Ship surveillance devices and methods

Abstract

To evaluate a risk caused by anchoring.SOLUTION: There are provided an acquisition part for acquiring an estimated position where a future position of an anchoring ship is estimated; an area calculation part for finding a prohibition area in reference to an object present around the ship; a risk calculation part for finding a risk degree based on a positional relationship between the estimated position and the prohibition area; and an output part for outputting the risk degree.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] A ship may be anchored in a harbor or on the open sea. In this case, depending on the situation such as rough weather, wind direction, and waves, there is a risk of dragging anchor. In order to grasp such a risk, there is a monitoring device for monitoring whether the ship is dragging anchor or not (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, while it is important to grasp whether the ship is dragging anchor or not, separately from this, when dragging anchor occurs when there are objects such as a quay wall or other ships around, depending on the motion state of the hull of the ship, there is a possibility that the anchored ship and the object may collide. Therefore, it is desirable to be able to grasp the risk of collision at the time of dragging anchor. Also, while at anchor, the behavior (swinging) of the ship is different from when it is not at anchor, so it is desirable to be able to grasp the risk of collision with surrounding objects regardless of whether the ship is dragging anchor or not.

[0005] The present invention has been made in view of such circumstances, and an object thereof is to provide a ship monitoring device and a ship monitoring method capable of evaluating risks associated with anchoring.

Means for Solving the Problems

[0006] To solve the above-mentioned problems, one aspect of the present invention is a ship monitoring device comprising: an acquisition unit that acquires an estimated position which is an estimated future position of an anchored ship; an area calculation unit that determines a prohibited area based on objects present around the ship; a risk calculation unit that determines the degree of risk based on the positional relationship between the estimated position and the prohibited area; and an output unit that outputs the degree of risk.

[0007] Furthermore, one aspect of the present invention is a ship monitoring method in which an acquisition unit acquires an estimated position which is the future position of an anchored ship, an area calculation unit determines a prohibited area based on objects present around the ship, a risk calculation unit determines the degree of risk based on the positional relationship between the estimated position and the prohibited area, and an output unit outputs the degree of risk. [Effects of the Invention]

[0008] As explained above, this invention makes it possible to evaluate the risks associated with anchoring. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic block diagram showing the configuration of a ship monitoring system S using a ship monitoring device according to one embodiment of this invention. [Figure 2] This figure shows an example of the content displayed on the display screen of the terminal device 50. [Figure 3] This figure shows an example of a screen displayed in display area R20. [Figure 4] This is a flowchart explaining the operation of the ship monitoring system S0. [Figure 5] This diagram illustrates the maximum travel distance and barriers. [Figure 6] This diagram illustrates the process of determining restricted areas. [Figure 7] This is a diagram explaining the safety zone. [Figure 8] This diagram illustrates the motion of a ship while it is at anchor. [Figure 9] This figure shows the relationship between the anchoring point AC and the trajectory of the ship's motion S0, based on the estimated latitude and longitude. [Figure 10] This is a flowchart explaining the operation of the ship monitoring system S0. [Modes for carrying out the invention]

[0010] The following describes a ship monitoring device according to one embodiment of the present invention with reference to the drawings. Figure 1 is a schematic block diagram showing the configuration of a ship monitoring system S using a ship monitoring device according to one embodiment of the present invention. The ship monitoring system S includes a ship information collection device 10, an environmental information collection device 20, a ship monitoring device 30, an intermediate server 40, and a terminal device 50. The ship monitoring system S can be used to monitor multiple vessels navigating in ports and other areas from a monitoring station located on land. Furthermore, the ship monitoring system S can be installed on a vessel and used for managing that vessel. In this embodiment, a case where a terminal device 50 is installed on the vessel being monitored, and the crew of that vessel monitors their own vessel, will be described as an example. Here, the vessels to be monitored may be vessels operated by a crew, or they may be vessels that can be operated without direct operation by a crew, such as autonomous vessels or self-driving vessels. When monitoring autonomous vessels, if there is a crew on board, the terminal device 50 may be installed on the autonomous vessel so that the crew can check the displayed content. If there is no crew on board, the terminal device 50 may be installed at a monitoring station so that a monitor can check the displayed content.

[0011] The ship information collection device 10 collects information about the vessel being monitored. This information includes, for example, the position information (latitude, longitude, heading), ship speed, wind conditions (wind direction, wind speed), and hull size (overall length) of the vessel being monitored. Position information, ship speed, and hull size can be obtained from the AIS (Automatic Identification System) installed on the vessel being monitored. Wind conditions can be obtained from measurement results obtained from wind speed sensors, wind direction sensors, etc., installed on the vessel being monitored. The ship information collection device 10 is connected to the ship monitoring device 30 via wireless or wired communication and transmits the collected information to the ship monitoring device 30.

