An autonomous ship port water area navigation scene self-adaptive identification method based on an electronic chart

Abstract

This invention provides an adaptive identification method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts. The method includes: systematically classifying port waterway navigation scenarios; loading electronic nautical charts, extracting landmarks in a hierarchical structure, and filtering landmarks based on their identification codes to assist in identifying navigation scenarios in port waters; parsing chart landmarks and constructing a geometric model including port boundaries, channel lines, and berth static landmarks; acquiring the vessel's latitude, longitude, speed, and heading information from AIS data, and combining this with the geometric model of the static landmarks to achieve real-time identification of port waterway scenarios. This invention enables real-time reading of electronic nautical charts and multi-dimensional scenario judgment based on dynamic vessel parameters (speed, heading, latitude, longitude, etc.). Therefore, the invention can efficiently and accurately identify the current navigation environment of a vessel, providing strong support for the autonomous navigation system of intelligent ships.

Description

Technical Field

[0001] This invention relates to the field of maritime traffic management technology, and more particularly to an adaptive recognition method for autonomous vessels navigating port waters based on electronic nautical charts. Background Technology

[0002] Port waters, as a crucial link connecting open waters and port nodes, experience a dynamic and ever-changing navigation environment. During navigation, MASS (Autonomous Surface Vessels) need to autonomously and dynamically adjust the types and accuracy of perceived information based on different navigation scenarios, and adopt different navigation decision-making modes according to different scenarios. When conducting remote monitoring, shore-based centers also need to provide corresponding maritime service information based on different scenarios. However, the unmanned or minimally staffed nature of MASS makes it impossible to rely on traditional manual methods to determine the current navigation scenario.

[0003] Against this backdrop, this invention develops an adaptive identification method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts, enabling autonomous vessels to determine their navigation scenarios in real time while navigating in port waters, thus providing a reliable environmental perception foundation for the autonomous navigation of MASS. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an adaptive identification method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts. This invention analyzes S-57 standard nautical chart data to construct geometric models of static landmarks such as port boundaries, channel lines, and berths. Combining this with dynamic vessel parameters (speed, heading, latitude and longitude, etc.), multi-dimensional judgment rules are designed to achieve accurate classification and real-time identification of port waters scenarios. The proposed method constructs a judgment system covering eight scenarios, enabling rapid and accurate identification of the current navigation scenario in port waters. This enhances the adaptability of the autonomous vessel navigation system (MASS) to complex port environments and provides a reliable environmental perception foundation for its autonomous navigation.

[0005] The technical means employed in this invention are as follows:

[0006] An adaptive recognition method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts includes:

[0007] S1. Systematically classify navigation scenarios in port waters.

[0008] S2. Load the electronic nautical chart, extract targets in a hierarchical structure, and filter targets in the port waters navigation scene based on the target identification code;

[0009] S3. Analyze nautical chart landmarks and construct a geometric model including port boundaries, channel lines, and static landmarks of berths;

[0010] S4. Obtain the latitude, longitude, speed, and heading information of ships from AIS data, and combine it with the geometric model of static objects to achieve real-time recognition of port waterway scenes.

[0011] Further, step S1 specifically includes:

[0012] S11. Set the actual navigation route of ships in the port waters, from berthing and unberthing, to navigation in the channel, and then to crossing the anchorage to enter the sea area.

[0013] S12. Based on the actual navigation routes of vessels in port waters, navigation scenarios are divided into eight categories: berthing, departure, entering the port, leaving the port, navigation in the channel, entering the anchorage, leaving the anchorage, and anchoring.

[0014] Further, step S2 specifically includes:

[0015] The original electronic chart files are read in a hierarchical structure, with each layer identified by a unique object code, representing a set of objects of the same type.

