gangways with wave compensation function and their flexible control methods

Abstract

This invention relates to a gangway with wave compensation function and its flexible control method, belonging to the field of gangways. Specifically, it includes a gangway, a wave compensation platform system, a measurement system, and a control module. The gangway includes a fixed gangway, a movable gangway, a gangway extension actuator, and a top-mounted device. The wave compensation platform system, from bottom to top, includes a platform base, a six-bar parallel actuator, a six-degree-of-freedom platform surface, a gangway slewing mechanism, a gangway slewing platform, and a gangway pitch actuator. In the wave compensation process, active heave compensation is achieved through the coordinated compensation of the pitch actuator and the six-bar parallel actuator. This coordinated compensation takes into account the efficiency of both the six-bar parallel actuator and the pitch actuator, resulting in high flexibility. This coordinated compensation method improves the redundancy of heave compensation, changing the traditional method of using only the six-bar parallel actuator for heave compensation, which limits the compensation range to the capability of the six-bar parallel actuator itself, thus expanding the system's heave compensation range.

Description

Technical Field

[0001] This invention relates to the field of gangway technology, specifically to a gangway with wave compensation function and its flexible control method. Background Technology

[0002] Offshore wind power platforms also require regular maintenance. To address this need, each offshore wind farm needs to be equipped with a maintenance vessel. These vessels are responsible for maintaining the wind power platforms within the offshore wind farm, a process that requires personnel to be transferred from the maintenance vessel to the wind power platform. This personnel transfer has always been a key focus within the wind power operation and maintenance industry.

[0003] Combining a six-degree-of-freedom (DOF) compensation platform with a sea gangway for berthing, most existing technologies use a six-DOF platform to compensate for the ship's roll, pitch, and heave. For example, CN108279661B discloses a "Debugging Method for a Six-DOF Displacement Variation Compensation Platform." Before assembling the platform, the hydraulic cylinders undergo open-loop debugging; the actual stroke of the hydraulic cylinders is checked against the set stroke using an electronic ruler; all six cylinders are jointly debugged, with each cylinder undergoing PID closed-loop adjustment until all six cylinders achieve synchronous linear motion and mutually sinusoidal curve motion; the attitude sensor is then arbitrarily swung, first debugging the following motion, then the compensating motion. This optimizes the factory performance of the six-DOF displacement variation compensation platform, reducing the difficulty and shortening the on-site debugging cycle.

[0004] For example, CN106320161A discloses a "Six-DOF Active Compensation Offshore Platform Boarding Threshold," 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 located below and connected to the boarding platform. The controller is electrically connected to the six-DOF compensation platform. The beneficial effects of this invention are: by setting a six-DOF compensation platform at the bottom of the boarding platform and controlling it through the controller, six-DOF motion compensation can be provided for the boarding pier, enabling rapid response to ship motion. It eliminates the need to rely on a fixed platform, and by using the six-DOF active compensation platform to eliminate the impact of waves on the ship's six degrees of freedom, it allows for direct and safe docking and free passage between the ship and the offshore platform, greatly improving the accessibility of offshore operating platforms.

[0005] Existing wave compensation methods are relatively simple, only considering a six-degree-of-freedom compensation platform, without comprehensively combining and controlling various motion mechanisms from a control strategy perspective. The compensation range is narrow and the flexibility is limited.

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

[0007] This invention addresses the shortcomings of existing technologies by providing a gangway with wave compensation function and its flexible control method, the technical solution of which is as follows:

[0008] On the one hand, a gangway with wave compensation function includes a gangway, which includes a fixed gangway, a movable gangway, a gangway extension actuator for driving the movable gangway, a top-mounted device, 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's deck, a six-bar parallel actuator, a six-degree-of-freedom platform surface, a gangway slewing mechanism for driving the gangway to rotate, a gangway slewing platform, and a gangway pitch 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 ship's three degrees of freedom of roll, pitch, and heave caused by waves. After the ramming device contacts the platform being rammed, it measures the gangway extension force along the gangway extension direction, the gangway pitch force along the gangway pitch direction, and the gangway traverse force along the gangway traverse direction through the ladder end force sensor.

