Ship monitoring device, ship monitoring method, and program

Abstract

The present invention provides a ship monitoring device that makes it easy to determine whether a ship is passing in front of or behind another ship. [Solution] The ship monitoring device includes a first data acquisition unit that acquires first ship data representing the position and speed of a first ship, a second data acquisition unit that acquires second ship data representing the position and speed of a second ship, a risk range identification unit that identifies a first range and a second range located away from the first range in the direction of travel of the second ship, assuming that the first ship changes course in any direction and crosses the predicted course of the second ship, based on the first and second ship data, where the risk of collision between the first and second ships is greater than a predetermined amount, and a display control unit that displays a first collision risk area including the first range and a second collision risk area including the second range on the predicted course of the second ship in an image showing the positions of the first and second ships, and displays the end of the first collision risk area on the second range side and the end of the second collision risk area on the first range side separately from the remaining end.

Description

Technical Field

[0001] The present invention relates to a ship monitoring device, a ship monitoring method, and a program.

Background Art

[0002] Conventionally, there are various methods for evaluating the risk of ships colliding with each other. For example, Non-Patent Document 1 discloses a method of displaying OZT (Obstacle Zone by Target).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the method of displaying a collision risk area such as OZT, the range where the collision risk area in the predicted course of the other ship is not displayed is the range where the own ship can navigate. However, it is difficult to grasp whether the own ship will pass in front of or behind the other ship just by a casual look.

[0005] The present invention has been made in view of the above problems, and its main object is to provide a ship monitoring device, a ship monitoring method, and a program that can easily grasp whether the own ship will pass in front of or behind the other ship.

Means for Solving the Problems

[0006] To solve the above problems, a ship monitoring device according to one aspect of the present invention includes: a first data acquisition unit that acquires first ship data representing the position and speed of a first ship; a second data acquisition unit that acquires second ship data representing the position and speed of a second ship; a risk range identification unit that identifies a first range and a second range located away from the first range in the direction of travel of the second ship, based on the first and second ship data, assuming that the first ship changes course in any direction and crosses the predicted course of the second ship; and a display control unit that displays a first collision risk area including the first range and a second collision risk area including the second range on the predicted course of the second ship in an image showing the positions of the first and second ships, and displays the end of the first collision risk area on the second range side and the end of the second collision risk area on the first range side separately from the remaining end. According to this, the ends of the two collision risk areas that enclose the area in which the first vessel passes in front of the second vessel are displayed separately from the remaining ends, making it easy to determine whether the first vessel is passing in front of or behind the second vessel.

[0007] In the above embodiment, the display control unit may make the shape of the end of the first collision risk area on the second range side and the end of the second collision risk area on the first range side different from the shape of the remaining end. This makes it easier to determine whether the first vessel is passing in front of or behind the second vessel based on the shape of the end of the collision risk area.

[0008] In the above embodiment, the end of the first collision risk area on the second range side and the end of the second collision risk area on the first range side may have a shape that indicates the direction of travel of the second vessel. This makes it easier to determine the direction of travel of the second vessel.

[0009] In the above embodiment, the end of the first collision risk area on the second range side may have a shape that protrudes in the direction of travel of the second vessel. This makes it easier to determine the direction of travel of the second vessel.

[0010] In the above embodiment, the end of the second collision risk area on the first range side may have a shape that is recessed in the direction of travel of the second vessel. This makes it easier to determine the direction of travel of the second vessel.

[0011] In the above embodiment, the end of the first collision risk area opposite to the second range and the end of the second collision risk area opposite to the first range may have a semicircular shape. This makes it easier to identify whether the first vessel is passing in front of or behind the second vessel.

[0012] In the above embodiment, the display control unit may add marks of a predetermined shape to the end of the first collision risk area on the second range side and to the end of the second collision risk area on the first range side. This makes it easy to determine whether the first vessel is passing in front of or behind the second vessel by the marks added to the ends of the collision risk areas.

[0013] In the above embodiment, the display control unit may add marks in a shape indicating the direction of travel of the second vessel to the ends of the first and second collision risk areas on the side facing the direction of travel of the second vessel. This makes it easier to determine the direction of travel of the second vessel.

[0014] In the above embodiment, the display control unit may change the number or shape of the marks according to the speed of the second vessel. This makes it easier to determine the speed of the second vessel.

