Ship collision risk early warning method and device based on VDES terminal

Abstract

The application provides a ship collision risk early warning method and device based on a VDES terminal, and the method comprises the following steps: obtaining the maximum turning speed and the minimum turning radius of the physical maneuvering boundary constraint corresponding to the reference maneuvering behavior by matching the space-time state flow in the preset maneuvering behavior library, taking the current position of a target ship as a starting point, and constructing a fan-shaped feasible region; determining the minimum intersection distance based on the spatial geometric relationship between the target ship candidate path cluster generated by the fan-shaped feasible region and the ship sailing track; performing consistency comparison on the curvature change trend of the main threat path which forms the greatest potential threat to the ship and the theoretical curvature form of the reference maneuvering behavior based on the minimum intersection distance, and obtaining a confidence interval; and determining whether there is a collision risk based on the overlap between the spatial occupation range of the main threat path in the target time window of the collision risk outbreak calibrated based on the confidence interval and the hull envelope of the ship. The application improves the authenticity and accuracy of collision risk prediction.

Description

Technical Field

[0001] This invention relates to the field of computer technology, and in particular to a method and device for ship collision risk early warning based on a VDES terminal. Background Technology

[0002] In the fields of vessel traffic management systems and maritime collision avoidance decision support, existing collision risk warning methods based on VDES (Very High Frequency Data Exchange System) or AIS mainly rely on kinematic extrapolation of the target vessel's historical trajectory. A typical existing method is to receive the target vessel's position, speed, and heading data. Assuming the target vessel maintains its current velocity vector or constant turning rate, a future predicted trajectory is directly generated using a linear or circular model. The nearest encounter distance (DCPA) and nearest encounter time (TCPA) between the vessel and this predicted trajectory are calculated, and an alarm is issued if the values ​​are below a safety threshold.

[0003] However, the prediction logic of existing methods is open-loop and static, failing to reflect the dynamic coupling between the physical inertia of ship maneuvering and the pilot's intention. In actual navigation, ships possess enormous mass and inertia; their turning and acceleration changes are gradual physical processes, not instantaneous geometric leaps. Simultaneously, the pilot's evasive intentions (such as a sharp right turn) severely limit the ship's maneuverability. Predicted trajectories generated by existing methods often contain numerous "pseudo-trajectories" that violate physical inertia (such as instantaneous right-angle turns) or pilot's intentions (such as predicting a left turn despite a clear right turn intention). These pseudo-trajectories cause the system to calculate numerous non-existent collision risks in complex interaction scenarios, resulting in a high false alarm rate, low reliability, and an inability to accurately identify real collision threats. Summary of the Invention

[0004] This invention provides a ship collision risk early warning method and device based on a VDES terminal, which can realize the constraint of the feasible domain of the target ship by physically manipulating the boundary, eliminate false trajectories that do not conform to the laws of physics from the source, and improve the authenticity and accuracy of collision risk prediction.

[0005] In a first aspect, the present invention provides a ship collision risk early warning method based on a VDES terminal, comprising: The spatiotemporal state flow of the target ship received by the VDES terminal is matched in a pre-set maneuvering behavior library to obtain the baseline maneuvering behavior. Based on the maximum turning rate and minimum turning radius of the physical maneuvering boundary constraints corresponding to the baseline maneuvering behavior, a sector-shaped feasible region is constructed starting from the current position of the target ship. Uniform sampling is performed based on the sector feasible region to generate a cluster of candidate paths for the target ship. Based on the spatial geometric relationship between the candidate path cluster and the ship's own trajectory, the minimum intersection distance between each candidate path and the ship's hull envelope is determined. Based on the minimum rendezvous distance, the main threat path that poses the greatest potential threat to the vessel is selected, and the curvature change trend of the main threat path is compared with the theoretical curvature shape of the benchmark maneuvering behavior to obtain a confidence interval that reflects the intention of the target vessel. Based on the overlap between the spatial extent of the main threat path and the ship's hull envelope within the target time window of the collision risk outbreak as defined by the confidence interval, it is determined whether a collision risk exists.

[0006] Secondly, the present invention also provides a ship collision risk warning device based on a VDES terminal, applied to the ship collision risk warning method based on a VDES terminal as described in the first aspect; the ship collision risk warning device based on a VDES terminal includes: The feasible region analysis module is used to match the spatiotemporal state flow of the target ship received by the VDES terminal with a pre-set maneuvering behavior library to obtain the baseline maneuvering behavior. Based on the maximum turning rate and minimum turning radius of the physical maneuvering boundary constraints corresponding to the baseline maneuvering behavior, a sector-shaped feasible region is constructed starting from the current position of the target ship. The spatial relationship analysis module is used to perform uniform sampling based on the sector feasible region to generate a cluster of candidate paths for the target ship, and to determine the minimum intersection distance between each candidate path for the target ship and the ship's hull envelope based on the spatial geometric relationship between the candidate path cluster and the ship's own trajectory. The path confidence analysis module is used to filter out the main threat path that poses the greatest potential threat to the ship based on the minimum rendezvous distance, and to compare the curvature change trend of the main threat path with the theoretical curvature shape of the benchmark maneuvering behavior to obtain a confidence interval that reflects the intention of the target ship. The collision warning module is used to determine whether there is a collision risk based on the overlap between the spatial occupancy range of the main threat path and the ship's hull envelope within the target time window of the collision risk outbreak calibrated by the confidence interval.

[0007] Thirdly, the present invention also provides an electronic device, comprising: a memory for storing computer software programs; and a processor for reading and executing the computer software programs, thereby realizing the ship collision risk warning method based on the VDES terminal as described above.

[0008] Fourthly, the present invention also provides a non-transitory computer-readable storage medium storing a computer software program, which, when executed by a processor, implements the ship collision risk warning method based on a VDES terminal as described above.

[0009] Fifthly, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the ship collision risk warning method based on a VDES terminal as described above.

[0010] The ship collision risk warning method based on a VDES terminal provided in this invention receives the spatiotemporal state stream of the target ship through the VDES terminal, matches it with a pre-set maneuvering behavior library to obtain a baseline maneuvering behavior, extracts the physical maneuvering boundary constraints (maximum turning rate and minimum turning radius) corresponding to the baseline maneuvering behavior, and constructs a sector-shaped feasible region starting from the target ship's current position. The core function of the sector-shaped feasible region is to accurately cover all physically feasible positions of the target ship under the current baseline maneuvering behavior, eliminating positions that violate the ship's physical inertia (such as instantaneous right-angle turns) from the source and avoiding the generation of false trajectories. Next, a cluster of candidate paths for the target ship is generated by uniform sampling based on the sector-shaped feasible region, ensuring that all candidate paths are within the physical feasible range. Then, by analyzing the spatial geometric relationship between the candidate path cluster and the ship's own trajectory, the minimum intersection distance between each candidate path and the ship's hull envelope is calculated and determined, avoiding risk misjudgment due to the lack of path basis. Then, based on the minimum intersection distance, the primary threat path posing the greatest potential threat to the vessel is selected. By comparing the curvature change trend of the primary threat path with the theoretical curvature shape of the baseline maneuvering behavior, a confidence interval reflecting the target vessel's intention is obtained. This effectively matches the driver's maneuvering intention (e.g., a right turn intention corresponds to a corresponding curvature trend), eliminating false trajectories that contradict the driver's intention and solving the problem that existing methods cannot reflect the driver's intention. Subsequently, based on the confidence interval, the target time window for collision risk outbreak is determined, focusing on high-risk periods. Then, by analyzing the overlap between the spatial occupancy range of the primary threat path and the vessel's hull envelope within this time window, the existence of collision risk is accurately determined, achieving accurate risk identification. Therefore, this embodiment of the invention solves the technical problem in the background art where the prediction logic is open-loop and static, failing to reflect the dynamic coupling relationship between the vessel's maneuvering physical inertia and the driver's intention, resulting in a large number of false trajectories reflecting the driver's intention, leading to a high false alarm rate and low reliability. It achieves the elimination of false trajectories that do not conform to physical laws from the source by constraining the feasible domain of the target vessel through physical maneuvering boundaries, thereby improving the authenticity and accuracy of collision risk prediction. Attached Figure Description

[0011] Figure 1This is a flowchart illustrating the ship collision risk early warning method based on a VDES terminal provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of the ship collision risk warning device based on the VDES terminal provided in an embodiment of the present invention; Figure 3 An embodiment diagram of the electronic device provided in this invention; Figure 4 An embodiment diagram of a computer-readable storage medium provided in accordance with the present invention. Detailed Implementation

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0013] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0014] In the description of this invention, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this invention is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

[0015] See Figure 1 , Figure 1 This is a flowchart illustrating the ship collision risk warning method based on a VDES terminal provided by the present invention. In this embodiment of the invention, the executing entity of the ship collision risk warning method based on a VDES terminal is a collision warning device. Therefore, the ship collision risk warning method based on a VDES terminal includes: Step 10: Based on the spatiotemporal state flow of the target vessel received by the VDES terminal, match it in a pre-set maneuvering behavior library to obtain the baseline maneuvering behavior. Then, based on the maximum turning rate and minimum turning radius of the physical maneuvering boundary constraints corresponding to the baseline maneuvering behavior, construct a sector-shaped feasible region starting from the target vessel's current position. The sector-shaped feasible region covers all physically feasible positions of the target vessel under the baseline maneuvering behavior.

