Reconfigurable multi-rotor drone based on bistable hinges

Abstract

The application discloses a reconfigurable multi-rotor unmanned aerial vehicle based on a bistable hinge, which comprises a bistable hinge, a rotor assembly, a magnet and a hand grabber, etc. The bistable hinge is composed of a fuselage module, a pin shaft and a tension spring. The unmanned aerial vehicle has two different fuselage configurations, i.e. a ring configuration (configuration A) and a "I" shape configuration (configuration B). The counter torque generated by the same direction clockwise / anticlockwise rotation of the rotor overcomes the magnet attraction and the spring tension, switches the fuselage hinge steady state, realizes the "opening" / "closing" of the fuselage of the unmanned aerial vehicle, changes the wheelbase of the unmanned aerial vehicle while converting the fuselage configuration of the unmanned aerial vehicle. Moreover, the tension of the tension spring and the attraction of the magnet together guarantee the structural stability of the unmanned aerial vehicle under the two fuselage configurations. In addition, the "I" shape fuselage configuration and the hollow ring fuselage configuration respectively make the unmanned aerial vehicle have the ability to shuttle in narrow space and grab objects.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) technology, specifically relating to a reconfigurable multi-rotor UAV based on a bistable hinge. Background Technology

[0002] Unmanned aerial vehicles (UAVs) are unmanned aircraft equipped with a series of complex electronic systems that can fly autonomously or semi-autonomously. With the continuous development of UAV technology, these devices have been widely used in fields such as aerial photography, forest fire prevention, farmland fertilization, and cargo transportation.

[0003] In post-disaster scenarios, rescue workers often face the challenge of entering confined and cluttered environments. Due to the maneuverability and versatility of drones, there is growing interest in developing drones for remote exploration of these dangerous and often inaccessible locations. However, entering confined spaces presents significant challenges for ordinary drones. Furthermore, in recent years, there has been increasing focus on the autonomous object-grabbing and cargo-transporting capabilities of drones. However, currently, most developments for these functions utilize robotic arms with drive mechanisms (servo motors). This design undoubtedly increases the weight of the drone, thereby reducing flight time.

[0004] Therefore, to address the aforementioned technical problems, there is an urgent need to design a new type of drone. This drone should be able to maneuver through narrow spaces by changing its configuration, and also have the function of grasping objects and transporting goods without additional propulsion. Summary of the Invention

[0005] The purpose of this invention is to provide a reconfigurable multi-rotor unmanned aerial vehicle (UAV) based on bistable hinges. This UAV has two different fuselage configurations: a ring-shaped configuration (configuration A) and a straight-line configuration (configuration B). The tension of the tension spring and the attraction of the magnet jointly ensure the structural stability of the UAV. In addition, the straight-line fuselage configuration and the hollow ring-shaped fuselage configuration respectively enable the UAV to navigate through narrow spaces and grasp objects. After changing the tilt angle of the two short sides of the fuselage module (11), when the UAV fuselage with (4n-1) bistable hinges (1) is in configuration A, the UAV is a 2n-rotor UAV with a fuselage in the shape of a regular 4n-gon, where n is an integer greater than or equal to 2.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A reconfigurable multi-rotor unmanned aerial vehicle based on a bistable hinge includes: a bistable hinge (1), a rotor assembly (2), a magnet (3), a fuselage front and rear joint surface (4), a gripper (5), a nut (6) and a screw (7);

[0008] Furthermore, when the UAV fuselage is in configuration A, the fuselage modules (11) are connected end to end to form a ring fuselage; when the UAV fuselage is in configuration B, the fuselage modules (11) are arranged in a straight line, and the two ends of the tension spring (13) and the axis of the pin (12) are on the same straight line, forming a straight fuselage. Under both fuselage configurations, the tension of the tension spring (13) and the attraction of the magnet (3) together ensure the structural stability of the UAV.

