A vertical takeoff and landing variant aircraft

Abstract

This invention discloses a vertical takeoff and landing (VTOL) variant aircraft, comprising: a level flight propulsion system, a nose, a fuselage, a tail, a frame, a VTOL propulsion system, an inner fixed wing, and an outer retractable wing. The level flight propulsion system is connected to the front interface of the nose, the rear interface of the nose is connected to the front interface of the fuselage, the rear interface of the fuselage is connected to the tail, the frame is connected to the front and rear interfaces of the fuselage side, the VTOL propulsion system is connected to the rear interface of the frame, the inner fixed wing is connected to the middle interface of the fuselage side, and the outer retractable wing is connected to the inner fixed wing. This invention can meet the needs of rotor verification, fixed-wing cruise, and variant flight experiments, and has good compatibility, reusability, and experimental safety.

Description

Technical Field

[0001] This invention relates to the field of aircraft design technology, and more particularly to a vertical takeoff and landing variant aircraft. Background Technology

[0002] Vertical takeoff and landing (VTOL) aircraft combine the advantages of multi-rotor aircraft (low takeoff and landing site requirements and strong hovering ability) with fixed-wing aircraft (high cruise efficiency and long range), making them highly valuable for applications such as low-altitude reconnaissance, surveying and inspection, emergency rescue, and scientific research verification. Existing compound-wing VTOL aircraft typically use a vertical takeoff propulsion system for takeoff, landing, and hovering, and a horizontal flight propulsion system and wings to generate lift for cruise flight, thus combining vertical takeoff and landing capabilities with fixed-wing cruise performance. However, existing compound-wing VTOL aircraft often employ an integrated or semi-integrated design, with fixed structural matching relationships between the nose, fuselage, tail, wings, frame, and propulsion system. When conducting verification experiments with different configurations, wing types, tail layouts, or flight missions, it is usually necessary to redesign or significantly modify the entire aircraft. This results in long design cycles, high manufacturing costs, inconvenient disassembly and maintenance, and low reusability, making it difficult to meet the needs of rapid verification for multiple missions and configurations.

[0003] For aircraft that need to take off and land in urban alleyways, woodlands, ship decks, underground garages, or other confined spaces, while the larger wingspan of fixed-wing aircraft is beneficial for improving level flight cruise efficiency, it increases space occupation and collision risk during takeoff and landing. Furthermore, the wing dimensions of traditional fixed-wing or compound-wing aircraft are usually determined before the mission and are not easily changed during flight, making it difficult to simultaneously meet the aerodynamic efficiency requirements of vertical takeoff and landing in confined spaces and fixed-wing cruise. While existing variator technologies can adjust aerodynamic characteristics by changing wing span, sweep angle, angle of attack, or dihedral, existing variator mechanisms are often designed for a single configuration or single aircraft platform. The high degree of coupling between the mechanism and the airframe results in insufficient versatility and scalability, making it difficult to quickly replace different types of wings on the same platform and to conduct comparative verification of wing performance under different variator configurations.

[0004] When an aircraft extends or retracts its outer wing section, changes its wing angle of attack, dihedral angle, or sweep angle while in fixed-wing flight, it causes changes in the aerodynamic center, lift distribution, drag characteristics, and attitude moments, which can easily lead to attitude disturbances or even instability. If the flight platform relies solely on the level flight propulsion system and conventional control surfaces for control, it is difficult to provide additional altitude holding, attitude assistance control, and instability protection capabilities in a timely manner, thus affecting the safety and reliability of variant flight experiments. In addition, existing multi-rotor demonstrator platforms have limited level flight efficiency and range, and existing fixed-wing or compound-wing platforms lack replaceable modules, retractable wings, replaceable tail sections, and interfaces for various variant mechanisms, making them difficult to use as reusable variant flight demonstrator platforms. Therefore, a single-configuration platform cannot simultaneously meet the needs of rotor mode verification, fixed-wing mode cruise, and multiple wing variant experiments. Summary of the Invention

[0005] Purpose of the invention: This invention provides a vertical takeoff and landing variant aircraft that can meet the needs of rotor verification, fixed-wing cruise and variant flight experiments, and has good compatibility, reusability and experimental safety.

