Air-ground amphibious unmanned aerial vehicle

Abstract

An air-ground amphibious unmanned aerial vehicle belongs to the technical field of unmanned aerial vehicles. Comprising a machine body, machine arms, a worm gear self-locking tilting mechanism, a swing mechanism, a single-motor dual-mode power multiplexing system and a control system. The four machine arms are symmetrically arranged on the two sides of the machine body through the machine arm frame, one ends of the machine arms are connected with the swing mechanism, the other ends of the machine arms are provided with the single-motor dual-mode power multiplexing system, the worm wheel self-locking tilting mechanism is arranged at one end of the machine body, and transmission worm wheels I at the tail end of the worm wheel self-locking tilting mechanism are symmetrically arranged on a transmission shaft II of the swing mechanism in a sleeving mode and installed on the machine arm frame through an installation frame of the worm wheel self-locking tilting mechanism. The control system is respectively connected with a driving motor I of the worm wheel self-locking tilting mechanism, a driving motor II of the swinging mechanism and a rotor motor of the single-motor dual-mode power multiplexing system, and is used for controlling the motors to act, so that tilting of the fuselage and swinging of the arms are realized. According to the invention, the switching stability of different motion modes is improved, and the problem of driving redundancy is effectively solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of unmanned aerial vehicles, and particularly relates to a land-air amphibious unmanned aerial vehicle. BACKGROUND

[0002] With the deepening of the application of unmanned aerial vehicles in complex scenes such as disaster relief and pipeline detection, the traditional single-mode unmanned aerial vehicle faces the barrier of environmental adaptability: the fixed-wing type is restricted by the landing site, the rotor unmanned aerial vehicle is insufficient in mobility in a narrow space, and the ground robot is difficult to cross obstacles.

[0003] However, the existing research has two bottlenecks of driving redundancy and insufficient switching stability. For example, the existing land-air amphibious robot adopting independent motor driving rotors and wheels can realize stable operation in double modes, but the system weight reaches 1.8 kg, and the endurance capacity is weakened; the existing land-air amphibious robot adopting a rotor tilting mechanism to realize mode conversion reduces the system weight, but has the problem of insufficient dynamic stability in the land-air switching process, especially in complex terrain conditions, attitude instability phenomenon is prone to occur. SUMMARY

[0004] In view of the above technical problems, the application provides a land-air amphibious unmanned aerial vehicle, which adopts a worm gear self-locking tilting mechanism, synchronously controls the tilting of the arm frame by a bevel gear set, the tilting angle is continuously adjustable at 0°-60°, and the stability of mode switching is greatly improved in combination with the self-locking characteristic; a single-motor double-mode power multiplexing system is adopted, rotors and wheels are cooperatively driven by a reduction gear set, the problem of driving redundancy is effectively solved, the land-air amphibious unmanned aerial vehicle of the application breaks through the limitation of a single environment through mode switching, and becomes a key technical direction for solving multi-scene collaborative operation.

[0005] The purpose of the application is achieved by the following technical solutions:

[0006] The land-air amphibious unmanned aerial vehicle comprises a fuselage, arms, a worm gear self-locking tilting mechanism, a swing mechanism, a single-motor double-mode power multiplexing system and a control system; the arms are four, symmetrically arranged on both sides of the fuselage through an arm frame, one end of the arm is connected to the swing mechanism, the other end is provided with the single-motor double-mode power multiplexing system, the worm gear self-locking tilting mechanism is arranged at one end of the fuselage, a drive worm gear I at the tail end of the worm gear self-locking tilting mechanism is symmetrically sleeved on a drive shaft II of the swing mechanism located on both sides of the fuselage, and the drive worm gear I is installed on the arm frame through an installation frame, the control system is respectively connected to a drive motor I of the worm gear self-locking tilting mechanism, a drive motor II of the swing mechanism and a rotor motor of the single-motor double-mode power multiplexing system, and the action of each motor is controlled.

[0007] Further, the worm self-locking tilting mechanism comprises a driving motor I, a transmission shaft I, a transmission worm I, a transmission worm wheel I and a bevel gear set, the output shaft of the driving motor I and the transmission shaft I are vertically arranged, and the output shaft of the driving motor I is symmetrically connected with two transmission shafts I through the bevel gear set, two transmission shafts I are symmetrically provided with transmission worms I, and the transmission worm wheel I meshing with the transmission worm I is arranged at the end of the transmission shaft II of the swing mechanism.

[0008] Further, the swing mechanism comprises a driving motor II, a transmission gear set, a transmission worm II, a transmission shaft II and a transmission worm wheel II, the output shaft of the driving motor II is connected with the swing transmission shaft II on both sides of the machine body through the transmission gear set, two transmission worms II are symmetrically arranged on each swing transmission shaft II, the transmission worm wheel II meshing with the transmission worm II is arranged at the end of the machine arm, and the transmission worm wheel II is rotatably arranged between the machine arm frames through its pin shaft, thereby driving the same side machine arm to swing synchronously, wherein the swing transmission shaft II is parallel to the output shaft of the driving motor II.

