Aircraft and Method

Abstract

To prevent freezing of an electrical component in a VTOL rotor.SOLUTION: An aircraft 100 includes: a fuselage 12; a VTOL rotor 20 having one or more blades 23 supported on a boom 18 separated from the fuselage and for generating thrust in a vertical direction at the time of taking off / landing, a motor 21 stored in the boom and for rotating the one or more blades, and an inverter 22 for controlling the motor; a detection part 80 for detecting a temperature of at least one device out of the motor and the inverter; and a control part 99 for operating at least one device on the basis of thrust request with respect to the plurality of VTOL rotors and the detection result of the temperature. The temperature of at least one of the devices out of the motor stored in the boom separated from the fuselage and the inverter is detected by the detection part, and at least one device is operated and made generate heat on the basis of the thrust request with respect to the VTOL rotor and the detection result of the temperature by the control part; thereby, freezing of those can be prevented without using a heating device.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an aircraft and a method.

Background Art

[0002] Conventionally, a vertical takeoff and landing (VTOL) aircraft (also simply called an aircraft) that takes off and lands vertically by ascending and descending in the vertical direction using VTOL rotors arranged on the left and right sides of the fuselage and flies horizontally using a cruising rotor arranged at the rear of the fuselage is known. Here, Patent Document 1 describes providing a chamber for storing rotor elements and a heating device for heating the chamber in order to prevent freezing of the rotor elements of the VTOL rotors due to low temperatures in winter or low temperatures associated with cruising altitudes. However, it is necessary to add a heating device, and a backup is also required in the event of a failure of the heating device. Patent Document 1 US Patent Application Publication No. 2020 / 0031478

Summary of the Invention

Means for Solving the Problems

[0003] In a first aspect of the present invention, there is provided an aircraft comprising: a fuselage; one or more blades supported on a support member spaced apart from the fuselage and generating a vertical thrust during takeoff and landing; a rotating device stored in the support member for rotating the one or more blades and a control device for controlling the rotating device; a detection unit for detecting the temperature of at least one of the rotating device and the control device; and a control unit for operating at least one of the devices based on a thrust requirement for the rotor and a detection result of the temperature.

[0004] In a second aspect of the present invention, there is provided a method comprising: receiving a thrust requirement for a rotor having one or more blades supported on a support member spaced from the fuselage and generating a vertical thrust during takeoff and landing, a rotating device stored in the support member for rotating the one or more blades, and a control device for controlling the rotating device; detecting a temperature of at least one of the rotating device and the control device; and operating at least one of the devices based on the thrust requirement and the detected temperature result.

[0005] Note that the above summary of the invention does not enumerate all the features of the present invention. Also, sub-combinations of these feature groups can also be inventions.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0007] Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Also, not all combinations of the features described in the embodiments are essential for the solution means of the invention.

[0008] Figure 1 shows the configuration of the aircraft 100 according to the present embodiment in a top view. The aircraft 100 includes a rotor having an electric motor as a drive source, generates thrust using a vertical takeoff and landing (VTOL) rotor to vertically take off and land, and is a vertical takeoff and landing aircraft that generates thrust using a cruise rotor (also called a cruise rotor) to fly horizontally. It is also a hybrid aircraft that can operate the electric motor with electric power supplied from each of a battery and a motor generator and charge the battery with the motor generator. The aircraft 100 according to the present embodiment is configured such that freezing of the electrical components of the VTOL rotor can be prevented without adding a heating device, and includes a fuselage 12, a front wing 14, a rear wing 16, two booms 18, eight VTOL rotors 20, two cruise rotors 29, a cooling system 60, a detection unit 80, a heating unit 90, and a control unit 99.

[0009] The fuselage 12 is a structure that provides a space for crew and passengers to board and for loading cargo and the like, and stores devices such as a battery and a motor generator (both not shown). The fuselage 12 is symmetric about the central axis L, has a shape that extends in the front-rear direction parallel to the central axis L and is narrow in the left-right direction orthogonal to the central axis L in the horizontal plane. Here, the direction parallel to the central axis L is the front-rear direction, the left and right sides of the drawing are the front (F) and the rear (B) respectively, the direction orthogonal to the central axis L in the horizontal plane is the width direction (or left-right direction), and the upper and lower sides of the drawing are the right (R) and the left (L) respectively. Also, the vertical direction is orthogonal to each of these front-rear and width directions, and the upward and downward directions in the vertical direction are also called the upper (U) and the lower (L) respectively. The fuselage 12 has a front end that is round and curved in a top view and a rear end that is somewhat narrower and parallel to the width direction with respect to the fuselage body.

[0010] The front wing 14 extends laterally from the fuselage 12 and is a wing body that generates lift when cruising, i.e., by moving forward, and functions as the empennage of the aircraft 100. The front wing 14 has a V-shaped configuration in which two wing bodies extend from the central portion to the left front and the right front respectively, and the opening of the V-shaped configuration faces forward and is fixed to the upper part of the front side of the fuselage 12 of the fuselage 12 at the central portion. The front wing 14 includes elevators 14a arranged on each of the double lines of the two wing bodies.

[0011] The rear wing 16 extends laterally from the fuselage 12 and is a wing body that generates lift when cruising, i.e., by moving forward, and functions as a retractable wing that reduces air resistance. The rear wing 16 has a V-shaped configuration in which two wing bodies extend from the central portion to the left rear and the right rear respectively, and the opening of the V-shaped configuration faces rearward and is fixed to the upper part of the rear end of the fuselage 12 at the central portion via a pylon 32. The rear wing 16 includes elevons 16a arranged on each of the double lines of the two wing bodies and vertical fins 16b arranged at the wing tips.

