Three-degree-of-freedom series-parallel connection wave compensation platform and compensation method

Abstract

The invention belongs to the technical field of wave compensation, and discloses a three-degree-of-freedom series-parallel wave compensation platform and a compensation method.The compensation platform comprises a platform base fixedly installed on a ship and provided with the height direction, and further comprises a transverse and longitudinal shaking platform, two electric cylinders arranged above the platform base in the height direction, and a connecting rod, the fixed ends of the two electric cylinders are hinged to the platform base, and the free ends of the two electric cylinders extend in the height direction, are jointly hinged to the transverse pitching platform and are used for being connected in parallel on the transverse pitching platform to form transverse pitching freedom degrees; and the heaving electric cylinder is arranged on the transverse and longitudinal rocking platform, the free end of the heaving electric cylinder supports the heaving platform and is used for forming a heaving freedom degree, and the heaving electric cylinder is connected with the two electric cylinders in series to form a three-freedom degree. According to the invention, the platform structure form is adjusted into a series-parallel connection degree of freedom, the number of driving levers is reduced, a four-cylinder statically indeterminate structure in the prior art is avoided, errors are avoided, and potential threats to the life safety of personnel and equipment on the operation platform are reduced or avoided.

Description

Technical Field

[0001] The invention belongs to the field of wave compensation, and in particular relates to a three-degree-of-freedom series-parallel wave compensation platform and a compensation method. Background Art

[0002] During the seaside lifting operation, due to the action of the waves, the ship where the crane is located may experience six degrees of freedom relative movement, which may cause the hoisted cargo to collide with surrounding objects. The collision may cause damage to the cargo, and even cause safety accidents in serious cases. Therefore, in order to ensure the smooth progress of the side-by-side lifting task, the ship crane needs to have a six-degree-of-freedom wave compensation function, so as to effectively eliminate the interference caused by the waves and ensure the accuracy, safety and efficiency of the operation.

[0003] At present, the three-degree-of-freedom motion of a ship, namely, roll, pitch and heave, is mostly compensated through a three-degree-of-freedom wave compensation platform.

[0004] However, the existing three-degree-of-freedom wave compensation usually adopts a parallel form, such as the heavy-duty three-degree-of-freedom wave compensation platform disclosed in the publication number CN115092316A, which includes a load-bearing platform and a compensation device; the compensation device includes at least four compensation mechanisms, each of which includes a telescopic member, an elastic pull rod, a base and a connecting assembly; the connecting assembly is used to install the load-bearing platform, the telescopic members all extend in the vertical direction, and the positioning end of the telescopic member is connected to the base ball joint, the telescopic end is connected to the connecting assembly ball joint, one end of the elastic pull rod is rotatably connected to the telescopic member, and the other end is rotatably connected to the base; when any one of the compensation mechanisms is used as a compensation reference, the other compensation mechanisms can move relative to the compensation mechanism used as the compensation reference, so that the load-bearing platform can always be in a horizontal state;

[0005] The above-mentioned existing patent mainly uses four groups of telescopic cylinders to form a quadrilateral operation, but when adopting this arrangement, the four groups of telescopic cylinders need to be controlled with quite high precision, that is, to achieve synchronous extension and retraction, and to keep the four groups of connecting parts in the same plane after extension and retraction. However, in actual operation, there may be a situation where the extension and retraction of the four groups of telescopic cylinders are not well coordinated, resulting in the four groups of connecting parts above the telescopic cylinders being unable to be accurately kept in the same plane, thereby causing the working plane where the working platform is located to warp and the groups of telescopic cylinders to be in an abnormal stress state. Severe cases may even directly lead to the overall failure of the wave compensation device. Therefore, this type of wave compensation device will pose a potential threat to the life safety and equipment of personnel on the working platform. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a three-degree-of-freedom series-parallel wave compensation platform and a compensation method. By adjusting the platform structure to series-parallel degrees of freedom, the number of driving rods can be reduced, thereby avoiding the four-cylinder hyperstatic structure commonly seen in the prior art, and errors caused by control accuracy will not occur.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A three-degree-of-freedom serial-parallel wave compensation platform comprises a platform base fixedly mounted on a ship, wherein the platform base has a height direction,

[0009] Also includes,

[0010] The horizontal and vertical shaking platform is located above the platform base in the height direction.

