A method, device and storage medium for dynamic fitting of marine ship trajectory curve

Abstract

The present application provides a method, device and storage medium for dynamically fitting a marine ship trajectory curve, the method comprising: obtaining a collection of ship trajectory position points; determining a judgment value of two adjacent position points, the judgment value being the absolute value of the difference between the estimated travel distance and the straight-line distance of the two adjacent position points; if the judgment value is greater than or equal to a first preset distance value, deleting the position point with a later time; if the judgment value is greater than or equal to a second preset distance value and less than the first preset distance value, supplementing a position point between the two adjacent position points; determining the density of three adjacent position points, if the density is greater than a preset density threshold, deleting the middle position point; fitting a trajectory curve based on the processed collection of position points. The trajectory curve fitted by this method has a small difference from the actual trajectory, which is convenient for monitoring the actual running trajectory of the ship.

Description

Technical Field

[0001] The present application relates to the general field of image processing or generation technology, and in particular to a method, device and storage medium for fitting a maritime navigation trajectory. Background Art

[0002] When a ship is sailing on the water, it is necessary to monitor the ship's trajectory to facilitate route planning, deviation alarms, etc., to ensure the ship's navigation safety.

[0003] Currently, the main method for depicting ship trajectories is to fit position points. First, multiple satellite positions reported by the moving ship are obtained, and then the ship's navigation trajectory is drawn based on the multiple position points of the ship.

[0004] However, the satellite position data reported by ships is affected by communication conditions, the natural maritime environment, and other factors, resulting in unstable data. For example, unstable communication can lead to data point loss, position point drift causing discrepancies with actual positions, and the overlap of numerous position points in small, localized areas. Lost data points can result in numerous long straight lines in the trajectory curve, drifting points can cause uneven curves, and the overlap of numerous position points in small, localized areas can cause localized curve overlap and jostling. These issues result in a significant discrepancy between the currently mapped navigation trajectory and the actual trajectory, making it difficult to monitor a ship's true trajectory. Summary of the Invention

[0005] The embodiments of the present application provide a method, device and storage medium for dynamic fitting of marine ship trajectory curves to solve the technical problems of uneven ship navigation trajectory drawing, missing data points and local curve overlap.

[0006] In a first aspect, an embodiment of the present application provides a method for dynamically fitting a trajectory curve of a marine vessel, the method comprising:

[0007] Obtain a collection of ship track position points;

[0008] Determining a judgment value of two adjacent position points, the judgment value being the absolute value of the difference between the estimated travel distance and the straight-line distance of the two adjacent position points; if the judgment value is greater than or equal to a first preset distance value, deleting the position point with the later time; and if the judgment value is greater than or equal to a second preset distance value and less than the first preset distance value, adding a position point between the two adjacent position points;

[0009] Determine the density of three adjacent position points, and if the density is greater than a preset density threshold, delete the middle position point;

[0010] The trajectory curve is fitted based on the processed set of position points.

[0011] In conjunction with the first aspect, in a possible implementation of the first aspect, determining the judgment value of two adjacent position points specifically includes:

[0012] Determine the horizontal coordinate value and the vertical coordinate value of each location point according to the longitude and latitude of each location point;

[0013] Determine the straight-line distance between two adjacent position points based on the horizontal and vertical coordinate values ​​of the two adjacent position points;

[0014] Obtain the time and speed values ​​of each location point to determine the estimated travel distance between two adjacent location points;

[0015] The judgment value is determined according to the straight-line distance between two adjacent position points and the estimated driving distance.

[0016] In conjunction with the first aspect, in another possible implementation of the first aspect, adding a location point between two adjacent location points specifically includes:

[0017] Determining the number of supplementary position points based on the ratio of the straight-line distance between two adjacent position points to the second preset distance;

[0018] The supplementary position points are evenly distributed between two adjacent position points.

