Tailstock type three-duct vertical take-off and landing aircraft and control method thereofTechnical Field
The invention relates to the technical field of aircrafts, in particular to a tailstock type three-duct vertical take-off and landing aircraft and a control method thereof.
Background
In recent years, with the wide application of unmanned aerial vehicles in various fields, the use environment and the operation task of the unmanned aerial vehicle are increasingly complex. The convenience and safety of the take-off and landing scheme are important factors for determining the continuous operation capability of the unmanned aerial vehicle in severe environments such as sea surfaces, mountain areas and the like. Therefore, the function characteristics of vertical take-off and landing have important significance for application expansion of the unmanned aerial vehicle. The multi-rotor unmanned aerial vehicle and the fixed-wing unmanned aerial vehicle have advantages in the aspects of vertical take-off and landing and high-speed cruising respectively, and how to fully combine the two advantages is a key problem for solving the large-scale application of the unmanned aerial vehicle in a limited environment.
The vertical take-off and landing aircrafts are divided into three main categories of tilting rotor type, compound type and tailstock type, for example, the Chinese patent literature with publication number of CN108482668A discloses a tilting type vertical take-off and landing aircrafts, and the Chinese patent literature with publication number of CN105923154A discloses a tandem type double-rotor fixed wing compound type vertical take-off and landing aircrafts. The tilting type vertical take-off and landing aircraft is complex in control in the tilting process, high in technical difficulty and high in risk, the composite type vertical take-off and landing aircraft comprises two sets of power systems for vertical take-off and landing and plane flight propulsion, so that the effective load is low, the flying resistance of a fixed wing caused by exposed blades is high, and the tailstock type vertical take-off and landing aircraft is arranged between the two power systems, so that the vertical take-off and landing aircraft not only has better load capacity, but also reduces the control complexity, and is the outline layout and the control form of the key development of the conventional vertical take-off and landing aircraft.
In the prior study, the elastic rotor tail seat type unmanned aerial vehicle of Aerovel company, TERN 'gull' tail seat type unmanned aerial vehicle proposed by Norger company in U.S. and VD-200 tail seat type unmanned aerial vehicle developed in China all adopt open propellers and integrated or longer wing structures, so that better flat flight performance can be achieved, but the problems of transition state stability, vertical take-off and landing flight resistance and the like are not considered, and the whole efficiency and safety of the aircraft are reduced due to the fact that a power system is exposed.
Therefore, it is a problem that needs to be solved by those skilled in the art to provide an aircraft that can take off and land vertically, cruises at high speed, and has higher efficiency and safety.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a tailstock type three-duct vertical take-off and landing aircraft, which can take off and land vertically and cruises in a fixed wing mode, can efficiently execute tasks in a scene with limited environment, and the unique design of the tailstock type three-duct vertical take-off and landing aircraft greatly improves the overall efficiency and the safety.
A tailstock type three-duct vertical take-off and landing aircraft comprises an aircraft body, wherein the front section of the aircraft body is an airborne equipment cabin, the middle section of the aircraft body is a load cabin, and the rear section of the aircraft body is a power cabin;
A pair of foldable wing parts are symmetrically arranged on two sides of the load cabin, and each foldable wing part comprises a first straight wing fixed on the outer wall of the load cabin, a second straight wing fixed on the first straight wing in a foldable manner, and an aileron arranged on the second straight wing;
Three power components are uniformly fixed on the outer wall of the power cabin along the circumferential direction, and each power component comprises a duct fixed with the outer wall of the power cabin, a motor fixed in the duct and a propeller connected with the output end of the motor;
The tail end of the power cabin is uniformly fixed with a plurality of tail wing parts, and each tail wing part comprises a tail wing fixed with the tail end of the power cabin, a tail wing rudder arranged on the tail wing and a landing gear arranged at the tail end of the tail wing;
And a flight controller for controlling the foldable wing part, the power part and the tail part and other necessary airborne equipment are arranged in the airborne equipment cabin and are used for controlling the flight process of the aircraft.
The tailstock type three-duct vertical take-off and landing aircraft provided by the invention can take off and land vertically and cruises in a fixed wing mode, the overall efficiency and the safety are greatly improved, and the technical problems of complex control system, high flight resistance and weak load capacity of the conventional vertical take-off and landing aircraft are solved.
