Landing docking for offshore wind farm inspection, unmanned ship, platform and method

Abstract

This invention discloses a take-off and landing docking device, unmanned surface vessel (USV), platform, and method for inspecting offshore wind farms. The take-off and landing docking device includes: a shipborne docking mechanism for capturing the USV during its descent phase to form a flexible connection with it; a rotating part for driving the shipborne docking mechanism to rotate so that the shipborne docking mechanism aligns with the descent direction of the USV; and a lifting mechanism for driving the rotating part to adjust its vertical height.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) take-off and landing technology, specifically relating to a take-off and landing docking device, unmanned vessel, platform, and method for offshore wind farm inspection. Background Technology

[0002] The inspection environment of offshore wind farms is extremely complex. Currently, it mainly relies on large and medium-sized manned maintenance vessels carrying drones or drones flying remotely from land to the wind farm for operations. However, large and medium-sized manned vessels are expensive to build and maintain, and pose significant safety risks to personnel; while land-based drones have limited range and short effective operating time. Utilizing unmanned surface vessels (USVs) as mobile platforms to carry drones is a trend to reduce costs and improve efficiency, but the harsh working conditions at sea pose serious challenges to drone take-off and landing. Due to the heave and roll of the hull caused by waves and the interference of variable sea winds, drones find it difficult to land accurately on the decks of small unmanned vessels with violent movements. Existing landing methods based on visual recognition or solely relying on flight control algorithms are prone to collisions, skidding, or even capsizing in poor sea conditions.

[0003] Therefore, how to develop a take-off and landing dock that can effectively compensate for ship motion and safely capture and fix drones in adverse sea conditions is a technical challenge that urgently needs to be solved in the field of intelligent inspection of offshore wind power. Summary of the Invention

[0004] In view of this, the main objective of the present invention is to provide a take-off and landing docking device, unmanned vessel, platform and method for offshore wind farm inspection.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A take-off and landing dock for offshore wind farm inspection includes: A shipborne docking mechanism is used to capture the drone during its landing phase, thereby forming a flexible connection with the drone. A rotating part is used to drive the shipborne docking mechanism to rotate so that the shipborne docking mechanism corresponds to the landing direction of the UAV; A lifting mechanism is used to drive the rotating part to adjust its vertical height.

[0006] Preferably, the shipborne docking mechanism includes a connecting screw and an electric gripper assembly; the lower end of the connecting screw is connected to the rotating part, and two electric gripper assemblies are provided and symmetrically arranged on both sides of the upper end of the connecting screw.

[0007] Preferably, the electric gripper assembly includes a gripper servo motor, a servo motor shaft, an arc-shaped gripper, and a fixed gripper; the gripper servo motor is fixed to one side of the upper end of the connecting screw, the output end of the gripper servo motor is connected to one end of the arc-shaped gripper through the servo motor shaft, and the fixed gripper is disposed on one side of the upper end of the connecting screw and abuts against the other end of the arc-shaped gripper in the closed state to form a closed gripper.

[0008] Preferably, a plurality of magnetic elements are arranged at intervals on the arc-shaped gripper.

[0009] Preferably, proximity sensors are provided on both sides of the upper end of the connecting screw, respectively, between the fixed gripper and the gripper servo, to detect whether the UAV has entered the preset capture range and trigger the sequential action of the magnetic component and the electric gripper assembly.

[0010] An unmanned vessel includes: The hull is used to carry the aforementioned take-off and landing dock and the drone after landing.

[0011] Preferably, the hull is provided with a landing platform; the take-off and landing dock is located at the bottom of the unmanned vessel and extends beyond the landing platform after passing through it.

[0012] A landing platform for inspecting offshore wind farms, comprising: The unmanned vessel as described in claim 6 or 7; The drone has an onboard docking mechanism at its bottom for docking with the take-off and landing docking device.

[0013] Preferably, the airborne docking mechanism includes a take-up and release winch, an elastic rope, and a loop connected to the end of the elastic rope; the take-up and release winch is fixed to the bottom of the UAV, the elastic rope is wound around the take-up and release winch, and the loop engages with the arc-shaped gripper when the UAV lands, so that the UAV and the unmanned vessel form a flexible connection.

