System and method for stabilizing the airframe of a free-wing aircraft

Abstract

The systems, methods, and other embodiments described herein relate to controlling the elevons of an aircraft to stabilize the fuselage of a free-wing aircraft. In one embodiment, the system includes a processor and a memory storing machine-readable instructions. When an instruction is executed by the processor, the processor 1) measures the fuselage pitch attribute of the aircraft, 2) measures the wing pitch angle of the wing assembly, and 3) controls the angles of the elevons of the wing assembly based on the fuselage pitch attribute and the wing pitch angle, so that the fuselage and wing assembly of the aircraft rotate independently of each other and freely around the pitch axis of the aircraft.

Description

Technical Field

[0001] The subject matter described herein generally relates to flapping wing aircraft and particularly to stabilizing the airframe of a flapping wing aircraft in a vertical flight mode.

Background Art

[0002] In an airplane, while the airplane is moving forward, lift is generated by air flowing over the wings. As a result, the aircraft must move horizontally to maintain altitude. In a helicopter, lift is generated by a horizontally rotating propeller. As a result, a helicopter has the ability of vertical takeoff and landing (VTOL) and can hover in the air. However, a helicopter cannot move as fast horizontally as an airplane. A flapping wing aircraft combines the forward flight mode of a fixed-wing aircraft, i.e., an airplane, and the VTOL and hovering capabilities of a helicopter.

[0003] A flapping wing aircraft has wings that pivot independently from the airframe about the pitch axis of the aircraft. This is achieved by connecting the wings to the airframe via bearings or bushings that pivot freely, i.e., with minimal mechanical friction or damping, in the pitch direction. All other degrees of freedom (roll, yaw, heave, sway, surge) are rigidly connected between the airframe and the wings. A propeller is attached to the wings to drive the flapping wing aircraft. When the wings are horizontal, the propeller pushes the flapping wing aircraft forward for horizontal flight. When the wings are vertical, the propeller enables vertical flight. The combination of the vertical flight mode and the horizontal flight mode results in an aircraft having the low infrastructure requirements of a helicopter and the efficiency of an airplane. Generally, enhanced VTOL flapping wing operation enables more effective and extensive use of such aircraft.

Summary of the Invention

[0004] In one embodiment, exemplary systems and methods relate to improving the airframe stability of an aircraft in which the fuselage and wings rotate independently around a pitch axis, i.e., a free-wing aircraft.

[0005] In one embodiment, an elevon control system for enhancing the stability of a free-wing aircraft is disclosed. An elevon is a movable device mounted on the trailing edge of the wing. The elevon combines the operation of an aircraft elevator for pitch control and the operation of an aircraft aileron for roll control. The system includes a processor and memory. The memory stores machine-readable instructions, and when a machine-readable instruction is executed by the processor, the processor measures the aircraft's fuselage pitch attribute. The aircraft's fuselage and wing assembly rotate independently of each other freely around the aircraft's pitch axis. The memory stores further machine-readable instructions, and when a machine-readable instruction is executed by the processor, the processor measures the wing pitch angle of the wing assembly and controls the angle of the elevons of the wing assembly based on the fuselage pitch attribute and the wing pitch angle.

[0006] In one embodiment, machine-readable instructions for controlling the angle of the elevons stabilize the aircraft when it is in vertical flight mode.

[0007] In one embodiment, a machine-readable instruction further includes an instruction, and when the instruction is executed by the processor, the processor determines when the aircraft is in level flight mode, and a machine-readable instruction for controlling the angle of the elevons includes an instruction, and when the instruction is executed by the processor, the processor controls the angle of the elevons based on the wing pitch angle without using the aircraft pitch attribute in level flight mode.

[0008] In one embodiment, a machine-readable instruction for determining when an aircraft is in level flight mode includes an instruction, which, when executed by the processor, determines that the aircraft is in level flight mode when the aircraft's airspeed is greater than a predetermined value.

[0009] In one embodiment, a machine-readable instruction for determining when an aircraft is in level flight mode includes an instruction, which, when executed by the processor, determines that the aircraft is in level flight mode when the wing pitch angle of the wing assembly is less than a predetermined value.

[0010] In one embodiment, the machine-readable instruction further includes an instruction which, once executed by the processor, progressively reduces the weight of the aircraft pitch attribute in the elevon control as the aircraft transitions from vertical flight mode to horizontal flight mode.

[0011] In one embodiment, the aircraft pitch attribute is the aircraft pitch rate, and machine-readable instructions for controlling the angle of the elevons of the wing assembly cancel out aircraft oscillation (swaying) when the aircraft is in vertical flight mode.

[0012] In one embodiment, the aircraft pitch attribute is the aircraft pitch angle, and a machine-readable instruction for controlling the angle of the wing elevons positions the aircraft at a predetermined pitch angle.

[0013] In one embodiment, a machine-readable instruction for controlling the angle of an elevon includes an instruction, which, when executed by the processor, sets the angle of the elevon such that the wing pitch angle decreases against the pitch of the aircraft when the aircraft's center of gravity is located ahead of the pivot point of the wing assembly.

[0014] In one embodiment, a machine-readable instruction for controlling the angle of an elevon includes an instruction, which, when executed by the processor, sets the angle of the elevon such that the wing pitch angle increases against the pitch of the aircraft when the center of gravity of the aircraft is located behind the pivot point of the wing assembly.

[0015] In one embodiment, a machine-readable instruction further includes an instruction, and when the instruction is executed by the processor, the processor receives a wing attitude instruction, and a machine-readable instruction for controlling the angle of the elevon further includes an instruction, and when the instruction is executed by the processor, the processor controls the angle of the elevon based on the wing attitude instruction.

[0016] In one embodiment, a non-transient machine-readable medium containing instructions for enhancing the stability of a free-wing aircraft is disclosed, the instructions, when executed by one or more processors, cause one or more processors to perform one or more functions. The instructions include instructions for measuring the aircraft's airframe pitch rate or airframe pitch angle during vertical flight mode. The aircraft's airframe and wing assemblies rotate independently of each other freely around the aircraft's pitch axis. The instructions include instructions for measuring the wing pitch angle of the wing assembly and adjusting the pitch of the wing assembly by controlling the angle of the elevons of the wing assembly based on the airframe pitch attribute and the wing pitch angle. Adjusting the pitch of the wing assembly attenuates the airframe pitch rate.

[0017] In one embodiment, machine-readable instructions for controlling the angle of the elevons stabilize the aircraft when it is in vertical flight mode.

[0018] In one embodiment, a machine-readable instruction further includes an instruction, which, when executed by the processor, determines when the aircraft is in level flight mode, and a machine-readable instruction for controlling the angle of the elevons includes an instruction, which, when executed by the processor, controls the angle of the elevons based on the wing pitch angle without using the aircraft pitch attribute in level flight mode.