[0009] Furthermore, the principle of the UAV's fuselage configuration conversion is as follows (from configuration A to configuration B, i.e., from a ring fuselage to a straight fuselage): When the propeller (21) rotates clockwise under the drive of the motor (22), it generates a counter-clockwise torque, and the fuselage rotates counter-clockwise under the action of the counter-torque; as the speed of the propeller (21) increases, its counter-torque also increases; when the counter-torque is greater than the sum of the attraction of the magnets (31, 33) and the tension of the tension spring (13), the UAV separates at the front and rear joint surfaces (4) of the fuselage; at this time, the UAV fuselage is separated from configuration A and is in a fuselage configuration transition state; as the included angle of the fuselage module (11) increases, the tension spring (13) stretches and the elastic potential energy increases; when the angle of the bistable hinge (1) becomes 180°, the UAV fuselage configuration changes and enters configuration B;

[0010] Furthermore, the principle of the UAV's fuselage configuration conversion is as follows (from configuration B to configuration A, i.e., from a straight fuselage to a ring fuselage): When the propeller (21) rotates counterclockwise under the drive of the motor (22), it generates a counter-torque in the clockwise direction, and the fuselage rotates clockwise under the action of the counter-torque; as the speed of the propeller (21) continues to increase, its counter-torque also continues to increase; when the counter-torque is greater than the sum of the attraction of the magnet (32) and the tension of the tension spring (13), the UAV begins to break away from configuration B; as the included angle of the fuselage module (11) continues to decrease, the tension spring (13) shortens and the elastic potential energy decreases; when the angle of the bistable hinge (1) becomes 135°, the UAV fuselage configuration changes and enters configuration A;

[0011] Furthermore, after changing the tilt angle of the two short sides of the fuselage module (11) to 67.5°, when the fuselage of the UAV with 7 bistable hinges (1) is in configuration A, the UAV is a quadcopter UAV with a regular octagonal fuselage, and n equals 2.

[0012] Further, the gripper (5) is fixedly connected to the fuselage module (11) by threads; the gripper (5) has compressive elasticity, enabling the drone to grasp objects of different sizes; in addition, the gripper (5) has a rough contact surface for increasing the friction force with the grasped object.

[0013] A bistable hinge (1) includes: a fuselage module (11), a pin shaft (12), and a tension spring (13); both ends of the tension spring (13) are fixedly connected to the midpoints of two adjacent fuselage modules (11) in the regular octagon fuselage, forming the bistable hinge (1).

[0014] A rotor assembly includes: a propeller (21) and a motor (22); the rotor assemblies (2) are evenly distributed on the fuselage module (11), and the motor (22) is fixedly connected to the propeller (21) by threads. The motor (22) is fixedly connected to the fuselage module (11) by four screws.

[0015] A reconfigurable quadrotor drone based on a bistable hinge; when n equals 2, the multi-rotor drone is a quadrotor drone; at this time, the flight principle of the quadrotor drone is as follows: the propellers (21-1, 21-4) rotate counterclockwise, and the propellers (21-2, 21-4) rotate clockwise; when hovering, the rotational speeds of the propellers (21-1, 21-2, 21-3, 21-4) are the same, that is, ω1 = ω2 = ω3 = ω4, and the counter torque and the pitching moment cancel each other out; for vertical movement, simultaneously increase / decrease the rotational speeds of the four propellers (21-1, 21-2, 21-3, 21-4) by the same amount, then the total lift force increases / decreases but the torque sum remains zero. When the lift force is greater / less than the weight of the drone, the drone moves upward / downward; for forward / backward movement, increase / decrease the rotational speeds of the propellers (21-1, 21-2) by the same amount, and simultaneously decrease / increase the rotational speeds of the propellers (21-3, 21-4) by the same amount, that is, ω1 = ω2 > ω3 = ω4 / ω1 = ω2 < ω3 = ω4, then it will cause the drone to pitch forward / backward and the counter torques cancel each other out. Under the action of the forward / backward component of the lift force, the drone moves forward / backward; for yaw movement, increase / decrease the rotational speeds of the propellers (21-2, 21-3) by the same amount, and simultaneously decrease / increase the rotational speeds of the propellers (21-1, 21-4) by the same amount, that is, ω2 = ω3 > ω1 = ω4 / ω2 = ω3 < ω1 = ω4. At this time, the counter torque M2 = M3 > M1 = M4 / M2 = M3 < M1 = M4 and the pitching moment cancel each other out. Under the action of the counter torque, the drone yaws counterclockwise / clockwise.

