Ship monitoring system, ship monitoring method, information processing device, and computer program product

Abstract

A ship monitoring system capable of visualizing the risk of collision or even approach in the width direction orthogonal to the heading direction of another ship. The ship monitoring system has: a first data generation section that generates first ship data indicating the position and speed of a first ship; a second data generation section that generates second ship data indicating the position and speed of a second ship; a risk range determination section that determines a risk range in which a risk value indicating the risk of collision of the first ship with the second ship reaches a threshold or more in the predicted heading of the second ship, based on the position of the first ship and the position of the second ship at each time predicted from the first ship data and the second ship data when the first ship is assumed to turn to an arbitrary direction and cross the predicted heading of the second ship; and a display section that displays an OZT (Obstacle Zone by Target) of a polygon having at least the rear end and the front end of the risk range and a representative point of the first ship located at a position corresponding to the rear end of the risk range as vertices.

Description

Technical Field

[0001] This invention relates to ship surveillance systems, ship surveillance methods, information processing devices, and computer program products. Background Technology

[0002] In the past, various methods have existed for assessing the risk of collisions between ships. For example, Non-Patent Document 1 discloses a method for displaying an OZT (Obstacle Zone by Target). In this method, a circular OZT with a radius of a prescribed safe separation distance is displayed on the predicted course of other ships.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Hayato Imatsu, Junji Fukuto, and Masayoshi Numano, “Regarding the Obstruction Zone Caused by Another Vessel and Its Display”, Proceedings of the Japan Navigation Society, 2002, Vol. 107, pp. 191-197. Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, in previous methods of displaying OZT, multiple circular OZTs were connected and displayed in the predicted course of other ships. However, since the width was constant only in the width direction orthogonal to the predicted course, it was difficult for users to grasp the risk of collision or even approach in the width direction.

[0008] The present invention was made in view of the above-mentioned problems, and its main objective is to provide a ship monitoring system, ship monitoring method, information processing device, and computer program product that can visualize the risk of collision or even approach in the width direction orthogonal to the heading direction of other ships.

[0009] means for solving problems

[0010] To address the aforementioned issues, a ship monitoring system according to one aspect of the present invention comprises: a first data generation unit that generates first ship data representing the position and speed of a first ship; a second data generation unit that generates second ship data representing the position and speed of a second ship; a risk range determination unit that, based on the positions of the first ship and the second ship predicted at various times according to the first ship data and the second ship data, assumes that the first ship turns in an arbitrary direction and crosses the predicted course of the second ship, determines a risk range in the predicted course of the second ship where the risk value representing the risk of a collision between the first ship and the second ship reaches a threshold or higher; and a display unit that displays an OZT (Obstacle Zone by Target) of a polygon with at least the rear end and front end of the risk range and a representative point of the first ship located at a position corresponding to the rear end of the risk range as vertices.

[0011] In another aspect of the ship monitoring method of the present invention, a first ship data representing the position and speed of a first ship is generated by a first data generation unit, and a second ship data representing the position and speed of a second ship is generated by a second data generation unit. Based on the positions of the first ship and the second ship at each time predicted according to the first ship data and the second ship data, assuming that the first ship turns in an arbitrary direction and crosses the predicted course of the second ship, a risk range in the predicted course of the second ship, representing the risk of a collision between the first ship and the second ship, is determined to be at least a threshold value. An OZT (Obstacle Zone by Target) of a polygon, which at least has the rear end and front end of the risk range and a representative point of the first ship located at the position corresponding to the rear end of the risk range as vertices, is displayed in a display unit.

[0012] Furthermore, another aspect of the information processing apparatus of the present invention includes: a risk range determination unit, which determines a risk range in the predicted course of the second vessel where the risk value representing the risk of a collision between the first vessel and the second vessel reaches a threshold or higher, based on the positions of the first vessel and the second vessel at each time predicted according to first vessel data representing the position and speed of the first vessel and second vessel data representing the position and speed of the second vessel, assuming that the first vessel turns in an arbitrary direction and crosses the predicted course of the second vessel; and a display control unit, which displays an OZT (Obstacle Zone by Target) of a polygon with at least the rear end and front end of the risk range and a representative point of the first vessel located at a position corresponding to the rear end of the risk range as vertices in the display unit.

[0013] Furthermore, another aspect of the computer program product of the present invention includes a computer program that causes a computer to perform: determining a risk range in the predicted course of the second vessel where the risk value representing the risk of a collision between the first vessel and the second vessel reaches a threshold or higher, based on the positions of the first vessel and the second vessel at each time predicted according to first vessel data representing the position and speed of the first vessel and second vessel data representing the position and speed of the second vessel, assuming that the first vessel turns in an arbitrary direction and crosses the predicted course of the second vessel; and displaying an OZT (Obstacle Zone by Target) of a polygon with at least the rear end and front end of the risk range and a representative point of the first vessel located at a position corresponding to the rear end of the risk range as vertices in a display unit.

[0014] The effects of the invention

[0015] According to the present invention, the risk of collision or even proximity with other ships in the width direction orthogonal to their course can be visualized. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating a structural example of a ship surveillance system implemented in this way.

[0017] Figure 2 This is a diagram representing an example of other ship management databases.

[0018] Figure 3 This is a diagram showing a previous example of OZT.

[0019] Figure 4 This is a diagram illustrating a structural example of an information processing apparatus for an implementation method.

[0020] Figure 5 It is a diagram used to illustrate dimensional data.

[0021] Figure 6 It is a diagram used to illustrate dimensional data.

[0022] Figure 7 This is a diagram illustrating an example of the steps involved in the risk scope determination process.

[0023] Figure 8A This is a diagram illustrating an example of OZT calculation.

[0024] Figure 8B This is a diagram showing an example of OZT.

[0025] Figure 9 This is a diagram illustrating an example of OZT calculation.

[0026] Figure 10 This is a diagram illustrating an example of OZT calculation.

