Navigation support equipment, navigation support methods, programs

Abstract

To provide a marine navigation support device capable of obtaining a marine navigation obstruction zone considering a margin.SOLUTION: A marine navigation support device for seeking a marine navigation obstruction zone from a relationship between the own ship and the other ship, comprises: a margin acquisition unit which acquires a margin indicating a degree of margin; and a calculation unit that obtains a marginal position which is a distance determined according to a marginal margin from at least one of bow and stern positions of the other ship in a target occupied space set based on a position of the other ship, obtains a collision course based on a position determined according to a motion vector of the other ship with the margin position as a reference, and calculates a marine navigation obstruction zone based on the determined collision course.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a navigation support device, a navigation support method, and a program. [Background technology]

[0002] In recent years, systems have emerged to support navigation by displaying the risk of collision between one's own vessel and another vessel. For example, there are systems that perform collision calculations for both one's own vessel and another vessel, and based on the results of these calculations, display the Obstacle Zone by Target (OZT) caused by the other vessel (see, for example, Patent Document 1). In such a system, navigators can specifically understand the area they need to be careful of when a navigation interference zone is displayed. Furthermore, by maneuvering their vessel to avoid the displayed navigation interference zone, navigators can avoid collisions with other vessels. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-095333 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, when one vessel passes another vessel, passing near the navigation obstruction zone will result in a close encounter. When one vessel approaches another vessel, the risk of collision increases, and it may also cause anxiety to the navigators of the other vessel. Therefore, it is preferable to be able to pass the navigation obstruction zone with a certain margin of safety.

[0005] This invention has been made in view of these circumstances, and its purpose is to provide a navigation support device, a navigation support method, and a program that can determine a navigation interference zone that takes into account a margin of safety. [Means for solving the problem]

[0006] To solve the above-mentioned problems, one aspect of the present invention is a navigation support device for determining a navigation interference zone from the relationship between one's own vessel and another vessel, comprising: a margin acquisition unit that acquires a margin degree indicating the degree of margin; a calculation unit that determines a margin position which is a position located at a distance determined according to the margin degree from at least one of the bow or stern positions of the other vessel in the target occupied space set with reference to the position of the other vessel, determines a collision course based on the position determined according to the motion vector of the other vessel with reference to the margin position, and calculates a navigation interference zone based on the determined collision course.

[0007] Furthermore, one aspect of the present invention is a navigation support method performed by a computer, which determines a navigation interference zone from the relationship between one's own vessel and another vessel, wherein a margin acquisition unit acquires a margin indicating the degree of margin, and a calculation unit determines a margin position which is a position located at a distance determined according to the margin from at least one of the bow or stern positions of the other vessel in the target occupied space set based on the position of the other vessel, determines a collision course based on the position determined according to the motion vector of the other vessel with respect to the margin position, and calculates a navigation interference zone based on the determined collision course.

[0008] Furthermore, one aspect of the present invention is a program that causes a computer to perform the following actions: obtain a margin degree indicating the degree of margin; determine a margin position which is a position located at a distance determined according to the margin degree from at least one of the positions of the other vessel's bow or stern in the target occupied space set based on the position of the other vessel; determine a collision course based on the position determined according to the motion vector of the other vessel with respect to the margin position; and calculate a navigation interference zone based on the determined collision course. [Effects of the Invention]

[0009] As described above, according to this invention, it is possible to obtain a navigation interference zone considering a margin.

Brief Description of the Drawings

[0010] [Figure 1] It is a schematic block diagram showing the configuration of a system in which a navigation support device is used. [Figure 2] It is a diagram showing an example of a display screen 100 on which a navigation interference zone is displayed. [Figure 3] It is a flowchart for explaining the operation of the navigation support device 20. [Figure 4] It is a diagram for explaining the occupied space of the own ship and the occupied space of the other ship. [Figure 5] It is a diagram for explaining a part of the calculation process for obtaining the collision course CO. [Figure 6] It is a diagram for explaining a part of the calculation process for obtaining the collision course CO. [Figure 7] It is a diagram for explaining the process of obtaining a navigation interference zone. [Figure 8] It is a diagram for explaining the processing when obtaining a navigation interference zone considering a margin. [Figure 9] It is a diagram for explaining the processing when obtaining a navigation interference zone considering a margin. [Figure 10] It is a diagram for explaining a display screen on which a navigation interference zone with a desired passing distance on the bow side and a navigation interference zone with a desired passing distance on the stern side are displayed.

Mode for Carrying Out the Invention

[0011] Hereinafter, a navigation support device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram showing the configuration of a system in which a navigation support device according to an embodiment of the present invention is used. The navigation management system 10 and the navigation support device 20 are communicably connected. The navigation management system 10 includes sensors such as radar (TT; Target Tracking), an Automatic Identification System (AIS), a gyroscope (GYRO), and a ship speed and distance meter. The navigation management system 10 supplies the results obtained from the various sensors to the navigation support system 20. This includes an Electronic Chart Display and Information System (ECDIS) and a ship's radar system.

[0012] The navigation support device 20 may be a computer, or it may be built into a radar or ECDIS as a module, or the output of the navigation support device 20 may be displayed on the radar or ECDIS. Alternatively, the functions of the navigation support system 20 may be realized by installing and running application software on a portable terminal device such as a smartphone or tablet. Such a navigation support system 20 is installed on a ship.

