0148] Thereafter, in step S105 related to anti-freeze control, rotation control is executed to drive the motor device 60 to rotate the propeller 20. In this rotation control, the motor device 60 is rotated in a state in which the effect on the flight state is minimized. For example, the motor device 60 may be driven to oscillate by alternately rotating forward and backward. Alternatively, the motor device 60 may be rotated in one direction at an extremely low speed. Alternatively, if the EPU 50 has a pitch angle adjustment device, the motor device 60 may be driven in a state in which the pitch angle is adjusted to a minimum.

[0149] The pitch angle adjustment device is a device that changes the pitch angle of the blades 21 to adjust it to an optimal pitch angle. Changing the pitch angle changes the rotational resistance of the blades 21 against the air, which in turn changes the rotational torque of the propeller 20. In the rotation control of step S105, it is desirable to minimize the pitch angle to minimize the rotational resistance. This can reduce the impact of the anti-icing control on the aircraft attitude and energy consumption.

[0150] In short, in the anti-freeze control in steps S104 and S105, the lock maintenance control is temporarily released while a lock command is being output from the flight control device 40. Then, the propeller 20 is operated with as little impact on the flight state as possible. The rotation control in step S105 is executed for a predetermined time or a predetermined number of times, after which the supply of power to the motor device 60 is stopped to stop the rotation of the propeller 20.

[0151] In the following step S106, the lock maintenance duration measured in step S101 is reset to 0. In the following step S107, in accordance with the lock maintenance request from the flight control device 40, lock control and lock maintenance control are executed.

[0152] As described above, the lock control device according to this embodiment includes an anti-freeze control unit that performs steps S104 and S105. The anti-freeze control by the anti-freeze control unit is performed to prevent freezing during the lock maintenance control period. This is expected to dissipate moisture adhering to mechanically operating parts. Therefore, freezing of mechanically operating parts and liquid refrigerant can be prevented during the lock maintenance control period. Examples of mechanically operating parts include the lock device 100 and the aforementioned bearings.

[0153] Furthermore, if the EPU 50 has a cooling structure that cools the motor device 60 and the inverter device 80 with liquid refrigerant, the anti-freeze control causes the stagnant liquid refrigerant to flow. If the circulation of the liquid refrigerant is stopped for a long period of time, the liquid refrigerant in the circulation path exposed to the low-temperature outside air will reach its lowest temperature, increasing the risk of freezing. In consideration of this, in this embodiment, the anti-freeze control is executed during the lock maintenance control period. This causes the stagnant liquid refrigerant to temporarily flow, promoting an increase in the liquid refrigerant temperature in the lowest point. This prevents freezing.

[0154] Furthermore, in this embodiment, the anti-freeze control unit temporarily releases the lock maintenance control and then operates the propeller 20. Specifically, after releasing the lock in step S104, rotation control is executed in step S105. Therefore, in addition to preventing the lock pin 101 and the shaft groove 55 from freezing by releasing the lock, the subsequent rotation control can also prevent the bearings and other parts related to the rotation of the propeller 20 from freezing.

[0155] Furthermore, in this embodiment, the anti-freeze control unit energizes the motor 61 without affecting the flight conditions. Therefore, anti-freeze can be achieved without the occupant of the eVTOL 10 feeling any change in the flight conditions.

[0156] Eighth Embodiment In this embodiment, a heater 101h shown in FIG. 12 is provided as a countermeasure against the freezing described above. The heater 101h is disposed in a location that needs to be prevented from freezing. The heater 101h is an electric heater that generates heat when powered. Powering the heater 101h on and off is controlled by the inverter control unit 82. In the example shown in FIG. 12, the heater 101h is attached to the lock pin 101. The heater 101h may be attached to a mechanically operating location such as a bearing. Alternatively, the heater 101h may be attached to a circulation path for the liquid refrigerant.

[0157] In this embodiment, the inverter device 80 takes measures against freezing by executing the process shown in Fig. 13. Note that the explanation of Fig. 11 is used for the processes denoted by the same reference numerals as in Fig. 11. The process of Fig. 13 is executed continuously during the period when lock maintenance control is required.

