Device and method for measuring buoyancy and stability of a floating body

Abstract

This invention belongs to the technical field of buoyancy performance testing and measurement. It discloses a buoyancy and stability measuring device and method for a buoy. The measuring device specifically comprises: a fixed platform connected to a support; a first telescopic mechanism connected vertically to the fixed platform, with its bottom connected to an intermediate platform; a connecting rod, a second telescopic mechanism, and a third telescopic mechanism connected vertically below the intermediate platform; a moving platform connected to the bottom of the connecting rod, with its bottom rotatably connected to the moving platform; the second telescopic mechanism rotatably connected to the moving platform and movable along the y-axis; the third telescopic mechanism rotatably connected to the moving platform and movable along the x-axis; and the moving platform is fixedly connected to the buoy. This invention, through the ingenious and reasonable arrangement of the three telescopic mechanisms, allows for arbitrary coupling of the buoy's roll angle, pitch angle, and draft through linear motion, thereby achieving high-precision simulation of various buoyancy states.

Description

Technical Field

[0001] This invention belongs to the technical field of buoyancy performance testing and measurement, and more specifically, relates to a buoyancy and stability measuring device and method for buoyancy. Background Technology

[0002] The relationship between the weight and buoyancy acting on a floating body determines its buoyancy and stability. Buoyancy characterizes how a floating body maintains a certain buoyancy under various load conditions (measured by draft d, heel angle φ, and pitch angle). The performance of a floating body (characterized by its shape) is characterized by its stability, which reflects its ability to resist external forces and return to its original equilibrium position. As the most fundamental overall performance characteristic of a floating body, buoyancy and stability can be characterized by the displacement volume curve, the center of buoyancy coordinate curve, and the stability cross-section curve, as well as their derived curves. The displacement volume curve is a curve corresponding to a certain heel angle φ and pitch angle... The curve showing the relationship between the drainage volume (▽) and draft (d) of the lower type; the buoyancy center coordinate curve is a curve corresponding to a certain heel angle (φ) and pitch angle (d). The lower center of buoyancy x-direction coordinates x B , y-coordinate of the center of buoyancy B , z-coordinate of the center of buoyancy B The relationship curve between draft (d) and transverse stability is represented by the dip angle. Without changing the position, a set of lateral shape stability levers l corresponding to a certain lateral tilt angle φ td The relationship curve between the type of drainage volume ▽; the longitudinal stability cross-sectional curve is a set of curves corresponding to a certain longitudinal angle when the lateral inclination angle φ remains constant. Longitudinal shape stability lever l ld The relationship curve between the displacement volume ▽ and the buoyancy. The buoyancy and stability analysis of a floating body is the process of solving the above four characteristic curves, and it is also a basic premise for the design of various floating bodies, represented by ships.

[0003] Currently, the buoyancy and stability analysis of floating bodies is mainly based on geometric methods. Starting from Archimedes' principle, the geometric method transforms the calculation of buoyancy into the calculation of the volume of water displaced by the floating body, thus being an indirect method. However, when the waterline of the analyzed object is not a single simply connected domain, the geometric method faces multiple challenges in model partitioning, accuracy, and self-checking, making it difficult to implement conventional geometric analysis methods for complex floating body configurations. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a buoyancy and stability measurement device and method for a floating body, which solves the problem that the current analysis of the buoyancy and stability of floating bodies is mainly based on geometric methods, and conventional geometric analysis methods are difficult to implement for floating bodies with complex configurations. The present invention realizes the experimental measurement of the buoyancy and stability performance of the floating body.

[0005] To achieve the above objectives, according to one aspect of the present invention, a buoyancy and stability measuring device for a floating body is provided, comprising a support, a fixed platform, a first telescopic mechanism, an intermediate platform, a connecting rod, a second telescopic mechanism, a third telescopic mechanism, a moving platform, and a water tank. The fixed platform is connected above the support, the first telescopic mechanism is vertically connected to the fixed platform, and the bottom of the first telescopic mechanism is connected to the intermediate platform.

[0006] The connecting rod, the second telescopic mechanism, and the third telescopic mechanism are respectively connected vertically below the intermediate platform. The motion platform is connected to the bottom of the connecting rod, the second telescopic mechanism, and the third telescopic mechanism. The bottom of the connecting rod is omnidirectionally connected to the motion platform. The second telescopic mechanism is omnidirectionally connected to the motion platform and movable along the y-axis. The third telescopic mechanism is omnidirectionally connected to the motion platform and movable along the x-axis. The x-axis is perpendicular to the y-axis. The motion platform is fixedly connected to the float. A water tank is provided below the float.

[0007] The buoyancy and stability measuring device for a floating body provided by the present invention further includes a six-component force gauge, which is connected between the bottom of the first telescopic mechanism and the intermediate platform.

[0008] According to the buoyancy and stability measuring device of the present invention, the first telescopic mechanism and the connecting rod are arranged in the same vertical direction, the connecting rod and the second telescopic mechanism are arranged in the same y-axis direction, and the connecting rod and the third telescopic mechanism are arranged in the same x-axis direction.

[0009] The buoyancy and stability measuring device for a floating body provided by the present invention further includes a test table, which is located near the water tank. The fixed platform is connected to the support through a moving mechanism, and the test table is located within the displacement range of the moving mechanism.

[0010] According to another aspect of the present invention, a method for measuring the buoyancy and stability of a float is provided, based on the buoyancy and stability measuring device for a float as described in any of the preceding claims, the measuring method comprising:

[0011] The float is fixedly connected to the bottom of the motion platform. The attitude of the float is adjusted by adjusting at least one of the first telescopic mechanism, the second telescopic mechanism and the third telescopic mechanism, and then the buoyancy and stability performance indicators of the float are measured.

[0012] Specifically, the first telescopic mechanism is adjusted to adjust the draft of the float in the pool, the second telescopic mechanism is adjusted to change the lateral tilt angle of the float, and the third telescopic mechanism is adjusted to change the longitudinal tilt angle of the float.