[0019] In one embodiment, the machine-readable instruction further includes an instruction which, once executed by the processor, progressively reduces the weight of the aircraft pitch attribute in the elevon control as the aircraft transitions from vertical flight mode to horizontal flight mode.

[0020] In one embodiment, a method for controlling elevons to stabilize a free-wing aircraft is disclosed. In one embodiment, the method includes the step of measuring the aircraft's airframe pitch attribute. The aircraft's airframe and wing assembly rotate independently of each other freely around the aircraft's pitch axis. The method also includes the steps of measuring the wing pitch angle of the wing assembly and controlling the angles of the elevons of the wing assembly based on the airframe pitch attribute and the wing pitch angle. The control stabilizes the wings and airframe when the aircraft is in vertical flight mode.

[0021] In one embodiment, the step of measuring the aircraft pitch attribute includes measuring the aircraft pitch rate, and the control of the elevon angle cancels out aircraft oscillation when the aircraft is in vertical flight mode.

[0022] In one embodiment, the method further includes the step of determining when the aircraft is in a level flight mode, and the step of controlling the angle of the elevons includes, in the level flight mode, controlling the angle of the elevons based on the pitch angle of the wings without using the aircraft pitch attribute.

[0023] In one embodiment, the method further includes the steps of controlling the angle of the elevons to decrease the wing pitch angle when the center of gravity of the aircraft is in front of the pivot point of the wing assembly, and controlling the angle of the elevons to increase the wing pitch angle when the center of gravity of the aircraft is behind the pivot point of the wing assembly.

[0024] In one embodiment, the method further includes the step of receiving a wing attitude command for a wing assembly, and the step of controlling the angle of the elevons based on the wing attitude command. [Brief explanation of the drawing]

[0025] [Figure 1A] Figure 1A shows one embodiment of a free-wing aircraft in which the systems and methods disclosed herein are implemented. [Figure 1B]Figure 1B shows one embodiment of a flapping wing aircraft in which the systems and methods disclosed herein are implemented. [Figure 2] Figure 2 shows one embodiment of an elevon control system related to stabilizing a flapping wing aircraft airframe. [Figure 3] Figure 3 shows one embodiment of elevon control of a flapping wing aircraft for stabilizing a flapping wing aircraft airframe. [Figure 4] Figure 4 shows one embodiment of elevon control of a flapping wing aircraft for stabilizing a flapping wing aircraft airframe. [Figure 5] Figure 5 shows one embodiment of elevon control of a flapping wing aircraft for stabilizing a flapping wing aircraft airframe. [Figure 6] Figure 6 shows a flowchart for one embodiment of a method related to stabilizing a flapping wing aircraft airframe. [Figure 7] Figure 7 shows a diagram of a control loop of an elevon control system related to stabilizing a flapping wing aircraft airframe. **DETAILED DESCRIPTION OF THE INVENTION**

[0026] The accompanying drawings are incorporated herein and form a part of this specification, and show various systems, methods, and other embodiments of the present disclosure. It should be understood that the element boundaries shown in the figures (e.g., boxes, box groups, or other shapes) represent one embodiment of the boundary. In some embodiments, one element may be designed as multiple elements, or multiple elements may be designed as one element. In some embodiments, an element shown as an internal component of another element may be implemented as an external component, and an element shown as an external component of another element may be implemented as an internal component. Further, the elements may not be drawn to scale.

[0027] Systems, methods, and other embodiments relating to the operation of free-wing aircraft are disclosed herein. As stated above, helicopters and airplanes are aircraft with different functions. Some aircraft attempt to combine the functions of helicopters and airplanes into a single aircraft. For example, some hovering aircraft add parts or actuators to enable forward flight. Tiltrotor and tiltwing aircraft operate the thrust lines of two rotors from vertical to horizontal. Other aircraft add horizontal thrusters separate from the vertical rotors. Another example is the multicopter, which has six or more rotors and is tolerant of partial failure of the propulsion system. Some aircraft combine some or all of the above features into a VTOL aircraft with many propulsion systems. The above approaches can increase the number of parts, often increasing the weight and drag of the aircraft and sacrificing the reliability of the system.

[0028] A free-wing aircraft is an example of an aircraft that combines the functions of both a helicopter and an airplane (i.e., a VTOL aircraft capable of both horizontal and vertical flight) with reduced parts count and weight compared to other solutions. In a free-wing aircraft, the wings and fuselage rotate and swivel independently around the pitch axis. The wings and fuselage are connected via bearings or bushings. The wings and fuselage swivel freely around the pitch axis, relative to each other and to the ground.

[0029] In contrast, tilt-wing aircraft use actuators to permanently control the angle between the wing and the fuselage. As described herein, free-wing aircraft do not include wing actuators, thereby reducing weight and eliminating critical points of failure. Tail-sitter aircraft do not require actuators because the wing and fuselage are permanently mounted at a fixed angle. In tail-sitter aircraft, the fuselage is nearly vertical during takeoff and landing. The fuselages of free-wing aircraft described herein can maintain a generally horizontal position throughout all stages of flight.

[0030] Compared to tiltwing and tailsitter aircraft, flight control of free-wing aircraft is achieved through the aircraft's pitch attitude and independent wing attitude. This wing independence reduces the pitch axis inertia by 80-90%, enabling extremely rapid pitch control. The reduction in inertia is due to the proportional relationship between inertia, mass, and the square of the mass distance from the axis (I=md 2 This is due to the fact that the mass of the laterally elongated (left and right) wings tends to be close to the pitch axis. In contrast, the mass of the longitudinally elongated (front and rear) fuselage tends to be farther from the pitch axis. Also, the wing mass of a free-wing aircraft can be made light with only the fuselage, four actuators (motors and control surfaces), and inertial measuring devices. Heavy items such as payloads, batteries and / or fuel, and electronic systems can be attached to the fuselage.

[0031] Providing aircraft capable of horizontal flight and hovering expands their capabilities, but achieving this is extremely difficult for several reasons. For example, during forward horizontal flight, the airframe of a free-wing aircraft is passively stabilized on the pitch axis by airflow over the horizontal stabilizer above the tail assembly. However, during hovering or vertical flight, the airframe is not passively stabilized on the pitch axis because there is no airflow over the horizontal stabilizer. Airframe movement during vertical / hovering flight can range from minor discomfort to serious impairment of mission performance. In some cases, the aircraft's pitch changes unrestricted upward or downward. Changes in pitch angle negatively affect flight control. That is, controlling an aircraft is difficult when the aircraft's mass, i.e., the airframe, is constantly shifting position and changing the aircraft's responsiveness to pilot commands.

