Ship berthing wind action measuring and calculating method based on triangular approximation algorithm

Abstract

The invention provides a ship berthing wind effect measuring and calculating method based on a triangular approximation algorithm, and the method comprises the steps: building a ship contour line function and a waterplane equation, and determining a waterplane segmentation position in real time; arranging the vertexes of the ship contour in sequence, calculating the contour wind area on the ship waterline by using a triangular approximation algorithm, and determining the centroid coordinate and centroid height of the ship; and converting the wind speed data into the wind force of the windward action point corresponding to the centroid height by adopting a conversion model. According to the method, the centroid height and the centroid coordinate are calculated firstly, and then the predicted wind or the actually measured wind is converted to the wind speed at the centroid height of the wind area of the ship, so that the wind power and the wind level borne by the ship are judged, and the error of the influence of an anemograph or weather forecast on the actual wind power of the ship is reduced; and taking corresponding measures based on the conversion and analysis results, so as to ensure that the operation ship can timely and accurately make corresponding adjustment in a complex sea condition environment, and ensure that the ship can safely and efficiently carry out related operation.

Description

Technical Field

[0001] The present invention relates to the technical field of wind force conversion when a ship berths or departs, and specifically relates to a method for measuring the wind force on a ship berthing based on a triangle approximation algorithm. Background Art

[0002] When a ship berths or departs, the management department will specifically evaluate the wind force on the ship according to the predicted wind speed and the measured wind speed, which is used to decide whether to stop port operations and whether the ship can depart. Under normal circumstances, the predicted wind speed of the weather forecast is usually used. This predicted wind speed usually refers to the wind at a height of 10 m above the sea surface, and the sea surface is relatively smooth and unobstructed, which is the wind under an ideal state. However, the predicted wind is not the wind at the center of the force on the ship. Another method is to use the measured wind speed on the ship. Usually, the ship anemometer is installed on an unobstructed mast, and the anemometer is often at a position more than 20 m above the sea surface. Wind speed is highly correlated with height. The higher the height, the greater the wind speed. Therefore, using the above two types of wind speeds to measure the wind at the height of the center of the wind force on the ship often has a certain speed deviation. The above-mentioned prior art has the following limitations: First, the prior art lacks a dynamic adjustment mechanism for the real-time operation state of the ship and the external sea conditions, and it is difficult to consider the dynamically changing state of the ship during the actual operation process. Because during the ship operation process, the dynamic characteristics of the hull and the changes in the external environment will cause the ship's waterplane equation to change at any time, which is likely to lead to difficulty in accurately calculating the position of the center of the wind force acting point on the ship. Second, the prior art fails to comprehensively consider the ship's windward area formula and the ship's wind speed height conversion model, so it is difficult to make real-time measurements according to the specific needs of the ship, and it is easy to cause inaccurate estimation of the actual wind force on the ship when berthing or departing in strong wind weather, which will affect the safety of ship operation.

[0003] The record of the above background technical knowledge is intended to help those of ordinary skill in the art understand the prior art relatively close to the present invention, and at the same time facilitate the understanding of the inventive concept and technical solution of the present invention. It should be clear that, in the case where there is no clear evidence indicating that the above content was publicly available before the filing date of this patent application, the above background art should not be used to evaluate the novelty of the technical solution of this application. Summary of the Invention

[0004] Technical Problem Considering the defects of the prior art in this field in the background art, it is necessary to convert the predicted wind speed or the measured wind speed to the wind speed at the centroid position of the ship's windward area, and then use it to judge the wind force on the ship and the wind level, which is used for port loading and unloading operations and departure safety decisions. In addition, the magnitude of this wind force can also be used to calculate the magnitude of the acting force of the wind on the ship and the wind-induced turning moment of the ship.

[0005] Technical Solution To achieve the above object, the inventors of the present application have conducted in-depth research and found that by establishing a waterplane equation, the windward area of the ship and the corresponding centroid height, i.e., the vertical distance between the centroid position and the waterplane, can be calculated in real time according to the draft change, so as to ensure that the ship can still be accurately measured in a harsh port environment, avoid misoperation of ship operations, thereby enhancing the operation safety of the ship, and further effectively preventing potential safety hazards caused by not understanding the specific wind force on the ship. It can also convert the predicted wind or measured wind to the wind speed at the centroid height of the windward area of the ship, and then use it to judge the magnitude of the wind force on the ship and the corresponding wind level, thereby improving the accuracy of the wind force measurement at the acting point of the wind on the ship, reducing the error of the influence of the anemometer or weather forecast on the actual wind force of the ship, and reducing the risk of operation errors. Based on the above conversion and analysis results, corresponding measures are taken to ensure that the operating ship can make timely and accurate adjustments in a complex sea state environment, and ensure the safe and efficient operation of the ship.

[0006] That is, the present invention includes the following technical solutions.

