Ship and method of controlling ship system

Abstract

To smoothly turn a hull when a steering angle exceeds a reference angle range while forming a wave used for wakesurfing in the rear direction of the hull.SOLUTION: A vessel includes a hull, a first propulsion device that generates a propulsive force along a first axis and is configured such that the first axis is displaceable, a second propulsion device that generates a propulsive force along a second axis and is configured such that the second axis is displaceable, an operation device that instructs a movement direction of the hull, and a controller. The controller is configured or programmed to set the first propulsion apparatus and the second propulsion apparatus to a first axial attitude in which the first axis and the second axis intersect each other in a rearward direction of the hull when a command direction commanded by the operation device is within a reference angular range including a straight traveling direction of the hull, and set the first propulsion apparatus and the second propulsion apparatus to a second axial attitude in which parallelism between the first axis and the second axis is higher than that in the first axial attitude when the command direction exceeds the reference angular range.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a method for controlling a ship and a ship system. [Background technology]

[0002] In recent years, a watercraft used for wakesurfing has become known (see Patent Document 1 below). In wakesurfing, a surfer uses a wakeboard to follow behind the watercraft while riding the wake created by the watercraft.

[0003] This type of watercraft includes a hull, a first propulsion unit, a second propulsion unit, an operating device, and a controller (see Patent Documents 2 and 3 below). The first propulsion unit is attached to the port side of the rear of the hull and generates propulsive force along a first axis. The first propulsion unit is configured so that the first axis is displaceable. The second propulsion unit is attached to the starboard side of the rear of the hull and generates propulsive force along a second axis. The second propulsion unit is configured so that the second axis is displaceable. For example, when wakesurfing mode is set using the operating device, the controller sets the first propulsion unit and the second propulsion unit to a toe-in position in which the first axis and the second axis intersect each other toward the rear of the hull. The toe-in position generates waves that are favorable for wakesurfing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 10,167,057 [Patent Document 2] Japanese Patent Application Laid-Open No. 2024-94107 [Patent Document 3] Patent No. 6557754 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional boats, the first and second propulsion units maintain a fixed toe-in position regardless of changes in the direction of travel instructed by the operating device. This leaves room for improvement in terms of maintaining the boat's maneuverability while also creating waves that are conducive to wakesurfing.

[0006] This problem is not limited to propulsion devices, but is a common issue for ships equipped with guides for surf points, for example.

[0007] This specification discloses a technique that can solve at least part of the above-mentioned problems. [Means for solving the problem]

[0008] The vessel disclosed in this specification includes a hull, a first propulsion unit attached to the port side of the rear of the hull and generating propulsive force along a first axis, the first axis being displaceable, a second propulsion unit attached to the starboard side of the rear of the hull and generating propulsive force along a second axis, the second axis being displaceable, an operation device for indicating the direction of movement of the hull, and a controller. When the direction indicated by the operation device is within a reference angle range that includes the straight ahead direction of the hull, the controller sets the first propulsion unit and the second propulsion unit to a first axis attitude in which the first axis and the second axis intersect each other in the rear direction of the hull, and when the indicated direction exceeds the reference angle range, the controller sets the first propulsion unit and the second propulsion unit to a second axis attitude in which the first axis and the second axis are more parallel to each other than in the first axis attitude.

[0009] Another watercraft disclosed in this specification includes a hull, a first generator attached to the port side of the rear of the hull and generating a water flow along a first axis, the first axis being displaceable, a second generator attached to the starboard side of the rear of the hull and generating a water flow along a second axis, the second axis being displaceable, an operation device for indicating the direction of movement of the hull, and a controller. When the direction indicated by the operation device is within a reference angle range including the straight ahead direction of the hull, the controller sets the first generator and the second generator to a first axial attitude in which the first axis and the second axis intersect each other in the rear direction of the hull, and when the indicated direction exceeds the reference angle range, the controller sets the first generator and the second generator to a third axial attitude in which at least one of the degree of parallelism between the first axis and the second axis is higher and the force generating the water flow is weaker than in the first axial attitude.

[0010] The technology disclosed in this specification can be realized in various forms, such as a ship, a ship system, a control method for a ship system, a computer program for realizing the functions or methods of these devices, or a recording medium on which the computer program is recorded. [Effects of the Invention]