[0027] Figure 11 This is a diagram illustrating an example of OZT calculation.

[0028] Figure 12 This is a diagram illustrating an example of OZT calculation.

[0029] Figure 13 This is a diagram illustrating an example of OZT calculation.

[0030] Figure 14 This is a diagram showing an example of OZT.

[0031] Figure 15A This is a diagram illustrating an example of OZT calculation.

[0032] Figure 15B This is a diagram showing an example of OZT.

[0033] Figure 15C This is a diagram showing an example of OZT.

[0034] Figure 16A This is a diagram illustrating an example of OZT calculation.

[0035] Figure 16B This is a diagram showing an example of OZT.

[0036] Figure 16C This is a diagram showing an example of OZT.

[0037] Figure 17 This is a diagram showing an example of OZT.

[0038] Figure 18A This is a diagram illustrating an example of OZT calculation.

[0039] Figure 18B This is a diagram illustrating an example of OZT calculation.

[0040] Figure 18C This is a diagram showing an example of OZT. Detailed Implementation

[0041] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0042] Figure 1 This is a block diagram illustrating a structural example of a ship surveillance system 100 according to an embodiment. The ship surveillance method of the embodiment is implemented in the ship surveillance system 100. The ship surveillance system 100 is a system mounted on a ship and used to monitor ships present in the surrounding area.

[0043] The vessel equipped with the vessel surveillance system 100 is an example of the first vessel, referred to as "this vessel" in the following description. Additionally, vessels existing around this vessel are examples of the second vessels, referred to as "other vessels" in the following description.

[0044] Additionally, in the following explanation, "speed" is a vector representing rate and bearing (the so-called ship speed vector), and "rate" is a scalar.

[0045] The ship surveillance system 100 includes an information processing unit 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 can be connected to a network N, such as a LAN, and can communicate with each other via the network.

[0046] Information processing device 1 is a computer including a CPU, RAM, ROM, non-volatile memory, and input / output interfaces. The CPU of information processing device 1 executes information processing according to a program loaded from ROM or non-volatile memory into RAM.

[0047] The program can be provided, for example, via information storage media such as optical discs or memory cards, or via communication networks such as the Internet or LAN.

[0048] Display unit 2 is, for example, a display device with a touch sensor. The touch sensor detects the position of a finger or other object within the screen. It is not limited to a touch sensor; the position can also be input via a trackball or similar device.

[0049] Radar 3 emits radio waves around the ship and receives their reflected waves, generating echo data based on the received signals. Additionally, Radar 3 identifies targets based on the echo data and generates target tracking data (TT data) indicating the target's position and velocity.

[0050] The AIS (Automatic Identification System) receives AIS data from other ships or land-based control systems in the vicinity of the vessel. It is not limited to AIS; VDES (VHF Data Exchange System) can also be used. AIS data includes the positions and speeds of other ships, etc.

[0051] GNSS receiver 5 detects the ship's position based on radio waves received from GNSS (Global Navigation Satellite System). Gyrocompass 6 detects the ship's bearing. It is not limited to a gyrocompass; a GPS compass or magnetic compass can also be used.

[0052] The ECDIS (Electronic Chart Display and Information System) 7 obtains the vessel's position from the GNSS receiver 5 and displays it on the electronic chart. Additionally, the ECDIS 7 also displays the vessel's planned route on the electronic chart. It is not limited to ECDIS; a GNSS plotter can also be used.

[0053] Alarm unit 8 issues an alarm when there is a risk of collision between the vessel and other vessels. Alarm unit 8 can be a visual alarm, an audible alarm, or a visual alarm. A visual alarm can be issued from display unit 2. That is, display unit 2 can also serve as alarm unit 8.

[0054] In this embodiment, the information processing device 1 is a standalone device, but it is not limited to this and can also be integrated with other devices such as ECDIS7. That is, the functional parts of the information processing device 1 can also be implemented by other devices such as ECDIS7.

[0055] In addition, the display unit 2 is also a separate device, but it is not limited to this. The display units of other devices such as ECDIS7 can also be used as the display unit 2 to display images generated by the information processing device 1.

[0056] In this embodiment, the group consisting of GNSS receiver 5 and ECDIS 7 is an example of a first data generation unit, which generates ship data representing the ship's position and speed. Specifically, GNSS receiver 5 detects the ship's position, and ECDIS 7 detects the ship's speed based on the time-varying changes in the ship's position.

[0057] Not limited to this, the ship's speed can also be detected based on the ship's bearing detected by the gyrocompass 6 and the ship's speed detected by the speedometer (not shown).

[0058] Additionally, radar 3 or AIS 4 is an example of a second data generation unit that generates data representing the positions and speeds of other ships. Specifically, the TT data generated by radar 3 is equivalent to the data of other ships. Similarly, the AIS data generated by AIS 4 is also equivalent to the data of other ships.

[0059] Figure 2 This diagram illustrates an example of other ship management databases built into the memory of information processing device 1. Other ship management databases contain data on other ships generated by radar 3 or AIS 4.

[0060] The other vessel management database includes fields such as "other vessel identification," "position," "speed," and "bearing." Furthermore, the positions and bearings of other vessels detected by Radar 3 are converted to the same coordinate system as GNSS.

[0061] Figure 3 This is a diagram showing a previous example of OZT. OZT (Obstacle Zone by Target) is the area where the vessel's navigation may be obstructed by other vessels, shown on the predicted course of those other vessels.

[0062] In previous methods of displaying OZTs, multiple circular OZTs were displayed in a series connecting areas indicating high collision risk on the predicted course of other vessels, making it easy for users to assess the risk of collision or even close proximity in that direction. However, in the width direction, which is orthogonal to the course, the width of the OZT remains constant, making it difficult for users to assess the risk of collision or even close proximity in that direction.