[0013] According to the buoyancy and stability measurement method of the present invention, the heel angle of the buoy is:

[0014]

[0015] Where, d L2 L represents the change in length of the second telescopic mechanism. AB d is the distance between point A, the intersection of the connecting rod and the intermediate platform, and point B, the intersection of the second telescopic mechanism and the intermediate platform; L2 The positive and negative values ​​correspond to the extension and retraction of the second telescopic mechanism, respectively;

[0016] The longitudinal tilt angle of the buoy is:

[0017]

[0018] Where, d L3 L represents the change in length of the third telescopic mechanism. AC d is the distance between point A, the intersection of the connecting rod and the intermediate platform, and point C, the intersection of the third telescopic mechanism and the intermediate platform; L3 The positive and negative values ​​correspond to the extension and shortening of the third telescopic mechanism, respectively;

[0019] The draft of the buoy is:

[0020]

[0021] Among them, F z The force in the z-direction at the current underwater force reference point is defined as follows: the z-axis is perpendicular to both the x-axis and y-axis, and is set vertically; ρ is the density of still water in the pool; g is the acceleration due to gravity; and s is the surface area of ​​the pool. The extension of the first telescopic mechanism after the bottom of the float contacts the still water surface.

[0022] According to the buoyancy and stability measurement method of the present invention, the measurement of the buoyancy and stability performance indicators of the buoyancy body specifically includes:

[0023] S1.1, Adjust the float to the tilt and pitch angles corresponding to the specified working condition, and keep them unchanged;

[0024] S1.2, Move the float along the z-axis until the distance between its lowest point and the still water surface is 0, wherein the z-axis is perpendicular to the x-axis and y-axis respectively and the z-axis is set in the vertical direction;

[0025] S1.3 After zeroing the six-component force gauge, begin moving the float downwards to measure and obtain the force F in the z-direction at the force reference point. z The relationship curve between draft and d;

[0026] S1.4, based on the force method analysis of the drainage volume and the force F in the z-direction at the force measurement reference point. z Based on the relationship between the two, obtain the displacement volume curve of the floating body;

[0027] The force method described in S1.4 is based on:

[0028]

[0029] Where ρ is the density of the still water in the pool, g is the acceleration due to gravity, and ∠F is the acceleration due to gravity. z These represent the displacement volume of the buoy corresponding to the current draft d and the force in the z-direction at the force measurement reference point, respectively.

[0030] The method for measuring the buoyancy and stability of a float according to the present invention further includes measuring the buoyancy and stability performance indicators of the float, and further comprising:

[0031] S2.11, Adjust the float to the tilt and pitch angles corresponding to the specified working condition, and keep them unchanged;

[0032] S2.12, Move the float along the z-axis until the distance between its lowest point and the still water surface is 0, wherein the z-axis is perpendicular to the x-axis and y-axis respectively and the z-axis is set in the vertical direction;

[0033] S2.13, After zeroing the six-component force gauge, begin moving the float downwards and measure the force F in the z-direction at the force reference point. z With bending moment M about the x-axis x The relationship curve between the two curves;

[0034] S2.14, Keeping the pitch angle constant, continuously change the roll angle, repeating steps S2.11 to S2.13 until a set of F values ​​corresponding to a certain roll angle φ is obtained. z With M x The relationship curve between the two is used to obtain the transverse stability curve of the floating body based on the force method analysis;

[0035] Alternatively, S2.21, the float is adjusted to the tilt and pitch angles corresponding to the upright buoyancy or the specified operating condition, and kept unchanged;

[0036] S2.22, Move the float along the z-axis until the distance between its lowest point and the still water surface is 0, wherein the z-axis is perpendicular to the x-axis and y-axis respectively and the z-axis is set in the vertical direction;

[0037] S2.23, After zeroing the six-component force gauge, begin moving the float downwards and measure the force F in the z-direction at the force reference point. z With bending moment M about the y-axis y The relationship curve between the two curves;

[0038] S2.24, Keeping the heel angle constant, continuously change the pitch angle, repeating steps S2.21 to S2.23 until a set of values ​​corresponding to a certain pitch angle is obtained. F z With M y The relationship curve between the two is used to obtain the longitudinal stability cross section curve of the floating body based on the force method analysis.

[0039] According to the buoyancy and stability measurement method of the floating body provided by the present invention, the force method described in S2.14 is based on:

[0040]

[0041] Where: ρ is the density of the still water in the pool, g is the acceleration due to gravity, and l td M x F z ▽ and ∠d represent the lateral shape stability lever arm corresponding to the current draft d, the moment about the x-axis at the force reference point, the z-direction force at the force reference point, and the displacement volume of the shape, respectively.

[0042] The force method described in S2.24 is based on:

[0043]

[0044] Where ρ is the density of the still water in the pool, g is the acceleration due to gravity, and l ld M y F z ▽ and ∠d represent the longitudinal shape stability lever arm corresponding to the current draft d, the moment about the y-axis at the force reference point, the force in the z-direction at the force reference point, and the displacement volume, respectively.

[0045] The method for measuring the buoyancy and stability of a float according to the present invention further includes measuring the buoyancy and stability performance indicators of the float, and further comprising:

[0046] S3.1, Adjust the float to the tilt and pitch angles corresponding to the specified working condition, and keep them unchanged;

[0047] S3.2, Move the float along the z-axis until the distance between its lowest point and the still water surface is 0, wherein the z-axis is perpendicular to the x-axis and y-axis respectively and the z-axis is set in the vertical direction;

[0048] S3.3 After zeroing the six-component force gauge, begin moving the float downwards and measure the force F in the z-direction at the force reference point. z Bending moment M about the x-axis x Bending moment M about the y-axis y Three relationship curves between draft d;

[0049] S3.4, the coordinate curve of the buoyancy center is obtained based on the force method analysis.

[0050] According to the buoyancy and stability measurement method of the present invention, the force method described in S3.4 is based on:

[0051]

[0052] Where, x B y B z B These are the global coordinate values ​​of the buoyancy center in the x, y, and z directions, respectively. R and y R M represents the global coordinates of the force measurement reference point in the x and y directions, respectively. x M y F z ▽ represents the bending moment about the x-axis, bending moment about the y-axis, force in the z-direction, and displacement volume at the force reference point corresponding to the current draft d, respectively; z is the current global z-coordinate value corresponding to the micro-volume d▽ on the floating body; dF z F is the value corresponding to the infinitesimal volume d▽ z Change value.

[0053] According to the buoyancy and stability measurement method of the present invention, the coordinate of the center of buoyancy of the buoy on the z-axis of the global coordinate system is z. B Specifically:

[0054] z B =H-d+z A ;

[0055]

[0056] Where H is the global coordinate system height of the water surface at the current draft d, and z A Let be the coordinate value of the center of buoyancy of the floating body in the z-direction of the local coordinate system, where the origin of the local coordinate system is located at the lowest point of the floating body, and d i Let the draft be a series of consecutive test points, starting from a draft of 0 and ending at the current draft d, where d0 = 0 and d...n =d,F z (d i ) corresponds to draft d i Force F in the z-direction at the force measurement reference point z .

