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

Abstract

[Problem] To provide a ship monitoring system capable of visualizing a collision risk taking into account a change of course of both ships. [Solution] This ship monitoring system is provided with: an acquiring unit for acquiring the current position of a first ship, and the course and vessel speed of the first ship at the current position, and the current position of a second ship, and the course and vessel speed of the second ship at the current position; a determination point setting unit for setting a determination point; a course changed route predicting unit which assumes a first changing-course route along which the first ship navigates, starting from the current position and changing course at the determination point, and a second changing-course route along which the second ship navigates, starting from the current position and changing course at the determination point; and a risk value calculating unit for calculating a collision risk value for the first ship and the second ship on the basis of the first changing-course route and the changing-course route of the second ship.

Description

[Technical Field]

[0001] The present invention relates to a ship monitoring system, a ship monitoring method, an information processing device, and a program. [Background technology]

[0002] Conventionally, there are various methods for assessing the risk of collision between ships. For example, a collision alarm such as a CPA (Closest Point of Approach) alarm is known, which issues an alarm when the distance and time to the CPA fall below a threshold. In addition, a method for displaying danger areas such as an OZT (Obstacle Zone by Target) is also known (see Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Imazu, Junji Fukuto, Masayoshi Numano, "About the Obstruction Zone and its Display by Other Vessels", Journal of the Japan Institute of Navigation, 2002, Vol. 107, pp. 191-197 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional collision warnings, the risk value is calculated under the assumption that both the ship and the other ship are proceeding in a straight line, and course changes by the ship and the other ship are not taken into consideration. Also, in conventional methods for displaying danger areas, the risk value is calculated under the assumption that the other ship is proceeding in a straight line, and course changes by the other ship are not taken into consideration.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its main purpose is to provide a ship monitoring system, a ship monitoring method, an information processing device, and a program that are capable of visualizing collision risk taking into account a ship's course changes. [Means for solving the problem]

[0006] In order to solve the above problem, one embodiment of the ship monitoring system of the present invention comprises an acquisition unit that acquires the current position, course and speed of a first ship at the current position, and the current position, course and speed of a second ship at the current position; a decision point setting unit that sets a decision point; a course change prediction unit that assumes a first course change route along which the first ship will change course from the current position to the decision point and navigate, and a second course change route along which the second ship will change course from the current position to the decision point and navigate; and a risk value calculation unit that calculates a collision risk value between the first ship and the second ship based on the first course change route and the course change route of the second ship.

[0007] In addition, another aspect of the ship monitoring method of the present invention acquires the current position, course and speed at the current position of a first ship, and the current position, course and speed at the current position of a second ship, sets a judgment point, assumes a first course-varying route in which the first ship changes course from the current position to the judgment point, and a second course-varying route in which the second ship changes course from the current position to the judgment point, and calculates a collision risk value between the first ship and the second ship based on the first course-varying route and the course-varying route of the second ship.

[0008] In addition, another aspect of an information processing device of the present invention includes an acquisition unit that acquires the current position, course and speed of a first ship at the current position, and the current position, course and speed of a second ship at the current position; a decision point setting unit that sets a decision point; a course change prediction unit that assumes a first course change route along which the first ship will change course from the current position to the decision point and navigate, and a second course change route along which the second ship will change course from the current position to the decision point and navigate; and a risk value calculation unit that calculates a collision risk value between the first ship and the second ship based on the first course change route and the course change route of the second ship.

