Aircraft with tilting fan assemblies

Abstract

To provide an aircraft with one or more tilting fan assemblies.SOLUTION: An aircraft comprises: a fuselage; a pair of wings coupled to both sides of the fuselage; and a plurality of tilting fan assemblies coupled to the pair of wings. The plurality of tilting fan assemblies is configured to move between a vertical lift position and a forward flight position. The plurality of tilting fan assemblies is configured to create a vertical lift when in the vertical lift position. The aircraft includes: the plurality of tilting fan assemblies; one or more battery units including a plurality of battery cells configured to power the plurality of tilting fan assemblies; and a control system configured to control the plurality of tilting fan assemblies between the vertical lift position and the forward flight position.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] Related Applications This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62 / 968,852, entitled "Aircraft with Tilting Fans," filed on January 31, 2020, the disclosure of which is incorporated herein by reference in its entirety for all purposes.

[0002] The described embodiments relate generally to aircraft having vertical take-off and landing capabilities. In particular, the embodiments provide an aircraft with one or more tilting fan assemblies that provide vertical and horizontal thrust in a controlled manner for hovering, transition, and cruise flight. [Background technology]

[0003] Aircraft with vertical takeoff and landing capabilities require lift fans so that they can hover, take off, and land vertically. However, such aircraft also require forward thrust so that they can cruise in the air. Thrust produced vertically provides lift for the aircraft. Thrust produced horizontally provides forward motion. A vertical takeoff and landing (VTOL) aircraft should be able to produce both vertical and horizontal thrust and be able to control these forces in a balanced manner. Summary of the Invention

[0004] Various embodiments provide an aircraft configured for vertical takeoff and landing. The aircraft includes a fuselage, a pair of wings coupled to opposite sides of the fuselage, a plurality of lift fan assemblies coupled to the pair of wings, a plurality of tilting fan assemblies, and a control system. The plurality of lift fan assemblies are configured to generate vertical lift. The plurality of tilting fan assemblies are configured to move between a vertical lift position and a forward flight position. The control system can be configured to control the plurality of tilting fan assemblies between the vertical lift position and the forward flight position.

[0005] Some embodiments provide an aircraft configured for vertical takeoff and landing. The aircraft includes a fuselage, a pair of wings coupled to opposite sides of the fuselage, a plurality of tilting fan assemblies coupled to the pair of wings configured to move between a vertical lift position and a forward flight position, and a control system configurable to control the plurality of tilting fan assemblies between the vertical lift position and the forward flight position. The plurality of tilting fan assemblies are configured to generate vertical lift when in the vertical lift position. The aircraft further includes one or more battery units including a plurality of battery cells configured to power the plurality of tilting fan assemblies.

[0006] An embodiment provides a method implemented by a control system coupled to an aircraft configured for vertical takeoff and landing for controlling one or more tilting fan assemblies of the aircraft, where the control system receives flight instructions, determines positions of a plurality of tilting fan assemblies coupled to the aircraft, controls one or more of the plurality of tilting fan assemblies between a vertical lift position and a forward flight position based on the flight instructions, and continuously monitors the positions of the plurality of tilting fan assemblies in view of the flight instructions.

[0007] If the flight instructions are takeoff instructions or landing instructions, the control system controls one or more of the tilting fan assemblies in the forward flight position to the vertical lift position.If the flight instructions are forward flight instructions, the control system controls one or more of the tilting fan assemblies in the vertical lift position to the forward flight position.

[0008] These and other embodiments are described in further detail below. [Brief description of the drawings]

[0009] [Figure 1A] 1 is a simplified diagram of an exemplary VTOL aircraft in accordance with various embodiments. [Figure 1B] 1A-1C are top, plan, side, and front views (starting clockwise from the upper left corner) of a VTOL aircraft with a pair of tilting fan assemblies in a forward flight position according to various embodiments. [Figure 1C] 1A-1C are top, plan, side, and front views (starting clockwise from the upper left corner) of a VTOL aircraft with a pair of tilting fan assemblies in a vertical lift position according to various embodiments. [Figure 2A] 1A-1C are top, plan, side, and front views (starting clockwise from the upper left corner) of a VTOL aircraft with a forward tilting fan assembly in a forward flight position according to various embodiments. [Figure 2B] 1A-1C are top, plan, side, and front views (starting clockwise from the upper left corner) of a VTOL aircraft with a forward tilting fan assembly in a vertical lift position according to various embodiments. [Figure 3A]1A-1C are top, plan, side, and front views (starting clockwise from the upper left corner) of a VTOL aircraft with a tilting fan assembly in a forward flight position according to various embodiments. [Figure 3B] 1A-1C are top, plan, side, and front views (starting clockwise from the upper left corner) of a VTOL aircraft with a tilting fan assembly in a vertical lift position according to various embodiments. [Figure 4] 1 is a flowchart illustrating an embodiment of a process for controlling flight of a VTOL aircraft through a transition between vertical lift and forward flight, in accordance with various embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The techniques disclosed herein generally relate to an aircraft with multiple lift fan assemblies and at least one tilting fan assembly. More specifically, the techniques disclosed herein provide a VTOL aircraft with multiple lift fan assemblies for vertical movement and one or more tilting fan assemblies configured to tilt between a forward flight position and a vertical lift position for forward movement. Various invention embodiments are described herein, including methods, processes, systems, and devices.

