Improved combined wing tilting ducted fan layout vertical take-off and landing aircraft

Abstract

The invention discloses a vertical take-off and landing aircraft with improved linked wing tilting ducted fan layout, and belongs to the technical field of pneumatic and power systems of vertical take-off and landing aircrafts. The aircraft comprises an improved joined wing structure layout and a tilting ducted fan system integrally designed with the improved joined wing structure layout. The improved joined wing structure layout comprises a front wing, a rear wing, a vertical connecting wing surface, a vertical stabilizer and a fuselage. The front wing is divided into a front wing inner side wing surface and a front wing outer side wing surface by a vertical connecting wing surface, and adopts a sweepback wing belt dihedral structure; two ends of the rear wing are respectively arranged above the front wing through a vertical connecting wing surface, the middle part of the rear wing is arranged above the tail part of the fuselage through a vertical stabilizer, and the rear wing adopts a forward swept wing structure; the tilting ducted fan system comprises a front wing integrated ducted fan flap 7, a rear wing integrated ducted fan lifting control surface 9 and a tail propelling ducted fan 16. The core problems that pitching of a traditional connected wing is out of control, the weight of a tilting structure is large, and the energy efficiency is low are solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of aerodynamics and power systems of vertical take-off and landing aircraft, and particularly relates to an improved joint wing tilt duct fan layout vertical take-off and landing aircraft. BACKGROUND

[0002] Urban Air Mobility requires vertical take-off and landing aircraft as a transportation carrier. The existing aircraft solutions include tilt rotors, tilt wings, tilt ducts, compound wings (lift + cruise configuration), quadcopters and other configurations. Among them, the tilt duct configuration (such as Germany's Lilium and Sabrewing Rhaegal) has the advantages of lower noise, higher efficiency of duct fan in design point cruise state, stronger high-energy rotor containment, and better vector control. However, it has problems such as a large increase in structural weight, higher manufacturing precision requirements, and increased resistance due to increased wetted area.

[0003] On the other hand, the joint wing layout has lighter structure weight and greater strength and stiffness than the conventional wing type. The beam box section of the joint wing layout has higher structural material utilization efficiency than the cantilever beam box section of the normal layout, and the front wing and rear wing of the joint wing are connected to each other to form a double support point beam, which reduces the root bending moment and improves the strength and stiffness of the structure. The joint wing layout effectively reduces induced drag, so the aerodynamic resistance of the aircraft is smaller than that of the conventional configuration. In addition, the joint wing has the advantages of good lift characteristics and high lift coefficient. However, the existing joint wing layout still faces many challenges in vertical take-off and landing applications: The aerodynamic interference between the front wing and the rear wing is complex and difficult to control. It is easy to have a difficult-to-control nose severe upward problem; The traditional tilt engine or duct layout has a large structure weight, which is not conducive to the improvement of range and load; The control of thrust vector and aerodynamic rudder surface is not coordinated, and the energy efficiency is low; There is a lack of efficient energy management and power system architecture suitable for multiple flight modes.

[0004] Therefore, there is an urgent need for a new aircraft design scheme that can inherit the aerodynamic and structural advantages of the joint wing layout and effectively integrate thrust vector control to achieve efficient vertical take-off and landing and high-speed cruise. SUMMARY

[0005] Technical problems to be solved: In order to avoid the shortcomings of the prior art, the application provides an improved joint wing tilt duct fan layout vertical take-off and landing aircraft, which successfully solves the core problems of the traditional joint wing pitch loss of control, large weight of the tilt configuration and low energy efficiency by improving the joint wing layout + tilt duct fan integrated design + splayed vector thrust + double closed loop control architecture + hybrid power system, and has significant creativity, practicality and technical advancement, and is suitable for engineering application of the vertical take-off and landing aircraft.

[0006] The technical scheme of the application is: an improved joint wing tilt duct fan layout vertical take-off and landing aircraft, comprising: an improved joint wing structure layout and a tilt duct fan system integrated with the same. The improved joint wing structure layout comprises: a front wing 1, a rear wing 4, a vertical connecting wing surface 2, a vertical stabilizer 5 and a fuselage 6. The front wing 1 is divided into a front wing inner wing surface 1a and a front wing outer wing surface 1b by the vertical connecting wing surface 2, and adopts a rear-swept wing with an up-angle configuration; the trailing edge of the front wing inner wing surface 1a is provided with a front wing integrated duct fan flap 7, and the trailing edge of the front wing outer wing surface 1b is provided with ailerons 8, and the wing tip is provided with wing tip ailerons 10. The rear wing 4 is arranged above the front wing 1 through the vertical connecting wing surface 2 at both ends, and is arranged above the tail of the fuselage 6 through the vertical stabilizer 5 at the middle, and adopts a forward-swept wing configuration, and the trailing edge of the rear wing 4 is provided with a rear wing integrated duct fan elevator surface 9 near the vertical stabilizer 5. The trailing edge of the vertical connecting wing surface 2 is provided with a first yawing surface 13, and the trailing edge of the vertical stabilizer 5 is provided with a second yawing surface 12. The tilt duct fan system comprises: the front wing integrated duct fan flap 7, the rear wing integrated duct fan elevator surface 9 and a tail propelling duct fan 16. The front wing integrated duct fan flap 7 and the rear wing integrated duct fan elevator surface 9 are connected with a fixed wing part 17 through a stepless adjustable rotating mechanism, so as to realize independent tilting in the range of -10° to +95°.