[0158] 13, if it is determined in step S102 that anti-freeze control is not necessary, the anti-freeze heater 101h is turned off in the next step S108. On the other hand, if it is determined that anti-freeze control is necessary, the anti-freeze heater 101h is turned on in the following step S109. The inverter control unit 82 when executing the process of step S109 corresponds to the "anti-freeze control unit."

[0159] In step S109, the ON state may be maintained, or the ON / OFF state may be repeated intermittently. Alternatively, the ON / OFF state may be repeated at regular intervals, and the intervals may be changed depending on conditions related to the susceptibility to freezing, such as the outside air temperature. The more susceptible the conditions to freezing, the shorter the OFF interval is preferably.

[0160] The heater 101h may be kept on when the outside air temperature is low, at or below a predetermined temperature. However, according to this embodiment, the heater 101h is turned on only when it is determined in step S102 that anti-freeze control is necessary, and power consumption can be reduced compared to when the heater 101h is kept on all the time.

[0161] As described above, the EPU 50 according to this embodiment includes the anti-freeze heater 101h. The lock control device according to this embodiment includes the anti-freeze control unit in step S109. The anti-freeze control is executed to prevent freezing during the lock maintenance control period. This allows the heater 101h to heat areas that may freeze during the lock maintenance control period, thereby preventing mechanically operated areas and liquid refrigerant from freezing during the lock maintenance control period.

[0162] Ninth Embodiment In this embodiment, the inverter device 80 executes the process shown in Fig. 14 to prevent freezing. The same processes as those in the previous drawings are denoted by the same reference numerals and the same explanations are applied. The process in Fig. 14 is executed continuously during the period when lock maintenance control is required.

[0163] In the process shown in FIG. 14, in step S110, it is determined whether the outside air temperature is low. For example, if it is below 0°C, it is determined to be low. Note that, in consideration of the fact that the freezing temperature varies depending on the flight altitude, the threshold for determining low temperature may be lowered as the flight altitude increases. If it is determined that the outside air temperature is not low, then in the next step S111, mechanical lock control is executed. If it is determined that the outside air temperature is low, then in the next step S112, electrical lock control is executed. When executing the process of step S112, the inverter control unit 82 corresponds to the "anti-freeze control unit."

[0164] Here, mechanical locking requires less energy to maintain lock than electrical locking. However, because locking is achieved by mechanical contact, there is a risk of the contact points freezing. In contrast, electrical locking does not increase the number of mechanical contact points, so there is a lower risk of freezing compared to mechanical locking. Furthermore, because torque is continuously applied to the motor 61 to the extent that the propeller 20 does not move, the motor 61 and inverter 81 themselves generate heat and act as heaters, making them less likely to freeze. Therefore, this embodiment, which selects electrical locking at low temperatures, reduces the risk of freezing.

[0165] In short, the anti-freeze control unit in step S112 switches from mechanical locking by the first locking device to electrical locking by the second locking device, thereby reducing the risk of freezing due to heat generation as described above.

[0166] Tenth Embodiment In this embodiment shown in Fig. 15, the process of step S112 in Fig. 14 is changed to step S113. In step S113, when it is determined that the temperature is low, the mechanical lock and the electrical lock are switched over at predetermined time intervals. When the inverter control unit 82 is executing the process of step S113, it corresponds to the "anti-freeze control unit."

[0167] The low temperature determination process in step S110 may be omitted, and mechanical lock control and electrical lock control may be switched periodically. Alternatively, the propeller 20 may be fixed or rotated during electrical lock control depending on weather conditions such as temperature, humidity, rain, or snow. Furthermore, the motor device 60 may be driven to vibrate by alternately rotating forward and backward.

[0168] In other words, the anti-freeze control unit in step S113 repeatedly switches from mechanical locking by the first locking device to electrical locking by the second locking device multiple times at predetermined time intervals, thereby reducing the risk of freezing due to heat generation as described above.

[0169] 16, the outside air temperature is measured in step S100. In step S120, the time during which the mechanical lock maintenance control is continued is measured. In step S121, it is determined whether or not anti-freeze control is necessary based on the outside air temperature and the lock maintenance duration obtained by the measurements.

[0170] In step S121, similarly to step S102 in FIG. 11, it is determined that anti-freeze control is necessary, for example, when the outside air temperature is 0° C. or lower and the lock maintenance duration is equal to or longer than a predetermined time.