[0011] Two electric cylinders, whose fixed ends are both hinged to the platform base, and whose free ends extend in the height direction and are jointly hinged to the transverse and pitch platform, so as to be connected in parallel on the transverse and pitch platform to form transverse and pitch degrees of freedom;

[0012] A column is fixed on the platform base, and the length of the column in the height direction is constant, and the column is hinged to the lower surface of the pan-tilt platform in the height direction; and is connected to the two electric cylinders on the platform base in a straight line to form a triangle;

[0013] The lifting and lowering electric cylinder is arranged on the transverse and pitching platform, and its free end supports the lifting and lowering platform to form the lifting and lowering freedom degree, and forms three degrees of freedom in series with the two electric cylinders.

[0014] Preferably, the two electric cylinders and a column are connected to each other in a straight line on the platform base to form an isosceles right triangle.

[0015] The above scheme is adopted in order to maximize the area of ​​the roll platform and optimize the calculation of the compensation amount of the roll angle.

[0016] Preferably, the column is at a right angle point of an isosceles right triangle.

[0017] Preferably, the three-degree-of-freedom series-parallel heave compensation platform further includes:

[0018] The cylindrical truss is inserted on the transverse and longitudinal roll platform along the height direction, and has a truss chamber on the cylindrical truss, which extends along the height direction and opens upward. The lifting and lowering electric cylinder is installed on the lower surface of the truss chamber, and its free end extends along the height direction and protrudes out of the cylindrical truss.

[0019] The purpose of adopting the above scheme is that the truss chamber in the cylindrical truss can accommodate the lifting and lowering electric cylinder, thereby saving the volume of the lifting and lowering electric cylinder, effectively lowering the center of gravity of the lifting and lowering platform, and ensuring the stability of the lifting and lowering platform.

[0020] Preferably, the three-degree-of-freedom series-parallel heave compensation platform further includes:

[0021] The guide rails all extend in the height direction and are inserted between the transverse and longitudinal rolling platforms and the heave platforms.

[0022] Furthermore, the number of the guide rails is four, and they are evenly inserted between the roll and pitch platforms and the heave platforms.

[0023] The purpose of adopting the above scheme is that the four guide rails can balance the load of the lifting and lowering platform, which not only eliminates the influence of the lifting and lowering platform's force points being concentrated at the center of the lifting and lowering platform, but also eliminates the horizontal force component generated when bearing.

[0024] Preferably, the lower surface of the cylindrical truss is close to the upper surface of the platform base.

[0025] Preferably, the lower surface of the guide rail is close to the upper surface of the platform base.

[0026] Preferably, a reserved standard threaded hole is provided on the heave platform.

[0027] The above scheme is adopted in order to make it easier to install other marine engineering equipment, such as sensors, by using the reserved standard threaded holes based on the three-degree-of-freedom series-parallel form of the compensation platform.

[0028] Preferably, the two electric cylinders serve as the first electric cylinder and the second electric cylinder respectively.

[0029] A three-degree-of-freedom series-parallel heave compensation method, implemented by the above platform, comprises the following steps:

[0030] Step 1: The first electric cylinder is used to compensate for the rolling motion of the ship, and the straight line formed between the first electric cylinder and the column, that is, one right-angled side of the isosceles right triangle, is used as the rolling axis of the ship. The second electric cylinder is used to compensate for the pitching motion of the ship, that is, the straight line formed between the second electric cylinder and the column, that is, the other right-angled side of the isosceles right triangle, is used as the pitching axis of the ship;

[0031] Step 2: With the hinged point between the column and the roll and pitch platform as a fulcrum, the roll axis of the ship is rolled and deflected by the extension and retraction of the first electric cylinder, and the pitch axis of the ship is rolled and deflected by the extension and retraction of the second electric cylinder;

[0032] Step 3: When the roll is turned, the first electric cylinder needs to be extended or shortened to keep the roll platform horizontal; when the pitch is turned, the second electric cylinder needs to be extended or shortened to keep the roll platform horizontal;

[0033] Step 4 is based on step 3, and the extension and contraction amount of the heave electric cylinder is obtained through the heave amount of the ship to compensate for the heave freedom movement of the ship.

