Control system, control method, and aircraft

Abstract

To suppress deterioration of a battery.SOLUTION: A control system 70 comprises: a VTOL rotor 20 and a cruise rotor 29 for generating thrust for making an aircraft 100 fly; a power generator 40a for generating power and supplying the power to the rotors; a power unit which has a battery 32 for storing the power supplied from the power generator and supplying the stored power to the rotors; and a control part 91 for calculating a battery charging period on the basis of, a required power storage amount indicating, an amount of power which should be stored in the battery when flying in a predetermined flight state, and a state of the battery, and determining a charging start time of the battery on the basis of the charging period and a flight time until the flight state becomes a predetermined flight state. Therefore, it is possible to start the charging of the battery at the charging start time, and store the required amount of power in the battery until the flight state becomes the predetermined flight state, maintain a charging amount of the battery to a low charging amount, until the charging start time comes, for suppressing deterioration of the battery.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a control system, a control method, and an aircraft. [Background technology]

[0002] Conventionally, vertical take-off and landing aircraft (VTOL aircraft, or simply aircraft) have been known. The aircraft takes off and lands by ascending and descending vertically using multiple VTOL rotors located on the left and right sides of the fuselage, and flies horizontally using a cruise rotor located at the rear of the fuselage. Such aircraft operate the multiple rotors using electric power generated by a power generation system including a gas turbine engine or electric power stored in a battery. In the aircraft described in Patent Document 1, the gas turbine engine is driven at high output to improve fuel consumption efficiency. Furthermore, during flight, the gas turbine engine is switched between an operating state and a stopped state based on the amount of electric power stored in the battery. During the operating state, the power generation system generates electric power to operate the rotors and charges the batteries to a full charge. During the stopped state, the batteries are discharged and the rotors are operated solely by the electric power. However, batteries have a problem in that they are prone to deterioration when their state of charge (SOC) is high. Patent Document 1: JP 2019-77361 A Summary of the Invention [Means for solving the problem]

[0003] In a first aspect of the present invention, there is provided a control system for controlling a power unit that charges a battery using a power generation device, the control system comprising: a power unit having a propulsion system that generates thrust for flying an aircraft, a power generation device that generates electricity and supplies power to the propulsion system, and a battery that stores the electricity supplied from the power generation device and supplies the stored electricity to the propulsion system; and a control unit that calculates a charging time for the battery based on the amount of electricity required to be stored in the battery when the aircraft flies in a predetermined flight state and the state of the battery, and determines a charging start time for the battery based on the charging time and the flight time until the predetermined flight state is reached.

[0004] In a second aspect of the present invention, there is provided an aircraft comprising the control system of the first aspect.

[0005] In a third aspect of the present invention, there is provided a control method for controlling a power unit that generates electricity using a power generation device and supplies power to a propulsion system that generates thrust for flying an aircraft, and that stores the electricity supplied from the power generation device using a battery and supplies the stored electricity to the propulsion system, the control method comprising the steps of: calculating a charging time for the battery based on the amount of electricity required to be stored in the battery when the aircraft flies in a predetermined flight state and the state of the battery; and determining a charging start time for the battery based on the charging time and the flight time until the aircraft reaches the predetermined flight state.

[0006] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also be inventions. [Brief explanation of the drawings]

[0007] [Figure 1] 1 shows a configuration of an aircraft according to this embodiment as viewed from above. [Figure 2]The configuration of the high voltage system and the communication system are shown. [Figure 3] An example of the time transition of the aircraft flight state, the power consumption by the rotor, the charge consumption to the battery, the total power consumption, and the remaining charge (SOC) of the battery is shown. [Figure 4] Indicates the remaining charge of the battery and the degree of deterioration of the battery relative to the temperature. [Figure 5] 3 shows a flow of a control method according to the present embodiment. [Figure 6] This shows the relationship between the battery's remaining charge (SOC) and the required output during charging in relation to temperature. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0009] 1 shows a top view of the configuration of an aircraft 100 according to this embodiment. The aircraft 100 is a vertical take-off and landing aircraft that has multiple rotors each having an electric motor as a drive source, and that takes off and lands vertically using take-off and landing rotors (also called VTOL rotors) 20 to generate thrust, and flies horizontally using cruise rotors (also called cruise rotors) 29 to generate thrust, and is also a hybrid aircraft that can operate the electric motors using power generated by a power generation device 40a (engine 44 and motor generator 42) and power charged in a battery 32, and can charge the battery 32 using the engine 44.

[0010] The aircraft 100 of this embodiment is configured to control a power unit that charges a battery 32 using a power generation device 40a, 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 high-voltage system 40, a communication system 49, and a control system 70.

[0011] The fuselage 12 is a structure that provides space for crew and passengers and for carrying cargo, etc., and also houses devices such as the battery 32, motor-generator 42, and engine 44. The fuselage 12 is symmetrical with respect to the central axis L, extends in a longitudinal direction parallel to the central axis L, and is narrow in a transverse direction perpendicular to the central axis L in a horizontal plane. Here, the direction parallel to the central axis L is referred to as the longitudinal direction, the left and right sides of the drawing are referred to as the forward (F) and rearward (B), respectively, the direction perpendicular to the central axis L in the horizontal plane is referred to as the width direction (or transverse direction), and the top and bottom sides of the drawing are referred to as the right (R) and left (L), respectively. The vertical direction is perpendicular to the longitudinal direction and the width direction, and the upward and downward vertical directions are also referred to as the upward (U) and downward (L), respectively. The fuselage 12 has a rounded front end in a top view and a rear end that is somewhat tapered relative to the fuselage and parallel to the width direction.

