Accommodation ladder with wave compensation function and flexible control method thereof

Abstract

The invention relates to a gangway ladder with a wave compensation function and a flexible control method thereof, and belongs to the field of gangway ladders. The device specifically comprises a gangway ladder, a wave compensation platform system, a measuring system and a control module. The gangway ladder comprises a fixed gangway ladder, a movable gangway ladder, a gangway ladder telescopic actuator and an abutting device. The wave compensation platform system sequentially comprises a platform base, a six-rod parallel actuator, a six-degree-of-freedom platform surface, a gangway ladder rotating mechanism, a gangway ladder rotating platform and a gangway ladder pitching actuator from bottom to top. In the process of wave compensation, active heave compensation is cooperatively compensated by the pitching actuator and the six-bar parallel actuator, the efficiency of the six-bar parallel actuator and the efficiency of the pitching actuator are both considered in the cooperative compensation, and the flexibility is high. According to the cooperative compensation mode, the redundancy of heave compensation is improved, the traditional compensation mode that only six-rod parallel actuators are used for heave compensation, and the compensation range is only limited to the capacity of six-rod parallel connection is changed, and the compensation range of the system for heave is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gangway ladders, in particular to a gangway ladder with a wave compensation function and a flexible control method thereof. Background Art

[0002] Offshore wind farm platforms also require regular maintenance. To meet this demand, each offshore wind farm is equipped with an operation and maintenance vessel. These vessels are responsible for maintaining the wind farm platforms within the offshore wind farm. This maintenance process requires the transfer of personnel from the vessel to the wind farm platforms. This personnel transfer process has always been a key focus within the wind farm operation and maintenance industry.

[0003] In the existing technology, a six-degree-of-freedom compensation platform is combined with a sea gangway for docking. The six-degree-of-freedom platform is generally used to compensate for the ship's roll, pitch, and heave. For example, the "A Debugging Method for a Six-Degree-of-Freedom Displacement Compensation Platform" disclosed in publication number CN108279661B , involves open-loop debugging of the hydraulic cylinders before assembling the six-degree-of-freedom displacement compensation platform. An electronic ruler is used to check whether the actual stroke of the hydraulic cylinders is consistent with the set stroke. The six hydraulic cylinders are then jointly debugged, with PID closed-loop adjustment and correction performed on each cylinder until all six achieve synchronized linear motion and mutually sine-cosine curve motion. The attitude sensor is then arbitrarily swung, first debugging the tracking motion and then the compensating motion. This optimizes the factory performance of the six-degree-of-freedom displacement compensation platform, reducing the difficulty and shortening the time required for on-site debugging.

[0004] Another example is the "Six-DoF Active Compensation Offshore Platform Boarding Pier" disclosed in publication number CN106320161A, which includes a controller, a six-DoF compensation platform, a boarding platform, and a pier. The boarding platform is connected to the pier, and the six-DoF compensation platform is disposed below and connected to the boarding platform; the controller is electrically connected to the six-DoF compensation platform. The beneficial effects of the present invention are: a six-DoF compensation platform is disposed at the bottom of the boarding platform, and the six-DoF compensation platform is controlled by a controller to provide six-DoF motion compensation for the boarding pier, achieving rapid response to ship motion without the need for a fixed platform. The six-DoF active compensation platform eliminates the impact of waves on the ship's six degrees of freedom, allowing for direct and safe docking and free passage between the ship and the offshore platform, greatly improving the accessibility of offshore operating platforms.

[0005] The wave compensation method in the existing technology is relatively simple, only considering the six-degree-of-freedom compensation platform, without comprehensive control of various motion mechanisms from the perspective of control strategy. The compensation range is narrow and the flexibility is limited.

[0006] Based on this, the present invention is proposed. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the present invention provides a gangway with wave compensation function and a flexible control method thereof, and the technical solution is as follows:

[0008] In one aspect, a gangway with a heave compensation function comprises a gangway, the gangway comprising a fixed gangway, a movable gangway, a gangway telescopic actuator for driving the movable gangway, a leaning device, a heave compensation platform system, a measurement system, and a control module. The heave compensation platform system comprises, from bottom to top, a platform base fixed to a ship deck, a six-bar parallel actuator, a six-degree-of-freedom platform surface, a gangway slewing mechanism for driving the gangway to slew, a gangway slewing platform, and a gangway pitching actuator for driving the gangway to pitch.

