Application of anchor position detection method based on Monte Carlo and data set optimization algorithm

Abstract

The invention provides application of an anchor position detection method based on Monte Carlo and a data set optimization algorithm, and the method comprises the steps: carrying out the successive operation of an anchor ground obstacle coordinate set and an anchor position point coordinate set which is generated through a Monte Carlo random algorithm and is used for simulating a to-be-moored ship through an anchoring region detection model of an anchored ship; obtaining a two-dimensional coordinate set of anchor position points of the ship to be moored meeting a ship safety spacing value, carrying out random sampling on the points in an anchor position circle by using a Monte Carlo random sampling model in combination with a data set optimization algorithm, and checking the set obtained by random sampling with a draught depth value of the ship to be moored; therefore, a to-be-moored ship anchoring position point meeting the two-dimensional plane and three-dimensional water depth requirements is obtained; the method can be applied to auxiliary ship anchoring operation. The three-dimensional detection of the ship anchor position can be realized through the water depth limitation on the basis of satisfying the two-dimensional safety spacing limitation, and the accuracy and safety of ship anchor position detection and selection in the actual anchoring operation are greatly improved.

Description

[0001] This invention is a divisional application of the Chinese invention patent application with application number "202410883855.7", application date "2024.07.03", and invention name "3D anchor detection method based on Monte Carlo algorithm and data set optimization algorithm". Technical Field

[0002] The invention relates to the technical field of ship anchoring, and in particular to an application of an anchor position detection method based on Monte Carlo and data set optimization algorithms. Background Art

[0003] At present, the development of various types of ship intelligent technology is in the ascendant, and has gradually become a carrier for the economic development of the shipping industry and a breakthrough in shipping digital technology. The intelligent anchor detection function of ships is one of the key technologies that must be possessed in ship intelligent navigation. In recent years, the Chinese government has paid great attention to and supported the development of various types of ship intelligent technologies. In actual operations, ships must have the ability to detect anchors at the starting port, destination port and near the route to meet the needs of emergency, loading and unloading cargo, getting on and off personnel and waiting for berthing. In navigation practice, due to the lack of scientific anchor detection methods, operators usually rely on external information such as surface obstacles and ship distribution and their own experience to select anchors. In addition, in actual operations, in order to ensure the safety of ship anchoring, a larger anchor radius is usually selected, which objectively causes a waste of anchorage resources. On the contrary, when the anchor radius selected by the ship for anchoring operation is too small, it will cause safety hazards. Therefore, whether the ship can reasonably plan and select the anchoring location and maintain safety during anchoring operations is one of the major challenges faced by ship intelligent detection technology. Therefore, an intelligent anchoring detection technology that takes into account both high efficiency and good safety performance is a key technology that needs to be studied urgently in the current field of intelligent ships.

[0004] Zhang Chunyu used a ship anchoring safety distance model that took wind factors into consideration to calculate the anchoring safety distances for three types of ships, optimized the navigation mode of single-anchored ships, and improved the safety of ship anchoring. At the same time, he combined the anchoring statistical data of Tianjin Port to carry out safety planning for the anchorage waters, solving the problem of uneven utilization of anchorage resources.

[0005] Sheth et al. proposed an improved model of the radius of the ship anchor circle, used the Monte-Carlo random algorithm to simulate the target ship to be moored, and used the improved model of the radius of the ship anchor circle to realize the ship anchor position detection in two-dimensional space on the water surface, solving the problem of two-dimensional plane anchor position detection.

[0006] Zhang Hongchi proposed a method for selecting a single anchoring position for unmanned ships based on a decision tree algorithm. He combined the decision tree algorithm with raster processing technology and preliminarily applied water depth information and bottom analysis to the intelligent anchoring position selection of unmanned ships.

[0007] Madadi, Bahman and others considered how to dynamically program the ships leaving and arriving at the anchorage to be placed in the polygonal anchorage. The study specifically considered the objectives of anchorage area utilization, ship collision risk and fuel consumption performance. These three objectives defined the objective function in a weighted summation manner, and proposed a spatiotemporal method for this multi-objective anchorage planning problem, in which the Monte Carlo simulation method was used to measure the impact of any specific combination of planning indicators (real-time measurement of incoming ships) on the objective function (measured in steady state). At the same time, the perturbation stochastic approximation (SPSA) algorithm was used to determine the linear combination of planning indicators that optimize the objective function.

[0008] Malekipirbazari et al. optimized the algorithm when studying the anchor allocation problem and introduced a heuristic algorithm to correct the MHDF algorithm, taking into account the unevenness of the anchorage water depth. The algorithm is called the non-uniform maximum voidness first algorithm (NU-MHDF), and experimental comparisons have verified that its effect is better than the MHDF algorithm.

[0009] Huang believes that the use capacity of anchorages depends on the choice of actual anchoring points for ships. This study uses a disk filling algorithm to model the anchor position allocation problem and proposes a maximum hole first algorithm (MHDF) to solve the problem. An anchor simulation tool is designed to evaluate the performance of the algorithm, which is also used in Singapore's ship traffic simulation system.