[0011] According to the watercraft disclosed in this specification, waves used for wakesurfing can be formed behind the hull, and the hull can be smoothly turned when the steering angle exceeds the reference angle range. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a side view showing a simplified configuration of a jet boat according to an embodiment. [Figure 2] A simplified top view of the jet boat configuration [Figure 3] Side cross section of a jet boat [Figure 4]A simplified bottom view of the jet boat configuration [Figure 5] FIG. 1 is an explanatory diagram illustrating a schematic configuration of the guide and its surroundings; [Figure 6] A simplified block diagram showing the electrical configuration of a jet boat [Figure 7] FIG. 1 is an explanatory diagram illustrating a first propulsion unit and a second propulsion unit in a toe-in position; [Figure 8] FIG. 10 is an explanatory diagram showing the state of the propulsion unit and the guide when the steering angle is in the straight-ahead position. [Figure 9] FIG. 10 is an explanatory diagram showing the state of the propulsion unit and the guide when the steering angle is between the straight ahead position and the right reference angle. [Figure 10] FIG. 10 is an explanatory diagram showing the state of the propulsion unit and the guide when the steering angle is between the straight ahead position and the left reference angle. [Figure 11] An explanatory diagram showing the state of the propulsion unit and guide when the steering angle exceeds the right-side reference angle. [Figure 12] An explanatory diagram showing the state of the propulsion unit and guide when the steering angle exceeds the left reference angle. [Figure 13] Flowchart showing the control process for the propulsion unit and the guide [Figure 14] Graph showing the relationship between steering angle and travel speed DETAILED DESCRIPTION OF THE INVENTION

[0013] A. Implementation: A-1. Jet Boat 10 Configuration: FIG. 1 is a side view showing a simplified configuration of a jet boat 10 according to this embodiment, and FIG. 2 is a top view showing a simplified configuration of the jet boat 10. Arrows representing each direction based on the position of the jet boat 10 are shown in FIGS. 1 and 2. More specifically, arrows representing the front, rear, left, right, upper, and lower directions are shown in each drawing. The front-to-rear direction, left-to-right direction, and up-and-down direction (vertical direction) are perpendicular to each other. The jet boat 10 is an example of a watercraft within the scope of the claims.

[0014] The jet boat 10 includes a hull 200, a first propulsion unit 100A, and a second propulsion unit 100B. In this embodiment, the jet boat 10 includes a pair of propulsion units 100A and 100B, but the jet boat 10 may include three or more propulsion units. The first propulsion unit 100A is an example of a first generator, and the second propulsion unit 100B is an example of a second generator.

[0015] The hull 200 has a deck 201 and a hull 202. The hull 202 is disposed below the deck 201. A helm station 220 is disposed on the deck 201. The first propulsion unit 100A and the second propulsion unit 100B are attached to the hull 200. The first propulsion unit 100A is attached to the port side of the rear of the hull 200. The second propulsion unit 100B is attached to the starboard side of the rear of the hull 200. The first propulsion unit 100A and the second propulsion unit 100B are jet propulsion units. The first propulsion unit 100A and the second propulsion unit 100B are disposed in positions symmetrical with respect to a central axis O that runs along the fore-and-aft direction and passes through the center of the hull 200 in the left-right direction. The central axis O is an example of a longitudinal central axis of the hull.

[0016] FIG. 3 is a side cross-sectional view of the jet boat 10. FIG. 3 shows a portion of the first propulsion unit 100A in cross section. As shown in FIG. 3, the first propulsion unit 100A is housed in the hull 200. The first propulsion unit 100A includes a first engine 104A, a first jet pump 105A, a first nozzle deflector 106A, and a first reverse gate 107A. The first engine 104A is connected to the first jet pump 105A. Driven by the first engine 104A, the first jet pump 105A sucks in and ejects water around the hull 200. As a result, the first jet pump 105A generates a propulsive force that moves the hull 200.

[0017] The first jet pump 105A includes a drive shaft 121, an impeller 122, and a pump housing 123. The drive shaft 121 is connected to an output shaft 125 of the first engine 104A via a coupling 124. The impeller 122 is connected to the drive shaft 121. The impeller 122 is disposed within the pump housing 123. The impeller 122 rotates together with the drive shaft 121 and draws water through a water suction port 126. The impeller 122 ejects the drawn water rearward from an ejection port of the pump housing 123.

[0018] The first nozzle deflector 106A is disposed behind the first jet pump 105A. The first nozzle deflector 106A is disposed so as to be swingable left and right and up and down. The first nozzle deflector 106A changes the direction of water jet from the first jet pump 105A left and right and up and down. The first reverse gate 107A is disposed behind the first nozzle deflector 106A. The first reverse gate 107A is disposed so as to be switchable between a forward position and a reverse position. By switching the first reverse gate 107A between the forward position and the reverse position, the direction of the jet from the first jet pump 105A is changed. This switches the jet boat 10 between forward and reverse.

[0019] The second propulsion device 100B has a configuration similar to that of the first propulsion device 100A. As shown in Fig. 2, the second propulsion device 100B includes a second engine 104B, a second jet pump 105B, a second nozzle deflector 106B, and a second reverse gate 107B. The second engine 104B, the second jet pump 105B, the second nozzle deflector 106B, and the second reverse gate 107B are similar to the first engine 104A, the first jet pump 105A, the first nozzle deflector 106A, and the first reverse gate 107A, and therefore detailed description thereof will be omitted.