[0057] In summary, compared with the prior art, the buoyancy and stability measuring device and method provided by this invention offer the following advantages:

[0058] 1. The system is equipped with a first telescopic mechanism, a second telescopic mechanism, and a third telescopic mechanism. Through the ingenious and reasonable arrangement of these three telescopic mechanisms, the system can achieve precise control and adjustment of the downward displacement, lateral tilt angle, and longitudinal tilt angle of the moving platform and the floating body through linear motion. This allows the lateral tilt angle, longitudinal tilt angle, and draft of the floating body to be arbitrarily coupled, thereby achieving high-precision simulation of various floating states of the floating body. This system can be used to measure the buoyancy and stability performance of the floating body.

[0059] 2. The bottom of the connecting rod is omnidirectionally connected to the motion platform, which allows for precise control of the lateral and longitudinal tilt rotation points of the float that is rigidly connected to the motion platform. This improves the accuracy of float attitude adjustment and, consequently, the accuracy of performance measurement.

[0060] 3. The local measurement coordinate system at the internal force reference point of the six-component force measuring instrument is set to be parallel to the global coordinate system during the measurement process, which ensures the direct measurement of force and torque at the force reference point in the global coordinate system and avoids the conversion of measurement results to the global coordinate system.

[0061] 4. A force method and specific analysis steps for buoyancy and stability analysis are proposed. Based on this force method, the force and torque measurement results at the force reference point under various floating states of the floating body can be used to analyze and obtain the displacement volume curve, stability cross section curve and buoyancy center coordinate curve of the floating body, thereby completing the buoyancy and stability analysis of the floating body. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the buoyancy and stability measuring device for a floating body provided by the present invention;

[0063] Figure 2 This is a top view of the motion platform provided by the present invention;

[0064] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0065] 1-Fixed platform; 2-Moving mechanism; 3-Support; 4-First telescopic mechanism; 5-Six-component force gauge; 6-Intermediate platform; 7-Connecting rod; 8-Second telescopic mechanism; 9-Third telescopic mechanism; 10-Universal hinge mechanism; 11-Motion platform; 12-Second telescopic mechanism bottom y-axis sliding mechanism; 13-Third telescopic mechanism bottom x-axis sliding mechanism; 14-Float; 15-Water tank; 15-1-Leak-proof base; 16-Debugging table. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0067] like Figure 1 and Figure 2 As shown, the present invention provides a buoyancy and stability measuring device for a floating body. The measuring device includes a support 3, a fixed platform 1, a first telescopic mechanism 4, an intermediate platform 6, a connecting rod 7, a second telescopic mechanism 8, a third telescopic mechanism 9, a moving platform 11, and a water tank 15. The fixed platform 1 is connected above the support 3. The first telescopic mechanism 4 is vertically connected to the fixed platform 1, and the bottom of the first telescopic mechanism 4 is connected to the intermediate platform 6.

[0068] The connecting rod 7, the second telescopic mechanism 8, and the third telescopic mechanism 9 are respectively connected vertically below the intermediate platform 6. The motion platform 11 is connected to the bottom of the connecting rod 7, the second telescopic mechanism 8, and the third telescopic mechanism 9. The bottom of the connecting rod 7 is omnidirectionally connected to the motion platform 11. The second telescopic mechanism 8 is omnidirectionally connected to the motion platform 11 and movable along the y-axis. The third telescopic mechanism 9 is omnidirectionally connected to the motion platform 11 and movable along the x-axis. The x-axis is perpendicular to the y-axis. The motion platform 11 is fixedly connected to the float 14. A water tank 15 is provided below the float 14.

[0069] The measuring device is equipped with three telescopic mechanisms, which can extend and retract along their own length with controllable extension and retraction. The extension and retraction of the second telescopic mechanism 8 can respectively cause the motion platform 11 to tilt in either the forward or reverse direction around the x-axis parallel axis, with the rotation point fixed at the bottom of the connecting rod 7, moving with the movement of the bottom of the connecting rod 7. The extension and retraction of the third telescopic mechanism 9 can respectively cause the motion platform 11 to tilt in either the forward or reverse direction around the y-axis parallel axis, with the rotation point fixed at the bottom of the connecting rod 7, moving with the movement of the bottom of the connecting rod 7. The extension and retraction of the first telescopic mechanism 4 can adjust the draft of the float 14 in the water tank 15. Furthermore, the linear movement of the three telescopic mechanisms can adjust and control the attitude of the float 14, which can then be used to measure the buoyancy and stability performance of the float 14.

[0070] The buoyancy and stability measuring device provided by this invention includes a first telescopic mechanism, a second telescopic mechanism, and a third telescopic mechanism. Through the ingenious and reasonable arrangement of these three telescopic mechanisms, precise control and adjustment of the downward displacement, yaw angle, and pitch angle of the moving platform and the float can be achieved through linear motion. This allows for arbitrary coupling of the float's yaw angle, pitch angle, and draft, thereby enabling high-precision simulation of various floating states of the float and facilitating the measurement of the float's buoyancy and stability performance. Furthermore, the bottom of the connecting rod is omnidirectionally connected to the moving platform, allowing for precise control of the yaw and pitch rotation points of the float, which is rigidly connected to the platform. This improves the accuracy of float attitude adjustment and, consequently, the accuracy of performance measurement.

[0071] Furthermore, the buoyancy and stability measuring device for the floating body also includes a six-component force gauge 5, which is connected between the bottom of the first telescopic mechanism 4 and the intermediate platform 6.

[0072] Furthermore, the first telescopic mechanism 4 and the connecting rod 7 are arranged in the same vertical direction, the connecting rod 7 and the second telescopic mechanism 8 are arranged in the same y-axis direction, and the connecting rod 7 and the third telescopic mechanism 9 are arranged in the same x-axis direction.

[0073] Furthermore, the buoyancy and stability measuring device for the float also includes a test table 16, which is located near the water tank 15. The fixed platform 1 is connected to the support 3 via a moving mechanism 2, and the test table 16 is located within the displacement range of the moving mechanism 2.

