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

Abstract

[Problem] To provide a ship monitoring system with which it is easy to ascertain whether a ship will pass on the front side or the rear side of another ship. [Solution] A ship monitoring system provided with: a first estimation unit that estimates, on the basis of a first calculation formula, from first ship data representing the position and speed of a first ship, a predicted position of the first ship in each direction after the elapse of a first period of time when it is assumed that the first ship will change heading at the current position and will navigate in any direction; a second estimation unit that estimates, on the basis of a second calculation formula, from second ship data representing the position and speed of a second ship, a predicted course of the second ship and a predicted position of the second ship after the elapse of a second period of time, the predicted position being included in the predicted course; and a passage determination unit that, of the predicted course of the second ship, determines a side closer to the current position of the second ship than a matching point at which the predicted position of the first ship and the predicted position of the second ship match when the first period of time and the second period of time are equal, to be a zone in which the first ship will pass on one side of the front side and the rear side of the second ship, and determines a side farther from the current position of the second ship than the match point to be a zone in which the first ship will pass on the other side of the front side and the rear side 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, various methods exist for evaluating the risk of collisions between ships. For example, Non-Patent Document 1 discloses a method for displaying the OZT (Obstacle Zone by Target). [Prior art documents] [Patent Documents]

[0003] [Non-Patent Document 1] Hayato Imazu, Junji Fukuto, Masayoshi Numano, "On Interference Zones by Other Vessels and Their Indication", Transactions of the Japan Institute of Navigation, 2002, Vol. 107, pp. 191-197. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Incidentally, in methods that display OZT, the area within the predicted course of other vessels where OZT is not displayed represents the area where ships can navigate. However, it is difficult to determine at a glance whether a ship will pass in front of or behind another vessel within such an area.

[0005] The present invention has been made in view of the above problems, and its main objective is to provide a ship monitoring system, ship monitoring method, information processing device, and program that make it easy to determine whether a ship is passing in front of or behind another ship. [Means for solving the problem]

[0006] To solve the above problems, a ship monitoring system according to one aspect of the present invention includes: a first estimation unit that estimates the predicted position of the first ship after a first time has elapsed in each direction, assuming that the first ship changes course in any direction at its current position and sails, based on a first calculation formula from first ship data representing the position and speed of the first ship; a second estimation unit that estimates the predicted course of the second ship and the predicted position of the second ship after a second time has elapsed, included in the predicted course, based on a second calculation formula from second ship data representing the position and speed of the second ship; and a passage determination unit that determines the side of the predicted course of the second ship that is closer to the current position of the second ship than the point of coincidence where the predicted position of the first ship and the predicted position of the second ship coincide when the first time and the second time are equal, as the range in which the first ship passes either in front of or behind the second ship, and determines the side of the predicted course of the second ship that is further from the current position of the second ship than the point of coincidence as the range in which the first ship passes either in front of or behind the second ship.

[0007] Furthermore, a ship monitoring system according to another aspect of the present invention includes: 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 first estimation unit that creates a first calculation formula representing the predicted position of the first ship after a first time has elapsed in each direction, assuming that the first ship changes course in any direction from its current position, based on the first ship data; a second estimation unit that creates a second calculation formula representing the predicted position of the second ship after a second time has elapsed, based on the second ship data; and a passage determination unit that determines, based on the solution to a system of equations including the first and second calculation formulas under the condition that the second time is greater than the first time or the second time is less than the first time, the range in which the first ship passes in front of the second ship and the range in which the first ship passes behind the second ship, among the predicted course of the second ship represented by the second calculation formula.

