A ship positioning and intelligent warning system based on Beidou satellites

Abstract

The present invention discloses a ship positioning and intelligent early warning system based on Beidou satellites, belonging to the technical field of ship safety management, and specifically including: obtaining ship data and wind force data of a target area; determining a buffer area for any ship outside the target area according to the ship data and the wind force data. If any ship is in the buffer area, the ship is marked as a pending ship, and a shortest distance change curve from the ship to the target area is generated within a monitoring period; obtaining characteristic points in the change curve and calculating a change coefficient Q, calculating an early warning score P according to the change coefficient and the change curve, calculating an early warning score P according to the change coefficient and the change curve. If P is greater than P', the pending ship is marked as an abnormal ship, and an early warning message is sent to the abnormal ship. The present invention improves the accuracy of ship supervision.

Description

Technical Field

[0001] The present invention relates to the technical field of ship safety management, and particularly relates to a ship positioning and intelligent warning system based on Beidou satellites. Background Art

[0002] A ship is a large waterborne vehicle mainly used for transporting goods and personnel and performing specific tasks. With the progress of technology and economic development, domestic and foreign trade has been growing continuously, and the volume of maritime transportation has also shown a large-scale growth trend. Ship traffic has become increasingly busy. To ensure the safety of ship navigation, tools such as the Automatic Identification System (AIS), Beidou positioning, and satellite navigation systems are mostly used to record and monitor the ship navigation trajectory.

[0003] The ship navigation trajectory refers to the path followed by a ship when sailing on the sea or inland river. These trajectories are determined by various factors, including nautical charts, route planning, weather conditions, the influence of sea currents and waves, and the technical performance of the ship. The recording of ship navigation trajectories is crucial for navigation safety, which helps to monitor the position of ships. By monitoring the navigation trajectory, collisions between ships and contact with ground obstacles can be avoided. At the same time, the historical data of the navigation trajectory can be used to analyze navigation patterns, predict future navigation conditions, and optimize waterways.

[0004] In a Chinese patent with the patent publication number CN115691224A, a ship monitoring method and system for an offshore wind farm based on intelligent navigation safety management are disclosed. In its solution, the offshore navigation environment is calibrated according to the wind farm area, and it is determined whether the position of the sailing ship is within the preset area range; if so, the position of the ship is identified as being at a preset position level, and corresponding electronic fence warnings are generated according to the position level to effectively reduce the occurrence of safety accidents. However, in practical applications, the existing method relies on static distance thresholds or one-way approach logics. When a ship approaches the area defined by the virtual electronic fence but does not actually intrude (such as sailing parallel to the boundary or turning after a short approach), the system is prone to trigger continuous false alarms due to environmental disturbances or track fluctuations. Frequent false alarms not only cause waste of monitoring resources but also affect the accuracy of ship supervision. Summary of the Invention

[0005] The purpose of the present invention is to provide a ship positioning and intelligent warning system based on Beidou satellites to solve the following technical problems:

[0006] In practical applications, the method relies on static distance thresholds or one-way approach logics. When a ship approaches the area defined by the virtual electronic fence but does not actually intrude (such as sailing parallel to the boundary or turning after a short approach), the system is prone to trigger continuous false alarms due to environmental disturbances or track fluctuations. Frequent false alarms not only cause waste of monitoring resources but also affect the accuracy of ship supervision.

[0007] The object of the present invention can be achieved by the following technical solutions:

[0008] A ship positioning and intelligent warning system based on Beidou satellites, comprising:

[0009] A data acquisition module, configured to determine a target area and acquire ship data and wind data of the waterway where the target area is located, the ship data including ship direction, ship position and ship speed; the wind data including wind direction and wind speed;

[0010] A data analysis module, configured to determine a buffer area of any ship outside the target area according to the ship data and the wind data. If there is any ship in the buffer area, mark the ship as a pending ship, preset a monitoring period [T, T + H], and periodically calculate the shortest distance S from the pending ship to the target area within the monitoring period, and generate a change curve S(t) of the shortest distance over time; where H is a preset monitoring duration;

[0011] A result generation module, configured to obtain the starting point, ending point, peak point and valley point in the change curve S(t) as reference points, calculate the slope k between adjacent reference points, and according to the calculation formula , calculate a change coefficient Q, calculate a warning score P according to the change coefficient and the change curve. If P is greater than P', mark the pending ship as an abnormal ship and send a warning message to the abnormal ship, where P' represents a preset warning score threshold; where hi is the duration between the i-th adjacent reference points, ki is the slope between the i-th adjacent reference points, n is the number of reference points in the change curve, and n' represents the number of tangents with a negative slope.