[0019] In conjunction with the first aspect, in another possible implementation of the first aspect, determining the density of three adjacent location points specifically includes:

[0020] Determine a straight-line distance in front of the first location point and the second location point, and a straight-line distance in back of the second location point and the third location point;

[0021] The density is determined according to the sum of the front straight-line distance and the rear straight-line distance.

[0022] In conjunction with the first aspect, in another possible implementation of the first aspect, fitting the trajectory curve specifically includes:

[0023] Determine the activity boundary of the ship based on the collection of ship trajectory position points;

[0024] Determine the center point of the ship's track and the display resolution;

[0025] Call the map curve drawing method to display the processed ship trajectory position point set.

[0026] In conjunction with the first aspect, in another possible implementation of the first aspect, determining the activity boundary of the ship based on the collection of ship trajectory position points specifically includes:

[0027] Determine the maximum and minimum longitude and latitude values ​​in the set of location points;

[0028] The ship's activity boundaries are determined based on the maximum and minimum values ​​of longitude and latitude.

[0029] In conjunction with the first aspect, in another possible implementation of the first aspect, determining the map center point and the display resolution specifically includes:

[0030] Determine the map center point P = {center_lon, center_lat} according to the following formula:

[0031]

[0032] The map display resolution r is determined according to the following formula:

[0033]

[0034] Among them, max_lat is the maximum latitude, min_lat is the minimum latitude, max_lon is the maximum longitude, min_lon is the minimum longitude, Δlat is the difference between the maximum latitude and the minimum latitude, and Δlon is the difference between the maximum longitude and the minimum longitude.

[0035] In a second aspect, an embodiment of the present application provides a device for dynamically fitting a trajectory curve of a marine vessel, the device comprising:

[0036] The acquisition module is used to obtain the collection of ship track position points;

[0037] a first processing module for determining a judgment value between two adjacent position points, the judgment value being the absolute value of the difference between the estimated travel distance and the straight-line distance of the two adjacent position points; if the judgment value is greater than or equal to a first preset distance value, deleting the position point with the later time; and if the judgment value is greater than or equal to a second preset distance value and less than the first preset distance value, adding a position point between the two adjacent position points;

[0038] A second processing module is used to determine the density of three adjacent position points, and if the density is greater than a preset threshold, delete the middle position point;

[0039] The fitting module is used to fit the trajectory curve based on the processed position point collection.

[0040] In a third aspect, an embodiment of the present application provides a device for dynamically fitting a trajectory curve of a marine vessel, the device comprising a memory and a processor;

[0041] The memory is used to store computer-executable instructions;

[0042] The processor is configured to execute the computer-executable instructions to implement the method described in the first aspect and various implementations of the first aspect.

[0043] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores executable instructions, and when a computer executes the executable instructions, the method described in the first aspect and various implementation methods of the first aspect can be implemented.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] This application provides a method for dynamically fitting a marine vessel trajectory curve. By comparing the judgment value of two adjacent position points with a first preset distance value and a second preset distance value, it can delete position points that are inconsistent with the actual position due to drift and replace lost position points. By comparing the density of three adjacent position points with a preset density threshold, it can delete overlapping position points. Based on the processed collection of position points, a trajectory curve is fitted. The trajectory curve fitted by this method is less different from the actual trajectory, facilitating the monitoring of the ship's actual operating trajectory. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A flow chart of a method for dynamically fitting a marine vessel trajectory curve according to an embodiment of the present invention;

[0047] Figure 2 A relationship diagram between longitude and latitude and horizontal and vertical coordinates provided in an embodiment of the present invention;

[0048] Figure 3 A schematic diagram of a location point that needs to be supplemented between two adjacent location points in a location point set provided by an embodiment of the present invention;

[0049] Figure 4 A schematic diagram showing a point in the middle of three adjacent points in a set of points provided by an embodiment of the present invention, in which the point needs to be deleted;

[0050] Figure 5 A schematic diagram of a processed location point collection provided by an embodiment of the present invention;