[0010] Oz et al. first considered the anchoring safety of ships in the anchor position allocation problem. In order to maximize the utilization of anchorages and minimize the risk of accidents, they proposed a multi-objective optimization anchor position allocation strategy. This study used the Monte Carlo simulation algorithm to establish a simulation system for solution and verification.

[0011] Existing technologies usually use traditional two-dimensional plane observation methods, ignoring the impact of water depth on anchoring safety. It is difficult for crew members and onshore managers to effectively evaluate the waters selected for anchoring. Therefore, during actual anchoring operations, it may cause practical problems such as low anchoring operation accuracy and greater safety hazards.

[0012] The above-mentioned record of background technical knowledge is intended to help ordinary technicians in this field understand the existing technologies that are 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

[0013] Technical issues In order to solve the above problems, the purpose of the present invention is to provide an application of an anchor detection method based on Monte Carlo and data set optimization algorithm. It is found in the Monte Carlo 3D anchor detection algorithm that there are a large number of repeated operations in the water depth anchor detection process, which need to be optimized. This method establishes an anchor detection optimization data set, optimizes a large number of repeated calculations in the Monte Carlo 3D anchor detection algorithm, reduces the amount of calculations in the water depth detection part of the anchor detection process by at least 60%, and significantly improves the detection efficiency.

[0014] Technical Solution In order to achieve the above-mentioned purpose, the inventors of the present application have conducted in-depth research and provided a three-dimensional anchor intelligent detection method and application that combines a Monte-Carlo algorithm with a data set optimization algorithm. The method can realize three-dimensional detection of ship anchor positions through water depth restrictions on the basis of satisfying two-dimensional safety spacing restrictions. Compared with the existing technology, both the observation accuracy and the safety of anchor selection have been significantly improved, and the application of the data set optimization algorithm further improves the computing efficiency.

[0015] That is, the present invention is: The 3D anchor detection method based on the Monte Carlo algorithm and the data set optimization algorithm includes: Using the anchoring area detection model of anchored ships shown in formula (6), the two-dimensional coordinate set of anchorage obstacles is and a set of coordinates randomly generated by the Monte Carlo random algorithm to simulate the anchoring location of the ship to be moored Perform successive calculations to obtain a two-dimensional coordinate set of the anchoring locations that meet the safety spacing value of the ship. ; (6) In formula (6), Indicates the actual distance between ships; express The minimum value of Indicates the position of existing ships or other objects that hinder anchoring operations in the anchorage corresponding to the plane rectangular coordinate system; point ( Is the value that meets the safety distance between ships The anchor point of by Draw an anchor circle with the anchor radius as the center and the anchor radius as the radius. Random sampling is performed within the anchor circle based on the Monte Carlo random sampling model shown in formula (8). The data set optimization algorithm is combined during random sampling. Specifically, after the first random sampling, a data dimension is added to the water depth verification result of the sampling point to indicate whether the water depth meets the requirements. Indicates that the safety depth limit is met. It means that the safety depth limit cannot be met. Represents the sampling point, and includes the data of the water depth verification operation into the set ; In the second random sampling, the sampling points and Compare the data points in the set. If there is such a data point, directly obtain the water depth verification data. Points without data will have their data values ​​added to the set after depth verification. In; the collection Check with the draft and water depth of the ship to be moored to obtain the anchoring position of the ship to be moored that meets the requirements of two-dimensional plane and three-dimensional water depth; (8) In formula (8), Indicates the angle of setting the simulation sampling point. The sampling range is ; Represents a random function, used to generate a random floating point number between 0 and 1; Indicates fixed base radius; Indicates setting the radius of the simulation sampling point. The sampling range is ; and It means that the coordinates of the extracted points in the plane rectangular coordinate system are calculated using the polar coordinate formula.

[0016] Furthermore, the draft depth value of the ship to be moored is obtained by the draft detection model of the ship to be moored shown in formula (7): (7) In formula (7), Indicates the safe anchoring depth required for the ship to be moored; Indicates the ship's draft when at anchor; represents the reference coefficient; Indicates the excess depth of waves; Indicates the simulated draft of the ship to be moored.