[0034] Preferably, in step 3, when the first electric cylinder is at rest, the original length of the first electric cylinder is L, and the original length is the length of the free end of the first electric cylinder when it is extended out of the first electric cylinder without being extended;

[0035] According to the anti-clockwise deflection angle of the ship's roll, the first electric cylinder needs to push the roll and pitch platform to deflect clockwise to compensate for the angle. At this time, the length of the free end of the first electric cylinder after extension is L1, and the extension of the first electric cylinder can be calculated as L1-L;

[0036] According to the clockwise deflection angle of the ship's roll, the first electric cylinder pulls the roll platform to deflect counterclockwise by a compensation angle when it contracts. The shortened length of the free end of the first electric cylinder is L2, so the shortening amount of the first electric cylinder can be calculated as L-L2.

[0037] Preferably, the counterclockwise deflection compensation method of the pitch is the same as the counterclockwise deflection compensation method of the roll, and the clockwise deflection compensation method of the pitch is the same as the clockwise deflection compensation method of the roll.

[0038] Preferably, after the roll or pitch deflection compensation of the roll platform, the roll platform remains absolutely horizontal, at which time the free end of the first electric cylinder and the free end of the second electric cylinder and the top surface of the column along the height direction are on the same horizontal plane; the change in the heave direction of the ship is multiplied by negative one, thereby achieving compensation of a single degree of freedom in the heave direction.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. Because the compensation platform in the present invention includes a platform base fixedly installed on the ship, the platform base has a height direction, the roll platform is arranged above the platform base along the height direction, and the two electric cylinders, whose fixed ends are both hinged to the platform base, and the free ends of the two electric cylinders are both extended along the height direction and jointly hinged to the roll platform, and are used to be connected in parallel on the roll platform to form roll freedom;

[0041] The lifting and lowering electric cylinder is arranged on the transverse and longitudinal roll platform, and its free end supports the lifting and lowering platform, which is used to form the lifting and lowering degrees of freedom, and three degrees of freedom formed in series with the two electric cylinders; the purpose is to adjust the platform structure to series-parallel degrees of freedom, which can reduce the number of driving rods, thereby avoiding the four-cylinder hyperstatic structure commonly seen in the prior art, and will not have errors caused by control accuracy, thereby avoiding the problem that the four groups of connecting parts above the telescopic oil cylinder in the prior art cannot be accurately maintained in the same plane, thereby causing the warping of the working plane where the working platform is located and the abnormal stress state of each group of telescopic oil cylinders, which may even directly lead to the overall failure of the wave compensation device, reducing or avoiding potential threats to the life safety and equipment of personnel on the working platform.

[0042] 2. Because the three-degree-of-freedom series-parallel wave compensation platform in the present invention also includes a column, which is fixed on the platform base, and the length of the column in the height direction is constant, and it is hinged to the lower surface of the roll platform along the height direction; and it is connected to each other in a straight line with two electric cylinders on the platform base to form a triangle, and the two electric cylinders and a column are connected to each other in a straight line on the platform base to form an isosceles right triangle, and the column is at the right angle point of the isosceles right triangle; the purpose is to determine the maximum area of ​​the roll platform within the rectangular installation plane of the platform base, and optimize the calculation of the compensation amount of the roll angle.

[0043] 3. Because the three-degree-of-freedom series-parallel wave compensation platform in the present invention also includes a cylindrical truss, which is inserted on the transverse and longitudinal roll platform along the height direction, and the cylindrical truss is provided with a truss chamber, which extends along the height direction and opens upward, and the lifting and sinking electric cylinder is installed on the lower surface of the truss chamber, and its free end extends along the height direction and protrudes out of the cylindrical truss, so as to save the volume of the lifting and sinking electric cylinder, effectively lower the center of gravity of the platform, and ensure the stability of the platform structure.

[0044] 4. Because the three-degree-of-freedom series-parallel wave compensation platform in the present invention also includes guide rails, all of which extend in the height direction and are inserted between the roll and pitch platforms and the heave platforms, the purpose is to balance the load of the heave platform, which not only eliminates the influence of the force point of the heave platform being concentrated at the center of the heave platform, but also eliminates the horizontal component force generated when bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a structural schematic diagram of the compensation platform in the present invention;

[0046] Figure 2 It is a schematic diagram of the principle of establishing the ship's roll axis and the ship's pitch axis in the present invention;

[0047] Figure 3 It is a schematic diagram of the compensation method in the present invention;

[0048] Figure 4 It is a side view of the compensation platform in the present invention.

