Ship early warning method based on bulking ellipse and bulking circle model

Abstract

The invention discloses a ship early warning method based on a bulking ellipse and bulking circle model, and relates to the technical field of early warning and monitoring. The early warning method comprises the following steps: establishing puffing elliptical models of two ships; calculating parameters such as a domain distance between the two ships, a safety distance, a linear distance, an included angle between a tangent line of a circle taking the safety distance as a radius and a relative position connecting line, and an included angle between a relative velocity vector and the relative position connecting line; each parameter is compared with the collision detection distance, the TCPA and the DCPA to realize blue early warning, orange early warning and red early warning. According to the method, the bulking ellipse model is constructed for the two ships, the relative position and the dynamic relation between the two ships can be predicted more comprehensively by calculating various parameters between the two bulking ellipses, and the method is used for carrying out early warning of different levels on collision risks of different degrees, so that the sailing safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of early warning monitoring, and in particular to a ship early warning method based on an expanded ellipse and expanded circle model. Background Art

[0002] The water depth is limited and the shallow water effect is obvious, which affects the ship's maneuverability. Affected by the tide, the density of ships is relatively high during peak periods, forming a dense ship area in local time and area, and advancing with the tide as a whole, making ship maneuvering and collision more difficult. The types of navigable ships are complex, especially small ships, with low crew quality and poor ship performance. The crew's ship handling skills and awareness of abiding by the rules are poor, and the operation is arbitrary, which is prone to collision hazards. When working on the ship, the driver needs to monitor whether there are other ships around him. If there are, he needs to further determine whether he needs to operate his own ship to avoid them.

[0003] Chinese patent document CN109697892A discloses a time-space-aware intelligent warning method for ship collision risk, which determines which ships in the target ship for collision warning and the surrounding ship object set A are directly included in the target ship for collision detection based on the target ship's area and the position of other ships, and outputs a set of ships that may collide with the target ship; the risk level of the ship's possible collision. However, the document only warns of collisions based on the distance between the two ships, ignoring other actual factors, resulting in low warning accuracy, and does not combine multiple factors to provide different levels of warnings on whether a collision will occur. Summary of the invention

[0004] In view of the fact that the current ship warning system has few factors for warning and does not integrate multiple factors to provide different levels of warnings on whether a collision will occur, resulting in the problem of low warning accuracy, the present invention provides a ship warning method based on an expanded ellipse and expanded circle model.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: a ship early warning method based on an expanded ellipse and expanded circle model, comprising the following steps: S1 obtains the longitude and latitude, speed and heading information of the ship and the other ship, establishes a rectangular coordinate system, and establishes an expanded ellipse model of the ship and the other ship; S2 calculates the field distance between the expanded ellipse of the ship and the other ship , the safe distance between our ship and other ships , the distance between our ship and other ships, and the safe distance The angle between the tangent line of the circle with radius and the line connecting the relative positions and the angle between the relative velocity vector and the relative position vector ; S3 determines whether the distance between our ship and the other ship is less than the collision detection distance If the condition is satisfied, then enter S4; S4 determines whether the distance between our ship and the other ship is within a safe distance. Collision detection distance If it is satisfied, then enter S5, if not, enter S6; S5 determines whether the angle between the speed vectors of our ship and the other ship is less than the angle between the relative speed vector and the relative position vector If the condition is met, a blue warning is issued; S6 calculation and ,judge and If any one of the conditions is met, an orange warning is issued; if both conditions are met, a red warning is issued; if both conditions are not met, enter S1.

