Measuring device and measuring method for stable center position of ship

Abstract

The invention relates to the technical field of ship steady center measurement, and discloses a ship steady center position measuring device and method, and the device comprises a base disposed on a keel of a ship, a guide mechanism disposed on the base, and a measuring table disposed on the guide mechanism in a sliding manner. A suspension point is arranged on the measuring table, a pendulum bob is connected to the suspension point through a cycloid, a speed sensor is arranged in the pendulum bob, and the speed sensor is used for acquiring the speed and acceleration of the pendulum bob during swinging; when the measuring table slides along the guide mechanism, the sliding direction of the suspension point is perpendicular to the datum plane of the keel, operation is easy and convenient, the stable center height of the ship can be rapidly determined, and safety evaluation of the ship can be completed easily.

Description

Technical Field

[0001] The present invention relates to the technical field of ship metacentric measurement, and in particular to a device and method for measuring the metacentric position of a ship. Background Art

[0002] When replacing equipment on a ship, if the volume, weight and installation position of the new equipment are basically the same as those of the old equipment, the center of gravity and metacentricity of the ship will basically not change, and will not affect the safety performance of the original ship. If the volume, weight and installation position of the new equipment are different from the old equipment being removed, the center of gravity and metacentricity of the ship may basically change, and may even affect the safety performance of the original ship. Therefore, it is necessary to measure the changes in the center of gravity and metacentricity of the ship before and after the equipment is replaced to evaluate the safety of the ship after the equipment is replaced.

[0003] The height of the center of gravity when the ship is unloaded is determined by the structure of the hull, so it is a fixed value for a particular ship. Generally speaking, after the ship is loaded with cargo, if the position of the cargo and the height of the center of gravity of the cargo relative to the ship do not change, the position of the center of gravity relative to the ship will not change either.

[0004] The center of buoyancy refers to the equivalent point of buoyancy. When an object is placed in a fluid, the pressure of the fluid on the upper and lower contact surfaces is different, with the upper surface being smaller and the lower surface being larger, so a pressure difference is generated, and the object is then subjected to the vertical upward pressure of the fluid, that is, the buoyancy of the fluid. The position of the center of buoyancy of a ship refers to the position of the center of gravity of the displaced fluid when the ship floats on the water. If the geometric shape of the displaced fluid is regular, then the center of buoyancy is at the original geometric center of the displaced fluid. The position of the center of buoyancy of a ship is determined by the external contour of the ship underwater. Unfortunately, the external contour of a ship is not a simple regular body, so the position of the center of buoyancy is not easy to measure by simple methods and usually requires more complex calculations.

[0005] The metacentricity of a ship refers to the center of curvature of the ship's buoyancy center curve. The intersection of the buoyancy lines of the ship when it is floating upright and when it is slightly tilted is called the "metacentricity", and the distance between the metacentricity and the ship's center of gravity is called the "metacentric height". Since the center of buoyancy of a ship is not easy to measure directly, it is also difficult to determine the metacentricity directly. Summary of the invention

[0006] The object of the present invention is to provide a device and method for measuring the metacentric position of a ship, aiming to solve or improve at least one of the above-mentioned technical problems.

[0007] To achieve the above object, the present invention provides the following solution: The present invention provides a device for measuring the metacentric position of a ship, comprising a base arranged on the keel of the ship, a guide mechanism arranged on the base, and a measuring platform slidably arranged on the guide mechanism;

[0008] The measuring platform is provided with a suspension point, the suspension point is connected to a pendulum via a cycloid, a velocity sensor is provided inside the pendulum, and the velocity sensor is used to obtain the velocity and acceleration of the pendulum when it is swinging;

[0009] When the measuring platform slides along the guide mechanism, the sliding direction of the suspension point is perpendicular to the reference plane of the keel.

[0010] Optionally, the guiding mechanism comprises a pair of positioning rods, the positioning rods are fixedly connected to the base via fasteners, the positioning rods are perpendicular to a reference plane of the keel, and the measuring platform is slidably connected to the pair of positioning rods.

[0011] Optionally, a pair of first through holes is opened on the measuring platform, and the pair of first through holes is arranged one by one on a pair of positioning rods, and a first locking piece is arranged between the first through holes and the positioning rods.