[0007] A further technical scheme of the application is that the left and right parts of the rear wing integrated duct fan elevator surface 9 can be differentially deflected, the differential deflection angle is not more than ±5°, the thrust vector layout forms a splayed type, and is used for generating a same-direction rolling moment while generating a yawing moment.

[0008] A further technical scheme of the application is that the sweep angle of the front wing 1 ranges from 15° to 35°, and the up-angle ranges from 5° to 20°. The forward-swept angle of the rear wing 4 ranges from 30° to 50°.

[0009] The further technical scheme of the present application is that the front wing integrated ducted fan flap 7 comprises a front wing arranged ducted fan group 23, a front wing arranged ducted fan tilting mechanism 31 for driving the tilting of the front wing arranged ducted fan group 23, and a front wing trailing edge extended ducted fan nozzle structure 29 integrated in the load-bearing frame. The rear wing integrated ducted fan elevator surface 9 comprises a rear wing arranged ducted fan group 20, a rear wing arranged ducted fan tilting mechanism 32 for driving the tilting of the rear wing arranged ducted fan group 20, and a rear wing trailing edge extended ducted fan nozzle structure 30 integrated in the load-bearing frame.

[0010] The further technical scheme of the present application is that the tilting ducted fan system is driven by a hybrid power system comprising a turbo-shaft engine 27, a generator system 24, a battery pack 22 and a converter 26; the turbo-shaft engine 27 operates at full power during the vertical take-off and mode conversion stage, and charges the battery pack 22, and adjusts to the high-efficiency power state during the cruising stage.

[0011] A method for controlling the improved joint wing tilting ducted fan layout vertical take-off and landing aircraft, characterized in that a hierarchical control architecture is adopted, comprising: An outer loop attitude control loop configured to receive the expected attitude angle instruction, and calculate the required control moment to be applied on the body axis according to the error between the expected attitude and the actual attitude; An inner loop vector thrust control loop operatively coupled to the outer loop attitude control loop, configured to receive the control moment instruction calculated by the outer loop attitude control loop, and solve and output the instruction for driving the rear wing integrated ducted fan elevator surface 9 to differentially deflect by using a control distribution algorithm to preferentially utilize the control moment generated by the thrust vector.

[0012] The further technical scheme of the present application is that during the vertical take-off stage, the front wing integrated ducted fan flap 7 is controlled to deflect downward by +75° to +95°, the rear wing integrated ducted fan elevator surface 9 is controlled to deflect downward by +80° to +95°, and the aileron 8 is controlled to deflect downward to the maximum angle, so as to provide vertical lift and maintain attitude stability. The further technical scheme of the present application is that during the mode conversion stage from vertical take-off to cruising climb, the following steps are performed: Start the tail propulsion ducted fan 16 to maximum power; Keep the front wing integrated ducted fan flap 7 and the rear wing integrated ducted fan elevator surface 9 in a large angle downward deflection state to provide lift; With the increase of airspeed, gradually tilt the front wing integrated ducted fan flap 7 and the rear wing integrated ducted fan elevator surface 9 back to the cruising state close to 0°, and gradually transfer the lift responsibility to the wing aerodynamic surface. The further technical scheme of the application is that when the aircraft needs to make a coordinated turn, the integrated ducted fan elevator surface 9 is controlled to make differential deflection, so that the resultant force of the lateral component of the thrust generated by the integrated ducted fan elevator surface 9 provides a yawing moment, and the axial moment component provides a rolling moment, and the excess of the additional rolling moment caused by the thrust vector is balanced by adjusting the differential of the aileron 8.

[0013] The further technical scheme of the application is that the fault-tolerant control strategy is further included: when the turbo-shaft engine 27 in the hybrid power system fails, the fuel supply is cut off, the battery pack 22 is used to power the tilting ducted fan system, and an emergency landing is performed; when a single or multiple ducted fans fail, the controllable flight or safe landing of the aircraft is maintained by adjusting the power and tilting angle of the remaining normally working ducted fans.

[0014] Advantages The application has the advantages that: 1. The integrated ducted fan surface is combined with the wing structure of the joined wing, the Coanda effect is effectively utilized to increase the lift, the time required for mode conversion is shortened, and the vertical take-off and landing capability of the aircraft is improved; the joined wing enables the integrated ducted fan elevator to be installed at a higher position, the influence of the main body of the fuselage on the longitudinal stabilizer and the control surface is reduced, and the longitudinal stability of the aircraft is improved; the layout of the joined wing connecting the vertical tail and the wing can optimize the stress distribution of the wing, can withstand the impact during vertical take-off and landing, and reduce the influence of the deformation of the wing on the deviation of the thrust vector.

[0015] 2. The integrated ducted fan surface arranged on the front and rear wings can reduce the risk of loss of control of the joined wing in pitch by means of the rapid response of the vector thrust of the ducted fan. In addition, the eight-shaped vector thrust layout of the integrated ducted fan elevator surface arranged on the rear wing can provide a same-direction rolling moment and a same-direction yawing moment, facilitates the control of the aircraft when yawing, and the excess thrust can be balanced by adjusting the differential aileron.

[0016] 3. The design difficulty of the application lies in achieving optimal matching between the ducted fan aerodynamic characteristics and the joined wing structural layout, that is, ensuring effective lift increase of the Coanda effect and not causing aerodynamic interference and efficiency loss due to deflection of the surface. The integrated ducted fan surface introduces high-degree-of-freedom thrust vector control in the front and rear wing arrangement, and the control law design and the surface response need to be accurately matched, otherwise it is easy to cause pitch overshoot or instability. The excess thrust needs to be balanced by the differential aileron, and the flight control system needs to have high robustness to realize real-time distribution in different flight states.

