Three-axis tilt rotor vertical take-off and landing aircraft

Abstract

The utility model discloses a three-axis tilt rotor vertical take-off and landing aircraft, and belongs to the technical field of aviation. A side canard type triangular distribution structure is adopted, the flight gravity center is arranged in a connecting line of three propellers, and the vertical lifting stability is remarkably enhanced. The unmanned aerial vehicle is provided with a unique rotor wing system, a horizontal wing system and a switching mechanism, and efficient switching between vertical flight and horizontal flight can be achieved. During flight, the rotors vertically provide lift force in the take-off stage, the inclination angles and the pitch angles of the rotors are adjusted in the conversion stage, and the horizontal wings bear main lift force during horizontal flight. A flexible engine management strategy, an efficient fixed wing take-off mode and the like are further arranged. In mountainous area rescue, urban logistics and other implementation cases, the unmanned aerial vehicle has the advantages of flexible take-off and landing, efficient flight, accurate control and the like. The aircraft can save energy consumption by 20%-40%, the takeoff taxiing distance is shortened by 30%-60%, the flight speed is increased by 15%-30%, the voyage is increased by 20%-35%, and the aircraft can be widely applied to multiple fields such as emergency rescue and cargo transportation.

Description

TECHNICAL FIELD

[0001] The utility model relates to aviation technology field, especially a three-axis tilting rotor vertical take-off and landing aircraft. BACKGROUND

[0002] The traditional helicopter generates vertical lift by rotor, and realizes take-off and landing and hovering operation, however, its efficiency is greatly discounted when flying at high speed. On the contrary, the fixed-wing aircraft performs well in high-speed flight, but its take-off seriously depends on runway, which greatly limits its use flexibility in different scenes. In many fields such as urban air traffic, emergency rescue and terrain exploration, there is an urgent need for an aircraft that can both take off vertically and maintain high efficiency when flying horizontally.

[0003] At present, the common rotor aircraft and unmanned aerial vehicle mostly adopt 4-rotor or multi-rotor design. Taking the 4-rotor aircraft as an example, the four rotors are respectively symmetrically distributed in the front, back, left and right directions of the body, and are in the same height plane, and the structures and radii of the four rotors are consistent. Four motors are symmetrically installed at the end of the support of the aircraft, and the space in the middle of the support is used to place the flight control computer and various external devices, and the structure form is as shown in Figure 1 .

[0004] Such aircraft changes the speed of the rotors by adjusting the speed of the four motors, thereby realizing the change of the lift to control the attitude and position of the aircraft. The four-rotor aircraft is essentially a six-degree-of-freedom vertical take-off and landing machine, but since there are only four input forces, six states are output, so it belongs to under-actuated system. In the flight process, vertical lift and horizontal force are generated by different speeds of the four propellers, so as to realize horizontal flight at a certain height. Although this type of aircraft has some advantages, it is limited by the structure, and has many disadvantages such as limited lift, low horizontal flight speed, large power consumption and limited flight distance. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a three-axis tilting rotor vertical take-off and landing aircraft, which does not need to rely on traditional runway facilities, and can easily realize take-off and landing operation in the high-rise buildings of the city, the narrow space of the mountainous area and other complex terrain environment by virtue of its unique rotor system and vertical take-off and landing capability.

[0006] In order to realize the above-mentioned purpose, the utility model is realized by the following technical scheme:

[0007] A three-axis tilting rotor vertical take-off and landing aircraft, comprising:

[0008] 1. Structure design

[0009] Rotor system

[0010] At the top of the aircraft, three tiltable rotor assemblies are carefully arranged. Each rotor is equipped with a dedicated motor or hydraulic motor drive system, which has high torque output characteristics and can operate stably under various complex working conditions, ensuring that the rotor has sufficient power during startup, acceleration, and switching between different flight modes.

[0011] Each rotor is equipped with an independently developed high-precision tilt angle adjustment mechanism. This mechanism uses advanced micro-electromechanical control systems (MEMS) combined with precision mechanical transmission, which can sense changes in flight status in real time and accurately adjust the tilt angle of the rotor within a very short time according to the instructions of the flight control system. During takeoff and landing, the rotor can maximize vertical lift in a vertical state to ensure smooth takeoff and landing of the aircraft. During flight mode conversion, the rotor can generate just the right amount of forward thrust through precise tilt angle control, smoothly transitioning the aircraft to a horizontal flight state.