[0012] Optionally, it further includes a fixing plate, which is provided with a pair of second through holes, the pair of second through holes are arranged one by one on a pair of positioning rods, and a second locking piece is arranged between the second through holes and the positioning rods.

[0013] Optionally, a digital inclinometer is provided on the measuring platform.

[0014] Optionally, a digital ultrasonic rangefinder is provided on the measuring platform.

[0015] Optionally, a plurality of level adjustment members are provided on the bottom surface of the base.

[0016] Optionally, a level is provided on the base.

[0017] A method for measuring a ship metacentric position, comprising:

[0018] The measuring device is arranged at the keel of the ship;

[0019] When the ship shakes, the pendulum swings, and the measuring platform slides along the guide mechanism so that the pendulum swings at different heights. When the velocity and acceleration obtained by the velocity sensor in the pendulum are close to zero, the suspension point is located at the metacenter of the ship.

[0020] Optionally, when the measuring platform is slid along the guide mechanism, it slides from the top of the positioning rod toward the base, and the speed and acceleration amplitude of the pendulum first decrease to approximately zero, and then gradually increase. The measuring platform is adjusted to the position where the speed and acceleration amplitude of the pendulum are minimum, and at this time, the suspension point is located at the metacenter of the ship. Alternatively, the speed and acceleration amplitude of the pendulum always gradually increase, and the height of the base is raised, and the sliding from the top of the positioning rod toward the base is repeated until the position where the speed and acceleration amplitude of the pendulum are minimum is obtained, and at this time, the suspension point is located at the metacenter of the ship.

[0021] The present invention discloses the following technical effects: when a ship shakes, the pendulum also shakes, so that by adjusting the height position of the measuring platform on the guide mechanism, the height position of the suspension point and the pendulum are adjusted, and the speed and acceleration of the pendulum at different height positions are obtained by a speed sensor. When the speed and acceleration obtained by the speed sensor in the pendulum are close to zero, at this time, the suspension point is located at the metacenter of the ship. The operation is simple and convenient, and the metacenter height of the ship can be quickly determined, which is helpful to complete the safety assessment of the ship. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1 It is a schematic diagram of the measuring device of the present invention;

[0024] Figure 2 It is a schematic diagram of the suspension points of the present invention being located above and below the metacenter.

[0025] In the figure: 1. base; 2. measuring table; 3. hanging point; 4. cycloid; 5. pendulum; 6. positioning rod; 7. fastener; 8. first locking piece; 9. fixing plate; 10. second locking piece; 11. digital inclinometer; 12. digital ultrasonic rangefinder; 13. horizontal adjustment piece; 14. spirit level; 15. median vertical line; K. reference point; B. center of gravity. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Reference Figure 1-Figure 2 The present invention provides a device for measuring the metacentric position of a ship, comprising a base 1 arranged on the keel of the ship, a guide mechanism arranged on the base 1, and a measuring platform 2 slidably arranged on the guide mechanism;

[0029] A suspension point 3 is provided on the measuring platform 2, and a pendulum 5 is connected to the suspension point 3 through a cycloid 4. A velocity sensor is provided inside the pendulum 5, and the velocity sensor is used to obtain the velocity and acceleration of the pendulum 5 when it is swinging;

[0030] When the measuring platform 2 slides along the guide mechanism, the sliding direction of the suspension point 3 is perpendicular to the reference plane of the keel.

[0031] When the ship shakes, the pendulum 5 also shakes, so the height position of the suspension point 3 and the pendulum 5 is adjusted by adjusting the height position of the measuring platform 2 on the guide mechanism, and the speed sensor is used to obtain the speed and acceleration of the pendulum 5 at different height positions. When the speed and acceleration obtained by the speed sensor in the pendulum 5 are close to zero, the suspension point 3 is located at the metacenter of the ship. The operation is simple and convenient, and the metacenter height of the ship can be quickly determined, which is helpful to complete the safety assessment of the ship.

[0032] Furthermore, the speed sensor can send the measured speed and acceleration data to the mobile phone via WIFI or the like.

