Piloting ship boarding and leaning device and telescopic compliance control system thereof

Abstract

The invention provides a piloting ship boarding and leaning device and a flexible and compliant control system thereof.The piloting ship boarding and leaning device comprises a base, a platform and a connecting and leaning mechanism, one end of the platform is fixedly connected to the base, the connecting and leaning mechanism comprises a support and a holder, the support is rotationally connected to the tail end of the platform, and the rotation axis of the support is arranged in the extending direction of the platform; the extending direction of the platform is the length direction of the platform, the holder is rotationally connected to the rotating shaft, the rotating axis of the holder is arranged in the width direction of the platform, the holder is of a semi-surrounding structure enveloping a target ship body, and the end of the holder is provided with a first connecting part used for making contact with the target ship body.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pilot boat docking, in particular, to a pilot boat docking device and a telescopic compliance control system thereof. BACKGROUND

[0002] Pilot boarding on target ships at sea is one of the most risky links in port operations. In rough sea conditions, the pilot boat and the target ship will experience severe relative motion under the influence of waves, including combined motion of six degrees of freedom, such as roll, pitch, heave, and sway. The traditional boarding method mainly relies on the experience and physical strength of the pilot, which is extremely low in safety and prone to collision accidents.

[0003] In the prior art, researchers have made various attempts to improve the intelligence and safety of boarding. For example, patent CN202311516095.8 discloses an intelligent pilot boat auxiliary boarding system, which moves forward and backward along the guide rail through the walking assembly to assist the pilot in approaching the target ship, and uses an electric control system to realize distance keeping and anti-collision functions. Although this system adds one degree of freedom in the horizontal direction, it can assist the operation to some extent, but in complex sea conditions, only one-dimensional horizontal compensation cannot offset the severe fluctuations of the ship body in the vertical direction (heave) and the angle direction (roll, pitch), resulting in limited application range and inability to fundamentally solve the problem of multi-dimensional motion compensation.

[0004] Another patent CN202222196753.7 discloses a safety combined ladder for a pilot boat, which reduces the risk of the pilot when crossing the gangway by combining the gangway mechanism with the soft ladder body and cooperating with the winding mechanism. Although this invention optimizes the convenience of boarding to some extent, it is still essentially a passive boarding equipment. Since it lacks an active power compensation mechanism and a follow-up control system, it cannot maintain stable adhesion to the target ship in real time when the two ships experience severe relative displacement, and the safety protection capability is still weak, making it difficult to meet the safety needs in deep sea or complex working conditions.

[0005] In summary, the existing technology mainly has the following technical bottlenecks: Missing compensation dimensions: Most existing auxiliary devices only have single degree of freedom adjustment in the horizontal or vertical direction, and cannot simultaneously decouple and compensate for the multi-dimensional attitude fluctuations of the pilot boat under wave action (such as roll, pitch, and heave).

[0006] Rigid collision risk: Existing devices are usually rigidly or semi-rigidly connected when contacting the target ship, lacking effective compliance control mechanisms. Under the action of the huge instantaneous force generated by sea waves, the device is easily damaged or damages the coating of the other ship body.

[0007] Poor geometric adaptability: The hull shape (curvature) of the target ships varies, and the existing end mechanism is difficult to achieve adaptive envelope fitting, resulting in unstable contact interface and potential safety hazards.

[0008] Therefore, developing a pilotship berthing device that can achieve multi-dimensional active wave compensation and has compliant adaptive fitting function is a key issue that urgently needs to be solved in the field of pilotage equipment. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the purpose of this invention is to provide a pilotship berthing device and its telescopic compliant control system.

[0010] According to one aspect of the present invention, a pilot ship berthing device is characterized in that it includes a base, a platform, and a berthing mechanism. One end of the platform is fixedly connected to the base. The berthing mechanism includes a bracket and a retainer. The bracket is rotatably connected to the end of the platform. The rotation axis of the bracket is arranged along the extension direction of the platform, which is the length direction of the platform. The retainer is rotatably connected to a rotating shaft. The rotation axis of the retainer is arranged along the width direction of the platform. The retainer is a semi-enclosed structure that encloses the target ship hull. The end of the retainer is provided with a first connecting part for contacting the target ship hull.