[0008] Furthermore, in another aspect of the present invention, a ship monitoring method estimates the predicted position of the first ship after a first time has elapsed in each direction, assuming that the first ship changes course in any direction at its current position, based on a first calculation formula, from first ship data representing the position and speed of the first ship; estimates the predicted course of the second ship and the predicted position of the second ship after a second time has elapsed, included in the predicted course, based on a second calculation formula, from second ship data representing the position and speed of the second ship; determines that the side of the predicted course of the second ship that is closer to the current position of the second ship than the point of coincidence where the predicted position of the first ship and the predicted position of the second ship coincide when the first time and the second time are equal is the range in which the first ship passes either in front of or behind the second ship; and determines that the side of the predicted course of the second ship that is further from the current position of the second ship than the point of coincidence is the range in which the first ship passes either in front of or behind the second ship.

[0009] Furthermore, an information processing device in another embodiment of the present invention includes: a first estimation unit that estimates the predicted position of the first vessel after a first time has elapsed in each direction, assuming that the first vessel changes course in any direction at its current position and sails, based on a first calculation formula from first vessel data representing the position and speed of the first vessel; a second estimation unit that estimates the predicted course of the second vessel and the predicted position of the second vessel after a second time has elapsed, included in the predicted course, based on a second calculation formula from second vessel data representing the position and speed of the second vessel; and a passage determination unit that determines the side of the predicted course of the second vessel that is closer to the current position of the second vessel than the point of coincidence where the predicted position of the first vessel and the predicted position of the second vessel coincide when the first time and the second time are equal, as the range in which the first vessel passes either in front of or behind the second vessel, and determines the side of the predicted course of the second vessel that is further from the current position of the second vessel than the point of coincidence as the range in which the first vessel passes either in front of or behind the second vessel.

[0010] Also, a program according to another aspect of the present invention is based on a first calculation formula, from first ship data representing the position and speed of a first ship, when it is assumed that the first ship changes course in an arbitrary direction at the current position and sails, estimating the predicted position of the first ship after a first time has elapsed in each direction; based on a second calculation formula, from second ship data representing the position and speed of a second ship, estimating the predicted course of the second ship and the predicted position of the second ship after a second time has elapsed included in the predicted course; and, of the predicted course of the second ship, the side closer to the current position of the second ship than the coincidence point where the predicted position of the first ship and the predicted position of the second ship coincide when the first time and the second time are equal is determined as the range where the first ship passes either in front of or behind the second ship, and the side farther from the current position of the second ship than the coincidence point is determined as the range where the first ship passes the other of in front of or behind the second ship, and causes a computer to execute this.

Effects of the Invention

[0011] According to the present invention, it becomes easy to grasp whether a ship passes in front of or behind another ship.

Brief Description of the Drawings

[0012] [Figure 1] It is a diagram showing a configuration example of a ship monitoring system according to an embodiment. [Figure 2] It is a diagram showing an example of other ship management database. [Figure 3] It is a diagram showing a display example of OZT (conventional example). [Figure 4] It is a diagram showing a configuration example of an information processing apparatus according to an embodiment. [Figure 5] It is a diagram for explaining calculation. [Figure 6] It is a diagram for explaining calculation. [Figure 7] It is a diagram showing a display example. [Figure 8] It is a diagram showing another display example.

Modes for Carrying Out the Invention

[0013] Embodiments of the present invention will be described below with reference to the drawings.

[0014] Figure 1 is a block diagram showing an example configuration of a ship monitoring system 100 according to an embodiment. The ship monitoring system 100 is a system installed on a ship for monitoring surrounding ships.

[0015] A vessel equipped with the ship monitoring system 100 is an example of the first vessel and will be referred to as "our vessel" in the following description. Vessels in the vicinity of our vessel are examples of the second vessel and will be referred to as "other vessels" in the following description.

[0016] Furthermore, in the following explanation, "velocity" is assumed to be a vector quantity representing speed and direction (the so-called ship speed vector), and "speed" is assumed to be a scalar quantity.

[0017] 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.

[0018] Information processing device 1 is a computer that includes a CPU, RAM, ROM, non-volatile memory, and input / output interfaces. The CPU of information processing device 1 performs information processing according to a program loaded into RAM from ROM or non-volatile memory.