[0012] The environmental information collection device 20 collects various types of information related to the sea area in which the ship is navigating. For example, the environmental information collection device 20 communicates with an external server device and receives various types of information from the server device. The information received includes weather and oceanographic information, water depth information, structural information, etc. Weather and oceanographic information includes information on weather and ocean conditions, such as weather, wave conditions (wave height, wave direction, period, etc.), and tidal levels. Depth information represents the water depth according to the seabed topography. Depth information is obtained from sensors installed on the vessel (e.g., depth measuring instruments, sonar). In addition to using sensors, the depth at the vessel's current position may also be obtained from data on electronic nautical charts. The data on electronic nautical charts may be stored in advance in the environmental information acquisition device or obtained from an external source. Structural information refers to information that describes the location and shape of structures such as quays and bridge piers. Structural information can be obtained from data on nautical electronic charts. The environmental information collection device 20 is wirelessly or wiredly connected to the ship monitoring device 30 and transmits the collected information to the ship monitoring device 30. The environmental information collection device 20 may also receive the results by sending a request to an external server device or the like using an API (Application Programming Interface).

[0013] The ship monitoring device 30 is communicably connected to the ship information collection device 10, the environmental information collection device 20, and the intermediate server 40 by wireless or wired means. The ship monitoring device 30 may be a single computer or a cloud server. The database 31 stores various data. For example, the database 31 stores the data received from the ship information collection device 10, the data received from the environmental information collection device 20, and the data received from the intermediate server 40. In addition, the database 31 reads and stores the data obtained from the missing value completion database 32.

[0014] The missing value completion database 32 stores the latitude and longitude, bow direction, ship speed, wind direction, and wind speed of past ships to be monitored.

[0015] The anchoring determination unit 33 determines whether the ship to be monitored is at anchor. The anchoring determination unit 33 includes a data completion unit 331 and an anchoring state determination engine 332. The data completion unit 331 complements the missing item values by estimating them based on the time-series trend of the combination of past latitude and longitude, bow direction, ship speed, wind direction, and wind speed from the missing value completion database 32.

[0016] The anchoring state determination engine 332 determines whether the ship to be determined is in an anchored state. For example, the anchoring state determination engine 332 estimates the motion state of the ship based on the relationship between the latitude and longitude, bow direction, ship speed, wind direction, and wind speed of the ship to be determined. If the estimated motion state of the ship matches the anchored state, it is estimated that the ship is at anchor; if it does not match, it is estimated that the ship is not at anchor. When the ship is at anchor, since the history of the ship's position tends to be within a certain range based on the anchoring point, it is possible to estimate whether the ship is at anchor based on this tendency. The anchoring determination unit 33 determines that the monitored vessel is at anchor if it is estimated to be at anchor by the anchoring status determination engine 332, and determines that it is not at anchor if it is estimated not to be at anchor. Furthermore, the anchoring status determination engine 332 may determine whether the data obtained from the AIS of the vessel to be determined includes data indicating that the vessel is at anchor. If the data includes data indicating that the vessel is at anchor, it determines that the vessel is at anchor. If the data does not include data indicating that the vessel is at anchor, or if the data includes data indicating that the vessel is not at anchor, it determines that the vessel is not at anchor.

[0017] The motion prediction unit 34 obtains positional information that estimates the future position of an anchored vessel. The vessel whose position is to be estimated only needs to be either a vessel that is actually anchored or a vessel that is estimated to be anchored. The motion prediction unit 34 includes an external force estimation unit 341 and a swing motion estimation engine 342. The external force estimation unit 341 estimates future external forces based on the history of past external forces. Examples of external forces include wind pressure, waves, and tidal currents. The swing motion estimation engine 342 estimates the future swing motion of a monitored vessel while it is anchored. For example, the swing motion estimation engine 342 estimates the swing motion of a vessel while it is anchored with one anchor by using a motion model based on external forces such as wind speed, wind pressure, waves, and currents, as well as the shape of the hull, the size of the hull, latitude and longitude, and the anchoring position. Existing technologies may also be used to estimate the swing motion. The future period to be predicted can be any period.

[0018] The accident risk calculation unit 35 has an acquisition function that obtains the estimated position, which is the estimated future position of an anchored vessel, from the motion prediction unit 34. The vessels from which this estimated position is obtained only need to be at least one of the following: a vessel that is actually anchored, or a vessel that is estimated to be anchored. The accident risk calculation unit 35 determines the degree of risk based on the positional relationship between the estimated position and the prohibited area. The prohibited area is an area where a risk will occur if a vessel enters that area.

[0019] The accident risk calculation unit 35 includes an area calculation unit 351, a factor-specific risk calculation unit 352, and an overall accident risk calculation unit 353.

[0020] The area calculation unit 351 determines the prohibited area based on objects present around the vessel. These objects include vessels, structures, and objects based on geographical factors. For example, the area calculation unit 351 determines the prohibited area based on the distance from the structure. The area calculation unit 351 also has the function of a distance calculation unit that determines the distance traveled by the ship from the anchoring point based on the length of the anchor chain, and the maximum travel distance, as well as the function of calculating the safe area for the monitored ship based on the determined maximum travel distance, and the function of calculating the no-entry area.

[0021] The factor-based risk calculation unit 352 calculates the risk level for each factor. The factors that the factor-based risk calculation unit 352 considers are, for example, the following four (1) to (4).

