Low-energy-consumption and variable-rigidity continuous robot for enhancing operation capability of unmanned aerial vehicle

Abstract

A low-energy-consumption and variable-rigidity continuous robot for enhancing the operation capability of an unmanned aerial vehicle belongs to the technical field of continuous robots and comprises a continuous robot arm body, a mechanical arm base, a driving device and an air pressure system. The continuous robot arm body is connected with the mechanical arm base, is formed by connecting N basic structures with the same shape in series through N-1 basic connecting units and is divided into M joint sections, each joint section is composed of N / M basic unit modules, and the basic unit modules have the bistable characteristic. The driving device is arranged on the mechanical arm base, the unmanned aerial vehicle is arranged above the driving device, and resetting and bending supporting of the continuous robot arm body are achieved through the air pressure system. The continuous robot arm body vertically extends out from the lower portion of the continuous robot arm body, high-degree-of-freedom pose transformation can be conducted in the space, and a grabbing task is executed in a complex environment; due to the bistable characteristic, the state of the arm body can be maintained under the condition that driving force is removed, the characteristic of saving energy is achieved, and the potential value is expanded.

Description

Technical Field

[0001] This invention belongs to the field of continuous robots and relates to a low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles (UAVs) and a method of using it. Background Technology

[0002] With the development of drone technology, the tasks of drones have gradually expanded from spatial imaging to three-dimensional grasping. However, existing grasping actuators are mainly rigid, resulting in poor environmental adaptability, low interaction safety, and limited task scope, failing to meet the dexterity requirements of drone systems operating in complex environments. Continuous robots, with their high flexibility and strong environmental adaptability, can effectively compensate for the shortcomings of traditional rigid actuators.

[0003] Continuous robots are typically composed of several identical rigid components flexibly connected in series. Due to their higher flexibility and compliance, which rigid robots lack, they are often used to perform complex tasks in harsh environments, such as medical surgery, environmental exploration, and space technology. Existing continuous robots often use ropes or pneumatic drives to control the position and attitude of the arm. However, since maintaining its posture still requires a continuous power input, it consumes a lot of energy and generates various types of noise and vibration.

[0004] Bistable structures are typically achieved through geometric or material nonlinearity. Their characteristic is that the structure possesses two attainable stable static equilibrium states, representing the lowest energy points of the structure's potential energy. When the structure is subjected to external forces and overcomes the energy barrier via a jump, the elastic potential energy stored within the structure is rapidly released, driving the structure to a steady-state transition. Due to their short switching response time, stable and controllable mechanical properties, and non-energy-consuming steady-state operation, bistable structures have demonstrated immense potential in structural development and applications across various fields.

[0005] When drones are equipped with actuators and robotic arms, their external dimensions limit their takeoff capabilities, typically requiring them to operate from elevated platforms. This severely restricts their adaptability to takeoff and landing in complex terrain conditions. The continuous robot structure described in this invention features longitudinal telescopic functionality: during takeoff and preparation, it can retract and be stored within the fuselage, enabling the drone to adapt to various terrain conditions and achieve smooth takeoff and landing. Furthermore, when a drone carries a heavy load and rapidly changes its motion, the load can sway, affecting the drone's flight stability. The continuous robot of this invention can adjust its stiffness through retraction and locking, effectively suppressing load oscillations and improving flight stability. Summary of the Invention

[0006] In response to the aforementioned deficiencies and improvement needs of existing technologies, this invention proposes a low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles (UAVs). While retaining the high flexibility, high response speed, and high adaptability to complex environments of existing continuous robots, it further possesses advantages such as low energy consumption, adjustable stiffness, and controllable structural parameters, significantly improving the overall operational performance and application potential of UAV systems.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles (UAVs), comprising a continuous robot arm 1, a robotic arm base 2, a drive unit 3, a UAV 4, and a pneumatic system, as detailed below:

[0009] The continuous robot arm 1 is composed of N identical basic structures 16 connected in series via N-1 basic connecting units 17. Two adjacent basic structures 16 and their connected basic connecting units 17 are called basic unit modules 5. Specifically:

[0010] The basic structure 16 is a part formed by 3D printing or other integrated processing technologies. It has a multi-level, radially symmetrical spatial configuration. Geometrically, it can be divided into three levels from top to bottom along the axis: a top part, a middle support area, and a bottom base. Specifically, the top part is mainly a flat solid. When viewed from above, four small squares are symmetrically distributed radially at the four corners of a large square and intersect with the large square. There is an axial hole at the center of the shape, and bolt through holes 11 are provided at the center of the four small squares as bolt connection holes for the first airbag, to reserve space for the installation of the air pressure system. The top part has upper pin holes 10 around its perimeter for engagement with pins. The middle support area has eight axially extending rib structures, two ribs in each of the four mutually perpendicular directions. One end is fixed to the top part, and the other end connects to the bottom base. The eight ribs form a hollow cavity, with a certain distance between adjacent ribs. The bottom base is a ring-shaped plate structure, with the outer circle connected to the end of the rib plate structure in the middle support area. The bottom base has base connection holes 8 and drive rope holes 9 evenly distributed around its circumference, which are used to fix the continuous robot arm 1 and to pass the drive rope, respectively. At the same time, the base is also provided with lower pin holes 7 around its perimeter for engagement with pins.

[0011] The basic connection unit 17 includes a connector 12, a spring steel sheet 13, and a pin 14. The connector 12 is a hexahedron with rounded corners. Two bolt holes 15 are symmetrically arranged perpendicularly to its largest face. A pin hole is located on its narrow side, offset from the axis of symmetry of the narrow side, to cooperate with the pin 14 to form a rotating pair. A gap is created by cutting through the hexahedron on the narrow side, serving as space for connecting the spring steel sheet 13. The spring steel sheet 13 is a matrix sheet of a certain thickness, with four through holes near its two short sides. The two short sides of the spring steel sheet 13 are inserted into the gaps reserved in the two connectors 12. Bolts pass through the bolt holes 15 and the through holes of the spring steel sheet 13 and are tightened, while ensuring that the pin holes are all offset from the axis of symmetry to one side.

[0012] One pin 14 on one side of the basic connecting unit 17 connects to the upper pin hole 10 of a basic structure 16, and the other pin 14 connects to the lower pin hole 7 of another basic structure 16. This installation is repeated circumferentially, and four basic connecting units 17 connect two basic structures 16. This entire assembly is called the basic unit module 5. By repeating the above installation process sequentially, that is, connecting the basic structures 16 and basic connecting units 17 in sequence, the continuous robot arm 1 is obtained. The continuous robot arm 1 is divided into M joint segments 6 to improve motion controllability, and each joint segment consists of N / M basic modules.

[0013] A single basic unit module 5 exhibits the following mechanical and kinematic characteristics, referred to as the bistable characteristic of basic unit module 5. The initial state of basic unit module 5 is an extended state, meaning the two basic structures 16 are far apart. When the first basic structure 16 is fixed and the second basic structure 16 is pressed down, all the spring steel sheets 13 connected to both bend, and the connecting piece 12 rotates around the pin 14. As the downward displacement increases, the applied external force continues to increase, and the energy stored in the spring steel sheets 13 continues to rise. When the downward displacement exceeds a certain point, the energy stored in the spring steel sheets 13 is immediately released, and the second basic structure 16 moves rapidly downward without further external force until it reaches the bottom. At this point, basic unit module 5 is in a compressed state, and the two basic structures 16 are close to each other. The energy displacement curve of the above process is peak-shaped. Basic unit module 5 in the compressed state has a self-locking capability; it can only be separated by applying a certain upward force to the top of the second basic structure 16, and the mechanics and kinematics exhibit the reverse process described above.

[0014] The robotic arm base 2 is a one-piece molded robotic arm base, which can be mainly composed of a lower hollow cylinder and an upper square thin plate according to its geometry. The internal gap of the lower hollow cylinder can just accommodate and nest the continuous robotic arm. A circular through hole is provided in the center of the upper square thin plate, which allows the relevant components of the air pressure system to pass through while also reducing the weight of the parts. Four bolt holes and four drive rope through holes are evenly and alternately distributed along the circumference of the upper square thin plate. The continuous robotic arm 1 is fixedly connected to the robotic arm base 2 through the base connection hole 8 on its front basic structure 16 and the bolt holes by bolt pairs.