[0006] Furthermore, in S2, the domain distance of our ship is calculated Distance from other ships :

[0007] Convert the longitude and latitude coordinates of our ship and the other ship into northeast coordinates, find the equation of the line connecting our ship and the other ship, and use the equation of the line to combine with the ellipse equation of our ship and the ellipse equation of the other ship, and find the two intersection points of the equation of the line and the ellipse equation of our ship: Point 1 ( , ), point 2 , find the two intersection points of the connecting line equation and the other ship ellipse equation: point 3 , , point 4 , ;

[0008] Use the Pythagorean theorem to find point 1( , ) and point 2 The distance between point 3 , With point 4 , The distance between

[0009] Let the coordinates of my ship be O 、The coordinates of the other ship are T , The OT equation of the line connecting the two ships:

[0010] ;

[0011] Joint:

[0012] ;

[0013] ;

[0014] In the formula, is the heading angle of my ship; is the heading angle of the other ship; the slope of the straight line is ; The straight line intercept is ;

[0015] Solve the equation to find point 1( , ), point 2 , point 3 , , point 4 , ;

[0016] ;

[0017] .

[0018] Furthermore, in S2, the safe distance between our ship and other ships is calculated. :

[0019] ;

[0020] In the formula, It is a distance determined by comprehensively considering the maneuverability of our ship and other ships, their respective speeds, relative speeds and water type conditions;

[0021] The calculation formula is:

[0022] ;

[0023] In the formula, is the time step, the unit is h; is the absolute value of the relative speed between our ship and the other ship when they are approaching each other, and takes 0 when they are moving away from each other, in knots; It is the time taken by the ship to turn at full speed and change the heading angle by 90°, in seconds; It is the longitudinal distance that the center of gravity moves when the ship turns at full speed and the heading angle changes by 90°, generally 2.8 to 4 times the length of the ship, in meters; The safety distance required under natural conditions is generally 0.5 nautical miles, but can also be set based on experience; The safety distance required for the waters in which the user is located is usually 0.5 nautical miles, but can also be set based on experience; for The coefficient of , the minimum value is 0, the maximum value is 1; for The minimum value is 0 and the maximum value is 1.

[0024] Further, among them, ;

[0025] In the formula, is the gyration radius; Take 3~7, ordinary merchant ships take 4~5, large ships take 5~7; For the captain;

[0026] Use the angular velocity to calculate the radius of gyration:

[0027] ;

[0028] In the formula, is the ship speed; is the angular velocity;

[0029] Rotation The time taken for the angle is:

[0030] ;

[0031] Arranged:

[0032] ;

[0033] Therefore:

[0034] .

[0035] Further, in S2, the safe distance is calculated The angle between the tangent line of the circle with radius and the line connecting the relative positions and the angle between the relative velocity vector and the relative position vector :

[0036] In the triangle OTS, equal The inverse tangent function of OS, the size of OS can be calculated by the Pythagorean theorem;

[0037] The size of the relative position vector OT and the relative position vector The arccosine function of the dot product is found;

[0038] Therefore:

[0039] ;

[0040] In the formula, is the straight-line distance between our ship O and his ship T; is the position vector of my ship O pointing to his ship T;

[0041] ;

[0042] In the formula, is the relative velocity vector of our ship O relative to the other ship T; is the dot product of the relative position vector and the relative velocity vector.

[0043] Further, in S3, the collision detection distance is calculated :

[0044] ;

[0045] ;

[0046] set up There are two factors to consider: (1) Overtaking situation: =0.5 nautical miles; Crossing and encounter situations: = 1 nautical mile; (2) : Set by yourself, : Obstacle expansion ellipse distance.

[0047] Furthermore, in S6, the calculation , Using the sine function in triangle OTP we find:

[0048] ;

[0049] calculate , The magnitude of is equal to the distance of PT divided by the velocity in the PT direction. PT is obtained by using the cosine of the modulus of the relative position vector through the triangle OTP:

[0050] ;

[0051] In the formula, is the magnitude of the relative velocity, and Equal in size.

[0052] Furthermore, in S5, the condition is satisfied , a blue warning is issued;

[0053] in, The distance between my ship and his ship.

[0054] Further, in S6, any condition is satisfied or , an orange warning is issued;

[0055] in, is the major semi-axis of the ellipse equation of the other ship; Set based on experience Threshold.

[0056] Furthermore, in S6, and , a red alert is issued.