[0016] Further, step S3 specifically includes:

[0017] S31. Based on the electronic chart analysis results, the chart is divided into point-type landmarks, linear landmarks, and area-type landmarks. Linear landmarks and area-type landmarks are abstracted into discrete sets of landmark points, as follows:

[0018]

[0019] Where t represents the number of landmark points on the landmark boundary;

[0020] S32. Map the latitude and longitude coordinates of the landmark point to a rectangular coordinate system using Mercator projection. The specific formula is as follows:

[0021] X n =K(L-L0)

[0022]

[0023]

[0024] Among them, X n Y is the x-coordinate of the object point in the plane; n L0 is the ordinate of the object point in the plane; B is the latitude, L is the longitude; a is the length of the Earth's semi-major axis; b is the length of the Earth's semi-minor axis; e is the Earth's first eccentricity; N is the radius of curvature of the zonal circle.

[0025] S33. Define a circular search zone and calculate the distance from ship P0(X,,Y,) to each point (X,Y,). i ,Y i The distance d of ,) iThe calculation formula is as follows:

[0026]

[0027] S34. If ship P0(X,Y) reaches every point (X... i ,Y i The distance d) i If the retrieval radius is less than 5 nautical miles, the location information of the feature object to which the feature point belongs is extracted, and the distance between the feature object and the ship is calculated. The final object to be retrieved is determined according to the nearest principle, and the navigation scenario to which the ship belongs is determined based on the object and the ship's AIS dynamic navigation information.

[0028] Further, step S34 specifically includes:

[0029] S341. When navigating in and out of port, the Harbour landmark of the area type is retrieved, and the navigation scenario to which the ship belongs is determined based on the Harbour landmark and the ship's AIS dynamic navigation information.

[0030] S342. When navigating a waterway, if the Fairway beacon for the line type is detected, the navigation scenario to which the ship belongs is determined based on the Fairway beacon and the ship’s AIS dynamic navigation information.

[0031] S343. When a vessel is at anchor or entering or leaving an anchorage, the Anchorage,area marker is retrieved as the boundary line of the anchorage, and the navigation scenario to which the vessel belongs is determined based on the Anchorage,area marker and the vessel's AIS dynamic navigation information.

[0032] S344. When a vessel is berthing or unberthing, the vessel retrieves a Berth landmark of the area shape and determines the navigation scenario of the vessel based on the Berth landmark and the vessel's AIS dynamic navigation information.

[0033] Further, step S341 specifically includes:

[0034] S3411. Let the point on the boundary of the port area be (x). n ,y n Establish the set of polygon vertices as follows:

[0035]

[0036] Where M represents the number of object markers on the boundary;

[0037] S3412. Based on the ray method, determine whether a ship is inside a polygonal port area, as follows:

[0038]

[0039] Where x0, y0 represent the ship's latitude and longitude coordinates mapped to a rectangular coordinate system after Mercator projection transformation; when When, it indicates that the ship is inside the polygon; when This indicates that the ship is outside the polygon;

[0040] S3413. Using the vector relationship between the ship and the centroid of the polygon, determine whether the ship enters or leaves the polygon, as follows:

[0041] S3414. Using one vertex of a polygon as the origin, connect all non-adjacent vertices to divide the original n-sided polygon into (n-2) triangles. Let the centroid of one of the triangles be O. i ,(x i y i The vertex coordinates are A1(x, ), a y a ), A2(x b y b ), A3(x c y c Then we have:

[0042]

[0043] Where s1 represents the area of ​​a triangle;

[0044] S3415. Using the area formula s1 for a triangle, the coordinates of the centroid of the polygon are O(O). x O y The formula is as follows:

[0045]

[0046] S3416. Based on the obtained centroid coordinates O(O) of the polygon... x O y This, together with the ship's coordinates P0(x0,y0), forms the ship-centroid vector. With velocity vector Perform the product:

[0047]

[0048] When T1 > 0, it indicates that the ship is entering the polygon, and the navigation state is port entry; when T1 < 0, it indicates that the ship is leaving the polygon, and the navigation state is port departure; when T1 = 0, it indicates that the velocity vector... and ship-center of mass vector If the ship is vertical, then select two more moments with different ship positions and speeds, and repeat the centroid method process to ensure the accuracy of the judgment.

[0049] Further, step S342 specifically includes:

[0050] S3421. When navigating a waterway, the Fairway landmark, representing the centerline of the waterway, can be retrieved. It is composed of discrete point set formulas.