[0017] Furthermore, the 3D anchor detection method based on the Monte Carlo algorithm and the data set optimization algorithm specifically includes: Step 1: Obtain the three-dimensional coordinates of each point on the bottom of the anchorage , whose coordinate set is recorded as ; and It represents the coordinates of a two-dimensional rectangular coordinate system, and can also represent each point on the water surface of the anchorage. Indicates water surface points Depth of water; Step 2: Obtain the 2D coordinates of the anchorage obstacle , whose coordinate set is recorded as ; Step 3: Construct the anchor point conversion model shown in formula (3) to convert the two-dimensional coordinates of the anchorage obstacle in step 2 into the anchor point of the existing anchored ship. , whose coordinate set is recorded as ; (3) In formula (3), It indicates the distance between the anchor point of the existing anchored ship and the point actually recorded by the ship. ≈Ship length + ship anchor chain length; It represents the angle between the bow direction and the abscissa in the coordinate system; Step 4: Set the safety radius with the two-dimensional coordinates of the anchorage obstacle in step 2 as the center of the circle. The restricted waters of ; and construct the safety spacing model shown in formula (4); (4) In formula (4), Indicates the value of safe distance between ships; and Respectively represent the captains of the existing anchored vessels and the vessels waiting to be anchored; and Respectively represent the mooring chain length of the existing anchored ship and the ship to be moored (m); and The radius of the anchorage circle of the existing anchored ships and the ships to be anchored (m); They represent the ship type coefficients of the existing anchored ships and the ships to be anchored respectively; Step 5: Import the relevant information such as the length of the existing anchored ship and the length of the anchored chain into the safety spacing model shown in formula (4) to calculate the radius of the anchor circle of the existing anchored ship and the safety spacing value of the ship to be anchored ; Step 6: Generate random numbers using the Monte Carlo random algorithm 2D coordinates , whose coordinate set is recorded as , used to simulate the selection of anchoring sites for ships to be moored; Step 7: Construct the anchoring area detection model of the anchored ship shown in formula (6): (6) In formula (6), Indicates the actual distance between ships; express The minimum value of Indicates the position of existing ships or other objects that hinder anchoring operations in the anchorage corresponding to the plane rectangular coordinate system; point ( It is the value of the safe distance between anchored ships The anchor point of Step 8: Using the anchoring area detection model of anchored ships shown in formula (6), the coordinate set and Perform calculations one by one to obtain the two-dimensional coordinates of the anchor point of the ship to be moored that meets the value of the safe distance between ships in step 7. , whose coordinate set is ; Step 9: Construct the draft detection model of the ship to be moored as shown in formula (7): (7) In formula (7), Indicates the safe anchoring depth required for the ship to be moored; Indicates the ship's draft when at anchor; represents the reference coefficient; Indicates the excess depth of waves; Indicates the simulated draft of the ship to be moored; Step 10: Construct the Monte Carlo random sampling model of anchorage area water depth shown in formula (8): (8) In formula (8), Indicates the angle of setting the simulation sampling point. The sampling range is ; Represents a random function, used to generate a random floating point number between 0 and 1; Indicates fixed base radius; Indicates setting the radius of the simulation sampling point. The sampling range is ; and It means that the coordinates of the extracted points in the plane rectangular coordinate system are calculated using the polar coordinate formula respectively; Step 11: Draw an anchor circle with the anchor radius as the center and the anchor radius as the radius. Random sampling is performed within the anchor circle based on the Monte Carlo random sampling model shown in formula (8). The data set optimization algorithm is combined during random sampling. Specifically, after the first random sampling, a data dimension is added to the water depth verification result of the sampling point to indicate whether the water depth meets the requirements. Indicates that the safety depth limit is met. It means that the safety depth limit cannot be met. Represents the sampling point, and includes the data that meets the water depth verification operation into the set ; In the second random sampling, the sampling points and Compare the data points in the set. If there is such a data point, directly obtain the water depth verification data. Points without data will have their data values ​​added to the set after depth verification. In; the collection The anchoring points of the ship to be moored are checked with the draft and depth of the ship to be moored to obtain the anchoring points that meet the requirements of the two-dimensional plane and three-dimensional water depth. The point set is recorded as , judged by The coordinate points inside are points inside the anchor circle drawn by the center of the circle, and are not in the point set In the , the set of points that meet the requirements is recorded as , whose coordinates are ( ; Step 12: Construct the anchor point conversion model shown in formula (9): (9) In formula (9), It indicates the distance between the anchor point of the ship to be anchored and the point actually recorded by the ship. ≈1.5×(ship length + ship anchor chain length); It is approximately expressed as the angle between the wind flow resultant force and the horizontal coordinate in the coordinate system; It is the collection in step 11 Anchor point within is the anchor point that meets the safety spacing and water depth limit obtained by calculation. The point set is recorded as .

[0018] Furthermore, in step 1, the third dimension data in the three-dimensional coordinates of the anchorage is the water depth of the location composed of the first two dimensions data.

[0019] Furthermore, in step 2, the anchorage obstacles include obstacles that cannot be moored and existing anchored ships.

[0020] Furthermore, in step 4, Can be set to 0.5 nautical miles, 1 nautical mile or 2 nautical miles.

[0021] Furthermore, in step 4, When the ship is an ordinary cargo ship, the lower limit is taken; when the ship is an oil, liquefied gas or chemical tanker, the upper limit is taken.

[0022] Furthermore, in step 9, the reference coefficient When there is no surge or the shielding is good, take 1.2; when there is surge or the shielding is poor, take 1.5.

[0023] The aforementioned 3D anchor position detection method based on Monte Carlo algorithm and data set optimization algorithm is applied in assisting ship anchoring operations.

[0024] Furthermore, the application includes sending a set of anchoring points that meet the safety spacing and water depth restrictions obtained according to the 3D anchor position detection method based on the Monte Carlo algorithm and the data set optimization algorithm to the ship to be moored to assist in anchoring.

[0025] 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 computer programs; the processor is used to execute the computer programs stored in the memory, and when the processor executes the computer program, at least one step of the aforementioned 3D anchor detection method based on the Monte Carlo algorithm and the data set optimization algorithm is implemented.

[0026] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements at least one step of the above-mentioned 3D anchor detection method based on the Monte Carlo algorithm and the data set optimization algorithm.

[0027] Based on the common knowledge in this field, the above-mentioned preferred conditions can be combined with each other to obtain a specific implementation method.