[0016] Optionally, the collision warning device receives the spatiotemporal state stream of the target vessel through the VDES terminal. The spatiotemporal state stream refers to a series of spatiotemporal state data of the target vessel within a continuous time period. Each spatiotemporal state data includes the target vessel's current position, current speed, current heading, and the corresponding data acquisition time. The data acquisition time interval is set according to the VDES transmission protocol to ensure that the motion change process of the target vessel can be fully reflected.

[0017] The maneuvering behavior database is a pre-stored database containing various typical maneuvering behaviors of ships. These typical maneuvering behaviors include, but are not limited to, common ship maneuvering actions such as straight navigation, constant speed turning, acceleration turning, and deceleration turning. Each typical maneuvering behavior corresponds to unique identification information, physical maneuvering boundary constraint parameters, and theoretical motion characteristic parameters. The physical maneuvering boundary constraint parameters refer to the range of motion parameters that a ship cannot exceed due to its own physical characteristics when performing the maneuvering behavior. The theoretical motion characteristic parameters refer to the motion law parameters that a ship should exhibit when performing the maneuvering behavior under ideal conditions.

[0018] The collision warning device matches the spatiotemporal state stream of the target vessel with various typical maneuvering behaviors in a pre-set maneuvering behavior library. The matching process is as follows: extract the motion change characteristics of the target vessel in the spatiotemporal state stream, including the rate of change of speed, the rate of change of course, and the shape of the trajectory of position change, etc., compare the above motion change characteristics with the theoretical motion characteristic parameters corresponding to each typical maneuvering behavior in the maneuvering behavior library, and select the typical maneuvering behavior that is closest to the current motion change characteristics of the target vessel. This typical maneuvering behavior is determined as the benchmark maneuvering behavior. The benchmark maneuvering behavior refers to the reference maneuvering behavior that best fits the current motion state of the target vessel and can be used to predict its subsequent motion trend.

[0019] The collision warning device extracts the maximum turning rate and minimum turning radius from the physical maneuvering boundary constraints corresponding to the reference maneuvering behavior. The maximum turning rate refers to the maximum speed at which the ship's course can change when performing the reference maneuvering behavior. Its value is determined by the ship's hull structure, power system, maneuvering system, and other physical characteristics. It is the upper limit of turning speed that the ship cannot exceed under this maneuvering behavior. The minimum turning radius refers to the minimum circular trajectory radius that the ship can complete when performing the reference maneuvering behavior. Its value is determined by the ship's physical characteristics. It is the minimum space requirement for the ship to turn under this maneuvering behavior.

[0020] The collision warning device constructs a sector-shaped feasible region based on the target vessel's current position, combined with the maximum turning rate and minimum turning radius. The sector-shaped feasible region refers to the fan-shaped area encompassing all physically feasible positions that the target vessel can reach within a certain timeframe, constrained by physical maneuvering boundaries when performing baseline maneuvers. The vertex is the target vessel's current position, and the two sides of the sector correspond to the motion boundaries of the target vessel turning left and right at its maximum turning rate. The radius of the sector corresponds to the maximum distance the target vessel can travel within a preset timeframe. The preset timeframe is set according to maritime navigation safety requirements to ensure coverage of the vessel's inertial response process. The sector-shaped feasible region completely covers all physically feasible positions of the target vessel under baseline maneuvers, effectively eliminating false motion positions that violate the vessel's physical inertia.

[0021] Step 20: Perform uniform sampling based on the sector feasible region to generate a cluster of candidate paths for the target ship, and determine the minimum intersection distance between each candidate path for the target ship and the ship's hull envelope based on the spatial geometric relationship between the candidate path cluster and the ship's own trajectory.

[0022] Optionally, the collision warning device performs uniform sampling based on a sector-shaped feasible region. Uniform sampling refers to selecting several sampling points at different directions and distances within the sector-shaped feasible region according to a preset sampling interval. The setting of the sampling interval needs to take into account both computational efficiency and prediction accuracy, ensuring that the sampling points can be evenly distributed throughout the entire sector-shaped feasible region. This avoids the situation where the sampling is too sparse, resulting in the omission of key feasible locations, or the situation where the sampling is too dense, resulting in excessive computation.

[0023] The collision warning device generates a cluster of candidate paths for the target ship based on the selected sampling points and the motion characteristics of the target ship's current speed and reference maneuvering behavior. The cluster of candidate paths is a set of multiple candidate paths. Each candidate path starts from the target ship's current position and takes a sampling point within the sector feasible region as a waypoint or end point. The direction and curvature of the path conform to the physical maneuvering boundary constraints corresponding to the reference maneuvering behavior, reflecting the various motion trajectories that the target ship may exhibit under the reference maneuvering behavior.

[0024] The collision warning device determines the minimum intersection distance between each candidate path of the target ship and the hull envelope of the ship based on the spatial geometric relationship between the candidate path cluster of the target ship and the ship's own trajectory, as described in steps 201 to 204.

[0025] Step 30: Based on the minimum rendezvous distance, the main threat path that poses the greatest potential threat to the ship is selected, and the consistency between the curvature change trend of the main threat path and the theoretical curvature shape of the benchmark maneuvering behavior is compared to obtain the confidence interval that reflects the intention of the target ship.

[0026] Optionally, the collision warning device filters out the main threat path that poses the greatest potential threat to the ship based on the minimum intersection distance between each candidate path of the target ship and the ship's hull envelope. The filtering logic is as follows: compare the minimum intersection distances corresponding to all candidate paths, and select the candidate path with the smallest minimum intersection distance as the main threat path. The smaller the minimum intersection distance, the closer the target ship's trajectory corresponding to the candidate path is to the ship, and the greater the potential collision threat to the ship. The main threat path refers to the path with the highest collision risk to the ship among all possible trajectories of the target ship.

[0027] The collision warning device compares the curvature change trend of the main threat path with the theoretical curvature shape of the baseline maneuvering behavior to obtain a confidence interval reflecting the target vessel's intention, as detailed in steps 301 to 304. The confidence interval refers to the probability range that reflects the target vessel's intention to perform the baseline maneuvering behavior. The narrower the confidence interval, the clearer the target vessel's intention to perform the baseline maneuvering behavior; the wider the confidence interval, the more ambiguous the target vessel's maneuvering intention.

[0028] Step 40: Based on the overlap between the spatial occupancy range of the main threat path within the target time window of the collision risk outbreak, as determined by the confidence interval, and the ship's hull envelope, determine whether a collision risk exists.

[0029] Optionally, the collision warning device extracts the target time window for the occurrence of collision risk as marked by the confidence interval. The target time window refers to the time period during which the main threat path of the target vessel may collide with the vessel, as predicted based on the confidence interval. The start and end times are jointly determined by the probability distribution of the confidence interval and the motion parameters of the main threat path, which can accurately pinpoint the time range in which the collision risk may occur.

[0030] The collision warning device acquires the spatial occupancy range of the main threat path within the target time window. The spatial occupancy range refers to all the spatial areas covered by the target vessel's hull when it moves along the main threat path within the target time window. The size and shape of this area are jointly determined by the target vessel's hull size, the direction of the main threat path, and its speed.

[0031] The collision warning device determines whether there is a collision risk based on the overlap between the spatial occupancy range of the main threat path and the ship's hull envelope within the target time window, as detailed in steps 401 to 404. Here, the ship's hull envelope refers to the closed outline that completely encloses the ship's hull, used to accurately define the ship's spatial occupancy range. The overlap refers to whether the spatial occupancy range of the main threat path intersects with the ship's hull envelope. If there is an intersection, a collision risk is determined; otherwise, no collision risk is determined.

[0032] The embodiments of the present invention enable the elimination of false trajectories that do not conform to physical laws by physically manipulating the boundary constraints of the target ship, thereby improving the authenticity and accuracy of collision risk prediction.

[0033] Optionally, the processes of steps 201 to 204 include: Step 201: Based on the time difference between the message timestamp in the spatiotemporal state stream and the current time of the ship's system, and combined with the maximum permissible angular acceleration of the target ship, construct a corresponding attitude uncertainty sector for each target ship candidate path in the target ship candidate path cluster.

[0034] Optionally, the collision warning device extracts the message timestamp from the spatiotemporal state stream. The message timestamp refers to the time information recorded when the spatiotemporal state data of the target vessel is collected and sent through the VDES terminal, used to identify the moment the spatiotemporal state data is generated. Simultaneously, it obtains the current time of its own system, which refers to the real-time time recorded by the vessel's own navigation system at the time of this step. The collision warning device calculates the time difference between the message timestamp and the current time of its own system. The calculation method is to subtract the corresponding message timestamp in the spatiotemporal state stream from the current time of the vessel's own system. The resulting time difference is the time elapsed from the collection and transmission of the target vessel's spatiotemporal state data to its reception and processing by the collision warning device.

[0035] The maximum permissible angular acceleration of a target vessel refers to the maximum acceleration of the change in heading angle when the target vessel performs maneuvering actions. Its value is determined by the physical characteristics of the target vessel, such as its hull structure, power system, and maneuvering system. It is the upper limit of angular acceleration that the target vessel cannot exceed during turning. This parameter is pre-stored in the parameter database of the collision warning device and can be adapted and adjusted according to the type and specifications of the target vessel.

