Electric mobile body

Abstract

An electric mobile body (510) includes an output shaft (531) and a plurality of motors (571, 572) that drive the output shaft. The electric mobile body executes a multi-drive control that assigns at least two of the plurality of motors to a drive state, in a case where the multi-drive control is executed and it is determined that one of the plurality of motors is abnormal, executes a single-drive control that assigns only one of the plurality of motors to the drive state and assigns the other motors to a stop state, and in a case where the single-drive control is executed, determines the abnormal drive motor based on a prescribed state quantity related to a drive state of a drive motor that is assigned to the drive state.

Description

[0001] Citation of relevant applications

[0002] This application is based on Japanese Patent Application No. 2020-164037, filed on September 29, 2020, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to an electrically powered mobile body. Background Technology

[0004] Previously, there were electric aircraft (electric mobile bodies) that included multiple electric motors driving a propeller (see Patent Document 1).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 6233671 Summary of the Invention

[0008] However, when multiple motors are in operation, even if an abnormality is detected in one motor, it is not easy to identify the abnormal motor.

[0009] This disclosure is made to solve the above-mentioned technical problems, and its main purpose is to make it easy to identify the abnormal motor in an electric moving body including multiple motors driving the output shaft, even when multiple motors are in a driving state.

[0010] A first approach to solve the aforementioned technical problem is an electric moving body, which includes an output shaft and a plurality of electric motors driving the output shaft, wherein the electric moving body includes:

[0011] The multi-drive control unit performs multi-drive control that assigns at least two of the plurality of motors to a drive state.

[0012] A single-drive control unit, which, when the multi-drive control unit performs the multi-drive control and determines that one of the multiple motors is malfunctioning, performs single-drive control that assigns only one of the multiple motors to a drive state while assigning the others to a stop state; and

[0013] The anomaly determination unit determines the abnormal drive motor based on a predetermined state quantity related to the drive state of the motor assigned to the drive state when the single drive control unit performs the single drive control.

[0014] According to the above structure, the electric moving body includes an output shaft and multiple electric motors that drive the output shaft. Therefore, even if any one of the multiple electric motors driving the output shaft malfunctions, the output shaft can still be driven by the other electric motors.

[0015] The multi-drive control unit performs multi-drive control, assigning at least two of the aforementioned multiple motors to a drive state. Therefore, by performing multi-drive control, the output performance of the electric moving body can be improved compared to assigning only one motor to a drive state.

[0016] In this case, for example, when multiple motors are directly connected to the output shaft, the rotational speeds of the multiple motors (defined state quantities related to the drive states of the drive motors) are the same. In this situation, even if multi-drive control is performed and one of the multiple motors is determined to be abnormal, the abnormal motor cannot be determined based on the defined state quantities of the multiple motors.

[0017] To address this, when the multi-drive control unit performs the aforementioned multi-drive control and determines that one of the multiple motors is malfunctioning, the single-drive control unit performs single-drive control, assigning only one of the multiple motors to a drive state and the others to a stop state. Furthermore, when the single-drive control unit performs the aforementioned single-drive control, the malfunction determination unit determines the malfunctioning motor based on a predetermined state quantity related to the drive state of the motor assigned to the drive state (i.e., the drive motor). Therefore, it is possible to change from a state where the drive states of multiple motors affect the predetermined state quantity to a state where the drive state of only one motor affects the predetermined state quantity. Therefore, in an electric moving body including multiple motors with a drive output shaft, even if multiple motors are in a drive state, the malfunctioning motor can be easily determined.

[0018] In single-drive control, if the motor assigned to the drive state is normal and there is an abnormal motor among the motors assigned to the stop state, the abnormality determination unit cannot identify the abnormal motor.

[0019] To address this, in the second approach, if the anomaly determination unit cannot identify a faulty drive motor, it assigns only one of the multiple motors that was different from the one assigned to a drive state in the previous single-drive control, and assigns the other motors to a stopped state, thereby re-executing the single-drive control. Therefore, even if the motor assigned to a drive state in the previous single-drive control is normal, only the one different from the one assigned to a drive state in the previous single-drive control is assigned to a drive state, thereby re-executing the single-drive control and re-determining the faulty motor by the anomaly determination unit. Therefore, it is easier to identify the faulty motor.

[0020] In the third approach, if the fault determination unit identifies a faulty drive motor and the plurality of motors includes a normal motor, the faulty drive motor is switched to the stop state, and at least one of the normal motors is switched to the drive state. With this structure, in addition to switching the faulty drive motor to the stop state, the drive of the output shaft can continue using the normal motors.

[0021] In the fourth approach, a clutch is included, which switches between a state in which torque is transmitted from each motor to the output shaft and a state in which torque is not transmitted. When the single drive control is performed by the single drive control unit, the abnormality determination unit switches the clutch to a state in which torque is not transmitted from the motor assigned to the stop state (i.e., the stop motor) to the output shaft and changes the stop motor to a drive state, and determines the abnormality of the stop motor based on a predetermined state quantity related to the drive state of the stop motor.

[0022] According to the above structure, the electric moving body includes a clutch that switches between a state in which torque is transmitted from each motor to the output shaft and a state in which no torque is transmitted. Therefore, by switching the clutch to a state in which no torque is transmitted from the motors that are in a stopped state to the output shaft, it is possible to suppress the transmission of braking torque, etc., from the stopped motors to the output shaft.

[0023] Furthermore, when the single-drive control is executed by the single-drive control unit, the aforementioned anomaly determination unit switches the clutch to a state where it does not transmit torque from the motor (i.e., the stop motor) assigned to the stop state to the output shaft, and changes the stop motor to a drive state. It then determines an anomaly of the stop motor based on a predetermined state quantity related to the drive state of the stop motor. Therefore, by utilizing the clutch to switch the clutch to a state where it does not transmit torque from the stop motor to the output shaft, anomalies of the stop motor can be determined at any time without changing the output of the output shaft. Thus, not only drive motors but also stop motors can be quickly determined.

[0024] In the fifth method, the clutch is a one-way clutch that allows torque to be transmitted from each motor to the output shaft and prohibits torque from being transmitted from the output shaft to each motor. When the single drive control is executed by the single drive control unit, the abnormality determination unit changes the stop motor to a drive state with a rotation direction opposite to that of the drive motor assigned to the drive state, and determines the abnormality of the stop motor based on the specified state quantity of the stop motor.

[0025] According to the above structure, the clutch is a one-way clutch that allows torque to be transmitted from each motor to the output shaft but prohibits torque transmission from the output shaft to each motor. Therefore, when each motor is in a driving state, the one-way clutch switches to a state that transmits torque from each motor to the output shaft. Furthermore, when each motor is in a stopped state or in a driving state in the opposite direction of rotation, the one-way clutch switches to a state that does not transmit torque from the output shaft to the motors, i.e., does not transmit negative torque from each motor to the output shaft. Therefore, even without clutch control, it is possible to switch to a state where torque is not transmitted from a motor in a stopped state to the output shaft using the one-way clutch, thus suppressing the transmission of braking torque from a stopped motor to the output shaft.

[0026] Furthermore, when the single-drive control is executed by the single-drive control unit, the aforementioned anomaly determination unit changes the stop motor to a drive state with a rotation direction opposite to that of the drive motor assigned to the drive state, and determines an anomaly of the stop motor based on the aforementioned predetermined state quantity of the stop motor. Therefore, when the stop motor is changed to a drive state with a rotation direction opposite to that of the drive motor, a state that does not transmit braking torque or the like from the stop motor to the output shaft can be switched using a one-way clutch, allowing for the determination of an anomaly of the stop motor at any time without changing the output of the output shaft.

[0027] In the sixth method, a battery is included to supply power to the plurality of motors, and an electrical disconnection mechanism is included to electrically disconnect each motor from the battery. When the single drive control is performed by the single drive control unit, the electrical disconnection mechanism electrically disconnects the motors that are assigned to the stopped state, i.e., the stopped motors, from the battery.

[0028] According to the above structure, the electric moving body includes a battery that supplies power to the plurality of motors and an electrical disconnection mechanism that electrically disconnects each motor from the battery. Therefore, by using the electrical disconnection mechanism to electrically disconnect the motors (stopped motors) in a stopped state from the battery, the transmission of braking torque from the stopped motors to the output shaft can be suppressed. Therefore, even if the electric moving body does not include a clutch that switches between a state where torque is transmitted from each motor to the output shaft and a state where no torque is transmitted, the transmission of braking torque from the stopped motors to the output shaft can still be suppressed. Furthermore, if the electric moving body includes a clutch, the transmission of braking torque from the stopped motors to the output shaft can be suppressed doubly by both the clutch and the electrical disconnection mechanism.

[0029] Furthermore, when the single-drive control is performed by the aforementioned single-drive control unit, the aforementioned electrical disconnection mechanism electrically disconnects the motor, which is in the stopped state (i.e., the stop motor), from the battery. Therefore, when single-drive control is performed, disconnecting the stop motor from the battery via the electrical disconnection mechanism can suppress the transmission of braking torque from the stop motor to the output shaft.

[0030] In the seventh method, when the single drive control is performed by the single drive control unit, the motor assigned to the stop state among the multiple motors driving the output shaft is driven by a constant torque smaller than the output torque of the motor assigned to the drive state (i.e., the drive motor).

[0031] Based on the above structure, in the case of single-drive control, by driving the stop motor with a constant torque smaller than the output torque of the drive motor, the transmission of braking torque from the stop motor to the output shaft can be suppressed. Therefore, even if the electric moving body does not include a clutch that switches between a state where torque is transmitted from each motor to the aforementioned output shaft and a state where no torque is transmitted, the transmission of braking torque from the stop motor to the output shaft can still be suppressed.

[0032] If the temperature of the magnet in the motor is lower than the specified temperature (e.g., -20°C), the output of the motor may be lower than the reference output.

[0033] To address this, in the eighth method, among the multiple motors driving the output shaft, if the motor assigned to the stop state (i.e., the stop motor) is not determined to be abnormal and the temperature of the magnet of the stop motor is below a predetermined temperature, the stop motor is driven with a constant torque smaller than the output torque of the motor assigned to the drive state (i.e., the drive motor). Therefore, compared to keeping the stop motor in the stop state, the temperature of the magnet of the stop motor can be increased, and the output of the stop motor can be prevented from becoming lower than the reference output when driving the stop motor.

