A folding-arm amphibious quadrotor drone

Abstract

The present invention relates to a folding arm amphibious quad-rotor unmanned aerial vehicle, comprising an arm movably connected to both sides of a fuselage, a rotor connected to a rotor motor is provided on the upper surface of the distal end of the arm, a wheel connected to the rotor motor through a reduction gear set is provided on the lower surface, a deformable servo is provided on the fuselage, an output shaft of the deformable servo is connected to a straight-line rudder arm, and the two ends of the straight-line rudder arm are respectively movably connected to a universal ball head support provided on the arm through a universal ball head connecting rod; the two ends of the straight-line rudder arm are driven to rotate around the output shaft by the deformable servo, and the universal ball head support and the arm are driven to move through the corresponding universal ball head connecting rod, so that the angle between the arm and the fuselage is changed to achieve unfolding or folding. On the basis of the quad-rotor unmanned aerial vehicle, the motion mode of the wheeled robot is added, and the robot has the ability to deform, and can switch between the wheeled robot and the quad-rotor unmanned aerial vehicle through folding and deformation, so that the unmanned aerial vehicle can adapt to different operational task requirements in ground scenes and aerial scenes.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles (UAVs), in particular to an amphibious quad-rotor UAV with folding arms. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Drones can be seen as robots that can perform specific tasks and can fly. However, some operational tasks are not limited to the air and may involve a combination of air and ground, which makes the drone's motion mode single and the scope of tasks that can be performed is limited. Although some structurally variable drone / mobile robot solutions can perform multi-habitat operations, they are usually fixed structures and large in size, with poor obstacle crossing capabilities, and there is still the problem of limited scope of executable tasks. At the same time, the current level of intelligence of drones is not ideal, and it is difficult to simultaneously meet the needs of multiple motion modes, obstacle crossing capabilities, precise control and autonomous decision-making capabilities. Summary of the invention

[0004] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a folding-arm amphibious quadrotor UAV, which combines the structure of a wheeled robot with a quadrotor UAV, so that the wheeled robot and the quadrotor UAV can be switched between the wheeled robot and the quadrotor UAV through folding and deformation, thereby enabling the UAV to adapt to different operational mission requirements in ground scenes and aerial scenes.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] The first aspect of the present invention provides a folding-arm amphibious quad-rotor UAV, comprising arms movably connected to both sides of a fuselage through hinged pins, an upper surface of the distal end of the arm is provided with a rotor connected to a rotor motor, a lower surface is provided with a wheel connected to the rotor motor through a reduction gear set, a deformable servo is provided on the fuselage, an output shaft of the deformable servo is connected to a straight-line rudder arm, and both ends of the straight-line rudder arm are movably connected to a universal ball head support provided on the arm through a universal ball head connecting rod respectively; the deformable servo drives the two ends of the straight-line rudder arm to rotate around the output shaft, and drives the universal ball head support and the arm to move through the corresponding universal ball head connecting rod, so that the angle between the arm and the fuselage is changed to achieve unfolding or folding.

[0007] The fuselage is equipped with an onboard computer, flight control board, power distribution board and battery; the upper surface of the fuselage is connected to the power distribution board, and there are two layers of partitions above the power distribution board. The space formed by the partitions accommodates the onboard computer and flight control board from top to bottom respectively, and a battery is installed inside the fuselage.

[0008] The proximal end of the arm is movably connected to the fuselage through an articulated pin, and a spring is provided in the middle of the articulated pin; the spring comprises a spiral spring body and two steel wires extending outwards connected to both ends of the spring body, one of which extends to the bottom of the arm and the other extends to the bottom of the fuselage.

[0009] The upper surface of the machine arm is connected to a universal ball head support and a limit support that rotate around a hinge pin. The universal ball head support is movably connected to one end of the I-shaped rudder arm through a corresponding universal ball head connecting rod. The I-shaped rudder arm and the connected deformable servo are both located on the upper surface of the fuselage.

[0010] A positioning rod is provided at the top of the limit support and extends above the fuselage. When the machine arm is unfolded to a horizontal state, the positioning rod abuts against the fuselage.

[0011] The universal ball head connecting rod includes a first ball head rod movably connected to the two ends of the I-shaped rudder arm; the top of the universal ball head support seat of each side of the machine arm is movably connected to the second ball head rod, and the ball heads of the two sets of second ball head rods are in opposite directions; the ball head of the first ball head rod is movably connected to the ball head of the second ball head rod at the top of the universal ball head support seat on the same side through a connecting rod.