[0009] In addition, another aspect of the program of the present invention causes a computer to function as an acquisition unit that acquires the current position, course and speed of a first vessel at the current position, and the current position, course and speed of a second vessel at the current position; a decision point setting unit that sets a decision point; a course change prediction unit that assumes a first course change route along which the first vessel will change course from the current position to the decision point and navigate, and a second course change route along which the second vessel will change course from the current position to the decision point and navigate, and a risk value calculation unit that calculates a collision risk value between the first vessel and the second vessel based on the first course change route and the course change route of the second vessel. [Effects of the Invention]

[0010] According to the present invention, it is possible to visualize the collision risk taking into account the course changes of ships. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating an example of the configuration of a vessel monitoring system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of a other ship management database. [Figure 3] FIG. 1 is a diagram illustrating an example of the configuration of an information processing device according to an embodiment. [Figure 4] 1 is a diagram showing an example of a procedure of a vessel monitoring method according to an embodiment; [Figure 5A] FIG. 10 is a diagram illustrating an example of calculating a risk value. [Figure 5B] FIG. 10 is a diagram illustrating an example of calculating a risk value. [Figure 5C] FIG. 10 is a diagram illustrating a display example of a risk map. [Figure 6] FIG. 10 is a diagram illustrating an example of calculating a risk value. [Figure 7] FIG. 10 is a diagram illustrating weight parameters. [Figure 8] FIG. 10 is a diagram illustrating a display example of a risk map. [Figure 9] FIG. 10 is a diagram for explaining a preference model. [Figure 10A]FIG. 1 is a diagram showing the relationship between TCPA and risk coefficient. [Figure 10B] FIG. 10 is a diagram showing the relationship between time and risk value. [Figure 11] FIG. 10 is a diagram illustrating a display example of a risk map. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] Fig. 1 is a block diagram showing an example of the configuration of a ship monitoring system 100 according to an embodiment. A ship monitoring method according to an embodiment is realized in the ship monitoring system 100. The ship monitoring system 100 is a system that is installed on a ship and monitors ships present in the vicinity.

[0014] The vessel equipped with the vessel monitoring system 100 is an example of a first vessel, and will be referred to as the "own vessel" in the following description. The vessels present around the own vessel are examples of second vessels, and will be referred to as the "other vessels" in the following description.

[0015] In the following description, "speed" is a vector quantity representing speed and direction (so-called ship speed vector), and "velocity" is a scalar quantity.

[0016] The vessel monitoring system 100 includes an information processing 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, and are capable of network communication with each other.

[0017] The information processing device 1 is a computer including a CPU, RAM, ROM, nonvolatile memory, an input / output interface, etc. The CPU of the information processing device 1 executes information processing in accordance with a program loaded from the ROM or nonvolatile memory to the RAM.

[0018] The program may be supplied via an information storage medium such as an optical disk or a memory card, or may be supplied via a communication network such as the Internet or a LAN.

[0019] The display unit 2 is, for example, a display device with a touch sensor. The touch sensor detects a position on the screen pointed to by a finger or the like. The pointed position may be input by a trackball or the like, instead of the touch sensor.

[0020] The radar 3 emits radio waves around the ship and receives the reflected waves, generating echo data based on the received signals. The radar 3 also identifies targets from the echo data and generates target tracking data (TT data) that indicate the position and speed of the targets.

[0021] The AIS (Automatic Identification System) 4 receives AIS data from other ships around the ship or from land-based control. Instead of AIS, a VDES (VHF Data Exchange System) may also be used. The AIS data includes the position and speed of other ships.

[0022] 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 heading. A GPS compass or a magnetic compass may be used instead of a gyrocompass.

[0023] An ECDIS (Electronic Chart Display and Information System) 7 acquires the ship's position from the GNSS receiver 5 and displays the ship's position on an electronic chart. The ECDIS 7 also displays the ship's planned route on the electronic chart. A GNSS plotter may be used instead of an ECDIS.

[0024] The warning unit 8 issues a warning when there is a risk of collision between the ship and another ship. The warning unit 8 may issue a warning by display, sound, or light, for example. A warning by display may be issued by the display unit 2. In other words, the display unit 2 may also function as the warning unit 8.

[0025] In this embodiment, the information processing device 1 is an independent device, but is not limited to this and may be integrated with another device such as the ECDIS 7. In other words, the functional units of the information processing device 1 may be realized by another device such as the ECDIS 7.

[0026] Furthermore, the display unit 2 is also an independent device, but is not limited to this. A display unit of another device such as the ECDIS 7 may be used as the display unit 2 that displays the image generated by the information processing device 1.