[0020] FIG. 4 is a bottom view showing a simplified configuration of the jet boat. As shown in FIG. 4, the jet boat 10 further includes a first guide 300A and a second guide 300B. The first guide 300A and the second guide 300B are attached to the underside of the rear (transom step 216) of the hull 200. The first guide 300A and the second guide 300B are disposed on the outer side in the left-right direction of the first propulsion unit 100A and the second propulsion unit 100B, respectively. The first guide 300A is disposed to the left of the first propulsion unit 100A (first nozzle deflector 106A). The second guide 300B is disposed to the right of the second propulsion unit 100B (second nozzle deflector 106B). The first guide 300A and the second guide 300B are disposed in positions that are symmetrical with respect to the central axis O of the hull 200. The first guide 300A is an example of a first generator, and the second guide 300B is an example of a second generator.

[0021] The first guide 300A and the second guide 300B each extend rearward to approach the central axis O of the hull 200. The first guide 300A is a plate-shaped member that extends diagonally rearward to the right so as to approach the central axis O as it extends rearward. The second guide 300B is a plate-shaped member that extends diagonally rearward to the left so as to approach the central axis O as it extends rearward. The guide axis of the first guide 300A, which follows the water guiding direction, and the guide axis of the second guide 300B, which follows the water guiding direction, intersect on the central axis O in the rearward direction of the hull 200. Hereinafter, the position in which the guide axis of the first guide 300A and the guide axis of the second guide 300B intersect in the rearward direction of the hull 200 is referred to as the guide effective position. The guide effective position is an example of the first guide position and the first axis position. The guide shaft of the first guide 300A is an example of a first shaft, and the guide shaft of the second guide 300B is an example of a second shaft.

[0022] FIG. 5 is an explanatory diagram schematically illustrating the peripheral configuration of the first guide 300A. The first guide 300A is provided on the hull 200 so as to be displaceable between a stowed position and a deployed position. In the stowed position, the first guide 300A is housed within the hull 200. In the deployed position, the first guide 300A protrudes downward from the hull 200 (see FIG. 4). Specifically, the jet boat 10 includes a first guide actuator 310A and an arm 312. The first guide 300A is supported on the hull 200 so as to be displaceable about a rotation shaft 314. The first guide actuator 310A controls the arm 312 to displace the first guide 300A between the stowed position (position indicated by the dotted line in FIG. 5) and the deployed position (position indicated by the solid line in FIG. 5). Similarly, the second guide 300B is displaced between the stored position and the deployed position under the control of the second guide actuator 310B.

[0023] Figure 6 is a block diagram showing a simplified electrical configuration of the jet boat. As shown in Figure 6, the jet boat 10 includes a controller 400. The controller 400 includes a processor such as a CPU and memories such as RAM and ROM. The controller 400 is programmed to control the jet boat 10.

[0024] The jet boat 10 includes a first steering actuator 131A and a first shift actuator 132A. The controller 400 is communicatively connected to the first engine 104A, the first steering actuator 131A, and the first shift actuator 132A.

[0025] The first steering actuator 131A is connected to the first nozzle deflector 106A of the first propulsion unit 100A. The first steering actuator 131A changes the first jetting direction D1, which is the direction in which water is jetted from the first nozzle deflector 106A. FIG. 7 is a simplified explanatory diagram showing the first propulsion unit 100A and the second propulsion unit 100B in a toe-in attitude. As shown in FIG. 7, the first jetting direction D1 is a direction facing rearward along the axis M1 of the first nozzle deflector 106A. The first jetting direction D1 can be expressed by the nozzle angle α of the first nozzle deflector 106A. The nozzle angle α is the angle formed between the first jetting direction D1 and the direction directly rearward in the fore-and-aft direction M0. The nozzle angle α is the angle of the axis M1 of the first nozzle deflector 106A extending rearward from the first nozzle deflector 106A relative to the fore-and-aft direction M0 of the jet boat 10. The first steering actuator 131A changes the nozzle angle α of the first jet direction D1 in which the first propulsion unit 100A pushes out water. The first steering actuator 131A is, for example, an electric motor. The first steering actuator 131A may also be another actuator, such as a hydraulic cylinder. The axis M1 is an example of a first axis.

[0026] The first shift actuator 132A is connected to the first reverse gate 107A of the first propulsion unit 100A. The first shift actuator 132A switches the position of the first reverse gate 107A between a forward position and a reverse position. The first shift actuator 132A is, for example, an electric motor. The first shift actuator 132A may also be another actuator, such as a hydraulic cylinder.

[0027] The jet boat 10 includes a second steering actuator 131B and a second shift actuator 132B. The controller 400 is communicatively connected to the second engine 104B, the second steering actuator 131B, and the second shift actuator 132B. The second steering actuator 131B changes a second jetting direction D2, which is the direction in which water is jetted from the second nozzle deflector 106B. As shown in FIG. 7 , the second jetting direction D2 is a direction toward the rear along the axis M2 of the second nozzle deflector 106B. The second jetting direction D2 can be expressed by a nozzle angle β of the second nozzle deflector 106B. The nozzle angle β is the angle between the second jetting direction D2 and the direction directly rearward in the fore-and-aft direction M0. The nozzle angle β is the angle of the axis M2 of the second nozzle deflector 106B extending rearward from the second nozzle deflector 106B relative to the fore-and-aft direction M0 of the jet boat 10. The second steering actuator 131B changes the nozzle angle β of the second jet direction D2 in which the second propulsion unit 100B pushes out water. The second steering actuator 131B is, for example, an electric motor. The second steering actuator 131B may also be another actuator, such as a hydraulic cylinder. The axis M2 is an example of a second axis.