[0171] If it is determined in step S121 that anti-freeze control is necessary, then in the following step S122, current is supplied to the motor 61 by d-axis current supply control. The d-axis current supply control is a control that causes heat by passing current through the motor 61 so that torque is not generated in the motor 61. With d-axis current supply, no rotational force is generated in the motor 61. Therefore, even in a mechanically locked state, current can be supplied to the motor 61 without applying a mechanical load to the motor 61 and the locking device 100. The inverter control unit 82 when executing the processing of step S122 corresponds to the "anti-freeze control unit."

[0172] In step S122, the d-axis current may be continuously applied or may be intermittently turned on and off. Alternatively, the d-axis current may be turned on and off at regular intervals, which may be changed depending on conditions related to the likelihood of freezing, such as the outside air temperature. The more likely the conditions are to cause freezing, the shorter the d-axis current-off interval should be. Furthermore, the cooling performance of the liquid refrigerant may be suppressed before or simultaneously with the application of current to the d-axis.

[0173] As described above, the lock control device according to this embodiment includes an anti-freeze control unit in step S122. This allows the motor 61 and the inverter 81 to also function as heaters by generating heat. This prevents mechanical operating parts and the liquid refrigerant from freezing during the lock maintenance control period.

[0174] In the seventh to eleventh embodiments described above, control is executed to prevent freezing beforehand (anti-freezing control), whereas in this embodiment, ice-breaking control is executed to break up the ice after it has already frozen.

[0175] 17 is executed by the inverter device 80 continuously during the period when lock maintenance control is required. First, in step S90, it is determined whether or not there is a request for unlocking. The request for unlocking is a command output from the flight control device 40 to the inverter device 80.

[0176] If it is determined that there is an unlock request, the outside air temperature is measured in the following step S100. In the following step S110, it is determined whether the outside air temperature is low. In this determination, as in FIG. 14, for example, if the temperature is below 0°C, it is determined to be low. If it is determined that the temperature is not low, normal unlock control is executed in the next step S130. On the other hand, if it is determined that the temperature is low, icebreak control, which is a different type of unlock control from the normal type, is executed in the next step S131. When executing the processing of step S131, the inverter control unit 82 corresponds to the "icebreak control unit."

[0177] In addition to the outside air temperature and the duration of lock maintenance, humidity, weather (rain, etc.), etc. may also be used as the determination conditions in step S110. The length of the predetermined time used for the determination may also be changed depending on the outside air temperature, humidity, weather (rain, etc.), etc. The lower the temperature and the higher the humidity, the more likely freezing occurs. Therefore, for example, the lower the temperature and the higher the humidity, the shorter the predetermined time may be set.

[0178] Details of the normal lock release control and the ice-break control will be explained below with reference to Figures 18 and 19. The upper part of these figures shows the control related to the mechanical lock mechanism, indicating the magnitude of current supplied to the solenoid coil 111. The lower part of the figures shows the magnitude of current supplied to the motor 61. The horizontal axis of these figures indicates elapsed time, and up until time t1, the vehicle is locked by the mechanical lock maintenance control.

[0179] As shown in Figure 18, under normal unlock control, the vehicle remains mechanically locked until time t1 when an unlock request is made, and motor torque is controlled to zero. Also, because the vehicle remains mechanically locked until time t1, power to the solenoid coil 111 is controlled to zero. Then, power to the solenoid coil 111 begins to be supplied at time t1, and power is continued to be supplied to maintain the unlocked state.

[0180] Here, even if no torque is being applied to the motor 61, the propeller 20 is subjected to torque due to the flight wind. For this reason, it is desirable to make it easy for the lock pin 101 to disengage from the shaft groove 55 and to prevent the propeller 20 from suddenly rotating immediately after disengagement. Therefore, from just before time t1, when the lock is released, to just after, a torque is generated in the motor 61 to offset the torque due to the flight wind. For example, a torque in a direction that reverses the propeller 20 is generated in the motor 61. Thereafter, to prevent a sudden change in torque, the motor torque is gradually increased in the period up to time t6.

[0181] 19, the vehicle is mechanically locked until time t1 when an unlock request is made, and motor torque is controlled to zero. Since the vehicle is mechanically locked until time t1, power supply to the solenoid coil 111 is controlled to zero. Power supply to the solenoid coil 111 then begins at time t1, and the power supply continues, maintaining the unlocked state.

