Ship propulsion systems

Abstract

The present invention provides a ship propulsion system that enables smooth transitions between states, such as when heel control is being performed, without compromising the ship's stability, acceleration, top speed, or fuel efficiency, and without causing the operator to feel any discomfort. [Solution] The ship's propulsion system includes a trim angle adjustment unit that adjusts the trim angle of each of the propulsion engines on both the left and right sides, and a control unit that controls the trim angle adjustment unit. The control unit performs heel control, and when a preset first condition is met while at least one propulsion engine has a trim angle that is tilted further aft in the direction of propulsion than a first trim angle reference value, the control unit adjusts the trim angle of the propulsion engine using the trim angle adjustment unit so that the trim angle of the propulsion engine becomes the first trim angle reference value, or so that the trim angle of the propulsion engine becomes tilted further forward in the direction of propulsion than the first trim angle reference value.

Description

Technical Field

[0001] The present invention relates to a marine vessel propulsion system.

Background Art

[0002] Conventionally, various techniques for automatically controlling marine vessel propulsion systems have been proposed to improve the stability, acceleration performance, maximum speed, fuel efficiency and the like of a marine vessel during navigation.

[0003] For example, Patent Document 1 discloses a configuration related to heel control for controlling the heel angle of a marine vessel. In this configuration, when it is determined that the marine vessel is not in a turning state according to the steering angle of the steering mechanism of the marine vessel, a difference is generated in the left and right lift forces of the marine vessel, so that the heel angle of the marine vessel is increased in the direction corresponding to the steering angle of the steering mechanism.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of Invention

Problem to be Solved by the Invention

[0005] Incidentally, in a marine vessel, not only heel control but also other controls may be executed depending on the navigation state of the marine vessel. For example, different controls may be executed when the marine vessel is in a straight traveling state and when it is in a turning state. In addition, when a vessel operator performs a manual operation, each part may be in a state different from the state under the automatically executed control. As described above, when shifting from a state in which heel control is being performed to another state, it is desired to smoothly perform the state transition so that the stability, acceleration performance, maximum speed, fuel efficiency and the like of the marine vessel are not impaired, and the vessel operator does not feel a sense of discomfort or the like. This invention has been made in view of the above circumstances, and aims to provide a ship propulsion system that can smoothly transition between states, such that the ship's stability, acceleration, maximum speed, fuel efficiency, etc., are not impaired when transitioning from a state in which heel control is being performed to another state, and the operator does not feel any discomfort. [Means for solving the problem]

[0006] To address the above issues, this disclosure adopts the following characteristics. (1) A propulsion system for a ship according to one aspect of the present disclosure comprises a drive source and a propulsion unit that generates thrust by power transmitted from the drive source, each having at least one propulsion unit on each side in the left-right direction with respect to the center of the ship, a trim angle adjustment unit that adjusts the trim angle of each of the propulsion units on both the left-right sides with respect to the ship, and a control unit that controls the trim angle adjustment unit, wherein the control unit adjusts the trim so that the angle of the trim is set according to the tilt of the ship in the roll direction in order to suppress the tilt of the ship in the roll direction Heel control, which adjusts the trim angle at the angle adjustment unit, is possible, and when heel control is being performed, and at least one of the propulsion units has a trim angle that is tilted rearward in the direction of propulsion of the hull compared to a preset first trim angle reference value, if a preset first condition is met, the trim angle adjustment unit adjusts the trim angle of the propulsion unit so that the trim angle of the propulsion unit becomes the first trim angle reference value, or so that the trim angle of the propulsion unit becomes tilted forward in the direction of propulsion compared to the first trim angle reference value.

[0007] (2) A propulsion system for a ship according to the embodiment of (1) above, further comprising a steering angle detection unit that detects the steering angle of the propulsion machine around the steering axis with respect to the hull based on an external input, and the control unit may determine that the ship is in a turning state based on the detected value of the steering angle detected by the steering angle detection unit, and that the first condition has been met.

[0008] (3) In the propulsion system of a ship according to the embodiment of (2) above, if it is determined that the ship is in a turning state, the trim angle adjustment unit may be used to adjust the trim angle of the propulsion machines in all of the propulsion machines on both the left and right sides so that the trim angle of the propulsion machines becomes the first trim angle reference value.

[0009] (4) A propulsion system for a ship according to any one of the embodiments described in (1) to (3) above, further comprising a trim angle operation unit which operates the trim angle adjustment unit by external input, and the control unit may determine that the first condition is met when it receives an operation input from the trim angle operation unit.

[0010] (5) A propulsion system for a ship according to any one of the embodiments of (1) to (4) above, further comprising an intermediate member provided between the hull and the propulsion machine, which increases the rearward inclination angle of the propulsion machine in the direction of propulsion, wherein the first trim angle reference value may be set based on the trim angle of the propulsion machine in the state in which the propulsion machine is most inclined rearward in the direction of propulsion when the propulsion machine is provided on the hull without the intermediate member.

[0011] (6) In the propulsion system of a ship according to the embodiment of (5) above, when the control unit performs heel control, the control unit may adjust the trim angle of the propulsion machine in the trim angle adjustment unit, using a second trim angle reference value set based on the trim angle of the propulsion machine when the propulsion machine provided on the hull via the intermediate member is tilted most to the rear in the direction of propulsion as the lower limit.

[0012] (7) In a propulsion system for a ship according to the embodiment of (2) or (3) above, the control unit may perform heel control when it is determined that the ship is moving in a straight line based on the detected value of the steering angle.

[0013] (8) In the propulsion system for a ship according to the embodiment of (7) above, the system further comprises a heel angle detection unit for detecting the heel angle, which is the inclination of the hull in the roll direction, and the control unit may perform heel control when the heel angle is equal to or greater than a preset heel angle reference value.

[0014] (9) In the propulsion system of a ship according to the embodiment of (2) or (3) above, the control unit may stop the execution of the heel control when it is determined that the ship is in a turning state based on the detected value of the steering angle.

[0015] (10) A propulsion system for a ship according to any one of the embodiments described in (1) to (9) above, further comprising a trim angle operation unit which operates the trim angle adjustment unit by external input, wherein the control unit may stop the execution of the heel control when it receives an operation input from the trim angle operation unit while the heel control is being executed.

[0016] (11) In a ship propulsion system according to any one of the embodiments of (1) to (10) above, the control unit is capable of performing trim support control, which involves adjusting the trim angle in the trim angle adjustment unit so that the trim support angle is set according to a preset ship speed or propulsion engine rotation speed, and in addition to the trim support control, the control unit may also perform heel control when a preset second condition is met, and adjust the propulsion engine to the heel suppression angle set in the trim angle adjustment unit based on the trim support angle of the propulsion engine. [Effects of the Invention]

[0017] According to the embodiment of (1), when heel control is performed and at least one propeller has a trim angle that is tilted further aft in the direction of propulsion than a first trim angle reference value, if a preset first condition is met, the trim angle of the propeller is adjusted so that the trim angle of the propeller becomes the first trim angle reference value, or so that the trim angle of the propeller becomes tilted further forward in the direction of propulsion than the first trim angle reference value. In other words, when the first condition is met, the propeller is pulled forward in the direction of propulsion from a state where the trim angle of the propeller is tilted further aft in the direction of propulsion than the first trim angle reference value to a state where the trim angle of the propeller becomes equal to or greater than the first trim angle reference value. This makes it possible to smoothly transition from a state in which heel control is performed to another state without impairing the stability, acceleration, maximum speed, fuel consumption, etc. of the ship, or causing the operator to feel any discomfort.

