Collision avoidance system, collision avoidance method, and collision avoidance program

Abstract

To execute an appropriate collision avoidance action against an obstacle such as a counter ship without causing any discomfort.SOLUTION: In a collision avoidance system comprising a control unit that executes a collision avoidance action of a ship based on a position of the ship and a position of an obstacle, the control unit generates a grid map in a grid shape by connecting a plurality of grid points, sets an avoidance azimuth and an avoidance speed at each grid point, and calculates an evaluation point based on an evaluation function for a grid point in a navigable range, the navigable range being a range that does not include a violation range or a collision range set on the grid map. The evaluation function includes a sea route evaluation parameter that evaluates a deviation of the ship from a target sea route, and a sensory evaluation parameter that sensorily evaluates a risk of collision until the closest approach to an obstacle. The lower the evaluation point is, the smaller the deviation from the target sea route is, and the lower the risk of collision is. The control unit executes a collision avoidance action such that the avoidance azimuth and the avoidance speed set to a grid point where the evaluation point has a minimum value are applied.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a collision avoidance system, a collision avoidance method, and a collision avoidance program for avoiding collisions of a ship with an obstacle.

Background Art

[0002] Conventionally, a ship collision prevention method for preventing a collision between a own ship and an opposing ship has been known (see, for example, Patent Document 1). In this collision prevention method, the future movement trend of the opposing ship is predicted, and the collision risk range between the own ship and the opposing ship is calculated and displayed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the collision prevention method of Patent Document 1, the own ship executes a collision avoidance action so as to avoid the collision risk range. Here, when the own ship is an automatic unmanned ship, the collision avoidance action of the own ship as seen from the opposing ship may be an unnatural collision avoidance action for the opposing ship, and may give a sense of discomfort to the opposing ship.

[0005] Therefore, an object of the present disclosure is to provide a collision avoidance system, a collision avoidance method, and a collision avoidance program that can appropriately execute a collision avoidance action without giving a sense of discomfort to an obstacle such as an opposing ship.

Means for Solving the Problems

[0006] The collision avoidance system of the present disclosure is a collision avoidance system for avoiding a collision of a ship with an obstacle. The collision avoidance system includes a first position acquisition unit that acquires the position of the ship, a second position acquisition unit that acquires the position of the obstacle, and a control unit that causes the ship to execute a collision avoidance action based on the position of the ship acquired by the first position acquisition unit and the position of the obstacle acquired by the second position acquisition unit. The control unit generates a grid map in a grid shape connecting a plurality of grid points, including the position of the ship, sets an avoidance direction and an avoidance speed at the grid points, sets a regulation violation range that violates maritime traffic regulations on the grid map, sets a collision range in which the ship collides with the obstacle within a finite time on the grid map, calculates an evaluation point based on an evaluation function for grid points in the navigable range on the grid map that does not include the regulation violation range and the collision range, and executes the collision avoidance action of the ship based on the evaluation point. The evaluation function includes a route evaluation parameter that evaluates the deviation from a preset route of the ship and a sensory evaluation parameter that sensorily evaluates the risk of collision until the ship gets closest to the obstacle. The evaluation point based on the route evaluation parameter indicates that the smaller the deviation from the route of the ship, the lower the score. The evaluation point based on the sensory evaluation parameter indicates that the lower the score, the lower the risk of collision. The control unit executes the collision avoidance action so that the avoidance direction and the avoidance speed set at the grid point where the evaluation point is the minimum value are adopted.

[0007] The collision avoidance method of the present disclosure is a collision avoidance method executed by a collision avoidance system for avoiding a collision of a ship with an obstacle. The collision avoidance system includes a first position acquisition unit that acquires the position of the ship, a second position acquisition unit that acquires the position of the obstacle, and a control unit that causes the ship to execute a collision avoidance action based on the position of the ship acquired by the first position acquisition unit and the position of the obstacle acquired by the second position acquisition unit. The control unit generates a grid map in a grid shape connecting a plurality of grid points, including the position of the ship, sets an avoidance direction and an avoidance speed at the grid points, sets a regulation violation range that violates the maritime traffic regulations on the grid map, sets a collision range that collides with the obstacle within a finite time on the grid map, calculates an evaluation point based on an evaluation function for grid points in the navigable range on the grid map that does not include the regulation violation range and the collision range, executes the collision avoidance action of the ship based on the evaluation point, the evaluation function includes a route evaluation parameter that evaluates the deviation from a preset route of the ship and a sensory evaluation parameter that sensually evaluates the risk of collision until approaching the obstacle closest, the evaluation point based on the route evaluation parameter is such that the smaller the deviation from the route of the ship, the lower the score, the evaluation point based on the sensory evaluation parameter is such that the lower the score, the lower the risk of collision, and the control unit executes the collision avoidance action so as to obtain the avoidance direction and the avoidance speed set at the grid point where the evaluation point is the minimum value.

[0008] The collision avoidance program of the present disclosure is a collision avoidance program executed by a collision avoidance system for avoiding a collision of a ship with an obstacle. The collision avoidance system includes a first position acquisition unit that acquires the position of the ship, a second position acquisition unit that acquires the position of the obstacle, and a control unit that causes the ship to execute a collision avoidance action based on the position of the ship acquired by the first position acquisition unit and the position of the obstacle acquired by the second position acquisition unit. The control unit generates a grid map in a grid shape connecting a plurality of grid points, including the position of the ship, sets an avoidance direction and an avoidance speed at the grid points, sets a range of violation of regulations that violates the maritime traffic regulations on the grid map, sets a collision range in which the ship collides with the obstacle within a finite time on the grid map, calculates an evaluation point based on an evaluation function for grid points in the navigable range on the grid map that does not include the range of violation of regulations and the collision range, causes the ship to execute the collision avoidance action based on the evaluation point, the evaluation function includes a route evaluation parameter that evaluates the deviation from a preset route of the ship and a sensory evaluation parameter that sensually evaluates the risk of collision until approaching the closest to the obstacle, the evaluation point based on the route evaluation parameter is such that the smaller the deviation from the route of the ship, the lower the score, and the evaluation point based on the sensory evaluation parameter is such that the lower the score, the lower the risk of collision. The control unit causes the collision avoidance action to be executed so that the avoidance direction and the avoidance speed set at the grid point where the evaluation point is the minimum value are obtained.

Effect of the Invention

[0009] According to the present disclosure, it is possible to appropriately execute a collision avoidance action without giving a sense of discomfort to an obstacle such as an oncoming ship.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

[0011] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited by this embodiment. In addition, the components in the following embodiments include those that can be replaced and are easy for those skilled in the art, or those that are substantially the same. Furthermore, the components described below can be combined as appropriate, and when there are multiple embodiments, the embodiments can also be combined.

[0012] [First Embodiment] FIG. 1 is a schematic configuration diagram of a ship collision avoidance system according to the first embodiment. FIG. 2 is an explanatory diagram of a grid map. FIG. 3 is a graph regarding sensory evaluation parameters. FIG. 4 is an explanatory diagram regarding the release of collision avoidance behavior. FIG. 5 is a flowchart showing an example of a collision avoidance method according to the first embodiment.

[0013] The collision avoidance system 10 of the ship 1 according to the first embodiment is a system that avoids a collision of the ship 1 with an obstacle and is mounted on the ship 1. The ship 1 is, for example, an unmanned ship that sails automatically, but it may be applied to a manned ship and is not particularly limited. Obstacles include dynamic obstacles such as other ships and static obstacles including prohibited areas such as land, shoals, and fishing grounds. In the first embodiment, it will be described by applying it to the ship 1 as a dynamic obstacle.

[0014] (Collision Avoidance System) The collision avoidance system 10 includes a ship identification device (obstacle identification device) 21, a control unit 23, and a storage unit 24.

[0015] The ship identification device 21 functions as a first position acquisition unit that acquires the position of ship 1 and also functions as a second position acquisition unit that acquires the position of an opposing ship. The ship identification device 21 is, for example, an Automatic Identification System (AIS) and acquires ship information such as the course, position, orientation, and speed of ship 1.

[0016] The control unit 23 includes, for example, an integrated circuit such as a Central Processing Unit (CPU). The control unit 23 controls the navigation operation of ship 1 and executes determination processing and arithmetic processing for controlling the navigation operation. The storage unit 24 is an arbitrary storage device such as a semiconductor storage device and a magnetic storage device. Information acquired from various systems, information generated by various processes, etc. are stored in this storage unit 24, and a collision avoidance program P for executing the collision avoidance method by the above-described collision avoidance system 10 is stored.

[0017] Based on the destination set for ship 1, the control unit 23 sets a target course and sails ship 1 along the target course.

[0018] Next, with reference to FIG. 2, the grid map M generated by the control unit 23 will be described. The control unit 23 generates a grid-shaped grid map M connecting a plurality of grid points O centered on the position of the own ship, ship 1.

[0019] The grid map M is a map in which the circumferential grid lines centered on the ship 5 and the radial grid lines centered on the ship 5 intersect, and the intersection points of the circumferential grid lines and the radial grid lines are the grid points O. The number of circumferential grid lines is according to the resolution of the target speed of the ship 1. The number of radial grid lines is according to the resolution of the target azimuth angle of the ship 1. At the grid point O, the avoidance azimuth and the avoidance speed are set when the collision avoidance action of the ship 1 is executed. Also, in the grid map M, the illegal range E1 and the collision range E2 are set when the collision avoidance action of the ship 1 is executed.

[0020] The illegal range E1 is a range that is illegal in the maritime traffic regulations. The collision range E2 is a range in which a collision with the other ship occurs within a finite time. When the collision avoidance action of the ship 1 is executed, the control unit 23 executes the collision avoidance action within the navigable range that does not include the illegal range E1 and the collision range E2.

[0021] (Collision Avoidance Method) Next, with reference to FIGS. 3 to 5, the collision avoidance method executed by the collision avoidance system 10 will be described. As shown in FIG. 5, the control unit 23 first executes the initialization of the collision avoidance action (step S1). In step S1, the control unit 23 initializes the value of the alarm for executing the collision avoidance action to "0", which is the value when the collision avoidance action is not executed. The initialization is set when there is no set value in steps S3 and S5 described later in the alarm value. That is, when there is a set value set in step S3 or step S5 in the alarm value, the alarm value is not initialized.

[0022] Subsequently, the control unit 23 executes a determination to start collision avoidance action based on the closest distance dcpa, the closest approach time tcpa, and the positional relationship between the own ship and the other ship (step S2). In step S2, the control unit 23 determines whether the closest distance dcpa between the own ship and the other ship obtained based on the positions of the own ship and the other ship is less than or equal to a predefined specified closest distance dcpamax. Further, the control unit 23 determines whether the closest approach time tcpa between the own ship and the other ship obtained based on the positions and speeds of the own ship and the other ship is less than or equal to a predefined specified closest approach time tcpamax. Furthermore, the control unit 23 determines whether the positional relationship between the own ship and the other ship obtained based on the positions of the own ship and the other ship is a Head on or Give way positional relationship.

[0023] Here, with reference to FIG. 4, the positional relationship between the own ship and the other ship will be described. Assuming that the straight-ahead direction u of the own ship is 0°, the range from -35° to +35° of the azimuth angle is the Head on range, the range from +35° to +105° of the azimuth angle is the Give way range, the range from +105° to +255° (-105°) of the azimuth angle is the Overtaking range, and the range from +255° to +325° (-35°) of the azimuth angle is the Standing on range. Note that the above-described positional relationship between the own ship and the other ship is an example and can be arbitrarily set from the outside. That is, in the positional relationship between the own ship and the other ship, for example, each range including the Head on range and the Give way range can have its azimuth angle range changed. Specifically, the storage unit 24 stores data related to the positional relationship between the own ship and the other ship, and can be arbitrarily set by changing the azimuth angle of each range via an operation unit (not shown) of the collision avoidance system 10.

[0024] In step S2, when the closest distance dcpa is less than or equal to the specified closest distance dcpamax, the closest approach time tcpa is less than or equal to the specified closest approach time tcpamax, and the positional relationship is a Head on or Give way positional relationship (step S2: Yes), the control unit 23 executes a collision avoidance action (step S3). In step S3, the control unit 23 sets the value of the alarm to "1", which is the value for executing the collision avoidance action.

[0025] The collision avoidance action in step S3 will be specifically described. When executing the collision avoidance action in step S3, the control unit 23 sets the avoidance direction and the avoidance speed at the grid point O of the grid map M. Subsequently, the control unit 23 sets the illegal range E1 and the collision range E2 on the grid map M. Then, the control unit 23 calculates the evaluation points based on the evaluation function for the grid points O within the navigable range on the grid map M.

[0026] The evaluation function is a function that includes a route evaluation parameter for evaluating the deviation from the target route of ship 1 and a sensory evaluation parameter for subjectively evaluating the risk of collision until approaching the other ship. The evaluation points calculated based on the route evaluation parameter decrease as the deviation from the target route of ship 1 decreases, and increase as the deviation from the target route of ship 1 increases.

[0027] The evaluation points calculated based on the sensory evaluation parameter decrease as the risk of collision with the other ship decreases, and increase as the risk of collision with the other ship increases. The risk of collision with the other ship is evaluated based on the sensory evaluation graph shown in FIG. 3. In FIG. 3, the vertical axis is the rate of change of the angular difference between the own ship and the other ship, and the horizontal axis is the relative distance between the own ship and the other ship. As shown in FIG. 3, the smaller the relative distance, the higher the risk, and the smaller the rate of change of the relative azimuth angle, the higher the risk is evaluated. In the sensory evaluation graph shown in FIG. 3, for example, the sensory evaluation is performed in three levels: dangerous, cautious, and safe. Note that the sensory evaluation is not particularly limited to the sensory evaluation graph shown in FIG. 3, and any sensory evaluation may be used.

[0028] For each grid point O within the navigable range, the control unit 23 selects the grid point O with the minimum value among the calculated evaluation points, and executes a collision avoidance action so as to obtain the avoidance direction and avoidance speed set for the grid point O. When there are multiple grid points O with the calculated minimum evaluation value, the control unit 23 selects the grid point O with the lower score of the evaluation points based on the route evaluation parameters.

[0029] After executing step S3, the control unit 23 terminates the control regarding the collision avoidance method. The control unit 23 repeats the execution of FIG. 5 until the execution of the collision avoidance action is released.

[0030] On the other hand, when the control unit 23 determines that the condition of step S2 is not satisfied (step S2: No), it executes an end determination of the collision avoidance action based on the value of the alarm and the positional relationship between the own ship and the other ship (step S4). In step S4, the control unit 23 determines whether the value of the alarm in the previous step is "1". Further, the control unit 23 determines whether the positional relationship between the own ship and the other ship obtained based on the positions of the own ship and the other ship is an Overtaking positional relationship, that is, whether the own ship has overtaken the other ship.

[0031] In step S3, when the value of the alarm in the previous step is "1" and the positional relationship is an Overtaking positional relationship (step S4: Yes), the control unit 23 does not execute the collision avoidance action (step S5). In step S5, the control unit 23 sets the value of the alarm to "0", which is a value indicating that the collision avoidance action is not executed. After executing step S5, the control unit 23 terminates the control regarding the collision avoidance method. When the value of the alarm continues to be "0", the control unit 23 may set the set value of the alarm to no setting.

[0032] [Second Embodiment] Next, referring to FIG. 6, the second embodiment will be described. FIG. 6 is an explanatory diagram of a grid map of a ship collision avoidance system according to the second embodiment. In the second embodiment, in order to avoid duplicate descriptions, parts different from the first embodiment will be described, and parts having the same configuration as the first embodiment will be described with the same reference numerals.

[0033] The collision avoidance system 10 of the ship 1 according to the second embodiment includes, as obstacles, not only dynamic obstacles such as the ship 1 but also static obstacles. In the collision avoidance system 10 of the second embodiment, chart information including information on the positions of static obstacles is stored in the storage unit 24. That is, the storage unit 24 functions as a second position acquisition unit that acquires the positions of static obstacles. Note that the chart information may be acquired from an external system.

[0034] Then, in the collision avoidance action in step S3, the control unit 23 sets, on the grid map M, in addition to the regulation violation range E1 and the collision range E2, a collision range E3. The collision range E3 is a range in which a collision with a static obstacle occurs within a finite time. When executing the collision avoidance action of the ship 1, the control unit 23 executes the collision avoidance action in a navigable range that does not include the regulation violation range E1, the collision range E2, and the collision range E3.

[0035] Regarding the grid map M used in the first and second embodiments, the grid width, which is the width between grid lines in the circumferential direction or the radial direction, may be changed. For example, the control unit 23 may change the grid width in the circumferential direction and the radial direction of the grid map M according to the avoidance direction and the avoidance speed set at the grid point O.

[0036] As described above, the collision avoidance system 10, the collision avoidance method, and the collision avoidance program described in the first and second embodiments are understood as follows, for example.

[0037] The collision avoidance system 10 according to the first aspect is a collision avoidance system 10 for avoiding a collision of the ship 1 with an obstacle. It includes a first position acquisition unit (ship identification device 21) for acquiring the position of the ship 1, a second position acquisition unit (ship identification device 21, storage unit 24) for acquiring the position of the obstacle, and a control unit 23 for causing the ship 1 to execute a collision avoidance action based on the position of the ship 1 acquired by the first position acquisition unit and the position of the obstacle acquired by the second position acquisition unit. The control unit 23 generates a grid map M in a grid shape connecting a plurality of grid points O, including the position of the ship 1, sets an avoidance direction and an avoidance speed at the grid points O, sets a regulation violation range E1 that violates the maritime traffic regulations on the grid map M, sets a collision range E2 in which the ship will collide with the obstacle within a finite time on the grid map M, calculates an evaluation point based on an evaluation function for the grid points O in the navigable range on the grid map M that does not include the regulation violation range E1 and the collision range E2, and executes the collision avoidance action of the ship 1 based on the evaluation point. The evaluation function includes a route evaluation parameter for evaluating the deviation from a preset route of the ship 1 and a sensory evaluation parameter for sensually evaluating the risk of collision until approaching the obstacle closest. The evaluation point based on the route evaluation parameter indicates that the smaller the deviation from the ship's route, the lower the score. The evaluation point based on the sensory evaluation parameter indicates that the lower the score, the lower the risk of collision. The control unit 23 executes the collision avoidance action so that the avoidance direction and the avoidance speed set at the grid point O where the evaluation point is the minimum value are obtained.

[0038] According to this configuration, it is possible to select an avoidance direction and an avoidance speed that are optimal for the collision avoidance action by using an evaluation function including a sensory evaluation parameter. Therefore, since the selected avoidance direction and avoidance speed are sensually evaluated, the collision avoidance action of the ship 1 can be an appropriate action without giving a sense of discomfort to an obstacle such as an oncoming ship.

[0039] As a second aspect, in the collision avoidance system 10 according to the first aspect, when there are a plurality of evaluation points that are the minimum values calculated by the evaluation function, the control unit 23 selects the grid point O with the lower score of the evaluation points based on the route evaluation parameter.

[0040] According to this configuration, even when there are a plurality of evaluation points that are the minimum values, it is possible to select the grid point O with the lower evaluation point based on the route evaluation parameter, so that a route closer to the target route can be selected.

[0041] As a third aspect, in the collision avoidance system 10 according to the first or second aspect, the obstacle is a moving dynamic obstacle, and the second position acquisition unit is an obstacle identification device (ship identification device 21) that identifies the dynamic obstacle and acquires the position of the dynamic obstacle.

[0042] According to this configuration, a collision of the ship 1 with a dynamic obstacle can be appropriately avoided by a sensorially evaluated collision avoidance action.

[0043] As a fourth aspect, in the collision avoidance system 10 according to any one of the first to third aspects, the obstacle is a stationary static obstacle, and the second position acquisition unit acquires a nautical chart including the position of the static obstacle.

[0044] According to this configuration, a collision of the ship 1 with a static obstacle can be appropriately avoided by a sensorially evaluated collision avoidance action based on the nautical chart.

[0045] As a fifth aspect, in the collision avoidance system 10 according to any one of the first to fourth aspects, when the control unit 23 determines that the positional relationship between the obstacle and the ship 1 is a positional relationship in which the ship 1 has overtaken the obstacle, the control unit 23 ends the execution of the collision avoidance action of the ship 1.

[0046] According to this configuration, when there is no risk of the ship 1 colliding with an obstacle, the execution of the collision avoidance action can be appropriately canceled.

[0047] As a sixth aspect, in the collision avoidance system 10 according to any one of the first to fifth aspects, the control unit 23 changes the grid width of the grid map M according to the avoidance direction and the avoidance speed set at the grid point O.

[0048] According to this configuration, since the resolution of the avoidance direction and the avoidance speed can be made variable according to the dynamic characteristics of the ship 1, it is possible to execute a collision avoidance action suitable for the dynamic characteristics of the ship 1.

[0049] The collision avoidance method according to the seventh aspect is a collision avoidance method executed by a collision avoidance system 10 for avoiding a collision of a ship 1 with an obstacle. The collision avoidance system 10 includes a first position acquisition unit (ship identification device 21) that acquires the position of the ship 1, a second position acquisition unit (ship identification device 21, storage unit 24) that acquires the position of the obstacle, and a control unit 23 that causes the ship 1 to execute a collision avoidance action based on the position of the ship 1 acquired by the first position acquisition unit and the position of the obstacle acquired by the second position acquisition unit. The control unit 23 generates a grid map M in a grid pattern connecting a plurality of grid points O, including the position of the ship 1, sets an avoidance direction and an avoidance speed at the grid points O, sets a regulation violation range E1 that violates maritime traffic regulations on the grid map M, sets a collision range E2 in which a collision with the obstacle occurs within a finite time on the grid map M, calculates an evaluation point based on an evaluation function for the grid points O in the navigable range on the grid map M that does not include the regulation violation range E1 and the collision range E2, executes the collision avoidance action of the ship 1 based on the evaluation point, the evaluation function includes a route evaluation parameter that evaluates the deviation from a preset route of the ship 1 and a sensory evaluation parameter that sensually evaluates the risk of a collision until the closest approach to the obstacle, the evaluation point based on the route evaluation parameter is such that the smaller the score, the smaller the deviation from the route of the ship 1, the evaluation point based on the sensory evaluation parameter is such that the smaller the score, the lower the risk of a collision, and the control unit 23 executes the collision avoidance action so as to obtain the avoidance direction and the avoidance speed set at the grid point where the evaluation point is the minimum value.

[0050] According to this configuration, it is possible to select an avoidance direction and an avoidance speed that are optimal for the collision avoidance action by using an evaluation function including a sensory evaluation parameter. Therefore, since the selected avoidance direction and avoidance speed are sensually evaluated, the collision avoidance action of the ship 1 can be an appropriate action without giving a sense of discomfort to an obstacle such as an oncoming ship.

[0051] The collision avoidance program P according to the eighth aspect is a collision avoidance program P executed by a collision avoidance system 10 that avoids a collision of the ship 1 with an obstacle. The collision avoidance system 10 includes a first position acquisition unit (ship identification device 21) that acquires the position of the ship 1, a second position acquisition unit (ship identification device 21, storage unit 24) that acquires the position of the obstacle, and a control unit 23 that causes the ship 1 to execute a collision avoidance action based on the position of the ship 1 acquired by the first position acquisition unit and the position of the obstacle acquired by the second position acquisition unit. The control unit 23 generates a grid map M in a grid shape connecting a plurality of grid points O, including the position of the ship 1, sets an avoidance direction and an avoidance speed at the grid points O, sets a regulation violation range E1 that violates maritime traffic regulations on the grid map M, sets a collision range E2 in which a collision with the obstacle occurs within a finite time on the grid map M, calculates an evaluation point based on an evaluation function for the grid points O in the navigable range on the grid map M that does not include the regulation violation range E1 and the collision range E2, causes the ship 1 to execute the collision avoidance action based on the evaluation point, the evaluation function includes a route evaluation parameter that evaluates the deviation from a preset route of the ship 1 and a sensory evaluation parameter that sensorily evaluates the risk of a collision until the closest approach to the obstacle, the evaluation point based on the route evaluation parameter indicates that the smaller the deviation from the route of the ship 1, the lower the score, and the evaluation point based on the sensory evaluation parameter indicates that the lower the score, the lower the risk of a collision, and the control unit 23 causes the ship 1 to execute the collision avoidance action so that the avoidance direction and the avoidance speed set at the grid point O where the evaluation point is the minimum value are obtained.

[0052] According to this configuration, it is possible to select an avoidance direction and an avoidance speed that are optimal for the collision avoidance action by using an evaluation function including a sensory evaluation parameter. Therefore, since the selected avoidance direction and avoidance speed are sensorily evaluated, the collision avoidance action of the ship 1 can be an appropriate action without giving a sense of discomfort to an obstacle such as an oncoming ship.

Explanation of Signs

[0053] 1 Ship 10 Collision avoidance system 21 Ship identification device 23 Control unit 24 Memory unit P Collision avoidance program M Grid map E1 Violation range E2, E3 Collision range

Claims

1. In a collision avoidance system for avoiding a collision of a ship with an obstacle, a first position acquisition unit that acquires the position of the ship; a second position acquisition unit that acquires the position of the obstacle; a control unit that causes the ship to execute a collision avoidance action based on the position of the ship acquired by the first position acquisition unit and the position of the obstacle acquired by the second position acquisition unit, wherein the control unit generates a grid map in a grid shape connecting a plurality of grid points, including the position of the ship, sets an avoidance direction and an avoidance speed at the grid points, sets a range of violation of maritime traffic regulations on the grid map, sets a collision range in which a collision with the obstacle occurs within a finite time on the grid map, calculates an evaluation point based on an evaluation function for grid points in a navigable range on the grid map that does not include the range of violation of regulations and the collision range, executes the collision avoidance action of the ship based on the evaluation point, wherein the evaluation function includes a route evaluation parameter for evaluating the deviation from a preset route of the ship and a sensory evaluation parameter for sensorily evaluating the risk of collision until approaching the closest to the obstacle, the evaluation point based on the route evaluation parameter is such that the smaller the deviation from the route of the ship, the lower the score, the evaluation point based on the sensory evaluation parameter is such that the lower the score, the lower the risk of collision, wherein the control unit is a collision avoidance system that executes the collision avoidance action so as to obtain the avoidance direction and the avoidance speed set at the grid point where the evaluation point becomes the minimum value.

2. The control unit selects the grid point with the lower score of the evaluation point based on the route evaluation parameter when there are a plurality of evaluation points that are the minimum values calculated by the evaluation function. The collision avoidance system according to claim 1.

3. The obstacle is a moving dynamic obstacle, and the second position acquisition unit is an obstacle identification device that identifies the dynamic obstacle and acquires the position of the dynamic obstacle. The collision avoidance system according to claim 1.

4. The obstacle is a stationary static obstacle, and the second position acquisition unit acquires a nautical chart including the position of the static obstacle. The collision avoidance system according to claim 1.

5. The control unit When it is determined that the positional relationship between the obstacle and the ship is such that the ship has passed the obstacle, the collision avoidance system according to claim 1 terminates the execution of the collision avoidance action of the ship.

6. The control unit The collision avoidance system according to claim 1, wherein the control unit changes the grid width of the grid map according to the avoidance direction and the avoidance speed set at the grid points.

7. In a collision avoidance method executed by a collision avoidance system for avoiding a collision of a ship with an obstacle, The collision avoidance system A first position acquisition unit that acquires the position of the ship, A second position acquisition unit that acquires the position of the obstacle, A control unit that executes a collision avoidance action of the ship based on the position of the ship acquired by the first position acquisition unit and the position of the obstacle acquired by the second position acquisition unit, The control unit Generates a grid-shaped grid map including the position of the ship and connecting a plurality of grid points, Sets an avoidance direction and an avoidance speed at the grid points, Sets a range of violation of regulations that is a violation in the maritime traffic regulations on the grid map, Sets a collision range in which the ship collides with the obstacle within a finite time on the grid map, Calculates an evaluation point based on an evaluation function for grid points in the navigable range on the grid map that does not include the range of violation of regulations and the collision range, Executes the collision avoidance action of the ship based on the evaluation point, The evaluation function includes a route evaluation parameter that evaluates the deviation from a preset route of the ship and a sensory evaluation parameter that sensorily evaluates the risk of collision until approaching the obstacle closest, The evaluation point based on the route evaluation parameter is such that the smaller the deviation from the route of the ship, the lower the score, The evaluation point based on the sensory evaluation parameter is such that the lower the score, the lower the risk of collision, The control unit A collision avoidance method for executing the collision avoidance action such that the avoidance direction and the avoidance speed are set at the grid point where the evaluation point becomes the minimum value.

8. In a collision avoidance program executed by a collision avoidance system for avoiding a collision of a ship with an obstacle, The collision avoidance system A first position acquisition unit that acquires the position of the ship, A second position acquisition unit that acquires the position of the obstacle, A control unit that causes the ship to execute collision avoidance actions based on the position of the ship acquired by the first position acquisition unit and the position of the obstacle acquired by the second position acquisition unit, In the control unit, A grid map is generated that includes the position of the ship and connects a plurality of grid points in a grid pattern, An avoidance direction and an avoidance speed are set for the grid points, A regulatory violation range that violates maritime traffic regulations is set on the grid map, A collision range in which the ship will collide with the obstacle within a finite time is set on the grid map, Evaluation points based on an evaluation function are calculated for the grid points in the navigable range on the grid map that do not include the regulatory violation range and the collision range, Based on the evaluation points, the ship is caused to execute the collision avoidance actions, The evaluation function includes a route evaluation parameter that evaluates the deviation from a preset route of the ship and a sensory evaluation parameter that sensorially evaluates the risk of collision until approaching the obstacle closest, The evaluation points based on the route evaluation parameter indicate that the smaller the deviation from the ship's route, the lower the score, The evaluation points based on the sensory evaluation parameter indicate that the lower the score, the lower the risk of collision, In the control unit, A collision avoidance program that causes the collision avoidance actions to be executed so that the avoidance direction and the avoidance speed are set to the grid point at which the evaluation point becomes the minimum value.

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