[0013] The navigation support system 20 has a function to display the Obstacle Zone by Target (OZT) caused by the other vessel by performing collision calculations based on the relationship between the vessel and the other vessel. Collision calculations are performed based on various information about the ship and the other ship (position, speed, direction of travel, etc.) and the safe passage distance. In this embodiment, in addition to this data, the collision calculation is performed while considering a desired passage distance in the bow or stern direction of the other ship, and a function is provided to determine the navigation interference zone.

[0014] The navigation support device 20 includes an input unit 210, an output unit 220, a calculation unit 230, and a storage unit 240. The input unit 210 acquires various types of data. For example, the input unit 210 acquires results from the navigation management system 10, specifically from the various sensors in the navigation management system 10. Furthermore, the input unit 210 acquires a margin value indicating the degree of margin. This margin value represents the degree of margin considered when performing collision calculations to determine a navigation interference zone that differs from the navigation interference zone based on the results of a general collision calculation, in order to display the navigation interference zone. More specifically, when one's own ship is passing another ship, passing near the navigation interference zone will result in approaching the other ship. However, a navigation interference zone is determined that has a certain passing distance as a margin in the bow or stern direction of the other ship. The margin value can indicate the passing distance set as a margin by degree. The degree may be a level, a percentage, or the passing distance itself. When using a level, the passing distance can be determined according to the level. When using a percentage, it may indicate what percentage of the size of the space occupied by the other ship is to be left as a margin.

[0015] The input unit 210 acquires the margin of safety according to the operation performed on the control panel provided on the navigation support device 20. The control panel may be, for example, a dial, a keypad, or a touch panel. The navigator or crew can set any margin of safety by operating this control panel as needed. Alternatively, the input from the control panel may be an operation input specifying a desired cruising distance instead of a margin of safety.

[0016] Furthermore, the input unit 210 can also acquire a margin of safety (or desired overrun distance) based on the angle of the other vessel relative to the own vessel, which is determined based on the positions of the own vessel and the other vessel. This angle can be determined based on the positions of the own vessel and the other vessel obtained from the navigation management system 10. When the input unit 210 acquires data indicating the positions of the own vessel and the other vessel, it can acquire a margin of safety by determining the angle of the other vessel relative to the own vessel and then determining the margin of safety corresponding to this angle. For example, the margin of safety is greater when the angle of the other vessel relative to the own vessel is large (when the other vessel is sailing toward the own vessel from a direction such as the side of the own vessel's course) compared to when the angle of the other vessel relative to the own vessel is small (when the other vessel is sailing toward the own vessel from the side of the course directly in front of the own vessel). In other words, the margin of safety may be changed according to the angle at which the other vessel is sailing toward the own vessel. In this case, the navigator and crew can have the margin of safety automatically set according to the positions of the own vessel and the other vessel without having to operate the controls.

[0017] Furthermore, the input unit 210 may acquire a margin of safety based on the type of vessel of the other vessel, obtained from the navigation management system 10. For example, if the navigation management system 10 includes an AIS (Automatic Identification System), the system may acquire vessel type information indicating the type of vessel of the other vessel from the AIS and acquire a margin of safety for each other vessel according to its type. If the other vessel is a small fishing boat or pleasure boat, it is easier for that vessel to take evasive action because it is highly maneuverable, so the margin of safety is set to be small for such vessels. On the other hand, if the other vessel is a type of vessel that is difficult to take evasive action, such as a container ship, the margin of safety is set to be large for that vessel. This makes it possible to set a margin of safety that takes into account how easy it is for the other vessel to take evasive action, based on its type.

[0018] The input unit 210 acquires the changed margin value in response to the change in the margin value. For example, the margin value can be reacquired every predetermined period of time (e.g., 1 second). Such an input unit 210 has the function of a margin acquisition unit.

[0019] The output unit 220 outputs data to a display device. For example, if a display device is provided in the navigation support device 20, the output unit 220 outputs data to this display device to display various data. Alternatively, the output unit 220 may output data to an electronic chart information display device or a ship's radar device to display the data on the electronic chart information display device or the ship's radar device. For example, the output unit 220 may display the navigation interference zone determined by the calculation unit 230 overlaid on the display area where the radar screen is displayed, or it may display it in a display area adjacent to the radar screen. Furthermore, the output unit 220 may switch the navigation interference zone between a hidden state and a displayed state in response to an instruction input from the control panel.

[0020] The calculation unit 230 performs various calculations based on the data obtained from the input unit 210 and outputs the calculation results via the output unit 220, thereby displaying various data on the display device. The arithmetic unit 230 can be configured by a processing unit such as a CPU (Central Processing Unit) or a dedicated electronic circuit.

[0021] The calculation unit 230 functions as a collision calculation unit 231. The collision calculation unit 231 performs a collision calculation to determine whether or not its own vessel and the other vessel will collide, based on various data obtained from the navigation management system 10, and calculates the navigating obstruction zone (OZT). There are several methods for calculating the OZT when performing a collision calculation, but in this embodiment, we will describe the case in which the OZT is calculated based on a method called "line segment OZT".