[0017] As shown in the example data, compared with the conventional 5-seat tilt ducted fan aircraft, under the condition of greater maximum take-off weight (2400 kg vs. 2200 kg), the application realizes comparable total hover power (798 kW vs. 714 kW) through higher aerodynamic and propulsion efficiency, but obtains better high-speed cruise efficiency and greater wing aspect ratio (5 vs. 3.03), indicating that it has a longer range and better cruise economy. The characteristic of "first rising and then falling" of power demand in the mode conversion process also verifies the significant improvement of aerodynamic efficiency of the distributed ducted fan after acceleration. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the aerodynamic shape of a vertical take-off and landing aircraft with an improved joined wing tilt ducted fan layout according to an embodiment of the application.

[0019] Figure 2 It is a top view of the aerodynamic shape of a vertical take-off and landing aircraft with an improved joined wing tilt ducted fan layout according to an embodiment of the application. Figure 3 It is a front view of the aerodynamic shape of a vertical take-off and landing aircraft with an improved joined wing tilt ducted fan layout according to an embodiment of the application.

[0020] Figure 4 It is a left view of the aerodynamic shape of a vertical take-off and landing aircraft with an improved joined wing tilt ducted fan layout according to an embodiment of the application.

[0021] Figure 5 It is a schematic diagram of the integrated ducted fan rudder in cruise state according to an embodiment of the application.

[0022] Figure 6 It is a schematic diagram of the integrated ducted fan rudder in vertical take-off and landing state according to an embodiment of the application.

[0023] Figure 7 It is a schematic diagram of the power system component arrangement of a vertical take-off and landing aircraft with an improved joined wing tilt ducted fan layout according to an embodiment of the application.

[0024] Figure 8 It is a schematic diagram of the "figure-eight" vector thrust action principle according to an embodiment of the application.

[0025] Figure 9 It is a schematic diagram of the "figure-eight" vector thrust hierarchical control architecture according to an embodiment of the application.

[0026] Figure 10 It is a power simulation result diagram of the mode conversion process according to an embodiment of the application.

[0027] Explanation of reference signs: 1, front wing; 1a, inner side wing surface of front wing; 1b, outer side wing surface of front wing; 2, vertical connecting wing surface; 3, wing surface connecting fairing; 4, rear wing; 5, vertical stabilizer; 6, fuselage; 7, front wing integrated ducted fan flap; 8, aileron; 9, rear wing integrated ducted fan elevator surface; 10, wing tip winglet; 11, air inlet lip; 12, second rudder surface; 13, first rudder surface; 14, rear landing gear cabin; 15, front landing gear cabin; 16, tail propulsion ducted fan; 17, fixed wing part; 18, integrated ducted fan control surface; 19, integrated ducted fan control surface rotation shaft; 20, rear wing arranged ducted fan group; 21, fuselage fuel tank; 22, battery pack; 23, front wing arranged ducted fan group; 24, generator system; 25, tail nozzle; 26, converter; 27, turbo shaft engine; 28, air inlet; 29, front wing trailing edge extended ducted fan nozzle structure; 30, rear wing trailing edge extended ducted fan nozzle structure; 31, front wing arranged ducted fan tilting mechanism; 32, rear wing arranged ducted fan tilting mechanism. DETAILED DESCRIPTION The embodiments described below are exemplary and are intended to explain the present application, and are not to be understood as limiting the present application.

[0028] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0029] At present, the tilting duct configuration has a fast response of the vector thrust, but the vertical take-off and landing stage has high requirements for structural strength and large demand for electric power, and the existing joint wing has better structural strength and aerodynamic performance but is prone to pitch loss of control. Therefore, the present application provides an improved joint wing tilting duct fan layout vertical take-off and landing aircraft, comprising: an improved joint wing structure layout and a tilting duct fan system integrated with the same; The improved joint wing structure layout comprises: a front wing 1, a rear wing 4, a vertical connecting wing surface 2, a vertical stabilizer 5 and a fuselage 6. The front wing 1 is divided into a front wing inner wing surface 1a and a front wing outer wing surface 1b by the vertical connecting wing surface 2, and adopts a rear-swept wing with an up-angle configuration; the trailing edge of the front wing inner wing surface 1a is provided with a front wing integrated ducted fan flap 7, and the trailing edge of the front wing outer wing surface 1b is provided with ailerons 8, and the wing tip of the ailerons 8 is provided with wing tip ailerons 10; The trailing edge of the vertical connecting wing surface 2 is provided with a first rudder surface 13, and the trailing edge of the vertical stabilizer 5 is provided with a second rudder surface 12. The trailing edge of the vertical connecting wing surface 2 is provided with a first rudder surface 13, and the trailing edge of the vertical stabilizer 5 is provided with a second rudder surface 12. The tilt ducted fan system comprises: a front wing integrated ducted fan flap 7, a rear wing integrated ducted fan elevator surface 9, and a tail propelling ducted fan 16. The front wing integrated ducted fan flap 7 and the rear wing integrated ducted fan elevator surface 9 are respectively connected with a fixed wing part 17 through a stepless adjustable rotating mechanism, so as to realize independent tilting in a range of -10° to +95°.

