Multi-degree-of-freedom active compensation stable boarding device and control method

Abstract

A multi-degree-of-freedom active compensation stable boarding device and a control method, belong to the field of ocean engineering operation safety technology. The stable boarding device can realize rotational motion around the X and Y axes and heave (up-down) motion along the Z axis, and can also realize composite motion of three degrees of freedom. The upper platform and the gangway can realize semi-automatic rotational motion around the Z axis, that is, yaw motion, pitch motion and extension and retraction motion along the gangway. The system has compact structure, small overall space occupation, adopts series-parallel hybrid structure, has good real-time compensation stability, relatively low cost, meets the needs of safe and stable boarding under sea conditions of 4 levels and below, and is especially suitable for offshore small operation and maintenance ships (CTV), especially for upgrading and modification of intelligent stable boarding system based on existing CTV operation and maintenance ships.

Description

Technical Field

[0001] This invention relates to a multi-degree-of-freedom active compensation stabilization boarding device and control method, belonging to the field of marine engineering operation and maintenance safety technology. Background Technology

[0002] Looking at the domestic situation, the shortcomings of traditional offshore maintenance vessels are: they basically do not have an active compensation boarding system, the safety of boarding operations at sea in relatively high sea states is low, and even casualties may occur, making it impossible to go to sea for maintenance operations in high sea states. Summary of the Invention

[0003] The multi-degree-of-freedom active compensation stabilization boarding system is a real-time active compensation device for relative motion processes under sea state 4 and below, as well as other dynamic conditions. It is applicable to marine engineering fields such as safe boarding, material replenishment, personnel transport and maintenance, and maritime rescue in offshore oil and gas, offshore wind power, offshore replenishment, and supply ships and maritime military facilities. To overcome the shortcomings of existing technologies, this invention provides a multi-degree-of-freedom active compensation stabilization boarding device and its usage method.

[0004] A control method for a multi-degree-of-freedom active compensation stabilization boarding device includes the following steps: using a high-precision, real-time-performance micro-mechanical electromechanical inertial navigation system as the measuring element for hull motion; calculating the hull's azimuth, roll angle, pitch angle, angular velocity, acceleration, Euler angle, and quaternion information using acceleration and angular velocity information; ensuring measurement accuracy through a filter algorithm with appropriate gain and a PID control algorithm; and eliminating errors and improving measurement accuracy by using multiple compensation strategies such as nonlinear compensation, orthogonal compensation, and temperature compensation for attitude motion parameters.

[0005] The measuring elements include a multi-dimensional force sensor installed at the junction of the gangway end and the tower, which is used to measure the force changes when the platform motion compensation is inadequate, and calculates the changes in posture and angle input values ​​that the platform should adjust in real time based on the intelligent spatial coordinate transformation algorithm.

[0006] The PID control algorithm is designed for wave spectrum motion. At each sampling time, based on the current measurement information, it solves a finite-time open-loop optimization problem online and applies the first element of the obtained control sequence to the controlled object. At the next sampling time, the above process is repeated: the new measurement value is used as the initial condition for predicting the future dynamics of the system, the optimization problem is refreshed and solved again.

[0007] The ship's motion includes rotation along the X-axis and Y-axis, heave along the Z-axis, and a combination of three degrees of freedom.

[0008] The ship's motion includes the semi-automatic rotation around the Z-axis via the upper platform and gangway, as well as yaw, pitch, and extension / retraction along the gangway.

[0009] The ship's motion includes the pitching, rolling, and heave movements of the pitching, rolling, and heave electric cylinders, as well as their combined movements. The control system and sensors collect the ship's rolling and heave motion signals and issue counter-compensation motion commands to the actuators of the pitching, rolling, and heave electric cylinders, including pitching, rolling, heave movements, and their combined movements.

