Ship berthing wind effect measuring and calculating method based on shoelace algorithm

Abstract

The invention provides a shoelace algorithm-based ship berthing wind effect measuring and calculating method, which comprises the following steps of: establishing a ship contour line function and a waterplane equation, and determining a waterplane segmentation position in real time; according to the ship contour coordinate point sequence, a shoelace algorithm is used to calculate a ship waterline upper contour wind area, and ship centroid coordinates and centroid height are determined; 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 is berthing or leaving a berth, and in particular to a method for calculating the wind force when the ship is berthing or leaving a berth based on a shoelace algorithm. Background Art

[0002] When a ship berths or leaves a berth, the management department will specifically assess the wind force acting on the ship based on the predicted wind speed and the measured wind speed, which will be used to decide whether to stop port operations and whether the ship should leave the port. Under normal circumstances, the predicted wind speed from the weather forecast is used. The predicted wind speed usually refers to the wind at a height of 10m above the sea surface, and the sea surface is relatively smooth and unobstructed. This is the wind under relatively ideal conditions, but the predicted wind is not the wind at the center of force acting on the ship. Another method uses the wind speed measured on-site on the ship. Usually, the ship's anemometer is installed on an unobstructed mast, and the anemometer is often more than 20m away from the sea surface. Wind speed is highly correlated with altitude. The higher the altitude, the greater the wind speed. Therefore, the use of the above two types of wind speeds to measure the wind at the height of the center of the ship's wind action often has a certain speed deviation. The above-mentioned existing technologies have the following limitations: First, the existing technologies lack a dynamic adjustment mechanism based on the real-time operating status of the ship and external sea conditions, making it difficult to consider the dynamic changes in the ship's state during actual operation. During the ship's operation, the dynamic characteristics of the hull and changes in the external environment will cause the ship's waterplane equation to change at any time, which can easily make it difficult to accurately measure the position of the center of the ship's wind action point. Second, the existing technologies fail to comprehensively consider the ship's windward area formula and the ship's wind speed height conversion model, making it difficult to make real-time measurements based on the specific needs of the ship. This can easily result in an inability to accurately estimate the actual wind force when the ship is berthing or leaving the berth in strong winds, thereby affecting the safety of ship operations.

[0003] The above-mentioned record of background technology knowledge is intended to help ordinary technicians in this field understand the existing technology that is 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 absence of clear evidence that the above-mentioned content has been disclosed before the filing date of this patent application, the above-mentioned background technology should not be used to evaluate the novelty of the technical solution of this application. Summary of the Invention

[0004] Technical issues Based on the consideration of the defects of the existing technology in this field in the background technology, it is necessary to convert the predicted wind speed or the measured wind speed into the wind speed at the centroid of the ship's windward area, and then use it to judge the wind force and wind level the ship is experiencing, which is used for port loading and unloading operations and unberthing safety decisions. In addition, the wind force can also be used to calculate the numerical value of the wind force acting on the ship and the ship's turning moment caused by the wind.

[0005] Technical Solution In order to achieve the above-mentioned purpose, the inventors of this application have conducted in-depth research and found that by establishing a waterplane equation, the windward side 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 the misoperation of the ship, thereby enhancing the operational safety of the ship, and effectively preventing the safety hazards caused by not understanding the specific wind force of the ship. The predicted wind or measured wind can also be converted to the wind speed at the centroid height of the ship's windward area, and then used to determine the size of the wind force and the corresponding wind level received by the ship, thereby improving the accuracy of the wind force measurement at the ship's windward point, thereby reducing the error of the anemometer or weather forecast on the actual wind force of the ship, and reducing the risk of operational errors. Based on the above conversion and analysis results, countermeasures are taken to ensure that in a complex sea environment, the operating ship can make corresponding adjustments in a timely and accurate manner, ensuring that the ship can carry out related operations safely and efficiently.

[0006] That is, the present invention is: (1) A method for calculating the wind effect on a ship berthing based on a shoelace algorithm includes the following steps: Step 1: Establish the ship contour function and waterplane equation, and determine the waterplane segmentation position in real time; Step 2: Calculate the wind-exposed area of ​​the ship's contour on the waterline using the shoelace algorithm through the ship's contour coordinate point sequence, and determine the coordinates and height of the ship's centroid; Step 3: Use the conversion model to convert the wind speed data to the wind force at the wind-receiving point corresponding to the centroid height.

