Vertical takeoff and landing (VTOL) air vehicle

Abstract

To provide a vertical takeoff and landing (vtol) air vehicle that is efficient in flight.SOLUTION: A flight control apparatus for fixed-wing aircraft includes: a first port wing 115 and a first starboard wing 120; a first port swash plate 145 coupled between a first port rotor 155 and a first port electric motor 135, the first port electric motor coupled to the first port wing 115; and a first starboard swash plate 150 coupled between a first starboard rotor 130 and a first starboard electric motor 140, the first starboard electric motor coupled to the first starboard wing 120.SELECTED DRAWING: Figure 3A

Description

[Technical field]

[0001] The field of the invention is aircraft flight control, and more particularly aircraft flight control for rotary fixed wing aircraft. [Background technology]

[0002] There are many applications for remotely or autonomously piloted unmanned aerial vehicles (UAVs) that can take off, loiter, and land without the aid of a runway. Vertical take-off and landing (VTOL) vehicles address this constraint and can come in the form of a manually launched aircraft with wing and vertical / horizontal stabilizer control surfaces operable to take off and land vertically, or a 3 or 4 rotorcopter. Aircraft with wing and vertical / horizontal stabilizer control surfaces tend to be more efficient and faster at cruise, while rotorcopters are less efficient in forward flight but have advantages in take-off and landing.

[0003] There remains a need to design and build aircraft that are efficient in flight and that can take off and land vertically. Summary of the Invention

[0004] A flight control system for a fixed wing aircraft is disclosed having a first port wing and a first starboard wing, a first port swash plate coupled between the first port rotor and a first port electric motor coupled to the first port wing, and a first starboard swash plate coupled between the first starboard rotor and a first starboard electric motor coupled to the first starboard wing. The system may further include a second port wing and a second starboard wing, a second port swash plate coupled between the second port rotor and a second port electric motor coupled to the second port wing, and a second starboard swash plate coupled between the second starboard rotor and a second starboard electric motor coupled to the second starboard wing. In one embodiment, the apparatus may have a horizontal stabilizer coupled to a fuselage and an elevator rotatably coupled to the horizontal stabilizer, the fuselage may be coupled between a first port wing and a second starboard wing and may have a left aileron rotatably located on a trailing edge of the first port wing and a starboard aileron rotatably located on a trailing edge of the first starboard wing. The apparatus may have first and second landing gear attached to the first port wing and first starboard wing, respectively, and a third landing gear attached to the horizontal stabilizer.

[0005] A method of flight control for a fixed-wing aircraft is further disclosed, the method including inducing a right roll of a fuselage coupled between the first port wing and the first starboard wing in response to i) generating a positive rotational moment in a first port rotor rotatably coupled to the first port wing in response to actuation of a first port swash plate, and ii) generating a negative rotational moment in a first starboard rotor rotatably coupled to the first starboard wing in response to actuation of the first starboard swash plate. In some embodiments, the method may include generating asymmetric collective control between the first port rotor and the first starboard rotor to generate a yaw moment about the fuselage. Utilized together, the asymmetric collective control, the positive rotational moment, and the negative rotational moment enable coordinated turn of the port and starboard wings. In one embodiment, the method may further include generating a left roll of the fuselage in response to generating a negative rotational moment on the first port rotor in response to actuation of the first port swash plate and generating a positive rotational moment on the starboard rotor in response to actuation of the first starboard swash plate. The method may further include providing pitch control of the fuselage in response to asymmetric collective control provided between at least the first port rotor and a second port rotor rotatably coupled to a second port wing coupled to the fuselage. In one embodiment, the method may include providing pitch control of the fuselage in response to providing a differential angular rate (RPM) between at least the first port rotor and a second port rotor rotatably coupled to a second port wing coupled to the fuselage, and may include providing pitch control of the fuselage in response to providing a differential angular rate (RPM) between the first starboard rotor and a second starboard rotor rotatably coupled to a second starboard wing. Further embodiments may include providing elevator control supplementing the providing pitch control to supplement the pitch moment with an additional pitch moment. In one embodiment, the method may include providing pitch control of the fuselage in response to elevator actuation.A right roll of the fuselage can be induced in response to generating a positive rotational moment in a second port rotor rotatably coupled to the second port wing in response to actuation of the second port swash plate, and generating a negative rotational moment in a second starboard rotor rotatably coupled to the second starboard wing in response to actuation of the second starboard swash plate, whereby positive and negative moments of forces in the second port rotor and second starboard rotor induce right roll of the second port wing and second starboard wing. The method may further include assisting the right roll of the fuselage in response to actuation of port and starboard ailerons rotatably coupled to the second port wing and second starboard wing, respectively.

[0006] A further method of vertical takeoff and horizontal flight of a fixed-wing aircraft discloses generating thrust in a first port rotor driven by a first port electric motor on a first port wing and a first starboard rotor driven by a first starboard motor on a first starboard wing to cause vertical takeoff of a fuselage coupled between a first port wing and a first starboard wing. In this disclosed method, the method may further include generating a negative rotational moment in the first port rotor and the first starboard rotor using cyclic rotor blade control to effectuate a transition of the first port wing and the first starboard wing from vertical takeoff to horizontal flight, and may include generating thrust in a second port rotor driven by a second port electric motor on a second port wing and a second starboard rotor driven by a second starboard motor on a second starboard wing. In many disclosed embodiments, the fuselage can transition from vertical takeoff to horizontal flight including in response to i) asymmetric collective control between the first port rotor and first starboard rotor on the one hand and the second port rotor and second starboard rotor on the other, and ii) differential rotor angular speed (RPM) control between the first port rotor and first starboard rotor on the one hand and the second port rotor and second starboard rotor on the other. Horizontal thrust can be provided in response to generating symmetric cyclic control of the first port rotor, first starboard rotor, second port rotor, and second starboard rotor, or in response to generating differential thrust on at least one pair of rotors selected from the group consisting of i) the first and second port rotors on the one hand and the first and second starboard rotors on the other, and ii) the first port rotor and first starboard rotor on the one hand and the second port rotor and second starboard rotor on the other.In one embodiment, pitch and roll station keeping control of the fuselage may be provided in response to generating symmetric cyclic control on the first port rotor, the first starboard rotor, the second port rotor, and the second starboard rotor to provide horizontal thrust, and generating differential thrust on at least one pair of rotors selected from the group consisting of: i) the first and second port rotors on the one and the first and second starboard rotors on the other; and ii) the first port rotor and first starboard rotor on the one and the second port rotor and second starboard rotor on the other, whereby the generation of differential thrust combined with the generation of the symmetric cyclic control causes the fuselage to remain stationary and in a pitch or roll angle relative to the horizontal.

[0007] A further method of controlling a fixed-wing aircraft includes providing rotor blade pitch control to a first port rotor coupled to a first port wing, the rotor blade pitch control for the first port rotor being selected from the group consisting of longitudinal cyclic control, lateral cyclic control, and collective pitch control to induce pitch, roll, and yaw moments, respectively; and providing rotor blade pitch control to a first starboard rotor coupled to a first starboard wing, the rotor blade pitch control for the first starboard rotor being selected from the group consisting of longitudinal cyclic control, lateral cyclic control, and collective pitch control to induce pitch, roll, and yaw moments, respectively. In this manner, pitch, yaw, and roll moments of the fixed-wing aircraft may be achieved without the assistance of wing control surfaces. In another embodiment, the method may further include providing rotor blade pitch control to a second port rotor coupled to the second port wing, the rotor blade pitch control selected from the group consisting of longitudinal cyclic control, lateral cyclic control, and collective pitch control; and providing rotor blade pitch control to a second starboard rotor coupled to the second starboard wing, the cyclic control selected from the group consisting of longitudinal cyclic control, lateral cyclic control, and collective pitch control.