[0034] In the ninth method,

[0035] Including multiple of the above-mentioned output axes,

[0036] The aforementioned multiple motors drive each output shaft.

[0037] Includes multiple batteries,

[0038] The aforementioned multiple motors and multiple batteries are connected in such a way that power is supplied from each battery to each motor group, which is composed of motors that drive different output shafts.

[0039] In the aforementioned single-drive control, the single-drive control unit assigns the plurality of motors driving each output shaft to a drive state and a stop state, so that the number of motors driving each output shaft is equal to the number of motors, and the number of motors powered by each battery is also equal to the number of motors.

[0040] The aforementioned electrically powered mobile body includes:

[0041] The switching unit performs switching control. When the abnormal motor, as determined by the abnormality determination unit, is in the driving state, the switching control switches the abnormal motor to the stopped state, and switches one of the motors that drive the output shaft of the abnormal motor, which is in the stopped state, to the driving state.

[0042] The redistribution control unit performs redistribution control. When the switching unit performs the switching control, the redistribution control assigns the motors constituting the motor group including the abnormal motor and the motors constituting the motor group including the switching motor to the driving state and the stopping state, so that the number of motors driving each output shaft is equal to each other, and the number of motors powered by each battery is equal to each other.

[0043] According to the above structure, the electric moving body includes multiple output shafts, multiple motors driving each output shaft, and multiple batteries. Therefore, even if any one of the multiple motors driving each output shaft malfunctions, the output shaft can still be driven by the other motors that drive the output shaft driven by the malfunctioning motor.

[0044] The aforementioned multiple motors and batteries are connected in such a way that power is supplied from each battery to each motor group, which consists of motors that drive different output shafts. Therefore, even if a battery supplying power to one motor group malfunctions, multiple output shafts can be driven by the motors by supplying power from other batteries to other motor groups. Furthermore, in the single-drive control, the aforementioned single-drive control unit assigns the aforementioned multiple motors driving each output shaft to drive and stop states, ensuring that the number of motors driving each output shaft is equal, and that the number of motors powered by each battery is equal. Therefore, it is possible to suppress deviations in the power supply to each battery while ensuring that the number of motors driving each output shaft is equal.

[0045] When the abnormal motor, as determined by the abnormality determination unit, is in the driving state, the switching unit switches the abnormal motor to the stopped state. Therefore, when the abnormal motor is in the driving state, switching it to the stopped state can suppress instability in the movement of the electric motor. Furthermore, the switching unit performs switching control, which switches one of the motors driving the output shaft driven by the abnormal motor from the stopped state to the driving state. Therefore, even when the abnormal motor is switched from the driving state to the stopped state, a decrease in the number of motors driving the output shaft driven by the abnormal motor can be prevented.

[0046] Here, if the faulty motor is switched to a stopped state and the switching motor is switched to a driven state, the number of motors powered by the batteries supplying the motor group containing the faulty motor and the number of motors powered by the batteries supplying the motor group containing the switching motor changes. Therefore, the number of motors powered by each battery will differ, and the power supply to each battery may deviate. To address this, the redistribution control unit performs redistribution control. When the switching unit performs the switching control, this redistribution control allocates the motors constituting the motor group containing the faulty motor and the motors constituting the motor group containing the switching motor to the driven state and the stopped state, respectively, so that the number of motors driving each output shaft is equal, and the number of motors powered by each battery is equal. Therefore, even in the event of a motor malfunction, deviations in the power supply to each battery can be suppressed.

[0047] In the tenth embodiment, multiple cooling devices are included. The multiple motors and the multiple cooling devices are connected to the multiple motors and the multiple batteries in such a way that refrigerant is supplied from each cooling device to each motor group consisting of motors that drive different output shafts. In the single drive control, the single drive control unit assigns the multiple motors that drive each output shaft to a drive state and a stop state, so that the number of motors driving each output shaft is equal to each other, and the number of motors in the drive state cooled by each cooling device is equal to each other. In the redistribution control, when the switching control is performed by the switching unit, the redistribution control unit assigns the motors constituting the motor group including the abnormal motor and the motors constituting the motor group including the switching motor to the drive state and the stop state, so that the number of motors driving each output shaft is equal to each other, and the number of motors in the drive state cooled by each cooling device is equal to each other.

[0048] According to the above structure, the electric moving body includes multiple output shafts, multiple motors driving each output shaft, and multiple cooling devices. Therefore, even if any one of the multiple motors driving each output shaft malfunctions, the output shaft can still be driven by the other motors that drive the output shaft driven by the malfunctioning motor.

[0049] The aforementioned multiple motors and multiple cooling devices are connected to the aforementioned multiple motors and multiple batteries in such a manner that refrigerant is supplied from each cooling device to each motor assembly consisting of motors that drive different output shafts. Therefore, even if a cooling device supplying refrigerant to one motor assembly malfunctions, by driving the motors that supply refrigerant to other motor assemblies from other cooling devices, multiple output shafts can be driven by the motors while the motor assemblies are being cooled. Furthermore, in the single-drive control, the aforementioned single-drive control unit assigns the aforementioned multiple motors driving each output shaft to drive and stop states, ensuring that the number of motors driving each output shaft is equal, and that the number of motors in the drive state cooled by each cooling device is equal. Therefore, it is possible to suppress deviations in the cooling load of each cooling device while ensuring that the number of motors driving each output shaft is equal.

[0050] As described above, when the abnormal motor, as determined by the abnormality determination unit, is in the driving state, the switching unit switches the abnormal motor to the stopped state. Furthermore, the switching unit performs switching control, which switches one of the motors driving the output shaft of the abnormal motor that is in the stopped state to the driving state.

[0051] Here, if the faulty motor is switched to a stopped state and the switching motor is switched to a driven state, the number of driven motors cooled by the cooling devices supplying refrigerant to the motor group containing the faulty motor and the cooling devices supplying refrigerant to the motor group containing the switching motor changes. Therefore, the number of driven motors cooled by each cooling device differs, and the cooling load of each cooling device may deviate. To address this, the redistribution control unit, in the redistribution control, when the switching unit performs the switching control, allocates the motors constituting the motor group containing the faulty motor and the motors constituting the motor group containing the switching motor to the driven state and the stopped state, so that the number of motors driving each output shaft is equal, and the number of driven motors cooled by each cooling device is equal. Therefore, even in the event of a motor malfunction, deviations in the cooling load of each cooling device can be suppressed. Attached Figure Description

[0052] The above-mentioned objects, other objects, features, and advantages of this disclosure will become clearer with reference to the accompanying drawings and the following detailed description. The accompanying drawings are described below.

[0053] Figure 1This is a schematic diagram of the electric aircraft according to the first embodiment.

[0054] Figure 2 This is a block diagram of the electric aircraft according to the first embodiment.

[0055] Figure 3 This is a circuit diagram showing the mechanism that electrically disconnects the motor from the battery.

[0056] Figure 4 This is a flowchart illustrating the processing steps for anomaly detection during the first control phase.

[0057] Figure 5 This is a timing diagram illustrating the method of anomaly determination during the first control phase.

[0058] Figure 6 This is a flowchart illustrating the processing steps for anomaly detection during third-level control.

[0059] Figure 7 This is a timing diagram illustrating the method of anomaly determination during third control.

[0060] Figure 8 This is a schematic diagram of the electric aircraft according to the second embodiment.

[0061] Figure 9 This is a schematic diagram of the electric aircraft according to the third embodiment.

[0062] Figure 10 This is a schematic diagram illustrating a variation of the electric aircraft according to the third embodiment.

[0063] Figure 11 This is a schematic diagram illustrating another variation of the electric aircraft according to the third embodiment.

[0064] Figure 12 This is a schematic diagram illustrating a variation of an electric aircraft.

[0065] Figure 13 This is a schematic diagram illustrating another variation of an electric aircraft.

[0066] Figure 14 This is a schematic diagram illustrating another variation of an electric aircraft.

[0067] Figure 15 This is a schematic diagram illustrating another variation of an electric aircraft.

[0068] Figure 16 This is a schematic diagram illustrating another variation of an electric aircraft. Detailed Implementation

[0069] (First Implementation)

[0070] Hereinafter, with reference to the accompanying drawings, a first embodiment implemented in an electric aircraft including multiple electric motors and multiple batteries will be described.

[0071] like Figure 1 As shown, the electric aircraft 10 includes batteries 21 and 22, propulsion units 51 and 52, output shafts 31 and 32, propellers 41 and 42, etc. Furthermore, the electric aircraft 10 includes multiple groups composed of these structures; the group shown in the figure will be described here.

[0072] Batteries 21 and 22 are rechargeable secondary batteries with the same rated voltage and rated capacity.

[0073] The propulsion units 51 and 52 receive power from batteries 21 and 22 and output propulsion force.

[0074] The propulsion unit 51 includes inverter (INV) units 61 and 62, and motors 71 and 72. INV units 61 and 62 convert DC power supplied from batteries 21 and 22 into AC power and supply it to motors 71 and 72, respectively. INV unit 61 is connected to battery 21 but not to battery 22. INV unit 62 is connected to battery 22 but not to battery 21. That is, each INV unit 61 and 62 of the propulsion unit 51 is connected to a different battery 21 or 22. Furthermore, the INV units and the motors powered by the INV units are collectively referred to as a "system." For example, the system may consist of INV unit 61 and motor 71.

[0075] Motors 71 and 72 are, for example, three-phase AC motors, which rotate their shafts by AC power supplied from INV units 61 and 62, respectively. The rotating shafts of motors 71 and 72 are directly connected to output shaft 31. Therefore, the rotational speeds of motors 71 and 72 are equal to the rotational speeds of output shaft 31. Output shaft 31 is directly connected to propeller 41. Alternatively, the rotating shafts of motors 71 and 72 can also be connected to output shaft 31 via a reducer.

[0076] The propulsion unit 52 has the same structure as the propulsion unit 51. That is, the propulsion unit 52 includes INV units 63 and 64, and motors 73 and 74, corresponding to the INV units 61 and 62 and motors 71 and 72 of the propulsion unit 51, respectively. INV units 63 and 64 convert the DC power supplied from batteries 21 and 22 into AC power and supply it to motors 71 and 72, respectively. INV unit 63 is connected to battery 21 but not to battery 22. INV unit 64 is connected to battery 22 but not to battery 21. In other words, each INV unit 63 and 64 of the propulsion unit 52 is connected to a different battery 21 or 22.

