JP7725297B2 - Standard route generation device, ship monitoring device - Google Patents

Description

This disclosure relates to a standard route generation device that generates a standard route area based on past ship tracks, and a ship monitoring device that uses the standard route area.

Patent document 1 discloses that navigable route information is generated from ship position information.

Japanese Patent Application Laid-Open No. 2018-176871

However, there is a demand for generating a ship's standard route area from its past track. A track is formed by connecting coordinate points containing the ship's latitude and longitude. The standard route area that is desired is an area with a certain width, but past tracks are composed of coordinate points and the lines connecting them, and no method has been proposed for obtaining an area from coordinate points and lines.

This disclosure provides a standard route generation device that generates a standard route area based on past ship tracks, and a ship monitoring device that uses the standard route area.

The standard route generation device disclosed herein comprises a memory unit that stores a map divided into multiple cells by a grid, and position information and navigation information showing the tracks of multiple ships; a route cell setting unit that sets multiple route cells that represent a standard route and include first and second route cells based on the position information; a line calculation unit that calculates lines connecting the first route cells and the second route cells among tracks that pass through both the first route cells and the second route cells on the same voyage of the same ship based on the position information and the navigation information; a route interpolation unit that changes cells that are not route cells to route cells based on the lines; and a standard route area generation unit that generates a standard route area based on the route cells.

FIG. 2 is a block diagram showing the configuration of a standard route generating device and a ship position acquiring unit 81. A diagram showing a map divided into multiple grid cells and ship tracks. FIG. 10 is a diagram relating to a process for identifying route cells based on coordinate points. FIG. 10 is a diagram relating to ship stoppage filtering processing. 1 is a diagram relating to grid interpolation processing. 1 is a diagram relating to grid interpolation processing. 10 is a diagram relating to adjacent filtering processing. 10 is a diagram relating to adjacent filtering processing. FIG. FIG. 10 is a diagram relating to the outer frame cell identification process. 10A to 10C are diagrams relating to the outer frame cell identification process. 10A to 10C are diagrams relating to the outer frame cell identification process. FIG. 10 is a diagram relating to a boundary cell identification process. FIG. 10 is a diagram relating to a boundary cell identification process. FIG. 10 is a diagram relating to a boundary cell identification process. FIG. 10 is a diagram relating to vector data generation processing. FIG. 10 is a diagram relating to vector data generation processing.

[Standard route generation device]
The standard route generation device 1 of the present disclosure will be described below with reference to the drawings.

The standard route generation device 1 generates a standard route area based on the tracks of multiple ships. Tracks are past routes that ships have actually passed. Standard routes are routes that multiple ships frequently pass through, determined based on past performance. Standard route areas represent standard routes as areas, rather than as points that represent a single route and lines connecting the points.

As shown in Figure 1, the standard route generation device 1 has a memory unit 10, a route cell identification unit 6, and a data conversion unit 7. If the raster data (described below) obtained by the route cell identification unit 6 is not converted into vector data (described below), the data conversion unit 7 can be omitted.

Figure 2 shows a map 3 divided into multiple grid cells 2 and a ship's track 4. The track 4 is represented by multiple coordinate points 40, shown as circles in the figure, and lines 41 connecting each of the coordinate points 40. Each of the coordinate points 40 that make up the track 4 can be connected to each other in chronological order using navigation information 5 and time.

The memory unit 10 stores a map 3 divided into multiple cells 2 by a grid, and location information indicating the tracks 4 of multiple ships. As shown in Figure 2, the track 4 is composed of coordinate points 40 containing the latitude and longitude of the ship and lines 41 connecting the coordinate points 40. As long as the location information can indicate the track, it is sufficient if it includes at least one of the coordinate points 40 and the lines 41. In this embodiment, as shown in Figure 2, one track 4 is represented by multiple coordinate points 40. One track 4 can be represented by connecting each coordinate point 40 in chronological order. In this embodiment, since there are many coordinate points that make up one track, resulting in a large amount of data, the coordinate points are thinned out. Specifically, the date and time (timestamp) of one coordinate point is set to be separated by a predetermined time or more from the date and time of the next coordinate point.