[0010] The extension and retraction of the pitch, roll, and heave electric cylinders ensure that the servo support and heave electric cylinders remain perpendicular to the horizontal plane of the geodetic coordinate system, keeping the upper platform level. The extension and retraction of the heave electric cylinders counteracts the heave motion of the maintenance vessel, achieving relative levelness and stability of the upper platform. The system's maximum heave compensation stroke is 1300mm. Upon system startup, it automatically pre-lifts to the neutral position and begins automatic heave compensation. The distances from the neutral position to the stop position and the highest position are 650mm, meaning the heave compensation capability is ±650mm.

[0011] A multi-degree-of-freedom active compensation stabilization boarding device comprises four lower hinge supports cross-shapedly distributed on a lower platform with the X and Y axes as references. The base of the follower support hinge support is fixedly connected to the lower platform at the center position of the Z axis. Four upper hinge supports are installed around the upper flange of the follower support, corresponding to each other and evenly distributed relative to the X and Y axes. The bottom of the follower support is fixedly connected to the top of the follower support hinge supports. The upper flange of the lifting electric cylinder is fixedly connected to the upper flange of the follower support. The pitching electric cylinder is fixedly connected to the hinge support and lower hinge support in the same direction on one side of the Y direction. The upper and lower ends of the yaw electric cylinder are fixedly connected to the hinge support in the same direction on one side of the X direction. The lower hinge supports are fixedly connected. The lifting electric cylinder is vertically installed in the follower support in the Z direction. The lifting cylinder and flange are connected to the follower support and flange. The cylinder rod of the lifting electric cylinder is fixedly connected to the fixed plate of the slewing bearing, i.e., the driven wheel. The upper platform is fixedly connected to the moving plate of the slewing bearing. Two damping cylinders are mirror-mounted in the X and Y directions relative to the roll electric cylinder and the pitch electric cylinder, respectively, on the corresponding upper hinge supports and lower hinge supports. The middle frame structure of the upper platform is fixedly connected to the moving plate of the slewing bearing. The rotary servo motor is fixedly connected to the upper platform. The driving wheel on the rotary servo motor is fixedly connected to the outer gear ring of the fixed plate of the slewing bearing, i.e., the driven wheel, after adjusting the meshing clearance.

[0012] Four upper hinge supports are installed in a cross shape at 90° intervals, with the X and Y axes as references. The upper platform consists of a profile frame, hot-dip galvanized grating, and guardrails. The gangway is hinged to the upper platform. The gangway pitch cylinder is hinged to both ends of the upper platform and the gangway, respectively. A gangway telescopic mechanism is provided at the bottom of the gangway. This invention can achieve rotational motion around the X and Y axes and heave motion along the Z axis, as well as composite motion of three degrees of freedom. The upper platform and gangway can achieve semi-automatic rotational motion around the Z axis, i.e., yaw motion, pitch motion, and telescopic motion along the gangway.

[0013] This invention features a compact structure with a small overall footprint. It employs a series-parallel hybrid structure, providing good real-time compensation stability and relatively low cost. It meets the requirements for safe and stable boarding in sea states of level 4 and below, and is particularly suitable for small offshore maintenance vessels (CTVs). In particular, it can be used to upgrade existing CTVs with an intelligent and stable boarding system.

[0014] This invention utilizes the extension and retraction of electric cylinders, roll cylinders, and heave cylinders. By controlling the system and sensors to collect ship roll and heave motion signals, it sends counter-compensation motion commands to the actuators of the aforementioned components. This achieves counter-compensation motion encompassing pitch, roll, heave, and their combined movements, ensuring that the servo support and heave cylinders remain perpendicular to the horizontal plane of the geodetic coordinate system. This keeps the upper platform level, and the extension and retraction of the heave cylinders counteracts the heave motion of the maintenance vessel, achieving relative levelness and stability of the upper platform. The system's maximum heave compensation stroke is 1300mm. Upon system startup, it automatically pre-lifts to the neutral position and begins automatic heave compensation. The distances from the neutral position to the stop position and the highest position are each 650mm, meaning the heave compensation capability is ±650mm.