[0009] Further, the transmission gear set comprises gears meshing and drivingly arranged on the output shaft of the driving motor II and the swing transmission shaft II, and is driven by the driving motor II to drive the transmission gear set connected therewith to rotate, thereby driving the swing transmission shaft II and the transmission worm II thereon to rotate, and driving the machine arm to swing through the transmission worm wheel II meshing therewith, so as to adjust the included angle between the machine arm and the machine body.

[0010] Further, the single-motor dual-mode power reuse system comprises a wheel, a wheel driving shaft, a support plate, a speed reduction gear set, a rotor motor, a support column and a propeller, the support column is arranged at the end of the machine arm, the support plate parallel to the machine arm is connected to the support column, one end of the wheel driving shaft is arranged on the machine arm, and the other end of the wheel driving shaft is provided with the wheel penetrating through the support plate, the wheel driving shaft is connected to the bottom output shaft of the rotor motor arranged on the machine arm through the speed reduction gear set, the rotor motor is provided with double output shafts, and the propeller is arranged on the top output shaft of the rotor motor.

[0011] Further, the machine body comprises an upper machine body and a lower machine body, the upper machine body is a cover structure, one end of the upper machine body is provided with a mounting plate for mounting the transmission gear set of the swing mechanism, the other end of the upper machine body is provided with a mounting cover for mounting the transmission shaft I of the worm self-locking tilting mechanism, mounting holes I for mounting the transmission shaft II of the swing mechanism are arranged on the outer side plate of the mounting cover, ear plates are symmetrically arranged on both outer sides of the upper machine body, and the ear plates are matched with the cover of the machine arm frame; the lower machine body is provided with an L-shaped plate at one end of a groove-shaped housing, the L-shaped plate is arranged outside the mounting plate of the upper machine body, and the gear set of the swing mechanism is arranged between the L-shaped plate and the mounting plate.

[0012] Furthermore, there are two boom frames, symmetrically arranged on both sides of the upper body. Each boom frame includes two symmetrically arranged side plates. One end of each side plate has a rectangular groove, and the other end has a trapezoidal groove. The rectangular groove has a cover for mounting the sway mechanism transmission worm gear II symmetrically arranged at both ends. The ends of the side plates at both ends of the trapezoidal groove have an inverted trapezoidal structure with mounting holes II for mounting the sway mechanism transmission worm gear II.

[0013] Furthermore, the control system includes an airborne section and a ground section. The airborne section includes a main control module, a power distribution board, a battery, an image transmission module, a data transmission module, a receiver, a GPS module, and a multimodal sensor group. The multimodal sensor group includes an IMU and magnetometer built into the main control module, as well as a barometer, ultrasonic sensor, wheel speed encoder, and angle sensor externally mounted on the fuselage. The ground section includes a ground station and a remote controller. The battery output is electrically connected to the power distribution board input. The power distribution board output is divided into two paths: one path is electrically connected to the main control module input for power supply, and the other path is electrically connected to the electronic speed controllers of drive motor I, drive motor II, and each arm rotor motor. The main control module is connected to the barometer, ultrasonic sensor, wheel speed encoder, and angle sensor to receive data. The image transmission module, data transmission module, receiver, and GPS module are connected to the main control module, ground station, and remote controller for wireless two-way communication, realizing automatic adjustment and remote control of the arm tilt and swing angles.

[0014] Furthermore, the automatic adjustment of the boom tilt angle is achieved by using an ultrasonic sensor mounted at the front of the fuselage to detect in real time the distance S between the two obstacles that the drone needs to pass through. This is combined with the fuselage pitch angle β measured by the IMU and the current boom tilt angle θ fed back by the angle sensor. The main control module then executes a proportional-derivative compensation algorithm to calculate the optimal tilt angle θ for the drone to pass through the middle of the two obstacles. target :

[0015]

[0016] Where: K p —Distance scaling factor;

[0017] K d — Rate of change compensation coefficient;

[0018] S safe —A safe distance for effective passage;

[0019] S meas —Real-time measurement of the distance between two obstacles.

[0020] Furthermore, the automatic adjustment of the boom swing angle is achieved by using an ultrasonic sensor installed at the bottom of the fuselage to detect the ground clearance h in real time, the wheel speed encoder to obtain the wheel speed v, the fuselage roll angle γ monitored by the IMU, and the current boom swing angle α fed back by the angle sensor. The main control module adopts a multimodal decision control algorithm to calculate and dynamically decide the boom swing angle α for safe passage through obstacles based on the terrain in real time. target :

[0021]

[0022] Where: K safe —Safety factor;

[0023] K γ —Roll angle compensation factor;

[0024] K obs —Obstacle avoidance strength coefficient;

[0025] h obs —Detection distance of the nearest obstacle;

[0026] g—acceleration due to gravity;

[0027] γ—roll angle;

[0028] λ — barrier attenuation coefficient.

[0029] The beneficial effects of this invention are as follows:

[0030] 1. This application utilizes a worm gear self-locking tilting mechanism to adjust the tilt angle of the boom relative to the fuselage in the vertical plane, thereby adjusting the drone's altitude and center of gravity. A swing mechanism adjusts the angle of the boom's swing along the boom frame, thus regulating the drone's circumferential dimensions. This allows the drone to flexibly change its attitude to adapt to different terrains, possessing stable ground driving and aerial flight modes, and adapting to common roads and relatively flat outdoor environments. It enables rapid, stable, and seamless mode switching between the two motion modes.