[0012] As a further solution of the present invention: in the data analysis module, the process of determining the buffer area is as follows:

[0013] Determine the minimum circumscribed circle of the target area, obtain the radius of the minimum circumscribed circle and mark it as Dbase, calculate a corrected radius D' according to the calculation D' = Dbase*(1 + Vw / Vcrit)+γ*Lcos(θwind - ship), and draw a circle with the corrected radius D' to obtain the buffer area, where Vcrit is a preset critical wind speed, Vw is the current wind speed, θw - ship is the included angle between the wind direction and the ship's course, γ is a preset unit coefficient, and L is the total length of the ship.

[0014] As a further solution of the present invention: in the data analysis module, the specific calculation process of the shortest distance S is as follows:

[0015] Sample along the boundary of the smallest circumscribed circle of the target area, record the position coordinates of all boundary points as (Je, We), obtain the position coordinates (J1, W1) of the current ship, calculate the Euclidean distance between each boundary point and the current ship in turn, and select the smallest Euclidean distance as the shortest distance S, where J is the longitude and W is the latitude.

[0016] As a further solution of the present invention: in the result generation module, the specific calculation process of the warning score is as follows:

[0017] ;

[0018] Among them, S(T + H) is the minimum distance corresponding to the undetermined ship at the (T + H)-th moment, S(T) is the minimum distance corresponding to the undetermined ship at the T-th moment, λ is a preset coefficient, and θw-ship is the included angle between the wind direction and the ship's course.

[0019] As a further solution of the present invention: it also includes that if the change coefficient Q is greater than or equal to 0, no subsequent operation is performed, and the monitoring period is corrected to [T + H, T + 2H].

[0020] As a further solution of the present invention: in the result generation module, it also includes setting a warning distance range [0, R], setting X distance levels at preset unit distance intervals within the warning distance range, the smaller the distance, the higher the warning level, and different warning levels correspond to different warning messages, where R is the preset warning distance and X is the total number of preset warning levels.

[0021] As a further solution of the present invention: in the data analysis module, it also includes obtaining the centroid position of the target area, constructing a reference ray with the position of the undetermined ship as the starting point and the centroid position of the target area as the end point, calculating the angle difference θ' between the reference ray and the ship direction of the undetermined ship, and if the angle difference θ' is less than or equal to the preset threshold, directly send a warning message.

[0022] As a further solution of the present invention: within the monitoring period, if any undetermined ship enters the target area, directly send the warning message corresponding to the highest warning level.

[0023] The beneficial effects of the present invention:

[0024] The present invention first obtains the ship data and wind data of the waterway where the target area is located, and determines the buffer area of any ship. When it is monitored that the ship enters the buffer area, it is possible that the ship sails parallel to the boundary of the target area or turns after a short approach as described in the background art. Therefore, the centroid position of the target area is obtained, and a reference ray is constructed with the position of the ship to be determined as the starting point and the centroid position of the target area as the end point. The angle difference θ' between the reference ray and the ship direction of the ship to be determined is calculated. If the angle difference θ' is less than or equal to the preset threshold, a warning message is directly sent. It can be understood that when the angle difference θ' is less than or equal to the preset threshold, it indicates that the actual heading of the ship to be determined currently in operation is highly consistent with the direction of the ray used as the reference standard. And once a ship enters a specific motion trajectory during navigation, it takes a certain amount of time and operating space to change its sailing direction. Therefore, to avoid the ship being unable to turn or decelerate in time due to inertial factors and finally accidentally entering the target area and causing potential safety risks, a warning message needs to be sent immediately. When the angle difference θ' is greater than the preset threshold, it indicates that the ship may sail parallel to the boundary of the target area. Therefore, the change trend of the shortest distance is obtained, and the warning score is comprehensively calculated according to the change trend of the shortest distance within the monitoring period. By analyzing the long-term trend of the distance change curve, the short-term approach caused by wind and waves or operation fine-tuning is effectively filtered, reducing false alarms. Finally, when the warning score is less than or equal to the preset warning score threshold, the ship to be determined is marked as an abnormal ship, and a warning message is sent to the abnormal ship, improving the accuracy of abnormal ship supervision. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] Figure 1 is a schematic diagram of a ship positioning and intelligent warning system based on Beidou satellite according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Please refer to Figure 1 as shown, the present invention is a ship positioning and intelligent warning system based on Beidou satellite, including:

[0029] A data acquisition module, which is used to determine a target area and acquire ship data and wind data of the waterway where the target area is located. The ship data includes ship direction, ship position, and ship speed; the wind data includes wind direction and wind speed.