[0077] The rotating shafts of motors 73 and 74 are directly connected to the output shaft 32. Therefore, the rotational speeds of motors 73 and 74 are equal to the rotational speed of the output shaft 32. The output shaft 32 is directly connected to the propeller 42.

[0078] Motors 71 and 73 constitute a first motor group that drives different output shafts 31 and 32 respectively. Motors 72 and 74 constitute a second motor group that drives different output shafts 31 and 32 respectively. That is, motors 71 to 74 (multiple motors) and batteries 21 and 22 (multiple batteries) are connected in such a way that power is supplied from batteries 21 and 22 (each battery) to the first motor group and the second motor group (each motor group) composed of motors that drive different output shafts 31 and 32 respectively.

[0079] Figure 2 This is a block diagram of electric aircraft 10.

[0080] The INV unit 61 includes an INV control unit 61a, an INV circuit 61b, a speed monitoring unit 61c, etc. The INV circuit 61b is a known three-phase full-bridge circuit (see reference). Figure 3 The INV control unit 61a controls each switching element of the INV circuit 61b based on instructions from the main control ECU 80. The INV unit 62 includes the INV control unit 62a, the INV circuit 62b, the speed monitoring unit 62c, etc. The INV unit 64 includes the INV control unit 64a, the INV circuit 64b, the speed monitoring unit 64c, etc.

[0081] The electric motor 71 includes a magnet 71a that generates a magnetic field and a rotation sensor 71b that detects the rotational speed of its own rotating shaft. When the temperature of the magnet 71a is, for example, below -20°C (a specified temperature), the magnetic field generated by the magnet 71a becomes weaker than a reference magnetic field. As a result, the output of the electric motor 71 is lower than the reference output. The rotation sensor 71b detects the rotational speed of the rotating shaft of the electric motor 71 (hereinafter referred to as "the rotational speed of the electric motor 71") and outputs the detected rotational speed to the speed monitoring unit 61c.

[0082] The speed monitoring unit 61c monitors whether the rotational speed of the motor 71, input from the rotation sensor 71b, deviates from a predetermined threshold range. The predetermined threshold range includes the speed command indicating the rotational speed of the motor 71, from its upper limit to its lower limit. If the rotational speed of the motor 71 deviates from the predetermined threshold range for a predetermined time Te and continues to do so, the speed monitoring unit 61c detects an abnormality in the rotational speed of the motor 71 (speed abnormality) and sends the detected speed abnormality to the main control ECU 80. Furthermore, an abnormal rotational speed of the motor 71 (speed abnormality) includes both a malfunction of the motor 71 and a malfunction of the INV unit 61. Conversely, if the rotational speed of the motor 71 remains within the predetermined threshold range for a predetermined time Te and continues to do so, the speed monitoring unit 61c detects a normal rotational speed (speed normal) and sends the detected speed normality to the main control ECU 80.

[0083] INV unit 62 has the same structure as INV unit 61. Motor 72 has the same structure as motor 71. Furthermore, propulsion unit 52 has the same structure as propulsion unit 51.

[0084] The main control ECU 80 includes a first control unit 81, a second control unit 82, a third control unit 83, an abnormality determination unit 84, a switching unit 85, and a single drive control unit 86, etc.

[0085] The first control unit 81 executes a first control that allocates the motors 71-74 (multiple motors) driving each output shaft 31, 32 to active and standby states, ensuring that the number of motors driving each output shaft 31, 32 is equal, and the number of motors powered by each battery 21, 22 is also equal. As the first control, for example, a first mode and a second mode are periodically switched. The first mode is a mode in which motors 71, 74 are set to active (driving state), and motors 72, 73 are set to standby (stop state). The second mode is a mode in which motors 72, 73 are set to active, and motors 71, 74 are set to standby. This reduces the differences in the consumption levels of INV units 61-64 and motors 71-74.

[0086] In the first mode, the first control unit 81 sends drive permission commands and speed commands to the INV control units 61a and 64a corresponding to the activated motors 71 and 74. The INV control units 61a and 64a control the switching elements of the INV circuits 61b and 64b to set the rotational speed of the motors 71 and 74 to the speed command. The first control unit 81 sends stop commands (speed command = 0) to the INV control units 62a and 63a corresponding to the standby motors 72 and 73. The INV control units 61a and 64a control the switching elements of the INV circuits 62b and 63b to set the motors 72 and 73 to a stopped state (rotational speed = 0). The second mode is the same.

[0087] like Figure 3 As shown, when the main control ECU 80 executes the first control, it electrically disconnects the standby motor (stop motor) and the battery corresponding to the standby motor via the first switch unit 91 (electrical disconnection mechanism). The first switch unit 91 includes switches 91a and 91b, a fuse 91c, etc. Switches 91a and 91b disconnect and connect the battery 21 and the INV circuit 61b. The standby motor and the INV unit that supplies power to the standby motor are collectively referred to as the "standby system".

[0088] Furthermore, when the main control ECU 80 executes the first control, it can also electrically disconnect the standby motor and the battery corresponding to the standby motor via the second switch unit 92 (electrical disconnection mechanism). The second switch unit 92 includes switches 92a to 92c, etc. Switches 92a to 92c disconnect and connect the INV circuit 61b and the motor 71. Additionally, when the main control ECU 80 executes the first control, it can also short-circuit the three-phase wiring of the motor 71 via the third switch unit 93. That is, the standby motor and the battery corresponding to the standby motor can also be substantially electrically disconnected via the third switch unit 93 (electrical disconnection mechanism). The third switch unit 93 is composed of the lower arm switch of the INV circuit 61b.

[0089] When the first control unit 81 performs the first control, the anomaly determination unit 84 determines whether the activated motor is abnormal based on the rotational speed (a specified state quantity related to the driving state) of the activated motor (drive motor), which is assigned to be activated. Specifically, the anomaly determination unit 84 determines whether the activated motor is abnormal based on the detection result of speed anomaly from the speed monitoring unit 61c. For example, if the speed monitoring unit 61c receives a speed anomaly from the motor 71, it determines that the motor 71 is abnormal. Furthermore, since the anomaly of the motor 71 is determined based on the detection result of speed anomaly from the speed monitoring unit 61c, the cases in which the activated motor is determined to be abnormal include the cases in which the motor 71 is abnormal and the cases in which the INV unit 61 is abnormal. The activated motor and the INV unit that supplies power to the activated motor are collectively referred to as the "activation system".

[0090] The switching unit 85 performs switching control. When a motor deemed abnormal by the abnormality determination unit 84 is active, the switching control switches the abnormal motor to standby and activates one of the standby motors among the motors driving the output shaft of the abnormal motor. The switching unit 85 sends a drive permission command and a speed command to the INV control unit corresponding to the switching motor, and sends a stop command to the INV control unit corresponding to the abnormal motor.

[0091] When the switching control is performed by the switching unit 85, the second control unit 82 performs a second control. This second control allocates the motors constituting the motor group including the faulty motor and the motor group constituting the motor group including the switching motor as active and standby, so that the number of motors driving each output shaft is equal to each other, and the number of motors powered by each battery is equal to each other. Furthermore, the third control unit 83 and the single-drive control unit 86 will be described later.

[0092] Figure 4 This is a flowchart illustrating the processing steps for anomaly detection during the first control phase. This series of processes is executed by the main control ECU 80.

[0093] First, a determination is made as to whether a detection of an abnormal motor rotation speed (speed abnormality) has been received from the speed monitoring unit of a certain INV unit (S10). In this determination, if it is determined that no speed abnormality has been detected from the speed monitoring unit of a certain INV unit (S10: No), the processing of S10 is executed again.

[0094] On the other hand, if it is determined that a speed abnormality is detected from the speed monitoring unit of a certain INV unit (S10: Yes), it is determined whether the standby system (the standby system included in the same propulsion unit as the abnormal system) that drives the output shaft of the system that detected the speed abnormality is normal (S11). For example, when the standby system is finally switched to the active system, if the speed monitoring unit of the standby system does not detect a speed abnormality, the standby system is determined to be normal; if a speed abnormality is detected, the standby system is determined to be abnormal. Alternatively, other methods can be used to determine whether the standby system is normal.

[0095] In the determination in S11, if the standby system driving the output shaft driven by the abnormal system is determined to be normal (S11: Yes), the activation / standby mode is switched (S12). For example, if the first mode is executed when a speed abnormality is detected from the speed monitoring unit of a certain INV unit, the first mode is stopped and the second mode is executed. That is, if the abnormal system is active, the abnormal system is switched to standby, and the standby system driving the output shaft driven by the abnormal system is switched to active. Then, the motors (systems) constituting the motor group containing the motor of the abnormal system and the motors (systems) constituting the motor group containing the motor of the normal system are assigned to active and standby, so that the number of systems driving each output shaft is equal to each other, and the number of systems powered by each battery is equal to each other. After that, the above series of processes ends (end).

[0096] On the other hand, in the determination in S11, if it is determined that the standby system driving the output shaft driven by the abnormal system is malfunctioning (S11: No), the propulsion unit containing the abnormal system is stopped (S13). Furthermore, even if the propulsion unit containing the abnormal system is stopped, the electric aircraft 10 can maintain its attitude through other propulsion units. Afterwards, the above series of processes ends (End).

[0097] Furthermore, the processing of S10 is equivalent to the processing of the abnormality determination unit 84, and the processing of S12 is equivalent to the processing of the switching unit 85 and the second control unit 82.

[0098] Figure 5 This is a timing diagram illustrating the method of anomaly detection during the first control phase. Here, we will use the case where an anomaly (speed anomaly) is detected in the rotational speed of motor 71 during the execution of the first mode as an example. Furthermore, this diagram only shows the speed command, rotational speed, speed deviation, and speed anomaly of motor 71; however, speed commands, rotational speeds, speed deviations, and speed anomalies are also acquired for motors 72 to 74.

[0099] At time t11, an anomaly occurs in the system consisting of INV unit 61 and motor 71, and the rotational speed of motor 71 begins to increase relative to the speed command for motor 71. Accompanying this, the speed deviation of motor 71—the value calculated by subtracting the speed command from the rotational speed of motor 71—begins to increase.