[0022] (1) Factors based on anchor dragging The factor-based risk calculation unit 352 determines whether the estimated position has exceeded the monitoring circle. The monitoring circle is the maximum movement range based on the maximum movement distance when the vessel is safely anchored, and uses the safety area described later. The factor-based risk calculation unit 352 determines that there is a risk due to anchor dragging if the estimated position exceeds the maximum movement range, and determines that there is no risk due to anchor dragging if the position does not exceed the maximum movement range. Since anchor dragging can cause movement in unintended directions, this risk can be managed.

[0023] (2) Factors based on the relationship with the structure Objects surrounding the monitored vessel include structures, such as bridge piers and quays. The risk of collision due to such structures is a potential factor.

[0024] (3) Factors based on relationships with other vessels Objects present around the monitored vessel include, for example, other ships. A risk of collision due to such other vessels is a possibility.

[0025] (4) Geographical factors Objects surrounding the monitored vessel are areas where the water depth, according to the underwater topography, is shallower than a predetermined depth. Such areas are areas with reefs or shoals. The predetermined depth can be determined based on the draft of the monitored vessel. For example, the ship monitoring device 30 acquires draft data representing the draft of the monitored vessel from the terminal device 50 via the intermediate server 40, and extracts areas shallower than the depth indicated by this draft data as objects. The factor-based risk calculation unit 352 determines the degree of risk based on the distance between the estimated location and the prohibited area, which is determined based on the shallow water depth area.

[0026] The risk calculation unit 352, when the factor is a structure or another vessel, determines the degree of risk based on the positional relationship between the estimated position and the no-entry area. The positional relationship includes whether the estimated position is inside the no-entry area, and the distance from the estimated position to the center within the no-entry area. Furthermore, the risk calculation unit 352 may, when the factor is another vessel, use the course of the other vessel in addition to the distance between the estimated position and the prohibited area to determine the degree of risk. In other words, even if the estimated position of the own vessel is within the prohibited area set for the other vessel, the risk of collision decreases if the course of the other vessel does not interfere with the estimated position of the own vessel.

[0027] The overall accident risk calculation unit 353 determines the degree of overall accident risk based on the degree of risk calculated for each factor. For example, the overall accident risk calculation unit 353 determines the degree of overall accident risk for each future time by calculating the sum of the risk degrees of each factor for each future time.

[0028] The prediction result storage unit 36 ​​stores the prediction results (degree of risk) in a time-series format for the future, which are calculated by the accident risk calculation unit 35. The data transmission unit 37 outputs the degree of risk calculated by the accident risk calculation unit 35. For example, the data transmission unit 37 transmits the degree of risk stored in the prediction result storage unit 36 ​​to the intermediate server 40. The transmitted prediction results may include not only the overall accident risk, but also the degree of risk for each factor, and display data showing the relationship between the monitored vessel and surrounding objects. The communication unit 38 is connected to the ship information collection device 10, the environmental information collection device 20, and the intermediate server 40 in a communication manner, and transmits and receives various types of data.

[0029] The intermediate server 40 displays the degree of risk on the display device of the terminal device 50 in a display mode corresponding to the degree of risk. The display mode may be a color (green, yellow, red, etc.) or text (level 1, level 2, etc.) corresponding to the degree of risk, or it may be a pop-up screen, or it may be an audible sound or a light flashing. When the estimated position exceeds the maximum movement range, the display device of the terminal device 50 is made to display the degree of risk in a display mode corresponding to the degree of risk. The intermediate server 40 transmits the prediction results obtained by the ship monitoring device 30 to the terminal device 50. The intermediate server 40 is connected to the ship monitoring device 30 wirelessly or via a wired connection for communication. The intermediate server 40 has a prediction result storage unit 41 and a set value storage unit 42.

[0030] The prediction result storage unit 41 stores the prediction results transmitted from the data transmission unit 37 of the ship monitoring device 30. The setting value storage unit 42 stores various setting values. For example, the setting value storage unit 42 stores reference values ​​corresponding to the level of attention. The reference values ​​are used to determine which alert level the degree of risk falls into, and there may be one or more reference values. If there is one reference value, it can be determined whether it is safe or not based on that reference value. If there are two reference values ​​(first reference value, second reference value) and they are different values, it can be determined whether it is safe, at a level requiring attention, or at a level requiring danger based on the relative magnitudes of the multiple reference values. There may be three or more reference values.

[0031] The terminal device 50 is, for example, a computer and is connected to the intermediate server 40 wirelessly or via a wired connection. The terminal device 50 may be a smartphone or a tablet. If the terminal device 50 is a smartphone or a tablet, the crew can carry it and check the forecast results at any location on board the ship. The terminal device 50 receives the prediction results from the intermediate server 40 and outputs the prediction results. The terminal device 50 is connected to a liquid crystal display device and outputs the prediction results by displaying them on the liquid crystal display device. The terminal device 50 displays the degree of risk for each target factor calculated by the accident risk calculation unit 35 in different display areas on the liquid crystal display device. Furthermore, the terminal device 50 may output a sound from a speaker corresponding to the prediction result, or it may illuminate a lamp corresponding to the prediction result. The terminal device 50 is connected to input devices such as a keyboard and a mouse, and accepts input such as ship data, anchor and anchor chain data, and safety parameters in response to operation input from the input devices.