[0008] A fixed-wing aircraft is also disclosed that may include a fuselage and first port and first starboard wings extending from opposite sides of the fuselage, the first port and first starboard wings being devoid of flight control surfaces; a first port rotor coupled to the first port wing, the first port rotor driven by a first electric motor and having a first swashplate; and a first starboard rotor coupled to the first starboard wing, the first starboard rotor driven by a second electric motor and having a second swashplate. In one embodiment of the aircraft, the first and second swashplates each independently enable first port rotor blade pitch control and first starboard rotor blade pitch control selected from the group consisting of longitudinal cyclic control, lateral cyclic control, and collective pitch control. The aircraft may further have a second port wing and a second starboard wing extending from opposite sides of the fuselage, a second port rotor coupled to the second port wing, the second port rotor driven by a third electric motor and having a third swashplate, and a second starboard rotor coupled to the second starboard wing, the second starboard rotor driven by a fourth electric motor and having a fourth swashplate. [Brief description of the drawings]

[0009] The components in the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Like reference numbers indicate corresponding parts throughout the different drawings. [Figure 1] FIG. 1 illustrates one embodiment of a two-rotor fixed-wing aircraft transitioning from vertical takeoff to horizontal flight. [Diagram 2] 2A, 2B, and 2C are starboard side, top, and perspective views, respectively, of the two-rotor fixed-wing aircraft first shown in FIG. 1, further illustrating pitch up, right yaw, and roll flight control inputs, respectively. [Figure 3A] FIG. 3A is a table illustrating the pitch, roll, yaw, and thrust effector inputs and associated diagrams for the two-rotor fixed-wing aircraft shown in FIGS. 1 and 2. [Figure 3B]FIG. 3B is a table describing an embodiment of effector control for the two-rotor fixed-wing aircraft shown in FIGS. 1, 2A, 2B, and 2C. [Figure 3C] FIG. 3C is another table describing an embodiment of effector control for the two-rotor fixed-wing aircraft shown in FIGS. 1, 2A, 2B, and 2C. [Figure 4] 4A, 4B, and 4C are front, top, and left side views, respectively, of another embodiment of a fixed-wing aircraft having four rotors and capable of vertical takeoff and landing. [Diagram 5] FIG. 5 is a table listing embodiments of vertical flight orientation modes and associated control effectors for the four-rotor fixed-wing aircraft shown in FIGS. 4A, 4B, and 4C. [Figure 6] FIG. 6 is a table listing embodiments of horizontal flight orientation modes and associated control effectors for the four-rotor fixed-wing aircraft shown in FIGS. 4A, 4B, and 4C. [Figure 7] 7A, 7B, and 7C illustrate one embodiment of aircraft orientation control for a four-rotor fixed-wing aircraft in calm conditions, horizontal wind conditions, and deck roll conditions, respectively. [Figure 8A] FIG. 8A is a top view of another embodiment of a four-rotor fixed-wing aircraft. [Figure 8B] FIG. 8B is a front view of another embodiment of the four-rotor fixed-wing aircraft. [Figure 8C] FIG. 8C is a perspective view of another embodiment of the four-rotor fixed-wing aircraft. [Figure 9] FIG. 9 is one embodiment of the system for use with a four-rotor or two-rotor (not shown) fixed-wing aircraft capable of ship launch and on-station loiter over land using satellite communications. [Figure 10] FIG. 10 is a block diagram illustrating one embodiment of a power generation and energy storage system for use with a four-rotor fixed-wing aircraft having four electric motors. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A vertical take-off and landing (VTOL) aircraft is disclosed that can take off and land vertically using one or more wings and two or more rotors operable to lift the aircraft vertically upward, transition the aircraft to horizontal flight, and then transition the aircraft back to vertical flight for landing vertically downward. During vertical flight, the wings point vertically and do not contribute to vertical lift, but the aircraft moves up and down (e.g., the wings point upward). When airborne, the aircraft can move at least substantially horizontally (e.g., sliding side to side) while maintaining its vertical orientation, and can use the rotors to rotate the aircraft from an at least generally vertical orientation to an at least generally horizontal orientation to transition to forward flight, and then transition from at least generally horizontal flight back to at least generally vertical flight for landing. During forward flight, the one or more wings generate lift and the rotors are oriented to propel the aircraft generally forward. In this way, the aircraft can utilize the efficiency of lift generated by the wings to maximize endurance during forward flight, but does not require long horizontal runways to take off and land, and is given the ability to take off and land vertically.

[0011] In some embodiments, the entire attitude control of the vehicle is generated by propulsion without the assistance of aerodynamic control surfaces such as ailerons, elevators, or rudders. The absence of control surfaces on the vehicle structure (usually located on the trailing edges of the wings or stabilizers) makes the vehicle lighter, more efficient (aerodynamically), more reliable, less complex, and typically more robust. The increased robustness allows the aircraft to be subjected to and operated in physical conditions that an aircraft with control surfaces would not typically be subjected to without damage or potential adverse effects on its control and operation. For example, an aircraft without control surfaces on its structure can land vertically in brush or rocky ground without the possibility of subsequent flight control problems due to damage to the flight control surfaces. Furthermore, the absence of control surfaces makes the aircraft less maintenance-intensive and less susceptible to damage during operations such as moving around on a ship. The absence of control surfaces on the aircraft reduces drag. In other embodiments, some control surfaces may be provided to supplement the attitude control provided by propulsion.

[0012] In some embodiments, the propulsion means is at least two rotors rotatably mounted on the wings via respective electric motors, each having a swashplate capable of providing pitch, yaw, and roll control of the aircraft by varying blade rotation rate (RPM) and / or blade pitch, such as by either cyclic or collective pitch control. In vertical flight (or at least approximately vertical flight), the majority of lift, attitude control, and thrust can be generated by at least two propellers. In horizontal flight (or at least approximately horizontal flight), the majority of lift can be generated by the wing surfaces, and vehicle attitude control and thrust can be generated by at least two rotors. That is, for horizontal flight, pitch, yaw, and roll control of the aircraft is provided by differential thrust and rotational moment generated by at least two rotors, each rotor consisting of at least two or three rotatable rotor blades with variable pitch controllable, for example, by a swashplate with two or three control axes. In some embodiments, aerodynamic control surfaces such as elevators and ailerons may be provided to assist in attitude control of vertical and horizontal flight.

[0013] 1 illustrates an embodiment of a two-rotor fixed-wing aircraft 100 that may have a fuselage 110 coupled between port and starboard wings (115, 120) having port and starboard rotors (125, 130). The port and starboard rotors (125, 130) are connected to and driven by respective port and starboard electric motors (135, 140) via respective port and starboard swash plates (145, 150), which provide collective control and preferably single-axis cyclic pitch control of the rotor blades 155. In other embodiments, the swash plates (135, 150) may provide collective control and two-axis cyclic pitch control of the rotor blades 155. In a further embodiment, to assist in pitch and / or roll attitude control of the aircraft 100, the port and starboard wings (115, 120) have port and starboard elevons (160, 165) extending generally into the rotor wakes aft of the port and starboard rotors (125, 130), respectively. When supplemental pitch control is desired, e.g., for use in transitioning between vertical and horizontal flight, the elevons (160, 165) operate in a "flap down" configuration to induce a forward tilting moment on the aircraft. Similarly, when supplemental roll control is desired, the elevons (160, 165) may operate as ailerons on a conventional wing and vertical / horizontal stabilizer aircraft. To move the aircraft forward or backward in vertical flight, the elevons (160, 165) may be used to maintain the aircraft's (at least generally) vertical orientation by generating a moment that counteracts the lift generated by the wing with the propeller wake airflow around the wing.