[0012] Here, the wing area of the rear wing 16 is larger than that of the front wing 14, and the wingspan of the rear wing 16 is longer than that of the front wing. Thereby, the lift generated by the rear wing 16 when moving forward is larger than the lift generated by the front wing 14, and the rear wing 16 functions as the main wing of the aircraft 100. Note that the wing area, length, etc. of the front wing 14 and the rear wing 16 may be determined based on the balance of the lift generated by each, the center of gravity position, the attitude of the aircraft during cruising, etc.

[0013] The two booms 18 are structures supported on the left and right sides of the fuselage 12 by the front wing 14 and the rear wing 16 respectively, and perform the function of supporting or storing the components of the VTOL rotors 20 and the cooling system 60 described later. The two booms 18 have a cylindrical shape extending in the front-rear direction in top view and have an airfoil cross-sectional shape with the upper side being round and curved and the lower side being tapered in front view, and are arranged symmetrically with respect to the fuselage 12 (i.e., the central axis L) in a pair. Note that the two booms 18 may be formed to extend in the front-rear direction and be arcuately curved in the width direction. The two booms 18 have their front ends located in front of the front wing 14 and are supported at the tips of the front wing 14 at the front fuselage part (between the two front VTOL rotors 20a and 20b), and their rear ends are located behind the rear wing 16 and are supported by the rear wing 16 at the rear fuselage part (between the two rear VTOL rotors 20c and 20d).

[0014] Figure 2A shows the internal structure of the boom 18. The boom 18 includes a skin 18a, ribs 18b, and spars 18c. The skin 18a is a member that constitutes the surface of the boom 18 and is formed into a cylindrical shape having an airfoil cross-sectional shape and extending in the front-rear direction. The skin 18a rises high upward and expands in the left-right direction at the location where the VTOL rotor 20 is arranged to form a space 18d, and rises slightly upward and expands in the left-right direction at the location where the cooling system 60 is arranged to form a space 18e. Note that the skin 18a is formed to include an inlet 70a for taking in an air flow and an outlet 70b for exhausting the air flow above and below the location where the cooling system 60 is arranged respectively. Also, it may include a shutter 70a for closing the inlet 70a. The ribs 18b are plate-like members having an airfoil shape and are arranged at a plurality of locations in the front-rear direction to hold the skin 18a from the inside. Note that the spaces 18d and 18e inside the boom 18 are partitioned by the ribs 18b. The spars 18c are rod-like members extending in the front-rear direction and constitute a framework for supporting the ribs 18b and other members. 0 The ribs 18b are plate-like members having an airfoil shape and are arranged at a plurality of locations in the front-rear direction to hold the skin 18a from the inside. Note that the spaces 18d and 18e inside the boom 18 are partitioned by the ribs 18b. The spars 18c are rod-like members extending in the front-rear direction and constitute a framework for supporting the ribs 18b and other members.

[0015] The eight VTOL rotors 20 (20a to 20d) are rotors supported by the two booms 18 and generate vertical thrust during takeoff and landing. Four of the eight VTOL rotors 20a to 20d are supported by the left boom 18 at substantially equal intervals, and the remaining four VTOL rotors 20a to 20d are supported by the right boom 18 at substantially equal intervals. Here, the VTOL rotor 20a is at the forefront, the two VTOL rotors 20b and 20c are arranged front and back between the front wing 14 and the rear wing 16, and the VTOL rotor 20d is at the rearmost. Among the left VTOL rotors 20a to 20d and the four right VTOL rotors 20a to 20d, two left and right VTOL rotors 20a to 20d with equal positions in the front-rear direction form a pair and are controlled to rotate in opposite directions. Unless otherwise specified, each of the eight VTOL rotors 20a to 20d is simply referred to as the VTOL rotor 20.

[0016] The VTOL rotor 20 has one or more blades 23, a motor 21, an inverter 22, a variable pitch mechanism 24, and an ECU 25. Note that the motor 21 and the inverter 22 are also referred to as electrical components.

[0017] One or more blades 23 are blade-like members supported on the boom 18 as shown in FIG. 2A and generate thrust in the vertical direction by rotating. In this embodiment, the number of blades 23 is two, but it may be one or any number of three or more. One or more blades 23 are supported at a position higher than the front wing 14 and the rear wing 16. In FIG. 1, the rotation plane of one or more blades 23 of each VTOL rotor 20 is shown using a two-dot chain line.

[0018] The motor (an example of a rotating device) 21 has a rotation axis 21a directed in the vertical direction and is an electric motor that rotates the blade 23 fixed to the motor 21 via a transmission (not shown) that converts the rotation speed of the rotation axis 21a. The motor 21 is supported by the spar 18c via a support member and is housed in the space 18d of the boom 18.

[0019] The inverter (an example of a control device) 22 receives DC power supply from a battery via a high-voltage system (also called a power distribution system (PDS)), and drives (turns on and off) a switching element according to a drive signal received from the ECU 25 described later, thereby converting DC power into AC power and supplying it to the motor 21. The inverter 22 is supported below the motor 21 by the spar 18c. The inverter 22 can control the rotational torque and rotational speed of the motor 21 by increasing or decreasing the amplitude and frequency of the AC power, respectively.