[0028] Beneficial Effects According to the present invention, by combining the Monte-Carlo random plane anchor detection algorithm with the Monte-Carlo random sampling water depth detection algorithm, three-dimensional detection of the ship anchor position can be achieved through water depth restriction on the basis of satisfying the two-dimensional safety spacing restriction. The method of the present invention establishes an anchor detection optimization data set, optimizes a large number of repeated calculations in the Monte Carlo 3D anchor detection algorithm, reduces the amount of calculation in the water depth detection part of the anchor detection process by at least 60%, and significantly improves the efficiency of the 3D anchor detection method.

[0029] The three-dimensional mooring intelligent detection technology considering water depth conditions proposed in the present invention will undoubtedly make actual mooring operations safer. In practical applications, the algorithm can be arranged on ship-related equipment, and the detected three-dimensional anchor position area can be intuitively displayed on the ECDIS system or other information systems, so that ship drivers can choose safe and controllable three-dimensional mooring anchor positions during normal operation or emergency situations.

[0030] The present invention adopts the above technical solution to achieve the above purpose, which makes up for the shortcomings of the prior art and has reasonable design and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to make the above and / or other purposes, features, advantages and examples of the present invention more obvious and easy to understand, the drawings required for use in the specific implementation of the present invention will be briefly introduced below. 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 paying creative work.

[0032] Figure 1 A technical roadmap of the 3D anchor detection method of the present invention is shown; Figure 2 It shows the simulation schematic diagram of NO.1 anchorage; Figure 3 It shows the simulation schematic diagram of NO.2 anchorage; Figure 4 Schematic diagram showing randomly generated anchor points in the matlab platform; Figure 5 A schematic diagram showing the anchoring position of the ship to be moored that meets the safety spacing value; Figure 6 Schematic diagram showing the simulation results of the anchoring point of a general cargo ship that meets the conditions at the No.1 anchorage; Figure 7 Schematic diagram showing the simulation results of the anchoring point of the oil tanker meeting the conditions at the NO.1 anchorage; Figure 8 Schematic diagram showing the simulation results of the anchoring point of the chemical tanker meeting the conditions at the NO.1 anchorage; Fig. 9 Schematic diagram showing the simulation results of the anchoring point of the container ship that meets the conditions at the No.1 anchorage; Fig.10 Schematic diagram showing the simulation results of the anchoring point of a general cargo ship that meets the conditions at the NO.2 anchorage; Fig.11 Schematic diagram showing the simulation results of the anchoring point of the oil tanker meeting the conditions at the NO.2 anchorage; Fig.12 Schematic diagram showing the simulation results of the anchoring point of the chemical tanker meeting the conditions at the NO.2 anchorage; Fig.13 Schematic diagram showing the simulation results of the anchoring point that meets the conditions for the container ship at the NO.2 anchorage.

[0033] Description of reference numerals: Figure 5 In the figure, blue represents the anchor points that meet the two-dimensional safety spacing, and dark blue represents that the anchor points in this area are dense; Figures 6 to 13 In the figure, the blue dots represent the anchoring points that meet the two-dimensional conditions and the water depth limit under ballast state, the pink dots represent the anchoring points that meet the water depth limit under full load state based on the blue dots, and the green dots are the anchoring points that are generated in the anchor circle and meet the water depth requirements based on the pink dots. It can be seen that there is no anchoring point that meets the water depth conditions in the 0-19.99m anchorage for container ships. DETAILED DESCRIPTION

[0034] Those skilled in the art can refer to the content of this article and appropriately replace and / or modify the process parameters to achieve the same. However, it should be particularly noted that all similar replacements 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 in the present invention have been described through preferred examples. It is obvious that relevant personnel can modify or appropriately change and combine the products and preparation methods described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0035] 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 the invention belongs. The present invention uses the methods and materials described herein; however, other suitable methods and materials known in the art may also be used. The materials, methods, and examples described herein are illustrative only and 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, shall prevail.

[0036] Unless specifically stated, 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 still described herein.

[0037] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without 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 without conflict.

[0038] Embodiment 1: like Figure 1 The technical route shown, this embodiment provides a 3D anchor detection method based on Monte Carlo algorithm and data set optimization algorithm, constructs a three-dimensional anchorage sea area in Matlab simulation software for 3D anchor detection, and specifically includes the following steps.

[0039] Step S1: Construct a three-dimensional anchorage sea area of ​​n nautical miles × n nautical miles in the MATLAB simulation software. Construct the plane matrix model as shown in formula (1); construct the anchorage water depth model as shown in formula (2). This simulation experiment uses a 3 nautical mile × 3 nautical mile chart scale.

[0040] (1) In formula (1), is the matrix data generated by meshgrid function, where The points contained in correspond to the coordinate axes The coordinates of the axis are denoted by , The points contained in correspond to the coordinate axes The coordinates of the axis are denoted by ,exist In the range of step length Divide and generate the corresponding grid matrix.

[0041] (2) In formula (2), and is the coordinate of the two-dimensional rectangular coordinate system of the plane, is the randomly generated simulated anchorage water depth. The coordinates of each bottom point in the anchorage are constructed by the coordinate points generated by the above-mentioned model (1) and model (2): The third dimension is the water depth of the point composed of the first two dimensions, and the coordinates of the bottom of the water surface in the anchorage constitute the coordinate set .