[0014] The aircraft is shown initially positioned on landing gear 170 on the ground and oriented in a vertical position at landing point A. Vertical takeoff of the aircraft 100 is achieved when vertical thrust is provided by first port rotor 125 and first starboard rotor 130, driven by first port electric motor and first starboard motor (135, 140), respectively. The rotors (125, 130) operate to generate symmetric or differential thrusts (X1, X2) using angular rate control or collective control inputs, and symmetric or differential rotational moments using cyclic control inputs, to collectively enable pitch, roll, yaw, and vertical / horizontal acceleration. For purposes of this application, an inertial frame of reference is provided in FIG. 2C and vertical / horizontal directions are provided in FIG. 1.

[0015] From a landing site (position A), the aircraft can transition to vertical flight and then to horizontal flight (position B) where the majority of the lift is provided by the wings (115, 120). Attitude control (pitch, roll, yaw) is provided by the rotors (125, 130) during both vertical and horizontal flight, as the pitch of each of the rotor blades 155 is guided by the swash plates (145, 150) and the rotors (125, 130) are driven in rotation by electric motors (135, 140). The horizontal thrust (Y1, Y2) during horizontal flight is sufficient to overcome the parasitic and induced drag of the wings (115, 120) and fuselage 110 during cruise, loiter, and even during ascent in horizontal flight.

[0016] 2A, 2B, and 2C are right plan, top, and perspective views, respectively, illustrating pitch up, right yaw, and roll flight control forces of a two-rotor aircraft. As shown in the side view of FIG. 2A, in forward flight, the aircraft 100 can use cyclic control of the rotors (125, 130) by the swash plates (145, 150) to generate a thrust T1 below the center of the rotors and therefore below the center of mass M of the aircraft 100, which is greater than a thrust T2 generated above the center of the rotors and above the center of mass M of the aircraft 100. In some embodiments, the hub and / or rotor blades can be hinged or gimbaled such that as the swash plates (145, 150) move, the rotors' angular position relative to the rotor initial position (or the aircraft) is displaced concomitantly with the swash plate displacement, resulting in a thrust vector that is tilted relative to the initial position (e.g., straight ahead), and this tilted force vector component imparts a force to the aircraft to cause it to rotate (e.g., pitch). The generated differential force and resulting rotational moment causes the aircraft 100 to pitch up when a negative rotational moment is produced from the cyclic control input, and pitch down when a positive rotational moment is produced from the cyclic control input. Similarly, a right roll of the fuselage 110 can be induced when the port rotor 125 generates a positive rotational moment in response to actuation of the port swash plate 145 and the starboard rotor 130 generates a negative rotational moment in response to actuation of the starboard swash plate 150.

[0017] 2B illustrates an aircraft in forward flight in a horizontal flight orientation, with yaw control affected by differential thrust (X-port, X-starboard) of the port and starboard rotors (125, 130). In the horizontal flight orientation, differential thrust (X-port, X-starboard) of the rotors (125, 130) can be achieved through asymmetric collective control provided by the port and starboard swash plates (145, 150) and / or, in a non-preferred embodiment, by differential motor angular velocity control (rotor RPM) of the port and starboard rotors (125, 130) using control of the port and starboard electric motors (135, 140). For example, a right yaw moment (yaw to the right) can be induced by i) increasing the thrust generated by the port rotor 125, ii) decreasing the thrust generated by the starboard rotor 130, or iii) increasing the thrust generated by the port rotor 125 and decreasing the thrust generated by the starboard rotor 130. Increasing the thrust generated by a particular rotor can be achieved by increasing the pitch angle of the associated rotor blades 155 through collective operation, or in a non-preferred embodiment, by increasing the angular rotation (RPM) of the particular rotor driven by its associated electric motor. Similarly, decreasing the thrust generated by a particular rotor can be achieved by decreasing the pitch angle of the associated rotor blades 155 through collective operation, or by decreasing the angular rotation (RPM) of the particular rotor driven by its associated electric motor.

[0018] In an alternative embodiment, symmetric cyclic control may be provided by the port rotor 125 and starboard rotor 130 to generate asymmetric blade thrust (shown in dashed lines) on the left and right sides to generate a net right moment of yaw. More specifically, the port swash plate 145 actuates the blade pitch of the port rotor 125 asymmetrically such that blades passing on the left side of the port rotor 125 (region 155a) generate more thrust than blades passing on the right side of the port rotor 125 (region 155b). Similarly, blades passing on the left side of the starboard rotor 130 (region 155a) generate more thrust than blades passing on the right side of the starboard rotor 130 (region 155b), with all of the blades collectively through the port and starboard wings (115, 120) generating a net right yaw of the fuselage 110.

[0019] FIG. 2C is a perspective view illustrating rotor cyclic control to induce a left roll of the fuselage. In one embodiment, a left roll of the fuselage is induced in response to generating a negative rotational moment Mleft in the first port rotor 125 in response to actuation of the first port swash plate 145, and generating a positive rotational moment Mright in the first starboard rotor 130 in response to actuation of the first starboard swash plate 150. Similarly, to impart a right roll to the fuselage, a positive rotational moment may be generated in the first port rotor in response to actuation of the first port swash plate, and a negative rotational moment may be generated in the starboard rotor in response to actuation of the first starboard swash plate. A right wing pitch up and a left wing pitch down causes the aircraft 100 to roll left (when viewed from behind). Similarly, reversing these pitch forces causes the aircraft 100 to roll right. FIG. 2C further illustrates horizontal thrust components T3, T4, T5, and T6, along with associated vertical thrust vector components Z1 (right wing), Z2 (left wing), showing the thrust magnitude of the associated blade 155 at the illustrated rotor blade position.

[0020] FIG. 3A describes one embodiment of pitch, roll, yaw and thrust effector inputs along with force vectors and diagrams associated with the two-rotor fixed-wing aircraft shown in FIGS. 1 and 2. Line 1 of FIG. 3A provides a front view of the aircraft 100 illustrating one embodiment of positive pitch control to cause the fuselage 110 to nose up by the port and starboard wings (115, 120). For example, pitch up can be induced using symmetric cyclic pitch control that generates a positive (and equal) rotational moment in each of the port and starboard rotors (125, 130) in response to the action of port and starboard swashplates, respectively, resulting in a pitch up force as shown by the two vertical force lines. Port and starboard plan views of the aircraft 100 are also provided illustrating the net nose up force vectors generated by the nose up symmetric cyclic pitch control.

[0021] Line 2 of Figure 3A provides a front view of the aircraft 100 illustrating a right (positive) roll of the fuselage. For example, a right (positive) roll may be induced using asymmetric cyclic control of the port and starboard rotors (125, 130) by generating a positive rotational moment in the port rotor 125 in response to appropriate actuation of the port swash plate and a negative rotational moment in the starboard rotor in response to appropriate actuation of the starboard swash plate. Although not shown in Figure 3A, asymmetric cyclic control of the port and starboard rotors (125, 130) may also be used to provide a left roll of the fuselage. For example, a left roll of the fuselage 110 may be induced by generating a negative rotational moment in the port rotor in response to appropriate actuation of the port swash plate and a positive rotational moment in the starboard rotor in response to appropriate actuation of the starboard swash plate. Asymmetric control of the elevons can also compensate for left roll of the fuselage, such as by extending the left elevon 160 upward to reduce the lift of the left wing 115 and extending the right elevon 165 downward to increase the lift of the right wing 165 (see FIG. 2B).

