WO2022239402A1

WO2022239402A1 - Ship monitoring system, ship monitoring method, information processing device, and program

Info

Publication number: WO2022239402A1
Application number: PCT/JP2022/009079
Authority: WO
Inventors: 悠太高橋; 優一竹林
Original assignee: 古野電気株式会社
Priority date: 2021-05-11
Filing date: 2022-03-03
Publication date: 2022-11-17
Also published as: JPWO2022239402A1

Abstract

[Problem] To provide a ship monitoring system in which an improvement in the accuracy of predicting a collision risk can be attained. [Solution] This ship monitoring system comprises: a turning information input unit into which is input the bearing and turn rate of a first ship at the current point in time; a position/ship speed information input unit into which is input the position and ship speed of the first ship at the current point in time; a second ship predicted route information input unit into which is input the position and ship speed of a second ship at the current point in time as well as the predicted route thereof after the current point in time; an assessment point setting unit which sets an assessment point along the predicted route on the basis of the position, ship speed, and predicted route of the second ship and which outputs the position of the assessment point and a second ship sailing time, which is the time required for the second ship to sail to the assessment point from the current point in time; a route setting unit which maintains the ship speed of the first ship at the current point in time starting from the bearing of the first ship and the position of the first ship, sets a route to sail toward the assessment point by turning at the turn rate to modify the course of the first ship toward the assessment point, and outputs the route and a first ship sailing time for reaching the assessment point; and a risk value calculation unit which calculates a collision risk value at the assessment point on the basis of the predicted route and second ship sailing time of the second ship, as well as the route and first ship sailing time of the first ship.

Description

SHIP MONITORING SYSTEM, SHIP MONITORING METHOD, INFORMATION PROGRAM, AND PROGRAM

The present invention relates to a ship monitoring system, a ship monitoring method, an information processing device, and a program.

Conventionally, there are various methods for evaluating the risk of collisions between ships. For example, Non-Patent Document 1 discloses a method of displaying an OZT (Obstacle Zone by Target).

By the way, in the conventional method of displaying OZT, the predicted position of the own ship is calculated based on the assumption that the own ship will change course instantaneously at its current position and proceed straight ahead. However, in reality, the own ship gradually changes its course while turning, so there is a risk that an error will occur in the predicted position of the own ship, causing a discrepancy between the area where the OZT is displayed and the area where there is an actual collision risk. be.

The present invention has been made in view of the above problems, and its main object is to provide a ship monitoring system, a ship monitoring method, an information processing device, and a program capable of improving the prediction accuracy of collision risk. to provide.

In order to solve the above problems, a ship monitoring system according to one aspect of the present invention includes a turning information input unit for inputting the current azimuth and turning rate of a first ship, and the current position and ship speed of the first ship. a position and speed information input unit for inputting a position and speed of the second ship at the current time, a second ship predicted route information input unit for inputting the predicted route after the current time, the position of the second ship, Setting a decision point on the predicted route based on the ship speed and the predicted route, and outputting the position of the decision point and the second ship's navigation time required for the second ship to navigate from the current point to the decision section. and a determination point setting unit, in which the first vessel maintains the current vessel speed with the bearing of the first vessel and the position of the first vessel as starting points, turns at the turning rate, and heads toward the determination point. a route setting unit that sets a route to navigate toward the decision point after changing the course and outputs the route and the navigation time of the first ship to reach the decision point; the predicted route of the second ship and the second ship; a risk value calculation unit that calculates a collision risk value at the decision point based on the navigation time and the route of the first ship and the navigation time of the first ship.

A ship monitoring method according to another aspect of the present invention inputs the current azimuth and turning rate of one ship, inputs the current position and speed of the first ship, inputs the current position and speed of the second ship, Input ship speed and predicted route after the current time point, set a decision point on the predicted route based on the position of the second ship, ship speed and predicted route, and set the position of the decision point and the second ship outputs the second ship's navigation time required to navigate from the current time to the determination unit, and the first ship maintains the ship's speed at the current time based on the bearing of the first ship and the position of the first ship. setting a route for sailing toward the decision point by turning at the turning rate and changing the course toward the decision point, outputting the route and the first vessel's navigation time to reach the decision point; A collision risk value at the decision point is calculated based on the predicted course of the second ship and the navigation time of the second ship, and the course of the first ship and the navigation time of the first ship.

