An electronic chart-based dynamic monitoring system and method for fishing boat lens

Abstract

The application belongs to the technical field of high-precision positioning, and discloses a kind of fishing boat dynamic supervision system and method based on electronic chart, including chart constraint construction module, for obtaining the electronic chart data corresponding to the supervision water area, based on electronic chart data division navigation unit, and according to the spatial connection between navigation unit Generation chart space constraint information;Dynamic aperture generation module, for calling chart space constraint information, determine the traffic boundary between navigation unit, generate dynamic aperture set, and establish the mapping relationship between dynamic aperture and navigation unit;Ship trajectory mapping module, for obtaining fishing boat continuous positioning data and motion state data, according to mapping relationship continuous positioning data is mapped to corresponding navigation unit, and according to navigation unit change order generates aperture state sequence;The accuracy, real-time performance and stability of fishing boat dynamic supervision under complex water environment are improved.

Description

Technical Field

[0001] This invention relates to the field of high-precision positioning technology, and more specifically, to a dynamic monitoring system and method for fishing vessel checkpoints based on electronic nautical charts. Background Technology

[0002] With the development of information technology in fisheries supervision, dynamic monitoring systems for fishing vessels based on positioning technology and electronic nautical charts are gradually being applied to scenarios such as monitoring key waters, analyzing navigation trajectories, and identifying illegal border crossings. Existing fishing vessel checkpoint monitoring methods typically determine whether a checkpoint crossing has occurred based on whether the fishing vessel's location crosses a preset boundary area. When a location point is detected moving from one side of the checkpoint to the other, a corresponding monitoring event is triggered.

[0003] However, in actual maritime navigation environments, fishing vessel positioning data is easily affected by factors such as satellite signal fluctuations, wave disturbances, equipment measurement errors, and low-speed course adjustments by the vessel. This causes the positioning point to fluctuate within a certain range near the checkpoint boundary, making it easy for traditional methods based on single-point boundary crossing judgments to mistake positioning errors for actual crossing behavior. Furthermore, existing methods typically rely on trajectory continuity or positional distance for judgment, lacking an effective description of the checkpoint state change process, making it difficult to accurately distinguish between actual crossings and instantaneous positional changes, thus affecting the stability of checkpoint event recognition.

[0004] Furthermore, existing methods for enhancing fishing vessel positioning typically only initiate the allocation of positioning assistance resources and positioning correction processing after the vessel has actually entered the preset positioning area. Since resource loading and correction calculations require time, this can easily lead to untimely improvements in positioning accuracy within critical areas, affecting subsequent trajectory analysis and checkpoint monitoring effectiveness. Simultaneously, existing positioning resource scheduling methods are primarily triggered by the current location, lacking prediction of the vessel's future movement trends and failing to prepare positioning resources in advance. When the vessel's course or speed changes, the already allocated resources may become ineffective, increasing system resource consumption.

[0005] In view of this, the present invention proposes a dynamic monitoring system and method for fishing vessel checkpoints based on electronic nautical charts to solve the above problems. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art and to achieve the above objectives, the present invention provides the following technical solution: a dynamic monitoring system for fishing vessel checkpoints based on electronic nautical charts, comprising: The chart constraint construction module is used to acquire electronic chart data corresponding to the regulated waters, divide navigation units based on the electronic chart data, and generate chart spatial constraint information according to the spatial connection relationship between the navigation units. The dynamic checkpoint generation module is used to call the spatial constraint information of the nautical chart, determine the passage boundary between navigation units, generate a dynamic checkpoint set, and establish the mapping relationship between the dynamic checkpoints and navigation units; The vessel trajectory mapping module is used to acquire continuous positioning data and motion status data of fishing vessels, map the continuous positioning data to the corresponding navigation unit according to the mapping relationship, and generate a checkpoint status sequence according to the change order of the navigation unit. The crossing status determination module is used to construct the checkpoint status bit based on the checkpoint status sequence, obtain the status jump variable, start the continuous confirmation counter, and determine the valid checkpoint crossing event based on the counting result and the direction of movement of the fishing boat. The positioning prefetching and scheduling module is used to extrapolate motion based on continuous positioning data and motion state data to obtain the predicted position. When the predicted position enters the preset positioning area and the current position does not enter the preset positioning area, the corresponding positioning resources are called, and positioning correction is performed after the fishing boat enters the preset positioning area.

[0007] Preferably, the method for dividing navigation units based on electronic chart data includes: Obtain electronic nautical chart data corresponding to the regulated waters. The electronic nautical chart data includes the geographical extent, water boundary, channel, and water attribute information of the regulated waters. The electronic nautical chart data is analyzed to extract the spatial boundaries of the regulated waters. Based on the spatial continuity and differences in water attributes, the regulated waters are divided into regions, and regions with continuous spatial ranges and consistent water attributes are divided into independent navigation units. Each navigation unit is assigned a corresponding unit identifier, and the spatial boundary information and location information of each navigation unit are recorded to form a navigation unit set.

[0008] Preferably, the method for generating nautical chart spatial constraint information includes: Obtain the spatial boundary information and position information of each navigation unit in the navigation unit set, and determine whether there is an adjacent boundary between any two navigation units and whether the passage conditions are met. When there is a continuous spatial region between two navigation units and there is no impassable area blocking them, it is determined that there is a spatial connection between the two navigation units, and the corresponding connection direction, connection position and connection type are recorded. Each navigation unit is treated as a spatial constraint node, the spatial connection relationship between navigation units is treated as a constraint edge between nodes, and the connection direction, connection position and connection type are associated as constraint attributes to generate nautical chart spatial constraint information.

[0009] Preferably, the method for generating the dynamic checkpoint set includes: The system retrieves spatial constraint information from nautical charts to identify adjacent navigation units with spatial connections. Based on the connection location, it determines the common boundary area between adjacent navigation units and the passage boundary between navigation units according to the connection direction and connection type. Each passage boundary is then configured as a corresponding checkpoint identifier to generate a dynamic checkpoint set.

[0010] Preferably, the method for establishing the mapping relationship between the dynamic checkpoint and the navigation unit includes: Obtain the checkpoint identifier, passage boundary information, and associated navigation unit information for each dynamic checkpoint in the dynamic checkpoint set; determine the navigation unit associated with each dynamic checkpoint based on the passage boundary position, and designate the navigation units on both sides of the passage boundary as the entry navigation unit and the exit navigation unit, respectively; establish the association between the dynamic checkpoint identifier and the corresponding navigation unit identifier, and generate the mapping relationship between the dynamic checkpoint and the navigation unit.

