Omni-directional decoupled ring vector tiltrotor aircraft and control method thereof

Abstract

The application discloses a kind of high-efficiency omni-directional decoupling annular vector tilt-rotor aircraft and control method thereof, aircraft includes fuselage, fuselage driving gear set, four tilting mechanisms, four annular vector tilt-rotor power groups and electronic equipment etc.Parts.The aircraft described in the application can realize six degrees of freedom omni-directional pose decoupling flight, the attitude angle is omni-directional arbitrary angle in it, including roll angle, pitch angle and yaw angle, can realize arbitrary attitude hovering and flight of aircraft.The aircraft described in the application solves the controllable attitude angle limit of conventional variable tilt-rotor mechanism from structure, improves the ability of complex space activity of aircraft, and fundamentally solves the problem of power offset and power redundancy, reduces energy loss, improves power efficiency, prolongs endurance time, and is suitable for application scenarios requiring strong anti-interference and air physical interaction capability, and has important significance and value in the future.

Description

Technical Field

[0001] This invention relates to the field of aviation technology, specifically to an omnidirectional decoupled ring vector tiltrotor aircraft and its control method. Background Technology

[0002] In recent years, with the development and maturation of UAV technology, the application scenarios of UAVs have been continuously expanded, such as missions in windy environments, missions in confined and complex spaces, automated inspection missions, aerial operation missions, vertical wall-mounted missions, and multi-directional missions. These diverse application scenarios and working environments place higher demands on UAV performance. In addition to stable hovering capabilities, UAVs also require higher anti-interference capabilities and aerial physical interaction capabilities. Currently, most conventional multi-rotor UAVs have rotors arranged in the same horizontal plane with the same rotor orientation, generating thrust in a single direction. While this structure is simple, reliable, and easy to maintain, it exhibits strongly coupled position and attitude dynamics characteristics. That is, changes in the aircraft's position must be achieved by tilting the fuselage to provide a horizontal component of force, and it is difficult to maintain a constant position while tilting the fuselage, thus preventing omnidirectional flight and significantly limiting the aircraft's controllability. To solve these problems, it is necessary to design a multi-rotor aircraft with decoupled position and attitude dynamics. Currently, there are schemes for achieving six degrees of freedom independent control of omnidirectional aircraft, which can be broadly divided into fixed tilt and variable tilt schemes.

[0003] Fixed tilt-rotor systems typically employ symmetrically distributed rotors facing different directions within a vertical plane, generating forces and torques in multiple directions. By coordinating the rotational speed of each rotor, they produce resultant forces and torques across the six degrees of freedom of the fuselage. Several fixed tilt-rotor aircraft capable of omnidirectional flight already exist, such as fixed-tilt hexacopter aircraft, cubic omnidirectional octopus aircraft, and rod-shaped octopus aircraft. In fixed tilt-rotor systems, the actuators are fixed-oriented motors; theoretically, at least six motors facing different directions are required to achieve full actuation of the six degrees of freedom. While fixed tilt-rotor systems offer simple control logic and structural stability, they suffer from severe power cancellation problems, resulting in low flight efficiency and short endurance.

[0004] Variable tilt designs alter rotor orientation by adding additional actuators, enabling each rotor to generate vector thrust within a certain range. By coordinating rotor orientation and rotational speed, resultant forces and moments are generated across the six degrees of freedom of the fuselage. Most existing variable tilt designs add tilt servos to the rotors of traditional quadcopters or hexcopters, such as variable tilt quadcopters, parallel-link quadcopters, and variable tilt hexcopters. These designs achieve flexible six-degree-of-freedom control, but due to structural limitations, the controllable angle is small, and there are power cancellation and redundancy issues, resulting in complex mechanical structures. A more successful design is the Voliro tilt hexcopter, where each power unit can tilt 360 degrees around an arm axis, using 6 motors and 6 servos—a total of 12 actuators. When flying near a horizontal attitude, all power units can fully provide lift, resulting in high efficiency. However, when the fuselage is tilted at a large angle, such as when hovering at a 90° roll angle, only the front and rear power units can provide vertical thrust, resulting in power cancellation, power redundancy, energy loss, and shortened flight time. Summary of the Invention

[0005] To address the problems of existing technologies, this invention provides an omnidirectionally decoupled ring-vector tiltrotor aircraft and its control method. The provided aircraft can achieve six-degree-of-freedom omnidirectional dynamic decoupling and is suitable for application scenarios such as flight under strong wind interference, navigating narrow spaces, tilting fuselage for shooting, firefighting with attitude change spraying, multi-directional spraying tasks, inspection and maintenance tasks, vertical wall tasks, aerial control tasks, and aerial docking tasks. It has strong maneuverability, environmental interactivity, adaptability to complex spaces and complex application scenarios, and has important significance and value in the future.