[0015] The follow-up support hinge is unconventionally positioned at the bottom of the multi-degree-of-freedom active compensation stabilization boarding system, making the upper platform a fixed platform and the lower platform a moving platform (generally, it is located at the top, with the upper platform being the moving platform and the lower platform being the fixed platform). The purpose is to bring its rotation center as close as possible to the X-axis of the ship's motion coordinate system, i.e., the ship's roll axis (stabilizing center), making it possible to compensate for horizontal position changes caused by rolling, which would otherwise be impossible. Moreover, this linear displacement compensation and roll angular displacement compensation are completed simultaneously, achieving twice the result with half the effort. Attached Figure Description

[0016] When considered in conjunction with the accompanying drawings, the invention will be more fully and better understood, and its many accompanying advantages will become readily apparent, by referring to the following detailed description. However, the accompanying drawings, which are provided to further illustrate the invention and form part of this invention, are used to explain the invention and do not constitute an undue limitation thereof, as shown in the figures:

[0017] Figure 1 1. This is a schematic diagram of the structure of the present invention.

[0018] Figure 2 1. This is a side view of the structure of the present invention.

[0019] Figure 3 The diagram shows the effect of multi-degree-of-freedom active compensation under the ±20° roll state of the present invention.

[0020] Figure 4 The diagram shows the effect of multi-degree-of-freedom active compensation when the maintenance vessel of the present invention pitches by -10°.

[0021] Figure 5 The diagram shows the effect of multi-degree-of-freedom active compensation when the maintenance vessel of the present invention pitches +10°.

[0022] Figure 6 The active compensation and stability boarding system of the present invention is installed on a catamaran maintenance vessel, and its X, Y, and Z coordinates are shown.

[0023] Figure 7 This is a schematic diagram of the invention installed on the foredeck of a maintenance vessel.

[0024] Figure 8 The diagram shows the effect of multi-degree-of-freedom active compensation when the maintenance vessel of the present invention experiences a heave of ±650mm.

[0025] Upper platform 1, pitch electric cylinder 2, follower support 3, upper hinge support 4 (4 pieces), lower hinge support 5 (4 pieces), follower support hinge support 6 (1 piece), lower platform 7, roll electric cylinder 8, damping cylinder 9 (2 pieces), slewing bearing 10 composed of driven plate 18, fixed plate (driven wheel) 20 and external gear ring, slewing servo motor 11 including a drive wheel 19 mounted on the shaft end, gangway 12, gangway pitch electric cylinder 13, gangway telescopic mechanism 14, heave electric cylinder 15, follower support and flange 16, lifting cylinder and flange 17, sensor, control system. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Obviously, many modifications and variations made by those skilled in the art based on the spirit of this invention fall within the scope of protection of this invention.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description, "multiple" means two or more, unless otherwise explicitly specified.

[0029] Unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] Those skilled in the art will understand that, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art.

[0031] To facilitate understanding of the embodiments, further explanations and descriptions will be provided below, and the various embodiments do not constitute a limitation on the embodiments.

[0032] Example 1: As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, a multi-degree-of-freedom active compensation stabilization boarding device and control method are disclosed, which is an intelligent stabilization boarding system for shipboard use to actively compensate for the swaying and heave of the hull under the action of ocean waves in real time.

[0033] A multi-degree-of-freedom active compensation stabilization boarding device comprises an upper platform 1, a pitch electric cylinder 2, a follower support 3, an upper hinge support 4 (4 pieces), a lower hinge support 5 (4 pieces), a follower support hinge support 6 (1 piece), a lower platform 7, a roll electric cylinder 8, a damping cylinder 9 (2 pieces), a slewing bearing 10 consisting of a driven disc 18, a fixed disc (or driven wheel) 20 and an external gear ring of the driven wheel, a slewing servo motor 11 including a drive wheel 19 mounted on the shaft end, a gangway 12, a gangway pitch electric cylinder 13, a gangway telescopic mechanism 14, a rise electric cylinder 15, a follower support and flange 16, a lifting cylinder and flange 17, sensors and a control system, etc.

[0034] The lower platform 7, which is connected to the foredeck of the offshore maintenance vessel, is mainly constructed of welded steel structures.