[0032] Figure 2 shows an example of the content displayed on the display screen of the terminal device 50. The display screen GM1 of the display device connected to the terminal device 50 includes a display area R10 and a display area R20. Display area R10 is a display area that overlays the relationship between the monitored vessel and its surrounding objects onto the electronic chart. Here, the figure representing the vessel S0 is displayed approximately in the center of display area R10. The orientation of the figure representing the vessel S0 is displayed according to the direction the vessel's bow is pointing. The safety zone is the area set as the position reference for the vessel S0, and within this range, the level of attention required is lower than outside the safety zone. In this diagram, the bridge pier BG, the quay GP, and another vessel S1 are shown as objects around the vessel S0. A no-entry area RBG is displayed around the bridge pier BG, a no-entry area RGP is displayed around the quay GP, and a no-entry area RS1 is displayed around the other vessel S1.

[0033] Display area R20 is the area where various risks are displayed. Display area R20 includes the overall accident risk display area R21, the anchor dragging risk display area R22, the grounding risk display area R23, the other vessel collision risk display area R24, the bridge girder collision risk display area R25, and the quay collision risk R26.

[0034] Figure 3 shows an example of a screen displayed in the display area R20. The R21 area for displaying the overall accident risk is the area where the overall accident risk, calculated based on the risks of anchor dragging, grounding, collision with other vessels, collision with bridge girders, and collision with the quay, is displayed. The overall accident risk may also be the sum of the risks of anchor dragging, grounding, collision with other vessels, collision with bridge girders, and collision with the quay. The R21 area, which displays the overall accident risk, shows a graph with the horizontal axis representing future time and the vertical axis representing the degree of overall accident risk. The anchor dragging risk display area R22 shows a graph with the horizontal axis representing future time and the vertical axis representing the degree of anchor dragging risk. The stranding risk display area R23 shows a graph with the horizontal axis representing future time and the vertical axis representing the degree of stranding risk. In the R24 area, which displays the risk of collision with other vessels, a graph is displayed with the horizontal axis representing future time and the vertical axis representing the degree of the risk of collision with other vessels. In the bridge girder collision risk display area R25, a graph is displayed with the horizontal axis representing future time and the vertical axis representing the degree of bridge girder collision risk.

[0035] Next, we will explain the operation of the aforementioned ship monitoring system S. Figures 4 and 10 are flowcharts illustrating the operation of the ship monitoring system S0. The terminal device 50 accepts input of ship data, chain / anchor chain data, and safety parameters (step S101). Ship data includes information such as latitude and longitude, ship type, ship speed, wind direction and speed, and hull size obtained by the ship information collection device 10; chain / anchor chain data represents specifications such as the length of the anchor chain; and safety parameters are parameters for defining no-entry areas, such as the distance from structures and the water depth to prevent grounding. The intermediate server 40 acquires ship data, chain / anchor chain data, and safety parameters from the terminal device 50 and transmits them to the ship monitoring device 30. The communication unit 38 of the ship monitoring device 30 receives the ship data, chain / anchor chain data, and safety parameters transmitted from the intermediate server 40. The database 31 stores the ship data, chain / anchor chain data, and safety parameters received by the communication unit 38. The communication unit 38 acquires data from the ship information collection device 10 at regular intervals, including the position information (latitude and longitude, heading), ship speed, wind direction and speed, and ship size of the ship S0 (step S102). Once received by the communication unit 38, the database 31 stores the received data.

[0036] The anchoring determination unit 33 determines whether the monitored vessel S0 is at anchor. Here, the data completion unit 331 obtains data on the vessel S0's latitude and longitude, heading, ship speed, wind direction, and wind speed from the database 31. If there are any missing values ​​in these sensor data, it completes them by reading data from the missing value completion database 32 (step S103). For example, if there is missing data, the data completion unit 331 completes it by estimating the value of the missing item based on the time-series trend of combinations of latitude and longitude, heading, ship speed, wind direction, and wind speed in past data.

[0037] The anchoring state determination engine 332 calculates the anchoring probability (step S104). Then, the anchoring state determination engine 332 determines whether the ship S0 is in an anchoring state by determining the relationship between the calculated anchoring probability and a reference value (step S105). If the anchoring probability exceeds the reference value, the anchoring state determination engine 332 determines that the ship is anchored (step S105-YES) and proceeds to step S106. If the anchoring probability does not exceed the reference value, the anchoring state determination engine 332 determines that the ship is not anchored (step S105-NO) and proceeds to step S102.

[0038] If it is determined that the ship is anchored, the area calculation unit 351 of the accident risk calculation unit 35 calculates the maximum travel distance relative to the anchor chain extension amount (step S106), and calculates the maximum travel range based on the maximum travel distance (step S107).