[0020] The variable pitch mechanism 24 is a mechanism that changes the angle (i.e., pitch) of each of one or more blades 23 with respect to the rotation plane. The variable pitch mechanism 24 includes an actuator 24a that rotates the base end of one or more blades 23. It receives low-voltage DC power from a battery via a low-voltage system (also called a low-voltage system (LVS)), and operates the actuator 24a to adjust the pitch of one or more blades 23. For example, by increasing the pitch, the thrust can be increased, and by decreasing the pitch, the thrust can be decreased. Thus, the thrust generated by the rotation of one or more blades 23 of the VTOL rotor 20 can be controlled.

[0021] The ECU (electronic control unit) 25 operates by receiving low-voltage DC power from a battery via a low-voltage system, and controls its operation by transmitting a drive signal to the inverter 22 to modulate the amplitude and frequency of the AC power. The ECU 25 is implemented by a microcontroller as an example.

[0022] The two cruising rotors 29 are rotors supported at the rear end of the fuselage 12 and generating thrust during cruising. The cruising rotors 29 are arranged side by side left and right with respect to the central axis L within a cylindrical duct 54 fixed to the rear end of the fuselage 12, are supported within the duct 54, and have one or more blades that generate thrust forward by rotating, a motor having a rotation axis oriented in the front-rear direction and rotating one or more blades fixed to the tip via this axis, and an inverter (none shown in the figures) that receives DC power supply from a battery, converts it to AC power, and supplies it to the motor. The inverter can control the rotation speed of the motor.

[0023] The cooling system (an example of a cooling device) 60 is a system that cools the motor 21 and the inverter 22 (also referred to as electrical components) that constitute the VTOL rotor 20 by using a radiator 61 disposed within the boom 18 in a liquid cooling method. In the present embodiment, one cooling system 60 is provided for each one VTOL rotor 20, and a total of eight cooling systems 60 are provided, but it is not limited to this, and one cooling system 60 may be provided for a plurality (for example, two) of VTOL rotors 20. The cooling system 60 includes a radiator 61, a pump 62, a coolant tank 63, pipes 64, 65, and a temperature sensor 66. Note that water can be used as the coolant.

[0024] Figures 2B and 2C show the configuration of the radiator 61 in a front view and a side view, respectively. The radiator 61 is a heat exchanger that cools the coolant for cooling the motor 21 and the inverter 22. Note that the radiator 61 is supported between two ribs 18b using a support member 61f and stored within the boom 18. The radiator 61 has a plurality of tubes 61a through which the coolant flows vertically, a plurality of fins 61b fixed to each of the plurality of tubes 61a to increase the surface area in contact with the air flow, an upper tank 61c that sends the coolant to the plurality of tubes 61a, a lower tank 61d that receives the coolant from the plurality of tubes 61a, and two fans 61e that send the air flow to the plurality of fins 61b.

[0025] A plurality of tubes 61a are arranged horizontally and assembled into a rectangular shape in a front view together with a plurality of fins 61b. An upper tank 61c is fixed above it and a lower tank 61d is fixed below it to form a radiator body. When a pump 62 described later operates, the coolant heated by circulating through the motor 21 and the inverter 22 is sent into the upper tank 61c through a pipe 64, flows downward through each of the plurality of tubes 61a, is cooled, and is sent to the lower tank 61d, and then is sent to the motor 21 and the inverter 22 through a pipe 65. At this time, two fans 61e operate to take in an air flow from an inlet 70a provided above the boom 18, send it in from one side of the radiator body (the right side in FIG. 2C), and contact the plurality of fins 61b to effect heat exchange between the air flow and the radiator body. The heated air flow exits from the other side of the radiator body (the left side in FIG. 2C) and is exhausted from an outlet 70b provided below the boom 18.

[0026] The pump 62 is connected to the radiator 61 through a pipe 65, receives the cooled coolant therefrom, and sends it into the motor 21 and the inverter 22. Accordingly, the coolant heated by passing through the motor 21 and the inverter 22 is sent into the radiator 61 through a pipe 64.

[0027] The coolant tank 63 is a container for storing the coolant. For example, when the coolant is insufficient, the coolant is sent from the coolant tank 63 into the cooling circuit to replenish the coolant.

[0028] The pipes 64 and 65 are members for transporting the coolant, connect the radiator 61 and the pump 62 to the motor 21 and the inverter 22, and form a cooling circuit through which the coolant circulates.

[0029] The temperature sensor 66 (see Fig. 3) is a sensor that detects the temperature of the coolant flowing through the pipes 64 and 65 and / or the pump 62. The temperature sensor 66 can be any type of temperature sensor, such as a thermistor or a thermocouple, as long as it can detect the temperature within the temperature range (e.g., -70 to 100 °C) of the coolant and / or the pump 62 during the operation and stop of the cooling system 60 (radiator 61). By using the temperature sensor 66 to detect the temperature of the coolant and / or the pump 62, when the coolant is at a low temperature, the heating unit 90 described below can be operated to generate heat for the electrical components of the VTOL rotor 20, thereby heating the coolant to prevent its freezing.

[0030] Fig. 2D shows the circuit configuration of the cooling system. The upper tank 61c of the radiator 61 is connected to the motor 21 and the inverter 22 by the pipe 64. The lower tank 61d of the radiator 61 is connected to the motor 21 and the inverter 22 via the pump 62 by the pipe 65. The coolant tank 63 is connected to the pipe 65. When the pump 62 operates, the coolant heated in the motor 21 and the inverter 22 is sent to the radiator 61 through the pipe 64, and the coolant cooled by the radiator 61 is sent to the motor 21 and the inverter 22 through the pipe 65.