[0042] In this simulation experiment, the water depth is divided into two intervals: This algorithm is also applicable to water depths above 45 m, but deep-water anchoring does not require much anchor position detection methods, so no relevant simulation experiments are conducted.

[0043] Step S2: Based on step S1, set the following anchorage: Construct a No.1 anchorage with a water depth of 0 to 19.99 m at 3 nautical miles x 3 nautical miles, such as Figure 2 shown.

[0044] Construct a No.2 anchorage with a water depth of 3 nautical miles x 3 nautical miles and a depth of 20 to 39.99 meters. Figure 3 shown.

[0045] Step S3: Mark the obstacle information that cannot be anchored collected or obtained by the ship's AIS equipment or radar and the two-dimensional coordinates of the existing anchored ship as , whose coordinate set is .

[0046] Step S4: Construct the anchor point conversion model shown in formula (3) to convert the two-dimensional coordinates of the anchorage obstacle in step S3 into the anchor point of the existing anchored ship , whose coordinate set is recorded as ; (3) In formula (3), It indicates the distance between the anchor point of the existing anchored ship and the point actually recorded by the ship. ≈Ship length + ship anchor chain length; represents the angle between the bow direction and the horizontal coordinate in the coordinate system; is the anchorage point of the existing ships in the anchorage obtained by calculation, and its coordinate set is recorded as S c .point is the two-dimensional coordinate of the existing ship recorded in step S3.

[0047] Step S5: Set the safety radius with the two-dimensional coordinates of the anchorage obstacle in step S4 as the center of the circle The restricted waters of According to the actual situation of the risk, Set to 3 levels: 0.5 nautical miles, 1 nautical mile, and 2 nautical miles.

[0048] Step S6: construct the safety spacing model shown in formula (4); (4) In formula (4), D represents the value of safe distance between ships; and Respectively represent the captains of the existing anchored vessels and the vessels waiting to be anchored; and Respectively represent the mooring chain length of the existing anchored ship and the ship to be moored (m); and The radius of the anchorage circle of the existing anchored ships and the ships to be anchored (m); They represent the ship type coefficients of the existing anchored ships and the ships to be anchored respectively; When the ship is an ordinary cargo ship, the lower limit is taken; when the ship is an oil, liquefied gas or chemical tanker, the upper limit is taken.

[0049] Step S7: Import the relevant information such as the length of the existing ship and the length of the anchor chain into the safety spacing model shown in formula (4) to calculate the radius of the anchor circle of the existing anchored ship. The static information related to the ship used in this simulation experiment is shown in Table 1.

[0050] Table 1-Ship type related parameters selected for simulation experiment (m)

[0051] According to the ship parameters in Table 1, the anchorage area detection test was carried out in the Matlab program. The existing ships and ships to be moored in the anchorage are all the above four types of ships, and the existing ship spacing in the anchorage meets the safety spacing requirements for anchored ships. The water depths of the anchorage are 0-19.99m and 20-39.99m respectively.

[0052] Step S8: Based on steps S6 and S7, the safe distance value of the ship to be moored is calculated according to the safe distance model. ,The experimental data includes two categories and a total of 4 groups, as shown in Tables 2-5.

[0053] Table 2-Safety distance data for ships in water depth of 19.99m and wind force ≤ 7 (m) Serial number Captain of ship 1 Chain length Safety radius Boat 2 Captain Chain length Safety radius Safety distance 1 135 150 285 185 150 335 687 2 135 150 285 346 150 496 781 3 135 150 285 160 150 310 657 4 185 150 335 346 150 496 898 5 346 150 496 160 150 310 868 6 185 150 335 160 150 310 774 Table 3-Safety distance data for ships in water depth of 19.99m and wind force > 7 (m)

[0054] Table 4-Safety distance data for ships in water depth of 39.99m and wind force ≤ 7 (m)

[0055] Table 5-Safety distance data for ships in water depth of 39.99m and wind force > 7 (m)

[0056] Step S9: Randomly generate using Monte Carlo random algorithm 2D coordinates , whose coordinate set is recorded as , used to simulate the selection of anchoring sites for ships to be moored. This simulation experiment randomly generates 5000 random points, as shown in the schematic diagram Figure 4 shown.

[0057] Step S10: construct the anchoring area detection model of the anchored ship shown in formula (6): (6) In formula (6), Indicates the actual distance between ships; express The minimum value of Indicates the position of existing ships or other objects that hinder anchoring operations in the anchorage corresponding to the plane rectangular coordinate system; point ( It is the value of the safe distance between anchored ships anchor point.

[0058] Step S11: Using the anchoring area detection model of the anchored ship shown in equation (6) of step S10, the coordinate set of step S3 is and the coordinate set of step S9 Perform calculations one by one to obtain the value of the safe distance between ships in step S8. The two-dimensional coordinates of the anchor point of the waiting ship , whose coordinate set is , its schematic diagram is as follows Figure 5 As shown, Figure 5 In the figure, blue represents anchor points that meet the two-dimensional safety spacing, and dark blue represents that the anchor points in this area are densely populated.