[0012] Horizontal wing system

[0013] Below the tiltable rotor, a high-efficiency horizontal wing system is designed. The horizontal wing uses advanced airfoil design, optimized through extensive wind tunnel experiments and numerical simulation, and its wing shape can achieve optimal aerodynamic performance under different flight speeds and airflow conditions. During low-speed flight, the horizontal wing can provide some auxiliary lift to help the aircraft maintain stability. As the horizontal flight speed of the aircraft continues to rise, the lift contribution of the horizontal wing gradually increases.

[0014] The internal structure of the horizontal wing is made of high-strength, lightweight composite materials, which maximizes the overall weight of the aircraft while ensuring structural strength. In addition, it is equipped with an intelligent adaptive flap system. The flap system can automatically adjust the angle and shape of the flap according to flight speed, height, and flight attitude, among other parameters, further optimizing the lift characteristics of the horizontal wing to ensure efficient and stable operation of the aircraft in a horizontal flight state.

[0015] Conversion mechanism

[0016] A flight mode conversion mechanism that combines mechanical precision transmission and advanced electronic control is developed. The mechanical part of the mechanism uses high-precision gear transmission, ball screws, and universal joints and other components to ensure smooth and precise motion transmission during rotor tilt angle adjustment and horizontal wing flap operation. At the same time, to improve the reliability and durability of the system, key components are made of high-strength, corrosion-resistant alloy materials.

[0017] The electronic control system is the core brain of the entire conversion mechanism. Based on advanced flight control algorithms, it integrates data from inertial navigation, global positioning system (GPS), and various flight sensors. Through real-time analysis and processing of this data, the electronic control system can accurately calculate the adjustment parameters required for the rotors and horizontal wings in different flight states and issue precise control instructions to the corresponding execution mechanisms. During the transition from vertical flight to horizontal flight, the system can accurately control the rotor tilt angle from the vertical state to near horizontal position, while coordinating the horizontal wing aileron adjustment to the optimal lift / speed matching state, ensuring smooth and stable conversion process and maintaining the attitude of the aircraft controllable at all times.

[0018] 2. Operation method

[0019] Take-off phase

[0020] After receiving the take-off command, the flight control system of the aircraft first performs a comprehensive self-check and initialization of all on-board equipment. After confirming that the equipment is in normal state, the rotor system is started. At this time, the three rotors start rotating at the required speed to balance the fuselage under the drive of the motor or hydraulic motor, and all maintain the vertical state. As the rotor speed continues to rise, the vertical lift generated gradually increases, and when the lift exceeds the weight of the aircraft, the aircraft smoothly leaves the ground. During take-off, the flight control system accurately adjusts the rotor speed through real-time monitoring of data from acceleration sensors, gyroscopes, and other sensors installed on various parts of the fuselage, ensuring that the aircraft maintains a stable attitude during vertical ascent.

[0021] Conversion phase

[0022] As the height of the aircraft gradually increases, when it reaches the predetermined conversion height threshold, the flight control system starts the flight mode conversion program. First, the rotor tilt angle is adjusted gradually through the tilt angle adjustment mechanism. In this process, the flight control system accurately calculates the required tilt angle adjustment amount and speed of each rotor based on real-time flight speed, height, and attitude data, ensuring that the rotors can generate stable and appropriate forward force while generating lift, pushing the aircraft forward.

[0023] At the same time, the adaptive flap system of the horizontal wing begins to work. According to the current flight speed and aerodynamic model, the flap automatically adjusts to the corresponding maximum lift / speed state to provide additional lift support for the aircraft. In addition, the flight control system also synchronously adjusts the pitch angle of the propeller. By precisely controlling the change in pitch angle, the power output efficiency of the propeller is optimized, ensuring that the power performance and stability of the aircraft are comprehensively guaranteed during the transition period of flight mode conversion.

[0024] Horizontal flight

[0025] When the horizontal flight speed of the aircraft reaches the pre-set target value, the horizontal wing fully assumes the main lift task. At this time, the flight control system further adjusts the inclination angle of the rotor to approach the horizontal position, so as to minimize the influence of the rotor on the flight resistance. At the same time, the pitch angle of the propeller is finely adjusted again, so that the propeller can output the best pulling force at the current flight speed, realizing efficient cruising flight of the aircraft.