[0011] To better appreciate the features and aspects of fan assembly orientations for aircraft according to the present disclosure, further context for the present disclosure is provided in the following sections by discussing specific implementations of VTOL aircraft according to embodiments of the present disclosure. These embodiments are merely for illustration purposes and other fan configurations may be used in connection with the VTOL aircraft described herein.

[0012] FIG. 1A illustrates a simplified diagram of an exemplary VTOL aircraft 100. According to various embodiments, the VTOL aircraft 100 may be an electrically powered aircraft. In some embodiments, the VTOL aircraft 100 may be configured to carry one or more passengers and / or cargo and may be automatically and / or remotely controlled (e.g., the aircraft may not require an on-board pilot to operate and may be controlled based on control signals or instructions received from a remote entity). In the example illustrated in FIG. 1A, the VTOL aircraft 100 includes a fuselage 102, which may include a cabin section 140 for carrying passengers and / or cargo. For example, the cabin section 140 may be provided toward the nose of the VTOL aircraft 100. The VTOL aircraft 100 may also include a horizontal stabilizer (e.g., tail) 130 coupled to an aft end of the fuselage 102. The tail 130 may be of any suitable shape or form. For example, the tail 130 may be V-shaped (e.g., V-tail). A pair of wings (e.g., first wing 106 and second wing 108) are coupled to opposite sides of fuselage 102. In some embodiments, the pair of wings may be coupled to the fuselage in a high-wing configuration. That is, the pair of wings may be mounted on an upper portion of the fuselage, as shown in FIG. 1A. Multiple fan assemblies (e.g., lift fan assemblies and / or tilting fan assemblies) may be coupled to the pair of wings. For example, VTOL aircraft 100 may include a total of 12 fan assemblies (e.g., fans, rotors, propellers) that are equally divided between the wings. In some embodiments, the fan assemblies may be coupled directly to the wings. In other embodiments, the fan assemblies may be mounted on a support structure 104 (e.g., a boom that may be coupled to the underside of wings 106, 108, etc.).

[0013] According to some embodiments, each wing 106, 108 can include two support structures (e.g., booms) 104, each including a pair of lift fan assemblies (also known as "lift fans") 110 mounted thereon. For example, each lift fan assembly can be coupled to an end of the boom 104 such that a first lift fan assembly 113 is at the front of the wing 106, 108 and a second lift fan assembly 110 is at the rear of the wing 106, 108. In some embodiments, the two lift fan assemblies 110, 113 coupled to opposite ends of the boom 104 can have their blades mounted at opposite angles of attack, such that the two lift fan assemblies 110, 113 can spin in opposite directions. The lift fan assemblies 110, 113 are configured to generate vertical lift for the VTOL air vehicle 100.

[0014] According to various embodiments, each lift fan assembly 110 may be in the form of an electric motor-driven rotor (e.g., a combined fan and motor) and may be configured to move the air vehicle 100 vertically, for example, during takeoff, hovering, and / or landing. The rotor may include blades attached to a hub or may be manufactured as a single piece with an integral hub. The hub provides a central structure to which the blades connect and, in some embodiments, is fabricated in a shape that encases the motor. In some embodiments, the motor parts are low profile, allowing the entire motor to fit within the rotor hub and present less resistance to airflow during forward flight. The rotor is attached to the rotating parts of the motor. The stationary parts of the motor are attached to the boom 104. In some embodiments, the motor is a permanent magnet motor and is controlled by an electronic motor controller. The electronic motor controller sends current to the motor in a precise sequence, allowing the rotor to spin at a desired speed or with a desired torque.