[0057] The beneficial effect of the present invention is that the present invention constructs an expanded ellipse model for two ships, and by calculating parameters such as the field distance, safety distance, straight-line distance and angle between the two expanded ellipses, it can more comprehensively predict and evaluate the relative position and dynamic relationship between the two ships, and is used to provide different levels of early warning for different degrees of collision risks, which can help operators to more accurately judge the potential collision risk between the two ships, and take collision avoidance measures in time to ensure navigation safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 Shown is a schematic diagram of the principle of an embodiment of the present invention.

[0059] Figure 2 Shown is a flow chart of the present invention.

[0060] Figure 3 Shown is a schematic diagram of constructing the puffed ellipse model.

[0061] Figure 4 Shown is a schematic diagram of calculating the field distance between two ships.

[0062] Figure 5 The figure shows a schematic diagram of calculating the safe distance between two ships.

[0063] Figure 6 The diagram shows a method of calculating the angle between the relative velocity vector and the relative position line and the angle between the tangent of a circle with the safety distance as the radius and the relative position line.

[0064] Figure 7 Shown is a schematic diagram for calculating TCPA and DCPA. DETAILED DESCRIPTION

[0065] The present invention discloses a ship early warning method based on an expanded ellipse and expanded circle model, and an implementation mode of the present invention is described in detail below in conjunction with the accompanying drawings.

[0066] The ship warning method based on the puffed ellipse and puffed circle model includes the following steps: S1 obtains the latitude and longitude, speed and heading information of the ship and the other ship, establishes a rectangular coordinate system, and establishes the puffed ellipse model of the ship and the other ship; S2 calculates the field distance between the puffed ellipse of the ship and the other ship , the safe distance between our ship and other ships , the distance between our ship and other ships, and the safe distance The angle between the tangent line of the circle with radius and the line connecting the relative positions and the angle between the relative velocity vector and the relative position vector ; S3 determines whether the distance between our ship and the other ship is less than the collision detection distance If the condition is satisfied, then enter S4; S4 determines whether the distance between our ship and the other ship is within a safe distance. Collision detection distance If it is satisfied, then enter S5, if not, enter S6; S5 determines whether the angle between the speed vectors of our ship and the other ship is less than the angle between the relative speed vector and the relative position vector If the condition is met, a blue warning is issued; S6 calculation and ,judge and If any one of the conditions is met, an orange warning is issued; if both conditions are met, a red warning is issued; if both conditions are not met, enter S1.

[0067] Furthermore, in S2, the domain distance of our ship is calculated Distance from other ships :

[0068] Convert the longitude and latitude coordinates of our ship and the other ship into northeast coordinates, find the equation of the line connecting our ship and the other ship, and use the equation of the line to combine with the ellipse equation of our ship and the ellipse equation of the other ship, and find the two intersection points of the equation of the line and the ellipse equation of our ship: Point 1 ( , ), point 2 , find the two intersection points of the connecting line equation and the other ship ellipse equation: point 3 , , point 4 , ;

[0069] Use the Pythagorean theorem to find point 1( , ) and point 2 The distance between point 3 , With point 4 , The distance between

[0070] Let the coordinates of my ship be O 、The coordinates of the other ship are T , The OT equation of the line connecting the two ships:

[0071] ;

[0072] Joint:

[0073] ;

[0074] ;

[0075] In the formula, is the heading angle of my ship; is the heading angle of the other ship; the slope of the straight line is ; The straight line intercept is ;

[0076] Solve the equation to find point 1( , ), point 2 , point 3 , , point 4 , ;

[0077] ;

[0078] .

[0079] Furthermore, in S2, the safe distance between our ship and other ships is calculated. :

[0080] ;

[0081] In the formula, It is a distance determined by comprehensively considering the maneuverability of our ship and other ships, their respective speeds, relative speeds, and water type.