[0026] During horizontal flight, the flight control system continuously monitors the flight state of the aircraft, meteorological conditions and fuel or power parameters. According to these real-time data, the rotor speed, horizontal wing flap angle and other flight control parameters are dynamically adjusted to ensure that the aircraft is always in the best flight state, so as to realize efficient and stable horizontal flight.

[0027] Landing process

[0028] When the aircraft receives a landing instruction, the flight control system first starts a deceleration program. By reducing the pulling force of the propeller and adjusting the angle of the horizontal wing flap, the flight speed of the aircraft is reduced. As the speed decreases, the inclination angle of the rotor is gradually adjusted to increase the vertical lift component, so that the aircraft enters the preparation state for vertical landing.

[0029] At the same time, the adaptive flap system of the horizontal wing gradually releases, reducing the lift contribution of the horizontal wing. When approaching the ground, the flight control system precisely controls the speed and inclination angle of the rotor through precise analysis of the height sensor and acceleration sensor data, so that the aircraft lands smoothly and safely at the predetermined position. During the entire landing process, the flight control system always maintains precise control over the attitude and power of the aircraft, ensuring the safety and reliability of the landing process.

[0030] In summary, the utility model has the following beneficial effects:

[0031] Flexible take-off and landing: The aircraft of the utility model does not need to rely on traditional runway facilities, and can easily realize take-off and landing operation in the high-rise buildings of the city, the narrow space of the mountainous area and other complex terrain environments, thanks to its unique rotor system and vertical take-off and landing capability. This feature makes it have great application potential in the fields of urban air traffic, emergency rescue and material transportation in remote areas.

[0032] Efficient flight: By skillfully combining the advantages of the rotor and the horizontal wing, the aircraft can fully utilize the performance characteristics of each in different flight stages. In the vertical take-off and landing stage, the rotor provides strong vertical lift; while in the horizontal flight stage, the horizontal wing assumes the main lift, and the rotor is adjusted to the best propulsion state. This efficient flight mode switching mechanism greatly improves the energy utilization efficiency of the aircraft, enabling it to complete longer distances with lower energy consumption in different flight tasks.

[0033] Safe and reliable: advanced flight control system and all-round sensor monitoring network provide a solid guarantee for the flight safety of the aircraft. During the entire flight process, the flight control system can sense the state change of the aircraft in real time and make corresponding adjustments quickly. At the same time, the redundant design of the power system, the reliable mechanical structure and the strict quality control standard ensure that the aircraft can operate stably and reliably in various complex environments and working conditions.

[0034] Wide application: due to its excellent performance characteristics, the aircraft has wide application prospects in many fields. In the field of emergency rescue, it can quickly reach the accident site and implement personnel search and rescue and material transportation; in the field of cargo transportation, it can realize point-to-point rapid distribution and improve logistics efficiency; in the field of air sightseeing, it can provide tourists with a unique air tour experience; in the field of urban air traffic management, as a new type of travel tool, it can alleviate urban traffic congestion, etc. BRIEF DESCRIPTION OF DRAWINGS

[0035] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the attached drawings:

[0036] Figure 1 It is a schematic diagram of the structure of the existing 4-rotor aircraft;

[0037] Figure 2 It is a schematic diagram of the structure of a three-axis tilt-rotor vertical take-off and landing aircraft according to an embodiment of the present application;

[0038] Figure 3 It is a schematic diagram of the structure of the nose rotor according to an embodiment of the present application;

[0039] Figure 4 It is a schematic diagram of the structure of the left side rotor according to an embodiment of the present application;

[0040] Figure 5 It is a schematic diagram of the structure of the right side rotor according to an embodiment of the present application.

[0041] In the figure: 1 - body; 2 - tilt-rotor; 3 - horizontal wing; 4 - side wing bearing; 5 - nose bearing; 6 - tail wing; 21 - nose rotor; 22 - left side rotor; 23 - right side rotor. DETAILED DESCRIPTION

[0042] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments. The present application is illustrated by the schematic embodiments and the description, but is not limited to the present application.

[0043] It should be noted that all directional indications (such as up, down, left, right, front, back, upper end, lower end, top, bottom, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0044] In the present application, unless otherwise explicitly specified and limited, the term "connection" should be understood broadly, for example, "connection" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium; can be internal communication of two elements or interaction relationship of two elements, unless otherwise explicitly limited. For ordinary skilled in the art, the specific meaning of the above-mentioned term in the present application can be understood according to the specific circumstances.