[0032] Changes in pitch attitude also affect sensor performance. Specifically, free-wing aircraft are equipped with various sensors and / or cameras. Aircraft oscillation negatively impacts the performance and output of these various sensors and / or cameras. For example, the aircraft includes a laser altimeter or other type of altimeter that records the aircraft's precise altitude. Measurements from the altimeter are used for various functions, such as landing and vertical navigation of the aircraft. The resulting fluctuations in sensor position due to the aforementioned aircraft oscillation make it difficult to perform certain operations, such as landing the aircraft accurately and smoothly without damaging the aircraft or any payload.

[0033] As another example, cameras on free-wing aircraft may be used to capture high-resolution images and / or videos of the area beneath the free-wing aircraft, for example, to locate injured persons during search and rescue missions. When the aircraft is rocking, the camera's ability to provide clear, in-focus images and / or videos is reduced. Therefore, this specification describes an aircraft capable of hovering and vertical flight like a helicopter, as well as forward flight like an aircraft, with a small number of parts, reduced actuators, reduced air resistance, and stable airframe during flight. Specifically, this specification describes an elevon control system that stabilizes the aircraft in vertical flight mode via a closed-wing control loop using pitch sensors of the aircraft. Any pitching motion of the aircraft is canceled out by rotating the wings forward or backward.

[0034] As described above, the wing is stabilized by adjusting the elevons at the trailing edge of the wing, which are within the turbulent region of the airflow generated by the propeller. Wing stabilization is achieved by closed-loop control of the wing pitch and attitude. The high maneuverability of the wing can be used to stabilize the aircraft. This is achieved by introducing an aircraft pitch rate or attitude error term into the wing control loop. Thus, aircraft stabilization is added to the wing stabilization task.

[0035] The systems and methods described herein assume that the aircraft's center of gravity is located at a constant perpendicular distance from the wing's pivot axis in order to avoid a natural tendency to invert; however, the systems and methods can also stabilize aircraft with a high center of gravity.

[0036] Thus, the disclosed systems, methods, and other embodiments improve the airframe stability of a free-wing aircraft while reducing the number of parts, weight, and drag compared to other configurations. Specifically, the wing pitch attitude is controlled using an actuated control surface (e.g., an elevon) enveloped in the propeller airflow. The airframe is freely suspended without requiring an active stabilization device. As a result, the free-wing aircraft described herein achieves hovering control and forward flight while maintaining a minimum of four actuators, namely two motors and two control surfaces.

[0037] As used herein and in the appended claims, the term “vertical flight mode” means a mode of an aircraft in which the pitch angle of the wing assembly is substantially perpendicular to the horizon. Vertical flight modes include VTOL, vertical flight (i.e., ascent and descent), and hovering.

[0038] Furthermore, as used herein and in the appended claims, the term “horizontal flight mode” means a mode of flight in which the pitch angle of the wing assembly is substantially parallel to the horizon.

[0039] Furthermore, as used herein and in the appended claims, the term “elevon” means a movable device mounted on the trailing edge of a wing. An elevon combines the functions of an aircraft elevator for pitch control and an aircraft aileron for roll control.

[0040] Referring to Figures 1A and 1B, an example of an aircraft 100 including the systems and methods disclosed herein is shown. The aircraft 100 is a free-wing aircraft in which the wing assembly (including both wings 102) rotates independently of the aircraft's fuselage 106. Some of the possible elements of the aircraft 100 are shown in Figures 1A and 1B and will be described in conjunction with the following figures. In addition, it will be understood that, in order to make the description concise and clear, reference numerals are repeated between different drawings where necessary to indicate corresponding or similar elements. In addition, this discussion outlines numerous specific details in order to provide a full understanding of the embodiments described herein. However, those skilled in the art will understand that the embodiments described herein may be practiced using various combinations of these elements. In any case, the aircraft 100 includes an elevon control system 112, which is implemented to perform methods and other functions such as those disclosed herein with respect to improving the stability of the aircraft during vertical flight and / or hovering flight.

[0041] The aircraft 100 includes a fuselage 106 or body that houses mechanical systems, electrical systems and / or control systems. As described above, the aircraft 100 has a variety of uses, and flight control components and components specific to a particular use are housed within the fuselage 106. In a particular example, the aircraft 100 may be unmanned. In this case, the fuselage 106 houses a communication system for receiving and executing commands from a remote pilot. In another example, the aircraft 100 is operated on-site by a pilot aboard the aircraft 100. In this example, the fuselage 106 includes a cockpit where the pilot sits to control the aircraft 100.

[0042] The aircraft 100 includes wings 102 that are rotatably coupled to a fuselage 106. The combination of wings 102 is referred to as a wing assembly. As described above, the wings 102 rotate or pivot independently of the fuselage 106 around the pitch axis 110 of the aircraft 100. As a result, the wings 102 and the fuselage 106 are coupled to each other via bearings or bushings that pivot freely, i.e., with minimal mechanical friction or damping, in the pitch direction. In one example, the wings 102 are rigidly coupled to each other so that the entire wing assembly rotates as a single unit independent of the fuselage 106. In another example, each wing 102 is rotatable independently of the other wings and the fuselage 106 around the pitch axis 110.

[0043] The wing pitch is controlled by an elevon 104, which is a control surface attached to the wing 102 in the airflow of the propeller driving the aircraft 100. By adjusting the pitch of the elevon 104 relative to the length dimension of the wing 102, the profile of the wing 102 is changed. As used herein and in the appended claims, the wing length dimension means the dimension extending from the leading edge to the trailing edge of the wing 102. The change in the profile of the wing 102 changes the airflow over the wing 102, generates a pitching moment, and changes the pitch angle of the wing assembly. As described above, the aircraft 100 is capable of horizontal or forward flight as depicted in Figure 1A, and vertical flight / hovering as depicted in Figure 1B. Switching between the two modes is performed by changing the dynamics of the airflow over the wing 102, i.e., by changing the angle of the elevon 104 relative to the length dimension of the wing 102.

[0044] The aircraft 100 also includes a horizontal stabilizer 108 that stabilizes the fuselage 106 during horizontal or forward flight. However, as described above, in vertical flight modes such as those depicted in Figure 1B (e.g., during VTOL, vertical flight, and hovering), there is no airflow over the horizontal stabilizer 108, and therefore the fuselage 106 is not passively stabilized in vertical flight mode. Accordingly, the aircraft 100 includes an elevon control system 112 that controls and stabilizes the wings 102 not only in forward and vertical flight but also in vertical flight by controlling the elevons 104 to stabilize the fuselage 106. That is, the elevons 104 of the aircraft 100 are positioned to counteract the oscillations of the fuselage 106. Examples of controlling the elevons 104 to counteract or cancel out the oscillations of the fuselage 106 are depicted in Figures 3 to 5.

