Marine navigation support system, marine navigation support method, and program

Abstract

To provide a marine navigation support system in which an avoidance route calculation can be stabilized.SOLUTION: A marine navigation support system comprises: a moving object data acquisition unit for acquiring moving object data including the position and velocity of a moving object running on water; a target data acquisition unit for acquiring target data including the position and velocity of each of the multiple targets existing around the moving object; an avoidance-route-target selection unit for selecting a target, the predicted position of which is included in the selected area based on the moving object from the multiple targets, on the basis of the moving object data and the target data; and an avoidance route generation unit for generating an avoidance route for the selected target as an avoidance-route-target.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a navigation support system, a navigation support method, and a program. [Background technology]

[0002] Patent Document 1 discloses a technology in which, if an obstacle is detected in the course of a ship following a tracking point, the ship will prioritize avoiding the obstacle before continuing to follow the tracking point. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2020 / 0310434 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if all targets detected by sensors are considered as avoidance targets when calculating an avoidance route, the calculation of the avoidance route may become unstable, for example, the avoidance route may meander unexpectedly in an attempt to avoid targets that are unnecessarily far away, and the calculation load may increase more than necessary.

[0005] The present invention has been made in view of the above-mentioned problems, and its main object is to provide a navigation support system, a navigation support method, and a program that are capable of stabilizing collision avoidance route calculations. [Means for solving the problem]

[0006] In order to solve the above problems, a navigation assistance system according to one aspect of the present invention includes: a mobile object data acquisition unit that acquires mobile object data including the position and speed of a mobile object moving on water; a target data acquisition unit that acquires target data including the position and speed of each of a plurality of targets present around the mobile object; a collision avoidance target selection unit that selects, from the plurality of targets based on the mobile object data and the target data, targets whose predicted positions are included in a selection region based on the mobile object; and a collision avoidance route generation unit that generates a collision avoidance route using the selected targets as collision avoidance routes. This makes it possible to stabilize collision avoidance route calculation.

[0007] In the above aspect, the collision avoidance target selection unit may calculate a risk area where there is a risk of collision between the moving body and each of the plurality of targets, and select, from the plurality of targets, a target whose selection area includes the risk area as the collision avoidance target. This makes it possible to select, as the collision avoidance target, a target whose selection area includes the risk area.

[0008] In the above aspect, the avoidance route generation unit may calculate a collision risk value between the moving body and the selected target, and generate the avoidance route based on the collision risk value. In this way, since the collision risk value is calculated for the selected target, it is possible to stabilize the calculation of the avoidance route.

[0009] In the above aspect, the avoidance route generation unit may generate one or more potential avoidance route patterns between an avoidance start point having the position of the moving body as a starting point and an avoidance end point that is an end point of the avoidance, and select the avoidance route from the potential avoidance route patterns based on the collision risk value calculated for the selected target for each of the potential avoidance route patterns. This makes it possible to stabilize the calculation of the avoidance route because the collision risk value is calculated for the selected target.

[0010] In the above aspect, the avoidance route generation unit may select, as the avoidance route, the potential avoidance route pattern that minimizes the collision risk value of the target with the largest collision risk value among the selected targets. This allows for the calculation of the avoidance route to be stabilized, since the collision risk value is calculated for the selected targets.

[0011] In the above aspect, the system may further include a planned route acquisition unit that acquires a planned route for the moving body, and the avoidance route generation unit may generate the avoidance route that deviates from the planned route and returns to the planned route. This makes it possible to generate an avoidance route that returns to the planned route.

[0012] In the above aspect, the avoidance route generation unit may generate the avoidance route within a search area that overlaps with the selection area, using the moving object as a reference. This makes it possible to stabilize the calculation of the avoidance route because the avoidance route is generated within the search area.

[0013] In the above aspect, the selection area may be set inside the search area, which makes it easier to generate an avoidance route that returns to the original route after avoiding the selected target.

[0014] In the above aspect, the boundary of the selection area may be set closer to the moving body than the boundary of the search area, which makes it easier to generate an avoidance route that returns to the original route after avoiding the selected target.

[0015] In the above aspect, the collision avoidance target selection unit may narrow the selection area so that the number of targets whose risk areas are included in the selection area is equal to or less than a predetermined number. This makes it possible to further stabilize the collision avoidance route calculation by reducing the number of targets selected as collision avoidance targets.

[0016] In the above aspect, the collision avoidance target selection unit may preferentially select, as the collision avoidance target, targets whose risk area is closer to the moving body or the course or heading of the moving body. This makes it possible to preferentially select, as the collision avoidance target, targets with a higher collision risk.

[0017] In the above aspect, the collision avoidance target selection unit may calculate, as the risk area, an area including a section on the predicted course of the target that poses a risk of collision with the moving object when the moving object is assumed to change course in an arbitrary direction and cross the predicted course of the target. This makes it possible to evaluate the collision risk on the predicted course of the target.

[0018] In the above aspect, the mobile unit may further include a navigation control unit that causes the mobile unit to navigate the avoidance route. This makes it possible to automatically cause the mobile unit to navigate the avoidance route.

[0019] In the above aspect, the navigation system may further include a display unit that displays the avoidance route, thereby making it possible to present the avoidance route to the user.

[0020] In the above aspect, the vehicle may further include at least one sensor selected from the group consisting of radar, lidar, sonar, and image sensor, which is mounted on the vehicle and generates the target data, thereby enabling targets to be selected using the target data generated by the sensor.

