Tiltrotor aircraft with swept wing distributed non-constant diameter rotors and method of control

Abstract

The application discloses a rear-swept wing distributed non-equal-diameter rotorcraft and a control method thereof, which comprises a fuselage, a wing, a tilt-rotor group, a landing gear, a horizontal tail and a vertical tail; the tilt-rotor group comprises four tilt-rotors which are connected to the leading edge of the wing through a support rod; the rotor disc area near the wing tip is larger than the rotor disc area near the wing root, so as to balance the flight efficiency at low speed and the flight speed at high speed, and the rear sweep of the wing is beneficial to improving the stability of the tilt-rotor aircraft in the fixed-wing mode flight, and the environmental adaptability of the aircraft is improved. The application balances the efficiency of the tilt-rotor aircraft in the hovering and cruising states, the aircraft structure is relatively simple, is beneficial to the attitude control of the aircraft and the flight control software design.

Description

Technical Field

[0001] This invention belongs to the field of tiltrotor technology, specifically relating to a swept-wing distributed non-uniform diameter rotor disk tiltrotor and its control method. Background Technology

[0002] Traditional aircraft are categorized into fixed-wing aircraft and rotorcraft. Fixed-wing aircraft possess more advanced manufacturing technology and, compared to rotorcraft, offer advantages such as higher speed, better maneuverability, longer range, and larger payload. However, they require longer runways for takeoff and landing and have stricter runway environmental requirements. Rotary aircraft, on the other hand, can take off and land vertically in confined spaces without runways, but they are slower and have shorter ranges.

[0003] Tiltrotors not only possess the vertical takeoff and landing capabilities of rotorcraft, but also combine the high speed and long range of fixed-wing aircraft. However, the mechanical structure of traditional tiltrotor aircraft is extremely complex, requiring a sophisticated cyclic pitch control system to manage the aircraft's power output and attitude. Furthermore, dedicated drive shafts are needed to maintain synchronization between the left and right rotor systems, making operation and maintenance far more difficult than with conventional aircraft.

[0004] Tiltrotor aircraft are a major focus in the future of aviation. Currently, vertical takeoff and landing (VTOL) aircraft typically rely on rotors / propellers, ducted fans, or thrust vectoring jet engines to ensure stability during takeoff and landing. Propellers, with their larger diameters, offer higher efficiency during both VTOL and normal cruise. Ducted fans and thrust vectoring jet engines generally have smaller diameters and higher thrust, but suffer from higher fuel consumption and lower cruise efficiency. For high-speed rotorcraft, using tiltrotors for VTOL and tiltrotor propulsion during cruise allows for a balance between VTOL capability and propulsion efficiency.

[0005] Traditional tiltrotor aircraft mostly use straight wings, which have weak anti-interference capabilities during cruise. Traditional multi-rotor tiltrotor aircraft mostly use rotor disks of equal diameter. If the rotor disk diameter is too large, it will increase flight drag, while if the rotor disk diameter is too small, it will be difficult to provide sufficient thrust, both of which are not conducive to improving cruise efficiency. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a swept-wing distributed non-uniform diameter rotor disk tiltrotor and its control method, so as to solve the problems of complex tiltrotor design, insufficient cruise stability and cruise flight efficiency in the prior art.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The present invention relates to a swept-wing distributed non-uniform diameter rotor tiltrotor aircraft, comprising: fuselage, wing, tiltrotor assembly, landing gear, horizontal tail and vertical tail;

[0009] The aircraft has two wings, symmetrically arranged on both sides of the fuselage. The wings include a main wing and an aileron. The main wing is connected to the middle of the fuselage and is used to generate lift. The aileron is installed on the trailing edge of the wing and is used to control the roll of the tiltrotor when it is flying in fixed-wing mode, and to decelerate the tiltrotor when it switches from fixed-wing to tiltrotor vertical take-off and landing.