Further, an information processing apparatus according to another aspect of the present invention includes a turning information input unit to which the current azimuth and turning rate of a first ship are input, and a position input unit to which the current position and speed of the first ship are input. a ship speed information input unit; a second ship predicted route information input unit to which the current position and ship speed of the second ship and the predicted route after the current time are input; and the second ship position, ship speed and predicted route A decision point setting unit that sets a decision point on the predicted route based on the above, and outputs the position of the decision point and the navigation time of the second ship required for the second ship to travel from the current point to the decision unit. Then, the first vessel maintains the current vessel speed with the bearing of the first vessel and the position of the first vessel as starting points, turns at the turning rate, and changes the course toward the judgment point. a route setting unit that sets a route for navigating toward a decision point and outputs the route and the navigation time of the first ship to reach the decision point; the predicted route of the second ship and the navigation time of the second ship; and a risk value calculation unit that calculates a collision risk value at the decision point based on the route of the first ship and the first ship navigation time.

Further, a program according to another aspect of the present invention includes a turning information input unit for inputting a current azimuth and turning rate of a first ship, and position and speed information for inputting a current position and speed of the first ship. an input unit, a second ship predicted route information input unit to which the current position and ship speed of the second ship and the predicted route after the current time are input, the prediction based on the position, speed and predicted route of the second ship a decision point setting unit for setting a decision point on a route and outputting the position of the decision point and the navigation time of the second ship required for the second ship to navigate from the current point to the decision unit; and the first ship. maintains the ship speed at the present time with the bearing of the first ship and the position of the first ship as starting points, turns at the turning rate, and sails toward the decision point by changing the course toward the decision point. a route setting unit for setting a route to be used, and outputting the route and the navigation time of the first ship to reach the judgment point; the predicted route of the second ship and the navigation time of the second ship; The computer is caused to function as a risk value calculation unit that calculates a collision risk value at the decision point based on the route and the first ship's navigation time.

According to the present invention, it is possible to improve the accuracy of collision risk prediction.

It is a figure which shows the structural example of the ship monitoring system which concerns on embodiment. It is a figure which shows the example of another ship management database. It is a figure which shows the calculation example of conventional OZT. It is a figure which shows the calculation example of conventional OZT. It is a figure which shows the structural example of the information processing apparatus which concerns on embodiment. It is a figure which shows the example of the content of a ROT threshold value table. It is a figure which shows the procedure example of the ship monitoring method which concerns on embodiment. It is a figure for demonstrating the calculation example of OZT. It is a figure for demonstrating the calculation example of OZT. It is a figure which shows the procedure example of the ship monitoring method which concerns on a modification. It is a figure for demonstrating the calculation example of OZT.

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

FIG. 1 is a block diagram showing a configuration example of a ship monitoring system 100 according to an embodiment. A ship monitoring method according to the embodiment is implemented in a ship monitoring system 100 . The ship monitoring system 100 is a system that is mounted on a ship and monitors surrounding ships.

The ship on which the ship monitoring system 100 is installed is an example of the first ship, and will be referred to as "own ship" in the following description. In addition, ships existing around the own ship are examples of the second ship, and are referred to as "other ships" in the following description.

Also, in the following explanation, "speed" is a vector quantity representing speed and direction (so-called ship speed vector), and "speed" is a scalar quantity.

The ship 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.

The information processing device 1 is a computer including a CPU, RAM, ROM, non-volatile memory, an input/output interface, and the like. The CPU of the information processing device 1 executes information processing according to a program loaded from the ROM or nonvolatile memory to the RAM.

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

The display unit 2 is, for example, a display device with a touch sensor. The touch sensor detects a position within the screen indicated by a finger or the like. The indicated position may be input by a trackball or the like instead of the touch sensor.

The radar 3 emits radio waves around its own ship, receives the reflected waves, and generates echo data based on the received signals. The radar 3 also identifies the target from the echo data and generates target tracking data (TT data) representing the position and speed of the target.

The AIS (Automatic Identification System) 4 receives AIS data from other ships around the ship or from land control. Not limited to AIS, VDES (VHF Data Exchange System) may be used. AIS data includes the positions and velocities of other ships.

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

The 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 the electronic chart. The ECDIS 7 also displays the scheduled route of the own ship on the electronic chart. Not limited to ECDIS, a GNSS plotter may be used.

The alarm unit 8 issues an alarm when there is a risk of the own ship colliding with another ship. The alarm unit 8 may be, for example, an alarm by display, or may be an alarm by sound or light. The display warning may be given on the display unit 2 . That is, the display unit 2 may also serve as the alarm unit 8 .

