Navigation assistance device, navigation assistance method, and program

Abstract

[Problem] To provide a navigation assistance device capable of presenting to a user, in an easy to understand manner, the time until a risk. [Solution] This navigation assistance device comprises: a first acquisition unit that acquires first ship data including the position and velocity of a first ship; a second acquisition unit that acquires second ship data including the position and velocity of a second ship; a specification unit that specifies a risk region in which the risk of the first ship and the second ship approaching each other is greater than or equal to a predetermined value; a calculation unit that calculates the arrival time of the first ship to reach the risk region; and a display unit that displays the risk region and displays the arrival time in association with the risk region.

Description

Navigation support device, navigation support method, and program

[0001] The present invention relates to a navigation support device, a navigation support method, and a program.

[0002] Patent Document 1 discloses a collision avoidance route search device that searches for a route when a predicted collision avoidance area is present on a straight line connecting the destination and the ship itself.

[0003] Japanese Patent Application Laid-Open No. 2021-160550

[0004] Conventionally, collision risk areas such as OZT have been displayed to visualize risks around a ship, but even if users can grasp the spatial distribution of risk, it is difficult for them to accurately grasp the time remaining until the risk occurs.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its main purpose is to provide a navigation support device, a navigation support method, and a program that can present the time until risk to the user in an easy-to-understand manner.

[0006] In order to solve the above problem, a navigation assistance device according to one aspect of the present invention includes a first acquisition unit that acquires first ship data including the position and speed of a first ship, a second acquisition unit that acquires second ship data including the position and speed of a second ship, an identification unit that identifies a risk area where the risk of the first ship and the second ship approaching each other is equal to or greater than a predetermined value, a calculation unit that calculates an arrival time for the first ship to reach the risk area, and a display unit that displays the risk area in the risk area and displays the arrival time in association with the risk area. This makes it possible to present the time to risk to a user in an easy-to-understand manner.

[0007] In the above aspect, the calculation unit may calculate the arrival time to a point in the risk area that is closest to the first vessel. This makes it possible to calculate the arrival time to the point that is closest to the first vessel.

[0008] In the above aspect, the calculation unit may calculate the arrival time to a point in the risk area on a bow direction of the first vessel. This makes it possible to calculate the arrival time to a point on a bow direction of the first vessel.

[0009] In the above aspect, the system may further include a determination unit that determines a match relationship between the first vessel and the second vessel, and the calculation unit may determine a point in the risk area for calculating the arrival time based on the match relationship. This makes it possible to determine the point for calculating the arrival time based on the match relationship.

[0010] In the above aspect, the display unit may further display the type of the arrival time in the risk region, which makes it possible to display the type of arrival time.

[0011] In the above aspect, the vessel may further include a determination unit that determines whether the risk area is included in a predetermined range relative to the first vessel, and the calculation unit may calculate the arrival time to the risk area included in the predetermined range. This makes it possible to calculate the arrival time to the risk area included in the predetermined range.

[0012] In the above aspect, the predetermined range may be a range in which the distance from the first vessel or the arrival time of the first vessel is equal to or less than a predetermined distance, thereby making it possible to calculate the arrival time to a risk area included in a range equal to or less than the predetermined distance.

[0013] In the above aspect, the predetermined range may be a predetermined angular range that includes a bow direction of the first vessel. This makes it possible to calculate the arrival time to a risk area included in the predetermined angular range.

[0014] In the above aspect, the calculation unit may calculate the arrival time to a portion of the risk area that is included in the predetermined range. This makes it possible to calculate the arrival time to the portion that is included in the predetermined range.

[0015] In the above aspect, the system may further include a route acquisition unit that acquires a planned route for the first vessel, and the calculation unit may calculate the arrival time required for the first vessel to navigate the planned route and reach the risk area. This makes it possible to calculate the arrival time required for the first vessel to navigate the planned route and reach the risk area.

[0016] In the above aspect, the calculation unit may calculate the arrival time to a point on the planned route within the risk area. This makes it possible to calculate the arrival time to a point on the planned route.

[0017] In the above aspect, the identification unit may identify, as the risk area, a section of the predicted route of the second vessel where the risk of the first vessel and the second vessel approaching each other is greater than or equal to a predetermined value when the first vessel changes course in an arbitrary direction and crosses the predicted route of the second vessel. This makes it possible to identify a risk area on the predicted route of the second vessel.

[0018] Another aspect of the navigation support method of the present invention includes acquiring first ship data including the position and speed of a first ship, acquiring second ship data including the position and speed of a second ship, identifying a risk area where the risk of the first ship and the second ship approaching each other is greater than or equal to a predetermined value, calculating an arrival time for the first ship to reach the risk area, displaying the risk area and displaying the arrival time in association with the risk area. This makes it possible to present the time to risk to a user in an easy-to-understand manner.

[0019] According to another aspect of the present invention, a program causes a computer to execute the following steps: acquire first ship data including the position and speed of a first ship; acquire second ship data including the position and speed of a second ship; identify a risk area where the risk of the first ship and the second ship approaching each other is greater than or equal to a predetermined value; calculate an arrival time for the first ship to reach the risk area; and display the risk area and the arrival time in association with the risk area. This makes it possible to present the time until risk to a user in an easy-to-understand manner.

