Control device for an electric drive system of an electric aircraft, electric aircraft and computer program product

Abstract

A control device (50) of an electric drive system (10) for rotating a rotating body of either one of a rotary wing (30) and a propeller, includes a lock control section (52) for locking the rotation of the rotating body within a set lock angle range.

Description

[0001] Mutual citation of related applications

[0002] This application is based on Japanese Patent Application No. 2019-210176, filed on November 21, 2019, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a control device for an electric drive system. Background Technology

[0004] In recent years, the development of manned or unmanned electric aircraft, known as electric vertical take-off and landing (eVTOL) aircraft, has become active as a different type of aircraft from those with gas turbine engines. EVTOL aircraft include multiple electric drive systems (EDS) for driving the rotors to rotate. Multiple rotors are driven by multiple motors to rotate, thereby generating lift and thrust for the fuselage (see, for example, Patent Document 1 below).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2018-131197 Summary of the Invention

[0008] In electric vertical takeoff and landing (EVTOL) aircraft, depending on flight conditions, sometimes a portion of the rotor is not used and does not rotate. The inventors have discovered that, in order to achieve a specific purpose, there are situations where it is desirable to lock the non-rotating rotor within a specific angle range. For these purposes, the inventors have envisioned situations such as: for example, to house the non-rotating rotor in a storage unit provided on the EVTOL aircraft; to suppress efficiency degradation caused by air resistance of the non-rotating rotor; and to suppress adverse conditions caused by rotor idling. These situations are not limited to electric drive systems installed in electric aircraft such as EVTOL aircraft, but are also common in electric drive systems installed in ships and other vessels used to drive and rotate propellers. Therefore, a technology is desired that allows the rotor and propeller, as rotating bodies, to be locked within a specific angle range.

[0009] This disclosure can be implemented in the following ways.

[0010] According to one aspect of this disclosure, a control device for an electric drive system is provided. The control device is for driving a rotating body, either a rotor or a propeller, to rotate, and includes a locking control unit that locks the rotation of the rotating body within a set locking angle range.

[0011] The control device for the electric drive system according to the above method includes a locking control unit that locks the rotation of the rotating body within a set locking angle range, thereby locking the rotating body within the locking angle range. Therefore, for example, a rotating body that is not driven to rotate can be stored in the storage unit, and efficiency degradation caused by resistance from external fluid to the rotating body that is not driven to rotate can be suppressed.

[0012] This disclosure can also be implemented in various ways. For example, it can be implemented as a control method for an electric drive system, an electric aircraft including a control device for an electric drive system, an electric mobile body, etc. Attached Figure Description

[0013] The above-mentioned objects, other objects, features, and advantages of this disclosure will become clearer with reference to the accompanying drawings and the following detailed description. The accompanying drawings are described below.

[0014] Figure 1 This is a perspective view showing the external structure of an electric vertical take-off and landing machine equipped with a control device for an electric drive system.

[0015] Figure 2 This is a block diagram showing the general structure of an electric vertical take-off and landing machine.

[0016] Figure 3 It is a block diagram used to illustrate the general structure of the control device.

[0017] Figure 4 This is an explanatory diagram used to illustrate the target lock location.

[0018] Figure 5 This is an explanatory diagram used to illustrate the method of locking based on a reference angle.

[0019] Figure 6 This is a flowchart illustrating the steps of the locking process.

[0020] Figure 7 This is a schematic diagram showing the connection relationship between the motor and the rotating body in the second embodiment.

[0021] Figure 8 This is an explanatory diagram used to illustrate the method of locking based on a reference angle.

[0022] Figure 9 This is an illustrative diagram showing another example of the relationship between the rotation angle and the electrical angle.

[0023] Figure 10 This is an illustrative diagram showing another example of the relationship between the rotation angle and the electrical angle.

[0024] Figure 11 This is a flowchart illustrating the steps of the locking process in the second embodiment.

[0025] Figure 12 This is a flowchart illustrating the steps of the locking process in the third embodiment.

[0026] Figure 13 This is a flowchart illustrating the steps of the locking process in the fourth embodiment.

[0027] Figure 14 This is a flowchart illustrating the steps of the locking process in the fifth embodiment.

[0028] Figure 15 This is a flowchart illustrating the steps of the locking process in the sixth embodiment.

[0029] Figure 16 This is a perspective view showing the schematic structure of the electric vertical take-off and landing machine according to the seventh embodiment.

[0030] Figure 17 This is a flowchart illustrating the steps of the locking process in the seventh embodiment.

[0031] Figure 18 This is an explanatory diagram showing the shape of the output pulse at the target lock position. Detailed Implementation

[0032] A. First implementation method:

[0033] A-1. Device Structure:

[0034] Figure 1The control device shown, as one embodiment of this disclosure, is installed in the electric drive system 10 (hereinafter also referred to as "EDS (Electric Drive System) 10") and controls the operation of the EDS 10. In this embodiment, a plurality of EDS 10s are installed in an electric vertical take-off and landing aircraft 100 (hereinafter also referred to as "eVTOL (electric Vertical Take-Off and Landing aircraft) 100"). The eVTOL 100 is configured as a manned aircraft that is electrically driven and capable of taking off and landing in the vertical direction. The eVTOL 100 includes: a fuselage 20; a plurality of rotors 30; and a plurality of EDS 10s, wherein the plurality of EDS 10s correspond to each rotor 30 and are used to drive each rotor 30 to rotate. The eVTOL 100 of this embodiment includes six rotors 30 and six EDS 10s. In addition, the number of rotors 30 and EDS 10s included in the eVTOL 100 is not limited to six, and may be any number such as four or nine.

[0035] The fuselage 20 corresponds to the part of the eVTOL 100 excluding the six rotors 30 and the six EDS10s. The fuselage 20 includes the main fuselage section 21, two main wings 25, and a tail section 28.

[0036] The fuselage main body 21 constitutes the trunk of the eVTOL 100 and is formed along the longitudinal direction of the eVTOL 100. A passenger compartment 22 is formed inside the forward side of the fuselage main body 21. Two rotor blades 30 are arranged vertically relative to each other on the rear side of the fuselage main body 21. Two main wings 25 extend from the fuselage main body 21 to the right and left, respectively. A rotor blade 30 is disposed approximately at the center of each main wing 25. A rotor blade 30 is disposed at the leading end of each main wing 25. A tail fin 28 is formed at the rear end of the fuselage main body 21.