The memory unit 10 may further store voyage information 5. The voyage information 5 is information related to the voyage associated with the track, and may include, for example, ship identification information such as a ship ID, voyage identification information which is an identification code assigned to each voyage from departure to port call, and time information for each coordinate point. It may also include information obtained from an Automatic Identification System (AIS). Examples of the voyage information 5 include the type of ship (cargo ship such as a container ship, LNG ship, or bulk carrier, or passenger ship, training ship, research vessel, etc.), ship characteristics (size, shape, engine, trial operation), and ship attributes (ship name, affiliated organization, flag, coastal ship, ocean-going ship). Position information may include latitude and longitude, date and time, course over ground, ground speed, and heading for each coordinate point.

<Route cell identification part>
The route cell identification unit 6 identifies a plurality of route cells 20 representing the standard route from a plurality of cells 2 constituting the map 3 based on the location information. The route cell identification unit 6 of this embodiment has, but is not limited to, a first identification unit 61, a second identification unit 62, a third identification unit 63, a fourth identification unit 64, a fifth identification unit 65, and a sixth identification unit 66. The combination of these units 61 to 66 can be changed as appropriate as long as route cells can be set.

<Initial Setting of Route Cells: First Identification Unit 61>
Based on the position information, the first identification unit 61 identifies a cell in which coordinate points 40 constituting the ship track 4 exist as a route cell 20. The route cell 20 stores the number of coordinate points 40 contained within the cell as its usage frequency. In Figure 3, a cell identified as a route cell 20 due to the presence of a coordinate point 40 is shown with diagonal lines, and its usage frequency is incremented by +1. Although Figure 3 shows only one route for one ship, route cells 20 can be identified for multiple ships and multiple routes, and the usage frequencies of the route cells 20 can be added together to set the frequency.

<Ship Stopping Filter; Second Identification Unit 62>
Ships may stop for reasons such as waiting in port or fishing. If coordinate points 40 are recorded at certain time intervals (regular or irregular intervals), multiple coordinate points 40 will be recorded for a single route while the ship is stopped. As shown in Figure 4, a ship is likely to remain in the same cell 2 on the map while stopped. Because the first identification unit 61 does not take into account stopping, the usage frequency of a route cell 20 corresponding to a stopping time should be counted as one, but is instead counted multiple times, resulting in an inflated usage frequency. Therefore, the stopping filter unit 62 (second identification unit 62) corrects the usage frequency for a route cell 20 identified by the first identification unit 61 based on the position information and voyage information when a predetermined stopping condition is met. Specifically, if a route cell 20 contains multiple coordinate points 40 for the same ship and the same voyage, the usage frequency is corrected to 1. For example, if a route cell 20 contains eight coordinate points for the same ship and the same voyage, the usage frequency of the route cell 20 identified by the first identification unit 61 will be eight. The ship stopping filter unit 62 corrects the above-mentioned frequency of use from 8 to 1. This makes it possible to suppress or eliminate an abnormal increase in frequency of use due to the ship being stopped.

<Grid Interpolation: Third Identification Unit 63>
The route cells 20 identified through the processing of the second identification unit 62 (ship stopping filter unit 62) are discrete, as shown by diagonal lines in Figure 3, because they are only cells where coordinate points 40 exist. These need to be connected with lines, and this processing is carried out by the third identification unit 63 (grid interpolation unit 63). The multiple route cells 20 identified by the first identification unit 61 and the second identification unit 62 include a first route cell 21 and a second route cell 22, as shown in Figure 3. The third identification unit 63 (grid interpolation unit 63) has a line calculation unit 631 and a route interpolation unit 632.

As shown in Figure 5, the line calculation unit 631 calculates a line L1 connecting the first route cell 21 and the second route cell 22 among the tracks that pass through both the first route cell 21 and the second route cell 22 during the same voyage of the same ship based on position information and voyage information.

Specifically, the line calculation unit 631 assumes that one of the route cells 20 is the first route cell 21, and identifies the track 4 constituted by the coordinate points 40 included in the first route cell 21. Utilizing the fact that each of the coordinate points 40 constituting one route 4 can be referenced in chronological order, the line calculation unit 631 identifies the route cell 20 before or after the first route cell 21 in the identified track 4 as the second route cell 22. The line calculation unit 631 calculates a line L1 connecting the position (coordinate point 40) of the ship in the first route cell 21 and the position (coordinate point 40) of the ship in the second route cell 22. When the first route cell 21 and the second route cell 22 are separated from each other, the line calculation unit 631 calculates a line L1 for the first route cell 21 and the second route cell 22, which are surrounded by non-route cells 23 that are not route cells 20. In this embodiment, the line L1 is a single straight line connecting the first route cell 21 and the second route cell 22, but is not limited to this. The line L1 may include a curve such as a Bezier curve, for example.