[0011] Preferably, the cage has a V-shaped structure, and the connection between the cage and the support is located at the inflection point of the cage.

[0012] Preferably, a gravity balance positioning mechanism is provided between the retainer and the support. The gravity balance positioning mechanism includes multiple tension springs, and at least one tension spring is provided between each of the two branch ends of the retainer and the support, so that the retainer is in a preset position.

[0013] Preferably, the bracket includes a rotating shaft, which is arranged along the width direction of the platform. A second connecting part is provided in the middle of the rotating shaft, and a mounting interface is provided at the end of the platform. The second connecting part is connected to the mounting interface through a rotating joint, and retainers are provided at both ends of the rotating shaft.

[0014] Preferably, the first connecting part is a roller structure, which includes a roller frame and a Mecanum wheel. The roller frame is disposed at the end of the cage, and the Mecanum wheel is rotatably connected in the roller frame.

[0015] Preferably, a multi-dimensional force sensor is provided on the first connecting part.

[0016] Preferably, the base includes a base, three electric push rods, and a support platform. The electric push rods are arranged in a non-collinear layout between the base and the support platform. The mounting base of the electric push rod is fixed on the base, and the telescopic part of the electric push rod is connected to the support platform.

[0017] Preferably, a rotary motor is provided between the platform and the base, the platform is a telescopic structure, the platform includes a first platform and a second platform, the first platform and the second platform are slidably connected, the first platform and the second platform are a semi-enclosed structure, a guide rail structure is provided between the first platform and the second platform, the first platform is connected to the output end of the rotary motor, the rotation axis of the rotary motor is set along the height direction of the platform, and the second platform is controlled to move by a drive motor.

[0018] According to another aspect of the present invention, a flexible control system is characterized by employing the apparatus according to any one of claims 1-8, the system comprising: Module M1: Acquires the average contact pressure when the end of the current docking mechanism presses against the target hull using a multi-dimensional force sensor; Module M2: Compares the current contact pressure with the preset expected contact pressure and calculates the deviation value. If the deviation value exceeds the threshold, it determines whether the current contact pressure is too high or too low. If the contact pressure is too high, it calculates the displacement and velocity that the second platform needs to retreat through the preset admittance equation. If the contact pressure is too low, it calculates the displacement that the second platform needs to increase through the preset admittance equation. Module M3: Based on the calculation results, it issues a correction command to control the drive motor to drive the second platform to slide linearly along the length direction, and perform a retraction or follow-up action.

[0019] Preferably, the admittance equation is as follows:

[0020] in, This is the working position at the end of the platform. For the desired contact force, For actual contact force, These are the inertia, damping, and stiffness coefficient matrices of the admittance model, respectively.

[0021] Compared with the prior art, the present invention has the following beneficial effects: 1. Achieving High-Precision Multidimensional Motion Compensation and Steady-State Base Construction: This invention integrates a 3-RPS parallel platform and a high-precision IMU inertial measurement unit, utilizing inverse kinematics technology to achieve kinematic decoupling between the support platform and the pilot vessel hull. Compared to traditional fixed or low-dimensional adjustment devices, this invention can actively compensate for and counteract the roll, pitch, and heave motions caused by wave impacts, constructing a relatively inertial stationary steady-state base even in turbulent sea conditions. Furthermore, combined with a support structure possessing rotational degrees of freedom, it ensures precise alignment of the boarding passage exit with the target vessel's access point, significantly improving the accuracy and safety of boarding operations in adverse sea conditions.

[0022] 2. Possessing excellent geometric adaptability and dynamic non-destructive engagement capability, the end-of-line engagement mechanism employs a 120° angled V-shaped contoured frame combined with cylindrical tension springs to construct a unique passive compliance mechanism, achieving geometrical envelope and stable multi-point contact with hulls of different curvatures and inclination angles. It innovatively introduces a Mecanum wheel contact matrix, utilizing its omnidirectional rolling characteristics to convert the destructive tangential friction force generated by the relative motion of the target hull into the rotational kinetic energy of the wheel system. This rigid-flexible coupling structure effectively solves the stress overload problem at the dynamic contact interface, achieving reliable dynamic tracking while avoiding rigid scratching of the target hull coating, significantly reducing maintenance costs.