[0031] 2. The worm gear self-locking tilting mechanism and swing mechanism of this application both adopt "two-bar coaxial" worm gear transmission to achieve synchronous adjustment of the arm on the same side. This structure not only avoids imbalance caused by asymmetrical movement, but also ensures structural stability through the self-locking property of the worm gear.

[0032] 3. This application uses a single-motor power reuse system design to control the overall weight of the machine to within 1.5kg. In ground mode, the overall dimensions of the machine are: length × width × height ≤ 450mm × 350mm × 200mm, ensuring passability in narrow spaces. Attached Figure Description

[0033] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0034] Figure 2 This is a schematic diagram of the planar structure of the present invention.

[0035] Figure 3 for Figure 1 A schematic diagram of the installation structure of the worm gear self-locking tilting mechanism.

[0036] Figure 4 for Figure 1 A schematic diagram of the structure of a single-motor dual-mode power reuse system.

[0037] Figure 5 for Figure 1 A schematic diagram of the fuselage structure.

[0038] Figure 6 for Figure 5 A schematic diagram of the upper fuselage.

[0039] Figure 7 for Figure 5 A schematic diagram of the lower fuselage.

[0040] Figure 8 for Figure 1 A schematic diagram of the structure of the machine tool boom.

[0041] Figure 9 This is a block diagram of the control system of this application.

[0042] Figure 10 This is a schematic diagram of relevant parameters when this application passes through an obstacle.

[0043] Figure 11 This is a schematic diagram of the relevant parameters when performing tilt adjustment for this application.

[0044] Figure 12 A schematic diagram of relevant parameters for swing adjustment in this application.

[0045] In the diagram: 1. Worm gear self-locking tilting mechanism; 11. Drive motor I; 12. Transmission shaft I; 13. Transmission worm I; 14. Transmission worm gear I; 15. Bevel gear set;

[0046] 2. Body, 21. Upper body, 211. Mounting plate, 212. Mounting cover, 213. Mounting hole I, 214. Ear plate, 215. Threaded connecting post; 22. Lower body, 221. Channel-shaped housing, 222. L-shaped plate, 223. Connecting cylinder;

[0047] 3. Oscillating mechanism; 31. Drive motor II; 32. Transmission gear set; 33. Transmission worm gear II; 34. Transmission shaft II; 35. Transmission worm wheel II;

[0048] 4. Single-motor dual-mode power reuse system, 41. Wheel, 42. Wheel drive shaft, 43. Support plate, 44. Reduction gear set, 45. Rotor motor, 451. Rotor motor I, 452. Rotor motor II, 453. Rotor motor III, 454. Rotor motor IV, 46. Support column, 47. Propeller;

[0049] 5. Machine arm;

[0050] 6. Boom frame, 61. Side plate, 62. Rectangular groove, 63. Trapezoidal groove, 64. Cover, 65. Mounting hole II. Detailed Implementation

[0051] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0052] Example: Figures 1-2 As shown, this invention discloses an amphibious unmanned aerial vehicle (UAV) comprising a fuselage 2, arms 5, a worm gear self-locking tilt mechanism 1, a swing mechanism 3, a single-motor dual-mode power multiplexing system 4, and a control system. Four arms 5 are symmetrically arranged on both sides of the fuselage 2 via arm frames 6. One end of each arm 5 is connected to the swing mechanism 3, and the other end is connected to the single-motor dual-mode power multiplexing system 4. The worm gear self-locking tilt mechanism 1 is located at one end of the fuselage 2, with its end-end transmission worm gear I14 symmetrically sleeved on the transmission shaft II34 of the swing mechanism 3 located on both sides of the fuselage 2. The transmission worm gear I14 is mounted on the arm frame 6 via its mounting bracket and does not rotate with the transmission shaft II34. The control system is connected to the drive motor I11 of the worm gear self-locking tilt mechanism 1, the drive motor II31 of the swing mechanism 3, and the rotor motor 45 of the single-motor dual-mode power multiplexing system 4, controlling the movement of each motor to control the movement of each mechanism and maintain stable operation.

[0053] like Figure 2 As shown, the worm gear self-locking tilting mechanism includes a drive motor I11, a transmission shaft I12, a transmission worm I13, a transmission worm wheel I14, and a bevel gear set 15. The output shaft of the drive motor I11 and the transmission shaft I12 are arranged vertically, and the output shaft of the drive motor I11 is symmetrically connected to the two transmission shafts I12 through the bevel gear set 15. The transmission worm I13 is symmetrically installed on both transmission shafts I12, and the transmission worm wheel I14, which meshes with the transmission worm I13, is sleeved on the end of the transmission shaft II34 of the swing mechanism 3.

[0054] The working principle of the worm gear self-locking tilting mechanism 1: Driven by the drive motor I11, the two transmission shafts I12 and their transmission worm gears I13 rotate through the bevel gear set 15, which in turn synchronously drive the transmission worm gear I14 meshing with it to rotate, causing the boom 6 and its connected boom 5 to tilt. When switching modes, the tilt angle of the two booms 5 relative to the body 2 in the vertical plane is adjusted by the boom 6. After the boom 5 tilts, to avoid the propeller 47 from contacting the ground, a safe and effective tilt angle range of 0 to 60 degrees is set. During ground movement, the tilt angle is adjusted according to different terrains.