Preferably, the load compartment is provided with a back compartment door and an abdomen compartment door. The belly cabin door can be used for military material delivery, and the back cabin door can be used for logistics transportation.
The power cabin is mainly used for placing a large-capacity lithium battery, a generator, fuel oil and the like. The fuel oil is supplied to the generator to generate electricity, the lithium battery is charged by the continuous power generation of the engine, and the lithium battery is used for supplying power to the motor.
Further, the wing profiles of the first straight wing and the second straight wing are NACA6412 and are connected through a hinge, the second straight wing is in a folded state when the aircraft vertically flies, and is in an unfolded state when the aircraft horizontally flies, and the maximum folding angle of the second straight wing is 120 degrees.
Further, the surfaces of the first straight wing and the second straight wing are covered with solar photovoltaic films, and electric energy output of the solar photovoltaic films is connected with a lithium battery arranged in the power cabin. The wing covers the solar photovoltaic film, so that the solar photovoltaic film has excellent performances of ultra-long endurance, silent flight, low emission and the like.
Further, one of the three power components is fixed under the power cabin, the other two power components are symmetrically fixed above the power cabin, the fixed angle interval between the three power components is 120 degrees, and the maximum available pulling force provided by the power components is not less than the takeoff weight of the unmanned aerial vehicle.
Further, two motors which are opposite to each other are arranged in the duct along the axial direction, each motor is connected with a corresponding propeller, the propellers are two-blade propellers meeting the tension requirement, the model is 2788, and the installation mode is coaxial inversion.
Further, the inner wall of the duct is provided with an annular cutting groove for inhibiting the tip vortex of the propeller, the length ratio of the cutting groove to the submerged part of the blade is 2:1, and the outer wall of the duct is provided with a streamline wing structure for increasing lift.
The aircraft body is designed to be a streamline with the cross section being bilateral symmetry, and the tail wing part and the power part are axially overlapped, so that the control surface control effect is improved to the greatest extent. Ailerons and tail rudders can deflect under the drive of a steering engine and a transmission mechanism.
The invention also provides a control method of the tailstock type three-duct vertical take-off and landing aircraft, wherein the task execution process of the aircraft comprises seven stages of ground preparation, vertical take-off, vertical-to-horizontal mode switching, task cruising, horizontal-to-vertical mode switching, vertical landing and ground recovery, and the control method of each stage comprises the following steps:
The aircraft realizes rapid deployment through modularized assembly, relevant system tests are carried out after the aircraft is deployed and the aircraft enters a state to be flown, at the moment, the aircraft body is kept in a vertical state with the ground, and the foldable wing parts are in a folded state;
The method comprises the steps of starting a motor, keeping idling, adjusting the motor rotation speed of each power component after confirming that the operation is normal, separating an aircraft from the ground after the thrust is greater than the gravity, starting accelerating and rising, keeping a folding state of the foldable wing component all the time before the flying speed reaches a designated mode switching speed, adjusting the position and the posture of the aircraft by adjusting the motor rotation speed of each power component, unfolding the foldable wing component when the aircraft enters a target height interval and the flying speed is greater than the designated mode switching speed, and enabling the aircraft to enter a mode switching stage;
The vertical-to-horizontal mode switching is carried out, namely, the engine body generates pitching moment by adjusting the rotating speed of a motor of each power part and the control surface of the tail wing, the pitching angle is adjusted from 90 degrees in the vertical rising process to a balancing value in the cruising state, and in the process, the flying height of the aircraft is gradually stabilized until the cruising flying state is finally established;
Task cruising, wherein the thrust of each power part is always equal in the stage, the attitude regulation and control of the aircraft is only determined by the control quantity of each control surface, and the specific control mode is to realize yaw and pitch movements of the aircraft through the tail wing control surface and control the rolling movement of the aircraft through the aileron;
The method comprises the following steps of switching a horizontal-rotation vertical mode, namely enabling a machine body to generate pitching moment by adjusting the rotating speed of a motor of each power part and a control surface of a tail wing, adjusting the pitching angle from a trimming value in a cruising state to 90 degrees of vertical landing, and gradually increasing the flying height of an aircraft in the process until a hovering flying state is finally established;
After the switching of the horizontal rotation and vertical falling modes is completed, folding the foldable wing parts of the aircraft, and regulating the position and the posture of the aircraft by regulating the rotation speed of the motor of each power part so as to gradually lower the height of the aircraft;
And (3) ground recovery, namely when the aircraft finishes the mission and falls to the ground, carrying out relevant maintenance and disassembly and transportation.