[0022] Line 3 of FIG. 3A provides a top view of the aircraft 100 illustrating a right (positive) yaw of the fuselage. This yaw can be generated using differential thrust of the port and starboard rotors (125, 130). Such differential thrust can be provided by either asymmetric collective control or differential rotational speed control of the port and starboard rotors (125, 130). As shown in line 3 of FIG. 3A, a nose-right (positive) yaw can be generated about the fuselage by the port rotor 125 providing more thrust than the starboard rotor 130. Similarly, a nose-left (negative) yaw can be generated about the fuselage by the port rotor 125 providing less thrust than the starboard rotor 130. In one embodiment, differential thrust can be provided using differential rotational speeds of the port and starboard rotors (125, 130), such as by port and starboard electric motors (135, 140) driving the port and starboard rotors (125, 130) at different revolutions per minute (RPM). In another embodiment, illustrated in FIG. 3A, asymmetric collective control of the rotors (125, 130) is used to provide differential thrust, such as by providing greater relative collective control to the port rotor 125 and less relative collective control to the starboard rotor 130.

[0023] Line 4 of Figure 3A further provides a top view of the aircraft 100 illustrating one embodiment of applying thrust. In one embodiment, thrust adjustments can be achieved using symmetric collective (forward positive) control of the rotors (125, 130). The rotors (125, 130) can be driven at a constant angular rotational speed by port and starboard electric motors (135, 140), and rotor thrust is varied by collective blade pitch adjustments made by each of the port and starboard swash plates (145, 150). To increase forward thrust, the port and starboard swash plates (145, 150) can increase their respective collective control inputs to symmetrically increase the pitch of each blade 155. To decrease forward thrust, the port and starboard swash plates (145, 150) can decrease their respective collective control inputs to symmetrically decrease the pitch of each blade 155.

[0024] 3B and 3C are tables illustrating different flight control effector embodiments capable of achieving horizontal or vertical flight, roll, yaw, and pitch in coordinated turns for the two-rotor fixed-wing aircraft illustrated in FIGS. 1, 2A, 2B, and 2C, along with associated diagrams illustrating the associated forces. Pitch control, and pitch control to / from vertical flight, can be achieved by at least two effector embodiments. In embodiment 1 (line 1), symmetric cyclic control inputs can be provided between the port and starboard rotors (125, 130). For example, pitch up control of the fuselage 110 can be generated in response to appropriate symmetric actuation of each of the port and starboard swash plates (145, 150) generating a positive rotational moment (i.e., symmetric cyclic rotor control) in each of the port and starboard rotors (125, 130). Similarly, pitch down control of the fuselage 110 can be generated in response to appropriate symmetric actuation of each of the port and starboard swash plates (145, 150) generating a negative rotational moment in each of the port and starboard rotors (125, 130). 3C, embodiment 2 of pitch control to and from vertical flight may utilize symmetric actuation of port and starboard elevons (160, 165) to supplement such pitch effector control. For example, if the port and starboard rotors (125, 130) cause the fuselage 110 to pitch up, the port and starboard elevons may act symmetrically (i.e., with substantially similar effector control inputs) to provide an additional fuselage pitch up force.

[0025] Roll control can be achieved with at least two different effector control embodiments. In embodiment 1, shown in FIG. 3B (line 2), asymmetric cyclic control of the port and starboard rotors (125, 130) can induce roll of the fuselage. For example, a left roll of the fuselage 110 can be induced by generating negative and positive rotational moments in the port and starboard rotors (125, 130), respectively, in response to actuation of the port and starboard swash plates (145, 150), respectively. Similarly, a right roll of the fuselage can be induced by generating positive and negative rotational moments in the port and starboard rotors (125, 130), respectively, in response to actuation of the port and starboard swash plates (145, 150), respectively. In embodiment 2 of aircraft roll effector control, shown in FIG. 3C, the asymmetric cyclic control of the port and starboard rotors (125, 130) can be supplemented by complementary asymmetric actuation of the port and starboard elevons (160, 165). For example, if the port and starboard rotors (125, 130) induce a left roll, the port and starboard elevons (160, 165) may act asymmetrically to provide an additional fuselage left roll force, similar to the action of aileron control in an aircraft with more conventional aileron and vertical stabilizer / elevator control surfaces.

[0026] Yaw control can be achieved using at least three different effector control embodiments. In embodiment 1, illustrated in FIG. 3B (line 3), a yaw moment can be induced about the fuselage 110 in response to generating asymmetric collective control (alternatively referred to as "asymmetric collective" control) between the port and starboard rotors (125, 130). For example, assuming a straight, steady-state flight attitude, a right (positive) yaw can be induced by increasing the relative collective control of the port rotor 125 and / or decreasing the relative collective control of the starboard rotor 130. Similarly, a left (negative) yaw can be induced about the fuselage 110 by decreasing the relative collective control of the port rotor 125 and / or increasing the relative collective control of the starboard rotor 130.

[0027] In embodiment 2 (line 3) shown in FIG. 3C , yaw control may be achieved using differential motor RPM control of port and starboard electric motors (135, 140) driving the port and starboard rotors (125, 130), respectively. For example, a right (positive) yaw may be induced about the fuselage 110 by increasing the RPM of the port rotor 125 by a proportional increase in the RPM of the port electric motor 135 and / or decreasing the RPM of the starboard rotor 130 by a proportional decrease in the RPM of the starboard electric motor 140. Similarly, a left (negative) yaw may be induced about the fuselage 110 by proportionally decreasing the RPM of the port rotor 125 by a proportional decrease in the RPM of the port electric motor 135 and / or increasing the RPM of the starboard rotor 130 by a proportional increase in the RPM of the starboard electric motor 140.

[0028] In embodiment 3 (line 3) shown in FIG. 3C , yaw control may be achieved using asymmetric collective control of the port and starboard rotors (125, 130) along with differential motor RPM control of the port and starboard electric motors (135, 140). For example, a right (positive) yaw may be induced in the fuselage 110 by increasing collective control of the port rotor 125 and / or decreasing relative collective control of the starboard rotor 130 in conjunction with increasing motor RPM control of the port electric motor 135 and / or decreasing motor RPM control of the starboard electric motor 140. Similarly, a left (negative) yaw may be induced in the fuselage 110 by decreasing collective control of the port rotor 125 and / or increasing relative collective control of the starboard rotor 130 in conjunction with decreasing motor RPM control of the port electric motor 135 and / or increasing motor RPM control of the starboard electric motor 140.

[0029] Figures 3B and 3C further describe at least four different effector control embodiments that may be utilized to achieve a coordinated turn using the inventive system described herein. In embodiment 1, described in Figure 3B (line 4), coordinated turn of the port and starboard wings may be achieved by using asymmetric cyclic control of the port and starboard rotors (125, 130) substantially simultaneously with asymmetric collective control of the port and starboard rotors (125, 130). For example, to achieve a coordinated right turn, asymmetric cyclic control of the port and starboard rotors (125, 130) may be achieved by generating a positive rotational moment in the port rotor 125 and a negative rotational moment in the starboard rotor 130 substantially simultaneously with increasing collective control of the port rotor 125 and / or decreasing collective control of the starboard rotor 130, respectively. In another example, to achieve a coordinated left turn, asymmetric cyclic control of the port and starboard rotors (125, 130) may be achieved by generating a negative rotational moment in the port rotor 125 and a positive rotational moment in the starboard rotor 130, substantially simultaneously decreasing collective control of the port rotor 125 and / or increasing collective control of the starboard rotor 130, respectively.