[0037] Two of the six rotors 30 located on the fuselage main body 21 and two rotors 30 located approximately at the center of each main wing 25 constitute lift rotors 31 that primarily obtain lift from the fuselage 20. The lift rotors 31 are driven to rotate when the eVTOL 100 is in takeoff mode or similar operating mode. Furthermore, when the eVTOL 100 is in cruise mode or similar operating mode, the lift rotors 31 are not driven to rotate. In this embodiment, each lift rotor 31, when not driven to rotate, is locked within a specific angle range and stored in a storage compartment 35, which is formed vertically below each lift rotor 31. The storage compartment 35 is formed in a direction approximately parallel to the longitudinal direction relative to the eVTOL 100. A detailed description of the locking of the lift rotors 31 will be given later. Additionally, the tilt angle of each lift rotor 31 is fixed.

[0038] Of the six rotors 30, the two rotors 30 located at the leading end of each main wing 25 constitute tilting rotors 32. Each tilting rotor 32 is configured to change its tilt angle. This is possible when the eVTOL 100 is in takeoff mode, etc. Figure 1 As shown, each tilting rotor 32 is tilted at an angle such that its rotation axis is aligned with the vertical direction. Figure 1 Depending on the state, when the eVTOL 100 is in cruise mode, each tilting rotor 32 is tilted at an angle such that its rotation axis is aligned with the horizontal direction. Furthermore, when the eVTOL 100 is in landing mode, the tilting rotor 32 is de-rotated. In this embodiment, each tilting rotor 32 is locked within a specific angle range while de-rotated. A detailed explanation of the locking of the tilting rotor 32 will be provided later.

[0039] Six rotating blades 30 are driven to rotate independently around their respective axes of rotation. Each rotating blade 30 has blades 33 symmetrically arranged about the axis of rotation in a direction perpendicular to it. The blades 33 have a generally plate-like shape and have the axis of rotation inserted approximately in the center. In this embodiment, each rotating blade 30 has two blades 33. These two blades 33 are configured to rotate independently.

[0040] The six EDS10s are configured as drive units to rotate each rotor 30. Four of the six EDS10s drive the lifting rotor 31 to rotate. Two of the six EDS10s drive the tilting rotor 32 to rotate. The structures of each EDS10 are approximately identical.

[0041] like Figure 2 As shown, each EDS10 includes a motor 11, an inverter circuit 12, and a control device 50.

[0042] Motor 11 outputs torque corresponding to the voltage and current supplied from inverter circuit 12, driving rotor 30 to rotate via shaft 19. Rotation control of motor 11 is performed using electrical angles and by outputting torque as instructed. In this embodiment, motor 11 includes, but is not limited to, a brushless motor, and may also include any type of motor such as an induction motor or reluctance motor. In this embodiment, the output of motor 11 is transmitted to rotor 30 without gears. Therefore, the mechanical angle of motor 11 coincides with the rotation angle of rotor 30. Figure 3 As shown, the motor 11 in this embodiment is equipped with an angle sensor 13, including a resolver, etc. Alternatively, the angle sensor 13 may be omitted.

[0043] Figure 2 The inverter circuit 12 shown includes switching elements such as IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), and converts the DC voltage supplied from the power supply unit 80 into a three-phase AC voltage and supplies it to the motor 11. The inverter circuit 12 switches the switching elements with a duty cycle corresponding to the control signal supplied from the control device 50.

[0044] Figure 3 The control device 50 shown includes a computer with a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The CPU functions as the inverter control unit 51, the locking control unit 52, and the angle acquisition unit 53 by executing a control program pre-stored in the ROM. The RAM and ROM of the control device 50 function as a reference angle storage unit 54. Furthermore, the control device 50 includes a pulse output unit 55.

[0045] The inverter control unit 51 outputs a control signal to the inverter circuit 12, thereby controlling the operation of the inverter circuit 12. The locking control unit 52 outputs a control signal to the inverter control unit 51 to control the motor 11, thereby locking the rotation of the rotor 30 within a preset angle range (hereinafter also referred to as the "locking angle range"). The angle acquisition unit 53 acquires the current angle of the motor 11. In this embodiment, the angle acquisition unit 53 acquires the electrical angle of the motor 11 using the value measured by the angle sensor 13, but it can also estimate the electrical angle of the motor 11 based on the values ​​measured by current sensors (not shown) respectively provided in each phase of the inverter circuit 12. The reference angle storage unit 54 stores the reference angle. The reference angle represents the angle corresponding to the target locking position when the rotation of the rotor 30 is locked within the locking angle range. As described later, the reference angle in this embodiment is represented by the electrical angle of the motor 11. The pulse output unit 55 has a circuit including a transistor and outputs pulses in response to the control signal received from the locking control unit 52. Detailed descriptions of the locking control unit 52, angle acquisition unit 53, reference angle storage unit 54, and pulse output unit 55 will be provided later.

[0046] like Figure 2 As shown, the eVTOL 100 is equipped with various components for controlling each EDS 10. Specifically, these include the flight control system 40, the communication device 70, the power supply unit 80, and the user interface unit 90 (hereinafter also referred to as "UI unit 90").

[0047] The flight control system 40 includes a computer with a CPU, ROM, and RAM. The CPU controls the overall operation of the eVTOL 100 by executing a control program pre-stored in the ROM. The overall operation of the eVTOL 100 includes, for example, takeoff, landing, and cruise maneuvers. These maneuvers can be executed based on a pre-set flight program or through passenger operation. The flight control system 40 is connected to each EDS 10 and outputs control commands to the control devices 50 of each EDS 10 according to the operating mode of the eVTOL 100. Furthermore, the flight control system 40 outputs a lock command to the control devices 50 of each EDS 10, which stops and locks the rotation of the rotor 30 when it is in a non-driven rotation state. For example, when the operating mode of the eVTOL 100 is cruise mode, a lock command is output to the control device 50 of the EDS 10 corresponding to the lift rotor 31. Furthermore, for example, when the eVTOL 100 is in landing mode, a lock command is output to the control device 50 of the EDS10 corresponding to the tiltrotor 32. A detailed explanation of the locking of the tiltrotor 30 will be provided later.