[0007] (1) A method for determining the centroid coordinates or centroid height of a ship berthing based on the triangle approximation algorithm, including: establishing a ship contour line function and a waterplane equation, and determining the waterplane segmentation position in real time; arranging the ship contour vertices in order, and using the triangle approximation algorithm to calculate the windward area of the ship's upper contour on the waterplane, and determining the centroid coordinates or centroid height of the ship.

[0008] Further, the calculation formula for the centroid coordinates is:

[0009] Wherein, is the abscissa of the centroid coordinates; is the ordinate of the centroid coordinates; and are the coordinates of the point in the ship's upper contour coordinate point sequence on the waterplane; and are the coordinates of the point in the ship's upper contour coordinate point sequence on the waterplane; is the total number of contour coordinate points; is the windward area of the ship's upper contour on the waterplane.

[0010] Further, the calculation formula for the centroid height is:

[0011] Wherein, are the positions of the ship's bow and stern water gauges and the real-time readings of the water gauges; are the abscissa and ordinate of the ship's centroid coordinates.

[0012] (2) A method for calculating the wind effect on a ship berthing based on a triangle approximation algorithm includes the following steps: Establish ship contour function and waterplane equation, and determine the waterplane segmentation position in real time; Arrange the vertices of the ship's contour in order, use the triangle approximation algorithm to calculate the windward area of the ship's contour on the waterline, and determine the coordinates and height of the ship's centroid; The conversion model is used to convert the wind speed data to the wind force at the wind-receiving point corresponding to the centroid height.

[0013] Furthermore, the step of establishing the ship contour function includes: Import ship engineering drawing data into the software and establish a rectangular coordinate system to generate a ship contour function .

[0014] Furthermore, the step of establishing the waterplane equation includes: According to the bow water gauge coordinates and the stern water gauge coordinates ,in, and is the position of the ship's fore and aft water gauge relative to the coordinate system The projection abscissa of the axis; is the ship's forward draft reading, is the ship's stern draft reading; Constructing the waterplane equation , where the coefficient are the coefficients given by the general equation of the line, is a constant, Not all zero at the same time; Substitute the bow water gauge coordinates and the stern water gauge coordinates into the waterplane equation , determine the coefficients of the equation.

[0015] Furthermore, the step of arranging the vertices of the ship contour in order and using a triangle approximation algorithm to calculate the windward area of the ship contour on the waterline includes: Waterplane surface equation With contour function Solve the intersection points together and split to obtain the area above the waterline; In the regular shape area containing the ship engineering drawing, the ship outline vertices are arranged in order as , and closed, that is , use the triangle approximation algorithm to calculate the windward area of the ship's waterline contour through the following formula:

[0016] Where A represents the windward area of the ship's waterline contour to be calculated; express The abscissa of the point; denote The abscissa of the point; denote The ordinate of the point; denote The ordinate of the point; denote The ordinate of the point; denote The abscissa of the point.

[0017] Furthermore, the centroid coordinates are calculated by the formula:

[0018] where and are the coordinates of the point in the sequence of profile coordinates of the ship's waterline; and are the coordinates of the point in the sequence of profile coordinates of the ship's waterline; is the total number of profile coordinate points; is the windward area of the ship's waterline profile.

[0019] Furthermore, using the waterplane equation and the centroid coordinates , the vertical distance from the centroid position to the waterplane, i.e., the centroid height is calculated by the following formula:

[0020] where are the positions of the ship's bow and stern draft marks and the real-time draft readings; are the horizontal and vertical coordinates of the ship's centroid position.

[0021] Furthermore, the wind speed data includes predicted wind data and / or measured wind data. The predicted wind data includes: predicted wind speed and predicted wind height ; The measured wind data includes: measured wind speed and measured wind height .

[0022] Furthermore, the conversion model is used to convert the predicted wind speed and / or measured wind speed at a certain height to the equivalent wind speed at the centroid height.

[0023] Furthermore, the equivalent wind speed at the centroid height is obtained according to the following first conversion model, and the formula is as follows:

[0024] Among them, is the equivalent wind speed at the centroid height converted from the predicted wind speed based on the first conversion model; is the predicted wind speed; is the predicted wind height; is the equivalent wind speed at the centroid height converted from the measured wind speed based on the first conversion model; is the measured wind speed; is the measured wind height; is the centroid height; is the ground roughness length.

[0025] Furthermore, the ground roughness length usually takes a value of 0.01 m (relative to the sea surface) Furthermore, the equivalent wind speed at the centroid height is obtained according to the following second conversion model, and the formula is as follows:

[0026] Among them, is the equivalent wind speed at the centroid height converted from the predicted wind speed based on the second conversion model; is the predicted wind speed; is the predicted wind height; is the equivalent wind speed at the centroid height converted from the measured wind speed based on the second conversion model; is the measured wind speed; is the measured wind height; is the centroid height; is the conversion exponent.