[0011] Preferably, the method for generating a checkpoint state sequence based on the change order of the navigation unit includes: Acquire continuous positioning data and motion status data of fishing vessels. Continuous positioning data includes positioning time, longitude coordinates and latitude coordinates, while motion status data includes sailing speed and heading information. Based on the mapping relationship between the dynamic checkpoint and the navigation unit, the spatial coordinates corresponding to each positioning point in the continuous positioning data are obtained. The spatial coordinates are matched with the spatial boundary information corresponding to the navigation unit. When the positioning point is within the spatial range of a certain navigation unit, the positioning point is associated with the corresponding navigation unit. The navigation units corresponding to each positioning point are sorted according to time sequence to obtain the order of navigation unit changes; when the navigation units corresponding to adjacent positioning points change, the corresponding dynamic checkpoints are determined according to the mapping relationship, and a checkpoint state sequence is generated according to the change order of the dynamic checkpoints.

[0012] Preferably, the method for determining valid checkpoint crossing events based on the counting results and the direction of movement of the fishing vessel includes: Based on the state change relationship of each dynamic checkpoint in the checkpoint state sequence, the checkpoint state bit is constructed, and the state of the fishing boat relative to each dynamic checkpoint is converted into discrete state values; an XOR operation is performed on the checkpoint state bit at the current time and the checkpoint state bit at the previous time to obtain the state jump variable; when the state jump variable indicates that a state transition has occurred, a continuous confirmation counter is started to count the continuous state change process. When the continuous confirmation count reaches the preset count threshold, the movement direction of the fishing boat relative to the corresponding dynamic checkpoint is obtained, and it is determined whether the movement direction of the fishing boat remains consistent within a continuous time period; when the continuous confirmation count reaches the preset count threshold and the movement direction of the fishing boat remains consistent, a valid checkpoint crossing event is determined.

[0013] Preferably, the method for obtaining the predicted location includes: The system acquires continuous positioning data and motion status data of the fishing vessel. Based on the continuous positioning data, it determines the spatial position of the fishing vessel at the current moment, and based on the speed and heading information in the motion status data, it determines the motion velocity vector of the fishing vessel at the current moment. It sets a prediction time interval and performs motion extrapolation based on the spatial position and motion velocity vector of the fishing vessel at the current moment to obtain the predicted position at the future moment.

[0014] Preferably, the method for performing positioning correction after the fishing vessel enters the preset positioning area includes: Based on the positional relationship between the predicted position obtained by motion extrapolation and the preset positioning area, a prefetch trigger flag is generated. When the predicted position enters the preset positioning area and the current position does not enter the preset positioning area, it is determined that the fishing boat is about to enter the preset positioning area, a positioning resource prefetch instruction is generated, and the positioning auxiliary resources corresponding to the preset positioning area are called. When a fishing vessel actually enters the preset positioning area, the pre-loaded positioning auxiliary resources are invoked to correct the vessel's current positioning data, and the corrected positioning result is obtained. When the predicted position is inconsistent with the actual navigation trajectory, causing the fishing vessel to fail to enter the preset positioning area, the corresponding positioning resource invocation is canceled and the loaded positioning auxiliary resources are cleared.

[0015] A method for dynamic monitoring of fishing vessels at checkpoints based on electronic nautical charts includes: S1. Obtain electronic nautical chart data corresponding to the regulated waters, divide navigation units based on the electronic nautical chart data, and generate nautical chart spatial constraint information according to the spatial connection relationship between navigation units; S2. Call the nautical chart spatial constraint information to determine the passage boundaries between navigation units, generate a dynamic checkpoint set, and establish a mapping relationship between the dynamic checkpoints and navigation units; S3. Acquire continuous positioning data and motion status data of fishing vessels, map the continuous positioning data to the corresponding navigation units according to the mapping relationship, and generate a checkpoint status sequence according to the change order of the navigation units. S4. Construct checkpoint status bits based on checkpoint status sequence, obtain status jump variables, start continuous confirmation counter, and determine valid checkpoint crossing events based on counting results and fishing boat movement direction. S5. Based on continuous positioning data and motion state data, extrapolate motion to obtain the predicted position; when the predicted position enters the preset positioning area and the current position does not enter the preset positioning area, call the corresponding positioning resources, and perform positioning correction after the fishing boat enters the preset positioning area.

[0016] Compared with the prior art, the present invention has the following beneficial effects: By constructing checkpoint status bits, the position of the fishing boat relative to the dynamic checkpoint is converted into discrete state values. Then, an XOR operation is used to obtain the state jump variable, transforming the original continuous trajectory judgment into a state transition judgment, thus improving the accuracy of crossing state recognition. Secondly, after detecting a state jump, a continuous confirmation counter is activated to accumulate confirmations of the state change. When the fishing boat's positioning point changes instantaneously at the checkpoint boundary due to error, failing to meet the continuous confirmation condition, it is automatically filtered out, solving the problem of a single jump directly triggering a crossing event and improving the checkpoint detection's anti-interference capability. When the continuous confirmation count reaches a preset threshold, a consistency judgment is made based on the fishing boat's movement direction. Only when the fishing boat completes the crossing in the corresponding direction is it considered a valid crossing event; back-and-forth adjustments or reverse movements do not generate events, further reducing the probability of false judgments.

[0017] After acquiring continuous positioning and motion data of fishing vessels, the velocity vector is determined based on the current position, speed, and heading. Extrapolation yields the predicted future position, allowing for advance understanding of motion trends and providing a basis for positioning resource scheduling. A positional relationship judgment mechanism generates trigger flags. When the predicted position enters a preset positioning area but the current position has not, positioning auxiliary resources are invoked in advance, changing the traditional post-entry response to pre-entry pre-scheduling, reducing resource waiting time after entry. Once the fishing vessel actually enters the preset positioning area, pre-loaded resources are directly invoked to complete positioning correction, improving positioning processing response speed and ensuring that positioning near dynamic checkpoints meets regulatory requirements. Simultaneously, a prediction failure handling mechanism is implemented. When the predicted position differs from the actual trajectory, the invocation is promptly canceled and loaded resources are cleared, avoiding invalid occupation and improving resource scheduling flexibility and system operating efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a dynamic monitoring system for fishing vessels based on electronic nautical charts according to the present invention. Figure 2 This is a schematic diagram of a dynamic monitoring method for fishing vessels based on electronic nautical charts according to the present invention. Detailed Implementation