[0014] Preferably, the method includes: Control the lifting mechanism to raise the shipborne docking mechanism to a predetermined safe height; The rotating part is controlled to drive the shipborne docking mechanism to rotate in the direction in which the UAV approaches; After the proximity sensor detects the ring dropped by the drone, the shipborne docking mechanism is activated to capture the ring; The lifting mechanism is controlled to descend, and the drone is simultaneously instructed to descend in sync until the drone lands safely on the landing platform.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves robust control of unmanned aerial vehicles (UAVs) throughout the entire takeoff and landing process on a dynamic maritime platform through the coordinated operation of a shipborne docking mechanism, a rotating unit, and a lifting mechanism. During the landing phase, rotational alignment and vertical lift compensation simplify the complex three-dimensional aerial capture into a controlled one-dimensional tension balance process, effectively absorbing the heave energy caused by waves and solving the technical problems of traditional landing methods being prone to capsizing and collisions in harsh sea conditions. During takeoff, rigid locking protection is provided before the UAV reaches a preset lift threshold, completely eliminating the risk of sideslip caused by hull swaying. Flexible damping constraint is provided by elastic ropes at the moment of release, ensuring smooth unhooking of the UAV and suppressing lateral drift caused by airflow interference. The entire system significantly improves the success rate and wind resistance of UAVs on small unmanned surface vessels, providing crucial support for efficient and safe inspection of offshore wind farms. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and, together with their descriptions, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This invention provides a schematic diagram of the structure of a take-off and landing docking device for offshore wind farm inspection. Figure 2 This invention provides a schematic diagram of the electric gripper assembly in the open state of a take-off and landing dock for offshore wind farm inspection, as provided in an embodiment of the invention. Figure 3 A schematic diagram of the structure of an unmanned vessel is also provided as an embodiment of the present invention.

[0017] Figure 4 This invention also provides a schematic diagram of the structure of a take-off and landing platform for offshore wind farm inspection; Figure 5 This invention also provides a schematic diagram of the structure of a take-off and landing platform for offshore wind farm inspection when a drone lands on an unmanned vessel. Figure 6 The present invention also provides a schematic diagram of the structure of a take-off and landing platform for offshore wind farm inspection, in which a drone lands in front of or after taking off from an unmanned vessel; Figure 7 The present invention also provides a schematic diagram of the action of the electric gripper assembly and the ring buckle during the landing process of a UAV in a take-off and landing platform for offshore wind farm inspection; Figure 8 As an embodiment of the present invention, a stress analysis diagram of a take-off and landing platform for offshore wind farm inspection compared with the prior art is also provided; Figure 9As an embodiment of the present invention, a schematic diagram of the elastic rope in a landing platform for offshore wind farm inspection under shortened and stretched conditions is also provided; Figure 10 A flowchart of a drone recovery method is also provided as an embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0020] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0021] This invention provides a take-off and landing docking device for offshore wind farm inspection, such as... Figure 1 , 2 As shown, it includes: Shipborne docking mechanism 1 is used to capture UAV 4 during the UAV landing phase so as to form a flexible connection with UAV 4; The rotating part 2 is used to drive the shipborne docking mechanism 1 to rotate so that the shipborne docking mechanism 1 corresponds to the landing direction of the UAV 4; The lifting mechanism 3 is used to drive the rotating part 2 to adjust its vertical height.

[0022] This invention achieves robust control of the entire take-off and landing process of a UAV on a dynamic maritime platform through the coordinated operation of the shipborne docking mechanism 1, the rotating part 2, and the lifting mechanism 3. During the landing phase, rotational alignment and vertical lift compensation simplify the complex three-dimensional aerial capture into a controlled one-dimensional tension balance process, effectively absorbing the heave energy caused by waves and solving the technical problems of traditional landing methods being prone to capsizing and collisions in harsh sea conditions. During the take-off phase, rigid locking protection is provided before the UAV 4 reaches the preset lift threshold, completely eliminating the risk of sideslip caused by hull swaying. Flexible damping constraint is provided by elastic ropes at the moment of release, ensuring that the UAV 4 can smoothly unhook and suppressing lateral drift caused by airflow interference. The entire device significantly improves the success rate and wind resistance of UAVs on small unmanned surface vessels, providing crucial support for efficient and safe inspection of offshore wind farms.

[0023] In some embodiments, the shipboard docking mechanism 1 includes a connecting screw 101 and an electric gripper assembly 102; the lower end of the connecting screw 101 is connected to the rotating part 2, and two electric gripper assemblies 102 are provided and symmetrically arranged on both sides of the upper end of the connecting screw 101.

[0024] Specifically, the connecting screw 101 serves as a core support component. Its bottom end is reliably connected to the rotating part 2 via a flange or fastening thread to ensure the smooth transmission of rotational torque. Two electric gripper assemblies 102 are symmetrically distributed on both sides of its top end. The symmetrical structure not only increases the capture range but also ensures uniform force when capturing the end ring of the drone 4, avoiding structural displacement or mechanical fatigue caused by unilateral force.

[0025] After the UAV 4 enters the capture window, the lifting mechanism 3 drives the shipborne docking mechanism 1 to rise, and the rotating part 2 drives the connecting screw 101 to perform phase alignment according to the real-time orientation of the UAV 4.