[0022] The collision calculation unit 231 performs collision calculations based on the margin input from the input unit 210. In performing collision calculations based on the margin, the collision calculation unit 231 functions as a margin position calculation unit that determines a margin position which is a position located a distance (pass distance) determined according to the margin from at least one of the positions of the other vessel's bow or stern in the target occupied space. The target occupied space is a space set based on the safe pass distance relative to the position of the other vessel. This target occupied space may be the other vessel range (for example, circle Sb described later) set relative to the position of the other vessel, or it may be a range that includes this other vessel range and adjacent ranges (for example, circles Sa and Sc described later) set according to the other vessel range at at least one adjacent position on either the bow or stern side of the other vessel relative to the said other vessel range. In other words, the target occupied space E1 may consist of not only one small circle, but also two small circles or three small circles. Furthermore, the adjacent range may be set to two or more on the bow side of the opposing vessel, or to two or more on the stern side of the opposing vessel. The number of such ranges may be determined, for example, according to the shape of the hull. The size of each circle may also be changed according to the shape of the hull. In this way, the target occupied space E1 may be modified according to the purpose and use.

[0023] Once the margin position is determined, the collision calculation unit 231 determines the collision course based on the position determined according to the motion vector of the other ship, using this margin position as a reference, and calculates the navigation interference zone based on the determined collision course.

[0024] When the collision calculation unit 231 receives the modified margin from the input unit 210 in response to the change in the margin, it determines the margin position corresponding to the modified margin and performs a collision calculation. As a result, the collision calculation unit 231 performs collision calculations in accordance with the change in the margin and displays the navigation interference zone.

[0025] The memory unit 240 stores various data. The memory unit 240 may store a computer program for realizing the functions of the input unit 210 for acquiring margins and the collision calculation unit 231, and the calculation unit 230 may read and execute this computer program to realize the functions of the input unit 210 for acquiring margins and the collision calculation unit 231. The storage unit 240 is composed of a storage medium, such as an 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. This storage unit 240 can, for example, use non-volatile memory.

[0026] Figure 2 shows an example of a display screen 100 in which navigation interference zones are displayed on the display device based on data output from the output unit 220. The display screen 100 shows the local vessel O, the opposing vessel T, the navigation interference zone OZTs and navigation interference zone OZTm caused by the opposing vessel. A concentric scale centered on the local vessel O is also displayed. Navigation interference zones OZTs and navigation interference zones OZTm represent the areas where there is a risk of collision between one's own vessel O and another vessel T. Navigation interference zones OZTs are navigation interference zones obtained by performing collision calculations based on general calculation methods, while navigation interference zones OZTm are navigation interference zones obtained by performing collision calculations considering margins, as shown in this embodiment. As will be explained in more detail later, the navigation interference zone OZTm is the navigation interference zone calculated by ensuring that the desired overrun distance is maintained on the bow side of the other vessel. Regarding the navigation interference zones OZTs and OZTm, if the course of your vessel O falls within the range indicated by the navigation interference zone, it indicates that in the future, the other vessel will be within safe passing distance relative to your vessel. Safe passing distance is the distance at which you can safely pass the closest approach distance of the other vessel.

[0027] Comparing the navigation interference zones OZTs and OZTm, one end (code Eda) of each navigation interference zone is in the same position, but the other end (code Eds) of OZTs and the other end (code Edm) of OZTm are in different positions. Here, one end (symbol Eda) of each of the obstruction zones OZTs and OZTm indicates the end of the obstruction zone on the stern side of the other vessel, while the other end (symbol Eds) of the obstruction zone OZTs and the other end (symbol Edm) of the obstruction zone OZTm indicate the ends of the obstruction zone on the bow side of the other vessel. In this example, since the desired overrun distance was set on the bow side of the other vessel, one end (symbol Eda) of each of the obstruction zones OZTs and OZTm are in the same position, while the other end (symbol Eds) of the obstruction zone OZTs and the other end (symbol Edm) of the obstruction zone OZTm are determined to be in different positions. Furthermore, the other end of the navigation interference zone OZTm (designated Edm) is located closer to the vessel than the other end of the navigation interference zone OZTs (designated Eds). In addition, when comparing the lengths of the line segments of navigation interference zone OZTs and navigation interference zone OZTm, navigation interference zone OZTm is longer than navigation interference zone OZTs. Thus, in this embodiment, by determining a navigation interference zone that takes into account the margin of safety and displaying it on the display screen, it is possible to display a navigation interference zone that differs from the navigation interference zone determined by a general method.

[0028] This display screen 100 describes the case where the navigation interference zones OZTs and OZTm are displayed, but it is also possible to display only the navigation interference zone OZTm without displaying the navigation interference zone OZTs. Furthermore, when both the navigation interference zone OZTs and OZTm are displayed, they may be displayed using different display methods. In the case of different display methods, the line segments or endpoints of the navigation interference zones may have different colors or shapes, or the shapes of the figures used may be different. In addition, each navigation interference zone may be displayed with a string of characters or symbols that make it clear whether it is a navigation interference zone that was determined without considering margins or one that was determined with margins in mind.