[0063] Figure 3 The example illustrates a situation where the ship merges with other vessels in an area where multiple other ships are sailing. Thus, when the ship takes route A, although it may appear to have sufficient space, in reality, other vessels approach closely to both sides, causing the navigator to feel tense. On the other hand, when the ship takes route B, due to the presence of other vessels' signs and other markings along the way, it may initially seem to lack sufficient space, but in reality, compared to route A, other vessels do not approach closely, and the navigator experiences far less tension.

[0064] Therefore, in this embodiment, as described below, by displaying a polygon OZT that takes into account the positional relationship between the vessel and other vessels when approaching, the risk of collision or even approach in the width direction orthogonal to the heading direction of other vessels is visualized.

[0065] Figure 4 This is a diagram illustrating a structural example of an information processing device 1 that implements an embodiment of the ship monitoring method. The information processing device 1 includes a risk range determination unit 11, a display control unit 12, and a size data holding unit 13.

[0066] The CPU of the information processing device 1 executes information processing according to the program, thereby realizing the risk range determination unit 11 and the display control unit 12. The size data holding unit 13 is built in the memory of the information processing device 1.

[0067] The risk range determination unit 11 determines the risk range L (referring to the risk value of collision between the ship and other ships in the predicted course of other ships within the predicted course of other ships) based on the ship's own data and the positions of other ships predicted at each moment, assuming the ship turns in an arbitrary direction and crosses other ships. Figure 8A ).

[0068] The display control unit 12 displays a quadrilateral OZT with vertices at the rear end LR and front end LF of the risk range L determined by the risk range determination unit 11, the representative point SF of the ship located at the position corresponding to the rear end LR, and the representative point SR of the ship located at the position corresponding to the front end LF. (Refer to...) Figure 8B ).

[0069] Figure 5 and Figure 6 This is a diagram used to illustrate the dimensional data of the ship held by the dimensional data holding unit 13. The dimensional data includes the lengths L1 and L2 of the ship area S occupied by the ship and the lengths PL1 and PL2 of the warning area P set around the ship.

[0070] The ship area S occupied by this vessel represents the physical size of the vessel. In this embodiment, the ship area S is represented by a line segment from the bow to the stern of the vessel. Length L1 is the length from the reference position RP of the vessel to the bow, and length L2 is the length from the reference position RP to the stern. The reference position RP of the vessel is relative to the GNSS receiver 5 (see reference). Figure 1 The antenna position corresponds to that of the antenna.

[0071] A collision is considered to have occurred if other vessels are present within the vessel's area S. Figure 6 As shown, within the ship's area S, the risk value is 1, which is the highest.

[0072] A warning zone P is established around the ship, located both forward and aft of the ship. In this embodiment, the warning zone P is represented by a line segment extending forward from the bow of the ship and a line segment extending aft from the stern of the ship. Length PL1 is the length from the bow of the ship to the bow of the warning zone P, and length PL2 is the length from the stern of the ship to the stern of the warning zone P.

[0073] Alternatively, a warning zone P can be established behind the ship. That is, the length PL2 can also be 0. Conversely, a warning zone P can also be established in front of the ship. That is, the length PL1 can also be 0.

[0074] Although the warning zone P will not have physical contact with other ships, it is set according to the area where the operator would psychologically not want other ships to intrude. The warning zone P can be compared to a personal space where a person would feel uncomfortable when close to others.

[0075] In this embodiment, such as Figure 6 As shown in (a), in the warning area P, similarly to the ship area S, the risk value is also the highest, 1. This is not limited to this, as... Figure 6 As shown in (b), in the warning area P, the risk value can also be set to gradually decrease the further away from the ship.

[0076] It should be noted that in this embodiment, the ship area S and the warning area P of the ship are represented by line segments in the forward and backward directions, but it is not limited to this. In addition to the length in the width direction, the ship area S and the warning area P of the ship can also be represented by a rectangular area, or by a cross-shaped line segment where the line segments in the forward and backward directions intersect with the line segments in the width direction, or by a buffer shape such as an ellipse, an oblong shape or an oval shape.

[0077] Similar to this vessel, ship zones are also defined for other vessels, as well as warning zones around them. The fore-and-aft lengths of other vessels can be, for example, the lengths of vessels included in the AIS data, or a prescribed length corresponding to the vessel type included in the AIS data. This is not limited to this; the fore-and-aft lengths of other vessels can also be inferred, for example, from the echo data of radar 3. The reference position of other vessels is, for example, a prescribed position such as the center of their ship zones.

[0078] Figure 7 This diagram illustrates an example of the specific processing steps performed by the risk scope determination unit 11. The information processing device 1 functions as the risk scope determination unit 11 by executing the processing shown in this diagram according to the program. Figure 8A and Figure 8B This is a diagram showing examples of OZT calculation and display.

[0079] First, the risk range determination unit 11 acquires the ship's data (S11), and calculates the predicted position of the ship at each time based on the acquired ship data (S12).

[0080] Specifically, the predicted position of the ship is calculated based on the assumption that the ship maintains its speed while turning in any direction from its current position. That is, it is assumed that the magnitude of the ship's speed vector is constant, while the direction of the ship's speed vector turns in any direction at a reference time, and then continues sailing in a constant direction from the ship's position at the reference time. Therefore, the predicted position of the ship at each time point exists on a concentric circle centered on the ship's position at the reference time. The radius of the circle is represented by the product of the time elapsed since the reference time and the magnitude of the ship's speed vector.

[0081] The predicted position of the ship at each time point is represented by a discrete set of concentric circles calculated separately for each discrete time point. However, it is not limited to this; the predicted position of the ship at each time point can also be represented as a circle that includes the time elapsed since the reference time (details will be described later).

[0082] It should be noted that in this embodiment, the predicted position of the ship is calculated based on the assumption that the ship's speed is constant, but it is not limited to this. The ship's speed can also be treated as a variable that changes with time. That is, it is only necessary to calculate the predicted position of the ship corresponding to the time elapsed since the reference time, and the ship's speed does not have to be constant. For example, the ship's speed can gradually increase or decrease over time.