[0030] The application also provides a method for controlling the improved joined wing tilt ducted fan layout vertical take-off and landing aircraft, which adopts a hierarchical control architecture, and comprises the following steps: An outer loop attitude control loop is configured to receive a desired attitude angle instruction, and calculate a required control moment to be applied on the body axis according to an error between a desired attitude and an actual attitude. An inner loop vector thrust control loop is operatively coupled to the outer loop attitude control loop, and is configured to receive the control moment instruction calculated by the outer loop attitude control loop, solve and output an instruction for driving the rear wing integrated ducted fan elevator surface 9 to differentially deflect, so as to preferentially utilize thrust vector to generate the control moment.

[0031] The above technical solutions are further analyzed in combination with the accompanying drawings as follows: In one embodiment, referring to Figures 1-8 An improved joined wing tilt ducted fan layout vertical take-off and landing aircraft comprises a joined wing layout and an integrated ducted fan system, and the integrated ducted fan system works cooperatively with the joined wing aircraft.

[0032] The joined wing layout comprises a front wing 1, a rear wing 4, a vertical connecting wing surface 3, a vertical stabilizer 5, a fuselage 6 and the like. The front wing 1 is divided into a front wing inner wing surface 1a and a front wing outer wing surface 1b, and the inner and outer sides of the front wing 1 are divided by a vertical connecting wing surface, and the configuration of the rear swept wing with an up angle is adopted. The front wing inner aileron is a differential aileron and is designed in an integrated manner with the ducted fan, and is responsible for providing vector thrust during vertical take-off and landing and improving the lift of the aircraft and assisting in rolling during flight. In order to maintain flight stability, the differential adjustment range of the front wing inner aileron is ± 5°, and the angle is positive rudder surface downward deflection. The wing tip of the front wing outer wing surface 1b is provided with a wing tip winglet 10, and the trailing edge of the front wing outer wing surface 1b is provided with a compensating aileron 8 responsible for rolling. Among them, the wing tip winglet 10 mainly adopts a zero-lift streamline airfoil, and the rest of the front wing mainly adopts a high-lift-drag ratio thin airfoil.

[0033] The rear wing 4 is installed on the upper side of the vertical stabilizer 2 and the vertical connecting wing surface 5. Near the trailing edge of the rear wing 4 close to the vertical stabilizer 5, there is a differential elevator surface designed in an integrated manner with the ducted fan, which is responsible for providing vector thrust during vertical take-off and landing and improving the lift of the aircraft and assisting in rolling during flight; The vertical connecting wing surface 2 is connected with the rear wing 4 and the front wing 1 on the upper and lower sides respectively, and the trailing edge of the vertical connecting wing surface 2 is provided with a linked rudder surface 13 responsible for controlling yaw, and the wing surface connecting fairing 3 is connected with the rear wing; The vertical stabilizer 5 is connected with the rear wing 4 and the fuselage 6 on the upper and lower sides respectively, and the trailing edge of the vertical stabilizer 5 is provided with a second rudder surface 12 responsible for controlling yaw; The overall profile of the fuselage 6 adopts a streamline design, the front side of the fuselage is a circular rectangular section, and the rear side of the fuselage is an oval shape. The fuselage 6 is transitioned at the connection with the front wing 1, and the landing gear compartments 14 and 15 adopt a semi-buried fuselage design; In one embodiment, the integrated ducted fan system includes: a front wing integrated ducted fan aileron 7, a rear wing integrated ducted fan elevator 9, and a tail propelling ducted fan 16; In this embodiment, the front wing aileron integrated ducted fan 7 includes: a front wing arranged ducted fan group 23, a front wing arranged ducted fan tilting mechanism 31, and a front wing trailing edge extended ducted fan nozzle structure 29; The front wing arranged ducted fan group 23 is a transversely arranged single ducted fan, and the power source is a hybrid power system; The front wing arranged ducted fan tilting mechanism 31 is connected with the front wing fixed wing part 17 by an integrated ducted fan control surface rotating shaft 19, and is a stepless adjustable rotating mechanism, which can drive the front wing aileron integrated ducted fan to rotate between -10° and +95°.

[0034] The front wing trailing edge ducted fan nozzle structure 29 is integrated on the load-bearing frame; In one embodiment, the rear wing elevator surface integrated ducted fan comprises: a rear wing arranged ducted fan 20, a rear wing arranged ducted fan tilting mechanism 32, a rear wing trailing edge extended ducted fan nozzle structure 30; The rear wing arranged ducted fan 20 is specifically implemented as a transversely arranged single-duct ducted fan, and the power source is a hybrid power system. The rear wing arranged ducted fan tilting mechanism 32 is connected by an integrated ducted fan control surface rotating shaft 19 and a rear wing fixed wing portion 17, and is a stepless adjustable rotating mechanism, which can drive the rear wing elevator surface integrated ducted fan 9 to rotate between -10° and +95°. In the event of yaw, in addition to deflecting the yaw rudder surfaces 12 and 13, the rear wing integrated ducted fan elevator surface 9 can also be adjusted to provide yaw force, and in addition, the splayed vector thrust provides a same-direction rolling moment while providing yaw force, facilitating the control of the aircraft in the event of yaw, and the thrust excess can be balanced by adjusting the differential ailerons 8.

[0035] The splayed vector thrust schematic diagram is as shown in Figure 8 The differential deflection of the rear wing integrated ducted fan elevator surface 9 in the coordinated turning process generates an axial moment that makes the aircraft roll, and the resultant force of the lateral component of the thrust provides a yaw moment for the aircraft, reducing the aerodynamic loss caused by large-angle actuation of the rudder surface. The control strategy adopted is characterized by adopting a hierarchical control architecture, including an outer loop attitude control loop and an inner loop vector thrust control loop, which are operatively coupled to achieve accurate and efficient coordinated control of the aircraft attitude.