[0012] The fore wings 14 extend laterally from the fuselage 12 and are wing bodies that generate lift during cruising, i.e., by moving forward, and function as canards for the aircraft 100. The fore wings 14 have a V-shape with two wing bodies extending from the center to the left and right front, respectively, and are fixed at the center to the upper part of the front body section of the fuselage 12 with the opening of the V-shape facing forward. The fore wings 14 include elevators 14a arranged on each of the double tracks of the two wing bodies.

[0013] The rear wings 16 extend laterally from the fuselage 12 and are wing bodies that generate lift during cruising, i.e., by moving forward, and function as swept-back wings that reduce air resistance. The rear wings 16 have a V-shape with two wing bodies extending from the center to the left rear and right rear, respectively, and are fixed at the center to the upper part of the rear end of the fuselage 12 via a pylon 16c, with the opening of the V-shape facing rearward. The rear wings 16 include elevons 16a arranged on the double tracks of each of the two wing bodies and vertical tails 16b arranged at the wing tips.

[0014] 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. As a result, the lift generated by the rear wing 16 as it moves 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 position of the center of gravity, the attitude of the aircraft during cruising, etc.

[0015] The two booms 18 are structures supported by the front wings 14 and rear wings 16 at a distance from the fuselage 12 on the left and right, respectively, and function to support or store each component of the VTOL rotor 20. The two booms 18 have a cylindrical shape extending in the fore-and-aft direction in a top view, and have an airfoil-like cross-sectional shape with a rounded upper side and a tapered lower side in a front view, and are arranged in pairs symmetrically with respect to the fuselage 12 (i.e., the central axis L). The two booms 18 may also be formed to extend in the fore-and-aft direction and curve in an arc in the width direction. The two booms 18 have their front ends positioned forward of the front wings 14 and supported on the tips of the front wings 14 at the front fuselage (between the two front VTOL rotors 20aL, 20bL and between the two front VTOL rotors 20aR, 20bR), and their rear ends positioned rearward of the rear wings 16 and supported on the rear fuselage (between the two rear VTOL rotors 20cL, 20dL and between the two rear VTOL rotors 20cR, 20dR).

[0016] The eight VTOL rotors 20 (20aL to 20dL, 20aR to 20dR) are an example of loads to which electric power generated by the power generation device 40a is supplied, and are propulsion systems supported by two booms 18 to generate thrust for flying the aircraft during takeoff and landing, i.e., vertical thrust. Of the eight VTOL rotors 20, four VTOL rotors 20aL to 20dL are supported at approximately equal intervals on the left boom 18, and the remaining four VTOL rotors 20aR to 20dR are supported at approximately equal intervals on the right boom 18. Here, of the left VTOL rotors 20aL to 20dL, the VTOL rotor 20aL is located at the forefront, the two VTOL rotors 20bL and 20cL are located at the front and rear of the left wing 14 and rear wing 16, respectively, and the VTOL rotor 20dL is located at the back. Similarly, of the right-side VTOL rotors 20aR to 20dR, the VTOL rotor 20aR is arranged at the forefront, the two VTOL rotors 20bR, 20cR are arranged in the front and rear between the front wing 14 and the rear wing 16, respectively, and the VTOL rotor 20dR is arranged at the back. Of these left-side VTOL rotors 20aL to 20dL and the four right-side VTOL rotors 20aR to 20dR, the two left and right VTOL rotors 20aL, 20aR, VTOL rotors 20bL, 20bR, VTOL rotors 20cL, 20cR, and VTOL rotors 20dL, 20dR that are positioned at the same position in the fore-and-aft direction form pairs and are controlled to rotate in opposite directions to each other.

[0017] Unless otherwise specified, each of the eight VTOL rotors 20aL to 20dL and 20aR to 20dR will be simply referred to as a VTOL rotor 20.

[0018] The VTOL rotor 20 has one or more blades 23, a motor 21, an inverter 22, and an ECU 25 (see FIG. 2).

[0019] The one or more blades 23 are wing-like members that are supported on the boom 18 and generate thrust in the vertical direction by rotating. In this embodiment, the number of blades 23 is two, but any number including one or three or more may be used. The 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 plane of rotation of the one or more blades 23 of each VTOL rotor 20 is indicated by a two-dot chain line.

[0020] The motor 21 is an electric motor that has a rotating shaft (not shown) facing in the vertical direction and rotates the blade 23 fixed to the motor 21 via a transmission (not shown) that converts the rotation speed of the rotating shaft. The motor 21 is housed in the boom 18.

[0021] The inverter 22 is a device that receives DC power from the battery 32 via the high-voltage system 40, converts the DC power into AC power by driving (turning on / off) a switching element in accordance with a drive signal received from the ECU 25, and supplies the AC power to the motor 21, and is housed in the boom 18 together with the motor 21. 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.