[0055] The self-locking of worm gear drives is due to the fact that when the worm lead angle is less than the friction angle, power can only be transmitted from the worm to the worm wheel (forward transmission). Reverse transmission (worm wheel driving worm) will be jammed, thus achieving "self-locking".

[0056] like Figures 2-3 As shown, the swing mechanism 3 includes a drive motor II 31, a transmission gear set 32, a transmission worm II 33, a transmission shaft II 34, and a transmission worm wheel II 35. The output shaft of the drive motor II 31 is connected to the swing transmission shafts II 34 on both sides of the machine body 2 through the transmission gear set 32. Two transmission worms II 33 are symmetrically arranged on each swing transmission shaft II 34. The transmission worm wheel II 35, which meshes with the transmission worm II 33, is installed at the end of the machine arm 5. The transmission worm wheel II 35 is rotatably installed between the machine arm frames 6 through its pin. The machine arm 5 is driven to swing through the transmission worm wheel II 35. The swing transmission shaft II 34 is parallel to the output shaft of the drive motor II 31.

[0057] The transmission gear set 32 ​​described in this example includes gears that mesh and drive each other, respectively mounted on the output shaft of the drive motor II 31 and the swing transmission shaft II 34. Driven by the drive motor II 31, the transmission gear set 32 ​​connected to it rotates, which in turn drives the swing transmission shaft II 34 and the transmission worm II 35 on it to rotate. The transmission worm wheel II 35 meshing with it drives the two sides of the machine arm 5 to swing synchronously. A "two-bar coaxial" worm gear transmission setting with two transmission worms II 33 symmetrically arranged on each swing transmission shaft II 34 realizes the synchronous adjustment of the machine arm 8 on the same side.

[0058] like Figure 3As shown, the horizontal angle between the boom 5 and the fuselage 2 is adjusted by the swing mechanism, and the vertical tilt angle between the boom 5 and the fuselage 2 is adjusted by the worm gear self-locking tilt mechanism 1. The two constitute a "two-dimensional adjustment system". The swing mechanism 3 is responsible for horizontal expansion, and the worm gear self-locking tilt mechanism 1 controls the vertical tilt angle, adjusting the drone's altitude and center of gravity position. The two work together to reconstruct the drone's ground mode shape, thereby enhancing its passability in complex terrain. For example, on soft ground, expanding the angle between the boom 5 and the fuselage 2 so that the two boom frames 6 are on the same plane, and swinging the boom 5 to a position perpendicular to the fuselage 2 to reach its maximum extension state, can reduce pressure and decrease the risk of sinking.

[0059] In ground mode, the wheelbase is adjusted by swinging the swing mechanism 3, changing the horizontal angle between the boom 5 and the fuselage 2. Simultaneously, the worm gear self-locking tilting mechanism 1 adjusts the vertical tilting angle of the boom 6 and the boom 5, thus flexibly changing the posture to adapt to different terrains. When there is a risk of rollover, the wheelbase is increased by controlling the swing mechanism 3, and the vertical tilting angle of the boom 6 is adjusted to effectively prevent rollover and ensure driving stability and passability in complex terrain.

[0060] The single-motor dual-mode power multiplexing system 4 consists of four sets, each connected to one of the four arms 5. Each set includes a wheel 41, a wheel drive shaft 42, a support plate 43, a reduction gear set 44, a rotor motor 45, a support column 46, and a propeller 47. A support column 46 is installed at the end of each arm 5, and a support plate 43 parallel to the arm 5 is connected to the support column 46. One end of the wheel drive shaft 42 is mounted on the arm 5, and the other end passes through the support plate 43 to mount the wheel 41. The rotor motor 45 has dual output shafts; a propeller 47 is mounted on the top output shaft above the arm 5. The wheel drive shaft 42 is connected to the bottom output shaft of the rotor motor 45, which extends into the arm 5, via the reduction gear set 44. In this example, the rotor motor 45 is a brushless motor.

[0061] This application uses a single rotor motor 45 to achieve power reuse through a reduction gear set 44, such as Figure 4 As shown, the main body of arm 5 is made of aluminum, with a thickness of 4mm in this example, ensuring both lightweight and high strength. Each arm 5 has a worm gear II 35 at its root, which drives the arm 5 to swing between the side plates 61 of the arm frame 6 via the swing mechanism 3. At the end of arm 5, a single-motor dual-mode power reuse system 4 is installed. Its rotor motor 45 directly drives the propeller 47 to rotate during flight. When walking on the ground, the rear shaft of the rotor motor 45 is connected to the wheels via a reduction gear set 44, achieving power reuse design and reducing the need for independent drive units.

[0062] The worm gear self-locking tilting mechanism 1 installed in this application has one end as the front end and the other end as the rear end. When the UAV is in a ground driving state, it is in a four-wheel two-drive state. The two front wheels are driving wheels, which are respectively connected to rotor motor I 451 and rotor motor II 452; the two rear wheels are follower wheels, which are respectively connected to rotor motor III 453 and rotor motor IV 454.