[0027] In this embodiment, the combination of the GNSS receiver 5 and the ECDIS 7 is an example of a first data generator, which generates ship data indicating 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 changes in the ship's position over time.

[0028] However, the speed of the ship may be detected based on the direction of the ship detected by the gyrocompass 6 and the speed of the ship detected by a ship's speedometer (not shown).

[0029] The radar 3 or the AIS 4 is an example of a second data generator, and generates other ship data indicating the position and speed of other ships. Specifically, the TT data generated by the radar 3 corresponds to other ship data. The AIS data generated by the AIS 4 also corresponds to other ship data.

[0030] 2 is a diagram showing an example of the other ship management database constructed in the memory of the information processing device 1. Other ship data generated by the radar 3 or the AIS 4 is registered in the other ship management database.

[0031] The other ship management database includes fields such as "other ship identifier," "position," "speed," and "direction." The positions and directions of other ships detected by radar 3 are converted into the same coordinate system as GNSS.

[0032] 3 is a diagram showing an example of the configuration of an information processing device 1 according to an embodiment, which realizes a ship monitoring method according to an embodiment. The information processing device 1 includes a predicted other ship route setting unit 11, a decision point setting unit 11, a course change route prediction unit 12, a risk value calculation unit 13, and a display control unit 14. These functional units are realized by the CPU of the information processing device 1 executing information processing in accordance with a program.

[0033] Based on the own ship data and other ship data, the information processing device 1 calculates a risk value representing the risk of collision between the own ship and the other ship at each of multiple decision points arranged two-dimensionally, assuming that the own ship and the other ship change course and proceed toward each of the multiple decision points (see Figures 5A and 5B).

[0034] The decision point setting unit 11 sets decision points for calculating a risk value. Specifically, the decision point setting unit 11 sets a plurality of decision points at different positions. For example, the decision point setting unit 11 sets a plurality of decision points arranged two-dimensionally.

[0035] The course change prediction unit 12 assumes a course change route for the ship itself, in which the ship starts from its current position, maintains its speed at the current position, and changes course to navigate to a decision point, and assumes a course change route for the other ship, in which the ship starts from its current position, maintains its speed at the current position, and changes course to navigate to a decision point.

[0036] The risk value calculation unit 13 calculates a collision risk value between the ship and the other ship based on the altered course of the ship and the altered course of the other ship. Specifically, the risk value calculation unit 13 calculates a collision risk value for each of the multiple determination units.

[0037] The risk value calculation unit 13 may also calculate the risk value using a weighting factor according to the angle at which the course is changed toward the decision point of the other ship. For example, the weighting factor decreases as the angle at which the course is changed from the course at the current position of the other ship increases.

[0038] Weighting parameters used to calculate the risk value are stored in the form of, for example, a table or a formula in the memory of the information processing device 1. The weighting has a magnitude according to the positional relationship with other ships (see FIG. 7), and is assigned to the surroundings based on the current position of the other ships (details will be described later).

[0039] The display control unit 14 displays the risk values ​​calculated at the plurality of determination points as numerical values ​​or as illustrations corresponding to the numerical values ​​at positions on the electronic nautical chart corresponding to the positions of the respective determination points.

[0040] Specifically, the display control unit 14 displays a risk map showing the distribution of risk values ​​calculated at each of a plurality of judgment points on the display unit 2 (see FIG. 5C). For example, the display control unit 14 indicates the positions of the ship and other ships in the risk map, and places tiles HM that represent the risk values ​​using colors, shading, etc. at the positions of the judgment points.

[0041] Fig. 4 is a diagram showing an example of the procedure of a ship monitoring method according to an embodiment. The information processing device 1 executes the process shown in the figure in accordance with a program. Figs. 5A and 5B are diagrams for explaining an example of calculating a risk value, and Fig. 5C is a diagram showing an example of displaying a risk map.