[0010] The top-mounted device contacts the platform being mounted and enters the automatic wave compensation mode.

[0011] The ladder end force sensor collects the ladder extension force, ladder pitch force, and ladder return force between the ladder and the boarding platform and feeds them back to the control module. The ladder extension actuator enters the force control mode and automatically controls the ladder extension force collected by the ladder end force sensor within the set range.

[0012] The gangway slewing mechanism enters the force control mode, controlling the gangway slewing force in the direction of the movable gangway slewing, and automatically controlling the gangway slewing force collected by the force sensor at the end of the ladder within the set range.

[0013] The control module measures the ship's roll and pitch angles and heave displacements using the motion measurement unit, and calculates the drive commands through coordinate changes to send to the six-bar linkage actuators, thereby achieving angular stabilization of the six-degree-of-freedom platform surface.

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

[0015] As a further embodiment 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 top support device is located in front of the ladder end force sensor.

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

[0017] Upon entering automatic wave compensation mode, the Z-axis displacement of the six-bar parallel actuator enters the working position, and the control module measures the displacement based on the motion measurement unit during compensation. This heave compensation center serves as the control zero point for the heave degree of freedom. This represents the average heave and sag displacement of the ship over a previous period.

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

[0019] The control module calculates the heave compensation displacement based on the current displacement of the gangway pitch actuator. .

[0020] As a further aspect 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 top-mounted device to the connection point between the fixed gangway and the gangway turning platform.

[0021] When the fixed gangway reaches its maximum pitch angle b and the movable gangway extends to its maximum displacement, the distance from the top-mounting device to the connection point between the fixed gangway and the gangway slewing platform is L1.

[0022] ;

[0023] The control module calculates , and Simultaneously record in real time The lifting speed of the six-bar parallel actuator at any given time is The pitch angular velocity value 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 of the ramming device caused by the pitch actuator is calculated based on the pitch angular velocity of the fixed gangway. , ;

[0024] set up This indicates the lifting displacement of a six-bar parallel actuator. This indicates that the gangway pitch actuator provides the lifting displacement to the top-mounting device. This indicates the lifting speed of the six-bar parallel actuator. The heave speed of the ramming device caused by the pitch actuator is calculated based on the pitch angular velocity of the fixed gangway. The lifting displacement value of the six-bar parallel actuator at any given time is The lifting displacement of the top support device is The next time the motion measurement unit transmits the measurement value is... Then in The lifting displacement value of the six-bar parallel actuator at any given time is The lifting displacement of the top support device is ;

[0025] Based on the known conditions, the time... At that time The motion between them is planned to satisfy the following constraints:

[0026]

[0027] set up For a six-bar parallel actuator at time At that time The heave motion function between them is :

[0028] ;

[0029] That is, a six-bar parallel actuator in The rate of rise and fall at any moment yes exist The first derivative at time t, , ;

[0030] For the top support device at time At that time The heave motion function between them is :

[0031] ;

[0032] That is, the top support device is The rate of rise and fall at any given moment is exist The first derivative at time t, , ;

[0033] The control module calculates based on the nonlinear programming method. and :

[0034] The calculation result is ; ,express Time's up At the moment in the One control clock cycle; This indicates the target heave displacement control of the six-bar parallel actuator in each control clock cycle;

[0035] The calculation results are as follows: In each control clock cycle, the gangway pitch actuator provides the top-mounting device with a heave displacement; based on the heave displacement provided to the top-mounting device and trigonometric function relationships... Solve for the pitch angle of the fixed gangway, and calculate the displacement control target of the gangway pitch actuator for each control clock cycle based on the pitch angle.