[0023] 3. Enhanced Control Stability and Operational Continuity in Complex Dynamic Environments: The compliant admittance control system of this invention endows the rigid telescopic boom with virtual "mass-damping-stiffness" physical characteristics through a closed-loop "sensing-computation-execution" strategy. For complex relative sway motion between two vessels, this control system can achieve a constant force follow-up response based on force feedback signals, enabling "active yielding under pressure to reduce impact force and rapid follow-up during separation to compensate for displacement deviation." This solution effectively avoids the technical defects of traditional rigid connections, such as collision damage or connection breakage, which are prone to occur under wave interference, greatly enhancing the control stability and system robustness of boarding operations in unstructured sea conditions. Attached Figure Description

[0024] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of a pilot ship berthing device provided in Embodiment 3; Figure 2 This is a schematic diagram of the docking mechanism in Embodiment 3; Figure 3 Block diagram of the admittance control system; In the diagram, 1. Platform base, 2. Rotation hinge, 3. Electric push rod, 4. Ball joint, 5. Loading platform on parallel platform, 6. Rotation motor, 7. Rotation platform fixing auxiliary device, 8. Rotation platform, 9. Telescopic platform, 10. Hanging hinge, 11. Rotating shaft, 12. V-shaped retainer, 13. Cylindrical tension spring, 14. Rotary wheel frame, 15. Mecanum wheel, 16. Multidimensional force sensor. Detailed Implementation

[0025] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0026] Example 1: This embodiment provides a pilot ship berthing device, including a base, a platform, and a berthing mechanism. One end of the platform is fixedly connected to the base. The berthing mechanism includes a bracket and a retainer. The bracket is rotatably connected to the end of the platform, and the axis of rotation of the bracket is set along the extension direction of the platform, which is the length direction of the platform. The retainer is rotatably connected to a rotating shaft, and the axis of rotation of the retainer is set along the width direction of the platform. The retainer is a semi-enclosed structure that encloses the target ship hull, and the end of the retainer is provided with a first connecting part for contacting the target ship hull.

[0027] Based on the above scheme, this device provides stable support through a base and utilizes the platform as a safe passage for pilots. The docking mechanism at the end, through a dual-axis rotation design of the bracket and retainer, gives the device initial degrees of freedom to adapt to different inclination angles of the hull sidewalls. When the platform extends toward the target ship, the semi-enclosed retainer structure can initially geometrically envelop the hull according to its geometric contours, ensuring that the first connection at the end can form a stable contact interface with the non-planar hull surface.

[0028] Understandably, the cage has a V-shaped structure, and the connection between the cage and the support is located at the cage inflection point.

[0029] Based on the above scheme, a V-shaped contoured frame design with a 120° included angle is adopted, which exhibits excellent geometric adaptability during contact. When the mechanism presses against the hull, the V-shaped structure can quickly transition from "point contact" to "multi-point surface contact" by utilizing its geometric characteristics, thereby adapting to cylindrical or complex curvature hulls and improving the stability of docking.

[0030] Understandably, a gravity balance positioning mechanism is provided between the retainer and the support. The gravity balance positioning mechanism includes multiple tension springs. At least one tension spring is provided between each of the two branch ends of the retainer and the support, so that the retainer is in a preset position. It should be noted that the preset position is to keep the retainer in a suitable position relative to the support.

[0031] Based on the above scheme, the mechanism utilizes the elastic restoring torque generated by the cylindrical tension spring to counteract the self-weight torque of the retainer. In the non-contact state, the spring system ensures that the V-shaped retainer overcomes gravity and droops, always maintaining a horizontal, ready-to-go attitude aligned with the target hull, thus preparing for adaptive adjustments during the docking process.

[0032] Understandably, the bracket includes a rotating shaft, which is arranged along the width direction of the platform. A second connecting part is provided in the middle of the rotating shaft, and a hanging interface is provided at the end of the platform. The second connecting part is connected to the hanging interface through a rotating joint, and a retainer is provided at each end of the rotating shaft.

[0033] It should be noted that the present invention does not impose specific restrictions on the rotating pair between the second connecting part and the interface, as long as the rotation effect can be achieved. For example, the second connecting part is a cylindrical structure, and the rotation is achieved inside the interface through a bearing. Existing technologies can achieve the above-mentioned functional effects.