[0036] The outer loop attitude control loop is configured to: receive a desired attitude angle instruction from a navigation system, the instruction including at least a desired roll angle and a desired yaw angle; obtain real-time attitude information of the aircraft; and calculate, by an attitude controller, a control moment required to track the desired attitude on the body axis based on the error between the desired attitude instruction and the current actual attitude, the moment including at least a roll control moment and a yaw control moment.

[0037] The inner loop vector thrust control loop is configured to: receive the desired control moment instruction calculated by the outer loop; monitor current flight state parameters such as total throttle instructions; and calculate and output optimal differential deflection instructions of the left and right vector thrust devices required to generate the desired control moment in real time by an embedded control distribution algorithm. The core of the control distribution algorithm is to efficiently map the high-level moment instruction to the action of the bottom-level actuator, and one of the optimization objectives is to maximize the use of thrust vector to generate moment, thereby reducing the resistance and aerodynamic loss caused by large-angle actuation of traditional aerodynamic rudders.

[0038] The vector thrust device comprises a rear wing integrated ducted fan and its elevon surfaces, in response to the differential deflection instructions, the left and right surfaces are differentially deflected, thereby changing the thrust direction, generating a roll moment around the longitudinal axis of the fuselage and a lateral component of the thrust along the normal direction of the fuselage, and the resultant of the lateral component forms a yaw moment. This process realizes rapid and accurate response to the desired moment of the outer ring, ultimately enables the aircraft to complete coordinated turning and other maneuvering actions, and significantly improves the energy efficiency and maneuvering performance of the entire control system.

[0039] The rear wing trailing edge ducted fan nozzle structure 30 is designed to be integrated on the load-bearing frame; In one embodiment, the tail propulsion ducted fan 16 is a single ducted fan driven by an external rotor motor, which provides thrust while reducing pressure difference resistance and reducing friction resistance through boundary layer suction to compensate for the characteristics of the wide fuselage. Its power source is a hybrid power system.

[0040] In this embodiment, the hybrid power system includes: a turbo shaft engine 27, a front wing arranged ducted fan group 23 and a rear wing arranged ducted fan group 20, a generator system 24, a battery pack 22, a converter 26, an electric motor system, a transmission gearbox, a ducted fan system, a surface actuator, a surface actuator controller, an energy management system, etc. In this embodiment, the energy management scheme of the hybrid power system in the take-off and landing stage and the modal conversion stage is: the turbo shaft engine 27 runs at full power, and the battery pack 22 is discharged as needed under the control of the energy management system. In the cruising stage, the turbo shaft engine 27 adjusts the power state to run and charges the battery pack 22.

