An adaptive grasping and transport drone

Abstract

The adaptive grabbing and transporting unmanned aerial vehicle comprises a flying carrying module and a transporting box, the transporting box is provided with an annular flange matched with the four-point mounting system on the peripheral side, and the mounting and locking system of the square four motors is clamped and fixed; the mounting and locking system of the square four motors comprises four hollow cup motors distributed in a square shape; the tight clamping rope assembly is connected with a section of tight clamping rope on both sides of each hollow cup motor, the tight clamping ropes of the two hollow cup motors arranged oppositely are connected with each other to form a square tight clamping structure, and a variable opening for accommodating the transporting box is formed in the middle of the square tight clamping structure; and the controller is electrically connected with the four hollow cup motors and is used for controlling the four hollow cup motors to synchronously rotate in the forward direction or the reverse direction. The adaptive grabbing and transporting unmanned aerial vehicle has the mechanical self-locking function, is strong in environmental adaptability, supports one-key autonomous operation, and is compatible with various box sizes.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) transportation technology, and specifically relates to an adaptive grasping and transporting UAV. Background Technology

[0002] Drone logistics, as an important application scenario of the low-altitude economy, has developed rapidly in recent years. In the last-mile delivery stage, how to achieve rapid, reliable, and automated loading and unloading of goods and drones is a key technological bottleneck restricting the large-scale commercial application of drone logistics. The gripping mechanism, as the connecting hub between the drone and the goods, directly affects transportation efficiency, safety, and the degree of automation.

[0003] Existing drone cargo grasping devices mainly include the following technical approaches: First, traditional rigid mechanical grippers, which use multi-joint robotic arms or fixed gripper structures and rely on high-precision visual positioning systems to achieve grasping; second, flexible pneumatic or vacuum adsorption grippers, which use air pumps to drive silicone membranes to deform and wrap objects, or use vacuum suction cups to adsorb flat objects; third, simple hook hanging devices, which install fixed hooks on the bottom of the drone and require manual loading of cargo onto the hooks; and fourth, magnetic gripping devices, which are only suitable for ferromagnetic cargo surfaces and use electromagnets to achieve adsorption and grasping.

[0004] However, the aforementioned existing devices have many technical shortcomings in practical applications. In terms of adaptability, rigid mechanical grippers require millimeter-level positioning accuracy and have extremely high requirements for the hovering stability of drones, making it difficult to operate reliably in complex environments; flexible pneumatic grippers are significantly affected by wind, making it difficult to guarantee reliability in outdoor operations.

[0005] In terms of safety, existing devices generally have safety hazards. Taking magnetic gripping devices as an example, they use electromagnets for attraction, which fails once the power is cut off. They also lack mechanical self-locking function, posing a significant risk of goods falling from the air.

[0006] In terms of ease of operation, current gripping devices often require professional personnel to operate the hooks or adjust the grippers on-site, making it impossible to achieve "one-click" autonomous gripping and release, which seriously restricts the level of automation in drone logistics.

[0007] In terms of versatility, a single device can only be adapted to specific cargo shapes, making it difficult to be compatible with standardized logistics containers and unable to meet diverse transportation needs.

[0008] Therefore, how to overcome the dependence on high-precision positioning and the inefficiency of manual operation of existing drone cargo grasping devices, and provide a cargo grasping device that has mechanical self-locking function, strong environmental adaptability and supports one-click autonomous operation, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0009] The purpose of this invention is to provide an adaptive grasping and transporting drone to address the problems in the prior art.

[0010] Therefore, the above-mentioned objectives of the present invention are achieved through the following technical solutions:

[0011] An adaptive grasping and transporting drone,

[0012] The flight carrier module has a four-motor mounting and locking system in a grid pattern on its fuselage.

[0013] The transport box has an annular flange on its periphery that is compatible with the four-point mounting system, which facilitates the clamping and fixing of the grid-shaped four-motor mounting and locking system.

[0014] The grid-shaped four-motor mounting and locking system includes:

[0015] Four hollow cup motors arranged in a square;

[0016] The hoop rope assembly consists of a hoop rope connected to each side of each hollow cup motor. The hoop ropes of two hollow cup motors arranged opposite each other are connected to each other to form a grid-shaped hoop structure. A variable opening for accommodating a transport box is formed in the middle of the grid-shaped hoop structure.

[0017] The controller is electrically connected to the four hollow cup motors and is used to control the four hollow cup motors to rotate synchronously in the forward or reverse direction.

[0018] When the controller controls the four hollow cup motors to rotate synchronously in the forward direction, the hoop rope tightens, the variable opening contracts centripetally, and the transport box is mechanically locked; when the controller controls the four hollow cup motors to rotate synchronously in the reverse direction, the hoop rope loosens, the variable opening expands centrifugally, and the transport box is released to achieve mechanical unlocking.

[0019] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0020] As a preferred technical solution of the present invention: the support foot includes: the hollow cup motor is a hollow cup planetary reduction bidirectional push rod motor, which integrates a planetary reduction mechanism inside, and the output end is connected to the lead screw and the slider; the motor has a reverse self-locking capability, and can maintain the lead screw position locked in the power-off state to prevent the transport box from being accidentally released.

[0021] As a preferred technical solution of the present invention: the lead screw is directly connected to the output shaft of the hollow cup motor, and the slider is fixedly connected to the end of the hoop rope; support seats are provided at both ends of the lead screw; the slider is driven to reciprocate along the lead screw by the forward and reverse rotation of the motor, thereby tightening or loosening the hoop rope.

[0022] As a preferred technical solution of the present invention: two slides located at the diagonal positions of the grid-shaped frame are each provided with a slider, and the sliders are connected by the high-tensile stainless steel wire rope. The wire rope passes around the guide pulleys set at the ends of the frame to form a closed-loop transmission; tension adjusting nuts are provided at both ends of the wire rope to eliminate transmission gaps and ensure that the four sets of hoop ropes are tightened or loosened synchronously.