[0028] The second shift actuator 132B is connected to the second reverse gate 107B of the second propulsion unit 100B. The second shift actuator 132B switches the position of the second reverse gate 107B between a forward position and a reverse position. The second shift actuator 132B is, for example, an electric motor. The second shift actuator 132B may also be another actuator, such as a hydraulic cylinder.

[0029] The jet boat 10 includes a steering member 214 (steering member) and a remote controller 215 (throttle unit). The controller 400 is communicatively connected to the steering member 214 and the remote controller 215. The steering member 214 and the remote controller 215 are disposed in the operator's seat 220. The steering member 214 is an example of an operating device (steering device).

[0030] The steering member 214 is operated to steer the jet boat 10. That is, the controller 400 controls the bow direction of the jet boat 10 in response to the operation of the steering member 214. The steering member 214 is, for example, a steering wheel. The steering member 214 includes a sensor 140. The sensor 140 outputs a steering signal indicating the direction and amount of operation of the steering member 214.

[0031] The controller 400 receives a steering signal from the sensor 140. Based on the steering signal, the controller 400 controls the first steering actuator 131A to control the nozzle angle α (first jet direction D1) of the first propulsion unit 100A. Based on the steering signal, the controller 400 controls the second steering actuator 131B to control the nozzle angle β (second jet direction D2) of the second propulsion unit 100B. This changes the bow direction of the jet boat 10 to the left or right.

[0032] The remote controller 215 is a device for adjusting the magnitude of thrust of the first propulsion unit 100A and the second propulsion unit 100B. The remote controller 215 includes a first throttle member 215A and a second throttle member 215B. The first throttle member 215A is operated to adjust the output of the first engine 104A and to switch between forward and reverse travel. The second throttle member 215B is operated to adjust the output of the second engine 104B and to switch between forward and reverse travel. The first throttle member 215A includes a sensor 151 (opening sensor). The sensor 151 outputs a first throttle signal indicating the direction and amount of operation of the first throttle member 215A. The second throttle member 215B includes a sensor 152 (opening sensor). The sensor 152 outputs a second throttle signal indicating the direction and amount of operation of the second throttle member 215B. The first throttle member 215A and the second throttle member 215B each include a lever.

[0033] The controller 400 receives a first throttle signal and a second throttle signal. The controller 400 controls the rotational speed of the first engine 104A in accordance with the amount of operation of the first throttle member 215A indicated by the first throttle signal. The controller 400 controls the rotational speed of the second engine 104B in accordance with the amount of operation of the second throttle member 215B indicated by the second throttle signal. The controller 400 controls the first shift actuator 132A in accordance with the operation direction of the first throttle member 215A indicated by the first throttle signal. This switches the direction of the thrust of the first propulsion unit 100A between the forward direction and the reverse direction. The controller 400 controls the second shift actuator 132B in accordance with the operation direction of the second throttle member 215B indicated by the second throttle signal. As a result, the direction of the propulsive force of the second propulsion unit 100B is switched between the forward direction and the reverse direction.

[0034] 6, the jet boat 10 includes a first rotation speed sensor 133A and a second rotation speed sensor 133B. The controller 400 is communicatively connected to the first rotation speed sensor 133A and the second rotation speed sensor 133B.

[0035] The first rotation speed sensor 133A detects the rotation speed of the first engine 104A. The first rotation speed sensor 133A outputs a first rotation speed signal indicating the rotation speed of the first engine 104A to the controller 400. The second rotation speed sensor 133B detects the rotation speed of the second engine 104B. The second rotation speed sensor 133B outputs a second rotation speed signal indicating the rotation speed of the second engine 104B to the controller 400. The controller 400 detects the traveling speed of the jet boat 10 from the first rotation speed signal or the second rotation speed signal. Note that the controller 400 is not limited to determining the travel speed from the first rotation speed signal and the second rotation speed signal, but may determine the travel speed of the jet boat 10 based on the opening degree of the first throttle member 215A indicated by the first throttle signal from the sensor 151 and the opening degree of the second throttle member 215B indicated by the second throttle signal from the sensor 152. The controller 400 may also determine the travel speed of the jet boat 10 using, for example, a global positioning system (GPS). The rotation speed sensor 133A and the second rotation speed sensor 133B are examples of speed sensors.

[0036] The controller 400 is communicatively connected to the first guide actuator 310A and the second guide actuator 310B. The controller 400 controls the first guide actuator 310A and the second guide actuator 310B. The first guide actuator 310A and the second guide actuator 310B are, for example, electric motors, but may also be other actuators such as hydraulic cylinders.