[0100] At time t12, the speed deviation of motor 71 exceeds the threshold N1, that is, the rotational speed of motor 71 deviates from the specified threshold range.

[0101] At time t13, the duration of the state in which the rotational speed of motor 71 deviates from the specified threshold range exceeds the specified time Te. Therefore, the rotational speed of motor 71 is detected as abnormal (speed abnormality). Then, the system switches from the first mode where motors 71 and 74 are active and motors 72 and 73 are in standby mode to the second mode where motors 72 and 73 are active and motors 71 and 74 are in standby mode.

[0102] At time t14, the duration of the state in which the rotational speed of motor 71 converges to a specified threshold range exceeds a specified time Te. Therefore, the rotational speed of motor 71 is detected as normal (speed normal).

[0103] The implementation method described above has the following advantages.

[0104] The electric aircraft 10 includes output shafts 31 and 32, motors 71 and 72 that drive each output shaft 31 and 32, motors 73 and 74, and batteries 21 and 22. Therefore, even if any of the motors 71 to 74 that drive each output shaft 31 and 32 malfunctions, the output shaft can still be driven by other motors that drive the output shaft driven by the malfunctioning motor.

[0105] Motors 71-74 and batteries 21, 22 are connected to supply power from each battery 21, 22 to a first motor group and a second motor group, each consisting of motors driving different output shafts. Therefore, even if a battery supplying power to one motor group malfunctions, the output shafts 31, 32 can be driven by motors supplying power from other batteries to other motor groups. Furthermore, the first control unit 81 executes a first control that assigns motors 71, 72, 73, 74 driving each output shaft 31, 32 to a driving state (activated) and a stopped state (standby), ensuring that the number of motors driving each output shaft 31, 32 is equal, and the number of motors powered by each battery 21, 22 is also equal. Therefore, it is possible to suppress deviations in the power supply to each battery while ensuring that the number of motors driving each output shaft 31, 32 is equal.

[0106] The anomaly determination unit 84 determines anomalies in motors 71 to 74. When a motor determined by the anomaly determination unit 84 to be abnormal (i.e., an abnormal motor) is in a driving state, the switching unit 85 switches the abnormal motor to a stopped state. Therefore, when an abnormal motor is in a driving state, switching it to a stopped state can suppress instability in the movement of the electric aircraft 10. Furthermore, the switching unit 85 performs switching control, which switches one of the motors driving the output shaft of the abnormal motor from a stopped state to a driving state. Therefore, even when the abnormal motor is switched from a driving state to a stopped state, the reduction in the number of motors driving the output shaft of the abnormal motor can be prevented.

[0107] If the faulty motor is switched to a stopped state and the switching motor is switched to a driven state, the number of motors powered by the batteries supplying the motor group containing the faulty motor and the number of motors powered by the batteries supplying the motor group containing the switching motor will change. Therefore, the number of motors powered by each battery 21 and 22 will differ, and the power supply to each battery may deviate. To address this, the second control unit 82, when the switching unit 85 has performed the switching control, executes a second control that assigns the motors constituting the motor group containing the faulty motor and the motors constituting the motor group containing the switching motor to driven and stopped states, ensuring that the number of motors driving each output shaft 31 and 32 is equal, and that the number of motors powered by each battery 21 and 22 is equal. Therefore, even in the event of a motor malfunction, deviations in the power supply to each battery can be suppressed.

[0108] When the first control unit 81 performs the first control, the anomaly determination unit 84 determines an anomaly of the drive motor based on a predetermined state quantity (rotation speed) related to the drive state of the motor assigned to the drive state, i.e., the drive motor (active motor). With this structure, when the first control is performed to assign the motors 71, 72, 73, and 74 driving each output shaft 31, 32 to drive and stop states, anomalies of the drive motor can be determined, thus increasing the determination frequency.

[0109] The electric aircraft 10 includes an electrical disconnection mechanism (first switch 91, second switch 92, and third switch 93) that electrically disconnects each of the electric motors 71-74 and each of the batteries 21 and 22. Therefore, by using the electrical disconnection mechanism to electrically disconnect the electric motors (stopped motors) in a stopped state from the batteries, the transmission of braking torque from the stopped motors (standby motors) to the output shafts can be suppressed. Therefore, even if the electric aircraft 10 does not include a clutch that switches between a state where torque is transmitted from each of the electric motors 71-74 to each of the output shafts 31 and 32 and a state where torque is not transmitted, the transmission of braking torque from the stopped motors to the output shafts can still be suppressed.

[0110] When the first control is executed by the first control unit 81, the electric motor, which is in a stopped state, and the battery corresponding to the stopped motor are electrically disconnected by the electrical disconnection mechanism. Therefore, when the first control is executed, by using the electrical disconnection mechanism to electrically disconnect the stopped motor from the battery, the transmission of braking torque from the stopped motor to the output shaft can be suppressed.

[0111] Alternatively, the first embodiment can also be modified and implemented as follows. For parts identical to those in the first embodiment, the same symbols are used and descriptions are omitted.

[0112] It can also be omitted Figure 4 The processing of S11 and S13. Even in this case, it is rare for anomalies to occur simultaneously in the activation system and the standby system. Therefore, by switching the standby system to activation and driving the output shafts, it is possible to suppress the instability of the movement of the electric aircraft 10. Furthermore, even if any of the motors 71 to 74 that drive each output shaft 31 and 32 malfunctions, it is possible to suppress the reduction in the number of motors driving the output shafts driven by the malfunctioning motor, and to suppress deviations in the power supply of each battery.

[0113] The third control unit 83 (multi-drive control unit) performs third control (multi-drive control) to assign the multiple motors 71, 72, and multiple motors 73, 74 that drive each output shaft 31, 32 to drive states (activation).

[0114] Here, even if an abnormality is determined in one of the drive motors based on the rotational speed (a specified state quantity) when the third control is executed, the abnormal drive motor cannot be identified if the rotational speeds of multiple drive motors are the same. In the above embodiment, since motors 71, 72 (73, 74) are directly connected to the output shaft 31 (32), the rotational speeds of motors 71, 72 (73, 74) are the same.

[0115] Therefore, the main control ECU 80 executes during the third control phase. Figure 6 The anomaly determination is shown.

[0116] S20 processing and Figure 4 The processing is the same as that of S10.

[0117] If it is determined that a speed abnormality is detected from the speed monitoring unit of a certain INV unit (S20: Yes), the control is switched from the third control to the first control (S21).

[0118] Next, a determination is made as to whether an abnormal system can be identified (S22). Specifically, after switching to first control, if a speed abnormality is detected in one of the propulsion units, the system that is activated in the propulsion unit where the speed abnormality was detected in the first control (i.e., the abnormal propulsion unit) is identified as an abnormal system, and the determination is made that an abnormal system can be identified. If, after switching to first control, no speed abnormality is detected in the abnormal propulsion unit, the determination is made that an abnormal system cannot be identified. In this determination, if the determination is made that an abnormal system cannot be identified (S22: No), the activation / standby mode is switched (S23). The processing of S23 is the same as... Figure 4 The processing is the same as that of S12.

[0119] Next, a determination is made as to whether an abnormal system can be identified (S24). Specifically, if a speed abnormality is detected in the abnormal propulsion unit after switching the activation / standby mode, the system set to activation in the abnormal propulsion unit is identified as an abnormal system, and the determination is made that an abnormal system can be identified. If no speed abnormality is detected in the abnormal propulsion unit after switching the activation / standby mode, the determination is made that an abnormal system cannot be identified. In this determination, if the abnormal system can be identified (S24: Yes), the process proceeds to S25. Additionally, in the determination in S22, if the abnormal system can be identified (S22: Yes), the process also proceeds to S25.

[0120] In S25, a determination is made regarding the existence of a normal system. Specifically, if the determination in S22 indicates that an abnormal system cannot be identified (S22: No), it is determined that a normal system exists in the abnormal propulsion unit. Conversely, if the determination in S22 indicates that an abnormal system can be identified (S22: Yes), the existence of a normal system is determined as follows: When the standby system, which was switched to first control, is finally switched to the active system, if the speed monitoring unit of the standby system does not detect a speed abnormality, the standby system is determined to be normal (a normal system exists); if a speed abnormality is detected, the standby system is determined to be abnormal (no normal system exists). Furthermore, if the determination in S22 indicates that an abnormal system can be identified (S22: Yes), it is also possible to determine that no normal system exists in the abnormal propulsion unit.

[0121] In the determination in S25, if it is determined that there is a normal system in the abnormal propulsion unit (S25: Yes), the abnormal system in the abnormal propulsion unit is stopped and the normal system is driven (S26). That is, if the abnormal system is active, the abnormal system is switched to standby, and the standby system that drives the output shaft driven by the abnormal system is switched to active (switching control). Then, the motors (systems) constituting the motor group containing the motor of the abnormal system and the motors (systems) constituting the motor group containing the motor of the normal system are assigned to active and standby (second control) so that the number of systems driving each output shaft is equal to each other, and the number of systems powered by each battery is equal to each other. After that, the above series of processes ends (end).

[0122] Furthermore, if the abnormal system cannot be determined in S24 (S24: No) and if the abnormal propulsion unit does not have a normal system in S25 (S25: No), the abnormal propulsion unit is stopped (S27). After that, the above series of processes ends (End).

[0123] Furthermore, the processing of S20, S22, and S24 is equivalent to the processing of the abnormality determination unit 84, the processing of S23 and S26 is equivalent to the processing of the switching unit 85, and the processing of S26 is equivalent to the processing of the second control unit 82.

[0124] Figure 7 This is a timing diagram illustrating the method of anomaly detection during the third control phase. Here, we will use the case where an anomaly (speed anomaly) is detected in the rotational speed of motor 71 in propulsion unit 51 as an example. Furthermore, this diagram only shows the speed command, rotational speed, speed deviation, and speed anomaly of motor 71; however, speed commands, rotational speeds, speed deviations, and speed anomalies are also acquired for motors 72 to 74.

[0125] At time t21, an anomaly occurs in the system consisting of INV unit 61 and motor 71, and the rotational speed of motor 71 begins to increase relative to the speed command for motor 71. Accompanying this, the speed deviation of motor 71 begins to increase.