[0019] The program may be supplied via an information storage medium such as an optical disc or memory card, or via a communication network such as the Internet or LAN.

[0020] The display unit 2 is, for example, a display device with a touch sensor. The touch sensor detects the position indicated on the screen by a finger or the like. The indicated position may be input not only by a touch sensor, but also by a trackball or the like.

[0021] Radar 3 emits radio waves around the vessel and receives the reflected waves, generating echo data based on the received signals. Radar 3 also identifies targets from the echo data and generates target tracking data (TT data) that represents the position and speed of the targets.

[0022] The Automatic Identification System (AIS) 4 receives AIS data from other vessels or shore-based control systems in the vicinity of the vessel. While AIS is not the only option, a VHF Data Exchange System (VDES) may also be used. The AIS data includes information such as the position and speed of other vessels.

[0023] The GNSS receiver 5 detects the ship's position based on radio waves received from the GNSS (Global Navigation Satellite System). The gyrocompass 6 detects the ship's bearing. A GPS compass or magnetic compass may be used instead of a gyrocompass.

[0024] The ECDIS (Electronic Chart Display and Information System) 7 obtains the ship's position from the GNSS receiver 5 and displays the ship's position on the electronic chart. The ECDIS 7 also displays the ship's planned route on the electronic chart. A GNSS plotter may be used instead of the ECDIS.

[0025] The alarm unit 8 issues an alarm when there is a risk of the vessel colliding with another vessel. The alarm unit 8 may be an alarm by display, a sound, or a light. An alarm by display may be provided by the display unit 2. In other words, the display unit 2 may also function as the alarm unit 8.

[0026] 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 ECDIS7. In other words, the functional parts of the information processing device 1 may be implemented by other devices such as ECDIS7.

[0027] Furthermore, although the display unit 2 is an independent device, it is not limited to this, and the display unit of another device such as ECDIS7 may be used as the display unit 2 that displays the image generated by the information processing device 1.

[0028] In this embodiment, the GNSS receiver 5 and ECDIS 7 are an example of a first data generation unit, which generates ship data representing the ship's position and speed. Specifically, the GNSS receiver 5 detects the ship's position, and the ECDIS 7 detects the ship's speed from the time change of the ship's position.

[0029] In addition, the ship's speed may be determined based on the ship's bearing detected by the gyrocompass 6 and the ship's speed detected by a speedometer (not shown).

[0030] Furthermore, radar 3 or AIS 4 is an example of a second data generation unit, and generates other vessel data representing the position and speed of other vessels. Specifically, the TT data generated by radar 3 corresponds to other vessel data. Similarly, the AIS data generated by AIS 4 also corresponds to other vessel data.

[0031] Figure 2 shows an example of a ship management database built in the memory of the information processing device 1. The ship management database registers ship data generated by the radar 3 or AIS 4.

[0032] The other vessel management database includes fields such as "other vessel identifier," "position," "speed," and "bearing." The position and bearing of other vessels detected by radar 3 are converted to the same coordinate system as GNSS.

[0033] Figure 3 shows an example of OZT display (conventional example). OZT is the zone in which the ship's navigation is obstructed by other ships, and is displayed on the predicted course of the other ships.

[0034] By the way, the range GP (Ground Position) in the predicted course of other ships where OZT (Oxygen-Zero Time) is not displayed represents the range in which one's own ship can navigate. However, it is difficult to determine at a glance whether one's own ship will be passing in front of or behind another ship within such a range.

[0035] Therefore, in this embodiment, as described below, it is determined and displayed whether the ship is passing in front of or behind another ship.

[0036] Figure 4 is a block diagram showing an example configuration of the information processing device 1 according to an embodiment. The information processing device 1 includes a first estimation unit 11, a second estimation unit 12, a passage determination 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 according to a program.

[0037] An example of the procedure for the ship monitoring method according to the embodiment is implemented by a first estimation unit 11, a second estimation unit 12, a passage determination unit 13, and a display control unit 14.

