A method for obtaining complexity of marine traffic flow

Abstract

The application relates to the technical field of maritime traffic, in particular to a maritime traffic flow complexity acquisition method. The specific steps are as follows: multi-source data of a target sea area is acquired, and the multi-source data is preprocessed, the multi-source data comprising ship data, channel data and hydro-meteorological data; an effective attribute field of the ship in the target sea area is calculated based on the hydro-meteorological data; parameters in the effective attribute field comprise effective speed, safe draught, turning flexibility and safety distance; real-time traffic flow complexity is calculated according to the effective attribute field; a dynamic traffic flow complexity threshold value is calculated according to the multi-source data, and a complexity grade is divided according to the real-time traffic flow complexity and the dynamic traffic flow complexity threshold value. The above maritime traffic flow complexity acquisition method fully considers the influence of hydro-meteorological conditions and the influence of actual ship conditions. The traffic flow complexity threshold value is dynamically adjusted according to the multi-source data, so that the complexity grade division is more reasonable.

Description

Technical Field

[0001] This invention relates to the field of maritime transportation technology, and in particular to a method for obtaining maritime traffic flow complexity. Background Technology

[0002] The complexity of maritime traffic flow is a core indicator for measuring the "disorderliness" and "uncertainty" of ship operations in maritime traffic systems. The higher the complexity of maritime traffic flow, the greater the impact on ship navigation, the easier it is to cause dangerous situations or make collision avoidance operations difficult, and it hinders the monitoring of maritime areas. A search revealed a patent with publication number CN116227780, which discloses a method for obtaining the complexity of maritime traffic flow based on field theory. The method specifically involves: acquiring the current position and scale information of a vessel; establishing a vessel's own attribute field based on the position and scale information; acquiring the position information of the current navigation channel line; establishing a channel boundary field based on the position and channel line position information; acquiring the speed information of each vessel in the current sea area; establishing a vessel speed field based on the speed information of each vessel in the current sea area; obtaining the essential complexity based on the position information, the vessel's own attribute field, the channel boundary field, and the vessel speed field; obtaining the essential complexity of each vessel in the current sea area; obtaining a complexity threshold based on the essential complexity of each vessel; and obtaining a cognitive complexity evaluation index for the current sea area based on the essential complexity and the complexity threshold. The resulting traffic flow complexity can more accurately represent the actual traffic flow state.

[0003] However, in reality, changes in marine weather conditions directly affect the navigation of ships at sea. At the same time, ship attributes only focus on position and size information, which cannot fully reflect the impact of different ship types and load conditions on complexity. Furthermore, the complexity evaluation is carried out by using fixed complexity thresholds and ship density, without taking into account actual weather conditions, ship attributes and other factors. As a result, the obtained complexity cannot provide data support for subsequent marine monitoring. Summary of the Invention

[0004] The purpose of this invention is to provide a method for obtaining the complexity of maritime traffic flow, thereby solving the aforementioned technical problems.

[0005] To achieve the above objectives, this invention provides a method for obtaining the complexity of maritime traffic flow, the specific steps of which are as follows:

[0006] Step S1: Acquire multi-source data of the target sea area and preprocess the multi-source data, which includes ship data, waterway data and hydro-meteorological data;

[0007] Step S2: Calculate the effective attribute field of ships in the target sea area based on hydrological and meteorological data; the parameters in the effective attribute field include effective speed, safe draft, maneuverability, and safe distance;

[0008] Step S3: Calculate the real-time traffic flow complexity based on the effective attribute field;

[0009] Step S4: Calculate the dynamic traffic flow complexity threshold based on multi-source data, and classify the complexity level according to the real-time traffic flow complexity and the dynamic traffic flow complexity threshold.

[0010] Preferably, in step S1, the ship data includes design speed, total ship weight, static water resistance, static water safety distance, ship size, draft, speed, maximum draft, set basic water depth, and total number of ships.

[0011] Hydrometeorological data include wind direction angle, wind speed, current speed, wave height, wave direction, actual water depth, real-time visibility, and set visibility value;

[0012] The waterway data includes waterway line location data and waterway classification, and the total waterway area is calculated based on the waterway line location data.

[0013] Preferably, in step S2, the first The effective speed of the ship The expression is as follows:

[0014] ;

[0015] in, For the first Only the ship's design speed, The influence coefficient related to the total weight of the ship. For the first The total resistance of the ship only For the first The static water resistance of the ship only;

[0016] The calculation formula is as follows:

[0017] ;

[0018] in, The first fitting coefficient, air density, For the reason about the The wind direction angle at the location of the ship only The drag coefficient function, For the first Only the height of the ship, For the first Only the ship's draft, The windward area function, For the first The wind speed at the location of the ship only. For the first The speed of the ship.