[0039] Next, the area calculation unit 351 uses its drawing function to determine the maximum range of motion and an arbitrarily set no-entry zone (hereinafter referred to as the barrier) (step S108). Figure 5 illustrates the maximum range of motion and the barrier. In this diagram, the maximum travel distance L0 is the distance from the anchoring point AC, which indicates the anchored position as viewed from above, to the position of the ship when the anchor chain is extended to its maximum extent. The maximum movement distance L1 is the maximum travel distance L0 plus the size of the ship S0's hull. The maximum range of motion RL1 is defined by the anchoring point AC as the center, with a radius equal to the maximum distance traveled L0 plus the size of the hull (total length) (maximum range of motion L1). The area calculation unit 351 can determine the maximum travel distance L0 based on the length of the anchor chain when it is extended to its maximum extent and the water depth at the ship's position. The area calculation unit 351 also determines the maximum range of motion RL1 by calculating the distance obtained by adding the ship's size (total length) to the maximum travel distance L0, and then drawing a circle with the anchoring point AC as the center and this calculated distance as the radius. The area calculation unit 351 calculates the maximum movement distance L0, adds the size of the ship S0 to determine the maximum motion distance L1, and calculates the maximum motion range RL1 by finding a circle centered on the anchoring point AC. In addition, the user can manually input a barrier RL2 around the ship via an input device to draw a barrier that should not be allowed to enter. The barrier RL2 is calculated by setting the radius to the distance obtained by adding the barrier distance L2 to the maximum motion distance L1, and centering it on the anchoring point AC.

[0040] Next, the area calculation unit 351 determines the no-entry area based on safety parameters for the object and geographical conditions (step S109). Figure 6 illustrates the process for determining restricted areas. The area calculation unit 351 determines the no-entry area for each object based on safety parameters. In this case, the objects are bridge pier BG, quay GP, other vessel S1, and reef SH. The area calculation unit 351 determines the location and shape of the bridge girder BG based on its shape and latitude and longitude, and then determines the no-entry area RBG relative to the bridge girder BG by finding a position (region) at a distance LBG based on safety parameters, starting from the shape of the bridge girder BG. The no-entry area RBG represents an area where the risk of collision with the bridge GP increases if the vessel S0 enters this region. The area calculation unit 351 determines the location and shape of the quay GP based on its outline and latitude and longitude, and then determines the no-entry area RGP relative to the quay GP by finding a position (region) at a distance LGP based on safety parameters, starting from the outline of the quay GP. The no-entry area RGP is an area where the risk of collision with the quay GP increases if the vessel S0 enters this region. The area calculation unit 351 determines the position and shape of the other vessel S1 based on the size and shape of the other vessel S1's hull and its latitude and longitude. It then determines the no-entry area RS1 for the other vessel S1 by finding a position (area) at a distance LS1 based on safety parameters, starting from the shape of the other vessel S1. The no-entry area RS1 represents an area where the risk of collision with the other vessel S1 increases if the own vessel S0 enters this area. The area calculation unit 351 identifies the location and shape of the reef SH based on topographic data and latitude and longitude, and identifies the area where the water depth of the reef is shallower than a predetermined depth. Then, the area calculation unit 351 determines the no-entry area RSH for the reef SH by starting from the outer perimeter of the identified area and finding a position (area) at a distance based on safety parameters. The no-entry area RSH is an area where the risk of grounding on the reef SH increases if the vessel S0 enters this area.

[0041] Once the no-entry zones for each object are determined, the area calculation unit 351 calculates the area obtained by excluding the no-entry zones from the barrier RL2 of the ship S0 as the safe area (step S110). Figure 7 is a diagram illustrating the safety zone. The area calculation unit 351 calculates the safe area by excluding each of the no-entry areas from the barrier RL2.

[0042] Next, we will explain the motion of a ship while it is at anchor using Figure 8. In this figure, symbol 9A indicates the relationship between anchor AN and the vessel S0 immediately after anchoring. Immediately after anchoring, anchor AN is located approximately directly below the anchor chain exit of the vessel S0. Subsequently, when the vessel S0 is subjected to an external force and motion occurs, the anchor chain ACC takes on a catenary shape at its suspension point, as shown by symbol 9B. This shape can be determined based on catenary theory. Furthermore, if the vessel S0 is subjected to external forces and moves away from anchor AC, as shown in symbol 9C, the extension of the anchor chain will eventually reach its maximum, and the distance between anchor AC and the position directly below the vessel S0 will reach the maximum movement distance MD. Then, if an external force exceeding the mooring force (holding force) acts on the vessel and anchor AC moves, there is a risk of anchor dragging, and the risk of anchor dragging increases. For example, if it is estimated that the wind pressure will increase, the latitude and longitude of the vessel S0 when the hull is subjected to that wind pressure will be estimated, and depending on the position of that latitude and longitude, it may be estimated that the anchor is dragging.