[0012] When the two ends of the straight-line rudder arm face the arms on both sides of the fuselage, the straight-line rudder arm drives the universal ball head connecting rod to apply force to the universal ball head support toward the arms on both sides, so as to push the arms to fold.

[0013] When the connecting line of the two ends of the I-shaped rudder arm points to the axis of the fuselage, the I-shaped rudder arm drives the universal ball head connecting rod to apply force to the universal ball head support toward the axis of the fuselage, pulling the arm to extend to a horizontal state.

[0014] One end of the output shaft of the rotor motor is connected to the rotor, and the other end is connected to the wheel through a reduction gear set.

[0015] Compared with the prior art, one or more of the above technical solutions have the following beneficial effects:

[0016] 1. On the basis of the quad-rotor drone, the motion mode of the wheeled robot is added, and it has the ability to deform. It can switch between the wheeled robot and the quad-rotor drone through folding and deformation, so that the drone can adapt to different operational mission requirements in ground scenes and aerial scenes.

[0017] 2. When the arms are folded, the sides of the wheels touch the ground, allowing the fuselage to be at a certain distance from the ground, thereby avoiding protrusions of a certain height on the ground, and having a certain degree of obstacle avoidance function; when encountering obstacles such as holes that cannot be passed during flight, the arms are retracted during the ascent phase of the drone and switched to a folded state to reduce the overall diameter of the drone, forming a free upward throw movement. After passing through the hole, the arms are unfolded again to resume flight, giving it a certain ability to avoid air obstacles. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] Figure 1 A schematic diagram of the structure of a rotating arm amphibious quad-rotor drone in a horizontal state, i.e., a top-down perspective in an aerial motion mode, provided by one or more embodiments of the present invention;

[0020] Figure 2 A schematic diagram of the front-view structure of a rotating-arm amphibious quad-rotor drone in a horizontal state, i.e., in an aerial motion mode, provided by one or more embodiments of the present invention;

[0021] Figure 3 A schematic diagram of the front-view structure of the rotating arm amphibious quad-rotor drone in a folded deformation state, i.e., a land motion mode, provided by one or more embodiments of the present invention;

[0022] Figure 4 A schematic diagram of a structure in which a fuselage and an arm are connected by a hinge pin according to one or more embodiments of the present invention;

[0023] Figure 5 A schematic diagram of the structure of a longitudinal folding deformation structure formed by a deformable servo, a straight-line rudder arm and a universal ball head connecting rod provided by one or more embodiments of the present invention;

[0024] Figure 6 A schematic diagram of the structure of a rotor rear shaft and a wheel shaft, and a matching reduction gear set provided in one or more embodiments of the present invention;

[0025] Figure 7 A schematic diagram of the electrical control system architecture of a rotating arm amphibious quad-rotor drone provided by one or more embodiments of the present invention;

[0026] Figure 8 A schematic diagram of the obstacle avoidance motion of a rotating arm amphibious quadrotor drone provided by one or more embodiments of the present invention;

[0027] In the figure, 1. fuselage; 2. arm; 3. deformable servo; 4. flight control board; 5. onboard computer; 6. distribution board; 7. battery; 8. articulated axle pin; 9. straight-line rudder arm; 10. universal ball joint connecting rod; 11. rotor motor; 12. wheel; 13. limit support; 14. universal ball joint support; 15. rear shaft; 16. wheel shaft; 17. reduction gear set; 18. partition; 19. slot; 20. spring. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] As described in the background technology, as a drone performing a mission, it will encounter obstacles during flight. The existing technology relies on complex control algorithms to achieve obstacle avoidance, which limits the operating range of the drone.

[0032] Therefore, the following embodiment provides a folding-arm amphibious quadrotor UAV, which combines the structure of a wheeled robot with a quadrotor UAV, so that the wheeled robot and the quadrotor UAV can be switched between the wheeled robot and the quadrotor UAV through folding and deformation, thereby enabling the UAV to adapt to different operational mission requirements in ground scenes and aerial scenes.