[0045] Figure 2 shows one embodiment of an elevon control system 112 for stabilizing the airframe 106 of a free-wing aircraft. The elevon control system 112 is shown as including a processor 218. In one or more configurations, the processor 218 may be the primary / centralized processor of the aircraft 100, or it may represent a number of distributed processing units. For example, the processor 218 may be an electronic control unit (ECU). Alternatively or in addition, the processor may include a central processing unit (CPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a microcontroller, a system-on-a-chip (SoC), and / or other electronic processing units that assist in the operation of the aircraft 100.

[0046] The processor 218 may be part of the elevon control system 112, which may include a processor separate from the processor 218 of the aircraft 100, or the elevon control system 112 may access the processor 218 through a data bus or another communication path separate from the aircraft 100. In one embodiment, the elevon control system 112 includes a memory 220 that stores a detection module 222 and an instruction module 224. The memory 220 is random access memory (RAM), read-only memory (ROM), a hard disk drive, flash memory, or another suitable memory for storing modules 222 and 224. Modules 222 and 224 are, for example, computer-readable instructions that, when executed by the processor 218, cause the processor 218 to perform various functions disclosed herein. In an alternative configuration, modules 222 and 224 are elements independent of the memory 220, consisting, for example, of hardware elements. Therefore, modules 222 and 224 are either ASICs, hardware-based controllers, logic gate components, or other hardware-based solutions.

[0047] Furthermore, in one embodiment, the elevon control system 112 includes a data store 214. The data store 214 may consist of volatile memory and / or non-volatile memory. Examples of memory forming the data store 214 include RAM (random access memory), flash memory, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), registers, magnetic disks, optical disks, hard drives, solid-state drives (SSDs), and / or other non-temporary electronic storage media. In one configuration, the data store 214 is a component of the processor 218. Generally, the data store 214 is operably connected to the processor 218 for use by the processor 218. As used herein, the term “operably connected” includes direct or indirect connections, and may include connections without direct physical contact.

[0048] In one embodiment, the data store 214 is an electronic data structure stored in memory 220 or another data storage device, and consists of routines that can be executed by processor 218 for analysis, provision, organization, etc., of the stored data. Thus, in one embodiment, the data store 214 stores data used by modules 222 and 224 when performing various functions. In one embodiment, the data store 214 stores sensor data 216, along with metadata that characterizes various aspects of the sensor data 216, for example. In one or more configurations, one or more data stores 214 contain various data elements to support functions of the aircraft 100, such as vertical and horizontal flight. Thus, the data store 214 stores map data and / or sensor data 216. In at least one approach, the map data includes maps of one or more geographical areas.

[0049] Sensor data 216 is data provided from one or more sensors of the aircraft 100's sensor system 228. Therefore, sensor data 216 includes observations of the aircraft 100's surrounding environment and / or information about the aircraft 100 itself. As used herein, “sensor” means an electronic and / or mechanical device that generates an output (e.g., an electrical signal) in response to a physical phenomenon such as electromagnetic radiation (EMR) or sound. The sensor system 228 and / or one or more sensors may be operably connected to the processor 218, the data store 214, and / or other elements of the aircraft 100. In some examples, one or more data stores 214 mounted on the aircraft 100 store at least a portion of the map data and / or sensor data 216. Alternatively or in addition, at least a portion of the map data and / or sensor data 216 may be stored in one or more data stores 214 located remotely from the aircraft 100.

[0050] Various examples of different types of sensors are described herein. However, it should be understood that embodiments are not limited to the specific sensors described. In various configurations, the sensor system 228 includes one or more aircraft sensors and / or one or more environmental sensors. The aircraft sensors function to detect information about the aircraft 100 itself. In one or more configurations, the aircraft sensors include one or more pitch sensors, accelerometers, one or more gyroscopes, inertial measuring units (IMUs), global navigation satellite systems (GNSS), global positioning systems (GPS), and / or other sensors for monitoring aspects of the aircraft 100.

[0051] As described, the sensor system 228 may include one or more environmental sensors that detect the surrounding environment of the aircraft 100 (e.g., the external environment). For example, one or more environmental sensors may detect objects in the surrounding environment of the aircraft 100. Such obstacles may be static objects and / or dynamic objects. Various examples of sensors in the sensor system 228 are described herein. Exemplary sensors are part of one or more environmental sensors and / or one or more vehicle sensors. However, it should be understood that embodiments are not limited to the specific sensors described. As an example, in one or more configurations, the sensor system 228 may include one or more aircraft pitch attribute sensors and wing pitch attribute sensors.

[0052] Sensor data 216 includes the output of the aircraft pitch sensor and indicates various aircraft pitch attributes. For example, the aircraft pitch sensor outputs the pitch angle of the aircraft 106, which is the angle of the longitudinal axis of the aircraft 106 with respect to the horizon. In one example, the aircraft pitch sensor outputs the pitch rate of the aircraft 106, which is the rate of change of the pitch angle over time. In yet another example, the aircraft pitch sensor outputs both the pitch angle and the pitch rate of the aircraft 106. In any case, the output of the aircraft pitch sensor is stored in sensor data 216 and used by the instruction module 224 when controlling the elevons 104 of the aircraft 100.

[0053] Sensor data 216 also includes the output of the wing pitch sensor. Similar to the airframe pitch sensor, the wing pitch sensor outputs at least one of the wing pitch angle and wing pitch rate. In either case, the output of the wing pitch sensor is stored in sensor data 216 and used by the command module 224 when controlling the elevons 104 of the aircraft 100. In other words, the command module 224 relies on both the wing pitch attribute and the airframe pitch attribute when controlling the elevons 104. As a result, when the aircraft 100 is in vertical flight mode, the elevon control stabilizes the wings and the airframe.

[0054] As described above, the aircraft 100 may include one or more modules, at least some of which are described herein. In at least one configuration, a module is implemented as a non-transient computer-readable instruction, which, when executed by the processor 218, implements one or more of the various functions described herein. In various configurations, one or more of the modules are components of the processor 218, or one or more of the modules run on and / or are distributed across other processing systems to which the processor 218 is operablely connected. Alternatively or in addition, one or more modules are implemented at least partially in hardware. For example, one or more modules consist of a combination of logic gates (e.g., metal-oxide-semiconductor field-effect transistors (MOSFETs)) configured to implement the described functions, an ASIC, a programmable logic array (PLA), a field-programmable gate array (FPGA), and / or another electronic hardware-based implementation for implementing the described functions. Furthermore, in one or more configurations, one or more of the modules may be distributed across multiple modules described herein. In one or more configurations, two or more of the modules described herein may be combined into a single module.