[0074] refer to Figure 1 and Figure 2The present invention provides a buoyancy and stability measuring device for a floating body. The measuring device includes a fixed platform 1, a moving mechanism 2, a support 3, a first telescopic mechanism 4, a six-component force gauge 5, an intermediate platform 6, a connecting rod 7, a second telescopic mechanism 8, a third telescopic mechanism 9, a universal hinge mechanism 10, a moving platform 11, a bottom y-axis sliding mechanism 12 of the second telescopic mechanism, a bottom x-axis sliding mechanism 13 of the third telescopic mechanism, a floating body 14, a water tank 15, and a test table 16.

[0075] Combination Figure 1 In order to better describe the relative relationships between the various devices and components, the measuring device needs to be placed in the global coordinate system Oxyz. This coordinate system conforms to the right-hand rule, with its positive z-axis pointing vertically upwards, and the origin fixed at the intersection of the bottom of the pool 15 and the extension line of the first telescopic mechanism 4.

[0076] Combination Figure 1 The bottom surface of the fixed platform 1 is rigidly connected to the support 3 through the moving mechanism 2. For example, the debugging table 16 and the water tank 15 can be set along the x-direction. The fixed platform 1 can move and lock along the x-direction on the support 3, which is achieved by the fixed platform x-direction moving mechanism 2. Specifically, the fixed platform 1 moves and locks along the x-direction on the support 3 through the x-direction track and locking mechanism. The purpose is to realize the movement of the fixed platform 1 between the test position and the debugging position. The fixed platform x-direction moving mechanism 2 is a slider-rail mechanism with a locking structure. The support 3 is horizontally fixed on the ground to ensure the stability of the fixed platform 1.

[0077] Combination Figure 1 The top of the first telescopic mechanism 4 is rigidly connected to the fixed platform 1, and the bottom is rigidly connected to the top of the six-component force measuring instrument 5, ensuring the complete transmission of force and torque among the three. The function of the first telescopic mechanism 4 is to generate telescopic movement in the z direction, which ultimately drives the motion platform 11 of the device to generate the same z-direction displacement.

[0078] Combination Figure 1 The bottom of the six-component force gauge 5 is rigidly connected to the intermediate platform 6. The measurement coordinate system O1x1, O1y1, and O1z1 axes at its internal force reference point are parallel to the Ox, Oy, and Oz axes of the global coordinate system, respectively. Moreover, the origin of the measurement coordinate system and the origin of the global coordinate system are located in the same z-axis direction, ensuring that the force and torque obtained at the force reference point do not require further transformation to the global coordinate system, thus realizing direct measurement of the force situation at the force reference point in the global coordinate system. At the same time, the six-component force gauge 5 only undergoes z-direction displacement with the first telescopic mechanism 4, ensuring that the internal measurement coordinate system of the six-component force gauge 5 will never form an angle with the global coordinate system, thus ensuring that the six-component force gauge 5 is always in the optimal working state.

[0079] Combination Figure 1 The upper surface of the intermediate platform 6 is rigidly connected to the bottom of the six-component force measuring instrument 5, ensuring the complete transmission of force and torque between the intermediate platform 6 and the six-component force measuring instrument 5.

[0080] Combination Figure 1 The bottom of the intermediate platform 6 is rigidly connected to the top of the connecting rod 7, the top of the second telescopic mechanism 8, and the top of the third telescopic mechanism 9, respectively, ensuring that the latter three will not rotate around the intermediate platform 6 and can transmit complete force and torque to the intermediate platform 6.

[0081] Combination Figure 1 and Figure 2 The bottom of the connecting rod 7 is connected to the motion platform 11 via a universal hinge mechanism 10, and the length of the connecting rod 7 remains unchanged. The connecting rod 7 cannot transmit bending moment to the motion platform 11. The connecting rod 7 and the first telescopic mechanism 4 are kept on the same vertical line, i.e., in the same vertical direction. While the bottom of the second telescopic mechanism 8 is connected to the motion platform 11 via the universal hinge mechanism 10, its bottom can also slide in the yOz plane on the motion platform 11 via the y-axis sliding mechanism 12 at the bottom of the second telescopic mechanism. While the bottom of the third telescopic mechanism 9 is connected to the motion platform 11 via the universal hinge mechanism 10, its bottom can also slide in the xOz plane on the motion platform 11 via the x-axis sliding mechanism 13 at the bottom of the third telescopic mechanism. The sliding mechanism at the bottom can be implemented by a slider-slide rail. For example, a slide rail-slider sliding structure can be set to achieve a sliding connection, and a universal rotational connection with the motion platform 11 can be achieved through the universal hinge connection between the corresponding telescopic mechanism and the corresponding slider.

[0082] When the intersection point of connecting rod 7 and intermediate platform 6 is A, the intersection point of second telescopic mechanism 8 and intermediate platform 6 is B, and the intersection point of third telescopic mechanism 9 and intermediate platform 6 is C, the following relationship exists between the three intersection points: AB is parallel to the y-axis, AC is parallel to the x-axis, and AB is perpendicular to AC; the bottom y-axis sliding mechanism 12 of the second telescopic mechanism is arranged along AB, and the bottom x-axis sliding mechanism 13 of the third telescopic mechanism is arranged along AC.

[0083] Combination Figure 1 A preferred embodiment of the first telescopic mechanism 4, the second telescopic mechanism 8, and the third telescopic mechanism 9 includes a motor, a Z-axis screw, a nut, and a controller. The controller controls the motor to rotate, which drives the screw to rotate in the fixed nut to generate controllable Z-axis movement, thereby achieving controllable extension or shortening of the entire telescopic mechanism.

[0084] In another preferred embodiment, the telescopic mechanism includes a motor, a z-axis linear guide rail, a slider, a z-axis connecting rod, and a controller. The top of the connecting rod is rigidly connected to the slider. The controller drives the slider to slide in the z-axis direction on the guide rail via the motor to achieve the overall controllable extension or shortening of the telescopic mechanism.

[0085] In another preferred embodiment, the telescopic mechanism includes a manual adjuster, a graduated Z-axis screw, a nut, and a self-locking mechanism. The adjuster drives the screw to rotate in the fixed nut and self-locks to generate controllable Z-axis movement. The self-locking mechanism can be a structure that locks and fixes the position of the manual adjuster, thereby realizing the overall controllable extension or shortening of the telescopic mechanism.