[0020] FIG. 1 is a diagram showing an example of an onboard system. FIG. 2 is a diagram showing an example of a navigation support device. FIG. 3 is a diagram showing an example of a other ship management database. FIG. 4 is a diagram showing an example of identifying a risk section. FIG. 5 is a diagram showing an example of calculating an arrival time. FIG. 6 is a diagram showing an example of calculating an arrival time. FIG. 7 is a diagram showing an example of calculating an arrival time. FIG. 8 is a diagram showing an example of calculating an arrival time. FIG. 9 is a diagram showing an example of calculating an arrival time. FIG. 10 is a diagram showing an example of calculating an arrival time. FIG. 11 is a diagram showing an example of calculating an arrival time.

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, elements similar to those described above with reference to the previous drawings will be designated by the same reference numerals, and detailed descriptions thereof may be omitted as appropriate.

[0022] 1 is a block diagram showing an example of the configuration of a shipboard system 100. The shipboard system 100 is a system installed on a ship. In the following description, the ship on which the shipboard system 100 is installed is referred to as the "own ship," and other ships are referred to as "other ships."

[0023] The shipboard system 100 includes a navigation assistance device 1, a display unit 2, a radar 3, an AIS 4, a camera 5, a GNSS receiver 6, a gyrocompass 7, an ECDIS 8, a wireless communication unit 9, and a ship maneuvering control unit 10. These devices are connected to a network N, such as a LAN, and are capable of network communication with each other.

[0024] The navigation support device 1 includes a computer including a CPU, RAM, ROM, non-volatile memory, an input / output interface, etc. The CPU of the navigation support device 1 executes information processing in accordance with a program loaded from the ROM or non-volatile memory to the RAM.

[0025] The program may be supplied via an information storage medium such as an optical disk or a memory card, or may be supplied via a communication network such as the Internet or a LAN.

[0026] The display unit 2 displays a display image generated by the navigation support device 1. The display unit 2 also displays a radar image, a camera image, an electronic nautical chart, or the like.

[0027] The display unit 2 is, for example, a display device with a touch sensor, a so-called touch panel. The touch sensor detects a position on the screen pointed to by a user's finger or the like. Alternatively, the pointed position may be input by a pointing device such as a trackball.

[0028] The radar 3 emits radio waves around the ship, receives reflected waves, and generates echo data based on the received signals. The radar 3 also identifies targets from the echo data and generates target tracking data (TT data) that indicates the position and speed of the targets.

[0029] The AIS (Automatic Identification System) 4 receives AIS data from other ships around the ship or from land-based control. Instead of AIS, a VHF Data Exchange System (VDES) may also be used. The AIS data includes the identification code, name, position, course, speed, type, length, and destination of other ships.

[0030] The camera 5 is a digital camera that captures images of the outside world from the ship and generates image data. The camera 5 is installed, for example, on the bridge of the ship, facing the bow. The camera 5 is, for example, a so-called PTZ camera that has pan / tilt and optical zoom functions.

[0031] The camera 5 may include an image recognition unit that estimates the position and type of a target, such as a ship, included in a captured image using an object detection model. The image recognition unit is not limited to the camera 5 and may be implemented in another device, such as the navigation assistance device 1.

[0032] The GNSS receiver 6 detects the ship's position based on radio waves received from the Global Navigation Satellite System (GNSS). The gyrocompass 7 detects the ship's heading. A GPS compass may be used instead of a gyrocompass.

[0033] An ECDIS (Electronic Chart Display and Information System) 8 acquires the ship's position from the GNSS receiver 6 and displays the ship's position on an electronic chart. The ECDIS 8 also displays the ship's planned route on the electronic chart. A GNSS plotter may be used instead of an ECDIS.

[0034] The wireless communication unit 9 includes wireless equipment for realizing satellite communication, and wireless equipment for realizing wireless communication using, for example, ultra-high frequency waves, very high frequency waves, short frequency waves, medium frequency waves, or medium waves.

[0035] The ship steering control unit 10 is a control device for realizing autonomous navigation, and controls the steering gear of the ship. The ship steering control unit 10 may also control the engine of the ship.

[0036] In this embodiment, the navigation support device 1 and the display unit 2 are independent devices, but this is not limiting, and the navigation support device 1 and the display unit 2 may be an integrated device.

[0037] Furthermore, although the navigation assistance device 1 is an independent device, it is not limited to this and may be integrated with another device such as the ECDIS 8. In other words, some or all of the functions of the navigation assistance device 1 may be realized by another device.

[0038] Furthermore, the display unit 2 is also an independent device, but is not limited to this. A display unit of another device such as ECDIS 8 may be used as the display unit 2 that displays the display image generated by the navigation assistance device 1.

[0039] In this embodiment, the navigation assistance device 1 is mounted on a ship, but is not limited to this. For example, it may be installed at a land-based control station and used to assist the navigation of ships under surveillance.

[0040] 2 is a block diagram showing an example of the configuration of the navigation assistance device 1. The navigation assistance device 1 includes a control unit 20. The control unit 20 is a computer including a CPU, RAM, ROM, non-volatile memory, an input / output interface, and the like.

[0041] The control unit 20 includes a ship data acquisition unit 11, another ship data acquisition unit 12, a route acquisition unit 13, a risk area identification unit 14, a display determination unit 15, an arrival time calculation unit 16, a display control unit 17, and a match relationship determination unit 18. These functional units are realized by the CPU of the control unit 20 executing information processing according to a program.

[0042] The ship data acquisition unit 11 acquires ship data including the ship's position and speed. The ship data acquisition unit 11 is an example of a first acquisition unit, the ship is an example of a first ship, and the ship data is an example of first ship data. Speed ​​is a vector quantity expressed by ship speed and course, and ship speed is a scalar quantity.