[0026] The symmetrical electric gripper assembly 102 design significantly increases the effective capture cross-sectional area, greatly reducing the difficulty of alignment in high-frequency swaying environments at sea. At the same time, the connecting screw 101 not only serves as a mechanical support but also provides a physical protection channel for the internal sensor cables and power lines, enhancing the equipment's operational lifespan in high-salt-spray and high-humidity environments at sea. Finally, through bidirectional limiting, it ensures that the UAV 4 will not slip horizontally during the subsequent cable retrieval and landing process.

[0027] During the takeoff preparation phase, the connecting screw 101 securely supports the electric gripper assembly 102 at its working height. At this time, the two symmetrically arranged electric gripper assemblies 102 are in a locked state, and the UAV's ring is securely positioned directly above the center of the landing platform 501 through symmetrical mechanical forces on both sides. When the propeller speed of the UAV 4 reaches the preset lift threshold, the rotating part 2 confirms the alignment phase for the last time, and then the electric gripper assemblies 102 on both sides open synchronously and quickly.

[0028] In some embodiments, the electric gripper assembly 102 includes a gripper servo motor 1021, a servo motor shaft 1022, an arc-shaped gripper 1023, and a fixed gripper 1024. The gripper servo motor 1021 is fixed to one side of the upper end of the connecting screw 101. The output end of the gripper servo motor 1021 is connected to one end of the arc-shaped gripper 1023 through the servo motor shaft 1022. The fixed gripper 1024 is disposed on one side of the upper end of the connecting screw 101 and abuts against the other end of the arc-shaped gripper 1023 in the closed state to form a closed gripper.

[0029] Specifically, the fixed gripper 1024 is installed on the top side of the connecting screw 101 as a reference limiting component, while the arc-shaped gripper 1023 is driven by the gripper servo motor 1021 and swings in a fan shape with the servo motor shaft 1022 as the center. Utilizing the physical characteristics of the arc surface, a funnel-shaped capture port with guiding function is formed in space, which can effectively accommodate the small swing deviation of the UAV 4 caused by the wind.

[0030] Upon detecting that the loop at the drone end has entered the effective capture range, the gripper servo 1021 immediately drives the arc-shaped gripper 1023 to rotate and close via the pivot 1022. As the arc-shaped gripper 1023 sweeps across, it pushes the loop towards the fixed gripper 1024 until the ends of the two grippers are tightly abutted, thus firmly restraining the loop within the fully enclosed geometric cavity formed by the two grippers. After locking, the gripper servo 1021 maintains torque to ensure that the loop will not come off during the subsequent elastic rope retrieval process.

[0031] The physical closed loop formed by the closed arc-shaped gripper 1023 can provide multi-dimensional limiting capabilities to prevent the buckle from jumping during violent sea turbulence. At the same time, through the cooperation of the fixed gripper 1024 and the arc-shaped gripper 1023, the originally complex aerial alignment is simplified into controlled circular motion capture, which greatly improves the success rate of establishing flexible connection between UAV and unmanned vessel in harsh sea conditions.

[0032] Upon triggering the takeoff command, the gripper servo 1021 receives a high-frequency control signal and drives the arc-shaped gripper 1023 to rapidly rotate and swing outward via the servo shaft 1022. The curved surface design of the arc-shaped gripper 1023 ensures sufficient physical clearance between it and the ring when exiting the closed state. The rotational release path of the arc-shaped gripper 1023 effectively reduces frictional resistance with the ring, achieving zero hook release. The high response speed of the gripper servo 1021 ensures that disengagement is completed within the transient calm period of wave ups and downs, greatly improving the safety window for takeoff.

[0033] In some embodiments, a plurality of magnetic elements 10231 are arranged at intervals on the arc-shaped gripper 1023.

[0034] Specifically, several magnetic components 10231 are embedded or fixedly arranged at equal intervals along the inner working surface of the arc-shaped gripper 1023, forming a continuous and uniform magnetic field coverage zone within the inner cavity of the arc-shaped gripper 1023. The arrangement of the magnetic components 10231 ensures that their magnetic field lines point towards the geometric center of the gripper, providing a directional gravitational field for the airborne ring buckle.

[0035] During the transient phase of landing and capture, when the UAV's ring lands on the capture window of the electric gripper assembly 102, if the ring experiences a slight displacement due to sea breeze interference or the ship's heave, the magnetic force generated by the magnetic component 10231 will take effect before the mechanical gripping. The ring is quickly attracted by the magnetic force and adheres to the inner arc surface of the arc-shaped gripper, achieving self-alignment and adsorption. Subsequently, the gripper servo motor 1021 drives the arc-shaped gripper 1023 to close, converting the unstable dynamic magnetic attraction into a stable physical rigid lock, completing the entire capture action.

