9-Dof Wave Compensation Platform and Operation Method

The present application relates to the field of marine engineering technology, and in particular to a 9-DOF wave compensation platform and an operation method thereof.

Under the dual pressure of global energy shortage and energy conservation and emission reduction, new renewable energy sources are extremely popular. Compared with the relatively high price of solar power generation and the nearly saturated hydropower resources, wind power generation has become the most sought-after “darling”. Among them, offshore wind power has quickly opened up a market with its advantages of rich resource reserves, stable power generation, and convenient grid access. Wind power transport ships and wind power installation platforms for offshore wind farm construction have gradually appeared. However, during the installation of offshore wind turbines, ups and downs of waves will cause a ship to present complex roll, pitch and vertical heave movements, and there is a risk of collision between the cargo and the ship. In severe cases, wire ropes may break, causing serious damage to the ship's lifting and lowering operations and the cargo.

The existing Chinese patent application published as CN117144780A discloses an offshore platform boarding bridge with wave compensation function, wherein the wave compensation control mechanism is fixed on the deck of the operation and maintenance ship through a base bottom plate, and a bottom universal joint is fixed on the upper surface of the base bottom plate, a top universal joint is fixed on the lower surface of the base top plate, the lower part of a compensation cylinder is connected to the bottom universal joint, and the upper part of the compensation cylinder is connected to the top universal joint; and the fixed end of a horizontal driving member of the bridge mechanism is connected to the fixed frame of the bridge, and the movable end of the horizontal driving member is connected to the movable frame of the bridge; and the horizontal driving member drives the movable frame of the bridge to move along a guide groove through a vertical guide member; and the wave compensation control mechanism also comprises a micro-inertial navigation sensor, and the compensation cylinder performs wave compensation on the bridge mechanism according to the operation and maintenance ship motion information transmitted by the micro-inertial navigation sensor.

In the prior art, the equipment deadweight of an offshore platform boarding bridge with wave compensation function generates a certain load on the driving components, so there is room for improvement.

In view of the defects in the prior art, an object of the present application is to provide a 9-DOF wave compensation platform and an operation method.

According to the present application, a 9-DOF wave compensation platform is provided, comprising a 6-DOF parallel stabilization platform and a 3-DOF tandem boarding bridge; wherein the 6-DOF parallel stabilization platform comprises a mounting base and a movable platform, and motion branch chains are provided between the mounting base and the movable platform, and the motion branch chain moves actively driven by a driving element, and a balancing cylinder system is further connected to the motion branch chain to counterbalance an equipment deadweight; and the 3-DOF tandem boarding bridge is installed on the movable platform.

Preferably, the motion branch chain comprises a connecting rod, a ball joint, a Hooke's joint and a slider, and the mounting base is provided with slide rails, and the slider is slidably arranged on one of the slide rails (P pair); and one end of the connecting rod is connected to the slider via the Hooke's joint (U pair), and another end of the connecting rod is connected to the movable platform via the ball joint (S pair), constituting a PUS single open chain, through which vertical push and pull forces of a driving element on the slider are transmitted to the movable platform to drive the movable platform.

Preferably, the balancing cylinder system comprises a piston rod, an oil cylinder and an accumulator; and the piston rod is fixedly mounted on the slider, and an oil delivery pipe of the accumulator is connected to the oil cylinder, and a gas bladder in the accumulator expands outward under air pressure, pressing hydraulic oil in the accumulator toward the oil cylinder through the oil delivery pipe, so that the oil cylinder lifts the piston rod to counterbalance the equipment deadweight.

Preferably, six groups of the motion branch chains are arranged between the mounting base and the movable platform.

Preferably, the 3-DOF tandem boarding bridge comprises a connecting base, a rotary platform, a fixed-pitching part and a telescoping part; wherein the connecting base is mounted on the movable platform; and the connecting base and the rotary platform are connected via a rotary bearing; and one end of the fixed-pitching part is connected to the rotary platform via a hinge; and a driving device capable of driving the fixed-pitching part to perform a pitching motion around a central axis of the hinge is provided between the fixed-pitching part and the rotary platform; and the telescoping part is arranged at an end of the fixed-pitching part away from the rotary platform.