[0042] First, the information processing device 1 acquires the own ship data and other ship data (S11: processing as an acquisition unit).

[0043] Next, the information processing device 1 sets a plurality of judgment points (S12: judgment point setting unit 11). The plurality of judgment points are arranged two-dimensionally in the virtual space together with the own ship and other ships. For example, as shown in FIG. 5A, the plurality of judgment points are arranged so as to radiate from the own ship as the center. This is not a limitation, but the plurality of judgment points may also be arranged in a grid pattern. This is not a limitation, but only one judgment point may be set, as shown in FIG. 6.

[0044] Next, the information processing device 1 acquires weighting (S13). As shown in FIG. 7, the weighting has a magnitude according to the course change angle from the current direction of the other ship. Specifically, the weighting increases as the course change angle from the current direction of the other ship decreases, and decreases as the course change angle increases. For example, the weighting has a normal distribution centered on the current direction of the other ship. The width of the distribution increases as the ship moves in the direction of the other ship's course.

[0045] Specifically, the information processing device 1 assigns a weight to each decision point according to its positional relationship with the other ship, with the current position of the other ship as the reference point. For example, the largest weight is assigned to a decision point on a course heading from the current position of the other ship toward the current direction, and the further away from the course a decision point is, the smaller the weight is assigned to the decision point.

[0046] Next, the information processing device 1 calculates a risk value in the event that the ship and other ships change course and proceed toward one of the judgment points, and associates the calculated risk value with the judgment point (S14, S15: processing as the course change route prediction unit 12 and risk value calculation unit 13).

[0047] As shown in Figure 5A, the risk value is calculated assuming that both the own ship and the other ships change course from their current positions toward the decision point and continue to proceed toward the decision point while maintaining their speed. Note that the speeds of the own ship and the other ships are not limited to being constant, but may be assumed to change over time. For example, the own ship's speed may gradually increase or decrease over time.

[0048] The risk value may be expressed, for example, as the probability that the ship and the other ship will be present at the decision point at the same time. Alternatively, the risk value may be expressed as the distance between the predicted positions of the ship and the other ship at the same time. The risk value may also be calculated based on the distance and time to the closest point of approach (CPA).

[0049] The risk value is calculated using the weighting assigned to the decision point. For example, the risk value obtained by the above method is corrected by multiplying it by a weighting in the range of 0 to 1, and the corrected risk value is calculated as the risk value associated with the decision point. Note that the use of weighting is not essential.

[0050] In this embodiment, it is assumed that both the ship and the other ship can proceed in any direction within a 360-degree radius, but if the risk value is calculated based on such an assumption, the displayed collision risk may be too broad. Therefore, by assigning weights as described above to the decision points, it is possible to display the collision risk by narrowing it down to areas where the actual risk of collision is high.

[0051] The information processing device 1 repeats the processes of S14 to S15 above until it has calculated risk values ​​for all judgment points (S16: NO), and when it has calculated risk values ​​for all judgment points (S16: YES), it outputs the risk values ​​associated with each judgment point and terminates the specified process.

[0052] If there are multiple other ships, the information processing device 1 executes the above-mentioned processes of S13 to S16 for each of the multiple other ships.

[0053] 5C, the information processing device 1 creates a risk map showing the distribution of the calculated risk values ​​of each judgment point, and displays it on the display unit 2. For example, the information processing device 1 represents the magnitude of the risk value by arranging tiles HM that are closer to red or have a higher density as the risk value of the judgment point increases (so-called heat map display).

[0054] By displaying such a risk map, it is possible to visualize the collision risk taking into account the course changes of both the own ship and other ships.

[0055] In this embodiment, the risk value is calculated taking into account not only the course changes of the ship itself but also the course changes of other ships, so compared to conventional methods of displaying dangerous areas such as OZT (Obstacle Zone by Target), the collision risk display using tiles HM is expanded in the width direction, which is perpendicular to the course direction of other ships. In other words, it is possible to visualize the collision risk not only in the course direction of other ships but also in the width direction.