[0043] Specifically, the ship data acquisition unit 11 sequentially acquires the ship's position detected by the GNSS receiver 6 and calculates the ship's speed from the change in the ship's position over time. However, the ship's speed may be acquired from a speedometer (not shown), and the ship's course may be acquired from the gyrocompass 7.

[0044] The other ship data acquisition unit 12 acquires other ship data including the position and speed of other ships. The other ship data acquisition unit 12 is an example of a second acquisition unit, the other ship is an example of a second ship, and the other ship data is an example of second ship data. The other ship data is generated based on data detected by the radar 3, AIS 4, or camera 5 installed on the ship.

[0045] Specifically, the other ship data acquisition unit 12 sequentially acquires, as other ship data, the TT data generated by the radar 3, the AIS data received by the AIS 4, or the identification data identified from the images captured by the camera 5. The other ship data acquisition unit 12 registers the acquired other ship data in a other ship management database constructed in memory.

[0046] As shown in Figure 3, the other ship management database includes fields such as "Ship ID," "Source," "Position," "Ship Speed," and "Course." "Ship ID" is an identifier assigned to other ships. "Source" indicates whether the other ship data was generated by the radar 3, the AIS 4, or the camera 5.

[0047] "Position" indicates the position of the other ship. The position of the other ship is expressed as latitude and longitude. The position of the other ship detected by the radar 3 or the camera 5 is expressed as a relative position to the own ship, so it is converted to an absolute position using the position of the own ship detected by the GNSS receiver 6.

[0048] "Ship speed" indicates the speed of the other ship. "Course" indicates the course of the other ship. The speed and course of the other ship detected by the radar 3 or the camera 5 are estimated from the change in the position of the other ship in the image over time.

[0049] In addition, if the position of other ship data sourced from one of AIS 3, radar 4, and camera 5 is the same as or similar to the position of other ship data sourced from another one of them, the other ship data will be combined into one record as being related to a common other ship.

[0050] Returning to the explanation of Figure 2, the route acquisition unit 13 acquires the planned route of the ship. For example, the route acquisition unit 13 acquires the planned route from another device such as the ECDIS 8. This planned route is a planned route to the destination based on the navigation plan. However, the route acquisition unit 13 may also calculate an avoidance route to avoid collision with other ships as the planned route based on the ship data and other ship data.

[0051] The risk area identification unit 14 identifies a risk area where the risk of the own ship and other ships approaching each other is greater than a predetermined level based on the own ship data acquired by the own ship data acquisition unit 11 and the other ship data acquired by the other ship data acquisition unit 12.

[0052] The risk area is, for example, an OZT (Obstacle Zone by Target). Display of the risk area will be described later. The risk area is not limited to the OZT, and a PAD (Predict Area of ​​Danger) or a DAC (Dangerous Area of ​​Collision) may also be used.

[0053] 4 is a diagram showing an example of identifying a risk area. The risk area identifying unit 14 identifies, based on the predicted positions of the ship SH and the other ship OP at each time point when it is assumed that the ship SH will change course in an arbitrary direction and cross the predicted route R of the other ship OP, risk sections La and Lb of the predicted route R of the other ship OP where the risk of collision or approach between the ship SH and the other ship OP is equal to or greater than a threshold, as sections for displaying the risk area.

[0054] The calculation of the ship SH's predicted position is performed under the assumption that the ship SH will maintain its speed and change course in any direction from its current position. In other words, the ship SH is assumed to have a constant magnitude of its own ship speed vector, but to change course in any direction at a reference point in time, and to continue sailing in a constant direction from its own ship position at the reference point thereafter. Therefore, the ship SH's predicted position at each point in time exists on concentric circles centered on the ship's position at the reference point in time. The radius of the circle is expressed as the product of the elapsed time from the reference point in time and the magnitude of the ship's own ship speed vector.

[0055] The predicted position of the ship SH at each time point is represented by a plurality of concentric circles calculated for each of a plurality of discrete time points. However, the predicted position of the ship SH at each time point may be represented by a circular formula including the elapsed time from a reference time point.

[0056] In this embodiment, the predicted position of the ship SH is calculated under the assumption that the speed of the ship SH is constant, but this is not limiting and the speed of the ship SH may be treated as a variable that changes over time. In other words, as long as the predicted position of the ship SH is calculated according to the elapsed time from a reference point in time, the speed of the ship SH does not have to be constant. For example, the speed of the ship SH may gradually increase or decrease over time.

[0057] The predicted position of the other ship OP is calculated under the assumption that the other ship OP will maintain its current speed. In other words, the other ship OP is assumed to continue sailing from its current position at a reference time with the magnitude and direction of its speed vector constant. Therefore, the predicted position of the other ship OP at each time point is on a straight line extending the speed vector of the other ship that passes through the other ship's position at the reference time point.

[0058] The predicted position of the other ship OP at each time point is represented by a plurality of discrete points arranged on a line, calculated for each of a plurality of discrete time points. However, the predicted position of the other ship OP at each time point may be represented by a linear function passing through the position of the other ship at the reference time point.

[0059] In this embodiment, the predicted position of the other ship OP is calculated under the assumption that the speed of the other ship OP is constant. However, this is not limiting, and at least one of the speed and direction of the other ship OP may be treated as a variable that changes over time. In other words, as long as the predicted position of the other ship OP can be calculated based on the elapsed time from a reference point in time, the speed of the other ship OP does not have to be constant. For example, the speed of the other ship OP may gradually increase or decrease over time. Furthermore, the other ship OP may change course in a predetermined direction or turn at a predetermined ROT (Rate of Turn).