[0027] Furthermore, the value range of the conversion exponent α is shown in Table 1: Table 1. Value range of the conversion exponent α

[0028] Furthermore, the value range of the conversion exponent α is 0.1 to 0.25.

[0029] Furthermore, the equivalent wind speed at the centroid height is obtained according to the following third conversion model, and the formula is as follows:

[0030] Among them, is the equivalent wind speed at the centroid height converted from the predicted wind speed based on the third conversion model; is the predicted wind speed; is the predicted wind height; is the equivalent wind speed at the centroid height converted from the measured wind speed based on the third conversion model; is the measured wind speed; is the measured wind height; is the centroid height; is the ground roughness length; α is the conversion exponent.

[0031] Furthermore, the ground roughness length usually takes a value of 0.01 m (relative to the sea surface) Furthermore, the value range of the conversion exponent α is from 0.1 to 0.25.

[0032] Furthermore, the equivalent wind speed at the centroid height is obtained according to the following fourth conversion model, and the formula is as follows:

[0033] Wherein, is the predicted wind friction velocity; is the coefficient; is the ground roughness length; is the measured wind friction velocity; is the equivalent wind speed at the centroid height converted from the predicted wind speed based on the fourth conversion model; is the predicted wind speed; is the predicted wind height; is the equivalent wind speed at the centroid height converted from the measured wind speed based on the fourth conversion model; is the measured wind speed; is the measured wind height; is the centroid height. First, and are substituted into the first formula as known information to obtain the predicted wind friction velocity , and then and are substituted into the third formula to obtain , and similarly can be obtained.

[0034] Furthermore, the coefficient usually takes a value of 0.4.

[0035] Furthermore, the ground roughness length usually takes a value of 0.01 m (relative to the sea surface).

[0036] In the method of the present invention, firstly, a ship contour function and a water surface line equation are constructed to determine the waterline segmentation position in real time, then the ship contour vertices are arranged in order, and a triangle approximation algorithm is used to calculate the wind-receiving area of the ship contour on the waterline, and the centroid coordinates and centroid height of the ship are determined; finally, based on the above-mentioned multiple conversion models including the first conversion model, the second conversion model, the third conversion model and the fourth conversion model, the corresponding different equivalent wind speeds can be obtained from the predicted wind data and / or the measured wind data That is, the predicted wind and measured wind are converted into the wind speed at the centroid height of the ship's windward area, which is then used to judge the size of the wind force and the corresponding wind level received by the ship, and used for port loading and unloading operations and safe decision-making for leaving berth, to ensure that the ship can still be accurately measured in harsh port environments, thereby avoiding misoperation of the ship, thereby enhancing the safety of the ship's operations, and effectively preventing safety hazards caused by not understanding the specific wind force received by the ship.

[0037] Furthermore, it also includes: converting the equivalent wind speed By comparing with the preset wind speed threshold, a signal of safe ship operation status is generated.

[0038] (3) A system for calculating the wind effect on a ship berthing based on a triangle approximation algorithm, wherein the system executes or does not execute any step of the method described in (1) or (2) above; The system comprises: Ship contour function generation module, used to establish a rectangular coordinate system, import ship engineering drawing data and generate ship contour function ; Water gauge coordinate input module, used to receive bow water gauge coordinates and the stern water gauge coordinates ; Waterline equation generation module, which generates dynamic waterline equations based on bow and stern waterline coordinates , where the coefficient , , ; Contour segmentation module, the water plane equation Function with ship contours Solve the intersection point together, and , segment to obtain the area above the waterline; The triangle approximation algorithm calculation module arranges the vertices of the ship contour in order: , and closed, that is , using the triangle approximation algorithm to calculate the windward area of the ship's waterline contour ; The centroid coordinate calculation module calculates the centroid coordinates of the windward area based on the contour coordinates of the ship's waterline and using the method of area weighting. ; The centroid height calculation module uses the waterplane equation and the centroid coordinates to calculate the vertical distance from the centroid position to the waterplane, i.e., the centroid height, through the point-line distance formula. ; The wind force data input module is used to receive predicted wind data and / or measured wind data; The measured wind height conversion module is used to process the height conversion of the linear distance between the anemometer position and the waterplane ; The conversion module uses a conversion model to convert the wind speed data to the wind force at the windward action point corresponding to the centroid height.

[0039] Furthermore, it further includes a safety decision module, which is used to compare the equivalent wind speed with a preset wind force threshold to generate a ship operation safety status signal.

[0040] (4) The application of the method described in (1) or (2) above or the system described in (3) during ship operation, characterized in that: Compare the equivalent wind speed at the centroid height with a preset wind force threshold to generate a ship operation safety status signal, which is applied to ship safety operation; if it exceeds the wind force threshold, generate an adjustment instruction to control the ship's power system or rudder to dynamically correct the berthing attitude.