[0082] The calculation formula is:

[0083] ;

[0084] In the formula, is the time step, the unit is h; is the absolute value of the relative speed between our ship and the other ship when they are approaching each other, and takes 0 when they are moving away from each other, in knots; It is the time taken by the ship to turn at full speed and change the heading angle by 90°, in seconds; It is the longitudinal distance that the center of gravity moves when the ship turns at full speed and the heading angle changes by 90°, generally 2.8 to 4 times the length of the ship, in meters; The safety distance required under natural conditions is generally 0.5 nautical miles, but can also be set based on experience; The safety distance required for the waters in which the user is located is usually 0.5 nautical miles, but can also be set based on experience; for The coefficient of , the minimum value is 0, the maximum value is 1; for The minimum value is 0 and the maximum value is 1.

[0085] Further, among them, ;

[0086] In the formula, is the gyration radius; Take 3~7, ordinary merchant ships take 4~5, large ships take 5~7; For the captain;

[0087] Use the angular velocity to calculate the radius of gyration:

[0088] ;

[0089] In the formula, is the ship speed; is the angular velocity;

[0090] Rotation The time taken for the angle is:

[0091] ;

[0092] Arranged:

[0093] ;

[0094] Therefore:

[0095] .

[0096] Further, in S2, the safe distance is calculated The angle between the tangent line of the circle with radius and the line connecting the relative positions and the angle between the relative velocity vector and the relative position vector :

[0097] In the triangle OTS, equal The inverse tangent function of OS, the size of OS can be calculated by the Pythagorean theorem;

[0098] The size of the relative position vector OT and the relative position vector The arccosine function of the dot product is found;

[0099] Therefore:

[0100] ;

[0101] In the formula, is the straight-line distance between our ship O and his ship T; is the position vector of my ship O pointing to his ship T;

[0102] ;

[0103] In the formula, is the relative velocity vector of our ship O relative to the other ship T; is the dot product of the relative position vector and the relative velocity vector.

[0104] Further, in S3, the collision detection distance is calculated :

[0105] ;

[0106] ;

[0107] set up There are two factors to consider: (1) Overtaking situation: =0.5 nautical miles; Crossing and encounter situations: = 1 nautical mile; (2) : Set by yourself, : Obstacle expansion ellipse distance.

[0108] Furthermore, in S6, the calculation , Using the sine function in triangle OTP we find:

[0109] ;

[0110] calculate , The magnitude of is equal to the distance of PT divided by the velocity in the PT direction. PT is obtained by using the cosine of the modulus of the relative position vector through the triangle OTP:

[0111] ;

[0112] In the formula, is the magnitude of the relative velocity, and Equal in size.

[0113] Furthermore, in S5, the condition is satisfied , a blue warning is issued;

[0114] in, The distance between my ship and his ship.

[0115] Further, in S6, any condition is satisfied or , an orange warning is issued;

[0116] in, is the major semi-axis of the ellipse equation of the other ship; Set based on experience Threshold.

[0117] Furthermore, in S6, and , a red alert is issued.

[0118] Combination Figure 1 and Figure 2 As shown, the research process of the present invention is to first convert the latitude and longitude spatial information of our ship and the other ship into the northeast coordinate of the northeast sky, where the east coordinate represents the longitude and the north coordinate represents the latitude, and then start to calculate the field distance R between the puffed ellipse of our ship and the other ship, and the safety distance d between our ship and the other ship m , the distance between our ship and the other ship, the safe distance d m The angle between the tangent of the circle with radius 1 and the relative position line and the angle between the relative velocity vector and the relative position line. After calculating these parameters, we start to judge whether the distance between our ship and the other ship is less than the collision detection distance. If it is, we judge whether the distance between the two ships is between the safe distance and the collision detection distance. If it is, we continue to judge whether the angle between the speed vectors of the two ships is less than the angle between the relative velocity vector and the relative position line. If it is, we issue a blue warning, otherwise we continue to judge the risk situation between the two ships at the next moment. If the distance between the two ships is less than or equal to the safe distance, we calculate the size of TCPA and DCPA. If any of the conditions 0<=TCPA<=TA or DCPA<=DA is met, we issue an orange warning. If both conditions are met, we issue a red warning. If neither condition is met, we continue to judge the risk situation between the two ships at the next moment.