[0036] Secondly, the flexible control method for the gangway with wave compensation function includes the following steps:

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

[0038] Step 2: The gangway extension actuator enters force control mode, and the gangway rotation mechanism enters force control mode;

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

[0040] Step 4: Calculate the current state of the six-bar parallel actuator. Calculate 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 velocity provided to the ramming device by the six-bar linkage and the gangway pitch actuator at the current moment, and use nonlinear programming to calculate the heave motion of the six-bar linkage. And the gangway pitch actuator provides power to the top-mounted device ;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 beneficial effects of the present invention are:

[0043] 1. During wave compensation, active heave compensation is achieved through the coordinated compensation of pitch actuator and six-bar linkage actuator. The coordinated compensation takes into account the efficiency of both the six-bar linkage actuator and the pitch actuator, resulting in high flexibility.

[0044] 2. This collaborative compensation method improves the redundancy of heave compensation, changing the traditional method of using only six-bar parallel actuators for heave compensation, which limits the compensation range to the compensation capacity of the six-bar parallel actuators themselves, and thus improving the system's range of heave compensation.

[0045] 3. In the calculation of control instructions in the algorithm, the planning and control of motion are aimed at minimizing energy consumption, which can save energy consumption to the greatest extent. Attached Figure Description

[0046] Figure 1 This is a spatial structural diagram of the gangway with wave compensation function of the present invention;

[0047] Figure 2 For calculation A schematic diagram. Detailed Implementation

[0048] The present invention will be described in detail below with reference to specific embodiments. These embodiments are merely some, not all, implementations of the present invention. All other implementations obtained by those skilled in the art based on the embodiments of the present invention without inventive effort 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 shipboard retractable ladder for personnel passage.

[0051] The wave compensation platform system includes a platform base 101, a six-bar 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, a gangway rear upper hinge shaft 205, and a gangway rear lower hinge shaft 206.

[0052] The gangway includes a fixed gangway 301, a gangway extension actuator 302, a movable gangway 303, and a top-mounting device 305;

[0053] The gangway slewing platform 202 is located above the gangway slewing mechanism 201. The gangway slewing platform 202 can rotate relative to the six-degree-of-freedom platform surface 104, and this rotation is controlled by the gangway slewing mechanism 201. The gangway pitch actuator 204 and the gangway slewing platform 202 are connected by 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 slewing platform 202 and the fixed gangway 301. The fixed gangway 301 can be mounted on the gangway 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, gangway pitch actuator 204, lower hinge shaft 206 at the rear end of the gangway, and fixed gangway 301 can rotate together with the gangway slewing platform 202; the movable gangway 303 is connected to the fixed gangway 301 and can extend and retract, and the extension and retraction of the movable gangway 303 relative to the fixed gangway 301 is controlled by the gangway extension and retraction actuator 302; the top-mounting device 305 is located in front of the ladder end force sensor 305; the top-mounting device 305 is used to contact the platform 401 being boarded during boarding.

[0054] The platform base 101 is fixed to the deck of the ship; the six-bar linkage actuator 103 can receive drive commands from the control module and move accordingly, controlling the six-degree-of-freedom platform surface 104 to perform three-degree-of-freedom translational and three-degree-of-freedom rotational movements 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 installed below the front side of the movable gangway 303. The motion measurement unit 102 is installed above the center point of the platform base 101 and can measure the motion values ​​of the ship's three degrees of freedom of roll, pitch, and heave caused by waves in real time. After the jacking device 305 contacts the platform 401 to be jacked, the ladder end force sensor 304 can measure the force values ​​along the three degrees of freedom of the gangway extension direction, the gangway pitch direction, and the gangway rotation direction, which correspond to the gangway extension force, gangway pitch force, and gangway rotation force, respectively.