[0048] The communication device 70 communicates with another eVTOL 100, a ground control tower, etc. The communication device 70 can be, for example, a civilian VHF (Very High Frequency) wireless device. In addition to civilian VHF, the communication device 70 can also be configured to perform communication such as wireless LAN as defined in IEEE 802.11 or wired LAN as defined in IEEE 802.3.

[0049] The power supply unit 80 functions as one of the power supply sources in the eVTOL 100, supplying three-phase AC power to the motor 11 via the inverter circuits 12 of each EDS 10. In this embodiment, the power supply unit 80 includes, but is not limited to, lithium-ion batteries; it may also include any secondary battery such as nickel-metal hydride batteries; it may also include any power supply source such as fuel cells or generators to replace secondary batteries; or it may include any power supply source such as fuel cells or generators in addition to secondary batteries.

[0050] The UI unit 90 provides a predetermined user interface. This user interface may include, for example, an input unit such as a keyboard and buttons, or a display unit such as an LCD panel. The UI unit 90 is, for example, installed in the passenger compartment 22 of the eVTOL 100. Passengers can use the UI unit 90 to change the operating mode of the eVTOL 100.

[0051] In this embodiment, the control device 50 of the EDS10 performs the locking process described later, thereby stopping and locking the rotation of the rotor 30 to a target locking position when the rotor 30 is planned to be de-driven and rotated in a state where it is currently driven to rotate. The locking angle range described above refers to the range of allowable offsets based on the target locking position. Therefore, the locking angle range includes the target locking position.

[0052] use Figure 4 and Figure 5 The relationship between the target locking position and the mechanical and electrical angles of motor 11 will be explained. Figure 4 In the diagram, the mechanical angle of motor 11 is represented by a dashed line, the electrical angle by a thin solid line, and the resolver angle by a thick solid line for reference. Furthermore, Figure 5 The horizontal axis represents time (s). In this embodiment, the output of motor 11 is transmitted to rotor 30 without passing through gears; therefore, the target locking position of rotor 30 can be represented by the mechanical angle of motor 11. Furthermore, Figure 4 and Figure 5 The example shown omits the illustration of the locking angle range.

[0053] As described above, electrical angles are used to control the rotation of motor 11. Figure 4 and Figure 5 The example shown illustrates the mechanical angle (deg) and electrical angle (deg) of a motor 11 with 4 pole pairs. The number of pole pairs is equivalent to the number of magnetic poles in motor 11 divided by 2. The number of cycles of the electrical angle is equivalent to the number of cycles of the mechanical angle multiplied by the number of pole pairs. Figure 4 and Figure 5 In the example shown, the ratio of the number of mechanical angle cycles of motor 11 per unit time to the number of electrical angle cycles of motor 11 per unit time is 1:4. During the rotation of motor 11, from 0° to 360°, there are four electrical angle cycles from 0° to 360°.

[0054] A-2. Locking Process:

[0055] When the rotation of the motor 11 in each EDS10 begins, the control device 50 of each EDS10 executes... Figure 6 The locking process is shown.

[0056] The locking control unit 52 detects a reference angle, that is, it detects the angle corresponding to the target locking position when the rotor 30 is locked within the locking angle range (step S110). In this embodiment, the reference angle is set as the value of the electrical angle of the motor 11 when the rotor 30 was last locked, and is stored in the reference angle storage unit 54. Therefore, in step S110, the value of this electrical angle is read from the reference angle storage unit 54 and detected. Alternatively, the reference angle can also be set as the value of the electrical angle when the start switch of the eVTOL 100 is turned on (time t0) and stored in the reference angle storage unit 54. Figure 5 In this context, the moment when the rotation of motor 11 begins is denoted as t0. As described above, if the electrical angle value at the time of the last lock is the reference angle, and eVTOL 100 remains in the locked state and stops, the electrical angle value at the time when the start switch of eVTOL 100 is turned on (time t0) is equivalent to the reference value.

[0057] like Figure 6 As shown, the locking control unit 52 counts the number of times the electrical angle of the motor 11 reaches 0 degrees (step S120). In Figure 5 In the example shown, the counter count becomes 1 at time t1, 2 at time t2, 3 at time t3, and 4 at time t4 as the motor 11 rotates.

[0058] like Figure 6As shown, the locking control unit 52 determines whether the counter count has reached the pole number (step S130). If it is determined that the counter count has not reached the pole number (step S130: No), it returns to step S120. On the other hand, if it is determined that the counter count has reached the pole number (step S130: Yes), the locking control unit 52 determines whether the current electrical angle of the motor 11 has reached the reference angle (step S140). Figure 5 As shown, the electrical angle at time t4, when the counter reaches the pole number, is 0 degrees. This electrical angle increases as the motor 11 rotates and reaches the reference angle at time t5.

[0059] like Figure 6 As shown, if it is determined that the current electrical angle of motor 11 has not reached the reference angle (step S140: No), the locking control unit 52 repeatedly performs step S140. On the other hand, if it is determined that the current electrical angle of motor 11 has reached the reference angle (step S140: Yes), the locking control unit 52 causes the pulse output unit 55 to output a pulse (step S150). Figure 5 In the example shown, a pulse is output at time t5. By performing the above control, the pulse output unit 55 outputs a pulse whenever the rotational position of the rotor 30 reaches the target locking position.

[0060] like Figure 6 As shown, the locking control unit 52 resets the counter count (step S160). The locking control unit 52 determines whether there is a locking command from the flight control system 40 (step S170). If it is determined that there is no locking command (step S170: No), it returns to step S120. On the other hand, if it is determined that there is a locking command (step S170: Yes), the rotation of the motor 11 is locked, thereby locking the rotation of the rotor blade 30 (step S180). In step S180, the rotation of the motor 11 is locked by setting the initial reference angle reached after the counter count reaches the number of pole pairs of the motor 11 as the target, thereby locking the rotation of the rotor blade 30. Figure 3 As shown, the current electrical angle of the motor 11 acquired by the angle acquisition unit 53 can be controlled to match the reference angle stored in the reference angle storage unit 54 to lock the rotation of the motor 11. Instead of abruptly stopping the rotation of the motor 11, the rotation speed can be gradually reduced, and the rotation can be stopped and locked when the reference angle is reached below a predetermined speed. The locking process ends by executing step S180.