[0060] The risk area identification unit 14 calculates the separation distance between the predicted position of the ship SH and the predicted position of the other ship OP at each point in time, and calculates the risk of collision or approach based on the separation distance and the ship size. As described above, the predicted position of the ship SH at a certain point in time is represented by a circle, so the risk area identification unit 14 extracts the position closest to the predicted position of the other ship OP at the same time from the circle representing the predicted position of the ship SH at the same time, and calculates the separation distance.

[0061] The risk area identification unit 14 determines that the risk is above a threshold when, for example, the area of ​​the own ship SH or a warning area P set around the own ship SH overlaps with a point representing the predicted position of the other ship OP, and identifies multiple risk sections La, Lb where the risk is above a threshold. Hereinafter, the direction of travel of the other ship OP will also be referred to as the forward direction, and the opposite direction will also be referred to as the aft direction.

[0062] For example, of the two risk zones La, Lb, for the first risk zone La located on the aft side, the aft end LaR of the first risk zone La is the position where the forward end of the warning area P of the own ship SH abuts on the point representing the predicted position of the other ship OP. The forward end LaF of the first risk zone La is the position where the aft end of the warning area P of the own ship SH abuts on the point representing the predicted position of the other ship OP.

[0063] On the other hand, for the second risk zone Lb, which is located on the forward side of the two risk zones La, Lb, the aft end LbR of the second risk zone Lb is a position where the aft end of the warning area P of the own ship SH abuts on the point representing the predicted position of the other ship OP. The forward end LbF of the second risk zone Lb is a position where the forward end of the warning area P of the own ship SH abuts on the point representing the predicted position of the other ship OP.

[0064] The range between the first risk zone La and the second risk zone Lb is the range in which the ship SH crosses ahead of the other ship OP. On the other hand, the range aft of the first risk zone La and the range forward of the second risk zone Lb are the range in which the ship SH crosses behind the other ship OP. When the ship SH crosses ahead of the other ship OP, more caution is required than when the ship SH crosses behind the other ship OP.

[0065] Without being limited to this, the risk area identification unit 14 may determine that the risk is above a threshold value, for example, when the alert area P set in the area of ​​the own ship SH or around the own ship SH overlaps with the alert area P set in the area of ​​the other ship OP or around the other ship OP. Furthermore, the risk area identification unit 14 may determine that the risk is above a threshold value, for example, when the separation distance between a point representing the predicted position of the own ship SH and a point representing the predicted position of the other ship OP is below a threshold value.

[0066] In this embodiment, the risk of collision or approach is calculated based on distance, such as the separation distance between the predicted position of the ship SH and the predicted position of the other ship OP. However, this is not limited to this, and the risk of collision or approach may also be calculated based on time, such as the approach time until the ship SH and the other ship OP are closest to each other, or the arrival time until the ship SH reaches the predicted position of the other ship OP.

[0067] Returning to the explanation of Figure 2, the display determination unit 15 determines whether the risk zone identified by the risk area identification unit 14 is included in a predetermined range based on the ship. This predetermined range is a range for determining whether or not to display the arrival time, which will be described later.

[0068] The arrival time calculation unit 16 calculates the arrival time required for the own ship to reach the risk zone based on the own ship data acquired by the own ship data acquisition unit 11 and the other ship data acquired by the other ship data acquisition unit 12.

[0069] The display control unit 17 displays risk areas such as OZT in the risk zone identified by the risk area identification unit 14 on the image output to the display unit 2, and also displays the arrival time calculated by the arrival time calculation unit 16 in association with the risk area.

[0070] The meeting relationship determination unit 18 determines the meeting relationship between the own ship and other ships based on the own ship data acquired by the own ship data acquisition unit 11 and the other ship data acquired by the other ship data acquisition unit 12. Specifically, the meeting relationship determination unit 18 calculates the course difference between the own ship and other ships, and classifies the meeting relationship based on the position and course difference of the other ship relative to the own ship. Meeting relationships include a crossing relationship, a crossing relationship, and an overtaking relationship.

[0071] 5 to 8 are diagrams for explaining the determination of a risk section by the display determination unit 15 and the calculation of the arrival time by the arrival time calculation unit 16. Figs. 9 and 10 are diagrams showing examples of an image MG displayed on the display unit 2 by the display control unit 17. Fig. 9 corresponds to Fig. 5, and Fig. 10 corresponds to Fig. 8.

[0072] 5, the display determination unit 15 determines whether the risk zones L1 and L2 related to the other ships OP1 and OP2 are included in a predetermined range DA based on the own ship SH. In the example shown in the figure, the risk zone L1 is within the predetermined range DA, and the risk zone L2 is outside the predetermined range DA.

[0073] The predetermined range DA is, for example, a range in which the distance from the ship SH or the arrival time of the ship SH is equal to or less than a predetermined value, and is a predetermined angular range that includes the bow direction HD of the ship SH. In other words, the predetermined range DA is a sector-shaped range centered on the bow direction HD of the ship SH.

[0074] The predetermined range DA corresponds to a range that requires attention when the ship SH is navigating. Note that the predetermined range DA may be a range within which the distance from the ship SH or the arrival time of the ship SH is within a predetermined range, or a predetermined angle range including the bow direction HD of the ship SH.

[0075] The arrival time calculation unit 16 calculates the arrival time AT to the risk zone L1 included in the predetermined range DA. Specifically, the arrival time calculation unit 16 calculates the arrival time AT to a point Lp selected from the risk zone L1.