[0006] Technical solution: The present invention discloses a vertical takeoff and landing variant aircraft, comprising: a level flight propulsion system, a nose, a fuselage, a tail, a frame, a vertical takeoff propulsion system, an inner fixed wing, and an outer retractable wing; the level flight propulsion system is connected to the front interface of the nose, the rear interface of the nose is connected to the front interface of the fuselage, the rear interface of the fuselage is connected to the tail, the frame is connected to the front and rear interfaces of the fuselage side, the vertical takeoff propulsion system is connected to the rear interface of the frame, the inner fixed wing is connected to the middle interface of the fuselage side, and the outer retractable wing is connected to the inner fixed wing.

[0007] Furthermore, the fuselage and frame can cooperate with the vertical takeoff and landing (VTOL) system to form a separate rotor verification platform. The VTOL system includes multiple VTOL power units, each located at the end of the frame. Each VTOL power unit includes a motor, a propeller, and an ESC. The motor is fixed at the end of the frame, the propeller is connected to the motor's output shaft, and the ESC is electrically connected to the motor and receives control signals from the flight control system to adjust the propeller speed. The fuselage and frame can cooperate with the VTOL system to form a rotor verification platform without assembling the nose, tail, inner fixed wing, outer retractable wing, or level flight power system. After the frame is connected to the fuselage, it forms the main body of the rotor platform. Each VTOL power unit is installed at the end of the frame, and the speed of each power unit is controlled by the flight control system to achieve vertical takeoff, hovering, attitude adjustment, and vertical landing of the platform. This can be used to verify the VTOL system, the structural strength of the frame, flight control, and stability in rotor mode.

[0008] Furthermore, the inner fixed wing section houses the outer telescopic wing section, and the inner fixed wing section is equipped with a telescopic drive device to drive the extension and retraction of the outer telescopic wing section.

[0009] Furthermore, the inner fixed wing has an interface on the outer side, through which different types of wings are assembled, and the performance of the assembled wings is verified through flight experiments.

[0010] Furthermore, the tail section has a built-in tail drive unit to achieve linear movement in the tail extension direction. At the same time, the tail section is a replaceable module, and different tail configurations can be combined according to the type of wings to be installed.

[0011] Furthermore, a variator drive is installed within the inner fixed wing and fuselage, which drives the inner fixed wing to achieve variator motions in the wing's angle of attack, dihedral angle, and sweep angle. A 3-DOF wing root variator mechanism, similar to a robotic arm joint, is installed between the inner fixed wing and the fuselage, allowing the inner fixed wing to change attitude relative to the fuselage through three rotational degrees of freedom at the wing root. The mechanism includes a fixed end connected to the fuselage, a moving end connected to the inner fixed wing, and three rotational joints positioned between them. Each rotational joint corresponds to wing angle adjustment in different directions. By driving the corresponding rotational joints, the inner fixed wing rotates approximately along the wing span, the fuselage longitudinal direction, or the vertical direction, thereby achieving changes in the wing's angle of attack, dihedral angle, and sweep angle, respectively. Thus, the inner fixed wing can perform multiple forms of variator motion on the same aircraft platform and drive the outer telescopic wing or assembled wing to move synchronously, meeting the flight verification requirements under different wing deformation modes.

[0012] Furthermore, the variant motion of the inner fixed wing section drives the motion of the outer telescopic wing section or the assembled wing section, thereby verifying the wing's performance under different deformation modes.

[0013] Furthermore, the level flight propulsion system provides propulsion for level flight cruise, while the vertical takeoff and landing (VTOL) system provides vertical takeoff and landing (VTOL) and altitude holding capabilities. When the aircraft performs wing variator motion in fixed-wing mode, the VTOL system participates in flight control to provide altitude holding, attitude assistance control, or instability protection. When wing variator motion causes changes in lift or a decrease in flight altitude, the flight control system increases the rotational speed of one or more VTOL units to generate additional lift and maintain altitude. When wing variator motion causes pitch, roll, or yaw attitude disturbances, the flight control system differentially adjusts the rotational speed of the front and rear or left and right VTOL units to generate corresponding attitude correction torques and achieve attitude assistance control. When parameters such as attitude angle, angular velocity, rate of descent, or angle of attack exceed preset safety thresholds, the flight control system enters a protection control state, restricts or stops wing variator motion, and increases the output of the VTOL system to restore the aircraft to a safe attitude or switch to rotor mode, thereby achieving instability protection.

[0014] Furthermore, the frame is shaped like an "I" and runs horizontally across the fuselage. The horizontal plane where the frame is located is higher than the horizontal plane where the inner fixed wing is located. The inner fixed wing is located between the frames to avoid interference between the inner fixed wing and the frame during the transformation process.