[0126] At time t22, the speed deviation of motor 71 exceeds the threshold N1, that is, the rotational speed of motor 71 deviates from the specified threshold range.

[0127] At time t23, the duration of the state in which the rotational speed of motor 71 deviates from the specified threshold range exceeds a specified time Te. Therefore, the rotational speed of motor 71 is detected as abnormal (speed abnormality). Then, in propulsion unit 51, the control switches from the third control to the first control. Here, in the first control, a first mode is executed where motors 71 and 74 are active and motors 72 and 73 are in standby mode.

[0128] At time t24, the duration of the state in which the rotational speed of motor 71 deviates from the predetermined threshold range exceeds a predetermined time Te. Therefore, the rotational speed of motor 71 is detected as abnormal (speed abnormality), and the system containing motor 71 is determined to be an abnormal system. Here, it is assumed that a normal system exists. Furthermore, in the abnormal propulsion unit, the abnormal system containing motor 71 is set to standby, and the normal system containing motor 72 is set to active. In addition, motor 73 is set to active, and motor 74 is set to standby, so that the number of systems driving each output shaft is equal to each other, and the number of systems powered by each battery is equal to each other.

[0129] At time t25, the duration of the state in which the rotational speed of motor 71 converges to a specified threshold range exceeds a specified time Te. Therefore, the rotational speed of motor 71 is detected as normal (speed normal). However, even if the speed of motor 71 is detected as normal, the system containing motor 71 may actually be malfunctioning.

[0130] According to the above structure, when the third control unit 83 (multi-drive control unit) performs third control (multi-drive control) and determines that one of the drive motors (activated motors) is abnormal based on a predetermined state quantity (rotation speed), the first control unit 81 performs first control. Then, when the first control unit 81 performs first control, the abnormality determination unit 84 determines the abnormal drive motor based on the predetermined state quantity. That is, by using the first control to assign the motors 71 and 72 that drive the output shaft 31 to a drive state (activated) and a stop state (standby), it is possible to determine whether the drive motor is abnormal based on the predetermined state quantity, and thus determine the abnormal drive motor.

[0131] (Second Implementation)

[0132] Hereinafter, with reference to the accompanying drawings, the second embodiment will be described focusing on its differences from the first embodiment. In this embodiment, each propulsion unit includes three systems, each powered by a battery.

[0133] like Figure 8 As shown, the electric aircraft 110 includes batteries 121-123, propulsion units 151-153, output shafts 131-133, propellers 141-143, etc. In addition, the electric aircraft 110 includes multiple groups composed of these structures (for example, propellers 144-146 shown in the figure), and the group shown in the figure will be described here.

[0134] Batteries 121 to 123 are rechargeable secondary batteries with the same rated voltage and rated capacity.

[0135] The propulsion units 151-153 receive power from all batteries 121-123 and output propulsion force.

[0136] The propulsion unit 151 includes inverter (INV) units 161-163 and motors 171-173. INV units 161-163 convert DC power supplied from batteries 121-123 into AC power and supply it to motors 171-173 respectively. INV unit 161 is connected to battery 121 but not to batteries 122 or 123. INV unit 162 is connected to battery 122 but not to batteries 121 or 123. INV unit 163 is connected to battery 123 but not to batteries 121 or 122. That is, each INV unit 161-163 of the propulsion unit 151 is connected to a different battery 121-123.

[0137] Motors 171 to 173 are, for example, three-phase AC motors, which rotate their shafts by AC power supplied from INV units 161 to 163. The shafts of motors 171 to 173 are directly connected to the output shaft 131. Therefore, the rotational speeds of motors 171, 172, and 173 are equal to the rotational speed of the output shaft 131. The output shaft 131 is directly connected to the propeller 141. Alternatively, the shafts of motors 171 to 173 can also be connected to the output shaft 131 via a reducer.

[0138] The propulsion unit 152 has the same structure as the propulsion unit 151. Specifically, the propulsion unit 152 includes INV units 164-166 and motors 174-175, corresponding to the INV units 161-163 and motors 171-173 of the propulsion unit 151, respectively. INV unit 164 is connected to battery 121 but not to batteries 122 and 123. INV unit 165 is connected to battery 122 but not to batteries 121 and 123. INV unit 166 is connected to battery 123 but not to batteries 121 and 122.

[0139] The rotating shafts of motors 174 and 175 are directly connected to the output shaft 132. Therefore, the rotational speeds of motors 174, 175, and 176 are equal to the rotational speed of the output shaft 132. The output shaft 132 is directly connected to the propeller 142. The same applies to the propulsion unit 153.

[0140] Motors 171, 174, and 177 constitute a first motor group that drives different output shafts 131, 132, and 133, respectively. Motors 172, 175, and 178 constitute a second motor group that drives different output shafts 131, 132, and 133, respectively. Motors 173, 176, and 179 constitute a third motor group that drives different output shafts 131, 132, and 133, respectively. That is, motors 171 to 179 (multiple motors) and batteries 121 to 123 (multiple batteries) are connected in such a way that power is supplied from batteries 121 to 123 (each battery) to the first motor group, the second motor group, and the third motor group (each motor group) composed of motors that drive different output shafts 131 to 133, respectively.

[0141] The first control unit 81 executes a first control, which assigns the motors 171-179 (multiple motors) driving each output shaft 131-133 to a drive state and a stop state, so that the number of motors driving each output shaft 131-133 is equal, and the number of motors powered by each battery 121-123 is equal. As the first control, it periodically switches between, for example, a first mode, a second mode, and a third mode. The first mode is a mode in which motors 171, 172, 174, 176, 178, and 179 are set to active (drive state), and motors 173, 175, and 177 are set to standby (stop state). The second mode is a mode in which motors 171, 173, 175, 176, 177, and 178 are set to active, and motors 172, 174, and 179 are set to standby. The third mode activates motors 172, 173, 174, 175, 177, and 179, while setting motors 171, 176, and 178 to standby. This reduces the differences in the consumption levels of INV units 161-169 and motors 171-179. Alternatively, a different mode can be executed based on predicted values ​​of the discharge current and voltage of each battery 121-123.

[0142] In each mode, the processing performed by each INV control unit (not shown) of each INV unit 161 to 169 is the same as in the first embodiment. In addition, when the main control ECU 80 performs the first control, it electrically disconnects the standby motor (stop motor) and the battery corresponding to the standby motor via the electrical disconnection mechanism, just like in the first embodiment.

[0143] Similar to the first embodiment, the anomaly determination unit 84, when the first control unit 81 performs the first control, determines whether the activated motor is abnormal based on the rotational speed (a predetermined state quantity related to the driving state) of the activated motor (drive motor) assigned to be activated. In the first control of this embodiment, since there are two activated motors in each propulsion unit, if either of the two activated motors in each propulsion unit becomes abnormal, it is determined that both activated motors are abnormal (the abnormal motor is not determined at that point in time).

[0144] Therefore, the single drive control unit 86 (refer to) Figure 2If the first control unit 81 (multi-drive control unit) performs the first control (multi-drive control) and determines that one of the multiple motors is abnormal, it performs single-drive control, which assigns only one of the multiple motors to the drive state and assigns the other motors to the stop state. In the case of executing single-drive control, the main control ECU 80, in the same manner as in the first embodiment, electrically disconnects the motor assigned to standby, i.e., the standby motor (stop motor), and the battery corresponding to the standby motor via the electrical disconnection mechanism.

[0145] The switching unit 85 performs switching control. When a motor deemed abnormal by the abnormality determination unit 84 is active, the switching control switches the abnormal motor to standby and activates one of the standby motors among the motors driving the output shaft of the abnormal motor. The switching unit 85 sends a drive permission command and a speed command to the INV control unit corresponding to the switching motor, and sends a stop command to the INV control unit corresponding to the abnormal motor.

[0146] When the switching control is performed by the switching unit 85, the second control unit 82 performs a second control, which assigns the motors constituting the motor group including the abnormal motor and the motors constituting the motor group including the switching motor to active and standby, so that the number of motors driving each output shaft is equal to each other, and the number of motors powered by each battery is equal to each other.

[0147] Then, after the single-drive control unit 86 performs single-drive control, the main control ECU 80, according to... Figure 4 The flowchart serves as the basis for the processing steps to perform exception detection.

[0148] Here, if the standby system driving the output shaft driven by the abnormal system is determined to be normal (S11: Yes), the activation / standby mode is switched (S12). Specifically, the mode is switched to set the abnormal system to standby. For example, if motor 171 is determined to be an abnormal motor, the third mode of setting motor 171 to standby is switched. That is, if the abnormal system is active, the abnormal system is switched to standby, and the standby system driving the output shaft driven by the abnormal system is switched to active. Then, the motors (systems) constituting the motor group containing the motor of the abnormal system and the motors (systems) constituting the motor group containing the motor of the normal system are assigned to active and standby, so that the number of systems driving each output shaft is equal to each other, and the number of systems powered by each battery is equal to each other. After that, the above series of processes ends (end).

[0149] The embodiment described above has the following advantages. Here, only the advantages that differ from the first embodiment are described.

[0150] The electric aircraft 110 includes output shafts 131-133, motors 171-173, 174-176, and 177-179 driving each output shaft 131-133, and batteries 121-123. Therefore, even if any of the motors 171-179 driving each output shaft 131-133 malfunctions, the output shaft can still be driven by other motors that drive the output shaft driven by the malfunctioning motor.

[0151] Motors 171-179 and batteries 121-123 are connected in such a way that power is supplied from each battery 121-123 to a first motor group, a second motor group, and a third motor group, each consisting of motors driving different output shafts. Therefore, even if a battery supplying power to one motor group malfunctions, the output shafts 131-133 can be driven by motors supplied from other batteries to other motor groups. Then, the first control unit 81 executes first control, which assigns motors 171-173, 174-176, and 177-179, which drive each output shaft 131-133, to a driving state (activated) and a stopped state (standby), ensuring that the number of motors driving each output shaft 131-133 is equal, and that the number of motors supplied by each battery 121-123 is equal. Therefore, it is possible to suppress deviations in the power supply of each battery while ensuring that the number of motors driving each output shaft 131-133 is equal.