[0036] The collision warning device constructs a corresponding attitude uncertainty sector for each candidate path in the candidate path cluster of the target ship, based on the time difference and the maximum permissible angular acceleration. The attitude uncertainty sector refers to the sector consisting of all reasonable ranges of the actual attitude (heading) of the target ship when moving on the corresponding candidate path, due to the time delay in the spatiotemporal state data and the constraint of the maximum permissible angular acceleration. The sector is centered on the instantaneous heading of the candidate path, and the angle of the sector is determined by the time difference and the maximum permissible angular acceleration. The larger the time difference and the larger the maximum permissible angular acceleration, the larger the angle of the sector, and vice versa.

[0037] Step 202: For each candidate path of the target ship, a non-uniform discrete node sequence is generated based on the boundary ray of the attitude uncertainty sector combined with the starting position and instantaneous speed of the path.

[0038] Optionally, for each candidate path of the target ship in the candidate path cluster, the collision warning device extracts two boundary rays of the attitude uncertainty sector corresponding to the path. The boundary rays refer to the rays formed by the two edges of the attitude uncertainty sector. The two boundary rays take the current position of the target ship as the starting point and correspond to the maximum left yaw and maximum right yaw that the target ship may have on the candidate path, respectively, thus completely defining the range of the attitude uncertainty sector.

[0039] The collision warning device obtains the starting position and instantaneous speed of the candidate path. The starting position is the current position of the target vessel, and the instantaneous speed is the speed of the target vessel at the current moment.

[0040] The collision warning device combines the two boundary rays of the attitude uncertainty sector, the starting position of the candidate path, and the instantaneous speed to generate a non-uniform discrete node sequence. This non-uniform discrete node sequence consists of a sequence of discrete nodes selected at non-equal intervals along the candidate path. The node selection rules are as follows: in path segments with significant attitude uncertainty (such as turning sections), the node selection interval is smaller to ensure accurate capture of the impact of attitude changes on the path; in path segments with less attitude uncertainty (such as straight-line navigation sections), the node selection interval is larger. Each discrete node contains specific spatial coordinates and corresponding time information. The time information is calculated based on the instantaneous speed and the distance between the node and the starting position; that is, the time corresponding to the node is equal to the starting time plus the distance between the node and the starting position divided by the instantaneous speed.

[0041] Step 203: Based on the displacement vector between adjacent discrete nodes on each non-uniform discrete node sequence and the beam direction vector of the target ship at the node, construct a sweep envelope along its extension direction, and determine the lateral avoidance plane of the ship based on the tangent direction of the ship's trajectory at the current moment and the longitudinal axis of the ship's hull.

[0042] Optionally, for each candidate path corresponding to a non-uniform discrete node sequence, the collision warning device extracts the displacement vector between two adjacent discrete nodes in the sequence one by one. The displacement vector is the vector from the previous discrete node to the next discrete node. Its magnitude is the straight-line distance between the two discrete nodes, and its direction is the direction from the previous discrete node to the next discrete node. It can accurately reflect the direction and distance of the target ship's movement between two adjacent nodes.

[0043] The collision warning device extracts the beam direction vector of the target vessel at each discrete node. The beam direction vector is a vector perpendicular to the instantaneous heading of the target vessel at that discrete node. It is divided into two directions, left and right, and its length is equal to the actual beam of the target vessel. The beam data is pre-stored in the vessel parameter library of the collision warning device and can be called according to the identification information of the target vessel. This vector is used to define the lateral space occupied by the target vessel at that node.

[0044] The collision warning device constructs a swept envelope along the candidate path extension direction based on the displacement vector between adjacent discrete nodes and the ship's beam direction vector at that node. The swept envelope refers to the three-dimensional structure formed by the entire spatial area swept by the target ship's hull as it moves along the candidate path. The construction process is as follows: using the ship's beam direction vector at each discrete node as the lateral boundary and the displacement vector between adjacent nodes as the longitudinal extension direction, the ship's beam boundaries of all adjacent nodes are connected by a smooth curved surface to form a complete swept envelope. This envelope can accurately represent the actual spatial occupancy range of the target ship when it moves along the candidate path, avoiding distance calculation errors caused by only considering the path line and ignoring the ship's dimensions.

[0045] The collision warning device acquires the tangential direction of the vessel's trajectory at the current moment. The vessel's trajectory refers to the recorded change in position of the vessel over a continuous period of time. The tangential direction at the current moment refers to the direction pointed to by the tangent to this trajectory at the vessel's current position, reflecting the vessel's current direction of travel. Simultaneously, the collision warning device acquires the longitudinal axis of the vessel's hull. The longitudinal axis of the vessel's hull is a virtual straight line running along the bow and stern direction and through the center of the hull, used to define the vessel's longitudinal extension direction.

[0046] The collision warning device determines the ship's lateral avoidance plane based on the tangent direction of the ship's current trajectory and the ship's longitudinal axis. The lateral avoidance plane is a plane perpendicular to the ship's current direction of travel and includes the ship's longitudinal axis. This plane is used to project the sweeping envelope of the target vessel, facilitating subsequent calculations of the spatial distance between the target vessel and the ship. Its orientation is determined by the ship's current direction of travel and the ship's longitudinal axis, ensuring accurate reflection of the ship's lateral avoidance space.

[0047] Step 204: Project the swept envelope onto the lateral avoidance plane to obtain the projected cross-sectional profile, and determine the minimum intersection distance for each candidate path of the target ship based on the relative velocity vector direction of the target ship relative to the ship and the projected cross-sectional profile.

[0048] Optionally, the swept envelope is projected onto the transverse avoidance plane to obtain the projected section profile. The projected section profile refers to the projected graphic of the swept envelope on the transverse avoidance plane, which can intuitively reflect the spatial occupancy of the target ship in the transverse avoidance space when the target ship moves along the candidate path. The projection process is executed according to the conventional spatial projection logic to ensure that the spatial relationship between the projected graphic and the swept envelope is consistent.

[0049] The collision warning device obtains the relative velocity vector direction of the target vessel relative to the ship itself. The relative velocity vector direction refers to the direction of motion of the target vessel relative to the ship itself. It is obtained by subtracting the instantaneous speed vector of the ship itself from the instantaneous speed vector of the target vessel, and can reflect the relative motion trend between the two.

[0050] The collision warning device determines the minimum intersection distance for each candidate path of the target vessel based on the relative velocity vector direction of the target vessel relative to the ship and the projected cross-sectional profile, as described in steps 2041 to 2043. The minimum intersection distance is the shortest straight-line distance between the sweep envelope of the target vessel and the hull envelope of the ship when the target vessel moves along the candidate path.

[0051] The embodiments of the present invention solve the problem of inaccurate distance calculation caused by simply calculating distances through geometric extrapolation and ignoring the uncertainty of ship attitude, ship size and relative motion trend. It ensures the authenticity and accuracy of the minimum rendezvous distance, provides support for screening the main threat path based on the minimum rendezvous distance and achieving accurate collision risk assessment, reduces false alarms or missed alarms caused by distance calculation deviations, improves the credibility of collision warnings, and thus improves the authenticity and accuracy of collision risk prediction.

[0052] Optionally, the processes of steps 2041 to 2043 include: Step 2041: Determine the principal axis of relative motion on the lateral avoidance plane based on the direction of the relative velocity vector of the target vessel relative to the vessel itself, and identify the leading edge vertex of the projected section profile on the principal axis of relative motion.

[0053] Optionally, the collision warning device projects the relative velocity vector direction onto the lateral avoidance plane and determines the relative motion principal axis based on the projection result. The relative motion principal axis refers to the straight line formed by the projection of the relative velocity vector direction onto the lateral avoidance plane, which accurately reflects the main motion direction of the target vessel relative to itself in the lateral avoidance space.

[0054] The collision warning device identifies the leading edge vertex of the projected cross-section profile on the relative motion principal axis. The leading edge vertex refers to the vertex on the projected cross-section profile that is closest to the envelope of the ship's hull along the direction of the relative motion principal axis. Its identification logic is as follows: along the relative motion principal axis from the ship to the opposite direction of the target ship, all vertices of the projected cross-section profile are traversed, and the vertex closest to the envelope of the ship's hull is selected. This vertex is the position where the target ship is most likely to have a spatial intersection with the ship when it moves along the current candidate path.

[0055] Step 2042: Based on the geometric positional relationship between the leading edge threat vertex and the hull envelope on the lateral avoidance plane, draw a line parallel to the principal axis of relative motion and intersect the hull envelope to determine the critical contact point pair on the ship's side corresponding to the leading edge threat vertex.

[0056] Optionally, the collision warning device defines the leading edge vertex as the leading edge threat vertex, which is the vertex on the projected cross-sectional profile closest to the ship along the direction of the principal axis of relative motion. Its spatial coordinates have been determined through the projection process. The collision warning device acquires the projection of the ship's hull envelope onto the lateral avoidance plane. This projection is the projection of the ship's hull envelope (a closed profile that completely encloses the ship's hull) onto the lateral avoidance plane (a plane perpendicular to the ship's current direction of travel and containing the ship's longitudinal axis), used to accurately define the space occupied by the ship within the lateral avoidance space.

[0057] The collision warning device analyzes the geometric positional relationship between the leading edge threat vertex and the ship's hull envelope on the lateral avoidance plane, determining their relative bearing and approximate distance. Subsequently, the collision warning device draws a line parallel to the principal axis of relative motion. This line must pass through the leading edge threat vertex and remain parallel to the principal axis of relative motion, ensuring that the line extends along the target vessel's primary direction of motion relative to the ship.