[0041] (5) A computer device, the computer device includes a memory, a processor, a communication interface, and a communication bus; wherein, the memory, the processor, and the communication interface communicate with each other through the communication bus; the memory is used to store a computer program; the processor is used to execute the computer program stored on the memory, and when the processor executes the computer program, it implements at least one step of the method described in (1) or (2) above.

[0042] (6) A computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements at least one step of the method described in (1) or (2).

[0043] On the basis of conforming to common knowledge in the art, the above preferred conditions can be combined with each other to obtain specific implementation manners.

[0044] Beneficial effects The ship berthing wind action measurement method based on the triangle approximation algorithm can calculate the windward side area and the corresponding centroid height of the ship in real time according to the draft change by establishing a waterplane equation, so as to ensure that the ship can still be accurately measured under bad sea conditions, avoid misoperation of the ship, enhance the operation safety of the ship, and effectively prevent potential safety hazards caused by not understanding the specific wind force on the ship.

[0045] The ship berthing wind action measurement method based on the triangle approximation algorithm provides a complete set of wind speed measurement methods through the combination of the triangle approximation algorithm and the conversion model. By comparing the measured wind and predicted wind data, the accuracy of the wind force measurement at the wind action point of the ship is improved, the error of the influence of the anemometer or weather forecast on the actual wind force of the ship is reduced, the risk of operation errors is reduced, and the operation of the ship during berthing and departure can be adjusted timely and accurately under complex sea conditions, ensuring the safe and efficient operation of the ship.

[0046] The present invention solves the ambiguity problem caused by ignoring the change of wind force height in the traditional method by converting the measured wind and predicted wind to the wind force at the center of the ship's force. The traditional method usually assumes that the wind force acts uniformly on the ship and ignores the change of wind force with height, resulting in a large deviation between the calculation result and the actual force. The present invention adopts the above technical solution to achieve the above purpose, makes up for the deficiencies of the prior art, and is reasonable in design and convenient in operation. Brief Description of the Drawings

[0047] To make the above and / or other purposes, features, and advantages of the present invention more obvious and understandable, the drawings required for the specific implementation of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative efforts.

[0048] Figure 1 It represents the simplified technical logic diagram of the present application; Figure 2 It represents the flow chart of calculating the centroid coordinates and centroid height in the technical route of the present application; Figure 3 It represents the flow chart of converting the measured wind and predicted wind into the equivalent wind speed at the wind force action point in the technical route of the present application; Figure 4 It represents the simplified drawing of the ship drawing of Ship II; Figure 5 It represents the schematic diagram of converting the predicted wind into the equivalent wind force based on the first conversion model for Ship I; Figure 6 It represents the schematic diagram of converting the measured wind into the equivalent wind force based on the first conversion model for Ship I; Figure 7 Schematic diagram showing that Ship II converts predicted wind into equivalent wind force based on the first conversion model; Figure 8 Schematic diagram showing that Ship II converts measured wind into equivalent wind force based on the first conversion model; Figure 9 Schematic diagram showing that Ship I converts predicted wind into equivalent wind force based on the second conversion model; Figure 10 Schematic diagram showing that Ship I converts measured wind into equivalent wind force based on the second conversion model; Figure 11 Schematic diagram showing that Ship II converts predicted wind into equivalent wind force based on the second conversion model; Figure 12 Schematic diagram showing that Ship II converts measured wind into equivalent wind force based on the second conversion model; Figure 13 Schematic diagram showing that Ship I converts predicted wind into equivalent wind force based on the third conversion model; Figure 14 Schematic diagram showing that Ship I converts measured wind into equivalent wind force based on the third conversion model; Figure 15 Schematic diagram showing that Ship II converts predicted wind into equivalent wind force based on the third conversion model; Figure 16 Schematic diagram showing that Ship II converts measured wind into equivalent wind force based on the third conversion model; Figure 17 Schematic diagram showing that Ship I converts predicted wind into equivalent wind force based on the fourth conversion model; Figure 18 Schematic diagram showing that Ship I converts measured wind into equivalent wind force based on the fourth conversion model; Figure 19 Schematic diagram showing that Ship II converts predicted wind into equivalent wind force based on the fourth conversion model; Figure 20 Schematic diagram showing that Ship II converts measured wind into equivalent wind force based on the fourth conversion model. Detailed implementation manners

[0049] Those skilled in the art can draw on the content of this article and appropriately replace and / or modify process parameters to achieve it. However, it should be particularly noted that all such similar replacements and / or modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The products and preparation methods described in the present invention have been described through preferred examples, and those skilled in the art can obviously make changes or appropriate alterations and combinations to the products and preparation methods described herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0050] Unless otherwise defined, the technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. This invention uses the methods and materials described herein; however, other suitable methods and materials known in the art may also be used. The materials, methods, and examples described herein are illustrative only and not intended to be limiting. All publications, patent applications, patents, provisional applications, database entries, and other references mentioned herein are incorporated herein by reference in their entirety. In case of conflict, the present specification, including definitions, shall prevail.

