Ship control device, ship control method, and ship control program

Abstract

[Problem] To provide a ship control technique for automatically shifting to different navigation control when another ship cannot be followed. [Solution] A ship control device 10 is provided with a detection unit 21, a mode selection unit 22, and a navigation control unit 29. The detection unit 21 detects another ship 89 around an own ship 80. The mode selection unit 22 selects another navigation mode by switching from an other ship following mode for following the other ship on the basis of a detection result of the other ship while the other ship following mode is selected. The navigation control unit 29 controls a moving direction or propulsive force of the own ship on the basis of the selected navigation mode.

Description

Ship control device, ship control method, and ship control program

[0001] The present invention relates to a technology for switching from manual ship operation to automatic navigation.

[0002] Patent Documents 1 and 2 describe technologies for automatically navigating while following a target ship.

[0003] Japanese Patent No. 7170019, European Patent No. 3893075

[0004] However, in automatic navigation by following another ship, there is a situation of losing the other ship (being unable to follow the target ship). When in the state of losing the other ship, automatic navigation by following the other ship becomes impossible, and other navigation controls are required.

[0005] Therefore, an object of the present invention is to provide a ship control technology that automatically shifts to other navigation controls when it becomes impossible to follow another ship.

[0006] The ship control device according to an embodiment of this invention includes a detection unit, a mode selection unit, and a navigation control unit. The detection unit detects other ships around the own ship. The mode selection unit selects another navigation mode by switching from the other-ship following mode based on the detection result of the other ship during the selection of the other-ship following mode. The navigation control unit controls the navigation device of the own ship based on the selected navigation mode.

[0007] With this configuration, during the execution of the other-ship following mode, it is possible to automatically shift to another navigation mode according to the situation of the other ship being followed.

[0008] In the ship control device according to an embodiment of this invention, the other navigation modes include a route following mode that follows a planned route based on a target position, a state holding mode that maintains a set bow azimuth or propulsion force, and a manual operation mode using a manual operation device for the ship. <F

[0009] With this configuration, an example of the other navigation modes is shown, and it is possible to automatically shift from the other-ship following mode to the other navigation modes within the range of automatic navigation control by these navigation modes.

[0010] In a ship control device according to one embodiment of this invention, the mode selection unit selects another navigation mode based on the result of detecting other ships, specifically when it is no longer possible to detect other ships.

[0011] This configuration allows for a transition from a mode that requires other vessels to follow other vessels to a navigation mode that does not require other vessels.

[0012] In a ship control device according to one embodiment of this invention, the detection unit detects other ships using the image captured by the camera, and detects that other ships can no longer be detected when there are no other ships in the captured image, or when the captured image has changed significantly due to the imaging environment.

[0013] This configuration illustrates an example of a situation where the system is unable to detect other vessels when using cameras for detection.

[0014] In a ship control device according to one embodiment of this invention, the mode selection unit selects the route-following mode with priority over the state-holding mode.

[0015] In this configuration, when switching from other-ship following mode, the route following mode takes priority. Since the route following mode navigates along a pre-set route, it can preferentially transition to the safer automatic navigation mode.

[0016] In a ship control device according to one embodiment of this invention, the mode selection unit selects the route following mode if the position of the ship at the time when it can no longer detect other ships is less than a predetermined distance from the planned route.

[0017] This configuration makes it easy to return to the route using the route-following mode.

[0018] In a ship control device according to one embodiment of this invention, the mode selection unit selects the state holding mode if the distance between the ship's position and the planned route when it can no longer detect other ships is greater than or equal to a predetermined distance.

[0019] In this configuration, even if the distance from the vessel to the shipping lane is large, the system can switch from following other vessels to safe automatic navigation while maintaining a constant speed and heading.

[0020] In a ship control device according to one embodiment of this invention, the mode selection unit selects a state-holding mode during the period from when it can no longer detect other ships until when it selects another navigation mode.

[0021] This configuration allows for a safer transition from following other vessels mode to other navigation modes.

[0022] In a ship control device according to one embodiment of this invention, the mode selection unit selects another navigation mode based on the detection result of another ship, where the distance between the position of the other ship and the planned route is greater than a predetermined distance.

[0023] In this configuration, the other-ship following mode can be deactivated when another vessel deviates significantly from the ship's planned route. This allows for a combination of other-ship following mode and other navigation modes, enabling safer navigation along the user's desired route.

[0024] A ship control device according to one embodiment of this invention includes a notification unit that notifies the user when switching from a ship-following mode to another navigation mode.

[0025] In this configuration, users can easily understand when switching from following another vessel mode to other navigation modes.

[0026] A ship control device according to one embodiment of this invention includes a planned route generation unit that generates a planned route based on the ship's current position and target position. The navigation control unit controls the propulsion force and rudder angle to navigate along the planned route when in route-following mode.

[0027] This configuration demonstrates a specific control example when executing the route-following mode.

[0028] In a ship control device according to one embodiment of this invention, when a specific input to a manual steering control device is detected, the manual steering mode is selected as the highest priority among the other navigation modes.

[0029] In this configuration, if manual steering interruption occurs, the system can reliably switch from following other vessels mode to manual steering mode.