[0015] Beneficial Effects: Compared with the prior art, the present invention has the following significant advantages: By modularly connecting the level flight propulsion system, nose, fuselage, tail, frame, vertical takeoff and landing (VTOL) system, inner fixed wing section, and outer retractable wing section, the aircraft can be quickly disassembled, assembled, and configured according to different experimental tasks; it can be used as a rotor verification platform independently or assembled into a compound wing VTOL aircraft; its outer retractable wing section can be extended and retracted, and the inner fixed wing section can be equipped with different types of wings, and can achieve variant movements such as angle of attack, dihedral angle, and sweep angle; at the same time, the VTOL system can participate in flight control during wing variant processes in fixed wing mode, providing altitude holding, attitude assistance control, and instability protection, thereby improving the platform's applicability, scalability, experimental efficiency, and flight safety. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the aircraft structure of the present invention.

[0017] Figure 2 This is a schematic diagram of the aircraft structure with an extended outer wing section, as per the present invention.

[0018] Figure 3 This is a schematic diagram of the aircraft structure with fixed inner section wing sweep angle deformation according to the present invention.

[0019] Figure 4 This is a schematic diagram of the aircraft structure with an internal fixed wing mounting angle deformation according to the present invention.

[0020] Figure 5 This is a schematic diagram of the aircraft structure in the dihedral deformation state of the inner section fixed wing of the present invention. Detailed Implementation

[0021] like Figure 1 As shown, a vertical takeoff and landing (VTOL) variant aircraft includes: a level flight propulsion system 101, a nose 102, a fuselage 103, a tail 104, a frame 105, a VTOL propulsion system 106, an inner fixed wing 107, and an outer retractable wing 108. The level flight propulsion system 101 is connected to the front interface of the nose 102, the rear interface of the nose 102 is connected to the front interface of the fuselage 103, the rear interface of the fuselage 103 is connected to the tail 104, the frame 105 is connected to the front and rear interface on the side of the fuselage 103, the VTOL propulsion system 106 is connected to the rear interface of the frame 105, the inner fixed wing 107 is connected to the middle interface on the side of the fuselage 103, and the outer retractable wing 108 is connected to the inner fixed wing 107.

[0022] The fuselage 103 and frame 105 can form a rotor verification platform independently through the vertical take-off and landing power system 106. The vertical takeoff and landing (VTOL) propulsion system 106 includes multiple VTOL power units, each of which is located at the end of the frame 105. Each VTOL power unit includes a motor, a propeller, and an electronic speed controller (ESC). The motor is fixed at the end of the frame 105, the propeller is connected to the motor's output shaft, and the ESC is electrically connected to the motor and receives control signals from the flight control system to adjust the propeller speed. The fuselage 103 and the frame 105 can cooperate with the VTOL propulsion system to form a rotor verification platform without assembling the nose 102, tail 104, inner fixed wing 107, outer retractable wing 108, or level flight propulsion system 101. After the frame 105 is connected to the fuselage 103, it forms the main body of the rotor platform. Each VTOL power unit is installed at the end of the frame 105, and the speed of each power unit is controlled by the flight control system to achieve vertical takeoff, hovering, attitude adjustment, and vertical landing of the platform. This allows the platform to be used to verify the VTOL propulsion system, the structural strength of the frame, flight control, and stability in rotor mode.

[0023] like Figure 2 As shown, the inner fixed wing 107 houses the outer telescopic wing 108, and the inner fixed wing 107 is equipped with a telescopic drive device that can drive the telescopic extension and retraction of the outer telescopic wing 108.

[0024] The inner fixed wing 107 has an interface on the outer side, through which different types of wings can be assembled, and the performance of the assembled wings can be verified through flight tests on the platform.

[0025] The tail section 104 has a built-in tail drive device that enables the extension and retraction of the tail section 104. At the same time, the tail section 104 is a replaceable module, and tail sections of different configurations can be combined according to the type of wings to be installed.