[0016] Different from traditional drones, the advantages of the present invention are as follows:

[0017] (1) It has rich functionality. The drone has two different fuselage configurations: a ring (configuration A) and a straight line (configuration B), which enables it to navigate through narrow spaces and grab objects.

[0018] (2) It can autonomously change the fuselage configuration without human intervention;

[0019] (3) The object can be grasped, transported and released without the need for additional drive devices (servo motors);

[0020] (4) The gripper with compressibility elasticity allows the drone to grab objects of different sizes. Attached Figure Description

[0021] The accompanying drawings are used to provide a further understanding of the technical solutions of this application or the prior art, and form part of the specification. The drawings illustrating examples of this application, together with the examples of this application, are used to explain the technical solutions of this application, but do not constitute a limitation on the technical solutions of this application.

[0022] Figure 1 This is a schematic diagram of the overall structure of the reconfigurable multirotor UAV based on a bistable hinge.

[0023] Figure 2 This is a schematic diagram illustrating the principle of the UAV fuselage configuration conversion (converting a ring fuselage into a straight line shape);

[0024] Figure 3 The diagram shows the flight principle of the aforementioned UAV (with a "I"-shaped fuselage).

[0025] Figure 4 This is a schematic diagram illustrating the principle of the UAV fuselage configuration conversion (converting a straight fuselage into a ring shape);

[0026] Figure 5 A schematic diagram of the drone passing through a narrow space;

[0027] Figure 6 This is a schematic diagram of the drone capturing an object;

[0028] Figure 7 This is a schematic diagram of the annular fuselage configuration of the multi-rotor UAV when n=3;

[0029] Figure 8 This is a schematic diagram of the annular fuselage configuration of the multi-rotor UAV when n=4.

[0030] Explanation of reference numerals in the attached diagram: 1—Bistable hinge, 11—Fuselage module, 12—Pin, 13—Tension spring, 2—Rotor assembly, 21—Propeller, 22—Motor, 3—Magnet, 4—Fuselage bow and stern mating surface, 5—Hand gripper, 6—Nut, 7—Screw; Figure 1 — Figure 6 The examples all take a quadcopter drone with n=2 as an example. Detailed Implementation

[0031] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0032] After changing the tilt angle of the two short sides of the fuselage module 11 to 67.5°, when the fuselage of the UAV with 7 bistable hinges 1 is in configuration A, the UAV is a quadcopter UAV with a regular octagonal fuselage, and n equals 2. The following uses the above quadcopter UAV as an example to further illustrate the technical solution of the present invention.

[0033] Figure 1 A schematic diagram of the overall structure of a reconfigurable multirotor unmanned aerial vehicle based on a bistable hinge according to an embodiment of the present disclosure is shown. Figure 1 As shown, a reconfigurable multi-rotor UAV based on a bistable hinge includes: a bistable hinge 1, a rotor assembly 2, a magnet 3, a fuselage front and rear mating surfaces 4, a gripper 5, a nut 6, and a screw 7.

[0034] It should be noted that the bistable hinge 1 includes: a fuselage module 11, a pin 12, and a tension spring 13; the eight fuselage modules 11 are connected end to end to form a regular octagonal fuselage (annular fuselage / configuration A); the two ends of the tension spring 13 are respectively fixed to the midpoints of two adjacent fuselage modules 11 in the regular octagonal fuselage to form the bistable hinge 1;

[0035] It should be noted that the rotor assembly 2 is evenly distributed on the four fuselage modules 11 of the regular octagonal fuselage, and includes: a propeller 21 and a motor 22. The motor 22 is fixedly connected to the propeller 21 by threads. The motor 22 is fixedly connected to the fuselage module 11 by four screws;

[0036] It should be noted that the gripper 5 is fixedly connected to the body module 11 by threads; the gripper 5 has compressibility elasticity, enabling the drone to grasp objects of different sizes; in addition, the gripper 5 has a rough contact surface to increase the friction with the grasped object.