[0061] In the locking process of this embodiment, when the operating mode of the eVTOL 100 is cruise mode, the lifting rotor 31, which is in a non-rotating state, is locked at a target locking position within the locking angle range. Here, the locking angle range of the lifting rotor 31 is included in the retraction angle range, which is the angle range within which the lifting rotor 31 can be retracted into the retraction portion 35. Therefore, the lifting rotor 31 stops rotating and locks at the angle within which it can be retracted into the retraction portion 35. As described above, the lifting rotor 31 of this embodiment has two blades 33, which are retracted into the retraction portion 35. When retracted into the retraction portion 35, the two blades 33 overlap in a manner that aligns with each other in the length direction. At this time, one of the two blades 33 can be locked at the target locking position, and the other blade 33 can overlap with the first blade 33. In this case, a mechanism for aligning the other blade 33 with the first blade 33 can be provided on the rotor 30. In addition, the two blades 33 can also be controlled to lock independently at their respective target locking positions.

[0062] Furthermore, in the locking process of this embodiment, when the operating mode of the eVTOL 100 is landing mode, the tilting rotor 32, which will be in a state of not being driven to rotate, will be locked within the locking angle range. The tilting rotor 32 stops rotating and locks at an angle where the air resistance value is minimized. In this embodiment, the tilting rotor 32 stops rotating and locks at an angle where the air resistance value experienced by the tilting rotor 32 according to its locked position is less than the midpoint between the maximum and minimum values. More specifically, the tilting rotor 32 stops rotating and locks at an angle where the air resistance value is minimized.

[0063] Furthermore, in this embodiment, when the number of blades 33 of the rotor 30 is set to A, the target locking position is set to B, and 180 degrees is set to π, the locking angle range is set to an angle range of [B-2π / A] or more and [B+2π / A] or less.

[0064] The control device 50 of the EDS10 according to the first embodiment described above includes a locking control unit 52 that locks the rotation of the rotor 30 within a set locking angle range. Therefore, the rotor 30 can be locked within the locking angle range. Thus, for example, the rotor 30 that is not driven to rotate can be stored in the storage unit 35, and the efficiency degradation caused by the air resistance of the rotor 30 that is not driven to rotate can be suppressed.

[0065] In a structure where the rotor 30, which is not being driven to rotate, is not locked, there are concerns that the idling of the rotor 30 may cause a decline in the lifespan of the rotor 30 and the motor 11, and may induce malfunctions in the rotor 30 and the motor. Furthermore, such malfunctions may cause the rotor 30 to fail to operate according to commands when it is intended to be driven to rotate. Therefore, in a structure where the rotor 30, which is not being locked to rotate, is not being driven to rotate, adverse conditions caused by the idling of the rotor 30 may occur.

[0066] In response, the control device 50 of the EDS10 according to this embodiment locks the non-driven rotating rotor 30 within the locking angle range, thereby suppressing adverse conditions caused by the idling of the rotor 30.

[0067] Furthermore, the locking angle range of the lifting rotor 31 is included within the angle range that allows the lifting rotor 31 to be housed in the housing 35, i.e., the housing angle range. Therefore, the lifting rotor 31, which is not driven to rotate, can be easily housed in the housing 35 provided on the fuselage 20 of the eVTOL 100. In addition, since the locking angle range is included within the housing angle range, it is possible to omit the need for guide members or the like in the housing 35 for housing the lifting rotor 31, thus reducing the structural complexity of the housing 35.

[0068] Furthermore, the locking angle range of the tilting rotor 32 is a range with relatively low air resistance compared to the midpoint between the maximum and minimum air resistance values ​​experienced by the tilting rotor 32 depending on its locked position. Therefore, efficiency degradation caused by air resistance when the tilting rotor 32 is not driven to rotate can be effectively suppressed. Moreover, the tilting rotor 32 stops rotating and locks at the angle with the minimum air resistance value, thus further suppressing efficiency degradation.

[0069] Furthermore, by setting the number of blades 33 of the rotor 30 to A, the target lock position to B, and 180 degrees to π, the lock angle range is set to an angle range of [B - 2π / A] to [B + 2π / A]. Therefore, it is possible to prevent the lock angle of the rotor 30 from deviating significantly from the target lock position.

[0070] Furthermore, the control device 50 has a reference angle storage unit 54 that stores the reference angle used to lock the rotor 30 within the locking angle range as the value of the electrical angle of the motor 11. Therefore, the motor 11 can be locked using the reference angle, and the control for locking the rotation of the motor 11 can be suppressed.

[0071] Furthermore, the locking control unit 52 counts the number of times the electrical angle of the motor 11 reaches 0 degrees, sets the initial reference angle reached after this number reaches the number of pole pairs of the motor 11 as the target, and locks the rotation of the motor 11, thereby locking the rotation of the rotor 30. Therefore, the rotation of the rotor 30 can be locked using the electrical angle of the motor 11, thus eliminating the need for a detection unit for detecting the current rotational position of the rotor 30, an angle sensor for detecting the current rotational angle of the rotor 30, and so on. Furthermore, the angle sensor 13 of the motor 11 can be omitted. Therefore, the structural complexity of the eVTOL 100, rotor 30, and EDS 10 can be suppressed, and the increased manufacturing cost of the eVTOL 100, rotor 30, and EDS 10 can be reduced.

[0072] B. Second implementation method:

[0073] like Figure 7 As shown, the EDS10 of the second embodiment, equipped with the control device 50, differs from the EDS10 of the first embodiment in that the output of the motor 11 is transmitted to the rotor 30 via the gear G. Consequently, the locking process of the second embodiment differs from the locking process of the first embodiment in that step S130a is performed instead of step S130. Other structures are the same as in the first embodiment; therefore, the same symbols are used for the same structures, and detailed descriptions are omitted.

[0074] In the second embodiment of EDS10, the output of motor 11 is transmitted to rotor 30 via gear G. Therefore, the mechanical angle of motor 11 is not the same as the rotation angle of rotor 30. Therefore, in order to stop and lock the rotation of rotor 30 at the target locking position, it is necessary to estimate the rotation angle of rotor 30 based on the electrical angle of motor 11 according to the gear ratio.