[0015] Lift fan assembly 110 can have any suitable number of blades that can be oriented in a predetermined manner. The orientation of lift fan assembly can be fixed (e.g., lift fan assembly 110 can be mounted in a fixed position relative to wings 106, 108). In some embodiments, one or more of lift fan assemblies 110 can be configured to be repositioned relative to wings 106, 108 manually or in response to a control signal (e.g., from control system 150 (e.g., a flight control system, etc.) that controls VTOL air vehicle 100). According to various embodiments, lift fan assembly 110 can have two blades with a predetermined angle of attack. In some embodiments, two adjacent lift fan assemblies (e.g., lift fan assembly 110 and lift fan assembly 111) can have opposite angles of attack such that the two adjacent fan assemblies spin in opposite directions. Two adjacent lift fan assemblies can be on the same wing (e.g., lift fan assemblies 110 and 111 in FIG. 1A) or on opposite wings (e.g., lift fan assemblies 117 and 119 in FIG. 1B). According to various embodiments, a first subset of the lift fan assemblies can spin in a first direction and a second subset of the lift fan assemblies (e.g., the remainder) can spin in a second direction (opposite the first direction).

[0016] In some embodiments, each wing 106, 108 may include at least one support structure (e.g., boom) 112 that carries at least one tilting fan assembly 114 (also known in various embodiments as a "propeller assembly" or "propeller fan assembly"). The tilting fan assembly 114 is configured to move between a forward flight position (as illustrated in FIG. 1B) and a vertical lift position (as illustrated in FIG. 1C). The boom 112 with the at least one tilting fan assembly 114 may be in addition to or instead of a boom carrying a lift fan assembly. The tilting fan assembly 114 may be switched (e.g., rotated) between a forward flight position (as illustrated in FIGS. 1A-1B) and a vertical lift position (as illustrated in FIG. 1C). The tilting fan assembly 114 may be coupled to the boom 112 via a tilting mechanism 116 (e.g., including a motor and a coupling mechanism). In a forward flight position, the tilting fan assembly 114 may be oriented substantially vertically relative to the fuselage 102. In a vertical lift position, the tilting fan assembly 114 may be oriented substantially horizontally relative to the fuselage 102.

[0017] Each tilting fan assembly 114 can include a combined rotor and motor. The rotor can include blades attached to a hub or can be manufactured as a single piece with an integral hub. The hub provides a central structure to which the blades connect and in some embodiments is made in a shape that encases the motor. In some embodiments, the motor parts are low profile, allowing the entire motor to fit within the hub of the rotor and present less resistance to the airflow during forward flight. The rotor is attached to the rotating part of the motor. The stationary part of the motor is attached to the boom 112 or other part of the fuselage 102. In some embodiments, the motor is a permanent magnet motor and is controlled by an electronic motor controller. The electronic motor controller sends current to the motor in a precise sequence, allowing the rotor to spin at a desired speed or with a desired torque. The tilting fan assembly 114 can have any suitable number of blades that can be oriented in a predetermined manner. For example, the tilting fan assembly 114 can have five blades with a predetermined angle of attack.

[0018] According to various embodiments, the tilting fan assembly 114 on the first wing 108 can tilt simultaneously with the tilting fan assembly 124 on the second wing 106. For example, the aircraft's control system 150 can simultaneously control at least a subset of the tilting fan assemblies. That is, the control system 150 can operate each of the tilting mechanisms 116 and 126 substantially simultaneously. In some embodiments, the tilting mechanisms 116 and 126 can be operated independently of one another. According to some embodiments, the control system 150 can be configured to automatically and / or remotely (e.g., via control signals received from a remote entity (e.g., a remote controller, a remote pilot, or a remote control tower, etc.)) control the VTOL aircraft 100 (e.g., control the position of the tilting fan assemblies). In various embodiments, the control system 150 includes one or more processors configured to perform the processing and control functions described herein.

[0019] In some embodiments, each wing 106, 108 may also include at least one support structure (e.g., a boom) 112 that carries one lift fan assembly 110 (e.g., an aft fan assembly) and one tilting fan assembly 114. For example, the lift fan assembly 110 may be coupled to the aft of the wings 106, 108, and the tilting fan assembly 114 may be coupled to the forward of the wings 106, 108. According to various embodiments, multiple lift fan assemblies may be coupled to the trailing edges of a pair of wings 106, 108 and / or multiple tilting fan assemblies may be coupled to the leading edges of a pair of wings 106, 108 via one or more tilting mechanisms.

[0020] The exemplary VTOL air vehicle 100 illustrated in FIGS. 1A-1C may include a total of 12 fan assemblies (10 lift fan assemblies and two tilting fan assemblies). In some embodiments, at least one (or preferably a pair) of the fan assemblies of the exemplary VTOL air vehicle is a tilting fan assembly. The tilting fan assemblies 114 and 124 may provide thrust for (and / or transition to) forward flight, climb, descent, and cruise when in a forward flight position. The lift fan assembly 110 provides sufficient thrust to lift the air vehicle off the ground and maintain control, for example, during takeoff, hovering, and / or landing. According to various embodiments, the lift fan assembly 110 may be stopped from operating during forward flight of the VTOL air vehicle 100.