As shown in Figures 3 and 5, the route interpolation unit 632 changes non-route cells 23 that are not route cells 20 to route cells 20 based on the line L1 calculated by the line calculation unit 631. The route interpolation unit 632 changes cells that overlap the calculated line L1 to route cells 20. The frequency of use of route cells 20 changed from non-route cells 23 can be set with one route counted, similar to the first route cell 21 and the second route cell 22. Figure 5 shows an example in which a new route cell 20 is set based on the line L1 connecting the first route cell 21 and the second route cell 22. However, if the first route cell 21 and the second route cell 22 are set as separate route cells 20 and applied to all combinations, multiple route cells 20 will be continuous as shown in Figure 6.
As a result, new track cells are set between the dispersed route cells based on the track, and the dispersed track cells are connected by lines.

<Track filter; fourth identification unit 64>
The fourth identification unit 64 (track filter unit 64) is a process for removing cells that do not satisfy conditions based on frequency of use from the route cells 20 identified through the processing of the third identification unit 63 (grid interpolation unit 63). Since the standard route is determined based on multiple routes, route cells whose frequency of use does not meet a predetermined threshold are removed. This process can also be called standard route creation processing. For example, the standard route creation processing can be said to identify, as route cells 20, cells in which a predetermined number or more coordinate points indicating the ship's position are counted.

<Adjacent Filter: Fifth Identification Unit 65>
The fifth identification unit 65 (adjacent filter unit 65) is a process for removing isolated cells (route cells with no other route cells around them) such as outliers or outliers from the route cells 20 identified through the processing of the fourth identification unit 64 (trace filter unit 64). The route cells 20 identified through the processing of the fourth identification unit 64 (trace filter unit 64) are set as first candidate cells 24, which are candidates for route cells indicating the standard route, before the adjacent filter processing. The fifth identification unit 65 (adjacent filter unit 65) has a determination target cell setting unit 651 and a second candidate cell identification unit 652.

As shown in FIG. 7, the target cell setting unit 651 sets at least one cell as the target cell 25 from a plurality of cells including the first candidate cell 24. In this embodiment, one first candidate cell is selected from the plurality of first candidate cells 24 and set as the target cell 25, but two or more first candidate cells may be selected from the plurality of first candidate cells 24 and set as the target cell 25.

The second candidate cell identification unit 652 identifies a determination target cell 25 whose positional relationship with the determination target cell 25 and a first candidate cell 24 other than the determination target cell 25 meets a specified adjacent condition as a second candidate cell 26, which is a candidate for a route cell indicating the standard route. In other words, it changes a first candidate cell 24 among multiple first candidate cells 24 whose positional relationship with other first candidate cells 24 meets a specified adjacent condition to a second candidate cell 26.

A specific method for identifying the second candidate cell 26 will be described next. The fifth identification unit 65 may further include a specific range setting unit 653. The specific range Ar1 is set to include multiple cells including the target cell 25. In this embodiment, the specific range Ar1 is a square that includes nine or more cells with the target cell as the center cell. The specific range Ar1 may be 3x3 cells or 4x4 cells, and may be set to a rectangle, diamond shape, or circle instead of a square.

The second candidate cell identification unit 652 is capable of processing to identify the target cell 25 as a second candidate cell 26 when the specific range Ar1 contains a predetermined number or more of first candidate cells 24. Furthermore, the second candidate cell identification unit 652 is capable of processing to identify the target cell 25 as a second candidate cell 26 when the specific range Ar1 contains a predetermined number or more of first candidate cells 24 other than the target cell 25. The size and predetermined number of the specific range Ar1 are set in advance and are changeable.

For example, in the case of Figure 7, the size of the specific range Ar1 is 3x3, with one surrounding block. If the specified number is set to 1, there is one first candidate cell 24 in the specific range Ar1, so the target cell 25 satisfies the specified adjacent condition and is recognized as the second candidate cell 26. On the other hand, if the specified number is set to 2 or more, there is only one first candidate cell 24 in the specific range Ar1, so the target cell 25 does not satisfy the specified adjacent condition, so the target cell 25 is not recognized as the second candidate cell 26 and remains the first candidate cell 24.