[0018] According to the embodiment of (2), if it is determined that the vessel is in a turning state, it is determined that the first condition has been met. This prevents the impediment to turning ability caused by the propulsion engine being tilted further aft in the direction of propulsion than the first trim angle reference value when transitioning from a state where heel control is being performed in a straight state to a turning state. Therefore, the vessel's stability, acceleration, maximum speed, fuel consumption, etc., are not impaired, and the state transition can be made smoothly.

[0019] According to the embodiment of (3), when it is determined that the ship is in a turning state, by setting the trim angle of all the propellers on both the left and right sides to the first trim angle reference value, if there is any propeller that is tilted forward more than the first trim angle reference value among all the propellers, aeration during turning can be prevented in that propeller.

[0020] According to the aspect (4), when a steering operator performs a manual operation to adjust the trim angle or the like of the propulsion unit, and an operation input from the trim angle operation unit is received, it is determined that the first condition is satisfied. This suppresses the steering operator from feeling discomfort when shifting from a state where the propulsion unit is tilted rearward in the propulsion direction beyond the first trim angle reference value to perform heel control, to a state where the propulsion unit is manually operated. Therefore, the state transition can be performed smoothly.

[0021] According to the aspect (5), an intermediate member is provided between the hull and the propulsion unit, which increases the tilt angle of the propulsion unit rearward in the propulsion direction. As a result, the propulsion unit can be tilted more greatly toward the rear in the propulsion direction of the vessel, the trim angle can be made larger in the negative direction, and heel control can be performed effectively. Further, the first trim angle reference value is set based on the trim angle of the propulsion unit when the propulsion unit is tilted most rearward in the propulsion direction in a case where the propulsion unit is provided on the hull without the intermediate member. When heel control is performed with the trim angle of the propulsion unit made larger in the negative direction, the state transition can be performed smoothly by returning the trim angle of the propulsion unit to the first trim angle reference value or more when shifting from the heel control state to another state.

[0022] According to the aspect (6), heel control can be performed effectively by performing the heel control with the second trim angle reference value, which is set based on the trim angle of the propulsion unit when the propulsion unit provided on the hull via the intermediate member is tilted most rearward in the propulsion direction, as the lower limit value.

[0023] According to the aspect (7), heel control is made executable when it is determined that the vessel is traveling straight based on the detected value of the steering angle. Thereby, when the vessel is in a state of traveling straight, heel control can be performed smoothly, and stability, acceleration performance, maximum speed, fuel efficiency and the like can be improved.

[0024] According to the aspect (8), the heel control is executed when the heel angle is equal to or greater than a preset heel angle reference value. As a result, as a first condition, when the vessel is traveling straight and the heel angle is large, the heel angle can be suppressed, so that the stability, acceleration performance, maximum speed, fuel efficiency and the like of the vessel can be improved.

[0025] According to the aspect (9), the execution of the heel control is stopped when it is determined that the vessel is in a turning state based on the detected value of the steering angle. Thereby, when the vessel is in a turning state, it is possible to prevent the turning performance from being impaired by the heel control.

[0026] According to the aspect (10), when an operation input from the trim angle operation unit is received while the heel control is being executed, the execution of the heel control is stopped. Thereby, when the operator of the vessel manually performs the trim angle operation, stopping the execution of the heel control can suppress the operator who performed the trim angle operation from feeling a sense of discomfort.

[0027] According to the aspect (11), when a preset second condition is satisfied, the heel control is executed in addition to the trim support control, and the trim angle adjustment unit adjusts the trim angle of the propulsion unit to a heel suppression angle set based on the trim support angle. Thereby, when the preset condition is satisfied, by executing the heel control in addition to the trim support control, the heel angle of the vessel can be suppressed while automatically adjusting the trim angle. Therefore, when transitioning from a state where the heel control is performed to another state, the state transition can be performed smoothly so that the stability, acceleration performance, maximum speed, fuel efficiency and the like of the vessel are not impaired, and the operator does not feel a sense of discomfort or the like. [Brief Description of the Drawings]

[0028] [Figure 1] It is a plan view of the vessel according to the present embodiment. [Figure 2] It is a functional block diagram of the propulsion system of the above-mentioned vessel. [Figure 3] It is a side view of the propulsion unit of the above-mentioned propulsion system. [Figure 4] This figure shows an example of trim support control, heel control, hump control, and wedge control performed according to the ship's speed in the above-mentioned propulsion system. [Figure 5] This diagram shows the state of trim support control being performed by the above propulsion system. [Figure 6] This figure shows an example of the trim support angle settings for trim support control, heel control, and hump control performed according to the ship speed in the above propulsion system. [Figure 7] This diagram shows the above-mentioned vessel in a state where heel control is being performed while it is listing to port. [Figure 8] This diagram shows the above-mentioned vessel in a state where heel control is being performed while it is listing to starboard. [Figure 9] This flowchart shows how heel control is performed when trim support control is being executed. [Figure 10] This is a timing chart illustrating an example of the operation of the above propulsion system. [Modes for carrying out the invention]

[0029] Embodiments of the present invention will be described below with reference to the drawings. In the following description, the directions of front, back, up, down, left, and right will correspond to the orientation of the vessel 1. In this case, arrow FR in the figure indicates the front of the vessel 1, arrow UP indicates the top of the vessel 1, and arrow LH indicates the left side of the vessel 1. The center line CL indicates the center position of the vessel 1 in the left-right direction (width direction).

[0030] Figure 1 is a plan view of the vessel according to this embodiment. Figure 2 is a functional block diagram of the vessel's propulsion system. As shown in Figure 1, the ship 1 comprises a hull 2 ​​and a propulsion system 20 provided on the hull 2. As shown in Figures 1 and 2, the propulsion system 20 comprises a plurality of thrusters 3, an operating unit 7, a detection unit 6 (see Figure 2), and a control unit 8 (see Figure 2).

[0031] (propulsion machine) As shown in Figure 1, the propulsion system 3 includes a right propulsion system 3a located on the right side of the stern 2b, straddling the centerline CL, and a left propulsion system 3b located on the left side of the stern 2b, straddling the centerline CL. The two propulsion systems 3 (right propulsion system 3a and left propulsion system 3b) are located on both the left and right sides of the stern 2b of the hull 2, straddling the centerline CL. In other words, the vessel 1 of this embodiment is a so-called twin-propulsion small vessel. In the following description, unless it is necessary to distinguish between the propulsion systems 3a and 3b, they will be referred to collectively as the propulsion system 3.

[0032] Figure 3 is a side view of the propulsion system's thruster. As shown in Figure 3, the propulsion system 3 is, for example, an outboard motor. The propulsion system 3 comprises a casing 31, a drive source 32, a drive shaft 33, a propulsion unit 34, and a shift switching mechanism 35. The casing 31 is attached to a bracket 22 located at the stern 2b via a rudder shaft 36 (swivel shaft) that extends vertically. The propulsion unit 3 is mounted to the hull 2 ​​so as to be rotatable around the rudder shaft 36 by the operation of a rudder actuator 41 (see Figure 2).