[0051] Figure 6 A device for dynamically fitting a marine vessel trajectory curve provided by an embodiment of the present invention;

[0052] Figure 7 Schematic diagram of a physical device for dynamic pseudo-fitting of marine vessel trajectory curves provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The advantages, features, and aspects of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. Thus, those skilled in the art can readily concretize the technical concept and scope of the present invention. Furthermore, if it is considered that a detailed description of the related art may obscure the viewpoint of the present invention, such detailed description will not be provided here. Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0054] The use of "for" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0055] Additionally, the use of “based on” is intended to be open and inclusive, as a process, step, calculation, or other action “based on” one or more conditions or values ​​may, in practice, be based on additional conditions or beyond values.

[0056] As used herein, "about" or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value, where the acceptable range of deviation is determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0057] like Figure 1 As shown, a dynamic fitting method for a marine vessel trajectory curve provided by an embodiment of the present invention includes the following steps:

[0058] Step S101: Obtain a collection of ship track position points.

[0059] Specifically, let the set of ship trajectory position points be: P = [p0, p1, ..., p n-1 ], scan to obtain a set of trajectory points. Among them, p i ={lat,lon,t,v,d}(i=0~n-1).

[0060] P=[p0,p1,...,p n-1 ]

[0061] =[{lat0,lon0,t0,v0,d0},{lat1,lon1,t1,v1,d1},...,{lat n-1 ,lon n-1 ,t n-1 ,v n-1 ,d n-1}].

[0062] Where: lat is latitude, lon is longitude; t is time; v is speed, in meters per second; d is the direction of travel, ranging from 0 to 360°, with due north being 0° and clockwise being 360°.

[0063] Step S102: Determine the judgment value of two adjacent position points, where the judgment value is the absolute value of the difference between the estimated driving distance and the straight-line distance of the two adjacent position points; if the judgment value is greater than or equal to a first preset distance value, delete the position point with the later time; if the judgment value is greater than or equal to a second preset distance value and less than the first preset distance value, add a position point between the two adjacent position points.

[0064] To facilitate the calculation of straight-line distance, the horizontal and vertical coordinate values ​​of each location point are determined according to the longitude and latitude of each location point, such as Figure 2 To convert the longitude lon and latitude lat of a location point into horizontal and vertical coordinate values, refer to the following formula:

[0065]

[0066] x=K(L-L0),

[0067]

[0068] in:

[0069] x: horizontal rectangular coordinate, in meters (m);

[0070] y: longitudinal rectangular coordinate, in meters (m);

[0071] B: latitude, in radians (rad);

[0072] L: longitude, in radians (rad);

[0073] B0: projection base latitude, B0=0, unit is radian ((rad);

[0074] L0: longitude of the origin of the coordinate system, L0=0, unit is radian (rad);

[0075] a: semi-major axis of the Earth ellipsoid, a=6378137.0000, in meters (m);

[0076] b: the semi-minor axis of the Earth ellipsoid, b = 6356752.3142, in meters (m);

[0077] e: first eccentricity;

[0078] e': second eccentricity.

[0079] N: The radius of curvature of the circle, in meters (m).

[0080] In the above formula:

[0081] PI=3.1415926;

[0082] B0=30×PI / 180;

[0083] B = lat × PI / 180;

[0084] e=0.000045420816532046692727888569;

[0085] e'=0.00004481472364144682862615441664;

[0086] N=(6399593.6258039771) / (1+(e'×cosB0)2).

[0087] Further expansion of the above formula yields:

[0088] x=N×cosB0×log(tan(PI / 4+B / 2)×pow((1-e×sin(lat×PI / 180)) / (1+e×sin(lat×PI / 180)),e / 2))

[0089] y=N×cosB0×(lon×PI / 180).

[0090] According to the horizontal and vertical coordinates of two adjacent position points, the straight-line distance between the two adjacent position points is determined by the calculation formula: The coordinates of one of the locations are (x i ,y i ), the coordinates of the other position point are (x i+1 ,y i+1 ).