[0007] Furthermore, in step 1, 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 the ship contour function .

[0008] Furthermore, in step 1, the step of establishing the waterplane equation includes: According to the bow water gauge coordinates and the stern water gauge coordinates ,in, and The coordinate system of the ship's front and rear water gauge positions The projected abscissa of the axis; is the ship's first 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 and stern water gauge coordinates into the waterplane equation , determine the coefficients of the equation.

[0009] Furthermore, in step 2, the step of calculating the windward area of ​​the ship's contour on the waterline using the shoelace algorithm through the ship's contour coordinate point sequence includes: The waterplane surface equation With the contour function Solve the intersection points together and split to obtain the area above the waterline; Get the coordinate point sequence of the ship's contour above the waterline , use the shoelace algorithm to calculate the wind-exposed area of ​​the ship's contour on the waterline using the following formula:

[0010] Where A represents the windward area of ​​the ship's waterline profile to be calculated; and Represents the sequence of ship outline coordinate points The horizontal and vertical coordinates of the point; Indicates the total number of contour coordinate points; and Represents the sequence of ship outline coordinate points The horizontal and vertical coordinates of the point.

[0011] Furthermore, in step 2, the centroid coordinates The calculation formula is:

[0012] in, and is the coordinate point sequence of the ship's waterline contour The coordinates of the point; and is the coordinate point sequence of the ship's waterline contour The coordinates of the point; is the total number of contour coordinate points; It is the wind-exposed area of ​​the ship's contour on the waterline.

[0013] Furthermore, in step 2, the water plane equation is used and centroid coordinates Calculate the vertical distance from the centroid to the waterline using the following formula: :

[0014] in, It is the bow and stern water gauge position of the ship and the real-time water gauge reading; are the horizontal and vertical coordinates of the ship's centroid.

[0015] Furthermore, in step 3, obtaining wind speed data includes obtaining predicted wind data and / or measured wind data, and the predicted wind data includes: predicted wind speed With predicted wind height ; The measured wind data includes: measured wind speed Measured wind height .

[0016] Furthermore, in step 3, the conversion model is used to convert the predicted wind speed and / or measured wind speed at a certain height into an equivalent wind speed at the centroid height.

[0017] Furthermore, in step 3, the equivalent wind speed at the centroid height is obtained according to the following first conversion model, and the formula is as follows:

[0018] in, is the equivalent wind speed at the centroid height obtained by converting the predicted wind speed based on the first conversion model; To predict wind speed; To predict wind height; is the equivalent wind speed at the centroid height obtained by converting the measured wind speed based on the first conversion model; is the measured wind speed; is the measured wind height; is the centroid height; The length of the rough ground.

[0019] Furthermore, the ground roughness length The value is usually 0.01m (relative to the sea surface) Furthermore, in step 3, the equivalent wind speed at the centroid height is obtained according to the following second conversion model, and the formula is as follows:

[0020] in, is the equivalent wind speed at the centroid height obtained by converting the predicted wind speed based on the second conversion model; To predict wind speed; To predict wind height; is the equivalent wind speed at the centroid height obtained by converting 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.

[0021] Furthermore, the value range of the conversion index α is shown in Table 1: Table 1. Value range of conversion index α

[0022] Furthermore, the conversion index α ranges from 0.1 to 0.25.

[0023] Furthermore, in step 3, the equivalent wind speed at the centroid height is obtained according to the following third conversion model, and the formula is as follows:

[0024] in, is the equivalent wind speed at the centroid height obtained by converting the predicted wind speed based on the third conversion model; To predict wind speed; To predict wind height; is the equivalent wind speed at the centroid height obtained by converting 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.

[0025] Furthermore, the ground roughness length The value is usually 0.01m (relative to the sea surface) Furthermore, the conversion index α ranges from 0.1 to 0.25.