[0033] The drive source 32 is, for example, an internal combustion engine. The drive source 32 is housed in the upper part of the casing 31 with the crankshaft aligned vertically. The power (engine speed) of the drive source 32 is set based on the opening of the throttle valve. The throttle valve is driven by the operation of the throttle actuator 42 (see Figure 2). The drive source 32 may also be an electric motor. The drive shaft 33 transmits power generated by the drive source 32 to the propulsion unit 34 via the shift switching mechanism 35. The drive shaft 33 extends vertically within the casing 31. The upper end of the drive shaft 33 is connected to the drive source 32.

[0034] The propulsion unit 34 comprises a propeller shaft 341 and a propeller 342. The propeller shaft 341 is rotatably mounted at the lower end of the casing 31 around an axis along the longitudinal direction. The front end of the propeller shaft 341 is connected to the shift switching mechanism 35 within the casing 31. The propeller 342 is mounted at the rear end of the propeller shaft 341, protruding outward from the casing 31. The propeller 342 rotates integrally with the propeller shaft 341.

[0035] The shift switching mechanism 35 includes a drive gear 351, a forward gear 352, a reverse gear 353, and a clutch 354. The drive gear 351 is located at the lower end of the drive shaft 33. The drive gear 351 is rotatable integrally with the drive shaft 33. The forward gear 352 and the reverse gear 353 are rotatably mounted on the propeller shaft 341, facing each other in the front-rear direction with the drive gear 351 in between. The forward gear 352 and the reverse gear 353 can mesh with the drive gear 351. The forward gear 352 and the reverse gear 353 rotate in opposite directions as the drive gear 351 rotates.

[0036] The clutch 354 switches the power connection or disconnection between the forward gear 352 or the reverse gear 353 and the propeller shaft 341. The clutch 354 is rotatably mounted integrally with the propeller shaft 341. The clutch 354 is movably mounted along the propeller shaft 341 in the forward and backward directions by the operation of the shift actuator 43. By selectively engaging with the forward gear 352 and the reverse gear 353, the clutch 354 switches the rotation direction of the propeller shaft 341 and the propeller 342, thereby switching the propulsion direction of the ship 1.

[0037] The propulsion unit 3 is supported by a bracket 22 attached to the stern 2b of the hull 2, so as to be rotatable around a support shaft 38 that extends in the left-right direction. This allows the propulsion unit 3 to rotate (oscillate) around the support shaft 38 with respect to a reference plane Fv. Here, the reference plane Fv is a virtual plane that lies along the vertical plane passing through the central axis of the support shaft 38 when the hull 2 ​​is simply floating on the water surface. Here, the trim angle θt is defined as the angle at which the direction in which the steering shaft 36 of the propulsion unit 3 extends is inclined in the longitudinal direction around the support shaft 38 with respect to the reference plane Fv. In this embodiment, the trim angle θt is expressed as positive (forward) when the lower end of the propulsion unit 3 moves away from the stern 2b, and negative (negative) when the lower end of the propulsion unit 3 moves towards the stern 2b.

[0038] The thruster 3 has an adjustable trim angle θt via a trim angle adjustment unit 45. The trim angle adjustment unit 45 uses an actuator (not shown) to rotate the thruster 3 around the support shaft 38 within a preset angular range. The thruster 3 is restricted from rotating in the positive and negative directions by abutting against a stopper (not shown) provided on the bracket 22. In this embodiment, the bracket 22 is attached to the mounting surface 2f formed on the stern 2b via an intermediate member 37. The intermediate member 37 is sandwiched between the bracket 22 and the mounting surface 2f. The intermediate member 37 is formed in a wedge shape, with its thickness gradually decreasing in the front-rear direction from top to bottom. As a result, the bracket 22 is positioned at a greater rearward inclination compared to when it is directly attached to the mounting surface 2f without using the intermediate member 37. This configuration allows the propulsion unit 3 to be set to a larger negative rotation angle (rotation range).

[0039] In this embodiment, the thruster 3 is rotatable, for example, within a range of approximately 20° in the positive direction and approximately -10° in the negative direction with respect to the reference plane Fv. Here, when the propulsion unit 3 is directly attached to the bracket 22 of the hull 2 ​​without the intermediate member 37, the trim angle θt of the propulsion unit 3 when it is tilted most aft in the direction of propulsion is, for example, around -5°. In the control unit 8 described later, this trim angle θt (= around -5°) is set as the first trim angle reference value θts1. Note that the first trim angle reference value θts1 may be set to an angle different from the trim angle θt of the propulsion unit 3 when it is directly attached to the bracket 22 of the hull 2 ​​without the intermediate member 37 and it is tilted most aft in the direction of propulsion. In this embodiment, the propulsion unit 3 is mounted on the bracket 22 of the hull 2 ​​via an intermediate member 37. By mounting the propulsion unit 3 on the bracket 22 of the hull 2 ​​via the intermediate member 37, the trim angle θt of the propulsion unit 3 when it is tilted most towards the rear in the direction of propulsion is, for example, around -10°. In other words, the intermediate member 37 is positioned so that the propulsion unit 3 is tilted by approximately 5° in the negative direction towards the rear in the direction of propulsion. In the control unit 8 described later, this trim angle θt (= around -10°) is used as the second trim angle reference value θts2.

[0040] (Operation unit) As shown in Figures 1 and 2, the control unit 7 is provided to allow the operator to input controls for steering the vessel 1. In this embodiment, the control unit 7 includes, for example, a steering angle input unit 71, a thrust input unit 72, a trim angle control unit 73, and an operation input unit 74.

[0041] The steering angle input unit 71 is located in the cockpit of the hull 2. The steering angle input unit 71 is, for example, a steering wheel that is rotatable in a reciprocating manner. The steering angle input unit 71 receives external input from the operator when changing the course of the vessel 1 (hull 2). That is, the steering angle input unit 71 receives operation by the operator to change the direction (steering angle) of the propulsion engine 3 around the steering axis 36. The steering angle is the angle of inclination of the propulsion engine 3 with respect to the centerline CL in a plan view. In this embodiment, the steering angle of the propulsion engine 3 when the course of the vessel 1 is in the straight direction is set as the reference value (0°). In addition to the steering wheel, the steering angle input unit 71 may also be a joystick, or it may be mounted as a switch on the operation input unit 74, etc.

[0042] The thrust input unit 72 is located in the cockpit of the hull 2. The thrust input unit 72 is, for example, a throttle lever. The thrust input unit 72 receives external input from the operator when changing the thrust of the propeller 3 or the shift position of the propeller 3. The thrust input unit 72 is configured to be able to move back and forth by rotation or sliding. The thrust input unit 72 can move back and forth within an operating area that has three shift areas aligned: forward position F, neutral position N, and reverse position R. When the thrust input unit 72 is in the forward position F, the propeller 3 exerts thrust to move the ship 1 forward. When the thrust input unit 72 is in the reverse position R, the propeller 3 exerts thrust to move the ship 1 backward. When the thrust input unit 72 is in the neutral position N, the drive gear 351 shown in Figure 3 is disconnected from the forward gear 352 and the reverse gear 353, and the propeller 3 does not exert thrust to propel the ship 1.

[0043] As shown in Figure 1, a trim angle control switch is provided near the thrust input section 72 as a trim angle control section 73. The operator of the ship 1 can change the trim angle θt of the propulsion unit 3 by manually operating the trim angle control switch (trim angle control section 73).