[0091] According to the time value and speed value of each location point, the estimated driving distance between two adjacent location points is determined by the calculation formula:

[0092] Among them, Δt is the running time between two adjacent position points, that is, Δt = t i+1 -t i ; Δv is the speed difference, that is, Δv=v i+1 -v i ; a is the acceleration, that is: Among them, the time value and speed value of a position point are t i 、v i , the time value and speed value of another position point are t i+1 、v i+1 .

[0093] The judgment value is determined according to the straight-line distance and the estimated travel distance of the two position points. The judgment value is the absolute value of the difference between the estimated travel distance and the straight-line distance of the two adjacent position points, that is, Δd=|sd|.

[0094] The first preset distance value and the second preset distance value can be specifically determined based on the actual water surface conditions, ship model, etc. For example, the first preset distance value and the second preset distance value can be determined based on the average spacing avg(d) of the set of position points. The first preset distance is set to 10×avg(d), and the second preset distance is set to avg(d). The average spacing calculation formula is as follows:

[0095]

[0096] The situation where additional location points are needed is as follows Figure 3 As shown, additional position points are added between two adjacent position points A and B, and the number and positions of the additional position points can be determined by calculation.

[0097] The number of supplementary position points is determined based on the ratio of the straight-line distance between two adjacent position points to the second preset distance. The calculation formula is as follows:

[0098]

[0099] Wherein, c is the number of supplementary position points, and avg(d) is the assumed second preset distance.

[0100] The supplementary position points are evenly distributed between two adjacent position points. The coordinate calculation formula of the supplementary position points is as follows:

[0101]

[0102] Step S103: Determine the density of three adjacent position points. If the density is greater than a preset density threshold, delete the middle position point. Figure 4 It shows the situation where the middle point among three adjacent points needs to be deleted.

[0103] Specifically, the density is a value reflecting the density of the three location points, and can be set according to actual conditions. A method for determining the density specifically includes the following steps.

[0104] A front straight-line distance between the first position point and the second position point, and a rear straight-line distance between the second position point and the third position point are determined.

[0105] Let the first position point be p k (x k ,y k ), the second position point is p k+1 (x k+1 ,yk+1 ), the third position point is p k+2 (x k+2 ,y k+2 ).

[0106] Calculate the straight-line distance ahead as The straight line distance behind is

[0107] The density is determined based on the sum of the front straight line distance and the rear straight line distance. The density calculation formula is as follows:

[0108]

[0109] If the density is greater than a preset density threshold, it means that the second position point coincides with the first position point, or the second position point coincides with the third position point, and the intermediate position point is deleted.

[0110] The density threshold can be set based on experience, for example, the density threshold can be set to

[0111] like Figure 4 As shown in the figure, point E, the middle point between points C and D, needs to be deleted. This phenomenon may be caused by the loss of position points in the previous period due to factors such as communication conditions and the natural environment at sea. When the satellite signal improves, the collected data is sent again, causing the position points to almost overlap. Deleting the middle position point can make the drawn ship's navigation track smoother.

[0112] After the above processing of the location point set, such as Figure 5 As shown in FIG, after the above processing method, the missing points in the middle of the ship trajectory diagram are supplemented, and points are removed where the data are densely accumulated.

[0113] Step S104: fitting a trajectory curve based on the processed set of position points.

[0114] Specifically, the ship's activity boundary is determined based on the collection of ship position points, which facilitates the determination of the range of the displayed fitted trajectory curve and prevents the trajectory curve from being incomplete.

[0115] The following steps can be used to determine the ship's activity boundary: determine the maximum and minimum longitude and latitude values ​​in the set of location points; and determine the ship's activity boundary based on the maximum and minimum longitude and latitude values. When determining the maximum and minimum longitude and latitude values ​​in the set of location points, a bubble sort or selection sort method can be used to sort all the longitude and latitude values ​​to find the maximum and minimum longitude and latitude values.