[0076] The point Lp for calculating the arrival time AT may be the point in the risk section L1 that is closest to the ship SH, or may be a point in the bow direction HD of the ship SH. In the example of Figure 5, the point Lp is the point that is closest to the ship SH and is also a point in the bow direction HD of the ship SH.

[0077] The time taken for the ship SH to reach a point on the bow direction HD is the so-called bow crossing time (BCT). Alternatively, the time to closest point of approach (TCPA) may be used as the time taken for the ship SH to reach the risk section L1.

[0078] As shown in Figure 6, when another ship OP crosses the bow direction HD of the first ship SH diagonally, the point closest to the first ship SH may not coincide with the point on the bow direction HD of the first ship SH. In this case, the point Lp for calculating the arrival time AT is, for example, the point closest to the first ship SH.

[0079] As shown in Figure 7, there may be cases where part of the risk section L is within the specified range DA and the rest is outside the specified range DA, in which case the point Lp for calculating the arrival time AT is selected from the part Lm of the risk section L within the specified range DA.

[0080] 9, the display control unit 17 displays an image MG that shows the positional relationship between the host ship SH and the other ships OP1 and OP2. In the image MG, symbols representing the host ship SH and the other ships OP1 and OP2 are arranged at positions within the image that correspond to their actual positions.

[0081] The display control unit 17 also displays risk areas OZ1 and OZ2 in the risk zones L1 and L2 related to the other ships OP1 and OP2. The risk areas OZ1 and OZ2 are, for example, areas of a predetermined width centered on the risk zones L1 and L2.

[0082] Furthermore, the display control unit 17 displays a character string JT representing the arrival time for the risk zone L1 within the predetermined range DA (see FIG. 5) in association with the risk area OZ1.

[0083] Specifically, the character string JT representing the arrival time is displayed, for example, inside or near the risk area OZ1, particularly near the point Lp1 at which the arrival time is calculated, making it easier to visually grasp the relationship between the character string JT representing the arrival time and the risk area OZ1.

[0084] 8, the arrival time calculation unit 16 may calculate the arrival time required for the own ship SH to navigate the planned route SR and reach the risk sections L1 and L2. The arrival time calculation unit 16 calculates the arrival time to points Lp1 and Lp2 on the planned route SR within the risk sections L1 and L2.

[0085] As shown in Figure 10, the display control unit 17 displays risk areas OZ1 and OZ2 in risk sections L1 and L2 on the planned route SR of the ship SH, and also displays strings JT1 and JT2 representing the arrival time in association with the risk areas OZ1 and OZ2.

[0086] As mentioned above, the risk section L is calculated under the assumption that the ship SH will change course in any direction from its current position and navigate in a straight line, so when the ship SH navigates along the planned route SR, the risk section L may deviate from the actual risk.

[0087] Therefore, when the ship SH is sailing along the planned route SR, it is preferable to calculate the risk section L using the method shown in FIG. 11 and described below.

[0088] The planned route SR includes multiple legs LG. The legs LG are a collective term for the first leg LG1 to the third leg LG3, etc. Specifically, the planned route SR includes the first leg LG1 from the current position of the ship SH to the first waypoint WP1, the second leg LG2 from the first waypoint WP1 to the second waypoint WP2, and the third leg LG3 from the second waypoint WP2 to the third waypoint (not shown).

[0089] The risk area identification unit 14 sets a virtual leg VLG corresponding to each leg LG, places a virtual own ship VS in the virtual leg VLG, and calculates a risk section L for each leg LG. The virtual leg VLG is a general term for the virtual first leg VLG1 to the virtual second leg VLG2, etc. The virtual own ship VS is a general term for the virtual first own ship VS1 to the virtual second own ship VS2, etc. The other ship OP is a general term for the other ships OP1-OP3. The risk section L is a general term for the risk sections L1-L3.

[0090] Specifically, for the first leg LG1, the risk area identification unit 14 calculates the risk section L between the own ship SH and the other ship OP during the period when the own ship SH is navigating the first leg LG1, as described above in Fig. 4. In the example of Fig. 11, the risk section L1 of the other ship OP1 is identified in relation to the first leg LG1.

[0091] Furthermore, for the second leg LG2, the risk area identification unit 14 sets a virtual first leg VLG1 extending from the first waypoint WP1 in the opposite direction to the second leg LG2, places the virtual first own ship VS1 on the virtual first leg VLG1, and calculates the risk section L between the other ship OP and the virtual first own ship VS1 during the period when the virtual first own ship VS1 navigates the second leg LG2. In the example of Figure 11, the risk section L2 of the other ship OP2 is identified in relation to the second leg LG2.

[0092] The virtual first leg VLG1 is aligned with the second leg LG2 and has the same length d1 as the length d1 of the first leg LG1. The virtual first own ship VS1 is located at the end of the virtual first leg VLG1 opposite the first waypoint WP1.

[0093] Furthermore, for the third leg LG3, the risk area identification unit 14 sets a virtual second leg VLG2 extending from the second waypoint WP1 in the opposite direction to the third leg LG3, places the virtual own ship VS2 on the virtual second leg VLG2, and calculates the risk section L between the virtual own ship VS2 and the other ship OP during the period when the virtual own ship VS2 is navigating the third leg LG3. In the example of Figure 11, the risk section L3 of the other ship OP3 is identified in relation to the third leg LG3.