[0083] Then, the risk range determination unit 11 acquires data on other ships (S13) and calculates the predicted positions of other ships at each time based on the acquired data on other ships (S14).

[0084] Specifically, the predicted positions of other ships are calculated based on the assumption that they maintain their speed from their current positions. That is, it is assumed that the magnitude and direction of the other ships' speed vectors are constant, and that they continue to sail from their positions at the reference time. Therefore, the predicted positions of other ships at each time point exist on a straight line extending from their positions at the reference time to their speed vectors.

[0085] The predicted positions of other ships at each time point are represented by a set of discrete points arranged along a straight line, calculated separately for each discrete time point. However, this is not a limitation; the predicted positions of other ships at each time point can also be represented by a linear function of the positions of other ships at a reference time point (details will be described later).

[0086] Furthermore, in this embodiment, the predicted positions of other ships are calculated based on the assumption that their speeds are constant. However, this is not a limitation; at least one of the speed and direction of other ships can also be treated as variables that change over time. That is, it is only necessary to calculate the predicted positions of other ships corresponding to the time elapsed since the reference time. The speeds of other ships do not necessarily have to be constant. For example, the speeds of other ships can gradually increase or decrease over time. In addition, other ships can also turn to a predetermined direction and can turn with a predetermined ROT (Rate of Turn).

[0087] Then, the risk range determination unit 11 calculates the interval distance between the predicted position of the ship and the predicted positions of other ships at each time (S15). The interval distance is expressed as the distance between the point representing the predicted position of the ship and the point representing the predicted position of other ships.

[0088] As described above, since the predicted position of the ship at a certain moment is represented by a circle, the risk range determination unit 11 selects the position closest to the predicted position of other ships at that moment from the circle representing the predicted position of the ship at a certain moment, and calculates the interval distance.

[0089] Then, the risk range determination unit 11 obtains size data from the size data holding unit 13 (S16), and calculates a risk value representing the risk of collision between the ship and other ships based on the interval distance and size data (S17).

[0090] exist Figure 8A In the example, the risk range determination unit 11 uses the ship's size data to set the ship area S and the warning area P (refer to...). Figure 5 and Figure 6 ( ), determine whether the ship's area S or warning area P includes a point indicating the predicted position of other ships.

[0091] For example, when the predicted position of this vessel is ahead of the predicted course of another vessel, if the interval distance is less than or equal to the distance L1 from the reference position RP of this vessel to the leading edge of the vessel area S, it is determined that the predicted position of the other vessel is included in the vessel area S. Conversely, if the interval distance is greater than L1 and less than or equal to the distance L1 + PL1 from the reference position RP of this vessel to the leading edge of the warning area P, it is determined that the predicted position of the other vessel is included in the vessel area P.

[0092] On the other hand, when the predicted position of this vessel is inside the predicted course of other vessels, if the interval distance is less than or equal to the distance L2 from the reference position RP of this vessel to the rear of the vessel area S, it is determined that the predicted positions of other vessels are included in the vessel area S. Furthermore, if the interval distance is greater than L2 and less than or equal to the distance L2 + PL2 from the reference position RP of this vessel to the rear of the warning area P, it is determined that the predicted positions of other vessels are included in the vessel area P.

[0093] Whether the predicted position of this vessel is ahead of or behind the predicted course of other vessels can be determined by the positive or negative sign of the distance.

[0094] In this embodiment, the distance between the point representing the predicted position of the ship and the point representing the predicted positions of other ships is calculated, but if... Figure 10 and Figure 11 As shown, when setting the ship area BS or warning area BP of other ships, the distance between the point representing the predicted position of this ship and the front or rear of the ship area BS or warning area BP of other ships can also be calculated.

[0095] If the predicted positions of other ships are included within the ship's area S or warning area P, the risk range determination unit 11 sets the risk value to the maximum of 1; otherwise, it sets the risk value to the minimum of 0 (see reference). Figure 6 (a) The threshold is set between 0 and 1. If the ship's area S or warning area P includes a point indicating the predicted position of other ships, the risk value is above the threshold.

[0096] This is not limited to this; within the warning zone P, the risk value can also be set to gradually decrease the further away from the ship (see [reference]). Figure 6 (b) In this case, if the warning area P of this vessel includes a point indicating the predicted position of another vessel and is in some way close to the vessel's area S, the risk value is above the threshold.

[0097] Furthermore, the calculations based on the risk scope determination unit 11 can be performed as follows. Here, an example will be given of calculating the position where the forward end of the ship's area abuts the rear end of the ship's area of ​​another ship.

[0098] like Figure 9 As shown, the initial position of the ship at t=0 (i.e., the current position of the ship) is set as the origin (0, 0) of the xy plane. Furthermore, the ship's velocity vector is set as V. o Additionally, the length from the ship's reference position to its bow is defined as L. of (equivalent to) Figure 4 L1). Assuming the ship can instantly turn 360 degrees from its current position and sail at a constant speed, the position of the ship's forehead after time t is given by a radius V centered at the origin (0, 0). o t+L of The circumference is represented by .

[0099] On the other hand, the initial positions of other ships at t=0 (i.e., their current positions) are set to (x, y) in the xy plane. Additionally, the velocity vector of this ship is set to V. t Additionally, the length from the reference position of other ships to the stern will be defined as L. tb Assuming other ships are sailing from their current positions with constant heading and speed, the position CP of the rear of the other ships' region after time t is represented by the following mathematical formula 1. Where V tx For V t The x component, Vty is V t The y component.

[0100] [Mathematical Expression 1]

[0101]

[0102] In this context, "the situation where the forward end of the vessel's area abuts the aft end of another vessel's area" refers to the situation where the aft end position CP of the other vessel's area is located within a radius V representing the forward end position of the vessel's area. o t+L of Therefore, the following mathematical expression 2 holds true on the circumference of the circle.