[0055] In one embodiment, the detection module 222 includes commands that cause the processor 218 to measure the fuselage pitch attribute and the wing pitch angle of the wing assembly of the aircraft 100. Specifically, the detection module 222 generally includes commands that function to control the processor 218 to receive data inputs from one or more sensors of the aircraft 100. In one embodiment, the inputs are the fuselage pitch attribute and the wing pitch attribute. In various embodiments, the detection module 222 receives various types or combinations of the fuselage pitch attribute and the wing pitch attribute. For example, the fuselage pitch attribute is the fuselage pitch angle, which is the absolute angle of the longitudinal axis of the fuselage 106 with respect to the horizon. In this example, controlling the angle of the elevon 104 of the wing 102 positions the fuselage 106 at a predetermined pitch angle. For example, it may be desirable to maintain the fuselage 106 at zero-degree pitch, i.e., parallel to the horizon. In this example, the elevon 104 moves to maintain the fuselage 106 at zero-degree pitch.

[0056] In another example, the aircraft's pitch attribute is the aircraft pitch rate, or the rate of change of the aircraft's orientation relative to a reference coordinate system such as the horizon. In this example, controlling the angle of the elevons 104 on the wing 102 counteracts the oscillation of the aircraft 106 when the aircraft 100 is in vertical flight mode. That is, the elevons 104 attenuate the pitch rate of the aircraft 106, reducing the time it takes for the aircraft 106 to reach its equilibrium position. In this case, since the aircraft pitch attitude is omitted in the elevon control loop, the absolute pitch angle of the aircraft 106 may vary based on factors such as payload. That is, for various reasons, it may be desirable for the aircraft 106's stable position to be other than horizontal (e.g., a certain degree of nose-up or nose-down). When the aircraft pitch attribute is the aircraft pitch rate rather than the aircraft pitch angle, the aircraft may maintain this non-horizontal stable pitch attitude. Similarly, the wing pitch attribute may be the wing pitch attitude, the wing pitch rate, or a combination thereof.

[0057] In one embodiment, the detection module 222 is further configured to perform additional tasks beyond controlling each pitch sensor to acquire and provide sensor data 216. For example, the detection module 222 determines the flight mode of the aircraft 100. As described above, the aircraft 100 may be in a horizontal flight mode, where the wing assembly has a relatively horizontal pitch angle. The aircraft 100 may also operate in a vertical flight mode, which includes situations where the aircraft is flying vertically (e.g., upward or downward) or hovering at a constant altitude. Generally, aircraft stabilization via elevon control occurs while the aircraft 100 is in vertical flight mode. That is, the control of the angle of the elevons 104 stabilizes the aircraft 106 when the aircraft 100 is in vertical flight mode, and not when the aircraft 100 is in horizontal flight mode. This is because aircraft stabilization via elevon control is unnecessary in horizontal flight mode, as the airflow over the horizontal tail fin 108 provides aircraft stabilization. Furthermore, supplying aircraft pitch attribute information to the command module 224 during level flight may introduce noise into the control of the elevon 104.

[0058] As a result, the detection module 222 determines when the aircraft 100 is in horizontal flight mode, depending on the sensor data 216 from the aircraft 100's sensor system 228. In horizontal flight mode, the angle control of the elevons 104 is based on the wing pitch angle without using the aircraft pitch attribute. In other words, in vertical flight mode (e.g., hovering or vertical maneuvering), elevon control is based on three inputs: 1) aircraft pitch attribute, 2) wing pitch attribute, and 3) wing attitude command. In contrast, in horizontal flight mode, elevon control is based on two inputs: 1) wing pitch attribute and 2) wing attitude command.

[0059] Determining whether aircraft 100 is in level flight mode can be done in several ways. In one example, the determination is based on the aircraft's airspeed. That is, the airspeed in level flight is generally higher than the airspeed in vertical flight. Therefore, when the aircraft's airspeed exceeds a predetermined value, the detection module 222 determines that aircraft 100 is in level flight mode and takes appropriate measures to ensure that elevon control is not based on aircraft pitch attributes. Such appropriate measures include blocking / interrupting the transmission path between the aircraft pitch sensor and the command module 224, or modifying the operation of the command module 224 so as not to ignore or acquire aircraft pitch attribute information from sensor data 216. To determine the aircraft's airspeed, the sensor system 228 includes an airspeed sensor such as a pitot tube connected to a pressure transducer, a GPS, or other sensors for determining the aircraft's airspeed. In this example, the sensor data 216 further includes thresholds that are compared to the airspeed to determine whether elevon-based aircraft stabilization should be implemented.

[0060] In one example, the determination is based on the pitch angle of the aircraft's wing assembly. The pitch angle of the wing assembly in horizontal flight is generally smaller than that of the wing assembly in vertical flight. Therefore, when the pitch angle of the wing assembly is less than a predetermined value, the detection module 222 determines that the aircraft 100 is in horizontal flight mode and takes appropriate measures to ensure that elevon control is not based on the aircraft pitch attribute. Such appropriate measures include blocking / interrupting the transmission path between the aircraft pitch sensor and the command module 224, or modifying the operation of the command module 224 so as not to ignore or acquire aircraft pitch attribute information from the sensor data 216. In this example, the sensor data 216 further includes a threshold that is compared to the wing pitch angle to determine whether elevon-based aircraft stabilization should be implemented.

[0061] In both of the aforementioned examples, it is explained that once level flight is achieved, the aircraft stabilization function by the elevon 104 is individually deactivated. In another example, the aircraft stabilization function is gradually deactivated as the wing 102 transitions from vertical to horizontal mode, as the airspeed increases, or both. For example, as depicted in Figure 6, the aircraft stabilization gain is multiplied by the sine of the trigonometric function of the wing angle relative to the horizon, so that it ranges from a value of 1 in a vertical attitude to a value of 0 in a horizontal attitude. In yet another example, the gain in Figure 6 is multiplied by a term proportional to the airspeed, or a term proportional to the airspeed raised to a mathematical exponent, such that the gain becomes zero when the gain exceeds a certain airspeed.

[0062] As described herein, in one embodiment, the detection module 222 acquires sensor data 216, including pitch sensor data. In a further configuration, the detection module 222 acquires sensor data 216 from additional sensors, such as an airspeed indicator and an input command sensor, among other sensors suitable for controlling the elevon 104 for stable flight.

[0063] Therefore, in one embodiment, the detection module 222 controls each sensor to provide data input in the form of sensor data 216. In addition, although the detection module 222 has been described as controlling various sensors to provide sensor data 216, in one or more embodiments, the detection module 222 may acquire sensor data 216 using other active or passive techniques. For example, the detection module 222 may passively sniff sensor data 216 from a stream of electronic information provided by various sensors to further components within the aircraft 100. Furthermore, when providing sensor data 216, the detection module 222 may employ various approaches to fusing data from multiple sensors. For this reason, in one embodiment, sensor data 216 represents a combination of perceptions acquired from multiple sensors.