[0019] 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. Example

[0020] Please see Figure 1 As shown, this embodiment provides a dynamic monitoring system for fishing vessel checkpoints based on electronic nautical charts, specifically including the following steps: The chart constraint construction module is used to acquire electronic chart data corresponding to the regulated waters, divide navigation units based on the electronic chart data, and generate chart spatial constraint information according to the spatial connection relationship between the navigation units. The dynamic checkpoint generation module is used to call the spatial constraint information of the nautical chart, determine the passage boundary between navigation units, generate a dynamic checkpoint set, and establish the mapping relationship between the dynamic checkpoints and navigation units; The vessel trajectory mapping module is used to acquire continuous positioning data and motion status data of fishing vessels, map the continuous positioning data to the corresponding navigation unit according to the mapping relationship, and generate a checkpoint status sequence according to the change order of the navigation unit. The crossing status determination module is used to construct the checkpoint status bit based on the checkpoint status sequence, obtain the status jump variable, start the continuous confirmation counter, and determine the valid checkpoint crossing event based on the counting result and the direction of movement of the fishing boat. The positioning prefetching and scheduling module is used to extrapolate motion based on continuous positioning data and motion state data to obtain the predicted position. When the predicted position enters the preset positioning area but the current position has not entered the preset positioning area, the corresponding positioning resources are invoked, and positioning correction is performed after the fishing vessel enters the preset positioning area. All modules are connected via wired and / or wireless means to achieve data transmission between modules.

[0021] Methods for dividing navigation units based on electronic chart data include: Obtain electronic nautical chart data corresponding to the regulated waters. The electronic nautical chart data includes the geographical extent, water boundary, channel, and water attribute information of the regulated waters. In this embodiment, it should be noted that: geographical range information is used to determine the overall coverage of the regulated waters, such as the latitude and longitude boundary coordinates of the regulated area; water area boundary information is used to describe the spatial separation relationship between different water areas, such as shoreline boundaries, harbor basin boundaries, and channel boundaries; channel information is used to characterize the location distribution of areas where ships can pass, such as the location of the main channel, branch channels, and channel centerline; and water area attribute information is used to describe the navigation attributes corresponding to different areas, such as ordinary navigation areas, restricted navigation areas, berthing areas, and prohibited navigation areas.

[0022] Electronic nautical chart data can be obtained through electronic nautical chart databases, maritime management platforms, or preset nautical chart data interfaces. After obtaining the electronic nautical chart data, the spatial elements in the data are analyzed, and the vector elements in the electronic nautical chart are uniformly transformed according to geographic coordinates, so that different types of chart elements are under the same spatial reference datum, thereby obtaining the spatial description information corresponding to the regulated waters.

[0023] The electronic nautical chart data is analyzed to extract the spatial boundaries of the regulated waters. Based on the spatial continuity and differences in water attributes, the regulated waters are divided into regions, and regions with continuous spatial ranges and consistent water attributes are divided into independent navigation units. After completing the analysis of electronic nautical chart data, the regulated waters are divided into regions based on the spatial boundaries obtained from the analysis. Specifically, the water boundaries, channel boundaries, and water attribute markers on the electronic nautical chart are used as the basis for region division, dividing the regulated waters into multiple navigation units with independent spatial ranges. During the navigation unit division process, it is first determined whether there is a continuous spatial range relationship between adjacent regions. When two regions are spatially continuous and have the same corresponding water attributes, they are assigned to the same navigation unit. When there is a clear spatial boundary between adjacent regions, or their corresponding water attributes are inconsistent, the two regions are divided into different navigation units, so that each navigation unit corresponds to a region within the regulated waters with a clearly defined spatial range and navigation attributes.

[0024] For example, in a certain regulated waterway, electronic chart data shows the existence of a continuous channel area, with ordinary waters and a port berthing area on either side. Since the ordinary waters and the port berthing area correspond to different water attributes, and there is a port basin boundary between them, the ordinary waters are designated as the first navigation unit, and the port berthing area as the second navigation unit. Within the same continuous channel, if there is no change in channel attributes, it remains classified as the same navigation unit.

[0025] Each navigation unit is assigned a corresponding unit identifier, and the spatial boundary information and location information of each navigation unit are recorded to form a navigation unit set.

[0026] After the navigation units are divided, a unique unit identifier is assigned to each navigation unit, and the spatial boundary information, center position coordinates, and coverage information of each navigation unit are recorded to form a navigation unit set. The unit identifier is used to distinguish different navigation units, for example, by configuring navigation unit numbers according to the generation order; the spatial boundary information describes the coverage area of ​​the navigation unit on the electronic chart; and the center position coordinates characterize the positional features of the navigation unit. For example, after dividing a regulated waterway into three navigation units, identifiers for the first, second, and third navigation units are assigned respectively, and the boundary coordinate sets and center latitude and longitude coordinates of each navigation unit are recorded, thus forming a navigation unit set containing multiple navigation units.

[0027] Methods for generating nautical chart spatial constraint information include: Obtain the spatial boundary information and position information of each navigation unit in the navigation unit set, and determine whether there is an adjacent boundary between any two navigation units and whether the passage conditions are met. It should be noted that spatial boundary information describes the coverage area of ​​the navigation unit in the electronic chart coordinate system, specifically including the set of boundary points, boundary segments, and closed area information of the navigation unit; location information describes the spatial location of the navigation unit in the regulated waters, specifically including the center coordinates of the navigation unit, area range coordinates, and spatial index information. Based on the navigation unit identifiers stored in the navigation unit set, the boundary coordinate set corresponding to each navigation unit is read sequentially, and the spatial positional relationship between different navigation units is calculated based on the unified coordinate system of the electronic chart.

[0028] For example, obtain the boundary coordinate set corresponding to the first navigation unit: {(120.10, 30.20), (120.15, 30.20), (120.15, 30.25), (120.10, 30.25)}; and the boundary coordinate set corresponding to the second navigation unit: {(120.15, 30.20), (120.20, 30.20), (120.20, 30.25), (120.15, 30.25)}; by comparing the boundary coordinate sets of the two navigation units, it is determined that the first navigation unit and the second navigation unit share a boundary line segment, that is, the two have a spatial adjacency relationship.

[0029] After determining that spatial adjacency exists between navigation units, it is then determined whether passage conditions are met between the two units. Specifically, the connection status between adjacent navigation units is assessed based on navigation restriction information, water area attribute information, and boundary attribute information on the electronic chart. If the common boundary between two navigation units corresponds to a navigable water area, and there are no prohibited areas, closed areas, or other impassable areas obstructing passage, then passage conditions are met between the two navigation units. Otherwise, no spatial connection is established. For example, if the first and second navigation units share a 500-meter-long common boundary that corresponds to a channel area, and no prohibited areas are marked on the electronic chart, then passage conditions are met between the first and second navigation units. However, although the third navigation unit shares a 300-meter-long boundary with the first navigation unit, this boundary corresponds to a prohibited area, therefore passage conditions are not met between the first and third navigation units.