[0033] Embodiment 1:

[0034] like Figure 1-8 As shown, a folding-arm amphibious quad-rotor UAV comprises: arms movably connected to both sides of a fuselage through hinged shaft pins, the upper surface of the distal end of the arms is provided with a rotor connected to a rotor motor, the lower surface is provided with a wheel connected to the rotor motor through a reduction gear set, a deformable servo is provided on the fuselage, the output shaft of the deformable servo is connected to a straight-line rudder arm, and the two ends of the straight-line rudder arm are movably connected to a universal ball head support provided on the arm through a universal ball head connecting rod respectively; the two ends of the straight-line rudder arm are driven by the deformable servo to rotate around the output shaft, and the universal ball head support is driven by the corresponding universal ball head connecting rod, so that the angle between the arm and the fuselage is changed to achieve folding.

[0035] Specific:

[0036] The side where the deformable servo 3 is located is defined as the front side of the quadcopter; a deformable servo 3 and a distribution board 6 are provided on the fuselage 1, and two layers of partitions 18 are provided above the distribution board 6, and a flight control board 4 and an onboard computer 5 are provided from bottom to top, and a battery 7 is provided inside the fuselage 1; symmetrical arms 2 are provided on both sides of the fuselage 1, and the arms 2 can rotate around the hinge pins 8 on both sides of the fuselage, a universal ball head support 14 is provided on the front side of the arm 2, and a limit support 13 is provided on the rear side, and a group of rotor motors 11 and wheels 12 are provided at the front and rear ends of the arm 2 on each side, and the rear output shaft 15 of the rotor motor 11 and the wheel shaft 16 are driven by a reduction gear set 17; the output shaft of the deformable servo 3 is provided with a straight-line rudder arm 9, which is connected to the universal ball head support 14 on the front side of the arm 2 through a universal ball head connecting rod 10, and the central symmetry principle is used to drive the arms 2 on both sides to rotate synchronously.

[0037] The fuselage 1 and the two layers of partitions 18 are supported and connected by M2.5 aluminum columns, and M2.5 holes are punched at corresponding positions of the fuselage 1 and the partitions 18 for installing screws. The power distribution board 6 is also fixed to the fuselage 1 by screws.

[0038] The deformable servo 3 is fixed to the plate in front of the fuselage 1 by M4 screws, and the straight rudder arm 9 extends above the fuselage 1.

[0039] Deformation mechanism connected by universal ball head combination rod 10: The folding and extension of the machine arm 2 are realized by the drive of the deformable servo 3 and the transmission of the deformable connection mechanism. Since the rotation of the deformable servo 3 is not coplanar with the rotation of the machine arm 2, the connection point is extremely unstable, and conventional connection means cannot meet the requirements. Therefore, a universal ball head combination rod 10 is designed to connect the deformable servo 3 and the machine arm 2.

[0040] like Figure 5 As shown, the output shaft of the deformed servo 3 is equipped with a straight-line rudder arm 9, and each end of the straight-line rudder arm 9 is respectively provided with a ball head rod, with the ball head facing downward; a ball head rod also extends from the top of the universal ball head support 14 of each side arm 2, the ball head of the left arm faces forward, and the ball head of the right arm faces backward; the ball head at the end of the rudder arm and the ball head at the top of the universal ball head support 14 on the same side are combined by a connecting rod to form a universal ball head connecting rod 10.

[0041] like Figure 1-2 As shown, when the straight-line rudder arm 9 is in the front-to-back orientation, the arm 2 is in a horizontal state, which is consistent with the appearance of a standard quadcopter.

[0042] like Figure 3 As shown, when the straight-line rudder arm 9 rotates counterclockwise, the rudder arm drives the universal ball head connecting rod 10 to apply force to the universal ball head support 14 on both sides, pushing the machine arm 2 to fold downward.

[0043] When the straight-line rudder arm 9 rotates counterclockwise, the rudder arm drives the universal ball head connecting rod 10 to exert force on the universal ball head support 14 toward the center, pulling the arm 2 to stretch upward and return to the Figure 1 and 2 horizontal state.

[0044] It can be seen that the deformation mechanism is stable, and the rotation angle of the servo is positively correlated with the rotation angle of the arm 2 and has a nonlinear relationship. The closer the arm 2 is to the flattened state, the more efficient the change in the rotation angle of the deformed servo 3 is in driving the change in the rotation angle of the arm 2.