[0152] The anomaly determination unit 84 determines anomalies in motors 171 to 179. When a motor determined by the anomaly determination unit 84 to be abnormal (i.e., an abnormal motor) is in a driving state, the switching unit 85 switches the abnormal motor to a stopped state. Therefore, when an abnormal motor is in a driving state, switching it to a stopped state can suppress instability in the movement of the electric aircraft 110. Furthermore, the switching unit 85 performs switching control, which switches one of the motors driving the output shaft of the abnormal motor from a stopped state to a driving state. Therefore, even when the abnormal motor is switched from a driving state to a stopped state, a decrease in the number of motors driving the output shaft of the abnormal motor can be prevented.

[0153] When the switching control is performed by the switching unit 85, the second control unit 82 performs a second control. This second control assigns the motors constituting the motor group including the faulty motor and the motor group constituting the switching motor to a drive state and a stop state, so that the number of motors driving each output shaft 131-133 is equal, and the number of motors powered by each battery 121-123 is equal. Therefore, even if a motor malfunctions, deviations in the power supply of each battery can be suppressed.

[0154] Alternatively, the second embodiment can also be modified and implemented as follows. For parts identical to those in the second embodiment, the same symbols are used and descriptions are omitted.

[0155] When the first control unit 81 (multi-drive control unit) performs first control (multi-drive control) and determines that one of the multiple motors is abnormal, the main control ECU 80 can also determine the abnormal system by sequentially changing the combination of assigning two motors to the drive state and assigning one motor to the stop state. For example, among motors 171 to 173, when two motors are set to active and one motor is set to standby, the system is determined to be normal or abnormal as follows: that is, assuming that motors 171 and 172 are determined to be abnormal, motors 172 and 173 are normal, and motors 171 and 173 are determined to be abnormal. In this case, it can be determined that motor 171 (including the system including motor 171) is abnormal.

[0156] In single-drive control, if the motor assigned to the drive state is normal and there is an abnormal motor among the motors assigned to the stop state, the abnormality determination unit 84 cannot clearly determine the abnormal motor.

[0157] Therefore, in single-drive control, if the faulty drive motor cannot be determined by the fault determination unit 84, the single-drive control unit 86 assigns only one of the multiple motors 171-173 that is different from the motor assigned to the drive state in the previous single-drive control to the drive state, and assigns the other motors to the stop state, thereby re-executing single-drive control. With this structure, even if the motor assigned to the drive state in the previous single-drive control is normal, only the one different from the motor assigned to the drive state in the previous single-drive control is assigned to the drive state, thereby re-executing single-drive control and determining the faulty motor by the fault determination unit 84. Therefore, it is easier to determine the faulty motor.

[0158] Furthermore, if the anomaly determination unit 84 determines that an abnormal drive motor is present, and the motor is among a group of normal motors, the electric aircraft 110 can switch the abnormal drive motor to a stop state and switch at least one of the normal motors to a drive state. With this configuration, in addition to switching the abnormal drive motor to a stop state, the drive of the output shaft can continue through the normal motors.

[0159] (Third Implementation)

[0160] Hereinafter, with reference to the accompanying drawings, the third embodiment will be described focusing on the differences from the first embodiment. For parts identical to those in the first embodiment, the same symbols are used and descriptions are omitted. In this embodiment, two cooling devices are included, each corresponding to one of the two motor units.

[0161] like Figure 9 As shown, in the electric aircraft 210, propulsion units 51 and 52 receive refrigerant from both cooling devices 11 and 12. Cooling devices 11 and 12 cool the INV units 61-64, motors 71-74, etc., by circulating refrigerant such as water within the propulsion units 51 and 52 for heat exchange. In this figure, the refrigerant supply path is indicated by dashed lines.

[0162] For INV units 61 and 62, refrigerant is supplied from cooling devices 11 and 12, respectively. For INV unit 61, refrigerant is supplied from cooling device 11, but not from cooling device 12. For INV unit 62, refrigerant is supplied from cooling device 12, but not from cooling device 11. That is, refrigerant is supplied to each INV unit 61 and 62 of the propulsion unit 51 from different cooling devices 11 and 12.

[0163] For INV units 63 and 64, refrigerant is supplied from cooling devices 11 and 12, respectively. For INV unit 63, refrigerant is supplied from cooling device 11, but not from cooling device 12. For INV unit 64, refrigerant is supplied from cooling device 12, but not from cooling device 11. That is, refrigerant is supplied to each INV unit 63 and 64 of the propulsion unit 52 from different cooling devices 11 and 12.

[0164] The motors 71-74 (multiple motors) and cooling devices 11, 12 (multiple cooling devices) are connected to the motors 71-74 and batteries 21, 22 (multiple batteries) in such a way that refrigerant is supplied from the cooling devices 11, 12 (each cooling device) to the first motor group and the second motor group (each motor group) which are composed of motors that drive output shafts 31, 32 (different output shafts) respectively.

[0165] In the first control, the first control unit 81 assigns the motors 71, 72, 73, and 74 (multiple motors) driving each output shaft 31, 32 to active and standby states, so that the number of motors driving each output shaft 31, 32 is equal to each other, and the number of motors in the drive state cooled by each cooling device 11, 12 is equal to each other. As the first control, similar to the first embodiment, the first mode and the second mode are switched periodically. The first mode is a mode in which motors 71 and 74 are set to active (drive state) and motors 72 and 73 are set to standby (stop state). The second mode is a mode in which motors 72 and 73 are set to active and motors 71 and 74 are set to standby.

[0166] In the second control, when the switching control is performed by the switching unit 85, the second control unit 82 assigns the motors constituting the motor group containing the abnormal motor and the motors constituting the motor group containing the switching motor to be active and standby, so that the number of motors driving each output shaft is equal to each other, and the number of motors in the driving state cooled by each cooling device 11, 12 is equal to each other.

[0167] Furthermore, in this embodiment, the main control ECU 80 also performs... Figure 4 The abnormal judgment and the first control shown Figure 6 The abnormality determination during the third control is shown.

[0168] The embodiment described above has the following advantages. Here, only the advantages that differ from the first embodiment are described.

[0169] Motors 71-74 and cooling devices 11 and 12 are connected in such a way that refrigerant is supplied from each cooling device 11 and 12 to a first motor group and a second motor group, each consisting of motors driving different output shafts. Therefore, even if a cooling device supplying refrigerant to one motor group malfunctions, by driving the motors that supply refrigerant from other cooling devices to other motor groups, the output shafts 31 and 32 can be driven by the motors while the motor groups are being cooled. Then, the first control unit 81 executes a first control that assigns the motors 71, 72, 73, and 74 driving each output shaft to a drive state and a stop state (standby), ensuring that the number of motors driving each output shaft 31 and 32 is equal, and that the number of motors in the drive state (activated) cooled by each cooling device 11 and 12 is equal. Therefore, while ensuring that the number of motors driving each output shaft 31 and 32 is equal, deviations in the cooling load of each cooling device can be suppressed.

[0170] If the faulty motor is switched to a stopped state and the switching motor is switched to a driven state, the number of driven motors cooled by the cooling devices supplying refrigerant to the motor group containing the faulty motor and the cooling devices supplying refrigerant to the motor group containing the switching motor changes. Therefore, the number of driven motors cooled by each cooling device 11, 12 differs, and the cooling load of each cooling device may deviate. To address this, the second control unit 82, when switching control is performed by the switching unit 85, performs a second control that assigns the motors constituting the motor group containing the faulty motor and the motor group constituting the motor group containing the switching motor to driven and stopped states, ensuring that the number of motors driving each output shaft 31, 32 is equal, and the number of driven motors cooled by each cooling device 11, 12 is equal. Therefore, even in the event of a motor malfunction, deviations in the cooling load of each cooling device can be suppressed.

[0171] Alternatively, the third embodiment can also be modified and implemented as follows. For parts identical to those in the third embodiment, the same symbols are used and descriptions are omitted.

[0172] like Figure 10 As shown, in the electric aircraft 310, the connections of multiple batteries and multiple systems can be changed, and the connections of multiple cooling devices and multiple systems can be changed accordingly. In this figure, INV unit 61 is connected to battery 321 but not to battery 322. INV unit 62 is connected to battery 322 but not to battery 321. That is, each INV unit 61 and 62 of the propulsion unit 51 is connected to a different battery 321 and 322. Correspondingly, INV unit 61 is connected to cooling device 311 but not to cooling device 312. INV unit 62 is connected to cooling device 312 but not to cooling device 311. That is, each INV unit 61 and 62 of the propulsion unit 51 is connected to a different cooling device 311 and 312.

[0173] INV unit 63 is connected to battery 322 but not to battery 321. INV unit 64 is connected to battery 321 but not to battery 322. That is, each INV unit 63 and 64 of the propulsion unit 52 is connected to a different battery 322 or 321. Correspondingly, INV unit 63 is connected to cooling device 312 but not to cooling device 311. INV unit 64 is connected to cooling device 311 but not to cooling device 312. That is, each INV unit 63 and 64 of the propulsion unit 52 is connected to a different cooling device 312 or 311. Based on the above structure, the same effects as in the third embodiment can be achieved.

[0174] like Figure 11 As shown, the connections of multiple cooling devices and multiple systems can also be changed (independently) without being related to the connections of multiple batteries and multiple systems. In this figure, INV units 61-64 are connected to battery 421. That is, each INV unit 61-64 is connected to the same battery 421.

[0175] INV unit 61 is connected to cooling device 11 but not to cooling device 12. INV unit 62 is connected to cooling device 12 but not to cooling device 11. That is, each INV unit 61 and 62 of propulsion unit 51 is connected to a different cooling device 311 and 312.

[0176] INV unit 63 is connected to cooling device 11 but not to cooling device 12. INV unit 64 is connected to cooling device 12 but not to cooling device 11. That is, each INV unit 63 and 64 of propulsion unit 52 is connected to a different cooling device 311 or 312.

[0177] The first control unit 81 executes a first control, which assigns the motors 71, 72, 73, and 74 (multiple motors) driving each output shaft 31, 32 to active and standby states, so that the number of motors driving each output shaft 31, 32 is equal to each other, and the number of motors in the drive state cooled by each cooling device 11, 12 is equal to each other. As with the first embodiment, the first mode and the second mode are periodically switched as the first control. The first mode is a mode in which motors 71 and 74 are set to active (drive state) and motors 72 and 73 are set to standby (stop state). The second mode is a mode in which motors 72 and 73 are set to active and motors 71 and 74 are set to standby.