[0030] When there is a continuous spatial region between two navigation units and there is no impassable area blocking them, it is determined that there is a spatial connection between the two navigation units, and the corresponding connection direction, connection position and connection type are recorded. The connection direction describes the accessible direction for a vessel between two navigation units, and can be determined based on the spatial relationship between the two navigation units and the channel direction. For example, when a vessel travels from the first navigation unit to the second navigation unit, the connection direction is recorded as from the first navigation unit to the second navigation unit; when bidirectional passage is permitted between the two navigation units, it is recorded as a bidirectional connection. The connection location describes the spatial intersection area between the two navigation units, and can be determined by the coordinates of the center point of the common boundary of the two navigation units or the set of coordinates of the boundary line segments. The connection type describes the connection state between the two navigation units, such as a direct adjacent connection, a channel transition connection, or a restricted connection.

[0031] For example, if the coordinates of the common boundary center between the first navigation unit and the second navigation unit are (120.15, 30.225), and the electronic chart shows that the vessel can enter the second navigation unit from the first navigation unit along the channel direction, then record: Connection direction: first navigation unit → second navigation unit; Connection position: (120.15, 30.225); Connection type: channel transition connection.

[0032] Each navigation unit is treated as a spatial constraint node, the spatial connection relationship between navigation units is treated as a constraint edge between nodes, and the connection direction, connection position and connection type are associated as constraint attributes to generate nautical chart spatial constraint information.

[0033] Specifically, the navigation unit identifier is used as the node index; for example, the first navigation unit is denoted as node N1, and the second navigation unit is denoted as node N2. When there is a spatial connection between N1 and N2, a constraint edge E12 is established between node N1 and node N2, and the corresponding connection attribute is written into the constraint edge. For example: N1 E12 Direction N1→N2; Location (120.15, 30.225); Type: Channel transition connection N2 E23 Direction N2→N3; Position (120.30, 30.250); Type: Direct Adjacency Connection By using the above method, discrete navigation unit spatial information is converted into nautical chart spatial constraint information containing nodes, connection relationships, and constraint attributes, enabling the system to quickly determine the spatial transition area between different navigation units based on the nautical chart spatial constraint information.

[0034] Methods for generating dynamic checkpoint sets include: The system retrieves spatial constraint information from nautical charts to identify adjacent navigation units with spatial connections. Based on the connection location, it determines the common boundary area between adjacent navigation units and the passage boundary between navigation units according to the connection direction and connection type. Each passage boundary is then configured as a corresponding checkpoint identifier to generate a dynamic checkpoint set.

[0035] Specifically, firstly, the spatial constraint information of the nautical chart is retrieved, and the recorded spatial constraint nodes and edges are traversed to obtain adjacent navigation units with spatial connections. By reading the node relationships in the nautical chart's spatial constraint information, combinations of navigation units connected by constraint edges are selected and used as candidate navigation units for dynamic checkpoint generation. Further, the common boundary area between adjacent navigation units is determined based on the connection positions recorded in the spatial constraint information. Specifically, based on the spatial boundary information and connection positions of two navigation units, the intersection area between adjacent navigation units is extracted, and the boundary area where the two navigation units spatially connect is taken as the common boundary area.

[0036] The common boundary region characterizes the range of possible spatial transitions between two navigation units and serves as the basis for subsequently determining the passage boundary. Further, the passage boundary between navigation units is determined based on the connection direction and connection type in the spatial constraint information. Specifically, the crossing direction when a ship enters another navigation unit is determined based on the connection direction, the connection method corresponding to the common boundary region is determined based on the connection type, and a boundary region conforming to the actual passage path of the ship is determined from the common boundary region; this boundary region is then defined as the passage boundary.

[0037] The passage boundary characterizes the spatial boundary area traversed by a vessel when entering another navigation unit. Compared to the entire navigation unit boundary, the passage boundary more accurately reflects the vessel's actual crossing position. After determining the passage boundaries, corresponding checkpoint identifiers are configured for each passage boundary, and the passage boundaries are associated with their corresponding navigation units to generate a dynamic checkpoint set. Specifically, a unique checkpoint number is assigned to each passage boundary, and the boundary coordinate range, associated navigation unit, and passage direction corresponding to that dynamic checkpoint are recorded, enabling the dynamic checkpoints to serve as spatial reference objects for subsequent fishing vessel trajectory mapping and crossing status determination.

[0038] For example, after the regulatory waters are divided, they form a first navigation unit N1, a second navigation unit N2, and a third navigation unit N3. The nautical chart spatial constraint information records that there is a spatial connection between the first navigation unit N1 and the second navigation unit N2. The connection location is located in the central area of ​​their common boundary, the connection direction is from N1 to N2, and the connection type is a channel transition connection.

[0039] After the system retrieves the spatial constraint information, it extracts the common boundary region between the first navigation unit N1 and the second navigation unit N2. Assuming this common boundary is 500 meters long, with a 100-meter section conforming to the channel's passage direction, this 100-meter section is designated as the first passage boundary, and a checkpoint identifier K1 is configured, recording: Checkpoint identifier: K1; Associated navigation units: N1, N2; Passage direction: N1→N2; Boundary range: 100-meter passage area. Similarly, if another passable boundary exists between the second navigation unit N2 and the third navigation unit N3, a second dynamic checkpoint K2 is generated. Finally, a dynamic checkpoint set is formed from multiple dynamic checkpoints.

[0040] Methods for establishing the mapping relationship between dynamic checkpoints and navigation units include: Obtain the checkpoint identifier, passage boundary information, and associated navigation unit information for each dynamic checkpoint in the dynamic checkpoint set; determine the navigation unit associated with each dynamic checkpoint based on the passage boundary position, and designate the navigation units on both sides of the passage boundary as the entry navigation unit and the exit navigation unit, respectively; establish the association between the dynamic checkpoint identifier and the corresponding navigation unit identifier, and generate the mapping relationship between the dynamic checkpoint and the navigation unit.

[0041] In this embodiment, it should be noted that the checkpoint identifier is configured when generating the dynamic checkpoint set to uniquely identify different dynamic checkpoints in the regulated waters. For example, the numbers K1, K2, etc. are configured according to the generation order of the dynamic checkpoints. The passage boundary information comes from the passage boundary determined during the generation process of the dynamic checkpoints and is used to describe the spatial location range of the dynamic checkpoints on the electronic chart. Specifically, it includes the boundary coordinate set, boundary length, and spatial location of the passage boundary. The associated navigation unit information comes from the adjacent navigation unit information corresponding to the generation of the passage boundary and is used to represent the two navigation units that form the dynamic checkpoint.