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

[0057] The methods for controlling heave are as follows:

[0058] Upon entering automatic wave compensation mode, the Z-axis displacement of the six-bar parallel actuator 103 enters the working position. The control module measures the displacement based on the motion measurement unit 102 during compensation. This heave compensation center serves as the control zero point for the heave degree of freedom. The average heave displacement of the ship over a previous period is the average heave displacement of the ship relative to the heave compensation center. The subsequent heave displacement of the ship relative to the gangway top abutment device 305 is the heave displacement of the gangway top abutment device 305.

[0059] The control module calculates the current ship's position in real time based on the heave displacement measurements from the motion measurement unit 102. , The heave increment is calculated based on the current state of the six-bar parallel actuator 103, resulting in a compensable displacement of heave. The control module calculates the heave compensation displacement based on the current displacement of the gangway pitch actuator 204. , To provide heave displacement to the ramming device 305 due to displacement changes under the current displacement condition 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; based on the current pitch angle of the fixed gangway 301 and the current extension of the movable gangway 303, the following can be calculated: .

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

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

[0062]

[0063] The control module calculates , and Simultaneously record in real time The lifting speed of the six-bar parallel actuator 103 at any given time is The pitch angular velocity value of the fixed gangway 301 is The pitch angle of the fixed gangway 301 is , The moment is when the motion measurement unit 102 transmits the collected data to the control module; the heave speed of the push-button device 305 caused by the pitch actuator 204 is calculated based on the pitch angular velocity of the fixed gangway 301. , .

[0064] set up This indicates the lifting displacement of the six-bar parallel actuator 103. This indicates that the gangway pitch actuator 204 provides the lifting displacement to the top abutment device 305. This indicates the lifting speed of the six-bar parallel actuator 103. The heave speed of the push-button device 305 caused by the pitch actuator 204 is calculated based on the pitch angular velocity of the fixed gangway 301. The heave displacement value of the six-bar parallel actuator 103 at any given time is The lifting displacement of the top support device 305 is The next time the motion measurement unit 102 transmits the measurement value is... Then in The heave displacement value of the six-bar parallel actuator 103 at any given time is The lifting displacement of the top support device 305 is .

[0065] Based on the known conditions, the time... At that time The following constraints apply to planning the motion between the elements:

[0066]

[0067] The motion of heave displacement is established as a cubic polynomial. , For polynomial coefficients, Cubic polynomials can satisfy constraints while consuming fewer computer resources. A cubic polynomial can be further written in vector form:

[0068]

[0069] This polynomial expresses the heave displacement of the six-bar parallel actuator 103 and the heave displacement provided by the gangway pitch actuator 204 to the abutment device 305. (Setting) For the six-bar parallel actuator 103 at time At that time The heave motion function between them is :

[0070]

[0071] Then there is That is, the six-bar parallel actuator 103 in The rate of rise and fall at any moment yes exist The first derivative at time t, , .

[0072] For the top support device 305 at time At that time The heave motion function between them:

[0073]

[0074] Then there is That is, the top support device 305 is in The rate of rise and fall at any given moment is exist The first derivative at time t, , .

[0075] Solve for the polynomial coefficients using nonlinear programming methods. The objective of nonlinear programming is... exist Time's up The six-bar parallel actuator of the moment 103 heave acceleration The square of exist Time's up The momentary gangway pitch actuator 204 provides acceleration to the top abutment device 305. The sum of the squares of accelerations. Research has found that the square of acceleration is positively correlated with the power consumed by the actuator. Minimizing the sum of the squares of accelerations is equivalent to minimizing power consumption and maximizing energy savings. The objective function is:

[0076]

[0077] The solution to this function is from Time's up At any given moment, the integral value of the square of the acceleration of the six-bar parallel actuator 103 and the top-mounted device 305 during that time period.