In this embodiment, the information processing device 1 is an independent device, but it is not limited to this, and may be integrated with other devices such as ECDIS 7 . That is, the functional units of the information processing device 1 may be implemented by other devices such as the ECDIS 7 .

The display unit 2 is also an independent device, but the display unit is not limited to this, and a display unit of another device such as the ECDIS 7 may be used as the display unit 2 for displaying the image generated by the information processing device 1. .

In this embodiment, the set of the GNSS receiver 5 and the ECDIS 7 is an example of the first data generation unit, and generates own ship data representing the position and speed of the own ship. Specifically, the GNSS receiver 5 detects the position of the own ship, and the ECDIS 7 detects the speed of the own ship from the time change of the position of the own ship.

Not limited to this, the speed of the own ship may be detected based on the bearing of the own ship detected by the gyrocompass 6 and the speed of the own ship detected by a speedometer (not shown).

Also, the radar 3 or AIS 4 is an example of a second data generation unit, and generates other ship data representing the position and speed of another ship. Specifically, the TT data generated by the radar 3 corresponds to other ship data. AIS data generated by the AIS 4 also corresponds to other ship data.

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

The other ship management database includes fields such as "other ship identifier", "position", "speed", and "azimuth". In addition, the position and direction of the other ship detected by the radar 3 are converted into the same coordinate system as GNSS.

　Figs. 3A and 3B are diagrams showing examples of conventional OZT calculations. An OZT (Obstacle Zone by Target) is a zone in which the navigation of one's own ship may be obstructed by another ship, and is displayed on the predicted course of the other ship.

In the conventional OZT calculation, as shown in Fig. 3A, the collision risk is calculated under the assumption that the own ship will change course instantly and proceed straight toward the decision point on the predicted course of the other ship. However, as shown in FIG. 3B, the own ship actually turns toward the decision point, so there may be a gap between the area where the OZT is displayed and the area where there is an actual collision risk.

For example, at the judgment point farthest from the own ship's bow line among the judgment points where the OZT is displayed, it is judged that there is a collision risk under the assumption that the own ship changes course instantly and goes straight, By the time the own ship turns and reaches the decision point, the other ship has already passed the decision point and no collision occurs. Thus, the OZT may be displayed at decision points where no collision actually occurs.

Therefore, in this embodiment, as described below, the accuracy of collision risk prediction is improved by performing risk calculations that take into account the turning of the own ship.

FIG. 4 is a diagram showing a configuration example of the information processing device 1 according to the embodiment, which implements the ship monitoring method according to the embodiment. The information processing device 1 includes a turning information input unit 11, a position ship speed information input unit 12, an other ship predicted route information input unit 13, a decision point setting unit 14, a route setting unit 15, a risk value calculation unit 16, and a display control unit. 17. These functional units are implemented by the CPU of the information processing apparatus 1 executing information processing according to programs.

Based on the own ship data and the other ship data, the information processing device 1 assumes that the own ship turns from the current position and current direction toward each decision point on the predicted course of the other ship. A risk value representing the risk of collision between the own ship and another ship is calculated at the decision point (see Fig. 7).

The turning information input unit 11 receives the current azimuth and turning rate of the own ship based on the own ship data. Hereinafter, the rate of turn is also referred to as "ROT" (Rate of Turn).

Specifically, the ROT threshold is input to the turning information input unit 11 . The ROT threshold is the upper limit of ROT allowed for own ship, and is an example of a predetermined ROT. The ROT threshold is set, for example, by user input. The turning information input unit 11 uses an ROT that is equal to or less than the ROT threshold.

However, the turning information input unit 11 prepares an ROT threshold table in which the total length of the ship and the ROT threshold are associated with each other, as shown in FIG. may Instead of ship length, other parameters describing ship size may be used, such as ship volume, weight, or ship type.

The position and speed information input unit 12 receives the current position and speed of the own ship based on the own ship data.

The other ship's predicted route information input unit 13 receives the current position and ship speed of the other ship, and the predicted route after the current time based on the other ship's data. The predicted course of the other ship is calculated under the assumption that the other ship will navigate from the current position while maintaining the ship's speed and heading.

A determination point setting unit 14 sets a determination point on the predicted route based on the position of the other ship, the speed of the ship, and the predicted route, and determines the position of the determination point and the position of the other ship from the current time to the determination unit. It outputs the other ship's navigation time required to do so. Specifically, the judgment point setting unit 14 sets a plurality of judgment points on the predicted route.