[0059] Step S12: constructing a draft detection model for the ship to be moored as shown in formula (7): (7) In formula (7), Indicates the safe anchoring depth required for the ship to be moored; Indicates the ship's draft when at anchor; It represents the reference coefficient, which is 1.2 when there is no surge or good shielding, and 1.5 when there is surge or poor shielding; Indicates the excess depth of waves; Represents the simulated draft of the ship to be moored. The relevant parameters of the simulation experiment ship are shown in Table 6.

[0060] Table 6-Simulation experiment ship parameters (m) Vessel Name Ship Type Theoretical full load draft of the ship Theoretical ballast draft of the ship Shielding factor Wave excess water depth Actual full load water depth Actual ballast water depth Ship 1 General cargo ship 8.5 4.3 1.5 1.7 14.5 8.2 Boat 2 tanker 12 6 1.5 2.4 20.4 11.4 Ship 3 Chemical tanker 9.8 4.9 1.5 2.0 16.7 9.4 Ship 4 container ship 14.5 7.3 1.5 2.9 24.7 13.9 To increase the safety of anchorage selection, the shielding factor Taking the upper limit value helps to fully consider the safety hazards caused by bad conditions such as poor shielding, ship pitching, surge, etc. in subsequent simulation tests. The wave surplus depth is based on the British "Marine Engineering Structures" and is 20% of the maximum draft of the ship.

[0061] Step S13: construct the Monte Carlo random sampling model of anchorage area water depth shown in formula (8): (8) In formula (8), Indicates the angle of setting the simulation sampling point. The sampling range is ; represents a random function, which is used to generate a random floating point number between 0 and 1. and The values ​​of the random functions can be the same or different; Indicates fixed base radius; Indicates setting the radius of the simulation sampling point. The sampling range is ; and It means that the coordinates of the extracted points in the plane rectangular coordinate system are calculated using the polar coordinate formula.

[0062] Step S14: An anchor circle is drawn with the anchor radius as the center. Within the anchor circle, random sampling with a sample capacity of 1000 times is performed based on the Monte Carlo random sampling model shown in formula (8). The data set optimization algorithm is combined during random sampling. Specifically, after the first random sampling, a new data dimension is added to the water depth verification result of the sampling point to indicate whether the water depth meets the requirements. Indicates that the safety depth limit is met. It means that the safety depth limit cannot be met. Represents the sampling point, and includes the data that meets the water depth verification operation into the set ; In the second random sampling, the sampling points and Compare the data points in the set. If there is such a data point, directly obtain the water depth verification data. Points without data will have their data values ​​added to the set after depth verification. In; the collection By comparing with the model water depth value shown in formula (7), the anchoring points that meet the requirements of two-dimensional plane and three-dimensional water depth are obtained. The point set is recorded as .

[0063] In step S14, if the random sampling with a sample size of 1000 times is performed directly based on the Monte Carlo random sampling model shown in formula (8), the random sampling result is checked with the model water depth value shown in formula (7), and the anchoring position that meets the two-dimensional plane and three-dimensional water depth requirements is obtained. The random sampling time is 38.5s. When combining the data set optimization algorithm during random sampling, the set and , will be collected By checking with the model water depth value shown in formula (7), the anchor position to be moored that meets the requirements of two-dimensional plane and three-dimensional water depth is obtained, and the random sampling time is 6.5s. Therefore, it can be seen that combining the data set optimization algorithm with Monte Carlo random sampling can greatly improve the operation efficiency, optimize a large number of repeated operations in the 3D anchor detection algorithm, thereby reducing a large number of operations in the water depth detection part, significantly improving the efficiency of the 3D anchor detection algorithm, and helping to assist ships to anchor in time and quickly.

[0064] Step S15: Determine The coordinate points inside are points inside the anchor circle drawn by the center of the circle, and are not in the point set In the , the set of points that meet the requirements is recorded as , whose coordinates are ( .

[0065] Step S16: construct the anchor point conversion model shown in formula (9): (9) In formula (9), It indicates the distance between the anchor point of the ship to be anchored and the point actually recorded by the ship. ≈1.5×(ship length + ship anchor chain length); It is approximately expressed as the angle between the wind flow resultant force and the horizontal coordinate in the coordinate system; is the set in step S15 Anchor point within is the anchor point that meets the safety spacing and water depth limit obtained by calculation. The point set is recorded as .

[0066] Step S17: Draw the anchor points of each reference ship that meet the safety distance and the water depth limit through simulation. Figures 6 to 13 As shown, Figures 6 to 9 The simulation results of anchoring points that meet the conditions for general cargo ships, oil tankers, chemical tankers and container ships at the No.1 anchorage are shown in the figure below. Figures 10 to 13 The simulation results of anchoring points that meet the conditions for general cargo ships, oil tankers, chemical tankers and container ships in the NO.2 anchorage are shown in the figure below. Figures 6 to 13 In the figure, the blue points represent the anchor points that meet the two-dimensional conditions and the water depth limit in the ballast state, the pink points represent the anchor points that meet the water depth limit in the full load state based on the blue points, and the green points are the anchor points that meet the requirements of the generated anchor circle and the water depth based on the pink points. Figures 6 to 13 It can be seen that the method of the present invention combines the Monte-Carlo random plane anchor detection algorithm with the Monte-Carlo random sampling water depth detection algorithm, and can realize three-dimensional detection of the ship anchor position through water depth restriction on the basis of satisfying the two-dimensional safety spacing restriction. The three-dimensional anchor intelligent detection technology considering the water depth condition will undoubtedly make the actual anchoring operation safer. In practical application, the algorithm can be arranged on ship-related equipment to assist the ship in anchoring. Fig. 9 It can be seen that there is no anchorage point that meets the water depth requirements for container ships in the 0-19.99m anchorage.