[0043] Figure 9 shows the relationship between the anchoring point AC and the trajectory of the ship's motion S0, based on the estimated latitude and longitude. Symbol 10A indicates the trajectory of the ship S0 when anchor dragging is not occurring. In this case, the trajectory tr is within a certain distance (maximum travel distance MD) from the anchoring point AC. Symbol 10B indicates the trajectory of the ship S0 when anchor dragging occurs. In this case, the trajectory tr reaches a position beyond a certain distance (maximum travel distance MD) from the anchoring point AC. In particular, it shows a case where the ship s0 was moving in an arc starting from the anchoring point ac, but from a certain point it moves in a roughly linear direction away from the anchoring point ac. In this case, it is assumed that the anchor is also moving in a linear direction along with the ship s0. Symbol 10C indicates the trajectory of the ship S0 when anchor dragging occurs. In this case, the trajectory tr reaches a position further than a certain distance (maximum travel distance MD) from the anchoring point AC. In particular, it shows the case where the ship s0 moves away from the anchoring point AC while tracing an arc starting from the anchoring point AC. Symbol 10D shows the trajectory of the ship S0 when anchor dragging occurs. In this case, the trajectory tr reaches a position further than a certain distance (maximum travel distance MD) from the anchoring point AC. In particular, the range of motion of the ship s0 is wider than in the case shown by symbol 10c. That is, in addition to the arc motion starting from the anchoring point AC, motion in the direction approaching the anchoring point AC and motion in the direction away from the anchoring point AC occur, and it is considered that the anchor has almost come off and the degrees of freedom are higher than in the case shown by symbol 10C.

[0044] Next, once the motion prediction results are obtained, the accident risk calculation unit 35 calculates the risk for each factor. Factors include, for example, anchor dragging, collision with other vessels, collision with structures (collision with quay, collision with bridge girders), and geographical conditions (grounding, etc.). The factor-based risk calculation unit 352 of the accident risk calculation unit 35 calculates the degree of risk for anchor dragging distance based on the estimated motion trajectory (step S114). For the vessel S0, the factor-based risk calculation unit 352 determines the degree of risk for each time in the time series such that the estimated future time-series motion trajectory (time-series position data) is outside the range of the safety area. Furthermore, the factor-based risk calculation unit 352 determines the degree of risk for each time in the time series such that the degree of risk increases as the estimated future time-series motion trajectory moves further away from the range of the safety area. The intermediate server 40 can display the determined degree of risk for anchor dragging distance on the display device of the terminal device 50, for example, in the form of a graph as shown in Figure 3, reference numeral R22 above.

[0045] Next, the factor-based risk calculation unit 352 uses a collision determination algorithm to determine the risk of collision with other vessels (step S115). The factor-based risk calculation unit 352 may also use the results obtained by using collision calculation algorithms such as OZT (Obstacle Zone by Target) and DAC (Dangerous Area of ​​Collision) to determine the future risk of collision between the vessel S0 and other vessels. The factor-based risk calculation unit 352 can determine the risk of collision with other vessels to be higher the higher the probability of a future collision with another vessel is determined. The intermediate server 40 can display the determined degree of collision risk with other vessels on the display device of the terminal device 50, for example, in the form of a graph as shown in Figure 3, part number R24 ​​above.

[0046] Next, the factor-based risk calculation unit 352 calculates the risk of collision with the quay based on the distance to the quay (step S116). For example, if the estimated future time-series motion trajectory of the vessel S0 falls within the range of the no-entry area RGP set for the quay GP, the factor-based risk calculation unit 352 calculates the risk for each time point in the time series such that the closer the estimated position is to the center of the intrusion area, the higher the degree of risk. Furthermore, the factor-based risk calculation unit 352 calculates the estimated future time-series motion trajectory so that the risk level increases as the location is within the no-entry area RGP and closer to the quay GP. The intermediate server 40 can display the calculated quay collision risk level on the display device of the terminal device 50, for example, in the form of a graph as shown by reference numeral R26 in Figure 3 above.

[0047] Next, the factor-based risk calculation unit 352 calculates the risk of collision with the bridge girder based on the distance to the bridge girder (step S117). For example, the factor-based risk calculation unit 352 calculates the risk for each time in the time series such that the degree of risk increases if the estimated future time-series motion trajectory of the vessel S0 falls within the range of the no-entry area RBG set for the bridge girder BG. Furthermore, the factor-based risk calculation unit 352 calculates the estimated future time-series motion trajectory so that the risk level increases as the trajectory is within the no-entry area RBG and closer to the bridge girder BG. The intermediate server 40 can display the calculated bridge girder collision risk level on the display device of the terminal device 50 using a graph, for example, as shown in Figure 3, part number R25 described above.

[0048] Next, the factor-based risk calculation unit 352 determines the risk based on geographical conditions (grounding risk) based on the water depth based on topographic data and the future time-series motion trajectory of the vessel S0 (step S118). For example, if the position of the vessel S0 in the estimated future time-series motion trajectory falls within the range of the no-entry area RSH set for the reef SH, the factor-based risk calculation unit 352 determines the risk level for each time in the time series so that it is higher. Furthermore, the factor-based risk calculation unit 352 calculates the estimated future time-series motion trajectory so that the degree of risk increases as the approach to the reef SH is within the range of the no-entry area RSH. The intermediate server 40 can display the calculated grounding risk degree on the display device of the terminal device 50, for example, in the form of a graph as shown by reference numeral R23 in Figure 3 above.

[0049] Once the risk for each factor is calculated by the factor-specific risk calculation unit 352, the overall accident risk calculation unit 353 calculates the overall accident risk based on the risks calculated for each factor (step S119). For example, the overall accident risk calculation unit 353 calculates the overall accident risk for each future time by calculating the sum of the risk levels for each factor at each future time. The intermediate server 40 can display the calculated overall accident risk on the display device of the terminal device 50, for example, in the form of a graph as shown in Figure 3, reference numeral R21 above.