[0041] In one embodiment, in the vertical take-off stage, the overall fuselage state control scheme is to keep the angle of attack at 2°, the yaw angle at 0°, and the roll angle at 0°, and the climb rate at 0.5 m / s. The control scheme of the surface is: the integrated tilting ducted fan flap 7 is deflected downward by +75° to +85°, the integrated tilting ducted fan elevator 9 is deflected downward by +80° to +90°, the ailerons 8 on both sides are deflected downward to the maximum angle and locked, and the yaw surfaces 12 and 13 are locked at the zero deflection position. At this time, the surface control system relies on the front wing integrated tilting ducted fan flap 7 and the rear wing integrated tilting ducted fan elevator 9 to adjust the attitude of the aircraft in the case of external interference. The front wing integrated tilting ducted fan flap 7 and the rear wing integrated tilting ducted fan elevator 9 can be differentially adjusted to meet the vertical take-off vector thrust demand of the overall system, and each sub-ducted fan in the integrated tilting arranged ducted fan system adjusts the output power according to the flight control system. In one embodiment, in the vertical take-off to climb mode transition phase, the overall machine state control scheme is to keep the angle of attack at +10°, the yaw angle at 0°, the roll angle at 0°, and the climb rate at 0 m / s. The control scheme of the control surface is as follows: first, start the tail propelling ducted fan 16 to the maximum power state, the integrated tilting ducted fan flap 7 is deflected downward by +75° to +85°, the integrated tilting ducted fan elevator surface 9 is deflected downward by +60° to +70°, the two side ailerons 8 are reset by the flight control system, the yaw control surface 12, 13 is unlocked by the flight control system; when the relative stable lift is established, the integrated tilting ducted fan flap is gradually recovered to +10° to +15°, the integrated tilting ducted fan elevator surface 9 is gradually recovered to +10° to +15°, the two side ailerons 8 are reset by the flight control system, and the yaw control surface 12, 13 is controlled by the flight control system; when the flight speed of the aircraft reaches 115% of the stall speed, the integrated tilting ducted fan flap 7 is gradually recovered to -5° to +5°, the integrated tilting ducted fan elevator surface 9 is gradually recovered to -5 to +5°, the two side ailerons 8 are reset by the flight control system, and the yaw control surface 12, 13 is controlled by the flight control system; in the take-off mode transition phase, the control surface control system relies on the front wing integrated tilting ducted fan flap 7, the rear wing integrated tilting ducted fan elevator surface 9, the auxiliary aileron 8 and the linkage yaw control surface 12, 13 to adjust the attitude of the aircraft in the case of encountering external interference, the front wing integrated tilting ducted fan flap 7 and the rear wing integrated tilting ducted fan elevator surface 9 can be differentially adjusted to meet the vector thrust requirement of the overall system in the mode transition phase, and each sub-ducted fan in the integrated tilting arrangement type ducted fan system outputs power according to the flight control system; In one embodiment, in the climb phase, the overall machine state control scheme is to keep the angle of attack at +5°, the yaw angle at 0°, the roll angle at 0°, and the climb rate at 4.5 m / s. The control scheme of the control surface is as follows: the integrated tilting ducted fan flap 7 is adjusted to -2° to +2°, the integrated tilting ducted fan elevator surface 9 is adjusted to -2° to +2°, the two side ailerons 8 are reset by the flight control system, and the yaw control surface 12, 13 is controlled by the flight control system. The control surface control system relies on the front wing integrated tilting ducted fan flap 7, the rear wing integrated tilting ducted fan elevator surface 9, the auxiliary aileron 8 and the linkage yaw control surface 12, 13 to adjust the attitude of the aircraft in the case of encountering external interference, the front wing integrated tilting ducted fan flap 7 and the rear wing integrated tilting ducted fan elevator surface 9 can be differentially adjusted to meet the vector thrust requirement of the overall system in the climb phase, and each sub-ducted fan in the integrated tilting arrangement type ducted fan system outputs power according to the flight control system; In one embodiment, in the cruise phase, the overall machine state control scheme is to keep the angle of attack at 0°, the yaw angle at 0°, the roll angle at 0°, and the climb rate at 0 m / s, and the control scheme of the control surface is that the integrated tilting ducted fan flap 7 adjusts in the range of 0°, the integrated tilting ducted fan elevator 9 adjusts in the range of -2° to +2°, the auxiliary aileron 8 is controlled by the flight control system, and the yaw control surface 12 and 13 are controlled by the flight control system. The control surface control system relies on the front wing integrated tilting ducted fan flap 7, the rear wing integrated tilting ducted fan elevator 9, the auxiliary aileron 8, and the linked yaw control surface 12 and 13 to adjust the attitude of the aircraft in the case of external interference. The front wing integrated tilting ducted fan 7 and the rear wing integrated tilting ducted fan 9 can be differentially adjusted to meet the non-uniform thrust requirement of the overall system in the cruise phase, and each sub-ducted fan in the integrated tilting ducted fan system outputs power according to the flight control system; In one embodiment, in the descent phase, the overall machine state control scheme is to keep the angle of attack at 0°, the yaw angle at 0°, the roll angle at 0°, and the descent rate at 3 m / s, and the control scheme of the control surface is that the integrated tilting ducted fan flap 7 adjusts in the range of -2° to +2°, the integrated tilting ducted fan elevator 9 adjusts in the range of -2° to +2°, the auxiliary aileron 8 is controlled by the flight control system, and the yaw control surface 12 and 13 are controlled by the flight control system. The control surface control system relies on the front wing integrated tilting ducted fan flap 7, the rear wing integrated tilting ducted fan elevator 9, the auxiliary aileron 8, and the linked yaw control surface 12 and 13 to adjust the attitude of the aircraft in the case of external interference. The front wing integrated tilting ducted fan 7 and the rear wing integrated tilting ducted fan 9 can be differentially adjusted to meet the non-uniform thrust requirement of the overall system in the cruise phase, and each sub-ducted fan in the integrated tilting ducted fan system outputs power according to the flight control system; In one embodiment, in the descent to vertical landing mode conversion phase, the overall body state control scheme is to keep the angle of attack at +10°, the yaw angle at 0°, the roll angle at 0°, and the climb rate at 0 m / s. The control scheme of the control surfaces is as follows: first, the integrated tilting ducted fan flap 7 is deflected downward by +75° to +85°, the integrated tilting ducted fan elevator 9 is deflected downward by +60° to +70°, the ailerons 8 on both sides are reset and controlled by the flight control system, and the yaw surfaces 12, 13 are controlled by the flight control system; when the full thrust is established, the tail propulsion ducted fan 16 is closed, the integrated tilting ducted fan flap 7 is deflected downward by +75° to +85°, the integrated tilting ducted fan elevator 9 is deflected downward by +80° to +90°, the ailerons 8 on both sides are deflected upward to the maximum angle and locked, and the yaw surfaces 12, 13 are locked at the zero deflection position; in the landing mode conversion phase, the control surface control system relies on the front wing integrated tilting ducted fan flap 7 and the rear wing integrated tilting ducted fan elevator 9 to adjust the attitude of the aircraft in the case of encountering external interference, and the front wing integrated tilting ducted fan flap 7 and the rear wing integrated tilting ducted fan elevator 9 can be differentially adjusted to meet the vector thrust requirement of the overall system in the mode conversion phase, and each sub-ducted fan in the integrated tilting arrangement ducted fan system outputs power according to the flight control system; In one embodiment, in the vertical landing phase, the overall body state control scheme is to keep the angle of attack at 2°, the yaw angle at 0°, and the roll angle at 0°. The control scheme of the control surfaces is as follows: the integrated tilting ducted fan flap 7 is deflected downward by +75° to +85°, the integrated tilting ducted fan elevator 9 is deflected downward by +80° to +90°, the ailerons 8 on both sides are deflected upward to the maximum angle and locked, and the yaw surfaces 12, 13 are locked at the zero deflection position. At this time, the control surface control system relies on the front wing integrated tilting ducted fan flap 7 and the rear wing integrated tilting ducted fan elevator 9 to adjust the attitude of the aircraft in the case of encountering external interference, and the front wing integrated tilting ducted fan flap 7 and the rear wing integrated tilting ducted fan elevator 9 can be differentially adjusted to meet the vector thrust requirement of the overall system in the vertical landing, and each sub-ducted fan in the integrated tilting arrangement ducted fan system outputs power according to the flight control system; In one embodiment, the aircraft can adopt coordinated control linkage yaw surfaces 12, 13, auxiliary ailerons 8, and rear wing integrated tilting ducted fan elevators 9 to realize yaw control or resist wind shear during cruising, climbing, and descending phases. When yawing to one side is needed, the linkage yaw surfaces 12, 13 are deflected to the same side, the same side rear wing integrated tilting ducted fan elevators 9 are deflected upward to maintain thrust, the opposite side rear wing integrated tilting ducted fan elevators 9 are deflected downward to maintain thrust, the same side auxiliary ailerons 8 are deflected downward, and the opposite side auxiliary ailerons 8 are deflected upward, thereby balancing the rolling force and realizing rapid yawing.