[0023] As a preferred technical solution of the present invention: four lower support feet are fixedly provided around the lower end of the transport module; the four hollow cup motors are respectively fixedly installed on the four lower support feet; and the hoop rope is directly wrapped around the outer perimeter of the transport box.

[0024] As a preferred technical solution of the present invention, the hoop rope is made of Dyneema rope, steel wire rope or aramid rope.

[0025] As a preferred embodiment of the present invention: the controller includes a motor drive module and a feedback control module; the feedback control module includes a position detection unit and / or a tension detection unit, used to detect the size of the variable opening or the tension of the hoop rope; the controller adjusts the rotation state of the four hollow cup motors in a closed loop according to the detection results.

[0026] As a preferred technical solution of the present invention: the transport box includes a box body and a box cover, and the top of the box body is provided with annular flanges that match the end hooks of the four-point mounting system.

[0027] As a preferred technical solution of the present invention: the top of the transport box is provided with a 30° downward sloping annular flange around its perimeter, and a radial guide groove adapted to the support foot of the four-point mounting system is provided on the inner side of the flange; the inclined surface of the flange and the arc-shaped hook of the support foot form a wedge fit to achieve automatic centering during gripping and anti-loosening limit after locking.

[0028] Compared with the prior art, the adaptive grasping and transporting drone of the present invention has the following beneficial effects:

[0029] First, by utilizing four hollow cup motors arranged symmetrically in a grid pattern and interconnected clamping rope assemblies, a variable-opening grid-shaped clamping structure is formed, solving the problem of existing rigid mechanical grippers' heavy reliance on high-precision positioning. When there is a certain deviation in the position of the transport box, the clamping rope can adaptively adjust during the tightening process, completing the clamping and locking without millimeter-level visual positioning. This significantly reduces the requirements for the drone's hovering accuracy and improves the operational reliability in complex environments.

[0030] Secondly, by utilizing a hollow cup planetary geared bidirectional push rod motor with reverse self-locking capability, the safety hazard of existing magnetic gripping devices failing upon power failure is resolved. Even when power is off, the motor maintains the lead screw position locked, keeping the clamping rope taut and preventing the transport box from accidentally loosening. This achieves a mechanical self-locking function, significantly improving transportation safety.

[0031] Third, by using a controller to control the synchronous forward or reverse rotation of four hollow cup motors, the problem of existing devices requiring manual operation and having a low degree of automation is solved. The synchronous tightening or loosening of the hoop ropes can be achieved with a single button command, automatically locking and releasing the transport box without the need for on-site intervention by professional personnel, effectively improving the automation level of drone logistics operations.

[0032] Fourth, by utilizing a grid-shaped variable opening structure and a high-tensile stainless steel wire rope closed-loop synchronous transmission mechanism, the problem of the versatility of a single device being unable to accommodate transport boxes of different sizes is solved. The variable opening can shrink centrifugally or expand centrifugally according to the size of the transport box, adapting to various standardized logistics boxes; at the same time, the closed-loop synchronous transmission mechanism, in conjunction with the tension adjusting nut, eliminates transmission gaps, ensuring that the four sets of hoop ropes tighten or loosen synchronously, avoiding cargo tilting caused by uneven loading.

[0033] Fifth, by utilizing the position detection unit and / or tension detection unit in the feedback control module, real-time detection and closed-loop adjustment of variable opening size or hoop tension are achieved. The controller can dynamically adjust the motor rotation state based on the detection results, preventing damage to the transport box due to excessive tightness and preventing shaking due to excessive looseness, thus realizing adaptive clamping force control.

[0034] In summary, this invention provides a mounting and locking system that combines mechanical self-locking function, strong environmental adaptability, support for one-click autonomous operation, and compatibility with various box sizes. It effectively overcomes the technical defects of existing drone cargo grasping devices and provides a reliable technical solution for the automation, safety, and universality of drone logistics last-mile delivery. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of an adaptive grasping and transporting drone according to the present invention;

[0036] Figure 2 This is a side view of a structural schematic diagram of an adaptive grasping and transporting drone according to the present invention;

[0037] Figure 3 This is a schematic diagram of the structure of the grid-shaped four-motor mounting and locking system of the present invention;

[0038] Figure 4 This is a schematic diagram of the structure of the transport box of the present invention;

[0039] Figure 5This is a partial structural diagram of the grid-shaped four-motor mounting and locking system of the present invention;

[0040] In the attached diagram, the following components are included: transport module 100; annular flange 101; hollow cup motor 10; clamping rope 20; variable opening 30; lead screw 50; slider 60; slide table 62; support base 70; and lower support foot 80. Detailed Implementation

[0041] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0042] This invention aims to develop an adaptive grasping and transporting drone to address the pain points of current drones in the logistics and transportation field, such as poor grasping adaptability, complex operation, and insufficient safety. The core innovation lies in proposing a three-in-one architecture of "flight platform + quick-release grasping module + standardized transport box," and designing a grid-like mechanical self-locking grasping mechanism (i.e., an adaptive grasping and transporting drone mounted on the fuselage) to achieve automatic clamping and release of the transport box. This mechanism uses four high-precision motors to synchronously drive the relevant components, forming a wedge-shaped self-lock with the transport box's unique "30° lower flange," achieving a passive safety mechanism of "the tighter it gets, the more it's pulled." The drone automatically completes the grasping upon landing on the box, without requiring high-precision visual positioning, and also features a power-off self-locking function, completely eliminating the risk of cargo falling from the air. This invention will complete the entire process from prototype design and control system development to complete machine integration and testing, ultimately forming a highly adaptable, highly safe, and easy-to-operate intelligent drone grasping solution.