[0015] In the above embodiment, the first data may include the position of the first vessel as detected by a GNSS (Global Navigation Satellite System) receiver installed on the first vessel. The second data may also include the position and speed of the second vessel as detected by a radar installed on the first vessel. The second data may also include the position and speed of the second vessel as detected by an AIS (Automatic Identification System) installed on the first vessel.

[0016] Furthermore, in another aspect of the present invention, a ship monitoring method involves a first data generation unit acquiring first ship data representing the position and speed of a first ship, a second data generation unit acquiring second ship data representing the position and speed of a second ship, and, based on the first and second ship data, identifying a first range and a second range located away from the first range in the direction of travel of the second ship, where the risk of collision between the first and second ships is greater than or equal to a predetermined value, assuming that the first ship changes course in any direction and crosses the predicted course of the second ship, using a display unit to display a first collision risk area including the first range and a second collision risk area including the second range on the predicted course of the second ship in an image showing the positions of the first and second ships, and displaying the end of the first collision risk area on the second range side and the end of the second collision risk area on the first range side separately from the remaining end. According to this, the ends of the two collision risk areas that enclose the area in which the first vessel passes in front of the second vessel are displayed separately from the remaining ends, making it easy to determine whether the first vessel is passing in front of or behind the second vessel.

[0017] Also, a program according to another aspect of the present invention includes acquiring first ship data representing the position and speed of a first ship, acquiring second ship data representing the position and speed of a second ship, and based on the first ship data and the second ship data, when it is assumed that the first ship changes course in an arbitrary direction and crosses the predicted course of the second ship, identifying a first range in the predicted course of the second ship where the risk of collision between the first ship and the second ship becomes a predetermined value or more and a second range that is away from the traveling direction of the second ship from the first range, and displaying a first collision risk area including the first range and a second collision risk area including the second range on the predicted course of the second ship in an image showing the positions of the first ship and the second ship, and displaying the end on the second range side of the first collision risk area and the end on the first range side of the second collision risk area separately from the remaining ends. According to this, since the ends of the two collision risk areas sandwiching the range where the first ship passes in front of the second ship are displayed separately from the remaining ends, it becomes easy to grasp whether the first ship passes in front of or behind the second ship.

Brief Description of the Drawings

[0018] [Figure 1] It is a diagram showing a configuration example of a ship monitoring system. [Figure 2] It is a diagram showing an example of an other ship management database. [Figure 3] It is a diagram showing a configuration example of a ship monitoring device. [Figure 4] It is a diagram showing a calculation example of a collision risk. [Figure 5] It is a diagram showing an example of a display image. [Figure 6] It is a diagram showing an example of a display image. [Figure 7] It is a diagram showing an example of a display image. [Figure 8] It is a diagram showing an example of a display image. [Figure 9] It is a diagram showing an example of a display image. [Figure 10] It is a diagram showing an example of a display image. [Figure 11] This is a diagram showing an example of an image.

Embodiment for Carrying out the Invention

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0020] FIG. 1 is a block diagram showing a configuration example of a ship monitoring system 100. The ship monitoring method is realized in the ship monitoring system 100. The ship monitoring system 100 is a system mounted on a ship for monitoring ships existing around it.

[0021] The ship on which the ship monitoring system 100 is mounted is an example of a first ship and is referred to as "own ship" in the following description. Also, the ships existing around the own ship are examples of second ships and are referred to as "other ships" in the following description.

[0022] Also, in the following description, "speed" is assumed to be a vector quantity (so-called ship speed vector) representing speed and direction, and "speed" is assumed to be a scalar quantity.

[0023] The ship monitoring system 100 includes a ship monitoring device 1, a display unit 2, a radar 3, an AIS 4, a GNSS receiver 5, a gyrocompass 6, an ECDIS 7, and an alarm unit 8. These devices are connected to a network N such as a LAN, for example, and can communicate with each other via the network.

[0024] The ship monitoring device 1 is a computer including a CPU, a RAM, a ROM, a non-volatile memory, an input / output interface, etc. The CPU of the ship monitoring device 1 executes information processing according to a program loaded from the ROM or the non-volatile memory into the RAM.

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

[0026] The display unit 2 is, for example, a display device with a touch sensor. The touch sensor detects the position indicated on the screen by a finger or the like. The indicated position may be input not only by a touch sensor, but also by a trackball or the like.