[0010] The tiltrotor assembly comprises two pairs of tiltrotors, each pair differing only in the size of its rotor disk. The tiltrotor with the larger rotor disk is mounted on the outer leading edge of the wing, while the tiltrotor with the smaller rotor disk is mounted on the inner leading edge of the wing. Each tiltrotor includes a strut, a tilting mechanism, a rotor disk, and a motor. One end of the strut is connected to the wing, and the other end is connected to one end of the tilting mechanism. The other end of the tilting mechanism is connected to the rotor disk and controls its rotation along the transverse axis of the fuselage. The motor is connected to the rotor disk drive, providing power to the rotor disk.

[0011] The number of landing gears is two, symmetrically arranged on both sides of the fuselage; the landing gear includes landing gear struts and wheels, one end of the landing gear struts is fixed to the fuselage, and the other end is connected to the wheels;

[0012] The number of horizontal tails is two, symmetrically arranged on both sides of the rear of the fuselage; the horizontal tails include a horizontal stabilizer and an elevator, the horizontal stabilizer is fixed to both sides of the rear of the fuselage, and the elevator is hinged to the trailing edge of the horizontal stabilizer, used to control the pitch of the tiltrotor.

[0013] The vertical tail is located at the upper end of the tail section of the fuselage. It includes a vertical stabilizer and a rudder. The vertical stabilizer is fixed to the upper end of the tail section of the fuselage, and the rudder is hinged to the trailing edge of the vertical stabilizer. It is used to control the yaw of the tiltrotor aircraft.

[0014] Furthermore, the wing adopts a swept-back wing, which increases the longitudinal distance between the inner and outer rotor disks, reduces the length of the strut, and improves the stability of the tiltrotor aircraft in fixed-wing mode.

[0015] Furthermore, the tilting mechanism includes: a sleeve, a tilting servo, and a motor base. The tilting servo is connected to the support rod through the sleeve and is bolted to the lugs of the sleeve. The motor base is connected to the output shaft of the tilting servo, which drives the tilting servo to tilt. The motor is fixedly installed on the motor base.

[0016] Furthermore, when flying in fixed-wing mode, the rotation axes of the propeller disks are all on the same horizontal plane, while when flying in vertical take-off and landing mode, the rotation axes of the large and small propeller disks are on the same vertical plane. Moreover, the tiltrotor on the inner side of the wing is closer to the nose in the longitudinal direction than the tiltrotor on the outer side of the wing, which can achieve pitch control when the same tiltrotor aircraft takes off and lands vertically, thus improving the efficiency of vertical take-off and landing.

[0017] The present invention discloses a control method for a swept-wing distributed non-uniform diameter rotor disk tiltrotor aircraft, based on the aforementioned tiltrotor aircraft, comprising the following steps:

[0018] Hovering vertical takeoff and landing mode:

[0019] The tilt-rotor controls all rotor disks to tilt forward or backward simultaneously to achieve forward or backward flight. A roll to the left is achieved by simultaneously increasing the speed of the right rotor disk, and a roll to the right is achieved by simultaneously increasing the speed of the left rotor disk. Yaw to the right is achieved by controlling the left-side tilt-rotor mechanism to tilt the left rotor disk forward while simultaneously controlling the right-side tilt-rotor mechanism to tilt the right rotor disk backward. Yaw to the left is achieved by controlling the right-side tilt-rotor mechanism to tilt the right rotor disk forward while simultaneously controlling the left-side tilt-rotor mechanism to tilt the left rotor disk backward.

[0020] Tilting transition mode:

[0021] When transitioning from fixed-wing mode to hovering VTOL mode, the tilt mechanism drives the small rotor disk to tilt forward at a constant speed. Once the rotation axis of the small rotor disk is parallel to the length of the fuselage and the aircraft reaches a certain speed, the tilt mechanism drives the large rotor disk to tilt forward at a constant speed. This process is the tilt transition mode. During this process, part of the tiltrotor's attitude control is consistent with that in fixed-wing mode, both achieved through the ailerons, the elevators of the horizontal tail, and the rudder of the vertical tail. Another part of the aircraft's attitude control provides a certain degree of attitude control by adjusting the speed difference of the four tilt rotor disks. The ratio of the two parts of the aircraft's attitude control is automatically allocated by the aircraft's control system based on its overall tilt angle and the tilt angle of the four tilt rotor disks. At this time, the aircraft's attitude control is in a hybrid control mode.