[0021] One or more battery units 135 may be coupled to VTOL air vehicle 100 and may power the fan assemblies (lift fan assembly and tilting fan assembly). More specifically, the fan assemblies may be driven by electric motors powered by a power system that includes one or more battery units 135. In some embodiments, each fan assembly may have a dedicated battery unit 135. Battery units 135 may be provided on a boom carrying the fan assembly, in the fuselage, or a combination thereof. Each battery unit 135 may include a number of battery cells configured to power the fan assembly. Thus, VTOL air vehicle 100 may be an electric aircraft. In an alternative embodiment, VTOL air vehicle 100 may be a hybrid electric aircraft.

[0022] FIG. 1B illustrates top, plan, side, and front views (starting clockwise from the upper left corner) of the VTOL air-vehicle 100 with the pair of tilting fan assemblies 114, 124 in a forward flight position.

[0023] FIG. 1C illustrates top, plan, side, and front views (starting clockwise from the upper left corner) of the VTOL air-vehicle 100 with the pair of tilting fan assemblies 114, 124 in a vertical lift position.

[0024] A control system 150 (e.g., a flight control system) coupled to the aircraft 100 may be configured to control the tilting fan assemblies between a vertical lift position and a forward flight position. For example, the control system 150 may be configurable to control the tilting mechanisms 116, 126 to switch the positioning of the tilting fan assemblies 114, 124 from a forward flight position (illustrated in FIGS. 1A-1B) to a vertical lift position (illustrated in FIG. 1C); and from the vertical lift position (illustrated in FIG. 1C) to a forward flight position (illustrated in FIG. 1A-1B). In some embodiments, the control system 150 may receive flight data from one or more sensors (e.g., sensors measuring air temperature, electric motor temperature, aircraft airspeed, etc.), computers, and other input / output devices coupled to the aircraft. The control system 150 can then control the tilting fan assemblies 114, 124 between the two positions based on sensor data and / or flight data received from sensors (e.g., sensors measuring air temperature, electric motor temperature, aircraft airspeed, etc.), computers, and other input / output devices coupled to the aircraft.

[0025] According to various embodiments, control system 150 may be configured to receive flight instructions (e.g., takeoff, hover, cruise, or landing instructions, etc.). Control system 150 may then determine a position of the plurality of tilting fan assemblies and control one or more of the plurality of tilting fan assemblies between a vertical lift position and a forward flight position based on the flight instructions. During operation of VTOL air-vehicle 100, control system 150 may be configured to continuously monitor the position of the plurality of tilting fan assemblies in view of the flight instructions.

[0026] The exemplary VTOL air vehicle 100 illustrated in FIGS. 1A-1C includes a pair of tilting fan assemblies 114, 124 closer to the fuselage 102 (one provided on each of the wings 106, 108). Those skilled in the art will recognize that the number and location of the tilting fan assemblies is not limited to those illustrated in FIGS. 1A-1C and that the VTOL air vehicle can include fewer or more tilting fan assemblies and / or lift fan assemblies. For example, according to an embodiment, the boom 112 can be swapped in place with any one of the booms 104. According to yet another embodiment, all of the forward fan assemblies (or all of the aft fan assemblies) can be tilting fan assemblies.

[0027] 2A-2B illustrate another exemplary embodiment of a VTOL aircraft with a tilting fan assembly. In the exemplary embodiment illustrated in FIGS. 2A-2B, multiple lift fan assemblies are provided on the trailing edges of a pair of wings, and multiple tilting fan assemblies are provided on the leading edges of a pair of wings. The exemplary VTOL aircraft 200 illustrated in FIGS. 2A-2B includes all forward fan assemblies configured as tilting fan assemblies 204. Thus, in the exemplary VTOL aircraft 200, all booms 206 are identical and each include a tilting fan assembly 204 at one end and a lift fan assembly 202 at the opposite end. Because all booms 206 are identical, the booms 206 may be interchangeable between positions on the wings. For example, a first boom closer to the fuselage may be interchangeable with an adjacent second boom (e.g., a middle boom above the wings) or a third boom further away from the fuselage. In some embodiments, each tilting fan assembly 204 may be coupled to the boom 206 via an individual tilting mechanism 208. For example, at least three tilting fan assemblies may be coupled to each of a pair of wings, as shown in FIG. 2A.

[0028] FIG. 2A illustrates top, plan, side, and front views (starting clockwise from the upper left corner) of VTOL air-vehicle 200 with forward tilting fan assembly 204 in a forward flight position.

[0029] FIG. 2B illustrates top, plan, side, and front views (starting clockwise from the upper left corner) of VTOL aircraft 200 with forward tilting fan assembly 204 in a vertical lift position (e.g., with forward tilting fan assembly 204 pointing upward toward the sky).