[0033] Furthermore, no matter where the suspension point 3 is located on the perpendicular midline 15 of the datum plane of the keel, when the ship tilts slightly, the pendulum 5 will deviate from the datum point K of the datum plane of the keel. When the tilt angle of the ship is the same, the higher the suspension point 3 is, the greater the distance that the pendulum 5 deviates from the datum point K. According to the definition of the metacenter B, when the suspension point 3 does not coincide with the metacenter B, the suspension point 3 will swing in an arc with the swaying of the ship. When the suspension point 3 is above the metacenter B, the suspension point 3 is at the highest point of the swing arc when the ship is balanced; when the suspension point 3 is below the metacenter B, the suspension point 3 is at the lowest point of the swing arc when the ship is balanced. Only when the suspension point 3 coincides with the metacenter B, although the datum point K will swing on both sides of the pendulum 5, the suspension point 3 will still remain basically motionless.

[0034] like Figure 2As shown, the suspension point 3 is located above the metacenter B. When the ship shakes, the pendulum 5 will also shake with it, and the shaking amplitude is large; the position of the suspension point 3 is gradually lowered, and the swing amplitude of the pendulum 5 gradually decreases; when the suspension point 3 coincides with the metacenter B, the pendulum 5 hardly shakes. The position of the suspension point 3 is further lowered, and the swing amplitude of the pendulum 5 gradually increases. By monitoring the swing of the pendulum 5 at different suspension positions through the speed sensor, it can be determined whether the suspension point coincides with the metacenter B position, thereby determining the metacenter position of the ship.

[0035] In a further optimized solution, the guide mechanism includes a pair of positioning rods 6, which are fixedly connected to the base 1 by fasteners 7, and the positioning rods 6 are perpendicular to the reference plane of the keel, and the measuring platform 2 is slidably connected to the pair of positioning rods 6. A pair of first through holes are opened on the measuring platform 2, and the pair of first through holes are set on the pair of positioning rods 6 one by one, and a first locking member 8 is provided between the first through holes and the positioning rods 6.

[0036] The first locking member 8 is a locking bolt, which can fix the height position of the measuring platform 2 on the pair of positioning rods 6 .

[0037] A further optimized solution also includes a fixing plate 9 , which is provided with a pair of second through holes. The pair of second through holes are one-by-one arranged on a pair of positioning rods 6 , and a second locking piece 10 is arranged between the second through holes and the positioning rods 6 .

[0038] The second locking member 10 is a locking bolt, which can fix the position of the fixing plate 9 on the pair of positioning rods 6 , and the fixing plate 9 can ensure the stability of the pair of positioning rods 6 .

[0039] To further optimize the solution, a digital inclinometer 11 is provided on the measuring platform 2 .

[0040] Digital inclinometer 11 can display the inclination of the measuring platform and the horizontal plane

[0041] To further optimize the solution, a digital ultrasonic rangefinder 12 is provided on the measuring platform 2 .

[0042] The digital ultrasonic distance meter 12 can display the distance between the measuring platform 2 and the upper surface of the base 1, that is, the distance between the suspension point 3 and the base 1, so as to determine the metacentric height.

[0043] According to a further optimized solution, a plurality of horizontal adjustment members 13 are provided on the bottom surface of the base 1 .

[0044] The horizontal adjustment member 13 is an adjustment nut, which can adjust the base 1 to be horizontal or tilted.

[0045] According to a further optimized solution, a level 14 is provided on the base 1 .

[0046] A method for measuring a ship metacentric position, comprising:

[0047] The measuring device is set at the keel of the ship; when the ship is not shaking, the horizontal adjustment member 13 is adjusted to make the pendulum 5 just above the reference point K. At this time, the reading of the digital inclinometer 11 on the measuring platform 2 is zero, and the speed and acceleration of the pendulum 5 are approximately zero;

[0048] When the ship shakes, the pendulum 5 swings and the measuring platform 2 slides along the guide mechanism so that the pendulum 5 swings at different heights. When the speed sensor in the pendulum 5 obtains a speed and acceleration close to zero, the suspension point 3 is located at the metacenter of the ship.