[0119] like Figure 3 As shown, the puffed ellipse model is constructed: the present invention is applied between every two ships. First, a puffed ellipse model is established for both the ship and the other ship. The major axis of the ellipse is consistent with the length of the ship, the minor axis of the ellipse is consistent with the width of the ship, and the center of the circle is the northeast coordinate converted from the longitude and latitude coordinates to the northeast celestial coordinates. The calculation formula for the major semi-axis of the ellipse is:

[0120] ;

[0121] In the formula, The unit is m; is the length of the ship, in m; is the ship speed, in m / s; is a positive proportionality coefficient.

[0122] The formula for calculating the minor semi-axis of an ellipse is:

[0123] ;

[0124] In the formula, The unit is m; Ship width, in meters.

[0125] In order to realize that each ship can always maintain the expanded ellipse model at any position and any heading in the two-dimensional plane. Therefore, the ellipse formula is:

[0126] ;

[0127] Modified to:

[0128] ;

[0129] The formula is to rotate the ellipse clockwise by a certain angle with the center point of the ellipse (m,n) as the center of the circle. Income, including It can be understood as the heading angle.

[0130] like Figure 4 As shown, calculate the range distance of my ship Distance from other ships :Convert the longitude and latitude coordinates of our ship and the other ship into northeast coordinates, find the equation of the line connecting our ship and the other ship, and use the equation of the line to combine with the ellipse equation of our ship and the ellipse equation of the other ship, and find the two intersection points of the equation of the line and the ellipse equation of our ship: Point 1 ( , ), point 2 , find the two intersection points of the connecting line equation and the other ship ellipse equation: point 3 , , point 4 , ; Use the Pythagorean theorem to find point 1( , ) and point 2 The distance between point 3 , With point 4 , The distance between.

[0131] Let the coordinates of my ship be O 、The coordinates of the other ship are T , The OT equation of the line connecting the two ships:

[0132] ;

[0133] Joint:

[0134] ;

[0135] ;

[0136] In the formula, is the heading angle of my ship; is the heading angle of the other ship; the slope of the straight line is ; The straight line intercept is ;

[0137] Solve the equation to find point 1( , ), point 2 , point 3 , , point 4 , ;

[0138] ;

[0139] .

[0140] like Figure 5 As shown, calculate the safe distance between our ship and other ships :

[0141] ;

[0142] In the formula, It is a distance determined by comprehensively considering the maneuverability of our ship and other ships, their respective speeds, relative speeds, and water type.

[0143] The calculation formula is:

[0144] ;

[0145] In the formula, is the time step, the unit is h; is the absolute value of the relative speed between our ship and the other ship when they are approaching each other, and takes 0 when they are moving away from each other, in knots; It is the time taken by the ship to turn at full speed and change the heading angle by 90°, in seconds; It is the longitudinal distance that the center of gravity moves when the ship turns at full speed and the heading angle changes by 90°, generally 2.8 to 4 times the length of the ship, in meters; The safety distance required under natural conditions is generally 0.5 nautical miles, but can also be set based on experience; The safety distance required for the waters in which the user is located is usually 0.5 nautical miles, but can also be set based on experience; for The coefficient of , the minimum value is 0, the maximum value is 1; for The minimum value is 0 and the maximum value is 1.

[0146] in, ;

[0147] In the formula, is the gyration radius; Take 3~7, ordinary merchant ships take 4~5, large ships take 5~7; For the captain;

[0148] Use the angular velocity to calculate the radius of gyration:

[0149] ;

[0150] In the formula, is the ship speed; is the angular velocity;

[0151] Rotation The time taken for the angle is:

[0152] ;

[0153] Arranged:

[0154] ;

[0155] Therefore:

[0156] .