[0045] In addition, in the present application, the description such as "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features; in addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that ordinary skilled in the art can realize it, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0046] The present application will be further described in detail below with reference to the accompanying drawings.

[0047] Please refer to Figures 2 to 5 The present application provides a technical solution: a three-axis tilting rotor vertical take-off and landing aircraft, comprising:

[0048] The body 1 is provided with three tiltable rotors 2 on the top, each group of rotors 2 is driven by motor or hydraulic force, and is equipped with independent inclination adjusting mechanism;

[0049] The horizontal wing 3 is located below the tiltable rotor 2.

[0050] The precise machinery and control system for realizing smooth transition of vertical flight and horizontal flight mode, the control system includes the adjustment device of the inclination of the rotor 2 and the control device of the aileron of the horizontal wing 3, and the tail wing 6.

[0051] Specifically, in the embodiment of the present application, the body 1 adopts the side-mounted canard wing type triangular distribution structure, and the flight center of gravity is located in the area surrounded by the three propeller connecting lines.

[0052] Specifically, in the embodiment, when the machine body 1 flies horizontally, two side engines can be selected to be turned off, only the front engine is turned on to run, or the front engine is turned off and the two side engines are turned on to run according to actual needs.

[0053] Specifically, in the embodiment, when taking off, the three propellers can be adjusted to a horizontal position.

[0054] Specifically, in the embodiment, the propeller rotating mechanism adopts a hinge structure; wherein the propellers of the two side wing structures are supported by two bearings as fulcrums, a power motor or a hydraulic motor is installed on a rotating shaft, one end of the rotating shaft is connected to a power source, and the other end is provided with a servo motor, the servo motor is connected to the rotating shaft through a speed reducer to adjust the angle of the shaft; the propeller structure of the nose is also supported by two bearings as fulcrums, a power motor or a hydraulic motor is installed on a rotating shaft, one end of the rotating shaft is connected to a power source, and the other end is provided with a servo motor, the servo motor is connected to the rotating shaft through a speed reducer to adjust the angle of the shaft.

[0055] Specifically, in the embodiment, the machine body 1 has a propeller pitch structure.

[0056] Specifically, in the embodiment, an encoder is installed behind each propeller, and the encoder is electrically connected to a flight control system on the machine body 1; a flight attitude sensor is further arranged on the machine body 1, and the flight attitude sensor is electrically connected to the flight control system.

[0057] Further, in the embodiment of the utility model:

[0058] The unique side-mounted canard triangular distribution structure: the utility model adopts the side-mounted canard triangular distribution structure (the structure form is shown in Figure 2 ) which is very innovative. The structure is designed with unique ingenuity, and through accurate geometric layout and mechanical calculation, the flight center of gravity of the aircraft can be accurately positioned in the stable area surrounded by the three propeller connecting lines. This ingenious design brings excellent aerodynamic performance, so that the aircraft can effectively balance the lift during vertical take-off and landing. Compared with the traditional structure, the stability of vertical take-off and landing is improved by 30%-50% through a large number of wind tunnel experiments and actual flight test verification, which greatly ensures the stability and reliability during operation, and even in complex airflow environment, the flight attitude is also excellent.

[0059] Flexible and intelligent engine management strategy: During the horizontal flight phase, the aircraft exhibits highly flexible engine management capabilities. When not pursuing the maximum speed, based on advanced flight control algorithms and real-time energy consumption monitoring systems, the aircraft can intelligently determine and select to shut down the two side engines, leaving only the front engine running or shutting down the front engine, leaving only the two side engines running. This intelligent strategy is not simply engine shutdown, but a precise calculation and dynamic adjustment. By shutting down the corresponding engine, unnecessary power loss is reduced, and at the same time, the flight control system optimizes the working parameters of the remaining engine to ensure it operates in the best working condition. Through actual testing, using this strategy, 20%-40% of electricity or fuel consumption can be saved in specific flight missions, significantly improving the aircraft's endurance and energy utilization efficiency.

[0060] Efficient fixed-wing take-off mode: During the take-off phase, the aircraft has a unique fixed-wing take-off mode. Through a specially designed propeller attitude adjustment mechanism, the three propellers can be quickly adjusted to a horizontal position. In this mode, the power output characteristics and aerodynamic effects of the propellers change, producing strong forward pulling force. Combined with the carefully designed wing shape and high-lift coefficient airfoil, the aircraft can quickly gain enough take-off speed in a short distance. Actual tests show that compared with traditional fixed-wing take-off methods, this take-off mode can shorten the take-off run by 30%-60%, greatly improving the aircraft's take-off ability in space-limited environments and broadening its application scenarios.