[0036] In harsh sea conditions, millimeter-level flight alignment is extremely difficult. The magnetic component 10231 effectively compensates for the relative motion error between the UAV 4 and the arc-shaped gripper 1023, preventing the ring from rebounding or slipping due to collision at the moment of closure. At the same time, the initial constraint force provided by the magnetic component 10231 reduces the impact load on the gripper servo 1021 at the moment of closure, improving the structural reliability and service life of the entire mechanism under long-term high-frequency operation at sea.

[0037] During the lift-up phase of the drone, the electromagnetic intensity is first reduced. Simultaneously, as the gripper servo 1021 drives the arc-shaped gripper 1023 to open, the magnetic component 10231 is completely de-energized or switches to a momentary like-pole repulsion mode. If a permanent magnet is used, the lift generated by the drone's upward jump forcibly overcomes the magnetic attraction. At the moment of release, the controllable change in magnetic force acts as virtual damping during takeoff, preventing the drone 4 from violently shaking due to airflow disturbances when the arc-shaped gripper 1023 just releases. The presence of the magnetic force ensures that the ring remains on the central axis for a very short time after the mechanical lock is released, until the drone 4 gains sufficient upward acceleration.

[0038] In some embodiments, proximity sensors 1025 are provided on both sides of the upper end of the connecting screw 101 at positions between the fixed gripper 1024 and the gripper servo 1021, respectively, to detect whether the UAV 4 has entered a preset capture range and to trigger the sequential action of the magnetic component 10231 and the electric gripper assembly 102.

[0039] Specifically, the proximity sensor 1025 (such as a high-precision inductive or infrared sensor) is symmetrically embedded on the side of the top of the connecting screw 101, and is precisely positioned in the gap between the fixed gripper 1024 and the gripper servo 1021, directly facing the geometric center of the capture area.

[0040] When the ring at the bottom of the drone 4 enters the preset capture threshold range, the proximity sensor 1025 immediately sends a trigger pulse to the controller. After receiving the signal, the magnetic component 10231 on the arc-shaped gripper 1023 is activated first, and the magnetic attraction 10231 is used to perform instantaneous dynamic alignment and adsorption of the ring. Within milliseconds after the magnetic force initially stabilizes the position of the ring, the electric gripper assembly 102 is then driven to complete the final mechanical closure. This sequential action ensures the continuity of the capture process and avoids blind gripping by the mechanical structure.

[0041] With precise feedback from the proximity sensor 1025, the controller can effectively distinguish between normal approach and successful capture of the UAV 4, thus avoiding wear on the gripper servo 1021 caused by frequent idle movements of the curved gripper 1023. Simultaneously, the sequential action logic of magnetic attraction followed by clamping, driven by the proximity sensor 1025, significantly shortens the unstable period during capture. Even amidst severe turbulence caused by waves, automated response ensures a high success rate of capture and structural safety.

[0042] During takeoff, proximity sensor 1025 switches to monitoring mode, confirming in real time whether the hook has completely disengaged from the enclosed space. When the sensor detects that the signal has changed from present to absent, it immediately sends a successful disengagement signal to the controller, which then triggers the lifting mechanism 3 to retract the takeoff and landing dock into the deck. Through the precise monitoring of proximity sensor 1025, the system can automatically determine whether takeoff was successful and immediately initiate the retraction procedure to protect the ship's equipment from subsequent airflow or waves.

[0043] This invention also provides an unmanned vessel, such as... Figure 3 As shown, it includes: The hull 5 is used to carry the aforementioned take-off and landing dock and the UAV 4 after landing.

[0044] In some embodiments, a landing platform 501 is provided on the hull 5; the take-off and landing dock is located at the bottom of the unmanned vessel and extends beyond the landing platform 501 after passing through it.

[0045] Specifically, the unmanned surface vessel adopts an integrated landing platform design. The hull 5 serves as the main load-bearing structure, with a landing platform 501 laid flat on top of it to provide physical support for the UAV after landing. The base of the take-off and landing dock is installed inside the hull 5 or on the bottom support frame. Its actuator passes through the reserved through hole and extends above the landing platform 501, which not only ensures the stability of the mechanical structure's center of gravity but also protects the precision drive mechanism below through the physical shielding of the deck.

[0046] As UAV 4 prepares to land, the landing dock located below landing platform 501 activates. Lifting mechanism 3 drives the shipborne docking mechanism to penetrate landing platform 501 from bottom to top, reaching operational height to capture the UAV. After capture, the landing dock reverses its movement, lowering the locked UAV 4 synchronously until its landing gear makes stable contact with the surface of landing platform 501. At this point, the landing dock remains tensioned or locked, ensuring that UAV 4 remains fixed in its preset position on landing platform 501 throughout the ship's navigation.