[0078] The control module calculates based on the nonlinear programming method. and This will control the clock cycle. Substituting the polynomial ; The calculation result is Calculate the expression ,express Time's up At the moment in the One control clock cycle; This indicates the target heave displacement control of the six-bar parallel actuator 103 in each control clock cycle; The calculation results show that in each control clock cycle, the gangway pitch actuator 204 needs to provide the top-mounting device 305 with a heave displacement; the heave displacement to be provided to the top-mounting device 305 as needed and the trigonometric function relationship are as follows. The pitch angle of the fixed gangway 301 can be solved, and the displacement control target of the gangway pitch actuator 204 for each control clock cycle can be calculated based on the pitch angle.

[0079] Example 2

[0080] The motion measurement unit 102 collects the ship's roll and pitch angles and heave displacements, while the ladder end force sensor 304 collects the gangway extension / retraction force, gangway pitch force, and gangway return force between the gangway tack device 305 and the boarding platform 401. Upon entering automatic wave compensation mode, the control module controls various actuators (six-bar parallel actuator 103, gangway pitch actuator 204, and gangway extension / retraction actuator 302) to achieve stable contact between the gangway tack device 305 and the boarding platform 401, improving the stability of personnel during the gangway boarding process. The specific method is as follows:

[0081] Step 1: After the top-mounting device 305 contacts the platform 401 being moored, it enters the automatic wave compensation mode and defines the heave compensation center based on the average heave displacement of the ship over a previous period. ;

[0082] Step 2: The gangway extension actuator 302 enters the force control mode, and the gangway rotation mechanism 201 enters the force control mode;

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

[0084] Step 4: Calculate the current state of the six-bar parallel actuator 103. Calculations are made 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 to the top abutment device 305 by the six-bar parallel actuator 103 and the gangway pitch actuator 204 at the current moment, and use nonlinear programming to calculate the polynomial coefficients of the heave motion of the six-bar parallel actuator 204. The polynomial coefficients that the gangway pitch actuator 204 needs to provide to the top abutment 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] Furthermore, it should be understood that those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A gangway with wave compensation function, comprising a gangway, the gangway including a fixed gangway, a movable gangway, a gangway extension actuator for driving the movable gangway, and a backing device; characterized in that: It also includes a wave compensation platform system, a measurement system and a control module. The wave compensation platform system, from bottom to top, includes a platform base fixed on the ship's deck, a six-bar parallel actuator, a six-degree-of-freedom platform surface, a gangway slewing mechanism for driving the gangway to rotate, a gangway slewing platform, and a gangway pitch actuator for driving the gangway 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 ship's three degrees of freedom of roll, pitch, and heave caused by waves. After the ramming device contacts the platform being rammed, it measures the gangway extension force along the gangway extension direction, the gangway pitch force along the gangway pitch direction, and the gangway traverse force along the gangway traverse direction through the ladder end force sensor. The top-mounted device contacts the platform being mounted and enters the automatic wave compensation mode. When entering automatic wave compensation mode, the heave control method includes the following steps: The six-bar parallel actuator enters the working position with its Z-axis displacement, and the control module measures the displacement based on the motion measurement unit during the compensation phase. This heave compensation center serves as the control zero point for the heave degree of freedom. This represents the average heave and sag displacement of the ship over a previous period. The control module calculates the current ship's position in real time based on the heave displacement measurements from the motion measurement unit. , The heave increment is calculated based on the current state of the six-bar parallel actuator, resulting in a compensable displacement of heave. ; The control module calculates the heave compensation displacement based on the displacement of the gangway pitch actuator and the displacement of the movable gangway. ; The ladder end force sensor collects the ladder extension force, ladder pitch force, and ladder return force between the top support device and the boarding platform and feeds them back to the control module. The ladder extension actuator enters the force control mode and automatically controls the ladder extension force collected by the ladder end force sensor within the set range. The gangway slewing mechanism enters the force control mode, controlling the gangway slewing force in the direction of the movable gangway slewing, and automatically controlling the gangway slewing force collected by the force sensor at the end of the ladder within the set range. The control module measures the ship's roll and pitch angles and heave displacements using the motion measurement unit, and calculates the drive commands through coordinate changes to send to the six-bar parallel actuators, thereby achieving angular stabilization of the six-degree-of-freedom platform surface. Let the current pitch angle of the fixed gangway be a, and the maximum pitch angle of the fixed gangway be b; L2 is the distance from the top-mounted device to the connection point between the fixed gangway and the gangway turning platform in the current state; When the fixed gangway reaches its maximum pitch angle b and the movable gangway extends to its maximum displacement, the distance from the top-mounting device to the connection point between the fixed gangway and the gangway slewing platform is L1. ； The control module calculates , and Simultaneously record in real time The lifting speed of the six-bar parallel actuator at any given time is The pitch angular velocity value 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 of the ramming device caused by the pitch actuator is calculated based on the pitch angular velocity of the fixed gangway. , ; set up This indicates the lifting displacement of a six-bar parallel actuator. This indicates that the gangway pitch actuator provides the lifting displacement to the top-mounting device. This indicates the lifting speed of the six-bar parallel actuator. The heave speed of the top-mounted device caused by the pitch actuator is calculated based on the pitch angular velocity of the fixed gangway. The lifting displacement value of the six-bar parallel actuator at any given time is The lifting displacement of the top support device is The next time the motion measurement unit transmits the measurement value is... Then in The lifting displacement value of the six-bar parallel actuator at any given time is The lifting displacement of the top support device is ; Based on the known conditions, the time... At that time The motion between them is planned to satisfy the following constraints: ； set up For a six-bar parallel actuator at time At that time The heave motion function between them is : ； That is, a six-bar parallel actuator in The rate of rise and fall at any moment yes exist The first derivative at time t, , ; For the top support device at time At that time The heave motion function between them is : ； That is, the top support device is The rate of rise and fall at any given moment is exist The first derivative at time t, , ; The control module calculates based on the nonlinear programming method. and : The calculation result is ; ,express Time's up At the moment in the One control clock cycle; This indicates the target heave displacement control of the six-bar parallel actuator in each control clock cycle; To control the clock cycle; The calculation results are as follows: In each control clock cycle, the gangway pitch actuator provides the top-mounting device with a heave displacement; based on the heave displacement provided to the top-mounting device and trigonometric function relationships... Solve for the pitch angle of the fixed gangway, and calculate the displacement control target of the gangway pitch actuator for each control clock cycle based on the pitch angle.