[0051] Unless otherwise specified, the materials, methods, and examples described herein are exemplary and not restrictive. Although methods and materials similar or equivalent to those described herein may be used in the practice or testing of this invention, suitable methods and materials are still described herein.

[0052] The technical solutions in the embodiments of the present invention will be described clearly and completely hereinafter. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by one of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the scope of protection of the present invention. At the same time, the embodiments in this application and the features in the embodiments may be combined with each other without conflict.

[0053] It should be understood that any technical solution claimed in the present invention does not relate to the diagnosis and treatment of diseases.

[0054] To facilitate the understanding of the embodiments of the present invention, the abbreviations and key terms that may be involved in the embodiments of the present invention are first explained or defined. For abbreviations or key terms that are not defined, they are commonly understood by those skilled in the art.

[0055] In addition, unless otherwise specified, the test methods used in the embodiments are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial sources. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase. All the published cases and other reference materials mentioned herein are incorporated herein by reference in their entirety.

[0056] The present invention is described in detail below Example 1: Provide a method for measuring the wind action on a ship berthing based on a triangular approximation algorithm. The technical route flowchart is as Figures 1 - 3As shown in the figure, firstly, the ship contour function and waterline equation are established to determine the waterline segmentation position in real time; then the ship contour vertices are arranged in order, and the windward area of the ship contour on the waterline is calculated using the triangle approximation algorithm to determine the ship centroid coordinates and centroid height; finally, the conversion model is used to convert the wind speed data to the wind force at the windward action point corresponding to the centroid height. The specific steps are as follows.

[0057] Establish a rectangular coordinate system in CAD, import ship CAD drawing data, and draw the ship contour function ; According to the front and rear water gauge position data, establish the bow water gauge coordinates and the stern water gauge coordinates ,in, and is the position of the ship's fore and aft water gauge relative to the coordinate system The projection abscissa of the axis; is the ship's forward draft reading, It is the ship's stern draft reading.

[0058] Establishing the waterplane equation of a ship , record the front and rear draft through the water gauge function and , substitute the water gauge coordinates into , determine the equation coefficients, split the ship profile into upper and lower parts, The equation is shown in the formula:

[0059] Where: are the coefficients given by the general equation of the line; is a constant, The above coefficients can be calculated using the coordinates of two points: , , ; Waterplane surface equation With contour function The intersection point is obtained by combining the solutions and , dividing the upper and lower areas of the waterline; In the regular shape area containing the ship engineering drawing, the ship outline vertices are arranged in order as , and closed, that is , use the triangle approximation algorithm to calculate the windward area of the ship's waterline contour through the following formula:

[0060] Where A represents the windward area of the ship's waterline contour to be calculated; express The horizontal coordinate of the point; represents the abscissa of the point; represents the ordinate of the point; represents the ordinate of the point; represents the ordinate of the point; represents the abscissa of the point.

[0061] It should be explained that the waterplane equation can calculate the windward area of the ship, the corresponding centroid height, and the height from the waterplane in real time according to the draft change.

[0062] Calculate the centroid coordinates of the upper part of the ship's waterline using the weighted method , as shown in the formula:

[0063] where, and are the coordinates of the point in the sequence of contour coordinate points on the ship's waterline; and are the coordinates of the point in the sequence of contour coordinate points on the ship's waterline; is the total number of contour coordinate points; is the windward area of the ship's waterline contour.

[0064] The centroid coordinates on the ship are the height of the center of the wind action point of the ship from the waterplane. Using the waterplane equation W and the centroid coordinates of the upper part of the waterline , calculate the vertical distance from the centroid to the waterplane, denoted as the centroid height , as shown in the following formula:

[0065] where, are the positions of the ship's bow and stern draft marks and the real-time readings of the draft marks; are the horizontal and vertical coordinates of the ship's centroid position. The obtained centroid height is an important parameter in the subsequent logarithmic model.

[0066] The wind speed data consists of the following two parts: predicted wind data (predicted wind speed and predicted wind height ), and measured wind data (measured wind speed and measured wind height ). represents the predicted wind speed representing the weather forecast wind force; represents the measured wind speed measured by the ship's own anemometer; the corresponding wind force heights of the two are and : is the reference height of wind force for weather forecast. In this embodiment, = 10m; is the vertical distance from the height of the anemometer to the water line; using the water plane equation and the position coordinates of the anemometer to calculate the vertical distance between the anemometer and the water line, as shown in the formula:

[0067] As Figure 1 shown, is the position coordinates of the anemometer (such as Figure 1 in ④) to the vertical distance (such as Figure 1 in ⑥) from the water plane equation W (such as Figure 1 in ③). The water plane equation W can be represented by the draft readings before and after recorded by the water gauge function passing through it and coordinate points. Therefore, the vertical distance from the height of the anemometer to the water line can be calculated through the above formula .