[0019] Preferably, in step S2, the first Only the safe draft of a ship The expression is as follows:

[0020] ;

[0021] in, For the first The maximum draft of the ship, The second fitting coefficient, For the first The wave height is determined solely by the location of the vessel. For the first The wave direction at the location of the ship only. For the first Only the actual water depth at the location of the vessel For the first The basic water depth for the vessel only. The third fitting coefficient, For the first The current velocity at the location of the ship only.

[0022] Preferably, in step S2, the first Only the ship's turning flexibility The expression is as follows:

[0023] ;

[0024] in, For the first The still water turning coefficient of a ship is related to its size. and All are correction factors.

[0025] Preferably, in step S2, the first safe distance between ships The expression is as follows:

[0026] ;

[0027] in, For the first The still water safety distance for ships.

[0028] Preferably, in step S3, the real-time traffic flow complexity The calculation formula is as follows:

[0029] ;

[0030] in, , as well as These are the density complexity weight coefficient, dynamic complexity weight coefficient, and constraint complexity weight coefficient, respectively. , as well as These are density complexity, dynamic complexity, and constraint complexity, respectively.

[0031] The preferred formula for calculating density complexity is as follows:

[0032] ;

[0033] in, For the first Only the safe distance between ships, , The total number of vessels in the target sea area. The average width of all ships. The total area of ​​the shipping lanes within the target sea area;

[0034] The formula for calculating dynamic complexity is as follows:

[0035] ;

[0036] in, The average effective speed of ships within the target sea area. The average turning maneuverability of ships within the target sea area;

[0037] The formula for calculating constraint complexity is as follows:

[0038] ;

[0039] in, This represents the average still-water safe distance for all vessels within the target sea area. and The first Only the length and width of the ship.

[0040] Preferably, in step S4, the dynamic traffic flow complexity threshold is determined as follows:

[0041] Calculate the basic saturation complexity The calculation formula is as follows:

[0042] ;

[0043] in, Regarding the waterway classification The relevant mapping function shows that the channel grade is positively correlated with the basic saturation complexity;

[0044] The dynamic threshold correction coefficient is calculated using the following formula:

[0045] ;

[0046] in, The maximum number of vessels designed for the target sea area and waterway. and These are the visibility variation coefficient and the wind speed variation coefficient, respectively. and These are the real-time average visibility and the set visibility value, respectively. The average wind speed in the target sea area's shipping lanes;

[0047] The dynamic traffic flow complexity threshold is calculated using the following formula:

[0048] .

[0049] Preferably, in step S4, the complexity levels are divided as follows:

[0050] when At that time, the complexity level is level one;

[0051] when At that time, the complexity level is level two;

[0052] when At that time, the complexity level was three.

[0053] when At that time, the complexity level was four.

[0054] Therefore, the present invention employs the above-mentioned method for obtaining the complexity of maritime traffic flow, which has the following beneficial effects:

[0055] (1) The effective attribute field is calculated by acquiring multi-source data, so that the effective attribute field is more in line with the actual situation and fully considers the influence of hydrology and meteorology as well as the actual situation of ships.

[0056] (2) Calculate the dynamic traffic flow complexity threshold based on multi-source data, and dynamically adjust the traffic flow complexity threshold to make the complexity level classification more reasonable.

[0057] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0058] Figure 1 This is a flowchart of a method for obtaining the complexity of maritime traffic flow according to the present invention. Detailed Implementation

[0059] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0060] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0061] like Figure 1 As shown, a method for obtaining the complexity of maritime traffic flow is characterized by the following specific steps:

[0062] Step S1: Acquire multi-source data of the target sea area and preprocess the multi-source data, which includes ship data, waterway data and hydro-meteorological data.

[0063] Ship data includes design speed, gross weight, static resistance, static safety distance, ship dimensions, draft, speed, maximum draft, set base depth, and total number of ships.

[0064] Hydrometeorological data include wind direction angle, wind speed, current speed, wave height, wave direction, actual water depth, real-time visibility, and set visibility values.

[0065] The waterway data includes waterway line location data and waterway classification, and the total waterway area is calculated based on the waterway line location data.

[0066] Step S2: Calculate the effective attribute field of ships in the target sea area based on hydrological and meteorological data; the parameters in the effective attribute field include effective speed, safe draft, maneuverability and safe distance.

[0067] No. The effective speed of the ship The expression is as follows:

[0068] ;

[0069] in, For the first Only the ship's design speed, The influence coefficient related to the total weight of the ship. For the first The total resistance of the ship only For the first The static water resistance of the ship only;

[0070] The calculation formula is as follows:

[0071] ;

[0072] in, The first fitting coefficient, air density, For the reason about the The wind direction angle at the location of the ship only The drag coefficient function, , For the first Only the height of the ship, For the first Only the ship's draft, The windward area function, B is the ship's width. For the first The wind speed at the location of the ship only. For the first The speed of the ship.