[0015] The drive unit 3 includes a drive rope, a bus servo 21, a drive unit base 22, a side plate 23, and a wire guide spool 24. The side plate 23 is the main mounting location for the bus servo 21. It is manufactured using a one-piece molding technique and is primarily a rectangular thin plate. A boss with holes near the shorter side is provided on the boss for mounting the bus servo 21. A square hexahedron is cut out on the other side to create a gap for the wire guide spool 24. Holes are also present along the thickness of the side plate 23. The drive unit base 22 is a square thin plate with a circular hole at its center along the axis to reduce weight. Four bolt holes are provided around its circumference for connection to the UAV 4, and bolt holes for connection to the side plate 23 are located near the edge of the thin plate. The side plates 23 are connected vertically end-to-end, with the drive unit base 22 covering them to form a square box. Self-tapping screws are used for connection at the joints. The bus servo motor 21 has a multi-rotation function, and each bus servo motor 21 independently controls the winding and unwinding of a single drive rope. The length of the drive rope is adjusted by the rotation angle of the bus servo motor 21. The bus servo motor 21 is fixed to the side plate 23 by bolt pairs connecting the holes on the bus servo motor 21 to the holes on the boss. The guide reel 24 is a type of wheel structure with grooves, where the grooves are used to accommodate the wound drive rope. It is fixed to the bus servo motor 21 by bolt pairs through bolt holes distributed circumferentially. One end of the drive rope is fixed to the guide reel 24, and the other end passes through the drive rope holes 9 of each basic structure 16 of the continuous robot arm 1 in sequence and is fixed at the end of each joint segment 6 by a wire lock. The guide reel 24 serves as an intermediate component for winding and storing the rope, or maintaining it in a pre-tensioned state. When the servo motor of the aforementioned drive device 3 rotates, it drives the guide reel 24 to rotate and realize the winding or unwinding of the drive rope.

[0016] The pneumatic system consists of an airbag 18 and an air supply device 19, used to achieve the reset and bending support of the continuous robot arm 1. The air supply device 19 mainly consists of an N20 mini air pump, an air pipe, and a power supply battery. When the power supply battery receives an activation signal, the N20 mini air pump starts working, introducing gas into the airbag 18 through the air pipe to inflate it. The airbag 18 is corrugated tubular in shape, with a square cross-section for each layer, and protruding tubes at the top and bottom for connection with the air pipe. The bottom layer of the airbag 18 has holes at the four corners as bolt connection holes 20 for the second airbag, used for fixing it to the basic structure 16. When the airbag 18 is filled with gas, it will inflate, pushing aside the next basic structure 16 connected to it, causing the basic unit module 5 to reset from a compressed state to an extended state.

[0017] The drone 4 is positioned above the drive unit 3, and the continuous robot arm 1 extends vertically from below it, enabling it to perform high-degree-of-freedom pose transformations in space and execute grasping tasks in complex environments.

[0018] Furthermore, the end effector 16 preferably adopts a robotic gripper, but includes, but is not limited to, industrial cameras, various sensors, etc. The end effector is lightweight, and its base is fixed to the upper frame of the end effector basic structure 16 by bolts.

[0019] Furthermore, the drive of the continuous robot arm 1 is controlled by a microcontroller unit (MCU).

[0020] Furthermore, in addition to being mounted on the drone 4, the continuous robot arm 1 can also be mounted on the end effector of an industrial rigid robot to expand its workspace and improve its dexterity in complex environments.

[0021] The working process of a low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles is as follows:

[0022] Drone 4, carrying the continuous robotic arm 1 in a retracted and ready-to-go state, flies to the designated target area and hovers. By activating the pneumatic system, the air supply device 19 continuously inflates the airbags 18, causing each airbag 18 to expand sequentially from the front to the rear. As each airbag 18 expands, the continuous robotic arm 1 gradually extends to its extended working state. At this time, the microcontroller unit (MCU) controls the drive bus motors 21 to adjust the continuous robot's posture and grasp the target object. After the mission is completed, all bus motors 21 retract their drive cables, causing the continuous robotic arm 1 to return to its retracted, ready-to-go state to improve flight stability. Under the control of the drone's handle, Drone 4 flies back to the recovery point to complete the operation.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) This invention uses a structure with bistable characteristics as the basic unit of a continuous robot. Rigid basic unit modules are connected by elastic sheets, enabling the continuous robot arm to have multi-segment extension and locking capabilities in the longitudinal direction. This allows it to lift and stably maintain a target object at a specified height after grasping it. The continuous robot arm's maintenance capability is determined by the structure's own energy barrier; theoretically, as long as the external load does not exceed the energy barrier threshold, the continuous robot can maintain its posture for a long time under zero-energy conditions. The elastic sheets themselves have good elasticity, thus the continuous robot arm has strong motion flexibility, while the circumferentially symmetrical arrangement of the elastic sheets provides the continuous robot with good automatic return-to-center capability.