[0038] Figure 5 is a diagram illustrating the calculations performed by the first estimation unit 11, the second estimation unit 12, and the pass / fail determination unit 13.

[0039] The first estimation unit 11 calculates, based on the first calculation formula (hereinafter also referred to as the first formula), the first time t in each direction, assuming that the ship changes course in any direction from its current position, using the ship's own data. O After (t=t O ) estimates the predicted position of the ship. Specifically, the first estimation unit 11 estimates the predicted position of the ship at the first time t O After (t=t O The first equation representing the predicted position of the ship is constructed as follows. The predicted position of the ship is expressed in coordinates (x,y) in the xy-plane. The initial position of the ship at t=0 is the origin of the xy-plane. The ship is moving at speed v O Assuming that the ship can instantly turn in all directions while maintaining its position, the predicted position of the ship is given by the radius v centered at the origin, as shown in Equation 1 below. O t O It can be expressed as a circle equation.

[0040] [Numeral]

[0041] The second estimation unit 12 estimates the predicted course of the other ship and the second time t included in the predicted course from the other ship data based on the second calculation formula (hereinafter also referred to as the second formula). T After the lapse of time (t = t T ), the predicted position of the other ship is estimated. Specifically, the second estimation unit 12 creates a second formula representing the predicted position of the other ship after the lapse of the second time t T After the lapse of time (t = t T ) as follows. The predicted position of the other ship is represented by coordinates (x, y) in the xy plane. Let the initial position of the other ship at t = 0 be (x0, y0). Assuming that the other ship moves straight while maintaining its speed, the predicted position of the other ship is represented by a linear function as in the following second formula. v Tx is the x component of the speed of the other ship. v Ty is the y component of the speed of the other ship.

[0042] [Numeral]

[0043] The passing determination unit 13 determines an "other ship forward passing range" in which the own ship passes in front of the other ship and an "other ship rear passing range" in which the own ship passes behind the other ship based on the first formula and the second formula.

[0044] The passing determination unit 13 determines that the side closer to the current position (initial position x0, y0) of the other ship than the coincidence points P1 and P2 where the predicted position of the own ship and the predicted position of the other ship coincide (that is, the intersection points P1 and P2 of the circle of the first formula and the straight line of the second formula) among the predicted courses of the other ship represented by the second formula is the range in which the own ship passes in front of or behind the other ship, and determines that the side farther from the current position of the other ship than the coincidence points is the range in which the own ship passes in the other of the front and rear of the other ship.​​​​​​​​

[0045] Specifically, the passing determination unit 13 determines the side closer to the current position of the other ship than the first matching point P1 from the current position of the other ship as the "other ship rear passing range", and determines the side farther from the current position of the other ship than the matching point P1 as the "other ship front passing range".

[0046] Also, the passing determination unit 13 determines the side closer to the current position of the other ship than the second matching point P2 from the current position of the other ship as the "other ship front passing range", and determines the side farther from the current position of the other ship than the matching point P2 as the "other ship rear passing range".

[0047] Furthermore, the passing determination unit 13 determines a predetermined range including the matching points P1 and P2 as a risk area where there is a risk of collision between the own ship and the other ship. The risk area is, for example, OZT (Obstacle Zone by Target). Not limited to this, the risk area may be PAD (Predict Area of Danger) or the like.

[0048] The calculation of OZT is based on the assumption that the own ship changes course in an arbitrary direction at the current position and sails while maintaining the speed, and the other ship sails while maintaining the speed from the current position, and a risk value representing the risk of collision between the own ship and the other ship is calculated. This assumption is common to the above first and second equations, so the calculation of OZT can be partially shared with the calculation of the above forward / backward passing range.