[0006] The present invention provides an omnidirectional decoupled ring vector tilt rotor aircraft, including a fuselage, a fuselage drive gear set, a ring vector tilt rotor power set, and electronic equipment fixed to the fuselage;

[0007] The fuselage drive gear set includes a fuselage center drive gear, an acceleration gear, a servo motor, and a servo disk. The servo motor is fixed at the center of the fuselage and drives the servo disk to rotate via a spline. The fuselage center drive gear is coaxially mounted and securely connected to the servo disk. Several acceleration gears mesh with the fuselage center drive gear. The number of acceleration gears is the same as that of the annular vector tilt rotor power set and they are symmetrically distributed around the fuselage center drive gear.

[0008] There are several annular vector tilt rotor power units, symmetrically distributed circumferentially relative to the geometric center of the fuselage. Each annular vector tilt rotor power unit includes a tilting mechanism, a flange ring, screws, nuts, an inner ring, a nylon bearing, and an outer ring. The tilting mechanism is interference-fitted through a carbon tube passing through the flange ring. The flange ring is connected and fastened to both ends of the inner ring. The inner ring and the outer ring are interference-fitted through the nylon bearing and mesh with the acceleration gear at the corresponding position. The inner ring and the tilting mechanism 3 fixed thereon are driven to rotate relative to the outer ring by the acceleration gear.

[0009] Further improvements include a fuselage comprising an upper plate, a lower plate, aluminum pillars, and landing gear. The upper and lower plates are supported and fixed together by the aluminum pillars. The landing gear is flush against the lower surface of the lower plate, and the aluminum pillars pass through holes in the lower plate for fastening. After assembly, these parts form the main fuselage body. The upper and lower plates are milled from carbon fiber sheets, and the landing gear is made of 3D-printed photopolymer material.

[0010] Further improvements include a tilting mechanism housing, a brushless motor, a propeller, a propeller clamp, a servo motor, a rudder arm, a moving gear, a fixed gear, bearings, and a base. The brushless motor is mounted on a motor mount in the tilting mechanism housing and secured. The propeller is coaxially mounted on the brushless motor and secured to the motor via the propeller clamp. A carbon fiber tube passes through two bearings mounted at the center of the tilting mechanism housing and the fixed gear located between the two bearings; the outer surface of the carbon fiber tube is interference-fitted with and bonded to the inner surfaces of the three components. The servo motor is mounted in a servo slot in the tilting mechanism housing and secured, driving the rudder arm to rotate via a spline. The rudder arm is coaxially mounted and secured to the moving gear. The moving gear meshes with the fixed gear, driving the entire tilting mechanism to tilt around the carbon fiber tube. The base is aligned with and fixed to the tilting mechanism housing, forming a complete streamlined tilting mechanism. The tilting mechanism housing, moving gear, fixed gear, and base are made of 3D printed photopolymer material.

[0011] In a further improvement, the electronic equipment includes a flight controller, an electronic speed controller, a power battery, a power module, a receiver, and an onboard GPS. The flight controller is used to automatically control the stable flight of the aircraft and output processed position and attitude signals. The electronic speed controller is used to power the brushless motor and adjust its speed. The power battery is used to power the entire aircraft's power system and control system. The power module is used to measure the battery's voltage and current and to power the flight controller. The receiver is used to receive signals from the remote controller. The onboard GPS is used to receive GPS satellite information and provide positioning and navigation information for the aircraft.