[0009] The measurement system includes a motion measurement unit and a ladder end force sensor. The motion measurement unit is used to measure the motion values of the three degrees of freedom of the ship's roll, pitch, and heave caused by waves. After the supporting device contacts the docked platform, the ladder end force sensor measures the extension force of the ladder along the extension direction, the pitch force of the ladder along the pitch direction, and the rotation force of the ladder along the rotation direction.

[0010] The supporting device contacts the platform being boarded and enters the automatic wave compensation mode;

[0011] The ladder end force sensor collects the extension and retraction force, pitch force, and slewing force of the gangway ladder between the gangway ladder and the platform being boarded and feeds them back to the control module. The gangway ladder extension actuator enters the force control mode and automatically controls the extension and retraction force collected by the ladder end force sensor within a set range.

[0012] The gangway ladder rotation mechanism enters a force control mode to control the gangway ladder rotation force in the rotation direction of the movable gangway ladder, and automatically controls the gangway ladder rotation force collected by the ladder end force sensor within a set range;

[0013] The control module uses the motion measurement unit to measure the ship's roll, pitch angles and heave displacement, and calculates the drive instructions through coordinate changes to give them to the six-rod parallel actuator to achieve angular stability of the six-degree-of-freedom platform surface.

[0014] As a further solution of the present invention, the wave compensation platform system also includes a pitch actuator ball joint, an upper hinge shaft at the rear end of the gangway ladder, and a lower hinge shaft at the rear end of the gangway ladder. The gangway ladder pitch actuator and the gangway ladder rotating platform are connected via the pitch actuator ball joint; the upper hinge shaft at the rear end of the gangway ladder connects the gangway ladder pitch actuator and the fixed gangway ladder, and the lower hinge shaft at the rear end of the gangway ladder connects the gangway ladder rotating platform and the fixed gangway ladder.

[0015] As a further solution of the present invention, the motion measurement unit is installed above the center point of the platform base, the ladder end force sensor is installed below the front side of the movable gangway, and the supporting device is located in front of the ladder end force sensor.

[0016] As a further solution of the present invention, the heave control method comprises the following steps:

[0017] Entering the automatic wave compensation mode, the Z-direction displacement of the six-rod parallel actuator enters the working position, and the control module measures the motion measurement unit when entering the compensation mode. As the heave compensation center, the heave compensation center is the control zero position of the heave freedom. is the average heave displacement of the ship in the previous period;

[0018] The control module calculates the current ship's displacement in real time based on the heave displacement measurement value of the motion measurement unit. , is the heave value increment, and the heave compensable displacement is calculated based on the current state of the six-bar parallel actuator: ;

[0019] The control module calculates the heave compensable displacement based on the current displacement of the gangway pitch actuator as follows: .

[0020] As a further solution of the present invention, the pitch angle of the current fixed gangway is a, b is the maximum pitch angle of the fixed gangway, and L2 is the distance from the supporting device to the connection between the fixed gangway and the gangway revolving platform;

[0021] When the fixed gangway ladder reaches the maximum pitch angle b and the movable gangway ladder is extended to the maximum displacement, the distance from the supporting device to the connection point between the fixed gangway ladder and the gangway ladder revolving platform is L1;

[0022] ;

[0023] The control module calculates 、 and , while recording in real time The heave speed of the six-bar parallel actuator is The pitch angular velocity of the fixed gangway is , the pitch angle of the fixed gangway is , The moment is when the motion measurement unit transmits the collected data to the control module; the heave speed value of the supporting device caused by the pitch actuator is calculated based on the pitch angular velocity of the fixed gangway. , ;

[0024] set up represents the heave displacement of the six-bar parallel actuator, Indicates the heave displacement provided by the ladder pitch actuator to the supporting device, represents the heave speed of the six-rod parallel actuator, Calculate the heave speed of the leaning device caused by the pitch actuator based on the pitch angular velocity of the fixed gangway; The heave displacement of the six-bar parallel actuator at the moment is , the heave displacement of the supporting device is The next time the motion measurement unit transmits a measurement value is , then in The heave displacement of the six-bar parallel actuator at the moment is , the heave displacement of the supporting device is ;