[0031] In the cooling circuit provided by the cooling system 60, the motor 21 and the inverter 22 are connected in series downstream of the pump 62. However, they may be connected in parallel instead. Also, other electrical components may be connected in series or parallel with the motor 21 and the inverter 22.

[0032] A cooling system configured similarly to the cooling system 60 may be provided to cool the electrical components of the cruise rotor 29.

[0033] The detection unit 80 is a unit that detects the temperatures of the electrical components of the eight VTOL rotors 20 (20a to 20d), and particularly includes temperature sensors 81 and 82 provided respectively on each of the motors 21 and inverters 22 of the eight VTOL rotors 20. The temperature sensors 81 and 82 can adopt any type of temperature sensor, such as a temperature resistor (thermistor), a thermocouple, etc., as long as they can detect the temperature within the temperature range during the operation and stop of the motors 21 and inverters 22 (for example, -70 to 300 °C).

[0034] The heat generating unit 90 is a unit that controls the heat generation of the electrical components of the VTOL rotor 20. In this embodiment, in particular, it is possible to prevent the freezing of the electrical components by generating heat during supercooling. It is also possible to prevent the freezing of the coolant in the radiator 61. The heat generating unit 90 can be configured to include the aforementioned ECU 25 and the variable pitch mechanism 24.

[0035] The ECU 25 is controlled by a control unit 99 described later and transmits a drive signal to the inverter 22, thereby increasing or decreasing the rotational speed of the motor 21 by increasing or decreasing the frequency of the AC power applied to the three-phase coil of the motor 21, and increasing or decreasing the rotational torque of the motor 21 by increasing or decreasing the amplitude of the AC power (i.e., voltage amplitude) applied to the three-phase coil of the motor 21. By increasing or decreasing the power (equal to the product of the rotational speed and the rotational torque) by one or both of these, and operating the motor 21, it is possible to generate an amount of heat corresponding to the power in the motor 21.

[0036] Further, the ECU 25 is controlled by a control unit 99 described later to increase the amount of current flowing through the switching elements of the inverter 22, thereby increasing the power loss and causing the inverter 22 to generate heat. Note that the amount of current flowing through the switching elements may be directly controlled by the control unit 99. Instead of or in addition to this, the ECU 25 controls the driving timing of the switching elements, modulates the phase of the AC power applied to the three-phase coils of the motor 21, and reduces the DC and AC power conversion efficiency, thereby increasing the power loss of the inverter 22 and causing it to generate heat. Here, the power conversion efficiency can be increased by setting the phase difference between the U, V, and W phases to 120 degrees, and can be reduced by shifting the phase difference of at least one of the U, V, and W phases with respect to the other layers from 120 degrees.

[0037] The variable pitch mechanism 24 is controlled by a control unit 99 described later. When the rotational speed of the motor 21 is increased or decreased by the ECU 25, the actuator 24a is driven by the VTOL rotor 20, that is, by the rotation of one or more blades 23, to adjust their pitch so that the required thrust can be obtained. For example, during cruising, when increasing the rotational speed of the motor 21 to generate heat causes the thrust generated by the VTOL rotor 20 to exceed the required thrust (thrust requirement), the variable pitch mechanism 24 reduces the pitch of one or more blades 23 (towards the rotation plane) to suppress the thrust. Also, when increasing the rotational speed of the motor 21 still results in the thrust generated by the VTOL rotor 20 being insufficient for the thrust requirement, or when the thrust requirement increases to lift the aircraft 100 and the thrust generated by the VTOL rotor 20 falls below the thrust requirement, the variable pitch mechanism 24 increases the pitch of one or more blades 23 (away from the rotation plane) to increase the thrust. In this way, the pitch of the blades 23 is optimized with respect to the rotational speed of the motor so that the thrust generated by the VTOL rotor 20 satisfies the thrust requirement.

[0038] Figure 3 shows the configuration of a control system for a heating unit 90 that causes the electrical components of the VTOL rotor 20 to generate heat and a cooling system 60 that cools them. For simplicity, only one VTOL rotor 20 and one cooling system 60 provided for that VTOL rotor 20 are illustrated, representing eight VTOL rotors 20. However, the control unit 99 controls the other VTOL rotors 20 and the cooling systems 60 provided for them in the same way.

[0039] The control unit 99 is a unit that controls the operation of the motors 21 and inverters 22 of the eight VTOL rotors 20 and the cooling system 60 (radiator 61), and can be implemented by a computer device that expresses control functions by starting a control program. The control unit 99 has an interface 99a such as a joystick and a thrust lever that receives operation signals from the pilot of the aircraft 100, such as signals related to the steering of the aircraft, thrust requests to the VTOL rotor 20, and thrust requests to the cruising rotor 29.

[0040] Based on the thrust request for the VTOL rotor 20 input via the interface 99a and the detection results of the temperatures of the motors 21 and inverters 22 detected by the detection unit 80, the control unit 99 operates the motors 21 and / or inverters 22 via the ECU 25 to cause them to generate heat. In addition to this, the control unit 99 may stop the cooling system 60 based on the detection results of the temperatures of the motors 21 and inverters 22 detected by the detection unit 80, and stop the cooling of the motors 21 and inverters 22. Here, the control unit 99 may stop the radiator 61 and / or the pump 62 provided in the cooling system 60, or may close the inlet 70a provided above the boom 18 for introducing an air flow into the radiator 61 with a shutter 70a 0 to stop the cooling function. Thereby, overcooling of the motors 21 and inverters 22 can be prevented.

