A method and system for planning routes in sea ice-containing areas based on hexagonal grid

Abstract

The present invention relates to the field of route planning, and in particular to a method and system for planning routes in sea ice-containing areas based on hexagonal grids. The method comprises the following steps: obtaining an electronic nautical chart corresponding to the navigation range of a ship; dividing the electronic nautical chart corresponding to the navigation range into a hexagonal grid map; the attribute values ​​of the hexagonal grids include passable and impassable; the attribute values ​​of the hexagonal grids at the initial moment are directly obtained based on the information in the electronic nautical chart; the changes in the attribute values ​​of the hexagonal grids at other moments are inferred based on the position and speed information of the moving ice; and then constructing a time-varying pass matrix that changes with time; and calculating the pass matrix based on the current position of the ship, the target position, and the f (t) , using a path-finding algorithm to calculate the current optimal route. The present invention fully considers the moving ice while planning the navigation route quickly and safely.

Description

Technical Field

[0001] The present invention relates to the field of route planning, and in particular to a hexagonal grid-based route planning method and system for a sea ice-containing area. Background Art

[0002] Sea ice is a key consideration for ship navigation routes in the Arctic. Currently, sea ice is classified into: primary ice, Nile ice, cake ice, early-stage ice, first-year ice, old ice, fast ice, and drift ice. Among these, mobile ice, such as first-year ice, old ice, and drift ice, significantly impacts navigation safety. Research on the movement of these three types of sea ice is crucial to ensuring safe navigation within ice-covered areas. Planning routes in ice-covered areas is a pressing issue. Summary of the Invention

[0003] In view of the above problems, the present invention proposes a technical solution:

[0004] A route planning method for sea ice-containing areas based on a hexagonal grid comprises the following steps:

[0005] S1: Obtain an electronic nautical chart corresponding to the vessel's navigation range. The electronic nautical chart includes information on the position and speed of moving ice. Moving ice refers to ice that moves over time.

[0006] S2: Divide the electronic nautical chart of the corresponding range into a hexagonal grid map; in the hexagonal grid map, the attribute of the hexagonal grid with time t, horizontal coordinate i and vertical coordinate j respectively is expressed as The attribute values ​​of the hexagonal grid include passable and impassable;

[0007] The hexagonal grid attribute values ​​at the initial moment are directly obtained from the information in the electronic nautical chart; the changes in the hexagonal grid attribute values ​​at other moments are inferred based on the position and speed information of the moving ice;

[0008] S4: Construct a time-varying access matrix that changes with time. The time-varying access matrix stores the values ​​of each hexagonal grid attribute at each moment, which is specifically expressed as

[0009]

[0010] Among them, f (t) is a time-varying matrix that records the values ​​of the attributes of each hexagonal grid at time t;

[0011] M is the value range of the horizontal coordinate i in the hexagonal grid map;

[0012] N is the value range of the vertical coordinate j in the hexagonal grid map;

[0013] S5: According to the current position of the ship, the target position and f (t), using a pathfinding algorithm to calculate the current optimal route. Preferably, the method further includes the steps of:

[0014] S6: Use the ship radar to scan regularly and update the hexagonal grid map within the radar scanning range at the corresponding time in the hexagonal grid map; use the updated hexagonal grid map to update f (t) , and then update the current optimal route.

[0015] Preferably, the path-finding algorithm is an A* algorithm.

[0016] Preferably, the speed direction of the moving ice is accurate to 60°, and the value is taken as the direction of the six sides of the hexagonal grid; the speed value of the moving ice is accurate to 1 grid / unit time.

[0017] The present invention also provides a route planning system for sea ice-containing areas based on a hexagonal grid, comprising the following modules:

[0018] Chart acquisition module: used to obtain electronic charts of the corresponding range according to the ship's navigation range. The electronic charts include the position and speed information of moving ice. Moving ice specifically refers to ice that moves over time.

[0019] Chart processing module: used to divide the electronic chart of the corresponding range into hexagonal grid maps; in the hexagonal grid map, the attribute of the hexagonal grid with time t, horizontal coordinate i and vertical coordinate j respectively is expressed as The attribute values ​​of the hexagonal grid include passable and impassable;

[0020] The hexagonal grid attribute values ​​at the initial moment are directly obtained from the information in the electronic nautical chart; the changes in the hexagonal grid attribute values ​​at other moments are inferred based on the position and speed information of the moving ice;

[0021] Matrix modeling module: used to construct a time-varying access matrix that changes with time. The time-varying access matrix stores the values ​​of each hexagonal grid attribute at each moment, specifically expressed as

[0022]

[0023] Among them, f (t) is a time-varying matrix that records the values ​​of the attributes of each hexagonal grid at time t;

[0024] M is the value range of the horizontal coordinate i in the hexagonal grid map;

[0025] N is the value range of the vertical coordinate j in the hexagonal grid map;

[0026] Route planning module: used to calculate the route according to the current position, target position and f (t) , use the path-finding algorithm to calculate the current optimal route.