[0030] In embodiment 2 (line 4) shown in FIG. 3C , a coordinated turn may be accomplished using asymmetric port and starboard elevons (160, 165) and substantially simultaneous asymmetric collective control of the port and starboard rotors (125, 130). For example, to accomplish a coordinated right turn, the port elevon 160 may be operated to increase lift on the port wing 115 and the starboard elevon 165 may be operated to decrease lift on the starboard wing 120, substantially simultaneously with increasing collective control of the port rotor 125 and / or decreasing relative collective control of the starboard rotor 130, respectively. Similarly, to accomplish a coordinated left turn, the port elevon 160 may be operated to decrease lift on the port wing 115 and the starboard elevon 165 may be operated to increase lift on the starboard wing 120, substantially simultaneously with decreasing collective control of the port rotor 125 and / or increasing relative collective control of the starboard rotor 130, respectively.

[0031] In embodiment 3 (line 4) shown in Figure 3C, a coordinated turn may be achieved using substantially simultaneous i) asymmetric cyclic control of the port and starboard rotors (125, 130), ii) asymmetric collective control of the port and starboard rotors (125, 130), and iii) asymmetric control of the port and starboard elevons (160, 165). For example, a coordinated right turn may be achieved in response to the right turn described above for embodiment 2, and additional asymmetric cyclic control of the port and starboard rotors (125, 130), such as by generating positive and negative rotational moments in the port and starboard rotors (125, 130) in response to actuation of the port and starboard swash plates (145, 150), respectively. Similarly, a balanced left turn can be achieved in response to the left turn described above for embodiment 2 and additional asymmetric cyclic control of the port and starboard rotors (125, 130), such as by generating negative and positive rotational moments in the port and starboard rotors (125, 130) in response to movement of the port and starboard swash plates (145, 150), respectively.

[0032] In embodiment 4 (line 4) of FIG. 3C, coordinated control can be achieved by utilizing substantially simultaneous i) asymmetric cyclic control of the port and starboard rotors (125, 130), ii) asymmetric actuation of the port and starboard elevons (160, 165), and iii) differential motor RPM control of the port and starboard electric motors (135, 140).

[0033] Figures 3B and 3C further describe at least three different effector control embodiments that can be utilized to achieve slow horizontal motion using the inventive system described herein. In embodiment 1 (line 5), slow horizontal motion can be achieved using symmetric cyclic (non-zero) rotor control of the port and starboard rotors. In embodiment 2 (line 5) shown in Figure 3C, slow horizontal motion can be achieved using i) symmetric cyclic (non-zero) rotor control of all rotors, and ii) elevon control to maintain a more vertical orientation of the aircraft. In embodiment 3 (line 5) shown in Figure 3C, horizontal motion can be achieved using asymmetric collective control of the port rotor relative to the starboard rotor.

[0034] 3A and 3B are described primarily with respect to a two-rotor fixed-wing aircraft 100, in non-preferred embodiments, such effector control inputs may also be utilized to provide attitudinal and thrust control for a four-rotor fixed-wing aircraft having two wing and horizontal stabilizer / elevator configurations, such as those shown in Figures 4A, 4B, and 4 C. In such applications, the effector controls are preferably located on one of the two wings of the four-rotor fixed-wing aircraft.

[0035] 4A, 4B, and 4C are front, top, and left side views, respectively, of another embodiment of a fixed-wing aircraft having four rotors and capable of vertical takeoff and landing. An aft wing 401 has aft left and aft starboard wings (402, 404) coupled to a fuselage 406. A forward wing 408 has forward left and forward starboard wings (410, 412) further coupled to the fuselage 406. An aft port swash plate 414 is coupled between the aft port rotor 416 and the aft port electric motor 418, which is coupled to the aft port wing 402. An aft starboard swash plate 420 is coupled between the aft starboard rotor 422 and the aft starboard electric motor 424, which is coupled to the aft starboard wing 404. The forward port swash plate 426 may be coupled between the forward port rotor 428 and the forward port electric motor 430, which is coupled to the forward port wing 410. The forward starboard swash plate 432 may be coupled between the forward starboard rotor 434 and the forward starboard electric motor 436, which is coupled to the forward starboard wing 412. In one embodiment, a horizontal stabilizer 438 may be coupled to the fuselage 406, with the fuselage 406 coupled between the forward port wing 410 and the forward starboard wing 412, and an elevator 440 may be rotatably coupled to the horizontal stabilizer 438. A port aileron 442 may be rotatably disposed on a trailing edge 444 of the aft port wing 402, and a starboard aileron 446 may be rotatably disposed on a trailing edge 448 of the aft starboard wing 404. Aft and forward landing gear (450, 452) may be attached to the aft port wing 402 and the aft starboard wing 404, respectively. Third landing gear 454 may be attached to horizontal stabilizer 438, for example, on opposite longitudinal sides of horizontal stabilizer 438.

[0036] For purposes of the preceding discussion and further description in the tables below, the described pitch, yaw, and roll motions resulting from "symmetric" and "differential" cyclic rotor control, collective rotor control, and motor RPMs assume symmetric or near-symmetric rotor arrangements about the center of mass of the aircraft, assume identical or nearly identical electric motor power outputs, and assume symmetric or near-symmetric parasitic drag of the aircraft structure about the center of mass in horizontal and vertical flight modes. In real world applications, bias or trim effector inputs may be provided to offset weight balance deviations and asymmetric parasitic drag of the aircraft structure to maintain the effectiveness of the effector controls below.

[0037] Symmetric collective effector control - the application of identical or similar collective control inputs between two sets of rotors (which may be single rotor) by each swashplate, resulting in identical or similar rotor force vectors between such sets.

[0038] Asymmetric collective effector control - the application of dissimilar collective control inputs between two sets of rotors (which may be single rotor) by respective swashplates, resulting in dissimilar rotor forces of equal or similar vector force directions between such sets.

[0039] Asymmetric Cyclic Effector Control - the application of dissimilar cyclic control inputs between two sets of rotors (which may be single rotor) by respective swashplates, resulting in rotor torques of dissimilar magnitudes and in opposite torque directions between such sets.

[0040] Symmetric Cyclic Effector Control - the application of identical or similar cyclic control inputs between two sets of rotors (which may be single rotor) by respective swashplates to produce rotor moment of the same or similar magnitude and direction between such sets. Symmetric cyclic effector control may be used to mean rotors all having the same magnitude moment with the same or similar moment direction.

[0041] Differential Motor RPM - The application of dissimilar rotational speeds between two pairs of motors (which may be single rotor pairs) configured to convert such dissimilar rotational speeds into rotor forces of proportionally dissimilar magnitudes between the pairs, but the same or similar vector force directions.