[0086] In another preferred embodiment, the telescopic mechanism includes a manual adjuster, a graduated Z-axis linear guide rail, a slider, a self-locking mechanism, and a Z-axis connecting rod. The top of the connecting rod is rigidly connected to the slider, allowing manual adjustment of the slider's Z-axis sliding on the guide rail and self-locking to achieve controllable extension or shortening of the entire telescopic mechanism.

[0087] Combination Figure 1 The universal joint mechanism 10 at the bottom of the connecting rod 7, the second telescopic mechanism 8, and the third telescopic mechanism 9 can be a ball joint or a universal joint.

[0088] Combination Figure 1 The bottom y-axis sliding mechanism 12 of the second telescopic mechanism and the bottom x-axis sliding mechanism 13 of the third telescopic mechanism are slider-rail structures. The bottom of the motion platform 11 is rigidly connected to the float 14 by more than three bolts.

[0089] Furthermore, the present invention also provides a method for measuring the buoyancy and stability of a floating body, based on the buoyancy and stability measuring device for a floating body described in any of the above embodiments, the measurement method comprising:

[0090] The float 14 is fixedly connected to the lower part of the motion platform 11. The attitude of the float 14 is adjusted by adjusting at least one of the first telescopic mechanism 4, the second telescopic mechanism 8 and the third telescopic mechanism 9, and then the buoyancy and stability performance indicators of the float 14 are measured.

[0091] Specifically, the first telescopic mechanism 4 is adjusted to adjust the draft of the float 14 in the water tank 15, the second telescopic mechanism 8 is adjusted to change the lateral tilt angle of the float 14, and the third telescopic mechanism 9 is adjusted to change the longitudinal tilt angle of the float 14.

[0092] Combination Figure 1 and Figure 2 When the second telescopic mechanism 8 extends or retracts independently, since the lengths of the connecting rod 7 and the third telescopic mechanism 9 remain unchanged, and the bottoms of the latter two are universally hinged to the motion platform 11, the second telescopic mechanism 8 will cause its bottom motion platform 11 to tilt around the AC line, i.e., the x-axis. The tilt angle control equation is:

[0093]

[0094] In the formula, d L2 L represents the change in length of the second telescopic mechanism 8. AB d is the distance between point A, the intersection of connecting rod 7 and intermediate platform 6, and point B, the intersection of second telescopic mechanism 8 and intermediate platform 6; L2 The positive and negative values ​​correspond to the extension and retraction of the second telescopic mechanism 8, respectively.

[0095] Combination Figure 1 and Figure 2 When the third telescopic mechanism 9 extends or retracts independently, since the lengths of the connecting rod 7 and the second telescopic mechanism 8 remain unchanged, and the bottoms of the latter two are universally hinged to the motion platform 11, the third telescopic mechanism 9 will cause its bottom motion platform 11 to tilt around the line AB, i.e., the y-axis. The control equation for the tilt angle is:

[0096]

[0097] In the formula, d L3 L represents the change in length of the third telescopic mechanism 9. AC d is the distance between point A, the intersection of connecting rod 7 and intermediate platform 6, and point C, the intersection of third telescopic mechanism 9 and intermediate platform 6; L3 The positive and negative values ​​correspond to the extension and retraction of the third telescopic mechanism 9, respectively.

[0098] Combination Figure 1 and Figure 2 When the second telescopic mechanism 8 and the third telescopic mechanism 9 extend and retract simultaneously, since they can slide in the y and x directions on the motion platform 11 respectively, they can drive the motion platform 11 to generate a specified coupled lateral tilt and longitudinal tilt around the intersection point A of the connecting rod 7 and the motion platform 11; and the motion platform 11 can generate a displacement in the z direction as the first telescopic mechanism 4 extends and retracts.

[0099] Combination Figure 1 The bottom of the motion platform 11 is rigidly connected to the float 14. This rigid connection is achieved by more than three bolts. The float 14 moves with the motion platform 11, rotating about the x-axis parallel axis, rotating about the y-axis parallel axis, and moving along the z-axis parallel axis. The intersection of the above three parallel axes is the rotation point. The rotation point is the same as the rotation point A of the motion platform 11. It is fixed to the bottom of the connecting rod 7 and moves with the movement of the connecting rod 7 in the z direction.

[0100] Combination Figure 1 The water tank 15 is located below the float 14 and is used to simulate still water after being filled with water. The draft d of the float 14 is changed by the z-axis movement of the float 14 when it is submerged in the water. The draft is defined as the distance from the lowest point of the float 14 to the water surface. The draft d of the float 14 in the water tank 15 is calculated by the following formula:

[0101]

[0102] In the formula, F z Let ρ be the force in the z-direction at the current underwater force reference point, ρ be the density of the still water in pool 15, g be the acceleration due to gravity, and s be the surface area of ​​the water in pool 15. This refers to the extension of the first telescopic mechanism 4 after the bottom of the float 14 contacts the still water surface; the current draft d can also be directly measured by the scale on the float 14.

[0103] The water tank 15 is equipped with a leak-proof base 15-1, which is used to support the water tank 15 and to store overflow.

[0104] Thus, the structure of this invention can simulate any floating state of the float 14, including the heel angle, pitch angle, and draft.

[0105] The debugging table 16 is located on one side of the pool 15 and is placed within the range that the fixed platform 1 can reach by moving in the x direction. It is used to place the float 14 and assist in completing the connection between the float 14 and the moving platform 11.

[0106] The fixed platform 1, the fixed platform x-axis moving mechanism 2, and the support 3 enable the overall device to move and be fixed between the test position and the debugging position; the first telescopic mechanism 4 is used to drive the motion platform 11 to generate controllable displacement in the z-direction; the six-component force gauge 5 is kept consistent with the global coordinate system and is used to measure the force state at the force measurement point; the second telescopic mechanism 8, in conjunction with the intermediate platform 6, the connecting rod 7, the universal hinge mechanism 10, and the y-axis sliding mechanism 12 at the bottom of the second telescopic mechanism, enables the motion platform 11 to rotate controllably in the x-direction around a specified rotation point; the third telescopic mechanism 9, in conjunction with the intermediate platform 6, the connecting rod 7, and the... The universal joint mechanism 10 and the bottom x-axis sliding mechanism 13 of the third telescopic mechanism cooperate to achieve controllable y-direction rotation of the motion platform 11 around a specified rotation point; the motion platform 11 is rigidly connected to the float 14 and cooperates with the still water surface in the pool 15 to achieve precise control of the float 14's floating state, including heel, trim, and draft; by applying the testing device proposed in this invention, the force state of the force measurement points under a series of different floating state combinations is obtained through specified steps, and by combining the force methods of buoyancy and stability, the characterization curves of ship buoyancy and stability, including the displacement volume curve, the stability cross section curve, and the buoyancy center coordinate curve, can be completed respectively. The measurement method of the curves is described in detail below.