[0026] Furthermore, in step 3, the equivalent wind speed at the centroid height is obtained according to the following fourth conversion model, and the formula is as follows:

[0027] in, To predict wind friction speed; is the coefficient; is the rough length of the ground; is the measured wind friction velocity; is the equivalent wind speed at the centroid height obtained by converting the predicted wind speed based on the fourth conversion model; To predict wind speed; To predict wind height; is the equivalent wind speed at the centroid height obtained by converting 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 Substitute the known information into the first equation to obtain the predicted wind friction speed , then and Substitute into the third formula to obtain , similarly we can find .

[0028] Furthermore, the coefficient The value is usually 0.4.

[0029] Furthermore, the ground roughness length The value is usually taken as 0.01m (relative to the sea surface).

[0030] In the method of the present invention, a ship contour line function and a water surface line equation are first constructed to determine the waterline segmentation position in real time. Then, through the ship contour coordinate point sequence, the shoelace algorithm is used to calculate the wind-exposed area of ​​the ship contour on the waterline, and the coordinates and centroid height of the ship are determined. Finally, based on 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 above-mentioned 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 unberthing safety decisions, to ensure that the ship can still be accurately measured in harsh port environments, thereby avoiding misoperation of the ship, thereby enhancing the operational safety of the ship, and effectively preventing safety hazards caused by not understanding the specific wind force received by the ship.

[0031] Furthermore, the method further includes step 4, converting the equivalent wind speed By comparing with the preset wind speed threshold, a signal of safe ship operation status is generated.

[0032] (2) A system for calculating wind effects on ships at berthing based on a shoelace algorithm, wherein the system executes or does not execute any step of the method described in (1); 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 With ship contour function Solve the intersection point by joint equations, and , segment to obtain the area above the waterline; The shoelace algorithm calculation module uses the shoelace algorithm to calculate the wind-exposed area of ​​the ship's waterline contour through the ship's contour coordinate point sequence. ; The centroid coordinate calculation module is based on the contour coordinate points on the waterline of the ship and uses the area weighted method to calculate the centroid coordinates of the wind-exposed area. ; Centroid height calculation module, using the waterplane equation and centroid coordinates The vertical distance from the centroid to the waterline plane is calculated by the point-line distance formula, that is, the centroid height ; A wind data input module, configured to receive predicted wind data and / or measured wind data; Measured wind height conversion module, used to process the straight-line distance between the anemometer position and the waterline Height conversion; The conversion module uses a conversion model to convert the wind speed data to the wind force at the wind-receiving point corresponding to the centroid height.

[0033] Furthermore, a safety decision module is included for converting the equivalent wind speed By comparing with the preset wind speed threshold, a signal of safe ship operation status is generated.

[0034] (3) A computer device comprising a memory, a processor, a communication interface, and a communication bus; wherein the memory, the processor, and the communication interface communicate with each other via the communication bus; the memory is used to store a computer program; the processor is used to execute the computer program stored in the memory, and when the processor executes the computer program, it implements at least one step of the aforementioned method for calculating the wind effect on a ship berthing based on the shoelace algorithm.

[0035] (4) A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, at least one step of the above-mentioned method for measuring the wind effect on a ship berthing based on the shoelace algorithm is implemented.

[0036] On the basis of conforming to the common sense in this field, the above-mentioned preferred conditions can be combined with each other to obtain a specific implementation method.

[0037] Beneficial effects This shoelace algorithm-based method for calculating the effects of wind on a ship while berthing can calculate the windward side area and the corresponding centroid height of the ship in real time according to changes in draft by establishing a waterplane equation, ensuring that the ship can still be accurately measured in severe sea conditions, thereby avoiding misoperation of the ship and enhancing the operational safety of the ship, and effectively preventing safety hazards caused by not understanding the specific wind force acting on the ship.

[0038] This shoestring algorithm-based method for calculating wind speed effects on ships during berthing combines the shoestring algorithm with a conversion model to provide a comprehensive set of wind speed calculation methods. By comparing measured wind speeds with predicted wind data, the accuracy of wind speed calculations at the ship's wind-exposed point is improved, thereby reducing the error in the influence of anemometers or weather forecasts on the ship's actual wind speeds. This reduces the risk of operational errors and enables timely and accurate adjustments to ship berthing and unberthing operations in complex sea conditions, ensuring safe and efficient ship operations.