[0022] The ECU (Electronic Control Unit) 25 is a unit that controls the operation of the inverter 22 by transmitting a drive signal to the inverter 22, modulating the amplitude and frequency of the AC power, and managing the state of the power input to the inverter 22. In this embodiment, the ECU 25 is provided in the inverter 22. The ECU 25 is implemented by, for example, a microcontroller, operates by receiving low-voltage DC power from the battery 32 via a low-voltage system (also referred to as a low-voltage system (LVS)), and performs its control function by executing a dedicated program stored in memory. Here, the state of the power input to the inverter 22 includes at least the voltage applied to the input terminals of the inverter 22 (also referred to as the terminal voltage), the current entering the input terminal, and the product thereof (i.e., power). The ECU 25 detects the state of the power input to the inverter 22 and transmits the detection results to the flight controller 92.

[0023] The two cruise rotors 29 (29L, 29R) are an example of a load supplied with electric power generated by the power generation unit 40a. They are propulsion systems supported at the aft end of the fuselage 12 and generate thrust for flying the aircraft 100 during cruising (see FIG. 2 ). The cruise rotors 29L, 29R are arranged side by side about the central axis L within a cylindrical duct 28 fixed to the aft end of the fuselage 12. The cruise rotors 29L, 29R are supported within the duct 28 and include one or more blades 23 that rotate to generate forward thrust; a motor 21 with a rotation shaft oriented in the fore-aft direction and that rotates the one or more blades 23 fixed to the tip of the motor 29; an inverter 22 that receives DC power from a battery 32, converts it to AC power, and supplies it to the motor 21; and an ECU 25 that controls the operation of the inverter 22. The inverter 22 can control the rotational speed of the motor 21. These components are configured in the same manner as those in the VTOL rotor 20.

[0024] Unless otherwise specified, each of the two cruise rotors 29L, 29R will be simply referred to as the cruise rotor 29. Furthermore, unless otherwise specified, the VTOL rotor 20 and the cruise rotor 29 will be collectively referred to as the rotors 20, 29.

[0025] FIG. 2 shows the configuration of a high-voltage system (also called a power distribution unit (PDU) or simply a power unit) 40 and the configuration of a communication system 49.

[0026] The high-voltage system 40 is an example of a power unit, and is configured to include one power generation device 40a and four group components G1 to G4. These components are connected via power lines (power cables shown by solid lines).

[0027] The power generation device 40a is a power source that generates electricity using an engine 44 based on a target power generation amount and supplies the generated electricity to a load, and is composed of an engine (ENG) 44, a motor generator (M / G) 42, and a power control unit (PCU) 41.

[0028] The engine 44 is an internal combustion engine such as a reciprocating engine or a gas turbine engine. The engine 44 generates rotational power and outputs it to the motor generator 42. The engine 44 is controlled by an ECU 44a provided therein.

[0029] The ECU 44a is a unit that controls power generation by operating the engine 44 based on a target power generation amount received from the control unit 91. The ECU 44a is implemented by, for example, a microcontroller, and operates by receiving low-voltage DC power from the battery 32 via a low-voltage system, and performs a control function by executing a dedicated program stored in a memory.

[0030] The motor generator 42 is an electric motor generator that functions as a starter when starting the engine 44 and as a generator after the engine 44 has started. The rotating shaft of the motor generator 42 is connected to the output shaft of the engine 44. The motor generator 42 receives power from the engine 44 to generate electricity, i.e., generate AC power (particularly three-phase AC power), output the power to the PCU 41, and supply the generated power to a load (i.e., the VTOL rotor 20 and the cruise rotor 29 that generate thrust for flight) via the PCU 41. Furthermore, when the engine 44 is started, the motor generator 42 receives the AC power to generate rotational power and outputs it to the engine 44.

[0031] The PCU 41 is a power conversion unit that uses an inverter circuit to convert AC power (particularly, three-phase AC power) input from the primary side into DC power and outputs it to the secondary side, and also converts DC power input from the secondary side into AC power (particularly, three-phase AC power) and outputs it to the primary side. The primary side terminal of the PCU 41 is connected to the motor generator 42, and the secondary side terminals are connected to each of the four group components G1 to G4. The PCU 41 can convert AC power output from the motor generator 42 into DC power and output it to each of the four group components G1 to G4, and can also convert DC power supplied from the batteries 32 included in the four group components G1 to G4 into AC power and output it to the motor generator 42. The PCU 41 is controlled by an ECU 41a provided therein.

[0032] The ECU 41a is a unit that controls power generation by operating the PCU 41 based on a target power generation amount received from the control unit 91. The ECU 41a is implemented by, for example, a microcontroller, and operates by receiving low-voltage DC power from the battery 32 via a low-voltage system, and performs a control function by executing a dedicated program stored in a memory.

[0033] Each of the four group components G1 to G4 is a group of electrical components assembled including any two of the eight VTOL rotors 20, and for group components G1 to G2, any one of the two cruise rotors 29, a battery 32 attached thereto, and a switch 36. These components, including the battery 32, are connected via circuit elements such as power lines (power cables shown by solid lines), conductors, and diodes.

[0034] The group component G1 includes the VTOL rotors 20aR, 20dL, the cruise rotor 29R, the battery 32, and the switch 36.