[0051]

[0052] S3422. Search for the nearest landmark within the search area, calculate the distance between the ship and the channel centerline, and let the ship's current position be P(x). o ,y o The closest distance is d. min The calculation formula is as follows:

[0053]

[0054] When d min If the width is less than half the width of the channel, it indicates that the vessel is inside the channel. W represents the channel width, which can be obtained by reading the additional fields in the nautical chart attributes.

[0055] Further, step S343 specifically includes:

[0056] S3431. Based on the fact that the ship's speed approaches zero while at anchor, a speed threshold is set, as follows:

[0057]

[0058] Where N = 60, it means the time window is 1 minute;

[0059] S3432. When a vessel is at anchor, its position remains relatively stable; the maximum drift radius R of the vessel is defined. d and location variance constraints as follows:

[0060]

[0061] As shown in the above formula, when the ship is located within the anchorage area and its speed is less than 0.5 knots, the drift radius R d <20 meters, location variance constraint When the distance is measured, determine if the vessel is at anchor.

[0062] S3433. Since the anchorage is a polygonal area on the electronic nautical chart, the method for determining whether a ship is entering or leaving the anchorage is similar to that for entering or leaving the port. First, the geometric area of ​​the anchorage is extracted from the electronic nautical chart. Then, the ray casting method is used to determine whether the ship's position is within the polygon of the anchorage. At that time, the ship was in the anchorage; when At that time, the ship was outside the anchorage;

[0063] S3434. Determining the direction of a ship's approach or departure using the center of mass method. The formula for the center of mass method is as follows:

[0064]

[0065] When T1 > 0, the ship is entering the anchorage; when T1 < 0, the ship is leaving the anchorage.

[0066] Further, step S344 specifically includes:

[0067] S3441. When a vessel locates a berth within the search circle, its position P0(x0,y0) is determined. The position P1(x1,y1) of the centroid of the berth area is calculated using the centroid method, and the vessel's velocity vector is obtained. and berth vector The formula for the vector product of the two is as follows:

[0068]

[0069] Where T2 represents the dot product of the velocity vector and the berth vector, T2 > 0 indicates that the ship is approaching the berth area; T2 < 0 indicates that the ship is moving away from the berth area.

[0070] S3442. Apply safety distance constraints to berthing and unberthing operations, assuming the set of points within the berth is:

[0071] {(x k y k )} 1≤k≤M

[0072] Let d2 be the distance between the ship and the nearest point of the berth. The formula for the safety distance constraint is:

[0073]

[0074] When d2>50 and T2>0, it is determined that the ship is berthing; when d2<50 and T2<0, it is determined that the ship is unberthing.

[0075] Compared with the prior art, the present invention has the following advantages:

[0076] 1. This invention provides an adaptive identification method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts. The method has comprehensive scenario coverage, analyzes the actual navigation scenarios of ships entering and leaving the port, constructs a port landmark model based on electronic nautical charts, and completes accurate judgment of eight types of scenarios, including entering and leaving the port.

[0077] 2. The present invention provides an adaptive identification method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts. Compared with traditional vessel navigation scenario identification models, the proposed model has more comprehensive discrimination factors. It constructs geometric models of static landmarks such as port boundaries, waterways, and berths, and designs multi-dimensional judgment rules in combination with dynamic vessel parameters (speed, heading, latitude and longitude, etc.), thereby achieving accurate classification and real-time identification of port waters scenarios.

[0078] 3. The present invention provides an adaptive identification method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts. By accurately identifying the navigation environment, it effectively improves the autonomous perception and identification capabilities of MASS of the current navigation environment, and provides reliable geographic information support for autonomous navigation systems.

[0079] Based on the above reasons, this invention can be widely applied in fields such as maritime transportation. Attached Figure Description

[0080] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0081] Figure 1 This is a flowchart of the method of the present invention.

[0082] Figure 2 This is a schematic diagram of the centroid method for solving the centroid of a surface object according to the present invention.

[0083] Figure 3 This is a diagram showing the correspondence between the object code and the specific object in this invention.

[0084] Figure 4 These are schematic diagrams illustrating various ship navigation scenarios provided in embodiments of the present invention.