[0042] When generating a dynamic checkpoint, the navigation unit identifiers involved in determining the passage boundary are synchronously written into the data record of the corresponding dynamic checkpoint. For example, when determining the passage boundary based on the spatial connection relationship between the first navigation unit and the second navigation unit, the first navigation unit identifier N1 and the second navigation unit identifier N2 are used as the associated navigation unit information corresponding to the passage boundary and are associated and stored with the dynamic checkpoint identifier K1.

[0043] Based on the location of the passage boundary corresponding to each dynamic checkpoint, the navigation unit associated with the dynamic checkpoint is determined, and the navigation units on both sides of the passage boundary are respectively designated as the entry navigation unit and the exit navigation unit. Specifically, based on the spatial coordinate range of the passage boundary, the boundary areas of the navigation units located on both sides of the passage boundary are obtained; combined with the passage direction information corresponding to the dynamic checkpoint, the navigation unit in which the vessel was located before crossing the dynamic checkpoint and the navigation unit it entered after crossing are determined. Among them, the navigation unit in which the vessel was located before entering the dynamic checkpoint is determined as the entry navigation unit, and the navigation unit in which the vessel entered after crossing the dynamic checkpoint is determined as the exit navigation unit.

[0044] For example, if the passage boundary corresponding to the dynamic checkpoint K1 is located between the first navigation unit N1 and the second navigation unit N2, and the nautical chart spatial constraint information records that the passage direction of this passage boundary is from N1 to N2, then it is determined that: entering navigation unit: N1; leaving navigation unit: N2.

[0045] If the dynamic checkpoint allows bidirectional passage, then record: Associated navigation units: N1, N2; Passage direction: N1↔N2. Further, establish the association between the dynamic checkpoint identifier and the corresponding navigation unit identifier, generating a mapping relationship between the dynamic checkpoint and the navigation unit.

[0046] Specifically, using dynamic checkpoint identifiers as indexes, the corresponding entry navigation unit identifiers, exit navigation unit identifiers, and travel direction information are associated and stored to form a dynamic checkpoint-navigation unit mapping table.

[0047] For example, the following mapping relationship can be established: K1 N1 N2 N1→N2 K2 N2 N3 N2→N3 Here, K1 represents the first dynamic checkpoint, and N1 and N2 represent the navigation units associated with both sides of this dynamic checkpoint. When the fishing vessel's continuous positioning data is subsequently acquired and it is determined that the fishing vessel enters N2 from N1, the corresponding dynamic checkpoint K1 can be quickly matched through the above mapping relationship.

[0048] Methods for generating checkpoint state sequences based on the change order of navigation units include: Acquire continuous positioning data and motion status data of fishing vessels. Continuous positioning data includes positioning time, longitude coordinates and latitude coordinates, while motion status data includes sailing speed and heading information. Based on the mapping relationship between the dynamic checkpoint and the navigation unit, the spatial coordinates corresponding to each positioning point in the continuous positioning data are obtained. The spatial coordinates are matched with the spatial boundary information corresponding to the navigation unit. When the positioning point is within the spatial range of a certain navigation unit, the positioning point is associated with the corresponding navigation unit. Specifically, the system first acquires the spatial coordinates of each positioning point in the continuous positioning data of the fishing vessel, and then maps the positioning points to the corresponding navigation units according to the mapping relationship between the dynamic checkpoint and the navigation units. The continuous positioning data records the position changes of the fishing vessel during its navigation process in chronological order, and each data point includes the positioning time, longitude coordinates, and latitude coordinates. After receiving the continuous positioning data, the system sequentially extracts the spatial coordinates corresponding to each positioning point and matches these spatial coordinates with the spatial boundary information corresponding to each navigation unit in the navigation unit set.

[0049] Based on the spatial boundary range corresponding to the navigation unit, it is determined whether the positioning point is located within the coverage area of ​​a certain navigation unit. When the spatial coordinates of the positioning point are within the boundary range of a certain navigation unit, the positioning point is associated with the corresponding navigation unit to obtain the navigation unit identifier corresponding to the positioning point.

[0050] For example, the regulated waters are divided into a first navigation unit N1 and a second navigation unit N2, wherein: the first navigation unit N1 corresponds to a spatial range of longitude 120.100°~120.150° and latitude 30.200°~30.250°; the second navigation unit N2 corresponds to a spatial range of longitude 120.150°~120.200° and latitude 30.200°~30.250°.

[0051] When the location point P1 = (120.130°, 30.220°) is acquired from the continuous positioning data of the fishing vessel, since this location point is within the range of the first navigation unit N1, the path P1→N1 is established. When the location point P2 = (120.170°, 30.220°) is subsequently acquired, since this location point enters the range of the second navigation unit N2, the path P2→N2 is established. Through this method, the continuous positioning data is converted into spatial state information corresponding to the electronic chart navigation unit.

[0052] The navigation units corresponding to each positioning point are sorted according to time sequence to obtain the order of navigation unit changes; when the navigation units corresponding to adjacent positioning points change, the corresponding dynamic checkpoints are determined according to the mapping relationship, and a checkpoint state sequence is generated according to the change order of the dynamic checkpoints.

[0053] Specifically, based on the time stamps in the continuous positioning data, the positioning points that have completed navigation unit mapping are sorted to form a navigation unit sequence arranged in chronological order; then it is determined whether the navigation unit stamps corresponding to adjacent time nodes have changed.

[0054] When adjacent positioning points correspond to the same navigation unit identifier, it means that the fishing vessel is still in the same navigation unit and maintains the current navigation unit state; when adjacent positioning points correspond to different navigation unit identifiers, it means that the fishing vessel has undergone a spatial area change, and the navigation unit change relationship is recorded.

[0055] For example, the continuous positioning data of a fishing vessel, after mapping, yields: t1 N1 t2 N2 t3 N3 t4 N4 t5 N5 The navigation unit change sequence is obtained in chronological order: N1→N2→N3. Here, N1 to N2 and N2 to N3 represent navigation unit transitions for the fishing vessel. Furthermore, when the navigation unit corresponding to an adjacent positioning point changes, the corresponding dynamic checkpoint is determined based on the mapping relationship between the dynamic checkpoint and the navigation unit, and a checkpoint state sequence is generated according to the change order of the dynamic checkpoint.

[0056] Specifically, the identifiers of the two navigation units before and after the change are obtained, and the navigation unit conversion relationship is matched with the dynamic checkpoint-navigation unit mapping relationship. When there is a dynamic checkpoint corresponding to the conversion relationship, the corresponding dynamic checkpoint identifier is obtained and arranged in the order of the actual sailing time of the fishing vessel to form a checkpoint status sequence.

[0057] For example, the dynamic checkpoint mapping relationship records: dynamic checkpoint K1 corresponds to entering navigation unit N1 and leaving navigation unit N2; dynamic checkpoint K2 corresponds to entering navigation unit N2 and leaving navigation unit N3. When the fishing vessel navigation unit change sequence is: N1→N2→N3, then: N1→N2 matches dynamic checkpoint K1; N2→N3 matches dynamic checkpoint K2. Therefore, the checkpoint state sequence is generated as: K1→K2.