[0034] Based on the above scheme, this design provides horizontal adjustment capability for the docking mechanism by connecting the end of the telescopic platform via a rotating joint. The retainers at both ends of the rotating shaft can independently make fine-tuning angles according to the concavity and convexity of the target hull surface. Through this passive conforming mechanism, efficient fitting to complex hull surfaces is achieved.

[0035] Understandably, the first connecting part is a roller structure, which includes a roller frame and a Mecanum wheel. The roller frame is located at the end of the cage, and the Mecanum wheel is movably located in the roller frame.

[0036] Based on the above solution, the safety hazards caused by relative motion between hulls are solved by utilizing the omnidirectional movement characteristics of the Mecanum wheel. When waves cause the target ship to heave or roll, the Mecanum wheel converts the potentially destructive frictional force into the rotational kinetic energy of the wheel by rolling along the axis or sliding laterally. This achieves dynamic tracking and fit while avoiding damage to the hull coating and mechanical structure caused by rigid scraping.

[0037] Understandably, a multi-dimensional force sensor is provided on the first connecting part.

[0038] Based on the above scheme, a multi-dimensional force sensor, acting as the system's sensing "touch," is installed at the Mecanum wheel axis to monitor the contact pressure between the device and the target hull in real time. The force feedback signal provided by this sensor is the core input data for the subsequent compliant admittance control algorithm, used to determine the engagement state and trigger displacement correction.

[0039] Understandably, the base includes a base, three electric actuators, and a support platform. The electric actuators are arranged in a non-collinear layout between the base and the support platform. The mounting base of the electric actuator is fixed on the base, and the telescopic part of the electric actuator is connected to the support platform.

[0040] Based on the above scheme, this is a 3-RPS parallel wave compensation structure, responsible for physically isolating the pilot ship from violent swaying. The system performs inverse kinematics calculations using real-time acquired IMU attitude data, instructing three electric actuators to perform high-frequency differential responses, actively canceling roll, pitch, and heave motions, thereby constructing a relatively inertial stationary stable base in a volatile environment.

[0041] It is understood that a rotary motor is provided between the platform and the base, the platform is a telescopic structure, the platform includes a first platform and a second platform, the first platform and the second platform are slidably connected, the first platform and the second platform are a semi-enclosed structure, a guide rail structure is provided between the first platform and the second platform, the first platform is connected to the output end of the rotary motor, the rotation axis of the rotary motor is set along the height direction of the platform, and the second platform is controlled to move by a drive motor.

[0042] The telescopic platform is slidably mounted on the rotating platform via a linear guide assembly, and the two are kinematically connected as a sliding joint. Specifically, the linear guide assembly is configured to constrain the telescopic platform's degree of freedom relative to the rotating platform, allowing it to move back and forth only along a preset straight trajectory. To ensure safety and controllability of the movement, a limit mechanism is provided along the engagement path of the rotating platform and the telescopic platform. This limit mechanism restricts the telescopic platform's maximum extension and retraction positions, thereby preventing the telescopic platform from detaching from the guide track or experiencing mechanical collisions during movement.

[0043] It should be noted that the telescopic drive mechanism in this embodiment aims to convert rotational motion into linear motion or directly generate linear thrust, and its specific mechanical configuration is not limited to a single form. In practical applications, the transmission component can be a lead screw and nut transmission module, which uses the rotation of the lead screw to drive the translation of the nut seat; it can also be a gear and rack transmission module, which drives the rack to move through gear meshing; or it can be a flexible transmission module such as a timing belt or chain; or even a friction wheel transmission module driven by contact friction. Those skilled in the art can choose any one or a combination of the above according to the actual load and accuracy requirements, all of which are covered within the concept of this application.

[0044] Based on the above scheme, the rotary motor enables the boarding passage to rotate 360° in the horizontal plane, which is used to compensate for the ship's heave motion and accurately align with the target ship's access point. The telescopic structure (first and second platforms) adjusts the passage length by linear translation to compensate for changes in the sway distance between the two ships, ensuring that the end of the passage can always be safely connected under dynamic sea conditions.