[0073] No. Only the safe draft of a ship The expression is as follows:

[0074] ;

[0075] in, For the first The maximum draft of the ship, The second fitting coefficient, For the first The wave height is determined solely by the location of the vessel. For the first The wave direction at the location of the ship only. For the first Only the actual water depth at the location of the vessel For the first The basic water depth for the vessel only. The third fitting coefficient, For the first The current velocity at the location of the ship only.

[0076] No. Only the ship's turning flexibility The expression is as follows:

[0077] ;

[0078] in, For the first The still water turning coefficient of a ship is related to the ship's size. , and The first (Only the length and width of the ship) and All are correction factors.

[0079] No. safe distance between ships The expression is as follows:

[0080] ;

[0081] in, For the first The still water safety distance for ships.

[0082] Step S3: Calculate the real-time traffic flow complexity based on the effective attribute field.

[0083] Real-time traffic flow complexity The calculation formula is as follows:

[0084] ;

[0085] in, , as well as These are the density complexity weight coefficient, dynamic complexity weight coefficient, and constraint complexity weight coefficient, respectively. , as well as These are density complexity, dynamic complexity, and constraint complexity, respectively.

[0086] The formula for calculating density complexity is as follows:

[0087] ;

[0088] in, For the first Only the safe distance between ships, , The total number of vessels in the target sea area. The average width of all ships. The total area of ​​the shipping lanes within the target sea area;

[0089] The formula for calculating dynamic complexity is as follows:

[0090] ;

[0091] in, The average effective speed of ships within the target sea area. The average turning maneuverability of ships within the target sea area;

[0092] The formula for calculating constraint complexity is as follows:

[0093] ;

[0094] in, This represents the average still-water safe distance for all vessels within the target sea area. and The first Only the length and width of the ship.

[0095] Step S4: Calculate the dynamic traffic flow complexity threshold based on multi-source data, and classify the complexity level according to the real-time traffic flow complexity and the dynamic traffic flow complexity threshold.

[0096] The process for determining the dynamic traffic flow complexity threshold is as follows:

[0097] First, calculate the basic saturation complexity. The calculation formula is as follows:

[0098] ;

[0099] in, Regarding the waterway classification The relevant mapping function is positively correlated with the basic saturation complexity; it takes 0.8 for Class I and 0.6 for Class II.

[0100] Secondly, the dynamic threshold correction coefficient is calculated using the following formula:

[0101] ;

[0102] in, The maximum number of vessels designed for the target sea area and waterway. and These are the visibility variation coefficient and the wind speed variation coefficient, respectively. and These are the real-time average visibility and the set visibility value, respectively. The average wind speed in the target sea area is the average wind speed in the shipping lane.

[0103] Finally, the dynamic traffic flow complexity threshold is calculated using the following formula:

[0104] .

[0105] The complexity levels are classified as follows:

[0106] when At that time, the complexity level is level one, which is very low.

[0107] when At that time, the complexity level is level two, which is relatively low.

[0108] when At that time, the complexity level was three, which is relatively high.

[0109] when At that time, the complexity level was four, which is very high.

[0110] To verify the effectiveness of the technical solution in this embodiment, a simulation experiment was conducted, the details of which are as follows:

[0111] Simulation tool: MATLAB R2023a, used for data processing and computation.

[0112] The simulation scenarios are shown in Table 1.

[0113] Table 1 Simulation Scenarios

[0114]

[0115] The corresponding values ​​are: the first fitting coefficient is 0.6, the second fitting coefficient is 0.5, the third fitting coefficient is 0.2, the correction coefficient is 0.5, the density complexity weight coefficient, the dynamic complexity weight coefficient, and the constraint complexity weight coefficient are 0.4, 0.3, and 0.3 respectively, and the visibility variation coefficient and the wind speed variation coefficient are 0.6 and 0.5 respectively.

[0116] The simulation results are shown in Table 2.