[0027] Preferably, the module also includes:

[0028] Radar update module: used to regularly scan with ship radar and update the hexagonal grid map at the corresponding time within the radar scanning range; use the updated hexagonal grid map to update the f (t) , and then update the current optimal route.

[0029] Preferably, the path-finding algorithm is an A* algorithm.

[0030] Preferably, the speed direction of the moving ice is accurate to 60°, and the value is taken as the direction of the six sides of the hexagonal grid; the speed value of the moving ice is accurate to 1 grid / unit time.

[0031] Beneficial Effects: This invention converts nautical charts into hexagonal grid maps and infers the behavior of moving ice. During the inference process, the direction and numerical accuracy of the moving ice speed are set to match the hexagonal grid map, making route planning simple and fast while ensuring safety. Furthermore, the hexagonal grid map is regularly updated using ship radar, further enhancing safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a diagram defining the hexagonal grid orientation in the embodiment;

[0033] Figure 2 is a hexagonal grid diagram in the embodiment;

[0034] Figure 3 for Figure 2 Enlarged view of the middle area; DETAILED DESCRIPTION

[0035] In order to make the purposes, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] like Figures 1 to 3 As shown, a route planning method for sea ice-containing areas based on a hexagonal grid includes the following steps:

[0037] S1: Obtain an electronic nautical chart corresponding to the vessel's navigation range. The electronic nautical chart includes information on the position and speed of moving ice. Moving ice refers to ice that moves over time.

[0038] S2: Divide the electronic nautical chart of the corresponding range into a hexagonal grid map; in the hexagonal grid map, the attribute of the hexagonal grid with time t, horizontal coordinate i and vertical coordinate j respectively is expressed as The attribute values ​​of the hexagonal grid include passable and impassable;

[0039] The hexagonal grid attribute values ​​at the initial moment are directly obtained from the information in the electronic nautical chart; the changes in the hexagonal grid attribute values ​​at other moments are inferred based on the position and speed information of the moving ice;

[0040] Electronic nautical charts include geographic information for various locations, as well as information such as the location and speed of moving ice. Based on this information in electronic nautical charts, it is easy to determine whether the corresponding location is passable. The source of electronic nautical charts is generally satellite data, etc. The specific content of electronic nautical charts belongs to existing technology and will not be repeated here.

[0041] In this embodiment, if Figure 3 As shown, the first two digits of the upper four digits of each hexagonal grid are the horizontal coordinate i, the last two digits are the vertical coordinate j, and the lower digits are the elevation, which is not related to the present invention; the dark blue hexagonal grid without other colors has the attribute value of passable, such as the hexagonal grids with coordinates 5561 and 5562; the colored hexagonal grid has the attribute value of impassable, and different colors in the figure represent different types of ice, for example, the hexagonal grids with coordinates 5765 and 5766 have the attribute value of impassable;

[0042] like Figure 1 As shown, in this embodiment, the direction of each hexagonal grid is defined as: the north direction is directly above the hexagonal grid; the north direction of the hexagonal grid is 0°, and the angle between the north direction and the clockwise direction is the azimuth with reference to the north direction.

[0043] Therefore, starting from the upper right corner and going clockwise, the directions of the six edges are:

[0044] (1) Azimuth 30°, i.e. 30° east of north;

[0045] (2) Azimuth 90°, i.e. due east;

[0046] (3) Azimuth 150°, i.e. 60° east by south;

[0047] (4) Azimuth 210°, i.e. 30° south-west;

[0048] (5) Azimuth 270°, i.e. due west;

[0049] (6) Azimuth 330°, i.e. 30° westward;

[0050] In this embodiment, the hexagonal grid attribute values ​​at the initial moment are directly obtained from the information in the electronic nautical chart, and the changes in the hexagonal grid attribute values ​​at other moments are inferred based on the position and speed information of the moving ice. The speed direction of the moving ice is accurate to 60° and is the direction of the six sides of the hexagonal grid. That is, the speed direction of the moving ice is 30°, 90°, 150°, 210°, 270°, and 330°. The speed value of the moving ice is accurate to 1 grid / unit time, where 1 grid refers to 1 hexagonal grid. In this embodiment, the unit time is day. The following is a specific example:

[0051] At time t=5, the hexagonal grid with i=88 and j=88 is mobile ice, and its attribute value is impassable, i.e. The speed of moving ice is 1 grid / day; the hexagonal grid attributes at the next moment are:

[0052] When the velocity direction of the moving ice is at an azimuth angle of 30°,

[0053] When the velocity direction of the moving ice is at an azimuth angle of 90°,

[0054] When the velocity direction of the moving ice is at an azimuth angle of 150°,

[0055] When the velocity direction of the moving ice is at an azimuth angle of 210°,

[0056] When the velocity direction of the moving ice is at an azimuth angle of 270°,

[0057] When the velocity direction of the moving ice is at an azimuth angle of 330°,