[0116] After determining the activity boundary of the ship, the center point of the map and the display resolution can be determined. The center point of the map P = {center_lon, center_lat} can be determined according to the following formula:

[0117]

[0118] The map display resolution r can be determined according to the following formula:

[0119]

[0120] Among them, max_lat is the maximum latitude, min_lat is the minimum latitude, max_lon is the maximum longitude, min_lon is the minimum longitude, Δlat is the difference between the maximum latitude and the minimum latitude, and Δlon is the difference between the maximum longitude and the minimum longitude.

[0121] Finally, the map curve drawing method is called to display the processed trajectory data.

[0122] The present invention also provides a device for dynamically fitting a marine vessel trajectory curve. Figure 6 As shown, the device includes an acquisition module 600, a first processing module 610, a second processing module 620, and a fitting module 630. The acquisition module 600 is used to obtain a collection of ship trajectory position points; the first processing module 610 is used to determine a judgment value of two adjacent position points, where the judgment value is the absolute value of the difference between the estimated travel distance and the straight-line distance of the two adjacent position points; if the judgment value is greater than or equal to a first preset distance value, the position point with the later time is deleted; if the judgment value is greater than or equal to the second preset distance value and less than the first preset distance value, a position point is added between the two adjacent position points; the second processing module 620 is used to determine the density of three adjacent position points, and if the density is greater than a preset threshold, the middle position point is deleted; and the fitting module 630 is used to fit a trajectory curve based on the processed collection of position points.

[0123] When in use, the known trajectory map of the acquisition module 600 is obtained, and after obtaining the scanned trajectory navigation map, the data is transmitted to the first processing module 610. The first processing module 610 determines the judgment value of two adjacent position points. If the judgment value is greater than or equal to the first preset distance value, the position point with the later time is deleted; if the judgment value is greater than or equal to the second preset distance value and less than the first preset distance value, a position point is added between the two adjacent position points. The second processing module 620 determines the density of the three adjacent position points based on the set of position points processed by the first processing module 610. If the density is greater than the preset density threshold, the middle position point is deleted, and finally the processed position point set is obtained; the fitting module 630 is used to fit a trajectory curve according to the processed position point set.

[0124] The embodiment of the present invention also provides a device for dynamically fitting the trajectory curve of a marine vessel. Figure 7 As shown, it includes a memory 720 and a processor 710; the memory 720 is used to store computer-executable instructions; the processor 710 is used to execute the computer-executable instructions to implement part or all of the steps of the method provided in this embodiment; a dynamic fitting device for a marine ship trajectory curve provided in the embodiment also includes a scanner 700, a display 730 and a bus 740, the scanner 700 is used to scan the ship trajectory curve to be processed into the device of the present invention; the display 730 displays the ship trajectory curve diagram processed by this method, and the bus 740 is used to transmit data.

[0125] The device for dynamically fitting a marine vessel trajectory curve can be a computing device such as a desktop computer, a laptop, a PDA, or a cloud server. Those skilled in the art will appreciate that the schematic diagram is merely an example of the device and does not limit the device. The device may include more or fewer components than shown, or a combination of certain components, or different components. For example, the device may also include input and output devices, network access devices, and the like.

[0126] The processor 710 may be a central processing unit (CPU), or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A memory may be used to store the computer program and / or modules, and the memory may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0127] An embodiment of the present invention further provides a computer storage medium, wherein the computer-readable storage medium stores executable instructions, and when a computer executes the executable instructions, it can implement some or all steps of the method provided in this embodiment.