[0041] Note that the control unit 99 may switch between the heat generating unit 90 and the cooling system 60 and operate them during vertical takeoff and landing and during cruising. For example, the cooling system 60 may be operated during the operation of the VTOL rotor 20, and during cruising or during the operation of the cruising rotor 29, the motors 21 and the inverters 22 of the VTOL rotor 20 may be operated via the heat generating unit 90 to generate heat therefrom.

[0042] FIG. 4 shows a flow S100 of a method for heat generation and cooling of the electrical components of the VTOL rotor 20. This flow describes the heat generation and cooling of the electrical components of one of the eight VTOL rotors 20 representative of them, but the heat generation and cooling of the electrical components of the other VTOL rotors 20 can be executed in the same manner.

[0043] In step S12, the control unit 99 receives a thrust request for the VTOL rotor 20 from the pilot of the aircraft 100 via the interface 99a.

[0044] In step S14, the control unit 99 determines whether the thrust generated by the VTOL rotor 20 is lower than the thrust request received in step S12. The thrust of the VTOL rotor 20 can be determined from the rotational speed and pitch of one or more blades 23. If the thrust of the VTOL rotor 20 is smaller than the thrust request, the process proceeds to step S16, and if it is larger, the process proceeds to step S32.

[0045] Note that instead of the determination based on the thrust of the VTOL rotor 20, the flow may be branched based on the determination of whether to operate the VTOL rotor 20 or the cruising rotor 29. For example, when the VTOL rotor 20 is fully operated such as during vertical takeoff rate, the process proceeds to step S16 to operate the cooling system 60, and when the cruising rotor 29 is operated as during cruising and the VTOL rotor 20 is stopped or not fully operated, the process proceeds to step S32 to temporarily operate the motors 21 and the inverters 22 to generate heat.

[0046] In step S16, the control unit 99 controls the ECU 25 to increase the rotational speed and / or rotational torque of the motor 21, thereby increasing the power of the motor 21. As a result, the rotational speed of one or more blades 23 increases.

[0047] In step S18, the control unit 99 controls the actuator 24a via the variable pitch mechanism 24 to adjust the pitch of one or more blades 23, thereby controlling the thrust generated by the rotation of one or more blades 23. For example, when the thrust of the VTOL rotor 20 is greater than the thrust requirement, the variable pitch mechanism 24 reduces the pitch of one or more blades 23 (bringing it closer to the rotation plane) to suppress the thrust. When the thrust of the VTOL rotor 20 is less than the thrust requirement, the variable pitch mechanism 24 increases the pitch of one or more blades 23 (moving it away from the rotation plane) to increase the thrust.

[0048] In step S20, the control unit 99 detects the temperature of the electrical components of the VTOL rotor 20 (rotor temperature) by the detection unit 80, and determines whether the detected rotor temperature is higher than a predetermined reference temperature. The rotor temperature may be given by the temperature of either the motor 21 or the inverter 22, or by the higher of those temperatures.

[0049] When the rotor temperature is high, the process proceeds to step S22 to operate the cooling system 60. The control unit 99 may increase the operating amount of the pump 62 of the cooling system 60 to increase the flow rate of the coolant in the radiator 61 or increase the rotational speed of the fan 61e to improve the cooling efficiency of the radiator 61. Thereby, the electrical components of the VTOL rotor 20 are cooled. After the operation of the cooling system 60, the process returns to step S12.

[0050] When the rotor temperature is low, the process proceeds to step S24 to stop the cooling system 60. Here, the control unit 99 may stop the radiator 61 and / or the pump 62 provided in the cooling system 60, or close the shutter 70a of the inlet 70a provided above the boom 18 for introducing an air flow into the radiator 61. 0The cooling function may be stopped by closing it. Also, the operation amount of the pump 62 of the cooling system 60 may be decreased to reduce the flow rate of the coolant in the radiator 61, or the rotation speed of the fan 61e may be decreased to reduce the cooling efficiency of the radiator 61. After the cooling system 60 stops, the process returns to step S12.

[0051] In addition, when the rotor temperature is low enough to be near the lower limit of the operating guarantee temperature of the electrical components of the VTOL rotor 20, the fan 61e of the cooling system 60 may be stopped or the inlet 70a may be closed by the shutter 70a 0 to stop the cooling function, and then the pump 62 may be operated to keep the electrical components of the VTOL rotor 20 warm.

[0052] In step S32, the control unit 99 detects the temperature of the electrical components of the VTOL rotor 20 (rotor temperature) by the detection unit 80, and determines whether the detected rotor temperature is higher than a predetermined reference temperature. The rotor temperature may be given by the temperature of either the motor 21 or the inverter 22, or by the higher of those temperatures.

[0053] When the rotor temperature is high, the process proceeds to step S34 to operate the cooling system 60. Similar to step S22, the control unit 99 may increase the operation amount of the pump 62 of the cooling system 60 to increase the flow rate of the coolant in the radiator 61, or increase the rotation speed of the fan 61e to increase the cooling efficiency of the radiator 61. Thereby, the electrical components of the VTOL rotor 20 are cooled. After the cooling system 60 operates, the process proceeds to step S38.