[0058] S4: Construct a time-varying access matrix that changes with time. The time-varying access matrix stores the values ​​of each hexagonal grid attribute at each moment, which is specifically expressed as

[0059]

[0060] Among them, f (t) is a time-varying matrix that records the values ​​of the attributes of each hexagonal grid at time t;

[0061] M is the value range of the horizontal coordinate i in the hexagonal grid map;

[0062] N is the value range of the vertical coordinate j in the hexagonal grid map;

[0063] S5: According to the current position of the ship, the target position and f (t), using a pathfinding algorithm to calculate the current optimal route path; in this embodiment, the pathfinding algorithm is the A* algorithm;

[0064] S6: Use the ship radar to scan regularly and update the hexagonal grid map within the radar scanning range at the corresponding time in the hexagonal grid map; use the updated hexagonal grid map to update f (t) , and then update the current optimal route.

[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A route planning method for sea ice-containing areas based on a hexagonal grid, characterized in that: The following steps are involved: S1: Obtain an electronic nautical chart corresponding to the vessel's navigation range. The electronic nautical chart includes information on the position and speed of moving ice. Moving ice refers to ice that moves over time. S2: Divide the electronic nautical chart of the corresponding range into a hexagonal grid map; in the hexagonal grid map, the attribute of the hexagonal grid with time t, horizontal coordinate i and vertical coordinate j respectively is expressed as The attribute values ​​of the hexagonal grid include passable and impassable; The hexagonal grid attribute values ​​at the initial moment are directly obtained from the information in the electronic nautical chart; the changes in the hexagonal grid attribute values ​​at other moments are inferred based on the position and speed information of the moving ice; S4: Construct a time-varying access matrix that changes with time. The time-varying access matrix stores the values ​​of each hexagonal grid attribute at each moment, which is specifically expressed as Among them, f (t) is a time-varying matrix that records the values ​​of the attributes of each hexagonal grid at time t; M is the value range of the horizontal coordinate i in the hexagonal grid map; N is the value range of the vertical coordinate j in the hexagonal grid map; S5: According to the current position of the ship, the target position and f (t) , use the path-finding algorithm to calculate the current optimal route.

2. The method for planning a route in an ice-covered area based on a hexagonal grid according to claim 1, characterized in that: Also includes the steps: S6: Use the ship radar to scan regularly and update the hexagonal grid map within the radar scanning range at the corresponding time in the hexagonal grid map; use the updated hexagonal grid map to update f (t) , and then update the current optimal route.

3. The method for planning a route in an ice-covered area based on a hexagonal grid according to claim 1, characterized in that: The path-finding algorithm is the A* algorithm.

4. The method for planning a route in an ice-covered area based on a hexagonal grid according to claim 1, wherein: The speed direction of the moving ice is accurate to 60°, and the value is taken as the direction of the six sides of the hexagonal grid; the speed value of the moving ice is accurate to 1 grid / unit time.

5. A route planning system for sea ice areas based on a hexagonal grid, characterized in that: Includes the following modules: Chart acquisition module: used to obtain electronic charts of the corresponding range according to the ship's navigation range. The electronic charts include the position and speed information of moving ice. Moving ice specifically refers to ice that moves over time. Chart processing module: used to divide the electronic chart of the corresponding range into hexagonal grid maps; in the hexagonal grid map, the attribute of the hexagonal grid with time t, horizontal coordinate i and vertical coordinate j respectively is expressed as The attribute values ​​of the hexagonal grid include passable and impassable; The hexagonal grid attribute values ​​at the initial moment are directly obtained from the information in the electronic nautical chart; the changes in the hexagonal grid attribute values ​​at other moments are inferred based on the position and speed information of the moving ice; Matrix modeling module: used to construct a time-varying access matrix that changes with time. The time-varying access matrix stores the values ​​of each hexagonal grid attribute at each moment, specifically expressed as Among them, f (t) is a time-varying matrix that records the values ​​of the attributes of each hexagonal grid at time t; M is the value range of the horizontal coordinate i in the hexagonal grid map; N is the value range of the vertical coordinate j in the hexagonal grid map; Route planning module: used to calculate the route according to the current position, target position and f (t) , use the path-finding algorithm to calculate the current optimal route.

6. The route planning system for sea ice-containing areas based on hexagonal grid according to claim 5, characterized in that: Also includes modules: Radar update module: used to regularly scan with ship radar and update the hexagonal grid map at the corresponding time within the radar scanning range; use the updated hexagonal grid map to update the f (t) , and then update the current optimal route.

7. The hexagonal grid-based route planning system for sea ice-containing areas according to claim 5, characterized in that: The path-finding algorithm is the A* algorithm.

8. The route planning system for sea ice-containing areas based on hexagonal grid according to claim 5, characterized in that: The speed direction of the moving ice is accurate to 60°, and the value is taken as the direction of the six sides of the hexagonal grid; the speed value of the moving ice is accurate to 1 grid / unit time.

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