[0037] A-2. Control process for propulsion and guide: 8 to 12 are explanatory diagrams showing the states of the propulsion unit and the guide. Each diagram also shows the state of the steering member 214 and a graph showing the relationship between the steering angle of the steering member 214 and the nozzle angle.

[0038] The horizontal axis of the graph represents the steering angle (Wheel angle) of the steering member 214. With respect to the origin, the negative side of the horizontal axis represents the steering angle toward the port side, and the positive side of the horizontal axis represents the steering angle toward the starboard side, with the origin representing the neutral position (straight ahead position). As the negative value increases, the steering member 214 is turned more to the left, and as the positive value increases, the steering member 214 is turned more to the right. The vertical axis of the graph represents the nozzle angle (Nozzle angle). The origin represents a state where the nozzle angle is zero, and the first jet direction D1 and the second jet direction D2 are aligned with the longitudinal direction M0. The positive side of the vertical axis represents the magnitude of the nozzle angle toward the starboard side, and the negative side of the vertical axis represents the magnitude of the nozzle angle toward the port side. As the positive value increases, the nozzle angle increases toward the port side, and as the negative value increases, the nozzle angle increases toward the starboard side. A first graph G1 shows the change in the nozzle angle α of the first nozzle deflector 106A relative to the steering angle, and a second graph G2 shows the change in the nozzle angle β of the second nozzle deflector 106B relative to the steering angle. The direction indicated by the steering angle of the steering member 214 is an example of a command direction.

[0039] FIG. 13 is a flowchart showing the control process for the propulsion unit and the guide, and FIG. 14 is a graph showing the relationship between the steering angle and the traveling speed. When the jet boat 10 is started, the controller 400 executes the control process shown in FIG. 13. The controller 400 determines whether the wake surfing mode is set (S110). The user can selectively set the normal mode or the wake surfing mode using an operation device (not shown) provided on the helm 220. The wake surfing mode is a mode for wake surfing, and the jet boat 10 generates a wake surfing wave W behind the hull 200 (see FIGS. 8 to 10). The normal mode is a mode for normal operation of the jet boat 10, and the jet boat 10 does not generate a wake surfing wave W (see FIGS. 11 and 12). The wake surfing mode is an example of a first mode, and the normal mode is an example of a second mode.

[0040] When the controller 400 determines that the wakesurfing mode is set (S110: YES), it determines whether the steering angle of the steering member 214 is within a reference angle range ER (S120). The reference angle range ER is narrower than the maximum possible range of steering angles of the steering member 214. The reference angle range ER ranges from the port upper limit angle to the starboard upper limit angle. The port upper limit angle is the angle of the neutral position (zero angle) + θ (for example, 50 degrees or less), and the starboard upper limit angle is the angle of the neutral position - θ.

[0041] If the controller 400 determines that the steering angle of the steering member 214 is within the reference angle range ER (S120: YES), it determines whether the travel speed (Boat speed) of the jet boat 10 is equal to or greater than a reference speed Va (see FIG. 14, e.g., 8 mph or less) (S130). If the controller 400 determines that the travel speed is equal to or greater than the reference speed Va (S130: YES), it executes toe-in attitude control (S140). Toe-in attitude control is control that places the first propulsion unit 100A and the second propulsion unit 100B in a toe-in attitude. The toe-in attitude is an attitude in which the axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B intersect in the rearward direction of the hull 200. When the first propulsion unit 100A and the second propulsion unit 100B are driven in a toe-in attitude, the propulsive force in the first jet direction D1 and the propulsive force in the second jet direction D2 intersect in the rear direction of the hull 200, generating a wakesurfing wave W. The toe-in attitude is an example of a first axial attitude.

[0042] In toe-in attitude control, the controller 400 also sets the first guide 300A and the second guide 300B to the deployed position to assume the guide active attitude. In the guide active attitude, the water flow along the guide axis of the first guide 300A and the water flow along the guide axis of the second guide 300B intersect in the rear direction of the hull 200, forming a wakesurfing wave W. At this time, the propulsion force of the first propulsion unit 100A and the second propulsion unit 100B, which are in the toe-in attitude, prevents water from splashing onto the wakesurfing wave W.

[0043] In the toe-in attitude control, the controller 400 maintains the toe-in attitude of the first propulsion unit 100A and the second propulsion unit 100B as long as the steering angle of the steering member 214 is within the reference angle range ER, and displaces the axis M1 (nozzle angle α) of the first nozzle deflector 106A and the axis M2 (nozzle angle β) of the second nozzle deflector 106B in accordance with changes in the steering angle of the steering member 214. Specifically, this is as follows.