[0063] The boom 5 and boom 6 are tilted at an angle so that the four wheels 41 remain in contact with the ground. The two rotor motors 45 at the front drive the drive wheels to rotate. The propeller 47 rotates with the rotor motors 45 but does not generate effective thrust. Through the reduction gear set 44, the wheel drive shaft 42 and the wheels 41 on it are driven to rotate, which in turn drives the rear wheels to rotate passively, thus completing the ground walking.

[0064] When switching to flight mode, the tilt angle of the boom 6 is adjusted to 0 degrees, the boom 5 remains horizontal, the rotor motor 45 drives the propeller 47 to rotate at high speed to generate lift, so that the UAV of this application takes off. At this time, the four wheels 41 follow and no longer provide driving force.

[0065] like Figures 5-7 As shown, the fuselage 2 includes an upper fuselage 21 and a lower fuselage 22. The upper fuselage 21 is a cover structure, with a mounting plate 211 at one end for mounting the transmission gear set 32 ​​of the swing mechanism 3, and a mounting cover 212 at the other end for mounting the transmission shaft I 12 of the worm gear self-locking tilting mechanism. The outer side plate of the mounting cover 212 has mounting holes I 213 for mounting the transmission shaft II 34 of the swing mechanism. The upper fuselage 21 has two ear plates 214 symmetrically mounted on its two outer sides, which are matched with the near ends of the two covers 64 of the boom frame 6. The lower fuselage 21 has an L-shaped plate 2 at one end of the groove-shaped shell 221. The upper and lower bodies 21 and 22 are configured such that an L-shaped plate 222 is placed outside the mounting plate 211 of the upper body 21, and the transmission gear set 32 ​​of the swing mechanism 3 is placed between the L-shaped plate 222 and the mounting plate 211. The upper body 21 is provided with four threaded connecting columns 215, and the lower body 22 is provided with four connecting cylinders 223 corresponding to the threaded connecting columns 215. The connecting cylinders 223 have through holes, and the threaded connecting columns 215 are placed inside the connecting cylinders 223. When the upper and lower bodies 21 and 22 are assembled, the threaded connecting columns 215 are connected by screws inserted into the bottom of the lower body 22 to connect and fix the upper and lower bodies 21 and 22.

[0066] The boom frame 6 consists of two symmetrically arranged on both sides of the upper body 21. The boom frame 6 includes two symmetrically arranged side plates 61. One end of the side plate 61 has a rectangular groove 62, and the other end has a trapezoidal groove 63. The rectangular groove 62 has a cover 64 symmetrically arranged at both ends for mounting the swing mechanism transmission worm gear II 33. The ends of the side plates 61 at both ends of the trapezoidal groove 63 are inverted trapezoidal structures, and mounting holes II 65 for mounting the swing mechanism transmission worm gear II 35 are opened on them.

[0067] This control system comprises an airborne section (located on the UAV fuselage) and a ground section. The airborne section includes a main control module, a power distribution board, a battery, an image transmission module, a data transmission module, a receiver, a GPS module, and a multimodal sensor array. This multimodal sensor array includes an IMU and magnetometer built into the main control module, as well as a barometer, ultrasonic sensor, wheel speed encoder, and angle sensor externally mounted on the fuselage. The ground section includes a ground station and a remote controller. The battery output is electrically connected to the power distribution board input. The power distribution board output is split into two paths: one path powers the main control module input, and the other path powers the electronic speed controllers of drive motors I11, II31, and each arm rotor motor 45. The main control module receives data via signal connections to the barometer, ultrasonic sensor, wheel speed encoder, and angle sensor. The image transmission module, data transmission module, receiver, and GPS module are connected to the main control module, ground station, and remote controller via wireless two-way communication, enabling automatic adjustment and remote control of the arm tilt and swing angles.

[0068] The main control module uses Pixhawk to control the operation of the UAV. It has a built-in IMU (Inertial Measurement Unit) and a magnetometer (magnetoresistive sensor). The IMU senses the UAV's attitude angular velocity and acceleration, and the magnetometer is used to detect the direction of the Earth's magnetic field, providing a heading reference for the flight control of the main control module.

[0069] There are two wheel speed encoders, which are installed on the wheel axles of the two front drive wheels respectively. They rotate synchronously with the wheels and are used to measure the wheel speed and travel distance for ground speed control and odometer positioning.

[0070] There are two angle sensors. The input shafts of the two angle sensors are directly coaxially connected to the output shafts of drive motor I11 and drive motor II31 through couplings. They are used to measure the rotation angle of the output shafts of drive motor I11 of the worm gear self-locking tilting mechanism 1 and drive motor II31 of the swing mechanism, so as to accurately control the tilting angle and swing angle of the arm 5.

[0071] The power distribution board is installed on the base plate of the lower fuselage 22 and is used to distribute the battery voltage to each electronic speed controller and the main control module. Each electronic speed controller is installed at each rotor motor, and its signal line is connected to the output channel of the main control module to receive the PWM signal of the main control module. During flight, the speed and direction of the four rotor motors 45 are adjusted through the electronic speed controller. In ground mode, since there are two drive wheels, only the speed and direction of rotor motor I 451 and rotor motor II 452 of the two front drive wheels are adjusted.