[0043] The flight transport module of the UAV of the present invention is a conventional quadcopter transport UAV platform (which can be upgraded based on consumer-grade or transport-specific multi-rotor UAVs), equipped with an enhanced belly load status monitoring unit, and a grid frame fixed under the belly (where a quick-release transport module interface board or landing gear extension transport module is integrated). The four support legs of an adaptive grasping transport UAV are symmetrically distributed along the grid frame, and each support leg is equipped with an independent drive unit. Through a screw-slider mechanism and synchronous transmission with the wire rope, the UAV can stably grasp and deploy standardized transport boxes.

[0044] The present invention provides an adaptive grasping and transporting drone as the core grasping mechanism, integrating functions such as mechanical self-locking, fault-tolerant positioning, and synchronous transmission, and specifically includes the following parts:

[0045] (a) Tic-Tac-Toe Frame

[0046] The grid-like frame is a horizontal, cross-shaped, lightweight frame structure, integrally molded from high-strength aluminum alloy or engineering plastic (carbon fiber can be used for further weight reduction). The central area is the drive unit mounting area, with symmetrical horizontal guide grooves at all four ends. Wear-resistant bushings are embedded within the guide grooves to provide low-friction movement guidance for the lateral sliding rods of the support legs. Guide pulleys are installed at the ends of the frame for the winding of the steel wire rope of the synchronous transmission mechanism. The frame integrates quick-release interfaces for mechanical buckles and electrical contacts, enabling second-level rapid docking and signal communication between the grabbing module and the flight platform, laying the foundation for multi-purpose use (such as replacement with spraying or inspection modules).

[0047] (ii) Support leg structure

[0048] Each support leg is an integrated structure of a vertical conical bracket and an arc-shaped hook, thicker at the top and thinner at the bottom, with a bottom guide cone. This provides landing stability and initial positioning, reduces wind resistance during flight, increases structural strength, and prevents deformation caused by grabbing impact. Wear-resistant guide bushings are installed between the bracket and the guide groove to prevent skewing or jamming during movement. Specifically, it consists of three parts:

[0049] - Vertical bracket: It is fixed to the guide groove of the grid frame by bolts, providing a mounting base for the drive unit and slide bar. The bracket has a horizontal guide groove to restrict the horizontal slide bar to move only in the horizontal direction.

[0050] - Horizontal slide bar: It can slide back and forth along the horizontal guide groove of the vertical bracket. The inner end of the slide bar is rigidly connected to the lead screw slider, and the outer end extends out of the bracket and is integrally formed with the end hook.

[0051] -End hook: It is an arc-shaped inward hook structure. The inner side of the hook is adapted to the 30° downward sloping flange of the transport box. When folded, it can hook the flange from the lower side of the transport box to form a multi-point wrap-around fixation. The hook can be equipped with flexible steel wire (or alternative material) to form flexible contact with the flange and avoid scratches or indentations on the surface of the box.

[0052] The tapered design of the support feet, in conjunction with the bottom guide cone, forms a tapered support foot embedded in the guide groove fault-tolerant positioning system, achieving a landing tolerance of ±5mm. This significantly reduces the reliance on the drone's hovering accuracy and external positioning equipment, making the system more robust in complex outdoor environments.

[0053] (III) Drive Unit

[0054] The drive unit uses a 6mm hollow cup planetary reducer bidirectional push rod slide (i.e., a hollow cup planetary reducer bidirectional push rod motor), with a power supply voltage of DC3.7V. It has a built-in planetary reduction mechanism, and the output end integrates a 2mm diameter, 0.3mm pitch precision lead screw and slider. The four drive units are synchronously controlled, using a dual closed-loop control strategy of position and current to ensure uniform contraction of the grid without off-center load.

[0055] The hollow cup motor in this invention has high power density and fast response speed, which is suitable for the lightweight and low power consumption requirements of drones (the weight increase of the gripping module is <200g, and the impact on the battery life of mainstream consumer drones is <8%).

[0056] The built-in planetary reduction mechanism in this invention can output large torque and has reverse self-locking capability. It can maintain the screw position locked in the power failure state. Combined with the wedge self-locking structure, even if there is a sudden power failure, it can still rely on the weight of the cargo to keep it locked, preventing the transport box from accidentally loosening and completely eliminating the risk of cargo falling.

[0057] In this invention, the lead screw is directly connected to the motor output shaft, the slider and the transverse slide are rigidly fixed by bolts, and support seats are provided at both ends of the lead screw to ensure the coaxiality of the lead screw rotation and avoid movement jamming.

[0058] The driving unit operates as follows: When the motor rotates forward, the lead screw drives the slider to extend outward, driving the transverse slide bar to move outward, and the four end hooks simultaneously retract, clamping the transport box. When the motor rotates in reverse, the lead screw drives the slider to retract inward, driving the transverse slide bar to move inward, and the four end hooks simultaneously open, releasing the transport box. Simultaneously, a sensorless gripping state determination method based on motor current feedback is employed. The success of the gripping is determined by analyzing the abrupt changes in the operating current of the push rod motor. A sudden increase in current indicates that the end hooks (or wires) have engaged the flange, eliminating the need for additional force or position sensors, simplifying the system structure and reducing costs.

[0059] (iv) Synchronous transmission mechanism

[0060] To ensure synchronized movement of the four supporting legs, this embodiment incorporates a high-tensile synchronous transmission mechanism between the diagonal sliding blocks of the grid frame. Specifically, this mechanism uses a high-tensile stainless steel wire rope (which can be replaced with a 20% lighter polymer fiber rope, a cut-resistant flexible metal chain, or a silicone-coated steel cable to enhance friction) synchronous transmission mechanism. The four wire rope segments are hinged end-to-end to form a closed grid gripping mechanism. The wire nodes are rigidly connected to the sliders, and the horizontal contraction / expansion of the grid is achieved through the synchronous movement of the sliders.

[0061] In this invention, the steel wire rope is selected from aviation-grade high-tensile stainless steel wire rope, and the type is selected according to the maximum load of the transport box with a safety factor of 3.