[0075] exist Figures 8-10 The relationship between the rotation angle of the rotor 30, the mechanical angle of the motor 11, and the electrical angle of the motor 11 is shown. Figure 8 The diagram illustrates the case where the gear ratio of gear G is 2 and the number of pole pairs of motor 11 is 4. Since the gear ratio of gear G is 2, the rotor 30 rotates twice during one rotation of motor 11. Therefore, there are two cycles of electrical angle from 0° to 360° between the mechanical angle reaching 180° during one rotation of rotor 30. The ratio of the rotation angle of rotor 30 to the electrical angle of motor 11 can be calculated using the gear ratio of gear G and the number of pole pairs of motor 11. Figure 8 In the example shown, the ratio of the number of cycles of the rotation angle of the rotor 30 per unit time to the number of cycles of the mechanical angle of the motor 11 per unit time to the number of cycles of the electrical angle of the motor 11 per unit time is 2:1:4. Furthermore, Figure 9 The diagram shows a structure with the following ratios: number of cycles of rotation angle of rotor 30 per unit time: number of cycles of mechanical angle of motor 11 per unit time: number of cycles of electrical angle of motor 11 per unit time = 3:12:32. Figure 10 The diagram shows a structure with the following ratios: number of cycles of rotation angle of rotor 30 per unit time: number of cycles of mechanical angle of motor 11 per unit time: number of cycles of electrical angle of motor 11 per unit time = 8:3:12.

[0076] The electrical angle of motor 11 at the moment when the rotation angle of rotor 30 is a certain value exhibits a periodically identical value. Therefore, the electrical angle of motor 11 when the rotation angle of rotor 30 is in the target-locked position exhibits a periodically identical value. More specifically, the same value is exhibited at least whenever the least common multiple of the ratio of the electrical angle of motor 11 to the rotation angle of rotor 30 is reached. For example, in... Figure 8 In the example shown, the rotation angle of the rotor 30 : the electrical angle of the motor 11 = 2 : 4 = 1 : 2. Therefore, the least common multiple of the ratio of the electrical angle of the motor 11 to the rotation angle of the rotor 30 is "2". Thus, every two cycles of the electrical angle of the motor 11, both the rotation angle of the rotor 30 and the electrical angle of the motor 11 become 0 degrees. Furthermore, for example in... Figure 9 In the example shown, the rotation angle of the rotor 30 : the electrical angle of the motor 11 = 3 : 32, therefore the least common multiple of the ratio of the electrical angle of the motor 11 to the rotation angle of the rotor 30 is "96". Therefore, every 96 cycles of the electrical angle of the motor 11, the rotation angle of the rotor 30 and the electrical angle of the motor 11 both become 0 degrees. Furthermore, for example in... Figure 10 In the example shown, the rotation angle of the rotor 30 : the electrical angle of the motor 11 = 8 : 12 = 2 : 3. Therefore, the least common multiple of the ratio of the electrical angle of the motor 11 to the rotation angle of the rotor 30 is "6". Thus, every 6 cycles of the electrical angle of the motor 11, the rotation angle of the rotor 30 and the electrical angle of the motor 11 both become 0 degrees.

[0077] Figure 11In the locking process of the second embodiment shown, after executing step S120, the locking control unit 52 determines whether the counter count has reached the least common multiple of the ratio of the electrical angle of the motor 11 to the rotation angle of the rotor 30 (step S130a). If it is determined that the counter count has not reached the least common multiple of the ratio of the electrical angle of the motor 11 to the rotation angle of the rotor 30 (step S130a: No), the process returns to step S120. On the other hand, if it is determined that the counter count has reached the least common multiple of the ratio of the electrical angle of the motor 11 to the rotation angle of the rotor 30 (step S130a: Yes), the locking control unit 52 determines whether the current electrical angle of the motor 11 has reached the reference angle (step S140). By performing the above control, whenever the electrical angle of the motor 11 is the reference angle and the rotation position of the rotor 30 reaches the target locking position, the pulse output unit 55 outputs a pulse. In step S180 of the locking process in the second embodiment, the rotation of the motor 11 is locked by setting the initial reference angle reached after the counter count reaches the least common multiple of the ratio of the electrical angle of the motor 11 to the rotation angle of the rotor 30. Thus, the rotation of the rotor 30 is locked. By executing step S180, the locking process ends.

[0078] The control device 50 of the EDS10 according to the second embodiment described above performs the same effect as the first embodiment. In addition, in the structure in which the output of the motor 11 is transmitted to the rotor 30 via the gear G, the rotation of the rotor 30 can also be locked within the locking angle range.

[0079] C. Third implementation method:

[0080] like Figure 12 As shown, the locking process performed in the control device 50 of the third embodiment differs from the locking process of the first embodiment in that it performs steps S112b, S114b, and S140b instead of steps S120 to S160. Other structures are the same as in the first embodiment; therefore, the same symbols are used for the same structures and their detailed descriptions are omitted.

[0081] After executing step S110, the locking control unit 52 calculates the mechanical angle corresponding to the reference angle detected in step S110 (step S112b). This mechanical angle is calculated by dividing the detected reference angle by the number of pole pairs of the motor 11.

[0082] The locking control unit 52 calculates the current mechanical angle of the motor 11 based on the current electrical angle of the motor 11 (step S114b). The current mechanical angle of the motor 11 is calculated by dividing the current electrical angle of the motor 11 by the number of pole pairs of the motor 11. The locking control unit 52 determines whether the current mechanical angle of the motor 11 calculated in step S114b reaches the mechanical angle corresponding to the reference angle of the motor 11 calculated in step S112b (step S140b). If it is determined that the current mechanical angle of the motor 11 does not reach the mechanical angle corresponding to the reference angle (step S140b: No), the process returns to step S114b. On the other hand, if it is determined that the current mechanical angle of the motor 11 reaches the mechanical angle corresponding to the reference angle (step S140b: Yes), the locking control unit 52 determines whether there is a locking command from the flight control system 40 (step S170). If it is determined that there is no locking command (step S170: No), the process returns to step S114b. On the other hand, if a locking command is detected (step S170: Yes), the rotation of motor 11 is locked, thereby locking the rotation of rotor 30 (step S180). In step S180, the rotation of motor 11 is locked when the current mechanical angle of motor 11 reaches the reference angle, thus locking the rotation of rotor 30. By executing step S180, the locking process ends.