[0035] As described above, the VTOL rotors 20aR, 20dL and the cruise rotor 29R each have a motor 21 that rotates one or more blades 23 and an inverter 22 that receives DC power from the battery 32, converts it into AC power, and supplies it to the motor 21. These three rotors 20, 29 are connected in parallel to the battery 32. For simplicity, the VTOL rotors 20aR, 20dL and the cruise rotor 29R are represented as a single rotor in FIG. 2.

[0036] The battery 32 is an internal power source that stores power supplied from the power generation device 40a, supplies the stored power to the engine 44 to start it, and supplies the stored power to the rotors 20, 29 to operate it. The battery 32 stores power supplied by the power generation device 40a, and supplies the stored power to the VTOL rotor 20 and the cruising rotor 29 (the motor 21 via the inverter 22). Here, the charge state of the battery 32 (particularly, the remaining charge amount or charge rate) is also referred to as SOC (State Of Charge). The battery 32 is connected between the three rotors 20, 29 and the switch 36. The battery 32 is managed by an ECU 33 provided therein.

[0037] The ECU 33 is a unit that manages the state of charge (SOC) of the battery 32. The ECU 33 is implemented, for example, by a microcontroller, and operates by receiving low-voltage DC power from the battery 32 via a low-voltage system, and performs control functions by executing dedicated programs stored in memory. Here, the state of charge of the battery 32 includes at least the charge amount, discharge amount (amount of discharged power), and temperature. The ECU 33 detects the state of charge of the battery 32 by any method, such as detecting the current output from the battery 32 and calculating the integrated amount, or detecting the potential at the output terminal. The detection result is transmitted to the control unit 91 via a communication line.

[0038] The switch 36 is an element for connecting and disconnecting the group component G1 to the secondary terminal of the PCU 41, and includes, for example, a rectifying element (diode) and a switching element connected in parallel. The rectifying element is an element that passes only power directed from the PCU 41 into the group component G1. The switching element is an element that shorts both ends of the rectifying element, and an element such as an insulated gate bipolar transistor (IGBT) can be used. Turning the switch 36 (switching element) off allows DC power output from the PCU 41 to be sent to the battery 32 and the three rotors 20, 29 via the rectifying element, and turning it on allows DC power to be sent from the battery 32 to the PCU 41 via the switching element.

[0039] Furthermore, since the switch 36 includes a rectifying element, it is possible to prevent power from being supplied from the battery 32 in one of the four group components G1 to G4 to other group components while the VTOL rotor 20 and the cruise rotor 29 are operating.

[0040] Group component G2 includes VTOL rotors 20aL, 20dR, a cruise rotor 29L, a battery 32, and a switch 36. These components are configured in the same manner as those in group component G1. For simplicity, in FIG. 2, the VTOL rotors 20aL, 20dR and the cruise rotor 29L are represented as a single rotor.

[0041] Group component G3 includes VTOL rotors 20bR, 20cL, a battery 32, and a switch 36. These components are configured in the same manner as those in group component G1. For simplicity, in FIG. 2, the VTOL rotors 20bR, 20cL are represented by a single rotor.

[0042] Group component G4 includes VTOL rotors 20bL, 20cR, a battery 32, and a switch 36. These components are configured in the same manner as those in group component G1. For simplicity, in FIG. 2, the VTOL rotors 20bL, 20cR are represented by a single rotor.

[0043] In the aircraft 100 according to the present embodiment, one battery 32 is provided for each of the four group components G1 to G4, for a total of four batteries, but this is not limiting, and any number of batteries 32 may be provided, such as one battery 32 for each of two of the four group components G1 to G4, for a total of two batteries 32, or two batteries 32 for each of the group components G1 to G4, for a total of eight batteries 32. The number of group components is also not limited to three rotors, and components may be provided for two rotors or four rotors. In addition, each group component may be provided with one or more batteries 32.

[0044] The communication system 49 includes a flight controller (FCU) 92, a control unit (MCU) 91, a status sensor 71, an ECU 44a provided in the engine 44, an ECU 41a provided in the PCU 41, four switches 36 included in the group components G1 to G4, four ECUs 33 respectively connected to the battery 32, and ten ECUs 25 respectively connected to the inverter 22. These are connected to each other so as to be able to communicate with each other via communication lines (communication cables indicated by dotted lines).

[0045] The flight controller 92 is a unit that receives operation signals from the crew of the aircraft 100 via an interface 92a, such as a control stick or thrust lever, and controls the operation of each component. The flight controller 92 is connected to the control unit 91 and the ECU 25 of the aircraft 10 via a communication line. The flight controller 92 is implemented, for example, by a microcontroller, and operates by receiving low-voltage DC power from the battery 32 via a low-voltage system, and performs control functions by executing a dedicated program stored in memory.