[0058] The collision warning device intersects the projection of the parallel line with the ship's hull envelope on the lateral avoidance plane, obtaining two intersection points. These two intersection points are identified as the critical contact point pair on the ship's side corresponding to the leading edge threat vertex. The critical contact point pair refers to the two points that are most likely to first contact the ship's hull envelope when the leading edge threat vertex extends along the relative motion direction. The straight line segment between the two points can accurately represent the spatial distance reference when the target vessel is closest to the ship.

[0059] Step 2043: Based on the proportional relationship between the length of the straight line segment between the critical contact point pairs and the magnitude of the relative velocity vector corresponding to the path, a time-space equivalent interval characterizing the urgency of the collision is constructed. The candidate path of the target ship corresponding to the time-space equivalent interval with the smallest lower limit value is taken as the main threat path, and the length of the straight line segment between the critical contact point pairs corresponding to the main threat path is determined as the minimum intersection distance.

[0060] Optionally, the collision warning device measures the length of the straight-line segment between the critical contact points. This length is the straight-line distance between the two critical contact points, which can intuitively reflect the proximity of the target vessel's position corresponding to the apex of the leading threat to the envelope of the ship's hull. The collision warning device obtains the magnitude of the relative velocity vector corresponding to the current candidate path. The magnitude of the relative velocity vector is the magnitude of the relative velocity of the target vessel relative to the ship, which is calculated from the magnitude of the relative velocity vector and can reflect the speed of the target vessel relative to the ship.

[0061] The collision warning device constructs a temporal-spatial equivalent interval characterizing the urgency of a collision based on the proportional relationship between the length of the straight segment between critical contact points and the magnitude of the relative velocity vector. The construction logic is as follows: dividing the length of the straight segment by the magnitude of the relative velocity vector yields the theoretical time required for the target vessel to move from its current position to the critical contact state with the vessel. Using this theoretical time as a benchmark, and combining it with a preset error correction coefficient, a time interval is determined. This time interval is the temporal-spatial equivalent interval. The difference between the upper and lower limits of the interval is determined by the error correction coefficient, which is preset based on the maritime navigation environment (such as wind, waves, and currents) to cover uncertainties in actual navigation. The smaller the value of the temporal-spatial equivalent interval, the higher the urgency of the collision. The collision warning device traverses all temporal-spatial equivalent intervals corresponding to candidate paths of the target vessel, selecting the temporal-spatial equivalent interval with the smallest lower limit. The candidate path of the target vessel corresponding to this interval is determined as the primary threat path, which is the path with the highest collision urgency and the greatest potential threat to the vessel among all candidate paths.

[0062] The collision warning device determines the length of the straight line segment between the critical contact points corresponding to the main threat path as the minimum intersection distance between the main threat path and the ship's hull envelope. This minimum intersection distance accurately reflects the shortest spatial distance between the target ship corresponding to the main threat path and the ship.

[0063] The embodiments of the present invention accurately determine the minimum intersection distance between each candidate path and the ship's hull envelope, and at the same time screen out the most threatening primary threat path, providing support for collision risk assessment based on the primary threat path, avoiding false alarms or missed alarms caused by distance calculation deviations, ensuring the credibility of collision warnings, and thus improving the authenticity and accuracy of collision risk prediction.

[0064] Optionally, the processes of steps 301 to 304 include: Step 301: Based on the relative positional relationship between the spatial geometric trajectory of the main threat path and the ship's own trajectory, extract the main threat path segments to be compared within the current collision avoidance decision time window.

[0065] Optionally, the collision warning device analyzes the spatial geometric trajectory of the main threat path and the relative positional relationship between the ship's navigation trajectory and the main threat path. Specifically, it analyzes the spatial distance, azimuth angle, and relative motion trend between the two at the current moment to clarify the positional distribution of the main threat path relative to the ship's navigation trajectory.

[0066] The current collision avoidance decision time window refers to a pre-defined specific time period used for collision avoidance decision analysis. The length of this time period is set based on maritime navigation safety requirements and the ship's maneuvering inertia characteristics, typically ranging from a few minutes to a dozen minutes. Its purpose is to focus on the time period that is practically significant for the current collision avoidance decision, avoiding computational redundancy or decision lag due to an excessively large analysis scope. The collision warning device, based on the relative positional relationship between the spatial geometric trajectory of the main threat path and the ship's own trajectory, and combined with the current collision avoidance decision time window, extracts the main threat path segment corresponding to the time window for comparison. The extraction logic is as follows: based on the speed of the main threat path and the duration of the current collision avoidance decision time window, the spatial range that the main threat path can cover within that time window is calculated. The portion of the main threat path located within this spatial range is extracted as the main threat path segment to be compared. This segment is the object of subsequent curvature consistency comparison and can accurately reflect the trajectory characteristics of the target ship during the critical collision avoidance decision period.

[0067] Step 302: Based on the angle difference between the starting tangent direction and the ending tangent direction of the main threat path segment to be compared, determine the total turning angle amplitude, and logically divide the theoretical curvature shape into a preset number of sub-curvature shape segments based on the total turning angle amplitude.

[0068] Optionally, the collision warning device determines the start and end points of the main threat path segment to be compared. The start point is the initial spatial position of the main threat path segment to be compared, and the end point is the final spatial position of the main threat path segment to be compared. The spatial coordinates of both are determined by the spatial geometric trajectory of the main threat path.

[0069] The collision warning device calculates the tangent directions at the starting and ending points of the target main threat path segment. The tangent direction refers to the direction pointed by the tangent at the corresponding endpoint of the path segment, reflecting the instantaneous movement direction of the path at that endpoint. The calculation method involves fitting a local path near the starting point of the target main threat path segment to obtain the tangent direction of that local path as the starting tangent direction; the same method is used to fit a local path near the ending point to obtain the ending tangent direction. The collision warning device calculates the angle difference between the starting and ending tangent directions, determining this angle difference as the total steering angle amplitude of the target main threat path segment. The total steering angle amplitude refers to the overall steering angle of the target main threat path segment from the starting point to the ending point, directly reflecting the overall steering degree of the path segment. A positive angle difference indicates clockwise steering, and a negative angle difference indicates counterclockwise steering; a larger absolute value indicates a larger steering amplitude.

[0070] The collision warning device determines the theoretical curvature shape corresponding to the reference maneuver behavior. The theoretical curvature shape refers to the ideal curvature change law that the target ship's trajectory should present when performing the reference maneuver behavior. This shape is determined by the physical maneuver boundary constraints of the reference maneuver behavior and the ship's maneuver characteristics, and is pre-stored in the maneuver behavior library of the collision warning device.

[0071] The collision warning device logically divides the theoretical curvature pattern into a preset number of sub-curvature pattern segments based on the calculated total steering angle amplitude. The preset number is a pre-defined number of segments used to divide the theoretical curvature pattern, typically set according to the steering amplitude and calculation accuracy requirements, usually between 3 and 5 segments. The division logic is as follows: the total steering angle amplitude is evenly distributed among the preset number of sub-segments, each sub-segment corresponding to a fixed cumulative steering angle range. Based on this range, the theoretical curvature pattern is divided into corresponding sub-curvature pattern segments. Each sub-curvature pattern segment corresponds to a continuous curvature change pattern, maintaining correspondence with the subsequent division of the main threat path segment to be compared.

[0072] Step 303: On the main threat path segment to be compared, search in sequence for spatial segmentation points where the cumulative turning angle reaches the cumulative turning angle boundary value corresponding to each sub-curvature shape segment, and extract the main threat path segment to be compared based on the spatial segmentation points to obtain the main threat path sub-segment.

[0073] Optionally, the collision warning device extracts the cumulative steering angle boundary value corresponding to each sub-curvature shape segment. The cumulative steering angle boundary value refers to the upper and lower limits of the cumulative steering angle corresponding to each sub-curvature shape segment. The boundary value is determined by the total steering angle amplitude and the preset number of divisions. For example, when the preset number is 3, the total steering angle amplitude is divided into 3 parts on average. The cumulative steering angle boundary values ​​corresponding to each sub-curvature shape segment are one-third, two-thirds and the entire total steering angle amplitude, respectively.

[0074] The collision warning device searches for spatial segmentation points along the main threat path segment to be compared, starting from the starting point and sequentially, when the cumulative turning angle reaches the cumulative turning angle boundary value corresponding to each sub-curvature shape segment. The search process is as follows: along the extension direction of the main threat path segment to be compared, the cumulative turning angle of the path is calculated point by point. The cumulative turning angle refers to the total turning angle from the starting point of the main threat path segment to the current point. The calculation method is to sequentially accumulate the turning angle between two adjacent points on the path. When the cumulative turning angle reaches the cumulative turning angle boundary value corresponding to a certain sub-curvature shape segment, that point is determined as a spatial segmentation point. The spatial segmentation point is a key node used to split the main threat path segment to be compared, and its spatial coordinates are determined by the geometric trajectory of the main threat path segment to be compared.