[0027] Radar 3 emits radio waves around the vessel and receives the reflected waves, generating echo data based on the received signals. Radar 3 also identifies targets from the echo data and generates target tracking data (TT data) that represents the position and speed of the targets.

[0028] The Automatic Identification System (AIS) 4 receives AIS data from other vessels or shore-based control systems in the vicinity of the vessel. While AIS is not the only option, a VHF Data Exchange System (VDES) may also be used. The AIS data includes information such as the position and speed of other vessels.

[0029] The GNSS receiver 5 detects the ship's position based on radio waves received from the GNSS (Global Navigation Satellite System). The gyrocompass 6 detects the ship's bearing. A GPS compass may be used instead of a gyrocompass.

[0030] The ECDIS (Electronic Chart Display and Information System) 7 obtains the ship's position from the GNSS receiver 5 and displays the ship's position on the electronic chart. The ECDIS 7 also displays the ship's planned route on the electronic chart. A GNSS plotter may be used instead of the ECDIS.

[0031] The alarm unit 8 issues an alarm when there is a risk of the vessel colliding with another vessel. The alarm unit 8 may issue an alarm by means of a display, or by means of sound or light. The alarm by display may be issued by the display unit 2. In other words, the display unit 2 may also function as the alarm unit 8.

[0032] In this embodiment, the ship monitoring device 1 is an independent device, but it is not limited to this and may be integrated with other devices such as ECDIS7. In other words, the functional parts of the ship monitoring device 1 may be implemented by other devices.

[0033] Furthermore, although the display unit 2 is an independent device, it is not limited to this, and the display unit of another device such as ECDIS7 may be used as the display unit 2 that displays the display image generated by the ship monitoring device 1.

[0034] In this embodiment, the GNSS receiver 5 and ECDIS 7 are examples of first data generation units, and generate ship data representing the ship's position and speed. Specifically, the GNSS receiver 5 detects the ship's position, and the ECDIS 7 detects the ship's speed from the time change of the ship's position.

[0035] In addition, the ship's speed may be determined based on the ship's bearing detected by the gyrocompass 6 and the ship's speed detected by a speedometer (not shown).

[0036] Furthermore, radar 3 or AIS 4 is an example of a second data generation unit, and generates other vessel data representing the position and speed of other vessels. Specifically, the TT data generated by radar 3 corresponds to other vessel data. Similarly, the AIS data generated by AIS 4 also corresponds to other vessel data.

[0037] Figure 2 shows an example of a ship management database built in the memory of the ship monitoring device 1. The ship management database registers ship data generated by radar 3 or AIS 4.

[0038] The other vessel management database includes fields such as "other vessel identifier," "position," "speed," and "bearing." The position and bearing of other vessels detected by radar 3 are converted to the same coordinate system as GNSS.

[0039] Figure 3 shows an example configuration of a ship monitoring device 1 that implements a ship monitoring method. The ship monitoring device 1 includes a self-ship data acquisition unit 11, a non-ship data acquisition unit 12, a risk range identification unit 13, an endpoint information calculation unit 14, an endpoint shape determination unit 15, and a display control unit 16. These functional units are realized by the CPU of the ship monitoring device 1 executing information processing according to a program.

[0040] The self-ship data acquisition unit 11 acquires self-ship data representing the position and speed of the ship from the GNSS receiver 5, etc. The self-ship data acquisition unit 11 is an example of a first data acquisition unit, and the self-ship data is an example of first ship data.

[0041] The other vessel data acquisition unit 12 acquires other vessel data representing the position and speed of other vessels from the radar 3 or AIS 4. The other vessel data acquisition unit 12 is an example of a second data acquisition unit, and the other vessel data is an example of second vessel data.

[0042] The risk range identification unit 13 performs calculations based on its own ship data and other ship data to display the OZT (Obstacle Zone by Target), which indicates that the risk of collision between the ship and other ships is above a predetermined level. The OZT is an example of a collision risk area.

[0043] Figure 4 shows an example of collision risk calculation. The risk range identification unit 13 identifies risk ranges L1 and L2 within the predicted course R of the other vessel CO, where the risk of collision between the own vessel CS and the other vessel CO is greater than or equal to a threshold, based on the predicted positions of the own vessel CS and the other vessel CO at each point in time, assuming that the own vessel CS changes course in any direction and crosses the predicted course R of the other vessel CO.