[0045] Regarding structural safety, it should be noted that when the telescopic platform of this device is in its maximum extended state, due to the significant increase in cantilever length, the root of the telescopic module and the connection area of ​​the rotating platform will indeed bear a large bending moment load under the rated load at the end. This is an inherent mechanical characteristic of this type of long-span trestle bridge passage device. To ensure the safety of the structure throughout its entire stroke range, the device has been designed with corresponding allowable load ranges for different extension lengths. By optimizing the structural stiffness and strengthening the materials of key load-bearing components (such as the overlapping area of ​​the telescopic joint and the connecting shaft of the rotating joint), it is ensured that the maximum stress under extreme working conditions is always within the safe threshold of the material's yield strength, thereby ensuring that the device will not experience structural failure or excessive deformation during long cantilever heavy-load operations.

[0046] In terms of overall stability, this device is primarily configured for installation on specific floating platforms (such as dedicated engineering vessels or wind power maintenance vessels), typically located in the central area of ​​the bow section of the hull. Although the device has a large span and weight when extended, its weight is extremely low compared to the overall displacement and deck structural strength of the vessel serving as the installation platform. The changes in center of gravity and overturning moments generated during its full-range extension and full-load operation are negligible compared to the enormous buoyancy support and restoring moments of the hull. Therefore, relying on the stable base and anti-overturning capabilities provided by the vessel, this device maintains excellent system stability during offshore operations, eliminating concerns about the risk of overall instability due to excessive moment from the device itself.

[0047] It should be noted that the description and accompanying drawings of the rotary drive mechanism in this embodiment are intended to focus on illustrating the connection relationship and operational logic of the upper platform relative to the base (or lower platform) to achieve rotary motion. The accompanying drawings only show the functional components necessary to constitute this kinematic pair using simplified structural diagrams, and do not strictly limit the specific model parameters or detailed internal mechanical structures of the drive motor, reducer, and controller. In actual industrial product design, those skilled in the art can adaptively select and design the drive source and transmission chain according to the specific load tonnage, speed requirements, and installation space, which does not deviate from the core technology of this application.

[0048] In one embodiment, the rotary drive mechanism is configured to employ a gear-driven transmission. Specifically, the mechanism mainly includes a rotary drive source (such as a servo motor or hydraulic motor) and a gear transmission assembly. The output end of the rotary drive source is connected to a drive gear (i.e., an external gear), while a matching internal gear ring (i.e., an internal gear ring) is fixedly disposed at the bottom or inner side of the upper platform. The drive gear and the internal gear ring maintain a meshing state.

[0049] Its working principle is as follows: When the rotary drive source is activated, it drives the drive gear to rotate. The drive gear, through meshing with the internal gear ring, transmits torque to the upper platform, thereby causing the upper platform to overcome frictional resistance and rotate smoothly relative to the base around a preset rotation center. It should be understood that the above gear transmission structure is only one exemplary embodiment of this application, and the scope of protection of this application also covers other transmission forms that can achieve the same rotary drive function, such as worm gear transmission, pin gear transmission, or direct drive by a torque motor.

[0050] Example 2: This embodiment provides a telescopic compliant control system using the device of Embodiment 1. The system includes: Module M1: acquiring the contact pressure when the end of the current docking mechanism presses against the target hull using a multi-dimensional force sensor; Module M2: comparing the current contact pressure with a preset expected contact pressure, calculating the deviation value, and determining whether the current contact pressure is too high or too low if the contact pressure is too high, calculating the required displacement and velocity of the second platform to retreat using a preset admittance equation; and Module M3: issuing a correction command based on the calculation results, controlling the drive motor to drive the second platform to slide linearly along the length direction, performing a retreat or follow-up action.

[0051] Based on the above scheme, the system constructs a virtual "mass-damping-stiffness" model within the controller using a closed-loop "sensing-computation-execution" strategy. When the deviation value indicates excessive thrust, the system simulates the compression of a spring, causing the platform to actively retreat to eliminate the impact load; when the deviation value indicates decreased thrust, the system simulates spring rebound, causing the platform to quickly follow to compensate for the displacement deviation. This admittance control achieves constant force follow-up response to unstructured environments, effectively solving the technical problem of rigid connections being prone to collision damage under wave disturbances.