[0029] Next, the operation of the navigation support device 20 described above will be explained. Figure 3 is a flowchart illustrating the operation of the navigation support device 20. Figure 4 is a diagram illustrating the space occupied by the own ship and the space occupied by the other ship. The input unit 210 of the navigation support device 20 acquires various data from the navigation management system 10 (step S101). The data acquired here includes, for example, the speed of the own vessel PO, the speed of the other vessel (other vessel PT), the position of the own vessel PO, the position of the other vessel PT, the course of the own vessel PO, the course of the other vessel PT, and the safe overrun distance.

[0030] The collision calculation unit 231 sets the space occupied by its own ship DO and the space occupied by the other ship DT based on various data obtained from the navigation management system 10 (step S102). Here, the space occupied by one's own ship, DO, is considered to be the territory of one's own ship. The space occupied by the other ship, DT, is considered to be the territory of the other ship. In other words, the state in which the two occupied spaces, DO and DT, are in contact indicates a state in which one's own ship and the other ship are in contact. The space occupied by the other vessel DT includes the other vessel's range (circle Sb), which is set based on the other vessel's position, and adjacent ranges, which are set according to the other vessel's range, at least one adjacent position on either the bow or stern side of the other vessel relative to the other vessel's range (circle Sb). Here, circle Sa is set as the adjacent range on the bow side of circle Sb, which is the other vessel's range, and circle Sc is set as the adjacent range on the stern side of circle Sb, so the space occupied by the other vessel DT is set as a region containing three circles. Furthermore, the adjacent ranges (circles Sa and Sc) are positioned adjacent to the other vessel's range (circle Sb) in a direction along the other vessel's course. The radii of these circles Sa, Sb, and Sc are the same. The overall length LT of the opposing ship is the sum of the diameters of the three circles (circle Sa, circle Sb, circle Sc).

[0031] Similarly, the ship's occupied space DO also includes a ship's range (circle Se) set based on the ship's position, and adjacent ranges set according to the ship's range at at least one adjacent position on either the bow or stern side of the ship relative to the ship's range (circle Se). Here, circle Sd is set as an adjacent range on the bow side of circle Se, and circle Sf is set as an adjacent range on the stern side of circle Se, so the ship's occupied space DO is set as a region containing three circles. Furthermore, the adjacent ranges (circles Sd and Sf) are positioned adjacent to the ship's range (circle Se) in a direction along the ship's course. The radii of these circles Sd, Se, and Sf are the same. The ship's overall length LO is the sum of the diameters of the three circles (circle Sd, circle Se, and circle Sf).

[0032] The radius of the other vessel's range can be set according to the size of the other vessel's hull and its safe cruising distance, and the radius of your own vessel's range can be set according to the size of your own vessel's hull and its safe cruising distance. The collision course CO can be determined as the course of the ship at which its occupied space DO and the other ship's occupied space DT come into contact.

[0033] Next, the collision calculation unit 231 determines the collision path CO (step S103). Figures 5 and 6 illustrate part of the calculation process for determining the collision path CO. In this step, the collision calculation unit 231 first determines the target occupied space E1. The target occupied space E1 is the region surrounding three circles (here, circles Sa, Sb, and Sc) that are centered on the enemy ship's position PT and have a radius equal to the distance LG between the occupied targets, arranged in accordance with the enemy ship's course. The target occupied space E1 is the same as the opponent's occupied space DT described above, but the target occupied distance LG (the radius of circle Sb in the opponent's occupied space DT) is set to be at least one-third of the sum of half the length of the own ship's total length LO and half the length of the opponent's total length LT. This target occupied distance LG can be expressed as shown in equation (1) below. LG≧((LO / 2)+(LT / 2)) / 3 ···(1) By setting the target occupancy distance LG in this way, the area of ​​the ship's occupied space DO can be included in the target occupancy space E1, and the ship's PO can be considered as a point.

[0034] Next, the collision calculation unit 231 determines the tangent line POA (Figure 5) that touches the target occupied space E1 at point A, and the tangent line POB (Figure 6) that touches the target occupied space E1 at point B, starting from the ship's position PO. The tangent line POA is the minimum tangential bearing from the ship's position PO to the target occupied space E1, and the tangent line POB is the maximum tangential bearing from the ship's position PO to the target occupied space E1. Point A is located in the direction of the other ship PT's course (bow side), and point B is located on the opposite side of the other ship PT's course (stern side).

[0035] Next, the collision calculation unit 231 determines endpoint C by drawing the motion vector UT of the other ship with contact point A as the tip (Figure 5), and determines endpoint D by drawing the motion vector UT of the other ship with contact point B as the tip (Figure 6). Here, the motion vector UT of the other ship is a vector whose magnitude is the speed VT of the other ship and whose direction is the course CT of the other ship.

[0036] Next, the collision calculation unit 231 finds a circle C1 centered at endpoint C with radius equal to the ship's speed VO, and determines the intersection point E of circle C1 and the tangent line POA (Figure 5). Furthermore, the collision calculation unit 231 finds a circle C2 centered at endpoint D with radius equal to the ship's speed VO, and determines the intersection point of circle C2 and the tangent line POB as F (Figure 6).