[0094] The virtual second leg VLG2 is aligned in a straight line with the third leg LG3 and has a length d2 equal to the total length d2 of the first leg LG1 and the second leg LG2. The virtual second own ship VS2 is located at the end of the virtual second leg VLG2 opposite the second waypoint WP2.

[0095] The risk area identification unit 14 calculates the risk section L when the ship SH is navigating the planned route SR by calculating the risk section for all legs LG included in the planned route SR using the method described above.

[0096] 13 and 14 are diagrams for explaining modified examples of calculation of arrival time. The arrival time calculation unit 16 may determine the point Lp for calculating the arrival time AT in the risk section L according to the meeting relationship between the own ship SH and the other ship OP determined by the meeting relationship determination unit 18.

[0097] For example, as shown in Figure 13, when another ship OP is in a crossing relationship with the bow line HD of the own ship SH, the point Lp for calculating the arrival time AT is determined as a point on the bow line HD of the own ship SH within the risk section L. In other words, the arrival time AT is BCT.

[0098] On the other hand, as shown in Figure 14, when the other ship OP is in an overtaking relationship with the ship SH, the point Lp for calculating the arrival time AT is determined as the point where the other ship OP overtakes the ship SH, i.e., the point where the other ship OP passes the beam line PS of the ship SH.

[0099] The main beam line PS is a line that intersects the bow line HD at right angles and is, for example, a line that passes through the center of the own ship SH. However, the main beam line PS may be set to pass through the bow, stern, or bridge of the own ship SH.

[0100] 15 to 17 are diagrams for explaining modified examples of the image MG displayed on the display unit 2. The display control unit 17 may further display the type of point Lp for calculating the arrival time within the risk area OZ.

[0101] Specifically, the display control unit 17 displays a character string JT representing the arrival time and a character string MT representing the type of arrival time in association with the risk area OZ. Note that the character string is not limited to a character string, and may be a symbol representing the type of arrival time.

[0102] For example, as shown in Figure 15, when the point Lp for calculating the arrival time is on the bow line HD of the ship SH (see Figure 13), the string MT indicating that the arrival time is BCT is displayed on the risk area OZ.

[0103] Also, as shown in Figure 16, if the point Lp for calculating the arrival time is located at the position where the ship SH and the other ship OP are closest to each other, the string MT indicating that the arrival time is TCPA is displayed on the risk area OZ.

[0104] Furthermore, as shown in Figure 17, when the point Lp for calculating the arrival time is on the main beam line PS of the own ship SH (see Figure 14), a character string MT indicating that the arrival time is the time to the point where the main beam line is crossed is displayed on the risk area OZ.

[0105] 12 is a diagram showing an example of the procedure of the navigation support method implemented in the navigation support device 1. The control unit 20 of the navigation support device 1 executes the information processing shown in the diagram in accordance with a program.

[0106] First, the control unit 20 acquires own ship data indicating the position and speed of the own ship SH from the GNSS receiver 6 or the like (S11, processing as the own ship data acquisition unit 11).

[0107] Next, the control unit 20 acquires other ship data indicating the position and speed of the other ship OP from the radar 3, the AIS 4, or the camera 5 (S12, processing as the other ship data acquisition unit 12).

[0108] Next, the control unit 20 acquires the planned route SR of the ship SH from the ECDIS 8 or the like (S13, processing as the route acquisition unit 13).

[0109] Next, the control unit 20 identifies a risk section L where the risk of the ship SH approaching the other ship OP is greater than a predetermined level in order to display the risk area OZ (S14, processing as the risk area identification unit 14, see Figure 4).

[0110] Next, the control unit 20 determines whether the identified risk section L is included in a predetermined range DA based on the own ship SH (S15, processing as the display determination unit 15, see Figures 5 to 7).

[0111] If the risk section L is included in the specified range DA (S15: YES), the control unit 20 calculates the arrival time required for the ship SH to reach the risk section L (S16, processing as the arrival time calculation unit 16, see Figures 5 to 7).

[0112] On the other hand, if the risk section L is not included in the predetermined range DA (S15: NO), the control unit 20 does not calculate the arrival time.

[0113] The control unit 20 performs the above-described processing of S14 to S16 for all other ships OP (S17).

[0114] Next, the control unit 20 displays an image MG including the risk area OZ1 and a character string JT representing the arrival time on the display unit 2 (S18, processing as the display control unit 17, see FIGS. 9 and 10).

[0115] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made by those skilled in the art.

[0116] Representative embodiments of the present invention will be listed below.

[0117] (1) A navigation assistance device comprising: a first acquisition unit that acquires first ship data including the position and speed of a first ship; a second acquisition unit that acquires second ship data including the position and speed of a second ship; an identification unit that identifies a risk area where the risk of the first ship and the second ship approaching each other is greater than or equal to a predetermined value; a calculation unit that calculates the arrival time for the first ship to reach the risk area; and a display unit that displays the risk area and displays the arrival time in association with the risk area.

[0118] (2) The navigation support device according to (1), wherein the calculation unit calculates the arrival time to a point in the risk area that is closest to the first ship.

[0119] (3) The navigation support device according to (1), wherein the calculation unit calculates the arrival time to a point in the risk area in the bow direction of the first vessel.

[0120] (4) A navigation support device described in any of (1) to (3), further comprising a determination unit that determines the match relationship between the first vessel and the second vessel, and the calculation unit determines a point in the risk area for calculating the arrival time based on the match relationship.

[0121] (5) The navigation support device according to any one of (1) to (4), wherein the display unit further displays the type of the arrival time within the risk area.