[0047] Before takeoff, the takeoff and landing dock penetrates from below landing platform 501 and rises to the operating height, lifting the drone a certain distance away from the platform surface. As the uncoupling operation is completed, the drone accelerates into the air, and the takeoff and landing dock quickly and vertically retracts to below landing platform 501, restoring the platform to a flat state, ready to receive the drone after it has completed its operation.

[0048] This invention also provides a landing platform for offshore wind farm inspection, such as... Figure 4-7 As shown, it includes: The unmanned vessel mentioned above; The drone 4 has an airborne docking mechanism 401 at its bottom for docking with the take-off and landing docking device.

[0049] In some embodiments, the airborne docking mechanism 401 includes a take-up and release winch 4011, an elastic rope 4012, and a loop 4013 connected to the end of the elastic rope 4012; the take-up and release winch 4011 is fixed to the bottom of the UAV 4, the elastic rope 4012 is wound around the take-up and release winch 4011, and when the UAV 4 lands, the loop 4013 docks with the arc-shaped gripper 1023 so that the UAV 4 and the unmanned vessel form a flexible connection.

[0050] Specifically, the airborne docking mechanism 401 is configured as a suspension system with dynamic adjustment capabilities. The cable reel 4011 is compactly installed at the center of the fuselage of the UAV 4 to ensure the stability of the UAV's center of gravity. The elastic rope 4012 is made of a high-strength flexible material with excellent elastic modulus. One end is fixed by the winch, and the other end is connected to a high-strength steel ring 4013.

[0051] After the landing mission is initiated, the winch 4011 rotates in a controlled manner, slowly lowering the elastic rope 4012 and its end loop 4013 to a predetermined depth below the drone. Once the loop 4013 enters the capture range of the ship-mounted arc-shaped gripper 1023 and is locked, a physical connection is immediately established between the drone and the ship. Subsequently, the winch 4011 actively retracts the rope based on feedback from the tension sensor, gradually pulling the drone 4 towards the ship's deck while maintaining a certain tension in the elastic rope 4012. During this process, the elastic deformation of the elastic rope 4012 absorbs and compensates for displacement fluctuations caused by the heave of the unmanned vessel in real time.

[0052] Through the connection of the elastic rope 4012, the random deviation of the UAV 4 on the horizontal plane is transformed into a tension balance problem along the cable axis, greatly simplifying the processing difficulty of the flight control algorithm under complex sea conditions. At the same time, the active contraction force of the cable reel 4011 and the passive elastic extension and contraction of the elastic rope 4013 combine to effectively eliminate the rigid impact force generated by the relative motion between the ship and the UAV, preventing the UAV 4 from capsizing or colliding due to the violent swaying of the ship, and ensuring the safety of docking operations in all weather conditions.

[0053] In the initial takeoff state, the UAV 4 is securely locked to the center of the landing platform 501, and the cable reel 4011 is in a self-locking or high-damping state, keeping the elastic rope 4012 within a predetermined tension range. The electric gripper assembly 102 of the shipborne docking mechanism 1 firmly locks the ring 4013, forming a closed-loop rigid constraint of the hull 5-landing docking device-elastic rope 4012-UAV 4, ensuring that the UAV 4 remains absolutely stationary due to the physical limit of the docking device, even in the face of strong sea winds or a large angle of hull tilt, before the propeller starts. During takeoff, the UAV 4 starts and gradually increases its speed until the lift is greater than the gravity and reaches a preset balance threshold (at which point the lift cancels out the gravity and the tension of the elastic rope). Then, the controller issues a command, and the electric gripper assembly 102 quickly opens and releases the ring 4013, releasing the physical lock. Driving with lift, UAV 4 ascends, while the onboard winch 4011 releases the cable with constant tension, using the tension of the elastic rope 4012 as a damper to eliminate lateral drift caused by airflow disturbances at takeoff. Once UAV 4 reaches a safe altitude, the winch quickly retracts the elastic rope and loop, completing the takeoff process.

[0054] The takeoff process of this invention completely eliminates the unconstrained window period during takeoff at sea. In traditional solutions, the moment the clamp is released until the drone takes off, the drone is highly susceptible to collision due to deck sideslip. This invention replaces the traditional instantaneous disconnection with the flexible traction of the elastic rope 4012, reducing the takeoff risk to one-dimensional tension control in the vertical direction. Furthermore, the pre-tension of the elastic rope 4012 provides additional takeoff stability for the drone 4, enabling small drones to have wind-resistant takeoff and landing capabilities comparable to medium and large manned vessels even in harsh sea conditions.