[0054] When the rotor temperature is low, the process proceeds to step S36 to stop the cooling system 60. Similar to step S24, the control unit 99 may stop the radiator 61 and / or the pump 62 provided in the cooling system 60, or close the inlet 70a provided above the boom 18 for introducing an air flow into the radiator 61 with the shutter 70a 0The cooling function may be stopped by closing it. Also, the operation amount of the pump 62 of the cooling system 60 may be decreased to reduce the flow rate of the coolant in the radiator 61 or the rotational speed of the fan 61e may be decreased to reduce the cooling efficiency of the radiator 61. Thereby, overcooling of the motor 21 and the inverter 22 can be prevented. After the cooling system 60 stops, the process proceeds to step S38.

[0055] In addition, when the rotor temperature is low to near the lower limit of the operating guarantee temperature of the electrical components of the VTOL rotor 20, the fan 61e of the cooling system 60 is stopped or the inlet 70a is closed by the shutter 70a 0 to stop the cooling function, and then the pump 62 may be operated to keep the electrical components of the VTOL rotor 20 warm.

[0056] In step S38, the control unit 99 detects the temperature (motor temperature) of the motor 21 of the VTOL rotor 20 by the detection unit 80, and determines whether the detected motor temperature is lower than a predetermined reference temperature. If the motor temperature is low, the process proceeds to step S40; if it is high, the process proceeds to step S42.

[0057] In step S40, the control unit 99 increases the power of the motor 21. Here, the control unit 99 increases the frequency of the AC power applied to the three-phase coil of the motor 21 to increase the rotational speed of the motor 21 by transmitting a drive signal from the ECU 25 to the inverter 22. Also, the control unit 99 increases the amplitude of the AC power (i.e., voltage amplitude) applied to the three-phase coil of the motor 21 to increase the rotational torque of the motor 21. By increasing the power (equal to the product of the rotational speed and the rotational torque) by one or both of these, the motor 21 is operated to generate an amount of heat corresponding to the power in the motor 21. After the motor 21 operates, the process proceeds to step S44.

[0058] In step S42, the control unit 99 reduces the power of the motor 21. Here, the control unit 99 transmits a drive signal from the ECU 25 to the inverter 22 to reduce the frequency of the AC power applied to the three-phase coil of the motor 21, thereby reducing the rotational speed of the motor 21. Further, the control unit 99 reduces the amplitude of the AC power (i.e., the voltage amplitude) applied to the three-phase coil of the motor 21 to reduce the rotational torque of the motor 21. By reducing the power (equal to the product of the rotational speed and the rotational torque) by one or both of these, and operating the motor 21, the heat generation amount of the motor 21 is suppressed. After the operation of the motor 21, the process proceeds to step S44.

[0059] In step S44, the control unit 99 controls the actuator 24a via the variable pitch mechanism 24 to adjust the pitch of one or more blades 23, thereby controlling the thrust generated by the rotation of the one or more blades 23. For example, when the thrust of the VTOL rotor 20 becomes larger than the thrust requirement due to an increase in the rotational speed of the motor 21 in step S40, the variable pitch mechanism 24 reduces the pitch of one or more blades 23 (bringing it closer to the rotation plane) to suppress the thrust. Also, for example, when the thrust of the VTOL rotor 20 becomes smaller than the thrust requirement due to a decrease in the rotational speed of the motor 21 in step S42, the variable pitch mechanism 24 increases the pitch of one or more blades 23 (moving it away from the rotation plane) to increase the thrust.

[0060] Note that there may be a case where the rotational speed of the motor 21 is reduced to reduce the noise of the VTOL rotor 20, and the pitch of the blade 23 is increased to increase the rotational torque and operate the motor 21. In such a case, in order to lower the motor temperature, in step S42, the rotational speed of the motor 21 is reduced, and in S44, the pitch of the blade 23 is increased to maintain the thrust while increasing the operating efficiency of the motor 21, thereby suppressing its heat generation. Also, in order to raise the temperature of the motor, in step S40, the rotational speed of the motor 21 is increased, and in step S44, the pitch of the blade 23 is reduced to lower the operating efficiency of the motor 21, thereby increasing the heat generation amount of the motor.

[0061] In step S46, the control unit 99 detects the temperature of the inverter 22 of the VTOL rotor 20 (inverter temperature) by the detection unit 80, and determines whether the detected inverter temperature is lower than a predetermined reference temperature. If the inverter temperature is low, the process proceeds to step S48; if it is high, the process proceeds to step S52.

[0062] In step S48, the control unit 99 increases the power loss of the inverter 22 (inverter loss). Here, the control unit 99 increases the current flowing through the switching element of the inverter 22 to increase the power loss of the inverter 22, thereby causing the inverter 22 to generate heat.

[0063] In step S50, the control unit 99 reduces the power conversion efficiency of the inverter 22. Here, the control unit 99 controls the driving timing of the switching element of the inverter 22 via the ECU 25 to modulate the phase of the AC power applied to the three-phase coil of the motor 21, thereby reducing the DC and AC power conversion efficiencies and increasing the power loss of the inverter 22 to increase the heat generation amount.

[0064] Note that only one of step S48 and step S50 may be executed.

[0065] In step S52, the control unit 99 reduces the power loss of the inverter 22 (inverter loss). Here, the control unit 99 reduces the current flowing through the switching element of the inverter 22 to reduce the power loss of the inverter 22, thereby suppressing the heat generation of the inverter 22.

[0066] In step S54, the control unit 99 increases the power conversion efficiency of the inverter 22. Here, the control unit 99 controls the driving timing of the switching element of the inverter 22 via the ECU 25 to modulate the phase of the AC power applied to the three-phase coil of the motor 21, thereby increasing the DC and AC power conversion efficiencies and reducing the power loss of the inverter 22 to suppress the heat generation amount.

[0067] Note that only one of step S52 and step S54 may be executed.