[0103] [Mathematical Expression 2]

[0104]

[0105] By solving mathematical formula 2, the time t at which the bow of this ship's area comes into contact with the stern of another ship's area can be calculated. Furthermore, by substituting the calculated time t into mathematical formula 1 above, the position at which the bow of this ship's area comes into contact with the stern of another ship's area can be calculated.

[0106] Here, the calculation of the position where the bow of this vessel's area abuts the stern of another vessel's area is explained, but... Figure 10 As shown, the forward end of the vessel's warning zone P is in contact with the aft end of another vessel's warning zone BS. Figure 11 Other situations, such as the situation where the front end of the ship's warning zone P is in contact with the rear end of the warning zone BP of other ships, can also be calculated in the same way.

[0107] Return to Figure 7 The risk range determination unit 11 determines the risk range L (S18) where the risk value calculated in S17 reaches or exceeds the threshold, and determines the rear LR and front LF of the risk range L, the representative point SF of the ship located at the position corresponding to the rear LR, and the representative point SR of the ship located at the position corresponding to the front LF (S19). The forward and backward directions of the risk range L correspond to the forward and backward directions of other ships.

[0108] As described above, in this embodiment, since the risk value exceeds the threshold when the ship's area S or warning area P includes points indicating the predicted positions of other ships, therefore, if Figure 8A As shown, the rear end LR of the risk range L is the point where the front end of the vessel's warning area P meets the point indicating the position of other vessels. Additionally, the front end LF of the risk range L is the point where the rear end of the vessel's warning area P meets the point indicating the position of other vessels.

[0109] Additionally, the representative point SF of the vessel, located at the position corresponding to the rear end LR of risk range L, is the forward end of the vessel's ship area S. Specifically, the position of the vessel corresponding to the rear end LR of risk range L refers to the vessel's position when the forward end of the vessel's warning area P is located at the rear end LR of risk range L. The representative point SF is not limited to the forward end of the vessel's ship area S; it can also be the reference position RP (refer to...). Figure 5 (e.g., the rear end of the ship's area S or the rear end of the ship's warning area P).

[0110] Additionally, the representative point SF of the vessel, located at the position corresponding to the leading edge LF of the risk zone L, is the aft end of the vessel's area S. Specifically, the position of the vessel corresponding to the leading edge LF of the risk zone L refers to the vessel's position when the aft end of the vessel's warning area P is located at the leading edge LF of the risk zone L. The representative point SF is not limited to the aft end of the vessel's area S; it can also be the reference position RP (see reference). Figure 5 ), the fore-end of the ship's area S or the fore-end of the ship's warning area P, etc.

[0111] The risk range determination unit 11 takes the positions of the rear end LR and front end LF of the risk range L, the representative point SF of the ship located at the position corresponding to the rear end LR, and the representative point SR of the ship located at the position corresponding to the front end LF as the vertices of OZT, outputs them to the display control unit 12, and ends the processing. In addition, if there are multiple other ships, the processing of S13 to S19 is performed on each of the multiple other ships respectively.

[0112] exist Figure 8B In this example, the display control unit 12 displays a quadrilateral OZT on the screen of the display unit 2, with the rear end LR and front end LF of the risk range L determined by the risk range determination unit 11, the representative point SF of the ship located at the position corresponding to the rear end LR, and the representative point SR of the ship located at the position corresponding to the front end LF as its vertices. It should be noted that the corners of the OZT can also be rounded.

[0113] Therefore, OZT is not a constant width, but rather a shape that extends towards the ship from the front and rear of the risk zone L.

[0114] Specifically, by setting the representative point SF of the vessel, located at the rear end LR of the risk range L, as the vertex of the OZT, the OZT extends from the rear of the risk range L toward the predicted position of the vessel. On the other hand, by setting the representative point SF of the vessel, located at the front end LF of the risk range L, as the vertex of the OZT, the OZT extends from the front of the risk range L toward the predicted position of the vessel.

[0115] By displaying OZTs of this shape, the risk of collision or even proximity with other vessels in the width direction orthogonal to their heading can be visualized.

[0116] Not limited to the examples mentioned above, such as Figure 10 As shown, the risk range determination unit 11 can also determine whether the ship's area S or warning range P overlaps with the ship's area BS of other ships. In this example, the rear end LR of the risk range L is the position where the front end of the ship's warning range P meets the rear end of the ship's area BS of other ships. The front end LF of the risk range L is the position where the rear end of the ship's warning range P meets the front end of the ship's area BS of other ships.

[0117] In addition, such as Figure 11 As shown, the risk range determination unit 11 can also determine whether the ship's area S or warning range P overlaps with the ship's area BS or warning range BP of other ships. In this example, the rear end LR of the risk range L is the position where the front end of the ship's warning range P meets the rear end of the warning range BP of other ships. The front end LF of the risk range L is the position where the rear end of the ship's warning range P meets the front end of the warning range BP of other ships.

[0118] Furthermore, the risk range determination unit 11 can also determine whether the ship's area S overlaps with a point indicating the position of another ship, a ship area BS, or a warning range BP, without setting a warning area P for the ship itself.

[0119] It should be noted that the encounters between this vessel and other vessels are not limited to the examples mentioned above; for example, such as... Figure 12 As shown, there are also cases where, in either the front (LF) or rear (LR) of the risk zone L, the front of the vessel's warning area P is adjacent to the rear of another vessel's vessel area BS (or warning area BP). In this case, the representative point SF of the vessel, located at the position corresponding to the front (LF) of the risk zone L, can be the front of the vessel's vessel area S, a reference position, the rear of the vessel's vessel area S, or the rear of the vessel's warning area P, etc.

[0120] In addition, such as Figure 13 As shown, when two risk zones L are generated, the following situation also exists in the risk zone L on the side away from other ships: the rear end LR of the risk zone L is the position where the rear end of the ship's warning area P meets the front end of the ship's area BS (or warning area BP) of other ships, and the front end LF of the risk zone L is the position where the front end of the ship's warning area P meets the rear end of the ship's area BS (or warning area BP) of other ships.

