Variable center of gravity strapdown rectifier wing twin boom aircraft and control method thereof

Abstract

This invention discloses a variable center of gravity twin-arm aircraft with a rectified wing and its control method, belonging to the field of low-altitude unmanned aerial vehicle (UAV) technology. The aircraft has only two supporting arms, front and rear. The ends of the arms are equipped with fixed-pitch propeller power units without variable pitch structures. Each arm has an independently driven, fully movable rectified wing hinged below it. The aircraft has no external tail or various independent control surfaces. The rectified wing integrates multiple functions, including airflow rectification, counteracting propeller anti-torque, dynamically adjusting the aircraft's center of gravity, and outputting attitude torque. The hardware of this invention relies on the lift difference between the two propellers and the synchronous or differential deflection of the two wings to coordinate and control the flight attitude. The control method enables vertical takeoff and landing, forward and backward level flight, lateral translation, and stationary spin flight in all attitudes. This invention features fewer structural components and lower manufacturing costs. The streamlined wing effectively reduces aerodynamic drag and increases cruising speed. It avoids the drawbacks of complex pitch control mechanisms in helicopters and redundant frames in multi-rotor aircraft. It offers flexible vertical takeoff and landing capabilities and can be widely used in various fields such as aerial photography, plant protection, surveying and mapping, and low-altitude inspection. It solves the technical pain points of existing aircraft in achieving low cost, high speed, and omnidirectional maneuverability.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle technology, specifically relating to a vertical take-off and landing aircraft structure with a dual-arm layout, dynamically adjustable center of gravity, and equipped with a deflectable rectifier wing, as well as a matching all-attitude flight control method. It can be widely used in scenarios such as aerial photography, agricultural and forestry plant protection, geographic surveying and mapping, and low-altitude inspection, and can also be extended to the research and development of small general aviation aircraft. Background Technology

[0002] Currently, the mainstream low-altitude aircraft on the market are divided into three main categories: multi-rotor aircraft, manned / unmanned helicopters, and fixed-wing aircraft. However, each has its own technical shortcomings that are difficult to overcome simultaneously.

[0003] Conventional quadcopter and hexacopter multirotor aircraft have a large number of arms, complex frame structure, many parts assembly processes, and high mass production costs; they also lack aerodynamic rectification structure, resulting in high frontal drag during flight and limited cruise speed.

[0004] Helicopters rely on a swashplate mechanism to drive the rotor blades to change pitch and counteract the torque. The mechanical transmission structure is complex, has a high failure rate, and results in high manufacturing, repair and maintenance costs.

[0005] Fixed-wing aircraft cannot take off and land vertically and must rely on runways or takeoff and landing sites, making them unsuitable for hovering operations in confined spaces.

[0006] Existing aircraft cannot simultaneously meet multiple usage requirements such as minimalist structure, low manufacturing cost, low aerodynamic drag, high flight speed, vertical takeoff and landing, and omnidirectional maneuverability. Therefore, this invention proposes a novel aircraft configuration to overcome the aforementioned deficiencies in existing technologies. Summary of the Invention

[0007] Purpose of the invention To address the technical problems of existing aircraft, such as complex structure, numerous components, high cost, high drag, low cruise speed, and limited maneuverability, this invention provides a variable center of gravity twin-arm aircraft with a rectifier wing and its control method. The entire aircraft consists of only two arms, front and rear, integrating a deflectable rectifier wing. The wing integrates multiple functions including rectification, anti-torsion, center of gravity adjustment, and torque output. It eliminates the need for helicopter pitch control mechanisms, independent tail fins, and control surfaces, relying on the difference in rotor speeds and wing deflection to achieve all flight attitudes, balancing low cost, high speed, and omnidirectional maneuverability. Technical solution

[0008] Aircraft structural design

[0009] A variable center of gravity twin-arm aircraft with a rectifier wing includes a central fuselage assembly, a power assembly, and an aerodynamic attitude control assembly. It consists of only two load-bearing arms, a front arm and a rear arm, arranged longitudinally along the fuselage's central axis, with no lateral extension arms. A front propeller power assembly is mounted at the distal end of the front arm, and a rear propeller power assembly is mounted at the distal end of the rear arm. Both power assemblies eliminate the blade-variable pitch swashplate transmission structure. A front all-moving rectifier wing is hinged to the lower side of the front arm, and a rear all-moving rectifier wing is hinged to the lower side of the rear arm. Each rectifier wing is equipped with an independent servo drive mechanism, enabling independent and continuous angle deflection and angle locking.