[0122] (6) A navigation support device described in any of (1) to (5), further comprising a determination unit that determines whether the risk area is included in a predetermined range based on the first ship, and the calculation unit calculates the arrival time to the risk area included in the predetermined range.

[0123] (7) The navigation support device according to (6), wherein the predetermined range is a range in which the distance from the first vessel or the arrival time of the first vessel is equal to or less than a predetermined range.

[0124] (8) The navigation support device according to (6) or (7), wherein the predetermined range is a predetermined angle range that includes a bow direction of the first vessel.

[0125] (9) The navigation support device according to any one of (6) to (8), wherein the calculation unit calculates the arrival time to a portion of the risk area that is included in the predetermined range.

[0126] (10) A navigation support device described in any of (1) to (9), further comprising a route acquisition unit that acquires a planned route of the first vessel, and the calculation unit calculates the arrival time required for the first vessel to navigate the planned route and reach the risk area.

[0127] (11) The navigation support device according to (10), wherein the calculation unit calculates the arrival time to a point on the planned route within the risk area.

[0128] (12) A navigation support device described in any of (1) to (11), wherein the identification unit identifies as the risk area a section of the predicted route of the second ship where the risk of the first ship and the second ship approaching each other is greater than or equal to a predetermined level, when it is assumed that the first ship changes course in an arbitrary direction and crosses the predicted route of the second ship.

[0129] (13) A navigation support method comprising: acquiring first ship data including the position and speed of a first ship; acquiring second ship data including the position and speed of a second ship; identifying a risk area where the risk of the first ship and the second ship approaching each other is greater than or equal to a predetermined value; calculating the arrival time for the first ship to reach the risk area; displaying the risk area and displaying the arrival time in association with the risk area.

[0130] (14) A program for causing a computer to execute the following steps: acquiring first ship data including the position and speed of a first ship; acquiring second ship data including the position and speed of a second ship; identifying a risk area where the risk of the first ship and the second ship approaching each other is greater than a predetermined value; calculating the arrival time for the first ship to reach the risk area; and displaying the risk area and displaying the arrival time in association with the risk area. term

[0131] Not necessarily all objects or advantages may be achieved in accordance with any particular embodiment described herein. Thus, for example, one skilled in the art will appreciate that a particular embodiment may be configured to operate to achieve or optimize one or more advantages as taught herein without necessarily achieving other objects or advantages as taught or suggested herein.

[0132] All processes described herein may be embodied and fully automated by software code modules executed by a computing system including one or more computers or processors. The code modules may be stored on any type of non-transitory computer-readable medium or other computer storage device. Some or all of the methods may be embodied in dedicated computer hardware.

[0133] Many other variations beyond those described herein will be apparent from this disclosure. For example, depending on the embodiment, certain operations, events, or functions of any of the algorithms described herein may be performed in a different sequence, added, merged, or omitted entirely (e.g., not all described acts or events are necessary to execute an algorithm). Furthermore, in certain embodiments, operations or events may be performed in parallel rather than sequentially, e.g., via multithreading, interrupt processing, or multiple processors or processor cores, or on other parallel architectures. Furthermore, different tasks or processes may be performed by different machines and / or computing systems that may function together.

[0134] The various illustrative logical blocks and modules described in connection with the embodiments disclosed herein may be implemented or executed by a machine such as a processor. The processor may be a microprocessor, but alternatively, the processor may be a controller, microcontroller, or state machine, or a combination thereof. The processor may include electrical circuitry configured to process computer-executable instructions. In another embodiment, the processor includes an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable device that performs logical operations without processing computer-executable instructions. A processor may also be implemented as a combination of computing devices, such as a combination of a digital signal processor (DSP) and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration. Although described herein primarily with reference to digital technology, a processor may also include primarily analog elements. For example, some or all of the signal processing algorithms described herein may be implemented by analog circuitry or mixed analog and digital circuitry. The computing environment can include any type of computer system, including, but not limited to, a microprocessor, mainframe computer, digital signal processor, portable computing device, device controller, or computer system based on a computational engine within an appliance.

[0135] Unless otherwise specified, conditional language such as "can," "could," "would," or "potential" is understood within the context in which it is generally used to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not. Thus, such conditional language does not generally imply that features, elements, and / or steps are required in any manner in one or more embodiments, or that one or more embodiments necessarily include logic for determining whether those features, elements, and / or steps are included in or performed in any particular embodiment.

[0136] Disjunctive language such as "at least one of X, Y, Z," unless specifically stated otherwise, is understood in its general context to indicate that an item, term, etc. can be either X, Y, Z, or any combination thereof (e.g., X, Y, Z). Thus, such disjunctive language does not generally imply that a particular embodiment requires at least one of X, at least one of Y, or at least one of Z, respectively, to be present.

[0137] Any process descriptions, elements, or blocks in the flow diagrams described herein and / or illustrated in the accompanying drawings should be understood as potentially representing modules, segments, or portions of code, comprising one or more executable instructions for implementing a particular logical function or element in the process. Alternative embodiments are included within the scope of the embodiments described herein, in which elements or functions may be performed out of order, substantially simultaneously, or in reverse order from that shown or described, depending on the functionality involved, as will be understood by those skilled in the art.

[0138] Unless otherwise expressly stated, numeral terms such as "one" should generally be construed to include one or more described items. Thus, phrases such as "one device configured to" are intended to include one or more listed devices. Such one or more listed devices may also be collectively configured to perform the recited reference. For example, "a processor configured to perform the following A, B, and C" may include a first processor configured to perform A and a second processor configured to perform B and C. Additionally, even if a specific number of enumerations of the introduced embodiments are explicitly recited, those skilled in the art should construe such enumerations to typically mean at least the recited number (e.g., the mere enumeration of "two enumerations" without other modifiers typically means at least two enumerations, or two or more enumerations).