[0052] The specific admittance equation is as follows:

[0053] in, This is the working position at the end of the platform. For the desired contact force, For actual contact force, These are the inertia, damping, and stiffness coefficient matrices of the admittance model, respectively.

[0054] Example 3: This embodiment provides an intelligent device specifically developed to solve the challenge of pilot boarding in adverse sea conditions. It innovatively employs a hybrid mechanical topology of a "3-RPS parallel stabilizing platform + RP series telescopic arm." The underlying control system, based on real-time inverse calculations using high-precision IMU data, drives three electric actuators to perform high-frequency differential response, actively counteracting the roll, pitch, and heave motions of the pilot vessel caused by waves, thus constructing a relatively inertial stationary stable base. The upper telescopic mechanism uses an admittance control algorithm to compensate for vessel bearing deviations while providing flexible follow-up and constant force maintenance for dynamic sway in the inter-ship distance. The device's end employs a composite docking system of a "V-shaped contoured frame + Mecanum wheel + elastic damping," achieving adaptive and non-destructive fitting to hull surfaces with different curvatures.

[0055] The following is combined Figure 1 and Figure 2 The structure of this device is described in detail. Base layer: Three-degree-of-freedom wave compensation structure The structure is a 3-RPS parallel platform, which is responsible for compensating for the main sway of the hull. The platform mainly consists of a fixed base, electric push rods, ball joints and upper bearing platform.

[0056] Platform base 1: Installed at the center of the bow tip of the pilot ship, serving as the overall foundation.

[0057] Rotation hinge point 2: responsible for fixing the lower end of the electric push rod 3 to the platform base 1.

[0058] Electric actuators 3: Three electric actuators 3 connect the platform base 1 and the upper support platform 5, forming a 3-RPS parallel mechanism. They have the characteristics of high rigidity, high load-bearing capacity and fast response.

[0059] Ball joint 4: It adopts a combination of Hooke's joint and rotary bearing to connect electric push rod 3 and bearing platform 5 on parallel platform to ensure the flexibility and reliability of motion transmission.

[0060] Parallel platform support platform 5: Under the coordinated drive of electric push rod 3, this platform can move with multiple degrees of freedom relative to the hull, and this support platform also serves as the installation foundation for subsequent structures.

[0061] Rotate and move layers: Orientation adjustment + distance scaling This part of the structure is located on the parallel platform and is responsible for adjusting the direction of the passage and providing direct passage for the pilot.

[0062] Rotating motor 6 and rotating platform fixing auxiliary device 7: The rotating motor 6 is installed on the bearing platform 5 of the parallel platform to provide rotational power for the rotating platform 8. The rotating platform fixing auxiliary device 7 ensures the stability of the structure so that personnel can pass through.

[0063] Rotating platform 8: It can rotate 360° around the vertical axis in the horizontal plane to ensure that the boarding passage can be aligned with the receiving point of the target vessel.

[0064] Telescopic platform 9: Installed on the rotating platform 8, it can extend and retract linearly along its length. By adjusting the extension length, it compensates for swaying caused by changes in distance between the pilot vessel and the target vessel, ensuring a safe connection at the end of the passage.

[0065] End-of-line docking mechanism This mechanism, located at the end of the pilotage boarding device, serves as the direct interface for contact with the target vessel. Its mechanical topology is primarily composed of the following key units: Mounting interface 10: The end docking mechanism pivot 11 is connected to the end of the telescopic platform 9 via a revolute joint. This hinged design provides the docking mechanism with an initial degree of freedom in the horizontal direction, enabling it to adapt to the hull sidewalls at different inclination angles.

[0066] Rotary shaft 11: The rotating shaft 11 is fixed to the end of the telescopic platform 9 by the mounting interface 10, and serves as the mounting base for the V-shaped retainer 12 and the cylindrical tension spring 13. It has only one degree of rotational freedom.

[0067] V-shaped cage 12: The cage is designed with a V-shaped structure with a 120° included angle. The two cages are mounted at both ends of the rotating shaft 11 via a revolute joint, forming a geometric configuration that can enclose the non-planar hull.