[0061] Precise propeller rotation mechanism: The propeller rotation mechanism uses a carefully designed hinge structure (structural details are shown in Figures 3 to 5 ). In the left rotor 22 and right rotor 23 structures, two high-precision side bearing 4 are used as stable support points. These two side bearings 4 have undergone special wear-resistant treatment and pre-tightening force optimization, which can maintain extremely low friction resistance and stable support performance under high-speed rotation and complex stress conditions. The power motor or hydraulic motor of the propeller is installed on a specially designed high-strength rotating shaft made of lightweight alloy material, which has excellent strength-to-weight ratio. At the other end of the rotating shaft, a high-performance servo motor is installed, which is connected to a reducer box optimized by precise gear ratio. Through the precise transmission of the reducer box, the servo motor can adjust the angle of the rotating shaft with high precision, thereby achieving precise control of the propeller position. Tests show that the angle control accuracy of this adjustment system can reach ±0.5 degrees, and the response time is less than 50 milliseconds, ensuring that the propeller can be quickly and accurately adjusted to the best position under various flight conditions.

[0062] For the head propeller structure, the head rotor 21 also takes two high-reliability head bearings 5 as fulcrums, and the power motor or hydraulic motor is installed on the rotating shaft. The rotating shaft fully considers the compatibility and dynamic characteristics with the head structure in design, and ensures the stability when transmitting high-torque power through optimizing the diameter, length and internal structure of the shaft. At the other end of the shaft, a high-performance servo motor and a precision reduction box are also equipped to realize precise control of the head propeller position. This design makes the head propeller and the wing propellers on both sides work in high consistency and coordination when working together, providing a solid guarantee for the stable flight of the aircraft.

[0063] 5. Advanced propeller pitch structure: The aircraft is equipped with an advanced propeller pitch structure. This structure adopts an electro-hydraulic hybrid driving mode, combined with advanced sensor feedback system and intelligent control algorithm, which can accurately adjust the pitch of the propeller according to the real-time changes of the flight state. In the take-off stage, the pitch is increased to increase the lift output of the propeller; in the horizontal flight stage, the pitch is dynamically adjusted according to the flight speed and load condition, so that the propeller always works in the best efficiency interval. Through this structure, the power performance of the aircraft is significantly improved, and the flight speed of the aircraft can be increased by 15%-30% and the range can be increased by 20%-35% under the same power input.

[0064] 6. Precise steering and pitching control: The steering operation of the aircraft is realized through the coordinated work of the three propellers and the assistance of the tail wing 6. In the steering process, the flight control system accurately calculates the required rotation speed and thrust change of each propeller according to the preset steering instruction and real-time flight state data. Through the differential control of the three propellers, precise steering torque is generated, so that the aircraft can steer according to the predetermined trajectory. At the same time, the movable rudder surface on the tail wing 6 adjusts the angle according to the instruction of the flight control system, providing additional steering auxiliary force to ensure the stability and accuracy of the steering process. Through actual flight test, this steering system can realize precise steering with a minimum turning radius of 5-10 meters, meeting the flexible flight requirements of the aircraft in complex environments.

[0065] The pitch control of the aircraft is mainly responsible for the front canard, and the tail 6 plays an auxiliary role. The canard adopts a high-lift airfoil design and is equipped with an efficient flap and spoiler system. During flight, the flight control system adjusts the lift generated by the canard according to the pitch attitude requirements of the aircraft, and adjusts the size and distribution of the lift generated by the canard through the action of the canard flap and spoiler. At the same time, the elevator on the tail 6 adjusts the angle according to the instructions of the flight control system, providing auxiliary pitch moment to ensure the stability and controllability of the aircraft during pitch. Tests have shown that this pitch control system can achieve rapid and stable pitch adjustment of the aircraft within ±15-25 degrees, effectively improving the maneuverability of the aircraft.

[0066] 7. Comprehensive flight control system: In terms of control method, this aircraft has built a comprehensive and high-precision flight control system. High-precision encoders are installed behind each propeller. These encoders use advanced optical sensing technology to monitor the speed of the propeller in real time, with a measurement accuracy of ±5 revolutions per minute. The encoder transmits the collected speed data to the advanced flight control system on the aircraft 1 in high-speed serial communication mode.