[0035] Four lower hinge supports 5 are installed on the lower platform 7 in a cross shape with the X and Y axes as references. The base of the follower support hinge support 6 is fixed to the lower platform 7 at the center of the Z axis. Four upper hinge supports 4 are installed around the upper flange of the follower support 3, and are evenly distributed in pairs relative to the X and Y axes. That is, the four upper hinge supports 4 are installed in a cross shape at 90° with the X and Y axes as references.

[0036] The bottom of the follower support 3 is fixedly connected to the upper part of the follower support hinge support 6, and the upper flange of the lifting electric cylinder 15 is fixedly connected to the upper flange of the follower support 3. The yaw electric cylinder 2 is fixedly connected to the hinge support 4 and the lower hinge support 5 in the same direction on one side of the Y direction.

[0037] The upper and lower ends of the horizontal rocker electric cylinder 8 are fixedly connected to the hinge support 4 and the lower hinge support 5 in the same direction on one side of the X direction. The lifting electric cylinder 15 is vertically installed in the follower support 3 in the Z direction (the lifting cylinder and flange 17 are connected to the follower support and flange 16). The cylinder rod of the lifting electric cylinder 15 is fixedly connected to the fixed plate (driven wheel) 20 of the slewing bearing 10. The upper platform 1 is fixedly connected to the moving plate 18 of the slewing bearing 10.

[0038] Two damping cylinders 9 are mounted mirror images of the roll electric cylinder 8 and the pitch electric cylinder 2 in the X and Y directions, respectively, on the corresponding upper hinge support 4 and lower hinge support 5.

[0039] The upper platform 1 is mainly composed of a profile frame, hot-dip galvanized grating, and guardrail. The middle frame structure is fixedly connected to the moving disc 18 of the slewing bearing 10. The slewing servo motor 11 is fixedly connected to the upper platform 1 (adjustable). The driving wheel on the slewing servo motor 11 is fixedly connected to the fixed disc (driven wheel) 20 of the slewing bearing 10, i.e., the outer gear ring of the driven wheel, after adjusting the meshing clearance.

[0040] The gangway 12 is connected to the upper platform 1 by a hinge. The two ends of the gangway pitch cylinder 13 are respectively hinged to the upper platform 1 and the gangway 12. The bottom of the gangway 12 is provided with a gangway telescopic mechanism 14.

[0041] Example 2: As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, a control method for a multi-degree-of-freedom active compensation stable boarding device can realize rotational motion around the X-axis and Y-axis and heave motion along the Z-axis, as well as composite motion of the three degrees of freedom.

[0042] The upper platform 1 and the gangway 12 can achieve semi-automatic rotation around the Z-axis, as well as yaw, pitch, and telescopic movements along the gangway 12.

[0043] A control method for a multi-degree-of-freedom active compensation stabilization boarding device: When approaching the boarding target at sea, the boarding personnel board the upper platform 1 via the gangway 12 (when the end descends to the deck), the multi-degree-of-freedom active wave compensation system is activated, and the upper platform 1 is pre-raised to a neutral position to prepare for real-time compensation.

[0044] The pitching electric cylinder 2, rolling electric cylinder 8, and heave electric cylinder 15 (anti-rotation cylinder) issue anti-compensation motion commands to the actuators of the above-mentioned actuators through the ship's rolling and heave motion signals collected by the control system and sensors, including pitching, rolling, heave motion and their combined motion.

[0045] See details Figures 3 to 5The movement of the upper platform 1 and the gangway 12 is semi-automatic. First, the azimuth angle (rotation range of ±90° around the Z-axis) is adjusted manually through the slewing bearing 10 and the slewing servo motor 11. The elevation angle (pitch range +20°-15°) is adjusted through the gangway pitch electric cylinder 13. The gangway telescopic mechanism 14 quickly approaches the target boarding point. The gangway 12, the gangway telescopic mechanism 14 and the sensing elements can automatically adjust the distance to the boarding point or maintain contact. At this time, the system is in a relatively stable state, and maintenance personnel can safely board and evacuate through the gangway 12.