[0121] In this case, the representative point SF of the vessel, located at the rear (LR) of the risk area L, can be the rear of the vessel's area S, a reference position, the front of the vessel's area S, or the front of the vessel's warning area P, etc. Similarly, the representative point SF of the vessel, located at the front (LF) of the risk area L, can be the front of the vessel's area S, a reference position, the rear of the vessel's area S, or the rear of the vessel's warning area P, etc.

[0122] Figure 14 It shows the situation in relation to the above. Figure 3This is a display example of a quadrilateral OZT in the present embodiment, which is the same as previous examples.

[0123] In this way, the risk of collision or even approach in the width direction orthogonal to the course of other vessels is visualized by the quadrangular OZT of this embodiment. As a result, when the vessel takes route A, other vessels are observed to approach on both port and starboard sides because of the presence of the OZT near route A. On the other hand, when the vessel takes route B, other vessels are observed not to approach because of the absence of the OZT near route B, allowing for navigation with ample space.

[0124] Thus, by displaying a rectangular OZT that takes into account the positional relationship between the vessel and other vessels during approach, the risk of collision or even approach can be visualized not only in the heading direction of other vessels, but also in the width direction orthogonal to it. Therefore, the actual risk can be represented more accurately through the OZT.

[0125] [First variation]

[0126] The first variation will be described below. For structures that are the same as those described in the above embodiments, detailed descriptions are sometimes omitted by using the same reference numerals. Figure 15A and Figure 15B This is a diagram showing the calculated and displayed examples of OZT for the first modified example.

[0127] like Figure 15A As shown, after determining the risk range L, the risk range determination unit 11 outputs the position of the OZT vertex as the position of the back end LR and front end LF of the risk range L, as well as the position of the representative point SF of the ship located at the position corresponding to the back end LR, to the display control unit 12.

[0128] like Figure 15B As shown, the display control unit 12 displays a triangle OZT on the screen of the display unit 2, with the rear end LR and front end LF of the risk range L determined by the risk range determination unit 11, and the representative point SF of the ship located at the position corresponding to the rear end LR as its vertices. It should be noted that the corners of the OZT can also be rounded.

[0129] That is, in this variant example, the representative point SR of the ship located at the position corresponding to the front end LF of the risk range L (refer to...) Figure 8A and Figure 8B Vertices not included in OZT.

[0130] In the illustrated example, the rear LR of risk zone L is the position where the front of the vessel's warning area P meets the rear of the other vessel's warning area BS. The front LF of risk zone L is the position where the rear of the vessel's warning area S meets the front of the other vessel's warning area BP. The figure shows an example where no warning area P is established behind the vessel or other vessels. The positions of the rear LR and front LF of risk zone L are not limited to these and can be determined using various methods as described above.

[0131] Additionally, the representative point SF of this vessel, located at the position corresponding to the rear end LR of the risk range L, is the reference position RP of this vessel (refer to...). Figure 5 (This is not limited to the above. The representative point SF of this ship can be either the fore-end or the stern of the ship's area S.)

[0132] like Figure 15A As shown, since the forward end LF of the risk zone L is the point where the rear end of the vessel's area S meets the forward end of the other vessel's area BP, the encounter relationship ahead of the risk zone L is one where the vessel crosses ahead of the other vessel. On the other hand, since the rear end LR of the risk zone L is the point where the forward end of the vessel's area P meets the rear end of the other vessel's area BS, the encounter relationship behind the risk zone L is one where the vessel crosses behind the other vessel.

[0133] like Figure 15B As shown, the OZT is a shape that gradually narrows in width towards the leading edge LF of the risk zone L and becomes sharper towards the front of the risk zone L; that is, it indicates the shape in front of the risk zone L. Therefore, when a user sees the OZT, they can not only understand the risk of collision, but also understand the encounter relationship between their own vessel and other vessels before and after the OZT.

[0134] Specifically, if one can determine that when the vessel is advancing to the sharp side of the OZT, i.e., the forward side of the OZT, the encounter relationship is such that the vessel is crossing ahead of other vessels. On the other hand, if one can determine that when the vessel is advancing to the non-sharp side of the OZT (the side with the edge extending towards the vessel), i.e., the aft side of the OZT, the encounter relationship is such that the vessel is crossing behind other vessels.

[0135] like Figure 15C As shown, the display control unit 12 can display an indicator MK in association with the front end LF of the risk range L. The indicator MK has a shape that indicates the front of the risk range L. Specifically, the indicator MK is, for example, mountain-shaped, and the direction is indicated by the orientation of the protrusions. It is not limited to this, and the indicator MK may also be, for example, arrow-shaped or dart-shaped.

[0136] Additionally, the indicator MK is associated with the leading edge LF of the risk range L by displaying it nearby. Specifically, the indicator MK is positioned ahead of the OZT on the predicted course of other vessels and indicates the course direction. However, it is not limited to this; the indicator MK can be connected to the leading edge LF of the risk range L, or it can be connected via a leader line.

[0137] By displaying this indicator MK, users can easily grasp the direction of other vessels. Additionally, by displaying the indicator MK, users can easily understand the encounter situation when their vessel is ahead of other vessels as it moves forward of the OZT.

[0138] Figure 16A and Figure 16B This is a diagram showing calculation and display examples of other OZT. For example... Figure 16A As shown, under conditions where other vessels have high speeds, there may be a situation where the front of the vessel's warning area P comes into contact with the rear of another vessel's vessel area BS, between the front LF and rear LR of the risk range L.

[0139] In this case, the risk range determination unit 11 takes the rear end LR and front end LF of the risk range L, the representative point SF of the ship located at the position corresponding to the rear end LR, and the representative point SR of the ship located at the position corresponding to the front end LF as the position of the OZT vertices, and outputs them to the display control unit 12.