[0042] FIG. 5 describes three flight control configuration embodiments that may be utilized to affect pitch, yaw, and roll control of the four-rotor fixed-wing aircraft first illustrated in FIGS. 4A, 4B, and 4C during a vertical flight orientation of the vehicle, such as during takeoff or hovering. Pitch from a vertical orientation to horizontal flight may be achieved by at least two effector embodiments. In flight control configuration embodiment 1 (line 1), pitch control of the fuselage 406 may be provided in response to providing differential motor RPM control between the aft port rotor 416 and / or aft starboard rotor 422 on the one hand and the forward port rotor 428 and / or forward starboard rotor 434 on the other. In embodiment 2 (line 1), pitch control of the fuselage may be provided in response to providing asymmetric collective control between the aft port rotor 416 and aft starboard rotor 422 on the one hand and the forward port rotor 428 and forward starboard rotor 434 on the other.

[0043] FIG. 5 further describes two different effector control embodiments that can be utilized to achieve slow horizontal movement when the aircraft 400 is in vertical orientation mode. In embodiment 1 (line 2), slow horizontal movement of the aft and aft port wings (402, 410) and the aft and aft starboard wings (404, 412) occurs by providing symmetric cyclic control to all rotors (416, 428, 422, and 434). In embodiment 2 (line 2), slow horizontal movement in vertical orientation mode can be provided by generating differential collectives between the aft starboard and aft port rotors (416, 422) on the one hand and the forward starboard and aft starboard rotors (428, 434) on the other. In an alternative embodiment, horizontal movement can be provided by generating differential collectives between the aft and aft port rotors (416, 428) on the one hand and the aft and aft starboard rotors (422, 434) on the other.

[0044] A static non-zero roll station-keeping control of the fuselage during the hover / vertical orientation mode can be achieved by at least two effector embodiments. In embodiment 1 (line 3), asymmetric collective control can be generated between the aft and aft starboard rotors (422, 434) on the one hand and the aft and aft port rotors (416, 428) on the other, each substantially simultaneously with symmetric cyclic control of the rotors (422, 434, 416, 428). In embodiment 2 (line 3), differential motor RPM control may be provided between the aft and aft starboard rotors (422, 412) on the one hand and the aft and aft port rotors (416, 428) on the other, each substantially simultaneously with non-zero symmetric cyclic control of all rotors (422, 434, 416, 428).

[0045] Static non-zero pitch angle station keeping control of the fuselage during hover / vertical orientation mode can be achieved by at least two effector embodiments. In embodiment 1 (line 4) shown in FIG. 5, asymmetric collective control can be generated between the aft port and starboard rotors (416, 422) on the one hand and the forward port and starboard rotors (416, 434) on the other, substantially simultaneously with symmetric cyclic control of the aft and aft port rotors (416, 428) on the one hand and the aft and aft starboard rotors (422, 434) on the other. In embodiment 2 (line 4), pitch angle station keeping may be provided by generating differential motor RPM control between the aft port rotor 416 and the aft starboard rotor 422 on the one hand and the forward port rotor 428 and the forward starboard rotor 434 on the other, substantially simultaneously with symmetric cyclic control of the aft port rotor 416, forward port rotor 428, aft starboard rotor 422 and forward starboard rotor 434.

[0046] A yaw moment can be generated about the fuselage during the hover / vertical orientation mode by at least two effector embodiments. In embodiment 1 (line 5) of Figure 5, the yaw moment can be generated in response to asymmetric cyclic control of the aft and forward port rotors (416, 428) on the one hand and the aft and forward starboard rotors (422, 434) on the other. In embodiment 2 (line 5), the yaw moment can be generated in response to differential motor RPM control between the aft port rotor 416 and forward starboard rotor 434 on the one hand and the forward port rotor 428 and aft starboard rotor 422 on the other.

[0047] Vertical takeoff can be provided by at least two effector embodiments. In embodiment 1 (line 6), takeoff can occur in response to symmetric motor RPM control of all rotors (422, 434, 416, 428). In embodiment 2 (line 6) of Figure 5, fuselage takeoff can occur in response to symmetric collective control of all rotors (422, 434, 416, 428).

[0048] Although Figure 5 describes two aircraft configuration embodiments that affect various aircraft attitude and translation control, other embodiments may be utilized for effector control in one aircraft configuration embodiment. For example, in any particular aircraft configuration embodiment, low speed horizontal transitions may be achieved using either symmetric cyclic (non-zero) rotor control or asymmetric collective rotor control, as described in Figure 5, line 2.

[0049] FIG. 6 describes three flight control embodiments that may be collectively utilized to affect pitch, yaw, and roll control of the four-rotor fixed-wing aircraft depicted in FIGS. 4A, 4B, and 4C when the aircraft is in a horizontal orientation, such as when the aft and forward wings (401, 408) are providing all or substantially all of the vertical lift during cruise or loiter. At least three different aircraft control configuration embodiments described in FIG. 6 may effect pitch control of the fuselage around the fuselage during flight in a horizontal flight orientation to transition from a horizontal flight orientation to a vertical flight orientation, such as in preparation for landing or hovering. In flight control embodiment 1, pitch to vertical flight may be effected by providing asymmetric collective control between the aft port and aft starboard rotors (416, 422) on the one hand and the forward port and forward starboard rotors (428, 434) on the other, and providing substantially simultaneous, complementary elevator actuation. In flight control embodiment 2 (line 1), pitch control of the aircraft can be achieved without the use of elevator actuation in response to providing asymmetric collective control between the aft port and aft starboard rotors (416, 422) on the one hand and the forward port and forward starboard rotors (428, 434) on the other. In flight control embodiment 3 (line 1), pitch control can be generated relative to the fuselage by providing differential motor RPM control between the aft port and aft starboard motors (418, 424) on the one hand and the forward port and forward starboard rotors (428, 434) on the other.

[0050] At least three different aircraft control configuration embodiments, as illustrated in FIG. 6, may be used to provide pitch control of the fuselage during flight while the aircraft is in a horizontal orientation. In flight control embodiment 1 (line 2), pitch may be induced by providing elevator control without the use of asymmetric collective rotor control. In embodiment 2 (line 2), pitch control may be induced by providing asymmetric collective control between the aft port and aft starboard rotors (416, 422) on the one hand and the forward port and forward starboard rotors (428, 434) on the other, preferably without the use of elevators. In embodiment 3 (line 2), pitch control may be induced relative to the fuselage by providing differential motor RPM control between the aft port and aft starboard motors (418, 424) on the one hand and the forward port and forward starboard rotors (428, 434) on the other, preferably without the aid of elevator action or asymmetric collective rotor control.

[0051] At least three aircraft control configuration embodiments described in FIG. 6 may induce a roll moment about the fuselage while flying in a horizontal flight orientation. In flight control embodiment 1 (line 3), roll may be induced by providing actuation of port and starboard ailerons (442, 446) rotatably coupled to the aft port wing 402 and aft starboard wing 404, respectively. Alternative embodiments may further include port and starboard ailerons on the forward port and starboard wings (410, 412) or on both the forward and main wings (401, 408). In embodiment 2 (line 3), roll control may be induced by providing asymmetric cyclic rotor control of the aft and forward port rotors (416, 428) on the one hand and the aft and forward starboard rotors (422, 434) on the other. In embodiment 3 (line 3), roll control may be provided by differential motor RPM control of the aft and forward port motors (430, 418) on the one hand and the aft and forward starboard motors (436, 424) on the other.

[0052] A yaw moment may be induced about the fuselage during flight in a horizontal flight orientation by at least three different aircraft control configuration embodiments described in Figure 6. In flight control embodiments 1 and 2 (line 4), a yaw moment may be induced about the fuselage in response to asymmetric collective control between the aft and aft port rotors (416, 428) on the one hand and the aft and aft starboard rotors (422, 434) on the other. In embodiment 3 (line 4), a yaw moment may be induced in response to differential motor RPM control between the aft and aft port rotors (416, 428) on the one hand and the aft and aft starboard rotors (422, 434) on the other.