The route setting unit 15 maintains the ship's current ship speed with its own ship's bearing and own ship's position as a starting point, turns at a turning rate, and changes its course toward the decision point. A route to be navigated is set, and the route and the own ship's navigation time to reach the judgment point are output. Specifically, the route setting unit 15 outputs a plurality of routes along which the ship travels toward each of the plurality of judgment points, and a plurality of own ship navigation times for reaching each of the plurality of judgment points.

The risk value calculation unit 16 calculates the collision risk value at the decision point based on the other ship's predicted route and other ship's navigation time, and the own ship's route and own ship's navigation time. Specifically, the risk value calculator 16 calculates a collision risk value at each of a plurality of determination points.

The display control unit 17 displays OZT at determination points where the risk value calculated by the risk value calculation unit 16 is equal to or greater than the threshold (see FIG. 7). Specifically, the display control unit 17 indicates the positions of the own ship and the other ship in the image displayed on the display unit 2, and arranges the OZT on the predicted course of the other ship.

FIG. 6 is a diagram showing a procedure example of the ship monitoring method according to the embodiment. The information processing device 1 executes the processing shown in the figure according to a program. FIG. 7 is a diagram showing a calculation example and a display example of OZT.

First, the information processing device 1 acquires own ship data and other ship data (S11), and acquires the ROT threshold (S12).

Next, the information processing device 1 sets a decision point on the predicted course of the other ship based on the data of the other ship (S13: processing by the decision point setting unit 14). A plurality of judgment points are set at equal intervals on the predicted course of the other ship. A plurality of determination points represent predicted positions of other ships at each point in time after each predetermined time period.

Specifically, the calculation of the predicted course of the other ship and the setting of the decision point are performed under the assumption that the other ship will maintain its speed from its current position. In other words, it is assumed that the other ship navigates from the position of the other ship at the reference time with the magnitude and direction of the ship speed vector constant. Therefore, the predicted course of the other ship becomes a straight line extending the ship speed vector and passing through the position of the other ship at the reference time, and the plurality of decision points are set on the straight line.

Not limited to this, it may be assumed that at least one of the other ship's speed and direction changes according to time. That is, the speed of the other ship need not be constant as long as the predicted position of the other ship after the elapse of the predetermined time can be calculated. For example, the speed of other ships may gradually increase or decrease over time. In addition, when the route data of the scheduled route of the other ship can be acquired, a plurality of judgment points may be set on the scheduled route of the other ship based on the route data.

Next, based on the own ship data, the information processing device 1 calculates the risk value when the own ship turns toward one of the determination points (S14: route setting unit 15 and risk value calculation unit 16 processing as). The risk value is expressed, for example, by the probability that the own ship and another ship are present at the decision point at the same time. Alternatively, the risk value may be represented by the separation distance between the predicted position of the own ship and the predicted positions of the other ships at the same point in time.

As shown in FIG. 7, the information processing device 1 calculates the risk value under the assumption that the own ship turns at a constant ROT that does not exceed the ROT threshold while maintaining the speed from the current position to the determination point. do. The ROT increases as the distance between the own ship's bow line and the judgment point increases.

In other words, the own ship reaches the decision point by changing the direction of the ship speed vector at a constant degree while keeping the size of the ship speed vector constant from the own ship position at the reference time.

In this example, the course of the own ship is represented by an arc extending from the current position of the own ship in the bow direction to the decision point. Therefore, the course of the own ship is longer than the straight line connecting the current position of the own ship and the decision point.

Not limited to this, as shown in FIG. 8, the information processing device 1 calculates the risk value based on the assumption that the own ship turns straight from the current position at the ROT threshold and then reaches the decision point. good too. In this example, the route of own ship is represented by a set of arc RP and straight line LP. Note that the turn may be performed at an ROT equal to or lower than the ROT threshold.

In this embodiment, it is assumed that the speed of the own ship is constant, but it is not limited to this, and it may be assumed that the speed of the own ship changes according to time. For example, the own ship's speed may gradually increase or decrease over time.

Next, when the calculated risk value is equal to or greater than the threshold (S15: YES), the information processing device 1 determines the determination point as the OZT display point (S16). On the other hand, when the calculated risk value is less than the threshold (S15: NO), the information processing device 1 does not set the OZT display point as the determination point.

The information processing device 1 repeats the processes of S14 to S16 until the risk values are calculated for all the determination points (S17: NO), and when the risk values are calculated for all the determination points (S17: YES), OZT display. Output the position of the point and terminate the process.