Preferably, a connection position between the fixed-pitching part and the rotary platform is located at a lower part of the fixed-pitching part; and the driving device comprises an electric cylinder, with a housing of the electric cylinder being pivotally connected to the rotary platform, and a telescoping rod of the electric cylinder being pivotally connected to an upper part of the fixed-pitching part; and a pivoting point between the electric cylinder and the fixed-pitching part, and a pivoting point between the fixed-pitching part and the rotary platform are both located at a same end along a length direction of the fixed-pitching part.

Preferably, a guide rail is arranged inside the fixed-pitching part along a length direction of the fixed-pitching part, wherein the telescoping part is arranged inside the fixed-pitching part, and the telescoping part moves along a direction of the guide rail.

Preferably, the fixed-pitching part and the telescoping part are both provided with skeletonized structures.

Preferably, the mounting base is mounted on a ship, for example on a deck of the ship.

The present application further provides an operation method of a 9-DOF wave compensation platform, including following steps:

Compared to the prior art, the present application has the following beneficial effects:

As shown in the figure:

The present application is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but are not intended to limit the present application in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present application. These all belong to the protection scope of the present application.

As shown in, a 9-DOF wave compensation platform provided according to the present application comprises a 6-DOF parallel stabilization platformand a 3-DOF tandem boarding bridge. The 6-DOF parallel stabilization platformcomprises a mounting baseand a movable platform, and motion branch chains are arranged between the mounting baseand the movable platform. The motion branch chain moves actively when driven by a driving element, and a balancing cylinder systemis further connected to the motion branch chain to counterbalance the deadweight of the equipment. The 3-DOF tandem boarding bridgeis installed on the movable platform.

The 6-DOF parallel stabilization platformof the present application is used to compensate for the high-frequency part of wave motion, and the 3-DOF tandem boarding bridgeis used to compensate for the low-frequency part of wave motion and drift motion, and the balancing cylinder systemis used to counterbalance the load generated by the equipment's own weight on the driving components.

As shown into, specifically, each motion branch chain comprises a connecting rod, a ball joint, a Hook's jointand a slider. Slide railsare provided on the mounting base, and the slideris slidably arranged on one of the slide rails, constituting a P pair. One end of the connecting rodis connected to the sliderthrough the Hook's joint, constituting a U pair, and the other end of the connecting rodis connected to the movable platformthrough the ball joint, constituting an S pair, wherein the three motion pairs constitute a PUS single open chain to transmit force and motion. Six groups of motion branch chains are provided between the mounting baseand the movable platform. The balancing cylinder systemcomprises a piston rod, an oil cylinderand an accumulator. The piston rodis fixedly installed with the slider, and an oil pipe of the accumulatoris connected with the oil cylinder. A gas bladder in the accumulatorexpands outward under air pressure, so that hydraulic oil in the accumulatoris pressed toward the oil cylinderthrough the oil pipe, and the oil cylinderlifts the piston rodto counterbalance the equipment deadweight.

Furthermore, between the movable platformand the mounting baseof the 6-DOF parallel stabilization platform, six identical motion branch chains are provided. The slide rail and the mounting baseare fixedly mounted, and the slider is configured to move along the length direction of the slide rail. The slider and the connecting rodare connected by a Hooke's joint, which is configured to generate rotational movement in two directions. The connecting rodand the movable platformare connected by a ball joint, which is configured to generate rotation in three directions. The movable platformis configured to generate 6-DOF movement relative to the mounting base. The slider is actively driven by a driving element. For example: a motor drives a ball screw or a hydraulic cylinder pushes.

By adjusting the position of the sliders on the slide rails in the six motion branch chains, the position and posture of the movable platformcan be changed. The piston rodof the balancing cylinder systemis fixedly installed with the slider, and the oil pipe of the accumulatoris connected to the oil cylinder. The gas bladder in the accumulatorexpands outward under the action of air pressure, so that the hydraulic oil in the accumulatoris pressed toward the oil cylinderthrough the oil pipe, and the oil cylinderlifts the piston rod. By adjusting the pressure of the gas bladder in the accumulator, the thrust of the piston rodand the gravity of the equipment can be counterbalanced, reducing the driving load of the slider driving element.