[0049] As will be described below, the passing determination unit 13 determines the "other ship front passing range" and the "other ship rear passing range" based on the solutions of the system of simultaneous inequalities including the first equation and the second equation under the condition that the second time t O is greater than the first time t T or under the condition that the second time t O is less than the first time t T Using arbitrarily set real numbers a, b, c (a < b < c), the first time t

[0050] and the second time t O and the second time t TThe relationship is given by the following equations 3 and 4. Here, b is preferably 0, but a value close to 0 is also acceptable.

[0051]

number

[0052]

number

[0053] The "area where other vessels can pass behind" is determined based on the solution to the system of inequalities Equations 1, 2, and 3 described above.

[0054] The first and second equations are t T Solving for this, we obtain equation (a) below.

[0055]

number

[0056] From equation (a) and equation 3, equations (b) and (c) below are obtained.

[0057]

number

[0058]

number

[0059] (i) formula, (iii) formula, t T In the intersection of ≥ 0 The range obtained by multiplying by TIFF0007842085000008.tif46 is the "range in which your ship can pass behind other ships". T The reason for setting it to ≥ 0 is to exclude the past.

[0060] On the other hand, the "range in which other vessels can pass ahead" is determined based on the solution to the simultaneous inequalities Equations 1, 2, and 4 above.

[0061] The first and second equations are t T Solving for this gives us equation (a) above.

[0062] From equation (a) and equation 4, equations (g) and (h) below are obtained.

[0063]

number

[0064]

number

[0065] (Ki) formula, (Ku) formula, t T In the intersection of ≥ 0 The range obtained by multiplying by TIFF0007842085000011.tif46 is the "range in which your ship can pass ahead of other ships". T The reason for setting it to ≥ 0 is to exclude the past.

[0066] Figure 6 shows the calculation results of the passing range in front of and behind other vessels by the passing determination unit 13. As shown in the figure, the passing range in front of other vessels is formed inside the circle in the first equation that indicates the predicted position of the own vessel, and the passing range behind other vessels is formed outside the circle.

[0067] Specifically, a range for other vessels to pass behind is formed on the side of the other vessel's current position that is closer to the first coincidence point P1 than the other vessel's current position, and a range for other vessels to pass in front of is formed on the side of the other vessel's current position that is further from the coincidence point P1 than the other vessel's current position.

[0068] Furthermore, a forward passing range for the other vessel is formed on the side closer to the other vessel's current position than the second coincidence point P2 from the other vessel's current position, and a rear passing range for the other vessel is formed on the side further from the other vessel's current position than the coincidence point P2.

[0069] Here, by setting c as the upper limit in the third equation above, the range Gc in which other ships arrive earlier than |c| (i.e., a range with sufficient margin for arrival time difference) is excluded from the range in which other ships will pass behind. If c is set to infinity, the entire range outside the circle in the first equation of the other ships' predicted course becomes the range in which other ships will pass behind.

[0070] Furthermore, by setting a as the lower limit in the fourth equation above, the region Ga in which the ship arrives earlier than |a| than other ships (i.e., the region with sufficient margin for arrival time difference) is excluded from the range in which other ships will pass. Note that if a is set to -∞, the entire range outside the circle in the first equation of the other ships' predicted course becomes the range in which other ships will pass.

[0071] According to the calculation method of this embodiment, since it is not necessary to perform calculations for each judgment point as in the calculation of OZT, it is possible to make the theoretical resolution of the "range in front of other ships" and the "range behind other ships" infinitesimally small, and the amount of computation can be suppressed.

[0072] The display control unit 14 generates a display image based on the "range for passing other vessels in front" and "range for passing other vessels behind" determined by the passage determination unit 13, and outputs it to the display unit 2.

[0073] Figure 6 shows an example of a display image shown on the display unit 2. In the display image, the OZT (Obstruction of Zoning) is displayed on the predicted course of the other vessel, indicating that the risk value of a collision between your vessel and the other vessel is above a threshold. Furthermore, the "other vessel forward passing range," where your vessel will pass in front of the other vessel, and the "other vessel rear passing range," where your vessel will pass behind the other vessel, are displayed on the other vessel's predicted course. The other vessel's predicted course is indicated by auxiliary lines, such as dashed lines.