[0083] The control device 50 of the EDS10 according to the third embodiment described above performs the same effect as the first embodiment. In addition, since the locking control unit 52 calculates the mechanical angle corresponding to the electrical angle, it is possible to omit counting the number of times the electrical angle of the motor 11 reaches 0 degrees and output a pulse at the reference angle.

[0084] D. Fourth Implementation Method:

[0085] The EDS10 of the fourth embodiment, equipped with a control device 50, differs from the EDS10 of the third embodiment in that the output of the motor 11 is transmitted to the rotor 30 via gear G. Along with this, Figure 13 The locking process of the fourth embodiment shown differs from that of the third embodiment in that steps S112c, S114c, and S140c are performed instead of steps S112b, S114b, and S140b. Other structures are the same as in the third embodiment; therefore, the same symbols are used for the same structures and their detailed descriptions are omitted.

[0086] After executing step S110, the locking control unit 52 calculates the rotation angle of the rotor 30 corresponding to the reference angle detected in step S110 (step S112c). This rotation angle is calculated by dividing the detected reference angle by the number of pole pairs of the motor 11 and multiplying it by the gear ratio of the gear G.

[0087] The locking control unit 52 calculates the current rotation angle of the rotor 30 based on the current electrical angle of the motor 11 (step S114c). The current rotation angle of the rotor 30 is calculated by dividing the current electrical angle of the motor 11 by the number of pole pairs of the motor 11 and multiplying by the gear ratio of the gear G. The locking control unit 52 determines whether the current rotation angle of the rotor 30 calculated in step S114c reaches the rotation angle of the rotor 30 corresponding to the reference angle of the motor 11 calculated in step S112c (step S140c). If it is determined that the current rotation angle of the rotor 30 does not reach the rotation angle corresponding to the reference angle (step S140c: No), the process returns to step S114c. On the other hand, if it is determined that the current rotation angle of the rotor 30 reaches the rotation angle corresponding to the reference angle (step S140c: Yes), the locking control unit 52 determines whether there is a locking command from the flight control system 40 (step S170). If no locking command is detected (step S170: No), the process returns to step S114c. On the other hand, if a locking command is detected (step S170: Yes), the rotation of motor 11 is locked, thereby locking the rotation of rotor 30 (step S180). In step S180, the rotation of motor 11 is locked when the current rotation angle of rotor 30 reaches the reference angle, thus locking the rotation of rotor 30. The locking process ends upon execution of step S180.

[0088] The control device 50 of the EDS10 according to the fourth embodiment described above performs the same effect as the third embodiment. In addition, in the structure in which the output of the motor 11 is transmitted to the rotor 30 via the gear G, the rotation of the rotor 30 can also be locked within the locking angle range.

[0089] E. Fifth implementation method:

[0090] In the control device 50 of the fifth embodiment, the angle acquisition unit 53 uses the value measured by the angle sensor 13 provided on the motor 11 to acquire the mechanical angle of the motor 11, and the reference angle storage unit 54 stores the angle corresponding to the target locking position, i.e., the reference angle, as the value of the mechanical angle of the motor 11. Along with this, the locking process of the fifth embodiment differs from that of the third embodiment in that steps S112b and S114b are omitted and step S140d is executed instead of step S140b. Other structures are the same as in the third embodiment, therefore the same reference numerals are used for the same structures and their detailed descriptions are omitted. Furthermore, in this embodiment, the output of the motor 11 is transmitted to the rotor 30 without passing through gears.

[0091] The locking control unit 52 detects the reference angle, which corresponds to the target locking position when the rotor 30 is locked within the locking angle range (step S110). In this embodiment, the reference angle is set to the value of the mechanical angle of the motor 11 when the rotor 30 was locked last time, and is stored in the reference angle storage unit 54. Alternatively, the reference angle can also be set to the value of the mechanical angle when the start switch of the eVTOL 100 is turned on and stored in the reference angle storage unit 54.

[0092] The locking control unit 52 determines whether the current mechanical angle of the motor 11 has reached the reference angle (step S140d). The current mechanical angle of the motor 11 is measured by the angle sensor 13 installed on the motor 11 and acquired by the angle acquisition unit 53. If it is determined that the current mechanical angle of the motor 11 has not reached the reference angle (step S140d: No), the locking control unit 52 repeats step S140d. On the other hand, if it is determined that the current mechanical angle of the motor 11 has reached the reference angle (step S140d: Yes), the locking control unit 52 determines whether there is a locking command from the flight control system 40 (step S170). If it is determined that there is no locking command (step S170: No), it returns to step S140d. On the other hand, if it is determined that there is a locking command (step S170: Yes), the rotation of the motor 11 is locked, thereby locking the rotation of the rotor 30 (step S180). In step S180, the rotation of motor 11 is locked when the current mechanical angle of motor 11 reaches the stored reference angle, thereby locking the rotation of rotor 30.

[0093] The control device 50 of the EDS10 according to the fifth embodiment described above performs the same effect as the third embodiment. In addition, the angle sensor 13 for detecting the mechanical angle of the motor 11 is provided on the motor 11, and the rotation of the rotor 30 is locked when the current mechanical angle of the motor 11 reaches the stored reference angle, so the calculation of the mechanical angle can be omitted.

[0094] F. Sixth Implementation Method:

[0095] In the EDS10 of the sixth embodiment, which is equipped with a control device 50, the output of the motor 11 is transmitted to the rotor 30 via the gear G; the rotor 30 is equipped with an angle sensor and the angle acquisition unit 53 acquires the rotation angle of the rotor 30; and the reference angle storage unit 54 stores the angle corresponding to the target locking position, i.e., the reference angle, as the value of the rotation angle of the rotor 30. Consequently, the locking process of the sixth embodiment differs from that of the fifth embodiment in that steps S110e and S140e are performed instead of steps S110 and S140d. Other structures are the same as in the fifth embodiment; therefore, the same symbols are used for the same structures, and detailed descriptions are omitted.