[0157] like Figure 6 As shown, the calculation is based on the safety distance The angle between the tangent line of the circle with radius and the line connecting the relative positions and the angle between the relative velocity vector and the relative position vector :

[0158] In the triangle OTS, equal The inverse tangent function of OS, the size of OS can be calculated by the Pythagorean theorem;

[0159] The size of the relative position vector OT and the relative position vector The arccosine function of the dot product is found;

[0160] Therefore:

[0161] ;

[0162] In the formula, is the straight-line distance between our ship O and his ship T; is the position vector of my ship O pointing to his ship T;

[0163] ;

[0164] In the formula, is the relative velocity vector of our ship O relative to the other ship T; is the dot product of the relative position vector and the relative velocity vector.

[0165] Calculating collision detection distance :

[0166] ;

[0167] ;

[0168] set up There are two factors to consider: (1) Overtaking situation: =0.5 nautical miles; Crossing and encounter situations: = 1 nautical mile; (2) : Set by yourself, : Obstacle expansion ellipse distance.

[0169] calculate , Using the sine function in triangle OTP we find:

[0170] ;

[0171] like Figure 7 As shown, calculation , The magnitude of is equal to the distance of PT divided by the velocity in the PT direction. PT is obtained by using the cosine of the modulus of the relative position vector through the triangle OTP:

[0172] ;

[0173] In the formula, is the magnitude of the relative velocity, and Equal in size.

[0174] According to the above parameters, the early warning judgment is carried out, and the judgment steps are as follows:

[0175] The first step is to determine the distance between our ship and his ship at a certain moment. Is it less than the collision detection distance? If it is satisfied, we will proceed to the second step; if it is not satisfied, it means that there is no risk between our ship and other ships at this time.

[0176] The second step is to determine the distance between our ship and his ship. and the angle between the relative velocity vector and the line connecting the relative position Whether the conditions are met: If the conditions are met, a blue warning is issued; if not, proceed to the third step.

[0177] The third step is to determine whether the conditions are met. , If any of the conditions is met, an orange warning will be issued; if both conditions are met, a red warning will be issued; if neither condition is met, it means that it is safe and risk-free at this time, and the staff can decide whether to continue to judge the collision risk between our ship and other ships at the next moment according to their needs. is the major semi-axis of the ellipse equation of the other ship; Set based on experience Threshold.

[0178] In practical application, the above formula The value is 1. The value is 1s, that is, 1 / 3600h. The value is 5. Take 0, Take 1, and Take 0.5 nautical miles for each When selecting 4 times the captain, The value is 6 minutes, or 360 seconds.

[0179] My ship 1: Longitude: 120.378757; Latitude: 38.184202; Length: 26m; Width: 6m; Speed: 7.2 knots; Course: 22.2 degrees;

[0180] Other ship 1: Longitude: 120.378147; Latitude: 38.198017; Length: 45m; Width: 7m; Speed: 6.3 knots; Course: 71.2 degrees;

[0181] It has been verified that the major semi-axis of our ship's ellipse is 48.147839999999995 meters, and the minor semi-axis is 11.11104 meters. The major semi-axis of the other ship's ellipse is 72.91619999999999 meters, and the minor semi-axis is 11.342519999999999 meters. The distance between our ship and the target is The distance from other ships is 26.89352819116253 meters. 12.079561607092643 meters, safe distance The distance for detecting collision with other ships is 973.336729557318 meters. is 2825.336729557318 meters, and the distance between the two ships is 1537.198175041334 meters. is 0.5829270545885261, is 0.6856662660393456. The distance between the two ships is greater than the safe distance And less than the collision detection distance of other ships ,and Less than , so a blue alert is issued.