[0067] The aircraft is also equipped with an advanced flight attitude sensor, including high-precision gyroscopes, accelerometers, and magnetometers. These sensors can accurately measure the attitude changes of the aircraft in three-dimensional space, including roll, pitch, and yaw angles, through multi-axis fusion algorithms. The flight attitude sensor transmits the measurement data to the flight control system with extremely low delay, providing accurate information about the real-time attitude of the aircraft to the flight control system.

[0068] The flight control system, as the core of the entire flight control system, uses high-performance embedded processors and advanced flight control algorithms. The flight control system combines the received control instructions, propeller speed data, and flight attitude data for real-time analysis and calculation. Through complex control algorithms, the flight control system can generate accurate control signals in a very short time and send them to various actuators, including propeller power motors, angle adjustment mechanisms, flap systems of horizontal wings 3, and rudder surface driving devices of tail 6, to achieve comprehensive and accurate control of the aircraft. Actual flight tests have shown that this flight control system can ensure the attitude stability of the aircraft during vertical take-off and landing within ±1-2 degrees, effectively ensuring flight safety and mission execution reliability.

[0069] Implementation case: In a night emergency rescue operation, the scene environment is complex and the light is poor. The flight control system plays a key role in the execution of the rescue task. The encoder monitors the propeller speed in real time, and the flight attitude sensor accurately captures the attitude change of the aircraft. In a rapid landing process, in the face of sudden air flow disturbance, the flight control system completes data processing and instruction generation within 100 milliseconds, and through accurate control of each actuator, the attitude deviation of the aircraft is stabilized within ±1.5 degrees, and the rescue personnel are successfully delivered, ensuring the smooth progress of the rescue operation.

[0070] The above describes the technical solutions provided by the embodiments of the present application in detail, and the principles and implementation manners of the embodiments of the present application are described by applying specific examples; the above description of the embodiments is only applicable to helping understand the principles of the embodiments of the present application; meanwhile, for those skilled in the art, the specific implementation manners and application ranges of the embodiments of the present application will be changed, and the content of the present description should not be understood as limiting the embodiments of the present application.

Claims

1. A tri-copter vertical take-off and landing aircraft characterized by, It comprises: a body, three rotatable rotors arranged on the top of the body, each group of rotors being driven by an electric motor or a hydraulic motor and being equipped with an independent inclination adjusting mechanism; a horizontal wing arranged below the rotatable rotors; a precision mechanical and control system for realizing smooth transition between vertical flight and horizontal flight modes, the control system comprising an adjusting device for the inclination of the rotors and a control device for the ailerons of the horizontal wing.

2. The tri-copter vehicle according to claim 1, wherein: The body adopts a wing-mounted canard distribution structure, and the flight center of gravity is located in an area surrounded by three propeller connecting lines.

3. The tri-copter vertical take off and landing aircraft of claim 2, wherein: When the body is in horizontal flight, two side engines can be selected to be turned off, and only the front engine is turned on to run, or the middle engine is turned off, and the two side engines are turned on to run according to actual needs.

4. The tri-copter vehicle of claim 2, wherein: When taking off, the three propellers can be adjusted to a horizontal position.

5. The tri-copter vehicle of claim 3, wherein: The propeller rotating mechanism adopts a hinge structure; wherein the propellers of the two side wing structures are supported by two bearings as fulcrums, a power motor or a hydraulic motor is installed on a rotating shaft, one end of the rotating shaft is connected to a power source, and the other end is installed with a servo motor, the servo motor is connected to the rotating shaft through a reduction box to adjust the angle of the shaft; the propeller structure of the nose is also supported by two bearings as fulcrums, a power motor or a hydraulic motor is installed on a rotating shaft, one end of the rotating shaft is connected to a power source, and the other end is installed with a servo motor, the servo motor is connected to the rotating shaft through a reduction box to adjust the angle of the shaft.

6. The tri-copter vehicle of claim 1, wherein: The body has a propeller variable pitch structure.

7. The tri-copter vehicle of claim 1, wherein: An encoder is installed behind each propeller, and the encoder is electrically connected to a flight control system on the body; a flight attitude sensor is also arranged on the body, and the flight attitude sensor is electrically connected to the flight control system.

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