[0046] For example, when the flight controller 92 receives a command related to steering the aircraft 100, a command for takeoff or cruising, or the like via the interface 92a, the ECU 25 detects the states (such as the rotation speed of the blades 23 and the voltage between the terminals of the inverter 22) of the VTOL rotor 20 and the cruising rotor 29 (i.e., the loads), determines the thrust required for each rotor (also referred to as a thrust command value) and the amount of power required to generate each thrust (i.e., the target power supply amount) based on these states, and transmits these values ​​to the ECUs 41a and 44a via the control unit 91, thereby causing the power generation device 40a to generate the power required to operate the rotors 20 and 29. At the same time, the thrust command value (or the rotation speed of the rotors 20 and 29 required to generate this thrust) is transmitted to the ECU 25, thereby operating the switching elements of the inverter 22, converting DC power output from the PCU 41 or DC power supplied from the battery 32 into AC power and outputting it to the motor 21. This causes the motor 21 to operate and the blades 23 to rotate, thereby enabling the VTOL rotor 20 and the cruise rotor 29 to generate the commanded thrust.

[0047] The control unit (MCU) 91 is a unit that controls the control units (i.e., ECUs) included in the communication system 49, and, for example, communicates with the switch 36 to control the operation of its switching element, transmits a target power generation amount to the ECUs 44a and 41a to control the engine 44 and the PCU 41, i.e., power generation by the power generation device 40a, and communicates with the ECU 33 to detect the state (particularly the charging state) of the battery 32. The control unit 91 is connected to the engine 44 (ECU 44a), the PCU 41 (ECU 41a), the four switches 36, and the four ECUs 33 via communication lines. The control unit 91 is implemented by, for example, a microcontroller, and operates by receiving low-voltage DC power from the battery 32 via the low-voltage system, and performs its control functions by executing dedicated programs stored in memory.

[0048] The status sensor 71 includes a plurality of sensors that detect the flight status of the aircraft 100. The flight status includes the status of the aircraft 100 (airframe), such as the altitude, attitude, speed, and position of the aircraft 100 (airframe); the status of the engine, such as the RPM of the engine 44 and the temperature and pressure of the intake and exhaust ports; and the status of the environment surrounding the aircraft 100 (here, the sky), such as the temperature, air pressure, and wind speed. The status sensor 71 includes an altitude sensor, an attitude sensor (gyro sensor), a speed sensor, and a GPS sensor for detecting the status of the aircraft; a RPM sensor, a temperature sensor, and a pressure sensor for detecting the status of the engine 44; and a temperature sensor, air pressure sensor, and wind speed sensor for detecting the status of the environment. The detection results of these sensors are transmitted to the control unit 91. The detection results of the sensors that detect the status of the engine 44 are transmitted to the control unit 91 via the ECU 44a.

[0049] The ECU 44a, the ECU 41a, the switch 36, the ECU 33, and the ECU 25 are configured as described above.

[0050] The control system 70 is a system that controls the power unit that charges the battery 32 using the power generation device 40a, and is configured to include, among the control units and the like included in the communication system 49, a control unit 91, a status sensor 71, an ECU 44a, an ECU 41a, and four ECUs 33. The control unit 91 in the control system 70 particularly calculates the charging time for the battery 32 based on the amount of power that should be stored in the battery 32 when the aircraft 100 flies in a predetermined flight state and the state of the battery 32, determines the battery charging start time based on the charging time and the flight time until the predetermined flight state is reached, and controls power generation by the power generation device 40a. The processing flow will be described later.

[0051] 3 show an example of time-dependent changes in the flight state of the aircraft 100, the amount of power consumed by the VTOL rotor 20 and the cruise rotor 29, the amount of charge consumed by the battery 32, the total power consumption, and the remaining charge (SOC) of the battery 32. Note that the amount of power generated by the power generation device 40a (i.e., power output) is equal to the greater of the total power consumption, which changes from moment to moment, and the amount of power that can be generated by the power generation device 40a (maximum output), as shown in the figure.

[0052] As shown in the upper part, the aircraft 100 (1) moves to the airfield by, for example, rolling on a taxiway at an airport (this is called taxiing), (2) operates the VTOL rotor 20 to take off, (3) further operates the cruise rotor 29 to accelerate upward, (4) stops the VTOL rotor 20 (minimizing power in this example) and cruises by operating only the cruise rotor 29, (4') when it arrives at its destination, it reduces the power of the cruise rotor 29 to (5) decelerate downward, (6) operates the VTOL rotor 20 to land at the destination airfield, and (7) stops the VTOL rotor 20 and rolls on the taxiway to evacuate from the airfield.

[0053] In the transition over time of the above-described flight states, as shown in the middle section, the amount of power consumed by the VTOL rotor 20 increases due to the operation of the VTOL rotor 20, particularly during (2) takeoff and (6) landing. The amount of power consumed by the VTOL rotor 20 at this time (i.e., the target power supply amount during takeoff and landing) is greater than the maximum output of the power generation device 40a, and the shortfall is compensated for by the discharged power from the battery 32 (this is called battery assist). As a result, as shown in the bottom section, the remaining charge (SOC) of the battery 32 decreases. Therefore, it is not appropriate to charge the battery 32 during these flight states.

[0054] On the other hand, the power consumption of the cruise rotor 29 is (3) ascending acceleration and (4) cruise rotor 29The power consumption by the cruise rotor 29 at this time is smaller than the maximum output of the power generation device 40a, so the surplus power generated can be charged to the battery 32. In particular, (4) during cruising, the aircraft 100 gains sufficient altitude, minimizes the output of the VTOL rotor 20, and operates the cruise rotor 29 to fly horizontally. Compared to takeoff and landing, the power consumption by the cruise rotor 29 (i.e., the target power supply amount during cruising) is smaller, and its fluctuations are generally smaller, and the duration of the cruising state is longer, making it suitable for stable charging of the battery 32.