[0039] By converting measured and predicted winds to wind forces at the ship's center of gravity, this method resolves the ambiguity caused by traditional methods that ignore the height variation of wind forces. Traditional methods typically assume that wind forces act uniformly on the ship, ignoring the variation of wind forces with height, resulting in significant deviations between calculated results and actual forces.

[0040] The overall technical solution is optimized, with fast and accurate calculations. This invention uses programming software to automate the entire process, from importing ship outline coordinates, calculating waterline equations, generating area, calculating centroid height, to analyzing wind force, all of which are achieved through optimization algorithms.

[0041] The present invention adopts the above technical solution to achieve the above purpose, which makes up for the shortcomings of the existing technology and has reasonable design and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to make the above-mentioned and / or other purposes, features, advantages and examples of the present invention more obvious and easy to understand, the following is a brief introduction to the drawings required for use in the specific embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 A simplified diagram showing the technical logic of this application; Figure 2 It represents the centroid coordinates and centroid high-speed calculation flow chart in the technical route of this application; Figure 3 A flow chart showing how to convert measured wind and predicted wind into equivalent wind speed at the wind action point in the technical route of this application; Figure 4A simplified diagram showing the ship No. II; Figure 5 A schematic diagram showing the conversion of predicted wind into equivalent wind force by ship I based on the first conversion model; Figure 6 Schematic diagram showing how ship I converts measured wind into equivalent wind force based on the first conversion model; Figure 7 A schematic diagram showing the conversion of predicted wind into equivalent wind force based on the first conversion model for ship II; Figure 8 Schematic diagram showing how ship II converts measured wind into equivalent wind force based on the first conversion model; Figure 9 A schematic diagram showing the conversion of predicted wind into equivalent wind force by ship I based on the second conversion model; Figure 10 Schematic diagram showing how ship I converts measured wind into equivalent wind force based on the second conversion model; Figure 11 A schematic diagram showing how ship II converts the predicted wind into equivalent wind force based on the second conversion model; Figure 12 Schematic diagram showing how ship II converts measured wind into equivalent wind force based on the second conversion model; Figure 13 A schematic diagram showing the conversion of predicted wind into equivalent wind force by ship I based on the third conversion model; Figure 14 Schematic diagram showing how ship I converts measured wind into equivalent wind force based on the third conversion model; Figure 15 Schematic diagram showing the conversion of predicted wind into equivalent wind force based on the third conversion model for ship II; Figure 16 Schematic diagram showing how the measured wind is converted into equivalent wind force based on the third conversion model for ship II; Figure 17 A schematic diagram showing the conversion of predicted wind into equivalent wind force by ship I based on the fourth conversion model; Figure 18 Schematic diagram showing how ship I converts measured wind into equivalent wind force based on the fourth conversion model; Figure 19 Schematic diagram showing the conversion of predicted wind into equivalent wind force based on the fourth conversion model for ship II; Figure 20 Schematic diagram showing how Ship II converts measured wind into equivalent wind force based on the fourth conversion model. DETAILED DESCRIPTION

[0044] Those skilled in the art may refer to the contents herein and appropriately substitute and / or modify the process parameters to achieve the desired effect. However, it should be noted that all such substitutions and / or modifications are obvious to those skilled in the art and are considered to be included in the present invention. The products and preparation methods described herein have been described through preferred embodiments. It is obvious that those skilled in the art can modify or appropriately change and combine the products and preparation methods described herein to implement and apply the technology of the present invention without departing from the content, spirit, and scope of the present invention.

[0045] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The present invention utilizes 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 are 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 the event of a conflict, the present specification, including definitions, will control.

[0046] Unless otherwise specified, the materials, methods, and examples described herein are illustrative only and not limiting. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

[0047] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. At the same time, the embodiments in this application and the features in the embodiments can be combined with each other unless there is a conflict.

[0048] It should be understood that any technical solution claimed for protection in the present invention does not involve the diagnosis and treatment of diseases.