8 , the specific range Ar1 has a size of 5×5 with two surrounding blocks. If the predetermined number is set to 3, there are three first candidate cells 24 in the specific range Ar1, and therefore the target cell 25 satisfies the predetermined adjacent condition and is recognized as the second candidate cell 26. On the other hand, if the predetermined number is set to 4 or more, there are only three first candidate cells 24 in the specific range Ar1, and therefore the target cell 25 does not satisfy the predetermined adjacent condition, and therefore the target cell 25 is not recognized as the second candidate cell 26, and remains the first candidate cell 24.
The second candidate cell 26 is also the first candidate cell 24, and is treated as the first candidate cell 24 when determining the target cell 25.

According to the above process, route cells 20 that satisfy the adjacent conditions are set as second candidate cells 26, and route cells 20 that do not satisfy the adjacent conditions are not set as second candidate cells 26. If only second candidate cells 26 are extracted, all extracted cells will be route cells that satisfy the adjacent conditions. The second candidate cells 26 are confirmed as route cells. Hereafter, the second candidate cells 26 will be referred to as route cells 20.

<Interpolation Unit; Sixth Identification Unit 66>
As shown in FIG. 9 , the sixth identification unit 66 (interpolation unit 66) is a process for changing a predetermined number or less of non-route cells 23 (shown by dotted lines in the figure) that are not route cells 20 and are sandwiched between two route cells 20, among the route cells 20 (second candidate cells 26) identified through processing by the fifth identification unit 65 (adjacency filter unit 65), into route cells 20. This makes it possible to merge a small number of route cells 20 into a group of route cells 20 even if they are slightly separated from the group of route cells 20. The predetermined number can be set to any value, for example, 3. In this embodiment, even if there are three or less non-route cells 23 vertically or horizontally between two route cells 20, these three or less non-route cells 23 are changed to route cells 20.

<Standard route area generation unit>
The standard route area generating unit 67 generates a standard route area by storing the route cells 20 identified by the first to sixth identifying units and the non-route cells 23 that are not route cells 20 in the storage unit 10. At this point, the standard route area is raster data expressed by a plurality of cells (particularly the route cells 20).

<Data conversion section>
The route cell identification unit 6 stores in the memory unit 10 a map 3 divided into a plurality of cells 2 by a grid, as well as route cells 20 representing the standard route and non-route cells 23 that are not route cells 20, as shown in FIG. 10 for example. Raster data expressing the standard route area using a plurality of cells (particularly route cells 20) is stored. The data conversion unit 7 converts the raster data into vector data. The vector data expresses the standard route area, which is a closed area, using vertices and lines connecting the vertices. The data conversion unit 7 includes an outer frame cell identification unit 71 and a vector data generation unit 72. The data conversion unit 7 may also include a boundary cell identification unit 73.

<Identifying outer frame cells>
The frame cell identification unit 71 identifies at least a portion of a group of frame cells 90 from the plurality of route cells 20. The frame cells 90 are cells that constitute a first cell block 200, which is a block of route cells 20 that meets a predetermined minimum size, and that are adjacent to non-route cells 23. The first cell block 200 is a block of all cells indicated by diagonal lines in FIG. 10 .

As shown in Figure 11, the outer frame cell identification unit 71 uses a reference grid 91, which is a block of cells that meets a predetermined minimum size, to detect a first cell block 200 from multiple route cells 20. Specifically, the 3x3 reference grid 91 is moved to search for a position where the entire reference grid 91 is included in the route cell 20 (see Figure 11). The fact that the entire reference grid 91 is included in the route cell 20 means that the reference grid 91 is included in the first cell block 200 and that the first cell block 200 meets the predetermined minimum size.

Next, as shown in Figure 12, the first reference cell 92, which is a route cell 20 adjacent to the non-route cell 23, is detected in a predetermined direction using the searched reference grid 91 (part of the first cell block 200) as a reference. The first reference cell 92 is also an outer frame cell 90. In this embodiment, the predetermined direction is the left direction, but it can be changed to any direction, such as the right direction, upward direction, or downward direction.

Next, as shown in FIG. 10, at least some of the corners of the group of outer frame cells 90 are identified along the rotation direction from the first reference cell 92. In this embodiment, the rotation direction is set to counterclockwise, and route cells 20 adjacent to the non-route cell 23 on the left side of the traveling direction are searched for as outer frame cells 90. In this case, it is not necessary to search all of the outer frame cells 90; it is sufficient to detect the cells that make up the corners of the outer frame cells 90. When the ship returns to the first reference cell 92 after rotating counterclockwise, the search for outer frame cells 90 ends. Note that in this embodiment, the rotation direction is counterclockwise, but this is not limited to this and may be clockwise. In this case, route cells 20 adjacent to the non-route cell 23 on the right side of the traveling direction are searched for as outer frame cells 90. FIG. 10 does not show all of the outer frame cells 90. Furthermore, the illustrated outer frame cells 90 include both corner cells and non-corner cells.