Compared with the prior art, the invention has the following beneficial effects:
1. The invention adopts a tailstock type vertical take-off and landing mode to take off and land, and adopts a fixed wing mode to carry out cruising flight in the plane flight stage. The vertical starting force and the horizontal flying force of the aircraft are combined into a whole, the overall efficiency is higher, the propeller of the aircraft is arranged in the duct by adopting the duct device, the aircraft is safer and has low noise, and the duct can reduce the induced resistance of the blade tip, has higher thrust and efficiency compared with the propeller with the same propeller disk diameter without the duct structure, so that the size of the propeller can be properly reduced and enough power can be provided.
2. The foldable wing designed by the invention can reduce the windward area of the aircraft in the take-off and landing process, and improves the anti-interference capability and the flight stability in the working process.
3. The invention adopts a range-extending type oil-electricity hybrid propulsion system. The propeller is driven by a motor, and the electric energy is supplemented by continuous power generation of the engine to increase endurance.
Drawings
FIG. 1 is a schematic view of the overall structure of a tailstock type three-duct vertical take-off and landing aircraft according to the present invention;
FIG. 2 is a schematic diagram showing the assembly and disassembly of the components of the present invention;
FIG. 3 is a schematic view of the aircraft during a horizontal flight phase;
FIG. 4 is a schematic view of the structure of an aircraft during a vertical takeoff and landing phase;
FIG. 5 is a schematic structural view of a power component;
Fig. 6 is a schematic illustration of a mission execution process for an aircraft of the present invention.
Detailed Description
The invention will be described in further detail with reference to the drawings and examples, it being noted that the examples described below are intended to facilitate the understanding of the invention and are not intended to limit the invention in any way.
As shown in fig. 1 and 2, a tailstock type three-duct vertical take-off and landing aircraft comprises an aircraft body 1, wherein the front section of the aircraft body 1 is an onboard equipment cabin 101, the middle section is a load cabin 102, and the rear section is a power cabin 103.
The load compartment 102 is provided with a back door 1021 and an abdominal door 1022. The belly door 1022 may be used for military supplies and the back door 1021 may be used for logistic transport.
A pair of foldable wing parts 2 are symmetrically arranged on both sides of the load compartment 102, and each foldable wing part 2 comprises a first straight wing 201 fixed to the outer wall of the load compartment 102, a second straight wing 202 foldably fixed to the first straight wing 201, and an aileron 203 arranged on the second straight wing 202.
Three power components 3 are uniformly fixed on the outer wall of the power cabin 103 along the circumferential direction, and each power component 3 comprises a duct 301 fixed with the outer wall of the power cabin 103, a motor 303 fixed in the duct 301 and a propeller 302 connected with the output end of the motor 303.
A plurality of tail units 4 are uniformly fixed to the tail end of the power compartment 103, and each tail unit 4 comprises a tail 401 fixed to the tail end of the power compartment 103, a tail rudder 402 arranged on the tail 401, and a landing gear 403 arranged at the tail end of the tail 401.
The onboard equipment bay 101 is provided with flight controls for controlling the foldable wing parts 2, the power parts 3 and the tail parts 4 and other necessary onboard equipment for controlling the flight of the aircraft.
In the embodiment of the invention, the wing sections of the first straight wing 201 and the second straight wing 202 are NACA6412 and are connected through a hinge, and the second straight wing 202 is in an unfolding state when the aircraft flies horizontally, as shown in FIG. 3, the wing is 5m long after being unfolded, and the average chord length is 0.3 m. The second straight wing 202 is folded when the aircraft is vertically flown, as shown in fig. 4, the maximum folding angle of the second straight wing 202 is 120 degrees.