[0182] However, from the start of energization until time t2, higher-output power is supplied than in normal unlock control. In short, the lock pin 101 is intended to be vigorously operated by high-output energization in a short period of time immediately after energization begins. This is intended to crush the ice that is adhering the lock pin 101 to the shaft groove 55. Note that the ice may also be crushed by repeatedly turning the power to the solenoid coil 111 on and off during the period immediately after energization begins. In this case, it is desirable to repeatedly turn the power on and off at high output.

[0183] In the ice-breaking control, the motor 61 is energized so as to generate a motor torque that oscillates by alternately rotating forward and backward from time t2 onward, when it is expected that the lock will be released. For example, forward torque is generated from time t2 to time t3, reverse torque is generated from time t3 to time t4, and forward torque is generated from time t4 to time t5. In the period from time t5 to time t6, the motor torque is increased gradually to prevent a sudden change in torque.

[0184] In other words, the control of the current supply to the locking device 100 from time t1 to time t2 corresponds to ice-breaking control for breaking the ice on the lock pin 101. The control of the current supply to the motor 61 from time t2 to time t6 corresponds to ice-breaking control for breaking the ice on bearings or the like.

[0185] Returning to the explanation of FIG. 17 , after steps S130 and S131, step S132 determines whether unlocking has been completed. For example, if the rotational speed of the propeller 20 remains zero, it is determined that unlocking has not been completed. If it is determined that unlocking has not been completed, the process proceeds to step S133, where it is assumed that an unlocking abnormality has occurred due to freezing or the like, and an unlocking abnormality flag is set to ON. The fact that an unlocking abnormality has occurred is then stored in the inverter control unit 82 or the flight control device 40. In this case, the flight control device 40 adjusts the output of the other functioning EPUs 50 to stabilize the aircraft attitude and continue flight control.

[0186] 17 may be always executed when conditions that tend to freeze, such as low temperatures, are met. Alternatively, normal unlocking control may be attempted first, and the control of FIG. 17 may be executed if unlocking is not possible or if unlocking is successful but the propeller 20 does not rotate.

[0187] Alternatively, whether to execute the control of FIG. 17 may be determined based on the history of outside temperature and weather conditions from when the lock was initiated to the present. For example, if the temperature has remained below 0°C for a long period of time while the lock is in operation, there is a possibility that the vehicle may be frozen even if the outside temperature exceeds 0°C when an unlock request is made. In consideration of this, the time during which a condition that may cause freezing has continued since the lock was initiated may be measured, and whether to execute the control of FIG. 17 may be determined based on that time. Furthermore, even if there is a history of a condition that may cause freezing continuing for a long period of time, normal unlock control may be selected as long as a sufficient amount of time has passed since the condition was resolved.

[0188] As described above, the lock control device according to this embodiment includes an ice-breaking control unit in step S131. This is expected to break the ice after it has been frozen.

[0189] 20, in the functional test mode, the anti-freeze control and ice-breaking control described above are executed to check whether these controls are operating normally. The functional test mode inspection is performed on the ground before takeoff or after landing of the eVTOL 10. Alternatively, the inspection is performed on an EPU 50 that is not generating thrust during flight. For example, the inspection is performed on a vertical takeoff EPU 50 that is stopped during horizontal flight.

[0190] The functional test mode inspection includes the following items: checking whether the input voltages and output values ​​to various sensors, control devices, and actuators, as well as the operation in response to commands from the control devices, are within the designed control ranges. This inspection also includes the propeller lock control, lock release control, anti-freeze control, and ice break control.

[0191] The process of Fig. 20 is executed by inverter control unit 82 in accordance with a command output from an inspection device (not shown). In the process of Fig. 20, first, in step S140, it is determined whether or not the function test mode is in effect. For example, if there is a command to execute the function test mode from the inspection device, it is determined that the function test mode is in effect.

[0192] In the next step S141, it is confirmed whether the motor 61 is energized and the propeller 20 is normally rotated. At this time, it is desirable to rotate the propeller 20 at a low speed that does not generate thrust.