[0026] like Figures 3 to 5 The inner fixed wing 107 and fuselage 103 are equipped with a variable displacement drive device, which can drive the inner fixed wing 107 to achieve variable displacement motion of wing installation angle, wing dihedral angle and wing sweep angle. A 3-DOF wing root variator mechanism, similar to a robotic arm joint, is installed between the inner fixed wing 107 and the fuselage 103. This mechanism allows the inner fixed wing 107 to change attitude relative to the fuselage 103 through three rotational degrees of freedom at the wing root. The mechanism includes a fixed end connected to the fuselage 103, a moving end connected to the inner fixed wing 107, and three rotational joints located between the two. Each rotational joint corresponds to wing angle adjustment in different directions. By driving the corresponding rotational joints, the inner fixed wing 107 can rotate around approximately the wing span, the fuselage longitudinal direction, or the vertical direction, thereby achieving changes in the wing installation angle, dihedral angle, or sweep angle, respectively. As a result, the inner fixed wing 107 can complete various forms of variator motion on the same aircraft platform and drive the outer telescopic wing or assembled wing to move synchronously, thus meeting the flight verification requirements under different wing deformation modes.

[0027] The variant motion of the inner fixed wing 107 can drive the motion of the outer telescopic wing 108 or the assembled wing, thereby verifying the performance of the wing under different deformation modes.

[0028] The level flight propulsion system 101 provides propulsion for level flight cruise, while the vertical takeoff and landing (VTOL) propulsion system 106 provides vertical takeoff and landing (VTOL) and altitude holding capabilities. When the aircraft performs wing variator motions in fixed-wing mode, the VTOL propulsion system 106 participates in flight control to provide altitude holding, attitude assistance control, or instability protection. When wing variator motions cause changes in lift or a decrease in altitude, the flight control system increases the rotational speed of one or more VTOL propulsion units to generate additional lift and maintain altitude. When wing variator motions cause pitch, roll, or yaw attitude disturbances, the flight control system differentially adjusts the rotational speeds of the front / rear or left / right VTOL propulsion units to generate corresponding attitude correction torques and achieve attitude assistance control. When parameters such as attitude angle, angular velocity, rate of descent, or angle of attack exceed preset safety thresholds, the flight control system enters a protection control state, limiting or stopping wing variator motions and increasing the VTOL propulsion system output to restore the aircraft to a safe attitude or switch to rotor mode, thereby achieving instability protection.

[0029] The frame 105 is shaped like an "I" and runs horizontally across the fuselage 103. The horizontal plane of the frame 105 is higher than the horizontal plane of the inner fixed wing 107. The inner fixed wing 107 is located between the frames 105 to avoid interference between the inner fixed wing 107 and the frame 105 during the transformation process.

[0030] In a specific flight experiment, when facing a flight mission requiring takeoff in a confined space and wing sweep angle variation, the outer retractable wing 108 and tail 104 are in a retracted state during takeoff. The vertical takeoff and landing (VTOL) system 106 drives the aircraft to take off vertically in rotor mode. After the aircraft ascends to an area with no space constraints, the outer retractable wing 108 and tail 104 extend, and the level flight propulsion system 101 drives the aircraft forward to accelerate and enter fixed-wing mode. In fixed-wing mode, the inner fixed wing 107 of the aircraft performs wing sweep angle variation motion, and the VTOL system 106 participates in altitude maintenance and attitude protection during the variation process. After the flight mission is completed, the aircraft switches from fixed-wing mode to rotor mode and lands vertically.

[0031] Therefore, this invention, through modular interface design, wing extension and multi-form variant design, and vertical takeoff and landing system protection design, can meet the needs of rotor verification, fixed-wing cruise and variant flight experiments, and has good compatibility, reusability and experimental safety.

Claims

1. A vertical takeoff and landing variant aircraft, characterized in that, include: The aircraft comprises a level flight propulsion system (101), a nose (102), a fuselage (103), a tail (104), a frame (105), a vertical takeoff and landing propulsion system (106), an inner fixed wing (107), and an outer retractable wing (108). The level flight propulsion system (101) is connected to the front end interface of the nose (102), the rear end interface of the nose (102) is connected to the front end interface of the fuselage (103), the rear end interface of the fuselage (103) is connected to the tail (104), the frame (105) is connected to the front and rear end interfaces of the side of the fuselage (103), the vertical takeoff and landing propulsion system (106) is connected to the end interface of the frame (105), the inner fixed wing (107) is connected to the middle interface of the side of the fuselage (103), and the outer retractable wing (108) is connected to the inner fixed wing (107).