[0030] A data analysis module, which is used to determine a buffer area of any ship outside the target area according to the ship data and the wind data. If there is any ship in the buffer area, the ship is marked as a pending ship. A preset monitoring period [T, T + H] is set, and the shortest distance S from the pending ship to the target area is periodically calculated within the monitoring period, and a change curve S(t) of the shortest distance over time is generated, where H is a preset monitoring duration.

[0031] A result generation module, which is used to obtain the starting point, ending point, peak point, and valley point in the change curve S(t) as reference points, calculate the slope k between adjacent reference points, and according to the calculation formula , calculate the change coefficient Q, calculate the warning score P according to the change coefficient and the change curve. If P is greater than P', the pending ship is marked as an abnormal ship, and a warning message is sent to the abnormal ship. P' represents a preset warning score threshold; where hi is the duration between the i-th adjacent reference points, ki is the slope between the i-th adjacent reference points, n is the number of reference points in the change curve, and n' represents the number of tangents with a negative slope.

[0032] The present invention first obtains the ship data and wind data of the waterway where the target area is located, and determines the buffer area of any ship. When it is monitored that the ship enters the buffer area, it is possible that the ship sails parallel to the boundary of the target area or turns after a short approach as described in the background art. Therefore, the centroid position of the target area is obtained, and a reference ray is constructed with the position of the ship to be determined as the starting point and the centroid position of the target area as the ending point. The angle difference θ' between the reference ray and the ship direction of the ship to be determined is calculated. If the angle difference θ' is less than or equal to a preset threshold, a warning message is directly sent. It can be understood that when the angle difference θ' is less than or equal to the preset threshold, it indicates that the actual course of the ship to be determined currently in operation is highly consistent with the direction of the ray used as the reference standard. And a ship has inertia during navigation. Once it enters a specific movement trajectory, it takes a certain amount of time and operating space to change its navigation direction. Therefore, to prevent the ship from being unable to turn or decelerate in time due to inertial factors and finally accidentally enter the target area, causing potential safety risks, a warning message needs to be sent immediately. When the angle difference θ' is greater than the preset threshold, it indicates that the ship may sail parallel to the boundary of the target area. Therefore, the change trend of the shortest distance is obtained, and the warning score is comprehensively calculated based on the change trend of the shortest distance within the monitoring period. By analyzing the long-term trend of the distance change curve, the short-term approach caused by wind and waves or operation fine-tuning is effectively filtered, reducing false alarms. Finally, when the warning score is less than or equal to the preset warning score threshold, the ship to be determined is marked as an abnormal ship, and a warning message is sent to the abnormal ship, improving the accuracy of abnormal ship supervision.

[0033] In a preferred embodiment of the present invention, in the data analysis module, the process of determining the buffer area is as follows:

[0034] The minimum circumscribed circle of the target area is determined according to the target area, the radius of the minimum circumscribed circle is obtained and marked as Dbase, and the corrected radius D' is calculated according to D' = Dbase*(1 + Vw / Vcrit)+γ*Lcos(θw - ship). A buffer area is drawn with the corrected radius D', where Vcrit is the preset critical wind speed, Vw is the current wind speed, θw - ship is the included angle between the wind direction and the ship course, γ is the preset unit coefficient, and L is the total length of the ship.

[0035] The ratio of the current wind speed Vw to the preset critical wind speed Vcrit (Vw / Vcrit) reflects the relationship between the actual wind speed and the critical wind speed. When the actual wind speed exceeds the critical wind speed, it will have a greater impact on the navigation safety of the ship. Therefore, through the Vw / Vcrit value, the proportion of the buffer area is determined to ensure that the ship has a longer safety response distance in a strong wind environment. At the same time, the angle θw-ship between the wind direction and the ship's heading takes into account the influence direction of the wind on the ship's navigation. The force of the wind on the ship is different at different angles, which in turn affects the risk degree of the ship deviating from the course. This influence can be reflected in the calculation through the cosine function cos(θw-ship). Downwind (θ = 0°): cosθ = 1, and the buffer area is expanded to cope with the potential loss of control caused by downwind acceleration; crosswind (θ = 90°): cosθ = 0, and only the wind speed correction term is retained to avoid being overly conservative; headwind (θ = 180°): cosθ = -1, so that the buffer area is dynamically adjusted according to the real-time risk, avoiding false alarms caused by a single scenario of the static threshold (such as the ship approaching briefly but not intruding). The preset unit coefficient γ and the total length L of the ship further refine the calculation of the buffer area to adapt to different safety requirements and scenario characteristics. The inclusion of the total length L of the ship takes into account the size factor of the ship itself, making the radius of the buffer area match the size of the ship and improving the accuracy of risk assessment.