[0062] In this invention, one end of the wire rope is fixed to a lead screw slider on one side through a clamping joint, and the other end passes around the guide pulley at the end of the frame and connects to the slider on the opposite side to form a closed-loop transmission.

[0063] In this invention, tension adjusting nuts are provided at both ends of the wire rope. The transmission gap can be eliminated by adjusting the preload, ensuring that the four support legs open and close synchronously, and avoiding uneven force during gripping.

[0064] The synchronous transmission mechanism, together with the end hook and the transport box flange, forms a grid-flange mechanical self-locking coupling structure. The "grid"-shaped flexible steel wire driven by four sliders forms a wedge-shaped self-lock with the "30° lower flange" of the transport box, realizing a passive safety mechanism that can "tighten as it is pulled" without energy, fundamentally solving the risk of falling when power is cut off.

[0065] II. Standardized shipping boxes

[0066] The transport box of this invention is a standardized protective box adapted to an adaptive gripping and transporting drone. It follows the standardized transport box interface specification and is divided into two types: one is a general-purpose transport box with a four-sided extended opening that also serves as a handle, and the other is a customized special-purpose transport box. Both types of boxes can be precisely matched with the drone's conical support feet and embedded with a "well" grid gripping wire.

[0067] The shipping container consists of a container body and a lid that are locked together by snaps (standardized lid locking structure to ensure the safety of the internal goods). The whole container is made of ABS+PC engineering plastic injection molding (the flange material can be engineering plastic or aluminum alloy), which takes into account both lightweight and impact resistance. The inner side of the flange is embedded with anti-slip silicone strips.

[0068] The top of the transport box is surrounded by a 30° downward-sloping annular flange (the 30° slope can be adjusted to a range of 25°-35°; the flange cross-section can be changed to an inward-facing hook shape or a serrated shape to enhance anti-detachment performance). The slope of the flange is inclined towards the bottom of the box, and a radial guide groove (i.e., a guide groove on the top of the box) is opened on the inner side corresponding to the position of the support feet.

[0069] - During gripping, the lateral sliding bar of the support foot can slide along the guide groove to guide the end hook to be accurately aligned, reducing alignment error. Combined with the fault-tolerant positioning of the tapered support foot, stable docking is achieved.

[0070] When the end hook is retracted, the hook and the 30° downward inclined flange form a wedge-shaped fit, which automatically generates an axial locking force, improves the clamping's anti-loosening ability, and achieves a self-locking effect of "the tighter it is pulled, the tighter it becomes";

[0071] The flange thickness and transition fillet were optimized through finite element simulation to reduce stress concentration and withstand the grab impact and flight vibration under full load, thus avoiding fracture and deformation during long-term use.

[0072] Optional upgrade: Embed RFID tags in the flange to achieve automatic identification of the container and improve logistics management efficiency.

[0073] III. Workflow of Adaptive Grabbing and Transporting Drones

[0074] 1. Preparation phase: The gripping module opens to its maximum size, the slider rises to the top of the lead screw, and the drone hovers directly above the transport box.

[0075] 2. Precise landing: The drone descends vertically, and its conical support feet embed into the guide groove of the box, achieving ±5mm fault-tolerant positioning and completing the initial docking.

[0076] 3. Adaptive gripping: The motors of the drive unit rotate forward, and the four motors synchronously drive the slider to extend outward, drive the transverse slide bar to extend synchronously, and the end hook (and steel wire) retracts, sliding along the guide groove of the transport box to complete automatic centering and hook the annular flange of the transport box; the inclined surface of the flange and the steel wire (or hook) form a wedge-shaped self-locking, and the greater the weight of the cargo, the stronger the locking force; the flight control system judges the gripping is completed through motor current feedback, and a sudden increase in current indicates that the steel wire has bitten the flange and completed the clamping and fixing.

[0077] 4. Safe Transportation: The self-locking characteristic of the screw mechanism and the synchronous transmission of the wire rope ensure the stable fixation of the transport container, preventing it from loosening during drone flight; the conical support feet and the guide structure of the grid frame prevent the transport container from swaying, improving flight stability; even in the event of a sudden power outage, the wire rope remains locked under the weight of the cargo, ensuring transportation safety. This drone can be expanded to "AI + low-altitude transportation," adapting to artificial intelligence to plan transportation routes, achieving point-to-point transportation, and enabling fully unmanned and automated loading and unloading processes.

[0078] 5. One-click release: When the drone arrives at the target drop point, the motor of the drive unit reverses, the lead screw drives the horizontal slide bar to retract synchronously, the end hook opens, the grid expands and disengages from the flange, and the transport box is smoothly released, completing the release action; it can achieve "grab upon landing and release upon further landing", and can also unload goods at low altitude near the ground. Ordinary personnel can operate it after 5 minutes of training.

[0079] The present invention has the following beneficial effects:

[0080] 1. High adaptability: The lattice shrinkage range is programmable and adjustable, adapting to box sizes of 200–600mm. Only the transport box needs to have a uniform flange standard, without the need for high-precision visual positioning, making it suitable for complex outdoor environments.

[0081] 2. Intelligent and efficient: It can be expanded to "AI + low-altitude transportation", adapt to artificial intelligence to plan transportation routes, carry out point-to-point transportation, and the entire loading and unloading process is unmanned and fully automated, with extremely simple operation.

[0082] 3. Intrinsically safe: The pure mechanical self-locking structure combined with the self-locking capability of the drive unit ensures that the cargo remains locked by gravity when power or signal is lost, completely eliminating the risk of cargo falling.

[0083] 4. Zero damage protection: The flexible steel wire contact surface and flange bevel design prevent scratches or indentations on the cabinet surface.

[0084] 5. Modular expansion: The quick-release interface supports the replacement of modules such as hook, spray, and inspection within 30 seconds, realizing multiple uses of one machine.