[0049] In the figure: platform base 1, transverse and longitudinal shaking platform 201, cylindrical truss 202, truss chamber 2021, column 203, first electric cylinder 204, second electric cylinder 205, lifting and lowering platform 301, lifting and lowering electric cylinder 302, guide rail 303. DETAILED DESCRIPTION

[0050] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is specifically described in the following embodiments in conjunction with the accompanying drawings. It should be noted that the description of these implementation methods is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0051] like Figure 1-4 As shown, a three-degree-of-freedom series-parallel wave compensation platform includes a platform base 1 fixedly mounted on a ship, the platform base 1 has a height direction H, and the platform base 1 has a rectangular mounting plane along the height direction H, and the upper surface of the platform base 1 is surrounded by a fence, and the fence has a gap. When the platform base 1 is installed at the installation location of large marine equipment on the ship, it is mainly connected by rigid connection, such as bolts, and universal wheels are installed at the bottom of the platform base 1 to facilitate the movement of the entire platform;

[0052] The horizontal and vertical shaking platform 201 is arranged above the platform base 1 along the height direction H.

[0053] Two electric cylinders, namely the first electric cylinder 204 and the second electric cylinder 205, each of which has a fixed end hinged to the platform base 1, and the free ends of the two electric cylinders extend along the height direction H and are jointly hinged to the transverse and pitch platform 201, so as to form transverse and pitch degrees of freedom in parallel on the transverse and pitch platform 201;

[0054] The cylindrical truss 202 is inserted on the roll platform 201 along the height direction H, and the lower surface of the cylindrical truss 202 is close to the upper surface of the platform base 1; specifically, the cylindrical truss 202 is inserted at the center of gravity of the roll platform 201 along the height direction H; and the cylindrical truss 202 has a truss chamber 2021, which extends along the height direction H and opens upward, and the lifting and lowering electric cylinder 302 is installed on the lower surface of the truss chamber 2021, and its free end extends along the height direction H and protrudes out of the cylindrical truss 202;

[0055] The lifting and lowering electric cylinder 302 is arranged on the transverse and pitching platform 201. Specifically, the truss chamber 2021 in the cylindrical truss 202 can accommodate the lifting and lowering electric cylinder 302, thereby saving the volume of the lifting and lowering electric cylinder 302, effectively lowering the center of gravity of the lifting and lowering platform 301, and ensuring the stability of the lifting and lowering platform 302;

[0056] The free end of the lifting and lowering electric cylinder 302 supports the lifting and lowering platform 301, which is used to form the lifting and lowering freedom degree, and forms three degrees of freedom in series with the two electric cylinders;

[0057] A column 203 is fixed on the platform base 1, and the length of the column 203 in the height direction H is constant, and is hinged to the lower surface of the pan-tilt platform 201 along the height direction H; and is connected to each other on the platform base 1 with two electric cylinders to form a triangle in a straight line, specifically: two electric cylinders and a column 203 are connected to each other on the platform base 1 to form an isosceles right triangle in a straight line, and the column 203 is at the right angle of the isosceles right triangle; the purpose is to maximize the area of ​​the pan-tilt platform 201 and optimize the calculation of the compensation amount of the pan-tilt angle, as follows:

[0058] The compensation method of this platform is as follows: when the platform base 1 moves in the three directions of heave, roll and pitch following the ship, the preset measurement and control system on the ship can measure the movement of the three degrees of freedom of the ship in real time, and resolve it into the extension of the electric cylinder, and send a control signal to the wave compensation platform. Among them, the measurement and control system collects the movement of the three degrees of freedom of the ship through sensors such as accelerometers and gyroscopes, and after signal processing and control algorithm calculation, generates a control signal for the electric cylinder of the compensation platform, and controls the extension and retraction of the electric cylinder to maintain the stability of the platform. At the same time, the system also monitors the compensation effect to ensure that the platform is in a balanced state. According to the control instructions issued by the measurement and control system, wave compensation is carried out in the following steps:

[0059] (1) First, the roll platform 201 is passed through the roll angle and pitch angle of the ship to inversely solve the elongation of the first electric cylinder 204 and the second electric cylinder 205 to compensate for the roll and pitch two-degree-of-freedom motion of the ship. Specifically, (2) The roll and pitch two-degree-of-freedom motion compensation method is: the isosceles right angle side length of the roll platform 201 is installed in a manner that the roll axis and pitch axis of the ship are collinear. The installation principle diagram is shown in the figure. Figure 2 As shown; the first electric cylinder 204 is used to compensate for the ship's rolling motion, specifically, the straight line formed between the first electric cylinder 204 and the column 203, that is, one right-angled side of the isosceles right triangle, is used as the ship's rolling axis, and the second electric cylinder 205 is used to compensate for the ship's pitching motion, that is, the straight line formed between the second electric cylinder 205 and the column 203, that is, the other right-angled side of the isosceles right triangle, is used as the ship's pitching axis. Take the first electric cylinder 204 as an example: the hinge between the column 203 and the roll and pitch platform 201 is used as a fulcrum, and the first electric cylinder 204 is extended and retracted to achieve the roll deflection of the ship's roll axis. When the roll deflection is achieved, in order to keep the roll and pitch platform level, the first electric cylinder 204 needs to be extended or shortened, as shown in FIG. Figure 3As shown: when the first electric cylinder 204 is not extended or retracted, the original length of the first electric cylinder 204 is L, which is the length of the first electric cylinder 204 when the free end is not extended. According to the roll angle of the ship, such as 15°, the first electric cylinder 204 needs to push the roll platform 201 to deflect 15° clockwise for angle compensation. At this time, the length of the free end of the first electric cylinder 204 after extension is L1, so the extension amount of the first electric cylinder 204 can be calculated as L1-L.

[0060] According to the clockwise deflection angle of the ship's roll, the first electric cylinder 204 pulls the roll platform 201 to deflect counterclockwise to a compensation angle, such as 15°, when it contracts. The length of the free end of the first electric cylinder 204 after shortening is L2, so the shortening amount of the first electric cylinder 204 can be calculated as L-L2. Similarly, when the ship is in a pitching motion, the second electric cylinder 205 is extended or shortened, which can also compensate for the pitching motion;

[0061] Secondly, on the basis of completing the roll or pitch compensation of the ship, the elongation of the heave electric cylinder 302 is inversely solved through the heave amount of the ship to compensate for the heave freedom movement of the ship; specifically, the heave single degree of freedom movement compensation method is: after the roll and pitch platform 201 compensation is completed, the roll and pitch platform 201 remains absolutely horizontal; therefore, it is only necessary to multiply the change in the heave direction of the ship by negative one, which is the elongation of the heave electric cylinder 302; for example, if the ship rises 300mm, the heave electric cylinder changes -300mm, that is, it drops 300mm, thereby achieving compensation for the single degree of freedom in the heave direction;

[0062] The guide rails 303 all extend in the height direction H and are inserted between the roll platform 201 and the heave platform 301; and the lower surface of the guide rails 303 is close to the upper surface of the platform base 1; specifically, there are four guide rails 303, which are evenly inserted between the roll platform 201 and the heave platform 301; the four guide rails 303 can balance the load of the heave platform 301, which not only eliminates the influence of the force point of the heave platform 301 being concentrated at the center of the heave platform 301, but also eliminates the horizontal force component generated when carrying;

[0063] A reserved standard threaded hole is provided on the heave platform 301; through the reserved standard threaded hole, it is possible to more conveniently install other marine engineering equipment, such as sensors, etc., by utilizing the compensation platform on the basis of the three-degree-of-freedom series-parallel form.

[0064] The above-mentioned implementation modes are preferred cases of the present invention and are not used to limit the protection scope of the present invention. Various deformations or modifications that can be made by ordinary technicians in this field without creative work within the scope of the attached claims are still within the protection scope of this patent.