[0068] Cylindrical tension spring 13: A cylindrical tension spring is used as a flexible connector between the V-shaped retainer 12 and the fixed bracket. The spring system plays a dual role of gravity balance and flexible positioning at this point.

[0069] Wheel carrier 14: Fixed to the end of V-cage 12, serving as a connecting component between V-cage 12 and Mecanum wheel.

[0070] Mecanum wheel 15: fixed to the end of V-shaped retainer 12 by wheel holder 14.

[0071] Multi-dimensional force sensor 16: installed at the axle of Mecanum wheel 15.

[0072] Working principle: Wave compensation: First, motion sensing: Sensors installed on the pilot ship detect in real time the multi-degree-of-freedom motions of the pilot ship caused by wave impact, including roll, pitch, heave, yaw, and sway. Then, the three-degree-of-freedom compensation control system calculates the amount of roll, pitch, and heave that needs to be compensated based on the sensor data. Kinematic calculations are performed, and finally, the system commands three electric push rods 3 to precisely and coordinately extend and retract, causing the platform 5 on the parallel platform to perform corresponding compensating motions relative to the fixed base 1 (i.e., the hull), thereby counteracting the hull's roll, pitch, and heave, and maintaining the stability of the platform 5's attitude and height in inertial space. For yaw compensation, the control system calculates the azimuth angle that needs to be compensated or adjusted based on the hull's yaw motion detected by the sensors, or according to operational commands requiring the channel to be vertically aligned with the target ship's access point. Then, the system commands the rotating motor 6 to drive the rotating platform 8 to rotate at an appropriate angle in the horizontal plane to compensate for the hull's yaw motion. For sway compensation, the control system calculates the required channel length or lateral position adjustment based on the change in distance between the pilot vessel and the target vessel, or the sway motion of the hull. The system then drives the moving platform 9 to slide linearly relative to the rotating platform 8. By precisely adjusting the extension length of the channel, it ensures that its end can safely attach to the target vessel.

[0073] End-point contact: A composite design combining a V-shaped conformal bracket, elastic reset balance, and Mecanum wheel rolling contact is employed to address the technical challenges of unstable contact under varying target hull curvature and dynamic sea conditions, achieving efficient and non-destructive bonding to the target hull. In the non-contact state, the elastic restoring torque generated by the cylindrical tension spring 13 effectively counteracts the self-weight torque of the V-shaped retainer 12. This mechanism ensures that when the V-shaped retainer 12 is naturally suspended, its V-shaped opening overcomes gravity and maintains a horizontal, ready-to-align position with the target hull, preparing for docking. During docking, the end-point docking mechanism, relying on the geometric characteristics of the V-shaped structure and the flexibility of the rotating joints, allows the left and right V-shaped retainers 12 to independently fine-tune their angles according to the concave and convex curvature of the target hull surface as the mechanism presses against the hull. This passive compliant mechanism enables the mechanism to quickly transition from initial "point contact" to stable "multi-point surface bonding," adapting to cylindrical or complex curved hull surfaces. Moreover, this structure fully utilizes the omnidirectional movement characteristics of the Mecanum wheel 15 to address safety hazards caused by relative motion of the hull. When waves cause the target vessel to experience heave or roll beyond the platform's compensation range, the Mecanum wheel 15 can roll along its axle or slide laterally using rollers. This dynamic contact method converts potentially destructive friction into the rotational kinetic energy of the wheel, achieving dynamic tracking and contact with the target vessel's hull while avoiding damage to the hull coating or overload impact on the mechanism caused by rigid scraping.

[0074] Telescopic Compliant Admittance Control: The telescopic platform 9 of this device is physically a rigid linear motion mechanism, driven by a rotary motor 6 to perform horizontal telescopic translation on a rotating platform 8. Under traditional control, the rigid arm is prone to structural damage or violent collision if subjected to strong pressure from a large ship. This platform constructs a virtual "mass-damping-stiffness" model within the controller through an algorithm, enabling the end-effector to exhibit compliant characteristics similar to a "high-strength spring" when in contact with the target ship, intelligently adjusting its extension length according to the force applied.

[0075] like Figure 3 As shown, based on the "sensing-computation-execution" principle of the device, the specific operation process of admittance control on the telescopic platform is as follows: Force sensing input: When the end contact mechanism presses against the target hull, the multi-dimensional force sensor 16 monitors the current contact pressure in real time.