[0044] The operation input unit 74 receives various operations on the vessel 1. The operation input unit 74 is configured to be manually operated by the operator, for example, as an MFD (Multi Function Display). The operation input unit 74 may also be an external device such as a portable terminal connected to the vessel 1 by wire or wireless connection.

[0045] (Detection unit) The detection unit 6 shown in Figure 2 detects the state (navigation state) of the vessel 1. In this embodiment, the detection unit 6 includes a position sensor 61, a ship speed sensor 62, a steering angle sensor (steering angle detection unit) 63, an inertia sensor 64, a trim operation sensor 65, a trim angle sensor 66, and an actual steering angle sensor 67. The position sensor 61 detects the position of the thrust input unit 72. The position sensor 61 outputs a detection signal based on the position of the thrust input unit 72 to the control unit 8.

[0046] The ship speed sensor 62 detects the ship speed V of the vessel 1. The ship speed sensor 62 is, for example, a GPS (Global Positioning System) and calculates the ship speed V based on positioning signals from positioning satellites. The ship speed sensor 62 may also be an acoustic or electromagnetic sensor that detects the ship speed (water speed) V of the vessel 1. The ship speed sensor 62 may also estimate the ship speed V based on the engine speed. The ship speed sensor 62 outputs a signal representing the detected ship speed V to the control unit 8.

[0047] The steering angle sensor 63 detects the amount of operation (steering instruction angle) caused by the rotational operation of the steering angle input unit 71. The steering angle sensor 63 outputs a detection signal based on the steering instruction angle of the steering angle input unit 71 to the control unit 8.

[0048] The inertial sensor 64 detects the tilt of the hull 2 ​​in the roll direction, i.e., the heel angle θh. The inertial sensor 64 can also detect the tilt of the hull 2 ​​in the pitch direction, etc. The inertial sensor 64 outputs detection signals based on the detected tilt of the hull 2 ​​in the roll direction to the control unit 8.

[0049] The trim operation sensor 65 detects whether or not an external operation input has been made to the trim angle operation switch, which is the trim angle operation unit 73. The trim operation sensor 65 outputs a detection signal to the control unit 8 indicating whether or not an operation input has been detected.

[0050] The trim angle sensor 66 is provided in the trim angle adjustment unit 45. The trim angle sensor 66 detects the actual trim angle θt adjusted by the trim angle adjustment unit 45. The trim angle sensor 66 outputs a detection signal indicating the detected trim angle θt to the control unit 8.

[0051] The actual steering angle sensor 67 is provided on the steering actuator 41. The actual steering angle sensor 67 detects the actual steering angle of the thruster 3 and outputs it to the control unit 8.

[0052] (Control Unit) The control unit 8 comprehensively controls the operation of the ship 1 (propulsion unit 3). The control unit 8 is one or more electronic control units provided by the ship 1. The control unit 8 is realized, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software) stored in a storage unit 80 such as a ROM (Read Only Memory) or RAM (Random Access Memory). Some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), GPU (Graphics Processing Unit), or SOC (System On Chip), or by the cooperation of software and hardware.

[0053] The control unit 8 includes a storage unit 80, an acquisition unit 81, a determination unit 82, and a drive processing unit 83.

[0054] The memory unit 80 stores programs and various data necessary for the navigation of the ship 1, such as trim support control, heel control, hump control, and wedge control. The acquisition unit 81 acquires the detection results of the various sensors of the detection unit 6. The determination unit 82 determines the state of the ship 1 based on the information obtained by the acquisition unit 81 and the information stored in the storage unit 80.

[0055] The drive processing unit 83 controls the operation of various actuators based on the determination result from the determination unit 82 and the information stored in the storage unit 80 and the acquisition unit 81. In this embodiment, if the determination unit 82 determines that a predetermined condition has been met, the drive processing unit 83 controls the operation of the trim angle adjustment unit 45, the steering actuator 41, etc., to perform trim support control, heel control, hump control, and wedge control. In this embodiment, the drive processing unit 83 performs trim support control, heel control, hump control, and wedge control when the vessel 1 is in a straight-ahead state. In this embodiment, the drive processing unit 83 determines that the vessel 1 does not perform wedge control.

[0056] (Trim support control) Figure 4 shows an example of trim support control, heel control, hump control, and wedge control performed in a propulsion system according to the ship's speed. As shown in Figure 4, when the vessel 1 is moving straight, the determination unit 82 determines that in the areas of heel control, hump control, and wedge control, the drive processing unit 83 executes trim support control according to the settings of the operator, for example, based on input from the trim angle operation unit 73 and the operation input unit 74.

[0057] Figure 5 shows an example of trim support angle settings for trim support control, heel control, and hump control performed in the propulsion system according to ship speed. As shown in Figure 5, the trim support control adjusts the trim angle θt in the trim angle adjustment unit 45 so that the trim support angle θsp is set according to a preset ship speed V (or propeller rotation speed). In this embodiment, when performing trim support control, the trim support angle θsp is set according to the ship speed V so that stability, acceleration, maximum speed, fuel consumption, etc., are optimized. The trim support angle θsp may also be set according to the propeller rotation speed. For this reason, the ship speed V (or propeller rotation speed) and the trim support angle θsp that optimizes stability, acceleration, maximum speed, fuel consumption, etc., are stored in the memory unit 80 in association with each other. In the example in Figure 6, the trim support angle θsp is set in steps with respect to the ship speed V (or propeller rotation speed). In this case, when performing trim support control, the trim support angle θsp of the thruster 3 is set with the first trim angle reference value θts1 as the lower limit.

[0058] The drive processing unit 83 obtains the trim support angle θsp associated with the ship speed, which is acquired by the acquisition unit 81, from the storage unit 80. The drive processing unit 83 controls the trim angle adjustment unit 45 so that the trim angle θt of the thruster 3 approaches the acquired trim support angle θsp. Figure 6 shows the state in which trim support control is being performed by the propulsion system. As shown in Figure 6, when the drive processing unit 83 performs trim support control, it sets the trim support angles θsp of the thrusters 3a and 3b on both sides in the left-right direction to the same value.

[0059] (Heel control) As shown in Figure 4, if the determination unit 82 determines that the ship 1 is moving straight, the ship speed V is equal to or greater than the second threshold V2, and trim support control is being performed, and the preset second condition is met, the drive processing unit 83 performs heel control in addition to trim support control. Specifically, the drive processing unit 83 performs heel control in addition to trim support control, that is, both trim support control and heel control, when the ship 1 is moving straight, trim support control is being performed, and the ship speed is equal to or greater than the second threshold V2. In this case, the drive processing unit 83 executes heel control when the heel angle θh, which is the inclination of the hull 2 ​​in the roll direction detected by the inertial sensor 64, is greater than or equal to a preset heel angle reference value θhs (for example, several degrees). In other words, if the heel angle θh is less than the heel angle reference value θhs, the drive processing unit 83 does not execute heel control and continues trim support control.

[0060] When the drive processing unit 83 performs heel control, it sets a target value for the heel suppression angle θd according to the heel angle θh of the hull 2. Here, the heel suppression angle θd is the trim angle of the propulsion units 3 on both the left and right sides to suppress the tilt of the hull 2 ​​in the roll direction. The drive processing unit 83 calculates a heel suppression angle θd that can effectively suppress the tilt of the hull 2 ​​in the roll direction according to the heel angle θh of the hull 2 ​​using a pre-set calculation formula.

