Ship positioning and intelligent early warning system based on Beidou satellite

Abstract

The invention discloses a ship positioning and intelligent early warning system based on a Beidou satellite, and belongs to the technical field of ship safety management, and the system specifically comprises the steps: obtaining ship data and wind power data of a target area; according to the ship data and the wind power data, determining a buffer area of any ship outside a target area, if any ship is located in the buffer area, calibrating the ship as an undetermined ship, and generating a shortest distance change curve from the ship to the target area in a monitoring period; feature points in the change curve are obtained, a change coefficient Q is calculated, an early warning score P is calculated according to the change coefficient and the change curve, if P is larger than P ', the undetermined ship is marked as an abnormal ship, and early warning information is sent to the abnormal ship. According to the invention, the accuracy of ship supervision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ship safety management, and particularly 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 track.

[0003] The ship navigation track refers to the path followed by a ship when sailing on the sea or inland river. These tracks 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 tracks is crucial for navigation safety, which helps to monitor the position of ships. By monitoring the navigation track, collisions between ships and contact with ground obstacles can be avoided. At the same time, the historical data of the navigation track 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 marine 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 the preset position level, and a corresponding electronic fence warning is 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 logic. 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: In practical applications, the method relies on static distance thresholds or one-way approach logic. 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.

[0006] The object of the present invention can be achieved by the following technical solutions: A ship positioning and intelligent warning system based on Beidou satellites, comprising: 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; 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, 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; 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', the pending ship is marked as an abnormal ship, and a warning message is sent 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.

[0007] As a further solution of the present invention: In the data analysis module, the process of determining the buffer area is as follows: Determine the minimum circumscribed circle of the target area according to 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.

[0008] 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: 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 in turn, and select the minimum Euclidean distance as the shortest distance S, where J is the longitude and W is the latitude.

[0009] As a further solution of the present invention: in the result generation module, the specific calculation process of the warning score is as follows: ; wherein, 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 T-th moment, λ is a preset coefficient, and θw-ship is the included angle between the wind direction and the ship's course.

[0010] As a further solution of the present invention: it further 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].

[0011] As a further solution of the present invention: in the result generation module, it further 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, wherein, R is the preset warning distance, and X is the total number of preset warning levels.

[0012] As a further solution 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 position of the ship to be determined as the starting point and the centroid position of the target area as the ending point, calculating the angle difference θ' between the reference ray and the ship direction of the ship to be determined, and if the angle difference θ' is less than or equal to a preset threshold, directly sending out a warning message.

[0013] As a further solution of the present invention: within the monitoring period, if any ship to be determined enters the target area, directly send out the warning message corresponding to the highest warning level.

[0014] The beneficial effects of the present invention: 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 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, triggering 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 approaches caused by wind and waves or operational fine-tuning are 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

[0015] The present invention will be further described below with reference to the accompanying drawings.

[0016] 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

[0017] 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. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] Please refer to Figure 1 as shown, the present invention is a ship positioning and intelligent warning system based on Beidou satellite, including: 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, where the ship data includes ship direction, ship position, and ship speed; the wind data includes wind direction and wind speed; A data analysis module, configured to determine a buffer area of 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 within the monitoring period, the shortest distance S from the pending ship to the target area is periodically calculated, and a variation curve S(t) of the shortest distance over time is generated, where H is a preset monitoring duration. A result generation module, configured to obtain the starting point, ending point, peak point and valley point in the variation curve S(t) as reference points, calculate the slope k between adjacent reference points, and according to the calculation formula , calculate a variation coefficient Q, calculate a warning score P according to the variation coefficient and the variation 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 variation curve, and n' represents the number of tangents with a negative slope.

[0019] The present invention first obtains 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 a 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 pending ship as the starting point and the centroid position of the target area as the ending point, and the angle difference θ' between the reference ray and the ship direction of the pending ship 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 heading of the currently running pending ship 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 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 variation trend of the shortest distance is obtained, and the warning score is comprehensively calculated according to the variation trend of the shortest distance within the monitoring period. By analyzing the long-term trend of the distance variation curve, the short-term approach caused by wind and waves or operation fine-tuning is effectively filtered, and false alarms are reduced. Finally, when the warning score is less than or equal to the preset warning score threshold, the pending ship is marked as an abnormal ship, and a warning message is sent to the abnormal ship, improving the accuracy of abnormal ship supervision.

[0020] In a preferred embodiment of the present invention, 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 the formula D' = Dbase * (1 + Vw / Vcrit) + γ * L * cos(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 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.

[0021] 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, the value of Vw / Vcrit is used to determine the proportion of the buffer area 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 course 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, the buffer area expands to cope with the potential loss of control caused by downwind acceleration; crosswind (θ = 90°): cosθ = 0, only the wind speed correction term is retained to avoid being overly conservative; headwind (θ = 180°): cosθ = -1, the buffer area is dynamically adjusted according to the real - time risk to avoid false alarms caused by a single - scenario static threshold (such as the ship approaching briefly but not intruding). The preset unit coefficient γ and the total length of the ship L further refine the calculation of the buffer area to adapt to different safety requirements and scenario characteristics. The inclusion of the total length of the ship L 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.

[0022] 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: 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 of the current ship (J1, W1), calculate the Euclidean distance between each boundary point and the current ship in turn, and select the minimum Euclidean distance as the shortest distance S, where J is the longitude and W is the latitude.

[0023] 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.

[0024] In another preferred embodiment of the present invention, in the result generation module, the specific calculation process of the warning score is as follows: ; where 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 T-th moment, λ is a preset coefficient, and θw-ship is the angle between the wind direction and the ship's course.