[0182] My ship 2: Longitude: 120.385813; Latitude: 38.19986; Length: 26m; Width: 6m; Speed: 7.5 knots; Course: 19 degrees;

[0183] Other ship 2: Longitude: 120.384; Latitude: 38.199547; Length: 45m; Width: 7m; Speed: 7.1 knots; Course: 71.3 degrees;

[0184] It has been verified that the major semi-axis of our ship's ellipse is 50.1539999999999996 meters, and the minor semi-axis is 11.573999999999998 meters. The major semi-axis of the other ship's ellipse is 82.17539999999998 meters, and the minor semi-axis is 12.782839999999998 meters. The distance between our ship and the target is The distance from other ships is 11.656582226698841 meters. 24.229729241981012 meters, safe distance The detection distance for collision with other ships is 970.0402063521217 meters. The distance between the two ships is 2822.0402063521215 meters. is 162.2154077901397 meters, is 82.175399999999998 meters, is 140.94667906038777 meters, The distance between the two ships is 12.45990846021347 seconds. Less than safe distance and , so an orange alert is issued.

[0185] My ship 3: Longitude: 120.38492; Latitude: 38.197902; Length: 26m; Width: 6m; Speed: 7.6 knots; Course: 10.7 degrees;

[0186] Other ship 3: longitude: 120.384; latitude: 38.199547; length: 45m; width: 7m; speed: 7.1 knots; heading: 71.3 degrees;

[0187] It has been verified that the major semi-axis of our ship's ellipse is 50.82272 meters, the minor semi-axis is 11.728319999999998 meters, the major semi-axis of the other ship's ellipse is 82.17539999999998 meters, the minor semi-axis is 12.782839999999998 meters, the range of our ship is The distance from other ships is 37.379055720168864 meters. 17.039938650551463 meters, safe distance The distance for detecting collision with other ships is 989.0793845746355 meters. , is 2841.0793845746357 meters, and the distance between the two ships is 199.8170662630768 meters. is 82.175399999999998 meters, is 75.97795969562506 meters, The distance between the two ships is 24.87627586457624 seconds. Less than safe distance and Less than , , so a red alert was issued.

[0188] In the present invention, the blue warning, orange warning and red warning are not specifically limited to the color or form of the warning, but are used to distinguish the warning level or the urgency of the warning. Among them, the urgency of the red warning is greater than the urgency of the orange warning, and the urgency of the orange warning is greater than the urgency of the blue warning.

[0189] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A ship warning method based on an expanded ellipse and expanded circle model, characterized in that: The following steps are involved: S1 obtains the latitude and longitude, speed and heading information of our ship and other ships, establishes a rectangular coordinate system, and establishes an expanded elliptical model of our ship and other ships; S2 calculates the area distance between my ship and the other ship's expanded ellipse , the safe distance between our ship and other ships , the distance between our ship and other ships, and the safe distance The angle between the tangent line of the circle with radius and the line connecting the relative positions and the angle between the relative velocity vector and the line connecting the relative position ; S3 determines whether the distance between our ship and the other ship is less than the collision detection distance , if satisfied, go to S4; S4 determines whether the distance between our ship and other ships is within a safe distance Collision detection distance If it is satisfied, go to S5, if it is not satisfied, go to S6; S5 determines the angle between the relative velocity vector and the relative position line between our ship and the other ship. , whether it meets the safety distance The angle between the tangent line of the circle with radius and the line connecting the relative positions , if it is met, a blue warning will be issued; S6 calculation and ,judge and , if any of the conditions are met, an orange warning will be issued; If both conditions are met, a red alert is issued; If both conditions are not met, go to S1.