[0044] In FIG. 8, the steering angle of the steering member 214 is in the neutral position. At this time, the first propulsion unit 100A and the second propulsion unit 100B are in a toe-in position, and the first guide 300A and the second guide 300B are in a guide-effective position. Hereinafter, the angle between the axis M1 and the axis M2 in the toe-in position will be referred to as the intersection angle γ. The intersection point P between the axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B is located on the central axis O of the hull 200. Therefore, the jet boat 10 travels straight and generates a wakesurfing wave W in the rearward direction. A user U can ride the wave W using a wakeboard S to perform wakesurfing.

[0045] In FIG. 9, the steering angle of the steering member 214 is shifted clockwise from the neutral position. In this case, the first propulsion unit 100A and the second propulsion unit 100B are in a toe-in position, and the first guide 300A and the second guide 300B are in a guide-effective position. The intersection angle γ in the toe-in position is the same angle (γα) as when traveling straight ( FIG. 8 ). The intersection point P between the axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B is located on the right side of the center axis O of the hull 200. Therefore, the jet boat 10 turns clockwise and generates a wakesurfing wave W in the rearward direction. The user U can perform wakesurfing.

[0046] In FIG. 10, the steering angle of the steering member 214 is offset from the neutral position in the counterclockwise direction. In this case, the first propulsion unit 100A and the second propulsion unit 100B are in a toe-in position, and the first guide 300A and the second guide 300B are in a guide-effective position. The intersection angle γ in the toe-in position is the same angle (γα) as when traveling straight ( FIG. 8 ). The intersection point P between the axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B is located on the left side of the center axis O of the hull 200. Therefore, the jet boat 10 turns left and generates a wakesurfing wave W in the rearward direction. The user U can perform wakesurfing.

[0047] When the controller 400 determines that the normal mode is set (S110: NO), it executes parallel attitude control (S150). That is, in normal mode, the controller 400 executes parallel attitude control regardless of whether the steering angle is within the reference angle range ER. Parallel attitude control is control for maintaining the first propulsion unit 100A and the second propulsion unit 100B in a parallel attitude. The parallel attitude is an attitude in which the axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B are substantially parallel to each other. When the first propulsion unit 100A and the second propulsion unit 100B are driven in the parallel attitude, the propulsive force in the first jet direction D1 and the propulsive force in the second jet direction D2 act in the same direction, propelling the jet boat 10. At this time, waves W for wakesurfing are not generated. The parallel attitude is an example of a second axial attitude.

[0048] When the controller 400 determines that the wakesurfing mode is set and that the steering angle of the steering member 214 has exceeded the reference angle range ER (S110: YES and S120: NO), it executes parallel attitude control (S150). At this time, the controller 400 displaces the axis M1 (nozzle angle α) of the first nozzle deflector 106A and the axis M2 (nozzle angle β) of the second nozzle deflector 106B in accordance with a change in the steering angle of the steering member 214, while keeping the first propulsion unit 100A and the second propulsion unit 100B in a parallel transition attitude or a parallel attitude. The parallel transition attitude is an attitude in which the axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B are more parallel (closer to the parallel attitude) than in the toe-in attitude. The parallel transition attitude is an example of the second axial attitude. Specifically, it is as follows.

[0049] In FIG. 11 , the steering angle of the steering member 214 exceeds the reference angle range ER by an excess angle ΔRB in the clockwise direction. At this time, the first propulsion unit 100A and the second propulsion unit 100B are in a parallel transition posture, and the first guide 300A and the second guide 300B are both in the retracted position, in a guide-invalid posture. The axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B are tilted obliquely rearward and rightward at a steering angle corresponding to the clockwise rotation angle of the steering member 214 from the neutral position. Therefore, the jet boat 10 turns smoothly to the right at a steering angle corresponding to the change in the rotation position of the steering member 214. The guide-invalid posture is an example of the second guide axis posture and the third axis posture.

[0050] The controller 400 gradually or continuously increases the parallelism between the axis M1 and the axis M2 as the excess angle ΔRB of the steering angle increases. That is, when the steering angle by the steering member 214 exceeds the reference angle range ER, the first propulsion unit 100A and the second propulsion unit 100B transition from a toe-in position to a parallel position as the excess angle ΔRB in the clockwise direction increases. The gradual transition from a toe-in position to a parallel position prevents the positional changes of the first propulsion unit 100A and the second propulsion unit 100B from affecting the smooth right turn of the jet boat 10.

[0051] In Figure 12, the steering angle of the steering member 214 exceeds the reference angle range ER by an excess angle ΔRA in the counterclockwise direction. At this time, the first propulsion unit 100A and the second propulsion unit 100B are in a parallel transition posture, and the first guide 300A and the second guide 300B are both in a guide-ineffective posture in the retracted position. The axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B are tilted obliquely leftward and rearward at a steering angle that corresponds to the counterclockwise rotation angle of the steering member 214 from the neutral position. As a result, the jet boat 10 turns smoothly left at a steering angle that corresponds to the change in the rotation position of the steering member 214.