[0044] The calculation of the predicted position of the vessel's CS is performed under the assumption that the vessel maintains its speed and changes course in any direction at its current position. That is, it is assumed that the magnitude of the vessel's speed vector is constant, but the direction of the speed vector changes course in any direction at the reference point, and thereafter continues to sail in a constant direction from the vessel's position at the reference point. Therefore, the predicted position of the vessel's CS at each point in time lies on concentric circles centered on the vessel's position at the reference point. The radius of the circle is expressed as the product of the elapsed time from the reference point and the magnitude of the vessel's speed vector.

[0045] The predicted position of the vessel's CS at each point in time is represented by multiple concentric circles calculated for each of several discrete time points. However, the predicted position of the vessel's CS at each point in time may also be represented by a circle equation that includes the elapsed time from the reference time point.

[0046] In this embodiment, the predicted position of the vessel CS was calculated under the assumption that the speed of the vessel CS is constant. However, the vessel CS's speed may be treated as a variable that changes with time. That is, as long as the predicted position of the vessel CS can be determined according to the elapsed time from a reference point, the speed of the vessel CS does not have to be constant. For example, the speed of the vessel CS may gradually increase or decrease with the passage of time.

[0047] The predicted position of the other vessel CO is calculated under the assumption that the other vessel CO maintains its speed from its current position. That is, it is assumed that the magnitude and direction of the other vessel CO's speed vector remain constant and that it continues sailing from the other vessel's position at the reference time. Therefore, the predicted position of the other vessel CO at each point in time lies on a straight line extending from the other vessel's speed vector, passing through the other vessel's position at the reference time.

[0048] The predicted position of other ships at each point in time is represented by a series of discrete points on a straight line, calculated for each of several discrete time points. However, the predicted position of other ships at each point in time may also be represented by a linear function that passes through the position of other ships at the reference time.

[0049] In this embodiment, the predicted position of the other vessel CO was calculated under the assumption that its speed was constant. However, the embodiment is not limited to this, and at least one of the speed and direction of the other vessel CO may be treated as a variable that changes with time. That is, as long as the predicted position of the other vessel CO can be determined according to the elapsed time from a reference point, the speed of the other vessel CO does not have to be constant. For example, the speed of the other vessel CO may gradually increase or decrease with the passage of time. In addition, the other vessel CO may change course in a predetermined direction or turn at a predetermined ROT (Rate of Turn).

[0050] The risk range identification unit 13 calculates the separation distance between the predicted position of the own vessel CS and the predicted position of the other vessel CO at each point in time, and calculates the risk of collision based on the separation distance and the size of the vessels. As described above, the predicted position of the own vessel CS at a given time is represented by a circle, so the risk range identification unit 13 extracts the position closest to the predicted position of the other vessel CO at the same time from the circle representing the predicted position of the own vessel CS at a given time, and calculates the separation distance.

[0051] The risk range identification unit 13 identifies multiple risk ranges L1 and L2 where the collision risk is above a threshold, for example, when the warning area P set in the area of ​​the own vessel CS or around the own vessel CS overlaps with a point representing the predicted position of another vessel CO. Hereinafter, the direction of travel of the other vessel CO will be referred to as forward, and the opposite direction as backward.

[0052] For example, of the two risk ranges L1 and L2, for the first risk range L1 located on the rear side, the rear end L1R of the first risk range L1 is the position where the front end of the ship's warning area P is in contact with the point representing the predicted position of the other ship CO. The front end L1F of the first risk range L1 is the position where the rear end of the ship's warning area P is in contact with the point representing the predicted position of the other ship CO.

[0053] On the other hand, of the two risk ranges L1 and L2, for the second risk range L2 located on the forward side, the aft end L2R of the second risk range L2 is the position where the aft end of the ship's warning area P is in contact with the point representing the predicted position of the other ship CO. The forward end L2F of the second risk range L2 is the position where the forward end of the ship's warning area P is in contact with the point representing the predicted position of the other ship CO.