[0055] like Figure 8 As shown, the mechanical principle and force analysis of the take-off and landing docking device are based on the core of this invention, which utilizes the elastic rope 4012 to reduce the three-dimensional free motion of the UAV 4 under complex sea conditions to a controlled one-dimensional axial motion. The following is a detailed force analysis with reference to the attached figures: Force balance and dimensional reduction principle during descent: In the synchronous pull-back phase of descent, UAV 4 establishes a flexible connection with the shipborne docking mechanism 1 via elastic rope 4012. Force model: At this time, UAV 4 is subjected to an upward lift force F. 升力 The downward force of gravity F 重力 And the downward tension F generated by the elastic rope 拉力 .

[0056] Resultant force relationship: The resultant force output of UAV 4 is expressed as F. 无人机 =F 升力 -F 重力 .

[0057] When in a steady state, the equilibrium equation is satisfied: Fnet force = Fnet 升力 -F 重力 -F 拉力 =0.

[0058] When the elastic rope 4012 is kept taut, any horizontal disturbance will be automatically corrected by the radial component of the tension. The force F is monitored in real time by a tension sensor. 拉力 Fluctuations, the drone flight control system dynamically adjusts F 升力 This ensures that the UAV 4 is always under the control of the rope axis, thus simplifying the complex three-dimensional obstacle avoidance landing into a single-dimensional vertical pull control.

[0059] Force balance and anti-skid analysis during takeoff: During the dynamic balance phase of takeoff, UAV 4 has not yet detached from the hook.

[0060] Pre-tensioned state: The electric gripper assembly 102 locks the ring 4013, and the take-up and unwinding winch 4011 is pre-tensioned. At this time, the UAV 4 is in a force-counteracting state under rigid limit.

[0061] Critical point force analysis: As the rotational speed increases, the force generated by UAV 4...升力 Gradually increasing. The system's set safe takeoff threshold is: F 升力 ≥F 重力 +F 拉力（预设）； At this time F 拉力 It acts as a virtual anchor point. When the waves cause the hull 5 to roll violently, the drone 4 will not shift on the deck due to the downward tension constraint. The resultant force vector always points in the direction of the extension line of the elastic rope 4012, ensuring that the drone has an initial upward acceleration at the moment of unhooking and will not slip laterally due to instantaneous weightlessness.

[0062] Mechanical feedback elastic displacement compensation in dynamic compensation: Due to the elasticity of the elastic rope 4012, when the hull 5 experiences instantaneous heave displacement Δh due to waves, the force sensor detects F... 拉力 A change in ΔF will occur.

[0063] The UAV 4 quickly adjusts the motor speed according to the sign of ΔF to compensate for displacement deviation. This is faster and more accurate than simple visual positioning feedback, and can effectively counteract the effects of high-frequency vibrations on the sea surface.

[0064] like Figure 9 As shown, during the dynamic docking process, the stretching and shortening of the elastic rope 4012 constitutes the core of real-time feedback. When the hull 5 sinks with the waves, causing the distance between the engine and the ship to increase, the elastic rope 4012 is passively stretched, and the resulting restoring tension guides the cable reeling winch 4011 to provide feedback adjustment, compensate for displacement, and prevent loss of control due to excessively rapid disengagement. When the hull 5 rises with the waves, causing the distance to shorten, the elastic rope 4012 quickly shortens and returns to its original position through its own elasticity, and works with the cable reeling winch 4011 to actively reel in the cable, eliminating the risk of entanglement caused by cable slack and ensuring that the engine and ship always maintain a stable force axis during complex heave and sag movements.

[0065] This invention also provides a method for recovering unmanned aerial vehicles (UAVs), applied to the aforementioned take-off and landing platform used for offshore wind farm inspection, such as... Figure 10 As shown, the method includes: Step 101: Control the lifting mechanism 3 to raise the shipborne docking mechanism 1 to a predetermined safe height; Specifically, after the UAV 4 performs its landing mission and enters the communication range of the unmanned vessel, the lifting mechanism 3 is activated. Through telescopic rods, it drives the rotating part 2 and the shipborne docking mechanism 1 to move vertically upwards, penetrating the landing platform 501 and extending above it. Raising it to a predetermined safe height is to avoid obstacles such as sensors and railings that may exist on the deck, providing ample physical space for subsequent ring-locking capture. At the same time, the higher operating position effectively reduces the impact of deck airflow disturbances on the swing of the UAV's bottom ring-locking mechanism, increasing the redundancy of the capture window.

[0066] Step 102: Control the rotating part 2 to drive the shipborne docking mechanism 1 to rotate in the direction in which the UAV 4 approaches; Specifically, airborne and shipborne RTK positioning data are extracted in real time to calculate the horizontal azimuth angle of the UAV 4 relative to the ship hull 5. The rotating part 2 drives the shipborne docking mechanism 1 to rotate in the horizontal plane according to the command, adjusting the opening phase formed by the two electric gripper assemblies 102 so that it faces the direction from which the UAV 4 is flying.