<Identifying Boundary Cells>
13 , when an unnavigable position P1 is set, the boundary cell identification unit 73 identifies at least a part of the group of boundary cells 93 based on the preset unnavigable position P1. The boundary cells 93 are cells that constitute a block (second cell block 201) of non-route cells 23 surrounded by the group of outer frame cells 90 and are adjacent to the first cell block 200.

Specifically, as shown in Figure 14, the boundary cell identification unit 73 detects a second reference cell 94, which is a non-route cell 23 adjacent to the route cell 20, in a predetermined direction based on the unnavigable position P1. In this embodiment, the predetermined direction is the leftward direction, but it can be changed to any direction, such as the rightward direction, upward direction, or downward direction.

Next, as shown in Figure 13, at least some of the corners of the group of boundary cells 93 are identified along the rotation direction from the second reference cell 94. In this embodiment, the rotation direction is set to counterclockwise, and the non-route cells 23 adjacent to the route cell 20 on the left side of the direction of travel are searched for as boundary cells 93. In this case, it is not necessary to search all of the boundary cells 93; it is sufficient to detect the cells that make up the corners of the boundary cells 93. When the rotation returns to the second reference cell 94 after rotating counterclockwise, the search for boundary cells 93 ends. Note that in this embodiment, the rotation direction is counterclockwise, but this is not limited to this and it may be clockwise.

As shown in Figure 15, a predetermined range Ar2 is set along with the unnavigable position P1. In this embodiment, the range Ar2 is circular, but the shape can be changed as appropriate. If the corners of the identified boundary cells 93 deviate from the predetermined range Ar2, the boundary cell identification unit 73 does not identify a group of boundary cells 93. In other words, if the corners of the identified boundary cells 93 deviate from the predetermined range Ar2, it is determined that there is no hollow cluster of boundary cells 93.

<Generating vector data>
As shown in Figure 16, the vector data generation unit 72 generates vector data of a closed area using the vertices of the outer frame cell 90 and the lines L2 connecting the vertices. When a boundary cell 93 is identified, the vector data generation unit 72 generates vector data of a standard route area having an inner periphery L3 within the outer periphery L2, based on the outer frame cell 90 and the boundary cell 93. In this case, as shown in Figure 17, the vector data connects the inner periphery L3 and the outer periphery L2 with two lines, and the inner periphery L3 and the outer periphery L2 are represented by a single line. In this way, standard route area data D1 represented by vector data is generated.

[Ship monitoring device 8]
As shown in FIG. 1 , a ship monitoring device 8 may be provided. The ship monitoring device 8 includes an acquisition unit 80 that acquires the standard route area data D1 (vector data) generated by the standard route generating device 1; a ship position acquisition unit 81 that acquires the detected ship position from a detection device 9 installed on land that detects the position of a ship at sea; and an alert output unit 82 that outputs an alert if the ship position acquired by the ship position acquisition unit 81 is outside the standard route area represented by the vector data. The detection device may be an AIS receiver that detects the ship's position by receiving an AIS signal, or a radar that detects the ship's position by emitting radio waves from land to a ship at sea. The alert output unit 82 only needs to output an alert, and may output the alert to a display, a speaker, or send a signal to an external computer. The acquisition unit 80 may store the standard route area data D1 and acquire it by reading the stored data, or it may acquire it from the standard route generating device 1 or external storage.
In this embodiment, the standard route area used for outputting the alert is represented by vector data, but it may also be represented by raster data.

As described above, although not particularly limited, as in this embodiment, the standard route generation device 1 may include a memory unit 10 that stores position information indicating a map 3 divided into a plurality of cells 2 by a grid and the tracks 4 of a plurality of ships, a first candidate cell identification unit (first identification unit 61 to fourth identification unit 64) that identifies a first candidate cell 24 that is a candidate for a cell representing the standard route from the plurality of cells 2 based on the position information, a determination target cell setting unit 651 that sets at least one cell from the plurality of cells including the first candidate cell 24 as a determination target cell 25, a second candidate cell identification unit 652 that identifies a determination target cell 25 whose positional relationship between the first candidate cell 24 and the determination target cell 25 meets a predetermined adjacent condition as a second candidate cell 26 that is a candidate for a cell indicating the standard route, and a standard route area generation unit 67 that generates a standard route area based on the second candidate cell 26.
In this way, a first candidate cell 24, which is a candidate for a cell indicating the standard route, is identified based on the position information indicating the tracks 4 of multiple ships. A determination target cell 25 is set from multiple cells including the first candidate cell 24. A determination target cell 25 that can be evaluated as being adjacent to the first candidate cell 24 is identified as a second candidate cell 26, and a standard route area is generated based on the narrowed-down second candidate cell 26. Therefore, since cells other than those in an adjacent state are removed, it is possible to prevent outlier cells from being included in the standard route area, making it possible to generate a standard route area with high accuracy.