2. The vertical takeoff and landing variant aircraft as described in claim 1, characterized in that, The fuselage (103) and frame (105) can cooperate with the vertical take-off and landing power system (106) to form a rotor verification platform. The vertical take-off and landing power system (106) includes multiple vertical take-off and landing power units, each of which is located at the end of the frame (105). Each vertical take-off and landing power unit includes a motor, a propeller and an electronic speed controller (ESC). The motor is fixed at the end of the frame (105), the propeller is connected to the output shaft of the motor, and the ESC is electrically connected to the motor and receives control signals from the flight control system to adjust the speed of each propeller. After the frame (105) is connected to the fuselage (103), it forms the main body of the rotor platform. Each vertical take-off and landing power unit is installed at the end of the frame (105). The speed of each power unit is controlled by the flight control system to realize the vertical take-off, hovering, attitude adjustment and vertical landing of the platform.

3. The vertical takeoff and landing variant aircraft as described in claim 1, characterized in that, The inner fixed wing (107) houses the outer telescopic wing (108), and the inner fixed wing (107) is equipped with a telescopic drive device to drive the telescopic extension and retraction of the outer telescopic wing (108).

4. The vertical takeoff and landing variant aircraft as described in claim 1, characterized in that, The inner fixed wing (107) has an interface on the outside, through which different types of wings are assembled, and the performance of the assembled wings is verified through flight experiments.

5. The vertical takeoff and landing variant aircraft as described in claim 1, characterized in that, The tail (104) has a built-in drive device to realize the extension and retraction of the tail (104). At the same time, the tail (104) is a replaceable module, and tails of different configurations can be combined according to the type of wings to be installed.

6. The vertical takeoff and landing variant aircraft as claimed in claim 1, characterized in that, A drive unit is installed inside the inner fixed wing (107) and the fuselage (103). The drive unit drives the inner fixed wing (107) to achieve variant motions of the wing installation angle, dihedral angle, and sweep angle. A 3-DOF wing root variant mechanism, similar to a robotic arm joint, is set between the inner fixed wing and the fuselage, so that the inner fixed wing can change its attitude relative to the fuselage through the three rotational degrees of freedom at the wing root. The mechanism includes a fixed end connected to the fuselage, a moving end connected to the inner fixed wing, and three rotational joints set between the two. Each rotational joint corresponds to the wing angle adjustment in different directions. By driving the corresponding rotational joints, the inner fixed wing can rotate around the approximate wing span, fuselage longitudinal or vertical direction, thereby realizing the changes in the wing installation angle, dihedral angle or dihedral angle, and sweep angle, respectively. Thus, the inner fixed wing can complete multiple forms of variant motion on the same aircraft platform and drive the outer telescopic wing or assembled wing to move synchronously to meet the flight verification requirements under different wing deformation modes.

7. The vertical takeoff and landing variant aircraft as claimed in claim 1, characterized in that, The variant motion of the inner fixed wing (107) drives the motion of the outer telescopic wing (108) or the assembled wing, thereby verifying the performance of the wing under different deformation modes.

8. The vertical takeoff and landing variant aircraft as claimed in claim 1, characterized in that, The level flight propulsion system (101) provides level flight cruise propulsion, and the vertical takeoff and landing (VTOL) propulsion system (106) provides vertical takeoff and landing and altitude holding capabilities. When the aircraft performs wing variator motion in fixed-wing mode, the VTOL propulsion system (106) participates in flight control to provide altitude holding, attitude assistance control, or instability protection. When wing variator motion causes changes in lift or a decrease in flight altitude, the flight control system increases the rotational speed of one or more VTOL propulsion units to generate additional lift and achieve altitude holding. When wing variator motion causes pitch, roll, or yaw attitude disturbances, the flight control system differentially adjusts the rotational speed of the front and rear or left and right VTOL propulsion units to generate corresponding attitude correction torque and achieve attitude assistance control. When parameters such as attitude angle, angular velocity, rate of descent, or angle of attack exceed preset safety thresholds, the flight control system enters a protection control state, restricts or stops wing variator motion, and increases the output of the VTOL propulsion system to restore the aircraft to a safe attitude or switch to rotor mode, thereby achieving instability protection.

9. The vertical takeoff and landing variant aircraft as claimed in claim 1, characterized in that, The frame (105) is shaped like an "I" and runs horizontally across the fuselage (103). The horizontal plane where the frame (105) is located is higher than the horizontal plane where the inner fixed wing (107) is located. The inner fixed wing (107) is located between the frames (105) to avoid interference between the inner fixed wing (107) and the frame (105) during the transformation process.

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