[0046] Example 3: As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, the other structures are the same as in Embodiment 1. A multi-degree-of-freedom active compensation stable boarding device has four lower hinge supports 5 installed in a cross distribution with the X and Y axes as references on the lower platform 7. The base of the follower support hinge support 6 is fixedly connected to the center of the lower platform 7. Four upper hinge supports 4 are installed around the upper end of the follower support 3, and are installed in a cross distribution with the X and Y axes as references.

[0047] The upper platform 1 is mainly composed of a profile frame, hot-dip galvanized grating, and guardrail. The middle frame structure is fixed to the slewing bearing 10 (moving disc) and the slewing servo motor 11 by bolts. The drive wheel installed on the shaft end of the slewing servo motor 11 meshes with the driven wheel (i.e., the outer gear ring of the fixed disc) installed on the slewing bearing 10 (fixed disc) to make the upper platform 1 perform positive and negative rotational motion around the Z-axis, i.e., yaw motion (motion range ±90°). Since the lifting cylinder 15 has an anti-rotation mechanism, the cylinder barrel and cylinder rod of the lifting cylinder 15 will not generate relative rotational motion when the upper platform rotates. The relative rotational motion around the Z-axis only exists relative to the moving disc and fixed disc of the slewing bearing 10.

[0048] The gangway 12 is connected to the upper platform 1 by a hinge. The two ends of the gangway pitching electric cylinder 13 are respectively hinged to the upper platform 1 and the gangway 12. The extension and retraction of the gangway pitching electric cylinder 13 can drive the pitching movement of the gangway 12. The gangway 12 is provided with a gangway extension mechanism 14 at the bottom.

[0049] A control method for a multi-degree-of-freedom active compensation stabilization boarding device: When approaching the boarding target at sea, boarding personnel (usually 1 to 2 people, 1 person at a time when boarding the gangway) ascend to the upper platform 1 via the gangway 12 that descends to the deck at the end, and the multi-degree-of-freedom active wave compensation system is activated.

[0050] The extension and retraction of the pitching electric cylinder 2, rolling electric cylinder 8, and heave electric cylinder 15 (first raised to the neutral position after startup) are achieved by the control system and sensors (the ship's roll signal sensor can be installed at a position parallel to the deck and upper platform 1, and the proximity or force sensor is installed at the end of the gangway) collecting ship roll, heave, and proximity motion signals (including angular displacement, linear displacement, displacement velocity, acceleration, force, etc.). These signals are then used to send anti-compensation motion commands to the actuators of the aforementioned actuators, thereby achieving anti-compensation motion including pitch, roll, heave, and their combined motions. This ensures that the follow-up support 3 and the heave electric cylinder 15 remain perpendicular to the horizontal plane of the earth coordinate system, and that the upper platform 1 remains horizontal. The lifting and lowering of the heave electric cylinder 15, the pitch cylinder 13 of the gangway (manual control), and the extension and retraction mechanism 14 (semi-automatic control) counteract the heave motion, distance, and angle changes, thereby achieving relative horizontality and stability of the system.

[0051] The control system is connected to the circuit control devices of the gangway pitch electric cylinder 13, pitch electric cylinder 2, roll electric cylinder 8 and heave electric cylinder 15 respectively.

[0052] The two damping cylinders 9 are follow-up mechanisms, which play a role in motion damping and auxiliary safety protection. They also play a role in fixing the system when the maintenance vessel is sailing, and can also serve as temporary fixing tools when the system is being repaired, disassembled and installed.

[0053] Platform 1 and gangway 12 are semi-automatic. First, the azimuth angle (rotation around the Z-axis) is adjusted by manually controlling the rotation of the slewing bearing 10 and the slewing servo motor 11. The elevation angle is adjusted by the extension and retraction of the gangway pitch electric cylinder 13. The gangway extension mechanism 14 quickly approaches the target boarding point. The gangway 12, the gangway extension mechanism 14 and the sensing elements can automatically adjust the distance to the boarding point or maintain contact. At this time, the system is in a relatively stable state, and maintenance personnel can safely board and evacuate via the gangway 12.