It should be noted that if there are a plurality of other ships, the information processing device 1 executes the processes of S13 to S17 for each of the plurality of other ships.

The information processing device 1 displays the OZT at the determined OZT display point (processing by the display control unit 17). A predetermined safety clearance is used for the radius of the OZT. As shown in FIG. 7, in the range where two or more OZT display points are continuous, the OZT may have a shape extending in the same direction as the predicted course of the other ship, for example, a rounded rectangular shape with semicircles at both ends. good.

According to the embodiment described above, the collision risk value is calculated assuming that the own ship turns from the current position and current direction toward each of the plurality of decision points on the predicted course of the other ship. It is possible to improve the prediction accuracy. That is, it is possible to suppress the deviation between the area where the OZT is displayed and the area where there is an actual collision risk.

FIG. 9 is a diagram showing a procedure example of a ship monitoring method according to a modification. FIG. 10 is a diagram for explaining a calculation example of OZT. A detailed description may be omitted by assigning the same numbers to configurations or procedures that overlap with the above embodiments.

When the information processing device 1 sets a decision point on the predicted course of the other ship (S13), the range of the decision points set on the predicted course of the other ship that the own ship can reach in a turn equal to or less than the ROT threshold. (S23). Then, the information processing apparatus 1 calculates a risk value for each of the extracted determination points and determines OZT display points (S14-S16 and S27).

On the other hand, the information processing apparatus 1 selects, among the determination points set for the predicted courses of other ships, determination points outside the reachable range of the own ship in a turn equal to or less than the ROT threshold (determination points marked with x in FIG. 10). ), the risk value is not calculated.

That is, as shown in FIG. 10, risk values are calculated for decision points inside a pair of left and right arcs representing the ROT threshold, and risk values are calculated for decision points outside the pair of left and right arcs representing the ROT threshold. No value is calculated.

According to this, the decision points for which the risk value is calculated are narrowed down to the decision points within the reachable range of the own ship by turning below the ROT threshold, so that the calculation speed is improved and the calculation load is reduced. becomes possible.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible for those skilled in the art.

In the above embodiment, the risk value is calculated on the assumption that the own ship turns at a predetermined ROT while maintaining its speed. The position of the own ship may be predicted using a parameter representing the turning performance of the own ship based on the According to this, it becomes possible to calculate the risk value taking into account even the fact that the speed of the own ship decreases during turning.

[Note]
The ship monitoring system includes a first data generation unit that generates first ship data representing the position and speed of the first ship, and a second data generation unit that generates second ship data representing the position and speed of the second ship. , based on the first ship data and the second ship data, it is assumed that the first ship turns from the current position and direction toward each of a plurality of decision points on the predicted course of the second ship. a risk value calculation unit that calculates a risk value representing a risk of collision between the first vessel and the second vessel at each of the plurality of determination points when the risk value among the plurality of determination points is and a display unit that displays an OZT (Obstacle Zone by Target) at a determination point equal to or greater than a threshold.

Further, the risk value calculation unit may calculate the risk value on the assumption that the first vessel turns at a predetermined ROT (Rate of Turn) or less. The risk value calculator may calculate the risk value on the assumption that the first vessel turns from the current position to the determination point at a constant ROT. The risk value calculation unit may calculate the risk value on the assumption that the first vessel reaches the decision point by going straight after turning at the predetermined ROT from the current position.

Further, the risk value calculation unit may use the ROT corresponding to the size of the first ship as the predetermined ROT. The risk value calculator may predict the position of the first vessel using a parameter representing turning performance of the first vessel.

Further, the risk value calculation unit calculates the risk value for each determination point within a range that the first ship can reach by turning at or below the predetermined ROT in the predicted course of the second ship. good too. The risk value calculation unit calculates the risk value for each determination point out of the range that the first ship can reach by turning at or below the predetermined ROT, in the predicted course of the second ship. good.

1 Information processing device, 2 Display unit, 3 Radar, 4 AIS, 5 GNSS receiver, 6 Gyro compass, 7 ECDIS, 8 Alarm unit, 11 Risk value calculation unit, 12 Display control unit, 13 Parameter storage unit, 100 Ship monitoring system