[0036] In another preferred embodiment of the present invention, in the data analysis module, the specific calculation process of the shortest distance S is as follows:

[0037] Sampling is carried out on the boundary of the smallest circumscribed circle of the target area, and the position coordinates of all boundary points are recorded as (Je, We). The position coordinates of the current ship are obtained as (J1, W1). The Euclidean distance between each boundary point and the current ship is calculated in turn, and the smallest Euclidean distance is selected as the shortest distance S, where J is the longitude and W is the latitude.

[0038] It should be noted that when calculating the Euclidean distance, the longitude and latitude coordinates need to be converted into plane coordinates for calculation, and the conversion of longitude and latitude into plane coordinates belongs to the prior art and will not be elaborated here.

[0039] In another preferred embodiment of the present invention, in the result generation module, the specific calculation process of the warning score is as follows:

[0040] ;

[0041] Among them, S(T + H) is the minimum distance corresponding to the ship to be determined at the (T + H)th moment, S(T) is the minimum distance corresponding to the ship to be determined at the Tth moment, λ is a preset coefficient, and θw-ship is the angle between the wind direction and the ship's heading.

[0042] In a maritime environment, the actual position of a ship is affected by wind force and actual crew operations.

[0043] Therefore, the actual minimum distance is determined by the influence of wind force and the ship itself. Thus, it is necessary to eliminate the passive drift error of the ship caused by wind force, enabling the system to accurately identify the ship's active navigation intention, and avoiding false alarms triggered by environmental interference. It can be understood that the change in the minimum distance of the ship during the monitoring period is S(T) - S(T + H). However, this also includes the influence of wind force factors. Therefore, it is necessary to subtract the environmental offset value to obtain the actual autonomous navigation displacement of the ship. It can be understood that the actual autonomous navigation displacement of the ship represents the ship's active navigation intention. The greater the autonomous navigation displacement, the greater the intention to sail towards the target area, and the higher the risk coefficient.

[0044] In another preferred embodiment of the present invention, it further includes that if the change coefficient Q is greater than or equal to 0, no subsequent operations are performed, and the monitoring period is corrected to [T + H, T + 2H].

[0045] During ship navigation, the distance curve may experience short-term fluctuations due to wind and waves, operation fine-tuning, etc. It can be understood that Q≥0 indicates that such fluctuations mean the ship is gradually moving away from the target area and no continuous risk trend is formed. Therefore, the monitoring period can be extended to avoid over-responding to instantaneous interference until the ship leaves the buffer area.

[0046] In another preferred embodiment of the present invention, in the result generation module, it further includes setting an early warning distance range [0, R], and setting X distance levels at preset unit distance intervals within the early warning distance range. The smaller the distance, the higher the early warning level. At the same time, different early warning levels correspond to different early warning messages, where R is the preset early warning distance and X is the total number of preset early warning levels.

[0047] By grading, a lower-level early warning can be issued when the ship is approaching but has not yet entered the dangerous area, rather than immediately triggering the highest alarm. This reduces false alarms caused by short-term approaches or marginal hovering. At the same time, high-level early warnings may involve more resources and more urgent responses, while low-level early warnings may only require monitoring or simple notifications, thus enabling reasonable allocation of resources and avoiding waste of resources.

[0048] In another preferred embodiment of the present invention, in the data analysis module, it further includes obtaining the centroid position of the target area, constructing a reference ray with the starting point being the position of the ship to be determined and the ending point being the centroid position of the target area, and calculating the angle difference θ' between this reference ray and the ship direction of the ship to be determined. If the angle difference θ' is less than or equal to the preset threshold, an early warning message is directly issued.

[0049] It can be understood that in the ship navigation monitoring and warning system, when the angle difference θ' detected in real time is less than or equal to the preset threshold, it indicates that the actual heading of the current pending ship is highly consistent with the ray direction as the reference standard. On the one hand, the ship may actively move towards the target area based on the operation instructions of its own power system; on the other hand, the ship may also be in a passive state, causing it to approach the target area without knowing it. Therefore, when such a highly consistent heading state is detected, a warning message is immediately triggered. This is because the ship has inertia during navigation. Once it enters a specific movement trajectory, it takes a certain amount of time and operation process to change its direction or speed. Therefore, in order to ensure that the ship can adjust its navigation state in time, avoid the target area, and prevent the potential safety risk caused by the inability to turn or decelerate in time due to inertia factors, a warning message must be sent in time.