[0010] The aircraft does not have separate tail fins, elevators, ailerons, or external control surfaces for the rudder; the front and rear all-moving rectifier wings simultaneously achieve four functions: airflow rectification and drag reduction, counteracting the propeller rotational torque, dynamically shifting the aircraft's center of gravity, and outputting attitude control aerodynamic torque; all flight attitudes of the aircraft are achieved through the cooperation of the lift difference between the two sets of propeller power components and the synchronous / differential angle deflection of the two sets of rectifier wings.

[0011] Aircraft control method scheme

[0012] Based on the aforementioned aircraft structure, the airborne flight control system coordinates the rotational speed of the twin propellers and the deflection angle of the twin rectifier wings to sequentially achieve all basic flight attitudes, including vertical takeoff and landing, forward and backward level flight, lateral translation, and stationary spin. 1) Vertical takeoff and landing: The speed of the two sets of power components is increased by the same amount simultaneously, and the total lift is greater than the weight of the aircraft, so the aircraft rises; the speed is decreased by the same amount simultaneously, and the total lift is less than the weight of the aircraft, so the aircraft descends; when the lift and weight are balanced, the aircraft hovers at a fixed point, and the wings remain in the neutral position when hovering. 2) Forward and backward level flight: The lift difference created by the front and rear propellers causes the fuselage to pitch, and the forward rectifier wing deflects synchronously to counteract the reverse torque of the propellers, thus achieving forward or backward flight; 3) Lateral translation: The front and rear fairings deflect synchronously in the same direction, the center of gravity of the whole aircraft shifts to the deflection side, and the aircraft moves laterally; 4) In-situ spin: The front and rear rectifier wings deflect in opposite directions, forming a torsional moment around the vertical central axis, achieving clockwise and counterclockwise rotation. Beneficial effects

[0013] Simplified structure and low cost: Only two load-bearing arms, no extra lateral arms, no pitch transmission mechanism, and no external independent control surface, significantly reducing the number of parts and significantly reducing processing, assembly, and subsequent maintenance costs;

[0014] Excellent aerodynamic performance: The streamlined wing wraps around the airflow of the fuselage arm, greatly reducing flight drag and achieving a cruise speed far superior to traditional wingless multi-rotor aircraft;

[0015] High integration and strong innovation: A single airfoil has multiple functions such as rectification, anti-torsion, center of gravity adjustment and torque output, without the need to add additional actuators, and the weight of the whole machine is further reduced.

[0016] It is highly maneuverable and widely applicable: it can take off and land vertically, hover in the air, fly forward and backward, move laterally, and spin in place, making it suitable for complex operating environments such as aerial photography, plant protection, and surveying.

[0017] The control logic is stable and reliable: relying solely on the combined control of speed difference and wing deflection, the number of faulty actuators is small, flight stability is strong, and it is easy to implement and mass-produce. Detailed Implementation

[0018] The present invention will now be fully described with reference to specific embodiments.

[0019] The aircraft consists of a central fuselage, a front arm, a rear arm, two sets of fixed-pitch propeller power units, and two sets of independently driven all-moving rectifier wings; the front and rear arms are rigidly connected to the central fuselage, forming the only main load-bearing frame.

[0020] Hovering condition: The front and rear propellers rotate at the same speed and have equal lift. The front and rear fairings are kept in a horizontal neutral position. The center of gravity of the whole aircraft is on the longitudinal centerline. The aircraft hovers stably in a fixed position.

[0021] Ascent and descent: The flight control system synchronously increases or decreases the speed of the two power motors, thereby changing the total lift and completing the vertical ascent and descent maneuvers.

[0022] Forward flight: Reduce the lift of the front propeller and increase the lift of the rear propeller to form a pitching moment. The front rectifier wing deflects to counteract the front propeller's anti-torque, and the fuselage tilts forward to fly at high speed and level. The logic of backward flight is the opposite. Throughout the process, the rear rectifier wing remains in the neutral position, and only the front wing performs torque compensation.

[0023] Lateral sway: The front and rear fairings yaw synchronously to the left, shifting the center of gravity of the aircraft to the left, and the aircraft flies laterally to the left; yaw synchronously to the right, and the aircraft moves horizontally to the right. During this process, the rotation speed of the two propellers remains consistent, and no lift difference is introduced.

[0024] Turning in place: The front rectifier wing deflects to the left and the rear rectifier wing deflects to the right differentially, driving the whole aircraft to rotate clockwise with the opposite aerodynamic torque; the aircraft can be rotated counterclockwise by adjusting the wing deflection direction in the opposite direction; the total lift of the two propellers remains unchanged during the rotation process, and the flight altitude does not drift.