[0025] According to the known conditions To time The motion between is planned, satisfying the following constraints:

[0026]

[0027] set up is the six-bar parallel actuator at time To time The heave motion function between :

[0028] ;

[0029] , that is, the six-bar parallel actuator is Heave speed at any moment yes exist The first derivative at time , 、 ;

[0030] For the supporting device at the time To time The heave motion function between :

[0031] ;

[0032] , that is, the supporting device is The heave speed at this moment is exist The first derivative at time , 、 ;

[0033] The control module calculates the and :

[0034] The calculation result is ; ,express Time has come At the moment Control clock cycles; It represents the heave displacement control target of the six-rod parallel actuator in each control clock cycle;

[0035] The calculation result is: in each control clock cycle, the heave displacement provided by the ramp pitch actuator to the leaning device; according to the heave displacement provided to the leaning device and the trigonometric function relationship , solve the pitch angle of the fixed gangway, and calculate the displacement control target of the gangway pitch actuator in each control clock cycle based on the pitch angle.

[0036] In a second aspect, the flexible control method of the gangway with wave compensation function comprises the following steps:

[0037] Step 1: After the docking device contacts the docked platform, it enters the automatic wave compensation mode and defines the heave compensation center based on the average heave displacement of the ship collected over the previous period. ;

[0038] Step 2: The gangway ladder telescopic actuator enters the force control mode, and the gangway ladder slewing mechanism enters the force control mode;

[0039] Step 3: The motion measurement unit measures the roll and pitch angles and heave displacement of the ship; the control module controls the six-bar parallel actuator to stabilize the angle compensation of the six-degree-of-freedom platform surface;

[0040] Step 4: Calculate the current state of the six-bar parallel actuator , calculated based on the displacement of the gangway pitch actuator and the displacement of the movable gangway ;

[0041] Step 5: Calculate the heave displacement and heave speed provided by the six-bar parallel actuator and the gangway pitch actuator to the supporting device at the current moment, and use nonlinear programming to calculate the heave motion of the six-bar parallel actuator. and the ramp pitch actuator provides the top device with ;according to 、 The displacement control targets of the six-bar parallel actuator and the gangway pitch actuator are calculated using trigonometric functions.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. In the process of wave compensation, active heave compensation is coordinated by the pitch actuator and the six-bar parallel actuator. The coordinated compensation takes into account the efficiency of the six-bar parallel actuator and the pitch actuator, and has high flexibility.

[0044] 2. This collaborative compensation method improves the redundancy of heave compensation, changing the traditional method of using only six-rod parallel actuators for heave compensation, where the compensation range is limited to the compensation capacity of the six-rod parallel actuator itself, thereby improving the system's heave compensation range.

[0045] 3. In the algorithm's control instruction calculation, motion planning and control with the goal of minimizing energy consumption can save energy consumption to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a diagram showing the spatial position structure of a gangway with wave compensation function according to the present invention;

[0047] Figure 2 To calculate Schematic diagram of . DETAILED DESCRIPTION

[0048] The present invention is described in detail below with reference to specific embodiments. The embodiments described below are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0049] Example 1

[0050] like Figure 1 As shown, the gangway with wave compensation function includes a wave compensation platform system, a gangway, a measurement system and a control module. The gangway is also called a telescopic step ladder for marine personnel.

[0051] The wave compensation platform system includes a platform base 101, a six-rod parallel actuator 103, a six-degree-of-freedom platform surface 104, a gangway slewing mechanism 201, a gangway slewing platform 202, a pitch actuator ball joint 203, a gangway pitch actuator 204, an upper hinge shaft 205 at the rear end of the gangway, and a lower hinge shaft 206 at the rear end of the gangway.