[0061] The drive processing unit 83 sets the heel suppression angle θd based on the trim support angle θsp of the thruster 3 at that time. The drive processing unit 83 sets the heel suppression angle θd of one thruster 3 in the left-right direction to a value greater than the trim support angle θsp, and sets the heel suppression angle θd of the other thruster 3 in the left-right direction to a value smaller than the trim support angle θsp. When heel control is performed, the heel suppression angle θd of the thruster 3 is set within a range greater than or equal to the second trim angle reference value θts2, with the second trim angle reference value θts2 being the lower limit.

[0062] Figure 7 shows the state of heel control when the vessel is tilting to port. Figure 8 shows the state of heel control when the vessel is tilting to starboard. For example, as shown in Figure 7, when the hull 2 ​​is tilted to the port side, the drive unit 83 sets the heel suppression angle θd2 of the right-side propulsion engine 3a to a value greater than the trim support angle θsp, and the heel suppression angle θd1 of the left-side propulsion engine 3b to a value less than the trim support angle θsp. For example, as shown in Figure 8, when the hull 2 ​​is tilted to the starboard side, the drive unit 83 sets the heel suppression angle θd1 of the left-side propulsion engine 3b to a value greater than the trim support angle θsp, and the heel suppression angle θd2 of the right-side propulsion engine 3a to a value less than the trim support angle θsp.

[0063] The drive processing unit 83 calculates heel suppression angles θd1 and θd2 based on the heel angle θh of the hull 2 ​​at that time, acquired by the acquisition unit 81, using the trim support angle θsp set at that time as a reference. The drive processing unit 83 calculates a trim angle addition value Δθt1 to be added to one of the propulsion units 3 in the left-right direction, and a trim angle subtraction value Δθt2 to be subtracted from the other propulsion unit 3 in the left-right direction, based on a preset calculation formula, with respect to the reference trim support angle θsp. Here, it is preferable that the absolute values ​​of the trim angle addition value Δθt1 and the trim angle subtraction value Δθt2 are the same. Here, the absolute values ​​of the trim angle addition value Δθt1 and the trim angle subtraction value Δθt2 are less than or equal to a preset size. However, the absolute values ​​of the trim angle addition value Δθt1 and the trim angle subtraction value Δθt2 may be different.

[0064] When the hull 2 ​​is tilted to the port side, the drive unit 83 calculates the heel suppression angle θd1 of the left propulsion unit 3b using the following equation (1), and the heel suppression angle θd2 of the right propulsion unit 3a using the following equation (2). θd1 = θsp - Δθt2 (1) θd² = θsp + Δθt¹ (2) When the hull 2 ​​is tilted to the starboard side, the drive unit 83 calculates the heel suppression angle θd1 of the left propulsion unit 3b using the following equation (3), and the heel suppression angle θd2 of the right propulsion unit 3a using the following equation (4). θd1 = θsp + Δθt1 (3) θd² = θsp - Δθt² (4)

[0065] The drive processing unit 83 uses the calculated heel suppression angles θd1 and θd2 as target values ​​and uses the trim angle adjustment unit 45 to adjust the trim angle θt of the thrusters 3 (3a, 3b) so that it approaches the heel suppression angles θd1 and θd2.

[0066] If the determination unit 82 determines that the ship speed V has fallen below a preset third threshold V3 while heel control is being performed, the drive processing unit 83 stops the execution of heel control. Here, the third threshold V3 is set lower than the second threshold V2.

[0067] Furthermore, the determination unit 82 determines whether, when heel control is being performed, the trim angle θt of at least one thruster 3 is smaller than the first trim angle reference value θts1. If the trim angle θt of at least one thruster 3 is smaller than the first trim angle reference value θts1, the determination unit 82 determines whether the preset first condition is met. In this embodiment, the first condition is, for example, Condition A: Ship 1 is in a turning state. Condition B: The trim angle of thruster 3 was manually operated. This is an example. The determination unit 82 determines that the first condition has been met if at least one of conditions A and B is met.

[0068] If the first condition is met, the drive processing unit 83 drives the thruster 3, whose trim angle θt is smaller than the first trim angle reference value θts1, with the trim angle adjustment unit 45, and adjusts its trim angle θt to, for example, the first trim angle reference value θts1. If condition A of the first conditions is met, the drive processing unit 83 adjusts the trim angle θt of all thrusters 3 on both the left and right sides to the first trim angle reference value θts1. Also, if condition B of the first conditions is met, the drive processing unit 83 adjusts the trim angle θ of thrusters 3 whose trim angle θt is smaller than the first trim angle reference value θts1 to the first trim angle reference value θts1, and adjusts the trim angle θt of thrusters 3 whose trim angle θt is greater than or equal to the first trim angle reference value θts1 according to manual operation.

[0069] To give a specific example, let's assume that, while heel control is being performed, the trim angle θt of the right thruster 3 is smaller than the first trim angle reference value θts1 (around -5°) (for example, around -10°), and the trim angle θt of the left thruster 3 is larger than the first trim angle reference value θts1 (for example, around 0°). Under these assumed conditions, when the vessel 1 is turning and condition A is met, all propulsion engines 3 on both the left and right sides are set to the first trim angle reference value θts1 (around -5°). This suppresses the impediment to turning ability in the right propulsion engine 3, where the trim angle θt was smaller than the first trim angle reference value θts1. Aeration is suppressed in the left propulsion engine 3, where the trim angle θt was larger than the first trim angle reference value θts1. Furthermore, under the above assumed conditions, when the trim angle of thruster 3 is manually operated and condition B is met, only the right thruster 3, whose trim angle θt is smaller than the first trim angle reference value θts1, will be raised to the first trim angle reference value θts1 (around -5°). In this case, if the trim angle θt of the left thruster 3 is greater than or equal to the first trim angle reference value θts1 (around -5°), the trim angle θt will be adjusted according to the manual operation.

[0070] Furthermore, when heel control is being performed, if the determination unit 82 receives a steering angle input from the steering angle input unit 71 via the steering angle sensor 63, it determines whether the vessel 1 is in a turning state based on the received steering angle input value. If the drive processing unit 83 determines that the vessel 1 is in a turning state, it stops the execution of trim support control and heel control. Furthermore, if the determination unit 82 determines that it has received an operation input from the trim angle control unit 73 by the operator while heel control is being performed, the drive processing unit 83 stops the execution of heel control.

[0071] (Hump control) Furthermore, as shown in Figure 4, if the determination unit 82 determines that the predetermined third condition is met while the vessel 1 is moving straight and the ship speed V is equal to or greater than the first threshold V1, the drive processing unit 83 performs hump control. The drive processing unit 83 also performs hump control when the vessel 1 is moving straight and the ship speed V is equal to or greater than the first threshold V1, but the ship speed V is less than the second threshold V2. Hump ​​control is performed to suppress excessive lift of the bow 2a when the bow 2a is significantly raised relative to the stern 2b. When performing hump control, the drive processing unit 83 sets the trim angles θt of the propellers 3a and 3b on both sides in the left and right directions to the same value.