[0037] Next, the collision calculation unit 231 determines the collision course for its own vessel PO to collide with the other vessel PT. Here, the collision calculation unit 231 determines the direction of the line segment EC connecting intersection point E to endpoint C as the collision course CO1, and the direction of the line segment FD connecting intersection point F to endpoint D as the collision course CO2. Here, the collision path CO can be determined based on the following equation (2).

[0038]

number

[0039] In equation (2), sin -1 It is expressed including sin. -1 Since two solutions can be found, two collision paths can be found for each tangent line. In other words, there are a total of two tangent lines: the smallest tangent line POA and the largest tangent line POB, and each of them is sin -1 Since two solutions are obtained, a total of four collision paths can be determined. Based on the four determined collision paths and a predetermined conditional expression based on TCPA (Time of Closest Approach), the number of collision paths will be either 0, 2, or 4. If there are no collision paths, no navigation interference zone is plotted. If there are two collision paths, one navigation interference zone is determined. If there are four collision paths, two navigation interference zones are determined. Here, we will explain the case where there are two collision paths (collision path CO1, collision path CO2) and one navigation interference zone is determined.

[0040] Once the collision course is determined, the collision calculation unit 231 calculates the navigation interference zone (step S104). Figure 7 illustrates the process of calculating the navigation interference zone. As shown in this figure, the collision calculation unit 231 calculates a straight line in the direction of the collision course CO1 with the ship's position PO as the starting point, and a straight line in the direction of the other ship's course CT with the point of contact A as the starting point, and determines the intersection of these two straight lines as intersection point G. The collision calculation unit 231 also calculates a straight line in the direction of the collision course CO2 with the ship's position PO as the starting point, and a straight line in the direction of the other ship's course CT with the point of contact B as the starting point, and determines the intersection of these two straight lines as intersection point H. The collision calculation unit 231 determines the straight line connecting the determined intersection points G and H as the navigation interference zone. It indicates that if the own ship PO sails through this navigation interference zone, it will pass through the target occupied space E1 and collide with the other ship PT.

[0041] Here, the navigation interference zone determined based on steps S103 and S104 described above is a generally required navigation interference zone. Next, we will explain the process for determining a navigation interference zone that takes safety margins into account. In this case, the collision calculation method has some commonalities with steps S103 to S104 described above. We will omit the explanation of the common parts and mainly explain the differences. Furthermore, when determining a navigation interference zone that takes safety margins into account, it is sufficient to use at least one of the following methods: either determine a collision course with a desired overrun distance on the bow side of the other vessel's PT and determine the navigation interference zone from the result, or determine a collision course with a desired overrun distance on the stern side of the other vessel's PT and determine the navigation interference zone from the result. Here, we will explain the case where a collision course with a desired overrun distance on the bow side of the other vessel's PT is determined and the navigation interference zone is determined from the result.

[0042] The input unit 210 acquires the margin (step S105). Here, for example, the margin is acquired based on the operation performed by the control. For example, if a certain margin is set by turning a control such as a dial, the input unit 210 acquires the set margin.

[0043] When the collision calculation unit 231 obtains a margin of safety from the input unit 210, it calculates a distance corresponding to the margin of safety as the margin distance (step S106). For example, if a certain margin of safety is specified, the margin distance is calculated to be 1 mile. If an operation that reduces the margin of safety is input, the collision calculation unit 231 shortens the distance set as the margin, such as 0.8 miles or 0.6 miles, according to the operation. If an operation that increases the margin of safety is input, it lengthens the distance set as the margin, such as 1.2 miles or 1.4 miles, according to the operation.

[0044] Figures 8 and 9 illustrate the process for determining a navigation interference zone that takes safety margins into account. The collision calculation unit 231 determines a point Ei within the circle Sa of the target occupied space E1 that lies on a straight line passing through the center of the other vessel PT and the center of circle Sa, and is located on the outer perimeter of the target occupied space E1. Then, using this point Ei as a base point, the collision calculation unit 231 determines a point I at a position BOW away from the other vessel PT in the direction of its course (bow side) (step S107). Here, BOW represents the desired pass-through distance (margin distance).

[0045] Next, the collision calculation unit 231 determines the endpoint J by drawing the motion vector UT of the other ship with point I as the tip (step S108), and then finds a circle C3 with endpoint J as the center and radius being the ship's speed VO (step S109). The collision calculation unit 231 finds a line POI from the ship PO to point I, and determines the intersection point K of the circle C3 and the line POI (step S110). The collision calculation unit 231 then determines the direction of the line segment KJ connecting the intersection point K to the endpoint J as the collision course CO3, which is the collision course in which the ship PO avoids a collision with a crossover distance of BOW in the direction of the bow of the other ship PT (step S111).

[0046] Next, the collision calculation unit 231 determines the navigation interference zone with a margin of safety (step S112). Figure 9 is a diagram illustrating the process of determining the navigation interference zone with a margin of safety. The collision calculation unit 231 determines a straight line in the direction of the collision course CO3, using its own ship's position PO as the starting point, and determines a straight line in the direction of the other ship's course CT, using point I as the starting point, and determines the intersection point L of these two straight lines. The collision calculation unit 231 calculates the navigation interference zone OZTm with the desired overrun distance (margin) on the bow side by determining the straight line connecting intersection point H and intersection point L. Here, one end of the navigation interference zone OZTs and one end of the navigation interference zone OZTm, obtained without considering any margins, overlap at intersection point H, but the other end of the navigation interference zone OZTs and the other end of one of the navigation interference zone OZTm are in different positions. When the collision calculation unit 231 determines the navigation interference zone, it outputs the navigation interference zone from the output unit 220 and displays it on the screen (step S113).