[0117] Table 2 Simulation Results

[0118]

[0119] The impact of single-factor disturbances (such as airspeed, wave height, and visibility) on real-time complexity ranges from 5% to 26%. Among these, wave height has the highest sensitivity to constraint complexity, while airspeed has the highest sensitivity to dynamic complexity. In scenarios with multiple disturbances, the superposition of multiple factors leads to a 40.7% increase in real-time complexity compared to the basic scenario, while the dynamic threshold decreases by 21.6%, directly driving the risk level towards higher complexity, which aligns with the actual characteristics of navigation risks. The dynamic threshold effectively adapts to environmental changes (e.g., the threshold decreases by 21.6% when visibility decreases), avoiding misjudgments of risk levels caused by static thresholds, thus validating the rationality of the technical solution.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for obtaining the complexity of maritime traffic flow, characterized in that, The specific steps are as follows: Step S1: Acquire multi-source data of the target sea area and preprocess the multi-source data, which includes ship data, waterway data and hydro-meteorological data; Step S2: Calculate the effective attribute field of ships in the target sea area based on hydrological and meteorological data, ship data, and waterway data; the parameters in the effective attribute field include effective speed, safe draft, maneuverability, and safe distance; Step S3: Calculate the real-time traffic flow complexity based on the effective attribute field; In step S3, the real-time traffic flow complexity The calculation formula is as follows: ； in, , as well as These are the density complexity weight coefficient, dynamic complexity weight coefficient, and constraint complexity weight coefficient, respectively. , as well as These are density complexity, dynamic complexity, and constraint complexity, respectively. The formula for calculating density complexity is as follows: ； in, For the first Only the safe distance between ships, , The total number of vessels in the target sea area. The average width of all ships. The total area of ​​the shipping lanes within the target sea area; The formula for calculating dynamic complexity is as follows: ； in, The average effective speed of ships within the target sea area. The average turning maneuverability of ships within the target sea area; For the first The effective speed of a ship; For the first Only the ship's maneuverability; The formula for calculating constraint complexity is as follows: ； in, This represents the average still-water safe distance for all vessels within the target sea area. and The first Only the length and width of the ship; For the first Only the safe distance between ships; Step S4: Calculate the dynamic traffic flow complexity threshold based on multi-source data, and classify the complexity level according to the real-time traffic flow complexity and the dynamic traffic flow complexity threshold; In step S4, the dynamic traffic flow complexity threshold is determined as follows: Calculate the basic saturation complexity The calculation formula is as follows: ； in, Regarding the waterway classification The relevant mapping function shows that the channel grade is positively correlated with the basic saturation complexity; The dynamic threshold correction coefficient is calculated using the following formula: ； in, The maximum number of vessels designed for the target sea area and waterway. and These are the visibility variation coefficient and the wind speed variation coefficient, respectively. and These are the real-time average visibility and the set visibility value, respectively. The average wind speed in the target sea area's shipping lanes; The dynamic traffic flow complexity threshold is calculated using the following formula: 。 2. The method for obtaining maritime traffic flow complexity according to claim 1, characterized in that: In step S1, the ship data includes design speed, total ship weight, static water resistance, static water safety distance, ship size, draft, speed, maximum draft, set base depth, and total number of ships. Hydrometeorological data include wind direction angle, wind speed, current speed, wave height, wave direction, actual water depth, real-time visibility, and set visibility value; The waterway data includes waterway line location data and waterway classification, and the total waterway area is calculated based on the waterway line location data.

3. The method for obtaining maritime traffic flow complexity according to claim 2, characterized in that: In step S2, the first The effective speed of the ship The expression is as follows: ； in, For the first Only the ship's design speed, The influence coefficient related to the total weight of the ship. For the first The total resistance of the ship only For the first The static water resistance of the ship only; The calculation formula is as follows: ； in, The first fitting coefficient, air density, For the reason about the The wind direction angle at the location of the ship only The drag coefficient function, For the first Only the height of the ship, For the first Only the ship's draft, The windward area function, For the first The wind speed at the location of the ship only. For the first The speed of the ship.

4. The method for obtaining maritime traffic flow complexity according to claim 3, characterized in that: In step S2, the first Only the safe draft of a ship The expression is as follows: ； in, For the first The maximum draft of the ship, The second fitting coefficient, For the first The wave height is determined solely by the location of the vessel. For the first The wave direction at the location of the ship only. For the first Only the actual water depth at the location of the vessel For the first The basic water depth for the vessel only. The third fitting coefficient, For the first The current velocity at the location of the ship only.

5. The method for obtaining maritime traffic flow complexity according to claim 4, characterized in that: In step S2, the first Only the ship's turning flexibility The expression is as follows: ； in, For the first The still water turning coefficient of a ship is related to its size. and All are correction factors.

6. The method for obtaining maritime traffic flow complexity according to claim 5, characterized in that: In step S2, the first safe distance between ships The expression is as follows: ； in, For the first The still water safety distance for ships.

7. The method for obtaining maritime traffic flow complexity according to claim 6, characterized in that, In step S4, the complexity levels are divided as follows: when At that time, the complexity level is level one; when At that time, the complexity level is level two; when At that time, the complexity level was three. when At that time, the complexity level was four.

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