[0049] To facilitate understanding of the embodiments of the present invention, abbreviations and key terms that may be involved in the embodiments of the present invention are first explained or defined. Undefined abbreviations or key terms are generally understood by those skilled in the art.

[0050] In addition, the experimental methods used in the examples are conventional methods unless otherwise specified. The materials and reagents used are commercially available unless otherwise specified. Reagents or instruments used without manufacturer indication are commercially available conventional products. All publications and other references cited herein are incorporated by reference in their entirety.

[0051] The present invention is described in detail below Example 1: Provides a method for calculating the wind effect on ships berthing based on the shoelace algorithm. The technical route flow chart is as follows: Figure 1-Figure 3 As shown in the figure, the ship's contour function and waterplane equation are first established to determine the waterplane segmentation position in real time. Then, the shoelace algorithm is used to calculate the wind-exposed area of ​​the ship's contour on the waterline using the ship's contour coordinate point sequence, determining the coordinates and height of the ship's centroid. Finally, a conversion model is used to convert the wind speed data to the wind force at the wind-exposed point corresponding to the centroid height. The specific steps are as follows.

[0052] 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 The coordinate system of the ship's front and rear water gauge positions The projected abscissa of the axis; is the ship's first draft reading, It is the ship's stern draft reading.

[0053] Establishing the ship waterplane equation , 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 outline into upper and lower parts, The equation is shown as follows:

[0054] 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: , , ; The waterplane surface equation With the contour function The intersection point is obtained by the combined solution and , dividing the upper and lower areas of the waterline; Obtain the coordinate point sequence of the ship's contour above the waterline within a regular-shaped area containing ship engineering drawings , use the shoelace algorithm to calculate the wind-exposed area of ​​the ship's contour on the waterline using the following formula:

[0055] Where A represents the windward area of ​​the ship's waterline profile to be calculated; and Represents the sequence of ship outline coordinate points The horizontal and vertical coordinates of the point; Indicates the total number of contour coordinate points.

[0056] It should be explained that the waterplane equation can calculate the windward side area of ​​the ship and the corresponding centroid height and height from the waterplane in real time according to the draft changes.

[0057] Calculating the centroid coordinates of the ship's waterline using the weighted method , as shown in the formula:

[0058] in, and is the coordinate point sequence of the ship's waterline contour The coordinates of the point; and is the coordinate point sequence of the ship's waterline contour The coordinates of the point; is the total number of contour coordinate points; It is the wind-exposed area of ​​the ship's contour on the waterline.

[0059] The centroid coordinates on the ship are the height of the center of the wind action point of the ship from the waterline surface. The waterline surface equation W and the centroid coordinates of the part on the waterline are used to calculate the centroid coordinates. , calculate the vertical distance from the centroid to the waterline, recorded as the centroid height , as shown in the following formula:

[0060] in, It is the bow and stern water gauge position of the ship and the real-time water gauge reading; is the horizontal and vertical coordinates of the ship's centroid. The obtained centroid height is an important parameter in the subsequent logarithmic model.

[0061] Wind speed data consists of the following two parts: predicted wind data (predicted wind speed With predicted wind height ), measured wind data (measured wind speed Measured wind height ). The predicted wind speed represents the wind force in the weather forecast; represents the actual wind speed measured by the ship's anemometer; the corresponding wind heights are and : is the wind reference height for weather forecast, in this embodiment, =10m; is the vertical distance from the anemometer height to the waterline; using the waterplane equation and anemometer location coordinates Calculate the vertical distance between the anemometer and the waterline as shown in the formula:

[0062] like Figure 1 As shown, The anemometer position coordinates (like Figure 1 ④) to the waterline surface equation W (such as Figure 1 The vertical distance of ③) (such as Figure 1 ⑥), where the waterline equation W can be recorded by the water gauge function through it. and The coordinate point is represented, so the vertical distance between the anemometer height and the waterline can be calculated by the above formula .