[0030] A control system 250 (e.g., a flight control system) coupled to aircraft 200 may be configured to control tilting mechanism 208 to switch the positioning of tilting fan assembly 204 from a forward flight position (illustrated in FIG. 2A ) to a vertical lift position (illustrated in FIG. 2B ); and from the vertical lift position (illustrated in FIG. 2B ) to the forward flight position (illustrated in FIG. 2A ). According to various embodiments, control system 250 may control tilting fan assembly 204 between the two positions based on sensor data and / or flight data received from sensors (e.g., sensors measuring air temperature, electric motor temperature, aircraft airspeed, etc.), computers, and other input / output devices coupled to the aircraft.

[0031] The tilting fan assemblies 204 may be coupled to the wing via one or more tilting mechanisms, and the tilting fan assemblies 204 may be individually controlled via the tilting mechanisms 208. The flight control system may be configured to simultaneously control the tilting mechanisms 208 to simultaneously position all of the tilting fan assemblies 204 in the same position. Alternatively, the flight control system may be configured to control the tilting mechanisms 208 independently of one another. In this manner, the flight control system may identify one or more tilting fan assemblies 204 and control the identified tilting fan assemblies 204 independently from the rest of the tilting fan assemblies. According to various embodiments, the flight control system may use symmetric and / or asymmetric tilting to enhance control during hovering and transitions (e.g., transitions between vertical lift and forward flight). The additional degrees of freedom of tilting may enhance control during motor-out and nominal conditions.

[0032] 2A-2B illustrate a tilting fan assembly 204 on a leading (e.g., leading) edge of the wing and a lift fan assembly 202 on an aft (e.g., trailing) edge of the wing, this configuration is for illustrative purposes and should not be construed as limiting. In some embodiments, the lift fan assembly 202 may be provided on the leading edge of the wing and the tilting fan assembly 204 may be provided on the trailing edge of the wing.

[0033] In yet another embodiment, the tilting fan assembly 204 and the lift fan assembly 202 may be alternated on one of the leading and trailing portions of the wing. For example, the leading edge of a first wing may include a first tilting fan assembly 204, a lift fan assembly 202, and a second tilting fan assembly 204. The leading edge of a second wing may include a tilting fan assembly 204, a lift fan assembly 202, and another tilting fan assembly 204. Alternatively, the leading edge of a second wing may include a first lift fan assembly 202, a tilting fan assembly 204, and a second lift fan assembly 202. A similar configuration may be applied to the trailing edges of the first and second wings as well.

[0034] 1A-2B illustrate the tilting fan mechanisms coupled to the wings, in alternative embodiments, the tilting fan mechanisms may be coupled to the fuselage. For example, the tilting fan mechanisms may be coupled to one or more lateral support structures (e.g., lateral booms) that are coupled to the fuselage.

[0035] 3A-3B illustrate another embodiment of a VTOL aircraft with a tilting fan assembly. The VTOL aircraft 300 illustrated in FIGS. 3A-3B includes a lateral boom 310 provided at the front of the wing, closer to the nose of the aircraft. One or more tilting fan assemblies 314, 324 are coupled to the lateral boom 310. In some embodiments, the lateral boom 310 can be a tilting boom that tilts about an axis parallel to the lateral axis of the aircraft, thereby allowing the tilting fan assemblies 314, 324 to move simultaneously between a forward flight position (illustrated in FIG. 3A) and a vertical lift position (illustrated in FIG. 3B). In such an embodiment, it may not be necessary to couple the tilting fan assemblies 314, 324 to the lateral boom 310 via a tilting mechanism if the lateral boom is itself a tilting boom. The tilting of the lateral boom 310 may be controlled to modify the position of the tilting fan assemblies 314, 324. In other embodiments, both the lateral boom and the tilting fan assembly may be capable of tilting independently of one another (e.g., the tilting fan assembly 314 may be coupled to the tilting lateral boom via one or more tilting mechanisms).

[0036] The lateral boom 310 may be formed as a single boom or may be formed as two separate lateral booms connected to either side of the fuselage. The lateral boom 310 may be connected to the fuselage forward of a pair of wings.

[0037] 1A-1C, the exemplary VTOL air vehicle 300 illustrated in FIGS. 3A-3B includes two booms 304, each carrying a pair of lift fan assemblies 302 on a respective wing. The exemplary VTOL air vehicle 300 further includes a shorter boom 306 coupled to each wing and extending on only one side (e.g., the aft side) of each wing carrying a single lift fan assembly 308. As illustrated in FIGS. 3A-3B, the exemplary VTOL air vehicle includes ten lift fan assemblies and two tilting fan assemblies.

[0038] FIG. 3A illustrates top, plan, side, and front views (starting clockwise from the upper left corner) of a VTOL air-vehicle 300 with tilting fan assemblies 314, 324 in a forward flight position.