[0047] The above-described process may be repeated at regular intervals (for example, every second) to update and display the navigation interference zone on the display screen. Alternatively, the above-described process may be executed when the margin input from the input unit 210 is changed. In the process described above, we explained the case where the navigation interference zone OZTs is determined by performing steps S103 and S104. However, it is also possible to determine the navigation interference zone OZTm without performing steps S103 and S104.

[0048] In the embodiment described above, the case of performing a collision calculation for one opposing vessel PT was explained. However, if there are multiple opposing vessels, the same procedure can be followed to perform a collision calculation for each of the opposing vessels. When there are multiple other vessels, if the navigation interference zone is displayed with a certain margin, there will be multiple navigation interference zones, and since the margin is taken into account, each navigation interference zone will be displayed as a longer line segment than usual. Then, it may become difficult to determine a course to avoid the navigation interference zones. In such a case, by operating the operator to reduce the margin, the length of the line segment of each navigation interference zone will become shorter according to the reduction of the margin, making it easier to determine a course to avoid the navigation interference zones.

[0049] In the above-described embodiment, the case where the navigation interference zone is obtained with a desired passing distance on the bow side of the other vessel PT has been described. Next, the case where the navigation interference zone is obtained with a desired passing distance on the stern side of the other vessel PT will be described.

[0050] FIG. 10 is a diagram for explaining a display screen when a navigation interference zone with a desired passing distance on the bow side of the other vessel PT and a navigation interference zone with a desired passing distance on the stern side of the other vessel PT are displayed. In this figure, a case where the other vessel PT is navigating from the right side to the left side with respect to the own vessel PO is illustrated. The collision calculation unit 231 sets a target occupancy space E1 for the other vessel PT according to the same procedure as the above-described collision calculation, and obtains general navigation interference zones OZTs without considering a margin. Further, the collision calculation unit 231 uses, as a reference point, a point on the bow side of the target occupancy space E1 from the own vessel PO, and obtains a position T that is separated by BOW (desired passing distance) in the course direction (bow side) of the other vessel PT. L1 And the collision calculation unit 231 determines this point T L1 From the obtained collision course CC L1 And the point T L1 From the other vessel course C T Intersection point R of the line L1 Is obtained. Further, the collision calculation unit 231 starts from the own vessel PO the goal A point T that touches the stern side of the occupancy space E1 is obtained, and this point T R Is obtained, and this point T ROne endpoint R of the navigation interference zone OZTs obtained from R And, intersection point R L1 The line segment connecting the two points is determined as the navigation interference zone OZTmb, which has the desired pass distance on the bow side of the opposing vessel PT.

[0051] Furthermore, the collision calculation unit 231 uses a point on the stern side of the target occupied space E1 from its own ship PO as a base point, and sets a position T at a distance of STERN (desired passing distance) on the opposite side (stern side) from the course direction of the opposing ship PT. R1 The collision calculation unit 231 then calculates this point T R1 Collision trajectory CC obtained from R1 And point T R1 From the opposing ship's course C T Intersection point R with the line R1 The collision calculation unit 231 calculates the value from the ship's PO. the goal Point T is adjacent to the bow side of the occupied space E1. L Find this point T L The other endpoint R of the navigation interference zone OZTs determined from L And, intersection point R R1 The line segment connecting the two points is determined as the navigation interference zone (OZTms) with the desired pass distance on the stern side of the opposing vessel's PT.

[0052] In this way, by determining the navigation interference zone with the desired overrun distance on the stern side, it can be displayed on the display screen. This section describes how to display three navigation interference zones on the display screen: the generally required OZTs, the OZTmb with a desired overrun distance towards the bow, and the OZTms with a desired overrun distance towards the stern. However, it is also possible to select and display only one of them. Furthermore, the OZTs, OZTmb, and OZTms may each be displayed in different ways.

[0053] Furthermore, the navigation interference zone OZTmb and the navigation interference zone OZTms may be determined using the same margin of safety, or they may be determined using different margins of safety. Generally, it is preferable to pay more attention to the bow side of an opposing vessel than to the stern side, so the margin of safety for the bow side may be made larger than that for the stern side.

[0054] Furthermore, according to the above embodiment, a point is determined that is a desired distance away from the target occupied space E1 of the opposing vessel PT, and then a navigation interference zone is determined that takes a margin into account. However, instead of determining a point, it may also be possible to modify the method by widening the spacing of the circles included in the target occupied space E1 (the spacing between the circle Sb indicating the range of the opposing vessel and the adjacent range).

[0055] Furthermore, simply extending the line segment of the navigation interference zone determined using general methods will not take into account the relative positions, course, and speed of the other vessel and your own vessel in the extended portion. Therefore, it is not possible to accurately represent the navigation interference zone. In this embodiment, the margin is obtained, and a collision calculation is performed after setting the desired passing distance from the space occupied by the other vessel according to that margin. Therefore, a navigation interference zone that takes into account the degree of margin (the passing distance according to the desired amount of margin) can be displayed. For example, if a margin of 1 mile is specified and input from the input unit 210, even if the vessel passes near the edge of the navigation interference zone displayed on the screen, it can navigate a course that secures a 1-mile margin. In this case, the vessel can also recognize that the passing distance with a margin of 1 mile and take a course accordingly.