[0052] The gangway ladder includes a fixed gangway ladder 301, a gangway ladder telescopic actuator 302, a movable gangway ladder 303, and a supporting device 305;

[0053] The gangway rotating platform 202 is located above the gangway rotating mechanism 201. The gangway rotating platform 202 can rotate relative to the six-degree-of-freedom platform surface 104, and the rotation is controlled by the gangway rotating mechanism 201. The gangway pitch actuator 204 and the gangway rotating platform 202 are connected via a pitch actuator ball joint 203. The upper hinge shaft 205 at the rear end of the gangway connects the gangway pitch actuator 204 and the fixed gangway 301. The lower hinge shaft 206 at the rear end of the gangway connects the gangway rotating platform 202 and the fixed gangway 301. The fixed gangway 301 can be adjusted by the pitch actuator 204. Under control, it rotates around the lower hinge shaft 206 at the rear end of the gangway; the pitch actuator ball joint 203, the ladder pitch actuator 204, the lower hinge shaft 206 at the rear end of the gangway, and the fixed gangway 301 can rotate together with the ladder rotating platform 202; the movable gangway 303 and the fixed gangway 301 are connected to each other and can perform telescopic movement, and the telescopic movement of the movable gangway 303 relative to the fixed gangway 301 is controlled by the ladder telescopic actuator 302; the leaning device 305 is located in front of the ladder end force sensor 305; the leaning device 305 is used to contact the boarded platform 401 during boarding.

[0054] The platform base 101 is fixed to the deck of the vessel; the six-bar parallel actuator 103 can receive driving instructions from the control module and move, controlling the six-degree-of-freedom platform surface 104 to perform three-degree-of-freedom translation and three-degree-of-freedom rotation in space; the gangway slewing mechanism 201 is installed above the six-degree-of-freedom platform surface 104. The control module can be a computer.

[0055] The measurement system includes a motion measurement unit 102 and a ladder-end force sensor 304 mounted below the front of the movable gangway 303. The motion measurement unit 102, mounted above the center point of the platform base 101, can measure the three degrees of freedom (DOF) of the ship's roll, pitch, and heave caused by waves in real time. After the supporting device 305 contacts the docked platform 401, the ladder-end force sensor 304 can measure the forces along the three degrees of freedom (DOF) of the gangway: extension, pitch, and rotation. These correspond to the extension force, pitch force, and rotation force of the gangway, respectively.

[0056] The supporting device 305 contacts the docked platform 401 and enters the automatic wave compensation mode. The ladder end force sensor 304 collects the gangway ladder extension and extension force, the gangway ladder pitch force, and the gangway ladder rotation force between the gangway ladder and the docked platform 401 and feeds them back to the control module. The gangway ladder extension and extension actuator 302 enters the force control mode and automatically controls the gangway ladder extension and extension force collected by the ladder end force sensor 304 within a set range. The gangway ladder rotation mechanism 201 enters the force control mode and controls the gangway ladder rotation force in the rotation direction of the movable gangway ladder 303, automatically controlling the gangway ladder rotation force collected by the ladder end force sensor 304 within a set range. The control module uses the motion measurement unit 102 to measure the ship's roll, pitch angle and heave displacement, calculates the drive command through coordinate changes and gives it to the six-bar parallel actuator 103, achieving angular stability of the six-degree-of-freedom platform surface 104.

[0057] Heave control methods are as follows:

[0058] Entering the automatic wave compensation mode, the Z-direction displacement of the six-bar parallel actuator 103 enters the working position. The control module measures the motion measurement unit 102 when entering the compensation mode. As the heave compensation center, the heave compensation center is the control zero position of the heave freedom. is the average heave displacement of the ship in the previous period; the subsequent heave displacement of the ship relative to the heave compensation center is the heave displacement of the gangway supporting device 305.

[0059] The control module calculates the current ship's displacement in real time based on the heave displacement measurement value of the motion measurement unit 102. , is the heave value increment, and the heave compensable displacement is calculated based on the current state of the six-bar parallel actuator 103: The control module calculates the heave compensable displacement according to the current displacement of the gangway pitch actuator 204: , is the heave displacement that can be provided to the supporting device 305 due to the displacement change under the condition of the current displacement of the gangway pitch actuator 204; the displacement of the gangway pitch actuator 204 can be calculated as the pitch angle of the fixed gangway 301; according to the current pitch angle of the fixed gangway 301 and the current extension of the movable gangway 303, it can be calculated .