[0025] (2) This invention is based on an unmanned aerial vehicle (UAV) platform, which has the characteristics of high mobility and high accessibility compared with robots based on planar mobile platforms. The continuous robot has variable stiffness and extension capabilities, which can effectively suppress the load swing of the UAV when it is flying with a heavy load, and significantly improve the stability of the system in dynamic tasks.

[0026] (3) This invention can change the structural energy barrier by adjusting parameters such as the material, thickness, or length of the elastic sheet, thereby adapting to the gripping and locking requirements under different load conditions. This design gives the robot arm good task adaptability, facilitates modular replacement, and significantly improves the versatility and practical value of the system.

[0027] (4) The continuous robot described in this invention has the characteristics of compact structure, light weight, flexible movement and easy manufacturing. The materials used are generally readily available, the processing and assembly process is simple, and it has good engineering application prospects and promotion potential. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the low-energy, variable-stiffness continuous robot operation state that enhances the operational capabilities of unmanned aerial vehicles according to the present invention. Figure 1 (a) The continuous robotic arm is in the extended working state; Figure 1 (b) The continuous robotic arm is in the retracted and ready state;

[0029] Figure 2 This is a schematic diagram of the continuous robot arm of the present invention; Figure 2 (a) is a front view of the main structure; Figure 2 (b) is an isometric drawing of the main structure;

[0030] Figure 3 This is a schematic diagram of the basic structure of the present invention.

[0031] Figure 4 This is a structural schematic diagram of the unit body connector of the present invention;

[0032] Figure 5 This is a structural schematic diagram of the unit module of the present invention; Figure 5 (a) is the extended working state of the unit module; Figure 5 (b) is the unit module shrinkage and preparation state;

[0033] Figure 6 This is a schematic diagram of the structure of the pneumatic system components of the present invention; Figure 6 (a) is a schematic diagram of the airbag structure; Figure 6 (b) is a schematic diagram of the gas supply equipment;

[0034] Figure 7 This is a schematic diagram of the unit structure of the airbag installation of the present invention;

[0035] Figure 8 This is a schematic diagram of the structure of the drone used in conjunction with the present invention;

[0036] Figure 9 This is a schematic diagram of the structure of the robotic arm drive module and the robotic arm base of the present invention; Figure 9 (a) is a schematic diagram of the main structure's appearance; Figure 9 (b) is a cross-sectional schematic diagram of the main structure;

[0037] In the diagram: 1. Continuous robot arm; 2. Robotic arm base; 3. Drive unit; 4. UAV; 5. Basic unit module; 6. Joint segment; 7. Lower pin hole; 8. Base connection hole; 9. Drive rope hole; 10. Upper pin hole; 11. First airbag bolt connection hole; 12. Connector; 13. Spring steel sheet; 14. Pin; 15. Connecting unit bolt hole; 16. Basic structure; 17. Basic connecting unit; 18. Airbag; 19. Air supply equipment; 20. Second airbag bolt connection hole; 21. Bus servo motor; 22. Drive unit base; 23. Side plate; 24. Guide wheel;

[0038] In this invention, the reserved holes are connected by corresponding bolt pairs of standard parts. Detailed Implementation

[0039] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0040] This invention provides a low-energy, variable-stiffness continuous robot that enhances the operational capabilities of unmanned aerial vehicles (UAVs), such as... Figure 1 As shown: including:

[0041] The continuous robot arm consists of 1. a robotic arm base; 2. a drive unit; 3. a drone; and 4. a pneumatic system, as detailed below:

[0042] The continuous robot arm 1 is composed of 12 identical basic structures 16 connected in series by 11 basic connecting units 17. Two adjacent basic structures 16 and their connected basic connecting units 17 are called basic unit modules 5. The basic structures 16 are parts formed by 3D printing or other integrated processing technologies, exhibiting a multi-level, radially symmetrical spatial configuration. Geometrically, they can be divided into three levels along the axis from top to bottom, with a total height of 40mm and a maximum width of 80mm. The top part is mainly a flat solid. Viewed from above, four small squares are radially symmetrically distributed at the four corners of a large square and intersect with it. A 10mm diameter hole is located at the center of the body along the axial direction. Bolt through holes with a diameter of 2.2mm are located at the centers of the four small squares to provide space for the installation of a pneumatic system. Pin holes 10 with a diameter of 2.3mm are located around the perimeter of the top part for engagement with 2mm diameter pins. The central support area features eight axially extending rib structures. Two ribs, each 12mm wide, are located in four mutually perpendicular directions. One end of each rib is fixed to the top, and the other end connects to the bottom base. The eight ribs form a hollow cavity, with a certain spacing between adjacent ribs. The bottom base is a ring-shaped plate structure, with its outer circle connected to the end of the central support ribs. The base has circumferentially distributed 2mm diameter base connection holes 8 and 2mm diameter drive rope holes 9, used to fix the continuous robot arm 1 and to allow the drive rope to pass through, respectively. Additionally, the base has 2.3mm diameter lower pin holes 7 around its perimeter for engagement with pins.

[0043] The basic connection unit 17 consists of a connector 12, a spring steel sheet 13, and a pin 14. The connector 12 is a hexahedron with a maximum length of 12mm, a maximum width of 10mm, and a thickness of 4.6mm. It has rounded corners with a radius of 3mm. Two 2mm diameter bolt holes 15 are symmetrically arranged perpendicularly to its maximum face. A 2.3mm diameter pin hole is located on its narrow side, offset 0.5mm from the axis of symmetry of the narrow side, to cooperate with the pin 14 to form a rotating pair. A 0.5mm gap is cut through the hexahedron on this face to provide space for the spring steel sheet connection. The spring steel sheet 13 is a matrix sheet with a thickness of 0.1mm, and has four 2mm diameter through holes near its two short sides. The short sides of the spring steel sheet 13 are inserted into the pre-reserved cut-off gaps of the two connectors 12 respectively. The bolts pass through the bolt holes 15 of the connecting unit and the through holes of the spring steel sheet 13 respectively and are tightened. At the same time, it is ensured that the pin holes are all offset from the axis of symmetry to one side.

[0044] One pin 14 on one side of the basic connecting unit 17 connects to the upper pin hole 10 of a basic structure 16, and the other pin 14 connects to the lower pin hole 7 of another basic structure 16. This installation is repeated circumferentially, and four basic connecting units 17 connect two basic structures 16. This entire assembly is called the basic unit module 5. By repeating the above installation process sequentially, that is, by connecting the basic structures 16 and the basic connecting units 17 in sequence, the continuous robot arm 1 is obtained. The continuous robot arm 1 is divided into three joint segments 6 to improve motion controllability, and each joint segment contains six basic modules.

[0045] A single basic unit module 5 exhibits the following mechanical and kinematic characteristics, referred to as the bistable characteristic of basic unit module 5. The initial state of basic unit module 5 is an extended state, meaning the two basic structures 16 are far apart. When the first basic structure 16 is fixed and the second basic structure 16 is pressed down, all the spring steel sheets 13 connected to both bend, and the connecting piece 12 rotates around the pin 14. As the downward displacement increases, the applied external force continues to increase, and the energy stored in the spring steel sheets 13 continues to rise. When the downward displacement exceeds a certain point, the energy stored in the spring steel sheets 13 is immediately released, and the second basic structure 16 moves rapidly downward without further external force until it reaches the bottom. At this point, basic unit module 5 is in a compressed state, and the two basic structures 16 are close to each other. The energy displacement curve of the above process is peak-shaped. Basic unit module 5 in the compressed state has a self-locking capability; it can only be separated by applying a certain upward force to the top of the second basic structure 16, and the mechanics and kinematics exhibit the reverse process described above.

[0046] The robotic arm base 2 is a one-piece molded base, which can be mainly composed of a lower hollow cylinder and an upper square thin plate according to its geometry. The lower hollow cylinder has a diameter of 89mm, and the internal gap can just accommodate the continuous robotic arm. Its diameter is 82mm. The upper square thin plate has a side length of 90mm and a thickness of 3.5mm. A circular through hole with a diameter of 50mm is provided in the center, which allows the relevant components of the pneumatic system to pass through while also reducing the weight of the parts. Four bolt holes with a diameter of 2mm and four drive rope through holes with a diameter of 2mm are evenly and alternately distributed along the circumference of the upper square thin plate. The aforementioned continuous robotic arm 1 is fixed to the robotic arm base 2 through the base connection hole 8 located on its front basic structure 16 and the aforementioned bolt holes by bolt pairs.