[0050] Once the overall accident risk level is calculated, the accident risk calculation unit 35 writes the risk level for each factor and the overall accident risk level as prediction results to the prediction result storage unit 36. When the prediction results are written to the prediction result storage unit 36, the data transmission unit 37 transmits the prediction results to the intermediate server 40. The intermediate server 40 stores the prediction results transmitted from the data transmission unit 37 in the prediction result storage unit 41, generates display data to be displayed on the display device of the terminal device 50 based on the setting values ​​stored in the setting value storage unit 42, and transmits it to the terminal device 50.

[0051] Here, the intermediate server 40 determines which alert level applies by comparing the degree of risk with a reference value. The intermediate server 40 stores reference values ​​for each item for the degree of risk for each factor and for the overall accident risk level, and determines the alert level for each item by determining the magnitude relationship with the reference value corresponding to that item (step S120). For example, the intermediate server 40 reads out the overall first reference value used to determine the overall accident risk level and the overall second reference value which is a larger value than the overall first reference value, stored in the setting value storage unit 42, and determines the magnitude relationship with the overall accident risk level.

[0052] The intermediate server 40 determines whether the overall accident risk level has reached the overall first threshold value within a predetermined time period from the present to the future. If it has not reached the threshold, it determines that the alert level is safe (step S121). In this case, the intermediate server 40 displays the background color of the overall accident risk level display area R21 on the display screen of the terminal device 50 in green. On the other hand, if the overall accident risk level has reached the overall first threshold, the intermediate server 40 determines whether the overall accident risk level has reached the overall second threshold, and if it has not reached the overall second threshold, it determines that the alert level is equivalent to a caution (step S122). In this case, the intermediate server 40 causes the background color of the overall accident risk level display area R21 on the display screen of the terminal device 50 to be yellow. On the other hand, if the overall accident risk level reaches the overall second threshold, the intermediate server 40 determines that the alert level is equivalent to a dangerous level (step S123). In this case, the intermediate server 40 displays the background color of the overall accident risk level display area R21 on the display screen of the terminal device 50 in red. In this way, the intermediate server 40 displays the display area in different display modes depending on the alert level.

[0053] Here, we have described how the intermediate server 40 determines the magnitude of the overall accident risk level relative to the standard value. However, the intermediate server 40 may similarly determine the magnitude of each of the following relative values: anchor dragging risk, grounding risk, collision risk with other vessels, bridge girder collision risk, and quay collision risk, and display the display area in a display manner based on the alert level corresponding to the determination result. For example, the intermediate server 40 reads out a first anchor dragging criterion value used to determine the degree of anchor dragging risk, and a second anchor dragging criterion value which is a larger value than the first anchor dragging criterion value, and determines the relationship between the degree of anchor dragging risk and the criterion value. The intermediate server 40 determines whether the anchor dragging risk level has reached the first anchor dragging threshold within a predetermined time period from the present to the future. If it has not reached the threshold, it determines that the alert level is safe. In this case, the intermediate server 40 displays the background color of the anchor dragging risk level display area R22 on the display screen of the terminal device 50 in green. On the other hand, if the anchor dragging risk level reaches the first anchor dragging threshold, the intermediate server 40 determines whether the anchor dragging risk level has reached the second anchor dragging threshold. If it has not reached the second anchor dragging threshold, it determines that the alert level is equivalent to a warning. In this case, the intermediate server 40 causes the background color of the anchor dragging risk level display area R22 on the display screen of the terminal device 50 to be yellow. On the other hand, if the anchor dragging risk level reaches the second anchor dragging threshold, the intermediate server 40 determines that the alert level is equivalent to a dangerous level. In this case, the intermediate server 40 displays the background color of the anchor dragging risk level display area R22 on the display screen of the terminal device 50 in red. In this way, the intermediate server 40 displays the display area in different display modes depending on the cause, according to the alert level.

[0054] In addition, the intermediate server 40 similarly determines the alert level for grounding risk, collision risk with other vessels, and bridge pier collision risk. If the alert level is equivalent to caution or danger, in addition to changing the display manner of the display area for each item in display area R20, the area of ​​the no-entry zone in display area R10 may be displayed in a color corresponding to the alert level.

[0055] Once these display controls are performed, the process proceeds to step S102.

[0056] The ship information collection device 10 transmits the latest information regarding the monitored ship to the ship monitoring device 30 at regular intervals. The ship monitoring device 30 acquires information regarding the monitored ship at regular intervals, and based on this, the processing from step S102 onward is executed.

[0057] In the embodiments described above, even if the vessel S0 is anchored but not dragging, the above processing can be used to determine and output various risks in the case of not dragging anchor. When the vessel S0 is at anchor, the so-called swinging behavior due to anchoring does not occur, but when it is anchored, a mooring force (holding force) is generated by the anchor, so the behavior (motion) of the vessel is different from when it is not anchored. Therefore, according to this embodiment, when the vessel is anchored, risks can be managed from a different perspective than when it is not anchored. Furthermore, even if there is a possibility of dragging anchor, the risks can be managed assuming that anchor dragging occurs.