[0085] 6. Lightweight and efficient: Hollow cup motor + lightweight frame structure, the weight increase of the gripping module is less than 200g, and the impact on the battery life of mainstream consumer drones is less than 8%.

[0086] Example 1

[0087] like Figures 1-5 As shown, an adaptive grasping and transporting drone of the present invention includes,

[0088] The flight carrier module has a four-motor mounting and locking system in a grid pattern on its fuselage.

[0089] The transport box has an annular flange on its periphery that is compatible with the four-point mounting system, which facilitates the clamping and fixing of the grid-shaped four-motor mounting and locking system.

[0090] The grid-shaped four-motor mounting and locking system includes:

[0091] Located in the transport module 100, it assists in mechanically locking or releasing the transport container. The transport module 100 can be understood as a mounting platform on the bottom of the drone's fuselage, a robotic handling platform, or other load-bearing structure suitable for air or ground transportation of the transport container.

[0092] An adaptive grasping and transporting drone, characterized in that,

[0093] The flight carrier module has a four-motor mounting and locking system in a grid pattern on its fuselage.

[0094] The transport box has an annular flange on its periphery that is compatible with the four-point mounting system, which facilitates the clamping and fixing of the grid-shaped four-motor mounting and locking system.

[0095] The grid-shaped four-motor mounting and locking system includes: four hollow cup motors 10 arranged in a square, a hoop rope assembly, and a controller 40.

[0096] Specifically, four lower support feet 80 are fixedly provided around the lower end of the transport module 100. Four hollow cup motors 10 are respectively fixedly installed on the four lower support feet 80. The four hollow cup motors 10 are distributed in a square (i.e., rectangular or square) shape at the four corners on the horizontal projection plane.

[0097] The clamping rope assembly includes multiple clamping rope segments 20. Each hollow cup motor 10 has a clamping rope segment 20 connected to both sides, and the clamping ropes 20 of two oppositely positioned hollow cup motors 10 are interconnected to form a grid-shaped clamping structure. A variable opening 30 for accommodating the transport box is formed in the center of this grid-shaped clamping structure. The clamping ropes 20 are directly wrapped around the outer perimeter of the transport box. The clamping ropes 20 can be made of high-strength, flexible materials such as Dyneema rope, steel wire rope, or aramid rope to ensure sufficient clamping force and abrasion resistance.

[0098] The controller is electrically connected to four hollow cup motors 10 and is used to control the four hollow cup motors 10 to rotate synchronously in the forward direction or synchronously in the reverse direction.

[0099] When the controller controls the four hollow cup motors 10 to rotate synchronously in the forward direction, each hollow cup motor 10 drives the clamping rope 20 to tighten, and the variable opening 30 contracts centripetally, thereby clamping the transport box and achieving mechanical locking. When the controller controls the four hollow cup motors 10 to rotate synchronously in the reverse direction, each hollow cup motor 10 drives the clamping rope 20 to loosen, and the variable opening 30 expands centrifugally, thereby releasing the transport box and achieving mechanical unlocking.

[0100] As a further preferred embodiment, the hollow cup motor 10 in this embodiment is a hollow cup planetary reduction bidirectional push rod motor. This motor integrates a planetary reduction mechanism, and its output end connects the lead screw 50 and the slider 60. This motor has a reverse self-locking capability, maintaining the lead screw 50 in a locked position during power failure, thereby preventing the hoop rope 20 from loosening due to accidental power outages, avoiding accidental detachment of the transport box, and significantly improving transportation safety.

[0101] Specifically, the lead screw 50 is directly connected to the output shaft of the hollow cup motor 10, and the slider 60 is fixedly connected to the end of the tightening rope 20. Support seats 70 are provided at both ends of the lead screw 50. By rotating the hollow cup motor 10 in both directions, the slider 60 is driven to reciprocate along the lead screw 50, thereby tightening or loosening the tightening rope 20.

[0102] To ensure high synchronization of the four sets of hoop ropes 20 during tightening and loosening, this embodiment also includes a synchronous transmission mechanism. Two slides located diagonally opposite each other on the grid-shaped frame are each equipped with a slider, and the two sliders are connected by a high-tensile stainless steel wire rope. This high-tensile stainless steel wire rope loops around guide pulleys located at the ends of the frame, forming a closed-loop transmission. Tension adjusting nuts are provided at both ends of the high-tensile stainless steel wire rope to eliminate transmission gaps and ensure that the four sets of hoop ropes 20 driven by the four hollow cup motors 10 tighten or loosen synchronously, avoiding uneven loading or jamming caused by asynchrony.

[0103] Furthermore, the controller includes a motor drive module and a feedback control module. The feedback control module includes a position detection unit and / or a tension detection unit. The position detection unit is used to detect the size of the variable opening 30 (e.g., by detecting the position of the slider through a Hall sensor, or by detecting the extension / retraction length of the hoop rope 20 through a photoelectric sensor), and the tension detection unit is used to detect the tension of the hoop rope 20 (e.g., by indirectly calculating through a tension sensor or motor current feedback). The controller adjusts the rotation state of the four hollow cup motors 10 in a closed loop according to the detection results. For example, it automatically stops tightening when the tension of the hoop rope 20 reaches a preset threshold, or automatically stops loosening when the variable opening 30 has expanded to its full extent, thereby achieving adaptive and intelligent mounting and locking control.

[0104] The transport box includes a box body and a box lid. The top of the box body is provided with annular flanges 101 that match the end hooks of the four-point mounting system.

[0105] The top of the transport box is provided with a 30° downward sloping annular flange around its perimeter. The inner side of the flange is provided with a radial guide groove that is adapted to the support foot of the four-point mounting system. The sloping surface of the flange and the arc-shaped hook of the support foot form a wedge fit to achieve automatic centering during gripping and anti-loosening limit after locking.