[0067] Step S18: Send the result of step S17 to the electronic chart or other related equipment to facilitate the ship to be moored to drop anchor at this location; the ship to be moored selects a suitable anchor point or ship position for the anchoring operation according to actual needs.

[0068] Embodiment 2: A computer-readable storage medium is also provided, which stores a computer program executable by a processor. When the computer program is executed by the processor, it runs at least one step of the aforementioned 3D anchor detection method based on the Monte Carlo algorithm and the data set optimization algorithm, and can achieve the same technical effect. To avoid repetition, this embodiment will not be described again.

[0069] Embodiment 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 computer programs; the processor is used to execute the computer programs stored in the memory, and when the processor executes the computer program, at least one step of the aforementioned 3D anchor detection method based on the Monte Carlo algorithm and the data set optimization algorithm is implemented, and the same technical effect can be achieved. To avoid repetition, this embodiment will not be described in detail.

[0070] Computer readable media include permanent and non-permanent, removable and non-removable media, and can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PR AM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0071] 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.

[0072] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0073] Although the present invention has been described in detail and some specific embodiments have been cited, it is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

[0074] Although the above-mentioned specific embodiments have been shown, described and pointed out the novel features applied to various embodiments, it should be understood that various omissions, substitutions and changes can be made to the form and details of the described device or method without departing from the spirit of the present disclosure. In addition, the above-mentioned various features and methods 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 obvious modifications and equivalents thereof. Therefore, the present invention is not intended to be limited by the specific disclosure of the preferred embodiments herein.

[0075] Matters not covered in the present invention are all known technologies.

Claims

1. A 3D anchor detection method based on a Monte Carlo algorithm and a data set optimization algorithm, characterized in that: include: Using the anchoring area detection model of anchored ships shown in formula (6), the two-dimensional coordinate set of anchorage obstacles is and a set of coordinates randomly generated by the Monte Carlo random algorithm to simulate the anchoring location of the ship to be moored Perform successive calculations to obtain a two-dimensional coordinate set of the anchoring locations that meet the safety spacing value of the ship. ; (6) In formula (6), Indicates the actual distance between ships; express The minimum value of Indicates the position of existing ships or other objects that hinder anchoring operations in the anchorage corresponding to the plane rectangular coordinate system; point ( Is the value of the safe distance between ships The anchor point of by Draw an anchor circle with the anchor radius as the center and the anchor radius as the radius. Random sampling is performed within the anchor circle based on the Monte Carlo random sampling model shown in formula (8). The data set optimization algorithm is combined during random sampling. Specifically, after the first random sampling, a data dimension is added to the water depth verification result of the sampling point to indicate whether the water depth meets the requirements. Indicates that the safety depth limit is met. It means that the safety depth limit cannot be met. Represents the sampling point, and includes the data of the water depth verification operation into the set ; In the second random sampling, the sampling points and Compare the data points in the set. If there is such a data point, directly obtain the water depth verification data. Points without data will have their data values ​​added to the set after depth verification. In; the collection Check with the draft and water depth of the ship to be moored to obtain the anchoring position of the ship to be moored that meets the requirements of two-dimensional plane and three-dimensional water depth; (8) In formula (8), Indicates the angle of setting the simulation sampling point. The sampling range is ; Represents a random function, used to generate a random floating point number between 0 and 1; Indicates fixed base radius; Indicates setting the radius of the simulation sampling point. The sampling range is ; and It means that the coordinates of the extracted points in the plane rectangular coordinate system are calculated using the polar coordinate formula.

2. The method according to claim 1, characterized in that: The draft depth value of the ship to be moored is obtained by the draft detection model of the ship to be moored shown in formula (7): (7) In formula (7), Indicates the safe anchoring depth required for the ship to be moored; Indicates the ship's draft when at anchor; represents the reference coefficient; Indicates the excess depth of waves; Indicates the simulated draft of the ship to be moored.