[0052] The controller 400 gradually or continuously increases the parallelism between the axis M1 and the axis M2 as the excess angle ΔRA of the steering angle increases. That is, when the steering angle of the steering member 214 exceeds the reference angle range ER, the first propulsion unit 100A and the second propulsion unit 100B transition from a toe-in position to a parallel position as the excess angle ΔRA in the counterclockwise direction increases. The gradual transition from a toe-in position to a parallel position prevents the positional displacement of the first propulsion unit 100A and the second propulsion unit 100B from interfering with the smooth left turning of the jet boat 10.

[0053] When the controller 400 determines that the steering angle of the steering member 214 is within the reference angle range ER and that the traveling speed of the jet boat 10 is less than the reference speed Va (S120: YES and S130: NO), the controller 400 executes parallel posture control (S150). The controller 400 displaces the axis M1 (nozzle angle α) of the first nozzle deflector 106A and the axis M2 (nozzle angle β) of the second nozzle deflector 106B in accordance with a change in the steering angle of the steering member 214, while keeping the first propulsion unit 100A and the second propulsion unit 100B in a parallel transition posture or a parallel posture. As shown in FIG. 14 , the controller 400 transitions the first propulsion unit 100A and the second propulsion unit 100B from the toe-in posture to the parallel posture as the traveling speed of the jet boat 10 decreases. Furthermore, the controller 400 transitions the first guide 300A and the second guide 300B from a guide-enabled position to a guide-disabled position. For example, if the user U falls off the wakeboard S, the operator of the jet boat 10 can slow down the jet boat 10, causing the first propulsion unit 100A and the second propulsion unit 100B to automatically transition to a parallel position, and the first guide 300A and the second guide 300B to automatically transition to a guide-disabled position. This improves the maneuverability (turning ability) of the jet boat 10, allowing the user U to be rescued quickly.

[0054] B. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the spirit thereof, for example, the following modifications are also possible.

[0055] The configuration of the jet boat 10 in the above embodiment is merely an example and various modifications are possible. For example, in the above embodiment, the first nozzle deflector 106A and the second nozzle deflector 106B may be able to swing left and right but not up and down. In the above embodiment, the jet boat 10 may not include the first guide 300A and the second guide 300B. In the above embodiment, the first nozzle deflector 106A and the second nozzle deflector 106B may always be parallel. In this case, the controller 400 sets the first guide 300A and the second guide 300B to the guide-enabled position when the steering angle of the steering member 214 is within the reference angle range ER, and sets the guide-disabled position when the steering angle exceeds the reference angle range ER.

[0056] In the above embodiment, the guide disabled posture is exemplified as the second guide axis posture, but for example, the second guide axis posture may be a posture in which the first guide 300A and the second guide 300B are in the deployed position and the guide axis of the first guide 300A and the guide axis of the second guide 300B are more parallel than in the above guide enabled posture.

[0057] In the above embodiment, the intersection angle γ is maintained constant in the toe-in attitude control, but the intersection angle γ may be changed according to the steering angle, for example.

[0058] In the above embodiment, the controller 400 may be configured to change the intersection angle γ between the axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B in response to an instruction from a mobile terminal (not shown) operated by the user U during execution of toe-in attitude control. Furthermore, the controller 400 may be configured to individually change the tilt angle of at least one of the axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B in response to an instruction from the mobile terminal operated by the user U during execution of toe-in attitude control. Furthermore, in the above embodiment, the controller 400 may be configured to change the angle (trim angle) in the up-down direction of at least one of the axis M1 of the first nozzle deflector 106A and the axis M2 of the second nozzle deflector 106B in response to an instruction from the mobile terminal operated by the user U during execution of toe-in attitude control. With this configuration, the user U can change the waveform of the wakesurfing wave W as desired while wakesurfing.

[0059] In the above embodiment, the jet boat 10 equipped with a jet propulsion unit is exemplified as the watercraft, but the watercraft is not limited to this, and may be, for example, a water jet propulsion boat, a watercraft equipped with an inboard motor, an inboard-outboard motor, or an outboard motor, etc. The drive source of the propulsion unit is not limited to an engine, but may be an electric motor or the like. [Explanation of symbols]

[0060] 10: Jet boat 100A: First propulsion unit 100B: Second propulsion unit 106A: First nozzle deflector 106B: Second nozzle deflector 133A: First rotation speed sensor 133B: Second rotation speed sensor 200: Hull 214: Steering member 300A: First guide 300B: Second guide 400: Controller D1: First jet direction D2: Second jet direction ER: Reference angle range M1: Axis line M2: Axis line O: Central axis P: Intersection point S: Wakeboard U: User

Claims

1. A vessel, The hull and a first propulsion unit attached to the port side of the rear of the hull and generating a propulsive force along a first axis, the first axis being configured to be displaceable; a second propulsion unit attached to the starboard side of the rear of the hull and generating a propulsive force along a second axis, the second axis being configured to be displaceable; an operating device for instructing the direction of movement of the hull; a controller; The controller when the direction indicated by the operating device is within a reference angle range that includes the straight ahead direction of the hull, the first propulsion unit and the second propulsion unit are set to a first axis attitude in which the first axis and the second axis intersect with each other in the rear direction of the hull; when the indicated direction exceeds the reference angle range, the first propulsion unit and the second propulsion unit are set to a second axial attitude in which the parallelism between the first axis and the second axis is higher than that of the first axial attitude; ship.