[0060] like Figure 2 As shown, the current pitch angle of the fixed gangway ladder 301 is a, b is the maximum pitch angle of the fixed gangway ladder 301, and L2 is the distance from the supporting device 305 to the connection between the fixed gangway ladder 301 and the gangway ladder rotating platform 202 (the lower hinge shaft 206 at the rear end of the gangway ladder) (corresponding to the pitch angle a);

[0061] When the fixed gangway 301 reaches the maximum pitch angle b and the movable gangway 303 is extended to the maximum displacement, the distance from the supporting device 305 to the connection between the fixed gangway 301 and the gangway rotating platform 202 (the lower hinge shaft 206 at the rear end of the gangway) is L1.

[0062]

[0063] The control module calculates 、 and ; Real-time recording at the same time At this moment, the heave speed of the six-bar parallel actuator 103 is The pitch angular velocity of the fixed gangway 301 is , the pitch angle of the fixed gangway 301 is , The moment is the moment when the motion measurement unit 102 transmits the collected data to the control module; the heave speed value of the supporting device 305 caused by the pitch actuator 204 is calculated based on the pitch angular velocity of the fixed gangway 301. , .

[0064] set up represents the heave displacement of the six-bar parallel actuator 103, represents the heave displacement provided by the ladder pitch actuator 204 to the supporting device 305, represents the heave speed of the six-bar parallel actuator 103, Calculate the heave speed of the leaning device 305 caused by the pitch actuator 204 based on the pitch angular speed of the fixed gangway 301; At the moment, the heave displacement value of the six-bar parallel actuator 103 is , the heave displacement of the supporting device 305 is The next transmission time of the motion measurement unit 102 is , then in At the moment, the heave displacement value of the six-bar parallel actuator 103 is , the heave displacement of the supporting device 305 is .

[0065] According to the known conditions To time The motion between them is planned with the following constraints:

[0066]

[0067] The motion of the heave displacement is formulated as a cubic polynomial , are the polynomial coefficients, The cubic polynomial can satisfy the constraints while taking up less computer resources. The cubic polynomial can be rewritten as a vector:

[0068]

[0069] This polynomial is used to express the heave displacement of the six-bar parallel actuator 103 and the heave displacement provided to the supporting device 305 by the ramp pitch actuator 204. The six-bar parallel actuator 103 is To time The heave motion function between :

[0070]

[0071] Then there is , that is, the six-bar parallel actuator 103 is Heave speed at any moment yes exist The first derivative at time , 、 .

[0072] The supporting device 305 is at the time To time The heave motion function between:

[0073]

[0074] Then there is , i.e. the supporting device 305 is The heave speed at this moment is exist The first derivative at time , 、 .

[0075] Use nonlinear programming methods to solve the polynomial coefficients The goal of nonlinear programming is exist Time has come The heave acceleration of the six-bar parallel actuator 103 at the moment The square of exist Time has come The ramp pitch actuator 204 provides the acceleration to the supporting device 305 at the moment The sum of the squares of acceleration. Studies have found that the square of acceleration is positively correlated with the power consumed by the actuator. Minimizing the sum of the squares of acceleration is the goal of minimizing power and saving energy to the greatest extent. The objective function is:

[0076]

[0077] The result of solving this function is Time has come At the moment, the integral value of the square of the acceleration of the six-bar parallel actuator 103 and the supporting device 305 during the period.

[0078] The control module calculates the and , will control the clock period Substitute the polynomial ; The calculation result is , in the calculation expression ,express Time has come At the moment Control clock cycles; represents the heave displacement control target of the six-bar parallel actuator 103 in each control clock cycle; The calculation result is the heave displacement that the ladder pitch actuator 204 needs to provide to the supporting device 305 in each control clock cycle; the heave displacement provided to the supporting device 305 as needed and the trigonometric function relationship The pitch angle of the fixed gangway 301 can be solved, and the displacement control target of the gangway pitch actuator 204 per control clock cycle can be calculated based on the pitch angle.