[0063] If the wind forecast under the weather forecast is used, then 、 Height to centroid , substitute into the first conversion model formula, and convert the equivalent wind speed at the centroid height obtained by converting the predicted wind speed based on the first conversion model If the actual wind speed measured by the ship's own anemometer is used, then the 、 Height to centroid , substituted into the first conversion model formula, and the centroid height obtained by converting the measured wind speed based on the first conversion model is obtained. The first conversion model formula is as follows:

[0064] in, is the ground roughness length, which is 0.01m.

[0065] This example uses the actual ship drawings of a 208,947-ton bulk carrier (denoted as Ship I) to calculate wind effects on the ship. The ship has a length of 299.95 m, a length between perpendiculars of 294.75 m, a molded breadth of 50 m, and a molded depth of 25.20 m. The ship's profile dataset is shown in Table 2-4.

[0066] Table 2. The first part of the No. 1 ship profile dataset

[0067] Table 3. The second part of the No. 1 ship profile dataset

[0068] Table 4. Part 3 of the Ship Profile Dataset No. 1

[0069] Furthermore, this embodiment uses the actual ship drawings of a bulk carrier with a gross tonnage of 1314 tons and a displacement of 1768.4 tons (denoted as Ship II) as the basis for calculating the wind effects on the ship. The ship has an overall length of 63.50 meters, an overall length excluding bulwarks of 61.97 meters, a molded width of 12.60 meters, a molded depth of 4.60 meters, and a designed draft of 3.20 meters. The simplified ship drawings of Ship II are shown in the following figure: Figure 4 shown.

[0070] For ship I, the first conversion model is applied to convert the predicted wind into the equivalent wind speed at the centroid height (9.6m). Figure 5 shown.

[0071] For ship I, the first conversion model is applied to convert the measured wind into the equivalent wind speed at the centroid height (9.6m). Figure 6 shown.

[0072] For ship II, the first conversion model is applied to convert the predicted wind into the equivalent wind speed at the centroid height (2.7431m). Figure 7 shown.

[0073] For ship II, the first conversion model is applied to convert the measured wind into the equivalent wind speed at the centroid height (2.7431m). Figure 8 shown.

[0074] Example 2: Based on the above embodiment, the second conversion model is used to replace the first conversion model to obtain the equivalent wind speed at the centroid height. The formula is as follows:

[0075] in, is the equivalent wind speed at the centroid height obtained by converting the predicted wind speed based on the second conversion model; To predict wind speed; To predict wind height; is the equivalent wind speed at the centroid height obtained by converting 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.

[0076] For ship I, the second conversion model is applied to convert the predicted wind into the equivalent wind speed at the centroid height. Figure 9 shown.

[0077] For ship I, the second conversion model is applied to convert the measured wind into the equivalent wind speed at the centroid height. Figure 10 shown.

[0078] For ship II, the second conversion model is applied to convert the predicted wind into the equivalent wind speed at the centroid height. Figure 11 shown.

[0079] For ship II, the second conversion model is applied to convert the measured wind into the equivalent wind speed at the centroid height. Figure 12 shown.

[0080] Example 3: Based on the above embodiment 1, the equivalent wind speed at the centroid height is obtained using the third conversion model, and the formula is as follows:

[0081] in, is the equivalent wind speed at the centroid height obtained by converting the predicted wind speed based on the third conversion model; To predict wind speed; To predict wind height; is the equivalent wind speed at the centroid height obtained by converting 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.

[0082] For ship I, the third conversion model is applied to convert the predicted wind into the equivalent wind speed at the centroid height. Figure 13 shown.

[0083] For ship I, the third conversion model is applied to convert the measured wind into the equivalent wind speed at the centroid height. Figure 14 shown.

[0084] For ship II, the third conversion model is applied to convert the predicted wind into the equivalent wind speed at the centroid height. Figure 15 shown.

[0085] For ship II, the third conversion model is applied to convert the measured wind into the equivalent wind speed at the centroid height. Figure 16 shown.

[0086] Example 4: Based on the above embodiment 1, the equivalent wind speed at the centroid height is obtained using the fourth conversion model, and the formula is as follows:

[0087] in, To predict wind friction speed; is the coefficient, take 0.4; is the ground roughness length, which is 0.01m; is the measured wind friction velocity; is the equivalent wind speed at the centroid height obtained by converting the predicted wind speed based on the fourth conversion model; To predict wind speed; To predict wind height; is the equivalent wind speed at the centroid height obtained by converting 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 Substitute the known information into the first equation to obtain the predicted wind friction speed , then and Substitute into the third formula to obtain , similarly we can find .