[0096] exist Figure 15 In step S110e, the locking control unit 52 detects the reference angle, which corresponds to the target locking position when the rotor 30 is locked within the locking angle range (step S110). In this embodiment, the reference angle is set to the value of the rotation angle of the rotor 30 when it was last locked, and stored in the reference angle storage unit 54. Alternatively, the reference angle can also be set to the value of the rotation angle of the rotor 30 when the start switch of the eVTOL 100 is turned on, and stored in the reference angle storage unit 54.

[0097] The locking control unit 52 determines whether the current rotation angle of the rotor 30 has reached the reference angle (step S140e). The current rotation angle of the rotor 30 is measured by an angle sensor installed on the motor 11 and acquired by the angle acquisition unit 53. If it is determined that the current rotation angle of the rotor 30 has not reached the reference angle (step S140e: No), the locking control unit 52 repeats step S140e. On the other hand, if it is determined that the current rotation angle of the rotor 30 has reached the reference angle (step S140e: Yes), the locking control unit 52 determines whether there is a locking command from the flight control system 40 (step S170). If it is determined that there is no locking command (step S170: No), it returns to step S140e. On the other hand, if it is determined that there is a locking command (step S170: Yes), the rotation of the motor 11 is locked, thereby locking the rotation of the rotor 30 (step S180). In step S180, the rotation of motor 11 is locked when the current rotation angle of rotor 30 reaches the stored reference angle. Thus, the rotation of rotor 30 is locked.

[0098] The control device 50 of the EDS10 according to the sixth embodiment described above performs the same effect as the fifth embodiment. Furthermore, since the rotor 30 is equipped with an angle sensor for detecting the rotation angle of the rotor 30, and the rotation of the rotor 30 is locked when the current rotation angle of the rotor 30 reaches a stored reference angle, the rotation of the rotor 30 can be locked within the locking angle range, even in a structure where the output of the motor 11 is transmitted to the rotor 30 via the gear G.

[0099] G. Seventh Implementation Method:

[0100] like Figure 16 As shown, the EDS10 of the seventh embodiment is installed in the eVTOL 100f. The eVTOL 100f differs from the eVTOL 100 of the first embodiment in that it also has a detection unit for detecting the rotational position of the rotor 30. Along with this, Figure 17 The locking process of the seventh embodiment shown differs from that of the first embodiment in that steps S110 to S130 and S160 are omitted and step S140f is performed instead of step S140. Other structures are the same as in the first embodiment, therefore the same symbols are used for the same structures and their detailed descriptions are omitted. Furthermore, in this embodiment, the output of the motor 11 is transmitted to the rotor 30 without gears, but it can also be transmitted to the rotor 30 via gears.

[0101] The eVTOL 100f of the seventh embodiment is equipped with a vision servo 92 and an infrared sensor 94 as detection units for detecting the rotational position of the rotor 30. The vision servo 92 includes, for example, a camera installed on the tail fin 28, and detects the rotational position of each rotor 30. The infrared sensor 94 is, for example, installed vertically below each rotor 30, and detects the rotational position of each rotor 30. Alternatively, either the vision servo 92 or the infrared sensor 94 may be omitted, or the infrared sensor 94 may be replaced by any detection unit capable of detecting the rotational position of the rotor 30, such as an ultrasonic sensor, a position sensor, a light sensor, or a photoelectric sensor.

[0102] like Figure 18 As shown, the pulse output unit 55 included in the EDS10 of the seventh embodiment outputs a pulse based on the detection results of the vision servo 92 and the infrared sensor 94 when the current rotational position of the rotor 30 coincides with the target locking position for locking the rotor 30 within the locking angle range. With the above structure, the pulse output unit 55 outputs a pulse every time the rotor 30 rotates one revolution.

[0103] like Figure 17As shown, the locking control unit 52 determines whether the current rotational position of the rotor 30, detected by the vision servo 92 and the infrared sensor 94, has reached the target locking position (step S140f). If it is determined that the current rotational position of the rotor 30 has not reached the target locking position (step S140f: No), the locking control unit 52 repeats step S140f. On the other hand, if it is determined that the current rotational position of the rotor 30 has reached the target locking position (step S140f: Yes), the locking control unit 52 determines whether there is a locking command from the flight control system 40 (step S170). If it is determined that there is no locking command (step S170: No), it returns to step S140f. On the other hand, if it is determined that there is a locking command (step S170: Yes), the rotation of the motor 11 is locked, thereby locking the rotation of the rotor 30 (step S180). In step S180, the locking control unit 52 locks the rotor 30 by setting the output of a pulse through the pulse output unit 55 as the target. The locking process ends after step S180 is executed.

[0104] The control device 50 of the EDS10 according to the seventh embodiment described above performs the same effect as the first embodiment. Furthermore, the eVTOL 100f is provided with a detection unit for detecting the rotational position of the rotor 30, and the pulse output unit 55 outputs a pulse when the target locking position for locking the rotor 30 within the locking angle range coincides with the current rotational position of the rotor 30. Therefore, the detection of electrical angles and the calculation of mechanical angles can be omitted, and the reference angle storage unit 54 can also be omitted. Furthermore, in the structure where the output of the motor 11 is transmitted to the rotor 30 via the gear G, the rotation of the rotor 30 can also be locked within the locking angle range.

[0105] H. Other implementation methods:

[0106] H-1. Other implementation methods 1:

[0107] In the above embodiments, each rotor 30 has two blades 33, but is not limited to two; it may also have one, three, or any number of blades 33. In a structure with one blade 33, the locking angle range can be set to a range between [B-45deg] and [B+45deg], where the number of blades 33 of the rotor 30 is set to A, the target locking position is set to B, and the locking angle range is set to [B-45deg]. According to this configuration, it is possible to further suppress significant deviations of the locking angle of the rotor 30 from the target locking position.

[0108] H-2. Other implementation methods 2:

[0109] In the above embodiments, control devices 50 are respectively installed in each EDS 10. However, it is also possible to install a control device 50 for one EDS 10 in each eVTOL 100 or 100f, which controls multiple EDS 10s. In this structure, the locking control unit 52 can determine the configuration of the locked rotor 30 among the multiple rotors 30 in accordance with the operating mode of the eVTOL 100 or 100f. For example, when the operating mode of the eVTOL 100 or 100f is cruise mode, the lifting rotor 31 is determined to be the locked rotor 30. According to this configuration, the rotors 30 that are not driven to rotate can be locked appropriately according to the operating mode of the eVTOL 100 or 100f.