[0079] Example 2

[0080] The motion measurement unit 102 collects the roll and pitch angles and heave displacements of the vessel, and the ladder end force sensor 304 collects the gangway ladder extension force, ladder pitch force, and ladder slewing force between the supporting device 305 and the docked platform 401. After entering the automatic heave compensation mode, the control module controls each actuator (six-bar parallel actuator 103, gangway ladder pitch actuator 204, and gangway ladder extension actuator 302) to achieve stable contact between the supporting device 305 and the docked platform 401, thereby improving the stability of personnel boarding the gangway ladder. The specific method is as follows:

[0081] Step 1: After the supporting device 305 contacts the docked platform 401, it enters the automatic wave compensation mode and defines the heave compensation center according to the average heave displacement of the ship collected in the previous period. ;

[0082] Step 2: the gangway ladder telescopic actuator 302 enters the force control mode, and the gangway ladder slewing mechanism 201 enters the force control mode;

[0083] Step 3: The motion measurement unit 102 measures the roll and pitch angles and heave displacement of the vessel; the control module controls the six-bar parallel actuator 103 to compensate and stabilize the angle of the six-degree-of-freedom platform 104;

[0084] Step 4: Calculate the current state of the six-bar parallel actuator 103 , calculated based on the displacement of the gangway pitch actuator 204 and the displacement of the movable gangway 303 ;

[0085] Step 5: Calculate the heave displacement and heave velocity provided by the six-bar parallel actuator 103 and the ramp pitch actuator 204 to the supporting device 305 at the current moment, and use nonlinear programming to calculate the polynomial coefficients of the heave motion of the six-bar parallel actuator 204. and the polynomial coefficients that the ramp pitch actuator 204 needs to provide to the leaning device 305 ; The displacement control targets of the six-bar parallel actuator 103 and the gangway pitch actuator 204 are calculated based on polynomials and trigonometric functions.

[0086] In addition, it should be understood that those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A gangway with heave compensation function, comprising a fixed gangway, a movable gangway, a gangway telescopic actuator for driving the movable gangway, and a supporting device; characterized in that: The system also includes a wave compensation platform system, a measurement system, and a control module. The wave compensation platform system includes, from bottom to top, a platform base fixed on the ship deck, a six-bar parallel actuator, a six-degree-of-freedom platform surface, a gangway ladder rotation mechanism for driving the gangway ladder to rotate, a gangway ladder rotation platform, and a gangway ladder pitching actuator for driving the gangway ladder to pitch. The measurement system includes a motion measurement unit and a ladder end force sensor. The motion measurement unit is used to measure the motion values of the three degrees of freedom of the ship's roll, pitch, and heave caused by waves. After the supporting device contacts the docked platform, the ladder end force sensor measures the extension force of the ladder along the extension direction, the pitch force of the ladder along the pitch direction, and the rotation force of the ladder along the rotation direction. The supporting device contacts the platform being boarded and enters the automatic wave compensation mode; The ladder end force sensor collects the extension and retraction force, pitch force, and slewing force of the gangway ladder between the gangway ladder and the platform being boarded and feeds them back to the control module. The gangway ladder extension actuator enters the force control mode and automatically controls the extension and retraction force collected by the ladder end force sensor within a set range. The gangway ladder rotation mechanism enters a force control mode to control the gangway ladder rotation force in the rotation direction of the movable gangway ladder, and automatically controls the gangway ladder rotation force collected by the ladder end force sensor within a set range; The control module uses the motion measurement unit to measure the ship's roll, pitch angles and heave displacement, and calculates the drive instructions through coordinate changes to give them to the six-rod parallel actuator to achieve angular stability of the six-degree-of-freedom platform surface.

2. The gangway with wave compensation function according to claim 1, characterized in that: The wave compensation platform system also includes a pitch actuator ball joint, an upper hinge shaft at the rear end of the gangway ladder, and a lower hinge shaft at the rear end of the gangway ladder. The gangway ladder pitch actuator and the gangway ladder rotating platform are connected through the pitch actuator ball joint; the upper hinge shaft at the rear end of the gangway ladder connects the gangway ladder pitch actuator and the fixed gangway ladder, and the lower hinge shaft at the rear end of the gangway ladder connects the gangway ladder rotating platform and the fixed gangway ladder.