[0047] The drive unit 3 includes a drive cable, a bus servo 21, a drive unit base 22, and a side plate 23. The side plate 23 is the main mounting location for the bus servo 21. It is manufactured using a one-piece molding technique and is primarily a rectangular thin plate with a length of 90mm, a width of 40mm, and a maximum thickness of 20.5mm. A boss with a length of 20mm, a width of 16mm, and a maximum thickness of 16mm is provided on one side near the shorter side. A 4.3mm diameter hole is provided on the boss for mounting the bus servo 21. An 8.8mm thick square hexahedron is cut out on the other side to create a gap for the wire guide plate 24. A 2mm diameter hole is also provided in the thickness direction of the side plate 23. The drive unit base 22 is a square thin plate with a side length of 90mm and a thickness of 3.5mm. A 50mm diameter circular hole is located at the center of the component along the axis to reduce weight. Four 3.2mm diameter bolt holes are provided around the circumference for connection to the UAV. Additionally, 2mm diameter bolt holes are located near the edge of the thin plate for connection to the side plate 23. The side plates 23 are connected vertically in sequence, with the drive unit base 22 covering them to form a 47mm thick, 90mm side square box. M2 self-tapping bolts are used for connection. The bus servo 21 uses a Fashion Star brand HP8-U45-M servo, featuring multi-rotation capability. Each bus servo independently controls the winding and unwinding of a single drive cable. The length of the drive cable is adjusted by controlling the rotation angle of the bus servo 21. Non-standard bolt pairs are provided to connect the holes on the bus servo 21 to the holes on the bosses of the side plate 23, thus securing the bus servo 21 to the side plate 23. The guide reel 24 is a type of grooved disc structure, where the grooves are used to accommodate the wound drive rope. It has a maximum diameter of 37.6 mm and is fixed to the bus servo motor 21 using bolt pairs through circumferentially distributed 2 mm diameter bolt holes. One end of the drive rope is fixed to the guide reel 24, and the other end passes sequentially through the drive rope holes 9 of each basic structure 16 of the continuous robot arm 1 and is secured at the end of each joint segment 6 by a cable lock. The guide reel 24 serves as an intermediary component for winding and storing the rope, or maintaining it in a pre-tensioned state. When the servo motor of the aforementioned drive device 3 rotates, it drives the guide reel 24 to rotate, thereby achieving the winding or unwinding of the drive rope.

[0048] The pneumatic system consists of an airbag 18 and an air supply device 19, used to achieve the reset and bending support of the continuous robot arm 1. The air supply device 19 mainly consists of an N20 mini air pump, an air tube, and a power supply battery. The inner diameter of the air tube is 3mm, and the battery voltage is 12V. When the battery receives an activation signal, the N20 mini air pump starts working, introducing gas through the air tube into the airbag 18 to inflate it. The airbag 18 is corrugated tubular in shape, with each layer having a square cross-section with a side length of 24mm. The top and bottom have protruding tubes that connect to the air tube. The bottom first layer of the airbag 18 has holes with a diameter of 2mm at the four corners for fixing to the basic structure 16. When the airbag 18 is filled with gas, it will inflate, and the entire airbag can extend to 40.4mm, pushing aside the next basic structure 16 connected to it, so that the basic unit module 5 resets from the compressed state to the extended state.

[0049] The drone 4 is positioned above the drive unit 3, and the continuous robot arm 1 extends vertically from below it, enabling it to perform high-degree-of-freedom pose transformations in space and perform grasping tasks in complex environments.

[0050] In this embodiment, the end effector 16 is preferably a robotic gripper, but includes, but is not limited to, industrial cameras, various sensors, etc. The end effector is lightweight, and its base is fixed to the upper frame of the end effector basic structure 16 by bolts.

[0051] In this embodiment, the drive of the continuous robot arm 1 is controlled by a microcontroller unit (MCU).

[0052] In this embodiment, the continuous robot arm 1 can be installed not only on the drone 4, but also on the end of an industrial rigid robot to expand its workspace and improve its dexterity in complex environments.