[0058] Furthermore, the checkpoint state sequence is stored in chronological order, so that each dynamic checkpoint state corresponds to a spatial transformation event during the actual navigation of the fishing vessel, thereby converting the continuous positioning trajectory into discrete checkpoint state change information.

[0059] Methods for determining valid checkpoint crossing events based on counting results and the direction of fishing vessel movement include: Based on the state change relationship of each dynamic checkpoint in the checkpoint state sequence, the checkpoint state bit is constructed, and the state of the fishing boat relative to each dynamic checkpoint is converted into discrete state values; an XOR operation is performed on the checkpoint state bit at the current time and the checkpoint state bit at the previous time to obtain the state jump variable. Perform an XOR operation: ;in, Indicates time The state jump variable is used to characterize whether a change in the checkpoint state has occurred between the current time and the previous time. Indicates time The checkpoint status bit is used to describe the status of the fishing vessel relative to the target dynamic checkpoint at the current moment; Indicates time The checkpoint status bit, that is, the checkpoint status corresponding to the previous sampling time; This represents the XOR operator, used to compare whether two status bits are the same; it outputs 1 when the two status bits are different and 0 when the two status bits are the same. Indicates the index at the current time; Indicates the index of the previous time step; When a state jump variable indicates a state transition, a continuous confirmation counter is started to count the continuous state change process; Counting continuous state change processes: ; where represents time. The corresponding consecutive acknowledgment count is used to record the number of times the state jump variable remains valid consecutively; Indicates the previous moment The continuous confirmation count value is used to achieve count accumulation; This indicates that a state transition has been detected, and the corresponding counter is incremented. This indicates that no state transition was detected, and the corresponding counter is cleared to zero. When the continuous confirmation count reaches the preset count threshold, the movement direction of the fishing boat relative to the corresponding dynamic checkpoint is obtained, and it is determined whether the movement direction of the fishing boat remains consistent within a continuous time period; when the continuous confirmation count reaches the preset count threshold and the movement direction of the fishing boat remains consistent, a valid checkpoint crossing event is determined.

[0060] It should be noted that the preset counting threshold is set by staff based on the results of historical data analysis. This historical analysis process includes collecting the counts of multiple counters and calculating their average value as a reference to obtain the preset counting threshold. During system operation, the staff will adjust the threshold according to the actual situation.

[0061] For example, in a certain regulated waterway, an electronic nautical chart divides the area into a first navigation unit N1 and a second navigation unit N2. A dynamic checkpoint K1 is set between the two navigation units, with the passage direction corresponding to the dynamic checkpoint K1 being from N1 to N2. The system acquires continuous positioning data of the fishing vessel and, based on the mapping relationship between the dynamic checkpoint and the navigation units, maps each positioning point to the corresponding navigation unit. When the navigation unit corresponding to the continuous positioning point of the fishing vessel changes from N1 to N2, it indicates that the fishing vessel is gradually entering the second navigation unit N2 from the first navigation unit N1, and a checkpoint state sequence of the dynamic checkpoint K1 is generated accordingly.

[0062] The checkpoint status bits are constructed based on the aforementioned checkpoint status sequence. Let the status bit be 0 when the fishing boat has not yet crossed dynamic checkpoint K1, and 1 after crossing K1. Then, the status bit sequence corresponding to consecutive sampling times t1 to t5 is 0, 0, 1, 1, 1. At time t3, the system obtains the current status bit and the previous status bit, and performs an XOR operation: Since the XOR result is 1, it indicates that the state corresponding to the dynamic checkpoint K1 has changed. The system determines that the state change is a suspected crossing event and starts a continuous confirmation counter to accumulate the data.

[0063] For example, if the continuous confirmation count threshold is set to 3, when the fishing boat's state continuously changes from a non-crossing state to a crossing state in the subsequent three consecutive sampling periods, the continuous confirmation counter will record 1, 2, and 3 respectively. When the count value reaches the preset threshold of 3, it indicates that the state change is continuous and does not belong to the instantaneous state change caused by a single positioning drift.

[0064] Furthermore, the system acquires the fishing vessel's direction of movement relative to the dynamic checkpoint K1. For example, during continuous positioning, the fishing vessel's spatial position gradually moves from the front to the rear of the dynamic checkpoint K1, while its direction of movement remains continuously from N1 to N2, consistent with the preset passage direction of the dynamic checkpoint K1. Therefore, the system determines that the continuous confirmation count meets the requirements and that the fishing vessel's direction of movement remains consistent, confirming that the fishing vessel has completed the crossing of the dynamic checkpoint K1 and generating a valid checkpoint crossing event.

[0065] Conversely, when a fishing boat is affected by positioning errors near the dynamic checkpoint K1 and experiences a back-and-forth state change from N1 to N2 to N1, although a state bit flip may occur, the system will not generate a valid checkpoint crossing event because the continuous confirmation count cannot reach the preset threshold, or the fishing boat's movement direction changes in the opposite direction. This avoids false alarms caused by positioning fluctuations near the boundary.

[0066] Methods for obtaining predicted locations include: The system acquires continuous positioning data and motion status data of the fishing vessel. Based on the continuous positioning data, it determines the spatial position of the fishing vessel at the current moment, and based on the speed and heading information in the motion status data, it determines the motion velocity vector of the fishing vessel at the current moment. It sets a prediction time interval and performs motion extrapolation based on the spatial position and motion velocity vector of the fishing vessel at the current moment to obtain the predicted position at the future moment.

[0067] The motion extrapolation process is represented as: ;in, Indicates fishing boats at future moments The corresponding predicted location; Indicates the current spatial position of the fishing vessel; This represents the velocity vector of the fishing boat at the current moment; Indicates the prediction time interval.

[0068] Methods for correcting the positioning of a fishing vessel after it enters a pre-defined positioning area include: Based on the positional relationship between the predicted position obtained by motion extrapolation and the preset positioning area, a prefetch trigger flag is generated. When the predicted position enters the preset positioning area and the current position does not enter the preset positioning area, it is determined that the fishing boat is about to enter the preset positioning area, a positioning resource prefetch instruction is generated, and the positioning auxiliary resources corresponding to the preset positioning area are called. Prefetch trigger flag: ;in, Indicates time The location resource prefetching trigger flag is used to indicate whether the conditions for early invocation of location auxiliary resources are met at the current time. This indicates a preset positioning area determined based on the dynamic checkpoint set; This variable represents the area range, used to describe a specified spatial range in an electronic nautical chart. This indicates that the predicted location is within the preset positioning area; This indicates that the current location has not yet entered the preset positioning area; This represents the logical AND operator, used to indicate that two conditions must both be true. This indicates a symbol used to determine whether a location is within a specified area. This indicates that it is not a symbol and is used to determine whether a certain position is not within the specified area.