[0076] Admittance model calculation: After receiving the changing force signal, the controller substitutes it into the preset admittance equation. If the thrust is detected to be too large, the algorithm calculates the displacement and velocity that the platform needs to retreat, simulating the compression process of the spring; if the thrust is detected to be reduced, the algorithm calculates the displacement that the platform needs to increase, simulating the rebound process of the spring.

[0077] Servo follow-up execution: The calculated position correction command is sent to the drive motor of the telescopic platform 9. The motor drives the telescopic platform 9 to slide linearly along the length direction, performing retraction or following actions.

[0078] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0079] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "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 application 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, they should not be construed as limitations on this application.

[0080] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A pilotship boarding device, characterized in that, The system includes a base, a platform, and a docking mechanism. One end of the platform is fixedly connected to the base. The docking mechanism includes a bracket and a retainer. The bracket is rotatably connected to the end of the platform, and the axis of rotation of the bracket is set along the extension direction of the platform, which is the length direction of the platform. The retainer is rotatably connected to a rotating shaft, and the axis of rotation of the retainer is set along the width direction of the platform. The retainer is a semi-enclosed structure that encloses the target hull, and the end of the retainer is provided with a first connecting part for contacting the target hull.

2. The apparatus according to claim 1, characterized in that, The cage has a V-shaped structure, and the connection between the cage and the support is located at the inflection point of the cage.

3. The apparatus according to claim 2, characterized in that, A gravity balance positioning mechanism is provided between the retainer and the support. The gravity balance positioning mechanism includes multiple tension springs. At least one tension spring is provided between each of the two branch ends of the retainer and the support, so that the retainer is in a preset position.

4. The apparatus according to claim 1, characterized in that, The support includes a rotating shaft, which is arranged along the width of the platform. A second connecting part is provided in the middle of the rotating shaft, and a mounting interface is provided at the end of the platform. The second connecting part is connected to the mounting interface through a rotating joint, and retainers are provided at both ends of the rotating shaft.

5. The apparatus according to claim 1, characterized in that, The first connecting part is a roller structure, which includes a roller frame and a Mecanum wheel. The roller frame is located at the end of the cage, and the Mecanum wheel is rotatably connected in the roller frame.

6. The apparatus according to claim 1, characterized in that, A multi-dimensional force sensor is provided on the first connecting part.

7. The apparatus according to claim 1, characterized in that, The base includes a base, three electric actuators, and a support platform. The electric actuators are arranged in a non-collinear layout between the base and the support platform. The mounting base of the electric actuator is fixed on the base, and the telescopic part of the electric actuator is connected to the support platform.

8. The apparatus according to claim 1 or 7, characterized in that, A rotary motor is provided between the platform and the base. The platform is a telescopic structure. The platform includes a first platform and a second platform. The first platform and the second platform are slidably connected. The first platform and the second platform are a semi-enclosed structure. A guide rail structure is provided between the first platform and the second platform. The first platform is connected to the output end of the rotary motor. The rotation axis of the rotary motor is set along the height direction of the platform. The second platform is moved by a drive motor.

9. A telescopic compliance control system, characterized in that, The system comprising: using the apparatus of any one of claims 1-8 Module M1: Acquires the contact pressure when the end of the docking mechanism presses against the target hull using a multi-dimensional force sensor; Module M2: Compares the current contact pressure with the preset expected contact pressure and calculates the deviation value. If the deviation value exceeds the threshold, it determines whether the current contact pressure is too high or too low. If the contact pressure is too high, it calculates the displacement and velocity that the second platform needs to retreat through the preset admittance equation. If the contact pressure is too low, it calculates the displacement that the second platform needs to increase through the preset admittance equation. Module M3: Based on the calculation results, it issues a correction command to control the drive motor to drive the second platform to slide linearly along the length direction, and perform a retraction or follow-up action.

10. The system according to claim 9, characterized in that, The admittance equation is as follows: in, This is the working position at the end of the platform. For the desired contact force, For actual contact force, These are the inertia, damping, and stiffness coefficient matrices of the admittance model, respectively. These represent the velocity and acceleration of the second platform, respectively.

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