[0140] like Figure 16B As shown, the display control unit 12 displays a quadrilateral OZT with the rear end LR and front end LF of the risk range L, the representative point SF of the ship located at the position corresponding to the rear end LR, and the representative point SR of the ship located at the position corresponding to the front end LF as vertices on the screen of the display unit 2.

[0141] By displaying this quadrangular OZT, users can understand their encounter relationships with other ships as they pass behind it, whether they are moving forward or backward.

[0142] In addition, such as Figure 16C As shown, the display control unit 12 can also display the indicator MK in association with the front end LF of the risk range L. By displaying this indicator MK, the user can easily grasp the direction of travel of other vessels.

[0143] [Second variation]

[0144] The second variation will now be described. For structures that are repeated in the above embodiments, detailed descriptions are sometimes omitted by using the same reference numerals.

[0145] Figure 17This is a diagram illustrating an example of the OZT representing the second variation. The diagram shows an example where OZT1, representing the collision risk of this vessel with another vessel 1, and OZT2, representing the collision risk of this vessel with another vessel 2, partially overlap.

[0146] The display control unit 12 makes the overlapping portion OL in OZT1 and OZT2 display differently from other portions in terms of density, color, or texture. For example, the display control unit 12 displays the overlapping portion OL as darker than other portions. By making semi-transparent OZT1 and OZT2 separately and displaying them overlapping, the overlapping portion OL is displayed as darker than other portions.

[0147] Therefore, by identifying and displaying the overlapping parts OL of multiple OZT1 and OZT2 vessels that may collide with multiple other vessels 1 and 2, users can easily identify areas with higher collision risks.

[0148] Figures 18A-18C This is a diagram showing calculation and display examples for other OZT. The risk range determination section 11 defines the collision range L1 (refer to) where the ship's area S overlaps with the ship's area BS of other ships. Figure 18A The proximity range L2 where the ship's warning zone P overlaps with the warning zones BP of other ships (refer to...) Figure 18B This is identified as a risk area.

[0149] like Figure 18A As shown, the rear end L1R of the collision range L1 is the point where the front end of the vessel's area S abuts with the rear end of the other vessel's area BS. The front end L1F of the collision range L1 is the point where the rear end of the vessel's area S abuts with the front end of the other vessel's area BS.

[0150] Additionally, the representative point S1F of the vessel, located at the rear end L1R of the collision range L1, and the representative point S1R of the vessel, located at the front end L1F of the collision range L1, are the reference positions RP of the vessel (refer to...). Figure 5 ).

[0151] like Figure 18B As shown, the rear end L2R of the approach range L2 is the position where the front end of the vessel's warning area P meets the rear end of the warning area BP of another vessel. The front end L2F of the approach range L2 is the position where the rear end of the vessel's warning area P meets the front end of the warning area BP of another vessel.

[0152] Additionally, the representative point S2F of the vessel, located at the rear end L2R of the approach range L2, and the representative point S1R of the vessel, located at the front end L1F of the collision range L1, are the reference positions RP of the vessel (refer to...). Figure 5 ).

[0153] The display control unit 12 displays the quadrilateral OZT1, which has vertices L1R, L1F, S1F, and S1R as points involved in the collision range L1, and the quadrilateral OZT2, which has vertices L2R, L2F, S2F, and S2R as points involved in the proximity range L2, on the screen of the display unit 2.

[0154] Collision range L1 covers OZT1, which is the area where the vessel has a high probability of colliding with other vessels in the future. Although approach range L2 covers OZT2, which does not have the same high probability of collision as OZT1, it is still the area where the vessel has a high probability of approaching other vessels in the future. OZT1 is included in OZT2.

[0155] The display control unit 12 makes the display methods of OZT1 involved in the collision range L1 and OZT2 involved in the proximity range L2 different from each other in terms of density, color, or texture. For example, the display control unit 12 displays OZT1 as denser than OZT2. By making semi-transparent OZT1 and OZT2 separately and displaying them over each other, OZT1 is displayed as denser than OZT2.

[0156] Therefore, since the OZT1 involved in the collision range L1 and the OZT2 involved in the approach range L2 are identified and displayed, users can easily grasp the degree of risk of collision or even approach.

[0157] The above describes the embodiments of the present invention. The present invention is not limited to the embodiments described above, and those skilled in the art can make various modifications.

[0158] Explanation of reference numerals in the attached figures:

[0159] 1. Information processing unit; 2. Display unit; 3. Radar; 4. AIS; 5. GNSS receiver; 6. Gyrocompass; 7. ECDIS; 8. Alarm unit; 11. Risk range determination unit; 12. Display and control unit; 13. Dimension data retention unit; 100. Ship surveillance system

Claims

1. A ship surveillance system, wherein, have: The first data generation unit generates first ship data representing the position and speed of the first ship. The second data generation unit generates second ship data representing the position and speed of the second ship. The risk range determination unit determines the risk range in the predicted course of the second vessel, based on the positions of the first vessel and the second vessel predicted at each time according to the data of the first vessel and the second vessel, assuming that the first vessel turns in an arbitrary direction and crosses the predicted course of the second vessel, and that the risk value representing the risk of a collision between the first vessel and the second vessel reaches a threshold or higher. as well as The display unit shows an OZT (Obstacle Zone by Target) of a polygon with at least the rear and front ends of the predicted course of the second vessel within the risk range, and a representative point of the first vessel located at a position corresponding to the rear end of the predicted course of the second vessel within the risk range as vertices.

2. The ship surveillance system as described in claim 1, wherein, The OZT is a quadrilateral with vertices at the rear and front ends of the risk range, a representative point of the first vessel located at the position corresponding to the rear end of the risk range, and a representative point of the first vessel located at the position corresponding to the front end of the risk range.

3. The ship surveillance system as described in claim 1 or 2, wherein, The rear end of the risk range is the position where the front end of the warning area set around the first vessel meets the point indicating the position of the second vessel, the rear end of the ship area occupied by the second vessel, or the rear end of the warning area set around the second vessel.