[0074] The areas where other vessels can pass in front of and behind are distinguished by different display methods, such as color or texture, so that they can be easily identified at a glance. Furthermore, text may be added to the "areas where other vessels can pass in front of" and "areas where other vessels can pass behind" to facilitate identification.

[0075] The areas for passing other vessels in front and behind have a predetermined width and are formed in a strip-like shape extending along the predicted course of the other vessel. The widths of the areas for passing other vessels in front and behind are narrower than the width of the OZT.

[0076] At least one of the passing ranges for other vessels in front of and behind other vessels is displayed superimposed on the OZT. For example, the passing ranges for other vessels in front of and behind other vessels may be placed on the OZT, or they may be placed below the OZT, which is formed as a semi-transparent object. Note that, as shown in Figure 8, the OZT does not have to be displayed.

[0077] According to the embodiment described above, the "range for passing ahead of other vessels" and the "range for passing behind other vessels" are displayed, making it easy to quickly determine whether one's own vessel is passing ahead or behind another vessel.

[0078] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are of course possible for those skilled in the art. [Explanation of Symbols]

[0079] 1 Information processing device, 2 Display unit, 3 Radar, 4 AIS, 5 GNSS receiver, 6 Gyrocompass, 7 ECDIS, 8 Alarm unit, 11 First estimation unit, 12 Second estimation unit, 13 Passage determination unit, 14 Display control unit, 100 Ship monitoring system

Claims

1. Based on a first calculation formula, a first estimation unit estimates the predicted position of the first vessel after a first time has elapsed in each direction, assuming that the first vessel changes course in any direction from its current position, using first vessel data representing the position and speed of the first vessel. A second estimation unit estimates the predicted course of the second vessel and the predicted position of the second vessel after a second time interval, which is included in the predicted course, from second vessel data representing the position and speed of the second vessel, based on a second calculation formula. A passage determination unit determines that the area of ​​the predicted course of the second vessel that is closer to the current position of the second vessel than the point of coincidence where the predicted position of the first vessel and the predicted position of the second vessel coincide when the first time and the second time are equal is the range in which the first vessel will pass either in front of or behind the second vessel, and the area that is further from the current position of the second vessel than the point of coincidence is the range in which the first vessel will pass either in front of or behind the second vessel. A ship monitoring system equipped with the following features.

2. The passage determination unit determines that the area from the current position of the second vessel closer to the current position of the second vessel than the first matching point is the range in which the first vessel will pass behind the second vessel, and that the area from the current position of the second vessel further from the matching point is the range in which the first vessel will pass in front of the second vessel. The ship monitoring system according to claim 1.

3. The passage determination unit determines that the area closer to the current position of the second vessel than the second matching point from the current position of the second vessel is the area in which the first vessel will pass in front of the second vessel, and that the area further from the current position of the second vessel than the matching point is the area in which the first vessel will pass behind the second vessel. The ship monitoring system according to claim 1 or 2.

4. The passage determination unit determines that a predetermined range including the point of agreement is a risk area where there is a risk of collision between the first vessel and the second vessel. A ship monitoring system according to any one of claims 1 to 3.

5. The passage determination unit determines the range in which the first vessel passes in front of the second vessel and the range in which the first vessel passes behind the second vessel, based on the solution to a system of equations including the first and second calculation formulas under the condition that the second time is greater than the first time or the second time is less than the first time. A ship monitoring system according to any one of claims 1 to 4.

6. The first calculation formula is given by t, where the first time is t Ｏ Let the speed of the first vessel be v Ｏ Let (x, y) be the position of the first vessel in the xy-plane, and let (x, y) be the initial position of the first vessel at the origin of the xy-plane. Then it can be expressed as follows: A ship monitoring system according to any one of claims 1 to 5.