[0088] For ship I, the fourth conversion model is applied to convert the predicted wind into the equivalent wind speed at the centroid height. Figure 17 shown.

[0089] For ship I, the fourth conversion model is applied to convert the measured wind into the equivalent wind speed at the centroid height. Figure 18 shown.

[0090] For ship II, the fourth conversion model is applied to convert the predicted wind into the equivalent wind speed at the centroid height. Figure 19 shown.

[0091] For ship II, the fourth conversion model is applied to convert the measured wind into the equivalent wind speed at the centroid height. Figure 20 shown.

[0092] According to the technical solution of the present invention, the contour area, centroid coordinates and centroid height of the ship on the waterline are first obtained based on the shoelace algorithm. The centroid height of ship No. I is calculated to be 9.6m, which is relatively close to the predicted wind height of 10m and the measured wind height of 11.15121m; while the centroid height of ship No. II is calculated to be 2.7431m, which is far from the predicted wind height of 10m and the measured wind height of 11.1512m. It can be seen from ships No. I and No. II that for different ship types, the present invention can accurately obtain the centroid coordinates and centroid height by applying the shoelace algorithm, which is beneficial to judge the actual wind action point of the ship, thereby helping to accurately and real-time adjust the ship operation parameters and improve the safety of ship operations.

[0093] from Figure 5-Figure 20 It can be seen that based on the first to fourth conversion models of the scheme of this embodiment, the predicted wind under the weather forecast and the wind speed measured by the ship's own anemometer are converted into the wind speed at the ship's wind-affected point, that is, the centroid position, and the equivalent wind speed at the centroid height is compared and judged with the wind force requirements of the terminal operating environment to achieve the expected effect.

[0094] This implementation uses normalization and comprehensive analysis of multiple key parameters of the vessel's berthing environment (such as the vessel's outline coordinates, draft, anemometer height, weather forecasts, and anemometer data) to accurately calculate the wind force at the center of the ship's wind-exposed point. This eliminates errors caused by environmental variations in different parameters, thereby reducing the impact of each parameter on the actual wind conditions experienced by the ship during berthing and unberthing. Furthermore, under the influence of these multiple factors, the vessel's draft fully reflects the vessel's actual requirements under different operating conditions, thereby avoiding errors caused by real-time changes in the vessel's waterplane equation. This allows the vessel to navigate stably under diverse navigation conditions, ensuring safety and efficiency. Furthermore, through the shoelace algorithm and conversion model, comprehensive height conversion is considered, accurately optimizing the vessel's operational efficiency and stability in various complex environments, thereby enhancing operational safety.

[0095] The conventional techniques in the above embodiments are prior arts known to those skilled in the art, and thus will not be described in detail here.

[0096] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

[0097] Although the present invention has been described in detail and certain specific embodiments have been cited, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

[0098] Although the above-mentioned specific embodiments have shown, described and pointed out the novel features applied to various embodiments, it should be understood that various omissions, replacements and changes can be made to the form and details of the described devices or methods without departing from the spirit of the present disclosure. In addition, the various features and methods described above can be used independently of each other, 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 above-mentioned embodiments include similar components, and therefore, these similar components are interchangeable in different embodiments. Although the present invention has been disclosed in the context of certain embodiments and examples, it should be understood by those skilled in the art that the present invention can extend beyond the specifically disclosed embodiments to other alternative embodiments and / or applications and their obvious modifications and equivalents. Therefore, the present invention is not intended to be limited by the specific disclosure of the preferred embodiments herein.

[0099] Matters not covered in the present invention are all known technologies.

Claims

1. A method for calculating the wind effect on a ship berthing based on a shoelace algorithm, characterized in that: include: Establish ship contour function and waterplane equation to determine waterplane segmentation position in real time; The shoelace algorithm is used to calculate the wind-exposed area of ​​the ship's waterline contour through the ship's contour coordinate point sequence, and to determine the coordinates and height of the ship's centroid. The conversion model is used to convert the wind speed data to the equivalent wind speed at the wind-affected point corresponding to the centroid height.