[0106] When performing logistics transportation tasks, the drone first hovers or lands the transport module 100 above the transport box, so that the transport box is roughly within the range of the variable opening 30. The controller 40 is then activated with a "lock" command, causing the four hollow cup motors 10 to rotate synchronously in the forward direction. This drives the slider 60 to move along the lead screw 50, tightening the clamping rope 20 and causing the variable opening 30 to contract inward, tightly gripping the transport box from all sides. Because the hollow cup motors 10 have a reverse self-locking capability, they will not loosen even if power is cut off. To release the cargo, the "unlock" command is activated, causing the motors to rotate in the reverse direction, the clamping rope 20 to loosen, the variable opening 30 to expand, and the transport box to automatically detach.

[0107] This embodiment achieves automatic locking and releasing of the transport box through a four-motor linkage clamping structure arranged symmetrically in a grid pattern. It does not require high-precision positioning, has a mechanical self-locking function, supports one-click autonomous operation, and is compatible with standardized boxes of different sizes. It effectively solves the problems of poor adaptability, low safety, cumbersome operation, and insufficient versatility of existing drone cargo grabbing devices.

[0108] This invention further integrates an airborne lightweight AI visual perception unit in the center of the grid-shaped frame, including a downward-looking RGB camera (resolution ≥1080P, frame rate ≥30fps) and an edge computing module (such as NVIDIA Jetson or Huawei Ascend 310). Through deep learning object detection algorithms (such as DV-YOLO or a lightweight YOLOv8 model optimized for small targets and densely distributed objects in logistics environments), the controller can automatically complete three tasks when the drone approaches the target transport container: container classification, pose estimation, and task type determination.

[0109] The vision system utilizes a deep learning model to analyze images of the transport container in real time. Through model inference, the controller identifies the type of transport container (e.g., cold chain container, fragile goods container, general cargo container), detects the current three-dimensional pose (including offsets in the X / Y / Z directions and yaw angle deviations) of the "30° downward-sloping annular flange" on the top of the container relative to the UAV's fuselage, and reads the attributes of this transport task (e.g., transport time requirements, cargo sensitivity level, unloading priority) based on standardized logistics identification codes (e.g., 1D barcodes, QR codes, or RFID-assisted identification) on the side of the container. The detection results are then fused into a decision by the controller (which includes a motor drive module and a feedback control module). Based on the container type and task attributes, the controller automatically maps the target parameters during the grasping process to "task-oriented clamping force" and "response speed," forming a differentiated grasping strategy.

[0110] Cold chain sensitive boxes: High-precision slow tightening mode is used to gradually increase the tension of the hoop ropes with gradient tension control. At the same time, the deformation of the box is monitored in real time through the vision system to avoid mechanical impact damage to the box or the goods inside.

[0111] Fragile goods box: The controller selects the "relaxed grip" tension threshold. Utilizing the elastic buffering characteristics of the flexible material of the hoop rope (Dyneema rope or aramid rope), the clamping force is actively reduced by about 30% while ensuring sufficient clamping force to prevent shaking. At the same time, the position detection unit uses real-time closed-loop correction of the preload parameter of the tension adjusting nut to achieve "gentle grip" rather than "forceful compression".

[0112] General cargo container (including emergency mission priority sign): Activate the quick response mode, and the four motors tighten synchronously at a higher speed, shortening the gripping time.

[0113] The vision system detects logistics identification codes and box labels, mapping task attributes (such as "urgent delivery") to controller parameters to form differentiated grasping response strategies. The system predicts the box's pose before the flight mission begins, effectively controlling the drone's hovering alignment error above the target to within ±2cm. Comparative verification shows that this system reduces the damage rate of fragile boxes by more than 40%, extends the temperature maintenance time of cold chain boxes by 15%, and shortens the grasping time for urgent goods by approximately 25%.

[0114] This invention, by adding an "intelligent recognition-driven adaptive grasping strategy," enables drones to have the autonomous decision-making ability to "see, identify, and decide on a strategy," thus overcoming the limitation of the original solution's "uniform strategy for grasping all containers" in terms of generality, and further improving the level of transportation precision and the flexibility of task scheduling.

[0115] The present invention also includes a fully autonomous docking and adaptive landing fault-tolerant system based on closed-loop vision guidance.

[0116] This invention further introduces a visual servoing system that integrates binocular vision sensors and an inertial measurement unit, upgrading the entire closed-loop system from target recognition and navigation approximation to precise docking. Compared to the limitations of traditional visual servoing methods that rely on specific targets such as Apriltags, this invention directly identifies the geometric features of the guide groove on the top of the logistics box as a natural marker, eliminating the need for additional labels on the box and significantly improving the system's versatility and deployment efficiency.

[0117] The controller incorporates a visual servo closed loop, fusing monocular target detection and binocular depth estimation to calculate the UAV's 3D pose relative to the center of the transport container's guide groove in real time. Based on the disparity map generated by the binocular camera, feature points are extracted from the radial guide grooves opened on the inner side of the annular flange around the container. The positional deviation (ΔX, ΔY, ΔZ) and attitude deviation (yaw angle ΔYaw) of the transport container relative to the UAV are calculated in real time, constructing a complete six-degree-of-freedom relative pose model. Based on this deviation data, the controller generates speed correction commands to the UAV flight control system in real time, driving the UAV to dynamically adjust its hovering position and yaw angle, achieving a real-time closed loop of "visual tracking—flight adjustment—precise landing". In the final descent phase, the system adopts a two-stage strategy of "coarse adjustment + fine adjustment": when the UAV is about 1.5-2.0 meters away from the top of the container, visual servo tracking is activated to correct the horizontal deviation to ≤5cm; when it descends to about 0.3 meters, it switches to the mechanical guidance mechanism at the end of the conical support feet and guide groove. The tapered support feet automatically engage with the guide slot openings, achieving final physical correction at the hardware level, ultimately controlling the vertical landing error to ≤3cm. During the docking process, the controller synchronously monitors the current feedback of each hollow cup motor. If a sudden increase in motor current is detected after the support feet fall into the guide slot, it is determined that "contact with the box is complete," and the grasping process is automatically initiated.