[0045] Spring and limit support: Figure 4 As shown, the spring 20 is located at the center of the hinge pin 8 on each side, and is composed of a spiral spring body and two steel wires extending outward, one of which extends to the bottom of the arm 2, and the other extends to the bottom of the fuselage 1. When the arm 1 is in a non-horizontal state, the spring 20 will exert an upward elastic force on the arm 2, which can effectively alleviate the vibration phenomenon caused by friction, airflow and other reasons during deformation.

[0046] A positioning rod is provided at the top of the limiting support 13, extending toward the top of the fuselage 1. When the arm 2 is unfolded to a horizontal state, the positioning rod abuts against the fuselage 1 to prevent the arm 2 from further turning up.

[0047] Speed ​​gear set: Figure 6 As shown, the rotor motor 11 is combined with the wheel 12 through the reduction gear set 17 to form a new type of integral structure, using one motor to drive the rotor and the wheel 12 at the same time, which cleverly simplifies the amphibious dual-mode motion mechanism, reduces the number of actuators, and reduces the size and weight of the platform.

[0048] The maximum speed of the rotor motor 11 in flight is about 30,000 RPM. Considering that the rotation of the rotor will provide lateral force when moving on the ground, the speed of the rotor motor 11 should not exceed 10,000 RPM. The diameter of the wheel is 8 mm. In order to control the maximum running speed on the ground at about 2 m / s, a transmission ratio of 20:1 is selected. According to the rotation direction of each rotor in the standard X-type quadrotor model, the two front gear sets adopt 2-stage transmission, and the transmission ratio is set to 4:1 and 5:1; the rear gear set adopts 3-stage transmission, that is, adding a 1:1 reverse rotation to ensure that the four wheels have the same rotation direction, and the forward direction of land movement is equivalent to the forward direction of flight in the air.

[0049] Electronic control part:

[0050] Control components: such as Figure 7As shown, the battery is used to power all components of the drone; the distribution board is used to divide the battery voltage into multiple strands for welding of various components; the onboard computer is used to obtain the flight status and experimental data of the drone, perform data processing or communicate with the ground station; the flight control board is used to convert the control signal of the onboard computer or remote control into the PWM signal of the rotor motor; the electric speed controller is used to convert the PWM signal into the input voltage of the rotor motor. After being transmitted by the above control components, the external control signal is finally converted into the speed of the rotor motor to control the movement of the drone.

[0051] Flight dynamics: The rotors are located in the left front, left rear, right front, and right rear directions of the drone, and are distributed in a rectangular shape. All attitude and position controls of the amphibious drone in the flight mode of this embodiment are achieved by adjusting the speed of the four drive motors. The motion states of the drone are mainly divided into lifting motion (including hovering), rolling motion, pitching motion, and yaw motion.

[0052] Lifting and hovering: While ensuring that the rotation speed of each rotor of the drone is the same and the rotation speeds of adjacent rotors are in opposite directions, the vertical movement of the drone can be achieved by increasing / decreasing the rotation speed of each rotor by the same amount at the same time; the necessary condition for hovering is that the total lift of the four rotors is exactly equal to the gravity of the drone.

[0053] Rolling motion: Rolling motion is achieved by changing the rotor speed at the left and right ends to form a lift difference between the left and right sides, thereby forming a certain torque on the front and rear axis of the fuselage and generating angular acceleration.

[0054] Pitch motion: Pitch motion is achieved by changing the rotation speed of the rotors at the front and rear ends to form a lift difference between the front and rear sides, thereby forming a certain torque on the lateral rotation axis of the fuselage and generating angular acceleration.

[0055] Yaw motion: Yaw motion is achieved by changing the rotation speed of the two sets of diagonal rotors. When the sum of the rotation speeds of the two diagonal rotors is different from that of the other set of rotors, the two sets of rotors rotate in different directions, which will lead to an imbalance in the anti-torque force. At this time, a reaction force around the longitudinal axis will be generated, generating angular acceleration.

[0056] Land kinematics: When moving on land, its motion is similar to that of a fixed-wheel four-wheel drive vehicle. When turning, the wheels will slip and be subject to unknown ground friction, so there is no accurate kinematic model, but it is roughly equivalent to a two-wheel differential motion model. That is, the speed difference is generated by changing the speed of the wheels on the left and right sides, thereby driving the vehicle body to turn.

[0057] When the arms are folded, they form a structure similar to that of a wheeled robot, using a rotor motor as power and wheels as driving components to perform required work tasks on the ground; when the arms are unfolded, they become a traditional quad-rotor drone that performs aerial work tasks.