[0107] Compared to geometric methods, the measuring device and method provided by this invention are not subject to the aforementioned limitations through experimental methods. They can adapt to the analysis needs of various complex waterplane area configurations of floating bodies and are also an important means of verifying the results of geometric method analysis. Therefore, analyzing the buoyancy and stability of floating bodies through experimental means has significant practical implications.

[0108] 1. Measurement of Displacement Volume Curve of Floating Body Type 14 Based on Force Method

[0109] When measuring the displacement volume curve of the buoy type 14 using the measuring device proposed in this invention, the following steps are included:

[0110] S1.1 Adjust the float 14 to the tilt and pitch angles corresponding to the upright buoyancy or the specified working condition, and keep them unchanged. Generally speaking, the displacement volume curve refers to the curve of displacement volume with draft in the upright buoyancy state. It can also measure the curve of displacement volume with draft of float 14 in the specified tilt and pitch states.

[0111] S1.2, move the float 14 along the z direction until the distance between its lowest point and the still water surface is 0, in order to facilitate the determination of the draft d;

[0112] S1.3 After zeroing the six-component force gauge 5, ensure that the force measured when the draft is 0 is also 0, then start moving the float 14 downwards and measure the force F in the z-direction at a force reference point. z The relationship curve between draft and d;

[0113] S1.4, the displacement volume curve of the floating body type 14 is obtained based on the force method analysis. The analysis principle is based on the following formula:

[0114]

[0115] In the formula, ρ is the density of the still water in pool 15, g is the acceleration due to gravity, and ∠F is the acceleration due to gravity. z These are the displacement volume of the float type 14 corresponding to the current draft d and the force in the z direction at the force measurement reference point, respectively. Combining the above relationship with the relationship curve measured in step 1.3, we can obtain the relationship curve between the displacement volume ▽ and the draft d, which is the displacement volume curve of the float type 14.

[0116] 2. Measurement of stability cross-section curve based on force method

[0117] The stability cross-section generally includes a transverse stability cross-section and a longitudinal stability cross-section. When measuring the stability cross-section of the float 14 using the measuring device proposed in this invention, the following steps are included:

[0118] S2.11, Adjust the float 14 to the upright position or the heel and pitch angles corresponding to the specified working condition, and keep them unchanged;

[0119] S2.12, Move the float 14 along the z direction until the distance between its lowest point and the still water surface is 0;

[0120] S2.13, after zeroing the six-component force measuring instrument 5, begin to move the float 14 downwards and measure the force F in the z-direction at a force measurement reference point. z With bending moment M about the x-axisx The relationship curve between the two curves;

[0121] S2.14, Keeping the pitch angle constant, continuously change the roll angle, repeating steps S2.11 to S2.13 until a set of F values ​​corresponding to a certain roll angle φ is obtained. z With M x The relationship curve between the two is obtained from the force method analysis, which yields the transverse stability curve of buoy 14. The analysis principle is based on the following formula:

[0122]

[0123] In the formula, ρ is the density of the still water in pool 15, g is the acceleration due to gravity, and l td M x F z ▽ and ∠d represent the lateral shape stability lever arm corresponding to the current draft d, the moment about the x-axis at the force reference point, the force in the z-direction at the force reference point, and the displacement volume, respectively. Combining these relationships with the relationship curve measured in step 2.13, we can obtain the pitch angle. Without changing the position, a set of lateral shape stability levers l corresponding to a certain lateral tilt angle φ td The relationship curve between the drainage volume ▽ and the transverse stability curve;

[0124] S2.21, Raise the float 14 to leave the water surface, adjust the float 14 to the upright position or the heel and pitch angles corresponding to the specified working condition, and keep them unchanged;

[0125] S2.22, Move the float 14 along the z direction until the distance between its lowest point and the still water surface is 0;

[0126] S2.23, after zeroing the six-component force measuring instrument 5, begin to move the float 14 downwards and measure the force F in the z-direction at a force measurement reference point. z With bending moment M about the y-axis y The relationship curve between the two curves;

[0127] S2.24, Keeping the heel angle constant, continuously change the pitch angle, repeating steps S2.21 to S2.23 until a set of values ​​corresponding to a certain pitch angle is obtained. F z With M y The relationship curve between the two is obtained from the force method analysis, which yields the longitudinal stability cross-section curve of buoy 14. The analysis principle is based on the following formula:

[0128]

[0129] In the formula, ρ is the density of the still water in pool 15, g is the acceleration due to gravity, and l ld M y Fz ▽ and ∠d represent the longitudinal shape stability lever arm corresponding to the current draft d, the moment about the y-axis at the force reference point, the force in the z-direction at the force reference point, and the displacement volume, respectively. Combining these relationships with the relationship curve measured in step 2.23, we can obtain a set of relationships corresponding to a certain longitudinal angle when the heel angle φ remains constant. Longitudinal shape stability lever l ld The relationship curve between the type of drainage volume ▽ and the longitudinal stability cross section curve.

[0130] 3. Measurement of buoyancy center coordinate curve based on force method

[0131] When measuring the coordinate curve of the center of buoyancy of buoy 14 using the measuring device proposed in this invention, the following steps are included:

[0132] S3.1 Adjust the float 14 to the upright position or the heel and pitch angles corresponding to the specified working condition, and keep them unchanged;

[0133] S3.2, Move the float 14 along the z direction until the distance between the bottom of the float 14 and the still water surface is 0;

[0134] S3.3 After zeroing the six-component force measuring instrument 5, begin to move the float 14 downwards and measure the force F in the z-direction at the force measurement reference point. z Bending moment M about the x-axis x Bending moment M about the y-axis y Three relationship curves between draft d;

[0135] S3.4, The coordinate curve of the center of buoyancy is obtained based on the force method analysis. The analysis principle is as follows:

[0136]

[0137] In the formula, x B y B z B These are the global coordinates of the center of buoyancy of floating body 14 in the x, y, and z directions, respectively, under a given floating state. R and y R M represents the x-coordinate and y-coordinate of the force measuring point, respectively. x M y F z ▽ represent the bending moment about the x-axis, the bending moment about the y-axis, and the force F in the z-direction at the force reference point corresponding to the current draft d, respectively. z The displacement volume is given by z, where z is the current global z-coordinate value corresponding to the micro-volume d▽ on float 14, and dF. z F is the value corresponding to the infinitesimal volume d▽ z The change value; combined with the relationship curve measured in step 3.3, the above relationship can be used to obtain a curve corresponding to a certain heave angle φ and pitch angle. The lower center of buoyancy x-direction coordinates x B , y-coordinate of the center of buoyancy B , z-coordinate of the center of buoyancy B The relationship curve between the draft d and the buoyancy center coordinate curve.