[0053] Coordinated turns of the forward and aft wings may also be achieved during flight in a horizontal flight orientation by at least three different aircraft control configuration embodiments described in Figure 6. In flight control embodiment 1 (line 5), coordinated turns of the aircraft 400 may be achieved by providing asymmetric aileron control between the port aileron 424 and the starboard aileron 446, simultaneously with asymmetric collective rotor control between the aft and aft port rotors (416, 428) on the one hand and the aft and aft starboard rotors (422, 434) on the other. In aircraft configuration embodiment 2 (line 5), coordinated turns of the aircraft 400 may be achieved by providing asymmetric cyclic control between the aft and aft port rotors (416, 428) on the one hand and the aft and aft starboard rotors (422, 434) on the other, approximately simultaneously with providing asymmetric collective control between the aft and aft port rotors (416, 428) on the one hand and the aft and aft starboard rotors (422, 434) on the other.

[0054] Figures 7A, 7B, and 7C illustrate the impact of several of the effector control modes described in Figure 5 used for different weather conditions that may be encountered when attempting to land on the deck surface of a moving vessel. More specifically, Figure 7A illustrates a vertically oriented air vehicle 400 hovering above a vessel deck 700 in calm wind conditions. The aft and aft port rotors (416, 428) and aft and aft starboard rotors (422, 434) can maintain the air vehicle 400 in a stable hover position and level flight (i.e., 0° pitch and roll angles relative to a horizontal plane), such as by using symmetric collective and / or motor RPM control of each rotor (416, 422, 428, 434) and symmetric cyclic control of each rotor (416, 422, 428, 434) at 0° relative to the vertical axis. In Fig. 7B, wind is illustrated from the left wing (402, 410) of the aircraft 400, requiring active flight control as described in embodiments 1 and 2 of line 2 of Fig. 5, which describes slow horizontal transition control of the fuselage while in a hover / vertical orientation. In an alternative embodiment, where the wind is coming horizontally from a forward position / orientation, embodiments 1 and 2 of line 2 of Fig. 5 can also be utilized to adjust the symmetric cyclic to provide thrust in the forward (x-axis) direction to counteract the wind force on the aircraft and maintain a stationary lateral position on the ship deck. In Fig. 7C, no wind is illustrated, but the ship deck at instantaneous pitch and roll angles from horizontal is illustrated, proposing the use of dynamic pitch and roll effector control of the aircraft 400 to achieve landing using a combination of control inputs selected from the embodiments described in lines 3 and 4 of Fig. 5, for example. For example, active pitch and roll angle manipulation can be induced in fuselage 446 as aircraft 400 descends to reduce undesirable lateral movement during descent, but still provide proper orientation of landing gear (450, 452, and 454) when contacting vessel deck 700, even when the vessel deck is rotating.

[0055] 8A, 8B, and 8C illustrate another embodiment of a four-rotor fixed-wing aircraft having a turbine and an internal combustion engine (ICE) for charging batteries that power electric motors that drive the rotors. The aircraft 800 may have an internal combustion engine 805 and a turbine 810 disposed within a fuselage 815. The internal combustion engine may be, for example, a diesel or jet fuel engine and may have one or more fuel tanks 820 provided for storing diesel and jet fuel available to the turbine and ICE (810, 805). The ICE and turbine may drive one or more generators electrically connected to batteries 825. A payload 830 having, for example, sensors, and avionics equipment 835 for remote communication and control of the aircraft may be disposed within the fuselage 815. Each rotor 840, as guided by a respective swashplate 850, is driven by a respective electric motor 845, each of which is powered directly by batteries 825, or by power generated by the ICE 805 or turbine 810, or by some combination of batteries, ICEs, or turbines (825, 805, 810). For example, during cruise or loiter, each electric motor 845 can be powered by the ICE 805. During vertical takeoff, each electric motor 845 can be powered by both the ICE 805 and turbine 810, or by the ICE, turbine, and batteries (805, 810, 825) collectively.

[0056] An aircraft 800 may be provided with four wings 860 in an X-wing configuration with a fuselage 815 at the center. The rotors may be arranged symmetrically around the fuselage 815, with each wing 860 having one rotor preferably arranged equidistant from the fuselage 815 along the respective wing 860. In one embodiment, each rotor 840 is arranged at a respective wing tip 865 to enhance attitudinal control of the fuselage 815. Each rotor 840 is provided with two blades 870, although each rotor may be a three or four blade rotor 840. Four landing gears 875 may extend from engine nacelles or other supports 880 to enable vertical takeoff and landing of the aircraft 800. The landing gears 875 may extend from the fuselage 815, from two or more wings 860, or from some combination of the fuselage 815, the wings 860, or the supports 880.

[0057] 9 is an embodiment of a system used for a fixed-wing aircraft with multi-rotor cyclic and collective control configured for vertical takeoff and landing with shipboard launch and on-station loiter over land using satellite communications. The aircraft 900 can take off vertically in a vertical flight orientation from a ship deck 905 using thrust controlled by motor RPM control or collective rotor control, or both, with takeoff power provided to electric motors using a combination of internal combustion engine generators, turbine generators, and previously stored battery power for supplemental power. The aircraft 900 can pitch forward to establish a horizontal flight orientation 910 using an embodiment of a flight control configuration that may include i) differential motor RPM control, or ii) asymmetric collective control (see FIG. 5, line 1).

[0058] Once a horizontal flight orientation is established, the aircraft preferably enters a fuel-efficient horizontal cruise mode 915 (versus vertical cruise), using power from only one of the internal combustion engine generators (see FIGS. 8A, 8B, 8C) to drive the rotors, with primary lift provided by the aircraft's wings for flight to the loiter position 910. In alternative embodiments, either the turbine generators or the batteries, or both, may be used for cruise when the internal combustion engine generators are insufficient or unavailable, or when additional power is required. In an aircraft control embodiment, pitch control about the fuselage may be achieved using i) elevator actuation, ii) asymmetric collective control, or iii) differential motor RPM control, as described in line 2 of FIG. 6. Roll control about the fuselage may be achieved using a) ailerons, b) asymmetric cyclic rotor control, or c) differential motor RPM control, as described in line 3 of FIG. 6. Yaw control about the fuselage may be achieved using asymmetric collective control or differential motor RPM control, as described in line 4 of FIG. 6. Coordinated turns can be achieved during cruise in a horizontal orientation using x) ailerons and asymmetric collective rotor control, y) asymmetric cyclic rotor control and asymmetric collective rotor control, or z) differential motor RPM control.

[0059] Communications with a command and control station, such as ship 920, can be via satellite 925.

[0060] Once the on-station loiter 910 is completed, the aircraft may return 930 to a landing destination, such as, for example, a ship's deck 905. Once at the landing destination, the aircraft may be pitched to a horizontal flight orientation 935, for example, using differential motor RPM control or asymmetric collective control to change flight orientation, as in the effector embodiment described in line 1 of FIG. 5. A slow translation of the aircraft may be used for final landing position control, using symmetric cyclic (non-zero) rotor control or asymmetric collective rotor control, as in line 2 of FIG. 5. If the landing destination is not level, or the ship's deck is rolling, the aircraft may align with the pitch and roll angles of the ship's deck 905 as it descends, using the effector control embodiment described in lines 3 and 4 of FIG. 5.