[0054] Example 4: Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, the other structures are the same as in the above embodiments. A multi-degree-of-freedom active compensation stabilization boarding device consists of an upper platform 1, a pitch electric cylinder 2, a follower support 3, an upper hinge support 4 (4 pieces), a lower hinge support 5 (4 pieces), a follower support hinge support 6 (1 piece), a lower platform 7, a roll electric cylinder 8, a damping cylinder 9, a slewing bearing 10, a slewing servo motor 11, a gangway 12, a gangway pitch electric cylinder 13, a gangway telescopic mechanism 14, and a heave electric cylinder 15.

[0055] The longitudinal rocker cylinder 2 is fixedly connected to the hinge support 4 and the lower hinge support 5 in the same direction on one side of the Y direction. The upper and lower ends of the transverse rocker cylinder 8 are fixedly connected to the hinge support 4 and the lower hinge support 5 in the same direction on one side of the X direction. The lifting cylinder 15 is vertically installed in the follower support 3 in the Z direction (the cylinder flange is connected to the follower support flange), and the cylinder rod is fixedly connected to the slewing bearing 10 (fixed plate).

[0056] Two damping cylinders 9 are mounted mirror images of the roll electric cylinder 8 and the pitch electric cylinder 2 in the X and Y directions, respectively, on the corresponding upper hinge support 4 and lower hinge support 5.

[0057] The upper platform 1 is mainly composed of a profile frame, hot-dip galvanized grating, and guardrail. The middle frame structure is fixed to the slewing bearing 10 (moving disc) and the slewing servo motor 11 by bolts. The shaft end of the slewing servo motor 11 is fixed to the driving wheel and drives the driven wheel (i.e., the outer gear ring of the fixed disc) of the slewing bearing 10 (fixed disc), so that the upper platform 1 makes ± rotational motion around the Z-axis, i.e., yaw motion (motion range ±90°).

[0058] The gangway 12 is connected to the upper platform 1 by a hinge. The two ends of the gangway pitch cylinder 13 are respectively hinged to the upper platform 1 and the gangway 12. The extension and retraction of the gangway pitch cylinder 13 can drive the pitch movement of the gangway 12. The gangway 12 is provided with a gangway extension and retraction mechanism 14 at the bottom.

[0059] When the shipborne multi-degree-of-freedom active compensation stabilization boarding system approaches the boarding target at sea, the boarding personnel (usually 1 to 2 people) ascend to the upper platform 1 via the gangway 12 that descends to the deck at the end and prepare to board. The multi-degree-of-freedom active wave compensation system is then activated.

[0060] A control method for a multi-degree-of-freedom active compensation stabilization boarding device is disclosed. The extension and retraction of the pitching electric cylinder 2, rolling electric cylinder 8, and heave electric cylinder 15, through the control system and sensors collecting ship roll and heave motion signals, send counter-compensation motion commands to the actuators of the aforementioned components. This achieves counter-compensation motion including pitching, rolling, heave, and their combined motions, ensuring that the follow-up support 3 and the heave electric cylinder remain perpendicular to the horizontal plane of the geodetic coordinate system, keeping the upper platform 1 always horizontal. The extension and retraction of the heave electric cylinder 15 counteracts the heave motion of the maintenance vessel, achieving relative horizontality and stability of the upper platform. The system's maximum heave stroke is 1300mm. Upon system startup, it automatically pre-raises to the neutral position. The distance from the neutral position to the stop position and the highest position is 650mm, meaning the heave compensation capability is ±650mm.

[0061] The follow-up support hinge 6 is unconventionally positioned at the bottom of the multi-degree-of-freedom active compensation stabilization boarding system, making the upper platform 1 a fixed platform and the lower platform a moving platform (generally, it is located at the top, with the upper platform as the moving platform and the lower platform as the fixed platform). The purpose is to bring its rotation center as close as possible to the X-axis (ship's roll axis) of the hull's coordinate system, making it possible to compensate for horizontal position changes caused by rolling, which would otherwise be impossible. Moreover, this linear displacement compensation and angular displacement compensation are completed simultaneously, achieving twice the result with half the effort (see...). Figures 3 to 5 ).