[0058] like Figure 8 As shown, when the arms are folded, the sides of the wheels touch the ground, so that the fuselage can be at a certain distance from the ground, thereby avoiding protrusions of a certain height on the ground, and having a certain degree of obstacle avoidance function; when encountering obstacles such as holes that cannot be passed through during flight, the arms are retracted during the ascent phase of the drone and switched to a folded state to reduce the overall diameter of the drone, forming a free upward throw movement. After passing through the hole, the arms are unfolded again to resume flight, so that it has a certain ability to avoid obstacles in the air.

[0059] The above-mentioned structure can switch between a wheeled robot and a quad-rotor drone through folding and deformation, so that the drone can adapt to different operational mission requirements in ground scenes and aerial scenes, and the structure itself has a certain obstacle avoidance capability.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A folding-arm amphibious quadrotor drone, characterized in that: The invention comprises an arm movably connected to both sides of the fuselage through an articulated shaft pin, a rotor connected to a rotor motor is arranged on the upper surface of the distal end of the arm, a wheel connected to the rotor motor through a reduction gear set is arranged on the lower surface, a deformable steering gear is arranged on the fuselage, an output shaft of the deformable steering gear is connected to a straight-line rudder arm, and two ends of the straight-line rudder arm are movably connected to a universal ball head support provided on the arm through a universal ball head connecting rod respectively; the two ends of the straight-line rudder arm are driven by the deformable steering gear to rotate around the output shaft, and the universal ball head support and the arm are driven to move through the corresponding universal ball head connecting rod, so that the angle between the arm and the fuselage is changed to realize unfolding or folding; The proximal end of the arm is movably connected to the fuselage through a hinge pin, and a spring is provided in the middle of the hinge pin; The spring comprises a spiral spring body and two steel wires connected to both ends of the spring body and extending outward, wherein one steel wire extends to the bottom of the machine arm and the other steel wire extends to the bottom of the machine body; When the two ends of the straight-line rudder arm face the arms on both sides of the fuselage, the straight-line rudder arm drives the universal ball head connecting rod to apply force to the universal ball head support toward the arms on both sides, pushing the arms to fold; When the arms are folded, the sides of the wheels touch the ground, allowing the fuselage to be at a certain distance from the ground, thus avoiding protrusions of a certain height on the ground; The maximum speed of the rotor motor in flight is about 30,000 RPM, and the speed of the rotor motor does not exceed 10,000 RPM when moving on the ground.

2. A folding-arm amphibious quadrotor drone as claimed in claim 1, characterized in that: The upper surface of the fuselage is connected to a power distribution board, and two layers of partitions are arranged above the power distribution board. The space formed by the partitions accommodates the onboard computer and the flight control board from top to bottom respectively, and a battery is arranged inside the fuselage.

3. The folding-arm amphibious quadrotor drone according to claim 1, characterized in that: The upper surface of the machine arm is connected to a universal ball head support and a limit support that rotate around a hinge pin. The universal ball head support is movably connected to one end of the I-shaped rudder arm through a corresponding universal ball head connecting rod. The I-shaped rudder arm and the connected deformable servo are both located on the upper surface of the fuselage.

4. The folding-arm amphibious quadrotor drone according to claim 3, characterized in that: A positioning rod is provided at the top of the position-limiting support and extends above the fuselage. When the machine arm is unfolded to a horizontal state, the positioning rod abuts against the fuselage.

5. The folding-arm amphibious quadrotor drone according to claim 1, characterized in that: The universal ball head connecting rod includes a first ball head rod movably connected to the two ends of the I-shaped rudder arm; a second ball head rod movably connected to the top of the universal ball head support of each side of the machine arm, and the ball heads of the two groups of second ball head rods are in opposite directions; the ball head of the first ball head rod is movably connected to the ball head of the second ball head rod at the top of the universal ball head support on the same side through a connecting rod.

6. The folding-arm amphibious quadrotor drone according to claim 1, characterized in that: When the connecting line of the two ends of the straight-line rudder arm points to the fuselage axis, the straight-line rudder arm drives the universal ball head connecting rod to apply force to the universal ball head support toward the fuselage axis, pulling the arm to extend to a horizontal state.

7. The folding-arm amphibious quadrotor drone according to claim 1, characterized in that: One end of the output shaft of the rotor motor is connected to the rotor, and the other end is connected to the wheel through a reduction gear set.

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