[0067] Step 103: After the proximity sensor detects the ring 4013 deployed by the UAV 4, the shipborne docking mechanism 1 is activated to capture the ring 4013; Specifically, the drone 4 hovers and lowers the elastic rope 4012 and the loop 4013. When the proximity sensor 1025 detects that the loop has entered the capture dead zone, the magnetic component 10231 on the arc-shaped gripper 1023 instantly attracts and constrains the position of the loop. Subsequently, the gripper servo 1021 drives the arc-shaped gripper to quickly rotate and close, locking it with the fixed gripper 1024. By using the proximity sensor 1025 to trigger the sequential action of magnetic attraction followed by clamping, the unstable aerial suspension state is instantly transformed into a stable physical flexible connection. This is the key to achieving one-dimensional control of three-dimensional motion reduction, ensuring the continuity and high success rate of capture actions amidst violent ups and downs in the ocean waves.

[0068] Step 104: Control the lifting mechanism 3 to descend, and simultaneously instruct the drone 4 to descend in sync until the drone 4 safely lands on the landing platform 501.

[0069] Specifically, after establishing the connection, the lifting mechanism 3 begins its uniform descent, simultaneously issuing a synchronous altitude descent command to the UAV 4. At this time, the onboard cable reel 4011 enters active cable reeling mode, and the tension sensor monitors the tension of the elastic rope 4013 in real time. The UAV 4 adjusts its lift to balance the rope tension. As the lifting mechanism retracts below the platform, the UAV's landing gear smoothly touches the surface of the landing platform 501. The synchronous descent process eliminates the relative sway between the aircraft and the ship through the tension of the elastic rope 4013, ensuring that the landing process is no longer affected by deck heave. Finally, the docking device firmly pulls the UAV 4 onto the deck, preventing the UAV from sideslipping or capsizing at sea through continuous physical restraint, ensuring the final closed-loop safety of the landing mission.

[0070] This invention also provides a takeoff control method for a marine unmanned surface-mounted drone, applied to the aforementioned takeoff and landing platform for offshore wind farm inspection, as shown in the figure. The method includes: Step 201: Control the lifting mechanism 3 to drive the shipborne docking mechanism 1 to be vertically lifted from the storage position to the preset take-off height. At this time, the electric gripper assembly 102 remains closed and locks the ring 4013 on the airborne docking mechanism 401, so that the UAV 4 and the ship 5 form a closed-loop rigid constraint through the elastic rope 4012. Specifically, during the initial takeoff phase, the control lifting mechanism 3 raises the shipborne docking mechanism 1 to a preset takeoff height, causing the UAV 4 to leave the surface of the landing platform 501 or be positioned in the optimal airflow zone at the center of the platform. At this time, the electric gripper assembly 102 remains closed, working together with the airborne elastic rope 4012 and the cable reel winch 4011 to form a complete closed-loop rigid constraint between the hull 5, the takeoff and landing dock, the elastic rope 4012, and the UAV 4. Even in strong sea winds or when the hull is swaying at a large angle, this physical constraint ensures that the UAV remains absolutely stationary before the propeller starts, eliminating the risk of sideslip or capsizing caused by violent hull movements.

[0071] Step 202: Instruct the UAV 4 to start the power system and gradually increase the rotation speed. Monitor the tension of the elastic rope 4012 in real time through the tension sensor and dynamically adjust the lift of the UAV until the resultant force of the lift, the weight of the UAV and the tension of the elastic rope reaches the preset balance threshold, and establish a force balance take-off state. Specifically, the command drone 4 starts its power system, and the propeller speed gradually increases, thereby increasing the upward lift. During the transition period before takeoff, drone 4 monitors the tension of the elastic rope 4012 in real time through a tension sensor and adjusts the lift until it reaches the preset balance threshold. At this time, the net force on drone 4 is in a stable state, that is, the lift is approximately equal to the sum of the drone's weight and the tension of the elastic rope. Dynamic force balance control provides a mechanical basis for the subsequent smooth release, ensuring that the drone has a clear upward vector at the moment of release, rather than oscillating randomly with the hull movement.

[0072] Step 203: When it is determined that the UAV 4 is in a state of force balance and the hull attitude is stable, a disengagement command is issued to drive the electric gripper assembly 102 to rotate and open rapidly to release the ring buckle 4013. At the same time, the airborne cable reeling winch 4011 is controlled to release the cable in a constant tension mode. The tension of the elastic rope 4012 is used as flexible damping to constrain the UAV 4 to take off along the vertical axis. Specifically, when the lift reaches a preset threshold and the ship's attitude is within a relatively stable window, the controller issues a disengagement command. The gripper servo 1021 in the electric gripper assembly 102 quickly drives the arc-shaped gripper 1023 to open, the magnetic component 10231 is de-energized or released from constraint, and the ring 4013 is released instantaneously. During the UAV's ascent, the onboard cable reel 4011 is not completely untensioned, but rather operates in a constant tension mode in conjunction with cable release. At this time, the elastic rope 4012 changes from a rigid connection to a flexible damper, using continuous tension to eliminate lateral deviations caused by momentary gusts or deck turbulence at takeoff, guiding the UAV 4 to ascend stably along the vertical axis.