[0069] When a fishing vessel actually enters the preset positioning area, the pre-loaded positioning auxiliary resources are invoked to correct the vessel's current positioning data, and the corrected positioning result is obtained. When the predicted position is inconsistent with the actual navigation trajectory, causing the fishing vessel to fail to enter the preset positioning area, the corresponding positioning resource invocation is canceled and the loaded positioning auxiliary resources are cleared.

[0070] For example, in a certain regulated waterway, a preset positioning area is set up for the dynamic checkpoint K1. This area is used to perform positioning enhancement processing when a fishing vessel approaches the dynamic checkpoint K1. The system continuously acquires the fishing vessel's continuous positioning data and motion status data. Currently, the system detects that the fishing vessel is outside the preset positioning area, about 800 meters away from the dynamic checkpoint K1, with a current speed of 12 knots and a heading towards the dynamic checkpoint K1.

[0071] The system extrapolates the fishing vessel's movement based on its current position, speed, and heading, predicting that the vessel will enter the preset positioning area corresponding to dynamic checkpoint K1 in approximately 60 seconds. Since the prediction indicates the vessel's future position is within the preset positioning area, and its current position has not yet entered this area, the system determines that the vessel is about to enter the positioning enhancement area. It then generates a positioning resource prefetching command and pre-calls the positioning auxiliary resources corresponding to dynamic checkpoint K1, including positioning correction parameters, auxiliary positioning information, and area positioning constraint data for that area, ensuring the relevant positioning resources are prepared in advance.

[0072] Subsequently, when the fishing vessel continues its original course and actually enters the preset positioning area, the system directly calls the pre-loaded positioning auxiliary resources to correct the vessel's current positioning data and obtain the corrected vessel position coordinates. Since the positioning auxiliary resources are prepared in advance, the system avoids the positioning response delay caused by loading resources after the vessel enters the area. In another scenario, if the fishing vessel temporarily changes course while approaching the dynamic checkpoint K1, for example, turning from its original course to sail in other waters, the system re-predicts its position based on the updated motion state. If it finds that the vessel's subsequent trajectory will not enter the preset positioning area, the system determines that the original prediction result is invalid, cancels the corresponding positioning resource call, and clears the pre-loaded but unused positioning auxiliary resources to avoid unnecessary resource occupation. Example

[0073] Please see Figure 2 As shown, for parts not described in detail in this embodiment, please refer to the description in Embodiment 1. A method for dynamic monitoring of fishing vessels at checkpoints based on electronic nautical charts is provided, including: S1. Obtain electronic nautical chart data corresponding to the regulated waters, divide navigation units based on the electronic nautical chart data, and generate nautical chart spatial constraint information according to the spatial connection relationship between navigation units; S2. Call the nautical chart spatial constraint information to determine the passage boundaries between navigation units, generate a dynamic checkpoint set, and establish a mapping relationship between the dynamic checkpoints and navigation units; S3. Acquire continuous positioning data and motion status data of fishing vessels, map the continuous positioning data to the corresponding navigation units according to the mapping relationship, and generate a checkpoint status sequence according to the change order of the navigation units. S4. Construct checkpoint status bits based on checkpoint status sequence, obtain status jump variables, start continuous confirmation counter, and determine valid checkpoint crossing events based on counting results and fishing boat movement direction. S5. Based on continuous positioning data and motion state data, extrapolate motion to obtain the predicted position; when the predicted position enters the preset positioning area and the current position does not enter the preset positioning area, call the corresponding positioning resources, and perform positioning correction after the fishing boat enters the preset positioning area. Example

[0074] This embodiment discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the operation mode of the above-described dynamic monitoring system for fishing vessels based on electronic nautical charts.

[0075] Since the electronic device described in this embodiment is the electronic device used to implement the dynamic monitoring system and method for fishing vessel checkpoints based on electronic nautical charts in this application embodiment, those skilled in the art can understand the specific implementation methods and various variations of the electronic device in this embodiment based on the dynamic monitoring system and method for fishing vessel checkpoints based on electronic nautical charts described in this application embodiment. Therefore, how the electronic device implements the method in this application embodiment will not be described in detail here. As long as those skilled in the art implement the electronic device used in the dynamic monitoring system and method for fishing vessel checkpoints based on electronic nautical charts in this application embodiment, it falls within the scope of protection of this application.

[0076] It should be noted that all formulas in this manual are calculated by removing dimensions and taking their numerical values. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters and thresholds in the formulas are set by those skilled in the art according to the actual situation.

[0077] The above description is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for users of ordinary technical skills, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A dynamic monitoring system for fishing vessel checkpoints based on electronic nautical charts, characterized in that, include: The chart constraint construction module is used to acquire electronic chart data corresponding to the regulated waters, divide navigation units based on the electronic chart data, and generate chart spatial constraint information according to the spatial connection relationship between the navigation units. The dynamic checkpoint generation module is used to call the spatial constraint information of the nautical chart, determine the passage boundary between navigation units, generate a dynamic checkpoint set, and establish the mapping relationship between the dynamic checkpoints and navigation units; The vessel trajectory mapping module is used to acquire continuous positioning data and motion status data of fishing vessels, map the continuous positioning data to the corresponding navigation unit according to the mapping relationship, and generate a checkpoint status sequence according to the change order of the navigation unit. The crossing status determination module is used to construct the checkpoint status bit based on the checkpoint status sequence, obtain the status jump variable, start the continuous confirmation counter, and determine the valid checkpoint crossing event based on the counting result and the direction of movement of the fishing boat. The positioning prefetching and scheduling module is used to extrapolate motion based on continuous positioning data and motion state data to obtain the predicted position. When the predicted position enters the preset positioning area and the current position does not enter the preset positioning area, the corresponding positioning resources are called, and positioning correction is performed after the fishing boat enters the preset positioning area.

2. The dynamic monitoring system for fishing vessels based on electronic nautical charts according to claim 1, characterized in that, The method for dividing navigation units based on electronic chart data includes: Obtain electronic nautical chart data corresponding to the regulated waters. The electronic nautical chart data includes the geographical extent, water boundary, channel, and water attribute information of the regulated waters. The electronic nautical chart data is analyzed to extract the spatial boundaries of the regulated waters. Based on the spatial continuity and differences in water attributes, the regulated waters are divided into regions, and regions with continuous spatial ranges and consistent water attributes are divided into independent navigation units. Each navigation unit is assigned a corresponding unit identifier, and the spatial boundary information and location information of each navigation unit are recorded to form a navigation unit set.