Claims

1. A three-degree-of-freedom series-parallel wave compensation platform, comprising a platform base fixedly mounted on a ship, the platform base having a height direction, characterized in that: Also includes, The horizontal and vertical shaking platform is located above the platform base in the height direction. Two electric cylinders, whose fixed ends are both hinged to the platform base, and whose free ends extend in the height direction and are jointly hinged to the transverse and pitch platform, so as to be connected in parallel on the transverse and pitch platform to form transverse and pitch degrees of freedom; A column is fixed on the platform base, and the length of the column in the height direction is constant, and the column is hinged to the lower surface of the pan-tilt platform in the height direction; and is connected to the two electric cylinders on the platform base in a straight line to form a triangle; The lifting and lowering electric cylinder is arranged on the transverse and pitching platform, and its free end supports the lifting and lowering platform to form the lifting and lowering freedom degree, and forms three degrees of freedom in series with the two electric cylinders.

2. A three-degree-of-freedom series-parallel heave compensation platform according to claim 1, characterized in that: The two electric cylinders and a column are connected to each other in a straight line on the platform base to form an isosceles right triangle.

3. A three-degree-of-freedom series-parallel heave compensation platform according to claim 2, characterized in that: The column is located at the right angle point of the isosceles right triangle.

4. A three-degree-of-freedom series-parallel heave compensation platform according to claim 3, characterized in that: The three-degree-of-freedom series-parallel wave compensation platform also includes: The cylindrical truss is inserted on the transverse and longitudinal roll platform along the height direction, and has a truss chamber on the cylindrical truss, which extends along the height direction and opens upward. The lifting and lowering electric cylinder is installed on the lower surface of the truss chamber, and its free end extends along the height direction and protrudes out of the cylindrical truss.

5. A three-degree-of-freedom serial-parallel heave compensation platform according to claim 4, characterized in that: The three-degree-of-freedom series-parallel wave compensation platform also includes: The guide rails all extend in the height direction and are inserted between the transverse and longitudinal rolling platforms and the heave platforms.

6. A three-degree-of-freedom serial-parallel heave compensation platform according to claim 5, characterized in that: The number of the guide rails is four, and they are evenly inserted between the roll and pitch platforms and the heave platforms.

7. The three-degree-of-freedom series-parallel heave compensation platform according to claim 1, characterized in that: The two electric cylinders serve as a first electric cylinder and a second electric cylinder respectively.

8. A three-degree-of-freedom series-parallel heave compensation method, implemented by the platform described in claims 1-7, characterized in that: The following steps are involved: Step 1: The straight line formed between the first electric cylinder and the column, that is, one right-angled side of the isosceles right triangle, is used as the ship's roll axis, and the straight line formed between the second electric cylinder and the column, that is, the other right-angled side of the isosceles right triangle, is used as the ship's pitch axis; Step 2: With the hinged point between the column and the roll and pitch platform as a fulcrum, the roll axis of the ship is rolled and deflected by the extension and retraction of the first electric cylinder, and the pitch axis of the ship is rolled and deflected by the extension and retraction of the second electric cylinder; Step 3: When the roll is turned, the first electric cylinder needs to be extended or shortened to keep the roll platform horizontal; when the pitch is turned, the second electric cylinder needs to be extended or shortened to keep the roll platform horizontal; Step 4 is based on step 3, and the extension and contraction amount of the heave electric cylinder is obtained through the heave amount of the ship to compensate for the heave freedom movement of the ship.

9. The compensation method according to claim 8, characterized in that: In step 3, when the first electric cylinder is at rest, the original length of the first electric cylinder is L, which is the length of the free end when it is extended out of the first electric cylinder without being extended; According to the anti-clockwise deflection angle of the ship's roll, the first electric cylinder needs to push the roll and pitch platform to deflect clockwise to compensate for the angle. At this time, the length of the free end of the first electric cylinder after extension is L1, and the extension of the first electric cylinder can be calculated as L1-L; According to the clockwise deflection angle of the ship's roll, the first electric cylinder pulls the roll platform to deflect counterclockwise by a compensation angle when it contracts. The shortened length of the free end of the first electric cylinder is L2, so the shortening amount of the first electric cylinder can be calculated as L-L2.

10. The compensation method according to claim 8, characterized in that: After the roll or pitch deflection compensation of the roll platform, the roll platform remains absolutely horizontal. At this time, the free end of the first electric cylinder and the free end of the second electric cylinder and the top surface of the column along the height direction are on the same horizontal plane; the change in the heave direction of the ship is multiplied by negative one, thereby realizing the compensation of single degree of freedom in the heave direction.

Images