[0075] The collision warning device, based on all the spatial segmentation points obtained from the search, extracts the main threat path segments to be compared, obtaining main threat path sub-segments that correspond one-to-one with the sub-curvature shape segments. The extraction logic is as follows: the starting point of the main threat path segment to be compared is taken as the starting point of the first main threat path sub-segment, and the first spatial segmentation point is taken as the ending point of the sub-segment, thus obtaining the first main threat path sub-segment; the first spatial segmentation point is taken as the starting point of the second main threat path sub-segment, and the second spatial segmentation point is taken as the ending point of the sub-segment, thus obtaining the second main threat path sub-segment; and so on, with the last spatial segmentation point as the starting point of the last main threat path sub-segment, and the ending point of the main threat path segment to be compared as the ending point of the sub-segment, ensuring that the cumulative steering angle of each main threat path sub-segment is consistent with the cumulative steering angle range of the corresponding sub-curvature shape segment.

[0076] Step 304: Perform consistency comparison based on each main threat path sub-segment and its corresponding sub-curvature morphology segment to obtain a confidence interval reflecting the target vessel's intent.

[0077] Optionally, the collision warning device obtains a confidence interval reflecting the target vessel's intention based on the consistency comparison results of all main threat path sub-segments and corresponding sub-curvature shape segments. Specifically, step 3041 refers to the process of step 3043. Here, the confidence interval refers to the probability range that can reflect the target vessel's intention to perform the benchmark maneuver. The higher the degree of fit of the comparison results, the narrower the numerical range of the confidence interval, indicating that the target vessel's intention to perform the benchmark maneuver is clearer; the lower the degree of fit of the comparison results, the wider the numerical range of the confidence interval, indicating that the target vessel's maneuvering intention is more ambiguous.

[0078] This invention addresses the problems of failing to reflect a ship's driving intentions and the difficulty in distinguishing between true and false trajectories. By comparing curvature consistency in stages, it accurately matches the actual maneuvering behavior of the target ship with the theoretical laws governing the baseline maneuvering behavior. This effectively eliminates false trajectories that violate driving intentions, ensuring that the obtained confidence intervals truly reflect the target ship's maneuvering intentions. It provides an intention reference for calibrating collision risk time windows based on confidence intervals and accurately determining collision risks, reducing false alarms caused by the inability to identify driving intentions, thereby improving the authenticity and accuracy of collision risk prediction.

[0079] Optionally, the processes of steps 3041 to 3043 include: Step 3041: Based on the curvature extrema and slope of change of each sub-curvature shape segment, determine the segmented curvature tolerance value of each sub-curvature shape segment, and based on the ratio of the chord height of each main threat path sub-segment to the length of the line connecting its start and end points, determine the equivalent curvature characterization value of each main threat path sub-segment.

[0080] Optionally, the collision warning device analyzes the curvature change pattern of each sub-curvature shape segment one by one to determine the curvature extrema and slope of change for each sub-curvature shape segment. The curvature extrema refer to the maximum and minimum values ​​of curvature within each sub-curvature shape segment, reflecting the fluctuation range of the ideal curvature of that sub-segment; the slope of change refers to the rate of change of curvature values ​​with path length within each sub-curvature shape segment, reflecting the trend of change of the ideal curvature of that sub-segment. Both the curvature extrema and the slope of change are determined by the theoretical curvature shape of the baseline manipulation behavior, directly retrieved from the manipulation behavior library and calculated in conjunction with the range of the sub-curvature shape segments.

[0081] The collision warning device determines the segmented curvature tolerance value for each sub-curvature shape segment based on the curvature extreme value and slope of change of each sub-curvature shape segment. The segmented curvature tolerance value refers to the reasonable deviation range between the actual curvature of the main threat path sub-segment and the theoretical curvature of the corresponding sub-curvature shape segment. Its determination logic is as follows: using the curvature extreme value of the sub-curvature shape segment as a benchmark, a deviation coefficient is set in combination with the slope of change. The larger the slope of change, the larger the deviation coefficient, and the wider the range of the segmented curvature tolerance value; the smaller the slope of change, the smaller the deviation coefficient, and the narrower the range of the segmented curvature tolerance value. The deviation coefficient is preset according to the ship's maneuvering inertia and the maritime navigation environment to ensure that the tolerance value can cover reasonable curvature fluctuations, while avoiding excessive deviation that would cause comparison failure.

[0082] The collision warning device determines the chord height and the length of the line connecting the start and end points of each main threat path segment. The chord height refers to the maximum vertical distance between the actual trajectory curve of the main threat path segment and the line connecting its start and end points. It is calculated by connecting the start and end points of the main threat path segment to obtain a straight line, measuring the vertical distance between this line and all points on the segment's trajectory curve, and selecting the maximum value as the chord height. The length of the line connecting the start and end points refers to the straight-line distance between the start and end points of the main threat path segment, directly calculated using the spatial coordinates of these two points. The collision warning device calculates the ratio of the chord height to the length of the line connecting the start and end points for each main threat path segment, and determines this ratio as the equivalent curvature characterization value for each main threat path segment. The equivalent curvature characterization value is a parameter used to quantify the actual curvature of the main threat path segment. Its value is positively correlated with the actual curvature. The larger the ratio, the greater the curvature of the main threat path segment and the greater the actual curvature; the smaller the ratio, the smaller the curvature of the main threat path segment and the smaller the actual curvature. This value can accurately characterize the actual curvature change characteristics of the main threat path segment.

[0083] Step 3042: Based on the equivalent curvature representation value of each main threat path segment and the theoretical mean curvature and segmented curvature tolerance value of the corresponding sub-curvature shape segment of each main threat path segment, perform interval coverage analysis to obtain the segmented consistency identifier of each main threat path segment.

[0084] Optionally, the theoretical mean curvature refers to the average value of all theoretical curvature values ​​within the corresponding sub-curvature shape segment, which is calculated from the theoretical curvature data of the sub-curvature shape segment.

[0085] The collision warning device performs interval coverage analysis based on the equivalent curvature representation value of each main threat path sub-segment, as well as the theoretical mean curvature and piecewise curvature tolerance value of its corresponding sub-curvature shape segment. Interval coverage analysis determines whether the equivalent curvature representation value falls within a reasonable interval formed by the theoretical mean curvature and the piecewise curvature tolerance value. The specific analysis logic is as follows: First, the upper and lower limits of the theoretical mean curvature and the piecewise curvature tolerance value are calculated. The upper limit is the theoretical mean curvature plus the piecewise curvature tolerance value, and the lower limit is the theoretical mean curvature minus the piecewise curvature tolerance value, forming a reasonable curvature interval. Then, it is determined whether the equivalent curvature representation value of the main threat path sub-segment falls within this reasonable interval. Based on the interval coverage analysis results, the collision warning device obtains a segment consistency identifier for each main threat path sub-segment. The segment consistency flag is used to mark whether the main threat path segment and the corresponding sub-curvature shape segment are consistent. It includes two states: when the equivalent curvature representation value falls within a reasonable range, it is marked as "consistent", indicating that the actual curvature change of the main threat path segment matches the ideal curvature change of the corresponding sub-curvature shape segment; when the equivalent curvature representation value does not fall within a reasonable range, it is marked as "inconsistent", indicating that the actual curvature change of the main threat path segment deviates from the ideal curvature change of the corresponding sub-curvature shape segment and exceeds the reasonable range.

[0086] Step 3043: Based on the time proportion of main threat path segments continuously marked as consistent in the segment consistency identifier and the distribution location of inconsistent main threat path segments, determine the confidence interval reflecting the target vessel's intention.

[0087] Optionally, the collision warning device extracts all segment consistency identifiers, counts the main threat path segments marked "consistent" one by one, and filters out the main threat path segments that are continuously marked "consistent" to determine the time length covered by these continuous consistent segments. A continuous main threat path segment marked "consistent" refers to multiple adjacent main threat path segments whose segment consistency identifiers are all "consistent" without interruption. The coverage time length refers to the total target vessel movement time corresponding to these continuous consistent segments, calculated from the length of each segment and the instantaneous speed of the target vessel. That is, the time corresponding to each segment is equal to the segment length divided by the instantaneous speed, and the total coverage time is obtained by adding the times of all continuous consistent segments.

[0088] The collision warning device calculates the ratio of the duration of continuous "consistent" main threat path segments to the total duration of the current collision avoidance decision window, obtaining a time ratio. This time ratio reflects the proportion of time the main threat path aligns with the theoretical curvature shape; a higher ratio indicates a higher degree of consistency between the target vessel's actual maneuvering behavior and the baseline maneuvering behavior. Simultaneously, the distribution location of main threat path segments marked "inconsistent" in the segment consistency indicators is analyzed. Distribution location refers to the specific interval within the main threat path segment to be compared, determining whether they are concentrated in a local area or dispersed throughout the entire path segment. Concentrated distribution indicates that the deviation only occurs in a localized period, while dispersed distribution indicates that the deviation persists throughout the entire collision avoidance decision window. The distribution location reflects the scope and severity of the deviation's impact.

[0089] The collision warning device comprehensively determines a confidence interval reflecting the target vessel's intention based on the aforementioned time ratio and the distribution location of inconsistency segments. The determination logic is as follows: the higher the time ratio and the more concentrated the inconsistency segments are in local areas, the clearer the target vessel's intention to perform baseline maneuvering behavior, and the narrower the numerical range of the confidence interval; the lower the time ratio and the more dispersed the inconsistency segments, the more ambiguous the target vessel's maneuvering intention, and the wider the numerical range of the confidence interval. The specific numerical range of the confidence interval is jointly determined by a preset ratio threshold and a distribution location weight. The weight is preset according to the degree of influence of the deviation, thus obtaining a result reflecting the target vessel's maneuvering intention.