[0012] This invention also provides a highly efficient flight control method for an omnidirectionally decoupled ring-vector tiltrotor aircraft. The main feature of the aircraft described in this invention is its ability to achieve six-degree-of-freedom omnidirectional dynamic decoupling. Specifically, it allows for changes in attitude angle by tilting the fuselage in a stationary position, and also allows for changes in the aircraft's speed and position in three-dimensional space while maintaining the same attitude angle. The attitude angles are arbitrary omnidirectional angles, including roll, pitch, and yaw, enabling hovering and flight in any attitude. The aircraft uses nine actuators to achieve independent control of six degrees of freedom, including four brushless rotor motors, four tilt mechanism tilt servos, and one fuselage center servo. The six degrees of freedom are forward / backward movement, lateral movement, elevation / recline, roll, pitch, and yaw.

[0013] The decoupling control logic of the aircraft in 6 degrees of freedom is as follows. Forward / backward movement: The four rotors tilt forward (or backward) around the tilt axis to change their angle, providing a longitudinal horizontal force, and appropriately increasing the rotor speed to ensure lift; Lateral movement: After the inner ring rotates 90°, the four rotors tilt left (or right) around the tilt axis to change their angle, providing a lateral horizontal force, and appropriately increasing the rotor speed to ensure lift; Climbing / Lifting: Simultaneously changing the speed of the four rotors generates acceleration in the vertical direction, thereby achieving climbing / lifting; Rolling / Rolling: After the inner ring rotates 90°, the four rotors maintain a constant speed and tilt around the tilt axis, while keeping the rotor rotors facing upward; Pitching / Pitching: The four rotors maintain a constant speed and tilt around the tilt axis, while keeping the rotor rotors facing upward; Yawing / Yawing: The inner ring of the four rotors (actually only one is needed) rotates until the tilt axis is collinear with the arm (through the aircraft's center of mass to ensure that subsequent vector tilting only generates yaw moment), the rotors tilt around the tilt axis to provide a horizontal moment around the center of mass, and appropriately increasing the speed to ensure lift.

[0014] The beneficial effects of this invention are as follows:

[0015] 1. The tilting mechanism in the four sets of annular vector tilt rotor power units of the aircraft tilts around a parallel pitch axis, which avoids the counteracting forces generated by the tilting of the rotors, and allows the rotors to provide lift to the aircraft as much as possible. This fundamentally solves the problems of power cancellation and power redundancy, reduces energy loss, and extends the endurance.

[0016] 2. Each annular vector tilt rotor power unit of the aircraft enables the rotors within it to point in any direction, thereby providing force and torque in any direction in a truly independent manner. This solves the problem of limited controllable attitude angle caused by the mechanical structure limitations of existing omnidirectional aircraft, and enables hovering at any large angle.

[0017] 3. It achieves dynamic decoupling control of six-degree-of-freedom omnidirectional position and attitude, giving the aircraft stronger anti-interference ability and controllability;

[0018] 4. The aircraft described in this invention is suitable for application scenarios such as flight under strong wind interference, passage through narrow spaces, shooting with tilted fuselage, fire-fighting and attitude-changing spraying, multi-directional spraying tasks, inspection and maintenance tasks, vertical wall tasks, aerial control tasks, and aerial docking tasks. It has strong maneuverability, environmental interactivity, adaptability to complex spaces and complex application scenarios, and has important significance and value in the future. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a perspective view of the overall shape of the annular vector tilt rotor aircraft of the present invention;

[0021] Figure 2 These are the side and front views of the annular vector tilt rotor aircraft of the present invention;

[0022] Figure 3 This is a gear distribution diagram of the fuselage drive gear set of the annular vector tiltrotor aircraft of the present invention;

[0023] Figure 4 This is a structural diagram of the tilting mechanism of the annular vector tilt rotor aircraft of the present invention;

[0024] Figure 5 This is a structural diagram of the annular vector tilting power unit of the annular vector tilting rotorcraft of the present invention;

[0025] Figure 6 This is a schematic diagram of the electronic equipment connections for the annular vector tiltrotor aircraft of the present invention;

[0026] Figure 7 This is a schematic diagram of the pitch attitude change of the annular vector tilt rotor aircraft of the present invention. Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] This invention provides a high-efficiency omnidirectional decoupled annular vector tiltrotor aircraft, comprising a fuselage 1, a fuselage drive gear set 2, four tilting mechanisms 3, four annular vector tiltrotor power units 4, and electronic equipment 5, etc. Figure 1 and Figure 2 As shown.