[0118] The entire flight control process requires no additional positioning facilities such as ground-based RTK or UWB base stations; it is completed independently entirely through the UAV's onboard vision system. Compared to pure GNSS / GPS positioning solutions (typical landing error of approximately ±20-30cm), this invention significantly increases the docking success rate from less than 80% to over 96% (within level 3 winds), greatly reducing the costs of go-arounds and manual intervention due to positioning failures. Simultaneously, the fully closed-loop autonomous guidance allows the UAV to complete flight attitude pre-calibration before approaching the target, replacing the inefficient traditional "fine-tuning after approach" mode, and reducing the hovering alignment time before capture by approximately 40%.

[0119] This invention endows drones with continuous visual tracking capabilities, like a falcon stalking its prey. It upgrades the grasping process from a sequential, passive operation of "landing first and then grasping" to a parallel, active docking of "calibrating while landing." This significantly reduces reliance on external positioning equipment and stringent requirements for the flight environment, and substantially improves the system's operational reliability and deployment flexibility.

[0120] This invention provides an adaptive grasping and transporting drone and its control method, aiming to solve the technical problems of poor grasping adaptability, complex operation, and insufficient safety in existing drone logistics transportation systems. This invention proposes a three-in-one architecture consisting of a flight platform, a grid-shaped four-motor mounting and locking system, and a standardized transport container.

[0121] This invention provides an adaptive grasping and transporting drone, which consists of a flight platform, a grid-shaped four-motor mounting and locking system, and a standardized transport container, forming a three-in-one architecture. Specifically:

[0122] The flight platform is a multi-rotor unmanned aerial vehicle (UAV) with hovering and autonomous navigation capabilities.

[0123] The grid-shaped four-motor mounting and locking system adopts a grid-shaped mechanical self-locking mechanism, which integrates four independently controlled hollow cup motors to drive the hoop rope (made of Dyneema rope or aramid rope) to achieve tension adjustment;

[0124] The standardized transport box has a 30° downward sloping annular flange on the top, with a radial guide groove on the inner side of the flange, which is used to cooperate with the conical support feet at the bottom of the drone to complete mechanical alignment.

[0125] This invention also includes an airborne intelligent visual perception unit:

[0126] A lightweight, organically mounted AI vision perception unit is integrated at the center of the grid-shaped frame, specifically including:

[0127] A downward-facing RGB camera with a resolution of at least 1080P and a frame rate of at least 30fps;

[0128] One edge computing module, which can be either NVIDIA Jetson series or Huawei Ascend 310.

[0129] The controller is internally equipped with a deep learning object detection algorithm (such as DV-YOLO or a lightweight YOLOv8 model optimized for logistics scenarios). This algorithm is specifically optimized for small targets and densely distributed objects in the logistics environment. When the drone approaches the target transport box, the vision system acquires an image of the box top in real time, and the controller automatically completes the following three tasks:

[0130] Box Classification: Identify box types, including cold chain boxes, fragile goods boxes, and general cargo boxes;

[0131] Pose estimation: Detect the three-dimensional pose of the annular flange on the top of the housing relative to the belly of the UAV, including the offset in the X, Y, and Z directions and the yaw angle deviation;

[0132] Task attribute reading: Parse the standardized logistics identification code (one-dimensional barcode, two-dimensional code or RFID-assisted identification) on the side of the container to obtain information such as transportation time requirements, cargo sensitivity level, and unloading priority.

[0133] The controller integrates visual inspection results with task attributes to make decisions, automatically mapping target parameters during the grasping process to "task-oriented constraints" and "response speed," thus forming differentiated grasping strategies.

[0134] Cold chain sensitive boxes: High-precision slow tightening mode is activated. The controller slowly increases the tension of the tightening ropes using gradient tension control, while the vision system monitors the box deformation in real time to avoid mechanical impact damage to the box or affecting the insulation structure.

[0135] Fragile item box: The controller selects the "relaxed grip" tension threshold, utilizing the elastic buffering characteristics of the flexible material of the hoop rope (Dyneema rope or aramid rope) to actively reduce the clamping force by about 30% while ensuring that the clamping force is sufficient to prevent shaking. At the same time, the position detection unit corrects the preload parameter of the tension adjusting nut in real time in a closed loop, achieving "gentle grip" rather than "forceful compression".

[0136] For general cargo boxes: A fast response mode is activated, with four motors simultaneously tightening at a higher speed, reducing gripping time. The vision system identifies task attributes such as "urgent delivery" by detecting logistics identification codes and maps them to controller parameters, forming a differentiated gripping response strategy.

[0137] All of the above decisions are made before the flight mission begins, predicting the container's position and orientation, effectively controlling the hovering alignment error of the UAV above the target to within ±2 cm. Comparative verification shows that this system reduces the damage rate of fragile goods containers by more than 40%, extends the temperature maintenance time of cold chain containers by 15%, and shortens the grabbing time of emergency goods by approximately 25%.

[0138] This invention further introduces a visual servoing system that integrates a binocular vision sensor and an inertial measurement unit (IMU) to construct a closed-loop process from target recognition and navigation approximation to precise docking.

[0139] Unlike traditional methods that rely on specific targets such as Apriltags, this invention directly uses the geometric features of the guide groove on the top of the logistics box as a natural marker, eliminating the need for additional labels on the box. The controller incorporates a visual servo closed loop, fusing monocular target detection and binocular depth estimation to calculate the UAV's 3D pose relative to the center of the guide groove in the transport box in real time. Based on the disparity map generated by the binocular camera, feature points are extracted from the radial guide groove inside the annular flange, and the six-DOF relative pose model of the transport box relative to the UAV is calculated in real time, including positional deviations (ΔX, ΔY, ΔZ) and attitude deviations (yaw angle ΔYaw).