[0042] In one embodiment, the aircraft in cruise, climb, descent phase can use coordinated control linkage rudder surfaces 12, 13, auxiliary ailerons 8 and rear wing integrated tilting ducted fan elevators 9 to achieve roll control, when roll to one side is required, the same side rear wing integrated tilting ducted fan elevators 9 are up deflected to maintain thrust, the opposite side rear wing integrated tilting ducted fan elevators 9 are down deflected to maintain thrust, the same side auxiliary ailerons 8 are up deflected, the opposite side auxiliary ailerons 8 are down deflected, the linkage rudder surfaces 12, 13 are deflected to the opposite side, achieving fast roll while balancing yawing force.

[0043] In one embodiment, the aircraft in cruise, climb, descent phase can use coordinated control linkage rudder surfaces 12, 13, auxiliary ailerons 8, front wing integrated tilting ducted fan flaps 7 and rear wing integrated tilting ducted fan elevators 9 to achieve coordinated turn control, when coordinated turn to one side is required, the front wing integrated tilting ducted fan flaps 7 are slightly down deflected, the same side rear wing integrated tilting ducted fan elevators 9 are slightly down deflected and thrust is reduced, the opposite side rear wing integrated tilting ducted fan elevators 9 are slightly down deflected and thrust is increased, the same side auxiliary ailerons 8 are up deflected, the opposite side auxiliary ailerons 8 are down deflected, the linkage rudder surfaces 12, 13 are deflected to the same side, overcoming the problem of losing altitude during coordinated turn for conventional aircraft by adjusting the down deflection of integrated tilting ducted fan surfaces, achieving fast coordinated turn while balancing yawing force and rolling force.

[0044] In one embodiment, the aircraft in cruise, climb, descent phase can use coordinated control linkage rudder surfaces 12, 13, auxiliary ailerons 8, front wing integrated tilting ducted fan flaps 7 and rear wing integrated tilting ducted fan elevators 9 to achieve coordinated turn control, when coordinated turn to one side is required, the front wing integrated tilting ducted fan flaps 7 are slightly down deflected, the same side rear wing integrated tilting ducted fan elevators 9 are slightly down deflected and thrust is reduced, the opposite side rear wing integrated tilting ducted fan elevators 9 are slightly down deflected and thrust is increased, the same side auxiliary ailerons 8 are up deflected, the opposite side auxiliary ailerons 8 are down deflected, the linkage rudder surfaces 12, 13 are deflected to the same side, overcoming the problem of losing altitude during coordinated turn for conventional aircraft by adjusting the down deflection of integrated tilting ducted fan surfaces, achieving fast coordinated turn while balancing yawing force and rolling force.

[0045] In one embodiment, the energy control scheme can use the turbine shaft engine 27 to run at full power when the battery pack 22 fails or thermal management is out of control, the aircraft can use conventional aircraft glide to land; the energy control scheme can cut off the turbine shaft engine fuel supply when the turbine shaft engine 27 fails or fault is out of control, the battery pack 22 continues to supply power, the aircraft can use emergency landing; the energy control scheme can use conventional aircraft glide to land or use the tilting ducted fan to perform vertical take-off and landing when the number of faults is small when the tilting ducted fan part fails or fault is out of control.

[0046] In one embodiment, the established 5-seat improved joint wing tilting ducted fan layout vertical take-off and landing aircraft and the traditional 5-seat tilting ducted vertical take-off and landing aircraft have the following basic design parameters as shown in Table 1.

[0047] Table 1 Basic design parameters of the vertical take-off and landing aircraft

[0048] Based on the established 5-seat improved joint-wing tilt duct fan layout vertical take-off and landing aircraft and the traditional 5-seat tilt duct vertical take-off and landing aircraft, the modal conversion process power simulation is carried out, and the actual power obtained is as shown in Figure 10

[0049] In this embodiment, the 5-seat improved joint-wing tilt duct fan layout vertical take-off and landing aircraft compared with the traditional 5-seat tilt duct vertical take-off and landing aircraft, in the modal conversion process presents the characteristics of power demand first increases and then decreases. The reason is that in the low-speed initial stage, the distributed small diameter duct fan compared with the traditional large size duct fan has the problem of insufficient aerodynamic efficiency, resulting in larger required power; with the gradual improvement of the speed of the aircraft in the acceleration process, the efficiency of the distributed duct fan is gradually improved, and the kermel effect begins to play the role of lift increase, so that the power demand is significantly reduced in the latter stage of the modal conversion.