[0090] The embodiments of the present invention solve the problems of being unable to accurately match the ship's driving intention and the difficulty in distinguishing between real and false trajectories. Through quantitative comparison and comprehensive analysis, false trajectories that violate the driving intention can be effectively eliminated, so that the obtained confidence interval can truly and accurately reflect the target ship's maneuvering intention. This provides an intention reference for calibrating the collision risk time window based on the confidence interval and accurately judging the collision risk, reducing false alarms caused by the inability to identify the driving intention, thereby improving the authenticity and accuracy of collision risk prediction.

[0091] Optionally, the processes of steps 401 to 404 include: Step 401: Based on the ship's heading angle and longitudinal axis at the start of the target time window, construct a relative motion coordinate system of the ship with the ship's center of gravity as the origin.

[0092] Optionally, the target time window for the occurrence of collision risk, as defined by the confidence interval of the collision warning device, refers to the time period during which the main threat path of the target vessel may collide with the vessel, as predicted based on the confidence interval. This includes a clearly defined start and end time. The collision warning device acquires the vessel's heading angle at the start of the target time window. The heading angle is the angle between the vessel's direction of travel and true north at the start of the target time window. This angle is collected in real time by the vessel's navigation system and transmitted to the collision warning device, accurately reflecting the vessel's bearing at the initial moment of the high-risk period. The collision warning device also acquires the vessel's longitudinal axis, which is a virtual straight line running along the bow and stern of the vessel and through the center of the hull. This axis defines the vessel's longitudinal extension direction, and this parameter is pre-stored in the collision warning device's vessel parameter database.

[0093] The collision warning device constructs a relative motion coordinate system of the ship with its own center of gravity as the origin. This coordinate system is used to analyze the relative motion relationship between the target ship and the ship and to determine the spatial overlap. Its construction logic is as follows: with the ship's center of gravity as the origin, the longitudinal axis of the ship moving forward is the longitudinal axis of the coordinate system, the direction perpendicular to the longitudinal axis of the ship and pointing to the right of the ship is the transverse axis of the coordinate system, and the direction perpendicular to the longitudinal axis and transverse axis and pointing upward is the vertical axis of the coordinate system. This coordinate system can convert the spatial position and motion trajectory of the target ship into relative coordinates relative to the ship.

[0094] Step 402: Based on the discrete time node sequence of the main threat path within the target time window, the target time window is divided into a preset number of sub-time intervals, and based on the start time and end time corresponding to each sub-time interval, the starting boundary contour and ending boundary contour of the spatial occupancy range of the main threat path within each sub-time interval are extracted.

[0095] Optionally, the collision warning device extracts a discrete time node sequence of the main threat path within the target time window. The discrete time node sequence refers to a sequence of several time nodes selected according to a preset time interval within the target time window. The preset time interval is set according to the collision warning accuracy requirements and computational efficiency, and is usually 1 to 5 seconds. Each time node corresponds to a specific spatial location on the main threat path. This sequence is automatically generated by the movement speed of the main threat path and the duration of the target time window.

[0096] The collision warning device divides the target time window into a preset number of sub-time intervals based on the discrete time node sequence. The preset number corresponds to the number of nodes in the discrete time node sequence. The division logic is as follows: the first node in the discrete time node sequence is the start time of the first sub-time interval, the second node is the end time of the first sub-time interval and the start time of the second sub-time interval, and so on, until the entire target time window is divided into several continuous and non-overlapping sub-time intervals. The duration of each sub-time interval is equal to the preset time interval. By dividing the sub-time intervals, the continuous motion of the target ship can be decomposed into segmented motions of multiple time periods.

[0097] The collision warning device extracts the initial and final boundary contours of the spatial occupancy range of the main threat path within each sub-time interval based on the start and end times of each sub-time interval. The spatial occupancy range refers to all the spatial areas covered by the target vessel's hull as it moves along the main threat path. The initial boundary contour refers to the boundary contour of the target vessel's spatial occupancy range at the start time of the sub-time interval, and the final boundary contour refers to the boundary contour of the target vessel's spatial occupancy range at the end time of the sub-time interval. Both are calculated using the spatial position of the main threat path at the corresponding time node, the target vessel's hull dimensions (length and width), and its instantaneous heading, accurately representing the spatial occupancy boundaries of the target vessel at the start and end times of the sub-time interval.

[0098] Step 403: Based on the starting boundary contour and the ending boundary contour, connect the corresponding vertices to form side lines, and construct a time-sweep body that covers the continuous motion trajectory of the target ship in each sub-time interval.

[0099] Optionally, the collision warning device extracts the starting and ending boundary contours of each sub-time interval. Each boundary contour contains several vertices, which are key feature points of the boundary contour and can define the shape and range of the boundary contour. The spatial coordinates of the vertices are determined by the boundary contour calculation process.

[0100] The collision warning device connects the corresponding vertices of the starting and ending boundary contours of each sub-time interval to form a side connection line. The corresponding vertices refer to the vertices in the starting and ending boundary contours that are in the same position. For example, the front vertex of the starting boundary contour corresponds to the front vertex of the ending boundary contour, and the right vertex of the starting boundary contour corresponds to the right vertex of the ending boundary contour. The side connection line is a straight line connecting the corresponding vertices, used to connect the starting and ending boundary contours to form a complete spatial closed structure.

[0101] The collision warning device constructs a time-sweep body covering the continuous motion trajectory of the target vessel within each sub-time interval, based on the initial boundary contour, the final boundary contour, and the side line connecting the two. The time-sweep body refers to the three-dimensional structure formed by the entire spatial area swept by the target vessel's hull as it moves continuously along the main threat path within that sub-time interval. This structure accurately characterizes the dynamic spatial occupancy range of the target vessel within that sub-time interval, avoiding the neglect of spatial occupancy during motion by only considering the static contours at the start and end times, thus ensuring the comprehensiveness and accuracy of subsequent overlap analysis.

[0102] Step 404: Based on the time period sweep body of each sub-time interval and the relative motion coordinate system of the ship, perform overlap analysis to determine whether there is a collision risk.

[0103] Optionally, the collision warning device performs an overlap analysis based on the time period sweeping body and the ship's relative motion coordinate system for each sub-time interval to determine whether there is a collision risk, as in steps 4041 to 4044.

[0104] This invention, through segmented dynamic analysis and precise overlap judgment, can effectively identify real collision threats and exclude minor overlap situations with no actual risk, thereby improving the reliability and accuracy of collision warnings. It solves the problem in the prior art that the prediction logic is open-loop and static, and cannot reflect the dynamic coupling relationship between the ship's physical inertia and driving intention, resulting in a high false alarm rate and low reliability, thus improving the authenticity and accuracy of collision risk prediction.

[0105] Optionally, the processes of steps 4041 to 4044 include: Step 4041: Based on the ship's relative motion coordinate system, project the time period swept body onto the two-dimensional horizontal plane where the ship is located to obtain the planar projection area of ​​the main threat path.

[0106] Optionally, the time-sweep body is a three-dimensional structure consisting of all the spatial areas swept by the target vessel's hull as it moves continuously along the main threat path within the corresponding sub-time interval. It can fully characterize the dynamic spatial occupancy range of the target vessel within that sub-time interval.

[0107] The collision warning device, based on the ship's relative motion coordinate system, projects the time-sweep of each sub-time interval onto the two-dimensional horizontal plane where the ship is located, thus obtaining the planar projection area of ​​the main threat path. The two-dimensional horizontal plane refers to a plane parallel to the ship's deck that includes the longitudinal and transverse axes of the ship's relative motion coordinate system. The projection process is as follows: the vertical axis coordinates of all spatial points on the time-sweep are reset to zero, while their longitudinal and transverse axis coordinates are retained. The closed area formed by all the points corresponding to the retained coordinates is the planar projection area, which can intuitively reflect the projection of the target ship's dynamic spatial occupancy range on the horizontal plane within the corresponding sub-time interval.

[0108] Step 4042: Based on the coordinate distribution of the ship's hull envelope in the ship's relative motion coordinate system, analyze the geometric boundary segments of the ship's hull envelope to obtain the ship's static envelope profile.

[0109] Optionally, the hull envelope of the vessel is a closed contour line that can completely enclose the hull of the vessel, used to accurately define the spatial occupancy range of the vessel, and it is pre-stored in the ship parameter library of the collision warning device.

[0110] The collision warning device acquires the coordinate distribution of the ship's hull envelope in the ship's relative motion coordinate system. The coordinate distribution refers to the set of longitudinal and transverse axis coordinates of all boundary points of the hull envelope in the ship's relative motion coordinate system. It is obtained by converting the original coordinates of the hull envelope (based on the geographic coordinate system) into coordinates in the ship's relative motion coordinate system, ensuring that the hull envelope and the planar projection area are under the same coordinate reference.

[0111] The collision warning device analyzes the geometric boundary segments of the hull envelope in the ship's relative motion coordinate system to obtain the ship's static envelope profile. A geometric boundary segment is a straight line segment connecting two adjacent boundary points of the hull envelope. The analysis process involves connecting adjacent boundary points sequentially according to the closing order of the hull envelope to form several continuous geometric boundary segments. All geometric boundary segments connected end-to-end constitute a closed static envelope profile of the ship. This profile defines the boundary of the ship's static spatial area on a two-dimensional horizontal plane, accurately defining the ship's spatial boundaries in the horizontal direction.