[0073] Step 204: After monitoring that the UAV 4 has risen to the predetermined safe height and left the ship's interference zone, control the airborne cable reeling winch 4011 to switch to high-speed cable reeling mode to retract the elastic rope 4012 and the ring buckle 4013 to the fuselage, and simultaneously control the lifting mechanism 3 to retract the shipborne docking mechanism 1 to below the landing platform 501.

[0074] Specifically, once the UAV 4 detects through RTK positioning or a barometer that it has risen to the predetermined safe obstacle avoidance height (e.g., 3-5 meters above the deck), the takeoff mission is considered successful. The cable reel winch 4011 then switches to high-speed cable reeling mode, quickly winding the elastic rope 4012 and the end loop 4013 back to the belly storage position to prevent the rope from getting tangled in the propeller. At the same time, the lifting mechanism 3 drives the takeoff and landing dock to retract downwards below the landing platform 501, restoring the deck to a flat state and providing a clear airspace for the subsequent landing of the UAV or navigation of the ship.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A landing dock for offshore wind farm inspection, characterized in that, include: A shipborne docking mechanism is used to capture the drone during its landing phase, thereby forming a flexible connection with the drone. A rotating part is used to drive the shipborne docking mechanism to rotate so that the shipborne docking mechanism corresponds to the landing direction of the UAV; A lifting mechanism is used to drive the rotating part to adjust its vertical height.

2. The take-off and landing docking device for offshore wind farm inspection according to claim 1, characterized in that, The shipborne docking mechanism includes a connecting screw and an electric gripper assembly; the lower end of the connecting screw is connected to the rotating part, and two electric gripper assemblies are provided and symmetrically arranged on both sides of the upper end of the connecting screw.

3. The take-off and landing docking device for offshore wind farm inspection according to claim 2, characterized in that, The electric gripper assembly includes a gripper servo motor, a servo motor shaft, an arc-shaped gripper, and a fixed gripper. The gripper servo motor is fixed to one side of the upper end of the connecting screw. The output end of the gripper servo motor is connected to one end of the arc-shaped gripper through the servo motor shaft. The fixed gripper is located on one side of the upper end of the connecting screw and abuts against the other end of the arc-shaped gripper in the closed state to form a closed gripper.

4. The take-off and landing docking device for offshore wind farm inspection according to claim 3, characterized in that, Several magnetic components are arranged at intervals on the arc-shaped gripper.

5. The take-off and landing docking device for offshore wind farm inspection according to claim 4, characterized in that, The upper end of the connecting screw is equipped with proximity sensors on both sides, located between the fixed gripper and the gripper servo, respectively. These sensors are used to detect whether the UAV has entered the preset capture range and to trigger the sequential action of the magnetic component and the electric gripper assembly.

6. An unmanned surface vessel, characterized in that, include: The hull is used to carry the take-off and landing dock as described in any one of claims 1-5 and the unmanned aerial vehicle after landing.

7. The unmanned vessel according to claim 6, characterized in that, The hull is equipped with a landing platform; the take-off and landing dock is located at the bottom of the unmanned vessel and extends beyond the landing platform.

8. A landing platform for inspecting offshore wind farms, characterized in that, include: The unmanned vessel as described in claim 6 or 7; The drone has an onboard docking mechanism at its bottom for docking with the take-off and landing docking device.

9. The landing platform for offshore wind farm inspection according to claim 8, characterized in that, The airborne docking mechanism includes a take-up and release winch, an elastic rope, and a loop connected to the end of the elastic rope. The take-up and release winch is fixed to the bottom of the UAV, and the elastic rope is wound around the take-up and release winch. When the UAV lands, the loop engages with the arc-shaped gripper to form a flexible connection between the UAV and the unmanned vessel.

10. A method for recovering a drone used in a take-off and landing platform for offshore wind farm inspection as described in claim 8 or 9, characterized in that, The method includes: Control the lifting mechanism to raise the shipborne docking mechanism to a predetermined safe height; The rotating part is controlled to drive the shipborne docking mechanism to rotate in the direction in which the UAV approaches; After the proximity sensor detects the ring dropped by the drone, the shipborne docking mechanism is activated to capture the ring; The lifting mechanism is controlled to descend, and the drone is simultaneously instructed to descend in sync until the drone lands safely on the landing platform.

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