2. The method according to claim 1, characterized in that The step of establishing the waterplane surface equation comprises: According to the bow water gauge coordinates and the stern water gauge coordinates ,in, and The coordinate system of the ship's front and rear water gauge positions The projected abscissa of the axis; is the ship's first 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 and stern water gauge coordinates into the waterplane equation , determine the coefficients of the equation.

3. The method according to claim 2, characterized in that The method of calculating the wind-exposed area of ​​the ship's waterline contour using the shoelace algorithm through the ship's contour coordinate point sequence specifically includes: The waterplane surface equation With the contour function Solve the intersection points together and split to obtain the area above the waterline; Get the coordinate point sequence of the ship's contour above the waterline , use the shoelace algorithm to calculate the wind-exposed area of ​​the ship's contour on the waterline using the following formula: Where A represents the windward area of ​​the ship's waterline profile to be calculated; and Represents the sequence of ship outline coordinate points The horizontal and vertical coordinates of the point; Indicates the total number of contour coordinate points.

4. The method according to claim 3, characterized in that Centroid coordinates The calculation formula is: in, and is the coordinate point sequence of the ship's waterline contour The coordinates of the point; and is the coordinate point sequence of the ship's waterline contour The coordinates of the point; is the total number of contour coordinate points; It is the wind-exposed area of ​​the ship's contour on the waterline.

5. The method according to claim 4, characterized in that Using the waterplane equation and centroid coordinates Calculate the vertical distance from the centroid to the waterline using the following formula: : in, It is the ship's bow and stern water gauge positions and real-time water gauge readings; are the horizontal and vertical coordinates of the ship's centroid.

6. The method according to claim 1, wherein The conversion model is used to convert the predicted wind speed and / or the measured wind speed into an equivalent wind speed at the centroid height.

7. The method according to claim 1 or 6, characterized in that The conversion model converts the equivalent wind speed at the centroid height according to the first conversion model shown in the following formula: in, is the equivalent wind speed at the centroid height obtained by converting the predicted wind speed based on the first conversion model; To predict wind speed; To predict wind height; is the equivalent wind speed at the centroid height obtained by converting the measured wind speed based on the first conversion model; is the measured wind speed; is the measured wind height; is the centroid height; The length of the rough ground.

8. The ship berthing wind effect measurement system based on the shoelace algorithm is characterized by: include: Software module for establishing a rectangular coordinate system, importing ship engineering drawing data and generating the ship contour function f(x); Water gauge coordinate input module, used to receive the water gauge coordinates of the bow of the ship and the stern water gauge coordinates ; Waterline equation generation module, which generates dynamic waterline equations based on bow and stern waterline coordinates ; Contour segmentation module, the water plane equation With ship contour function Solve the intersection points together to split the area above and below the waterline; The shoelace algorithm calculation module uses the shoelace algorithm to calculate the wind-exposed area of ​​the ship's waterline contour through the ship's contour coordinate point sequence. ; The centroid coordinate calculation module calculates the centroid coordinates of the wind-exposed area based on the partial contour coordinate points on the ship and using the area weighted method. ; Centroid height calculation module, using the waterplane equation and centroid coordinates The vertical distance from the centroid to the waterline plane, i.e. the centroid height, is calculated using the point-line distance formula. ; Measured wind height conversion module, used to process the straight-line distance between the anemometer position and the waterline Height conversion; A wind data acquisition module, configured to receive predicted wind data and / or measured wind data; The equivalent wind speed conversion module is used to convert the wind force data into the wind speed at the wind-receiving point corresponding to the centroid height, that is, the equivalent wind speed, in combination with the centroid height.

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

10. Use of the method according to any one of claims 1 to 7 or the system according to claim 8 or 9 in a ship operation process, characterized in that: Compare the equivalent wind speed at the centroid height with the preset wind threshold to generate a ship operation safety status signal for safe ship operation; If the wind speed threshold is exceeded, an adjustment command is generated to control the ship's power system or steering gear to dynamically correct the berthing attitude.

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