[0022] Fixed-wing mode:

[0023] When flying in fixed-wing mode, the rotation axes of the four propeller disks are along the longitudinal axis of the fuselage, and the rotation of the four tiltrotor disks generates a force that pulls the aircraft forward. When the aircraft speed is lower than the set value, the main power is distributed to the rotation of the large propeller disk, while the small propeller disk maintains a certain speed to resist the drag. When the aircraft speed is higher than the set value, the main power is distributed to the rotation of the small propeller disk, while the large propeller disk maintains a certain speed to resist the drag. The attitude control of the aircraft is achieved through the ailerons, the elevators of the horizontal tail, and the rudder of the vertical tail.

[0024] The beneficial effects of this invention are:

[0025] (1) This invention takes into account both the take-off and landing advantages of rotorcraft and the high-efficiency cruise advantages of fixed-wing aircraft.

[0026] (2) The present invention uses a tilting mechanism to control the tilting of the propeller disk, and the mechanical structure is relatively simple;

[0027] (3) In this invention, the wing adopts a swept wing layout, which makes the tiltrotor aircraft more stable when flying in fixed wing mode. The tilt rotors are distributed along the leading edge of the wing, and the rotor disks on the same wing are staggered, which makes the tiltrotor aircraft have higher vertical take-off and landing efficiency.

[0028] (4) The present invention adopts a large and small rotor disk layout, which takes into account both the efficiency of the tiltrotor aircraft in low-speed flight when flying in fixed-wing mode and the demand of the tiltrotor aircraft to pursue high-speed flight. Attached Figure Description

[0029] Figure 1 This is a three-dimensional structural diagram of the tiltrotor aircraft in hovering vertical takeoff and landing mode in this invention;

[0030] Figure 2 This is a front view of the tiltrotor aircraft in hovering vertical takeoff and landing mode in this invention;

[0031] Figure 3 This is a top view of the tiltrotor aircraft in hovering vertical takeoff and landing mode in this invention;

[0032] Figure 4 This is a three-dimensional structural diagram of the tiltrotor aircraft in the tilt transition mode of this invention;

[0033] Figure 5 This is a front view of the tiltrotor aircraft in the tilt transition mode in this invention;

[0034] Figure 6 This is a top view of the tiltrotor aircraft in tilt transition mode in this invention;

[0035] Figure 7 This is a three-dimensional structural diagram of the tiltrotor aircraft in fixed-wing mode during flight, as described in this invention.

[0036] Figure 8 This is a front view of the tiltrotor aircraft in fixed-wing mode during flight, as described in this invention.

[0037] Figure 9 This is a top view of the tiltrotor aircraft in fixed-wing mode during flight, as described in this invention.

[0038] Figure 10This is a perspective view of the structure and connection relationship of the tilting mechanism of the tilt rotor in this invention;

[0039] Figure 11 This is a top view of the tiltrotor aircraft yawing to the right when it is in hovering vertical takeoff and landing mode in this invention;

[0040] Figure 12 This is a top view of the tiltrotor aircraft yawing to the left when it is in hovering vertical takeoff and landing mode in this invention. Detailed Implementation

[0041] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0042] Reference Figures 1-12 As shown, a swept-wing distributed non-uniform diameter rotor tiltrotor of the present invention includes: fuselage 10, wing 20, tiltrotor assembly 30, landing gear 40, horizontal tail 50 and vertical tail 60.

[0043] The number of wings 20 is two, symmetrically arranged on both sides of the fuselage 10; the wings include a main wing 21 and an aileron 22. The main wing 21 is connected to the middle of the fuselage 10 and is used to generate lift; the aileron 22 is installed on the trailing edge of the wing and is used to control the roll of the tiltrotor when the tiltrotor is in fixed-wing mode, and to decelerate the tiltrotor when the tiltrotor switches from fixed-wing flight to tiltrotor vertical take-off and landing.