[0193] In the next step S142, the electric lock control is executed to check whether the electric lock is properly performed. In the next step S143, the electric lock control is released. Then, by checking whether the propeller 20 is driven again, it is checked whether the electric lock release is properly performed.

[0194] In the next step S144, mechanical lock control is executed to check whether the mechanical lock is properly established. In the next step S145, control to release the mechanical lock control is executed. Then, by checking whether the propeller 20 is driven again, it is confirmed whether the mechanical lock release is properly established.

[0195] In the next step S146, the mechanical lock control is executed again. In the next step S147, the anti-freeze control is executed to check whether it operates normally. In the next step S148, the ice-break control is executed to check whether it operates normally.

[0196] If it is determined in the following step S149 that all of the above checks are normal, the process of Figure 20 ends. If an abnormality is confirmed in at least one of the checks, the abnormality is stored in step S150. The storage location may be the inspection device, the inverter control unit 82, or the flight control device 40.

[0197] (Other Embodiments) The disclosure of this specification is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and modifications thereto by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and elements shown in the embodiments, and can be implemented in various modifications. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses embodiments in which parts and elements of the embodiments are omitted. The disclosure encompasses the substitution or combination of parts and elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is defined by the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the claims.

[0198] In the first to third embodiments, both a mechanical locking device and an electrical locking device may be provided, as in the fourth to sixth embodiments, or the mechanical locking device may be eliminated and an electrical locking device may be provided instead.

[0199] The first to fifth embodiments may be combined with the sixth embodiment as appropriate. For example, if locking is not possible even after executing the processes shown in Figures 5 to 9, multiple inverter control units 82 may cooperate to execute locking control as shown in Figure 10.

[0200] If the propeller 20 that is not driven to rotate is left unlocked, the propeller 20 may spin freely, which may shorten the lifespan of the propeller 20 and the motor 61 or induce a malfunction. Therefore, locking control may be performed on a propeller 20 that cannot be driven to rotate by the motor 61 due to a malfunction or the like, or a propeller 20 that is normal but not driven to rotate.

[0201] In each of the above embodiments, the rotation sensor 52 may detect any rotation as long as a propulsion control device such as the inverter control unit 82 can acquire the propeller rotation speed. For example, the rotation sensor 52 may directly detect the rotation of the propeller 20, or may detect the rotation of the motor shaft 65.

[0202] In each of the above embodiments, the eVTOL 10 does not have to be a tilt rotor aircraft. That is, the propellers 20 of the eVTOL 10 do not have to be able to tilt. For example, the multiple propellers 20 of the eVTOL 10 may include a lift propeller 20 and a cruise propeller 20. In this eVTOL 10, for example, the lift propeller 20 is driven when ascending, and the cruise propeller 20 is driven when moving forward.

[0203] 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. For example, the aircraft may be a rotary-wing aircraft or a fixed-wing aircraft. Furthermore, the aircraft may be an unmanned aerial vehicle.

[0204] The lock control device according to each of the above embodiments is premised on having a plurality of control devices 80. In contrast, a lock control device having at least one of anti-freeze control and ice-breaking control is not limited to having a plurality of control devices 80, and may have only one control device 80.

[0205] In each of the above embodiments, the flight control device 40 is provided by a control system including at least one computer. The control system includes at least one processor that is hardware. If this processor is referred to as a hardware processor, the hardware processor can be provided by the following (i), (ii), or (iii):

[0206] (i) A hardware processor may be a hardware logic circuit. In this case, the computer is implemented by a digital circuit including a number of programmed logic units. The logic units may be, for example, gate circuits. The digital circuit may include a memory that stores at least one of a program and data. The computer may be implemented by an analog circuit. The computer may be implemented by a combination of a digital circuit and an analog circuit.

[0207] (ii) The hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, a computer is provided by at least one memory and at least one processor core. The processor core is referred to as a CPU, for example. The memory is also referred to as a storage medium. The memory is a non-transitory, tangible storage medium that non-temporarily stores "at least one of a program and data" that can be read by the processor.

[0208] (iii) The hardware processor may be a combination of (i) above and (ii) above, where (i) and (ii) are located on different chips or on a common chip.

[0209] That is, at least one of the means and functions provided by the flight control device 40 can be provided by hardware alone, software alone, or a combination thereof.