[0029] The fuselage 1 includes an upper plate 101, a lower plate 102, aluminum pillars 103, screws 104, and landing gear 105. The upper plate 101 and the lower plate 102 are supported by the aluminum pillars 103 and fixedly installed by the screws 104. The landing gear 105 is close to the lower surface of the lower plate 102, with the aluminum pillars 103 passing through holes and fastened by the screws 104. After the above parts are assembled, the main body of the fuselage is formed. The upper and lower plates are milled and cut from carbon fiber plates, and the landing gear is made of 3D printed photopolymer material.

[0030] The fuselage drive gear set 2 includes a central drive gear 201, acceleration gears 202, a servo motor 203, a servo disc 204, shoulder screws 205, and fastening nuts 206. The servo motor 203 is fixed to the center of the lower fuselage plate 101 with screws and drives the servo disc 204 to rotate via a spline. The central drive gear 101 and the servo disc 204 are coaxially mounted and fastened together with screws. The shoulder screws 205 pass through the acceleration gear 202, are fixed by the fastening nuts 206 through holes in the upper and lower fuselage plates, and simultaneously limit the movement of the acceleration gear 202. The central drive gear 101 meshes with four circumferentially symmetrically distributed acceleration gears 202, driving the acceleration gears to rotate. The gears are made of 3D printed photopolymer material. The gear distribution is as follows. Figure 3 As shown.

[0031] The structural design of the tilt mechanism 3 is based on part of the applicant's published invention, "Longitudinal Dynamics Decoupling Tilted Rotor Aircraft and Its Flight Control Method," patent number CN202210698675.2. Its working principle will not be elaborated here. The tilt mechanism 3 includes a tilt mechanism housing 301, a brushless motor 302, a propeller 303, a propeller clamp 304, screws 305 and 306, a servo motor 307, a servo arm 308, a moving gear 309, a fixed gear 310, a bearing 311, a base shell 312, and a carbon fiber tube 313. The brushless motor 302 is mounted on a motor mount in the tilt mechanism housing 301 and secured with screws 305. The propeller 303 is coaxially mounted on the brushless motor 302, and the propeller 303 and brushless motor 302 are secured together by the propeller clamp 304. The carbon tube 313 passes through two bearings 311 installed at the center of the tilting mechanism housing 301, and the fixed gear 310 located between the two bearings. The outer surface of the carbon tube 313 is interference-fitted with and bonded to the inner surfaces of the three bearings. The servo motor 307 is installed in the servo motor slot of the tilting mechanism housing 301 and fastened with screws 306, driving the servo arm 308 to rotate via a spline. The servo arm 308 is coaxially mounted with the moving gear 309 and fastened together with screws 305. The moving gear 309 meshes with the fixed gear 310, driving the entire tilting mechanism to tilt around the carbon tube 313. The bottom shell 312 is aligned and fixed to the tilting mechanism housing 301, thus assembling a complete streamlined tilting mechanism. The tilting mechanism housing, moving gear, fixed gear, and bottom shell are made of 3D printed photopolymer material, and the carbon tube is a carbon fiber tube. The structure of the tilting mechanism 3 is as follows: Figure 4 As shown.

[0032] The annular vector tilt rotor power unit 4 includes a tilt mechanism 3, flange rings 401, screws 402, nuts 403, an inner ring 404, a nylon bearing 405, and an outer ring 406. The carbon tube 313 within the tilt mechanism 3 passes through two flange rings 401 with an interference fit. The flange rings 401 are connected to both ends of the inner ring 404 and secured by screws 402 and nuts 403. The inner ring 404 and the outer ring 406 are interference-fitted through the nylon bearing 405 and mesh with the acceleration gear 202 within the fuselage drive gear set 2. The inner ring 404 and the tilt mechanism 3 fixed thereto can rotate relative to the outer ring 406 by the acceleration gear 202. The annular vector tilt rotor power units 4 are symmetrically distributed circumferentially with respect to the geometric center of the fuselage, with a total of four units. The structure of the annular vector tilt rotor power unit 4 is as follows: Figure 5 As shown. The flange ring, inner ring, and outer ring are made of 3D-printed photopolymer material, and the nylon bearing is made of custom nylon material. The structure of the annular vector tilt rotor power unit 4 is as follows. Figure 5 As shown.