[0044] The tiltrotor assembly 30 includes two pairs of tiltrotors, each pair differing only in the size of the rotor disk. The tiltrotor with the larger rotor disk is mounted on the outer side of the leading edge of the wing 20, while the tiltrotor with the smaller rotor disk is mounted on the inner side of the leading edge of the wing 20. The tiltrotor includes a strut 31, a tilting mechanism 32, a rotor disk 33, and a motor 34. One end of the strut 31 is connected to the wing 20, and the other end is connected to one end of the tilting mechanism 32. The other end of the tilting mechanism 32 is connected to the rotor disk 33 and controls the rotor disk 33 to rotate along the transverse axis of the fuselage. The motor 34 is driven by the rotor disk 33, providing power to the rotor disk 33.

[0045] The number of landing gear 40 is two, symmetrically arranged on both sides of the fuselage 10; the landing gear 40 includes landing gear struts 41 and wheels 42, one end of the landing gear struts 41 is fixed to the fuselage 10, and the other end is connected to the wheels 42;

[0046] The number of horizontal tail 50 is two, symmetrically arranged on both sides of the tail of the fuselage 10; the horizontal tail 50 includes a horizontal stabilizer 51 and an elevator 52. The horizontal stabilizer 51 is fixed to both sides of the tail of the fuselage, and the elevator 52 is hinged to the trailing edge of the horizontal stabilizer 51 and is used to control the pitch of the tiltrotor.

[0047] The vertical tail 60 is located at the upper end of the tail of the fuselage 10. It includes a vertical stabilizer 61 and a rudder 62. The vertical stabilizer 61 is fixed to the upper end of the tail of the fuselage 10, and the rudder 62 is hinged to the trailing edge of the vertical stabilizer 61. It is used to control the yaw of the tiltrotor aircraft.

[0048] The wing 20 is a swept wing, which increases the longitudinal distance between the inner and outer rotor disks, reduces the length of the strut 31, and improves the stability of the tiltrotor aircraft in fixed-wing mode.

[0049] The tilting mechanism 32 includes a sleeve 321, a tilting servo motor 322, and a motor base 323. The tilting servo motor 322 is connected to the support rod 31 through the sleeve 321 and is bolted to the lug of the sleeve 321. The motor base 323 is connected to the output shaft of the tilting servo motor 322 and is driven to tilt by the tilting servo motor 322. A motor 34 is fixedly installed on the motor base 323.

[0050] When flying in fixed-wing mode, the rotation axes of the rotor disk 33 are all on the same horizontal plane. When flying in vertical take-off and landing mode, the rotation axes of the large and small rotor disks are on the same vertical plane. Moreover, the tilt rotor on the inner side of the wing is closer to the nose in the longitudinal direction than the tilt rotor on the outer side of the wing. This enables pitch control during vertical take-off and landing of the same tilt rotor aircraft, thus improving vertical take-off and landing efficiency.

[0051] The present invention discloses a control method for a swept-wing distributed non-uniform diameter rotor disk tiltrotor aircraft, based on the aforementioned tiltrotor aircraft, comprising the following steps:

[0052] Figures 1-3 Hovering vertical takeoff and landing mode:

[0053] The tilt-rotor controls all rotor disks to tilt forward or backward simultaneously to achieve forward or backward flight. A roll to the left is achieved by simultaneously increasing the speed of the right rotor disk, and a roll to the right is achieved by simultaneously increasing the speed of the left rotor disk. Yaw to the right is achieved by controlling the left-side tilt-rotor mechanism to tilt the left rotor disk forward while simultaneously controlling the right-side tilt-rotor mechanism to tilt the right rotor disk backward. Yaw to the left is achieved by controlling the right-side tilt-rotor mechanism to tilt the right rotor disk forward while simultaneously controlling the left-side tilt-rotor mechanism to tilt the left rotor disk backward.