[0064] In one embodiment, the instruction module 224 includes instructions that cause the processor 218 to control the angle of the elevons 104 of the wing assembly based on aircraft pitch attributes and wing pitch angles. The instruction module 224 includes hardware and software components for generating electrical signals that physically move the elevons 104 based on sensor data 216. Specific examples of the control of the elevons 104 by the instruction module 224 are provided below in relation to Figures 3 to 5.

[0065] In one example, the instruction module 224 provides control signals to the elevon 104 based on other information. For example, the elevon 104 changes the pitch and yaw angles of the aircraft 100 during hovering flight. Such changes are based on pilot input, regardless of whether the pilot is located inside the cabin of the aircraft 100 or at a remote location from the aircraft 100. Thus, the elevon control system 112 receives wing attitude commands for the wing assembly from the pilot and controls the angles of the elevon 104 based on the received wing attitude commands. In another example, the wing attitude commands are generated autonomously on the aircraft 100 without the pilot commanding the angles. As part of an autonomous flight control system, the wing angles are autonomously controlled to achieve a certain flight speed, aircraft position, or other maneuver.

[0066] Furthermore, the elevon control system 112 located within the aircraft 100 functions in cooperation with the communication system 226. Through the communication system 226, the elevon control system 112 receives sensor data 216 from the sensor system 228 in accordance with the principles described herein. Furthermore, through the communication system 226, control signals are transmitted to the elevon 104 in accordance with the principles described herein.

[0067] In one example, the communication system 226 includes a physical bus or multiple buses for transmitting information between connected components. In another example, the communication system 226 is a wireless system that communicates with the relevant components according to one or more wireless communication standards. For example, the communication system 226 may include multiple different antennas / transmitters and / or other hardware elements to communicate at different frequencies according to their respective protocols. In one configuration, the communication system 226 communicates via a communication protocol such as WiFi, DSRC, or another protocol suitable for communication between the elevon control system 112 and other entities within the aircraft 100. In any case, the elevon control system 112 can utilize various wireless communication technologies to provide communication with other components of the aircraft 100.

[0068] Figure 3 shows one embodiment of elevon control of a free-wing aircraft 100 to stabilize the fuselage 106 of the free-wing aircraft. As described above, in horizontal or forward flight, the fuselage 106 is stabilized by the airflow passing over the horizontal stabilizer 108. However, in vertical flight mode, as depicted in Figure 3, there is no airflow over the horizontal stabilizer 108 to stabilize the fuselage 106. Instead, the fuselage 106 is freely suspended and prone to swaying back and forth around the pivot point 330. Figure 3 depicts the center of gravity 332 of the fuselage 106, the pivot point 330 of the wing 102, and the length dimension 336 of the wing 102. Figure 3 also depicts the pitch angle 334 of a given body, which is defined as the angle of the longitudinal axis of the body with respect to the horizon. In the example depicted in Figure 3, the fuselage 106 has a pitch angle of zero, i.e., the fuselage 106 is parallel to the horizon.

[0069] Figure 4 shows one embodiment of elevon control of a free-wing aircraft 100 for stabilizing the fuselage 106 of the free-wing aircraft. As described above, the fuselage 106 rotates or turns freely around the aircraft's pitch axis 110. Due to various reasons, including pilot pitch commands, the center of gravity 332 of the fuselage 106 shifts forward. Due to the pitch of the fuselage 106, when the center of gravity 332 of the fuselage 106 is located in front of the pivot point 330 of the wing assembly, the fuselage 106 swings to a nose-up position, as indicated by arrow 438. As described above, the swinging motion of the fuselage 106 is determined by the aircraft's pitch angle sensor or pitch gyro sensor.

[0070] In response to this detected oscillation, the elevon control system 112 sets the angle 440 of the elevon 104 so that the wing pitch angle decreases in opposition to the pitch of the fuselage 106, as illustrated by arrow 442. That is, when the fuselage 106 is in a nose-up position, the elevon control system 112 moves the pivot point 330 forward to counteract the upward movement of the fuselage 106's nose. The elevon control system 112 changes the angle 440 of the elevon 104 relative to the wing 102, as illustrated in Figure 4, to rotate the wing assembly forward, as illustrated by arrow 442. The forward orientation of the wing assembly also rotates the propeller thrust forward, moving the wing's pivot point 330 forward. As a result, the elevon control system 112 dampens the fuselage pitch rate, achieving a more rapid and stable fuselage than an aircraft without dampening the fuselage pitch rate. In another example, the elevon control system 112 stabilizes the aircraft's pitch angle, resulting in a more rapid and stable aircraft than an aircraft without a stabilized pitch angle.

[0071] Figure 5 shows one embodiment of elevon control of a free-wing aircraft 100 for stabilizing the fuselage 106 of the free-wing aircraft. At the time depicted in Figure 5, the center of gravity 332 of the fuselage 106 is shifted aft. Due to the pitch of the fuselage 106, when the center of gravity 332 of the fuselage 106 is located behind the pivot point 330 of the wing assembly, the fuselage 106 swings to a nose-down position, as indicated by arrow 544.

[0072] In response to this detected oscillation, the elevon control system 112 sets the angle 440 of the elevon 104 so that the wing pitch angle increases against the pitch of the fuselage 106, as illustrated by arrow 546. That is, when the fuselage 106 is in a nose-down position, the elevon control system 112 moves the pivot point 330 aft to counteract the downward movement of the fuselage 106's nose. The elevon control system 112 changes the angle 440 of the elevon 104 relative to the wing 102, as illustrated in Figure 5, to rotate the wing assembly aft, as illustrated by arrow 546. The aft orientation of the wing assembly also rotates the propeller thrust aft, moving the wing's pivot point 330 aft. As a result, the elevon control system 112 dampens the fuselage pitch rate, achieving a more rapid and stable fuselage than an aircraft without dampening the fuselage pitch rate. In another example, the elevon control system 112 stabilizes the aircraft's pitch angle, resulting in a more rapid and stable aircraft than an aircraft without a stabilized pitch angle.

[0073] The operations depicted in Figures 4 and 5 may be repeated each time the aircraft 100 oscillates around the pitch axis, and the elevon control dampens, suppresses, or cancels out the natural oscillating motion of the airframe 106, thus bringing the airframe 106 to a balanced position more quickly than if the airframe pitch were not dampened.