2. 2. The watercraft of claim 1, The controller When the indicated direction is within a reference angle range, the first axis and the second axis are displaced in accordance with a change in the indicated direction.

3. 2. The watercraft of claim 1, The controller When the indicated direction is within the reference angle range, the vessel maintains the intersection angle between the first axis and the second axis substantially constant regardless of a change in the indicated direction.

4. 2. The watercraft of claim 1, The controller When the indicated direction exceeds a reference angle range, the first axis and the second axis are displaced in accordance with the change in the indicated direction.

5. 2. The watercraft of claim 1, The controller When the indicated direction exceeds the reference angle range, the parallelism between the first axis and the second axis is increased stepwise or continuously as the angle by which the indicated direction exceeds the reference angle range increases.

6. 2. The watercraft of claim 1, The vessel, wherein the second axis attitude includes an attitude in which the first axis and the second axis are substantially parallel to each other.

7. 2. The watercraft of claim 1, The controller a first mode in which the first propulsion unit and the second propulsion unit are set to the first axial attitude when the commanded direction is within the reference angle range, and a second mode in which the first propulsion unit and the second propulsion unit are set to the second axial attitude regardless of whether the commanded direction is within the reference angle range.

8. 2. The watercraft of claim 1, The vessel further includes a guide disposed at the rear of the hull outboard of both the first propulsion unit and the second propulsion unit, the guide having a first guide posture extending rearward so as to approach the longitudinal center axis of the hull.

9. 9. The vessel of claim 8, the guide is displaceable between the first guide position and a second guide position in which the guide function for water is lower than that of the first guide position, The controller If the pointing direction is within the reference angle range, the guide is set to the first guide posture; When the indicated direction exceeds the reference angle range, the guide is set to the second guide posture.

10. 2. The watercraft of claim 1, Further, a speed sensor for measuring the moving speed of the vessel is provided, The controller when the indicated direction is within the reference angle range and the speed measured by the speed sensor is equal to or greater than a reference speed, setting the first propulsion unit and the second propulsion unit to the first axial attitude; and when the indicated direction is within the reference angle range and the speed measured by the speed sensor is less than a reference speed, the first propulsion unit and the second propulsion unit are set to the second shaft attitude.

11. 11. The watercraft of claim 10, The controller When the indicated direction is within the reference angle range and the speed measured by the speed sensor is less than a reference speed, the parallelism between the first axis and the second axis is increased stepwise or continuously as the measured speed becomes slower.

12. 2. The watercraft of claim 1, The controller When the indicated direction is within a reference angle range, the vessel changes the intersection angle between the first axis and the second axis in accordance with an instruction from a mobile terminal operated by a user.

13. 2. The watercraft of claim 1, The controller When the indicated direction is within a reference angle range, the trim angle of at least one of the first axis and the second axis is changed in accordance with an instruction from a mobile terminal operated by a user.

14. A method for controlling a marine vessel system including a first propulsion unit attached to a port side of a rear portion of a hull and generating a propulsive force along a first axis, a second propulsion unit attached to a starboard side of a rear portion of the hull and generating a propulsive force along a second axis, and an operating device for instructing a direction of movement of the hull, the method comprising: when the direction indicated by the operating device is within a reference angle range that includes the straight ahead direction of the hull, the first propulsion unit and the second propulsion unit are set to a first axis attitude in which the first axis and the second axis intersect with each other in the rear direction of the hull; when the indicated direction exceeds the reference angle range, the first propulsion unit and the second propulsion unit are set to a second axial attitude in which the parallelism between the first axis and the second axis is higher than that of the first axial attitude; A method for controlling a marine system.

15. A vessel, The hull and a first generator attached to the port side of the rear of the hull and configured to generate a water flow along a first axis, the first generator being configured so that the first axis is displaceable; a second generator attached to the starboard side of the rear of the hull and configured to generate a water flow along a second axis, the second generator being configured so as to be displaceable; an operating device for instructing the direction of movement of the hull; a controller; The controller When the direction indicated by the operating device is within a reference angle range including the straight ahead direction of the hull, the first generator and the second generator are set to a first axis attitude in which the first axis and the second axis intersect with each other in the rear direction of the hull, When the indication direction exceeds the reference angle range, the first generator and the second generator are set to a third axial posture that satisfies at least one of the following: a higher parallelism between the first axis and the second axis and a weaker force for generating a water flow, compared to the first axial posture. ship.

16. 16. The watercraft of claim 15, At least one of the first generator and the second generator has a guide extending rearward so as to approach the longitudinal center axis of the hull, In the first axial position, the guide is in a deployed position protruding from the hull, In the third axial position, the guide is in a stored position in which it protrudes less from the hull than in the deployed position.

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