[0068] If the predicted wind under meteorological forecast is adopted, then combine , with the centroid height , substitute them into the first conversion model formula, and convert to obtain the equivalent wind speed at the centroid height converted from the predicted wind speed based on the first conversion model ; if the measured wind under the ship's own anemometer measurement is adopted, then combine , with the centroid height , substitute them into the first conversion model formula, and convert to obtain the at the centroid height converted from the measured wind speed based on the first conversion model. The first conversion model formula is as follows:

[0069] Among them, is the ground roughness length, and the value is 0.01m.

[0070] In this embodiment, the calculation of the ship's wind action is carried out based on the actual ship drawing information of a 208947-ton bulk carrier (denoted as Ship No. I). The ship has a length of 299.95m, a length between perpendiculars of 294.75m, a molded breadth of 50m, and a molded depth of 25.20m. The ship's contour data set is shown in Table 2-4.

[0071] Table 2. The First Part of the Ship's Contour Data Set of Ship No. I

[0072] Table 3, the second part of the I - ship contour dataset

[0073] Table 4, the third part of the I - ship contour dataset

[0074] Furthermore, in this embodiment, based on the actual ship drawing information of a bulk carrier (denoted as Ship II) with a gross tonnage of 1314 tons and a displacement of 1768.4 tons, the measurement of the ship's wind - induced effect is carried out. The total length of this ship is 63.50 m, the length without bulwarks is 61.97 m, the molded breadth is 12.60 m, the molded depth is 4.60 m, and the designed draft is 3.20 m. The simple sketch of the ship drawing of Ship II is as Figure 4 shown.

[0075] For Ship I, applying the first conversion model, the result of converting the predicted wind into the equivalent wind speed at the centroid height (9.6 m) is as Figure 5 shown.

[0076] For Ship I, applying the first conversion model, the result of converting the measured wind into the equivalent wind speed at the centroid height (9.6 m) is as Figure 6 shown.

[0077] For Ship II, applying the first conversion model, the result of converting the predicted wind into the equivalent wind speed at the centroid height (2.74311 m) is as Figure 7 shown.

[0078] For Ship II, applying the first conversion model, the result of converting the measured wind into the equivalent wind speed at the centroid height (2.74311 m) is as Figure 8 shown.

[0079] Example 2: Based on the foregoing embodiment, replacing the first conversion model with the second conversion model to obtain the equivalent wind speed at the centroid height, the formula is as follows:

[0080] wherein, is the equivalent wind speed at the centroid height converted from the predicted wind speed based on the second conversion model; is the predicted wind speed; is the predicted wind height; is the equivalent wind speed at the centroid height converted from the measured wind speed based on the second conversion model; is the measured wind speed; is the measured wind height; is the centroid height; is the conversion index, with a value of 0.1.

[0081] For Ship I, applying the second conversion model, the result of converting the predicted wind into the equivalent wind speed at the centroid height is as Figure 9 shown.

[0082] For Ship I, applying the second conversion model, the result of converting the measured wind into the equivalent wind speed at the centroid height is as Figure 10 shown.

[0083] For Ship II, applying the second conversion model, the result of converting the predicted wind into the equivalent wind speed at the centroid height is as Figure 11 shown.

[0084] For Ship II, applying the second conversion model, the result of converting the measured wind into the equivalent wind speed at the centroid height is as Figure 12 shown.

[0085] Example 3: Based on the foregoing Example 1, the equivalent wind speed at the centroid height is obtained by using the third conversion model, and the formula is as follows:

[0086] Wherein, is the equivalent wind speed at the centroid height converted from the predicted wind speed based on the third conversion model; is the predicted wind speed; is the predicted wind height; is the equivalent wind speed at the centroid height converted from the measured wind speed based on the third conversion model; is the measured wind speed; is the measured wind height; is the centroid height; is the ground roughness length; α is the conversion index.

[0087] For Ship I, applying the third conversion model, the result of converting the predicted wind into the equivalent wind speed at the centroid height is as Figure 13 shown.

[0088] For Ship I, applying the third conversion model, the result of converting the measured wind into the equivalent wind speed at the centroid height is as Figure 14 shown.

[0089] For Ship II, applying the third conversion model, the result of converting the predicted wind into the equivalent wind speed at the centroid height is as Figure 15 shown.

[0090] For Ship II, applying the third conversion model, the result of converting the measured wind into the equivalent wind speed at the centroid height is as Figure 16 shown.