[0085] Figure 5 This is a schematic diagram illustrating the principle of ship entry and exit scenario judgment provided in an embodiment of the present invention. Detailed Implementation

[0086] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0087] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or device.

[0088] like Figure 1 As shown, this invention provides an adaptive identification method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts, including:

[0089] S1. Systematically classify navigation scenarios in port waters.

[0090] S2. Load the electronic nautical chart, extract targets in a hierarchical structure, and filter targets in the port waters navigation scene based on the target identification code;

[0091] S3. Analyze nautical chart landmarks and construct a geometric model including port boundaries, channel lines, and static landmarks of berths;

[0092] S4. Obtain the latitude, longitude, speed, and heading information of ships from AIS data, and combine it with the geometric model of static objects to achieve real-time recognition of port waterway scenes.

[0093] In a specific implementation, as a preferred embodiment of the present invention, step S1 specifically includes:

[0094] S11. Set the actual navigation route of ships in the port waters, from berthing and unberthing, to navigation in the channel, and then to crossing the anchorage to enter the sea area.

[0095] S12. Based on the actual navigation routes of vessels in port waters, navigation scenarios are divided into eight categories: berthing, departure, entering port, leaving port, channel navigation, entering anchorage, leaving anchorage, and anchoring. Navigation scenarios are as follows: Figure 2 As shown.

[0096] In a specific implementation, as a preferred embodiment of the present invention, step S2 specifically includes:

[0097] The original electronic chart file is read in a hierarchical structure, with each layer identified by a unique object code, representing a set of objects of the same type. The encoding is as follows: Figure 3 As shown.

[0098] In a specific implementation, as a preferred embodiment of the present invention, step S3 specifically includes:

[0099] S31. Based on the electronic chart analysis results, the chart is divided into point-type landmarks, linear landmarks, and area-type landmarks. Linear landmarks and area-type landmarks are abstracted into discrete sets of landmark points, as follows:

[0100]

[0101] Where t represents the number of landmark points on the landmark boundary;

[0102] S32. Map the latitude and longitude coordinates of the landmark point to a rectangular coordinate system using Mercator projection. The specific formula is as follows:

[0103] X n =K(L-L0)

[0104]

[0105] Among them, X n Y is the x-coordinate of the object point in the plane; n L0 is the ordinate of the object point in the plane; B is the latitude, L is the longitude; a is the length of the Earth's semi-major axis; b is the length of the Earth's semi-minor axis; e is the Earth's first eccentricity; N is the radius of curvature of the zonal circle.

[0106] S33. Define a circular search zone and calculate the distance from ship P0(X,,Y,) to each point (X,Y,). i ,Y i The distance d of ,) i The calculation formula is as follows:

[0107]

[0108] S34. If ship P0(X,Y) reaches every point (X... i ,Y i The distance d) i If the retrieval radius is less than 5 nautical miles, the location information of the feature object to which the feature point belongs is extracted, and the distance between the feature object and the ship is calculated. The final object to be retrieved is determined according to the nearest principle, and the navigation scenario to which the ship belongs is determined based on the object and the ship's AIS dynamic navigation information.

[0109] In a specific implementation, as a preferred embodiment of the present invention, step S34 specifically includes:

[0110] S341. When navigating in and out of port, the Harbour landmark of the area type is retrieved, and the navigation scenario to which the ship belongs is determined based on the Harbour landmark and the ship's AIS dynamic navigation information.

[0111] S342. When navigating a waterway, if the Fairway beacon for the line type is detected, the navigation scenario to which the ship belongs is determined based on the Fairway beacon and the ship’s AIS dynamic navigation information.

[0112] S343. When a vessel is at anchor or entering or leaving an anchorage, the Anchorage,area marker is retrieved as the boundary line of the anchorage, and the navigation scenario to which the vessel belongs is determined based on the Anchorage,area marker and the vessel's AIS dynamic navigation information.

[0113] S344. When a vessel is berthing or unberthing, the vessel retrieves a Berth landmark of the area shape and determines the navigation scenario of the vessel based on the Berth landmark and the vessel's AIS dynamic navigation information.