2. The ship warning method based on the puffed ellipse and puffed circle model according to claim 1 is characterized in that: In S2, calculate the range distance of my ship Distance from other ships : Convert the longitude and latitude coordinates of our ship and the other ship into northeast coordinates, find the equation of the line connecting our ship and the other ship, and use the equation of the line to combine with the ellipse equation of our ship and the ellipse equation of the other ship, and find the two intersection points of the equation of the line and the ellipse equation of our ship: Point 1 ( , ), point 2 , find the two intersection points of the connecting line equation and the other ship ellipse equation: point 3 , , point 4 , ; Use the Pythagorean theorem to find point 1( , ) and point 2 The distance between point 3 , With point 4 , The distance between Let the coordinates of my ship be O 、The coordinates of the other ship are T , The OT equation of the line connecting the two ships: ； Joint: ； ； In the formula, is the heading angle of my ship; is the heading angle of the other ship; the slope of the straight line is ; The straight line intercept is ; Solve the equation to find point 1( , ), point 2 , point 3 , , point 4 , ; ； 。 3. The ship early warning method based on the puffed ellipse and puffed circle model according to claim 2 is characterized in that: In S2, calculate the safe distance between our ship and other ships : ； In the formula, It is a distance determined by comprehensively considering the maneuverability of our ship and other ships, their respective speeds, relative speeds and water type conditions; The calculation formula is: ； In the formula, is the time step, the unit is h; is the absolute value of the relative speed between our ship and the other ship when they are approaching each other, and takes 0 when they are moving away from each other, in knots; It is the time taken by the ship to turn at full speed and change the heading angle by 90°, in seconds; It is the longitudinal distance that the center of gravity moves when the ship turns at full speed and the heading angle changes by 90°, generally 2.8 to 4 times the length of the ship, in meters; As the safety distance required under natural conditions, 0.5 nautical miles is taken; The safety distance required for the waters in which you are located is 0.5 nautical miles; for The coefficient of , the minimum value is 0, the maximum value is 1; for The minimum value is 0 and the maximum value is 1.

4. The ship warning method based on the puffed ellipse and puffed circle model according to claim 3 is characterized in that: in, ； In the formula, is the gyration radius; Take 3~7, ordinary merchant ships take 4~5, large ships take 5~7; For the captain; Use the angular velocity to calculate the radius of gyration: ； In the formula, is the ship speed; is the angular velocity; Rotation The time taken for the angle is: ； Arranged: ； Therefore: 。 5. The ship warning method based on the puffed ellipse and puffed circle model according to claim 4 is characterized in that: In S2, the safe distance is calculated The angle between the tangent line of the circle with radius and the line connecting the relative positions and the angle between the relative velocity vector and the relative position vector : In the triangle OTS, equal The inverse tangent function of OS, the size of OS can be calculated by the Pythagorean theorem; The size of the relative position vector OT and the relative position vector The arccosine function of the dot product is found; Therefore: ； In the formula, is the straight-line distance between our ship O and his ship T; is the position vector of my ship O pointing to his ship T; ； In the formula, is the relative velocity vector of our ship O relative to the other ship T; is the dot product of the relative position vector and the relative velocity vector.

6. The ship warning method based on the puffed ellipse and puffed circle model according to claim 5 is characterized in that: In S3, calculate the collision detection distance : ； ； set up There are two factors to consider: (1) Overtaking situation: =0.5 nautical miles; Crossing and encounter situations: = 1 nautical mile; (2) : Set by yourself, : Obstacle expansion ellipse distance.

7. The ship warning method based on the puffed ellipse and puffed circle model according to claim 6 is characterized in that: In S6, calculate , Using the sine function in triangle OTP we find: ； calculate , The magnitude of is equal to the distance of PT divided by the velocity in the PT direction. PT is obtained by using the cosine of the modulus of the relative position vector through the triangle OTP: ； In the formula, is the magnitude of the relative velocity, and Equal in size.

8. The ship warning method based on the puffed ellipse and puffed circle model according to claim 7 is characterized in that: In S5, the condition is met , a blue warning is issued; in, The distance between my ship and his ship.

9. The ship warning method based on the puffed ellipse and puffed circle model according to claim 8 is characterized in that: In S6, any of the conditions is met or , an orange warning is issued; in, is the major semi-axis of the ellipse equation of the other ship; Set based on experience Threshold.

10. The ship warning method based on the puffed ellipse and puffed circle model according to claim 9 is characterized in that: In S6, both and , a red alert is issued.

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