[0091] Example 4: On the basis of the foregoing Example 1, the equivalent wind speed at the centroid height is obtained by using the fourth conversion model, and the formula is as follows:

[0092] Among them, is the predicted wind friction velocity; is a coefficient, taking 0.4; is the ground roughness length, taking 0.01 m; is the measured wind friction velocity; is the equivalent wind speed at the centroid height converted from the predicted wind speed based on the fourth conversion model; is the predicted wind speed; is the predicted wind height; is the equivalent wind speed at the centroid height converted from the measured wind speed based on the fourth conversion model; is the measured wind speed; is the measured wind height; is the centroid height. First, and are substituted as known information into the first formula to obtain the predicted wind friction velocity , and then and are substituted into the third formula to obtain , and can be obtained in the same way.

[0093] For Ship I, applying the fourth conversion model, the result of converting the predicted wind to the equivalent wind speed at the centroid height is as Figure 17 shown.

[0094] For Ship I, applying the fourth conversion model, the result of converting the measured wind to the equivalent wind speed at the centroid height is as Figure 18 shown.

[0095] For Ship II, applying the fourth conversion model, the result of converting the predicted wind to the equivalent wind speed at the centroid height is as Figure 19 shown.

[0096] For Ship II, applying the fourth conversion model, the result of converting the measured wind to the equivalent wind speed at the centroid height is as Figure 20 shown.

[0097] According to the technical solution of the present invention, first, based on the triangular approximation algorithm, the area, centroid coordinates, and centroid height of the ship's waterline contour are obtained. For Ship I, the calculated centroid height is 9.6 m, which is relatively close to the predicted wind height of 10 m and the measured wind height of 11.15121 m; while for Ship II, the calculated centroid height is 2.74311 m, which is far from the predicted wind height and the measured wind height. From Ship I and Ship II, it can be seen that for different ship types, applying the triangular approximation algorithm of the present application can accurately obtain the centroid coordinates and centroid height, which is conducive to judging the actual wind action point of the ship, thereby helping to accurately and real-time adjust the ship operation parameters and improve the ship operation safety.

[0098] From Figures 5 - 20 It can also be known that based on the first to fourth conversion models of the present invention, the predicted wind under the weather forecast and the measured wind speed by the ship's own anemometer are converted into the wind speed at the centroid position, which is the wind action point of the ship. The equivalent wind speed at the centroid height is compared with the wind force requirement of the terminal operation environment to achieve the expected effect. It can be seen that it is necessary to convert the predicted wind speed and / or the actual wind speed into the equivalent wind speed at the centroid height, which helps to more accurately evaluate the influence of the wind action when the ship berths and departs, and then accurately control the actual operation of the ship to improve the ship operation safety.

[0099] In this embodiment, by normalizing and comprehensively analyzing multiple key parameters of the ship berthing operation environment (such as ship contour coordinates, ship draft depth, anemometer height, weather forecast, and anemometer data, etc.), the wind force at the center of the wind action point of the ship is accurately calculated, and the error caused by environmental differences of different parameters is avoided, thereby reducing the influence of each parameter on the actual wind received by the ship when berthing and departing. At the same time, under the action of multiple factors, the draft depth of the ship can fully reflect the actual needs of the ship in different operation states, thereby avoiding the situation of errors caused by the real-time change of the ship's waterplane equation, and then enabling the ship to sail stably under different navigation conditions to ensure safety and efficiency; secondly, through the triangular approximation algorithm and the conversion model, the height conversion can be comprehensively considered, so as to accurately improve the adjustment efficiency and stability of the ship in various complex environments during the actual operation scenario, and then improve the operation safety of the ship.

[0100] The conventional technologies in the above embodiments are the existing technologies known to those skilled in the art, so they will not be elaborated in detail here.

[0101] The specific embodiments described herein are only illustrative of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0102] Although the present invention has been described in detail and specific embodiments have been cited, it will be apparent to those skilled in the art that various changes or modifications can be made without departing from the spirit and scope of the present invention.

[0103] While the foregoing specific embodiments have shown, described, and pointed out novel features applied to various embodiments, it should be understood that various omissions, substitutions, and changes in the form and details of the apparatus or method illustrated can be made without departing from the spirit of the present disclosure. Additionally, the various features and methods can be used independently of one another or can be combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of the present disclosure. Many of the foregoing embodiments include similar components and, accordingly, these similar components may be interchangeable in different embodiments. While the present invention has been disclosed in the context of certain embodiments and examples, those skilled in the art will understand that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or applications and their obvious modifications and equivalents. Accordingly, the present invention is not intended to be limited by the specific disclosure of the preferred embodiments herein.

[0104] Matters not covered by the present invention are well-known techniques.