[0062] like Figure 3 The diagram shows the effect of multi-degree-of-freedom active compensation under a roll of ±20°.

[0063] like Figure 4 The diagram shows the effect of multi-degree-of-freedom active compensation when the maintenance vessel pitches by -10°.

[0064] like Figure 5 The diagram shows the effect of multi-degree-of-freedom active compensation when the maintenance vessel pitches +10°.

[0065] Example 5: Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, a control method for a multi-degree-of-freedom active compensation stabilization boarding device includes the following steps: A high-precision, real-time-performance micro-mechanical electromechanical inertial navigation system is used as the measuring element for the ship's motion. The azimuth, roll, pitch, angular velocity, acceleration, Euler angles, and quaternion information of the ship are calculated using acceleration and angular velocity information. The measurement accuracy is ensured by using filters and algorithms with appropriate gain. The attitude motion parameters are significantly improved by applying various compensation strategies such as nonlinear compensation, orthogonal compensation, and temperature compensation, which greatly eliminates errors and enhances measurement accuracy.

[0066] At the point where the gangway meets the control tower (the boarding point), a multi-dimensional force sensor is installed to measure the force changes when the platform's motion compensation is inadequate. Based on the intelligent spatial coordinate transformation algorithm, the sensor calculates in real time the changes in the platform's posture and angle input values ​​that should be adjusted.

[0067] For wave spectrum motion, a PID control algorithm is employed. At each sampling time, based on the obtained current measurement information, a finite-time open-loop optimization problem is solved online, and the first element of the resulting control sequence is applied to the controlled object. At the next sampling time, the above process is repeated: the new measurement value is used as the initial condition for predicting the future dynamics of the system, the optimization problem is refreshed, and a new solution is obtained.

[0068] By extending and retracting the electric cylinders 2, 8, and 15, and by transmitting anti-compensation motion commands to the actuators of the aforementioned components based on the ship's rolling and heave motion signals collected by the control system and sensors, anti-compensation motion is achieved, including pitching, rolling, heave, and their combined motions. This ensures that the follow-up support 3 and the heave cylinder 15 remain perpendicular to the horizontal plane of the geodetic coordinate system, keeping the upper platform 1 in a horizontal state. The extension and retraction of the heave cylinder 15 counteracts the heave motion of the maintenance vessel, achieving relative horizontality and stability of the upper platform. The maximum heave stroke of the system is 1300mm. When the system is started, it automatically pre-raises to the neutral position. The distance from the neutral position to the stop position and the highest position is 650mm, meaning the heave compensation capability is ±650mm.

[0069] Furthermore, the follow-up support hinge 6 is unconventionally positioned at the bottom of the multi-degree-of-freedom active compensation stabilization boarding system, making the upper platform 1 a fixed platform and the lower platform a moving platform (generally, it is located at the top, with the upper platform as the moving platform and the lower platform as the fixed platform). The purpose is to bring its rotation center as close as possible to the X-axis of the ship's motion coordinate system, i.e., the ship's roll axis (stabilizing center), making it possible to compensate for horizontal position changes caused by rolling, which would otherwise be impossible. Moreover, this linear displacement compensation and roll angular displacement compensation are completed simultaneously, achieving twice the result with half the effort (see...). Figures 3 to 5 ).

[0070] The embodiments of the present invention have been described in detail; however, many modifications are possible without departing substantially from the inventive point and effects of the present invention, as will be apparent to those skilled in the art. Therefore, all such modifications are also included within the protection scope of the present invention.