[0112] Step 4043: Based on the boundary line segments of the planar projection area and the geometric boundary line segments of the static envelope contour of the ship, perform pairwise intersection determination analysis to detect whether the vertex of the planar projection area is located inside the static envelope contour of the ship, and obtain the single-time overlap status identifier.

[0113] Optionally, the collision warning device extracts the boundary segments of the planar projection area. These boundary segments are components of the closed contour of the planar projection area, formed by sequentially connecting adjacent vertices of the planar projection area, and can completely define the shape and extent of the planar projection area. The collision warning device extracts the geometric boundary segments of the ship's static envelope contour and performs pairwise intersection determination analysis on each boundary segment of the planar projection area and each geometric boundary segment of the ship's static envelope contour. The pairwise intersection determination analysis refers to determining whether there is an intersection point between a boundary segment of the planar projection area and a boundary segment of the ship's static envelope contour. The determination logic is as follows: calculate whether the extensions of the two segments intersect. If they intersect and the intersection point is located between the endpoints of the two segments, then the two segments are determined to intersect; if the intersection point is not located between the endpoints of the two segments or they do not intersect, then the two segments are determined to not intersect. This process is repeated for all pairwise comparisons of the boundary segments.

[0114] The collision warning device extracts all vertices of the planar projection area. A vertex is the endpoint of the boundary line segment of the planar projection area, and its coordinates are determined by the projection process of the planar projection area, accurately representing the key positions within the area. The collision warning device detects whether each vertex of the planar projection area is located inside the ship's static envelope contour. The detection logic is as follows: draw a ray from the vertex in any direction outside the ship's static envelope contour, and count the number of intersections between this ray and the geometric boundary line segment of the ship's static envelope contour. If the number of intersections is odd, the vertex is determined to be inside the ship's static envelope contour; if the number of intersections is even, the vertex is determined to be outside the ship's static envelope contour. This process is repeated for all vertices.

[0115] The collision warning device obtains a single-time-period overlap status identifier based on the results of pairwise intersection determination analysis and vertex detection. The single-time-period overlap status identifier is used to mark whether there is an overlap between the planar projection area and the static envelope contour of the ship within the corresponding sub-time interval. It includes: if at least one boundary line segment of the planar projection area intersects with the geometric boundary line segment of the ship's static envelope contour, or if at least one vertex of the planar projection area is located inside the ship's static envelope contour, it is marked as "overlapping"; if all boundary line segments do not intersect and all vertices are located outside the ship's static envelope contour, it is marked as "non-overlapping".

[0116] Step 4044: If there is at least one sub-time interval corresponding to a single time period overlap status indicator indicating overlap, then it is determined that there is a collision risk; otherwise, it is determined that there is no collision risk.

[0117] Optionally, the collision warning device constructs a time segment list, which is a list used to record all sub-time intervals within the target time window and their corresponding single-time period overlap status identifiers. Each entry in the list contains the start time, end time of the sub-time interval, and the corresponding single-time period overlap status identifier.

[0118] The collision warning device iterates through all entries in the time segment list, checking if there is at least one sub-time interval whose single-period overlap status indicator is "overlapping". If at least one such sub-time interval is found, it means that the dynamic space occupied by the target vessel in that sub-time interval overlaps with the static space occupied by the ship, and there is a possibility of collision, so a collision risk is determined. If all sub-time intervals are found to have single-period overlap status indicators that are "non-overlapping", it means that the dynamic space occupied by the target vessel in the entire target time window does not overlap with the static space occupied by the ship, and there is no possibility of collision, so no collision risk is determined.

[0119] The embodiments of the present invention can accurately identify the overlap between the target vessel and the vessel within the target time window, accurately distinguish between scenarios with collision risk and those without collision risk, and solve the problem of high false alarm rate and low reliability caused by the open-loop and static prediction logic, which cannot reflect the dynamic coupling relationship between the physical inertia of vessel handling and driving intention. This improves the reliability and accuracy of collision warning, thereby enhancing the authenticity and accuracy of collision risk prediction.

[0120] Furthermore, the ship collision risk warning device based on the VDES terminal provided by the present invention will be described below. The ship collision risk warning device based on the VDES terminal described below and the ship collision risk warning method based on the VDES terminal described above can be referred to in correspondence.

[0121] Optional, refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of the ship collision risk warning device based on the VDES terminal provided by the present invention. The ship collision risk warning device based on the VDES terminal includes: The feasible region analysis module 210 is used to match the spatiotemporal state flow of the target ship received by the VDES terminal in a pre-set maneuvering behavior library to obtain the baseline maneuvering behavior, and construct a sector-shaped feasible region based on the maximum turning rate and minimum turning radius of the physical maneuvering boundary constraints corresponding to the baseline maneuvering behavior, starting from the current position of the target ship. The spatial relationship analysis module 220 is used to perform uniform sampling based on the sector feasible region to generate a cluster of candidate paths for the target ship, and to determine the minimum intersection distance between each candidate path for the target ship and the ship's hull envelope based on the spatial geometric relationship between the candidate path cluster for the target ship and the ship's own trajectory. The path confidence analysis module 230 is used to screen out the main threat path that poses the greatest potential threat to the ship based on the minimum rendezvous distance, and to compare the consistency between the curvature change trend of the main threat path and the theoretical curvature shape of the baseline maneuvering behavior to obtain a confidence interval that reflects the intention of the target ship. The collision warning module 240 is used to determine whether there is a collision risk based on the overlap between the spatial occupancy range of the main threat path and the ship's hull envelope within the target time window of the collision risk outbreak, which is calibrated by a confidence interval.

[0122] The embodiments of the present invention enable the elimination of false trajectories that do not conform to physical laws by physically manipulating the boundary constraints of the target ship, thereby improving the authenticity and accuracy of collision risk prediction.

[0123] Please see Figure 3 , Figure 3 An embodiment diagram of an electronic device provided in accordance with the present invention. For example... Figure 3 As shown, this embodiment of the invention provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and executable on the processor 320. When the processor 320 executes the computer program 311, it performs the following steps: The spatiotemporal state flow of the target ship received by the VDES terminal is matched in a pre-set maneuvering behavior library to obtain the baseline maneuvering behavior. Based on the maximum turning rate and minimum turning radius of the physical maneuvering boundary constraints corresponding to the baseline maneuvering behavior, a sector-shaped feasible region is constructed starting from the current position of the target ship. Uniform sampling is performed based on the sector feasible region to generate a cluster of candidate paths for the target ship. Based on the spatial geometric relationship between the candidate path clusters and the ship's own trajectory, the minimum intersection distance between each candidate path and the ship's hull envelope is determined. The main threat path that poses the greatest potential threat to the vessel is selected based on the minimum rendezvous distance. The consistency between the curvature change trend of the main threat path and the theoretical curvature shape of the baseline maneuvering behavior is compared to obtain the confidence interval that reflects the intention of the target vessel. Based on the overlap between the spatial extent of the main threat path and the ship's hull envelope within the target time window of the collision risk outbreak, as determined by the confidence interval, it is determined whether a collision risk exists.

[0124] Please see Figure 4 , Figure 4 An embodiment diagram of a computer-readable storage medium provided in accordance with an embodiment of the present invention is shown. Figure 4 As shown, this embodiment provides a computer-readable storage medium 400 on which a computer program 311 is stored. When the computer program 311 is executed by a processor, it performs the following steps: The spatiotemporal state flow of the target ship received by the VDES terminal is matched in a pre-set maneuvering behavior library to obtain the baseline maneuvering behavior. Based on the maximum turning rate and minimum turning radius of the physical maneuvering boundary constraints corresponding to the baseline maneuvering behavior, a sector-shaped feasible region is constructed starting from the current position of the target ship. Uniform sampling is performed based on the sector feasible region to generate a cluster of candidate paths for the target ship. Based on the spatial geometric relationship between the candidate path clusters and the ship's own trajectory, the minimum intersection distance between each candidate path and the ship's hull envelope is determined. The main threat path that poses the greatest potential threat to the vessel is selected based on the minimum rendezvous distance. The consistency between the curvature change trend of the main threat path and the theoretical curvature shape of the baseline maneuvering behavior is compared to obtain the confidence interval that reflects the intention of the target vessel. Based on the overlap between the spatial extent of the main threat path and the ship's hull envelope within the target time window of the collision risk outbreak, as determined by the confidence interval, it is determined whether a collision risk exists.

[0125] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the ship collision risk warning method based on the VDES terminal provided by the above methods, the method including: The spatiotemporal state flow of the target ship received by the VDES terminal is matched in a pre-set maneuvering behavior library to obtain the baseline maneuvering behavior. Based on the maximum turning rate and minimum turning radius of the physical maneuvering boundary constraints corresponding to the baseline maneuvering behavior, a sector-shaped feasible region is constructed starting from the current position of the target ship. Uniform sampling is performed based on the sector feasible region to generate a cluster of candidate paths for the target ship. Based on the spatial geometric relationship between the candidate path clusters and the ship's own trajectory, the minimum intersection distance between each candidate path and the ship's hull envelope is determined. The main threat path that poses the greatest potential threat to the vessel is selected based on the minimum rendezvous distance. The consistency between the curvature change trend of the main threat path and the theoretical curvature shape of the baseline maneuvering behavior is compared to obtain the confidence interval that reflects the intention of the target vessel. Based on the overlap between the spatial extent of the main threat path and the ship's hull envelope within the target time window of the collision risk outbreak, as determined by the confidence interval, it is determined whether a collision risk exists.