[0054] The area between the first risk range L1 and the second risk range L2 is the area where your vessel's CS crosses in front of the other vessel's CO. On the other hand, the area behind the first risk range L1 and in front of the second risk range L2 is the area where your vessel's CS crosses behind the other vessel's CO. When your vessel's CS crosses in front of the other vessel's CO, more caution is required compared to when your vessel's CS crosses behind the other vessel's CO.

[0055] The risk range identification unit 13 may also determine that the risk of collision is above a threshold when, for example, the area of ​​the own vessel's CS or the warning area P set around the own vessel's CS overlaps with the area of ​​the other vessel's CO or the warning area set around the other vessel's CO. Furthermore, the risk range identification unit 13 may also determine that the risk of collision is above a threshold when, for example, the separation distance between the point representing the predicted position of the own vessel's CS and the point representing the predicted position of the other vessel's CO is below a threshold.

[0056] Returning to the explanation of Figure 3, the endpoint information calculation unit 14 calculates endpoint information that represents the spatial relationship between the own vessel's CS and other vessels' CO at the endpoints L1R, L1F, L2R, and L2F of the risk ranges L1 and L2. The endpoint information is calculated, for example, based on BCR (Bow Crossing Range).

[0057] BCR is the predicted distance from your ship's bowline (CS) to the other ship's crossing line (CO) when the other ship crosses the same bowline (CS). A positive BCR indicates that your ship's CS will cross behind the other ship's CO, while a negative BCR indicates that your ship's CS will cross in front of the other ship's CO.

[0058] In the example shown in Figure 4, the BCR is positive at the rear end L1R of the first risk range L1, and negative at the front end L1F of the first risk range L1. Also, the BCR is negative at the rear end L2R of the second risk range L2, and positive at the front end L2F of the second risk range L2.

[0059] As mentioned above, when two risk ranges L1 and L2 exist, the range between them is the range in which the own vessel's CS crosses in front of the other vessel's CO, and the front-to-back relationship between the own vessel's CS and the other vessel's CO at the endpoint is clear, so there is no need to calculate the BCR.

[0060] Alternatively, since the process of determining the overlap relationship between the own vessel's CS and the other vessel's CO considers the sequence of events between the own vessel's CS and the other vessel's CO, i.e., the same calculation as BCR is performed, the results may be used.

[0061] The endpoint shape determination unit 15 determines the shape of the ends of the OZT based on the endpoint information of the endpoints L1R, L1F, L2R, and L2F of the risk ranges L1 and L2. The shape of the ends of the OZT will be described later.

[0062] The display control unit 16 generates a display image DM based on the self-ship data acquired by the self-ship data acquisition unit 11, the other-ship data acquired by the other-ship data acquisition unit 12, and the risk ranges L1 and L2 calculated by the risk range identification unit 13, and transmits it to the display unit 2. The display image DM transmitted to the display unit 2 is displayed on the screen of the display unit 2.

[0063] Figure 5 shows an example of a display image DM. The display image DM is an image that shows the positional relationship between the own ship and other ships. In the display image DM, the ship object SS representing the own ship and the other ship object OS representing other ships are placed in positions within the image that correspond to their actual positions.

[0064] The ship's object SS and the other ship's object OS are accompanied by vector lines VS and VO representing velocity vectors. The display image DM may also display the ship's planned route and surrounding nautical charts obtained from ECDIS7.

[0065] The display image DM shows the predicted course R of other vessels calculated based on other vessel data, and OZT1 and OZT2 are displayed on the predicted course R as collision risk areas. OZT1 and OZT2 have a shape that extends in the same direction as the predicted course R of other vessels with a certain width.

[0066] OZT1 and OZT2 are displayed in the risk ranges L1 and L2 (see Figure 4) identified by the risk range identification unit 13. OZT1 is displayed in the first risk range L1, and OZT2 is displayed in the second risk range L2.

[0067] Specifically, OZT1 includes the first risk range L1, with the rear end of OZT1 corresponding to the rear end L1R of the first risk range L1, and the front end of OZT1 corresponding to the front end L1F of the first risk range L1.

[0068] Furthermore, OZT2 includes a second risk range L2, with the rear end of OZT2 corresponding to the rear end L2R of the second risk range L2, and the front end of OZT2 corresponding to the front end L2F of the second risk range L2.

[0069] Of these, the forward end Z1F of OZT1 and the aft end Z2R of OZT2, which straddle the range JM in which the own vessel's CS crosses in front of the other vessel's CO, are displayed separately from the other aft end Z1R of OZT1 and the forward end Z2F of OZT2.