[0072] (Bogen control) Furthermore, the drive processing unit 83 performs wedge control when the ship speed V is less than the first threshold V1. Wedge control steers the multiple propulsion units 3 in the yaw direction in a direction that intersects the longitudinal direction of the hull 2. When the ship 1 is moving straight and the ship speed V is less than the first threshold V1, wedge control rotates the left and right propulsion units 3 around the swivel axis in opposite directions and at the same steering angle. Wedge control reduces the forward thrust acting on the entire hull 2 ​​compared to when the propulsion units 3 are arranged parallel to the longitudinal direction of the hull 2, making it possible to sail the hull 2 ​​at low speed or very low speed. In this embodiment, the specific details of wedge control are not limited in any way.

[0073] (Propulsion System Control Method) Next, the operation method of the propulsion system will be described. The processing described below is repeatedly executed at a predetermined control cycle (for example, several tens of [msec]).

[0074] Here, trim support control is executed at an appropriate timing according to the setting of the vessel operator. In the trim support control, the control unit 8 sets a trim support angle θsp that optimizes stability, acceleration, maximum speed, fuel efficiency and the like according to the vessel speed V, as a target value. The control unit 8 controls the trim angle adjustment unit 45 such that the trim angles θt of the propulsion units 3 on both left and right sides approach the trim support angle θsp set as the target value.

[0075] Figure 9 is a flowchart showing a heel control execution method during execution of the trim support control. When the trim support control is being executed, in step S141, the control unit 8 acquires the detection result of the vessel speed from the vessel speed sensor 62 by the acquisition unit 81 at a predetermined control cycle. In step S142, the control unit 8 determines whether or not the vessel speed V is equal to or greater than a second threshold value V2 based on the detection result of the vessel speed sensor 62.

[0076] If the determination result in step S142 is "No" (V<V2), the process is terminated, the processes from step S141 are repeated at each predetermined control cycle, and the trim support control is continued. If the determination result in step S142 is "Yes" (V≧V2), the process proceeds to step S143, and the control unit 8 brings the heel control into an executable state. In other words, the control unit 8 puts the heel control into a standby state.

[0077] Next, in step S144, the acquisition unit 81 acquires the detection result of the heel angle θh of the hull 2 from the inertial sensor 64. In step S145, the control unit 8 determines whether or not the heel angle θh is equal to or greater than a heel angle reference value θhs based on the detection result of the inertial sensor 64.

[0078] If the result of step S145 is "No" (θh < θhs), the process returns to step S144, and after a predetermined control cycle has elapsed, step S144 is repeated. If the result of the judgment in step S145 is "Yes" (θh≧θhs), proceed to step S146.

[0079] In step S146, the control unit 8 performs heel control in addition to trim support control. In step S146, the control unit 8 sets the heel suppression angle θd according to the heel angle θh of the hull 2. The control unit 8 sets the heel suppression angle θd based on the trim support angle θsp of the propulsion engine 3 at that time. Based on the heel angle θh of the hull 2 ​​at that time, acquired by the acquisition unit 81, the drive processing unit 83 calculates a trim angle addition value Δθt1 to be added to one propulsion engine 3 in the left-right direction and a trim angle subtraction value Δθt2 to be subtracted from the other propulsion engine 3 in the left-right direction, based on a preset calculation formula, with the trim support angle θsp as the reference. If the hull 2 ​​is tilted to port, the drive unit 83 calculates the heel suppression angle θd1 of the left propulsion unit 3b using equation (1) above, and the heel suppression angle θd2 of the right propulsion unit 3a using equation (2) above. If the hull 2 ​​is tilted to starboard, the drive unit 83 calculates the heel suppression angle θd1 of the left propulsion unit 3b using equation (3) above, and the heel suppression angle θd2 of the right propulsion unit 3a using equation (4) above. The drive processing unit 83 uses the calculated heel suppression angles θd1 and θd2 as target values ​​and causes the trim angle adjustment unit 45 to adjust the trim angle θt of the thrusters 3 (3a, 3b).

[0080] In step S147, the control unit 8 determines whether the ship speed V has become less than or equal to a preset third threshold V3 while heel control is being performed. If the result of step S147 is "No" (i.e., the ship speed V is not below the third threshold V3), proceed to step S149. If the result of step S147 is "Yes" (i.e., the ship speed V is less than or equal to the third threshold V3), the process proceeds to step S148, where heel control is stopped and only trim support control continues.

[0081] In step S149, the control unit 8 determines whether or not it has received an operation input from the trim angle control unit 73 by the operator's manual operation. If the result of step S149 is "No" (meaning no manual operation by the operator was performed), proceed to step S153. If the result of step S149 is "Yes" (meaning manual operation by the operator was performed), proceed to step S150.

[0082] In step S150, the control unit 8 determines whether the trim angle θt of at least one of the thrusters 3 is less than the first trim angle reference value θts1. In other words, the control unit 8 determines whether the trim angle θt of at least one of the thrusters 3 at that time is significantly tilted to the negative side (towards the rear in the direction of thrust) than the first trim angle reference value θts1.

[0083] If the result of step S150 is "No" (i.e., the trim angle θt of both thrusters 3 is greater than or equal to the first trim angle reference value θts1), step S151 is skipped and the process proceeds to step S152. If the result of step S150 is "Yes" (i.e., the trim angle θt of at least one of the thrusters 3 is less than the first trim angle reference value θts1), proceed to step S151.

[0084] If the result of the determination in step S149 is "Yes" and the above condition B is met, in step S151, the control unit 8 uses the trim angle adjustment unit 45 to return the trim angle θt of the thruster 3, which is smaller than the first trim angle reference value θts1, back to the first trim angle reference value θts1. The control unit 8 returns the trim angle θt of the thruster 3, which was tilted significantly to the negative side of the first trim angle reference value θts1, back to the first trim angle reference value θts1. The control unit 8 may also return the thruster 3 to a state where the trim angle θt of the thruster 3 is more positive than the first trim angle reference value θts1 (a state where the thruster 3 is tilted further forward in the direction of propulsion than the first trim angle reference value θts1). At this time, the control unit 8 adjusts the trim angle θt of the thruster 3 whose trim angle θt is equal to or greater than the first trim angle reference value θts1, in response to the operation input from the trim angle operation unit 73, using the trim angle adjustment unit 45.

[0085] In step S152, the execution of heel control is stopped, and after a predetermined control cycle has elapsed, the process from S141 onwards is repeated.

[0086] In step S153, the control unit 8 determines whether the vessel 1 is turning. In this case, the control unit 8 determines whether the vessel 1 is turning based on the actual steering angle detected by the actual steering angle sensor 67.

[0087] If the result of the determination in step S153 is "No" (meaning that ship 1 is not turning, i.e., ship 1 is moving in a straight line), the process ends, and after a predetermined control cycle has elapsed, the process from step S141 is repeated. If the result of step S153 is "Yes" (indicating that the ship 1 is in a turning state), the process proceeds to step S150, where the control unit 8 determines, based on the detection result of the inertial sensor 64, whether the trim angle θt of at least one of the propulsion units 3 is less than the first trim angle reference value θts1.

[0088] If the result of step S150 is "No", step S151 is skipped and the process proceeds to step S152. If the result of step S150 is "Yes", proceed to step S151.

[0089] If the result of step S153 is "Yes" and the above condition A is met in step S153, then in step S151, the control unit 8 uses the trim angle adjustment unit 45 to return the trim angle θt of all thrusters 3 to the first trim angle reference value θts1.