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, and a lower hinge shaft at the rear end of the gangway. The gangway pitch actuator and the gangway slewing platform are connected by the pitch actuator ball joint. The upper hinge shaft at the rear end of the gangway connects the gangway pitch actuator and the fixed gangway, and the lower hinge shaft at the rear end of the gangway connects the gangway slewing platform and the fixed gangway.

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 top support device is located in front of the ladder end force sensor.

4. The flexible control method for a gangway with wave compensation function as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: After the jacking device contacts the platform being jacked, it enters the automatic wave compensation mode and defines the heave compensation center based on the average heave displacement of the ship over a previous period. ; Step 2: The gangway extension actuator enters force control mode, and the gangway rotation mechanism enters force control mode; Step 3: The motion measurement unit measures the ship's roll and pitch angles and heave displacement; the control module controls the six-bar parallel actuator to compensate for and stabilize the angle of the six-degree-of-freedom platform surface; Step 4: Calculate the current state of the six-bar parallel actuator. Calculate based on the displacement of the gangway pitch actuator and the displacement of the movable gangway. ; Step 5: Calculate the heave displacement and heave velocity provided to the ramming device by the six-bar linkage and the gangway pitch actuator at the current moment, and use nonlinear programming to calculate the heave motion of the six-bar linkage. And the gangway pitch actuator provides power to the top-mounted device ;according to , The displacement control targets of the six-bar parallel actuator and the gangway pitch actuator are calculated using trigonometric functions.

Images