[0126] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0127] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0128] 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ship collision risk early warning method based on a VDES terminal, characterized in that, include: The spatiotemporal state flow of the target ship received by the VDES terminal is matched in a pre-set maneuvering behavior library to obtain the baseline maneuvering behavior. Based on the maximum turning rate and minimum turning radius of the physical maneuvering boundary constraints corresponding to the baseline maneuvering behavior, a sector-shaped feasible region is constructed starting from the current position of the target ship. Uniform sampling is performed based on the sector feasible region to generate a cluster of candidate paths for the target ship. Based on the spatial geometric relationship between the candidate path cluster and the ship's own trajectory, the minimum intersection distance between each candidate path and the ship's hull envelope is determined. Based on the minimum rendezvous distance, the main threat path that poses the greatest potential threat to the vessel is selected, and the curvature change trend of the main threat path is compared with the theoretical curvature shape of the benchmark maneuvering behavior to obtain a confidence interval that reflects the intention of the target vessel. Based on the overlap between the spatial extent of the main threat path and the ship's hull envelope within the target time window of the collision risk outbreak as defined by the confidence interval, it is determined whether a collision risk exists.

2. The ship collision risk early warning method based on a VDES terminal according to claim 1, characterized in that, Determining whether there is a collision risk includes: Based on the ship's heading angle and longitudinal axis at the start of the target time window, a relative motion coordinate system of the ship is constructed with the ship's center of gravity as the origin; Based on the discrete time node sequence of the main threat path within the target time window, the target time window is divided into a preset number of sub-time intervals, and based on the start time and end time corresponding to each sub-time interval, the start boundary contour and end boundary contour of the spatial occupancy range of the main threat path within each sub-time interval are extracted. Based on the start and end boundary contours of each sub-time interval, connecting the corresponding vertices to form side lines, a time-sweep body covering the continuous motion trajectory of the target ship in each sub-time interval is constructed. Overlap analysis is performed based on the time-sweep body of each sub-time interval and the relative motion coordinate system of the ship to determine whether there is a collision risk.

3. The ship collision risk early warning method based on a VDES terminal according to claim 2, characterized in that, The overlap analysis based on the time-sweep body of each sub-time interval and the ship's relative motion coordinate system is used to determine whether there is a collision risk, including: Based on the ship's relative motion coordinate system, the swept body of the time period is projected onto the two-dimensional horizontal plane where the ship is located to obtain the planar projection area of ​​the main threat path; Based on the coordinate distribution of the ship's hull envelope in the ship's relative motion coordinate system, the geometric boundary line segments of the ship's hull envelope are analyzed to obtain the ship's static envelope profile. Based on the pairwise intersection determination analysis of the boundary line segments of the planar projection area and the geometric boundary line segments of the static envelope contour of the ship, the vertex of the planar projection area is detected to be inside the static envelope contour of the ship, and a single time period overlap status identifier is obtained. If at least one sub-time interval has a single-time period overlap status indicator indicating overlap, then a collision risk is determined to exist; otherwise, no collision risk is determined to exist.

4. The ship collision risk early warning method based on a VDES terminal according to claim 1, characterized in that, Determine the minimum intersection distance for each candidate path for the target ship, including: Based on the time difference between the message timestamp in the spatiotemporal state stream and the current time of the ship's system, and combined with the maximum permissible angular acceleration of the target ship, a corresponding attitude uncertainty sector is constructed for each target ship candidate path in the target ship candidate path cluster. For each candidate path for the target ship, a non-uniform discrete node sequence is generated based on the boundary rays of the attitude uncertainty sector combined with the starting position and instantaneous speed of the path. Based on the displacement vector between adjacent discrete nodes on each non-uniform discrete node sequence and the beam direction vector of the target ship at the node, a sweep envelope is constructed along its extension direction. Based on the tangent direction of the ship's trajectory at the current moment and the longitudinal axis of the ship's hull, the lateral avoidance plane of the ship is determined. The swept envelope is projected onto the lateral avoidance plane to obtain the projected cross-sectional profile. Based on the relative velocity vector direction of the target vessel relative to the ship and the projected cross-sectional profile, the minimum intersection distance of each candidate path of the target vessel is determined.

5. The ship collision risk early warning method based on a VDES terminal according to claim 4, characterized in that, The determination of the minimum intersection distance for each candidate path of the target vessel, based on the relative velocity vector direction of the target vessel relative to the vessel itself and the projected cross-sectional profile, includes: Based on the direction of the relative velocity vector of the target vessel relative to the vessel itself, the principal axis of relative motion is determined on the lateral avoidance plane, and the leading edge vertex of the projected cross section profile on the principal axis of relative motion is identified; Based on the geometric positional relationship between the leading edge threat vertex and the hull envelope on the lateral avoidance plane, draw a line parallel to the main axis of relative motion and intersect the hull envelope to determine the critical contact point pair on the ship side corresponding to the leading edge threat vertex. Based on the proportional relationship between the length of the straight segment between the critical contact point pairs and the magnitude of the relative velocity vector corresponding to the path, a time-space equivalent interval characterizing the urgency of the collision is constructed. The candidate path of the target ship corresponding to the time-space equivalent interval with the smallest lower limit value is taken as the main threat path, and the length of the straight segment between the critical contact point pairs corresponding to the main threat path is determined as the minimum intersection distance.

6. The ship collision risk early warning method based on a VDES terminal according to claim 1, characterized in that, The confidence interval reflecting the target vessel's intention is obtained, including: Based on the relative positional relationship between the spatial geometric trajectory of the main threat path and the ship's navigation trajectory, extract the main threat path segments to be compared within the current collision avoidance decision time window on the main threat path; Based on the angle difference between the starting tangent direction and the ending tangent direction of the main threat path segment to be compared, the total turning angle amplitude is determined, and based on the total turning angle amplitude, the theoretical curvature shape is logically divided into a preset number of sub-curvature shape segments. On the main threat path segment to be compared, spatial segmentation points that have reached the cumulative turning angle boundary value corresponding to each sub-curvature shape segment are sequentially searched, and the main threat path segment to be compared is cut off based on the spatial segmentation points to obtain the main threat path sub-segment; Consistency comparison is performed on each main threat path sub-segment and its corresponding sub-curvature morphology segment to obtain a confidence interval reflecting the target vessel's intent.

7. The ship collision risk early warning method based on a VDES terminal according to claim 6, characterized in that, The consistency comparison based on each main threat path sub-segment and its corresponding sub-curvature shape segment yields a confidence interval reflecting the target vessel's intent, including: Based on the curvature extrema and slope of change of each sub-curvature shape segment, the piecewise curvature tolerance value of each sub-curvature shape segment is determined, and based on the ratio of the chord height of each main threat path sub-segment to the length of the line connecting its start and end points, the equivalent curvature characterization value of each main threat path sub-segment is determined. Based on the equivalent curvature representation value of each main threat path segment and the theoretical mean curvature and segmented curvature tolerance value of the corresponding sub-curvature shape segment of each main threat path segment, an interval inclusion analysis is performed to obtain the segmented consistency identifier of each main threat path segment. Based on the time proportion of main threat path segments continuously marked as consistent in the segment consistency identifier and the distribution location of inconsistent main threat path segments, a confidence interval reflecting the target vessel's intent is determined.

8. A ship collision risk early warning device based on a VDES terminal, characterized in that, Applied to the ship collision risk warning method based on VDES terminal as described in any one of claims 1 to 7; The ship collision risk early warning device based on the VDES terminal includes: The feasible region analysis module is used to match the spatiotemporal state flow of the target ship received by the VDES terminal with a pre-set maneuvering behavior library to obtain the baseline maneuvering behavior. Based on the maximum turning rate and minimum turning radius of the physical maneuvering boundary constraints corresponding to the baseline maneuvering behavior, a sector-shaped feasible region is constructed starting from the current position of the target ship. The spatial relationship analysis module is used to perform uniform sampling based on the sector feasible region to generate a cluster of candidate paths for the target ship, and to determine the minimum intersection distance between each candidate path for the target ship and the ship's hull envelope based on the spatial geometric relationship between the candidate path cluster and the ship's own trajectory. The path confidence analysis module is used to filter out the main threat path that poses the greatest potential threat to the ship based on the minimum rendezvous distance, and to compare the curvature change trend of the main threat path with the theoretical curvature shape of the benchmark maneuvering behavior to obtain a confidence interval that reflects the intention of the target ship. The collision warning module is used to determine whether there is a collision risk based on the overlap between the spatial occupancy range of the main threat path and the ship's hull envelope within the target time window of the collision risk outbreak calibrated by the confidence interval.

9. An electronic device, comprising: Memory, used to store computer software programs; A processor for reading and executing the computer software program, characterized in that, when the processor executes the computer software program, it implements the ship collision risk warning method based on a VDES terminal as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium, wherein a computer software program is stored therein, characterized in that, When the computer software program is executed by the processor, it implements the ship collision risk warning method based on the VDES terminal as described in any one of claims 1 to 7.

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