Claims

1. A control method for a multi-degree-of-freedom active compensation stable boarding device, the multi-degree-of-freedom active compensation stable boarding device comprising: Four lower hinge supports are cross-shaped and installed on the lower platform with the X and Y axes as references. The base of the follower support hinge support is fixed to the lower platform at the center of the Z axis. Four upper hinge supports are installed around the upper flange of the follower support, corresponding to each other on the X and Y axes and evenly distributed. The bottom of the follower support is fixed to the top of the follower support hinge support. The upper flange of the lifting electric cylinder is fixed to the upper flange of the follower support. The yaw electric cylinder is fixed to the hinge support and lower hinge support on the same direction on the Y side. The upper and lower ends of the yaw electric cylinder are fixed to the hinge support and lower hinge support on the same direction on the X side. The lifting electric cylinder is vertically installed inside the follower support in the Z direction. The lifting cylinder and flange are connected to the follower support and flange. The cylinder rod of the lifting electric cylinder is connected to the return... The fixed plate (driven wheel) of the slewing bearing is fixedly connected to the fixed plate of the slewing bearing. The upper platform is fixedly connected to the moving plate of the slewing bearing. Two damping cylinders are mirror-mounted in the X and Y directions relative to the roll and pitch electric cylinders on the corresponding upper and lower hinge supports. The middle frame structure of the upper platform is fixedly connected to the moving plate of the slewing bearing. The slewing servo motor is fixedly connected to the upper platform. The driving wheel on the slewing servo motor is fixedly connected to the external gear ring of the fixed plate (driven wheel) of the slewing bearing after adjusting the meshing clearance. Four upper hinge supports are installed in a cross shape at 90° with the X and Y axes as references. The upper platform consists of a profile frame, hot-dip galvanized grating, and guardrails. The gangway is connected to the upper platform by a hinge. The two ends of the gangway pitch cylinder are hinged to the upper platform and the gangway, respectively. A gangway telescopic mechanism is provided at the bottom of the gangway. Its features include the following steps: employing a high-precision, real-time-performance micro-mechanical electromechanical inertial navigation system as the measuring element for ship motion; calculating the ship's azimuth, roll, pitch, angular velocity, acceleration, Euler angles, and quaternion information using acceleration and angular velocity data; ensuring measurement accuracy through a filter algorithm with appropriate gain and a PID control algorithm; and eliminating errors and improving measurement accuracy by employing multiple compensation strategies, including nonlinear compensation, orthogonal compensation, and temperature compensation, for attitude motion parameters. The measuring elements include a multi-dimensional force sensor installed at the junction of the gangway end and the control tower, used to measure force changes when platform motion compensation is inadequate. Based on an intelligent spatial coordinate transformation algorithm, it calculates in real time the necessary adjustments to the platform's posture and angle input values. The PID control algorithm, designed for wave spectrum motion, solves a finite-time open-loop optimization problem online at each sampling time based on the current measurement information. The first element of the resulting control sequence is then applied to the controlled object. At the next sampling time, this process is repeated: the new measurement value is used as the initial condition for predicting the system's future dynamics, the optimization problem is refreshed, and a new solution is found. The ship's motion includes rotation along the X and Y axes, heave along the Z axis, and combined motions of these three degrees of freedom. The ship's motion includes semi-automatic rotation around the Z-axis via the upper platform and gangway, as well as yaw, pitch, and extension / retraction along the gangway. The ship's motion includes the pitching, rolling, and heave movements, as well as their combined movements, generated by the pitching, rolling, and heave electric cylinders. The control system and sensors collect the ship's rolling and heave motion signals and issue counter-compensation motion commands to the actuators of the pitching, rolling, and heave electric cylinders, including the pitching, rolling, heave, and their combined movements. The extension and retraction steps of the pitch, roll, and heave electric cylinders ensure that the follow-up support and heave electric cylinders remain perpendicular to the horizontal plane of the geodetic coordinate system, keeping the upper platform in a horizontal and relatively stable position. The extension and retraction of the heave electric cylinders counteract the relative heave motion between the maintenance vessel and the boarding point, thus stabilizing the relative height of the upper platform. The maximum heave compensation stroke of the system is 1300mm. When the system is started, it automatically pre-lifts to the neutral position and begins automatic heave compensation. The distance from the neutral position to the stop position and the highest position is 650mm, that is, the heave compensation capability is ±650mm.

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