[0178] When the switching control is performed by the switching unit 85, the second control unit 82 performs a second control, which assigns the motors constituting the motor group including the abnormal motor and the motors constituting the motor group including the switching motor to active and standby, so that the number of motors driving each output shaft is equal to each other, and the number of motors in the driving state cooled by each cooling device 11, 12 is equal to each other.

[0179] Furthermore, instead of "making the number of motors powered by each battery 21, 22 equal to each other", the main control ECU 80 executes "making the number of motors in drive state cooled by each cooling device 11, 12 equal to each other". Figure 4 The abnormal judgment and the first control shown Figure 6The abnormality determination during the third control is shown. Based on the above structure, even in the event of an abnormality in the motor, deviations in the cooling load of each cooling unit can be suppressed.

[0180] (Fourth Implementation)

[0181] Hereinafter, with reference to the accompanying drawings, the fourth embodiment will be described focusing on the differences from the first embodiment. In this embodiment, a battery is provided for each propulsion unit.

[0182] like Figure 12 As shown, the electric aircraft 510 includes batteries 521 and 522, a propulsion unit 551, an output shaft 531, a propeller 541, etc. Furthermore, the electric aircraft 510 includes multiple groups composed of these structures; the group shown in the figure will be described here.

[0183] Batteries 521 and 522 are rechargeable secondary batteries with the same rated voltage and rated capacity.

[0184] The propulsion unit 551 receives power from batteries 521 and 522 and outputs propulsion force.

[0185] The propulsion unit 551 has the same structure as the propulsion unit 51. INV unit 561 is connected to battery 521 but not to battery 522. INV unit 562 is connected to battery 522 but not to battery 521. That is, each INV unit 561 and 562 of the propulsion unit 551 is connected to a different battery 521 and 522.

[0186] The third control unit 83 (multi-drive control unit) performs third control (multi-drive control) to assign multiple (at least two) motors 571, 572 of the drive output shaft 531 to drive states (activation).

[0187] As described above, when the third control is executed, even if an abnormality is determined to be one of the drive motors based on the rotational speed (a specified state quantity), the abnormal drive motor cannot be identified if the rotational speeds of multiple drive motors are the same.

[0188] Therefore, when the third control unit 83 (multi-drive control unit) performs third control (multi-drive control) and determines that one of the multiple motors is abnormal, the single drive control unit 86 performs single drive control that assigns only one of the multiple motors to the drive state and assigns the other motors to the stop state.

[0189] The switching unit 85 performs switching control. When a motor deemed abnormal by the abnormality determination unit 84 is active, the switching control switches the abnormal motor to standby and activates one of the standby motors among the motors driving the output shaft of the abnormal motor. The switching unit 85 sends a drive permission command and a speed command to the INV control unit corresponding to the switching motor, and sends a stop command to the INV control unit corresponding to the abnormal motor.

[0190] When the single drive control is performed by the single drive control unit 86, the abnormality determination unit 84 determines the abnormal drive motor based on the specified state quantity related to the drive state of the motor assigned to the drive state, i.e., the drive motor.

[0191] This embodiment has the following advantages. Here, only the advantages that differ from the first embodiment are described.

[0192] The multi-drive control unit (third control unit 83) performs multi-drive control, assigning at least two of the multiple motors 571, 572 to a drive state. Therefore, by performing multi-drive control, the output performance of the electric moving body can be improved compared to assigning only one motor to a drive state. Specifically, in the multi-drive control, the multi-drive control unit assigns all motors 571, 572 that drive the output shaft 531 to a drive state. Therefore, by performing multi-drive control, the maximum output performance of the electric aircraft 510 can be ensured.

[0193] When the multi-drive control unit 86 performs multi-drive control and determines that one of the multiple motors 571 and 572 is abnormal, it performs single-drive control that assigns only one of the multiple motors 571 and 572 to the drive state and assigns the others to the stop state. Furthermore, when the single-drive control unit 86 performs single-drive control, the abnormal motor is determined based on a predetermined state quantity related to the drive state of the motor assigned to the drive state (i.e., the drive motor). Therefore, it is possible to change the state from one where the drive states of multiple motors 571 and 572 affect the predetermined state quantity to one where the drive state of only one motor affects the predetermined state quantity. Therefore, in an electric aircraft 510 including multiple motors 571 and 572 with a drive output shaft 531, even if multiple motors 571 and 572 are in the drive state, the abnormal motor can be easily determined.

[0194] Alternatively, the fourth embodiment can also be modified and implemented as follows. For parts identical to those in the fourth embodiment, the same symbols are used and descriptions are omitted.

[0195] like Figure 13 As shown, the electric aircraft 810 may also include a battery 621 instead. Figure 12 Batteries 521 and 522 are used. The propulsion unit 651 receives power from the battery 621 and outputs propulsion force. The propulsion unit 651 has the same structure as the propulsion unit 51. INV units 661 and 662 are connected to the battery 621. With this structure, the same effect as in the fourth embodiment can be achieved.

[0196] (Other implementation methods)

[0197] In addition, the first to fourth embodiments can also be modified and implemented as follows. For parts that are the same as in the first to fourth embodiments, the same symbols are used and the descriptions are omitted.

[0198] In single-drive control, the single-drive control unit 86 assigns multiple motors driving each output shaft to drive and stop states, ensuring that the number of motors driving each output shaft is equal and that the number of motors powered by each battery is equal. With this structure, it is possible to suppress deviations in the power supply of each battery while ensuring that the number of motors driving each output shaft is equal.

[0199] Furthermore, when the switching control is performed by the switching unit 85, the second control unit 82 (redistribution control unit) performs a second control (redistribution control). This second control allocates the motors constituting the motor group including the faulty motor and the motor group constituting the motor group including the switching motor to a drive state and a stop state, so that the number of motors driving each output shaft is equal to each other, and the number of motors powered by each battery is equal to each other. Therefore, even if a motor malfunctions, deviations in the power supply of each battery can be suppressed.

[0200] Furthermore, in single-drive control, the single-drive control unit 86 assigns multiple motors driving each output shaft to drive and stop states, ensuring that the number of motors driving each output shaft is equal, and that the number of motors in the drive state cooled by each cooling device is also equal. With this structure, it is possible to suppress deviations in the cooling load of each cooling device while ensuring that the number of motors driving each output shaft is equal.

[0201] Furthermore, in the second control (redistribution control) process, when the switching control is executed by the switching unit 85, the second control unit 82 (redistribution control unit) allocates the motors constituting the motor group including the faulty motor and the motors constituting the motor group including the switching motor to a drive state and a stop state, so that the number of motors driving each output shaft is equal to each other, and the number of motors in the drive state cooled by each cooling device is equal to each other. Therefore, even if a motor malfunctions, it is possible to suppress deviations in the cooling load of each cooling device.

[0202] like Figure 14 As shown, the electric aircraft 710 may also include clutches 71c, 72c, 73c, and 74c that switch between a state in which torque is transmitted from each of the electric motors 71, 72, 73, and 74 to each of the output shafts 31 and 32 and a state in which torque is not transmitted. Clutches 71c to 74c are known clutches that connect and disconnect each of the electric motors 71 to 74 and each of the output shafts 31 and 32.

[0203] Furthermore, when the first control (single drive control) is executed by the first control unit 81 (single drive control unit 86), the abnormality determination unit 84 switches the clutch to a state where it does not transmit torque from the motor assigned to the stop state (i.e., the stop motor) to the output shaft corresponding to the stop motor, and changes the stop motor to a drive state. It then determines the abnormality of the stop motor based on a specified state quantity (e.g., rotational speed) related to the drive state of the stop motor.

[0204] Based on the above structure, by switching the clutches 71c to 74c to a state where torque is not transmitted from the motor in a stopped state to the output shaft, the transmission of braking torque and other torques from the stopped motor to the output shaft can be suppressed. Furthermore, by switching the clutches 71c to 74c to a state where torque is not transmitted from the stopped motor to the output shaft, abnormalities of the stopped motor can be determined at any time without changing the output of the output shaft. Therefore, not only drive motors but also stopped motors can be quickly identified.

[0205] Furthermore, when changing a stopped motor to a driven state, multiple stopped motors can be changed to a driven state simultaneously. Also, when changing a stopped motor to a driven state, it can rotate either forward or reverse.

[0206] like Figure 15As shown, the electric aircraft 810 may also include one-way clutches 71d, 72d, 73d, and 74d, which allow torque to be transmitted from each of the electric motors 71, 72, 73, and 74 to each of the output shafts 31 and 32 and prohibit torque transmission from each of the output shafts 31 and 32 to each of the electric motors 71, 72, 73, and 74.

[0207] Furthermore, when the first control (single drive control) is executed by the first control unit 81 (single drive control unit 86), the abnormality determination unit 84 changes the stop motor to a drive state with a rotation direction opposite to that of the motor assigned to the drive state, i.e., the drive motor, and determines the abnormality of the stop motor based on the specified state quantity of the stop motor (e.g., rotation speed).

[0208] According to the above structure, when the motors 71, 72, 73, and 74 are in a driving state, each one-way clutch 71d, 72d, 73, and 74 switches to a state that transmits torque from each motor 71, 72, 73, and 74 to each output shaft 31 and 32. Furthermore, when the motors 71, 72, 73, and 74 are in a stopped state or in a driving state with the opposite rotation direction, each one-way clutch 71d, 72d, 73d, and 74 switches to a state that does not transmit torque from each output shaft 31 and 32 to each motor 71, 72, 73, and 74, that is, a state that does not transmit negative torque from each motor 71, 72, 73, and 74 to each output shaft 31 and 32. Therefore, even without clutch control, it is possible to switch to a state where torque is not transmitted from the motor in the stopped state to the output shaft via the one-way clutches 71d to 74d, thus suppressing the transmission of braking torque and other torques from the stopped motor to the output shaft.