[0056] Furthermore, as shown in Figure 8, even if there is no collision risk when the other ship is proceeding straight, and a collision risk occurs only when the other ship changes course, the collision risk is displayed using tile HM, making it possible to visualize collision risks that would not have been noticed using conventional methods of displaying dangerous areas.

[0057] If risk values ​​are calculated for each of multiple other ships, the risk map is created using the maximum risk value among the multiple risk values ​​associated with each decision point. Therefore, areas of the risk map where no tiles HM are displayed represent a low risk of collision with any other ship.

[0058] The weighting may be determined based on a preference model that indicates the preference of maneuvering, as shown in Figure 9. The preference model is a model that correlates the course change angle, speed change rate, and maneuvering preference with each other. The center of the course change angle represents the current direction of the other ship. For the speed change rate, 0 represents maintaining the speed and 1 represents stopping.

[0059] In the desirability model, the magnitude of the desirability depends on the course change angle from the current direction of the other ship, similar to the weights having a normal distribution shown in Figure 7. Furthermore, the desirability increases as the speed change rate decreases, and decreases as the speed change rate increases.

[0060] The information processing device 1 determines the weight based on the desirability estimated from the turning angle of the other ship from the current direction using the desirability model. The desirability may be set, for example, in the range of 0 to 1 and used as the weight as is.

[0061] A modified example in which the CPA (Closest Point of Approach) and the bumper model are used to calculate the risk value will be described below.

[0062] Fig. 10A is a diagram showing the relationship between TCPA (Time to Closest Point of Approach) and risk coefficient, Fig. 10B is a diagram showing the relationship between elapsed time and risk value, and Fig. 11 is a diagram showing an example of a displayed risk map.

[0063] As shown in Figure 10A, the risk coefficient for other ships passing within the bumper area gradually increases as TCPA decreases toward 0, and reaches a maximum of 1 when TCPA reaches 0, i.e., when the ship reaches the point where it is closest to the other ship.

[0064] In the conventional example, when TCPA becomes smaller than 0, that is, when the own ship avoids the other ship, the risk coefficient suddenly drops to 0. In this case, as shown in Figure 10B, the collision risk value also gradually increases over time and suddenly drops to 0 when the own ship passes the time ML, when it is closest to the other ship, so the tile HM is interrupted at the line of time ML, resulting in an unnatural display.

[0065] Therefore, in this modification, the information processing device 1 calculates a risk value greater than 0 even when the TCPA is less than 0. Specifically, as shown in FIG. 10A, a bumper region is set so that the risk coefficient remains greater than 0 even when the TCPA becomes smaller than 0. In other words, the bumper region is expanded into the range where the TCPA is negative. For example, as the TCPA decreases from 0, the risk coefficient gradually decreases from 1 until it reaches 0.

[0066] In this case, as shown in Figure 10B, the collision risk value does not suddenly become 0 even after passing the time ML when the ship is closest to the other ship, but gradually decreases until it reaches 0. Therefore, as shown in Figure 11, the tile HM representing the collision risk on the risk map does not end at the line of time ML, and the risk value gradually decreases once the line of time ML is passed. This eliminates the unnatural display.

[0067] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made by those skilled in the art.

[0068] [Note] The ship monitoring system 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 value calculation unit that calculates, based on the first ship data and the second ship data, a risk value that represents the risk of collision between the first ship and the second ship at each of a plurality of judgment points arranged two-dimensionally when it is assumed that the first ship and the second ship change course and proceed toward each of the plurality of judgment points; and a display unit that displays a risk map showing the distribution of the risk values ​​calculated at each of the plurality of judgment points.

[0069] The risk value calculation unit may calculate the risk value using a weight according to a course change angle from the current direction of the second vessel, and the weight may decrease as the course change angle from the current direction of the second vessel increases.