[0068] Furthermore, the control unit 99 detects the temperature of the coolant of the radiator 61 and / or the temperature of the pump 62 by the temperature sensor 66, and when the detected temperature is lower than a predetermined reference temperature, the heat generating unit 90 is operated, that is, the power of the motor 21 is increased in the same manner as in step S40 and / or the inverter loss is increased in the same manner as in step S48 to generate heat therefrom to heat the coolant. Thereby, freezing of the coolant can be prevented.

[0069] When steps S46 to S52 are completed, the process returns to step S12.

[0070] As described above, when receiving a thrust request for the VTOL rotor 20 and detecting the temperatures of the motor 21 and the inverter 22 of the VTOL rotor 20 stored in the boom 18, and operating the motor 21 and the inverter 22 to generate heat based on the thrust request and the detection results of the temperatures, it is possible to prevent their freezing without using a heating device.

[0071] FIG. 5 shows another flow S110 of the heat generation and cooling method of the electrical components of the VTOL rotor 20. This flow describes the heat generation and cooling of the electrical components of one of the eight VTOL rotors 20 representative of them, but the heat generation and cooling of the electrical components of the other VTOL rotors 20 can be executed in the same manner. Steps S12 to S24 of this flow are the same as those in the aforementioned flow S100. In step S14, when the control unit 99 determines that the thrust generated by the VTOL rotor 20 is not lower than the thrust request received in step S12, the process proceeds to step S62.

[0072] In step S62, the control unit 99 detects the temperature of the electrical components of the VTOL rotor 20 (the temperature of the motor 21 and / or the inverter 22) by the detection unit 80, and detects the temperature of the coolant of the radiator 61 and / or the pump 62 by the temperature sensor 66, and determines whether at least one of the detected temperatures of the motor 21, etc. (referred to as the rotor temperature) is lower than a predetermined reference temperature. When the rotor temperature is high, the process proceeds to step S64 to operate the cooling system 60. The details are the same as those of step S22 described above. After the operation of the cooling system 60, the process returns to step S12. When the rotor temperature is low, the process proceeds to step S66.

[0073] In step S66, the cooling function of the cooling system 60 is stopped. Here, the control unit 99 stops the fan 61e of the cooling system 60 and / or closes the inlet 70a with the shutter 70a to stop the cooling function, and then operates the pump 62 to keep the electrical components of the VTOL rotor 20 warm. 0 After stopping the cooling function by closing the inlet 70a with the shutter 70a, the pump 62 is operated to keep the electrical components of the VTOL rotor 20 warm.

[0074] In step S68, the control unit 99 detects the rotor temperature again and determines whether it is lower than a predetermined reference temperature. When the rotor temperature is high, assuming that the electrical components of the VTOL rotor 20 can be kept warm in step S66, the process returns to step S12. When the rotor temperature is still low, the process proceeds to step S70.

[0075] In step S70, the control unit 99 controls the driving timing of the switching elements of the inverter 22 via the ECU 25 to send DC power to the motor 21 via the inverter 22, thereby increasing the power loss of the motor 21 and the inverter 22 and generating heat without rotating the motor 21. Note that the control unit 99 can adjust the power loss of the motor 21 and the inverter 22, that is, the amount of heat generation, by increasing or decreasing the current amount of the DC power.

[0076] In step S72, the control unit 99 detects the rotor temperature again, and determines whether the temperature of the motor 21, the coolant of the radiator 61, and / or the pump 62 (referred to as the motor 61, etc.) is still lower than a predetermined reference temperature despite the temperature of the inverter 22 increasing. If the temperature of the motor 61, etc. is high, assuming that the electrical components of the VTOL rotor 20 could be kept warm in step S68, the process returns to step S12. If the temperature of the motor 61, etc. is still low, the process proceeds to step S74.

[0077] In step S74, the control unit 99 controls the actuator 24a via the variable pitch mechanism 24 to reduce the pitch of one or more blades 23 (bringing it closer to the rotation plane) to suppress the thrust, and controls the driving timing of the switching elements of the inverter 22 via the ECU 25 to send alternating current power to the motor 21 to rotate the motor 21. Thereby, the heat generation of the inverter 21 is alleviated and the motor 21 is made to generate heat. When step S74 ends, the process returns to step S12.

[0078] Note that in step S68, a plurality of reference temperatures may be defined and different processes may be executed. For example, when the rotor temperature is lower than a first reference temperature which is relatively high, the process proceeds to step S70, and the power losses of the motor 21 and the inverter 22 are increased to generate heat without rotating the motor 21. When the rotor temperature is lower than a second reference temperature which is relatively low, steps S70 to S72 are skipped and the process proceeds to step S74, and while rotating the motor 21, the power losses of the motor 21 and the inverter 22 are increased to generate heat. Thereby, when icing rain or fog occurs and the rotor temperature becomes extremely low (for example, -10 to 0 °C), freeze protection can be quickly achieved.

[0079] As described above, upon receiving a thrust request for the VTOL rotor 20, detecting the temperatures of the motor 21 and the inverter 22 of the VTOL rotor 20 stored in the boom 18, and operating the motor 21 and the inverter 22 to generate heat based on the thrust request and the detection results of the temperatures, it is possible to prevent their freezing without using a heating device.