[0056] The navigation support device 20 in the above-described embodiment may be implemented using a computer. In that case, the program for implementing these functions 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 an 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 used 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 such cases. Furthermore, the above-mentioned program may be for implementing a part of the functions described above, or it may be a program that can implement the above-mentioned functions 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).

[0057] Although 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]

[0058] PO...Own ship, PT...Other ship, 10...Navigation management system, 20...Navigation support system, 210...Input unit, 220...Output unit, 230...Calculation unit, 231...Collision calculation unit, 240...Storage unit

Claims

1. A navigation support system that determines the navigation interference zone based on the relationship between one's own vessel and the other vessel, A margin acquisition unit that acquires a margin level indicating the degree of margin, A calculation unit determines a first margin position, which is a position in the target occupied space set based on the position of the other vessel, that is located a distance determined according to the margin from the bow position of the other vessel in the direction of the other vessel's course. Based on the position determined according to the motion vector of the other vessel, with respect to the first margin position, it determines the collision course. It finds the intersection point of the determined collision course and the course of the other vessel from the first margin position, finds a point located on the stern side of the target occupied space from the own vessel, and calculates a navigation interference zone with a desired pass distance on the bow side of the other vessel by drawing a line segment connecting one endpoint of the navigation interference zone determined from this point and the intersection point. A navigation support system having [a certain feature].

2. A navigation support system that determines the navigation interference zone based on the relationship between one's own vessel and the other vessel, A margin acquisition unit that acquires a margin level indicating the degree of margin, A calculation unit determines a second margin position, which is located in the target occupied space set based on the position of the other vessel, at a distance determined according to the margin, on the opposite side of the direction of the other vessel's course from the position of the other vessel's stern, and determines the collision course based on the position determined according to the motion vector of the other vessel, finds the intersection point of the determined collision course and the course of the other vessel from the second margin position, finds a point located on the bow side of the target occupied space from the own vessel, calculates the line segment connecting the other endpoint of the navigation interference zone determined from this point and the intersection point as a navigation interference zone with a desired pass distance on the stern side of the other vessel, A navigation support system having [a certain feature].

3. A navigation support system that determines the navigation interference zone based on the relationship between one's own vessel and the other vessel, A margin acquisition unit that acquires a margin level indicating the degree of margin, A first margin position is determined, which is a position in the target occupied space set based on the position of the other vessel, that is located a distance determined according to the margin from the bow position of the other vessel in the direction of the other vessel's course. Based on the position determined according to the motion vector of the other vessel, with respect to the first margin position, the collision course is determined. The intersection point of the determined collision course and the course of the other vessel from the first margin position is determined, and a point located on the stern side of the target occupied space from one's own vessel is determined. The line segment connecting one endpoint of the navigation interference zone determined from this point and the intersection point is calculated as a navigation interference zone with a desired pass distance on the bow side of the other vessel. A calculation unit that determines a second margin position, which is located at a distance determined according to the margin, on the opposite side of the opposing ship's course direction from the position of the opposing ship's stern in the target occupied space, determines the collision course based on the position determined according to the opposing ship's motion vector with respect to the second margin position, finds the intersection point of the determined collision course and the course of the opposing ship from the second margin position, finds a point located on the bow side of the target occupied space from the ship's own ship, calculates a line segment connecting the other endpoint of the navigation interference zone determined from this point and the intersection point, and determines a navigation interference zone with a desired pass distance on the stern side of the opposing ship. A navigation support system having [a certain feature].

4. The aforementioned margin acquisition unit acquires a margin corresponding to the operation performed on the operator. Navigation support device according to any one of claims 1 to 3.

5. The margin acquisition unit acquires a margin corresponding to the angle of the other ship relative to the self-ship, which is determined based on the position of the self-ship and the position of the other ship. Navigation support device according to any one of claims 1 to 4.

6. The aforementioned target occupied space includes an opponent vessel range set based on the position of the opponent vessel, and an adjacent range set in accordance with the opponent vessel range at at least one adjacent position on either the bow or stern side of the opponent vessel relative to the opponent vessel range. Navigation support device according to any one of claims 1 to 5.

7. The margin acquisition unit acquires the modified margin in response to the change in the margin, The calculation unit determines the margin position corresponding to the modified margin and calculates the navigation interference zone based on the margin position corresponding to the modified margin. Navigation support device according to any one of claims 1 to 6.

8. This is a navigation assistance method performed by a computer, which determines the navigation interference zone based on the relationship between one's own vessel and the other vessel. The margin acquisition unit acquires a margin that indicates the degree of margin, The calculation unit determines a first margin position, which is a position in the target occupied space set based on the position of the other ship, that is located a distance determined according to the margin from the position of the bow of the other ship in the direction of the other ship's course. Based on the position determined according to the motion vector of the other vessel with respect to the first margin position, the collision course is determined, and the intersection point of the determined collision course and the course of the other vessel from the first margin position is determined. Determine the point located on the stern side of the target occupied space from your own ship, The line segment connecting one endpoint of the navigation obstruction zone determined from this point to the aforementioned intersection is calculated as the navigation obstruction zone with the desired overrun distance on the bow side of the other vessel. Navigation aid methods.