[0061] In an alternative embodiment, the aircraft 900 is a two-rotor aircraft as illustrated in Figures 1 and 2A, 2B, 2C with effectors as in the configuration of Figures 3A and 3B. As in Figure 9, the fixed-wing aircraft can take off vertically in a vertical orientation from a ship deck 905 using thrust controlled by motor RPM control, collective rotor control, or both. The aircraft can pitch forward to establish a horizontal flight orientation 910 using flight control configuration embodiments that may include i) symmetric cyclic control, or ii) symmetric cyclic control with symmetric elevon actuation (see Figure 3B, line 1). Once a horizontal flight orientation is established, the aircraft can enter a fuel-efficient horizontal orientation cruise mode 915 (versus vertical orientation cruise) that uses vertical lift primarily generated from the wings (115, 120) (see Figure 1) to fly to the loiter position 910. Aircraft control embodiments can achieve pitch control around the fuselage using i) symmetric cyclic control, or ii) symmetric rotor control and symmetric elevon actuation. Roll control about the fuselage may be achieved using a) asymmetric cyclic rotor control, or b) asymmetric cyclic control. Yaw control about the fuselage may be achieved using x) asymmetric cyclic rotor control, or y) asymmetric cyclic rotor control and asymmetric elevon actuation. Coordinated turns may be achieved using I) asymmetric cyclic rotor control with asymmetric collective rotor control, II) asymmetric collective rotor control with asymmetric elevon actuation, or III) asymmetric cyclic rotor control with asymmetric collective and asymmetric elevon actuation, or IV) asymmetric cyclic rotor control with asymmetric elevon actuation and differential RPM control.

[0062] Once the two-rotor aircraft has completed its on-station loiter 910, it may return 930 to a landing site, such as, for example, a ship's deck 905. Once at the landing site, the aircraft may be pitched to a horizontal orientation using either symmetric cyclic rotor control or symmetric elevon actuation in conjunction with symmetric cyclic rotor control.

[0063] 10 is a block diagram illustrating an embodiment of a hybrid power system with power generation and energy storage for use with a four-rotor fixed-wing aircraft with four electric motors. An aircraft 1000 is shown with four electric motors 1005 in electrical communication with a hybrid power system 1010, which may consist of a hover battery 1015, an internal combustion engine generator 1020, and a turbine generator 1025. Diesel and jet fuel tanks (1035, 1040) may be in fluid communication with the internal combustion engine generator and the turbine generator (1020, 1025), respectively. Payloads 1045, such as image or thermal sensors, transceivers, or atmospheric sensors, may be in electrical communication with the hybrid power system 1005.

[0064] While various embodiments of the present application have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this invention.

Claims

1. 1. A flight control system for a fixed-wing aircraft comprising: a first left wing and a first right wing; a first port swash plate coupled between the first port rotor and a first port electric motor, the first port electric motor coupled to the first port wing; a first starboard swash plate coupled between a first starboard rotor and a first starboard electric motor, the first starboard electric motor coupled to the first starboard wing; a horizontal stabilizer connected to the fuselage; an elevator rotatably connected to the horizontal stabilizer; It has the fuselage being coupled between the first left wing and the second right wing.

2. 2. The system of claim 1, wherein the pitch, yaw, and roll moments of the first starboard rotor and the first port rotor are achieved without assistance from wing control surfaces.

3. The apparatus of claim 1 further comprising: a second left wing and a second right wing; a second port swash plate coupled between the second port rotor and a second port electric motor, the second port electric motor coupled to the second port wing; a second starboard swash plate coupled between the second starboard rotor and a second starboard electric motor, the second starboard electric motor coupled to the second starboard wing; An apparatus comprising:

4. 4. The apparatus of claim 3, wherein the first left wing and the first right wing are coupled to the fuselage at a first end of the fuselage and the second left wing and the second right wing are coupled to the fuselage at a second end of the fuselage, the first end of the fuselage being distal from the second end of the fuselage.

5. The apparatus of claim 3 further comprising: an apparatus comprising: first and second landing gear attached to said first port wing and said first starboard wing, respectively;

6. The apparatus of claim 5 further comprising: a third landing gear attached to said horizontal stabilizer.

7. The apparatus of claim 1 further comprising: a left aileron rotatably disposed on a trailing edge of the first left wing; a right aileron rotatably disposed on the trailing edge of the first right wing; An apparatus comprising:

8. 1. A method of flight control for a fixed-wing aircraft, comprising: generating a negative rotational moment in a first port rotor rotatably coupled to the first port wing in response to actuation of the first port swashplate; and generating a positive rotational moment in a first starboard rotor rotatably coupled to the first starboard wing in response to actuation of the first starboard swashplate; generating a left roll of a fuselage coupled between the first left wing and the first right wing in response to a left roll of the fuselage is obtained without assistance from control surfaces of the first left wing and the first right wing; a horizontal stabilizer coupled to the fuselage, and an elevator rotatably coupled to the horizontal stabilizer.

9. The method of claim 8 further comprising: generating a yaw moment about the fuselage in response to generating asymmetric collective control between the first port rotor and the first starboard rotor.

10. 10. The method of claim 9, wherein generating an asymmetric collective control, generating a positive rotational moment on the first port rotor, and generating a negative rotational moment on the first starboard rotor collectively effect a coordinated turn of the port and starboard wings.

11. The method of claim 8 further comprising: generating a positive rotational moment on the first port rotor in response to actuation of the first port swash plate; and generating a negative rotational moment on the first starboard rotor in response to actuation of the first starboard swash plate; generating a right roll of the fuselage in response to a right roll of the fuselage is achieved without assistance from control surfaces on the first left wing and the first right wing.

12. The method of claim 8 further comprising: providing pitch control of the fuselage in response to providing asymmetric collective control between at least the first port rotor and a second port rotor rotatably coupled to a second port wing coupled to the fuselage.

13. The method of claim 8 further comprising: providing pitch control of the fuselage in response to providing differential motor RPM control between at least the first port rotor and a second port rotor rotatably coupled to a second port wing coupled to the fuselage.

14. 14. The method of claim 13 further comprising: providing pitch control of the fuselage in response to providing differential motor RPM control between the first starboard rotor and a second starboard rotor rotatably coupled to a second starboard wing.

15. The method of claim 14 further comprising: providing elevator control supplementing said step of providing pitch control to supplement said pitch moment with an additional pitch moment.

16. The method of claim 8 further comprising: providing pitch control of the fuselage in response to elevator actuation.

17. The method of claim 8 further comprising: generating a negative rotational moment in a second port rotor rotatably coupled to the second port wing in response to actuation of the second port swashplate; generating a positive rotational moment in a second starboard rotor rotatably coupled to the second starboard wing in response to actuation of the second starboard swashplate; generating a right roll of the fuselage in response to; wherein positive and negative moments of forces generated in the second port rotor and the second starboard rotor induce a right roll of the second port wing and second starboard wing without assistance from a wing control surface.

18. 18. The method of claim 17 further comprising: supplementing right roll of the fuselage in response to actuation of port and starboard ailerons rotatably coupled to the second port and second starboard wings, respectively.

19. The method of claim 8 further comprising: generating a positive rotational moment on the first starboard rotor in response to actuation of a first starboard swashplate; and generating a positive rotational moment on the first port rotor in response to actuation of the first starboard swash plate; providing pitch up control of the fuselage in response to a rotational velocity of the fuselage.

Images