[0055] As shown in the lower part, the remaining charge (SOC) of the battery 32 is significantly reduced (2) by discharging the battery 32 at takeoff to supply power to the VTOL rotor 20 and assisting the battery. (4) The battery is charged to full charge by supplying power from the power generation device 40a at any timing during cruising. (6) The battery is then discharged again at landing to supply power to the VTOL rotor 20 and assist the battery. Therefore, the discharged amount required for the battery assist at landing (6) must be charged during cruising (4). In this case, if the battery 32 stores the minimum remaining charge required to avoid an emergency (emergency charge amount), the amount of battery assist at landing can be charged at any timing during cruising (4). However, as shown by the dotted line, if the battery 32 is charged early during cruising (4), the battery 32 will remain fully charged for a longer period of time, which will likely accelerate deterioration of the battery 32.

[0056] Figure 4 shows the progression of battery 32 degradation relative to the remaining state of charge (SOC) and temperature of the battery 32. The higher the remaining state of charge (SOC) and the higher the temperature, the greater the internal resistance of the battery 32, resulting in greater power loss during charging and discharging, and thus more likely to progress in degradation. Therefore, as shown by the solid line in the bottom half of Figure 3, it is appropriate to (4) charge the battery 32 as late as possible during cruising to maintain the lowest SOC possible.

[0057] 5 shows a flow S100 of the control method according to this embodiment. This flow can be executed by the control unit 91 before the start of flight or at any timing after the start of flight, for example, at regular intervals.

[0058] In step S102, the control unit 91 determines the required amount of power that should be stored in the battery 32 when the aircraft 100 flies in a predetermined flight state. In this embodiment, the predetermined flight state is a landing state ((6) in FIG. 3 ) that requires battery assistance through discharge from the battery 32, and the battery 32 is charged in the cruising state (4) before this flight state. Here, the required amount of power can be determined from the sum of the required power supply amount that needs to be supplied from the battery 32 to the propulsion system, i.e., the VTOL rotor 20 and / or the cruising rotor 29, upon landing (i.e., the difference between the target power supply amount of the rotors 20, 29 and the maximum output of the power generation device 40a) and the emergency power supply amount that needs to be stored to avoid an emergency. By including not only the required power supply amount but also the emergency power supply amount in the required amount of power supply, it is possible to continue flight and avoid an emergency by supplying power from the battery 32 to operate the VTOL rotor 20 and / or the cruising rotor 29 even in the event of an emergency.

[0059] The required power supply amount can be determined based on the flight plan. The control unit 91 acquires the flight plan before flight, for example, by inputting it via the interface 92a by the crew or by receiving it from the airport (or its control tower) that is the departure airport, and then acquires the air route to the destination airport from the flight plan and weather information for that airport, and calculates the thrust to be generated by the VTOL rotor 20 upon landing. Note that the weather information may also be received from the airport (or its control tower). In particular, if the wind speed at the destination is high, a large load is applied to the aircraft 100's airframe, and in order to withstand this load and maintain the aircraft's attitude, the thrust to be generated by the VTOL rotor 20 increases, resulting in a large required power supply amount. Therefore, the control unit 91 determines the required power supply amount to be supplied to the VTOL rotor 20 upon landing in accordance with the flight plan, and corrects the required power supply amount by multiplying it by a disturbance coefficient based on the weather information for the destination.

[0060] The emergency storage capacity can be determined based on the detection results of the status sensor 71. If an emergency occurs during flight, such as a failure of an aircraft device, power system device, or communication device, the thrust to be generated by the VTOL rotor 20 and the cruise rotor 29 increases to maintain a safe flight state, and the power to be supplied to them also increases. Furthermore, if the power generation device 40a fails, the power supply from the power generation device 40a decreases, and the amount of power to be supplied from the battery 32 to the rotors 20 and 29 increases. The amount of increase varies greatly depending on the flight state. Therefore, the control unit 91 identifies the flight state ((1) to (7) in FIG. 3) based on the aircraft's altitude, speed, attitude, etc., based on the detection results of the status sensor 71, and accordingly determines the emergency storage capacity, for example, to charge more at (2) takeoff, (6) landing, and (1) and (5) before them, and to charge less at (3) ascent acceleration and (4) cruising.

[0061] The control unit 91 may previously store the amount of stored power for emergency situations as a function or a map according to the altitude, speed, and flight state of the aircraft 100. Alternatively, the required amount of stored power may be determined in advance for each of the anticipated emergencies according to the altitude, speed, and flight state of the aircraft 100, and the amount of stored power for emergency situations may be determined from among them based on the required amount of stored power for the emergency situation corresponding to the altitude, speed, and flight state of the aircraft 100. While lift is generated during (4) cruising, lift is not generated during (2) takeoff, (3) ascending acceleration, (5) descending deceleration, and (6) landing, and therefore the amount of stored power required to generate thrust by the rotor 20 tends to be large. More specifically, for example, (2) when flying at low speeds and low altitudes, such as during takeoff, it is necessary to set the emergency storage capacity particularly large to compensate for failure of the power generation device 40a, (4) when cruising, the aircraft is flying with the cruising rotor 29 operating, so the required power is relatively small and the emergency storage capacity can be set small, and (6) when landing, the aircraft is flying with the VTOL rotor 20 operating, so the required power is relatively large and the emergency storage capacity must be set large.