7. The second calculation formula is given by t over the second time. Ｔ Let v be the x-component of the speed of the second vessel. Ｔｘ Let v be the y component of the speed of the second vessel. Ｔｙ Let (x, y) be the position of the second vessel in the xy plane, and let (x) be the initial position of the second vessel. ０ , y ０ When this is the case, it can be expressed as follows: A ship monitoring system according to any one of claims 1 to 6.

8. The system further includes a display unit that shows the range in which the first vessel will pass in front of the second vessel and the range in which the first vessel will pass behind the second vessel on the predicted course of the second vessel. A ship monitoring system according to any one of claims 1 to 7.

9. A first data generation unit generates first ship data representing the position and speed of the first ship, A second data generation unit generates second ship data representing the position and speed of the second ship, A first estimation unit creates a first calculation formula representing the predicted position of the first vessel after a first time has elapsed in each direction, assuming that the first vessel changes course in any direction from its current position based on the first vessel data. A second estimation unit creates a second calculation formula representing the predicted position of the second vessel after a second time has elapsed, based on the second vessel data. A passage determination unit that determines, based on the solution to a system of equations including the first and second calculation formulas under the condition that the second time is greater than the first time or the second time is less than the first time, the range in which the first vessel passes in front of the second vessel and the range in which the first vessel passes behind the second vessel, of the predicted course of the second vessel represented by the second calculation formula, A ship monitoring system equipped with the following features.

10. By computer, Based on the first calculation formula, the predicted position of the first vessel after a first time interval is estimated in each direction, assuming that the first vessel changes course in any direction from its current position, using the first vessel data representing the position and speed of the first vessel. Based on the second calculation formula, the predicted course of the second vessel and the predicted position of the second vessel after a second time interval, which are included in the predicted course, are estimated from the second vessel data representing the position and speed of the second vessel. Of the predicted course of the second vessel, the side closer to the current position of the second vessel than the point of coincidence where the predicted position of the first vessel and the predicted position of the second vessel coincide when the first time and the second time are equal is determined to be the range in which the first vessel passes either in front of or behind the second vessel, and the side further from the current position of the second vessel than the point of coincidence is determined to be the range in which the first vessel passes either in front of or behind the second vessel. Ship monitoring method.

11. Based on a first calculation formula, a first estimation unit estimates the predicted position of the first vessel after a first time has elapsed in each direction, assuming that the first vessel changes course in any direction from its current position, using first vessel data representing the position and speed of the first vessel. A second estimation unit estimates the predicted course of the second vessel and the predicted position of the second vessel after a second time interval, which is included in the predicted course, from second vessel data representing the position and speed of the second vessel, based on a second calculation formula. A passage determination unit determines that the area of ​​the predicted course of the second vessel that is closer to the current position of the second vessel than the point of coincidence where the predicted position of the first vessel and the predicted position of the second vessel coincide when the first time and the second time are equal is the range in which the first vessel will pass either in front of or behind the second vessel, and the area that is further from the current position of the second vessel than the point of coincidence is the range in which the first vessel will pass either in front of or behind the second vessel. An information processing device equipped with the following features.

12. Based on the first calculation formula, estimate the predicted position of the first vessel after a first time interval in each direction, assuming that the first vessel changes course in any direction from its current position, using first vessel data representing the position and speed of the first vessel. Based on the second calculation formula, estimate the predicted course of the second vessel and the predicted position of the second vessel after a second time interval, which is included in the predicted course, from the second vessel data representing the position and speed of the second vessel, and The area of ​​the predicted course of the second vessel that is closer to the current position of the second vessel than the point of coincidence where the predicted position of the first vessel and the predicted position of the second vessel coincide when the first time and the second time are equal is determined to be the range in which the first vessel passes either in front of or behind the second vessel, and the area that is further from the current position of the second vessel than the point of coincidence is determined to be the range in which the first vessel passes either in front of or behind the second vessel. A program that causes a computer to execute something.

Images