3. The method according to claim 1 or 2, characterized in that: Step 1: Obtain the three-dimensional coordinates of each point on the bottom of the anchorage , whose coordinate set is recorded as ; and It represents the coordinates of a two-dimensional rectangular coordinate system, and can also represent each point on the water surface of the anchorage. Indicates water surface points Depth of water; Step 2: Obtain the 2D coordinates of the anchorage obstacle , whose coordinate set is recorded as ; Step 3: Construct the anchor point conversion model shown in formula (3) to convert the two-dimensional coordinates of the anchorage obstacle in step 2 into the anchor point of the existing anchored ship. , whose coordinate set is recorded as ; (3) In formula (3), It indicates the distance between the anchor point of the existing anchored ship and the point actually recorded by the ship. ≈Ship length + ship anchor chain length; It represents the angle between the bow direction and the abscissa in the coordinate system; Step 4: Set the safety radius with the two-dimensional coordinates of the anchorage obstacle in step 3 as the center of the circle. The restricted waters of ; and construct the safety spacing model shown in formula (4); (4) In formula (4), Indicates the value of safe distance between ships; and Respectively represent the captains of the existing anchored vessels and the vessels waiting to be anchored; and Respectively represent the mooring chain length of the existing anchored ship and the ship to be moored (m); and The radius of the anchorage circle of the existing anchored ships and the ships to be anchored (m); They represent the ship type coefficients of the existing anchored ships and the ships to be anchored respectively; Step 5: Import the relevant information such as the length of the existing anchored ship and the length of the anchored chain into the safety spacing model shown in formula (4) to calculate the radius of the anchor circle of the existing anchored ship and the safety spacing value of the ship to be anchored ; Step 6: Generate random numbers using the Monte Carlo random algorithm 2D coordinates , whose coordinate set is recorded as , used to simulate the selection of anchoring sites for ships to be moored; Step 7: Construct the anchoring area detection model of the anchored ship shown in formula (6): (6) In formula (6), Indicates the actual distance between ships; express The minimum value of Indicates the position of existing ships or other objects that hinder anchoring operations in the anchorage corresponding to the plane rectangular coordinate system; point ( Is the value that meets the safety distance between ships The anchor point of Step 8: Using the anchoring area detection model of anchored ships shown in formula (6), the coordinate set and Perform calculations one by one to obtain the two-dimensional coordinates of the anchor point to be moored that meets the ship safety spacing value in step 5 , whose coordinate set is ; Step 9: Construct the draft detection model of the ship to be moored as shown in formula (7): (7) In formula (7), Indicates the safe anchoring depth required for the ship to be moored; Indicates the ship's draft when at anchor; represents the reference coefficient; Indicates the excess depth of waves; Indicates the simulated draft of the ship to be moored; Step 10: Construct the Monte Carlo random sampling model of anchorage area water depth shown in formula (8): (8) In formula (8), Indicates the angle of setting the simulation sampling point. The sampling range is ; Represents a random function, used to generate a random floating point number between 0 and 1; Indicates fixed base radius; Indicates setting the radius of the simulation sampling point. The sampling range is ; and It means that the coordinates of the extracted points in the plane rectangular coordinate system are calculated using the polar coordinate formula respectively; Step 11: Draw an anchor circle with the anchor radius as the center and the anchor radius as the radius. Random sampling is performed within the anchor circle based on the Monte Carlo random sampling model shown in formula (8). The data set optimization algorithm is combined during random sampling. Specifically, after the first random sampling, a data dimension is added to the water depth verification result of the sampling point to indicate whether the water depth meets the requirements. Indicates that the safety depth limit is met. It means that the safety depth limit cannot be met. Represents the sampling point, and includes the data of the water depth verification operation into the set ; In the second random sampling, the sampling points and Compare the data points in the set. If there is such a data point, directly obtain the water depth verification data. Points without data will have their data values ​​added to the set after depth verification. In; the collection The anchoring points of the ship to be moored are checked with the draft and depth of the ship to be moored to obtain the anchoring points that meet the requirements of the two-dimensional plane and three-dimensional water depth. The point set is recorded as ,judge The coordinate point inside the anchor circle is the center of the circle and the point inside the circle is not in the point set The set of points that meet the requirements is recorded as , and label the coordinates as ( ; Step 12: Construct the anchor point conversion model shown in formula (9): (9) In formula (9), It indicates the distance between the anchor point of the ship to be anchored and the point actually recorded by the ship. ≈1.5×(ship length + ship anchor chain length); It is approximately expressed as the angle between the wind flow resultant force and the horizontal coordinate in the coordinate system; is a set of points Anchor point within is the anchor point that meets the safety spacing and water depth limit obtained by calculation. The point set is recorded as .

4. The method according to claim 3, characterized in that: In step 1, the third dimension data in the three-dimensional coordinates of the anchorage is the water depth of the location composed of the first two dimensions data.

5. The method according to claim 3, characterized in that: In step 2, the anchorage obstacles include obstacles that cannot be moored and existing anchored ships.

6. The method according to claim 3, characterized in that: In step 4, Can be set to 0.5 nautical miles, 1 nautical mile or 2 nautical miles.

7. The method according to claim 3, characterized in that: When the ship is an ordinary cargo ship, the lower limit is taken; when the ship is an oil, liquefied gas or chemical tanker, the upper limit is taken.

8. The method according to claim 3, characterized in that: In step 9, the reference coefficient When there is no surge or the shielding is good, take 1.2; when there is surge or the shielding is poor, take 1.

5.

9. Application of the 3D anchor position detection method based on Monte Carlo algorithm and data set optimization algorithm as described in any one of claims 1 to 8 in assisting ship anchoring operations.

10. The use according to claim 7, characterized in that: The application includes sending a set of anchoring points satisfying safety spacing and water depth restrictions obtained according to the 3D anchor position detection method based on the Monte Carlo algorithm and the data set optimization algorithm to the ship to be moored to assist in anchoring.

Images