[0039] FIG. 3B illustrates top, plan, side, and front views (starting clockwise from the upper left corner) of VTOL air-vehicle 300 with tilting fan assemblies 314, 324 in a vertical lift position.

[0040] A control system 350 (e.g., a flight control system) coupled to the aircraft 300 may be configured to control the tilting fan assemblies 314, 324 from a forward flight position (illustrated in FIG. 3A ) to a vertical lift position (illustrated in FIG. 3B ); and from the vertical lift position (illustrated in FIG. 3B ) to the forward flight position (illustrated in FIG. 3A ). According to various embodiments, the control system may control the tilting of the tilting fan assemblies 314, 324 between the two positions based on sensor data and / or flight data received from sensors (e.g., sensors measuring air temperature, electric motor temperature, aircraft airspeed, etc.), computers, and other input / output devices coupled to the aircraft.

[0041] In embodiments in which the lateral boom 310 is a tilting boom, the control system 350 may be configured to control the tilting of the lateral boom 310 to switch the positioning of the tilting fan assemblies 314, 324 from a forward flight position (illustrated in FIG. 3A) to a vertical lift position (illustrated in FIG. 3B); and from the vertical lift position (illustrated in FIG. 3B) to a forward flight position (illustrated in FIG. 3A). According to various embodiments, the control system may control the tilting of the lateral boom 310 between the two positions based on sensor and / or flight data received from sensors (e.g., sensors measuring air temperature, electric motor temperature, aircraft airspeed, etc.), computers, and other input / output devices coupled to the aircraft.

[0042] In some embodiments, the lateral boom 310 may be provided behind the wing, closer to (or above) the tail of the aircraft. In such an embodiment, a shorter boom 306 extending to only one side of each wing carrying a single lift fan assembly 308 may extend toward the leading edge of the wing.

[0043] According to alternative embodiments, the tilting fan assemblies 314, 324 may be coupled to the lateral boom 310 via respective tilting mechanisms. Thus, the lateral boom 310 itself may or may not be a tilting boom. In such embodiments, the tilting fan assemblies 314, 324 may be individually controlled to switch positions (between a vertical lift position and a forward flight position). In such embodiments, it may still be possible to perform an emergency landing by removing the failed (e.g., broken or stuck) tilting fan assembly and by controlling the remaining tilting fan assemblies from the forward flight position to a vertical lift position. For example, the tilting fan assemblies 314, 324 may be individually controlled to switch positions simultaneously. According to yet another example, the tilting fan assemblies 314, 324 may be individually controlled to switch positions at different times (e.g., consecutively, one after the other).

[0044] According to various embodiments, any number of lift fan assemblies may be coupled to the VTOL aircraft. For example, the aircraft may include three lift fan assemblies coupled to each wing (as shown in FIG. 2A ), or the aircraft may include five lift fan assemblies coupled to each wing (as shown in FIGS. 1A and 3A ). Other embodiments may include no lift fan assemblies (e.g., lift is generated using a tilting fan assembly in a vertical position, and thus the aircraft may include any number of tilting fan assemblies), two lift fan assemblies, four lift fan assemblies, or six (or more) lift fan assemblies. According to various embodiments, the combined number of lift fan assemblies and tilting fan assemblies coupled to the aircraft may be at least twelve.

[0045] In various embodiments, a control system (e.g., a flight control system of an aircraft, etc.) may be configured to control actuators (rotors, aerodynamic control surfaces, tilting fan assemblies, lift fan assemblies) of the aircraft to cause the aircraft to transition between a vertical lift (e.g., takeoff / hover / landing) mode and a forward flight mode. For example, the control system may be configured to receive flight instructions (e.g., takeoff instructions, hover instructions, landing instructions, or forward flight instructions, etc.). If the flight instructions are takeoff instructions or landing instructions, the control system may control one or more of the tilting fan assemblies in a forward flight position to a vertical lift position. If the flight instructions are forward flight instructions, the control system may control one or more of the tilting fan assemblies in a vertical lift position to a forward flight position. The control system may then determine a position of the plurality of tilting fan assemblies coupled to the aircraft and control one or more of the plurality of tilting fan assemblies between the vertical lift position and the forward flight position based on the flight instructions. The control system may continuously monitor the position of the plurality of tilting fan assemblies in view of the flight instructions.

[0046] FIG. 4 is a flowchart illustrating an embodiment of a process for controlling flight of a VTOL aircraft configured for vertical takeoff and landing through the transition between vertical lift and forward flight.

[0047] In step S400, the aircraft may be in a stationary position above the ground. For example, the aircraft may be parked at a charging station to charge its batteries. Alternatively, the aircraft may be parked at a location waiting to receive cargo or passengers. The flight control system of the VTOL aircraft may receive a flight plan (e.g., from an autopilot, a pilot, or a remote controller pilot) for reaching a predetermined destination. The flight plan may include instructions for taking off from the ground.