4. The ship surveillance system as described in claim 1 or 2, wherein, The front end of the risk range is the position where the rear end of the warning area set around the first vessel meets the point indicating the position of the second vessel, the front end of the ship area occupied by the second vessel, or the front end of the warning area set around the second vessel.

5. The ship surveillance system as described in claim 1 or 2, wherein, The rear end of the risk range is the position where the rear end of the warning area set around the first vessel meets the point indicating the position of the second vessel, the front end of the ship area occupied by the second vessel, or the front end of the warning area set around the second vessel.

6. The ship surveillance system as described in claim 1 or 2, wherein, The front end of the risk range is the position where the front end of the warning area set around the first vessel meets the point indicating the position of the second vessel, the rear end of the ship area occupied by the second vessel, or the rear end of the warning area set around the second vessel.

7. The ship surveillance system as described in claim 1 or 2, wherein, The representative point of the first vessel located at the position corresponding to the rear end of the risk range is the front end of the ship area occupied by the first vessel, the point indicating the position of the first vessel, the rear end of the ship area occupied by the first vessel, or the rear end of the warning area set around the first vessel.

8. The ship surveillance system as described in claim 1 or 2, wherein, The representative point of the first vessel located at the position corresponding to the front end of the risk range is the rear end of the ship area occupied by the first vessel, the point indicating the position of the first vessel, the front end of the ship area occupied by the first vessel, or the front end of the warning area set around the first vessel.

9. The ship surveillance system as claimed in claim 1, wherein, The OZT is a triangle with vertices at the rear and front ends of the risk range and the representative point of the first vessel located at the position corresponding to the rear end of the risk range.

10. The ship surveillance system as claimed in claim 9, wherein, In the event of an encounter where the first vessel is traversing ahead of the second vessel in front of the risk range, the display unit shows the OZT as a triangle with the rear and front ends of the risk range and the representative point of the first vessel located at the position corresponding to the rear end of the risk range as its vertices.

11. The ship surveillance system as claimed in claim 10, wherein, In the case where the second vessel is crossing ahead of the first vessel at the front end of the risk range, the display unit displays the OZT in a quadrilateral with the rear and front ends of the risk range, the representative point of the first vessel located at the position corresponding to the rear end of the risk range, and the representative point of the first vessel located at the position corresponding to the front end of the risk range as vertices.

12. The ship surveillance system as claimed in any one of claims 9 to 11, wherein, The display unit displays indicators in association with the front end of the risk range of the OZT.

13. The ship surveillance system as described in any one of claims 1, 2, 9, and 10, wherein, The display unit makes the display method of overlapping portions of the multiple OZTs displayed for the multiple second vessels different from the display method of non-overlapping portions of the multiple OZTs.

14. The ship surveillance system as described in any one of claims 1, 2, 9, and 10, wherein, The risk range determination unit determines the collision range where the ship area occupied by the first vessel overlaps with the ship area occupied by the second vessel, and the approach range where the warning zone set around the first vessel overlaps with the ship area occupied by the second vessel or the warning zone set around the second vessel, as the risk range. The display unit displays the collision range in a different way than it displays the proximity range.

15. The ship surveillance system as described in any one of claims 1, 2, 9, and 10, wherein, The first data generation unit includes a GNSS receiver mounted on the first vessel, which detects the position of the first vessel based on radio waves received from GNSS (Global Navigation Satellite System).

16. The ship surveillance system as described in any one of claims 1, 2, 9, and 10, wherein, The second data generation unit includes a radar mounted on the first vessel, which detects the position and speed of the second vessel based on echo data generated by receiving reflected waves of radio waves emitted around the first vessel.

17. A method for ship surveillance, wherein, The first data generation unit generates first ship data representing the position and speed of the first ship. The second data generation unit generates second ship data representing the position and speed of the second ship. Based on the predicted course of the second vessel, assuming the first vessel turns in an arbitrary direction and crosses the second vessel, and the predicted positions of the first and second vessels at various times using data from both vessels, a risk range is determined where the risk value in the predicted course of the second vessel indicates a risk of collision between the first and second vessels exceeding a threshold. The OZT (Obstacle Zone by Target) of a polygon, which has at least the rear and front ends of the predicted course of the second vessel within the risk range and the representative point of the first vessel located at the position corresponding to the rear end of the predicted course of the second vessel within the risk range as vertices, is displayed in the display unit.

18. An information processing apparatus, wherein, have: The risk range determination unit determines the risk range in the predicted course of the second vessel, based on the first vessel data representing the position and speed of the first vessel and the second vessel data representing the position and speed of the second vessel, which are predicted at each moment according to the first vessel data representing the position and speed of the first vessel and the second vessel data representing the position and speed of the second vessel, and determines the risk range in the predicted course of the second vessel, where the risk value representing the risk of a collision between the first vessel and the second vessel reaches a threshold or higher. as well as The display control unit displays an OZT (Obstacle Zone by Target) of a polygon, which has at least the rear and front ends of the predicted course of the second vessel within the risk range, and a representative point of the first vessel located at a position corresponding to the rear end of the predicted course of the second vessel within the risk range as vertices.

19. A computer program product comprising a computer program that causes a computer to perform: Based on the predicted course of the second vessel, assuming the first vessel turns in an arbitrary direction and crosses the second vessel, and using first vessel data representing the position and speed of the first vessel and second vessel data representing the position and speed of the second vessel, the risk values ​​representing the risk of a collision between the first and second vessels in the predicted course of the second vessel are determined to be above a threshold risk range; and The OZT (Obstacle Zone by Target) of a polygon, which has at least the rear and front ends of the predicted course of the second vessel within the risk range and the representative point of the first vessel located at the position corresponding to the rear end of the predicted course of the second vessel within the risk range as vertices, is displayed in the display unit.

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