Ship berthing wind action measuring and calculating method based on Monte Carlo algorithm
By applying the Monte Carlo algorithm and conversion model on the ship, the position of the center of the wind action point on the ship is accurately determined and the wind speed is converted, which solves the problem of inaccurate wind force assessment on the ship in the existing technology and improves the safety and efficiency of port operations.
Patent Information
- Application Number
- CN202510733258.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-04
- Publication Date
- 2025-09-12
AI Technical Summary
Existing technologies make it difficult to accurately determine the center of the ship's wind-exposed point and convert the wind speed to the centroid height of the ship's windward area, resulting in inaccurate assessment of the wind force acting on the ship and affecting the safety of port operations.
The Monte Carlo algorithm-based method is used to establish the ship contour function and waterplane equation, and the windward side area and centroid height of the ship are calculated in real time. The wind speed data is then converted to the equivalent wind speed at the centroid height through a conversion model.
The accuracy of wind force measurement at the ship's wind-affected point is achieved, the error of the anemometer and weather forecast on the actual wind force is reduced, and the safety and efficiency of ship operations are improved.
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Figure CN120632254A_ABST
Abstract
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 Monte Carlo 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 existing technical defects in this field in the background technology, this application first needs to accurately determine the center of the wind action point of the ship, that is, the position of the centroid height, and secondly, it needs 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 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 wind-induced ship-turning moment.
[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 includes the following technical solutions.
[0007] (1) A method for determining the centroid height of a ship berthing based on a Monte Carlo algorithm, including: Establish ship contour function and waterplane equation to determine waterplane segmentation position in real time; Based on the Monte Carlo algorithm, the number of random points inside and outside the ship's contour line on the waterline is counted, the wind-exposed area of the ship's contour on the waterline is calculated, and the ship's centroid height is determined.
[0008] Furthermore, it also includes determining the coordinates of the centroid of the ship.
[0009] (2) A method for calculating the wind effect on a ship berthing based on a Monte Carlo algorithm includes the following steps: Establish ship contour function and waterplane equation to determine waterplane segmentation position in real time; Based on the Monte Carlo algorithm, the number of random points inside and outside the ship's waterline contour line is counted to calculate the wind-exposed area of the ship's waterline contour line, and the coordinates and height of the ship's centroid are determined; A conversion model is used to convert wind speed data to the wind force at the wind-receiving point corresponding to the centroid height.
[0010] Furthermore, the steps of establishing the ship contour function include: Import ship engineering drawing data into the software and establish a rectangular coordinate system to generate the ship contour function .
[0011] Furthermore, the steps of establishing the waterplane equation include: 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 level 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.
[0012] Furthermore, the steps of counting the number of random points inside and outside the contour line on the waterline of the ship based on the Monte Carlo algorithm and calculating the windward area of the contour line on the waterline of the ship include: The waterplane surface equation With the contour function Solve the intersection points together and split to obtain the area above the waterline; The Monte Carlo method is used to randomly generate sampling points in a regular shape area containing the ship engineering drawings. The proportion of points falling in the area above the waterline is counted, and the windward area of the ship's contour on the waterline is calculated using the following formula:
[0013] Where A represents the windward area of the ship's waterline profile to be calculated; Represents the area of a regular shape containing ship engineering drawings; represents the number of random points that fall within the contour of the ship's waterline; Indicates the total number of random points.
[0014] Furthermore, the centroid coordinates The calculation formula is:
[0015] in, and is the first point in the sequence of the contour coordinate points on the ship's waterline The coordinates of the points; and is the first point in the sequence of the contour coordinate points on the ship's waterline The coordinates of the points; is the total number of contour coordinate points; It is the wind-exposed area of the ship's contour on the waterline.
[0016] Furthermore, using the waterplane equation and centroid coordinates Calculate the vertical distance from the centroid to the waterline using the following formula: :
[0017] 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.
[0018] Furthermore, obtaining wind speed data includes obtaining predicted wind data and / or measured wind data, wherein the predicted wind data includes: predicted wind speed With predicted wind height ; The measured wind data includes: measured wind speed Measured wind height .
[0019] Furthermore, the conversion model is used to convert the predicted wind speed and / or measured wind speed into an equivalent wind speed at the centroid height.
[0020] Furthermore, the equivalent wind speed at the centroid height is obtained according to the following first conversion model, and the formula is as follows:
[0021] 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.
[0022] Furthermore, the ground roughness length The value is usually 0.01m (relative to the sea surface) Furthermore, the equivalent wind speed at the centroid height is obtained according to the second conversion model described below, and the formula is as follows:
[0023] 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.