Although not particularly limited, as in this embodiment, the system may further include a specific range setting unit 653 that sets a specific range Ar1 that includes multiple cells including the target cell 25, and the second candidate cell identification unit 652 may identify the target cell 25 as the second candidate cell 26 when the number of first candidate cells 24 included in the specific range Ar1 is greater than or equal to a predetermined value.
According to this configuration, for each first candidate cell 24, a determination is made as to whether it is a second candidate cell 26 or not depending on the number of other first candidate cells 24 within the specific range Ar1, thereby making it possible to provide suitable adjacent conditions.

Although not particularly limited, as in this embodiment, the second candidate cell identification unit 652 may identify the target cell 25 as the second candidate cell 26 when the number of first candidate cells 24 other than the target cell 25 included in the specific range Ar1 is greater than or equal to a predetermined value.
This configuration makes it possible to provide more appropriate adjacency conditions.

Although not particularly limited, as in this embodiment, the specific range Ar1 may include nine or more cells, with the target cell 25 as the center cell.
This configuration makes it possible to provide appropriate adjacent conditions.

Although not particularly limited, as in this embodiment, the location information may include a coordinate point 40 indicating the position of the ship, and the first candidate cell identification unit (first identification unit 61 or fourth identification unit 64) may identify a cell in which the coordinate point 40 is counted a predetermined number of times or more as the first candidate cell 24.
According to this configuration, a cell that the ship passes through many times is identified as the first candidate cell 24, thereby improving the accuracy of generating the standard route area.

Although not particularly limited, as in this embodiment, the location information may include ship identification information that identifies the ship, and the first candidate cell identification unit (second identification unit 62) may count the coordinate point of the same ship as one time if it is counted multiple times in the same cell.
According to this configuration, the route of an anchored ship includes multiple coordinate points 40 in the same cell in the position information, so that anchoring the ship can prevent it from being identified as a standard route.

Although not particularly limited, as in this embodiment, an interpolation unit (interpolation unit 66) may be provided that identifies a predetermined number or less of cells among the multiple cells 2 in the map 3 that are not second candidate cells and are sandwiched between two second candidate cells 26 (route cells 20) as second candidate cells 26 (route cells 20).
With this configuration, even if a small number of second candidate cells 26 (route cells 20) are slightly distant from the cluster of second candidate cells 26 (route cells 20), they can be merged into the cluster of second candidate cells 26 (route cells 20).

Although not particularly limited, as in this embodiment, the standard route generating device 1 may include a memory unit 10 that stores a map 3 divided into multiple cells 2 by a grid and location information and navigation information indicating the tracks 4 of multiple ships, a route cell setting unit (first identification unit 61, second identification unit 62) that sets multiple route cells 20 that represent the standard route and include a first route cell 21 and a second route cell 22 based on the location information, a line calculation unit 631 that calculates a line L1 connecting the first route cell 21 and the second route cell 22 among the tracks 4 that pass through both the first route cell 21 and the second route cell 22 on the same voyage of the same ship based on the location information and navigation information, a route interpolation unit 632 that changes cells that are not route cells 20 to route cells 20 based on the line L1, and a standard route area generating unit 67 that generates a standard route area based on the route cells 20.
In this way, a plurality of route cells 20 indicating the standard route are set based on the position information indicating the tracks 4 of a plurality of ships. The plurality of route cells 20 include a first route cell 21 and a second route cell 22 spaced apart from the first route cell 21. The tracks 4 of a plurality of ships may include tracks that do not pass through both the first route cell 21 and the second route cell 22, and tracks that pass through both the first route cell 21 and the second route cell 22. Of the tracks 4 that pass through both the first route cell 21 and the second route cell 22 on the same voyage of the same ship, a line L1 connecting the first route cell 21 and the second route cell 22 is calculated, and an interpolation process is performed to change non-route cells 23 that are not route cells 20 to route cells 20 based on this line L1. This allows the non-route cells 23 between route cells 20 to be interpolated into the route cells 20 while taking into account the actual track 4, making it possible to generate an accurate standard route area that takes into account past performance.