[0114] In a specific implementation, as a preferred embodiment of the present invention, step S341 specifically includes:

[0115] S3411. Let the point on the boundary of the port area be (x). n ,y n Establish the set of polygon vertices as follows:

[0116]

[0117] Where M represents the number of object markers on the boundary;

[0118] S3412. Based on the ray method, determine whether a ship is inside a polygonal port area, as follows:

[0119]

[0120] Where x0, y0 represent the ship's latitude and longitude coordinates mapped to a rectangular coordinate system after Mercator projection transformation; when When, it indicates that the ship is inside the polygon; when This indicates that the ship is outside the polygon;

[0121] S3413. Using the vector relationship between the ship and the centroid of the polygon, determine whether the ship enters or leaves the polygon. A schematic diagram is shown below. Figure 4 As shown, the details are as follows:

[0122] S3414. Using one vertex of a polygon as the origin, connect all non-adjacent vertices to divide the original n-sided polygon into (n-2) triangles. Let the centroid of one of the triangles be O. i ,(x i y i The vertex coordinates are A1(x, ), a y a ), A2(x b y b ), A3(x c y c Then we have:

[0123]

[0124] Where s1 represents the area of ​​a triangle;

[0125] S3415. Using the area formula s1 for a triangle, the coordinates of the centroid of the polygon are O(O). x O y The formula is as follows:

[0126]

[0127] S3416. Based on the obtained centroid coordinates O(O) of the polygon... x O y This, together with the ship's coordinates P0(x0,y0), forms the ship-centroid vector. With velocity vector Perform the product:

[0128]

[0129] When T1 > 0, it indicates that the ship is entering the polygon, and the navigation state is port entry; when T1 < 0, it indicates that the ship is leaving the polygon, and the navigation state is port departure; when T1 = 0, it indicates that the velocity vector... and ship-center of mass vector If the ship is vertical, then select two more moments with different ship positions and speeds, and repeat the centroid method process to ensure the accuracy of the judgment.

[0130] In a specific implementation, as a preferred embodiment of the present invention, step S342 specifically includes:

[0131] S3421. When navigating a waterway, the Fairway landmark, representing the centerline of the waterway, can be retrieved. It is composed of discrete point set formulas.

[0132]

[0133] S3422. Search for the nearest landmark within the search area, calculate the distance between the ship and the channel centerline, and let the ship's current position be P(x). o ,y o The closest distance is d. min The calculation formula is as follows:

[0134]

[0135] When d min If the width is less than half the width of the channel, it indicates that the vessel is inside the channel. W represents the channel width, which can be obtained by reading the additional fields in the nautical chart attributes.

[0136] In a specific implementation, as a preferred embodiment of the present invention, step S343 specifically includes:

[0137] S3431. Based on the fact that the ship's speed approaches zero while at anchor, a speed threshold is set, as follows:

[0138]

[0139] Where N = 60, it means the time window is 1 minute;

[0140] S3432. When a vessel is at anchor, its position remains relatively stable; the maximum drift radius R of the vessel is defined. d and location variance constraints as follows:

[0141]

[0142] As shown in the above formula, when the ship is located within the anchorage area and its speed is less than 0.5 knots, the drift radius R d <20 meters, location variance constraint When the distance is measured, determine if the vessel is at anchor.

[0143] S3433. Since the anchorage is a polygonal area on the electronic nautical chart, the method for determining whether a ship is entering or leaving the anchorage is similar to that for entering or leaving the port. First, the geometric area of ​​the anchorage is extracted from the electronic nautical chart. Then, the ray casting method is used to determine whether the ship's position is within the polygon of the anchorage. At that time, the ship was in the anchorage; when At that time, the ship was outside the anchorage;

[0144] S3434. Determining the direction of a ship's approach or departure using the center of mass method. The formula for the center of mass method is as follows:

[0145]

[0146] When T1 > 0, the ship is entering the anchorage; when T1 < 0, the ship is leaving the anchorage.