[0139] In general, it will be appreciated by those skilled in the art that the terms used herein generally intend "non-limiting" terms (e.g., the term "including" should be interpreted as "including but not limited to at least," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including, but not limited to," etc.).

[0140] For purposes of description, the term "horizontal" as used herein is defined as a plane parallel to the plane or surface of the floor of the area in which the described system is used or the plane in which the described method is performed, regardless of its orientation. The term "floor" can be interchanged with the terms "ground" or "water surface." The term "vertical / plumb" refers to a direction perpendicular / vertical to a defined horizontal line. Terms such as "upper," "lower," "below," "top," "side," "higher," "lower," "above," "over," "below," etc. are defined relative to the horizontal plane.

[0141] As used herein, the terms "attach," "connect," "mate," and other related terms, unless otherwise noted, should be interpreted to include detachable, movable, fixed, adjustable, and / or removable connections or couplings. Connections / couplings include direct connections and / or connections with intermediate structures between the two components described.

[0142] Unless otherwise expressly stated, as used herein, numbers preceded by terms such as "approximately," "about," and "substantially" are inclusive of the recited number and also refer to an amount close to the recited amount that performs the desired function or achieves the desired result. For example, "approximately," "about," and "substantially" refer to values ​​less than 10% of the recited numerical value, unless otherwise expressly stated. As used herein, features of the disclosed embodiments preceded by terms such as "approximately," "about," and "substantially" refer to features that have some variability that also perform the desired function or achieve the desired result for that feature.

[0143] Many variations and modifications may be made to the above-described embodiments, and these elements should be understood to be among other acceptable examples. All such modifications and variations are intended to be included within the scope of this disclosure and are protected by the following claims.

[0144] DESCRIPTION OF SYMBOLS 1 Navigation support device, 2 Display unit, 3 Radar, 4 AIS, 5 Camera, 6 GNSS receiver, 7 Gyrocompass, 8 ECDIS, 9 Wireless communication unit, 10 Ship maneuvering control unit, 20 Control unit, 11 Own ship data acquisition unit (example of first acquisition unit), 12 Other ship data acquisition unit (example of second acquisition unit), 13 Route acquisition unit, 14 Risk area identification unit, 15 Display determination unit, 16 Arrival time calculation unit, 17 Display control unit, 18 Matching relationship determination unit, 100 Shipboard system

Claims

1. A navigation support device comprising: a first acquisition unit that acquires first ship data including the position and speed of a first ship; a second acquisition unit that acquires second ship data including the position and speed of a second ship; an identification unit that identifies a risk area where the risk of the first ship and the second ship approaching each other is greater than a predetermined value; a calculation unit that calculates an arrival time for the first ship to reach the risk area; and a display unit that displays the risk area and displays the arrival time in association with the risk area.

2. A navigation support device as described in claim 1, wherein the calculation unit calculates the arrival time to a point in the risk area that is closest to the first ship.

3. A navigation support device as described in claim 1, wherein the calculation unit calculates the arrival time to a point in the risk area in the bow direction of the first ship.

4. A navigation support device as described in claim 1, further comprising a determination unit that determines a match relationship between the first ship and the second ship, and the calculation unit determines a point within the risk area for calculating the arrival time in accordance with the match relationship.

5. The navigation support device according to claim 1, wherein the display unit further displays the type of the arrival time within the risk area.

6. A navigation support device as described in claim 1, further comprising a judgment unit that judges whether the risk area is included in a specified range based on the first ship, and the calculation unit calculates the arrival time to the risk area included in the specified range.

7. A navigation support device as described in claim 6, wherein the specified range is a range in which the distance from the first ship or the arrival time of the first ship is less than a specified value.

8. A navigation support device as described in claim 6, wherein the predetermined range is a predetermined angle range that includes the bow direction of the first vessel.

9. The navigation support device according to claim 6, wherein the calculation unit calculates the arrival time to a portion of the risk area that is included in the predetermined range.

10. A navigation support device as described in claim 1, further comprising a route acquisition unit that acquires a planned route for the first ship, wherein the calculation unit calculates the arrival time required for the first ship to navigate the planned route and reach the risk area.

11. The navigation support device according to claim 10, wherein the calculation unit calculates the arrival time to a point on the planned route within the risk area.

12. The navigation support device described in claim 1, wherein the identification unit identifies as the risk area a section of the predicted route of the second ship where there is a predetermined or greater risk of the first ship and the second ship approaching each other, when it is assumed that the first ship changes course in an arbitrary direction and crosses the predicted route of the second ship.

13. A navigation support method comprising: acquiring first ship data including a position and speed of a first ship; acquiring second ship data including a position and speed of a second ship; identifying a risk area where the risk of the first ship and the second ship approaching each other is greater than or equal to a predetermined value; calculating an arrival time for the first ship to reach the risk area; displaying the risk area and displaying the arrival time in relation to the risk area.

14. A program for causing a computer to execute the following steps: acquiring first ship data including the position and speed of a first ship; acquiring second ship data including the position and speed of a second ship; identifying a risk area where the risk of the first ship and the second ship approaching each other is greater than or equal to a predetermined value; calculating the arrival time for the first ship to reach the risk area; and displaying the risk area and displaying the arrival time in association with the risk area.