[0210] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0211] (Technical Idea 1) A lock control device applied to an electric aircraft (10) that flies with a propeller (20) rotated by an electric motor (61) and has a crew compartment or a luggage compartment on its airframe, the lock control device comprising: a plurality of control devices (80, 80A, 80B) provided for one of the motors, each of which can control the motor by any of the plurality of control devices; each of the plurality of control devices having a lock control section (S10, S16, S16e, S10a, S10b) that controls a lock device (100) that locks the propeller in a non-rotatable state; and any one of the plurality of control devices that executes lock control by the lock control section in response to an external lock request.

[0212] (Technical Idea 2) The lock control device according to Technical Idea 1, wherein if a first control device among the plurality of control devices executes the lock control and the locking is not completed normally, a second control device among the plurality of control devices executes the lock control.

[0213] (Technical Idea 3) A lock control device according to Technical Idea 1 or 2, wherein a first control device among the plurality of control devices executes the lock control, and a second control device among the plurality of control devices determines whether locking by the lock control has been completed normally.

[0214] (Technical Idea 4) A lock control device according to any one of Technical Ideas 1 to 3, wherein each of the plurality of control devices has a lock maintenance control section (S14, S20) that maintains the propeller in a locked state, and when locking is successfully completed as a result of executing the lock control, the lock maintenance control is executed by the lock maintenance control section.

[0215] (Technical Concept 5) The lock control device according to Technical Concept 4, wherein any one of the plurality of control devices executes the lock maintenance control by the lock maintenance control unit.

[0216] (Technical Idea 6) A lock control device according to Technical Idea 5, in which, when a first control device among the plurality of control devices executes the lock maintenance control and fails to maintain the lock, resulting in the lock being released, a second control device among the plurality of control devices executes the lock control.

[0217] (Technical Concept 7) The lock control device according to any one of Technical Concepts 4 to 6, further comprising an anti-freezing control unit (S104, S105, S109, S112, S113, S122) for preventing freezing during execution of the lock maintenance control.

[0218] (Technical Concept 8) The lock control device according to Technical Concept 7, wherein the anti-freeze control unit temporarily releases the lock maintenance control to operate the propeller.

[0219] (Technical Concept 9) The lock control device according to Technical Concept 7, wherein the antifreeze control unit activates a heater (101h) that heats a target portion to be antifreeze.

[0220] (Technical Idea 10) The lock control device according to Technical Idea 7, wherein the anti-freezing control unit energizes the motor in a manner that does not affect the flight state of the electric aircraft.

[0221] (Technical Idea 11) A lock control device according to Technical Idea 7, wherein a plurality of the locking devices are provided for one propeller, a first locking device among the plurality of locking devices is a device that mechanically locks the propeller by a locking member (101) inhibiting rotation of the propeller, and a second locking device among the plurality of locking devices is a device that locks the propeller by an electrical braking force of the motor, and the anti-freeze control unit switches from mechanical locking by the first locking device to electrical locking by the second locking device.

[0222] (Technical Idea 12) A lock control device according to Technical Idea 6, comprising: an ice-breaking control unit (S131) ​​that executes ice-breaking control to break the freezing if the freezing has occurred during execution of the lock maintenance control when unlocking is requested; and a normal unlocking control unit (S130) that executes normal unlocking control that differs from the ice-breaking control if the freezing has not occurred when unlocking is requested.

[0223] (Technical Concept 13) The lock control device according to Technical Concept 12, wherein the icebreak control unit increases the amount of electricity supplied to the lock device or the motor compared to normal.

[0224] (Technical Idea 14) A lock control device according to any one of Technical Ideas 1 to 13, wherein a plurality of the locking devices are provided for one of the propellers, at least one of the lock control units is capable of executing the locking control for the plurality of the locking devices, and when locking is not completed normally as a result of executing the locking control for a first locking device among the plurality of the locking devices, the locking control unit executes the locking control for a second locking device among the plurality of the locking devices.

[0225] (Technical Idea 15) The lock control device according to Technical Idea 14, wherein the first locking device is a device that mechanically locks the propeller by a locking member (101) inhibiting rotation of the propeller, and the second locking device is a device that locks the propeller by an electrical braking force of the motor.