Although not particularly limited, as in this embodiment, the voyage information may include at least a portion of the time information corresponding to the position information and the identification code assigned to each voyage.
Time information and identification codes make it possible to determine that the tracks are from the same ship on the same voyage.

Although not particularly limited, the route interpolation unit 632 may change the cells that overlap the calculated line L1 to route cells 20, as in this embodiment.
This is a preferred embodiment.

Although not particularly limited, as in this embodiment, the line calculation unit 631 may calculate a line L1 connecting the position of the ship in the first route cell 21 and the position of the ship in the second route cell 22.
This is a preferred embodiment.

Although not particularly limited, as in this embodiment, the line calculation unit 631 may calculate a line L1 for the first route cell 21 and the second route cell 22 that are surrounded by cells that are not route cells 20.
This configuration makes it possible to interpolate route cells.

Although not particularly limited, the line L1 may be configured with at least one straight line, as in this embodiment.
This is a preferred embodiment.

Although not particularly limited, as in this embodiment, line L1 may be a single straight line connecting the first route cell 21 and the second route cell 22.

Although not particularly limited, as in this embodiment, the standard route generation device 1 may include a map 3 divided into multiple cells 2 by a grid, a memory unit 10 that stores route cells 20 representing the standard route and non-route cells 23 that are not route cells 20, an outer frame cell identification unit 71 that identifies at least a portion of a group of outer frame cells 90 from the multiple route cells 20, which are cells that constitute a first cell block 200, which is a block of route cells 20 that meets a predetermined minimum size and are adjacent to the non-route cells 23, and a vector data generation unit 72 that generates vector data of a closed area as a standard route area using the vertices of the identified outer frame cells 90 and lines connecting the vertices.
With this configuration, compared to raster data that represents the standard route area using multiple cells 2, vector data is generated that represents the standard route area, which is a closed area, using vertices and lines connecting the vertices, making it easy to determine whether the area is inside or outside the standard route area based on coordinate positions.

Although not particularly limited, as in this embodiment, the outer frame cell identification unit 71 may detect a first reference cell 92, which is a route cell 20 adjacent to a non-route cell 23 in a predetermined direction using a part of the first cell block 200 as a reference, and identify at least some of the corners of a group of outer frame cells 90 along the circumferential direction from the detected first reference cell 92.
This is a preferred embodiment.

Although not particularly limited, as in this embodiment, the first cell block 200 may be detected from multiple route cells 20 using a reference grid 91, which is a block of cells that meets a predetermined minimum size.
This configuration makes it possible to exclude route cells 20 that do not meet the size of the reference grid 91 and are, for example, outliers.

Although not particularly limited, as in this embodiment, the system may further include a boundary cell identification unit 73 that identifies at least a portion of a group of boundary cells 93, which are cells that constitute a second cell block 201, which is a block of non-route cells 23 surrounded by the identified group of outer frame cells 90, and are adjacent to the first cell block 200, based on a predetermined unnavigable position P1, and the vector data generation unit 72 generates vector data of a standard route area having an inner peripheral edge L3 within an outer peripheral edge L2 based on the identified outer frame cells 90 and the identified boundary cells 93.
This configuration makes it possible to represent the standard route area around an unnavigable position P1 such as an island.

Although not particularly limited, as in this embodiment, the boundary cell identification unit 73 may detect a second reference cell 94, which is a non-route cell 23 adjacent to the route cell 20 in a predetermined direction based on a predetermined unnavigable position P1, and identify at least some of the corners of a group of boundary cells 93 along the circumferential direction from the detected second reference cell 94.
This is a preferred embodiment.

Although not particularly limited, as in this embodiment, a predetermined range Ar2 is set along with a pre-set unnavigable position P1, and the boundary cell identification unit 73 may not identify the group of border cells 93 if some corners of the identified group of border cells 93 deviate from the predetermined range Ar2.
This configuration makes it possible to generate standard route areas appropriately even for terrain such as an inlet.

Although not particularly limited, as in this embodiment, the vector data may be such that the inner periphery L3 and the outer periphery L2 are connected by two lines, and the inner periphery L3 and the outer periphery L2 and the two lines are represented in a single stroke.
This configuration makes it possible to provide data that allows easy determination of whether a ship is inside or outside the standard route area based on its coordinate position.