[0090] In step S152, the execution of trim support control and heel control is stopped, and then, if the vehicle returns from a turning state to a straight-ahead state, the process shown in the flowchart of Figure 9 is executed.

[0091] Figure 10 is a timing chart showing an example of the operation of the propulsion system. In Figure 10, for each of the following flags: "Ship Speed ​​Determination Flag", "Straight Track Determination Flag", "Heel Control Implementation Determination Flag", "Trim Operation Determination Flag", "Left Trim Angle UP" Flag, "Right Trim Angle UP" Flag, "Left Trim Angle DW (Down)" Flag, "Right Trim Angle DW" Flag, and "Indicated Position Match Determination Flag", "0" indicates that the determination result in the control unit 8 is "No" or that control by the control unit 8 is "OFF", and "1" indicates that the determination result in the control unit 8 is "Yes" or that control by the control unit 8 is "ON".

[0092] As shown in Figure 10, when the ship 1 is moving in a straight line and trim support control is in operation, for example, when the lever opening is increased by the operator's operation of the thrust input unit 72 (time t1), the ship speed V increases. When the ship speed V exceeds the second threshold V2 (time t2), the ship speed determination flag in the control unit 8 in step S142 changes from "0" to "1". On the other hand, based on the detection value of the actual steering angle sensor 67, the straight-ahead determination flag is "0", and it is determined that the ship 1 is in a straight-ahead state. Therefore, the conditions that the ship 1 is in a straight-ahead state and the ship speed V is greater than or equal to the second threshold V2 are met, and the heel control implementation determination flag changes from "0" to "1". Then, the control unit 8 turns the heel control mode "ON" and starts executing heel control. In this state, the heel angle θh of the ship 1 is smaller than the heel angle reference value θhs, so the control unit 8 sets the trim angle operation instruction judgment flag to "0", which is the mode in which the trim angle θt of the propulsion unit 3 is not adjusted by heel control.

[0093] Subsequently, when the heel angle θh of the ship 1 to the right exceeds the heel angle reference value θhs (time t3), the control unit 8, which is performing heel control, switches the trim angle operation instruction judgment flag to mode "1", which increases the trim angle θt of the left propulsion unit 3 and decreases the trim angle θt of the right propulsion unit 3. In response, the control unit 8 sets the left trim angle UP flag and the right trim angle DW flag to "1" in order to suppress the heel angle θh to the right, increasing the trim angle θt of the left propulsion unit 3 and decreasing the trim angle θt of the right propulsion unit 3.

[0094] Subsequently, when the trim angle θt of the right thruster 3 decreases to the second trim angle reference value θts2 (around -10°), which is the lower limit of the trim angle (time t4), the control unit 8 resets the right trim angle DW flag to "0". From this point onward, the trim angle θt of the right thruster 3 maintains the lower limit of the trim angle.

[0095] When the heel control reduces the heel angle θh of the ship 1 to a predetermined threshold at the time of return (time t5), the control unit 8 resets the trim angle operation instruction determination flag to mode "0". As a result, the left trim angle UP flag returns to "0", and from this point onward, the left thruster 3 maintains the trim angle θt at that time.

[0096] Subsequently, when the helmsman performs a steering operation to the right using the steering angle input unit 71 (time t6), the steering angle to the right increases. When the actual steering angle detected by the actual steering angle sensor 67 becomes greater than the steering angle threshold to the right (time t7), the straight-ahead determination flag changes from "1" to "0". As a result, in step S153, it is determined that the vessel 1 is in a turning state, and the heel control implementation determination flag changes from "1" to "0". Then, in steps S150 and S151, the control unit 8 proceeds to the process of releasing the heel control, and based on the trim angle θt state of each thruster 3 at that time, switches the trim angle operation instruction judgment flag to mode "2", which decreases the trim angle θt of the left thruster 3 and increases the trim angle θt of the right thruster 3. Accordingly, the control unit 8 sets the left trim angle DW flag to "1" and the right trim angle UP flag to "1". As a result, the trim angle θt of the left thruster 3 decreases and the trim angle θt of the right thruster 3 increases.

[0097] Subsequently, when the trim angle θt of both the left thruster 3 and the right thruster 3 returns to the first trim angle reference value θts1, and the instruction position matching determination flag becomes "1" (time t8), the control unit 8 finishes the process of releasing the heel control.

[0098] Thus, the propulsion system 20 of this embodiment performs heel control, and in at least one propulsion unit 3, when the first condition is met while the propulsion unit 3 has a trim angle θt that is tilted more aft in the direction of propulsion of the hull 2 ​​than the first trim angle reference value θts1, the trim angle θt of the propulsion unit 3 is adjusted so that the trim angle θt of the propulsion unit 3 becomes the first trim angle reference value θts1, or so that the trim angle θt of the propulsion unit 3 becomes tilted more aft in the direction of propulsion than the first trim angle reference value θts1. In other words, when the first condition is met, the propulsion unit 3 is pulled forward in the direction of propulsion from a state where the trim angle θt of the propulsion unit 3 is tilted more aft in the direction of propulsion than the first trim angle reference value θts1 to a state where the trim angle θt of the propulsion unit 3 becomes greater than or equal to the first trim angle reference value θts1. This allows for a smooth transition from a state where heel control is being performed to another state, without compromising the stability, acceleration, maximum speed, fuel efficiency, etc., of the vessel 1, or causing the operator to feel any discomfort.

[0099] Furthermore, the propulsion system 20 of this embodiment determines that the first condition has been met when it is determined that the vessel 1 is in a turning state. This prevents the trim angle θt of the propulsion unit 3 from becoming excessively small and hindering turning performance when transitioning from a state where heel control is being performed to a turning state, thereby enabling a smooth transition between states.

[0100] Furthermore, in this embodiment, when the propulsion system 20 determines that the ship 1 is turning, the trim angle θt of all the propulsion units 3 on both the left and right sides is set to the first trim angle reference value θts1. As a result, if any of the propulsion units 3 are tilted forward more than the first trim angle reference value θts1, aeration during turning can be prevented in that propulsion unit 3.

[0101] Furthermore, in this embodiment, the propulsion system 20 determines that the first condition has been met when the operator manually adjusts the trim angle θt of the propulsion engine 3 and receives an input from the trim angle control unit 73. This prevents the operator from feeling uncomfortable due to an excessively small trim angle θt of the propulsion engine 3 when the propulsion engine 3 is being manually operated from a state where heel control is being performed, and allows for a smooth transition between states.

[0102] Furthermore, the propulsion system 20 of this embodiment includes an intermediate member 37 between the hull 2 ​​and the propulsion unit 3, which increases the inclination angle of the propulsion unit 3 toward the rear in the direction of propulsion. This allows the propulsion unit 3 to be tilted more significantly toward the rear in the direction of propulsion of the ship 1, making the trim angle θt larger in the negative direction, and enabling effective heel control. Furthermore, the first trim angle reference value θts1 is set based on the trim angle θt of the propeller 3 when the propeller 3 is tilted most aft in the propulsion direction, assuming that the propeller 3 is installed on the hull 2 ​​without the intermediate member 37. When heel control is performed with the trim angle θt of the propeller 3 larger in the negative direction, when transitioning from the heel control state to another state, the trim angle θt of the propeller 3 can be returned to the first trim angle reference value θts1, making it less likely for the operator to feel any discomfort.