[0033] The electronic device 5 includes a flight controller 501, an electronic speed controller 502, a power battery 503, a power module 504, a receiver 505, and an onboard GPS 506. The flight controller 501 is used to automatically control the stable flight of the aircraft and output processed position and attitude signals. The electronic speed controller 502 is used to power the brushless motor 302 and adjust its speed. The power battery 503 is used to power the entire aircraft's power system and control system. The power module 504 is used to measure the battery's voltage and current and to power the flight controller 501. The receiver 505 is used to receive signals from the remote controller. The onboard GPS 506 is used to receive GPS satellite information and provide positioning and navigation information for the aircraft. The electronic devices are connected as follows: Figure 6 As shown.

[0034] This invention also provides a highly efficient flight control method for an omnidirectionally decoupled ring-vector tiltrotor aircraft. The main feature of the aircraft described in this invention is its ability to achieve six-degree-of-freedom omnidirectional dynamic decoupling. Specifically, it allows for changes in attitude angle by tilting the fuselage in a stationary position, and also allows for changes in the aircraft's speed and position in three-dimensional space while maintaining the same attitude angle. The attitude angles are arbitrary omnidirectional angles, including roll, pitch, and yaw, enabling hovering and flight in any attitude. The aircraft uses nine actuators to achieve independent control of six degrees of freedom, including four brushless rotor motors, four tilt mechanism tilt servos, and one fuselage center servo. The six degrees of freedom are forward / backward movement, lateral movement, elevation / recline, roll, pitch, and yaw.

[0035] The decoupled control logic of the aircraft in 6 degrees of freedom is as follows: Forward and backward movement: The four rotors tilt forward (or backward) around the tilt axis to change the angle and provide longitudinal horizontal force, and appropriately increase the rotor speed to ensure lift; Lateral movement: After the inner ring rotates 90°, the four rotors tilt left (or right) around the tilt axis to change the angle and provide lateral horizontal force, and appropriately increase the rotor speed to ensure lift; Heave and descent: The rotation speed of the four rotors is changed simultaneously to generate acceleration in the vertical direction, thereby achieving heave and descent; Roll: After the inner ring rotates 90°, the four rotors maintain a constant rotation speed and tilt around the tilt axis, while keeping the rotor rotors facing upward; Pitch: The four rotors maintain a constant rotation speed and tilt around the tilt axis, while keeping the rotor rotors facing upward; Yaw: The inner ring of the four rotors (actually only one is needed) rotates until the tilt axis is collinear with the arm (through the aircraft's center of mass to ensure that the subsequent vector tilt only generates yaw moment), the rotor tilts around the tilt axis to provide horizontal torque around the center of mass, and appropriately increases the rotation speed to ensure lift. The attitude change process of the aircraft from a pitch angle of 90° to -90° is as follows: Figure 7 As shown.