[0037] Specifically, the fuselage module 11, the gripper 5, the nut 6, and the screw 7 are all made of plastic to reduce the weight of the drone and increase its battery life.

[0038] Figure 2 A schematic diagram illustrating the principle of unmanned aerial vehicle (UAV) fuselage configuration conversion according to an embodiment of this disclosure (conversion of a regular octagon to an "I" shape). For example... Figure 2As shown, when the propellers 21 rotate clockwise under the drive of the motor 22, counterclockwise counter-torque is generated, and the fuselage rotates counterclockwise under the action of the counter-torque; as the rotational speed of the propellers 21 continuously increases, its counter-torque also continuously increases; when the counter-torque is greater than the sum of the attraction forces of the magnets 31 and 33 and the pulling force of the tension spring 13, the UAV separates at the joint surface 4 of the fuselage head and tail; as the included angle of the fuselage module 11 continuously increases, the tension spring 13 elongates and its elastic potential energy increases; when the angles of the bistable hinges 1 both become 180°, the configuration of the UAV fuselage changes and enters Configuration B.

[0039] Figure 3 Figure 4 shows the flight principle diagram of a UAV (a "one"-shaped fuselage) according to an embodiment of the present disclosure. As Figure 3 shown, when the UAV is in the "one"-shaped fuselage configuration, the axes of the two end points of the tension spring 13 and the pin shaft 12 are located on the same straight line;

[0040] It should be noted that the flight principle of the UAV at this time is as follows: the propellers 21-1 and 21-4 rotate counterclockwise, and the propellers 21-2 and 21-4 rotate clockwise; when hovering, the rotational speeds of the propellers 21-1, 21-2, 21-3, and 21-4 are the same, that is, ω1 = ω2 = ω3 = ω4, and the counter-torque and pitch moment cancel each other out; for vertical movement, simultaneously and equally increase / decrease the rotational speeds of the four propellers 21-1, 21-2, 21-3, and 21-4, then the total pulling force increases / decreases but the torque sum is still zero. When the pulling force is greater / less than the weight of the UAV, the UAV moves upward / downward; for forward and backward movement, simultaneously and equally increase / decrease the rotational speeds of the propellers 21-1 and 21-2, and simultaneously and equally decrease / increase the rotational speeds of the propellers 21-3 and 21-4, that is, ω1 = ω2 > ω3 = ω4 / ω1 = ω2 < ω3 = ω4, then it will cause the UAV to pitch forward / backward and the counter-torques cancel each other out. Under the action of the forward / backward component of the pulling force, the UAV moves forward / backward; for yaw movement, simultaneously and equally increase / decrease the rotational speeds of the propellers 21-2 and 21-3, and simultaneously and equally decrease / increase the rotational speeds of the propellers 21-1 and 21-4, that is, ω2 = ω3 > ω1 = ω4 / ω2 = ω3 < ω1 = ω4. At this time, the counter-torques M2 = M3 > M1 = M4 / M2 = M3 < M1 = M4 and the pitch moments cancel each other out. Under the action of the counter-torque, the UAV yaws counterclockwise / clockwise.

[0041] Figure 4 Figure 13 shows the schematic diagram of the principle of the UAV fuselage configuration conversion (from "one"-shaped to regular octagon) according to an embodiment of the present disclosure. As Figure 4As shown, when the propeller (21) rotates counterclockwise under the drive of the motor (22), it generates a counter-torque in the clockwise direction. The fuselage rotates clockwise under the action of the counter-torque. As the speed of the propeller (21) increases, its counter-torque also increases. When the counter-torque is greater than the sum of the attraction of the magnet (32) and the tension of the tension spring (13), the UAV begins to change its fuselage configuration. As the included angle of the fuselage module (11) decreases, the tension spring (13) shortens and the elastic potential energy decreases. When the angle of the bistable hinge (1) becomes 135°, the fuselage configuration of the UAV changes and enters configuration A.