[0021] In the above aspect, the vehicle may further include an automatic identification device mounted on the vehicle and receiving the target data. This makes it possible to select targets using the target data received by the automatic identification device.

[0022] Another aspect of the navigation support method of the present invention includes acquiring moving body data including the position and speed of a moving body moving on water, acquiring target data including the position and speed of each of a plurality of targets present around the moving body, selecting from the plurality of targets based on the moving body data and the target data those targets whose predicted positions are included in a selection region based on the moving body, and generating an avoidance route using the selected targets as avoidance targets. This makes it possible to stabilize the calculation of the avoidance route.

[0023] According to another aspect of the present invention, a program causes a computer to execute the following steps: acquire mobile object data including the position and speed of a mobile object moving on water; acquire target data including the position and speed of each of a plurality of targets existing around the mobile object; select, from the plurality of targets based on the mobile object data and the target data, targets whose predicted positions are included in a selection region based on the mobile object; and generate an avoidance route using the selected targets as avoidance targets. This makes it possible to stabilize the calculation of the avoidance route. [Effects of the Invention]

[0024] According to the present invention, it is possible to stabilize the calculation of a collision avoidance route. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 illustrates an example of a navigation support system. [Figure 2] FIG. 1 illustrates an example of an information processing device. [Figure 3] FIG. 2 is a diagram illustrating an example of a target management database. [Figure 4] FIG. 4 is a diagram illustrating a display example of a display unit. [Figure 5] FIG. 2 is a diagram illustrating a configuration example of a collision avoidance target selection unit. [Figure 6] FIG. 10 is a diagram illustrating an example of a selection region and a search region. [Figure 7] FIG. 10 is a diagram showing examples of a selection area and a risk area. [Figure 8]FIG. 10 is a diagram illustrating an example of a selection database. [Figure 9] FIG. 10 is a diagram showing an example of limiting a selection region. [Figure 10] FIG. 10 is a diagram showing an example of limiting a selection region. [Figure 11] FIG. 10 is a diagram illustrating an example of calculating a risk area. [Figure 12] FIG. 10 is a diagram illustrating an example of an avoidance route generation unit. [Figure 13] FIG. 10 is a diagram illustrating an example of generating a pattern. [Figure 14] FIG. 10 is a diagram showing an example of selection of an avoidance route. [Figure 15] FIG. 10 is a diagram illustrating an example of a procedure for a navigation support method. [Figure 16] FIG. 10 is a diagram showing a modified example of a navigation support method. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, elements similar to those described above with reference to the previous drawings will be designated by the same reference numerals, and detailed descriptions thereof may be omitted as appropriate.

[0027] [Navigation support system] FIG. 1 is a block diagram showing an example of the configuration of a navigation assistance system 100. The navigation assistance system 100 is a system installed on a ship. In the following description, the ship on which the navigation assistance system 100 is installed is also referred to as the "own ship," and other ships are also referred to as "other ships." The own ship is an example of a mobile body that moves on water.

[0028] The navigation support system 100 includes an information processing device 1, a display unit 2, a radar 31, a lidar 32, a sonar 33, an image sensor 34, an AIS 4, a GNSS receiver 6, a plotter 7, and a navigation control unit 9. These devices are connected to a network N such as a LAN, and are capable of network communication with each other.

[0029] The information processing device 1 includes a computer including a CPU, RAM, ROM, nonvolatile memory, an input / output interface, etc. The CPU executes information processing according to a program loaded from the ROM or nonvolatile memory to the RAM.

[0030] The program may be supplied via an information storage medium such as an optical disk or a memory card, or may be supplied via a communication line such as the Internet or a LAN.

[0031] The display unit 2 displays a display image generated by the information processing device 1. The display unit 2 also displays a radar image, a camera image, an electronic nautical chart, or the like.

[0032] The display unit 2 is, for example, a display device with a touch sensor, a so-called touch panel, and detects a position on the screen pointed to by a user's finger, etc. Alternatively, the pointed position may be input by a pointing device such as a trackball.

[0033] The radar (radio detection and ranging device) 31, the lidar (light detection and ranging device) 32, the sonar (acoustic navigation and ranging device) 33, and the image sensor 34 are examples of sensors that generate target data including the position and speed of targets such as other ships. The targets are not limited to targets on the water such as other ships, but may also be underwater targets such as reefs.

[0034] The radar 31 emits radio waves around the ship, receives reflected waves, and generates echo data. The radar 31 also identifies targets on the water from the echo data and generates target data. The target data generated by the radar 31 is also called TT data (Target Tracking Data).

[0035] The LIDAR 32 emits laser light around the ship, receives the reflected light, and generates image data. The LIDAR 32 also identifies targets on the water from the image data and generates target data.

[0036] The sonar 33 emits ultrasonic waves around the ship, receives the reflected waves, and generates echo data. The sonar 33 also identifies underwater targets from the echo data and generates target data.

[0037] The image sensor 34 captures images of the surroundings of the ship and generates image data. The image sensor 34 identifies targets included in the image data and generates target data. The function of generating target data may be realized in the information processing device 1.

[0038] The AIS (Automatic Identification System) 4 receives AIS data from other ships around the ship or from land-based control. The AIS data includes the identification codes, ship names, positions, courses, speeds, ship types, ship lengths, and destinations of other ships, and may be used as target data.

[0039] The GNSS receiver 6 detects the position of the ship based on radio waves received from the GNSS (Global Navigation Satellite System).

[0040] The plotter 7 acquires the position of the ship from the GNSS receiver 6 and displays the position of the ship on an electronic nautical chart. The plotter 7 also displays the planned route of the ship on the electronic nautical chart.

[0041] The navigation control unit 9 is a control device for realizing autonomous navigation, and controls the steering gear of the ship. The navigation control unit 9 may also control the engine of the ship.

[0042] In this embodiment, the information processing device 1 and the display unit 2 are independent devices, but this is not limiting, and the information processing device 1 and the display unit 2 may be an integrated device.

[0043] Furthermore, although the information processing device 1 is an independent device, it is not limited to this and may be integrated with another device such as a plotter 7. In other words, some or all of the functions of the information processing device 1 may be realized by another device.

[0044] Furthermore, the display unit 2 is also an independent device, but is not limited to this. A display unit of another device such as a plotter 7 may be used as the display unit 2 that displays the display image generated by the information processing device 1.

[0045] [Information processing device] Fig. 2 is a block diagram showing an example of the configuration of the information processing device 1. Fig. 3 is a diagram showing an example of a target management database constructed in the memory of the information processing device 1. Fig. 4 is a diagram showing an example of a display on the display unit 2.

[0046] 2, the information processing device 1 includes a processing unit 10. The processing unit 10 includes an own ship data acquisition unit 11, a target data acquisition unit 12, a planned route acquisition unit 13, a collision avoidance target selection unit 14, and a collision avoidance route generation unit 15. These functional units are realized by the processing unit 10 executing information processing in accordance with a program.

[0047] The ship data acquisition unit 11 acquires ship data including the ship's position and speed. The ship data acquisition unit 11 is an example of a moving body data acquisition unit, and the ship data is an example of moving body data. Speed is a vector quantity expressed by ship speed and direction, and ship speed is a scalar quantity. Direction is the course, but may also be the heading (heading).

[0048] Specifically, the ship data acquisition unit 11 successively acquires the ship's position detected by the GNSS receiver 6 and calculates the ship's speed from the change in the ship's position over time. However, the ship's speed may be acquired from a speedometer (not shown), and the ship's direction may be acquired from a compass (not shown).

[0049] The target data acquisition unit 12 acquires target data including the position and speed of each of a plurality of targets present around the ship. The target data acquisition unit 12 sequentially acquires the target data from the radar 31, the lidar 32, the sonar 33, the image sensor 34, or the AIS 4 mounted on the ship.

[0050] The target data acquisition unit 12 registers the acquired target data in a target management database. The target management database includes fields such as "target ID," "position," "ship speed," and "direction," as shown in Fig. 3, for example.

[0051] The position of the target is expressed as latitude and longitude. The position of the target detected by a sensor such as the radar 31 is a relative position with respect to the ship itself, so it is converted into an absolute position using the position of the ship itself detected by the GNSS receiver 6.

[0052] The speed and direction of the target are estimated from the change in the target's position over time. Note that if the positions of multiple target data from different sources are the same or similar, the target data may be grouped together as representing a common target.

[0053] The planned route acquisition unit 13 acquires the planned route of the ship. The planned route is the route that the ship should follow from the departure point to the destination. The planned route acquisition unit 13 may acquire the planned route from another device such as the plotter 7, or may create the planned route itself by accepting operation input from the user.

[0054] The ship navigates by automatic navigation or manual navigation so as to follow the planned route, or the ship may navigate by manual navigation without following the planned route.

[0055] The avoidance route generation unit 15 generates an avoidance route when the need for avoidance arises while the ship is sailing, and outputs the generated avoidance route to the display unit 2 and the navigation control unit 9. The display unit 2 displays the avoidance route, and the navigation control unit 9 causes the ship to sail along the avoidance route.

[0056] 4, an image MG showing the positional relationship between the ship SH and targets OP1 and OP2 (hereinafter also collectively referred to as "targets OP") is displayed on the display unit 2. The image MG is, for example, a radar image, an electronic chart, or a composite image thereof.

[0057] The image MG displays risk areas OZ1 and OZ2 (hereinafter also collectively referred to as "risk areas OZ") where there is a risk of collision between the own ship SH and targets OP1 and OP2. The risk areas OZ are, for example, OZT (Obstacle Zone by Target).

[0058] The image MG also displays the planned route PR of the own ship SH, as well as an avoidance route AR. Figure 4 shows an example of an avoidance route AR that avoids the risk area OZ1 of the target OP1 and returns to the planned route PR.

[0059] However, if all targets acquired by the target data acquisition unit 12 are considered as targets for avoidance in the calculation of an avoidance route by the avoidance route generation unit 15, the calculation of the avoidance route may become unstable, for example, the avoidance route may meander unexpectedly in an attempt to avoid targets that are unnecessarily far away, and the calculation load may increase more than necessary.

[0060] Therefore, in this embodiment, a collision avoidance target selection unit 14 for selecting targets to be collision avoidance targets is provided before the collision avoidance route generation unit 15, and targets that do not need to be avoided are excluded from the collision avoidance targets, thereby realizing stabilization of collision avoidance route calculation. Below, specific configurations and operations of the collision avoidance target selection unit 14 and the collision avoidance route generation unit 15 will be described.

[0061] [Collision Avoidance Target Selection Department] Fig. 5 is a block diagram showing a specific example of the configuration of the avoidance target selection unit 14. Fig. 6 is a diagram showing an example of a selection area FT and a search area SC. Fig. 7 is a diagram showing an example of a selection area FT and a risk area OZ. Fig. 8 is a diagram showing an example of a selection database for managing selected targets OP.

[0062] The target selection unit 14 selects targets OP to be avoided from among multiple targets OP present around the own ship SH, based on the own ship data acquired by the own ship data acquisition unit 11 and the target data acquired by the target data acquisition unit 12, and selects targets OP whose predicted positions are included in a selection area FT based on the own ship SH as targets to be avoided.

[0063] As shown in FIG. 5, the collision avoidance target selection unit 14 includes a selection area setting unit 141, a risk area calculation unit 142, and an inclusion determination unit 143.

[0064] The selection area setting unit 141 sets a selection area FT for selecting targets OP to be avoided, based on the own ship SH. As shown in Fig. 6, the selection area FT is, for example, a sector-shaped area whose distance from the own ship SH or arrival time of the own ship SH is less than a predetermined value and whose center is the course or heading of the own ship SH.

[0065] For the sake of explanation, Figure 6 shows the search area SC for generating an escape route along with the selection area FT. The search area SC includes a large number of search points SD arranged radially around the own ship SH. Only some of the search points SD are shown in the figure.

[0066] The search area SC is also set based on the own ship SH and overlaps with the selection area FT. Like the selection area FT, the search area SC is a sector-shaped area centered on the bow direction of the own ship SH, with the distance from the own ship SH or the arrival time of the own ship SH being less than a specified value. The selection area FT and the search area SC are similar to each other.

[0067] The selection area FT is preferably set inside the search area SC. In other words, the outer peripheral edge FTb, which is the radial boundary of the selection area FT, is preferably set closer to the ship SH than the outer peripheral edge SCb, which is the radial boundary of the search area SC. The reason for this will be described later.

[0068] The side FTr, which is the circumferential boundary of the selection region FT, may coincide with the side SCr, which is the circumferential boundary of the search region SC, or may be located in front of or behind the side SCr. The shape of the selection region FT is not limited to a fan shape, and may be a shape that extends forward or a shape that widens from left to right.

[0069] The risk area calculation unit 142 calculates a risk area OZ for each of the multiple targets OP, where there is a risk of collision with the own ship SH. The risk area OZ is, for example, an area of a predetermined width that includes a section on the predicted route of the target OP where there is a risk of collision with the own ship SH.

[0070] The risk area OZ is, for example, OZT, but is not limited to this and may be a collision point, a PAD (Predict Area of Danger), a DAC (Dangerous Area of Collision), etc. A specific method for calculating the risk area OZ will be described later.

[0071] The inclusion determination unit 143 selects, from among multiple targets OP, targets OP whose selection area FT includes a risk area OZ, as targets for avoidance. Fig. 7 shows an example in which the risk area OZ1 of target OP1 is included in the selection area FT, and the risk area OZ2 of target OP2 is not included in the selection area FT.

[0072] In this embodiment, the risk area OZ is a two-dimensional area, but is not limited to this and may be, for example, a line segment or a point. The risk area OZ is an example of the predicted position of the target OP. Regardless of the presence or absence of the risk area OZ, a target OP that is predicted to enter the selection area FT may be selected as an avoidance target.

[0073] The inclusion determination unit 143 registers the target data of the selected targets in the selection database. The selection database may include a "risk area" field that indicates the position of the risk area OZ, in addition to fields such as "position," "ship speed," and "direction," as shown in Fig. 8, for example.

[0074] In order to prevent the number of selected targets OP from becoming too large, the selection area FT may be variable, for example, as shown in Figure 9 or 10. That is, the selection area FT may be narrowed in stages (FT1 → FT2 → FT3) so that the number of targets OP that include the risk area OZ in the selection area FT is equal to or less than a predetermined number.

[0075] Specifically, if the number of targets OP whose risk areas OZ are included in the selection area FT1 exceeds a predetermined number, the selection area setting unit 141 applies a selection area FT2 that is narrower than the selection area FT1. If the number of targets OP whose risk areas OZ are included in the selection area FT2 is equal to or less than a predetermined number, the inclusion determination unit 143 selects those targets OP as targets for avoidance.

[0076] On the other hand, if the number of targets OP whose risk areas OZ are included in the selection area FT2 exceeds a predetermined number, the selection area setting unit 141 applies a selection area FT3 that is narrower than the selection area FT2. If the number of targets OP whose risk areas OZ are included in the selection area FT3 is equal to or less than a predetermined number, the inclusion determination unit 143 selects those targets OP as targets for avoidance.

[0077] The selection area FT is narrowed toward the ship SH or toward the course or heading of the ship SH. For example, as shown in Figure 9, the side FTr, which is the circumferential boundary, may be brought closer to the course or heading of the ship SH, or the width of the selection area FT may be narrowed with the course or heading of the ship SH at its center, as shown in Figure 10.

[0078] Narrowing the selection area FT in this way means that targets OP whose risk area OZ is closer to the ship SH or to the course or heading of the ship SH are selected as targets for avoidance with priority. A predetermined number of targets OP may be extracted in order of the proximity of the risk area OZ to the ship SH or to the course or heading of the ship SH.

[0079] Hereinafter, an example of calculation of the risk area OZ by the risk area calculation unit 142 will be described with reference to FIG.

[0080] The risk area calculation unit 142 identifies the risk sections La, Lb of the predicted route R of the target OP, where there is a risk of collision between the own ship SH and the target OP, as the central section of the risk area OZ, based on the predicted positions of the own ship SH and the target OP at each time, assuming that the own ship SH changes course in an arbitrary direction and crosses the predicted route R of the target OP.

[0081] The calculation of the predicted position of the ship SH is performed under the assumption that the ship SH will maintain its speed and change course in any direction from its current position. In other words, the magnitude of the ship SH's speed vector is constant, while the direction of the ship's speed vector is assumed to change course in any direction at a reference point in time, and then the ship SH will continue to navigate in a constant direction from its position at the reference point in time. Therefore, the predicted position of the ship SH at each point in time exists on concentric circles centered on the ship's position at the reference point in time. The radius of the circle is expressed as the product of the elapsed time from the reference point in time and the magnitude of the ship's speed vector.

[0082] The predicted position of the ship SH at each time point is represented by multiple concentric circles calculated for each of multiple discrete time points. However, the predicted position of the ship SH at each time point may also be represented by a circular equation that includes the elapsed time from a reference time point.

[0083] In this embodiment, the predicted position of the ship SH is calculated under the assumption that the speed of the ship SH is constant, but this is not limiting and the speed of the ship SH may be treated as a variable that changes over time. In other words, as long as the predicted position of the ship SH is calculated according to the elapsed time from a reference point in time, the speed of the ship SH does not have to be constant. For example, the speed of the ship SH may gradually increase or decrease over time.

[0084] The predicted position of the target OP is calculated under the assumption that the target OP will maintain its speed from its current position. That is, the target OP is assumed to continue traveling from its target position at the reference time point with the magnitude and direction of the target velocity vector being constant. Therefore, the predicted position of the target OP at each time point exists on a straight line extending the target velocity vector and passing through the target position at the reference time point.

[0085] The predicted position of the target OP at each time point is expressed by a plurality of discrete points arranged on a line, which are calculated for each of a plurality of discrete time points. However, the predicted position of the target OP at each time point may be expressed by a linear function passing through the target position at the reference time point.

[0086] In this embodiment, the predicted position of the target OP is calculated under the assumption that the speed of the target OP is constant. However, this is not limiting, and at least one of the speed and direction of the target OP may be treated as a variable that changes with time. In other words, as long as the predicted position of the target OP is calculated according to the elapsed time from a reference time point, the speed of the target OP does not have to be constant. For example, the speed of the target OP may gradually increase or decrease over time. Furthermore, the target OP may change course in a predetermined direction or may turn at a predetermined ROT (Rate of Turn).

[0087] The risk area calculation unit 142 calculates the separation distance between the predicted position of the ship SH and the predicted position of the target OP at each point in time, and calculates the risk of collision or approach based on the separation distance and ship size. As described above, the predicted position of the ship SH at a certain point in time is represented by a circle, so the risk area calculation unit 142 extracts the position closest to the predicted position of the target OP at the same time from the circle representing the predicted position of the ship SH at the same time, and calculates the separation distance.

[0088] The risk area calculation unit 142 identifies risk sections La and Lb, assuming that there is a collision risk when, for example, the area of the own ship SH overlaps with a point representing the predicted position of the target OP. This is not limiting, and it may also be possible to determine that there is a collision risk when a warning area set around the own ship SH overlaps with a point representing the predicted position of the target OP. Hereinafter, the traveling direction of the target OP will be referred to as "forward," and the opposite direction will be referred to as "aft."

[0089] For example, of the two risk sections La and Lb, the first risk section La, which is located on the aft side, has its aft end Lar at the point where the forward end of the ship SH abuts on the point representing the predicted position of the target OP. The forward end Laf of the first risk section La is the point where the aft end of the ship SH abuts on the point representing the predicted position of the target OP.

[0090] On the other hand, for the second risk section Lb, which is located further forward of the two risk sections La and Lb, the aft end Lbr of the second risk section Lb is the position where the aft end of the own ship SH abuts on the point representing the predicted position of the target OP, and the forward end Lbf of the second risk section Lb is the position where the forward end of the own ship SH abuts on the point representing the predicted position of the target OP.

[0091] The range between the first risk zone La and the second risk zone Lb is the range in which the ship SH crosses ahead of the target OP. On the other hand, the range behind the first risk zone La and the range ahead of the second risk zone Lb are the ranges in which the ship SH crosses behind the target OP.

[0092] Without being limited to this, the risk area calculation unit 142 may determine that there is a collision risk when a warning area set in or around the area of the own ship SH overlaps with a warning area set in or around the area of the target OP. Furthermore, the risk area calculation unit 142 may determine that a collision point where a point representing the predicted position of the own ship SH and a point representing the predicted position of the target OP overlap is a risk area.

[0093] In this embodiment, the collision risk is calculated based on distances such as the separation distance between the predicted position of the ship SH and the predicted position of the target OP, but this is not limited to this. The collision risk may also be calculated based on time, such as the approach time until the ship SH and the target OP are closest to each other, or the arrival time until the ship SH reaches the predicted position of the target OP.

[0094] [Evasive Route Generation] Fig. 12 is a block diagram showing a specific example of the configuration of the avoidance route generation unit 15. Fig. 13 is a diagram showing an example of generation of potential avoidance route patterns TP1 to TP5. Fig. 14 is a diagram showing an example of selection of an avoidance route AR.

[0095] The avoidance route generating unit 15 generates an avoidance route AR using the target OP selected by the avoidance target selecting unit 14 as an avoidance route. That is, the avoidance route generating unit 15 calculates a collision risk value between the own ship SH and the selected target OP, and generates the avoidance route AR based on the calculated collision risk value.

[0096] As shown in FIG. 12, the collision avoidance route generation unit 15 includes a collision risk value calculation unit 151, a collision risk assessment unit 152, a pattern generation unit 153, a pattern assessment unit 154, and a collision avoidance route selection unit 155.

[0097] The collision risk value calculation unit 151 calculates a collision risk value between the own ship SH and the selected target OP when the own ship SH navigates the planned route PR based on the own ship data acquired by the own ship data acquisition unit 11, the target data of the target OP selected by the avoidance target selection unit 14, and the planned route PR of the own ship SH acquired by the planned route acquisition unit 13.

[0098] When the navigation is not based on the planned route PR, the collision risk value calculation unit 151 treats an extension of the course of the own ship SH as the planned route.

[0099] 13 and 14 show an example in which the planned route PR of the own ship SH interferes with the predicted route of the selected target OP1. In other words, when the own ship SH navigates the planned route PR, it passes through the risk area OZ1 of the target OP1. In such a case, the collision risk value becomes high.

[0100] Specifically, the collision risk value calculation unit 151 calculates the collision risk value using TCPA (Time to Closest Point of Approach) and DCPA (Distance to Closest Point of Approach) of the CPA collision warning. However, without being limited to this, BCT (Bow Crossing Time) and BCR (Bow Crossing Range) may also be used.

[0101] The collision risk value calculation unit 151 may also calculate the collision risk value using the time it takes for the target OP to enter a bumper area set based on the own ship SH, and the distance to the own ship SH when the target OP enters the bumper area. Conversely, a bumper area may be set for the target OP.

[0102] The collision risk assessment unit 152 determines whether or not the ship SH needs to deviate from the planned route PR and avoid the selected target OP, based on the collision risk value calculated by the collision risk value calculation unit 151. The collision risk assessment unit 152 determines that avoidance is necessary when the collision risk value is equal to or greater than a threshold value.

[0103] The pattern generation unit 153, the pattern evaluation unit 154, and the avoidance route selection unit 155 calculate an avoidance route AR for avoiding the selected target OP when the collision risk evaluation unit 152 determines that avoidance is necessary.

[0104] The pattern generating unit 153 generates a plurality of potential avoidance route patterns TP1 to TP5 (hereinafter also collectively referred to as "potential avoidance route patterns TP") within the search area SC, for example, as shown in Fig. 13. The potential avoidance route patterns TP are patterns that are candidates for the avoidance route AR.

[0105] The potential avoidance route pattern TP is generated between the avoidance start point SP and the avoidance end point EP. The avoidance start point SP starts from the position of the own ship SH. The avoidance end point EP is the intersection of the planned route PR and the boundary of the search area SC.

[0106] The potential avoidance route pattern TP is constructed by sequentially connecting the search points SD arranged radially within the search area SC from the position of the ship SH outward to the boundary of the search area SC.

[0107] As described above, in this embodiment, the selection area FT is set inside the search area SC. This makes it possible to form a potential avoidance route pattern TP within the selection area FT so as to avoid the target OP, while also forming a potential avoidance route pattern TP in an area outside the selection area FT and within the search protuberance SC so as to head toward the avoidance end point EP, as shown in Fig. 13 .

[0108] In other words, the area outside the selection area FT and within the search protuberance SC (more specifically, the peripheral area outside the boundary of the selection area FT and inside the boundary of the search area SC) can be used as an area for directing the terminal portion of the potential avoidance route pattern TP toward the avoidance end point EP.

[0109] The pattern evaluation unit 154 calculates a collision risk value for the selected target OP for each potential avoidance route pattern TP. The collision risk value for a potential avoidance route pattern TP is a value obtained by calculating the collision risk value between the own ship SH and the target OP at each position within the pattern and integrating these values.

[0110] Furthermore, the pattern evaluation unit 154 calculates the route length for each of the potential avoidance route patterns TP.

[0111] The collision avoidance route selection unit 155 selects an collision avoidance route AR from the potential collision avoidance route patterns TP. Specifically, the collision avoidance route selection unit 155 selects, from the potential collision avoidance route patterns TP, the potential collision avoidance route pattern TP that has the lowest cost based on the collision risk value and the route length as the collision avoidance route AR.

[0112] FIG. 14 shows an example in which, of the potential avoidance route patterns TP1 to TP5, the potential route pattern TP3, which passes behind the target OP1 and has the shortest route length, is selected as the avoidance route AR.

[0113] In addition, when there are multiple selected targets OP, it is preferable that the avoidance route selection unit 155 selects, as the avoidance route AR, the potential avoidance route pattern TP that minimizes the collision risk value of the target OP with the largest collision risk value among the selected targets OP.

[0114] [Navigation support method] 15 is a flow diagram showing an example of the procedure of a navigation assistance method realized in the navigation assistance system 100. The processing unit 10 of the information processing device 1 executes the information processing shown in the diagram in accordance with a program.

[0115] First, the processing unit 10 acquires own ship data (S11, processing as the own ship data acquisition unit 11).

[0116] Next, the processing unit 10 acquires target data for each of a plurality of targets OP present around the own ship SH (S12, processing as the target data acquisition unit 12).

[0117] Next, the processing unit 10 sets a selection area FT based on the own ship SH (S13, processing as the selection area setting unit 141, see FIG. 6).

[0118] Next, the processing unit 10 calculates a risk area OZ between the own ship SH and each of the plurality of targets OP (S14, S15, processing as the risk area calculation unit 142, see FIG. 7).

[0119] Next, the processing unit 10 selects, from among the multiple targets OP, targets OP whose selection area FT includes the risk area OZ as targets for avoidance (S16, processing as the inclusion determination unit 143).

[0120] Furthermore, if the number of targets OP whose risk areas OZ are included in the selection area FT exceeds a predetermined number (S17: NO), the processing unit 10 limits the selection area FT (S18, see Figure 9 or Figure 10) and selects targets OP whose risk areas OZ are included in the limited selection area FT as targets for avoidance (S16).

[0121] Next, the processing unit 10 calculates a collision risk value between the own ship SH and the selected target OP (S21, processing as the collision risk value calculation unit 151).

[0122] Next, the processing unit 10 determines whether or not there is a need for avoidance based on the calculated collision risk value (S22, processing as the collision risk assessment unit 152).

[0123] If it is determined that there is a need for collision avoidance (S22: YES), the processing unit 10 generates a plurality of potential collision avoidance route patterns TP (S23, processing as the pattern generating unit 153, see FIG. 13).

[0124] Next, the processing unit 10 calculates a collision risk value and a route length for each potential collision avoidance route pattern TP, and evaluates each potential route pattern TP (S24, processing as the pattern evaluation unit 154).

[0125] Thereafter, the processing unit 10 selects an avoidance route AR based on the evaluation of each potential route pattern TP (S25, processing as the avoidance route selection unit 155, see FIG. 14). The selected avoidance route AR is output to the display unit 2 and the navigation control unit 9, and the series of processes ends.

[0126] However, this order is not limited to this, and as shown in the example of Figure 16, the collision risk value between the own ship SH and the target OP may be calculated (S21), and after determining whether or not there is a need for avoidance (S22: YES), the process for selecting the target OP (S13 to S17) may be executed.

[0127] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made by those skilled in the art.

[0128] Representative embodiments of the present invention will be listed below.

[0129] (1) a mobile object data acquisition unit that acquires mobile object data including the position and speed of a mobile object moving on water; a target data acquisition unit that acquires target data including a position and a velocity for each of a plurality of targets present around the moving object; a collision avoidance target selection unit that selects, from the plurality of targets, targets whose predicted positions are included in a selection region based on the moving body, based on the moving body data and the target data; an avoidance route generating unit that generates an avoidance route using the selected targets as avoidance targets; A navigation support system comprising:

[0130] (2) The collision avoidance target selection unit calculating a risk area in which there is a risk of collision between the moving body and each of the plurality of targets; selecting, from the plurality of targets, targets whose selection area includes the risk area as targets to be avoided; (1) A navigation support system as described above.

[0131] (3) The avoidance route generation unit calculating a collision risk value between the moving body and the selected target; generating the avoidance route based on the collision risk value; A navigation support system according to (1) or (2).

[0132] (4) The avoidance route generation unit generating one or more potential collision avoidance route patterns between a collision avoidance start point, which is a starting point of the position of the moving body, and a collision avoidance end point, which is an end point of the collision avoidance; selecting the avoidance route from the potential avoidance route patterns based on the collision risk value calculated for the selected target for each of the potential avoidance route patterns; (3) A navigation support system as described above.

[0133] (5) The avoidance route generation unit selecting, as the avoidance route, the potential avoidance route pattern that minimizes the collision risk value of the target with the maximum collision risk value among the selected targets; (4) A navigation support system according to the present invention.

[0134] (6) A planned route acquisition unit for acquiring a planned route of the moving body is further provided, the avoidance route generation unit generates the avoidance route that deviates from the planned route and returns to the planned route. A navigation support system according to any one of (1) to (5).

[0135] (7) the avoidance route generation unit generates the avoidance route within a search area that overlaps with the selection area, using the moving body as a reference; A navigation support system according to any one of (1) to (6).

[0136] (8) The selection area is set inside the search area. (7) A navigation support system according to (7).

[0137] (9) the boundary of the selection area is set closer to the moving object than the boundary of the search area; A navigation support system according to (7) or (8).

[0138] (10) the collision avoidance target selection unit narrows the selection area so that the number of targets including the risk area in the selection area is equal to or less than a predetermined number. A navigation support system according to any one of (1) to (9).

[0139] (11) the collision avoidance target selection unit prioritizes selecting, as the collision avoidance target, a target whose risk area is closer to the moving body or the course or heading of the moving body; A navigation support system according to any one of (1) to (10).

[0140] (12) the collision avoidance target selection unit identifies, as the risk area, an area including a section on the predicted course of the target that poses a risk of collision with the moving object when it is assumed that the moving object changes course in an arbitrary direction and crosses the predicted course of the target; (2) A navigation support system as described above.

[0141] (13) a navigation control unit that causes the moving body to navigate the avoidance route, A navigation support system according to any one of (1) to (12).

[0142] (14) further comprising a display unit that displays the avoidance route, A navigation support system according to any one of (1) to (13).

[0143] (15) The vehicle further includes at least one sensor selected from the group consisting of a radar, a lidar, a sonar, and an image sensor, which is mounted on the vehicle and generates the target data. A navigation support system according to any one of (1) to (14).

[0144] (16) further comprising an automatic identification device mounted on the moving body and receiving the target data; A navigation support system according to any one of (1) to (15).

[0145] (17) Acquire moving object data including the position and speed of a moving object moving on the water; acquiring target data including a position and a velocity for each of a plurality of targets present around the moving body; selecting, from the plurality of targets, targets whose predicted positions are included in a selection region based on the moving body, based on the moving body data and the target data; generating an avoidance route using the selected target as an avoidance target; Navigation aid methods.

[0146] (18) Acquiring moving object data including the position and speed of a moving object moving on water; acquiring target data including a position and a velocity for each of a plurality of targets present around the moving body; selecting, from the plurality of targets, targets whose predicted positions are included in a selection region based on the moving body, based on the moving body data and the target data; and generating an avoidance route using the selected target as an avoidance target; A program that causes a computer to execute the following. [Explanation of symbols]

[0147] 1 Information processing device, 2 Display unit, 31 Radar, 32 Lidar, 33 Sonar, 34 Image sensor, 4 AIS, 6 GNSS receiver, 7 Plotter, 9 Navigation control unit, 10 Processing unit, 11 Own ship data acquisition unit, 12 Target data acquisition unit, 13 Planned route acquisition unit, 14 Collision avoidance target selection unit, 15 Collision avoidance route generation unit, 100 Navigation support system, 141 Selection area setting unit, 142 Risk area calculation unit, 143 Inclusion determination unit, 151 Collision risk value calculation unit, 152 Collision risk evaluation unit, 153 Pattern generation unit, 154 Pattern evaluation unit, 155 Collision avoidance route selection unit

Claims

1. a mobile object data acquisition unit that acquires mobile object data including the position and speed of a mobile object moving on water; a target data acquisition unit that acquires target data including a position and a velocity for each of a plurality of targets present around the moving object; a collision avoidance target selection unit that selects, from the plurality of targets, targets whose predicted positions are included in a selection region based on the moving body, based on the moving body data and the target data; an avoidance route generating unit that generates an avoidance route using the selected targets as avoidance targets; A navigation support system comprising:

2. The collision avoidance target selection unit calculating a risk area in which there is a risk of collision between the moving body and each of the plurality of targets; selecting, from the plurality of targets, targets whose selection area includes the risk area as targets to be avoided; The navigation support system according to claim 1 .

3. The avoidance route generation unit calculating a collision risk value between the moving body and the selected target; generating the avoidance route based on the collision risk value; The navigation support system according to claim 1 .

4. The avoidance route generation unit generating one or more potential collision avoidance route patterns between a collision avoidance start point, which is a starting point of the position of the moving body, and a collision avoidance end point, which is an end point of the collision avoidance; selecting the avoidance route from the potential avoidance route patterns based on the collision risk value calculated for the selected target for each of the potential avoidance route patterns; The navigation support system according to claim 3 .

5. The avoidance route generation unit selecting, as the avoidance route, the potential avoidance route pattern that minimizes the collision risk value of the target with the maximum collision risk value among the selected targets; The navigation support system according to claim 4.

6. A planned route acquisition unit for acquiring a planned route of the moving body is further provided, the avoidance route generation unit generates the avoidance route that deviates from the planned route and returns to the planned route. The navigation support system according to claim 1 .

7. the avoidance route generation unit generates the avoidance route within a search area that overlaps with the selection area, using the moving body as a reference; The navigation support system according to claim 1 .

8. The selection area is set inside the search area. The navigation support system according to claim 7.

9. the boundary of the selection area is set closer to the moving object than the boundary of the search area; The navigation support system according to claim 7.

10. the collision avoidance target selection unit narrows the selection area so that the number of targets including the risk area in the selection area is equal to or less than a predetermined number. The navigation support system according to claim 1 .

11. the collision avoidance target selection unit prioritizes selecting, as the collision avoidance target, a target whose risk area is closer to the moving body or the course or heading of the moving body; The navigation support system according to claim 1 .

12. the collision avoidance target selection unit calculates, as the risk area, an area including a section on the predicted course of the target that poses a risk of collision with the moving object when it is assumed that the moving object changes course in an arbitrary direction and crosses the predicted course of the target; The navigation support system according to claim 2 .

13. a navigation control unit that causes the moving body to navigate the avoidance route, The navigation support system according to claim 1 .

14. further comprising a display unit that displays the avoidance route, The navigation support system according to claim 1 .

15. The vehicle further includes at least one sensor selected from the group consisting of a radar, a lidar, a sonar, and an image sensor, which is mounted on the vehicle and generates the target data. The navigation support system according to claim 1 .

16. further comprising an automatic identification device mounted on the moving body and receiving the target data; The navigation support system according to claim 1 .

17. Acquire moving object data including the position and speed of a moving object moving on the water; acquiring target data including a position and a velocity for each of a plurality of targets present around the moving body; selecting, from the plurality of targets, targets whose predicted positions are included in a selection region based on the moving body, based on the moving body data and the target data; generating an avoidance route using the selected target as an avoidance target; Navigation aid methods.

18. Acquiring moving object data including the position and speed of a moving object moving on water; acquiring target data including a position and a velocity for each of a plurality of targets present around the moving body; selecting, from the plurality of targets, targets whose predicted positions are included in a selection region based on the moving body, based on the moving body data and the target data; and generating an avoidance route using the selected target as an avoidance target; A program that causes a computer to execute the following.

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