[0025] In a marine environment, the actual position of a ship is affected by wind force and actual crew operations. 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 so that the system can accurately identify the ship's active navigation intention and avoid 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), but 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.

[0026] 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 operation is performed, and the monitoring period is corrected to [T + H, T + 2H].

[0027] During ship navigation, the distance curve may fluctuate briefly due to wind waves, operation fine-tuning, etc. It can be understood that Q ≥ 0 indicates that such fluctuations are caused by the ship gradually moving away from the target area and do not form a continuous risk trend. Therefore, the monitoring period can be extended to avoid over-response to instantaneous interference until the ship leaves the buffer area.

[0028] In another preferred embodiment of the present invention, in the result generation module, it further includes setting a warning distance range [0, R], and 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.

[0029] By grading, a lower-level warning can be issued when the ship approaches but has not yet entered the dangerous area, rather than immediately triggering the highest alarm. This reduces false alarms caused by brief approaches or marginal hovering. At the same time, high-level warnings may involve more resources and more urgent responses, while low-level warnings may only require monitoring or simple notification. Therefore, resources can be reasonably allocated to avoid waste of resources.

[0030] 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 starting from the position of the ship to be determined and ending at the centroid position of the target area, calculating the angle difference θ' between the reference ray and the ship direction of the ship to be determined, and if the angle difference θ' is less than or equal to a preset threshold, directly sending out a warning message.

[0031] It can be understood that in the ship navigation monitoring and warning system, when the real-time monitored angle difference θ' is less than or equal to the preset threshold, it indicates that the actual heading of the currently operating ship to be determined is highly consistent with the direction of the ray used 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 monitored, 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 timely adjust its navigation state, avoid the target area, and prevent potential safety risks caused by being unable to turn or decelerate in time due to inertial factors and finally accidentally entering the target area, a warning message must be sent out in time.

[0032] In another preferred embodiment of the present invention, within the monitoring period, if any ship to be determined enters the target area, directly send out a warning message corresponding to the highest warning level.

[0033] 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 "actual violation", so a warning message corresponding to the highest warning level is directly sent out.

[0034] The above has described an embodiment of the present invention in detail, but the content described is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the present invention application should still fall within the scope covered by the patent of the present invention.

Claims

1. A Beidou satellite-based ship positioning and intelligent early warning system, characterized in that: include: A data acquisition module, used to determine the target area and acquire ship data and wind data of the channel where the target area is located, wherein the ship data includes the ship direction, ship position and ship speed; and the wind data includes wind direction and wind speed; A data analysis module is used to determine the buffer area of ​​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 monitoring period [T, T+H] is preset. The shortest distance S from the pending ship to the target area is periodically calculated during the monitoring period, and a curve S(t) of the change of the shortest distance over time is generated, wherein H is a preset monitoring time. The result generation module is used to obtain the starting point, end point, peak point and valley point in the change curve S(t) and use them as reference points to calculate the slope k between adjacent reference points. , calculate the variation coefficient Q, calculate the warning score P according to the variation coefficient and the variation curve, if P is greater than P', mark the undetermined ship as an abnormal ship, send warning information to the abnormal ship, P' represents the preset warning score threshold; wherein, 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 variation curve, and n' represents the number of tangents with negative slopes.

2. The Beidou satellite-based ship positioning and intelligent early warning system according to claim 1, characterized in that: In the data analysis module, the process of determining the buffer area is as follows: The minimum circumscribed circle of the target area is determined, 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 circle is drawn with the corrected radius D' to obtain the buffer area, wherein Vcrit is the preset critical wind speed, Vw is the current wind speed, θw-ship is the angle between the wind direction and the ship's heading, γ is the preset unit coefficient, and L is the total length of the ship.

3. The Beidou satellite-based ship positioning and intelligent early warning system according to claim 2 is characterized in that: In the data analysis module, the specific calculation process of the shortest distance S is: Sampling is performed with the boundary of the minimum outer 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 (J1, W1), the Euclidean distance between each boundary point and the current ship is calculated, and the minimum Euclidean distance is selected as the shortest distance S, where J is longitude and W is latitude.

4. The Beidou satellite-based ship positioning and intelligent early warning system 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 time, S(T) is the minimum distance corresponding to the pending ship at the T time, λ is the preset coefficient, and θw-ship is the angle between the wind direction and the ship's heading.

5. The Beidou satellite-based ship positioning and intelligent early warning system according to claim 1, characterized in that: 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].

6. The Beidou satellite-based ship positioning and intelligent early warning system according to claim 1, characterized in that: The result generation module also includes setting a warning distance range [0, R], and setting X distance levels at preset unit distance intervals within the warning distance range. The smaller the distance, the higher the warning level. Different warning levels correspond to different warning information, wherein R is the preset warning distance, and X is the total number of preset warning levels.

7. The Beidou satellite-based ship positioning and intelligent early warning system according to claim 1 is characterized in that: The data analysis module also includes obtaining the center of gravity position of the target area, constructing a reference ray with the position of the ship to be determined as the starting point and the center of gravity position of the target area as the end point, calculating the angle difference θ' between the reference ray and the ship direction of the ship to be determined, and directly issuing an early warning message if the angle difference θ' is less than or equal to a preset threshold.

8. The Beidou satellite-based ship positioning and intelligent early warning system according to claim 6, characterized in that: During the monitoring period, if any pending ship enters the target area, an early warning message corresponding to the highest early warning level will be directly issued.

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