Sea ice-containing area route planning method and system based on hexagonal lattice

Abstract

The invention relates to the field of route planning, in particular to a sea ice-containing area route planning method and system based on hexagonal lattices. The method comprises the following steps: acquiring an electronic chart of a corresponding range according to the navigation range of a ship; dividing the electronic chart in the corresponding range into a hexagonal lattice map; the attribute values of the hexagonal grids comprise passable values and impassable values; the hexagonal lattice attribute value at the initial moment is directly obtained according to information in the electronic chart; the value change of the hexagonal lattice attributes at other moments is speculated according to the position and speed information of the moving ice; a time-varying passing matrix changing along with time is constructed in sequence; and according to the current position, the target position and f (t) of the ship, calculating a current optimal route by using a way-finding algorithm. According to the method, moving ice is fully considered, and the navigation route is rapidly and safely planned.

Description

Technical Field

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

[0002] Sea ice is the main consideration for ship navigation routes in the Arctic region. At present, the main categories of sea ice are: primary ice, Nile ice, cake ice, initial ice, one-year ice, old ice, fixed ice and drift ice. Among them, mobile ice such as one-year ice, old ice and drift ice is an important factor affecting the safety of ship navigation. It is necessary to study the movement of the three types of sea ice to ensure safe navigation of ships in sea ice areas. How to plan routes in areas with sea ice is an urgent problem to be solved. Summary of the invention

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

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

[0005] S1: According to the navigation range of the ship, an electronic nautical chart of the corresponding range is obtained, and the electronic nautical chart includes the position and speed information of moving ice; moving ice specifically refers to ice whose position moves over time;

[0006] S2: The electronic nautical chart of the corresponding range is divided 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] Among them, 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 the attributes of each hexagonal grid at each moment, which is specifically expressed as

[0009]

[0010] Among them, f (t) is a time-varying row matrix, which 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 ordinate j in the hexagonal grid map;

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

[0014] S6: regularly use the ship radar to scan 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 navigation range of the ship, which include the position and speed information of moving ice; moving ice specifically refers to ice whose position moves over time;

[0019] The chart processing module is used to divide the electronic 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 coordinates i and vertical coordinates j respectively is expressed as The attribute values ​​of the hexagonal grid include passable and impassable;

[0020] Among them, 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, which is specifically expressed as

[0022]

[0023] Among them, f (t) is a time-varying row matrix, which 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 ordinate 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 in the hexagonal grid map; 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: The present invention converts the nautical chart into a hexagonal grid map and makes an inference on the behavior of the 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 the process of planning the route simple and fast while ensuring safety. At the same time, the hexagonal grid map is regularly updated using ship radar to further enhance safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a hexagonal grid orientation definition diagram in the embodiment;

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

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

[0035] In order to make the purpose, 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 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 a sea ice-containing area based on a hexagonal grid includes the following steps:

[0037] S1: According to the navigation range of the ship, an electronic nautical chart of the corresponding range is obtained, and the electronic nautical chart includes the position and speed information of moving ice; moving ice specifically refers to ice whose position moves over time;

[0038] S2: The electronic nautical chart of the corresponding range is divided 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] Among them, 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 of various locations, as well as the location and speed of moving ice. Based on this information in the 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 the existing technology and will not be repeated here.

[0041] In this embodiment, if Figure 3 As shown, among the four digits at the top of each hexagonal grid, the first two digits are the horizontal coordinate i, the last two digits are the vertical coordinate j, and the lower digits are the elevation, which is irrelevant to the present invention; the attribute value of the dark blue hexagonal grid without other colors is passable, such as the hexagonal grids with coordinates of 5561 and 5562; the attribute of the colored hexagonal grid is impassable, and different colors in the figure represent different types of ice, for example, the attribute value of the hexagonal grid with coordinates of 5765 and 5766 is 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, taking the north direction as a reference.

[0043] Therefore, from the edge of the upper right corner in clockwise direction, 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 according to the information in the electronic nautical chart, and the changes in the hexagonal grid attribute values ​​at other moments are inferred according to the position and speed information of the moving ice; wherein, the speed direction of the moving ice is accurate to 60°, and the values ​​are taken as the directions of the six sides of the hexagonal grid; that is, the speed direction of the moving ice is taken as azimuth 30°, azimuth 90°, azimuth 150°, azimuth 210°, azimuth 270°, azimuth 330°; the speed value of the moving ice is accurate to 1 grid / unit time, where 1 grid refers to 1 hexagonal grid, and in this embodiment, the unit time is day; the following are specific examples:

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

[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 the attributes of each hexagonal grid at each moment, which is specifically expressed as

[0059]

[0060] Among them, f (t) is a time-varying row matrix, which 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 ordinate j in the hexagonal grid map;

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

[0064] S6: regularly use the ship radar to scan 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 principle 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: According to the navigation range of the ship, an electronic nautical chart of the corresponding range is obtained, and the electronic nautical chart includes the position and speed information of moving ice; moving ice specifically refers to ice whose position moves over time; S2: The electronic nautical chart of the corresponding range is divided 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; Among them, 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 the attributes of each hexagonal grid at each moment, which is specifically expressed as Among them, f (t) is a time-varying row matrix, which 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 ordinate j in the hexagonal grid map; S5: Based on the current position of the ship, the target position and f (t) , use the path-finding algorithm to calculate the current optimal route.

2. A route planning method for sea ice-containing areas based on hexagonal grid according to claim 1, characterized in that: Also includes the steps: S6: regularly use the ship radar to scan 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-containing 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-containing area based on a hexagonal grid according to claim 1, characterized in that: The speed direction of 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 moving ice is accurate to 1 grid / unit time.

5. A route planning system for sea ice areas based on hexagonal grid, characterized in that: Includes the following modules: Chart acquisition module: used to obtain electronic charts of the corresponding range according to the navigation range of the ship, which include the position and speed information of moving ice; moving ice specifically refers to ice whose position moves over time; The chart processing module is used to divide the electronic 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 coordinates i and vertical coordinates j respectively is expressed as The attribute values ​​of the hexagonal grid include passable and impassable; Among them, 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, which is specifically expressed as Among them, f (t) is a time-varying row matrix, which 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 ordinate 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. A hexagonal grid-based route planning system for sea ice-containing areas 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 in the hexagonal grid map; use the updated hexagonal grid map to update the f (t) , and then update the current optimal route.

7. The route planning system for sea ice-containing areas based on hexagonal grid 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 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 moving ice is accurate to 1 grid / unit time.

Images