[0072] The image transmission module is located at the rear of the fuselage and is connected to a camera. It is responsible for transmitting the real-time video signals captured by the camera to the ground station to enable remote monitoring of the footage. The data transmission module is located inside the fuselage and is responsible for two-way data communication between the UAV and the ground control terminal (such as the remote controller or ground station) to enable real-time transmission of flight data, commands and other information. The receiver is fixed on the fuselage and receives real-time control commands (such as manual control signals for throttle, heading, pitch, etc.) issued by the remote controller and forwards them to the main control module.

[0073] The GPS is located on the aircraft body and is used to provide latitude and longitude coordinates, altitude, ground speed and heading; the ground station is the ground operation terminal, used for mission planning, status monitoring, mode switching, etc.

[0074] The barometer is installed at the bottom of the fuselage or belly of the aircraft. It determines the flight altitude by measuring changes in atmospheric pressure, thus enabling constant altitude flight.

[0075] Ultrasonic sensors are installed on the bottom and front of the fuselage to provide accurate altitude data in flight mode and obstacle data in ground mode.

[0076] The control system of this invention can automatically adjust the tilt angle and swing angle of the boom. The specific adjustment and control method is as follows:

[0077] like Figure 10 , Figure 11 As shown, the automatic adjustment of the boom tilt angle is achieved by using an ultrasonic sensor mounted at the front of the fuselage to detect in real time the distance S between the two obstacles that the drone needs to pass through. This is combined with the fuselage pitch angle β measured by the IMU and the current boom tilt angle θ fed back by the angle sensor. The main control module then executes a proportional-derivative compensation algorithm to calculate the optimal tilt angle θ for the drone to pass through the middle of the two obstacles. target :

[0078]

[0079] Where: K p —Distance scaling factor;

[0080] K d — Rate of change compensation coefficient;

[0081] S safe —A safe distance for effective passage;

[0082] S meas —Real-time measurement of the distance between two obstacles;

[0083] β—Fuse pitch angle, which refers to the angle of rotation of the UAV around the horizontal axis of the fuselage, describing the degree of pitch of the UAV nose up and down;

[0084] The algorithm dynamically generates PWM commands to control the speed of the electronic speed controller of drive motor I11, thereby controlling the rotation of drive motor I11, which in turn drives the transmission worm I13 and transmission worm wheel I14 of the worm wheel self-locking tilting mechanism to rotate, and precisely adjusts the tilt angle of the boom 6 to θ (0°-60° range). The worm wheel self-locking characteristic automatically maintains the angle stability after adjustment without the need for continuous power supply.

[0085] For example, when a drone is traveling in a narrow passage, an ultrasonic sensor installed at the front of the fuselage 2 detects the passage width S in real time. The main control module combines the passage width S, the fuselage pitch angle β measured by the IMU, and the current boom tilt angle θ fed back by the angle sensor, and immediately calculates the safe tilt angle θ that can pass through the passage using the above formula (1). target The drive motor I11 drives the transmission worm gear I14 via the transmission worm I13, raising the boom 6 to θ. target This adjustment increases the ground clearance of the fuselage 2 and reduces the overall width of the drone, allowing the wheels to pass smoothly through narrow areas. The angle sensor continuously monitors the actual tilt angle, and the main control module adjusts the tilt angle according to the target value θ. target The deviation from the actual value is adjusted in a closed loop to ensure that the tilt angle error is less than ±1°.

[0086] like Figure 11 , Figure 12 As shown, the automatic adjustment of the boom swing angle is achieved by real-time detection of the ground clearance h by an ultrasonic sensor installed at the bottom of the fuselage 2, the wheel speed v obtained by the wheel speed encoder, the fuselage roll angle γ monitored by the IMU, and the current boom swing angle α fed back by the angle sensor. The main control module adopts a multi-modal decision control algorithm to calculate and dynamically decide the boom swing angle α for safe passage through obstacles based on the terrain in real time. target :

[0087]

[0088] Where: K safe —Safety factor;

[0089] K γ —Roll angle compensation factor;

[0090] K obs —Obstacle avoidance strength coefficient;

[0091] h obs —Detection distance of the nearest obstacle;

[0092] g—acceleration due to gravity;

[0093] γ—roll angle, refers to the angle of rotation of the drone around its longitudinal axis, describing the degree of tilt of the drone to the left or right;

[0094] v—wheel speed;

[0095] λ — barrier attenuation coefficient;

[0096] The algorithm uses a dual closed-loop control system for drive motor II31: the inner loop is for PID control of the drive motor II31's speed, and the outer loop is for position control of the arm swing angle α, thereby reducing the synchronization error of the swing of the two arms 5; the drive motor is started by adjusting the speed of the electronic speed controller of drive motor II31 of the swing mechanism 3.

[0097] II31 drives the coaxial transmission worm II33 and transmission worm wheel II35 to mesh and transmit power, thus achieving synchronous swinging of the same-side arm 5.