[0070] In other words, the shapes of the front end Z1F of OZT1 and the rear end Z2R of OZT2 differ from the shapes of the other rear end Z1R of OZT1 and the front end Z2F of OZT2 in order to indicate that the area JM is where the ship's CS crosses in front of the other ship's CO.

[0071] In the example shown in Figure 5, the front end Z1F of OZT1 and the rear end Z2R of OZT2 have shapes that indicate the direction of travel of other vessels. For example, the front end Z1F of OZT1 has a corner shape that protrudes toward the direction of travel of other vessels. The rear end Z2R of OZT2 has a corner shape that is recessed toward the direction of travel of other vessels.

[0072] According to this, the range JM in which the own vessel's CS crosses in front of the other vessel's CO is sandwiched between the front end Z1F of OZT1 and the rear end Z2R of OZT2, which have a shape indicating the direction of travel of the other vessel. Therefore, it becomes easier to determine the range JM in which the own vessel's CS crosses in front of the other vessel's CO, and furthermore, it becomes easier to determine the direction of travel of the other vessel.

[0073] On the other hand, the aft end Z1R of OZT1 and the forward end Z2F of OZT2 have a semicircular shape and do not have a shape that indicates the direction of travel of other vessels. This makes it easier to distinguish between the area JM in which the own vessel's CS crosses in front of the other vessel's CO and the area in which the own vessel's CS crosses behind the other vessel's CO.

[0074] Conversely, the front end Z1F of OZT1 and the rear end Z2R of OZT2, which straddle the area JM in which the own vessel's CS crosses in front of the other vessel's CO, may be made semicircular in shape, while the remaining rear end Z1R of OZT1 and the front end Z2F of OZT2 may be shaped to indicate the direction of travel of the other vessel. This also makes it easier to distinguish the area JM in which the own vessel's CS crosses in front of the other vessel's CO from the area in which the own vessel's CS crosses behind the other vessel's CO.

[0075] Furthermore, as shown in Figures 6 and 7, predetermined shaped marks GM, HM, and FM representing the relative positions of one's own vessel CS and another vessel CO may be added to the ends Z1F, Z1R, Z2F, and Z2R of OZT1 and OZT2.

[0076] Specifically, as shown in Figure 6, by adding a dot-shaped mark GM, for example, to the side furthest from the ship's CS at the front end Z1F of OZT1 and the rear end Z2R of OZT2, which straddle the range JM in which the ship's CS crosses in front of the other ship's CO, it becomes visually clear that the ship's CS is crossing in front of the other ship's CO.

[0077] Furthermore, by adding a dot-shaped mark HM, for example, to the side of the aft end Z1R of OZT1 and the forward end Z2F of OZT2 that is closer to the ship's CS, it is possible to visually make it easier to understand that the ship's CS is crossing behind the other ship's CO. Note that either mark GM or mark HM may be omitted.

[0078] Similarly, as shown in Figure 7, by adding a protruding mark EM to the front end Z1F of OZT1 and the rear end Z2R of OZT2, which straddle the range JM in which the own vessel's CS crosses in front of the other vessel's CO, the fact that the own vessel's CS is crossing in front of the other vessel's CO can be visually made clearer.

[0079] Furthermore, by adding a protruding mark FM to the rear end Z1R of OZT1 and the front end Z2F of OZT2, which protrude towards the side closer to the ship's CS, it is possible to visually make it easier to understand that the ship's CS is crossing behind the other ship's CO. Note that either mark EM or mark FM may be omitted.

[0080] Furthermore, OZT1 and OZT2, shown in Figures 6 and 7, may also be provided with shapes or marks indicating the direction of other vessels, or, as will be described later, their shapes or the number of marks may be changed according to the speed of other vessels.

[0081] Furthermore, as shown in Figures 8 and 9, the display control unit 16 may change the shape of the front end Z1F of OZT1 and the rear end Z2R of OZT2 that indicates the direction of travel of other vessels, according to the speed of the other vessels. For example, the angular shape that protrudes or is recessed toward the direction of travel of the other vessels may be extended so that it becomes sharper as the speed of the other vessels increases. This makes it easier to grasp the speed of other vessels.