[0030] Figure 1 is a functional block diagram showing an example of a ship control system according to an embodiment of the present invention. Figure 2 is a diagram showing an example of the situation when the other ship following mode is executed. Figure 3 is a diagram showing an example of the situation when the route following mode is executed. Figure 4 is a diagram showing an example of the situation when the state holding mode is executed. Figure 5 is a flowchart showing an example of switching control from another mode to the other ship following mode. Figure 6 is a diagram showing an example of the situation of another ship and the own ship, and is an explanatory diagram of the concept of determining the ship to be followed. Figure 7 is a flowchart showing an example of the selection process for the ship to be followed. Figure 8(A) is a diagram showing an example of the selection state using a plotter image, and Figure 8(B) is a diagram showing an example of the selection state using a camera image. Figure 9 is a flowchart showing an example of switching control from the other ship following mode to another navigation mode. Figure 10 is a flowchart showing an example of lost ship determination. Figure 11 is a diagram showing an example of the concept of calculating the distance between the position of the own ship and the planned route. Figure 12 is a diagram showing an example of the behavior of a ship when transitioning from lost ship to route following mode. Figure 13 is a flowchart showing how to switch from following another vessel mode to another navigation mode based on the distance between the other vessel's position and the vessel's planned route.

[0031] A ship control technology according to an embodiment of the present invention will be described with reference to the figures.

[0032] (Configuration of the ship control system) Figure 1 is a functional block diagram showing an example of a ship control system according to an embodiment of the present invention. As shown in Figure 1, the ship control system 1 comprises a ship control device 10, a camera 300, a rudder 71, a propulsion force generator 72, and a manual steering control device 700. The camera 300, the rudder 71, the propulsion force generator 72, and the manual steering control device 700 are connected to the ship control device 10.

[0033] Camera 300 is mounted on the ship (vehicle) on which the ship control system 1 is installed, and its field of view is set to include a predetermined range in the forward area of ​​the ship. Camera 300 captures images of the area in front of the ship (towards the bow) and generates a camera image with a predetermined field of view. Camera 300 captures images continuously in time or at predetermined time intervals, and sequentially generates a plurality of camera images that are continuous in time or have predetermined time intervals.

[0034] The rudder gear 71 and the thrust generator 72 are installed, for example, in an outboard motor. The rudder gear 71 adjusts the rudder angle according to the input command rudder angle (automatic navigation mode) or rudder angle adjustment value (manual steering mode). The thrust generator 72 adjusts the magnitude of the thrust according to the input throttle opening. The rudder gear 71 and the thrust generator 72 constitute the navigation system 70.

[0035] The manual steering controls 700 include, for example, a throttle lever, a steering wheel, and a joystick. The manual steering controls 700 set the throttle opening using the throttle lever and the rudder angle adjustment value using the steering wheel.

[0036] The ship control device 10 includes a control unit 20, a sensor 31, an automatic navigation operation unit 32, a notification unit 33, a communication unit 34, and a data communication network 100. The control unit 20 includes a detection unit 21, a mode selection unit 22, a planned route generation unit 23, a follow target determination unit 241, a follow target setting unit 242, a track calculation unit 25, a follow route generation unit 26, and a navigation control unit 29.

[0037] The control unit 20 is composed of, for example, a combination of a calculation processing unit and a program executed by the calculation processing unit. The calculation processing unit is connected to the sensor 31, the automatic navigation operation unit 32, the notification unit 33, and the communication unit 34 via the data communication network 100.

[0038] The control unit 20 and the manual steering controls 700 are connected to the steering gear 71 and the propulsion generator 72 via the switch 40.

[0039] Sensor 31 includes, for example, a GPS positioning device and an attitude angle sensor, and acquires navigation status data indicating the state of the ship, such as the ship's position (position coordinates), heading, ship speed, angular velocity, and rudder angle.

[0040] The operation unit 32 for automatic navigation is composed of, for example, a touch panel, physical buttons, switches, etc. The operation unit 32 for automatic navigation accepts operations for settings related to automatic navigation control. For example, the operation unit 32 for automatic navigation accepts operations such as setting a route for automatic navigation. Also, the operation unit 32 for automatic navigation accepts an operation of selecting a following target ship from a plurality of other ships.

[0041] The notification unit 33 is composed of various display devices. The notification unit 33 displays information related to navigation control such as a plotter image and a camera image, and the navigation status of the own ship.

[0042] The communication unit 34 communicates with the outside. For example, the communication unit 34 is used when acquiring nautical charts, etc. from the outside.

[0043] A camera image captured by the camera 300 is input to the detection unit 21. The detection unit 21 detects other ships 89 around the own ship 80 based on the camera image. For example, the detection unit 21 performs image analysis of the camera image and extracts an image of a ship to detect the other ship 89. The detection unit 21 detects the other ship 89 based on the camera image at a predetermined time interval. This detection interval may or may not be constant.

[0044] The mode selection unit 22 selects one of a plurality of types of automatic navigation modes based on the detection result of other ships by the detection unit 21. The plurality of types of automatic navigation modes include an other-ship following mode, a route following mode, and a state holding mode. The other-ship following mode, the route following mode, and the state holding mode are modes that perform the following controls roughly.

[0045] The other-ship following mode is an automatic navigation mode in which the own ship follows other ships around it, mainly other ships sailing ahead.

[0046] The route following mode is an automatic navigation mode in which the ship sails according to a preset route.

[0047] The state holding mode is an automatic navigation mode in which the ship's heading (direction of movement) and propulsive force (throttle opening) are kept constant while sailing.

[0048] The mode selection unit 22 preferentially selects the following-other-ship mode over the route following mode. The mode selection unit 22 preferentially selects the route following mode over the safety speed mode.

[0049] The planned route generation unit 23 creates a planned route based on an operation input from the user. The operation input from the user is performed, for example, by the automatic navigation operation unit 32.

[0050] The following target determination unit 241 determines the other ship (the following target ship) to be followed in the following-other-ship mode.

[0051] The following target setting unit 242 sets the other ship (the following target ship) to be followed in the following-other-ship mode based on an operation input from the user.

[0052] The track calculation unit 25 calculates the track of the following target ship in the following-other-ship mode.

[0053] The following route generation unit 26 generates a following route for following the following target ship based on the track of the following target ship.

[0054] The navigation control unit 29 includes a rudder angle control unit and a propulsion force control unit. The navigation control unit 29 executes rudder angle control with the rudder angle control unit and executes propulsion force control with the propulsion force control unit according to the automatic navigation mode selected by the mode selection unit 22.

[0055] The rudder angle control unit sets a command rudder angle (moving direction) for executing rudder angle control in various automatic navigation modes and outputs it to the switch 40. The propulsion force control unit sets a throttle opening for executing propulsion force control in various automatic navigation modes and outputs it to the switch 40.

[0056] When the automatic navigation mode is not being executed, that is, when the manual steering mode is being executed, the switch 40 connects the manual steering operator 700 to the steering gear 71 and the propulsion device 72.

[0057] When the automatic navigation mode is activated, the switch 40 disconnects the manual steering controls 700 from the steering gear 71 and the thrust generator 72, connects the rudder angle control unit to the steering gear 71, and connects the thrust control unit to the thrust generator 72. The switch 40 outputs the commanded rudder angle from the rudder angle control unit to the steering gear 71 and the throttle opening from the thrust control unit to the thrust generator 72.

[0058] The switching of connection relationships by the switch 40 is controlled, for example, by the navigation control unit 29.

[0059] (Explanation of each automatic navigation mode) A. Other ship following mode Figure 2 is a diagram showing an example of the situation when the other ship following mode is in operation.

[0060] The other ships to be followed (target ships) 89 are determined by the target ship determination unit 241 or set by the target ship setting unit 242.

[0061] The track calculation unit 25 calculates the provisional track WK89tmp of the other ship (following target ship) 89 based on the positions P89t1, P89t2, P89t3, and P89t4 of the other ship to be followed at multiple time points. The provisional track WK89tmp is constructed by sequentially connecting the positions P89t1, P89t2, P89t3, and P89t4 at multiple time points with straight lines.

[0062] The follow-path generation unit 26 smooths the provisional track WK89tmp to generate the follow-path track WK89.

[0063] The navigation control unit 29 controls the rudder angle and thrust to navigate along the track WK 89. At this time, the navigation control unit 29 obtains the speed of the other ship being followed and controls the thrust so that the distance between the other ship 89 and the own ship 80 is within a certain distance range and approximately equidistant.

[0064] B. Route Following Mode Figure 3 shows an example of the situation when the route following mode is being executed.

[0065] The planned route generation unit 23 generates a planned route based on the current position P80 of the vessel 80 and the target position WPo. In this process, the planned route generation unit 23 can set multiple waypoints WP1, WP2, and WP3 between position P80 and the target position WPo.

[0066] The planned route generation unit 23 calculates a provisional planned route WKtmp based on position P80, multiple waypoints, WP1, WP2, WP3, and target position WPo. The provisional planned route WKtmp is constructed by sequentially connecting position P80, multiple waypoints, WP1, WP2, WP3, and target position WPo with straight lines.

[0067] The planned route generation unit 23 smooths the provisional planned route WKtmp to generate the planned route WKs.

[0068] The navigation control unit 29 controls the rudder angle and thrust to navigate along the planned route WKs.

[0069] C. State Holding Mode Figure 4 is a diagram showing an example of the situation when the state holding mode is being executed.

[0070] The navigation control unit 29 stores the ship speed V80 and heading HDG of the ship 80 at the time the state holding mode was selected.

[0071] The navigation control unit 29 controls the rudder angle and thrust to maintain a constant ship speed V80 and heading HDG.

[0072] (Control to switch to other-ship following mode) Figure 5 is a flowchart showing an example of control to switch from other modes to other-ship following mode.

[0073] The ship control device 10 is executing one of the following modes: route following mode, state holding mode, or manual maneuvering mode (S11).

[0074] As described above, the detection unit 21 detects other vessels based on the images captured by the camera 300 (S12: YES). While the detection unit 21 is unable to detect other vessels (S12: NO), the ship control device 10 continues to execute the navigation mode that was performed in step S11 above.

[0075] The follow target determination unit 241 determines from the detected other ships whether or not there is another ship that meets the follow target conditions (S13).

[0076] Figure 6 is an example showing the situation of other ships and one's own ship, and is an explanatory diagram of the concept of determining which ship to follow.

[0077] The tracking target determination unit 241 acquires the position P80, speed V80, and heading HDG of the vessel 80 from the sensor 31. The position P80, speed V80, and heading HDG are acquired, for example, in an absolute coordinate system (Earth coordinate system).

[0078] The tracking target determination unit 241 obtains the position P89, speed V89, and heading COG of the other vessel 89 from the detection results of the other vessel 89 by the detection unit 21. The position P89, speed V89, and heading COG of the other vessel 89 can be obtained in the absolute coordinate system (Earth coordinate system) by pre-setting the coordinate transformation matrix between the coordinate system of the captured image and the absolute coordinate system.

[0079] The tracking target determination unit 241 calculates the detection direction DST from the position P80 of the own ship 80 toward the position P89 of the other ship 89.

[0080] The tracking target determination unit 241 calculates the detection direction angle ψ of the other ship. The detection direction angle ψ of the other ship is the angle between the heading HDG of the own ship 80 and the detection direction DST.

[0081] The tracking target determination unit 241 calculates the direction angle φ of the other vessel. The direction angle φ of the other vessel is the angle formed by the heading COG and detection direction DST of the other vessel 89.

[0082] The tracking target determination unit 241 compares the detection direction angle ψ of the other ship with the first threshold angle THψ. The first threshold angle THψ is set based on the field of view of the camera 300.

[0083] For example, the first threshold angle THψ is set to a predetermined angle narrower than half the field of view of the camera 300. As an example, if the field of view of the camera 300 (horizontal field of view) is 160°, the first threshold angle THψ is set to approximately 60°.

[0084] The tracking target determination unit 241 compares the direction angle φ of the other ship with the second threshold angle THφ. The second threshold angle THφ is set based on the direction of travel of the other ship 89 relative to the own ship 80.

[0085] For example, the second threshold angle THφ is set to an angle that determines whether the other vessel 89 is not heading toward the own vessel 80. As an example, the second threshold angle THφ is set to an angle that does not exceed 90°.

[0086] The tracking target determination unit 241 compares the speed V89 of the other vessel with a speed threshold. The speed threshold is set based on the speed of the other vessel, which indicates that it is sailing stably. For example, the speed threshold is set to approximately 3 knots.

[0087] Note that the specific numerical examples for the first threshold angle THψ, the second threshold angle THφ, and the ship speed threshold are just examples and can be adjusted as needed.

[0088] The tracking target determination unit 241 determines a target vessel to follow if (α) the detection direction angle ψ of the other vessel is less than the first threshold angle THψ, (β) the direction angle φ of the other vessel is less than the second threshold angle THφ, and (γ) the speed V89 of the other vessel is greater than the threshold speed. The tracking target determination unit 241 can also determine a target vessel to follow if it satisfies at least conditions (α) and (β).

[0089] The follow target determination unit 241 determines whether all other vessels detected by the detection unit 21 are follow target vessels. That is, if multiple other vessels are detected, the follow target determination unit 241 determines whether all of the detected multiple other vessels are follow target vessels.

[0090] The follow target determination unit 241 outputs the determination result of the follow target ship to the mode selection unit 22. If at least one follow target ship exists (S13: YES), the mode selection unit 22 selects the other ship follow mode. If no follow target ship exists, in other words, if all detected other ships do not meet the follow target conditions (S13: NO), the mode selection unit 22 continues to select the navigation mode that was executed in step S11 above.

[0091] If there is only one ship to follow (S14: YES), the mode selection unit 22 selects a follow mode for this ship.

[0092] If there are multiple ships to follow (S14: NO), the mode selection unit 22 instructs the target ship setting unit 242 to select a ship to follow.

[0093] The follow target setting unit 242 uses the notification unit 33 and the automatic navigation operation unit 32 to allow the user to select a ship to follow (S17).

[0094] Figure 7 is a flowchart showing an example of the process for selecting a target vessel to follow. Figure 8(A) shows an example of a selection state using a plotter image, and Figure 8(B) shows an example of a selection state using a camera image. In Figures 8(A) and 8(B), the notification unit 33 is composed of a flat-panel display, and the automatic navigation operation unit 32 is composed of a touch panel attached to the flat-panel display.

[0095] The notification unit 33 highlights other ships that have been determined to be ships to be followed by the follow target setting unit 242 (other ships that can be followed) (S161).

[0096] The automatic navigation control unit 32 detects the user's touch operation position (S162: YES) and outputs it to the follow target setting unit 242. The follow target setting unit 242 stores the position coordinates on the display (touch panel position coordinates) of multiple other ships that can be followed. Based on the touch operation position, the follow target setting unit 242 detects the selected other ship. At this time, it is preferable for the follow target setting unit 242 to further highlight the selected other ship.

[0097] The mode selection unit 22 sets the selected other ship as the ship to follow (S163).

[0098] In the case of Figure 8(A), the plotter image IMGP displays the own ship 80, other ships 89 and 89s that can be followed, and other ships 89n that are not to be followed. The other ships 89 and 89s that can be followed are displayed in a different manner than the other ships 89n that are not to be followed; specifically, the other ships 89 and 89s that can be followed are highlighted.

[0099] When the user operates the cursor CS on the plotter image IMGP and selects a followable other ship 89, the mode selection unit 22 sets the other ship 89 as the ship to be followed. The target ship 89 is displayed in a different display manner from the other followable other ships 89s; specifically, the target ship 89 is highlighted.

[0100] In Figure 8(B), the camera image IMGC displays other ships 89 and 89s that can be followed. The other ships 89 and 89s that can be followed are displayed in a different manner than the other ships that are not targets for follow (which are not shown in Figure 8(B)). Specifically, the other ships 89 and 89s that can be followed are highlighted.

[0101] When a user touches the touch panel with their finger FIN and selects a followable other vessel 89, the mode selection unit 22 sets the other vessel 89 as the target vessel for follow. The target vessel 89 is displayed in a different display manner from the other followable other vessels 89s; specifically, the target vessel 89 is highlighted.

[0102] If there is only one ship to follow, or if a ship to follow is selected, the notification unit 33 notifies the user that the system will switch from the currently running automatic navigation mode or manual steering mode to the other ship following mode (S15).

[0103] The mode selection unit 22 outputs to the navigation control unit 29 the other ship follow mode and the other ship to be followed in this other ship follow mode. The navigation control unit 29 terminates the navigation mode that was being executed up to this point and executes the other ship follow mode (S16).

[0104] In this way, the ship control device 10 can smoothly switch from the manual navigation mode, the route following mode, and the other ship following mode to the other ship following mode by detecting other ships that can be followed while the manual navigation mode, the route following mode, and the state holding mode are being executed. At this time, the ship control device 10 can select other ships that are suitable for following for the ship 80, and can achieve a smooth transition from other navigation modes to the other ship following mode.

[0105] When navigating in a narrow waterway, there is a high probability that the vessel 80 can navigate safely by following another vessel already sailing ahead of it. Therefore, as described above, by detecting another vessel and switching to a vessel-following mode to follow it, the ship control device 10 can achieve safer automatic navigation in environments where vessel-following is more suitable, such as narrow waterways.

[0106] Furthermore, even if there are multiple other ships that can be followed, the user can, for example, select which other ship they wish to follow. In this case, by displaying different information for ships that cannot be followed and ships that can be followed, the user can easily identify which ships can be followed.

[0107] Furthermore, by displaying different information for other vessels that are not intended for following and other vessels that can be followed, the ship control device 10 can prevent the user from selecting other vessels that are not intended for following. Therefore, the ship control device 10 can prevent the user from selecting vessels that are unsuitable for following.

[0108] Furthermore, by displaying different information for other ships that can be followed and the ship being followed, users can easily distinguish between the ship being followed and other ships that can be followed. In other words, users can easily understand which other ships they will be following in other ship following mode.

[0109] Furthermore, the ship control device 10 notifies the user when it switches from another navigation mode to the other ship following mode. This allows the user to easily and reliably understand when switching from another navigation mode to the other ship following mode.

[0110] In this case, the ship control device 10 notifies the user before the start of the other-ship following mode. This allows the user to be aware of the switch to the other-ship following mode before the navigation mode actually changes. Therefore, the ship control device 10 can prevent unforeseen problems caused by the user being unaware of the navigation mode change. For example, the ship control device 10 can prevent user confusion caused by the user being unaware of the navigation mode change.

[0111] (Control for switching from other vessel following mode to other navigation modes) Figure 9 is a flowchart showing an example of control for switching from other vessel following mode to other navigation modes.

[0112] The ship control device 10 is executing the other ship follow mode (S51).

[0113] If the detection unit 21 has not lost track of the target ship to be followed (S52: NO), the ship control device 10 continues to execute the other ship following mode.

[0114] Loss of another vessel means that the system can no longer detect another vessel after previously being able to do so. Specifically, loss of another vessel is defined as a state in which the target vessel is no longer present within the image (field of view) captured by camera 300, or a state in which the image has changed significantly due to the imaging environment.

[0115] The state in which the target vessel is no longer within the image (angle of view) captured by camera 300 means, for example, that the target vessel has moved from within the angle of view of camera 300 to outside of it. A state in which the captured image changes significantly due to the imaging environment is, for example, a change from sunny to rainy weather, or backlighting.

[0116] Figure 10 is a flowchart showing an example of a lost item determination.

[0117] When the detection unit 21 can no longer detect the target vessel (S61: YES), it starts timing (S62). After timing starts, the detection unit 21 continues detection to see if it can re-detect the target vessel.

[0118] If the detection unit 21 fails to re-detect the target vessel after the start of re-detection and up to the determination threshold time (S63: NO, S64: YES), it determines that the target vessel has been lost (S65).

[0119] If the detection unit 21 can re-detect the target ship after the start of re-detection and before the determination threshold time is reached (S63: YES), it will not determine that the target ship has been lost.

[0120] When the detection unit 21 detects that the target vessel has been lost (S52: YES), the notification unit 33 notifies that the target vessel has been lost (S53).

[0121] When the navigation control unit 29 detects that the target vessel has been lost, it executes a provisional state holding mode (S54).

[0122] In provisional state holding mode, the navigation control unit 29 controls the ship speed to converge from the ship speed at the time the lost status of the following ship is acquired to a preset provisional ship speed. The provisional ship speed is set to a low speed that allows the ship 80 to navigate safely. In addition, in provisional state holding mode, the navigation control unit 29 controls the rudder angle to maintain the ship's heading (direction of travel) at the time the lost status of the other ship is acquired. By using this provisional state holding mode, the ship control device 10 can transition (switch) from the other ship following mode to other navigation modes more safely.

[0123] The navigation control unit 29 calculates the distance XTE between the position P80 of the ship 80 at the time the target ship is lost and the planned route WKs of the ship 80 (S55). The planned route WKs is calculated by the track calculation unit 25, as described in the explanation of the route following mode above.

[0124] Figure 11 shows an example of the concept for calculating the distance between the position of one's own vessel and the planned route. In Figure 11, the dotted line representing another vessel 89 indicates a lost vessel (a vessel to follow). The dotted line represents the planned route WKs of the own vessel 80.

[0125] The navigation control unit 29 calculates the distance XTE between the position P80 of its own vessel 80 and the planned route WKs when the target vessel is lost. For example, the navigation control unit 29 detects the position of the foot of a perpendicular line drawn from position P80 to the planned route WKs and calculates the distance between position P80 and the foot as the distance XTE. Alternatively, the navigation control unit 29 linearly approximates the portion of the planned route WKs close to position P80 and creates a straight line. The navigation control unit 29 calculates the distance XTE by substituting this straight line and position P80 into the formula for the distance between a point and a straight line.

[0126] The navigation control unit 29 compares the distance XTE with the determination threshold THd. The determination threshold THd is defined by distance (length). The determination threshold THd is set, for example, so that the vessel 80 can navigate along the planned route WKs within a predetermined time (relatively short time) without making significant changes to the rudder angle. In other words, the determination threshold THd is set by the distance at which the vessel can safely transition to the route-following mode.

[0127] If the distance XTE is less than the determination threshold THd (S56: YES), the notification unit 33 notifies the user to switch to the route following mode (S571). Then, the navigation control unit 29 stops the execution of the other ship following mode and executes the route following mode (S572).

[0128] Figure 12 shows an example of the behavior of a ship when transitioning from the lost position of another ship to the route-following mode. As shown in Figure 12, when transitioning from the lost position of the target ship to the route-following mode, the navigation control unit 29 limits the range of rudder angle change to a predetermined range. The range of rudder angle change within the predetermined range means, for example, a range of rudder angle change that allows for safe navigation for the user.

[0129] Furthermore, the navigation control unit 29 limits the range of change in ship speed to within a predetermined speed difference. The predetermined speed difference means, for example, the amount of speed change within a range that allows for safe navigation for the user.

[0130] By imposing restrictions on the range of change in rudder angle and ship speed, the ship control device 10 can suppress abrupt changes in the behavior of its own ship 80 (changes in ship speed and heading), and can safely and smoothly transition from following other ships mode to following a route mode.

[0131] If the distance XTE is greater than or equal to the determination threshold THd (S56: NO), the notification unit 33 notifies the user to switch to state-holding mode (S581). Then, the navigation control unit 29 executes state-holding mode (S582). Thus, the ship control device 10 can suppress the forced change of navigation mode to the route-following mode. Consequently, the ship control device 10 can achieve safer automatic navigation after losing the target ship to follow.

[0132] Furthermore, it is possible to switch from the other-ship following mode to the manual steering mode by, for example, an operation input to the automatic navigation control unit 32 or a specific operation input to the manual steering control device 700. A specific operation input is, for example, that the operating position of the manual steering control device 700 is above a predetermined position, or that the operating speed is above a certain speed. In this case, the manual steering mode is set to have a higher priority than the route following mode and the state holding mode. In other words, the route following mode and the state holding mode are executed when the manual steering mode is not selected. This ensures that if a user interrupts with manual steering during automatic navigation, the system can reliably switch to the manual steering mode in response to the user's intention.

[0133] Furthermore, the ship control device 10 executes a provisional state holding mode when switching from the other ship following mode to another navigation mode. This allows the ship control device 10 to suppress abrupt changes in the automatic navigation mode. In addition, the ship control device 10 can ensure time to notify the user of the switch in the automatic navigation mode, suppress abrupt changes in the behavior of the ship 80 at the time of notification, and achieve a safe switch to a navigation mode.

[0134] (An example of switching navigation modes based on the distance between the position of another vessel and the planned route of the own vessel) Figure 13 is a flowchart of the case in which switching from following another vessel mode to another navigation mode is performed based on the distance between the position of another vessel and the planned route of the own vessel.

[0135] As shown in Figure 13, the mode selection unit 22 calculates the distance between the position P89 of the other ship 89, which is the ship to be followed, and the planned route WKs of the own ship 80 while the other ship following mode is being executed (S71). The distance between the two ships can be calculated in the same way as the distance XTE between the position P80 of the own ship 80 and the planned route WKs described above.

[0136] If the distance between the position P89 of the other ship 89, which is the ship being tracked, and the planned route WKs is greater than a predetermined distance (S72: YES), the mode selection unit 22 cancels the other ship tracking mode with the other ship 89 and selects another navigation mode, switching from the other ship tracking mode to another navigation mode (S73).

[0137] As a result, the ship control device 10 can deactivate the other ship follow mode when the other ship 89 deviates significantly from the planned route WKs of its own ship 80. Therefore, the ship control device 10 can combine the other ship follow mode with other navigation modes to perform navigation control using a route desired by the user, which is highly safe.

[0138] <1> A ship control device comprising: a detection unit for detecting other ships in the vicinity of the ship; a mode selection unit for selecting another navigation mode by switching from the other ship following mode based on the detection result of the other ship while the ship is in the other ship following mode; and a navigation control unit for controlling the ship's navigation equipment based on the selected navigation mode.

[0139] <2> A ship control device as described in <1>, wherein the other navigation modes include a route-following mode that follows a planned route based on a target position, a state-holding mode that maintains a set heading or propulsion force, and a manual steering mode using a manual steering control device.

[0140] <3> A ship control device according to <1> or <2>, wherein the mode selection unit selects the other navigation mode based on the result of detecting the other ship, that the other ship can no longer be detected.

[0141] <4> A ship control device as described in <3>, wherein the detection unit detects the other ship using the image captured by the camera, and detects that the other ship can no longer be detected when the other ship is not present in the image, or when the image has changed significantly due to the imaging environment.

[0142] <5> A ship control device according to <2>, wherein the mode selection unit selects the route following mode with priority over the state holding mode.

[0143] <6> A ship control device as described in <2>, wherein the mode selection unit selects the route following mode if the position of the ship when it can no longer detect the other ship is less than a predetermined distance from the planned route.

[0144] <7> A ship control device as described in <2>, wherein the mode selection unit selects the state holding mode if the distance between the position of the ship at the time when it can no longer detect the other ship and the planned route is greater than or equal to a predetermined distance.

[0145] <8> A ship control device as described in <2>, wherein the mode selection unit selects the state holding mode during the period from when it can no longer detect the other ship until when it selects the other navigation mode.

[0146] <9> A ship control device as described in <2>, wherein the mode selection unit selects the other navigation mode based on the detection result of the other ship, where the distance between the position of the other ship and the planned route is greater than a predetermined distance.

[0147] <10> A ship control device according to any one of <1> to <9>, comprising a notification unit that notifies that the ship has switched from the other ship following mode to another navigation mode.

[0148] <11> A ship control device according to <2>, comprising a planned route generation unit that generates the planned route based on the current position of the ship and the target position, wherein the navigation control unit controls the propulsion force and the rudder angle to navigate along the planned route when in the route following mode.

[0149] <12> A ship control device according to any one of <1> to <11>, wherein the mode selection unit selects the manual operation mode as the highest priority when it detects a specific input to a manual operation device. term

[0150] Not all objectives or effects / benefits can necessarily be achieved in accordance with any particular embodiment described herein. Therefore, for example, a person skilled in the art will realize that a particular embodiment may be configured to achieve or optimize one or more effects / benefits taught herein, without necessarily achieving other objectives or effects / benefits taught or suggested herein.

[0151] All processes described herein can be fully automated and implemented by software code modules executed by a computing system including one or more computers or processors. The code modules can be stored in any type of non-temporary computer-readable medium or other computer storage device. Some or all of these methods can be implemented in dedicated computer hardware.

[0152] It will be apparent from this disclosure that there are many other variations not described herein. For example, depending on the embodiment, any particular operation, event, or function of any of the algorithms described herein may be performed in different sequences, and may be added, merged, or excluded entirely (e.g., not all described actions or events are necessary for the execution of the algorithm). Furthermore, in certain embodiments, the operations or events may be performed in parallel rather than sequentially, for example, through multithreading, interrupt handling, or via multiple processors or processor cores, or on other parallel architectures. In addition, different tasks or processes may also be performed by different machines and / or computing systems that can work together.

[0153] Various exemplary logic blocks and modules described in relation to the embodiments disclosed herein can be implemented or executed by a machine such as a processor. The processor may be a microprocessor, but alternatively, the processor may be a controller, a microcontroller, or a state machine, or a combination thereof. The processor may include electrical circuits configured to process computer-executable instructions. In another embodiment, the processor may include an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable device that performs logic operations without processing computer-executable instructions. The processor may also be implemented as a combination of computing devices, for example, a combination of a digital signal processor (digital signal processing device) and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration. Although the description herein mainly concerns digital technology, the processor may also include mainly analog elements. For example, some or all of the signal processing algorithms described herein may be implemented by analog circuits or mixed analog and digital circuits. The computing environment may include, but is not limited to, any type of computer system based on a microprocessor, mainframe computer, digital signal processor, portable computing device, device controller, or in-device computing engine.

[0154] Unless otherwise specified, conditional language such as “can,” “could,” “will,” or “may” is understood to mean in the context of commonly used expressions to convey that a particular embodiment includes certain features, elements, and / or steps, but other embodiments do not. Thus, such conditional language does not generally mean that features, elements, and / or steps are any way required in one or more embodiments, or that one or more embodiments necessarily include logic for determining whether these features, elements, and / or steps are included in or performed in any particular embodiment.

[0155] Disjunctive language, such as the phrase "at least one of X, Y, and Z," is understood in contexts where it is commonly used to indicate that an item, term, etc., can be any one of X, Y, Z, or any combination thereof, unless otherwise specified (e.g., X, Y, Z). Therefore, such disjunctive language does not generally imply that a particular embodiment requires each of at least one of X, at least one of Y, or at least one of Z, each of which exists.

[0156] Any process description, element, or block in the flowcharts described herein and / or shown in the accompanying drawings should be understood as representing a potentially module, segment, or portion of code containing one or more executable instructions for implementing a particular logical function or element in the process. Alternative embodiments are included within the scope of the embodiments described herein, where elements or functions may be removed, performed in no particular order, substantially simultaneously or in reverse order, depending on the relevant functionality, as will be understood by those skilled in the art.

[0157] Unless otherwise explicitly stated, numerals such as “one” should generally be interpreted as including one or more described items. Thus, phrases such as “one device configured to do…” are intended to include one or more enumerated devices. Such one or more enumerated devices may also be collectively configured to perform the stated citation. For example, “a processor configured to perform A, B and C below” could include a first processor configured to perform A and a second processor configured to perform B and C. In addition, even if an enumeration of a specific number of the introduced embodiments is explicitly listed, a person skilled in the art should interpret such an enumeration as typically meaning at least the number listed (for example, a mere enumeration of “two enumerations” without other modifiers usually means at least two enumerations, or two or more enumerations).

[0158] In general, a person skilled in the art will find that the terms used herein are generally intended to be "non-limiting" terms (for example, the term "including" should be interpreted as "including, but at least," the term "having" should be interpreted as "having at least," and the term "including" should be interpreted as "including, but not limited to, the following").

[0159] For illustrative purposes, the term “horizontal” as used herein is defined as a plane parallel to the floor or surface of the area in which the system described is used, or the plane on which the method described is implemented, regardless of its direction. The term “floor” may be replaced with the terms “ground” or “water surface.” The term “vertical / perpendicular” refers to a direction perpendicular / perpendicular to the defined horizontal line. Terms such as “upper side,” “lower side,” “below,” “up,” “on the side,” “higher,” “lower,” “above,” and “below” are defined in relation to the horizontal plane.

[0160] As used herein, the terms “adhere,” “connect,” “pair,” and other related terms should be interpreted, unless otherwise noted, as including removable, movable, fixed, adjustable, and / or removable connections or linkages. Connections / linkages include direct connections and / or connections having an intermediate structure between the two components described.

[0161] Unless otherwise explicitly stated, the numbers preceded by terms such as “approximately,” “about,” and “substantially,” as used herein, include the enumerated numbers and represent quantities close to the stated quantities that further perform the desired function or achieve the desired result. For example, “approximately,” “about,” and “substantially,” unless otherwise explicitly stated, mean values ​​less than 10% of the stated numbers. Features of embodiments disclosed preceded by terms such as “approximately,” “about,” and “substantially,” as used herein, represent features with some variability that further perform the desired function or achieve the desired result with respect to that feature.

[0162] Many variations and modifications can be made to the embodiments described above, and these elements should be understood as being within other acceptable examples. All such modifications and variations are intended to be within the scope of this disclosure and are protected by the following claims.

[0163] 1: Ship control system 10: Ship control device 20: Control unit 21: Detection unit 22: Mode selection unit 23: Planned route generation unit 25: Track calculation unit 26: Follow route generation unit 29: Navigation control unit 31: Sensor 32: Automatic navigation operation unit 33: Notification unit 34: Communication unit 40: Switch 71: Steering gear 72: Propulsion generation device 80: Own ship 89, 89n, 89s: Other ships 100: Data communication network 241: Follow target determination unit 242: Follow target setting unit 300: Camera 700: Manual steering control unit COG: Heading CS: Cursor DST: Detection direction FIN: Pointer HDG: Heading IMGC: Camera image IMGP: Plotter image XTE: Distance φ: Direction of travel angle ψ: Detection direction angle

Claims

1. A ship control device comprising: a detection unit for detecting other ships in the vicinity of the ship; a mode selection unit for selecting another navigation mode by switching from the other ship following mode based on the detection result of the other ship while the other ship following mode is selected; and a navigation control unit for controlling the ship's navigation equipment based on the selected navigation mode.

2. A ship control device according to claim 1, wherein the other navigation mode includes a route-following mode that follows a planned route based on a target position, a state-holding mode that maintains a set heading or propulsion force, and a manual steering mode using a manual steering control device.

3. A ship control device according to claim 1, wherein the mode selection unit selects another navigation mode based on the result of detecting another ship, that the other ship can no longer be detected.

4. A ship control device according to claim 3, wherein the detection unit detects the other ship using an image captured by a camera, and detects that the other ship can no longer be detected when the other ship is not present in the image, or when the image has changed significantly due to the imaging environment.

5. A ship control device according to claim 2, wherein the mode selection unit selects the route following mode with priority over the state holding mode.

6. A ship control device according to claim 2, wherein the mode selection unit selects the route following mode if the position of the ship at the time when it can no longer detect the other ship is less than a predetermined distance from the planned route.

7. A ship control device according to claim 2, wherein the mode selection unit selects the state holding mode if the distance between the position of the ship at the time it can no longer detect the other ship and the planned route is greater than or equal to a predetermined distance.

8. A ship control device according to claim 2, wherein the mode selection unit selects the state holding mode during the period from when it can no longer detect the other ship until when it selects the other navigation mode.

9. A ship control device according to claim 2, wherein the mode selection unit selects the other navigation mode based on the detection result of the other ship, where the distance between the position of the other ship and the planned route is greater than a predetermined distance.

10. A ship control device according to claim 1, comprising a notification unit that notifies that the ship has switched from the other ship following mode to another navigation mode.

11. A ship control device according to claim 2, comprising a planned route generation unit that generates the planned route based on the current position of the ship and the target position, wherein the navigation control unit controls the navigation device to navigate along the planned route when in the route following mode.

12. A ship control device according to claim 1, wherein the mode selection unit, when it detects a specific input to a manual steering control device, selects the manual steering mode as the highest priority.

13. A ship control method comprising: detecting other ships in the vicinity of one's own ship; selecting a ship-following mode in which one follows the other ship; switching from the ship-following mode to another navigation mode based on the detection result of the other ship; and controlling the navigation state of one's own ship based on the selected navigation mode.

14. A ship control program that, while in a ship-following mode in which the ship follows other ships in its vicinity, causes a processing unit to execute a process to switch from the ship-following mode to another navigation mode based on the detection results of the other ships, and to control the ship's navigation state based on the selected navigation mode.

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