[0062] In step S104, the control unit 91 calculates the charging time based on the charging state of the battery 32. Here, the charging state of the battery 32, particularly the remaining charge amount and temperature of the battery 32, are detected by the ECU 33. The control unit 91 calculates the charging time based on the detection result.

[0063] 6 shows the relationship between the required charging output and the remaining charge (SOC) and temperature of the battery 32. The required charging output is the output power of the power generation device 40a required to charge a unit amount of power into the battery 32, and increases as the remaining charge of the battery 32 decreases and the temperature decreases, resulting in greater internal resistance and loss. Therefore, in order to reduce loss and prevent deterioration of the battery 32, it is advisable to control the charging rate so that the charging rate is slow for battery states where the required charging output is high and fast for battery states where the required charging output is low.

[0064] Note that the required output during charging may be considered to be substantially constant relative to the battery SOC, and the charging power to be charged into the battery 32 may be determined from the battery SOC, and the charging rate may be determined from the battery temperature.

[0065] The control unit 91 determines the charging power to be charged to the battery 32 based on the required amount of power determined in step S102 and the detection results of the remaining charge amount of the battery 32, determines the charging rate based on the remaining charge amount and temperature of the battery 32, and calculates the charging time required to charge the battery 32 based on the determined charging power and charging rate. By determining the charging power and charging rate of the battery 32 based on the required amount of power and the state of the battery 32 in this way, the load on the battery 32 can be reduced by charging with charging power at a charging rate according to the state of the battery 32.

[0066] In step S106, the control unit 91 calculates the flight time based on the detection results of the status sensor 71. The control unit 91 detects, in particular, the speed and position of the aircraft 100 using the status sensor 71, calculates the remaining flight distance to the destination based on the position detection results, and calculates the flight time until a predetermined flight state, i.e., the flight time until the aircraft reaches the destination and enters the landing state, based on the remaining flight distance and the speed.

[0067] In step S108, the control unit 91 determines the charging start time for the battery 32 based on the charging time calculated in step S104 and the flight time calculated in step S106.

[0068] In step S110, the control unit 91 controls the operation of the power generation device 40a based on the charging start time and the charging power of the battery 32 determined in step S108. When the charging start time arrives, as shown in FIG. 3, the control unit 91 allocates the generated power of the power generation device 40a to the battery 32 over the charging time at the charging rate determined in step S104, thereby charging the battery 32 with the required charging power. At this time, the target power generation amount of the power generation device 40a is given by the sum of the target power supply amount during cruising to supply power to the rotors 20, 29 and the charging power required to charge the battery 32. The control unit 91 transmits the target power generation amount to the ECUs 44a, 41a to control the engine 44 and the PCU 41, i.e., the power generation by the power generation device 40a. As a result, the power generation device 40a generates only the amount of power required for the aircraft 100 to fly until the charging start time, thereby making it possible to reduce fuel consumption.

[0069] Charging of the battery 32 to the required amount of charge is completed before the aircraft 100 enters a landing state, and in this example, before it enters a deceleration descent state. This ends the flow.

[0070] The control system 70 according to this embodiment includes a VTOL rotor 20 and a cruising rotor 29 that generate thrust for flying the aircraft 100, a power generation device 40a that generates electricity and supplies it to the rotors 20, 29, a power unit having a battery 32 that stores the electricity supplied from the power generation device 40a and supplies the stored electricity to the rotors 20, 29, and a control unit 91 that calculates the charging time for the battery 32 based on the required amount of electricity that should be stored in the battery 32 when the aircraft 100 flies in a predetermined flight state and the state of the battery 32, and determines the charging start time for the battery 32 based on the charging time and the flight time until the predetermined flight state is reached. The charging time of the battery 32 is calculated based on the required amount of electricity that should be stored in the battery 32 when the aircraft 100 flies in a predetermined flight state and the state of the battery 32, and the charging start time of the battery 32 is determined based on the charging time and the flight time until the predetermined flight state is reached.This makes it possible to start charging the battery 32 at the charging start time and store the required amount of electricity in the battery 32 by the time the predetermined flight state is reached, and also to maintain the charge amount of the battery 32 low until the charging start time, thereby suppressing deterioration.

[0071] The aircraft 100 according to this embodiment includes a control system 70. This makes it possible to suppress deterioration of the battery 32.

[0072] The control method according to this embodiment is a method for controlling a power unit that generates electricity using a power generation device 40a to supply power to the VTOL rotor 20 and the cruising rotor 29, which generate thrust for flying the aircraft 100, and stores the electricity supplied from the power generation device 40a using a battery 32 and supplies the stored electricity to the rotors 20, 29. The control method includes a step of calculating the charging time for the battery 32 based on the required amount of electricity that should be stored in the battery 32 when the aircraft 100 flies in a predetermined flight state and the state of the battery 32, and a step of determining the start time for charging the battery 32 based on the charging time and the flight time until the predetermined flight state is reached. The charging time of the battery 32 is calculated based on the required amount of electricity that should be stored in the battery 32 when the aircraft 100 flies in a predetermined flight state and the state of the battery 32, and the charging start time of the battery 32 is determined based on the charging time and the flight time until the predetermined flight state is reached.This makes it possible to start charging the battery 32 at the charging start time and store the required amount of electricity in the battery 32 by the time the predetermined flight state is reached, and also to maintain the charge amount of the battery 32 low until the charging start time, thereby suppressing deterioration.