[0053] The working process of a low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles is as follows:

[0054] Drone 4, carrying the continuous robotic arm 1 in a retracted and ready-to-go state, flies to the designated target area and hovers. By activating the pneumatic system, the air supply device 19 continuously inflates the airbags 18, causing each airbag 18 to expand sequentially from the front to the rear. As each airbag 18 expands, the continuous robotic arm 1 gradually extends to its extended working state. At this time, the microcontroller unit (MCU) controls the drive bus motors 21 to adjust the continuous robot's posture and grasp the target object. After the mission is completed, all bus motors 21 retract their drive cables, causing the continuous robotic arm 1 to return to its retracted, ready-to-go state to improve flight stability. Under the control of the drone's handle, Drone 4 flies back to the recovery point to complete the operation.

[0055] The operator guides the drone 4 to take off from any flat ground, at which point the continuous robotic arm 1 is in a retractable state. Once the drone 4 reaches the vicinity of the designated target location and hovers stably, the air pressure system activates, and the air supply device 19 continuously inflates the airbag 18. The airbag expands sequentially from the base to the end of the robotic arm, propelling the continuous robotic arm 1 to its working state. At this point, the drive unit 3, under the control of the microcontroller unit (MCU), drives the continuous robotic arm 1 to adjust its posture in three-dimensional space, and the end effector grasps the target object. After the task is completed, the continuous robotic arm 1 retracts back to its retractable state, facilitating the high-speed movement of the drone 4 and maintaining flight stability during transport. Finally, the drone 4 returns to flat ground along the predetermined route to complete the task.

[0056] The above embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles (UAVs), characterized in that, The low-energy, variable-stiffness continuous robot includes a continuous robot arm (1), a robotic arm base (2), a drive device (3), a drone (4), and a pneumatic system; The continuous robot arm (1) is composed of N basic structures (16) of the same shape connected in series via N-1 basic connecting units (17). The basic connecting unit (17) connected to two adjacent basic structures (16) is called a basic unit module (5). The continuous robot arm (1) is divided into M joint segments (6), and each joint segment is composed of N / M basic unit modules (5). The basic unit module (5) has bistable characteristics, extended state and compressed state, and the basic unit module (5) in the compressed state has self-locking capability. The continuous robot arm (1) is connected to the robot arm base (2) through its basic structure (16) at the head end; The drive device (3) includes a drive rope, a bus servo motor (21), a drive device base (22), a side plate (23), and a wire reel (24), which are located on the top of the robotic arm base (2); when the bus servo motor (21) rotates, it drives the wire reel (24) to rotate and realizes the winding or releasing of the drive rope on the wire reel (24); The drone (4) is placed above the drive device (3), and the continuous robot arm (1) extends vertically from below it, enabling it to perform high-degree-of-freedom pose transformations in space and perform grasping tasks in complex environments. The pneumatic system consists of an airbag (18) and an air supply device (19), which is used to realize the reset and bending support of the continuous robot arm (1); the airbag (18) is inflated to reset the basic unit module (5) from the compressed state to the extended state.

2. The low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles according to claim 1, characterized in that, The basic structure (16) has a multi-level, radially symmetrical spatial configuration. Geometrically, it includes a top part, a middle support area, and a bottom base along the axis from top to bottom. The top part is a flat solid with four small squares symmetrically distributed radially at the four corners of a large square and intersecting the large square. A hole is provided along the axis at the center of the large square. A first airbag bolt connection hole (11) is provided at the center of the four small squares. The top part has upper pin holes (10) around its perimeter, which cooperate with the pins. The middle support area has eight axially extended rib structures, arranged in pairs. One end is fixed to the top part, and the other end is connected to the bottom base. The eight ribs surround to form a hollow cavity, and there is no contact between adjacent ribs. The bottom base is an annular plate structure, with the outer circle connected to the end of the rib structure in the middle support area; the bottom base has base connection holes (8) and drive rope holes (9) evenly distributed around its circumference, and lower pin holes (7) are provided around the base to cooperate with the pins.

3. A low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles according to claim 2, characterized in that, The basic connection unit (17) includes a connector (12), a spring steel sheet (13), and a pin (14). The connector (12) is a hexahedron with a bolt hole (15) on its largest face and a pin hole on its narrow side, which is used to cooperate with the pin (14) to form a rotating pair. The spring steel sheet (13) has through holes at both ends, and the spring steel sheet (13) is inserted into the gap reserved by the two connectors (12) and connected by bolts.