[0098] For example, when the UAV is traveling on rugged terrain, the ultrasonic sensor monitors the changing ground clearance h in real time. The main control module uses a dynamic decision algorithm to integrate the ground clearance h, the vehicle speed v obtained by the wheel speed encoder, the fuselage roll angle γ monitored by the IMU, and the current arm swing angle α fed back by the angle sensor. The optimal arm swing angle α for overcoming obstacles is calculated in real time using formula (2). target This reduces the wheelbase and increases the chassis ground clearance. Drive motor II drives transmission worm gear II via transmission worm gear II, dynamically adjusting the boom to α. target Meanwhile, the IMU continuously monitors the roll angle γ of the fuselage, and the algorithm automatically fine-tunes the sway angle through the outer ring position control to compensate for the center of gravity shift, ensuring driving stability and enabling the drone to smoothly pass through rugged terrain.

[0099] The respective operating modes of this invention during operation are as follows:

[0100] (1) Ground mode

[0101] This application's UAV employs a two-wheel drive system to achieve ground mobility. Specifically, in ground mode, the worm gear self-locking tilting mechanism 1 drives its bevel gear set 15 to synchronously rotate the two-sided transmission worm gear I 13 and the meshing transmission worm wheel I 14, adjusting the tilt angle of the boom 6 relative to the fuselage 2 in the vertical direction. Simultaneously, the swing mechanism 3 drives the four booms 5 to swing, synchronously adjusting the swing angle of the four booms 5 on both sides, causing the wheels 41 at the ends of the booms 5 to move along the ground. The worm gear self-locking tilting mechanism 1 and the swing mechanism 3 drive the booms 5 on the same side to synchronously adjust the angle between the boom 5 and the fuselage 2 in a "two-bar coaxial" manner, completing attitude adjustment and achieving seamless switching from flight mode to ground mode. This design effectively improves mobility in compact spaces through angle control, significantly reduces the risk of getting stuck on obstacles, and enhances adaptability to complex environments.

[0102] (2) Flight Mode

[0103] The drone uses four rotor motors 45 to drive flight. In flight mode, a worm gear self-locking tilting mechanism 1 keeps the boom 6 and boom 5 in a horizontal position. A swing mechanism 3 causes boom 5 to swing relative to boom 6 in an "X" shape. The propeller 47 is mounted on boom 5 and driven by rotor motors 45 (brushless motors are used in this example) to ensure that the lift generated by the propeller 47 is vertically upward, achieving stable flight. This flight structure is universal and has the advantages of simple structure and high flexibility.

[0104] (3) Mode switching

[0105] When the drone switches from flight mode to ground mode, it first reduces its flight speed and altitude. After the wheels contact the ground, the boom 5, driven by the worm gear self-locking tilting mechanism 1, tilts downward at a certain angle, causing the power generated by the propeller 47 to be converted into the power to propel the wheels 41 forward. At the same time, the rotational speed of the propeller 47 decreases accordingly. At this point, the drone changes from relying on the lift generated by the propeller 47 to fly in the air, to relying on the wheels 41 to roll on the ground, thus realizing the switch from air mode to land mode.

[0106] When the drone switches from ground mode to flight mode, it first adjusts arm 5 to a horizontal position, enabling propeller 47 to generate vertical upward lift. Then, the rotational speed of propeller 47 gradually increases, generating enough lift to overcome the gravity of the fuselage 2, allowing the drone to leave the ground. As the lift continues to increase, the drone gradually ascends to a certain altitude, adjusts its flight attitude, and finally enters a stable aerial flight mode.

[0107] Components not described in detail in this application are all existing conventional technologies and will not be described further here.

[0108] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

Claims

1. An amphibious unmanned aerial vehicle (UAV), characterized in that: The system includes a fuselage, arms, a worm gear self-locking tilting mechanism, a swing mechanism, a single-motor dual-mode power multiplexing system, and a control system. Four arms are symmetrically arranged on both sides of the fuselage via arm frames. One end of each arm is connected to the swing mechanism, and the other end is equipped with the single-motor dual-mode power multiplexing system. The worm gear self-locking tilting mechanism is located at one end of the fuselage, with its end-end transmission worm gear I symmetrically mounted on the transmission shafts II of the swing mechanism located on both sides of the fuselage. The transmission worm gear I is mounted on the arm frame via its mounting bracket. The control system is connected to the drive motor I of the worm gear self-locking tilting mechanism, the drive motor II of the swing mechanism, and the rotor motor of the single-motor dual-mode power multiplexing system, controlling the operation of each motor.

2. The amphibious unmanned aerial vehicle according to claim 1, characterized in that: The worm gear self-locking tilting mechanism includes a drive motor I, a transmission shaft I, a transmission worm I, a transmission worm wheel I, and a bevel gear set. The output shaft of the drive motor I and the transmission shaft I are arranged perpendicularly, and the output shaft of the drive motor I is symmetrically connected to the two transmission shafts I through the bevel gear set. The transmission worm I is symmetrically installed on both transmission shafts I, and the transmission worm wheel I that meshes with the transmission worm I is sleeved on the end of the transmission shaft II of the swing mechanism.

3. The amphibious unmanned aerial vehicle according to claim 1, characterized in that: The swing mechanism includes a drive motor II, a transmission gear set, a transmission worm II, a transmission shaft II, and a transmission worm wheel II. The output shaft of the drive motor II is connected to the swing transmission shafts II on both sides of the machine body through the transmission gear set. Two transmission worms II are symmetrically arranged on each swing transmission shaft II. The transmission worm wheel II, which meshes with the transmission worm II, is installed at the end of the machine arm and is rotatably mounted between the machine arm frames through its pin, driving the machine arm on the same side to swing synchronously. The swing transmission shaft II is parallel to the output shaft of the drive motor II.