[0042] Figure 5 and Figure 6 A schematic diagram of a drone passing through a narrow space and a schematic diagram of the drone grasping an object, according to an embodiment of the present disclosure, are shown respectively. The drone has two different fuselage configurations: a regular octagon and a straight line. The tension of the tension spring (13) and the attraction of the magnet (3) together ensure the structural stability of the drone. When the drone is in the regular octagonal fuselage configuration, its dimensions are 180mm × 180mm × 36mm (length × width × height). When the drone is in the straight line fuselage configuration, its dimensions are 400mm × 70mm × 36mm (length × width × height), and its width is reduced by 60% compared to the regular octagonal fuselage. Therefore, as Figure 5 As shown, when the drone is in a straight-line fuselage configuration, it has a good ability to maneuver through narrow spaces; as Figure 6 As shown, when the drone is in an octagonal fuselage configuration, the hollow octagonal fuselage structure enables the drone to grasp objects.

[0043] In the description of this specification, the terms "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0044] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A reconfigurable multirotor unmanned aerial vehicle based on a bistable hinge, characterized in that: The drone has two fuselage configurations. By using the counter-torque generated by the clockwise / counterclockwise rotation of the rotor to overcome the magnetic attraction and spring tension, the fuselage hinge is switched to a steady state, realizing the "opening" / "closing" of the drone fuselage. The drone wheelbase is changed at the same time as the fuselage configuration is changed. After the fuselage configuration is changed, the rotor rotation returns to normal, and the UAV enters cruise mode normally; the UAV structure includes: bistable hinge, rotor assembly, magnet, fuselage front and rear joint surfaces, gripper, fuselage module, pin shaft and tension spring; When the drone body is in configuration A, the body modules are connected end to end to form a ring-shaped body; when the drone body is in configuration B, the body modules are arranged in a straight line, and the two ends of the tension spring and the axis of the pin are on the same straight line to form a straight body.

2. The reconfigurable multirotor UAV based on a bistable hinge according to claim 1, characterized in that: The principle behind the transformation of the drone's fuselage configuration from configuration A to configuration B, i.e., from a ring-shaped fuselage to a straight fuselage, is as follows: When the propellers rotate in the same direction, the fuselage rotates in the opposite direction under the action of counter-torque; the counter-torque increases with the increase of the propeller speed; when the counter-torque is greater than the sum of the attraction force of the magnet and the tension force of the tension spring, the drone separates at the joint surface of the front and rear of the fuselage; at this time, the drone fuselage detaches from configuration A and is in a transitional state of fuselage configuration; as the included angle of the fuselage modules continues to increase, the tension spring stretches and the elastic potential energy increases; when the angles of the bistable hinges all become 180°, the drone fuselage configuration changes and enters configuration B.

3. The reconfigurable multi-rotor UAV based on a bistable hinge according to claim 1, characterized in that: The two ends of the tension spring are respectively fixed to the midpoints of the two adjacent body modules to form the bistable hinge.

4. A reconfigurable multirotor UAV based on a bistable hinge according to claim 1, characterized in that: The rotor assembly is evenly distributed on the fuselage module and includes a propeller and a motor.

5. A reconfigurable multi-rotor UAV based on a bistable hinge according to claim 2, characterized in that: The principle by which the UAV transforms from steady state B to steady state A is the same as the principle of configuration transformation; under both fuselage configurations, the tension of the tension spring and the attraction of the magnet together ensure the structural stability of the UAV.

6. A reconfigurable multi-rotor UAV based on a bistable hinge according to claim 1, characterized in that: After changing the tilt angle of the two short sides of the fuselage module, when the fuselage of the UAV with (4n-1) bistable hinges is in configuration A, the UAV is a 2n-rotor UAV with a fuselage in the shape of a regular 4n-gon, where n is an integer greater than or equal to 2.

7. A reconfigurable multi-rotor UAV based on a bistable hinge according to claim 1, characterized in that: The gripper has compressible elasticity, enabling the drone to grasp objects of different sizes; in addition, the gripper has a rough contact surface to increase friction with the object being grasped.

Images