[0025] This embodiment does not require any additional control surfaces or pitch control mechanisms to fully realize all conventional flight attitudes. It has a simple structure and strong engineering feasibility. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the aircraft of the present invention;

[0027] Figure 2 This is a comparison diagram of structures with independently adjustable blade angles and those with non-adjustable blade angles; Explanation of reference numerals in the attached diagram: 1- Front arm, 2- Rear arm, 3- Front power unit, 4- Rear power unit, 5- Front fairing wing (can yaw left and right), 6- Fuselage, 7- Adjustable steering knuckle (can only rotate left and right, not up and down), 8- Rear fairing wing (can yaw left and right); Figure 2 In the diagram, the left side shows the structure with independently adjustable blade angles, while the right side shows the structure with non-adjustable blade angles. The two structures have distinct characteristics. This invention adopts the right-side structure design, which has significantly better reliability than the left-side structure.

Claims

1. A variable center of gravity twin-arm aircraft with a streamlined wing, comprising a central fuselage assembly, a power assembly, and an aerodynamic attitude control assembly, characterized in that: The aircraft has only two load-bearing arms, a front arm and a rear arm, arranged along the longitudinal centerline of the fuselage, without any lateral extension arms. The front arm is equipped with a front propeller power unit at its far end, and the rear arm is equipped with a rear propeller power unit at its far end. Neither power unit is equipped with a blade pitch swashplate drive mechanism. The front arm is hinged to the lower side with an independently deflectable front all-moving rectifier wing, and the rear arm is hinged to the lower side with an independently deflectable rear all-moving rectifier wing. Each rectifier wing is equipped with an independent servo drive mechanism. The aircraft does not have an independent tail, elevator, aileron, or external control surfaces for the rudder. The front and rear all-moving rectifier wings simultaneously have four functions: airflow rectification and drag reduction, counteracting propeller anti-torque, dynamically adjusting the aircraft's center of gravity, and outputting attitude control aerodynamic torque. All flight attitudes of the aircraft are achieved through the difference in lift between the two propellers and the synchronous or differential deflection of the two rectifier wings.

2. The variable center of gravity twin-arm aircraft with a rectified wing according to claim 1, characterized in that: Both the front and rear arms are rigidly fixed to the central fuselage, forming the sole main load-bearing frame of the entire aircraft. The core actuators of the entire aircraft consist only of the twin arms, two sets of propeller power components, two sets of rectifier wings, and their matching servo drive mechanisms.

3. The variable center of gravity twin-arm aircraft with a rectified wing according to claim 1, characterized in that: Both the front and rear propeller power units are fixed-pitch propeller units, and the output lift is adjusted only by changing the motor speed, while the blade pitch remains constant.

4. The variable center of gravity twin-arm aircraft with a rectified wing according to claim 1, characterized in that: The front and rear all-moving fairings adopt a streamlined airfoil structure, which wraps around the airflow under the arms during flight, reducing the overall aerodynamic drag and increasing the cruise speed.

5. The variable center of gravity twin-arm aircraft with a rectified wing according to claim 1, characterized in that: The synchronous and unidirectional deflection of the two sets of rectifier wings can shift the center of gravity of the aircraft to achieve lateral translation, while the differential deflection in opposite directions can generate a torsional moment around the vertical axis, enabling the fuselage to spin.

6. A control method for a variable center of gravity twin-arm aircraft with a rectified wing, based on any one of claims 1 to 5, characterized in that, The airborne flight control system executes the following attitude control logic: (1) Vertical lift: The speed of the two propeller power components is increased or decreased synchronously to achieve lift and descent. When the speed matches the weight, the aircraft hovers at a fixed point. When hovering, the two sets of rectifier wings remain in the center position. (2) Forward and backward level flight: The lift difference between the front and rear propellers causes the fuselage to pitch, while the front rectifier wing deflects to counteract the reverse torque, thus achieving forward and backward flight; (3) Lateral translation: The two sets of fairings deflect synchronously in the same direction, the center of gravity shifts laterally, and the aircraft moves laterally; (4) Fuselage spin: Two sets of rectifier wings deflect in opposite directions to form a torsional torque, achieving clockwise and counterclockwise in-place turning.

7. The control method according to claim 6, characterized in that: During level flight, the propeller's anti-torque is counteracted by adjusting the angle of the front rectifier wing, while the rear rectifier wing is kept in a neutral position or slightly compensated for by deflection.

8. The control method according to claim 6, characterized in that: During lateral translation flight, the lift output of the front and rear propellers remains consistent, and the lateral movement is completed solely by adjusting the center of gravity through synchronous wing deflection, without the need to introduce lift difference to assist maneuvering.

9. The control method according to claim 6, characterized in that: During the fuselage spin, the total lift of the two propellers remains constant, the aircraft maintains a stable altitude, and the turning action is completed only by the differential deflection of the wings, without altitude drift.

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