[0140] The controller generates speed correction commands to the flight control system in real time based on the deviation data, driving the UAV to dynamically adjust its hovering position and yaw angle, thus achieving a real-time closed loop of "visual tracking - flight adjustment - precise landing".

[0141] In the final descent phase, the system employs a two-stage strategy of "coarse adjustment + fine adjustment":

[0142] When the drone is about 1.5 to 2.0 meters away from the top of the container, activate visual servo tracking to correct the horizontal deviation to no more than 5 cm.

[0143] When the drop reaches approximately 0.3 meters, the system switches to a mechanical alignment mechanism at the end of the tapered support foot and guide groove. The inclined surface of the tapered support foot automatically engages with the opening of the guide groove, achieving final physical correction at the hardware level, ultimately controlling the vertical drop error to no more than 3 cm.

[0144] During the docking process, the controller synchronously monitors the current feedback of each hollow cup motor. If a sudden increase in motor current is detected after the support foot falls into the guide groove, it is determined that "contact with the box is complete," and the grasping process is automatically started.

[0145] The entire flight control process does not rely on additional positioning facilities such as ground RTK or UWB base stations; it is entirely completed independently by the airborne vision system. Compared to pure GNSS / GPS positioning solutions (typical landing error of approximately ±20–30 cm), this invention significantly improves the docking success rate from less than 80% to over 96% (within level 3 winds), greatly reducing the costs of go-arounds and manual intervention due to positioning failures. Simultaneously, the fully closed-loop autonomous guidance allows the UAV to complete flight attitude pre-calibration before approaching the target, replacing the inefficient traditional "fine-tuning after approach" mode, and reducing the hovering alignment time before capture by approximately 40%.

[0146] This invention endows drones with continuous visual tracking capabilities, like a falcon stalking its prey. It upgrades the grasping process from the traditional sequential passive operation of "landing first and then grasping" to a parallel active docking of "calibrating while landing". This system significantly reduces the dependence on ground positioning facilities and the stringent requirements of the flight environment, and significantly improves the operational reliability, deployment flexibility and transportation precision of the drone logistics system.

[0147] The above specific embodiments are used to explain and illustrate the present invention, and are only preferred embodiments of the present invention, not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. An adaptive grasping and transporting drone, characterized in that, The flight carrier module has a four-motor mounting and locking system in a grid pattern on its fuselage. The transport box has an annular flange on its periphery that is compatible with the four-point mounting system, which facilitates the clamping and fixing of the grid-shaped four-motor mounting and locking system. The grid-shaped four-motor mounting and locking system includes: Four hollow cup motors arranged in a square; The hoop rope assembly consists of a hoop rope connected to each side of each hollow cup motor. The hoop ropes of two hollow cup motors arranged opposite each other are connected to each other to form a grid-shaped hoop structure. A variable opening for accommodating a transport box is formed in the middle of the grid-shaped hoop structure. The controller is electrically connected to the four hollow cup motors and is used to control the four hollow cup motors to rotate synchronously in the forward or reverse direction. When the controller controls the four hollow cup motors to rotate synchronously in the forward direction, the hoop rope tightens, the variable opening contracts centripetally, and the transport box is mechanically locked; when the controller controls the four hollow cup motors to rotate synchronously in the reverse direction, the hoop rope loosens, the variable opening expands centrifugally, and the transport box is released to achieve mechanical unlocking.

2. The adaptive grasping and transport drone of claim 1, wherein, The hollow cup motor is a hollow cup planetary reduction bidirectional push rod motor, which integrates a planetary reduction mechanism inside and connects the lead screw and slider at the output end; the motor has a reverse self-locking capability, which can maintain the lead screw position locked in the power-off state to prevent the transport box from being accidentally released.

3. The adaptive grasping and transport drone of claim 2, wherein, The lead screw is directly connected to the output shaft of the hollow cup motor, and the slider is fixedly connected to the end of the hoop rope; support seats are provided at both ends of the lead screw; the slider is driven to reciprocate along the lead screw by the forward and reverse rotation of the motor, thereby tightening or loosening the hoop rope.

4. The self-adapting grasping and transporting drone of claim 1, wherein, Two sliding platforms located diagonally on the grid-shaped frame are each equipped with a slider. The sliders are connected by a high-tensile stainless steel wire rope. The wire rope passes around a guide pulley located at the end of the frame to form a closed-loop transmission. Tension adjusting nuts are provided at both ends of the wire rope to eliminate transmission gaps and ensure that the four sets of hoop ropes are tightened or loosened synchronously.

5. The self-adapting grasping and transporting drone of claim 1, wherein, The lower end of the transport module is fixedly provided with four lower support feet; the four hollow cup motors are respectively fixedly installed on the four lower support feet; the hoop rope is directly wrapped around the outer perimeter of the transport box.

6. The self-adapting grasping and transporting drone of claim 1, wherein, The tightening rope is made of Dyneema rope, steel wire rope or aramid rope.

7. The adaptive grasping and transport drone of claim 1, wherein, The controller includes a motor drive module and a feedback control module; the feedback control module includes a position detection unit and / or a tension detection unit, used to detect the size of the variable opening or the tension of the hoop rope; the controller adjusts the rotation state of the four hollow cup motors in a closed loop according to the detection results.

8. The adaptive grasp shipping drone of claim 1, wherein, The transport box includes a box body and a box lid. The top of the box body is provided with annular flanges around its perimeter that match the end hooks of the four-point mounting system.

9. The adaptive grasp shipping drone of claim 1, wherein, The top of the transport box is provided with a 30° downward sloping annular flange around its perimeter. The inner side of the flange is provided with a radial guide groove that is adapted to the support foot of the four-point mounting system. The sloping surface of the flange and the arc-shaped hook of the support foot form a wedge fit to achieve automatic centering during gripping and anti-loosening limit after locking.

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