[0147] In a specific implementation, as a preferred embodiment of the present invention, step S344 specifically includes:

[0148] S3441. When a vessel locates a berth within the search circle, its position P0(x0,y0) is determined. The position P1(x1,y1) of the centroid of the berth area is calculated using the centroid method, and the vessel's velocity vector is obtained. and berth vector The formula for the vector product of the two is as follows:

[0149]

[0150] Where T2 represents the dot product of the velocity vector and the berth vector, T2 > 0 indicates that the ship is approaching the berth area; T2 < 0 indicates that the ship is moving away from the berth area.

[0151] S3442. Due to the precision required for berthing and unberthing operations, safety distance constraints are necessary. Let the set of points within the berth be:

[0152] {(x k y k )} 1≤k≤M

[0153] Let d2 be the distance between the ship and the nearest point of the berth. The formula for the safety distance constraint is:

[0154]

[0155] When d2 > 50 and T2 > 0, the vessel is determined to be berthing; when d2 < 50 and T2 < 0, the vessel is determined to be unberthing. The diagram is shown below. Figure 5 As shown.

[0156] 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 the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive recognition method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts, characterized in that, include: S1. Systematically classify navigation scenarios in port waters; S2. Load the electronic nautical chart, extract targets in a hierarchical structure, and filter targets in the port waters navigation scene based on the target identification code; S3. Analyze nautical chart landmarks and construct a geometric model including port boundaries, channel lines, and static berth landmarks, including: S31. Based on the electronic chart analysis results, the chart is divided into point-type landmarks, linear landmarks, and area-type landmarks. Linear landmarks and area-type landmarks are abstracted into discrete sets of landmark points, as follows: in, t Indicates the number of landmark points on the boundary of the object; S32. Map the latitude and longitude coordinates of the landmark point to a rectangular coordinate system using Mercator projection. The specific formula is as follows: Among them, is the abscissa of the object point plane; is the ordinate of the object point plane; is the central meridian; B is the latitude, L is the longitude; a is the length of the semi-major axis of the earth; b is the length of the semi-minor axis of the earth; e is the first eccentricity of the earth; N is the radius of curvature of the prime vertical; S33. Define a circular search area and calculate the number of ships. , ) to each point distance The calculation formula is as follows: S34, If the ship , ) to each point distance If the search radius is less than 5 nautical miles, the location information of the feature point to which it belongs is extracted, and the distance between the feature point and the ship is calculated. Based on the nearest principle, the final target to be searched is determined, and the ship's navigation scenario is determined based on the target and the ship's AIS dynamic navigation information, including: S341. When navigating in and out of port, the Harbour landmark of the area type is retrieved, and the navigation scenario to which the ship belongs is determined based on the Harbour landmark and the ship's AIS dynamic navigation information. S342. When navigating a waterway, if the Fairway beacon for the line type is detected, the navigation scenario to which the ship belongs is determined based on the Fairway beacon and the ship’s AIS dynamic navigation information. S343. When a vessel is at anchor or entering or leaving an anchorage, the Anchorage area markers of the area type are retrieved as the boundary line of the anchorage, and the navigation scenario to which the vessel belongs is determined based on the Anchorage area markers and the vessel’s AIS dynamic navigation information. S344. When a vessel is berthing or unberthing, if a Berth object of a certain shape is retrieved, the navigation scenario to which the vessel belongs is determined based on the Berth object and the vessel’s AIS dynamic navigation information. S4. Obtain the latitude, longitude, speed, and heading information of ships from AIS data, and combine them with the geometric model of static objects to achieve real-time recognition of port waterway scenes.

2. The adaptive recognition method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts according to claim 1, characterized in that, Step S1 specifically includes: S11. Set the actual navigation route of ships in the port waters, from berthing and unberthing, to navigation in the channel, and then to crossing the anchorage to enter the sea area. S12. Based on the actual navigation routes of vessels in port waters, navigation scenarios are divided into eight categories: berthing, departure, entering the port, leaving the port, navigation in the channel, entering the anchorage, leaving the anchorage, and anchoring.

3. The adaptive recognition method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts according to claim 1, characterized in that, Step S2 specifically includes: The original electronic chart files are read in a hierarchical structure, with each layer identified by a unique object code, representing a set of objects of the same type.