[0226] (Technical Idea 16) The lock control device according to Technical Idea 15, wherein when the lock control for the first lock device is executed by a first control device among the plurality of control devices, the lock control for the second lock device thereafter is also executed by the first control device.

[0227] (Technical Idea 17) The lock control device according to Technical Idea 15, wherein, when a first control device among the plurality of control devices executes the lock control for the first lock device and the locking is not completed normally, a second control device among the plurality of control devices executes the lock control for the second lock device.

Claims

1. A lock control device applied to an electric aircraft (10) having a passenger compartment or a cargo compartment in the airframe and flying by a propeller (20) rotated by an electric motor (61), comprising a plurality of control devices (80, 80A, 80B) provided for one said motor and each capable of controlling the said motor, each of the plurality of said control devices having a lock control unit (S10, S16, S16e, S10a, S10b) for controlling a lock device (100) that locks the propeller in a non-rotatable state, and a lock control device in which any one of the plurality of said control devices executes lock control by the said lock control unit in response to a lock request from the outside.

2. The lock control device according to claim 1, wherein when the first control device among the plurality of said control devices executes the lock control and the lock is not completed normally, the second control device among the plurality of said control devices executes the lock control.

3. The lock control device according to claim 1 or 2, wherein the first control device among the plurality of said control devices executes the lock control, and the second control device among the plurality of said control devices determines whether the lock by the said lock control is completed normally.

4. Each of the plurality of said control devices has a lock maintenance control unit (S14, S20) for maintaining the locked state of the propeller, and when the lock is completed normally as a result of executing the lock control, the lock maintenance control by the said lock maintenance control unit is executed. The lock control device according to claim 1 or 2.

5. The lock control device according to claim 4, wherein any one of the plurality of said control devices executes the lock maintenance control by the said lock maintenance control unit.

6. The lock control device according to claim 5, wherein when the first control device among the plurality of said control devices executes the lock maintenance control and the lock maintenance fails and the lock is released, the second control device among the plurality of said control devices executes the lock control.

7. The lock control device according to claim 4, comprising a freeze prevention control unit (S104, S105, S109, S112, S113, S122) for preventing freezing during the execution of the lock maintenance control.

8. The lock control device according to claim 7, wherein the freeze prevention control unit temporarily releases the lock maintenance control and operates the propeller.

9. The anti-freezing control unit operates a heater (101h) that heats a location to be protected from freezing, the lock control device according to claim 7.

10. The anti-freezing control unit energizes the motor in a state that does not affect the flight state of the electric aircraft, the lock control device according to claim 7.

11. A plurality of the lock devices are provided for one of the propellers. Among the plurality of lock devices, a first lock device is a device that mechanically locks by a lock member (101) inhibiting the rotation of the propeller. Among the plurality of lock devices, a second lock device is a device that locks the propeller by the electric braking force of the motor. The anti-freezing control unit switches from mechanical locking by the first lock device to electric locking by the second lock device, the lock control device according to claim 7.

12. An ice break control unit (S131) that executes ice break control for breaking freezing when freezing has occurred during the execution of the lock maintenance control when a lock release is requested, and a normal lock release control unit (S130) that executes normal lock release control different from the ice break control when freezing has not occurred when a lock release is requested, the lock control device according to claim 6.

13. The ice break control unit increases the amount of power supplied to the lock device or the motor compared to normal times, the lock control device according to claim 12.

14. A plurality of the lock devices are provided for one of the propellers. At least one of the lock control units is capable of executing the lock control for the plurality of lock devices. If the lock control is not completed normally as a result of executing the lock control for a first lock device among the plurality of lock devices, the lock control is executed for a second lock device among the plurality of lock devices, the lock control device according to claim 1 or 2.

15. The first lock device is a device that mechanically locks by a lock member (101) inhibiting the rotation of the propeller. The second lock device is a device that locks the propeller by the electric braking force of the motor, the lock control device according to claim 14.

16. When the lock control for the first locking device is executed by a first control device among the plurality of control devices, the subsequent lock control for the second locking device is also executed by the first control device. The lock control device according to claim 15.

17. As a result of the first control device among the plurality of control devices executing the lock control for the first locking device, if the locking is not completed normally, the second control device among the plurality of control devices executes the lock control for the second locking device. The lock control device according to claim 15.

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