[0082] Furthermore, as shown in Figures 10 and 11, marks BM of a predetermined shape, such as a boomerang shape, indicating the direction of travel of other vessels may be added to the front end Z1F of OZT1 and the front end Z2F of OZT2, and the number of marks BM may be changed according to the speed of the other vessels. For example, the number of marks BM may be increased as the speed of the other vessels increases. This also makes it easier to grasp the speed of other vessels.

[0083] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are of course possible for those skilled in the art. [Explanation of Symbols]

[0084] 1. Ship monitoring device, 2. Display unit, 3. Radar, 4. AIS, 5. GNSS receiver, 6. Gyrocompass, 7. ECDIS, 8. Alarm unit, 11. Self-ship data acquisition unit, 12. Other ship data acquisition unit, 13. Risk range identification unit, 14. Endpoint information calculation unit, 15. Endpoint shape calculation unit, 16. Display control unit, 100. Ship monitoring system

Claims

1. A first data acquisition unit that acquires first ship data representing the position and speed of the first ship, A second data acquisition unit acquires second vessel data representing the position and speed of the second vessel, Based on the first and second vessel data, a risk range identification unit identifies a first range within the predicted course of the second vessel in which the risk of collision between the first and second vessels is greater than or equal to a predetermined value, assuming that the first vessel changes course in any direction and crosses the predicted course of the second vessel, and a second range located away from the first range in the direction of travel of the second vessel. A display control unit displays a first collision risk area including the first range and a second collision risk area including the second range on the predicted course of the second vessel in an image showing the positions of the first and second vessels, and displays the shapes of the end of the first collision risk area on the second range side and the end of the second collision risk area on the first range side as equal. A ship monitoring device equipped with the following features.

2. The end of the first collision risk area on the second range side and the end of the second collision risk area on the first range side have a shape indicating the direction of travel of the second vessel. The ship monitoring device according to claim 1.

3. The end of the first collision risk area on the second range side has a shape that protrudes in the direction of travel of the second vessel. The ship monitoring device according to claim 1.

4. The end of the second collision risk area on the first range side has a shape that is recessed in the direction of travel of the second vessel. The ship monitoring device according to claim 1.

5. The end of the first collision risk area opposite to the second range side and the end of the second collision risk area opposite to the first range side have a semicircular shape. The ship monitoring device according to claim 2.

6. The display control unit changes the shape according to the speed of the second vessel. The ship monitoring device according to claim 1.

7. The first ship data includes the position of the first ship as detected by a GNSS (Global Navigation Satellite System) receiver installed on the first ship. The ship monitoring device according to claim 1.

8. The second ship data includes the position and speed of the second ship as detected by radar installed on the first ship, The ship monitoring device according to claim 1.

9. The second vessel data includes the position and speed of the second vessel detected by the AIS (Automatic Identification System) installed on the first vessel. The ship monitoring device according to claim 1.

10. By computer, The first data generation unit acquires first ship data representing the position and speed of the first ship, The second data generation unit acquires second ship data representing the position and speed of the second ship. Based on the first and second vessel data, assuming that the first vessel changes course in any direction and crosses the predicted course of the second vessel, a first range within the predicted course of the second vessel in which the risk of collision between the first and second vessels exceeds a predetermined level is identified, and a second range located away from the first range in the direction of travel of the second vessel. The display unit displays a first collision risk area including the first range and a second collision risk area including the second range on the predicted course of the second vessel in an image showing the positions of the first and second vessels, and displays the shapes of the end of the first collision risk area on the second range side and the end of the second collision risk area on the first range side as equal. Ship monitoring method.

11. To acquire the first vessel data representing the position and speed of the first vessel, To acquire second vessel data representing the position and speed of the second vessel, Based on the first and second vessel data, assuming that the first vessel changes course in any direction and crosses the predicted course of the second vessel, a first range within the predicted course of the second vessel in which the risk of collision between the first and second vessels exceeds a predetermined level is identified, and a second range located away from the first range in the direction of travel of the second vessel, and In an image showing the positions of the first and second vessels, a first collision risk area including the first range and a second collision risk area including the second range are displayed on the predicted course of the second vessel, and the shapes of the end of the first collision risk area on the second range side and the end of the second collision risk area on the first range side are displayed to be equal. A program that causes a computer to execute something.

Images