[0209] Furthermore, when the first control unit 81 (single drive control unit 86) executes the first control (single drive control), the fault determination unit 84 changes the stop motor to a drive state with a rotation direction opposite to that of the drive motor assigned to the drive state, and determines a fault in the stop motor based on a predetermined state quantity of the stop motor. Therefore, when the stop motor is changed to a drive state with a rotation direction opposite to that of the drive motor, a one-way clutch can be used to switch to a state where braking torque, etc., is not transmitted from the stop motor to the output shaft, allowing fault determination of the stop motor at any time without changing the output of the output shaft. In addition, when changing the stop motor to a drive state with a reverse rotation direction, multiple stop motors can be changed to drive states with opposite rotation directions simultaneously.

[0210] In addition, electric aircraft may also include Figure 3 The electrical cut-off mechanism (91-93) shown and Figure 14 Clutch 71c~74c or Figure 15 One-way clutches 71d to 74d. With this structure, the transmission of braking torque from the stop motor to the output shafts 31 and 32 can be suppressed in two ways, through clutches 71c to 74c or one-way clutches 71d to 74d and an electrical cut-off mechanism.

[0211] Furthermore, the periods during which the stop motor is changed to the opposite direction of rotation to determine if there is an abnormality in the stop motor can also be during inertial flight of the electric aircraft or when the propeller of the electric aircraft stops before takeoff. That is, even if the speed command is 0, an abnormality in the stop motor can be determined.

[0212] like Figure 16 As shown, the electric aircraft 910 may also include a battery 923 that supplies power to INV units 61-64. That is, power can be supplied to a system from multiple batteries. With this structure, even if any of the batteries 21 and 22 malfunctions, power can still be supplied from battery 923 to the INV units that receive power from the malfunctioning battery. Therefore, even if any of the batteries 21 and 22 malfunctions, the maximum output performance of the electric aircraft 910 can be ensured.

[0213] When the first control (single drive control) is executed by the first control unit 81 (single drive control unit 86), the motor assigned to the stop state among the multiple motors driving the common output shaft can be driven with a constant torque smaller than the output torque of the motor assigned to the drive state (i.e., the drive motor). According to this structure, when the first control (single drive control) is executed, by driving the stop motor with a constant torque (0 or more) smaller than the output torque of the drive motor, the transmission of braking torque from the stop motor to the output shaft can be suppressed. Therefore, even if the electric moving body does not include a clutch that switches between the state of transmitting torque from each motor to each output shaft and the state of not transmitting torque, the transmission of braking torque from the stop motor to the output shaft can be suppressed.

[0214] If the temperature of the magnet (e.g., magnet 71a) in each motor (e.g., motor 71) is lower than a specified temperature (e.g., -20°C), the output of each motor may be lower than the reference output. Therefore, among the multiple motors driving a common output shaft, if the motor assigned to the stop state (i.e., the stop motor) is not determined to be abnormal and the temperature of the magnet in the stop motor is lower than the specified temperature, the stop motor can be driven with a constant torque smaller than the output torque of the motor assigned to the drive state (i.e., the drive motor). According to this structure, compared with the case where the stop motor is kept in the stop state, the temperature of the magnet of the stop motor can be increased, and the output of the stop motor can be prevented from becoming lower than the reference output when driving the stop motor.

[0215] For a single output shaft, the system can include four or more INV units and motors. Furthermore, the number of output shafts can be arbitrary.

[0216] As a specified state quantity related to the driving state of the drive motor, the rotational speed of the output shaft driven by the drive motor, the motor torque output by the drive motor, and the output shaft torque output by the output shaft driven by the drive motor can also be used. In this case, instead of the speed monitoring unit 61c, the specified state quantity monitoring unit can monitor whether the specified state quantity deviates from the specified threshold range. In addition, when multiple motors are directly connected to the output shaft, since the rotational speed of the drive motor is the same as the rotational speed of the stop motor, the rotational speed of the stop motor can be used as the specified state quantity.

[0217] It can also replace the main control ECU 80 and consist of an INV control unit (INV unit) including a first control unit 81 to a third control unit 83, an abnormality determination unit 84, a switching unit 85 and a single drive control unit 86.

[0218] The electric motors used are not limited to AC motors; DC motors can also be used. In this case, a current control unit or similar device can be used to control the current flowing through the DC motor, instead of an INV unit.

[0219] Alternatively, each electric motor can be replaced with a motor generator capable of both driving and generating electricity. Furthermore, the control functions of the first to fourth embodiments can be performed by replacing the driving of each electric motor with the generation of electricity by each electric motor. With this structure, even in the event of a malfunction in the motor generator, deviations in the amount of electricity received (charge) of each battery can be suppressed.

[0220] The above embodiments are not limited to electric aircraft; they can also be applied to electric vehicles (electric mobile bodies) or electric ships (electric mobile bodies). In this case, the electric vehicle may include a drive wheel instead of the propeller, and the electric ship may include a propeller instead of the propeller.

[0221] While this disclosure has been described based on embodiments, it should be understood that this disclosure is not limited to the above embodiments and structures. This disclosure also includes various modifications and equivalent variations. Furthermore, various combinations and arrangements, and consequently, combinations and arrangements containing only one element, or more than or less thereof, also fall within the scope and spirit of this disclosure.

Claims

1. An electrically powered moving body, the electrically powered moving body comprising an output shaft and a plurality of electric motors driving the output shaft, The electrically powered mobile body includes: A multi-drive control unit that performs multi-drive control to assign at least two of the plurality of motors to a drive state; A single-drive control unit, when the multi-drive control unit performs the multi-drive control and determines that one of the multiple motors is abnormal, performs single-drive control that assigns only one of the multiple motors to the drive state and assigns the other motors to the stop state. as well as An anomaly determination unit, when the single drive control is executed by the single drive control unit, determines an abnormal drive motor based on a predetermined state quantity related to the drive state of the motor, i.e., the drive motor, which is assigned to the drive state.

2. The electrically powered mobile body as described in claim 1, characterized in that, If the abnormal drive motor cannot be determined by the abnormality determination unit, the single drive control unit assigns only one of the plurality of motors that is different from the motor assigned to the drive state in the previous single drive control to the drive state, and assigns the other motors to the stop state, thereby executing the single drive control again.

3. The electrically powered mobile body as described in claim 1 or 2, characterized in that, If the abnormality determination unit determines that an abnormal drive motor is present, and the plurality of motors include a normal motor, the abnormal drive motor is switched to the stop state, and at least one of the normal motors is switched to the drive state.

4. The electrically powered mobile body as described in claim 1 or 2, characterized in that, The electric moving body includes a clutch that switches between a state where torque is transmitted from each motor to the output shaft and a state where no torque is transmitted. When the single drive control is executed by the single drive control unit, the abnormality determination unit switches the clutch to a state where it does not transmit torque from the motor assigned to the stopped state (i.e., the stop motor) to the output shaft and changes the stopped motor to a drive state, and determines the abnormality of the stopped motor based on a predetermined state quantity related to the drive state of the stopped motor.

5. The electrically powered mobile body as described in claim 4, characterized in that, The clutch is a one-way clutch that allows torque to be transmitted from each motor to the output shaft but prohibits torque from being transmitted from the output shaft to each motor. When the single drive control is executed by the single drive control unit, the abnormality determination unit changes the stop motor to a drive state with a rotation direction opposite to that of the motor assigned to the drive state, i.e., the drive motor, and determines the abnormality of the stop motor based on the predetermined state quantity of the stop motor.

6. The electrically powered mobile body as described in claim 1 or 2, characterized in that, The electric mobile body includes a battery that supplies power to the plurality of electric motors. The electric moving body includes an electrical disconnection mechanism that electrically disconnects each motor from the battery. When the single drive control is performed by the single drive control unit, the electric motor, which is in the stopped state, is electrically disconnected from the battery by the electrical disconnection mechanism.

7. The electrically powered mobile body as described in claim 1 or 2, characterized in that, When the single drive control is performed by the single drive control unit, the motor assigned to the stop state among the multiple motors driving the output shaft is driven by a constant torque smaller than the output torque of the motor assigned to the drive state (i.e., the drive motor).

8. The electrically powered mobile body as described in claim 1 or 2, characterized in that, Among the multiple motors driving the output shaft, if the motor assigned to the stop state (i.e., the stop motor) is not determined to be abnormal and the temperature of the magnet of the stop motor is lower than a specified temperature, the stop motor is driven with a constant torque smaller than the output torque of the motor assigned to the drive state (i.e., the drive motor).

9. The electrically powered mobile body as described in claim 1 or 2, characterized in that, The electric moving body includes a plurality of the output shafts. The multiple motors drive each output shaft. The electric mobile unit includes multiple batteries. The plurality of electric motors and the plurality of batteries are connected in such a manner that power is supplied from each battery to each motor group consisting of electric motors that drive different output shafts. In the single-drive control, the single-drive control unit assigns the plurality of motors driving each output shaft to a drive state and a stop state, such that the number of motors driving each output shaft is equal to the number of motors, and the number of motors powered by each battery is also equal. The electrically powered mobile body includes: A switching unit performs switching control, wherein when a motor determined by the abnormality determination unit to be abnormal (i.e., an abnormal motor) is in the driving state, the switching control switches the abnormal motor to the stopped state, and switches one of the motors in the stopped state among those driving the output shaft driven by the abnormal motor to the driving state; and The redistribution control unit performs redistribution control. When the switching control is performed by the switching unit, the redistribution control assigns the motors constituting the motor group including the abnormal motor and the motors constituting the motor group including the switching motor to the drive state and the stop state, so that the number of motors driving each output shaft is equal to each other, and the number of motors powered by each battery is equal to each other.

10. The electrically powered mobile body as claimed in claim 9, characterized in that, The electric mobile body includes multiple cooling devices. The connections of the plurality of electric motors and the plurality of cooling devices to the plurality of electric motors and the plurality of batteries are respectively arranged such that refrigerant is supplied from each cooling device to each motor assembly consisting of electric motors that drive different output shafts. In the single-drive control, the single-drive control unit assigns the plurality of motors driving each output shaft to a drive state and a stop state, such that the number of motors driving each output shaft is equal to the number of motors in the drive state, and the number of motors in the drive state cooled by each cooling device is equal to the number of motors in the drive state. In the redistribution control, when the switching control is executed by the switching unit, the redistribution control unit assigns the motors constituting the motor group including the abnormal motor and the motors constituting the motor group including the switching motor to the drive state and the stop state, so that the number of motors driving each output shaft is equal to each other, and the number of motors in the drive state cooled by each cooling device is equal to each other.

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