4. The adaptive recognition method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts according to claim 1, characterized in that, Step S341 specifically includes: S3411, Let the point on the boundary of the port area be... Create a set of polygon vertices as follows: in, M Indicates the number of landmarks on the boundary; S3412. Based on the ray method, determine whether a ship is inside a polygonal port area, as follows: in, This represents the ship's latitude and longitude coordinates mapped to a rectangular coordinate system after Mercator projection transformation; when When, it indicates that the ship is inside the polygon; when This indicates that the ship is outside the polygon; S3413. Using the vector relationship between the ship and the centroid of the polygon, determine whether the ship enters or leaves the polygon, as follows: S3414. Taking one vertex of the polygon as the origin, connect all non-adjacent vertices, and then... n The polygon is divided into ( n -2) triangles, let the centroid of one of the triangles be... ( , The vertex coordinates are... ( , ), ( , ), ( , Then we have: in, Represents the area of ​​a triangle; S3415, From the formula for the area of ​​a triangle The centroid coordinates of the polygon are obtained as follows: The formula is as follows: S3416. Based on the obtained centroid coordinates of the polygon... ), and ship coordinates , ) constitutes the ship-center-of-mass vector , With velocity vector Perform the product: when When this indicates that the ship is entering the polygon, its navigation status is port entry; when When this indicates that the ship is leaving the polygon, its navigation status is departure from port; when When, it indicates the velocity vector and ship-center of mass vector If the ship is vertical, then select two more moments with different ship positions and speeds, and repeat the centroid method process to ensure the accuracy of the judgment.

5. The adaptive recognition method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts according to claim 1, characterized in that, Step S342 specifically includes: S3421. When navigating a waterway, the Fairway landmark, representing the centerline of the waterway, is retrieved and is composed of a discrete point set formula: S3422. Search for the nearest landmark within the search area, calculate the distance between the ship and the channel centerline, and let the ship's current position be P. The closest distance is The calculation formula is as follows: when If the width is less than half the width of the channel, it indicates that the vessel is inside the channel. , W This indicates the width of the channel, which can be obtained by reading the additional fields in the nautical chart attributes.

6. The adaptive recognition method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts according to claim 1, characterized in that, Step S343 specifically includes: S3431. Based on the fact that the ship's speed approaches zero while at anchor, a speed threshold is set, as follows: in N =60 indicates that the time window is 1 minute; S3432. When a vessel is at anchor, its position remains relatively stable; the maximum drift radius of the vessel is defined. and location variance constraints ,as follows: As shown in the above formula, when the ship is located within the anchorage area and its speed is less than 0.5 knots, the drift radius is... <20 meters, location variance constraint When the distance is less than 25 meters, the vessel is judged to be in an anchored state; S3433. Extract the geometric region of the anchorage from the electronic nautical chart, and use the ray casting method to determine whether the ship's position is within the anchorage polygon, i.e., when... At that time, the ship was in the anchorage; when At that time, the ship was outside the anchorage; S3434. Determining the direction of a ship's approach or departure using the center of mass method. The formula for the center of mass method is as follows: when At that time, the ship was entering the anchorage; when At that time, the ship was leaving the anchorage.

7. The adaptive recognition method for autonomous vessel navigation scenarios in port waters based on electronic nautical charts according to claim 1, characterized in that, Step S344 specifically includes: S3441. When a vessel finds a berth within the search area, determine the vessel's position. The position of the centroid of the berth area was calculated using the centroid method. The velocity vector of the ship is obtained. and berth vector The formula for the vector product of the two is as follows: in, This represents the dot product of the velocity vector and the berth vector. >0 indicates that the vessel is approaching the berth area; <0 indicates that the vessel is moving away from the berth area; S3442. Apply safety distance constraints to berthing and unberthing operations, assuming the set of points within the berth is: set up The safe distance constraint formula is: (This is the distance between the ship and the nearest point of the berth.) when >50, When the value is greater than 0, it is determined that the vessel will proceed with berthing operations. <50, When the time is less than 0, it is determined that the vessel is in the process of unberthing.

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