[0048] In step S402, the flight control system may determine whether all tilting fan assemblies of the aircraft are in a vertical lift position. According to various embodiments, it may be desirable to have all fan assemblies in a vertical lift position generate vertical lift. In some embodiments, the aircraft may be configured to maintain all tilting fan assemblies in a vertical lift position when the aircraft is not in use (e.g., when parked on the ground or charging).

[0049] If, in step S402, it is determined that not all of the fan assemblies are in the vertical lift position, the flight control system may control one or more of the tilting fan assemblies in the forward flight position to switch to the vertical lift position (step S404). For example, one or more of the tilting fan assemblies may have been switched to a forward flight position while the aircraft was on the ground for testing or maintenance purposes.

[0050] In step S406, the flight control system may initiate a takeoff sequence to lift the aircraft off the ground. During the takeoff sequence, the lift fan mechanisms and the tilting fan mechanisms in the vertical lift position may all be activated.

[0051] In step S408, a predetermined amount of time after performing step S406, the flight control system may receive instructions to transition to forward flight. Before switching to forward flight mode, the control system may check one or more of the aircraft's altitude, speed, and orientation to ensure that the parameters are within predetermined desired ranges. In some embodiments, the control system may communicate the parameters to a remote entity (e.g., a remote control tower, a remote pilot).

[0052] In various embodiments, the transition to forward flight can be accomplished by achieving a desired altitude (e.g., greater than a design minimum or threshold) and by substantially continuously rotating the tilting fan assembly to a forward flight position while increasing the forward airspeed so that the tilting fan assembly is rotated to a forward flight position and begins to generate sufficient lift to maintain altitude, while modulating power to the rotors as needed to maintain stability and altitude.

[0053] Upon receiving the instruction to transition to forward flight, in step S410, the control system may control one or more of the tilting fan assemblies to switch from a vertical lift position to a forward flight position. In some embodiments, the tilting fan assemblies may be controlled substantially simultaneously.

[0054] In step S412, the control system may receive instructions (e.g., from an autopilot, a pilot, or a remote entity) to hover or land. In response, in step S414, the flight control system may control one or more of the tilting fan assemblies to switch from a forward flight position to a vertical lift position. In step S416, the flight control system may initiate a hover or landing sequence to cause the aircraft to hover or land on the ground.

[0055] Various embodiments discussed herein are illustrated in Figures 1A-3B and use aircraft with a particular tail. However, the embodiments are not limited to the particular tail or aircraft configurations illustrated in the figures. Those skilled in the art will recognize that the embodiments may be combined with aircraft with alternative tails or alternative designs, including, but not limited to, aircraft with conventional tails, aircraft with multiple tails, or aircraft without a tail.

[0056] For simplicity, various active and passive circuit components are not shown in the figures. In the foregoing specification, embodiments of the present disclosure have been described with reference to numerous specific details that may vary from implementation to implementation. Accordingly, the specification and drawings should be regarded in an illustrative and not a restrictive sense. The sole and exclusive indicator of the scope of the present disclosure, and what is intended by the applicant to be the scope of the present disclosure, is the literal and equivalent scope of the set of claims issuing from this application, including any subsequent modifications in the specific form in which such claims arise. The specific details of specific embodiments may be combined in any suitable manner without departing from the spirit and scope of the embodiments of the present disclosure.

[0057] The electronic components of the described embodiments may be specially constructed for the required purposes, or may include one or more general-purpose computers selectively activated or reconfigured by a computer program stored in the computer. Such computer programs may be stored in a computer-readable storage medium (such as, but not limited to, a floppy disk, an optical disk, a DVD, a CD-ROM, a magneto-optical disk, a read-only memory (ROM), a random access memory (RAM), an EPROM, an EEPROM, a magnetic or optical card, an application specific integrated circuit (ASIC), or any type of disk including any type of medium suitable for storing electronic instructions) and each coupled to a computer system bus.

[0058] Additionally, spatially relative terms (e.g., "front" or "back") may be used to describe the relationship of an element and / or feature to another element and / or feature, for example, as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and / or operation in addition to the orientation shown in the figures. For example, if the device in the figures is turned over, an element described as being on a "front" surface may be oriented "back" from the other element or feature. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein will be interpreted accordingly.

Claims

1. 1. An aircraft, comprising: The torso and; a pair of wings connected to opposite sides of the fuselage; a plurality of tilting fan assemblies coupled to the pair of wings, the plurality of tilting fan assemblies configured to move between a vertical lift position and a forward flight position, the plurality of tilting fan assemblies configured to generate vertical lift when in the vertical lift position; one or more battery units including a plurality of battery cells configured to power the plurality of tilting fan assemblies; a control system configured to control the plurality of tilting fan assemblies between the vertical lift position and the forward flight position; and Including, aircraft.