[0049] When the measuring platform 2 is slid along the guide mechanism, it slides from the top of the positioning rod 6 toward the base 1, and the speed and acceleration change amplitude of the pendulum 5 first decrease to approximately zero, and then gradually increase. The measuring platform 2 is adjusted to the position where the speed and acceleration amplitude of the pendulum 5 are the smallest. At this time, the suspension point 3 is located at the metacenter of the ship. Alternatively, the speed and acceleration change amplitude of the pendulum 5 always gradually increase. Then, the height of the base 1 is raised, and the sliding from the top of the positioning rod 6 toward the base 1 is repeated until the position where the speed and acceleration amplitude of the pendulum 5 are the smallest is obtained. At this time, the suspension point 3 is located at the metacenter of the ship.

[0050] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "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 invention, 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 invention.

[0051] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A device for measuring the metacentric position of a ship, characterized in that: It comprises a base (1) arranged on the keel of a ship, a guide mechanism arranged on the base (1), and a measuring platform (2) slidably arranged on the guide mechanism; The measuring platform (2) is provided with a suspension point (3), the suspension point (3) is connected to a pendulum (5) via a cycloid (4), a velocity sensor is provided inside the pendulum (5), and the velocity sensor is used to obtain the velocity and acceleration of the pendulum (5) when it is swinging; When the measuring platform (2) slides along the guide mechanism, the sliding direction of the suspension point (3) is perpendicular to the reference plane of the keel.

2. A device for measuring the metacentric position of a ship according to claim 1, characterized in that: The guide mechanism comprises a pair of positioning rods (6), the positioning rods (6) are fixedly connected to the base (1) via fasteners (7), the positioning rods (6) are perpendicular to the reference plane of the keel, and the measuring platform (2) is slidably connected to the pair of positioning rods (6).

3. A device for measuring the metacentric position of a ship according to claim 2, characterized in that: The measuring platform (2) is provided with a pair of first through holes, the pair of first through holes are arranged one by one on a pair of positioning rods (6), and a first locking piece (8) is arranged between the first through holes and the positioning rods (6).

4. A device for measuring the metacentric position of a ship according to claim 2, characterized in that: It also includes a fixing plate (9), on which a pair of second through holes are opened. The pair of second through holes are arranged one by one on the pair of positioning rods (6), and a second locking piece (10) is arranged between the second through holes and the positioning rods (6).

5. The device for measuring the metacentric position of a ship according to claim 1, characterized in that: The measuring platform (2) is provided with a digital display inclinometer (11).

6. The device for measuring the metacentric position of a ship according to claim 1, characterized in that: A digital ultrasonic rangefinder (12) is provided on the measuring platform (2).

7. The device for measuring the metacentric position of a ship according to claim 1, characterized in that: The bottom surface of the base (1) is provided with a plurality of horizontal adjustment members (13).

8. The device for measuring the metacentric position of a ship according to claim 1, characterized in that: A level (14) is provided on the base (1).

9. A ship metacentric position measurement method, based on a ship metacentric position measurement device according to any one of claims 1 to 8, characterized in that: include: The measuring device is arranged at the keel of the ship; When the ship shakes, the pendulum (5) swings, and the measuring platform (2) slides along the guide mechanism, so that the pendulum (5) swings at different heights. When the velocity and acceleration obtained by the velocity sensor in the pendulum (5) are close to zero, the suspension point (3) is located at the metacenter of the ship.

10. A ship metacentric position measurement method according to claim 9, characterized in that: When the measuring platform (2) is slid along the guide mechanism, it slides from the top of the positioning rod (6) toward the base (1), and the speed and acceleration change amplitude of the pendulum (5) first decrease to approximately zero, and then gradually increase. The measuring platform (2) is adjusted to the position where the speed and acceleration amplitude of the pendulum (5) are minimum. At this time, the suspension point (3) is located at the metacenter of the ship. Alternatively, if the speed and acceleration change amplitude of the pendulum (5) always gradually increase, the height of the base (1) is raised, and the sliding from the top of the positioning rod (6) toward the base (1) is repeated until the position where the speed and acceleration amplitude of the pendulum (5) are minimum is obtained. At this time, the suspension point (3) is located at the metacenter of the ship.

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