[0054] Figures 4 to 6 As shown, tilt transition mode:

[0055] When transitioning from fixed-wing mode to hovering VTOL mode, the tilt mechanism drives the small rotor disk to tilt forward at a constant speed. Once the rotation axis of the small rotor disk is parallel to the length of the fuselage and the aircraft reaches a certain speed, the tilt mechanism drives the large rotor disk to tilt forward at a constant speed. This process is the tilt transition mode. During this process, part of the tiltrotor's attitude control is consistent with that in fixed-wing mode, both achieved through the ailerons, the elevators of the horizontal tail, and the rudder of the vertical tail. Another part of the aircraft's attitude control provides a certain degree of attitude control by adjusting the speed difference of the four tilt rotor disks. The ratio of the two parts of the aircraft's attitude control is automatically allocated by the aircraft's control system based on its overall tilt angle and the tilt angle of the four tilt rotor disks. At this time, the aircraft's attitude control is in a hybrid control mode.

[0056] Figures 7 to 9 As shown, fixed-wing mode:

[0057] When flying in fixed-wing mode, the rotation axes of the four propeller disks are along the longitudinal axis of the fuselage, and the rotation of the four tiltrotor disks generates a force that pulls the aircraft forward. When the aircraft speed is lower than the set value, the main power is distributed to the rotation of the large propeller disk, while the small propeller disk maintains a certain speed to resist the drag. When the aircraft speed is higher than the set value, the main power is distributed to the rotation of the small propeller disk, while the large propeller disk maintains a certain speed to resist the drag. The attitude control of the aircraft is achieved through the ailerons, the elevators of the horizontal tail, and the rudder of the vertical tail.

[0058] Figure 11 and 12 As shown in the example, the tiltrotor yaws during hovering vertical takeoff and landing mode:

[0059] like Figure 11 As shown, when the tiltrotor yaws to the right, the tilt mechanism 32 drives the left rotor disk to tilt forward, and simultaneously drives the right rotor disk to tilt backward. At this point, the tiltrotor will rotate clockwise around its vertical axis, thus achieving a rightward yaw. Figure 12 As shown, when the tiltrotor yaws to the left, the tilt mechanism 32 drives the right rotor disk to tilt forward, and at the same time drives the left rotor disk to tilt backward. At this point, the tiltrotor will rotate counterclockwise around the vertical axis of the fuselage, thereby achieving the yaw of the entire aircraft to the left.

[0060] This invention has many specific applications. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A swept-wing distributed non-uniform diameter rotor disc tiltrotor, characterized in that, include: Fuselage, wings, tiltrotor assembly, landing gear, horizontal tail and vertical tail; The aircraft has two wings, symmetrically arranged on both sides of the fuselage. The wings include a main wing and an aileron. The main wing is connected to the middle of the fuselage and is used to generate lift. The aileron is installed on the trailing edge of the wing and is used to control the roll of the tiltrotor when it is flying in fixed-wing mode, and to decelerate the tiltrotor when it switches from fixed-wing to tiltrotor vertical take-off and landing. The tiltrotor assembly comprises two pairs of tiltrotors, each pair differing only in the size of its rotor disk. The tiltrotor with the larger rotor disk is mounted on the outer leading edge of the wing, while the tiltrotor with the smaller rotor disk is mounted on the inner leading edge of the wing. Each tiltrotor includes a strut, a tilting mechanism, a rotor disk, and a motor. One end of the strut is connected to the wing, and the other end is connected to one end of the tilting mechanism. The other end of the tilting mechanism is connected to the rotor disk and controls the rotor disk to rotate along the transverse axis of the fuselage. The motor is connected to the rotor disk drive and provides power to the rotor disk. The number of landing gears is two, symmetrically arranged on both sides of the fuselage; the landing gear includes landing gear struts and wheels, one end of the landing gear struts is fixed to the fuselage, and the other end is connected to the wheels; The number of horizontal tails is two, symmetrically arranged on both sides of the rear of the fuselage; the horizontal tails include a horizontal stabilizer and an elevator, the horizontal stabilizer is fixed to both sides of the rear of the fuselage, and the elevator is hinged to the trailing edge of the horizontal stabilizer, used to control the pitch of the tiltrotor. The vertical tail is located at the upper end of the tail section of the fuselage. It includes a vertical stabilizer and a rudder. The vertical stabilizer is fixed to the upper end of the tail section of the fuselage, and the rudder is hinged to the trailing edge of the vertical stabilizer. It is used to control the yaw of the tiltrotor aircraft.