9. This is a navigation assistance method performed by a computer, which determines the navigation interference zone based on the relationship between one's own vessel and the other vessel. The margin acquisition unit acquires a margin that indicates the degree of margin, The calculation unit determines a second margin position, which is a position in the target occupied space set based on the position of the other ship, that is located on the opposite side of the direction of the other ship's course, at a distance determined according to the margin, from the position of the stern of the other ship. Based on the position determined according to the motion vector of the other vessel with respect to the second margin position, the collision course is determined, and the intersection point of the determined collision course and the course of the other vessel from the second margin position is determined. Determine the point located on the bow side of the target occupied space from your own ship, The line segment connecting the other endpoint of the navigation interference zone determined from this point and the aforementioned intersection point is calculated as a navigation interference zone with the desired passing distance on the stern side of the other vessel. Navigation aid methods.

10. This is a navigation assistance method performed by a computer, which determines the navigation interference zone based on the relationship between one's own vessel and the other vessel. The margin acquisition unit acquires a margin that indicates the degree of margin, The calculation unit determines a first margin position, which is a position in the target occupied space set based on the position of the other ship, that is located a distance determined according to the margin from the position of the bow of the other ship in the direction of the other ship's course. Based on the position determined according to the motion vector of the other ship, with respect to the first margin position, it determines the collision course. It finds the intersection point of the determined collision course and the course of the other ship from the first margin position, finds a point located on the stern side of the target occupied space from the ship's own ship, calculates a line segment connecting one endpoint of the navigation interference zone determined from this point and the intersection point, and defines the navigation interference zone with the desired pass distance on the bow side of the other ship. A second margin position is determined, which is a distance determined according to the margin, on the opposite side of the opposing vessel's course direction from the position of the opposing vessel's stern in the target occupied space. Based on the position determined according to the opposing vessel's motion vector with respect to the second margin position, the collision course is determined. The intersection point of the determined collision course and the opposing vessel's course from the second margin position is determined, and a point located on the bow side of the target occupied space from one's own vessel is determined. The line segment connecting the other endpoint of the navigation interference zone determined from this point and the aforementioned intersection point is calculated as a navigation interference zone with a desired pass distance on the stern side of the opposing vessel. Navigation aid methods.

11. We obtain a margin level that indicates the degree of leeway, A first margin position is determined, which is a position in the target occupied space set based on the position of the other vessel, that is located a distance from the position of the bow of the other vessel in the direction of the other vessel's course, determined according to the margin. Based on the position determined according to the motion vector of the other vessel with respect to the first margin position, the collision course is determined, and the intersection point of the determined collision course and the course of the other vessel from the first margin position is determined. Determine the point located on the stern side of the target occupied space from your own ship, From this point, the line segment connecting one endpoint of the navigation obstruction zone and the aforementioned intersection is used to calculate the navigation obstruction zone with the desired overrun distance on the bow side of the opposing vessel. A program that causes a computer to perform a task.

12. We obtain a margin level that indicates the degree of leeway, A second margin position is determined, which is a position in the target occupied space set based on the position of the other vessel, that is located on the opposite side of the other vessel's course direction from the position of the stern of the other vessel, at a distance determined according to the margin. Based on the position determined according to the motion vector of the other vessel with respect to the second margin position, the collision course is determined, and the intersection point of the determined collision course and the course of the other vessel from the second margin position is determined. Determine the point located on the bow side of the target occupied space from your own ship, From this point, the line segment connecting the other endpoint of the navigation interference zone and the aforementioned intersection point is used to calculate a navigation interference zone with the desired pass distance on the stern side of the other vessel. A program that causes a computer to perform a task.

13. We obtain a margin level that indicates the degree of leeway, A first margin position is determined, which is a position in the target occupied space set based on the position of the other vessel, that is located a distance from the position of the bow of the other vessel in the direction of the other vessel's course, determined according to the margin. Based on the position determined according to the motion vector of the other vessel with respect to the first margin position, the collision course is determined, the intersection point of the determined collision course and the course of the other vessel from the first margin position is determined, a point located on the stern side of the target occupied space from one's own vessel is determined, and the line segment connecting one endpoint of the navigation interference zone determined from this point and the aforementioned intersection point is calculated as a navigation interference zone with a desired pass distance on the bow side of the other vessel, A second margin position is determined, which is a distance determined according to the margin, on the opposite side of the opposing vessel's course direction from the position of the opposing vessel's stern in the target occupied space. Based on the position determined according to the opposing vessel's motion vector with respect to the second margin position, the collision course is determined. The intersection point of the determined collision course and the opposing vessel's course from the second margin position is determined, and a point located on the bow side of the target occupied space from one's own vessel is determined. The line segment connecting the other endpoint of the navigation interference zone determined from this point and the aforementioned intersection point is calculated as a navigation interference zone with a desired pass distance on the stern side of the opposing vessel. A program that causes a computer to perform a task.

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