3. The dynamic monitoring system for fishing vessels based on electronic nautical charts according to claim 2, characterized in that, The method for generating nautical chart spatial constraint information includes: Obtain the spatial boundary information and position information of each navigation unit in the navigation unit set, and determine whether there is an adjacent boundary between any two navigation units and whether the passage conditions are met. When there is a continuous spatial region between two navigation units and there is no impassable area blocking them, it is determined that there is a spatial connection between the two navigation units, and the corresponding connection direction, connection position and connection type are recorded. Each navigation unit is treated as a spatial constraint node, the spatial connection relationship between navigation units is treated as a constraint edge between nodes, and the connection direction, connection position and connection type are associated as constraint attributes to generate nautical chart spatial constraint information.

4. The dynamic monitoring system for fishing vessels based on electronic nautical charts according to claim 3, characterized in that, The method for generating the dynamic checkpoint set includes: The system retrieves spatial constraint information from nautical charts to identify adjacent navigation units with spatial connections. Based on the connection location, it determines the common boundary area between adjacent navigation units and the passage boundary between navigation units according to the connection direction and connection type. Each passage boundary is then configured as a corresponding checkpoint identifier to generate a dynamic checkpoint set.

5. A dynamic monitoring system for fishing vessels based on electronic nautical charts according to claim 4, characterized in that, The method for establishing the mapping relationship between the dynamic checkpoint and the navigation unit includes: Obtain the checkpoint identifier, passage boundary information, and associated navigation unit information for each dynamic checkpoint in the dynamic checkpoint set; determine the navigation unit associated with each dynamic checkpoint based on the passage boundary position, and designate the navigation units on both sides of the passage boundary as the entry navigation unit and the exit navigation unit, respectively; establish the association between the dynamic checkpoint identifier and the corresponding navigation unit identifier, and generate the mapping relationship between the dynamic checkpoint and the navigation unit.

6. The dynamic monitoring system for fishing vessels based on electronic nautical charts according to claim 5, characterized in that, The method for generating a checkpoint state sequence based on the navigation unit change order includes: Acquire continuous positioning data and motion status data of fishing vessels. Continuous positioning data includes positioning time, longitude coordinates and latitude coordinates, while motion status data includes sailing speed and heading information. Based on the mapping relationship between the dynamic checkpoint and the navigation unit, the spatial coordinates corresponding to each positioning point in the continuous positioning data are obtained. The spatial coordinates are matched with the spatial boundary information corresponding to the navigation unit. When the positioning point is within the spatial range of a certain navigation unit, the positioning point is associated with the corresponding navigation unit. The navigation units corresponding to each positioning point are sorted according to time sequence to obtain the order of navigation unit changes; when the navigation units corresponding to adjacent positioning points change, the corresponding dynamic checkpoints are determined according to the mapping relationship, and a checkpoint state sequence is generated according to the change order of the dynamic checkpoints.

7. A dynamic monitoring system for fishing vessels based on electronic nautical charts according to claim 6, characterized in that, The method for determining valid checkpoint crossing events based on counting results and the direction of movement of fishing vessels includes: Based on the state change relationship of each dynamic checkpoint in the checkpoint state sequence, the checkpoint state bit is constructed, and the state of the fishing boat relative to each dynamic checkpoint is converted into discrete state values; an XOR operation is performed on the checkpoint state bit at the current time and the checkpoint state bit at the previous time to obtain the state jump variable; when the state jump variable indicates that a state transition has occurred, a continuous confirmation counter is started to count the continuous state change process. When the continuous confirmation count reaches the preset count threshold, the movement direction of the fishing boat relative to the corresponding dynamic checkpoint is obtained, and it is determined whether the movement direction of the fishing boat remains consistent within a continuous time period; when the continuous confirmation count reaches the preset count threshold and the movement direction of the fishing boat remains consistent, a valid checkpoint crossing event is determined.

8. A dynamic monitoring system for fishing vessels based on electronic nautical charts according to claim 7, characterized in that, The method for obtaining the predicted location includes: The system acquires continuous positioning data and motion status data of the fishing vessel. Based on the continuous positioning data, it determines the spatial position of the fishing vessel at the current moment, and based on the speed and heading information in the motion status data, it determines the motion velocity vector of the fishing vessel at the current moment. It sets a prediction time interval and performs motion extrapolation based on the spatial position and motion velocity vector of the fishing vessel at the current moment to obtain the predicted position at the future moment.

9. A dynamic monitoring system for fishing vessels based on electronic nautical charts according to claim 8, characterized in that, The method for performing positioning correction after the fishing vessel enters the preset positioning area includes: Based on the positional relationship between the predicted position obtained by motion extrapolation and the preset positioning area, a prefetch trigger flag is generated. When the predicted position enters the preset positioning area and the current position does not enter the preset positioning area, it is determined that the fishing boat is about to enter the preset positioning area, a positioning resource prefetch instruction is generated, and the positioning auxiliary resources corresponding to the preset positioning area are called. When a fishing vessel actually enters the preset positioning area, the pre-loaded positioning auxiliary resources are invoked to correct the vessel's current positioning data, and the corrected positioning result is obtained. When the predicted position is inconsistent with the actual navigation trajectory, causing the fishing vessel to fail to enter the preset positioning area, the corresponding positioning resource invocation is canceled and the loaded positioning auxiliary resources are cleared.

10. A method for dynamic monitoring of fishing vessel checkpoints based on electronic nautical charts, implemented by a dynamic monitoring system for fishing vessel checkpoints based on electronic nautical charts as described in any one of claims 1 to 9, characterized in that, include: S1. Obtain electronic nautical chart data corresponding to the regulated waters, divide navigation units based on the electronic nautical chart data, and generate nautical chart spatial constraint information according to the spatial connection relationship between navigation units; S2. Call the nautical chart spatial constraint information to determine the passage boundaries between navigation units, generate a dynamic checkpoint set, and establish a mapping relationship between the dynamic checkpoints and navigation units; S3. Acquire continuous positioning data and motion status data of fishing vessels, map the continuous positioning data to the corresponding navigation units according to the mapping relationship, and generate a checkpoint status sequence according to the change order of the navigation units. S4. Construct checkpoint status bits based on checkpoint status sequence, obtain status jump variables, start continuous confirmation counter, and determine valid checkpoint crossing events based on counting results and fishing boat movement direction. S5. Based on continuous positioning data and motion state data, extrapolate motion to obtain the predicted position; when the predicted position enters the preset positioning area and the current position does not enter the preset positioning area, call the corresponding positioning resources, and perform positioning correction after the fishing boat enters the preset positioning area.

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