[0050] Although the embodiments of the present application have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and modifications to the above-mentioned embodiments without departing from the principles and purposes of the present application within the scope of the present application.​

Claims

1. An improved tilt ducted fan layout vertical take-off and landing aircraft characterized by The application relates to an improved joint wing structure layout and a tilting duct fan system integrated with the same. The improved joint wing structure layout comprises a front wing (1), a rear wing (4), a vertical connecting wing surface (2), a vertical stabilizer (5) and a fuselage (6). The front wing (1) is divided into a front wing inner wing surface (1a) and a front wing outer wing surface (1b) by the vertical connecting wing surface (2) and adopts a backward swept wing with an up-angle configuration; the trailing edge of the front wing inner wing surface (1a) is provided with a front wing integrated duct fan flap (7), and the trailing edge of the front wing outer wing surface (1b) is provided with an aileron (8), and the wing tip of the aileron (8) is provided with a wing tip winglet (10). The rear wing (4) is arranged above the front wing (1) through the vertical connecting wing surface (2) at both ends, is arranged above the tail of the fuselage (6) through the vertical stabilizer (5) at the middle, adopts a forward swept wing configuration, and is provided with a rear wing integrated duct fan elevator surface (9) at the trailing edge close to the vertical stabilizer (5). The trailing edge of the vertical connecting wing surface (2) is provided with a first rudder surface (13), and the trailing edge of the vertical stabilizer (5) is provided with a second rudder surface (12). The tilting duct fan system comprises the front wing integrated duct fan flap (7), the rear wing integrated duct fan elevator surface (9) and a tail propelling duct fan (16). The front wing integrated duct fan flap (7) and the rear wing integrated duct fan elevator surface (9) are connected with a fixed wing part (17) through stepless adjustable rotating mechanisms and can be independently tilted in a range of -10 DEG to +95 DEG. The left and right parts of the rear wing integrated duct fan elevator surface (9) can be differentially deflected, the differential deflection angle is not more than + / - 5 DEG, the thrust vector layout forms an eight-shaped pattern and is used for generating a same-direction rolling moment while generating a yawing moment.

2. An improved wing-in-ground-effect vehicle according to claim 1, characterised in that: The backward sweep angle of the front wing (1) ranges from 15 DEG to 35 DEG, and the up-angle ranges from 5 DEG to 20 DEG.

3. An improved wing-in-ground-effect vehicle according to claim 1, characterised in that: The forward sweep angle of the rear wing (4) ranges from 30 DEG to 50 DEG. The front wing integrated duct fan flap (7) comprises a front wing arranged duct fan group (23), a front wing arranged duct fan tilting mechanism (31) for driving the tilting of the front wing arranged duct fan group (23) and a front wing trailing edge extended duct fan nozzle structure (29) integrated in a bearing frame.

4. An improved wing-in-ground-effect vehicle according to claim 1, characterised in that: The rear wing integrated duct fan elevator surface (9) comprises a rear wing arranged duct fan group (20), a rear wing arranged duct fan tilting mechanism (32) for driving the tilting of the rear wing arranged duct fan group (20) and a rear wing trailing edge extended duct fan nozzle structure (30) integrated in a bearing frame. The tilting duct fan system is driven by a hybrid power system which comprises a turbine shaft engine (27), a generator system (24), a battery pack (22) and a converter (26); the turbine shaft engine (27) is operated at full power in a vertical take-off and landing and mode conversion stage and charges the battery pack (22) and is operated at an efficient power state in a cruising stage.

5. An improved wing-in-ground-effect vehicle according to claim 1, characterised in that: A hierarchical control architecture is adopted, comprising:

6. A method for controlling the improved joined wing tilswath and ducted fan layout vertical take off and landing aircraft of any of claims 1-5, characterized by, ​ An outer loop attitude control loop configured to receive a desired attitude angle command and calculate a required control moment to be applied on the body axis according to the error between the desired attitude and the actual attitude; An inner loop vector thrust control loop operatively coupled to the outer loop attitude control loop configured to receive the control moment command calculated by the outer loop attitude control loop, solve and output a command to drive the differential deflection of the rear wing integrated ducted fan elevator surface (9) to generate control moment preferentially by thrust vector.

7. The method of claim 6, wherein: During the vertical take-off phase, the front wing integrated ducted fan flap (7) is controlled to deflect downward by +75° to +95°, the rear wing integrated ducted fan elevator surface (9) is controlled to deflect downward by +80° to +95°, and the aileron (8) is controlled to deflect downward to the maximum angle to provide vertical lift and maintain attitude stability.

8. The method of claim 6, wherein: During the mode transition phase from vertical take-off to cruising climb, the following steps are performed: Start the tail propelling ducted fan (16) to maximum power; Keep the front wing integrated ducted fan flap (7) and the rear wing integrated ducted fan elevator surface (9) in a large angle downward deflection state to provide lift; As the airspeed increases, gradually tilt the front wing integrated ducted fan flap (7) and the rear wing integrated ducted fan elevator surface (9) back to near 0° cruising state to gradually transfer the lift responsibility to the wing aerodynamic surface.

9. The method of claim 6, wherein: When the aircraft needs to make coordinated turns, the rear wing integrated ducted fan elevator surface (9) is controlled to deflect differentially to make the lateral component of the thrust force provide a yawing moment, while the axial component of the moment provides a rolling moment, and the differential adjustment of the aileron (8) is used to balance the excess rolling moment generated by thrust vectoring.

10. The method of claim 6, wherein: A fault-tolerant control strategy is also included: when the turbine shaft engine (27) in the hybrid power system fails, its fuel supply is cut off, the battery pack (22) is used to power the tilting ducted fan system, and an emergency landing is performed; when a single or multiple ducted fans fail, the power and tilt angle of the remaining normal working ducted fans are adjusted to maintain controllable flight or safe landing of the aircraft.

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