2. 2. The aircraft of claim 1, further comprising a plurality of support structures coupled to undersides of the pair of wings, and wherein at least one of the plurality of tilting fan assemblies is coupled to an end of a first support structure of the plurality of support structures via a tilting mechanism.

3. 2. The aircraft of claim 1, further comprising a plurality of support structures coupled to undersides of the pair of wings, a tilting fan assembly of the plurality of tilting fan assemblies coupled to ends of respective support structures.

4. 2. The aircraft of claim 1, wherein the plurality of tilting fan assemblies are coupled to leading edges of the pair of wings via one or more tilting mechanisms.

5. 2. The aircraft of claim 1, wherein at least three tilting fan assemblies are coupled to each of the pair of wings.

6. 2. The aircraft of claim 1, wherein the control system is configurable to control a first tilting fan assembly and a second tilting fan assembly of the plurality of tilting fan assemblies independently of each other.

7. 2. The aircraft of claim 1, wherein the control system is configurable to simultaneously control at least a subset of the plurality of tilting fan assemblies.

8. 2. The aircraft of claim 1, wherein the control system is configurable to control the position of the tilting fan assembly based on flight data received by sensors coupled to the aircraft.

9. 2. The aircraft of claim 1, wherein the control system is configurable to automatically control the position of the tilting fan assembly.

10. 10. The aircraft of claim 1, wherein the control system is configurable to control the position of the tilting fan assembly based on a signal received from a remote entity.

11. 10. The aircraft of claim 1, further comprising a tail in the form of a V-tail connected to an aft end of the fuselage.

12. 1. A method for controlling one or more tilting fan assemblies of an aircraft, the method comprising: receiving flight instructions by a control system coupled to an aircraft including a pair of wings and at least three support structures coupled to each of the pair of wings, each lift fan assembly of a plurality of lift fan assemblies non-tiltably mounted to a first end of a respective support structure and each tilting fan assembly of a plurality of tilting fan assemblies mounted to a second end of a respective support structure via a tilting mechanism, forming a plurality of identical structures each including a support structure with a lift fan assembly at one end and a tilting fan assembly at an opposite end, the plurality of identical structures being interchangeable, the number of tilting fan assemblies equal to the number of lift fan assemblies; determining, by the control system, positions of the plurality of tilting fan assemblies coupled to the aircraft, the aircraft being configured for vertical takeoff and landing; controlling, by the control system, one or more of the plurality of tilting fan assemblies between a vertical lift position and a forward flight position based on the flight instructions, the plurality of lift fan assemblies being provided on the trailing edges of the pair of wings and the plurality of tilting fan assemblies being provided on the leading edges of the pair of wings; continuously monitoring, by the control system, the positions of the plurality of tilting fan assemblies in view of the flight instructions; A method comprising:

13. The method of claim 12 , further comprising controlling, by the control system, a first tilting fan assembly and a second tilting fan assembly of the plurality of tilting fan assemblies independently of one another.

14. The method of claim 12 , further comprising controlling, by the control system, at least a subset of the plurality of tilting fan assemblies simultaneously.

15. The method of claim 12 , further comprising automatically controlling, by the control system, the positions of the plurality of tilting fan assemblies.

16. The method of claim 12 , further comprising controlling, by the control system, a position of the plurality of tilting fan assemblies based on a signal received from a remote entity.

17. The flight instructions are takeoff instructions, and the step of controlling one or more of the plurality of tilting fan assemblies includes: determining whether each of the plurality of tilting fan assemblies is in a vertical lift position; controlling one or more of the plurality of tilting fan assemblies to the vertical lift position; The method of claim 12, comprising:

18. 13. The method of claim 12, wherein the flight instructions are hovering instructions or landing instructions, and controlling one or more of the plurality of tilting fan assemblies includes controlling one or more of the plurality of tilting fan assemblies into the vertical lift position.

19. 13. The method of claim 12, wherein the flight instructions are instructions to switch to forward flight, and controlling one or more of the plurality of tilting fan assemblies includes controlling one or more of the plurality of tilting fan assemblies into the forward flight position.

20. 20. The method of claim 19, further comprising controlling a plurality of lift fan assemblies to cease operating during forward flight of the aircraft, thereby shutting down all fan assemblies downstream from the pair of wings.

21. The method comprises: receiving, by the control system, flight data from one or more sensors coupled to the aircraft; controlling the position of the plurality of tilting fan assemblies based on the flight data received from the one or more sensors coupled to the aircraft; The method of claim 12 further comprising:

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