Claims

a turning information input unit for inputting the current azimuth and turning rate of the first ship;
a position and speed information input unit for inputting the current position and speed of the first ship;
a second vessel forecasted route information input unit for inputting the current position and speed of the second vessel and the forecasted course after the current time;
A decision point is set on the predicted route based on the position, ship speed and predicted route of the second ship, and the position of the decision point and the number of times required for the second ship to navigate from the current point to the decision section. 2 a judgment point setting unit that outputs the ship navigation time;
Said first ship maintains said current ship speed starting from said first ship's bearing and said first ship's position, turns at said turning rate, and changes course toward said decision point. a route setting unit that sets a route to navigate toward and outputs the route and the navigation time of the first ship to reach the judgment point;
a risk value calculation unit that calculates a collision risk value at the decision point based on the predicted route and the second ship navigation time of the second ship, and the route and the first ship navigation time of the first ship;
a vessel monitoring system.
The decision point setting unit sets a plurality of the decision points on the predicted route,
The route setting unit outputs a plurality of routes for navigating toward each of the plurality of judgment points and a plurality of navigation times of the first vessel that reach each of the plurality of judgment points,
wherein the risk value calculation unit calculates a collision risk value at each of the plurality of decision points;
A ship monitoring system according to claim 1 .
The turning information input unit receives a turning rate less than or equal to a predetermined turning rate.
The vessel surveillance system according to claim 1 or 2.
The route setting unit sets the route under the assumption that the first ship turns from the current position to the determination point at a constant turning rate.
A vessel monitoring system according to claim 3.
The risk value calculation unit sets the route on the assumption that the first ship turns at a predetermined turning rate from the current position and then proceeds straight to reach the decision point.
A vessel monitoring system according to claim 3.
The turning information input unit sets the route using a turning rate corresponding to the size of the first vessel.
A ship monitoring system according to any one of claims 1 to 5.
The risk value calculation unit calculates the risk value for each determination point within a range that the first ship can reach by turning at a turning rate equal to or less than the predetermined turning rate, in the predicted route of the second ship.
A vessel monitoring system according to claim 3.
The risk value calculation unit does not calculate the risk value for each determination point on the predicted route of the second ship that is outside a range that the first ship can reach by turning at a turning rate equal to or less than the predetermined turning rate.
A vessel monitoring system according to claim 7.
Enter the current heading and turning rate of the first vessel,
Inputting the current position and speed of the first vessel,
Enter the current position of the second ship, the speed of the ship, and the predicted route after the current time,
A decision point is set on the predicted route based on the position, ship speed and predicted route of the second ship, and the position of the decision point and the number of times required for the second ship to navigate from the current point to the decision section. 2 output ship navigation time and
Said first ship maintains said current ship speed starting from said first ship's bearing and said first ship's position, turns at said turning rate, and changes course toward said decision point. Set a route to navigate toward, output the route and the first ship navigation time to reach the decision point,
calculating a collision risk value at the decision point based on the predicted route and second ship navigation time of the second ship, and the route and first ship navigation time of the first ship;
Vessel surveillance method.
a turning information input unit for inputting the current azimuth and turning rate of the first ship;
a position and speed information input unit for inputting the current position and speed of the first ship;
a second vessel forecasted route information input unit for inputting the current position and speed of the second vessel and the forecasted course after the current time;
A decision point is set on the predicted route based on the position, ship speed and predicted route of the second ship, and the position of the decision point and the number of times required for the second ship to navigate from the current point to the decision section. 2 a judgment point setting unit that outputs the ship navigation time;
Said first ship maintains said current ship speed starting from said first ship's bearing and said first ship's position, turns at said turning rate, and changes course toward said decision point. a route setting unit that sets a route to navigate toward and outputs the route and the navigation time of the first ship to reach the judgment point;
a risk value calculation unit that calculates a collision risk value at the decision point based on the predicted route and the second ship navigation time of the second ship, and the route and the first ship navigation time of the first ship;
An information processing device.
a turning information input unit for inputting the current azimuth and turning rate of the first ship;
a position and speed information input unit for inputting the current position and speed of the first ship;
A second ship predicted route information input unit for inputting the current position of the second ship, the ship speed, and the predicted route after the current time,
A decision point is set on the predicted route based on the position, ship speed and predicted route of the second ship, and the position of the decision point and the number of times required for the second ship to navigate from the current point to the decision section. 2 a decision point setting unit that outputs the ship navigation time;
Said first ship maintains said current ship speed starting from said first ship's bearing and said first ship's position, turns at said turning rate, and changes course toward said decision point. A route setting unit that sets a route to navigate toward and outputs the route and the navigation time of the first ship to reach the judgment point;
A risk value calculation unit that calculates a collision risk value at the decision point based on the predicted route and the second ship navigation time of the second ship and the route of the first ship and the first ship navigation time;
A program that allows a computer to function as a