[0070] In addition, the risk value calculation unit may calculate the weight based on the desirability of maneuvering estimated from the turning angle from the current direction of the second vessel, using a model that correlates the turning angle, the rate of change of speed, and the desirability of maneuvering with each other. [Explanation of symbols]

[0071] 1 Information processing device, 2 Display unit, 3 Radar, 4 AIS, 5 GNSS receiver, 6 Gyrocompass, 7 ECDIS, 8 Alarm unit, 11 Decision point setting unit, 12 Course change prediction unit, 13 Risk value calculation unit, 14 Display control unit, 100 Ship monitoring system

Claims

1. an acquisition unit that acquires the current position, course, and speed of the first vessel at the current position, and the current position, course, and speed of the second vessel at the current position; a decision point setting unit that sets a decision point; a course change prediction unit that predicts a first course change route along which the first vessel changes course from the current position to the decision point and navigates, and a second course change route along which the second vessel changes course from the current position to the decision point and navigates, a risk value calculation unit that calculates a collision risk value between the first vessel and the second vessel based on the first altered course and the altered course of the second vessel; Equipped with the risk value calculation unit calculates the collision risk value using a weighting factor according to a course change angle at which the second vessel changes course toward the judgment point, Ship monitoring system.

2. the decision point setting unit sets a plurality of decision points at different positions, the risk value calculation unit calculates the collision risk value for each of the plurality of judgment points; The vessel monitoring system according to claim 1.

3. The weighting decreases as the turning angle based on the course at the current position of the second vessel increases.

3. A vessel monitoring system according to claim 1 or 2.

4. the risk value calculation unit calculates the weighting in accordance with the desirability of maneuvering estimated from the turning angle from the current direction of the second vessel, using a model that correlates the turning angle, the rate of change of speed, and the desirability of maneuvering with each other.

4. A vessel monitoring system according to claim 1.

5. A display unit is further provided which displays the risk values ​​calculated at the plurality of judgment points at positions corresponding to the positions of each judgment point on an electronic nautical chart as numerical values ​​or as illustrations corresponding to the numerical values. The vessel monitoring system according to claim 2 .

6. the risk value calculation unit calculates the risk value greater than 0 even when the TCPA (Time to Closest Point of Approach) is less than 0; 6. A vessel monitoring system according to any one of claims 1 to 5.

7. By computer, Acquire the current position, course and speed of the first vessel at the current position, and the current position, course and speed of the second vessel at the current position; Set the decision point, A first course-changing route is assumed in which the first vessel changes course from the current position to the decision point, and a second course-changing route is assumed in which the second vessel changes course from the current position to the decision point, calculating a collision risk value between the first vessel and the second vessel based on the first altered course and the altered course of the second vessel; A vessel monitoring method, comprising: the calculation of the collision risk value is performed by using a weighting factor corresponding to a course change angle at which the second vessel changes course toward the decision point; Ship monitoring method.

8. an acquisition unit that acquires the current position, course, and speed of the first vessel at the current position, and the current position, course, and speed of the second vessel at the current position; a decision point setting unit that sets a decision point; a course change prediction unit that predicts a first course change route along which the first vessel changes course from the current position to the decision point and navigates, and a second course change route along which the second vessel changes course from the current position to the decision point and navigates, a risk value calculation unit that calculates a collision risk value between the first vessel and the second vessel based on the first altered course and the altered course of the second vessel; Equipped with the risk value calculation unit calculates the collision risk value using a weighting factor according to a course change angle at which the second vessel changes course toward the judgment point, Information processing device.

9. an acquisition unit that acquires the current position, course, and speed of the first vessel at the current position, and the current position, course, and speed of the second vessel at the current position; a decision point setting unit that sets a decision point; a course change prediction unit that predicts a first course change route along which the first vessel changes course from the current position to the decision point and navigates, and a second course change route along which the second vessel changes course from the current position to the decision point and navigates, and a risk value calculation unit that calculates a collision risk value between the first vessel and the second vessel based on the first altered course and the altered course of the second vessel; Make the computer function as the risk value calculation unit calculates the collision risk value using a weighting factor according to a course change angle at which the second vessel changes course toward the judgment point, program.

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