[0138] Specifically, when a local coordinate system of the float 14 is set with its origin at the lowest point of the float 14, the global z-coordinate of the center of buoyancy is z B The numerical value and the local z-coordinate of the floating body 14 A The numerical values ​​of are related as follows:

[0139] z B =H-d+z A ;

[0140] In the formula, H is the global coordinate system height corresponding to the current draft d, and the local z-coordinate of the buoy 14 is z. A The following methods can be used to further obtain the result:

[0141]

[0142] In the formula, d i Let the draft be a series of consecutive test points, starting from a draft of 0 and ending at the current draft d, where d0 = 0 and d... n =d,F z (d i ) corresponds to draft d i Force F in the z-direction at the force measurement reference point z .

[0143] It should be noted that the force F in the x-direction at the force measurement reference point... x Force F in the y direction y and the torque M about the z-axis z All measured values ​​should be zero after taking into account the error caused by the instrument's precision, which is determined by the basic principle of the force method.

[0144] Through the above specific implementation methods, it can be seen that the measuring device proposed in this invention can realize the buoyancy and stability analysis of the float 14 based on the force method.

[0145] To address the challenges faced by existing geometric-based buoyancy and stability analysis methods when dealing with complex floating bodies, this invention proposes a force-based experimental measurement device for buoyancy and stability. This device can achieve high-precision simulation of the floating body's heel, trim, and draft, and measure the force state at a reference point under different combinations of heel, trim, and draft. Furthermore, this invention proposes a corresponding force method to analyze the above data and obtain core curves characterizing buoyancy and stability, such as the shaped displacement volume curve, stability cross-section curve, and buoyancy center coordinate curve.

[0146] Compared with existing methods or technologies, the beneficial technical effects of the present invention are as follows:

[0147] 1) The measuring device proposed in this invention includes a novel mechanism that can independently realize the z-axis movement of its bottom motion platform 11 through the z-axis extension and retraction of its first telescopic mechanism 4; it can achieve precise control of the tilt angle of its bottom motion platform 11 through the simple extension and retraction of its second telescopic mechanism 8 in conjunction with the intermediate platform 6, connecting rod 7, universal hinge mechanism 10, and bottom y-axis sliding mechanism 12 of the second telescopic mechanism; it can achieve precise control of the pitch angle of its bottom motion platform 11 through the simple extension and retraction of its third telescopic mechanism 9 in conjunction with the intermediate platform 6, connecting rod 7, universal hinge mechanism 10, and bottom x-axis sliding mechanism 13 of the third telescopic mechanism; the tilt and pitch rotation point positions of the float 14 rigidly connected to the motion platform 11 can be precisely controlled; the tilt angle, pitch angle, and draft of the float can be arbitrarily coupled, thereby realizing high-precision simulation of various floating states of the float.

[0148] 2) In the measurement process, the local measurement coordinate system O1x1 axis, O1y1 axis and O1z1 axis at the internal force measurement reference point of the six-component force measuring instrument used in this invention are parallel to the Ox axis, Oy axis and Oz axis of the global coordinate system, respectively. This ensures the direct measurement of force and torque at the force measurement reference point in the global coordinate system and avoids the conversion of measurement results to the global coordinate system.

[0149] 3) This invention proposes a force method and specific analysis steps for buoyancy and stability analysis. Based on this force method, the force and torque measurement results at the force reference point under various floating states of the floating body can be used to analyze and obtain the shape displacement volume curve, stability cross section curve and buoyancy center coordinate curve of the floating body, thereby completing the analysis of the buoyancy and stability of the floating body.

[0150] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for measuring the buoyancy and stability of a floating body, characterized in that, It includes a support frame, a fixed platform, a first telescopic mechanism, an intermediate platform, a connecting rod, a second telescopic mechanism, a third telescopic mechanism, a moving platform, and a water tank. The fixed platform is connected above the support frame, the first telescopic mechanism is vertically connected to the fixed platform, and the bottom of the first telescopic mechanism is connected to the intermediate platform. The connecting rod, the second telescopic mechanism, and the third telescopic mechanism are respectively connected vertically below the intermediate platform. The moving platform is connected to the bottom of the connecting rod, the second telescopic mechanism, and the third telescopic mechanism. The bottom of the connecting rod is omnidirectionally connected to the moving platform. The second telescopic mechanism is omnidirectionally connected to the moving platform and movable along the y-axis. The third telescopic mechanism is omnidirectionally connected to the moving platform and movable along the x-axis. The x-axis is perpendicular to the y-axis. The moving platform is fixedly connected to the float. A water tank is provided below the float. It also includes a six-component force gauge, which is connected between the bottom of the first telescopic mechanism and the intermediate platform; The first telescopic mechanism and the connecting rod are arranged in the same vertical direction, the connecting rod and the second telescopic mechanism are arranged in the same y-axis direction, and the connecting rod and the third telescopic mechanism are arranged in the same x-axis direction; It also includes a test table, which is located near the water tank. The fixed platform is connected to the support through a moving mechanism, and the test table is located within the displacement range of the moving mechanism.

2. A method for measuring the buoyancy and stability of a floating body, characterized in that, Based on the buoyancy and stability measuring device of the float as described in claim 1, the measuring method includes: The float is fixedly connected to the bottom of the motion platform. The attitude of the float is adjusted by adjusting at least one of the first telescopic mechanism, the second telescopic mechanism and the third telescopic mechanism, and then the buoyancy and stability performance indicators of the float are measured. Specifically, the first telescopic mechanism is adjusted to adjust the draft of the float in the pool, the second telescopic mechanism is adjusted to change the lateral tilt angle of the float, and the third telescopic mechanism is adjusted to change the longitudinal tilt angle of the float.