3. The gangway with wave compensation function according to claim 1, characterized in that: The motion measurement unit is installed above the center point of the platform base, the ladder end force sensor is installed below the front side of the movable gangway, and the supporting device is located in front of the ladder end force sensor.

4. The gangway with wave compensation function according to claim 1, characterized in that: The heave control method comprises the following steps: Entering the automatic wave compensation mode, the Z-direction displacement of the six-rod parallel actuator enters the working position, and the control module measures the motion measurement unit when entering the compensation mode. As the heave compensation center, the heave compensation center is the control zero position of the heave freedom. is the average heave displacement of the ship in the previous period; The control module calculates the current ship's displacement in real time based on the heave displacement measurement value of the motion measurement unit. , is the heave value increment, and the heave compensable displacement is calculated based on the current state of the six-bar parallel actuator: ; The control module calculates the heave compensable displacement based on the current displacement of the gangway pitch actuator as follows: .

5. The gangway with wave compensation function according to claim 4, characterized in that: The current pitch angle of the fixed gangway is a, b is the maximum pitch angle of the fixed gangway, and L2 is the distance from the supporting device to the connection between the fixed gangway and the gangway revolving platform; When the fixed gangway ladder reaches the maximum pitch angle b and the movable gangway ladder is extended to the maximum displacement, the distance from the supporting device to the connection point between the fixed gangway ladder and the gangway ladder revolving platform is L1; ； The control module calculates 、 and , while recording in real time The heave speed of the six-bar parallel actuator is The pitch angular velocity of the fixed gangway is , the pitch angle of the fixed gangway is , The moment is when the motion measurement unit transmits the collected data to the control module; the heave speed value of the supporting device caused by the pitch actuator is calculated based on the pitch angular velocity of the fixed gangway. , ; set up represents the heave displacement of the six-bar parallel actuator, Indicates the heave displacement provided by the ladder pitch actuator to the supporting device, represents the heave speed of the six-rod parallel actuator, Calculate the heave speed of the leaning device caused by the pitch actuator based on the pitch angular velocity of the fixed gangway; The heave displacement of the six-bar parallel actuator at the moment is , the heave displacement of the supporting device is The next time the motion measurement unit transmits a measurement value is , then in The heave displacement of the six-bar parallel actuator at the moment is , the heave displacement of the supporting device is ; According to the known conditions To time The motion between is planned, satisfying the following constraints: ； set up is the six-bar parallel actuator at time To time The heave motion function between : ； , that is, the six-bar parallel actuator is Heave speed at any moment yes exist The first derivative at time , 、 ; For the supporting device at the time To time The heave motion function between : ； , that is, the supporting device is The heave speed at this moment is exist The first derivative at time , 、 ; The control module calculates the and : The calculation result is ; ,express Time has come At the moment Control clock cycles; It represents the heave displacement control target of the six-rod parallel actuator in each control clock cycle; The calculation result is: in each control clock cycle, the heave displacement provided by the ramp pitch actuator to the leaning device; according to the heave displacement provided to the leaning device and the trigonometric function relationship , solve the pitch angle of the fixed gangway, and calculate the displacement control target of the gangway pitch actuator in each control clock cycle based on the pitch angle.

6. The flexible control method for a gangway with a wave compensation function according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: After the docking device contacts the docked platform, it enters the automatic wave compensation mode and defines the heave compensation center based on the average heave displacement of the ship collected over the previous period. ; Step 2: The gangway ladder telescopic actuator enters the force control mode, and the gangway ladder slewing mechanism enters the force control mode; Step 3: The motion measurement unit measures the roll and pitch angles and heave displacement of the ship; the control module controls the six-bar parallel actuator to stabilize the angle compensation of the six-degree-of-freedom platform surface; Step 4: Calculate the current state of the six-bar parallel actuator , calculated based on the displacement of the gangway pitch actuator and the displacement of the movable gangway ; Step 5: Calculate the heave displacement and heave speed provided by the six-bar parallel actuator and the gangway pitch actuator to the supporting device at the current moment, and use nonlinear programming to calculate the heave motion of the six-bar parallel actuator. and the ramp pitch actuator provides the top device with ;according to 、 The displacement control targets of the six-bar parallel actuator and the gangway pitch actuator are calculated using trigonometric functions.

Images