[0110] H-3. Other implementation methods 3:

[0111] The EDS10 of each of the above embodiments includes a motor 11 that drives the rotor 30 to rotate, but the EDS10 may also not include the motor 11. That is, the EDS10 may also be a system that controls a motor 11 disposed externally to the EDS10. With this structure, the same effect as the above embodiments can be achieved.

[0112] H-4. Other implementation methods 4:

[0113] The structures of the eVTOLs 100 and 100f described in the above embodiments are merely examples and can be modified in various ways. For instance, in the above embodiments, the eVTOLs 100 and 100f include a tilting rotor 32 capable of changing its tilt angle, but the tilting rotor 32 can be substituted for it, or a cruise rotor 30 with a fixed tilt angle can be included as the rotor 30 in addition to the tilting rotor 32. Furthermore, for example, a storage section can be provided for the tilting rotor 32, storing the tilting rotor 32, which is not driven to rotate, within the storage section. In this configuration, the tilting rotor 32 can stop rotating and lock at an angle where it can be stored within the storage section. Furthermore, for example, the storage section for the lifting rotor 31 can be omitted. In this configuration, the lifting rotor 31 can stop rotating and lock at an angle where the air resistance value is reduced. With the above structures, the same effects as the above embodiments can be achieved.

[0114] H-5. Other implementation methods 5:

[0115] The EDS10 of the above embodiments is installed in eVTOL 100, 100f, but is not limited to eVTOL 100, 100f. It can also be installed in any manned or unmanned electric aircraft, and is not limited to electric aircraft. It can also be installed in any electric mobile body such as ships, submarines, or propellers that are driven to rotate, which are operated remotely via wireless communication. That is, generally speaking, the control device 50 of EDS10 can also be configured as a control device 50 for driving either the rotor 30 or the propeller to rotate. In addition, the locking angle range can also be an angle range with a smaller resistance value compared to the midpoint between the maximum and minimum resistance values ​​experienced by the rotating body from the external fluid depending on the locking position of the rotating body. With this structure, the same effect as the above embodiments can be achieved.

[0116] H-6. Other implementation methods 6:

[0117] In the eVTOL 100 of the first to sixth embodiments described above, a detection unit capable of detecting the rotational position of the rotor 30 may also be provided in the eVTOL 100f, similar to the eVTOL 100f of the seventh embodiment. By cooperating with this detection unit, the rotor 30 can be locked at the target locking position. According to this structure, the accuracy of locking the rotor 30 within the locking angle range can be improved.

[0118] This disclosure is not limited to the embodiments described above, and can be implemented through various structures without departing from the above-described spirit. For example, the technical features in each embodiment corresponding to the technical features described in the summary section can be appropriately replaced or combined to solve part or all of the above-described technical problems, or to achieve part or all of the above-described effects. Furthermore, the above-described technical features can be appropriately deleted unless they are described as essential structures in this specification.

[0119] The control device, external device, and method described in this disclosure can also be implemented using a dedicated computer, which is provided by comprising a processor and memory, the processor being programmed to perform one or more functions embodied in the computer program. Alternatively, the control unit and method described in this disclosure can also be implemented using a dedicated computer, which is provided by comprising a processor composed of one or more dedicated hardware logic circuits. Alternatively, the control device, external device, and method described in this disclosure can also be implemented using one or more dedicated computers, which are configured by a combination of a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. Furthermore, the computer program can also be stored on a computer-readable, non-transitory tangible storage medium as instructions to be executed by a computer.

Claims

1. An electric vertical take-off and landing machine, characterized in that, include: body; Multiple rotors; Multiple electric drive systems are provided, each electric drive system being correspondingly arranged with respect to each rotor and used to drive each rotor to rotate. as well as Flight control system The multiple electric drive systems include: Inverter circuit; A motor, which outputs torque corresponding to the voltage and current supplied from the inverter circuit, rotates a rotor corresponding to an electric drive system via a shaft drive; and Control device, A portion of the electric drive system drives a lifting rotor used to generate lift for the fuselage, thereby rotating the lifting rotor. Another part of the electric drive system drives the tilting rotor to rotate in a manner that changes the tilt angle of the tilting rotor. The flight control system outputs locking commands to the control units of each electric drive system to stop and lock the rotation of the undriven rotor. When the electric vertical takeoff and landing (EVTOL) aircraft is in takeoff mode, a lock-on command is output to the control unit of the electric drive system corresponding to the lifting rotor. When the electric vertical takeoff and landing (EVTOL) is in cruise mode, the lock-on command is output to the control unit of the electric drive system corresponding to the tiltrotor. The control devices of each electric drive system have: An angle acquisition unit is configured to acquire the rotation angle of the rotor. The locking control unit is configured to lock the rotation of the rotor within a set locking angle range based on the rotation angle obtained by the angle acquisition unit. Reference angle storage unit, When locking the rotation of the motor, the locking control unit gradually reduces the motor speed. Once the speed reaches a predetermined level, it locks the motor's rotation, thereby locking the rotation of the rotor blade. The reference angle storage unit stores the reference angle used to lock the motor within the locking angle range as the value of the motor's electrical angle when the rotor was last locked.

2. The electric vertical lift as described in claim 1, characterized in that, The locking angle range is an angle range where the drag value is smaller than the midpoint between the maximum and minimum drag values ​​experienced by the rotor from the external fluid depending on the locking position of the rotor.

3. The electric vertical lift as described in claim 1, characterized in that, Multiple electric drive systems are installed on the fuselage of the electric vertical take-off and landing machine for use. The lifting rotor is stored in a storage compartment located on the fuselage without being driven to rotate. The locking angle range is included in the storage angle range, which is the angle range within which the lifting rotor can be stored in the storage section.

4. The electric vertical lift as described in claim 1, characterized in that, Each of the multiple rotating blades has blades that are symmetrically formed about the axis of rotation along a direction perpendicular to the axis of rotation. With the number of blades set to A, the target locking position set to B, and 180 degrees set to π, the locking angle range is the range of angles above [B-2π / A] and below [B+2π / A].

Images