As shown inand, more specifically, the 3-DOF tandem boarding bridgecomprises a connecting base, a rotary platform, a fixed-pitching partand a telescoping part. The connecting baseis installed on the movable platform. The connecting baseand the rotary platformare connected by a rotary bearing. One end of the fixed-pitching partis connected to the rotary platformby a hinge, and a driving device that can drive the fixed-pitching partto perform a pitching motion around the central axis of the hinge is also provided between the fixed-pitching partand the rotary platform. The telescoping partis provided at one end of the fixed-pitching partaway from the rotary platform.

The connection position between the fixed-pitching partand the rotary platformis located at the lower part of the fixed-pitching part. The driving device comprises an electric cylinder. The housing of the electric cylinderis pivotally connected to the rotary platform, and the telescoping rod of the electric cylinderis pivotally connected to the upper part of the fixed-pitching part. The hinge point between the electric cylinderand the fixed-pitching part, and the hinge point between the fixed-pitching partand the rotary platformare both located at the same end along the length direction of the fixed-pitching part. A guide rail is arranged inside the fixed-pitching partalong the length direction of the fixed-pitching part, and the telescoping partis arranged inside the fixed-pitching part, and the telescoping partmoves along the direction of the guide rail.

Preferably, as shown in, the fixed-pitching partand the telescoping partare both provided with skeletonized structures.

Furthermore, the 3-DOF tandem boarding bridgeis connected to the movable platformof the 6-DOF parallel stabilization platformthrough the connecting base. The connecting baseand the rotary platformare connected through a rotary bearing, so that the rotary platformand the connecting basecan rotate relative to each other to realize the rotation movement of the bridge. The rotary platformand the fixed-pitching partare directly connected through a hinge to generate relative rotation. In addition, the rotary platformand the fixed-pitching partare also connected through an electric cylinder. The electric cylinderis mounted through hinges provided on the rotary platformand on the fixed-pitching part, and acts as a driving unit to perform telescoping movement, so that the bridge performs a pitch movement. The fixed-pitching partand the telescoping partare connected through the guide rail and can translate relative to each other to realize the telescoping movement of the bridge.

It should be noted that the mounting baseof the present application is installed on a ship, for example on the deck of the ship.

The present application also provides an operation method of a 9-DOF wave compensation platform, which is used to operate the above-mentioned 9-DOF wave compensation platform and includes the following steps: the ship motion information is measured by a motion attitude sensor, and the measured information is input into a high-pass filter and a low-pass filter respectively, wherein the high-pass filter extracts the high-frequency part of the ship motion information, and the low-pass filter extracts the low-frequency part of the ship motion information.

The 6-DOF parallel stabilization platformreceives the high-frequency motion information, and through active control, the movable platformgenerates opposite motion to counterbalance the high-frequency motion of the ship. The 3-DOF tandem boarding bridgereceives low-frequency motion information, and through active control, the distal end of the telescoping partcontacts the bridged object to control the bridge to generate opposite motion to counterbalance the low-frequency ship motion, consequently achieving full compensation of the ship motion and keeping the bridging end of the bridge stationary relative to an inertial reference system.

The technical solution of the present application combines a 6-DOF parallel stabilization platformand a 3-DOF tandem boarding bridge, utilizing the advantages of the parallel mechanism's fast response and suitability for compensating high-frequency motion, as well as the advantages of the tandem mechanism's large working space, to achieve targeted compensation for the low-frequency parts and the high-frequency parts of the ship motion.

The present application adopts a balanced hydraulic cylinder to counterbalance the driving load generated by the gravity of the components in the compensation platform in advance, so that the driving load of the compensation platform during operation is significantly reduced, and the total energy consumption of the system is lower, and the range of selectable driving elements is wider.

The 3-DOF tandem boarding bridgeof the present application controls the contact force between the bridge and the bridged object on the basis of receiving low-frequency motion information, further realizing stable contact between the bridge and the bridged object, and consequently realizing full compensation of the ship motion.

In the description of the present application, it should be understood that the terms “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

The above describes the specific embodiments of the present application. It should be understood that the present application is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present application. When there is no conflict, the embodiments of the present application and the features in the embodiments can be freely combined with each other.