[0073] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0074] 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, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0075] 12...fuselage, 14...canard, 14a...elevator, 16...rear wing, 16a...elevon, 16b...vertical stabilizer, 16c...pylon, 18...boom, 20 (20aL to 20dL, 20aR to 20dR...VTOL rotor (rotor), 21...motor, 22...inverter, 23...blade, 25...ECU, 28...duct, 29 (29L, 29R)...cruise rotor (rotor), 32...battery, 33...ECU, 36...switch, 40...high voltage system, 40a...power generation unit, 41...PCU, 41a...ECU, 42...motor generator, 44...engine, 44a...ECU, 49...communication system, 70...control system, 71...status sensor, 91...control unit, 92...flight controller, 92a...interface, 100...aircraft, G1 to G4...group component, L...central axis.

Claims

1. A control system for controlling a power unit that charges a battery using a power generation device, a propulsion system that generates thrust to fly the aircraft; a power unit including a power generation device that generates electricity and supplies the electricity to the propulsion system, and a battery that stores the electricity supplied from the power generation device and supplies the stored electricity to the propulsion system; a control unit that calculates a charging time for the battery based on a required amount of power that should be stored in the battery when the aircraft flies in a predetermined flight state and a state of the battery, and determines a charging start time for the battery based on the charging time and a flight time until the aircraft reaches the predetermined flight state, the state of the battery is the remaining power amount and temperature of the battery; The control unit determines the charging power of the battery based on the required storage amount and the remaining power amount of the battery, determines the charging speed based on the remaining power amount and temperature of the battery, and determines the charging time based on the charging power and the charging speed.

2. The control system according to claim 1 , wherein the control unit controls the operation of the power generation device based on the charging start time and the charging power of the battery.

3. 3. The control system according to claim 1, wherein the control unit determines the required amount of stored power from the sum of a required amount of power that needs to be supplied to the propulsion system when the aircraft flies in the predetermined flight state and an emergency storage amount that needs to be stored to avoid an emergency.

4. The control system according to claim 3 , wherein the control unit determines the required power supply amount based on a flight plan.

5. Further comprising a sensor for detecting a flight state of the aircraft; The control system according to claim 3 or 4, wherein the control unit determines the amount of stored power for emergency use based on a detection result of the sensor.

6. Further comprising a sensor for detecting a flight state of the aircraft; The control system according to claim 1 , wherein the control unit calculates the flight time based on a detection result of the sensor.

7. 7. The control system of claim 1, wherein the predetermined flight state is a landing state.

8. A control system for controlling a power unit that charges a battery using a power generation device, a propulsion system that generates thrust to fly the aircraft; a power unit including a power generation device that generates electricity and supplies the electricity to the propulsion system, and a battery that stores the electricity supplied from the power generation device and supplies the stored electricity to the propulsion system; a control unit that calculates a charging time for the battery based on a required amount of power that should be stored in the battery when the aircraft flies in a predetermined flight state and a state of the battery, and determines a charging start time for the battery based on the charging time and a flight time until the aircraft reaches the predetermined flight state, The control unit determines the required amount of stored power from the sum of a required amount of power that needs to be supplied to the propulsion system when the aircraft flies in the predetermined flight state and an emergency storage amount that needs to be stored to avoid an emergency.

9. An aircraft comprising a control system according to any one of claims 1 to 8.

10. A control method for controlling a power unit that generates electricity using a power generation device, supplies electricity to a propulsion system that generates thrust for flying an aircraft, and stores the electricity supplied from the power generation device using a battery and supplies the stored electricity to the propulsion system, comprising: calculating a charging time for the battery based on a required amount of power that should be stored in the battery when the aircraft flies in a predetermined flight state and a state of the battery; determining a charging start time for the battery based on the charging time and the flight time until the predetermined flight state is reached; the state of the battery is the remaining power amount and temperature of the battery; In the determining step, a charging power of the battery is determined based on the required storage amount and the remaining power amount of the battery, a charging speed is determined based on the remaining power amount and temperature of the battery, and a charging time is determined based on the charging power and the charging speed.

11. A control method for controlling a power unit that generates electricity using a power generator, supplies power to a propulsion system that generates thrust for flying an aircraft, and stores the power supplied from the power generator using a battery and supplies the stored power to the propulsion system, comprising: calculating a charging time for the battery based on a required amount of power that should be stored in the battery when the aircraft flies in a predetermined flight state and a state of the battery; determining a charging start time for the battery based on the charging time and the flight time until the predetermined flight state is reached; In the determining step, the required storage amount is determined from the sum of a required power supply amount that needs to be supplied to the propulsion system when the aircraft flies in the predetermined flight state and an emergency storage amount that needs to be stored to avoid an emergency.

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