Although not particularly limited, as in this embodiment, the ship monitoring device may include an acquisition unit 80 that acquires the standard route area generated by the standard route generation device 1, a ship position acquisition unit 81 that acquires the position of the ship detected from a detection device 9 that is installed on land and detects the position of the ship at sea, and an alert output unit 82 that outputs an alert when the position of the ship acquired by the ship position acquisition unit 81 is outside the standard route area.
According to this configuration, an alert is output when the ship's position deviates from the standard route area based on the performance of many ships, making it possible to provide a new service.

The program according to this embodiment is a program that causes a computer (one or more processors) to execute the above method. Furthermore, a computer-readable temporary recording medium according to this embodiment stores the above program.

Although embodiments of the present disclosure have been described above with reference to the drawings, the specific configurations should not be considered limited to these embodiments. The scope of the present disclosure is indicated not only by the description of the above embodiments but also by the claims, and further includes all modifications that are equivalent in meaning to and within the scope of the claims.

For example, the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings, can be implemented in any order, as long as the output of a previous process is not used in a subsequent process. Even if the flow in the claims, specifications, and drawings is described using terms such as "first" and "next" for convenience, this does not mean that the processes must be executed in that order.

The units 6 and 7 shown in Figure 1 are implemented by executing a specific program on a processor, but each unit may also be configured using dedicated memory or dedicated circuitry.

In the device of the above embodiment, each of the units 6 and 7 is implemented in the processor of a single computer, but each of the units 6 and 7 may be distributed and implemented on multiple computers or in the cloud. In other words, the above method may be executed on one or multiple processors.

The structures used in the above embodiments can be used in any other embodiment. For ease of explanation, Figure 1 shows components 6 and 7, but some of these components can be omitted as desired.

The specific configuration of each part is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of this disclosure.

10 Memory unit 2 Cell 21 First route cell 22 Second route cell 23 Non-route cell 24 First candidate cell 25 Determination target cell 26 Second candidate cell 651 Determination target cell setting unit 652 Second candidate cell identification unit 653 Identification range setting unit 67 Standard route area generation unit 71 Outer frame cell identification unit 72 Vector data generation unit 73 Boundary cell identification unit 8 Ship monitoring device 80 Acquisition unit 81 Ship position acquisition unit 82 Alert output unit 631 Line calculation unit 632 Route interpolation unit 66 Interpolation unit (interpolation unit)
90 Outer frame cell 93 Boundary cell Ar1 Specific range Ar2 Predetermined range L1 Line L2 Outer periphery L3 Inner periphery

Claims (8)

a storage unit that stores a map divided into a plurality of cells by a grid, position information indicating the tracks of a plurality of ships, and navigation information;
a route cell setting unit that sets a plurality of route cells that represent a standard route and include a first route cell and a second route cell based on the position information;
a line calculation unit that calculates a line connecting the first route cell and the second route cell among the tracks that pass through both the first route cell and the second route cell on the same voyage of the same ship based on the position information and the voyage information;
a route interpolation unit that changes the cells that are not route cells into route cells based on the line;
a standard route area generation unit that generates a standard route area based on the route cells;
A standard route generating device comprising: The standard route generation device described in claim 1, wherein the navigation information includes at least a portion of the time information corresponding to the position information and an identification code assigned to each voyage. A standard route generation device as described in claim 1 or claim 2, wherein the route interpolation unit changes cells that overlap the calculated line to the route cells. A standard route generation device according to any one of claims 1 to 3, wherein the line calculation unit calculates a line connecting the position of the ship within the first route cell and the position of the ship within the second route cell. A standard route generation device according to any one of claims 1 to 4, wherein the line calculation unit calculates the line for the first route cell and the second route cell that are surrounded by cells that are not route cells. A standard route generation device according to any one of claims 1 to 5, wherein the line is composed of at least one straight line. A standard route generation device as described in claim 6, wherein the line is a single straight line connecting the first route cell and the second route cell. an acquisition unit that acquires the standard route area generated by the standard route generation device according to any one of claims 1 to 7;
a ship position acquisition unit that acquires the position of the ship detected by a detection device that is installed on land and detects the position of the ship at sea;
an alert output unit that outputs an alert when the position of the ship acquired by the ship position acquisition unit is outside the standard route area;
A ship monitoring device comprising: