Ship

Abstract

To suitably control movement of own vessel and carry out approach safely and accurately to a mooring position even when disturbance or inertia due to wind, for example, is great.SOLUTION: A vessel includes a hull, a plurality of propulsion devices 30, and a plurality of direction change units 60 capable of independently changing direction of each propulsion device 30, the propulsion device 30 includes a propulsion unit 40 for generating propulsion force and a resistance generating unit 50 for generating resistance of water by receiving water flow along with movement on a side surface 51, has position of own vessel approach the mooring position MP by propulsion force of the propulsion unit 40 as well as having one portion of propulsion devices 30 of the plurality of propulsion devices 30 work as propulsion device for braking 30X when carrying out mooring action for moving position of own vessel to approach the mooring position MP, and having the direction of the propulsion devices for braking 30X be crossed with moving direction TF of own vessel having braking force generated to the moving direction TF of own vessel by resistance of the water generated by the resistance generation unit 50.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a ship equipped with a plurality of propulsion devices. More specifically, the present invention relates to a ship that generates braking force by a resistance generating unit provided in each propulsion device by changing the direction of each propulsion device.

Background Art

[0002] In recent years, automation has been promoted in various industrial fields. For example, in the field of aquaculture fisheries, the introduction of automatic feeding machines has been progressing. An automatic feeding machine is a device installed in an offshore aquaculture farm (aquaculture net cage) that automatically feeds the fish and shellfish being raised. By introducing an automatic feeding machine, the labor burden in aquaculture fisheries can be reduced to some extent.

[0003] However, even if an automatic feeding machine is introduced, at present, the work of transporting feed to the automatic feeding machine installed at sea is carried out by aquaculture fishermen themselves operating a workboat. Generally, aquaculture net cages are installed at multiple locations at sea, and aquaculture fishermen load feed on the workboat, go around each aquaculture net cage, and replenish the feed to the automatic feeding machine installed for each aquaculture net cage. For example, in the case of an aquaculture fisherman who owns 30 aquaculture net cages, the feed supply of approximately 300 kg to one automatic feeding machine is carried out about three times a week. That is, it is necessary to carry out the transportation work of feed with a total weight of about 9 tons once every about two days. Therefore, even if an automatic feeding machine is introduced, the work of transporting feed to the automatic feeding machine remains a heavy labor burden.

[0004] In addition, there are cases where it is difficult to install an automatic feeding machine, such as when the aquaculture net cage is installed in the open sea. In such aquaculture net cages, aquaculture fishermen themselves load feed on the workboat and transport it, and carry out feeding work at each aquaculture net cage.

[0005] Thus, in the field of aquaculture, the transportation work of transporting a large amount of feed to the offshore aquaculture cages is a heavy labor burden. Therefore, for example, it is conceivable to apply an autopilot to a conventional workboat to automate the feed transportation work by the workboat.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, when replenishing the automatic feeder with feed from the workboat that has arrived at the offshore aquaculture cage or feeding the feed directly from the workboat, it is necessary to temporarily moor the workboat to the aquaculture cage. Among the series of ship operations for the transportation work, the particularly difficult operation is to approach the workboat to the aquaculture cage and stop it at the mooring position.

[0008] Many of the conventional workboats are fishing boat types with a single rudder on a single-axis propeller. Such a fishing boat type of workboat is difficult to operate, although it has a high loading capacity and good navigation performance in rough weather. It is a very inconvenient form for automating the operation. Also, when the workboat is fully loaded with feed close to the limit of its loading capacity, it is prone to inertia, and the effectiveness of the rudder also decreases at very low speeds, making it even more difficult to operate. Furthermore, even for a skilled operator, it is extremely difficult to operate in the presence of external disturbances such as wind.

[0009] For this reason, when an autopilot is applied to a conventional workboat, even if it can approach the aquaculture cage to a certain extent, it is considered extremely difficult to approach and stop automatically at the mooring position of the aquaculture cage.

[0010] On the one hand, as a technology for controlling the position of a ship, a technology for dynamically maintaining the position of a ship using a plurality of propulsion devices is known (see, for example, Patent Document 1). In the ship disclosed in Patent Document 1, the position of the ship is controlled against disturbances such as wind by changing the balance of the propulsion forces of the plurality of propulsion devices. However, in the ship of Patent Document 1, when the position of the own ship is displaced due to disturbances such as wind or inertia, it is necessary to frequently operate the propulsion device to control the position. In addition, when a heavy object is loaded, inertia is likely to occur, and it is necessary to increase the propulsion force of the propulsion device, and there is also a problem that the energy consumption for generating braking force increases.

[0011] In this way, if the ship can move to the mooring position, which is the destination, by automatic operation, the labor of the operator who operates the ship can be reduced. However, when approaching the mooring position, if the position, moving speed, and course of the own ship cannot be accurately controlled, the ship may collide with the mooring position or its surroundings, and there is a risk of damaging the ship and surrounding facilities. In particular, when the disturbances such as wind received by the ship and inertia increase, it is difficult to safely approach the mooring position if the movement of the ship cannot be appropriately braked.

[0012] An object of the present invention is to provide a ship that can appropriately brake the movement of the own ship and safely and accurately approach the mooring position even when disturbances such as wind and inertia are large.

Means for Solving the Problems

[0013] The ship of the present invention a hull floating on the water surface, a plurality of propulsion devices supported by the hull, a plurality of direction changing parts capable of changing the directions of the propulsion devices, and is provided with each of the propulsion devices has a propulsion part for generating a propulsion force and a resistance generating part for generating water resistance by receiving the water flow accompanying the movement on the side surface. Taking the longitudinal direction among the directions in which the side surface of the resistance generating part extends horizontally as the longitudinal direction of the resistance generating part, When performing a mooring operation of moving the position of the own ship closer to the mooring position for mooring, while approaching the position of the own ship to the mooring position by the propulsion force of the propulsion part, a part of the plurality of propulsion devices is operated as a braking propulsion device, and the direction of the braking propulsion device is set such that the moving direction of the own ship and the longitudinal direction of the resistance generating part intersect, and a braking force with respect to the moving direction of the own ship is generated by the water resistance generated by the resistance generating part.

Effect of the Invention

[0014] According to the ship of the present invention, even when there are large disturbances such as wind or inertia, the movement of the own ship can be appropriately braked, and it is possible to safely and accurately approach the mooring position.

Brief Description of the Drawings

[0015]

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Mode for Carrying Out the Invention

[0016] A ship according to an embodiment of the present invention includes a hull floating on the water surface, a plurality of propulsion devices supported by the hull, a plurality of direction changing parts capable of changing the direction of the propulsion devices, and is provided with Each of the propulsion devices has a propulsion part that generates a propulsion force and a resistance generating part that generates water resistance by receiving the water flow accompanying movement on the side surface. With the longitudinal direction among the directions in which the side surface of the resistance generating part extends horizontally as the longitudinal direction of the resistance generating part, When performing a mooring operation to move the position of the own ship closer to the mooring position for mooring, the position of the own ship is brought closer to the mooring position by the propulsion force of the propulsion part, and a part of the plurality of propulsion devices is operated as a braking propulsion device, and the direction of the braking propulsion device is set such that the moving direction of the own ship and the longitudinal direction of the resistance generating part intersect, so that a braking force with respect to the moving direction of the own ship is generated by the water resistance generated by the resistance generating part (first configuration).

[0017] According to the above configuration, when performing the mooring operation, some of the plurality of propulsion devices are operated as braking propulsion devices, and the direction of the braking propulsion devices is set such that the moving direction of the own ship and the longitudinal direction of the resistance generating portion intersect, and due to the water resistance generated by the resistance generating portion, a braking force with respect to the moving direction of the own ship is generated. Thereby, even when there is a large disturbance such as wind or inertia, the movement of the own ship can be appropriately braked, and it is possible to safely and accurately approach the mooring position.

[0018] In the above first configuration, the plurality of propulsion devices are respectively arranged on the bow side and the stern side of the ship center line in the plan view of the hull, when moving the hull laterally by the mooring operation, at least one of the propulsion devices arranged on the bow side and the stern side of the hull may be operated as the braking propulsion device (second configuration).

[0019] According to the above configuration, when moving the hull laterally by the mooring operation, at least one of the propulsion devices arranged on the bow side and the stern side of the hull is operated as the braking propulsion device. Therefore, the braking force by the resistance generating portion can be generated in a well-balanced manner on the bow side and the stern side of the hull to suppress the rotation of the hull, and the movement of the own ship can be braked while maintaining the attitude of the hull.

[0020] In the above second configuration, the plurality of propulsion devices are respectively arranged on both the left and right sides with respect to the ship center line of the hull in the plan view, and at least one is arranged on each of the bow side and the stern side of the hull, when moving the hull laterally by the mooring operation, the propulsion devices arranged on the bow side and the stern side of the hull and on the mooring position side with respect to the ship center line of the hull may be operated as the braking propulsion devices (third configuration).

[0021] According to the above configuration, when the hull is moved laterally by the mooring operation, the propulsion devices located on the bow side and the stern side of the hull and on the mooring position side with respect to the fore-and-aft line of the hull are operated as braking propulsion devices. Since the resistance generating portions that generate braking force are arranged on the mooring position side of the hull on both the bow side and the stern side, braking force can be generated by the resistance generating portions on the mooring position side, and the hull can be moved toward the mooring position by the propulsion force of the propulsion devices on the side opposite to the mooring position. Therefore, it is possible to move toward the mooring position while appropriately generating both the braking force and the propulsion force.

[0022] In the above second or third configuration, the Mooring operation in which the direction of the braking propulsion device may be set such that the longitudinal direction of the resistance generating portion is parallel to the fore-and-aft line of the hull in plan view (fourth configuration).

[0023] According to the above configuration, Mooring operation in which the direction of the braking propulsion device is set such that the longitudinal direction of the resistance generating portion is parallel to the fore-and-aft line of the hull in plan view. Since the braking force with respect to the moving direction of the own ship can be maximized, even when there are large disturbances such as wind or inertia, the movement of the own ship can be appropriately braked, and it is possible to approach the mooring position safely and accurately.

[0024] In the above first to fourth configurations, the resistance generating portion may be set such that the length in the longitudinal direction of the resistance generating portion is 5% or more and 20% or less of the waterline length, which is the length in the fore-and-aft direction of the draft line of the hull (fifth configuration).

[0025] According to the above configuration, the resistance generating portion is set such that the length in the longitudinal direction of the resistance generating portion is 5% or more and 20% or less of the waterline length, which is the length in the fore-and-aft direction of the draft line of the hull. Therefore, even when the hull is moving at a very low speed, it is possible to generate sufficient braking force while preventing interference with the resistance generating portion of the adjacent propulsion device. In addition, by being able to shorten the vertical length of the resistance generating portion while ensuring the size of the resistance generating portion, the draft of the ship can be made shallower, and it can be easier to avoid interference with obstacles and the like.

[0026] In the above first to fifth configurations, the resistance generating portion may be set such that the ratio of the length in the longitudinal direction of the resistance generating portion to the length in the vertical direction is from 1:0.5 to 1:2.0 (sixth configuration).

[0027] According to the above configuration, the resistance generating portion is set such that the ratio of the length in the longitudinal direction of the resistance generating portion to the length in the vertical direction is from 1:0.5 to 1:2.0. Therefore, even when the hull is moving at a very low speed, it is possible to generate sufficient braking force while preventing interference with the resistance generating portion of the adjacent propulsion device. In addition, by being able to shorten the vertical length of the resistance generating portion while ensuring the size of the resistance generating portion, the draft of the ship can be made shallower, and it can be easier to avoid interference with obstacles and the like.

[0028] In the above first to sixth configurations, the resistance generating portion can be changed in direction around the rotation axis by the direction changing portion, and in a side view orthogonal to the longitudinal direction of the resistance generating portion, the rotation axis may be arranged so as to overlap with the area center of the side surface of the resistance generating portion (seventh configuration).

[0029] According to the above configuration, the resistance generating portion changes its direction around the rotation axis arranged so as to overlap with the area center in side view. Therefore, the moment around the rotation axis caused by the resistance of the water generated by the resistance generating portion is canceled, and the load when changing the direction by the direction changing portion can be reduced. In addition, since the movable area of the resistance generating portion around the rotation axis can be reduced, adjacent propulsion devices can be arranged close to each other.

[0030] In the above first to seventh configurations, Some or all of the plurality of propulsion devices may be arranged inside the waterline, which is the line where the water surface contacts the hull, in a plan view (eighth configuration).

[0031] According to the above configuration, some or all of the plurality of propulsion devices are arranged inside the waterline in a plan view. Therefore, the portion protruding outside the hull in a plan view can be reduced, and the ship can be made compact.

[0032] In the above first to seventh configurations, Some or all of the plurality of propulsion devices are arranged outside the waterline, which is the line where the water surface contacts the hull, in a plan view, The Waterline propulsion device arranged outside may be supported by a support portion provided on the hull (ninth configuration).

[0033] According to the above configuration, some or all of the plurality of propulsion devices are arranged outside the waterline in a plan view. Since the resistance generating portion that generates the braking force is arranged outside the waterline of the hull, even if the resistance generating portion is enlarged, it can be prevented from interfering with the hull. Furthermore, the braking force generated by the resistance generating portion is likely to generate a turning moment on the hull, facilitating the attitude control of the hull. In addition, since it is supported by the support portion, it is easy to attach to the hull.

[0034] [Embodiment 1] Hereinafter, with reference to the drawings, a ship 100 according to Embodiment 1 of the present invention will be described in detail. The same or corresponding parts in the drawings are denoted by the same reference numerals and their descriptions will not be repeated. For the sake of clarity of explanation, in the drawings referred to below, the configuration is shown in a simplified or schematic manner, or some of the constituent members are omitted. Also, the dimensional ratios between the constituent members shown in each figure do not necessarily represent the actual dimensional ratios.

[0035] FIG. 1 is a perspective view of a ship 100 according to Embodiment 1 of the present invention. The ship 100 according to the present embodiment is used as a work ship that automatically transports feed W toward a fish cage 300 installed at sea (see FIG. 9). However, the use of the ship of the present invention is not limited to aquaculture. For example, it may be used as a research ship that performs operations such as underwater environmental surveys by automatic operation in the ocean or a lake.

[0036] The ship 100 has a plurality of operation modes for performing operations such as a fixed-point holding operation, a navigation operation, and a mooring operation. In the fixed-point holding mode, a fixed-point holding operation is executed to hold the position of the own ship at a fixed point. In the navigation mode, a navigation operation is executed to move the position of the own ship without performing the fixed-point holding operation. In the mooring mode, a mooring operation is executed, and while generating a braking force by the resistance generating unit 50 to facilitate holding the position and course of the ship 100, it approaches the mooring position MP. In the present embodiment, the mooring position MP is set at the fish cage 300 installed at sea (see FIG. 9).

[0037] When the ship 100 transports the feed W to the fish cage 300, it moves toward the target position (the mooring position MP set at the fish cage 300) in the navigation mode by automatic operation. After moving near the mooring position MP in the navigation mode, it is switched to the mooring mode, approaches the mooring position MP set at the fish cage 300 while performing a mooring operation by automatic operation, and stops when it reaches the mooring position MP.

[0038] [Ship] First, the overall configuration of the ship 100 will be described. FIG. 2 is a plan view showing an example of the state where the ship 100 is in the parallel arrangement PA. FIG. 3 is a side view of the ship 100. FIG. 4 is (a) a plan view of the propulsion device 30 and (b) a side view of the propulsion device 30. FIG. 5 is a plan view for explaining a changing operation of changing the leading edge direction DF of the propulsion device 30.

[0039] As shown in FIGS. 1 to 3, the ship 100 includes a hull 20, four propulsion devices 30 (a first propulsion device 301, a second propulsion device 302, a third propulsion device 303, and a fourth propulsion device 304), a direction changing unit 60, and a control unit 180. In the following description, when the first propulsion device 301, the second propulsion device 302, the third propulsion device 303, and the fourth propulsion device 304 are not distinguished and described, they may simply be referred to as the propulsion device 30.

[0040] The hull 20 is a part that serves as the base of the ship 100. The four propulsion devices 30 are each supported by the hull 20. The direction changing unit 60 changes the orientation of each propulsion device 30 with respect to the hull 20. The control unit 180 controls the automatic operation of the ship 100.

[0041] In the present embodiment, the orientation of each propulsion device 30 is not fixed, and it is possible to independently change the posture of each propulsion device 30 corresponding to the operation mode. Since the posture of each propulsion device 30 changes, the relationship between the front, rear, left, and right of the ship 100 and the front, rear, left, and right of each propulsion device 30 is not constant. Therefore, in order to distinguish the orientations of the ship 100 and each propulsion device 30, the following definitions are made.

[0042] The front part of the ship 100 coincides with the front part of the hull 20, and the front of the ship 100 is indicated by the arrow F. The rear part of the ship 100 coincides with the rear part of the hull 20, and the rear of the ship 100 is indicated by the arrow B. The left part of the ship 100 coincides with the left part of the hull 20, and the left of the ship 100 is indicated by the arrow L. The right part of the ship 100 coincides with the right part of the hull 20, and the right of the ship 100 is indicated by the arrow R. Also, the direction in which the front part of the ship 100 faces is defined as the ship's heading direction (heading) HD, and is indicated by the arrow HD. The ship's heading direction HD coincides with the front F of the ship 100. Also, the upper part of the ship 100 is indicated by the arrow U, and the lower part of the ship 100 is indicated by the arrow D.

[0043] The front with respect to the traveling direction of the ship 100 is indicated by the arrow TF, the rear with respect to the traveling direction of the ship 100 is indicated by the arrow TB, the right with respect to the traveling direction of the ship 100 is indicated by the arrow TR, and the left with respect to the traveling direction of the ship 100 is indicated by the arrow TL (see Fig. 7).

[0044] Depending on the operation mode, the ship 100 can move straight ahead and turn in the forward F, rear B, right R, left L, and diagonal directions of the ship 100. Therefore, the forward F, rear B, right R, left L of the ship 100 and the forward TF, rear TB, right TR, left TL in the traveling direction of the ship 100 do not necessarily coincide.

[0045] As shown in Fig. 4, each propulsion device 30 has a propulsion unit 40 and a resistance generating unit 50. The propulsion units 40 generate propulsion forces that propel the ship 100 respectively. The acting direction of the propulsion force by the propulsion unit 40 is defined as the propulsion force acting direction DS.

[0046] In the resistance generating portion 50 shown in Fig. 4a, a center line SCL and a central portion WB are shown. The center line SCL indicates the longitudinal direction among the directions in which the side surface 51 extends in the horizontal direction. The line indicating the central portion WB indicates the short-side direction among the directions in which the side surface 51 extends in the horizontal direction. The center line SCL is a straight line connecting the front edge 50F and the rear edge 50B of the resistance generating portion 50 in a plan view. The direction in which the center line SCL extends is the longitudinal direction of the resistance generating portion 50 in a plan view, which corresponds to the longitudinal direction of the resistance generating portion in the present invention. The direction in which the center line SCL of the resistance generating portion 50 is extended toward the front edge 50F side is defined as the front edge direction DF, and the direction in which the center line SCL is extended toward the rear edge 50B side is defined as the rear edge direction DB.

[0047] Subsequently, the configuration of each part of the ship 100 will be described in detail. As shown in Figs. 1 to 3, the hull 20 has a ship shape that floats on water by buoyancy. In the present embodiment, in order to be able to load the feed W on the hull 20 and transport it to the aquaculture net cage 300, a ship shape with a high loading capacity is preferable. The ship shape is not limited, but for example, a displacement ship shape or a semi-planing ship shape is preferable. The upper surface of the deck 21 is used as a loading portion for loading the feed W and the like. A storage space is formed below the deck 21. The control unit 180, a power supply device (not shown), and the like are stored in the storage space. A current position information acquisition unit 190 is provided at the rear part of the hull 20. The current position information acquisition unit 190 has a GNSS sensor 191 and a direction sensor 192 (see Fig. 8).

[0048] In Figs. 1 and 3, a waterline WL is shown on the side surface of the hull 20. As shown in Fig. 3, the length of the waterline WL in the front-rear direction is defined as the waterline length LWL of the hull 20. In Fig. 2, a center line (center line) CL connecting the bow 20F and the stern 20B of the hull 20 in a plan view is shown. The position of the waterline WL in a plan view is also shown. The central portion of the center line CL of the hull 20 in a plan view is defined as the hull center position CB. In the present embodiment, the four propulsion devices 30 are arranged outside the region surrounded by the waterline WL in a plan view (see Fig. 2).

[0049] The four propulsion devices 30 are each supported by the hull 20 via a support portion 31 and a direction-changing portion 60. The first propulsion device 301 and the second propulsion device 302 are arranged on the bow 20F side of the hull center position CB. The third propulsion device 303 and the fourth propulsion device 304 are arranged on the stern 20B side of the hull center position CB. Also, the first propulsion device 301 and the fourth propulsion device 304 are arranged on the left side of the hull 20 with respect to the fore-and-aft line CL. The second propulsion device 302 and the third propulsion device 303 are arranged on the right side of the hull 20 with respect to the fore-and-aft line CL. The propulsion portions 40 and the resistance generating portions 50 provided in the four propulsion devices 30 each have substantially the same shape.

[0050] As shown in FIG. 4, the propulsion portion 40 is a portion that generates a propulsion force for propelling the ship 100. The propulsion portion 40 of the present embodiment is a propeller provided on the trailing edge 50B side of the resistance generating portion 50. The propeller is driven by a drive source 32 and generates a propulsion force by rotating in water. The drive source 32 of the present embodiment is an electric motor, and the magnitude of the propulsion force of each propulsion portion 40 is changed by changing the rotation speed of each electric motor. By changing the rotation direction of each electric motor forward and backward, the propulsion force of each propulsion portion 40 can also be switched to the leading edge direction DF or the trailing edge direction DB. The electric power for driving the drive source 32 of each propulsion device 30 is supplied from a power supply device (not shown) mounted on the hull 20. The operation of the drive source 32 is controlled by a control unit 180. Note that the drive source 32 is not limited to an electric motor, and may be, for example, an internal combustion engine such as a gasoline engine. Also, the propulsion portion 40 is not limited to a propeller.

[0051] A support column 34 is attached to the lower part of the drive source 32. The support column 34 extends downward, and a lower case 35 is provided at the lower end. The support column 34 and the lower case 35 are arranged inside the resistance generating portion 50. Inside the support column 34, a drive shaft 36 is arranged, and inside the lower case 35, a propeller shaft 37 is arranged. The drive shaft 36 and the propeller shaft 37 are connected by gears or the like. A propulsion unit 40 is attached to the end of the propeller shaft 37. The driving force of the drive source 32 is transmitted to the propulsion unit 40 via the drive shaft 36 and the propeller shaft 37. In FIG. 4, gears, bearings, etc. arranged in the middle of the drive shaft 36 and the propeller shaft 37 are omitted.

[0052] The resistance generating portion 50 is a portion that generates water resistance by receiving the water flow accompanying the movement of the ship 100 on the side surface 51. As shown in FIG. 4a, the resistance generating portion 50 has an airfoil shape in the cross-sectional shape in the horizontal plane, and the length of the center line SCL (chord length) is longer than the wingspan. Specifically, the cross-sectional shape of the resistance generating portion 50 is symmetric with respect to the center line SCL. The wingspan is the widest at the central portion WB of the center line SCL, and gradually becomes narrower as it goes from the central portion WB toward the leading edge direction DF side and the trailing edge direction DB side. The resistance generating portion 50 is attached to the support column 34 such that the center line SCL (the longitudinal direction of the resistance generating portion) is parallel to the propulsion force acting direction DS of the propulsion unit 40. Note that the resistance generating portion 50 is not limited to being attached parallel to the propulsion force acting direction DS. For example, depending on the cross-sectional shape of the resistance generating portion 50, the center line SCL (the longitudinal direction of the resistance generating portion) and the propulsion force acting direction DS may not be parallel. Also, if necessary, the resistance generating portion 50 may be attached at an angle with respect to the propulsion force acting direction DS of the propulsion unit 40.

[0053] When the ratio of the wing width to the length of the center line SCL in the central part WB of the resistance generating part 50 is defined as WB / SCL, WB / SCL is not particularly limited, but is preferably 0.5 or less. In the present embodiment, WB / SCL is approximately 0.2. Note that the side surface 51 of the resistance generating part 50 does not have to be formed as a curved surface, and may be, for example, a flat surface.

[0054] Since the cross-sectional shape of the resistance generating part 50 is an elongated shape, when the moving direction of the ship 100 is parallel to the center line SCL of the resistance generating part 50, the water resistance generated by receiving the water flow accompanying the movement of the ship 100 on the side surface 51 is relatively small. When the moving direction of the ship 100 intersects the center line SCL of the resistance generating part 50, the water resistance generated by receiving the water flow accompanying the movement of the ship 100 on the side surface 51 becomes relatively large. In particular, when the moving direction of the ship 100 is orthogonal to the center line SCL of the resistance generating part 50, the water resistance becomes the largest. In the present invention, the direction of the propulsion device 30 is changed so that the moving direction of the ship 100 intersects the center line SCL of the resistance generating part 50, and the resistance generating part 50 generates water resistance, thereby generating a braking force with respect to the moving direction of the ship 100.

[0055] In order to be able to appropriately brake the movement of the ship 100 due to inertia when the hull 20 is loaded with the feed W and becomes heavy, or the movement due to disturbances such as wind, the ratio of the side area of the resistance generating part 50 to the hull 20 is set large. In the present embodiment, the length of the center line SCL of the resistance generating part 50 (the length in the longitudinal direction of the resistance generating part) is set according to the ratio to the waterline length LWL which is the length in the fore-and-aft direction of the waterline WL of the hull 20. Specifically, the length of the center line SCL is preferably set to 5% or more and 20% or less of the waterline length LWL of the hull 20, and more preferably set to 8% or more and 15% or less.

[0056] In this case, even when the hull 20 is moving at a very low speed, it is possible to generate sufficient braking force while preventing interference with the resistance generating portion 50 of the adjacent propulsion device 30. Further, by being able to shorten the vertical length HL of the resistance generating portion 50 while securing the size of the resistance generating portion 50, the draft of the ship 100 can be made shallow, and it is possible to easily avoid interference with obstacles and the like.

[0057] On the other hand, when the length of the center line SCL is less than 5% of the waterline length LWL of the hull 20, the ratio of the side area of the resistance generating portion 50 with respect to the hull 20 becomes small, and the braking force tends to be insufficient. Further, when the length of the center line SCL is more than 20% of the waterline length LWL of the hull 20, the movable area of the resistance generating portion 50 becomes wide when changing the direction of the resistance generating portion 50, and it becomes easy to interfere with the hull 20 and the like.

[0058] In the present embodiment, the length of the center line SCL is set to about 10% of the waterline length LWL of the hull 20. For example, when the waterline length LWL of the hull 20 is about 15 m, the length of the center line SCL of the resistance generating portion 50 is set to about 1.5 m.

[0059] Further, the vertical length HL of the resistance generating portion 50 is set from both aspects of ensuring the side area of the resistance generating portion 50 necessary for appropriately generating the braking force and the relationship with the draft depth of the hull 20 (the depth from the waterline WL to the bottom of the ship). As the relationship with the draft depth of the hull 20, it is preferable that the lower end portion of the resistance generating portion 50 is located above or at the same depth as the bottom of the hull 20, and even if it is located below the bottom of the hull 20, it is preferably as close as possible to the depth of the bottom of the hull 20. In the present embodiment, the vertical length HL of the resistance generating portion 50 is set by the ratio with the length of the center line SCL of the resistance generating portion 50 (the length in the longitudinal direction of the resistance generating portion). Specifically, it is preferable that the ratio of the length of the center line SCL of the resistance generating portion 50 to the vertical length HL is set to be from 1:0.5 to 1:2.0.

[0060] In this case, the area of the resistance generating portion 50 can be increased, and it is possible to generate sufficient braking force even when the hull 20 is moving at a very low speed, while preventing interference with the resistance generating portion 50 of the adjacent propulsion device 30. Further, by being able to shorten the vertical length HL of the resistance generating portion 50 while ensuring the size of the resistance generating portion 50, the draft of the ship 100 can be made shallow, and it is easier to avoid interference with obstacles and the like.

[0061] On the other hand, when the vertical length HL is shorter than 1:0.5, the ratio of the side area of the resistance generating portion 50 to the hull 20 becomes small, and the braking force is likely to be insufficient. Further, when the vertical length HL is longer than 1:2.0, the lower end portion of the resistance generating portion 50 is likely to be below the bottom of the hull 20, the draft depth of the ship 100 becomes deep, and it becomes easy to interfere with underwater obstacles and the like.

[0062] In the present embodiment, the ratio of the length of the center line SCL to the vertical length HL is set to 1:1. For example, when the length of the center line SCL of the resistance generating portion 50 is about 1.5 m, the vertical length HL of the resistance generating portion 50 is set to about 1.5 m.

[0063] The direction changing portion 60 is configured to be able to change the leading edge direction DF of the propulsion device 30 with respect to the ship's bow direction HD. Specifically, the direction changing portion 60 is configured to integrally change the orientation of the propulsion device 30 (the drive source 32, the strut 34, the lower case 35, the propulsion portion 40, and the resistance generating portion 50) with respect to the hull 20 and the support portion 31.

[0064] Here, as shown in FIG. 4b, when changing the direction of the propulsion device 30, the virtual rotation center axis CR overlaps with the center position of the support column 34. Further, this rotation center axis CR is set to pass through the area center 51C of the side surface 51 when the resistance generating portion 50 is viewed from the side. For this reason, the moment around the rotation center axis CR due to the water resistance generated by the resistance generating portion 50 is canceled out, and the load when changing the direction by the direction changing portion 60 can be reduced. Further, the movable area of the resistance generating portion 50 around the rotation center axis CR can be made small, and it is possible to make it difficult to interfere with other propulsion devices 30 and the hull 20.

[0065] The direction changing portion 60 can change the leading edge direction DF of the propulsion device 30 horizontally in all directions (360 degrees) (see FIG. 5). The distance between each propulsion device 30 and the hull 20 is set so that each propulsion device 30 does not interfere with the hull 20 when the leading edge direction DF of each propulsion device 30 is changed.

[0066] The direction changing portion 60 includes a motor such as a servo motor or a stepping motor, for example, and can control the rotation angle around the rotation center axis CR of the propulsion device 30 with respect to the hull 20 via a gear or the like. By controlling the rotation angle of the rotation axis of the motor, the attitude (direction of the leading edge direction DF) of the propulsion device 30 can be controlled. The operation of the direction changing portion 60 is controlled by the control portion 180. The electric power for driving the motor of each direction changing portion 60 is supplied from a power supply device (not shown) mounted on the hull 20. Note that the direction changing portion 60 is not limited to a configuration that changes the propulsion device 30 in all directions (360 degrees). As long as it is possible to perform necessary operation modes (such as a fixed point holding mode, a navigation mode, and a mooring mode), the angle range that can be changed may be less than 360 degrees (for example, 270 degrees).

[0067] The control portion 180 constitutes a ship control system 200 that controls the automatic operation of the ship 100 (see FIG. 8). The control portion 180 controls the operations of the propulsion device 30 and the direction changing portion 60 in order to control the automatic operation of the ship 100. The specific configuration of the control portion 180 will be described later.

[0068] FIG. 5 is a plan view for explaining the changing operation of the leading edge direction DF of the first propulsion device 301. The changing operation of the leading edge direction DF will be described by taking the first propulsion device 301 as an example.

[0069] In FIG. 5, a state where the first propulsion device 301 changes from the attitude 301PA to the attitude 301NPA is shown. The attitude 301PA is the attitude of the first propulsion device 301 in the parallel arrangement PA shown in FIG. 2. The attitude 301NPA is the attitude of the first propulsion device 301 in the non-parallel arrangement NPA shown in FIG. 6. In the attitude 301PA which is the state before the change, the leading edge direction DF is parallel to the ship's bow direction HD. In the change from the attitude 301PA to the attitude 301NPA, the leading edge direction DF is changed clockwise by an angle θ1 = 135 degrees around the direction changing portion 60 (rotation center axis CR).

[0070] This change of the leading edge direction DF is executed by controlling the direction changing portion 60 provided in the first propulsion device 301 with the control unit 180. Similar to the first propulsion device 301, for the second propulsion device 302, the third propulsion device 303, and the fourth propulsion device 304, the change of the leading edge direction DF is also executed by controlling the direction changing portion 60 provided in each propulsion device 30 with the control unit 180. Note that the operation of the direction changing portion 60 is not limited to the operation shown in FIG. 5. The changing angle θ1 of the leading edge direction DF can be set to an arbitrary angle.

[0071] Next, the arrangements and operations that each propulsion device 30 can take in each operation mode will be described. FIG. 2 is a plan view showing an example of a state where the ship 100 is in the parallel arrangement PA in the navigation mode. FIG. 6 is a plan view showing an example of a state where the ship 100 is in the non-parallel arrangement NPA in the fixed-point holding mode. FIG. 7 is a plan view showing an example of a state where the ship 100 is in the mooring arrangement PB for performing a mooring operation in the mooring mode.

[0072] As shown in FIG. 2, the parallel arrangement PA is a state in which the leading edge directions DF of the respective propulsion devices 30 are arranged to be parallel to each other. The parallel arrangement PA is mainly the attitude when the ship 100 performs a navigation operation in the navigation mode. In the state of the parallel arrangement PA in FIG. 2, when the ship 100 moves in the ship's bow direction HD, each propulsion device 30 will move in the leading edge direction DF. In this case, the resistance received by the resistance generating portion 50 of each propulsion device 30 is smaller than that in the non-parallel arrangement NPA (see FIG. 6). By controlling the distribution of the propulsion force of each propulsion device 30 in this state, a propulsion force in the forward F and rearward B directions of the ship 100 and a steering force (turning moment) in the rightward R and leftward L directions are generated. Therefore, the ship 100 can move in the forward F and rearward B directions and turn to the right R and leftward.

[0073] As shown in FIG. 6, the non-parallel arrangement NPA is a state in which the leading edge direction DF of each propulsion device 30 is non-parallel to the other leading edge directions DF. In FIG. 6, the resistance generating portion 50 of each propulsion device 30 is arranged such that the center line SCL is substantially X-shaped in plan view. The leading edge direction DF of each propulsion device 30 faces the vicinity of the hull center position CB, and the trailing edge direction DB of each propulsion device 30 faces radially outward with respect to the hull center position CB.

[0074] The non-parallel arrangement NPA is mainly the attitude when the ship 100 performs a fixed-point holding operation in the fixed-point holding mode. In the state of the non-parallel arrangement NPA, no matter in which direction the ship 100 moves, the resistance generated by the resistance generating portion 50 becomes large, and a braking effect is produced that makes it difficult to move from the fixed point even in the presence of wind disturbances. By controlling the distribution of the propulsion force by each propulsion device 30 in this state, the moving direction of the ship 100 can be freely controlled omnidirectionally (360 degrees) in the horizontal direction including the forward F, rearward B, rightward R, leftward L, and diagonal directions of the ship 100.

[0075] FIG. 7 shows an example of a state in which the ship 100 has become a mooring arrangement PB for performing a mooring operation in the mooring mode. The mooring arrangement PB is an arrangement for generating a braking force by the water resistance generated by the resistance generating unit 50 when performing a mooring operation in the mooring mode, so that even when there are disturbances such as wind or large inertia, the movement of the ship 100 can be appropriately braked. FIG. 7 shows a state in which there is a mooring position MP in the traveling direction of the ship 100 (the direction indicated by the arrow TF) (see FIG. 10). By the mooring operation, the position of the ship 100 is moved so as to approach the mooring position MP set in the aquaculture net 300.

[0076] In the mooring arrangement PB, some of the plurality of propulsion devices 30 are operated as braking propulsion devices 30X. It is preferable to select the propulsion devices 30 arranged on the bow 20F side and the stern 20B side of the hull 20 as the propulsion devices 30 to be operated as the braking propulsion devices 30X. In this case, the braking force by the resistance generating unit 50 can be generated well-balanced on the bow 20F side and the stern 20B side of the hull 20 to suppress the rotation of the hull 20, and the movement of the ship 100 can be braked while maintaining the attitude of the hull 20. In FIG. 7, two of the propulsion devices 30 on the bow 20F side and the stern 20B side of the hull 20, that is, the first propulsion device 301 and the fourth propulsion device 304 closer to the mooring position MP, are set as the braking propulsion devices 30X.

[0077] The mooring operation includes movement in a direction intersecting the leading edge direction DF of the braking propulsion device 30X. For example, in FIG. 7, when the ship 100 moves in the direction of arrow TF, the ship 100 moves in a direction orthogonal to the leading edge direction DF of the braking propulsion device 30X (the first propulsion device 301 and the fourth propulsion device 304). When the ship 100 moves in a direction intersecting the leading edge direction DF of the braking propulsion device 30X, the water resistance generated by the resistance generating portion 50 increases, and when decelerating or stopping the ship 100, or when it is easy to obtain braking force against the wind and current. Therefore, even when there are large disturbances such as wind or inertia, the movement of the ship 100 can be appropriately braked and safely and accurately approached to the mooring position MP. As shown in FIG. 7, when the ship 100 moves in a direction orthogonal to the leading edge direction DF of the braking propulsion device 30X (the first propulsion device 301 and the fourth propulsion device 304), the braking force by the braking propulsion device 30X becomes the largest.

[0078] In the mooring arrangement PB, when there are a plurality of braking propulsion devices 30X, it is preferable that the respective leading edge directions DF are arranged parallel to each other. In FIG. 7, the first propulsion device 301 and the fourth propulsion device 304 are arranged such that their respective leading edge directions DF are parallel to each other. In particular, in FIG. 7, the respective leading edge directions DF are arranged parallel to the bow-stern line CL of the hull 20. By making the postures of the plurality of braking propulsion devices 30X like this, when the ship 100 moves in a direction intersecting the leading edge direction DF of the braking propulsion device 30X, the water resistance by the braking propulsion device 30X can be increased, and the braking force can be easily obtained.

[0079] When the propulsion device 30 other than the braking propulsion device 30X is set as the non-mooring propulsion device 30NX, in Fig. 7, two units, i.e., the second propulsion device 302 and the third propulsion device 303, are set as the non-mooring propulsion device 30NX. And it is preferable that the mooring operation is executed in a state where the leading edge direction DF of the braking propulsion device 30X and the leading edge direction DF of the non-mooring propulsion device 30NX intersect with each other. In this case, due to the water resistance by the braking propulsion device 30X and the non-mooring propulsion device 30NX, the braking force in the longitudinal direction and the lateral direction of the ship 100 can be easily obtained. In Fig. 7, the leading edge direction DF of the braking propulsion device 30X and the leading edge direction DF of the non-mooring propulsion device 30NX are arranged so as to intersect with each other. Thereby, the braking force in the longitudinal direction (arrows TF, TB) and the lateral direction (arrows TR, TL) in the traveling direction of the ship 100 can be easily obtained.

[0080] Also, as shown in Fig. 7, when the leading edge direction DF of the braking propulsion device 30X and the leading edge direction DF of the non-mooring propulsion device 30NX are arranged so as to intersect with each other, the movement and course change during the mooring operation become easy. When the ship 100 moves in the direction indicated by the arrow TF (arrow TB), the hull 20 can be moved by being pushed (pulled) by the propulsion force of the non-mooring propulsion device 30NX (the second propulsion device 302 and the third propulsion device 303). By changing the balance of the propulsion force of the non-mooring propulsion device 30NX (the second propulsion device 302 and the third propulsion device 303), a steering force (turning moment) for changing the traveling direction of the ship 100 can also be generated. Further, when the ship 100 moves in the direction indicated by the arrow TR (arrow TL), it can be moved while applying the propulsion force of the braking propulsion device 30X (the first propulsion device 301 and the fourth propulsion device 304).

[0081] Note that the mooring arrangement PB is not limited to the arrangement in Fig. 7. For example, the braking propulsion device 30X is not limited to the first propulsion device 301 and the fourth propulsion device 304, and any propulsion device 30 may be set as the braking propulsion device 30X. Also, the braking propulsion device 30X is not limited to two units, and may be one unit. Further, depending on the number and arrangement of the hulls, the number of the braking propulsion devices 30X may be arbitrarily set.

[0082] FIG. 8 is a schematic diagram showing the configuration of the ship control system 200. The ship control system 200 is a system that controls the automatic operation of the ship 100. In FIG. 8, among the ship control system 200, the configuration mainly for controlling the movement of the ship 100 is shown. The ship control system 200 includes a control unit 180, a current position information acquisition unit 190, a propulsion device 30 (drive source 31), and a direction change unit 60.

[0083] The current position information acquisition unit 190 has a GNSS sensor 191 and a direction sensor 192. The GNSS sensor 191 receives GNSS signals from GNSS (Global Navigation Satellite System) satellites. The GNSS signals received by the GNSS sensor 191 are input to the control unit 180. The direction sensor 192 detects the direction of the ship's bow direction HD of the ship 100. The detection signal from the direction sensor 192 is input to the control unit 180. Note that the current position information acquisition unit 190 may have other sensors, such as a wind direction / wind speed sensor, a tidal current sensor, etc.

[0084] The propulsion device 30 (drive source 31) and the direction change unit 60 are connected to the control unit 180. The control unit 180 controls the automatic operation of the ship 100 by controlling the propulsion device 30 (drive source 31) and the direction change unit 60.

[0085] The control unit 180 includes a memory 181, a current position information calculation unit 182, a first operation mode determination unit 183, a second operation mode determination unit 184, a hull direction control unit 185, and a propulsion device control unit 187.

[0086] The memory 181 stores data related to the automatic operation of the ship 100. In the memory 181, route data DE1, first operation mode determination reference data DE2, second operation mode determination reference data DE3, hull direction control data DE4, and propulsion force distribution data DE5 are stored.

[0087] The route data DE1 records position data regarding the positions (mooring positions) MP1 to MPN of a plurality of aquaculture cages 300, which are the destinations of the feed W, and data regarding the route for navigating to the plurality of mooring positions MP1 to MPN in a predetermined order.

[0088] The first operation mode determination reference data DE2 records the determination criteria for determining whether the operation mode is the navigation mode or the fixed-point holding mode.

[0089] The second operation mode determination reference data DE3 records the determination criteria for determining whether the operation mode is the navigation mode or the mooring mode. In the present embodiment, the second operation mode determination reference data DE3 records that when the distance from the current position to the mooring position MP is equal to or greater than a predetermined reference distance, the operation mode is the navigation mode, and when the distance from the current position to the mooring position is less than the predetermined reference distance, the operation mode is the mooring mode. Further, when the ship 100 performs a mooring operation in the mooring mode and reaches the mooring position MP, that is, when the distance from the current position to the mooring position becomes 0, the determination criteria for stopping at that position in the mooring mode are also recorded.

[0090] The hull direction control data DE4 records data regarding the operation of the direction changing unit 60. Specifically, settings for taking the posture of each propulsion device 30 suitable for each operation mode (navigation mode, fixed-point holding mode, mooring mode) and data regarding the operation of the direction changing unit 60 for changing the leading edge direction DF of each propulsion device 30 are recorded.

[0091] In the present embodiment, in the navigation mode, each propulsion device 30 is set to take a parallel arrangement PA (see FIG. 2). Then, in order for each propulsion device 30 to take the parallel arrangement PA, the operation data of the direction changing unit 60 is set such that the angle formed by each leading edge direction DF and the ship's bow direction HD of the ship 100 is 0 degrees for each propulsion device 30.

[0092] In the fixed-point holding mode, each propulsion device 30 is set to be in the non-parallel arrangement NPA (see FIG. 6). Then, in order for each propulsion device 30 to be in the non-parallel arrangement NPA, the operation data of the direction changing unit 60 is set so that the angle formed by the leading edge direction DF of each propulsion device 30 and the ship's bow direction HD of the ship 100 becomes a predetermined angle for each propulsion device 30.

[0093] In the mooring mode, each propulsion device 30 is set to be in the mooring arrangement PB (see FIG. 7). Then, in order for each propulsion device 30 to be in the mooring arrangement PB, the operation data of the direction changing unit 60 is set so that the angle formed by the leading edge direction DF of each propulsion device 30 and the ship's bow direction HD of the ship 100 becomes a predetermined angle for each propulsion device 30.

[0094] The propulsion force distribution data DE5 records data regarding the distribution of the propulsion force of the propulsion device 30 in each operation mode (navigation mode, fixed-point holding mode, mooring mode).

[0095] In the present embodiment, in the navigation mode, since the ship 100 takes the parallel arrangement PA, data regarding the distribution of the propulsion force to be output to each propulsion device 30 is recorded according to the relationship between the azimuth of the ship's bow direction HD of the ship 100 in the parallel arrangement PA and the azimuth from the current position to the mooring position MP. By controlling the distribution of the propulsion force of each propulsion device 30, the operation data of the propulsion device 30 is set so as to generate the propulsion force in the forward F and backward B directions of the ship 100 and the steering force (turning moment) in the right R and left L directions of the ship 100.

[0096] In the fixed-point holding mode, since the ship 100 assumes a non-parallel arrangement NPA, data regarding the distribution of the propulsion force to be output to each propulsion device 30 is recorded according to the relationship between the azimuth of the ship's bow direction HD of the ship 100 in the non-parallel arrangement NPA and the azimuth from the current position to the target position. By controlling the distribution of the propulsion force of each propulsion device 30, the operation data of the propulsion device 30 is set so that the moving direction of the ship 100 can be freely controlled omnidirectionally (360 degrees) in the horizontal direction including the forward F, backward B, left L, right R, and diagonal directions.

[0097] In the mooring mode, since the ship 100 assumes a mooring arrangement PB, data regarding the distribution of the propulsion force to be output to each propulsion device 30 is recorded according to the relationship between the azimuth of the ship's bow direction HD of the ship 100 in the mooring arrangement PB and the azimuth from the current position to the mooring position MP. By controlling the distribution of the propulsion force of each propulsion device 30, the operation data of the propulsion device 30 is set so as to generate the propulsion force in the forward TF and backward TB directions in the traveling direction of the ship 100 and the steering force (turning moment) in the right TR and left TL directions.

[0098] The current position information calculation unit 182 calculates the position information at the current position and information regarding the moving speed and the like based on the detection signal from the current position information acquisition unit 190. Specifically, the current position information calculation unit 182 calculates the coordinates of the current position of the ship 100 (current position GNSS coordinates) based on the GNSS signal from the GNSS sensor 191, and calculates the azimuth of the ship's bow direction HD of the ship 100 based on the detection signal from the azimuth sensor 192. Further, the current position information calculation unit 182 refers to the mooring position MP and the data regarding the route recorded in the route data DE1 stored in the memory 181, and calculates the distance to the mooring position MP and the azimuth of the mooring position MP with respect to the ship's bow direction HD of the ship 100.

[0099] The first operation mode determination unit 183 determines the operation mode (navigation mode or fixed-point holding mode) by referring to the first operation mode determination reference data DE2 stored in the memory 181.

[0100] The second operation mode determination unit 184 refers to the second operation mode determination reference data DE3 stored in the memory 181, and determines an operation mode (navigation mode or fixed-point holding mode) suitable for the movement to the mooring position MP.

[0101] Specifically, when the distance from the current position to the mooring position MP is equal to or greater than a predetermined reference distance, the operation mode is set to the navigation mode. When the distance from the current position to the mooring position MP is less than the predetermined reference distance, it is determined that the operation mode is set to the mooring mode. Further, when the ship 100 performs a mooring operation in the mooring mode and reaches the mooring position MP, that is, when the distance from the current position to the mooring position MP becomes 0, it is determined to stop at that position while remaining in the mooring mode.

[0102] The hull direction control unit 185 refers to the hull direction control data DE4 stored in the memory 181, and controls the operation of the direction change unit 60 provided in each propulsion device 30 in correspondence with each operation mode (navigation mode, fixed-point holding mode, mooring mode) determined by the first operation mode determination unit 183 and the second operation mode determination unit 184.

[0103] The propulsion device control unit 187 refers to the propulsion force distribution data DE5 stored in the memory 181, and controls the operation of each propulsion device 30 (drive source 32) in correspondence with each operation mode (navigation mode, fixed-point holding mode, mooring mode) determined by the first operation mode determination unit 183 and the second operation mode determination unit 184.

[0104] [Operation] Next, the operation of the ship 100 will be described. FIG. 9 is a perspective view showing the aquaculture net cage 300 in which the mooring position MP is set and the ship 100 that has reached the mooring position MP.

[0105] As shown in Fig. 9, the aquaculture cage 300 is a facility installed on the sea or the like for culturing fishery products or temporarily breeding the caught fishery products. The aquaculture cage 300 includes a floating body 310, a net body 320, and an automatic feeder 330. The floating body 310 has buoyancy to float on water and is provided for installing the aquaculture cage 300 near the water surface. A plurality of floating bodies 310 are connected by ropes or the like and arranged to surround a predetermined area. For example, in the present embodiment, a plurality of floating bodies 310 are arranged to surround a substantially square area of about 20 m in length and width. The net body 320 is connected to the plurality of floating bodies 310 and installed in water, and the fishery products are enclosed inside by the side surface 325 and the bottom surface (not shown). The automatic feeder 330 is a device that automatically feeds the fishery products bred in the aquaculture cage 300. The automatic feeder 330 is installed on the water surface in the aquaculture cage 300 by a floating body 335. The aquaculture cage 300 is installed at a predetermined position above the water surface by an anchor or the like fixed to the seabed.

[0106] The replenishment of the feed W to the automatic feeder 330 is performed using the ship 100 of the present embodiment. The ship 100 loaded with the feed W approaches the mooring position MP set for the aquaculture cage 300 in automatic operation and is moored to the aquaculture cage 300 when it reaches the mooring position MP. For example, a conveyor 340 is used to convey the feed W from the ship 100 to the automatic feeder 330.

[0107] In the case of an aquaculture cage not provided with the automatic feeder 330, the feeding of the fishery products may be directly performed from the ship 100. In this case, the ship 100 is provided with a feeding device (not shown) for feeding the feed W loaded on the hull 20 to the aquaculture cage. The ship 100 loaded with the feed W and the feeding device approaches the mooring position MP set at a predetermined position of the aquaculture cage in automatic operation and is moored to the aquaculture cage 300 when it reaches the mooring position MP. In that state, the feed W is directly fed from the ship 100 by the feeding device.

[0108] In addition, in this embodiment, since the ship 100 is used as a workboat that automatically transports the feed W toward the aquaculture net cage 300, a mooring position MP is set for the aquaculture net cage 300. However, the mooring position MP is not limited to being set for the aquaculture net cage 300. In addition to the facilities installed on the water surface, the mooring position MP may be set at a harbor, a pier, or the like. Further, when the ship according to the present invention is used for other purposes such as underwater environment surveys, the mooring position MP can be appropriately set at a position where the ship needs to approach and be moored. In addition, the mooring to the mooring position MP includes not only mooring with a mooring rope or the like and mooring with an automatic mooring device, but also a state in which the ship 100 substantially stops near the mooring position MP without physically fixing the ship 100.

[0109] FIG. 10 is a plan view showing an example of the operation of the ship 100 in which the operation mode is switched from the navigation mode to the mooring mode, and the mooring operation is performed so as to approach the aquaculture net cage 300 in the mooring mode. FIG. 11 is a plan view showing the ship 100 that has reached the mooring position MP. As shown in FIGS. 10 and 11, when the ship 100 approaches the aquaculture net cage 300 by automatic operation for replenishment of the feed W, first, the ship 100 moves near the aquaculture net cage 300 (mooring position MP) in the navigation mode. When the distance from the ship 100 to the mooring position MP becomes less than a predetermined reference distance, the operation mode is switched from the navigation mode to the mooring mode, and is switched from the parallel arrangement PA in the navigation mode to the mooring arrangement PB for performing the mooring operation in the mooring mode. Then, the ship 100 moves to the mooring position MP in the mooring mode. Hereinafter, the operation of the ship 100 after the operation mode of the ship 100 is switched from the navigation mode to the mooring mode will be described.

[0110] FIG. 10 shows a case where the ship 100 approaches the mooring position MP in a posture where the ship 100 is sideways to the aquaculture net cage 300 so as to easily supply the feed W from the ship 100 to the aquaculture net cage 300. As shown in FIG. 11, in a state where the ship 100 has reached the mooring position MP, the bow-stern line CL of the hull 20 is parallel to the first direction D1 in which the aquaculture net cage 300 extends.

[0111] In the mooring operation, the current position information calculation unit 182 calculates the position information (current position GNSS coordinates) at the current position based on the detection signal from the current position information acquisition unit 190. Further, the current position information calculation unit 182 refers to the mooring position MP and the data related to the route recorded in the route data DE1 stored in the memory 181, and calculates the distance to the mooring position MP and the azimuth of the mooring position MP with respect to the ship's bow direction HD of the ship 100.

[0112] The propulsion device control unit 187 controls the operation of each propulsion device 30 by referring to the propulsion force distribution data DE5. The propulsion device control unit 187 controls the balance of the propulsion forces of mainly the non-mooring propulsion devices 30NX (the second propulsion device 302 and the third propulsion device 303) so that the ship 100 moves in the azimuth of the mooring position MP. By each propulsion device 30 taking the mooring arrangement PB, the braking force with respect to the moving direction of the ship 100 can be easily obtained due to the water resistance of the resistance generating unit 50 of the braking propulsion devices 30X (the first propulsion device 301 and the fourth propulsion device 304). Therefore, even when there are disturbances such as wind acting on the ship 100, or when a large amount of feed W is loaded and the total weight is heavy, and the amount of movement due to inertia is large, the movement of the ship 100 can be appropriately braked and it can approach the mooring position MP safely and accurately.

[0113] Depending on the disturbances such as wind acting on the ship 100 and the azimuth of the mooring position MP with respect to the ship's bow direction HD of the ship 100, in order to generate a steering force (turning moment), not only the propulsion force by the non-mooring propulsion devices 30NX (the second propulsion device 302 and the third propulsion device 303), but also the propulsion force by the braking propulsion devices 30X (the first propulsion device 301 and the fourth propulsion device 304) may be used. Further, the direction changing unit 60 may be controlled to change the leading edge direction DF of the non-mooring propulsion devices 30NX (the second propulsion device 302 and the third propulsion device 303) to generate a steering force (turning moment) by the propulsion devices 30.

[0114] In this way, while appropriately braking the movement of the ship 100 by using the braking force of the braking propulsion devices 30X (the first propulsion device 301 and the fourth propulsion device 304), the ship 100 is made to reach the mooring position MP. The ship 100 that has reached the mooring position MP is moored to the aquaculture net 300 by an automatic mooring device (not shown) or the like.

[0115] According to the ship 100 of the present embodiment described above, even when the disturbance such as wind or inertia received by the ship 100 is large, the movement of the ship 100 can be appropriately braked, and it is possible to safely and accurately approach the mooring position MP.

[0116] [Embodiment 2] Next, the ship 100A according to Embodiment 2 of the present invention will be described. The ship 100A according to Embodiment 2 is different from the ship 100 of Embodiment 1 in that four propulsion devices 30A are arranged inside the area (see FIG. 12) surrounded by the waterline WL in plan view. The same reference numerals are given to the same components as in Embodiment 1, and detailed description thereof is omitted.

[0117] FIG. 12 is a plan view of the ship 100A according to Embodiment 2 of the present invention. FIG. 13 is a side view of the ship 100A according to Embodiment 2 of the present invention. In FIGS. 12 and 13, the position of the waterline WL where the hull 20A contacts the water surface is shown. In the present embodiment, the four propulsion devices 30A are arranged inside the area (see FIG. 12) surrounded by the waterline WL in plan view.

[0118] The four propulsion devices 30A are each supported on the deck 21A of the hull 20A via a direction changing part 60A. The first propulsion device 301A and the second propulsion device 302A are arranged on the bow 20AF side of the center position CB of the hull. The third propulsion device 303A and the fourth propulsion device 304A are arranged on the stern 20AB side of the center position CB of the hull. Also, the first propulsion device 301A and the fourth propulsion device 304A are arranged on the left side of the hull 20A with respect to the fore-and-aft line CL. The second propulsion device 302A and the third propulsion device 303A are arranged on the right side of the hull 20A with respect to the fore-and-aft line CL.

[0119] As shown in FIG. 13, a support column 34A is attached to the lower part of the drive source 32 of each propulsion device 30A. The support column 34A extends downward and penetrates the deck 21A and the bottom of the hull 20A. A bearing (not shown) is provided at the penetration part of the bottom of the hull to rotatably support the support column 34A and ensure watertightness.

[0120] The resistance generating part 50 is attached to the support column 34A such that the center line SCL (the longitudinal direction of the resistance generating part) is parallel to the propulsion force acting direction DS of the propulsion part 40. The resistance generating part 50 is arranged below the bottom of the hull so as not to interfere with the bottom of the hull when the direction of the propulsion device 30A is changed.

[0121] The direction changing part 60A can change the leading edge direction DF of the propulsion device 30A horizontally in all directions (360 degrees). The interval between the propulsion devices 30A is set so that the propulsion devices 30 do not interfere with each other when the leading edge direction DF of each propulsion device 30A is changed.

[0122] FIG. 14 shows an example of a state in which the ship 100A is in a mooring arrangement PB for performing a mooring operation in the mooring mode. The mooring position MP is assumed to be in the traveling direction of the ship 100A (the direction indicated by the arrow TF). In FIG. 14, among the propulsion devices 30A on the bow 20AF side and the stern 20AB side of the hull 20A, two units, the first propulsion device 301A and the fourth propulsion device 304A, closer to the mooring position MP, are set as braking propulsion devices 30X. Also, two units, the second propulsion device 302A and the third propulsion device 303A, are set as non-mooring propulsion devices 30NX. In FIG. 14, the leading edge direction DF of the braking propulsion device 30X and the leading edge direction DF of the non-mooring propulsion device 30NX are arranged to be orthogonal to each other. Thereby, braking forces in the front-rear direction (arrows TF, TB) and the left-right direction (arrows TR, TL) in the traveling direction of the ship 100 are easily obtained.

[0123] According to the ship 100A described above, each propulsion device 30A is arranged inside the waterline WL in plan view. For this reason, it is possible to reduce the portion protruding outside the hull 20A in plan view, and the ship 100A can be made compact.

[0124] [Modification Example] The ship according to the present invention is not limited to the above-described embodiment. For example, although the ship of this embodiment is assumed to perform automatic operation, it may be controlled from the outside by wireless communication or the like. Also, part or all of the operation may be by an operator's operation. For example, an operator on board the ship may perform some ship operations.

[0125] In this embodiment, the direction changing part 60 is provided in each propulsion device 30 so that the leading edge direction DF can be changed. However, the direction changing part 60 may be provided in some of the propulsion devices 30 of a plurality of hulls so that the leading edge direction DF can be changed. For example, among the four propulsion devices 30, the leading edge direction DF of two of them may be made changeable, and the leading edge direction DF of the remaining two may be fixed.

[0126] In this embodiment, the ship 100 has a configuration with four propulsion devices 30, but it may have a configuration with two, three, or five or more propulsion devices 30.

[0127] The propulsion device may arrange different types of propulsion parts. Also, the propulsion device may be configured by attaching a resistance generating part to a conventionally known outboard motor.

[0128] In this embodiment, a ship used as a working ship for aquaculture fishing has been described, but the use of the ship, the size of the ship, etc. are not limited. Also, the shape of each part is not limited either.

[0129] Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiments, and it is possible to appropriately modify and implement the above-described embodiments without departing from the gist thereof.

Description of Symbols

[0130] 100 Ship 20 Hull 30 Propulsion device 40 Propulsion unit 50 Resistance generating part 60 Direction changing part SCL Center line (longitudinal direction of resistance generating part) DS Propulsion force acting direction MP Mooring position 30X Propulsion device for braking

Claims

1. A hull floating on the water surface, a plurality of propulsion devices supported by the hull, a plurality of direction changing parts capable of changing the direction of the propulsion devices, comprising: each of the propulsion devices has a propulsion part that generates propulsion force and a resistance generating part that generates water resistance by receiving the water flow accompanying movement on the side surface, the propulsion devices are respectively arranged on the bow side and the stern side of the center of the fore-and-aft line in the plan view of the hull, among the directions in which the side surface of the resistance generating part extends horizontally, taking the longitudinal direction as the longitudinal direction of the resistance generating part, the length of the resistance generating part in the longitudinal direction of the resistance generating part is set to be 5% or more and 20% or less of the waterline length, which is the length of the hull in the fore-and-aft direction at the draft line, the arrangement positions of the plurality of propulsion devices are set so as to prevent interference between the propulsion devices and the hull, and to prevent interference between the adjacent propulsion devices in the fore-and-aft direction and / or the left-right direction of the hull, when performing a mooring operation of moving the position of the own ship closer to the mooring position for mooring, approaching the position of the own ship to the mooring position by the propulsion force of the propulsion part, operating a part of the plurality of propulsion devices as braking propulsion devices, and making the direction of the braking propulsion devices such that the moving direction of the own ship and the longitudinal direction of the resistance generating part intersect, so as to generate a braking force with respect to the moving direction of the own ship by the water resistance generated by the resistance generating part, a ship.

2. The resistance generating part has the shape of a rudder that generates a steering force by changing its direction with respect to the hull, the ratio of the length of the resistance generating part in the longitudinal direction of the resistance generating part to the length in the vertical direction is set to be from 1:0.5 to 1:2.0, The ship according to Claim 1.

3. The resistance generating part has a side surface formed of a curved surface or a flat surface, when the side surface is a curved surface, the cross-sectional shape in the horizontal plane has the shape of an airfoil, the ratio of the width of the resistance generating part to the length of the center line of the resistance generating part, which is the ratio of the length of the center line extending in the longitudinal direction of the resistance generating part to the width at the center of the center line, is 0.5 or less, The ship according to Claim 2.

4. When moving the hull laterally by the mooring operation, operating at least one of the propulsion devices arranged on the bow side and the stern side of the hull as the braking propulsion device, The ship according to any one of Claims 1 to 3.

5. The plurality of propulsion devices are arranged on both the left and right sides with respect to the bow-stern line of the hull in plan view, and at least one is arranged on each of the bow side and the stern side of the hull. When moving the hull laterally by the mooring operation, the propulsion devices arranged on the bow side and the stern side of the hull and on the mooring position side with respect to the bow-stern line of the hull are operated as the braking propulsion devices. The ship according to any one of claims 1 to 4.

6. In the mooring operation, the direction of the braking propulsion device is set such that the longitudinal direction of the resistance generating portion is parallel to the bow-stern line of the hull in plan view. The ship according to claim 4 or claim 5.

7. The resistance generating portion can change its direction around the rotation axis by the direction changing portion, and in a side view orthogonal to the longitudinal direction of the resistance generating portion, the rotation axis is arranged so as to overlap with the area center of the side surface of the resistance generating portion. The ship according to any one of claims 1 to 6.

8. Some or all of the plurality of propulsion devices are arranged inside the waterline, which is the line where the water surface contacts the hull, in plan view. The ship according to any one of claims 1 to 7.

9. Some or all of the plurality of propulsion devices are arranged outside the waterline, which is the line where the water surface contacts the hull, in plan view. The propulsion devices arranged outside the waterline are supported by support portions provided on the hull. The ship according to any one of claims 1 to 7.

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