3. The method for measuring the buoyancy and stability of a floating body as described in claim 2, characterized in that, The tilt angle of the buoy is: ； in, This represents the change in length of the second telescopic mechanism. The distance between point A, the intersection of the connecting rod and the intermediate platform, and point B, the intersection of the second telescopic mechanism and the intermediate platform; The positive and negative values ​​correspond to the extension and retraction of the second telescopic mechanism, respectively; The longitudinal tilt angle of the buoy is: ； in, The change in length of the third telescopic mechanism. The distance between point A, the intersection of the connecting rod and the intermediate platform, and point C, the intersection of the third telescopic mechanism and the intermediate platform; The positive and negative values ​​correspond to the extension and shortening of the third telescopic mechanism, respectively; The draft of the buoy is: ； in, The force in the z-direction at the current underwater force measurement reference point is defined. The z-axis is perpendicular to both the x-axis and y-axis, and is set along the vertical direction. The density of the still water in the pool is given by [the value of the water]. g It is the acceleration due to gravity. s The water surface area of ​​the pool is [area missing]. The extension of the first telescopic mechanism after the bottom of the float contacts the still water surface.

4. The method for measuring the buoyancy and stability of a floating body as described in claim 2, characterized in that, The measurement of the buoyancy and stability performance indicators of the aforementioned float specifically includes: S1.1, Adjust the float to the tilt and pitch angles corresponding to the specified working condition, and keep them unchanged; S1.2, Move the float along the z-axis until the distance between its lowest point and the still water surface is 0, wherein the z-axis is perpendicular to the x-axis and y-axis respectively and the z-axis is set in the vertical direction; S1.3 After zeroing the six-component force gauge, begin moving the float downwards to measure and obtain the force in the z-direction at the force measurement reference point. With draft d The relationship curve between the two curves; S1.4, based on the force method analysis of the drainage volume and the force in the z-direction at the force measurement reference point. Based on the relationship between the two, obtain the displacement volume curve of the floating body; The force method described in S1.4 is based on: ； in, The density of the still water in the pool. g It is the acceleration due to gravity. and The current draft d The corresponding displacement volume of the floating body and the force in the z-direction at the force measurement reference point.

5. The method for measuring the buoyancy and stability of a floating body as described in claim 2, characterized in that, Measuring the buoyancy and stability performance indicators of the aforementioned float also includes: S2.11, Adjust the float to the tilt and pitch angles corresponding to the specified working condition, and keep them unchanged; S2.12, Move the float along the z-axis until the distance between its lowest point and the still water surface is 0, wherein the z-axis is perpendicular to the x-axis and y-axis respectively and the z-axis is set in the vertical direction; S2.13, After zeroing the six-component force measuring instrument, begin moving the float downwards and measure the force in the z-direction at the force measurement reference point. With and around x Axial bending moment The relationship curve between the two curves; S2.14, Keeping the pitch angle constant, continuously change the roll angle, repeating steps S2.11 to S2.13 until a set of values ​​corresponding to a certain roll angle is obtained. of and The relationship curve between the two is used to obtain the transverse stability curve of the floating body based on the force method analysis; Alternatively, S2.21, the float is adjusted to the tilt and pitch angles corresponding to the upright buoyancy or the specified operating condition, and kept unchanged; S2.22, Move the float along the z-axis until the distance between its lowest point and the still water surface is 0, wherein the z-axis is perpendicular to the x-axis and y-axis respectively and the z-axis is set in the vertical direction; S2.23, After zeroing the six-component force gauge, begin moving the float downwards and measuring the force reference point. z Directional force With and around y Axial bending moment The relationship curve between the two curves; S2.24, Keeping the heel angle constant, continuously change the pitch angle, repeating steps S2.21 to S2.23 until a set of values ​​corresponding to a certain pitch angle is obtained. of and The relationship curve between the two is used to obtain the longitudinal stability cross section curve of the floating body based on the force method analysis.

6. The method for measuring the buoyancy and stability of a floating body as described in claim 5, characterized in that, The force method described in S2.14 is based on: ； in: The density of the still water in the pool is given by [the value of the water]. g It is the acceleration due to gravity. l td , , and The current draft d The corresponding transverse shape stability lever arm, and the force measurement reference point around x Torque on the shaft, at the force reference point z Directional force and drainage volume; The force method described in S2.24 is based on: ； in, The density of the still water in the pool is given by [the value of the water]. g It is the acceleration due to gravity. l ld , , and The current draft d The corresponding longitudinal shape stability lever arm, around the force measurement reference point y Torque on the shaft, at the force reference point z Directional force and drainage volume.

7. The method for measuring the buoyancy and stability of a floating body as described in claim 2, characterized in that, Measuring the buoyancy and stability performance indicators of the aforementioned float also includes: S3.1, Adjust the float to the tilt and pitch angles corresponding to the specified working condition, and keep them unchanged; S3.2, Move the float along the z-axis until the distance between its lowest point and the still water surface is 0, wherein the z-axis is perpendicular to the x-axis and y-axis respectively and the z-axis is set in the vertical direction; S3.3 After zeroing the six-component force gauge, begin moving the float downwards and measuring the force reference points at each point. z Directional force , around x Axial bending moment , around y Axial bending moment With draft d The three relationship curves between them; S3.4, the coordinate curve of the buoyancy center is obtained based on the force method analysis.

8. The method for measuring the buoyancy and stability of a floating body as described in claim 7, characterized in that, in, The force method described in S3.4 is based on: ； in, , , The centers of buoyancy of the buoys are respectively x direction, y direction and z Global coordinates of direction and These are the force measurement reference points. x direction and y Global coordinates of direction , , , The current draft d Around the corresponding force reference point x Axial bending moment, circumference y Axial bending moment, z Directional force and drainage volume, z For the micro-volume on the floating body The corresponding current global z Coordinate values For micro volume Corresponding Change value.

9. The method for measuring the buoyancy and stability of a floating body as described in claim 7, characterized in that, The coordinate of the center of buoyancy of the floating body on the z-axis of the global coordinate system Specifically: ； ； in, H For the current draft of the water surface d The corresponding global coordinate system height, Let the center of buoyancy of the floating body be in the local coordinate system. z The upward coordinate values, where the origin of the local coordinate system is located at the lowest point of the buoy. For a series of consecutive test points, starting from a draft of 0 and up to the current draft. d Finish, , , To correspond to draft At the force measurement reference point z Directional force .

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