[0080] The aircraft 100 according to this embodiment includes a fuselage 12, one or more blades 23 supported on a boom 18 spaced apart from the fuselage 12 to generate thrust during takeoff and landing, a motor 21 stored in the boom 18 to rotate the one or more blades 23, an inverter 22 for controlling the motor 21, a detection unit 80 for detecting the temperature of at least one of the motor 21 and the inverter 22, and a control unit 99 for operating at least one of the devices based on the thrust requirement for the plurality of VTOL rotors 20 and the detection result of the temperature. According to this, the detection unit 80 detects the temperature of at least one of the motor 21 and the inverter 22 stored in the boom 18 spaced apart from the fuselage 12, and the control unit 99 operates at least one of the devices based on the thrust requirement for the VTOL rotor 20 and the detection result of the temperature to generate heat, so that it is possible to prevent their freezing without using a heating device.

[0081] The method for generating heat of the electrical components of the VTOL rotor 20 according to this embodiment includes the steps of receiving a thrust requirement for the VTOL rotor 20 having one or more blades 23 supported on a boom 18 spaced apart from the fuselage 12 to generate thrust during takeoff and landing, a motor 21 stored in the boom 18 to rotate the one or more blades 23, and an inverter 22 for controlling the motor 21, detecting the temperature of at least one of the motor 21 and the inverter 22, and operating at least one of the devices based on the thrust requirement and the detection result of the temperature. According to this, while receiving the thrust requirement for the VTOL rotor 20, the temperature of at least one of the motor 21 and the inverter 22 stored in the boom 18 spaced apart from the fuselage 12 is detected, and at least one of the devices is operated based on the thrust requirement and the detection result of the temperature to generate heat, so that it is possible to prevent their freezing without using a heating device.

[0082] As described above, the present invention has been described using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

[0083] It should be noted that the execution order of each process such as operations, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, the specification, and the drawings is not explicitly indicated as "earlier" or "preceding" etc., and can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flows in the claims, the specification, and the drawings, even if they are described for convenience using "first," "next," etc., it does not mean that it is essential to implement in this order.

Explanation of Reference Numerals

[0084] 12… fuselage, 14… front wing, 14a… elevator, 16… rear wing, 16a… elevon, 16b… vertical tail, 18… boom, 18a… skin, 18b… rib, 18c… spar, 18d, 18e… space, 20(20a~20d)… VTOL rotor, 21… motor, 21a… rotating shaft, 22… inverter, 23… blade, 24… variable pitch mechanism, 24a… actuator, 25… ECU (electronic control unit), 29… cruising rotor, 32… pylon, 54… duct, 60… cooling system, 61… radiator, 61a… tube, 61b… fin, 61c… upper tank, 61d… lower tank, 61e… fan, 61f… support member, 62… pump, 63… coolant tank, 64, 65… piping, 66… temperature sensor, 70a… inlet, 70a 0 … shutter, 70b… outlet, 80… detection unit, 81, 82… temperature sensors, 90… heat generating part, 99… control unit, 99a… interface, 100… aircraft, L… central axis.

Claims

1. a fuselage, one or more blades supported on a support member spaced apart from the fuselage and generating a vertical thrust during takeoff and landing, a rotating device stored in the support member for rotating the one or more blades, and a control device for controlling the rotating device, a rotor having; a detection unit for detecting the temperature of at least one of the rotating device and the control device; a control unit that operates at least one of the devices when the thrust generated by the rotor is greater than the thrust requirement and the temperature of at least one of the devices is lower than a predetermined reference temperature based on the thrust requirement for the rotor and the detection result of the temperature; an aircraft comprising.

2. The aircraft according to claim 1, wherein the control unit controls at least one of the rotational speed and the rotational torque of the rotating device.

3. The rotor further has an actuator for adjusting the pitch of the one or more blades, The aircraft according to claim 2, wherein the control unit further controls the thrust generated by the rotation of the one or more blades by operating the actuator to adjust the pitch of the one or more blades.

4. The aircraft according to any one of claims 1 to 3, wherein the control unit controls the amount of current flowing through the switching element of the control device.

5. The aircraft according to any one of claims 1 to 4, wherein the control unit controls the driving timing of the switching element of the control device to adjust the power conversion efficiency.

6. further comprising a cooling device for cooling at least one of the devices, The aircraft according to any one of claims 1 to 5, wherein the control unit stops the cooling device when the temperature is lower than a predetermined reference temperature based on the detection result by the detection unit.

7. The aircraft according to claim 6, wherein the control unit stops the fan or pump of the radiator included in the cooling device.

8. The aircraft according to claim 6 or 7, wherein the control unit closes an inlet for introducing an air flow into the radiator included in the cooling device.

9. further comprising a cooling device for cooling at least one of the rotating device and the control device, further comprising a cruising rotor provided at the rear end of the fuselage and having one or more blades that generate thrust during cruising, The control unit operates the cooling device during operation of the rotor, and operates at least one of the rotating device and the control device to generate heat during operation of the cruising rotor. The aircraft according to any one of claims 1 to 5.

10. Further comprising a wing body extending laterally from the fuselage and generating lift during cruising, The support member is supported away from the fuselage by the wing body. The aircraft according to any one of claims 1 to 9.

11. Receiving a thrust request for a rotor having one or more blades that are supported on a support member spaced apart from the fuselage and generate a vertical thrust during takeoff and landing, a rotating device that stores the one or more blades in the support member and rotates the one or more blades, and a control device that controls the rotating device; Detecting the temperature of at least one of the rotating device and the control device; Based on the thrust request and the detection result of the temperature, operating the at least one device when the thrust generated by the rotor is greater than the thrust request and the temperature of the at least one device is lower than a predetermined reference temperature; A method comprising.

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