[0103] Furthermore, the propulsion system 20 of this embodiment can effectively perform heel control by using a second trim angle reference value θts2, which is set based on the trim angle θt of the propulsion unit 3 when the propulsion unit 3, which is installed on the hull 2 ​​via the intermediate member 37, is tilted most towards the rear in the direction of propulsion, as the lower limit.

[0104] Furthermore, the propulsion system 20 of this embodiment is capable of performing heel control when it is determined that the vessel 1 is moving in a straight line based on the input value of the steering angle. This allows for smooth heel control when the vessel 1 is moving in a straight line, resulting in improved stability, acceleration, maximum speed, fuel efficiency, and other performance characteristics.

[0105] Furthermore, the propulsion system 20 of this embodiment performs heel control when the heel angle θh is greater than or equal to a preset heel angle reference value θhs. As a result, under the primary condition that the vessel 1 is moving in a straight line and the heel angle θh is large, the heel angle θh can be suppressed, thereby improving the stability, acceleration, maximum speed, fuel efficiency, etc., of the vessel 1.

[0106] Furthermore, the propulsion system 20 of this embodiment stops executing heel control when it is determined that the vessel 1 is in a turning state based on the input value of the steering angle. This prevents the turning ability from being hindered by heel control when the vessel 1 is in a turning state.

[0107] Furthermore, in this embodiment, if the propulsion system 20 receives an input from the trim angle control unit 73 while heel control is being performed, it stops the execution of heel control. This prevents the operator of the vessel 1 from feeling any discomfort when the trim angle θt is manually adjusted by the operator of the vessel 1, by stopping the execution of heel control.

[0108] Furthermore, the propulsion system 20 of this embodiment performs heel control in addition to trim support control when a preset second condition is met, and adjusts the trim angle adjustment unit 45 to a heel suppression angle θd set based on the trim support angle θsp of the propulsion engine 3. As a result, when a preset condition is met, heel control is performed in addition to trim support control, thereby automatically adjusting the trim angle θt while suppressing the heel angle θh of the vessel 1. Therefore, when transitioning from a state in which heel control is being performed to another state, the transition can be made smoothly so that the stability, acceleration, maximum speed, fuel efficiency, etc. of the vessel 1 are not impaired, and the operator does not feel any discomfort.

[0109] It should be noted that the present invention is not limited to the embodiments described above with reference to the drawings, and various modifications are conceivable within its technical scope. For example, in the above embodiment, trim support control, heel control, etc., are performed based on the ship speed V, but instead of the ship speed V, trim support control, heel control, etc., may be performed based on the rotational speed of the propulsion engine 3.

[0110] Furthermore, in the above embodiment, examples were given of a case where only trim support control is performed while the vessel 1 is moving straight, and a case where both trim support control and heel control are performed according to the ship speed V. However, it is also possible to perform only heel control while the vessel 1 is moving straight, according to the ship speed V.

[0111] Furthermore, in the above embodiment, one thruster 3 is provided on each side (left and right), but multiple thrusters may be provided on each side. Furthermore, the control procedures and content executed by the control unit 8 can be modified as appropriate. Furthermore, the configuration in the above embodiment is just one example of the present invention, and various modifications are possible without departing from the spirit of the invention. [Explanation of symbols]

[0112] 1 ship 2 hull 3 Propulsion machine 6. Detection Unit 8 Control Unit 20 Propulsion System 32 Power source 34 Promotion Department 36 Steering axis 37 Intermediate member 45 Trim angle adjustment section 63. Steering Angle Sensor (Steering Angle Detection Unit) 71 Steering angle input section 73 Trim angle control section

Claims

1. A propulsion unit having a drive source and a propulsion unit that generates thrust by power transmitted from the drive source, and having at least one propulsion unit on each side in the left-right direction with respect to the center of the hull, A trim angle adjustment unit for adjusting the trim angle of each of the propulsion units on both the left and right sides relative to the hull, A ship propulsion system comprising a control unit for controlling the trim angle adjustment unit, The control unit, In order to suppress the tilt of the hull in the roll direction, heel control can be performed by adjusting the trim angle in the trim angle adjustment unit so that the trim angle becomes a heel suppression angle set according to the tilt of the hull in the roll direction. When heel control is performed and at least one of the propulsion units has a trim angle that is tilted rearward in the direction of propulsion of the hull compared to a preset first trim angle reference value, and a preset first condition is met, the trim angle adjustment unit adjusts the trim angle of the propulsion unit so that the trim angle of the propulsion unit becomes the first trim angle reference value, or so that the trim angle of the propulsion unit becomes tilted forward in the direction of propulsion compared to the first trim angle reference value. A ship's propulsion system.

2. The system further includes a steering angle detection unit that detects the steering angle of the propulsion engine around the steering axis relative to the hull based on external input, The control unit, If, based on the detected value of the steering angle detected by the steering angle detection unit, it is determined that the vessel is in a turning state, then it is determined that the first condition has been met. The propulsion system for a ship according to claim 1.

3. If it is determined that the vessel is in a turning state, the trim angle adjustment unit adjusts the trim angle of all of the propulsion units on both the left and right sides so that the trim angle of each propulsion unit becomes the first trim angle reference value. The propulsion system for a ship according to claim 2.

4. The system further includes a trim angle control unit that operates the trim angle adjustment unit via external input, The control unit, When an operation input is received from the trim angle control unit, it is determined that the first condition has been met. A ship propulsion system according to claim 1 or 2.

5. The vessel further comprises an intermediate member provided between the hull and the propulsion unit, which increases the rearward inclination angle of the propulsion unit in the direction of propulsion, The first trim angle reference value is set based on the trim angle of the propeller when the propeller is tilted most towards the rear in the propulsion direction, when the propeller is installed on the hull without the intermediate member. A ship propulsion system according to claim 1 or 2.

6. The control unit, When performing the heel control described above, the trim angle of the propulsion unit is adjusted by the trim angle adjustment unit, using a second trim angle reference value, which is set based on the trim angle of the propulsion unit when the propulsion unit, which is installed on the hull via the intermediate member, is tilted most towards the rear in the direction of propulsion, as the lower limit. The propulsion system for a ship according to claim 5.

7. The control unit, If it is determined that the vessel is moving in a straight line based on the detected value of the steering angle, the heel control can be executed. The propulsion system for a ship according to claim 2.

8. The system further includes a heel angle detection unit that detects the heel angle, which is the inclination of the hull in the roll direction, The control unit, The heel control is executed when the heel angle is equal to or greater than a preset heel angle reference value. The propulsion system for a ship according to claim 7.

9. The control unit, If, while the heel control is being performed, it is determined that the vessel is in a turning state based on the detected value of the steering angle, the execution of the heel control is stopped. The propulsion system for a ship according to claim 2.

10. The system further includes a trim angle control unit that operates the trim angle adjustment unit via external input, The control unit, If an operation input is received from the trim angle control unit while the heel control is being performed, the execution of the heel control is stopped. A ship propulsion system according to claim 1 or 2.

11. The control unit, It is possible to perform trim support control, which adjusts the trim angle in the trim angle adjustment unit so that the trim support angle is set according to a preset ship speed or propulsion engine rotation speed. When the pre-set second condition is met, the heel control is executed in addition to the trim support control, and the thruster is adjusted by the trim angle adjustment unit to the heel suppression angle set based on the trim support angle of the thruster. A ship propulsion system according to claim 1 or 2.

Images