Claims

1. A method for determining the centroid coordinates of a ship berthing based on a triangular approximation algorithm, characterized in that, Including: Establish a ship contour line function and a waterplane equation to determine the waterplane segmentation position in real time; arrange the ship contour vertices in sequence, and use the triangular approximation algorithm to calculate the windward area of the upper contour of the ship's waterline, and determine the centroid coordinates of the ship.

2. The method according to claim 1, characterized in that: The calculation formula for the centroid coordinates is: Among them, is the abscissa of the centroid coordinate; is the ordinate of the centroid coordinate; and are the coordinates of the point in the sequence of contour coordinate points on the waterline of the ship; and are the coordinates of the point in the sequence of contour coordinate points on the waterline of the ship; is the total number of contour coordinate points; is the windward area of the ship's waterline contour.

3. A method for measuring the wind action on a ship berthing based on a triangle approximation algorithm, characterized in that, Including: Based on the method described in claim 1 or 2, determine the windward area of the upper contour of the ship's waterline, the centroid coordinates of the ship and the centroid height; Use a conversion model to convert the wind speed data to the equivalent wind speed at the wind action point corresponding to the centroid height.

4. The method according to claim 3, wherein The steps of establishing the waterplane equation include: According to the bow draft coordinates and the stern draft coordinates , where and are the abscissas of the projections of the positions of the bow and stern drafts on the axis of the coordinate system; is the bow draft reading, is the stern draft reading; Construct the waterplane equation , where the coefficients are the coefficients given by the general form equation of a straight line, is a constant, not all zero at the same time; Substitute the bow draft mark coordinates and the stern draft mark coordinates into the waterplane equation , and determine the equation coefficients.

5. The method according to claim 4, characterized in that The steps of arranging the ship contour vertices in sequence and using the triangular approximation algorithm to calculate the windward area of the upper contour of the ship's waterline include: Solve the intersection points by simultaneously solving the waterplane equation and the contour line function to obtain the area above the waterline by segmentation; Arrange the vertices of the ship's contour in order as , and it is closed, that is . Use the triangular approximation algorithm to calculate the windward area of the ship's contour above the waterline through the following formula: Among them, A represents the windward area of the ship's waterline outline to be calculated; represents the abscissa of point represents the abscissa of point represents the ordinate of point represents the ordinate of point represents the ordinate of point represents the abscissa of point 6. The method according to claim 5, wherein The conversion model is used to convert the predicted wind speed and / or measured wind speed into the equivalent wind speed at the centroid height.

7. The method according to claim 3 or 6, characterized in that, The conversion model obtains the equivalent wind speed at the centroid height by conversion according to the first conversion model shown in the following formula: Wherein, is the equivalent wind speed at the centroid height converted from the predicted wind speed based on the first conversion model; is the predicted wind speed; is the predicted wind height; is the equivalent wind speed at the centroid height converted from the measured wind speed based on the first conversion model; is the measured wind speed; is the measured wind height; is the centroid height; is the ground roughness length.

8. A ship berthing wind action measurement system based on a triangle approximation algorithm, characterized in that, Including: A software module for establishing a rectangular coordinate system, importing ship engineering drawing data and generating a ship contour line function f(x); The draft coordinate input module is used to receive the bow draft coordinates of the ship and the stern draft coordinates ; The waterplane equation generation module generates a dynamic waterplane equation based on the bow draft mark coordinates and the stern draft mark coordinates ; The contour segmentation module solves the intersection points by simultaneously solving the waterplane equation and the ship contour line function to divide the regions above and below the waterline; Triangle approximation algorithm calculation module, which arranges the vertices of the ship's contour in order and calculates the windward area of the contour on the waterline of the ship using the triangle approximation algorithm ; The centroid coordinate calculation module calculates the centroid coordinates of the windward area based on the coordinate points of the upper part of the ship's contour and uses the method of area weighting. ; Centroid height calculation module, using the waterplane equation and centroid coordinates Calculate the vertical distance from the centroid to the waterplane, i.e., the centroid height, through the point-line distance formula ; Measured wind height conversion module, used to process the height conversion of the linear distance between the anemometer position and the waterline ; A wind force data acquisition module for receiving predicted wind data and / or measured wind data; An equivalent wind speed conversion module for converting the wind force data to the wind speed at the wind action point corresponding to the centroid height in combination with the centroid height, that is, the equivalent wind speed.

9. The system according to claim 8, wherein It further includes a safety decision module for comparing the equivalent wind speed with a preset wind force threshold to generate a ship operation safety status signal.

10. The application of the method according to any one of claims 3-7 or the system according to claim 8 or 9 in the process of ship operation, characterized in that: Compare the equivalent wind speed at the centroid height with a preset wind force threshold to generate a ship operation safety status signal for ship safety operation; if the wind force threshold is exceeded, generate an adjustment instruction to control the ship's power system or rudder to dynamically correct the berthing attitude.

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