2. The swept-wing distributed non-uniform diameter rotor disc tiltrotor according to claim 1, characterized in that, The wing is a swept wing.

3. The swept-wing distributed non-uniform diameter rotor disc tiltrotor according to claim 1, characterized in that, The tilting mechanism includes a sleeve, a tilting servo, and a motor base. The tilting servo is connected to the support rod through the sleeve and is bolted to the lugs of the sleeve. The motor base is connected to the output shaft of the tilting servo, which drives the tilting mechanism to tilt. The motor is fixedly installed on the motor base.

4. The swept-wing distributed non-uniform diameter rotor disc tiltrotor according to claim 1, characterized in that, When flying in fixed-wing mode, the rotation axes of the rotor disks are all on the same horizontal plane. When flying in hovering vertical take-off and landing mode, the rotation axes of the large and small rotor disks are on the same vertical plane. Furthermore, the tilt rotor on the inner side of the wing is closer to the nose in the longitudinal direction than the tilt rotor on the outer side of the wing, which enables pitch control during vertical take-off and landing of the same tilt rotor aircraft.

5. A control method for a swept-wing distributed non-uniform diameter rotor disk tiltrotor, based on the tiltrotor described in any one of claims 1-4, characterized in that, The steps are as follows: Hovering vertical takeoff and landing mode: The tilt-rotor controls all rotor disks to tilt forward or backward simultaneously to achieve forward or backward flight. A roll to the left is achieved by simultaneously increasing the speed of the right rotor disk, and a roll to the right is achieved by simultaneously increasing the speed of the left rotor disk. Yaw to the right is achieved by controlling the left-side tilt-rotor mechanism to tilt the left rotor disk forward while simultaneously controlling the right-side tilt-rotor mechanism to tilt the right rotor disk backward. Yaw to the left is achieved by controlling the right-side tilt-rotor mechanism to tilt the right rotor disk forward while simultaneously controlling the left-side tilt-rotor mechanism to tilt the left rotor disk backward. Tilting transition mode: When transitioning from fixed-wing mode to hovering VTOL mode, the tilt mechanism drives the small rotor disk to tilt forward at a constant speed. Once the rotation axis of the small rotor disk is parallel to the length of the fuselage and the aircraft reaches a certain speed, the tilt mechanism drives the large rotor disk to tilt forward at a constant speed. This process is called the tilt transition mode. During this process, part of the tiltrotor's attitude control is consistent with that in fixed-wing mode, both achieved through the ailerons, the elevators of the horizontal tail, and the rudder of the vertical tail. Another part of the aircraft's attitude control provides a certain degree of attitude control by adjusting the speed difference of the four tilt rotor disks. The ratio of the two parts of the aircraft's attitude control is automatically allocated by the aircraft's control system based on its overall tilt angle and the tilt angle of the four tilt rotor disks. Fixed-wing mode: When flying in fixed-wing mode, the rotation axes of the four propeller disks are along the longitudinal axis of the fuselage, and the rotation of the four tiltrotor disks generates a force that pulls the aircraft forward. When the aircraft speed is lower than the set value, the main power is distributed to the rotation of the large propeller disk, while the small propeller disk maintains a certain speed to resist the drag. When the aircraft speed is higher than the set value, the main power is distributed to the rotation of the small propeller disk, while the large propeller disk maintains a certain speed to resist the drag. The attitude control of the aircraft is achieved through the ailerons, the elevators of the horizontal tail, and the rudder of the vertical tail.

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