[0024] Furthermore, the value range of the conversion index α is shown in Table 1: Table 1. Value range of conversion index α
[0025] Furthermore, the conversion index α ranges from 0.1 to 0.25.
[0026] Furthermore, the equivalent wind speed at the centroid height is obtained according to the third conversion model described below, and the formula is as follows:
[0027] 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.
[0028] 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.
[0029] Furthermore, the equivalent wind speed at the centroid height is obtained according to the fourth conversion model described below, and the formula is as follows:
[0030] 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 .
[0031] Furthermore, the coefficient The value is usually 0.4.
[0032] Furthermore, the ground roughness length The value is usually taken as 0.01m (relative to the sea surface).
[0033] 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, 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.
[0034] Furthermore, it also includes: the equivalent wind speed By comparing with the preset wind speed threshold, a signal of safe ship operation status is generated.
[0035] (3) A system for calculating the wind effect on a ship berthing based on a Monte Carlo algorithm, wherein the system executes or does not execute any of the steps in the method described in (1) or (2); 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; Monte Carlo algorithm calculation module, used to calculate the wind-exposed area of the ship's waterline contour using the Monte Carlo formula based on the ratio of the number of random points inside and outside the contour line on the ship's waterline ; 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.
[0036] 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.
[0037] (4) The application of the aforementioned method for calculating the wind effect on a ship berthing based on the Monte Carlo algorithm or the system for calculating the wind effect on a ship berthing based on the Monte Carlo algorithm in the process of ship operation includes: The equivalent wind speed at the centroid height is compared with the preset wind threshold to generate a ship operation safety status signal, which is used for ship safety. If the wind speed exceeds the threshold, an adjustment command is generated to control the ship's power system or steering gear to dynamically correct the berthing posture.
[0038] 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.
[0039] Beneficial effects This Monte Carlo algorithm-based method for calculating the effects of wind on ships at berthing can calculate the windward side area of the ship and the corresponding centroid height in real time according to the draft changes by establishing a waterplane equation, ensuring that the ship can still be accurately measured under severe sea conditions, thereby avoiding ship misoperation, thereby enhancing the operational safety of the ship and effectively preventing safety hazards caused by not understanding the specific wind force acting on the ship.
[0040] This Monte Carlo-based method for calculating wind speed effects on ships at berthing combines the Monte Carlo algorithm with a transformation 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.
[0041] By converting measured and predicted winds to wind forces at the ship's center of gravity, this present invention addresses the ambiguity inherent in conventional methods, which ignore the variations in wind forces with altitude. Conventional methods typically assume that wind forces act uniformly on the ship, ignoring the variations in wind forces with altitude, resulting in significant deviations between calculated results and actual forces. The present invention employs the aforementioned technical solution to achieve this objective, addressing the shortcomings of existing technologies with a rational design and ease of 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 flowchart 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 4 A 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: Provide a method for calculating the wind effect on ships berthing based on the Monte Carlo algorithm. The technical route flow chart is as follows: Figure 1-Figure 3As 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, a Monte Carlo algorithm is used to count the number of random points inside and outside the ship's contour on the waterline, calculate the wind-exposed area of the ship's contour on the waterline, and determine 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 for 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; Using Monte Carlo formula and ship profile function Used to calculate the windward area of a ship on the waterline, the formula is as follows:
[0055] in, Indicates the contour area of the ship above the waterline to be calculated; Indicates the regular shape (referred to as "bounding box") that contains the ship CAD drawing. Since the shape of the "bounding box" is often a regular shape (mostly a rectangle), Easier to obtain; represents the number of random points that fall within the contour of the ship's waterline; Indicates the total number of random 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 first point in the sequence of the contour coordinate points on the ship's waterline The coordinates of the points; and is the first point in the sequence of the contour coordinate points on the ship's waterline The coordinates of the points; 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 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 waterplane 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 , substituted into the first conversion model formula, and the equivalent wind speed at the centroid height obtained by converting the predicted wind speed based on the first conversion model is obtained. 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 equivalent wind speed at 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 (2.7415m). 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 (2.7415m). 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 outline area, centroid coordinates, and centroid height of the ship's waterline are first obtained using a Monte Carlo algorithm. For Ship I, the centroid height is calculated to be 9.6m, which is relatively close to the predicted wind height of 10m. However, for Ship II, the centroid height is calculated to be 2.7415m, which is significantly different from the predicted wind height of 10m. As shown by Ships I and II, the Monte Carlo algorithm of this application can accurately obtain the centroid coordinates and centroid height for different ship types, facilitating the determination of the ship's actual wind exposure point, thereby facilitating the precise and real-time adjustment of ship operating parameters and improving ship operation safety.