[0058] Furthermore, in the embodiments described above, the vessel being monitored may be an autonomous vessel, also known as an automated vessel, which can be operated without direct crew intervention. In this case, even with a system that does not have a crew on board, for example, it is possible to estimate the hull motion of the vessel before and during anchoring and assess the risk of anchoring accidents such as dragging the anchor.

[0059] In the above embodiment, the use of the ship monitoring system S for monitoring one's own ship was described, but it may also be used at a monitoring station on land. In this case, the terminal device 50 may be installed at the monitoring station and display risk prediction results for multiple ships navigating ports, etc.

[0060] In the embodiment described above, the ship monitoring device 30 transmits the prediction results to the intermediate server 40, and the intermediate server 40 displays the prediction results (degree of risk) on the display device of the terminal device 50. However, the functions of the intermediate server 40 may be provided in the ship monitoring device 30 and configured as a single device. Alternatively, the functions of the intermediate server 40 may be provided in the terminal device 50.

[0061] The aforementioned database 31, missing value completion database 32, prediction result storage unit 36, prediction result storage unit 41, and setting value storage unit 42 are composed of storage media, such as HDD (Hard Disk Drive), flash memory, EEPROM (Electrically Erasable Programmable Read Only Memory), RAM (Random Access read / write Memory), ROM (Read Only Memory), or any combination of these storage media. These databases 31, missing value completion database 32, prediction result storage unit 36, prediction result storage unit 41, and setting value storage unit 42 can, for example, use non-volatile memory. The anchoring determination unit 33, motion prediction unit 34, accident risk calculation unit 35, and data transmission unit 37 may be composed of a processing unit such as a CPU (Central Processing Unit) or a dedicated electronic circuit.

[0062] The anchoring determination unit 33, motion prediction unit 34, accident risk calculation unit 35, data transmission unit 37, and communication unit 38 in the above-described embodiment may be implemented using a computer. In that case, the program for implementing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be loaded into a computer system and executed. Here, "computer system" includes hardware such as the OS and peripheral devices. Furthermore, "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and storage devices such as hard disks built into a computer system. Moreover, "computer-readable recording medium" may also include those that dynamically hold programs for a short period of time, such as communication lines when transmitting programs via networks such as the Internet or communication lines such as telephone lines, and those that hold programs for a certain period of time, such as volatile memory inside a computer system that acts as a server or client in that case. Furthermore, the above-mentioned program may be for implementing a part of the above-mentioned function, or it may be a program that can implement the above-mentioned function in combination with a program already recorded in the computer system, or it may be implemented using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0063] While embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and includes designs and the like that do not depart from the spirit of this invention. [Explanation of symbols]

[0064] 10...Ship information collection device, 20...Environmental information collection device, 30...Ship monitoring device, 31...Database, 32...Database for missing value completion, 33...Anchor determination unit, 34...Motion prediction unit, 35...Accident risk calculation unit, 36...Prediction result storage unit, 37...Data transmission unit, 38...Communication unit, 40...Intermediate server, 41...Prediction result storage unit, 42...Set value storage unit, 50...Terminal device, 331...Data completion unit, 332...Anchor state determination engine, 341...External force estimation unit, 342...Motion estimation engine, 351...Area calculation unit, 352...Risk calculation unit by factor, 353...Overall accident risk calculation unit, S...Ship monitoring system

Claims

1. An acquisition unit that obtains an estimated position, which is an estimate of the future position of a ship that is anchored, An area calculation unit that determines a prohibited area based on objects present around the aforementioned vessel, A risk calculation unit that determines the degree of risk based on the positional relationship between the estimated position and the prohibited area, An output unit that outputs the degree of the aforementioned risk and A ship monitoring device that has the following features.

2. A distance calculation unit that determines the maximum distance a ship can travel from the anchoring point where it drops anchor, based on the length of the anchor chain, A determination unit that determines whether the estimated position exceeds the maximum movement range based on the maximum movement distance, It has, The output unit is, If the estimated position exceeds the maximum movement range, the display unit will display the position in a display manner corresponding to the degree of risk. The ship monitoring device according to claim 1.

3. The aforementioned object is a structure, The area calculation unit determines the prohibited area based on the distance from the structure, The risk calculation unit determines the degree of risk based on the positional relationship between the estimated location and the prohibited area. The ship monitoring device according to claim 1.

4. The aforementioned object is the other ship, The risk calculation unit determines the degree of risk based on the prohibited area determined using the position of the other vessel as a reference, and the course of the other vessel. The ship monitoring device according to claim 1.

5. The aforementioned object is located in an area shallower than the depth determined according to the underwater topography, The risk calculation unit determines the degree of risk based on the positional relationship between the estimated position and the prohibited area determined based on the shallow area. The ship monitoring device according to claim 1.

6. The output unit displays the degree of risk for each factor calculated by the risk calculation unit in different display areas on the display unit. A ship monitoring device according to any one of claims 1 to 5.

7. The acquisition unit acquires the estimated position, which is the estimated future position of the anchored vessel. The area calculation unit determines the prohibited area based on objects present around the vessel, The risk calculation unit determines the degree of risk based on the positional relationship between the estimated location and the prohibited area. The output unit outputs the degree of the aforementioned risk. Ship monitoring methods.

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