[0128] The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0129] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for dynamically fitting a marine ship trajectory curve, characterized in that: include: Obtain a collection of ship track position points; Determine a judgment value of two adjacent position points, wherein the judgment value is an absolute value of a difference between an estimated driving distance and a straight-line distance of the two adjacent position points; If the judgment value is greater than or equal to the first preset distance value, delete the location point with a later time; If the judgment value is greater than or equal to the second preset distance value and less than the first preset distance value, a position point is added between two adjacent position points; Determine the density of three adjacent position points, and if the density is greater than a preset density threshold, delete the middle position point; According to the processed position point collection, a trajectory curve is fitted; The step of determining the judgment value of two adjacent position points specifically includes: Determine the horizontal coordinate value and the vertical coordinate value of each location point according to the longitude and latitude of each location point; Determine the straight-line distance between two adjacent position points according to the horizontal coordinate value and the vertical coordinate value of the two adjacent position points; Obtain the time and speed value of each location point to determine the estimated travel distance between two adjacent location points; The judgment value is determined according to the straight-line distance between two adjacent position points and the estimated driving distance.

2. The method for dynamic fitting of marine ship trajectory curve according to claim 1, characterized in that: The step of supplementing a position point between two adjacent position points specifically includes: Determining the number of supplementary position points according to the ratio of the straight-line distance between two adjacent position points and the second preset distance; The supplementary position points are evenly distributed between two adjacent position points.

3. The method for dynamic fitting of marine ship trajectory curve according to claim 1, characterized in that: The step of determining the density of three adjacent position points specifically includes: Determine a front straight-line distance between the first position point and the second position point, and a rear straight-line distance between the second position point and the third position point; The density is determined according to the sum of the front straight-line distance and the rear straight-line distance.

4. The method for dynamic fitting of marine ship trajectory curve according to claim 1, characterized in that: The step of fitting a trajectory curve specifically includes: Determine the activity boundary of the ship based on the collection of ship track position points; Determine the center point of the ship's track and the display resolution; Call the map curve drawing method to display the processed ship track position point set.

5. The method for dynamically fitting a marine ship trajectory curve according to claim 4, characterized in that: Determining the activity boundary of the ship according to the collection of ship trajectory position points specifically includes: Determine the maximum and minimum values ​​of longitude and latitude in the collection of location points; The activity boundaries of the ship are determined based on the maximum and minimum values ​​of longitude and latitude.

6. The method for dynamically fitting a marine ship trajectory curve according to claim 5, characterized in that: Determining the map center point and display resolution specifically includes: Determine the map center point P = {center_lon, center_lat} according to the following formula: The map display resolution r is determined according to the following formula: Among them, max_lat is the maximum latitude, min_lat is the minimum latitude, max_lon is the maximum longitude, min_lon is the minimum longitude, Δlat is the difference between the maximum latitude and the minimum latitude, and Δlon is the difference between the maximum longitude and the minimum longitude.

7. A dynamic fitting device for marine ship trajectory curve, characterized in that: include: An acquisition module is used to obtain a collection of ship track position points; A first processing module is used to determine a judgment value of two adjacent position points, wherein the judgment value is an absolute value of a difference between an estimated driving distance and a straight-line distance of the two adjacent position points; if the judgment value is greater than or equal to a first preset distance value, the position point with a later time is deleted; If the judgment value is greater than or equal to the second preset distance value and less than the first preset distance value, a position point is added between two adjacent position points; A second processing module is used to determine the density of three adjacent position points, and if the density is greater than a preset threshold, delete the middle position point; A fitting module is used to fit a trajectory curve according to the processed set of position points; The step of determining the judgment value of two adjacent position points specifically includes: Determine the horizontal coordinate value and the vertical coordinate value of each location point according to the longitude and latitude of each location point; Determine the straight-line distance between two adjacent position points according to the horizontal coordinate value and the vertical coordinate value of the two adjacent position points; Obtain the time and speed value of each location point to determine the estimated travel distance between two adjacent location points; The judgment value is determined according to the straight-line distance between two adjacent position points and the estimated driving distance.

8. A dynamic fitting device for marine ship trajectory curve, characterized in that: including memory and processor; The memory is used to store computer executable instructions; The processor is configured to execute the computer executable instructions to implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores executable instructions, and when a computer executes the executable instructions, the method according to any one of claims 1 to 6 can be implemented.

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