4. The amphibious unmanned aerial vehicle according to claim 3, characterized in that: The transmission gear set includes gears that mesh and drive each other, respectively mounted on the output shaft of the drive motor II and the swing transmission shaft II. Driven by the drive motor II, the transmission gear set connected to it rotates, which in turn drives the swing transmission shaft II and the transmission worm II on it to rotate. The transmission worm wheel II meshing with it drives the machine arm to swing, adjusting the angle between the machine arm and the machine body.

5. The amphibious unmanned aerial vehicle according to claim 1, characterized in that: The single-motor dual-mode power reuse system includes a wheel, a wheel drive shaft, a support plate, a reduction gear set, a rotor motor, a support column, and a propeller. A support column is installed at the end of the arm, and a support plate parallel to the arm is connected to the support column. One end of the wheel drive shaft is installed on the arm, and the other end passes through the support plate to install a wheel. The wheel drive shaft is connected to the bottom output shaft of the rotor motor located on the arm through the reduction gear set. The rotor motor has dual output shafts, and a propeller is installed on its top output shaft.

6. The amphibious unmanned aerial vehicle according to claim 1, characterized in that: The fuselage includes an upper fuselage and a lower fuselage. The upper fuselage is a cover structure with a mounting plate at one end for mounting the transmission gear set of the swing mechanism, and a mounting cover at the other end for mounting the transmission shaft I of the worm gear self-locking tilting mechanism. The outer side plate of the mounting cover has a mounting hole I for mounting the transmission shaft II of the swing mechanism. The upper fuselage has two ear plates symmetrically mounted on both outer sides, which cooperate with the cover of the boom frame. The lower fuselage is formed by a groove-shaped shell with an L-shaped plate at one end. The L-shaped plate is placed outside the mounting plate of the upper fuselage, and the transmission gear set of the swing mechanism is placed between the L-shaped plate and the mounting plate.

7. The amphibious unmanned aerial vehicle according to claim 1, characterized in that: The boom consists of two symmetrically arranged on both sides of the upper body. Each boom includes two symmetrically arranged side plates. One end of each side plate has a rectangular groove, and the other end has a trapezoidal groove. The rectangular groove has a cover for mounting the sway mechanism transmission worm gear II symmetrically arranged at both ends. The ends of the side plates at both ends of the trapezoidal groove have an inverted trapezoidal structure with mounting holes II for mounting the sway mechanism transmission worm gear II.

8. The amphibious unmanned aerial vehicle according to claim 1, characterized in that: The control system includes an airborne section and a ground section. The airborne section includes a main control module, a power distribution board, a battery, an image transmission module, a data transmission module, a receiver, a GPS module, and a multimodal sensor group. The multimodal sensor group includes an IMU and a magnetometer built into the main control module, as well as a barometer, an ultrasonic sensor, a wheel speed encoder, and an angle sensor externally mounted on the fuselage. The ground section includes a ground station and a remote controller. The battery output is electrically connected to the input of the power distribution board; the output of the power distribution board is divided into two paths: one path is electrically connected to the input of the main control module for power supply, and the other path is electrically connected to the electronic speed controllers of drive motor I, drive motor II, and each arm rotor motor; the main control module is connected to the barometer, ultrasonic sensor, wheel speed encoder, and angle sensor to receive data; the image transmission module, data transmission module, receiver, and GPS module are connected to the main control module, ground station, and remote controller to enable wireless two-way communication, realizing automatic adjustment and remote control of the arm tilt angle and swing angle.

9. The amphibious unmanned aerial vehicle according to claim 8, characterized in that: The automatic adjustment of the boom tilt angle is achieved by using an ultrasonic sensor mounted at the front of the fuselage to detect in real time the distance S between the two obstacles that the drone needs to pass through. This is combined with the fuselage pitch angle β measured by the IMU and the current boom tilt angle θ fed back by the angle sensor. The main control module then executes a proportional-derivative compensation algorithm to calculate the optimal tilt angle θ for the drone to pass through the middle of the two obstacles. target : Where: K p —Distance scaling factor; K d — Rate of change compensation coefficient; S safe —A safe distance for effective passage; S meas —Real-time measurement of the distance between two obstacles.

10. The amphibious unmanned aerial vehicle according to claim 8, characterized in that: The automatic adjustment of the boom swing angle is achieved through real-time detection of ground clearance h by an ultrasonic sensor installed at the bottom of the fuselage, wheel speed v obtained by a wheel speed encoder, fuselage roll angle γ monitored by an IMU, and the current boom swing angle α fed back by an angle sensor. The main control module employs a multimodal decision control algorithm to calculate and dynamically decide the boom swing angle α for safe obstacle passage based on the terrain in real time. target : Where: K safe —Safety factor; K γ —Roll angle compensation factor; K obs —Obstacle avoidance strength coefficient; h obs —Detection distance of the nearest obstacle; g—acceleration due to gravity; γ—roll angle; λ — barrier attenuation coefficient.

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