4. A low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles according to claim 3, characterized in that, The pin (14) on one side of the basic connecting unit (17) is connected to the upper pin hole (10) of a basic structure (16), and the pin (14) on the other side is connected to the lower pin hole (7) of another basic structure (16). The above installation is repeated along the circumference, and the four basic connecting units (17) connect the two basic structures (16). This whole is called the basic unit module (5). The above installation process is repeated in sequence, that is, the basic structure (16) and the basic connecting unit (17) are connected in sequence to obtain the continuous robot arm body (1).

5. A low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles according to claim 4, characterized in that, Each basic unit module (5) has bistable characteristics. Specifically, the initial state of the basic unit module (5) is an extended state, with the two basic structures (16) far apart from each other. When the first basic structure (16) is fixed and the second basic structure (16) is pressed down, all the spring steel sheets (13) connected to both bend, and the connecting piece (12) rotates around the pin (14). When the pressing displacement exceeds a certain point, the energy stored in the spring steel sheets (13) is released, and the second basic structure (16) will move downward quickly without the need for external force until it reaches the bottom. At this time, the basic unit module (5) is in a compressed state, with the two basic structures (16) close to each other. The compressed basic unit module (5) has a self-locking capability, and it can only be separated by applying a certain upward force to the top of the second basic structure (16), while also having the above reverse process.

6. A low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles according to claim 5, characterized in that, The robotic arm base (2) is integrally formed, including a lower hollow cylinder and an upper square thin plate; the internal gap of the lower hollow cylinder can just accommodate the nested continuous robotic arm (1); the upper square thin plate has a circular through hole at the center, through which the relevant components of the air pressure system pass, and bolt holes and drive rope through holes are evenly and alternately distributed along the circumference; the continuous robotic arm (1) is fixedly connected to the robotic arm base (2) through the base connection hole (8) on its head basic structure (16) and the bolt hole through the bolt pair.

7. A low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles according to claim 6, characterized in that, The drive device (3) includes a drive rope, a bus servo (21), a drive device base (22), a side plate (23), and a wire reel (24); the bus servo (21) and the wire reel (24) are installed on the side plate (23), and the side plate (23) has holes in the thickness direction; the drone (4) is installed on the drive device base (22) and connected to the side plate (23) to form a square box; The bus servo (21) has a multi-rotation function. Each bus servo (21) independently controls the winding and unwinding of a single drive rope. The length of the drive rope is adjusted by controlling the rotation angle of the bus servo (21). The holes on the bus servo (21) are connected to the holes on the boss of the side plate (23) by bolts, so that the bus servo (21) is fixed on the side plate (23). The guide wheel (24) is provided with a drive rope, which is fixed to the bus servo (21). One end of the drive rope is fixed to the guide wheel (24), and the other end passes through the drive rope holes (9) of each basic structure (16) of the continuous robot arm (1) in sequence and is fixed at the end of each joint segment (6) by a wire lock.

8. A low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles according to claim 7, characterized in that, In the pneumatic system: The gas supply device (19) introduces gas into the air bag (18) to inflate it; The airbag (18) is corrugated tube-like, with a square cross-section for each layer and a convex tube at the top and bottom for connecting to the trachea. The bottom first layer of the airbag (18) has bolt holes (20) for connecting to the second airbag at the four corners, which are fixed to the basic structure (16). When the airbag (18) is filled with gas, it will expand and push open the next basic structure (16) connected to it, so that the basic unit module (5) can be reset from the compressed state to the extended state.

9. A low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles according to claim 8, characterized in that: The basic structure (16) is a part formed by 3D printing or other integrated processing technology, using a robotic gripper. The hexahedron of the connector (12) is rounded, and the connector pin hole on the narrow side is offset from the axis of symmetry of the narrow side. The connection between the base (22) of the drive device and the side plate (23) is made by self-tapping bolts.

10. A low-energy, variable-stiffness continuous robot for enhancing the operational capabilities of unmanned aerial vehicles according to claim 9, characterized in that: The drive of the continuous robot arm (1) is controlled by a microcontroller unit (MCU); The continuous robot arm (1) can be installed not only on the drone (4) but also on the end of an industrial rigid robot.

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