[0074] Additional aspects of aircraft stabilization are described in relation to Figure 6. Figure 6 shows a flowchart of method 600 relating to the control of elevons 104 for stabilizing the aircraft 106 during vertical flight mode. Method 600 is described in relation to the elevon control system 112 in Figures 1A, 1B, and 2. Although method 600 is described in relation to the elevon control system 112, it should be noted that method 600 is not limited to being implemented within the elevon control system 112, but is merely an example of a system in which method 600 can be implemented. For example, method 600 can be implemented in an analog control system (mechanical or electrical) to control aircraft stabilization via wing pitch control.

[0075] In 610, the detection module 222 controls the sensor system 228 to measure the aircraft pitch attribute of the aircraft 100, in which the wing assembly and the fuselage 106 rotate independently around the pitch axis. In 620, the detection module 222 controls the sensor system 228 to measure the wing pitch angle of the wing assembly. The detection module 222 controls the sensor system 228 to acquire sensor data 216. In one embodiment, the detection module 222 controls the aircraft's airframe pitch sensor and wing pitch sensor to observe the aircraft pitch attribute (e.g., airframe pitch angle, airframe pitch rate) and wing pitch attribute (e.g., wing pitch angle, wing pitch rate), respectively. Thus, in one embodiment, the detection module 222 controls the sensors to acquire sensor data 216 of the surrounding environment and the aircraft 100.

[0076] In addition, in a further embodiment, the detection module 222 controls the sensor to acquire sensor data 216 in continuous iterations or time steps. Thus, in one embodiment, the elevon control system 112 iteratively performs the functions described in blocks 610-630 to acquire sensor data 216 and provide information from the sensor data 216. Furthermore, in one embodiment, the detection module 222 performs one or more of the described functions in parallel for separate observations in order to maintain updated perception.

[0077] In 630, the elevon control system 112, more specifically the command module 224, controls the angle of the elevons 104 of the wing assembly based on the aircraft pitch attribute and the wing pitch attribute. That is, while the aircraft 100 is in vertical flight modes, including vertical flight and hovering, the elevon control system 112 receives the aircraft pitch attribute and the wing pitch attribute as input along with any wing attitude command and adjusts the elevons 104 as described above in relation to Figures 4 and 5 to counteract and cancel out and / or attenuate the relevant pitch attribute of the aircraft 106. During horizontal wing modes, elevon control based on aircraft pitch is deactivated, and instead, elevon control is performed based solely on the wing pitch attribute and wing attitude command to stabilize the wings in forward flight and perform any intended flight maneuvers, while aircraft stabilization is provided by the horizontal tail 108 on the aircraft 106.

[0078] Figure 7 shows a diagram of the control loop 746 of the elevon control system 112 related to the stabilization of the airframe 106 of a free-wing aircraft. As described above, wing attitude commands are received from the pilot, whether they are commands from the onboard pilot or from a remote pilot, such as when the aircraft 100 is a drone. In horizontal flight mode, the wing attitude command is combined with a wing attitude error term derived from the wing pitch attribute measured by the wing pitch sensor. These two values ​​are combined and processed to generate an elevon command, which is sent to the elevon 104 to control the physical angle of the elevon 104 relative to the length dimension 336 of the wing 102.

[0079] In vertical flight mode, aircraft pitch attributes, i.e., aircraft pitch attitude or aircraft pitch rate, are received and multiplied by a certain gain coefficient. This processed aircraft pitch attribute signal is combined or summed with wing attitude commands and wing attitude measurements to generate an elevon command, as depicted in Figure 7. As a result, the elevon command not only stabilizes the wing 102 by the wing attitude term, taking into account the wing attitude command from the pilot, but also stabilizes the aircraft 106 by the aircraft pitch term. Aircraft stabilization elevon control requires processing an additional term to the loop, i.e., the aircraft pitch attribute term. Considering the undamped oscillation of the aircraft 106, processing the aircraft pitch attribute command places a greater load on the elevon 104, so despite the added term, the load on the elevon 104 decreases.

[0080] Thus, the disclosed systems, methods, and other embodiments improve the airframe stability of a free-wing aircraft while reducing the number of parts, weight, drag, and operational complexity compared to other configurations. Specifically, the elevons 104 are controlled to stabilize not only the wing assembly but also the airframe 106, reducing the overall load on the elevons 104 compared to an undamped or unstabilized airframe.

[0081] Detailed embodiments are disclosed herein. However, it should be understood that the disclosed embodiments are intended to be merely examples. For this reason, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as the basis for the claims and as representative grounds for teaching those skilled in the art to apply the embodiments described herein in a variety of substantially any suitable detailed structures. Furthermore, the terms and phrases used herein are not intended to be limiting, but rather to provide an understandable description of possible implementations. Various embodiments are shown in Figures 1 to 7, but these embodiments are not limited to the illustrated structures or applications.

[0082] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible embodiments of systems, methods, and computer program products according to various embodiments. In this regard, each block in a flowchart or block diagram represents a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. Note that in some alternative embodiments, the functions described within a block may occur in a different order than shown in the figure. For example, two consecutively shown blocks may actually be executed almost simultaneously, or these blocks may be executed in reverse order depending on the functions involved.

[0083] The systems, components, and / or processes described above can be implemented in hardware or a combination of hardware and software, and can be implemented centrally in a single processing system or in a distributed manner in which various elements are distributed across several interconnected processing systems. The systems, components, and / or processes can also be embedded in computer-readable storage, such as a machine-readable computer program product or other data program storage device, which concretely embodies a program of machine-executable instructions for performing the methods and processes described herein. These elements can also be embedded in an application product that includes features enabling the implementation of the methods described herein and, when loaded into a processing system, can perform these methods.

[0084] Furthermore, the configurations described herein may take the form of a computer program product in which computer-readable program code is embodied, for example, in one or more computer-readable media on which it is stored. Any combination of one or more computer-readable media can be used. The term "computer-readable storage medium" means a non-temporary storage medium. A computer-readable storage medium is, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, equipment, or device, or any suitable combination thereof. A non-exclusive list of computer-readable storage media may include portable computer diskettes, hard disk drives (HDDs), solid-state drives (SSDs), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), digital multipurpose disks (DVDs), optical storage devices, magnetic storage devices, or any combination thereof. In the context of this document, a computer-readable storage medium is, for example, a tangible medium that stores a program used by or in connection with an instruction execution system, equipment, or device.

[0085] Program code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, cable, RF, or any suitable combination thereof. Computer program code for performing operations for aspects of this configuration is written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java®, Smalltalk, C++, or their equivalents, and conventional procedural programming languages ​​such as the C programming language or similar programming languages. The program code may run fully on the user's computer, partially on the user's computer as a standalone software package, partially on the user's computer and partially on a remote computer, or fully on a remote computer or server. In the latter scenario, the remote computer is connected to the user's computer through any type of network, including a local area network (LAN) or wide area network (WAN), or to an external computer (e.g., through the Internet using an Internet Service Provider).