The surfaces of the first straight wing 201 and the second straight wing 202 are covered with solar photovoltaic films, and the electric energy collected by the solar photovoltaic films is stored in a high-capacity lithium battery positioned in the power cabin 103.
One of the three power components is fixed under the power cabin 103, the other two power components are symmetrically fixed above the power cabin 103, the fixed angle interval between the three power components is 120 degrees, and the maximum available pulling force provided by the power components is not less than the takeoff weight of the unmanned aerial vehicle.
As shown in fig. 5, two motors 303 are arranged in the duct 301 along the axial direction, each motor 303 is connected with a corresponding propeller 302, the propellers 302 are two-blade propellers meeting the tension requirement, the model is 2788, and the installation mode is coaxial reverse rotation, so that the reactive torque of the upper propeller and the lower propeller are mutually offset when the power component works, and the unstable attitude of the aircraft is avoided.
The inner wall of the duct 301 is provided with an annular cutting groove 304 for inhibiting the tip vortex of the propeller, the outer wall of the duct 301 is provided with a streamline wing structure 305 for increasing lift, and the aerodynamic performance of the aircraft is improved.
The aircraft fuselage 1 is designed to be a streamline with a laterally symmetrical cross section, and the tail wing part and the power part are axially overlapped so as to improve the control surface control effect to the greatest extent. Ailerons 203 and tail rudders 402 can deflect under the drive of steering engines and transmission mechanisms.
As shown in FIG. 6, the task execution process of the aircraft of the invention is divided into seven stages of ground preparation, vertical take-off, vertical-to-horizontal mode switching, task cruising, horizontal-to-vertical mode switching, vertical landing and ground recovery, and the control method of each stage is as follows:
The aircraft realizes rapid deployment through modularized assembly, relevant system tests are carried out after the aircraft is deployed and the aircraft enters a state to be flown, at the moment, the aircraft body is kept in a vertical state with the ground, and the foldable wing parts are in a folded state;
The vertical take-off comprises the steps of starting a motor and keeping idle speed, regulating the motor rotation speed of each power component after confirming that the operation is normal, enabling an aircraft to leave the ground after the thrust is greater than the gravity, starting accelerating and rising, and keeping the folding wing component in a folding state all the time before the flying speed reaches the designated mode switching speed, wherein the position and the gesture of the aircraft are regulated and controlled by regulating the motor rotation speed of each power component. When the aircraft enters the target altitude interval and the flight speed is greater than the designated modal switching speed, the foldable wing part is unfolded, and the aircraft enters the modal switching stage;
And (3) switching a vertical-to-horizontal mode, namely enabling the engine body to generate pitching moment by adjusting the rotating speed of a motor of each power part and the control surface of the tail wing, and adjusting the pitching angle from 90 degrees in the vertical lifting process to a trimming value in the cruising state, wherein the flying height of the aircraft is gradually stabilized in the process until the cruising flying state is finally established.
Task cruising, wherein the thrust of each power part is always equal in the stage, the attitude regulation and control of the aircraft is only determined by the control quantity of each control surface, and the specific control mode is to realize yaw and pitch movements of the aircraft through the tail wing control surface and control the rolling movement of the aircraft through the aileron;
The method comprises the following steps of switching a horizontal-rotation vertical mode, namely enabling a machine body to generate pitching moment by adjusting the rotating speed of a motor of each power part and a control surface of a tail wing, adjusting the pitching angle from a trimming value in a cruising state to 90 degrees of vertical landing, and gradually increasing the flying height of an aircraft in the process until a hovering flying state is finally established;
After the switching of the horizontal rotation and vertical falling modes is completed, folding the foldable wing parts of the aircraft, and regulating the position and the posture of the aircraft by regulating the rotation speed of the motor of each power part so as to gradually lower the height of the aircraft;
And (3) ground recovery, namely when the aircraft finishes the mission and falls to the ground, carrying out relevant maintenance and disassembly and transportation.
The foregoing embodiments have described in detail the technical solution and the advantages of the present invention, it should be understood that the foregoing embodiments are merely illustrative of the present invention and are not intended to limit the invention, and any modifications, additions and equivalents made within the scope of the principles of the present invention should be included in the scope of the invention.