[0036] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, for the device embodiments, the above descriptions are merely preferred embodiments of the present invention. Since they are fundamentally similar to the method embodiments, the descriptions are relatively simple, and relevant parts can be referred to the descriptions of the method embodiments. The above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention, without departing from the principle of the present invention, should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An omnidirectional decoupled annular vector tiltrotor aircraft, characterized in that: It includes the fuselage, fuselage drive gear set, annular vector tilt rotor power unit, and electronic equipment fixed to the fuselage; The fuselage drive gear set includes a fuselage center drive gear, an acceleration gear, a servo motor, and a servo disk. The servo motor is fixed at the center of the fuselage and drives the servo disk to rotate via splines. The fuselage center drive gear is coaxially mounted and securely connected to the rudder disk. Several acceleration gears mesh with it around the fuselage center drive gear. The number of acceleration gears is the same as that of the annular vector tilt rotor power unit and they are symmetrically distributed around the fuselage center drive gear. The annular vector tiltrotor power unit comprises several units, symmetrically distributed circumferentially relative to the geometric center of the fuselage. Each annular vector tiltrotor power unit includes a tilting mechanism, a flange ring, screws, nuts, an inner ring, a nylon bearing, and an outer ring. The tilting mechanism is press-fitted through a carbon tube passing through the flange ring. The flange ring is connected and fastened to both ends of the inner ring. The inner and outer rings are press-fitted through the nylon bearing and mesh with the acceleration gear at the corresponding position. The inner ring and the tilting mechanism fixed thereon are driven to rotate relative to the outer ring by the acceleration gear. The tilting mechanism includes a tilting mechanism housing, a brushless motor, a propeller, a propeller clamp, a servo motor, a servo arm, a moving gear, a fixed gear, a bearing, and a base; the brushless motor is mounted on a motor mount in the tilting mechanism housing and is secured. The propeller is coaxially mounted on the brushless motor, and the propeller and the brushless motor are fastened together by a propeller clamp; The carbon tube passes through two bearings installed at the center of the tilting mechanism housing, and the fixed gear located between the two bearings. The outer surface of the carbon tube is interference-fitted with and bonded to the inner surfaces of the three bearings. The servo is installed in the servo slot of the tilting mechanism housing and is fastened, driving the servo arm to rotate via a spline. The servo arm is coaxially mounted with the moving gear and fastened. The moving gear meshes with the fixed gear, driving the entire tilting mechanism to tilt around the carbon tube. The bottom shell is aligned with and fixed together with the tilting mechanism housing, forming a complete streamlined tilting mechanism.

2. The omnidirectional decoupled annular vector tilt rotorcraft according to claim 1, characterized in that: The fuselage includes an upper plate, a lower plate, aluminum columns, and landing gear. The upper plate and the lower plate are supported and fixed by the aluminum columns. The landing gear is close to the lower surface of the lower plate, and the aluminum columns are fastened by passing through holes on the lower plate. After the upper plate, lower plate, aluminum columns, and landing gear are assembled, the main body of the fuselage is formed.

3. The omnidirectional decoupled annular vector tilt rotorcraft according to claim 2, characterized in that: The upper and lower plates are milled and cut from carbon fiber plates, and the landing gear is made of 3D printed photocurable material.

4. The omnidirectional decoupled annular vector tilt rotorcraft according to claim 1, characterized in that: The tilting mechanism's outer shell, moving gear, fixed gear, and bottom shell are made of 3D-printed photocurable material.

5. The omnidirectional decoupled annular vector tilt rotorcraft according to claim 1, characterized in that: The electronic equipment includes a flight controller, an electronic speed controller, a power battery, a power module, a receiver, and an onboard GPS. The flight controller is used to automatically control the stable flight of the aircraft and output processed position and attitude signals. The electronic speed controller is used to power the brushless motor and adjust its speed. The power battery is used to power the entire aircraft's power system and control system. The power module is used to measure the voltage and current of the battery and to power the flight controller. The receiver is used to receive signals from the remote controller. The onboard GPS is used to receive GPS satellite information and provide positioning and navigation information for the aircraft.

6. A control method for an omnidirectionally decoupled ring vector tiltrotor aircraft, employing the omnidirectionally decoupled ring vector tiltrotor aircraft as described in claim 1, characterized in that: The motion includes six degrees of freedom: forward / backward movement, lateral movement, vertical movement, roll, pitch, and yaw. Forward and backward movement: The four rotors tilt forward or backward around the tilt axis to change the angle and provide longitudinal horizontal force, and appropriately increase the rotor speed to ensure lift; Lateral movement: After the inner ring rotates 90°, the four rotors tilt to the left or right around the tilt axis to change the angle and provide a lateral horizontal force, and increase the rotor speed to ensure lift; Lifting and lowering motion: Simultaneously changing the rotational speed of the four rotors generates acceleration in the vertical direction, thereby achieving lifting and lowering; Rolling motion: After the inner ring rotates 90°, the four rotors maintain a constant speed and tilt around the tilt axis while keeping the rotor rotors facing upwards; Pitch motion: The four rotors maintain a constant rotational speed and tilt around the tilt axis while keeping the rotor rotors pointing upwards; Yaw motion: The inner rings of the four rotors rotate until the tilt axis is collinear with the arms, passing through the aircraft's center of mass to ensure that the subsequent vector tilt only generates yaw moment. The rotors tilt around the tilt axis to provide horizontal torque around the center of mass and increase the rotational speed to ensure lift.

Images