[0086] As used herein, the articles "a" and "an" are defined as one or more. As used herein, the term "plural" is defined as two or more. As used herein, the term "another" is defined as at least two or more. As used herein, the terms "contain" and / or "have" are defined as having (i.e., having open language). As used herein, the phrase "at least one of" refers to and encompasses any possible combination of one or more of the relevant list items. For example, the phrase "at least one of A, B, and C" includes A only, B only, C only, or any combination thereof (e.g., AB, AC, BC, or ABC).

[0087] The embodiments described herein may be embodied in other forms without departing from these ideas or essential attributes. Accordingly, the following claims, rather than the above specification, should be used to illustrate the scope of the invention.

Claims

1. Processor and Memory for storing machine-readable instructions, A system equipped with, When the machine-readable instruction is executed by the processor, the processor: Measure the aircraft's airframe pitch attributes, The wing pitch angle of the wing assembly of the aforementioned aircraft is measured, The angle of the elevons of the wing assembly is controlled based on the aircraft pitch attribute and the wing pitch angle. A system in which the aircraft's fuselage and wing assembly rotate independently of each other and freely around the aircraft's pitch axis.

2. The system according to claim 1, wherein the machine-readable command for controlling the angle of the elevon stabilizes the aircraft when it is in vertical flight mode.

3. If the machine-readable instruction further includes an instruction, and the instruction is executed by the processor, the processor determines whether the aircraft is in level flight mode. The system according to claim 1, wherein the machine-readable instruction for controlling the angle of the elevon includes an instruction, and when the instruction is executed by the processor, the processor controls the angle of the elevon based on the wing pitch angle without using the aircraft pitch attribute in the horizontal flight mode.

4. The system according to claim 3, wherein the machine-readable instruction for determining when the aircraft is in the horizontal flight mode includes an instruction, and when the instruction is executed by the processor, the processor determines that the aircraft is in the horizontal flight mode when the aircraft's airspeed is greater than a predetermined value.

5. The system according to claim 3, wherein the machine-readable instruction for determining when the aircraft is in the horizontal flight mode includes an instruction, and when the instruction is executed by the processor, the processor determines that the aircraft is in the horizontal flight mode when the wing pitch angle of the wing assembly is less than a predetermined value.

6. The system according to claim 1, wherein the machine-readable instruction further includes an instruction, and when the instruction is executed by the processor, the processor progressively reduces the weight of the aircraft pitch attribute in the elevon control as the aircraft transitions from vertical flight mode to horizontal flight mode.

7. The aforementioned aircraft pitch attribute is the aircraft pitch rate. The system according to claim 1, wherein the machine-readable command for controlling the angle of the elevons of the wing assembly cancels out the swing of the aircraft when the aircraft is in vertical flight mode.

8. The aforementioned aircraft pitch attribute is the aircraft pitch angle, The system according to claim 1, wherein the machine-readable command for controlling the angle of the elevons of the wing positions the aircraft at a predetermined pitch angle.

9. The system according to claim 1, wherein the machine-readable instruction for controlling the angle of the elevon includes an instruction, and when the instruction is executed by the processor, the processor sets the angle of the elevon such that the wing pitch angle decreases against the pitch of the aircraft when the center of gravity of the aircraft is located in front of the pivot point of the wing assembly.

10. The system according to claim 1, wherein the machine-readable instruction for controlling the angle of the elevon includes an instruction, which, when executed by the processor, sets the angle of the elevon such that the wing pitch angle increases against the pitch of the aircraft when the center of gravity of the aircraft is located behind the pivot point of the wing assembly.

11. The machine-readable instruction further includes an instruction, and when the instruction is executed by the processor, the processor receives a wing attitude instruction. The system according to claim 1, wherein the machine-readable instruction for controlling the angle of the elevon further includes an instruction, and when the instruction is executed by the processor, the processor controls the angle of the elevon based on the wing attitude instruction.

12. A non-temporary machine-readable medium containing instructions, When the aforementioned instruction is executed by the processor, the processor: During vertical flight mode, the aircraft's fuselage pitch rate is measured. The wing pitch angle of the wing assembly of the aforementioned aircraft is measured, The pitch of the wing assembly is adjusted by controlling the angle of the elevons of the wing assembly based on the aircraft pitch attributes and the wing pitch angle. The aircraft's fuselage and wing assembly rotate independently of each other and freely around the aircraft's pitch axis. The pitch adjustment of the wing assembly is a non-transient, machine-readable medium that attenuates the aircraft pitch rate.

13. The non-transient machine-readable medium according to claim 12, wherein the machine-readable instruction for controlling the angle of the elevon stabilizes the aircraft when the aircraft is in vertical flight mode.

14. If the machine-readable instruction further includes an instruction, and the instruction is executed by the processor, the processor determines whether the aircraft is in level flight mode. The non-transient machine-readable medium according to claim 12, wherein the machine-readable instruction for controlling the angle of the elevon includes an instruction, and when the instruction is executed by the processor, the processor controls the angle of the elevon based on the wing pitch angle without using the aircraft pitch attribute in the horizontal flight mode.

15. The non-transient machine-readable medium according to claim 12, wherein the machine-readable instruction further includes an instruction, and when the instruction is executed by the processor, the processor progressively reduces the weight of the aircraft pitch attribute in the elevon control as the aircraft transitions from vertical flight mode to horizontal flight mode.

16. A step of measuring the fuselage pitch attribute of an aircraft, wherein the fuselage and wing assembly of the aircraft rotate independently of each other and freely around the pitch axis of the aircraft; A step of measuring the wing pitch angle of the wing assembly, A step of controlling the angle of the elevons of the wing assembly based on the aircraft pitch attribute and the wing pitch angle, wherein the control stabilizes the wings and the aircraft when the aircraft is in vertical flight mode. Methods that include...

17. The step of measuring the aircraft pitch attribute includes measuring the aircraft pitch rate, The method according to claim 16, wherein the control of the angle of the elevon cancels out the oscillation of the aircraft when the aircraft is in the vertical flight mode.

18. The method further includes the step of determining whether the aircraft is in a horizontal flight mode, The method according to claim 16, wherein the step of controlling the angle of the elevon includes, in the horizontal flight mode, controlling the angle of the elevon based on the wing pitch angle without using the aircraft pitch attribute.

19. The steps include controlling the angle of the elevon to reduce the wing pitch angle when the center of gravity of the aircraft is in front of the pivot point of the wing assembly, When the center of gravity of the aircraft is behind the pivot point of the wing assembly, the steps include controlling the angle of the elevon to increase the wing pitch angle, and The method according to claim 16, further comprising:

20. The process further includes receiving a wing attitude command for the wing assembly, The method according to claim 16, wherein the step of controlling the angle of the elevon is based on the wing attitude command.

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