[0050] In another preferred embodiment of the present invention, during the monitoring period, if any pending ship enters the target area, a warning message corresponding to the highest warning level is directly sent.

[0051] At this time, the nature of the ship's behavior has undergone a fundamental change. Before this, the ship may only be in a state of "potential risk", that is, there is a possibility of violating the regulations and entering the target area, but it has not really constituted a substantial violation. However, once it directly enters the target area, this potential risk instantly turns into an "actual violation", so a warning message corresponding to the highest warning level is directly sent.

[0052] The above has described a specific embodiment of the present invention in detail, but the content described above is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. Any equivalent changes and improvements made within the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A ship positioning and intelligent early warning system based on Beidou satellites, characterized in that, Including: A data acquisition module, which is used to determine a target area and acquire ship data and wind data of the waterway where the target area is located. The ship data includes ship direction, ship position and ship speed; the wind data includes wind direction and wind speed; A data analysis module, which is used to determine a buffer area for any ship outside the target area according to the ship data and wind data. If any ship is in the buffer area, the ship is marked as a pending ship. A preset monitoring period [T, T + H] is set, and the shortest distance S from the pending ship to the target area is periodically calculated within the monitoring period, and a variation curve S(t) of the shortest distance with time is generated, where H is the preset monitoring duration; A result generation module is configured to obtain starting points, ending points, peak points and valley points in a change curve S(t) as reference points, calculate slopes k between adjacent reference points, and according to the calculation formula , calculate a change coefficient Q, calculate a warning score P according to the change coefficient and the change curve, and if P is greater than P', mark the ship to be determined as an abnormal ship and send a warning message to the abnormal ship, where P' represents a preset warning score threshold; where hi is the duration between the i-th adjacent reference points, ki is the slope between the i-th adjacent reference points, n is the number of reference points in the change curve, and n' represents the number of tangents with negative slopes.

2. The ship positioning and intelligent warning system based on Beidou satellite according to claim 1, wherein In the data analysis module, the process of determining the buffer area is as follows: Determine the minimum circumscribed circle of the target area, obtain the radius of the minimum circumscribed circle and mark it as Dbase, calculate the corrected radius D' according to D' = Dbase * (1 + Vw / Vcrit) + γ * Lcos(θw - ship), and draw a circle with the corrected radius D' to obtain the buffer area, where Vcrit is the preset critical wind speed, Vw is the current wind speed, θw - ship is the included angle between the wind direction and the ship's course, γ is the preset unit coefficient, and L is the total length of the ship.

3. The ship positioning and intelligent warning system based on Beidou satellite according to claim 2, characterized in that, In the data analysis module, the specific calculation process of the shortest distance S is as follows: Sample the boundary of the minimum circumscribed circle of the target area, record the position coordinates of all boundary points as (Je, We), obtain the position coordinates (J1, W1) of the current ship, calculate the Euclidean distance between each boundary point and the current ship, and select the minimum Euclidean distance as the shortest distance S, where J is the longitude and W is the latitude.

4. A ship positioning and intelligent early warning system based on Beidou satellites according to claim 1, characterized in that In the result generation module, the specific calculation process of the warning score is as follows: ； Among them, S(T + H) is the minimum distance corresponding to the pending ship at the (T + H)-th moment, S(T) is the minimum distance corresponding to the pending ship at the T-th moment, λ is the preset coefficient, and θw - ship is the included angle between the wind direction and the ship's course.

5. A ship positioning and intelligent early warning system based on Beidou satellites according to claim 1, characterized in that, It also includes that if the variation coefficient Q is greater than or equal to 0, no subsequent operation is performed, and the monitoring period is corrected to [T + H, T + 2H].

6. A ship positioning and intelligent early warning system based on Beidou satellites according to claim 1, characterized in that, In the result generation module, it also includes setting a warning distance range [0, R], setting X distance levels at preset unit distance intervals within the warning distance range. The smaller the distance, the higher the warning level. At the same time, different warning levels correspond to different warning messages, where R is the preset warning distance and X is the total number of preset warning levels.

7. The ship positioning and intelligent early warning system based on Beidou satellites according to claim 1, characterized in that, In the data analysis module, it also includes obtaining the centroid position of the target area, constructing a reference ray with the position of the pending ship as the starting point and the centroid position of the target area as the ending point, and calculating the angle difference θ' between the reference ray and the ship direction of the pending ship. If the angle difference θ' is less than or equal to the preset threshold, a warning message is directly sent.

8. The ship positioning and intelligent early warning system based on Beidou satellite according to claim 6, characterized in that Within the monitoring period, if any pending ship enters the target area, a warning message corresponding to the highest warning level is directly sent.

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