[0093] from Figure 5-Figure 20 It can also be seen that based on the first to fourth conversion models of the present invention, the predicted wind speed from the weather forecast and the wind speed actually measured by the ship's own anemometer are converted into the wind speed at the ship's wind-exposed point, i.e., the centroid. The equivalent wind speed at the centroid height is then compared and judged with the wind force requirements of the terminal operating environment, achieving the desired effect. It can be seen that converting the predicted and / or actual wind speeds to the equivalent wind speed at the centroid height is necessary, as it helps to more accurately assess the impact of wind on the ship during berthing and unberthing, thereby precisely controlling the actual ship operations and improving ship operation safety.
[0094] In this implementation, by normalizing and comprehensively analyzing multiple key parameters of the vessel's berthing environment (such as the vessel's outline coordinates, ship's draft, anemometer height, weather forecast, and anemometer data), the wind force at the center of the ship's wind-exposed point is accurately calculated. This avoids errors in different parameters due to environmental differences, thereby reducing the impact of each parameter on the actual wind speed experienced by the ship during berthing and unberthing. Simultaneously, under the influence of multiple factors, the ship's draft can fully reflect the ship's actual needs in different operating states, thereby avoiding errors caused by real-time changes in the ship's waterplane equation. This allows the ship to navigate stably under various navigation conditions, ensuring safety and efficiency. Secondly, through the Monte Carlo algorithm and conversion model, height conversion can be comprehensively considered, thereby accurately determining the ship's adjustment efficiency and stability in various complex environments during actual operating scenarios, thereby improving the ship's 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 determining the centroid height of a ship berthing based on a Monte Carlo algorithm, characterized in that: include: Establish ship contour function and waterplane equation to determine waterplane segmentation position in real time; Based on the Monte Carlo algorithm, the number of random points inside and outside the ship's contour line on the waterline is counted, the wind-exposed area of the ship's contour on the waterline is calculated, and the ship's centroid height is determined.
2. A method for calculating the wind effect on ships berthing based on the Monte Carlo algorithm is characterized by: include: Establish ship contour function and waterplane equation to determine waterplane segmentation position in real time; Based on the Monte Carlo algorithm, the number of random points inside and outside the ship's waterline contour line is counted to calculate the wind-exposed area of the ship's waterline contour line, and the coordinates and height of the ship's centroid are determined; 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.
3. The method according to claim 2, 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.
4. The method according to claim 3, characterized in that The step of counting the number of random points inside and outside the contour line on the ship's waterline based on the Monte Carlo algorithm and calculating the windward area of the contour line on the ship's waterline comprises: The waterplane surface equation With the contour function Solve the intersection points together and split to obtain the area above the waterline; The Monte Carlo method is used to randomly generate sampling points in a regular shape area containing the ship engineering drawings. The proportion of points falling in the area above the waterline is counted, and the windward area of the ship's contour on the waterline is calculated using the following formula: Where A represents the windward area of the ship's waterline profile to be calculated; Represents the area of a regular shape containing ship engineering drawings; represents the number of random points that fall within the contour of the ship's waterline; Indicates the total number of random points.
5. The method according to claim 4, characterized in that Centroid coordinates The calculation formula is: in, and is the first point in the sequence of the contour coordinate points on the ship's waterline The coordinates of the points; and is the first point in the sequence of the contour coordinate points on the ship's waterline The coordinates of the points; is the total number of contour coordinate points; It is the wind-exposed area of the ship's contour on the waterline.
6. The method according to claim 5, 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 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.
7. The method according to claim 2, characterized in that 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.
8. The method according to claim 2 or 7, 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.
9. A system for calculating wind effects on ships at berth based on Monte Carlo algorithm, characterized in that: 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; Monte Carlo algorithm calculation module, used to calculate the windward area above the waterline using the Monte Carlo formula based on the ratio of the number of random points inside and outside the contour line on the waterline of the ship ; 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.
10. Use of the method according to any one of claims 2 to 8 or the system according to claim 9 in a ship operation process, characterized in that: The equivalent wind speed at the centroid height is compared with the preset wind threshold to generate a ship operation safety status signal, which is used for ship safety. If the wind speed exceeds the threshold, an adjustment command is generated to control the ship's power system or steering gear to dynamically correct the berthing posture.